Proceedings of International Forestry and Environment Symposium
This symposium is a forum for researchers in the fields of Natural Resources Management, to present their research findings, and networking with policy makers and industry.
Investigating the Consumers’ Willingness-to-Pay for a Deposit Refund System for Tetra Pak Recycling in the Western Province of Sri Lanka
Tetra Pak cartons are emerging as a significant part of packaging waste due to their widespread use in food and beverage packaging. Despite being fully recyclable, the lack of dedicated local recycling facilities has resulted in most post-consumer Tetra Pak cartons ending up in landfills or open dumps, exacerbating environmental and public health risks, particularly during the monsoon season. This study focused on estimating consumer Willingness-to-Pay (WTP) for implementing a Deposit Refund System (DRS) for Tetra Pak recycling in the Western Province, using the Contingent Valuation Method (CVM). The influence of socio-demographic variables on WTP was also investigated. Data were gathered from a sample of 275 individuals in Colombo, Gampaha, and Kalutara districts, and the double-bounded dichotomous choice approach was used to obtain the WTP. Data were analyzed using STATA. Results revealed a strong public preference for a volume-based DRS, with most respondents expressing willingness to participate and pay towards a refundable deposit to enable recycling. Having an education level up to Advanced Level (β=63.81, p<0.001), diploma (β=69.12, p<0.001), and a degree or a postgraduate qualification (β= 70.17, p<0.001), compared to people who have an education level less than O/L positively influences the WTP. Living in an area under the Municipal Council (β=13.69, p<0.05) and an Urban Council (β=16.78, p<0.05) compared to the Pradeshiya Saba also positively influences WTP. The impact of income (β=0.0000102, p<0.01) and household size (β=6.06, p<0.05) on WTP is positive. The respondents are willing to pay a considerable amount for a DRS for Tetra Pak packaging for a 1 L family-size product, and the estimate is statistically significant (p<0.001). The estimated aggregate WTP suggests that a well-designed DRS could be economically viable and socially acceptable, offering a practical solution to enhance Tetra Pak recycling rates, reduce environmental harm, and support sustainable community livelihoods. This research provides critical insights for policymakers, waste management authorities, and industry stakeholders seeking to develop effective recycling strategies based on extended producer responsibility, tailored to Sri Lanka’s urban context. Keywords: Tetrapak recycling, Deposit refund system, Willingness to pay, Contingent valuation method
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Factors Influencing Green Purchasing: Biodegradable Fabric Products in Kalutara District in Sri Lanka
The increasing awareness of environmental degradation and pollution caused by synthetic fibers such as nylon, acrylic, and polyester, particularly microfiber contamination, is significantly influencing consumers to shift toward biodegradable alternatives. This study aims to investigate the factors influencing consumers’ willingness to purchase biodegradable fabric products, such as ready-made clothing, bedding, curtains, towels, and other household fabric items, which are emerging as sustainable options. The Theory of Planned Behavior (TPB) was the foundation of the study. A structured questionnaire was utilized to collect primary data from 227 respondents within the Kalutara District of Sri Lanka. Partial Least Squares Structural Equation Modeling (PLS-SEM) was used to analyze the data. According to the results, most consumers preferred cotton and linen materials and were willing to pay a slightly higher price, mostly 5% more for ready-made and traditional costumes. The findings revealed that Attitude Toward biodegradable fabrics (ATD) (β=0.164, p<0.05), subjective norms (SN) (β 0.098, p<0.05), Perceived Inconvenience (PI) (β=0.298, p<0.001), and perceived price (PP) (β=0.281, p<0.001) significantly influence Willingness-To-Purchase (WTP). Unexpectedly, both PI and PP had positive and statistically significant effects on WTP, which diverges from traditional assumptions and suggests that consumers may associate these perceptions with product authenticity and sustainability value. Although Environmental Concern (EC) (β=0.042, p<0.05) and perceived benefits (PB) (β=0.092, p<0.05) significantly influenced WTP through attitude, they did not directly affect WTP, which reflects the full mediation effect of ATD. Internal consistency reliability, convergent validity and discriminant validity were established, with an acceptable model fit. These findings highlight the crucial role of ATD, SN, PI, PP, EC and PB in influencing green purchasing behavior. Outcomes of the study provide valuable insights for policymakers and other key stakeholders to develop strategies to strengthen positive attitudes toward biodegradable fabrics through targeted awareness campaigns, sustainability communication, and value-based pricing strategies that signal a higher price and inconvenience as indicators of authenticity and environmental value. Keywords: Biodegradable fabric products, Microfiber pollution, Willingness to purchase, Theory of planned behavior, PLS-SEM
Urban Household’s Preferences for Sustainable Air Quality Management Practices: A Choice Experiment Approach
Sri Lanka is currently experiencing air pollution due to increased vehicle use, improper waste disposal, and industrial and construction activities, which severely affect air quality parameters, particularly in urban areas. However, there is a lack of evidence on individuals’ preferences for improving air quality. Therefore, this study aims to understand the preferences of urban households for various air quality interventions and to estimate their willingness to pay for such improvements in the urban areas of the Jaffna District. The study employed a choice experiment with attributes including vehicle emission reductions (10%,25%,50% and no reduction), expansion of urban green space (25%,50% increases and no change), plastic and rubber waste management practices (ban on open burning, separation at source, and current management), and an annual household contribution (local tax) of LKR 0,750,1,500, and 4,000. Data were collected from 302 households and analysed using a random parameter logit model. The results indicate that households significantly value higher levels of emission reduction and green space improvement. Moreover, households are willing to pay higher amounts for greater emission reductions, with LKR 1,079.50 for a 25% reduction and LKR 1,097.95 for a 50% reduction, and for increased green space, with LKR 703.14 for a 25% increase and LKR 1,300.66 for a 50% increase. Among waste management strategies, banning open burning was highly preferred, whereas separation and collection of waste showed no significant effect. Households are willing to pay LKR 725.48 to ban the open burning of plastic and rubber. We further employed a mixed logit model with interaction effects to examine heterogeneity in preferences. Results revealed that household age and income significantly influence their preferences for green space improvement and the separation and collection of rubber and plastic waste in the urban areas. The findings of this study will guide policymakers and local authorities in designing cost-effective interventions to improve urban air quality and environmental sustainability. Keywords: Air quality, Choice experiment, Green space, Rubber and plastic waste, Vehicle emission, Willingness to pay
The Relationship Between the Water Stress, Population Growth, Industrialization, and Agricultural Land in China: Evidence from an ARDL Approach
Water stress has been a global environmental and socio-economic concern, which is especially considered a pressing issue in China for more than two decades. While historical water stress was mostly caused by natural climate variability, recent trends reveal that economic and demographic factors increasingly outweigh natural drivers. However, there have been a limited number of studies focusing on the dynamic short-run and long-run impacts of economic and demographic factors. Therefore, this study intends to evaluate how the total population, Gross Domestic Product (GDP) related to the industrial sector and cultivated area as a percentage of total country area, affects water stress in China in the short-run and long-run. Annual data related to these variables from 1980 to 2022 were obtained from the database of the Food and Agriculture Organization of the United Nations. The Autoregressive Distributed Lag (ARDL) approach was employed for the data analysis, and the Granger Causality test was also used. The ARDL (4,6,6,5) model was estimated using the EViews software package. As revealed by the results of the ARDL Bounds test, cointegration exists between water stress, population, industrial sector GDP and cultivated area. The model satisfies all the requirements related to diagnostic tests, including tests for serial correlation, the Jarque-Bera test for normality, and the Breusch-Pagan-Godfrey test for heteroscedasticity. Stability of the model was confirmed by the results of the CUSUM and CUSUM of Squares tests. In the long-run, lag values of population, industrial sector GDP and the cultivated area positively and significantly influence the water stress. There is an impact from these variables in the short-run as well. The coefficient of the Error Correction Term (ECT) is negative and statistically significant, and approximately 85.15% of the discrepancy between long-term and short-term water stress levels is corrected within a year. The results of the Granger Causality test found the existence of unidirectional causality from cultivated area as a percentage of total country area to water stress (F=3.21, p<0.05). Overall, the findings of the study reveal that the water stress is exacerbated by population growth, industrial activity and agricultural land expansion via the increased water demand. These outcomes emphasize the importance of integrated water management policies that improve industrial water efficiency, promote sustainable agricultural practices, and effectively manage the water demand to ensure water security, while maintaining a balance between economic growth and environmental protection in China. Keywords: ARDL approach, Cointegration, Water stress, Population, Cultivated area, Industrial sector GDP
Life Cycle Assessment of Feeding Strategies in Sri Lankan Smallholder Dairying: A Comparison of Greenhouse Gas Emission Costs
The Sri Lankan dairy industry plays a vital role in meeting national nutritional requirements, with smallholder farmers contributing a substantial share of production. However, this sector also generates significant Green House Gas (GHG) emissions, highlighting the need for sustainable feeding practices. This study employs a Life Cycle Assessment (LCA) framework to analyze the environmental implications of two semi-intensive feeding strategies commonly practiced by smallholders in the North-Western province, which contributes 18-22% of Sri Lanka’s milk output. A cradle-to-gate system boundary and a functional unit of 10 L of raw cow milk were considered. The first feeding strategy (FS1) consists of cultivated fodder (Guinea grass), coconut poonac, and commercial cattle feed, while the second strategy (FS2) relies on natural pasture grazing with supplementary commercial feed. Results indicate that FS2 produces 474.13 kgCO2eq/10 L of milk, nearly four times greater than FS1 (120.62 kgCO2eq/ 10 L). Moreover, FS2 exhibited higher eutrophication potential due to greater ammonia volatilization and nitrate leaching. Life Cycle Costing (LCC) analysis further revealed that the emission-related cost of FS2 was markedly higher, reflecting its elevated Methane (CH4) and Nitrous Oxide (N2O) outputs. Conversely, FS1 demonstrated more efficient land utilization, lower emission intensity, and reduced climate costs, underscoring its relative sustainability. The findings emphasize that feed quality, nutrient management, and land use efficiency are central to lowering the environmental footprint of smallholder dairy production. By integrating economic and environmental perspectives, this research provides evidence-based insights for promoting climate-smart feeding strategies in Sri Lanka’s dairy sector. Such insights can guide policymakers in designing interventions that enhance both ecological and economic sustainability, thereby supporting the development of a low-emission dairy industry. Keywords: Climate smart practices, Dairy sustainability, Environmental footprint, Life cycle costing, Nutrient management
Towards Sustainable Wetland Management: Understanding Public Preferences for the Key Attributes of Bundala Wetland
Wetlands are recognized as ecosystems that are rich in biodiversity and have the ability to reduce the negative effects of climate change. Bundala Wetland, situated in the climate-vulnerable region of southern Sri Lanka, is acknowledged as a prominent bird sanctuary. Currently, it is being degraded as a result of ill-planned development activities. Thus, the concept of sustainable wetland management is recognized as essential for this wetland to ensure the wise use of its resources, mitigate the adverse impacts of climate change and safeguard it for future generations. This study applied a choice experiment method to identify public preferences and estimate the economic value of key attributes associated with a sustainable management plan for the Bundala Wetland. Lagoon fish production, biodiversity conservation, eco-tourism and resource governance were the selected wetland attributes. The levels of the attributes were increase in lagoon fish catch by 4 kg and 8 kg for lagoon fish production; facilitating arrival of local and migratory bird species by 10 species and 20 species for biodiversity conservation and providing trainings on eco-tourism activities for 50,70 and, 100 people. Resource governance attribute consists of the levels of managing the wetland by the government, government and community partnership or government, community and private partnership. Respondents were asked to consider a monthly contribution of 50,100,125 and, 175 Sri Lankan Rupees to manage the wetland as the payment attribute. Primary data were collected through randomly selected 171 respondents who resided within 10 km from the Bundala Wetland. A conditional logit model was used to estimate the Marginal Willingness- To-Pay (MWTP) for each attribute. According to the results, all the attributes, except eco-tourism were found to have significant and positive impacts on the choice. It was observed that the payment attribute had a negative effect on the utility of choosing a choice with a higher monthly payment value for the Bundala protection Fund. Participatory governance received a higher MWTP, with a preference for a governing structure that involves the government, community and private sector rather than a single party. The findings of this study are intended to assist policymakers in the formulation of a socially acceptable and economically efficient wetland management plan for Bundala Wetland. Keywords: Choice experiment, Climate change, Marginal willingness to pay, Participatory governance, Wetland
The Moragahakanda Irrigation Project & Its Impact on Environmental Poverty Within the Kuznets Curve Framework
Environmental poverty (Lee Liu, 2012) is defined as the lack of a healthy environment required for the survival and development of society as a direct result of environmental degradation caused by human activities. When discussing environmental poverty, it is important to consider the Environmental Kuznets Curve (EKC), which describes an inverted U-shaped relationship between environmental degradation and income, where environmental quality initially declines and then improves with economic growth, meaning that environmental quality deteriorates in the early stages of economic development and improves later (Masaaki Kijima et al., 2010). The Moragahakanda Irrigation Project, implemented as the final phase of the Mahaweli Development Program in the Matale District of Sri Lanka, was introduced with objectives such as agricultural development, hydroelectric power generation, freshwater fisheries, resettlement, irrigation facilities and access to clean drinking water. However, discussions with residents revealed that despite these intended benefits, the project has created several new environmental, social and economic problems. Many stated that the construction of the project did not provide adequate solutions to their earlier challenges, and in some cases existing issues worsened, while they also reported environmental problems that did not exist before the project. The Moragahakanda project displaced 5,870 people from 1,181 families in 11 Grama Niladhari Divisions (Senanayake, 2018). Accordingly, the primary objective of the present study was to investigate the impact of the Moragahakanda Irrigation Project on environmental poverty. A sample of 361 people was selected from a population of 5,870 using stratified random sampling from 3 Grama Niladhari Divisions, although data were obtained from only 300 respondents. Primary Data were collected through a questionnaire including multiple-choice and open-ended questions, interviews and observations, and analyzed using SPSS software. A multiple regression model was used to measure the influence of socio-economic independent variables on the dependent variable of environmental poverty. Findings revealed that all independent variables had a statistically significant effect on environmental poverty. Considering the collected primary data and the observed details, the study confirmed that environmental poverty has further increased due to the social and economic factors resulting from the project construction. Although development benefits have been generated, they have not been equally distributed across all areas, and although economic growth has occurred, it has not yet improved environmental quality. Therefore, it can be concluded that some areas remain in the initial stage of the EKC curve and that social inequality, environmental damage, economic difficulties, unemployment and displacement have increased for the people living in the project-affected areas. Keywords: Environmental poverty, Kuznets curve, Moragahakanda irrigation project
Erosion Dynamics and Conservation Willingness: A Pathway for Sustainable Land Management in the Gurugoda Oya Basin
Soil erosion and sedimentation are pressing environmental challenges in Sri Lanka, threatening agricultural productivity, water security, and hydropower generation. The Gurugoda Oya Basin, a sub-basin of the Kelani River that includes the Ganthuna Small Hydropower Plant catchment, is of high ecological and economic significance, and vulnerable to land degradation. Understanding both the physical drivers of erosion and the socioeconomic willingness of communities to invest in conservation is critical for designing sustainable watershed management strategies. This study aims to assess soil erosion and sediment export in the Gurugoda Oya Basin and evaluate farmers’ Willingness To Pay (WTP) for conservation interventions that mitigate these challenges. Primary data were collected from 301 randomly selected smallholder farmers across different elevations and land uses through structured questionnaires and group interviews. Double-bounded dichotomous choice method was used to assess the WTP of the respondents. Socioeconomic variables such as education, income, and awareness levels were analyzed using a bivariate probit model, while erosion and sediment export were estimated using the InVEST Sediment Delivery Ratio (SDR) model integrated with ArcMap 10.8.2. Results indicate that built-up lands contribute disproportionately to soil erosion (USLE C-factor=0.1), whereas forests and agricultural areas show much lower values (0.001). Annual soil loss was estimated at 17,399.75 tons and 19,100.41 tons in two sub-watersheds, while sediment export to streams was comparatively low (913.81 and 976.20 tons/year), reflecting the critical role of vegetation in sediment retention. Socioeconomic analysis revealed that education, income level, and awareness of ecosystem services significantly influenced WTP. Farmers expressed an average willingness to contribute Rs. 1,400 per year for watershed conservation. The findings underscore the importance of linking biophysical assessments of erosion with socioeconomic mechanisms for conservation financing. Mobilizing community contributions could support interventions such as sustainable farming practices, erosion-control infrastructure, integrated watershed management, and awareness programs. By combining physical modeling and farmer participation, this study highlights a feasible, community-based pathway to mitigate erosion and sedimentation, thereby enhancing agricultural resilience and sustaining hydropower generation in the Gurugoda Oya Basin. Keywords: Community-based conservation, Sedimentation, Soil erosion, Watershed management, Willingness to pay
Understanding the Preferences for Green Tires: A Choice Experiment Approach
Increasing environmental impacts associated with end-of-life tires have intensified interest in green tire technologies. Empirical evidence on willingness to pay (WTP) a price premium for such products remains limited in the developing country contexts. This study investigates the preference of individuals to pay a price premium for green tires and their WTP for these eco-friendly products using the choice experiment method. Tire lifespan, biodegradability and the price premium were the three attributes considered in this study. Data were collected from 256 randomly selected respondents in the Gampaha District of Sri Lanka. Random Parameter Logit (RPL) model was employed and the data were analyzed using NLOGIT and STATA software packages. The results show that higher levels of biodegradability significantly and positively affect utility, and the individuals also value enhanced tire lifespan. Considering the marginal WTP, consumers are willing to pay price premiums of 85.30%, 79.17% and 77.49% for 50%, 75% and 95% of biodegradability, respectively. Marginal WTP for a tire with a 50% higher lifespan than a traditional tire is 46.15%. Meanwhile, consumers are willing to pay 60.28% more when the tire lifespan is 80% longer than that of a traditional tire. In addition, there is no evidence of unobserved preference heterogeneity for these attributes in this study. Based on these findings, manufacturers and policymakers should prioritize the development of green tires that combine biodegradability with enhanced tire lifespan, as consumers show a clear willingness to pay price premiums for both attributes. Moreover, uniform pricing and product strategies may be effective across consumer segments. Keywords: Green tires, Biodegradability, Durability, Choice experiment approach, Marginal willingness to pay
Effects of Calcium Silicate-Containing Civil Construction Waste on Soil N2O Emissions
Currently, there is a trend to utilize calcium silicate (CaSiO3) containing civil construction waste as a soil amendment or conditioner in Japan as well as in European countries. Autoclaved lightweight Aerated Concrete (AAC) is a CaSiO3 containing porous material made from industrial waste of civil construction. AAC is utilized as a soil amendment that can influence terrestrial carbon dioxide (CO2) emissions. Still, no evidence exists regarding its impact on the emission of nitrous oxide (N2O), which has a higher global warming potential than CO2. This study investigated the impact of AAC (Inenica, Clion Co., Ltd, Japan) on N2O emissions from paddy soil under both compacted and non-compacted conditions, at 60% and 100% Water-Holding Capacity (WHC). Samples (24) were incubated in glass vials (25°C) for 21 days. During the incubation, the vials were covered with a polyethylene film (0.02 mm thickness) to ensure minimal evaporation while maintaining air exchange. Emissions of N2O were measured at 0 (incubation starting day), 1,3,7,14 and, 21 days using gas chromatography during the incubation period. All measurements were performed in triplicate. In addition, a separate set of samples was incubated under the same conditions for NH4+-N, and NO3–-N measurements. Results revealed that AAC significantly (p<0.05) lowered N2O emission during the whole period of incubation. The cumulative N2O emissions of samples with AAC were approximately 43% and 51% lower, respectively, in compacted and non-compacted soils, compared with samples without AAC at 60% WHC. At 100% WHC, the cumulative N2O emissions of samples with AAC in compacted and non-compacted soils respectively, showed 52% and 67% decline (significant at p<0.05), compared with samples without AAC. When compacted, the N2O was significantly high, showing the influence of soil physical conditions, and N2O emissions were significantly lower at higher WHC (100%). AAC suppressed N2O emissions from soil under both compaction and WHC levels. Results confirm that AAC supports suppressing terrestrial N2O emission, indicating its potential as a sustainable soil amendment that enhances climate change resilience. Keywords: Autoclaved lightweight aerated concrete, Calcium silicate, Greenhouse gases, Nitrous oxide
Assessing the Effect of Selected Soil Quality Parameters on the Risk Levels of Urban Trees in Colombo
Urban tree failure poses growing risks to public safety and infrastructure in densely built cities like Colombo, where trees are subjected to compacted soils, restricted rooting spaces, and altered hydrological conditions. Understanding how certain soil properties influence tree stability is crucial for developing sustainable urban forestry practices. Therefore, this study assessed how selected soil quality parameters: dry and wet bulk density, soil temperature, oxidation-reduction potential (ORP), pH, and soil moisture influenced the risk level of urban trees in two selected locations: Viharamahadevi park which represented an open green space and Keppetipola road which represented a confined roadside. Three soil samples were collected per tree within a 2.5 m radius from the root collar, from 15 trees for each location which were previously categorized into 3 risk levels; low, moderate and high. Risk categorization was done using Visual Tree Risk Assessment (VTRA). The risk of each tree was quantified, assigning a risk score to each tree. Relationships between soil properties and quantified tree risk scores were evaluated using Spearman’s rank correlation (MINITAB 21) statistical software. Moisture content showed a strong positive correlation with overall tree risk level among all tested soil parameters according to the correlation analysis in Viharamahadevi park. In Keppetipola road, moisture content showed a moderately negative correlation and dry bulk density showed a moderately positive correlation indicating contrasting patterns to the other location. Findings suggested that waterlogged soils may weaken anchorage and encourage internal root decay in trees at Viharamahadevi park, and drier soils in compacted tree pits may worsen stability and increase physiological stress in trees at Keppetipola road. This inverse relationship emphasizes how soil conditions in urban settings vary depending on the context. Keywords: Urban forestry, Tree stability, Soil properties, Urban tree risk assessment, Colombo Sri Lanka
Morphological and Molecular Characterization of Microcystin-Lr Producing Cyanobacteria in Beira and Boralesgamuwa Lakes, Sri Lanka
The proliferation of toxic and non-toxic cyanobacteria in freshwater ecosystems has emerged as a critical ecological and public health concern, particularly in urban environments where eutrophication and anthropogenic runoff accelerate bloom formation. Among cyanobacterial toxins, microcystin-LR (MC-LR) is one of the most potent hepatotoxins, frequently implicated in deteriorating water quality and health risks. This study aimed to investigate the occurrence of MC-LR-producing cyanobacteria in two major urban recreational lakes in Sri Lanka, Beira Lake and Boralesgamuwa Lake, by integrating morphological and molecular approaches. Triplicate surface water samples were collected from each lake to enhance statistical reliability, reduce random variability, and ensure MC-LR-producing cyanobacteria reflected true lake conditions. The samples were subsequently concentrated through sequential centrifugation. Cyanobacterial morphotypes were initially identified microscopically, with species such as Microcystis aeruginosa, Microcystis incerta, Oscillatoria gardhii, and Spirulina sp. Genomic DNA was subsequently extracted from concentrated samples using thermal lysis, followed by centrifugation to obtain DNA-rich supernatants. Polymerase Chain Reaction (PCR) amplification was performed using gene-specific primers targeting the mcyA and mcyB gene clusters, which are critical for MC-LR biosynthesis. Amplification products were analyzed by agarose gel electrophoresis alongside a 100 bp DNA ladder for size confirmation. Microscopic examination revealed variations in species dominance between the two lakes, Spirulina sp. was dominant in Beira Lake, while Oscillatoria gardhii and Lyngbya limnetica were more abundant in Boralesgamuwa Lake. Nevertheless, toxin-producing Microcystis species were consistently observed in both sites. Molecular analysis confirmed the presence of the mcyA gene in all six samples. In contrast, the mcyB gene was absent in two samples, Beira 1 and Boralesgamuwa 3, suggesting potential strain-level variation, partial gene loss, or genetic degradation within these populations. The presence of both toxin-producing and non-toxin-producing cyanobacteria in recreational lakes, along with the detection of toxin genes, indicates serious potential for MC-LR contamination that poses health risk to local communities engaged in recreational and occupational activities. Keywords: Cyanobacteria, Microcystin-LR, Polymerase chain reaction, Toxic blooms, Water quality monitoring
Surveillance of Antibiotic Resistance in Salmonella Spp. and Shigella Spp. from the Surface and Groundwater of Kelani River Basin, Sri Lanka
Antibiotic Resistance (AR) among waterborne pathogens is a growing public health concern, particularly in regions with high environmental contamination. The Kelani River, a critical freshwater resource in Sri Lanka, is exposed to sewage discharge and agricultural runoff, creating conditions conducive to the persistence and dissemination of AR bacteria. This study aimed to characterize the antibiotic resistance profiles of Salmonella spp. and Shigella spp. Isolated from the transition zone of the Kelani River Basin. Twenty-seven surface and groundwater samples yielded 29 bacterial isolates, which were identified using standard biochemical assays. Antibiotic susceptibility test was evaluated for four commonly used antibiotics: Tetracycline (TET), Oxytetracycline (OTC), Sulfonamide (SUF), and Sulfadiazine (SDI) at concentrations ranging from 60 to 360 μg/mL. Minimum Inhibitory Concentration (MIC) testing of 29 isolates revealed high resistance to SUF (37%) and SDI (39%) at 60 μg/mL, persisting in 40% and 60% at 360 μg/mL, respectively. In contrast, resistance to TET and OTC was lower, showing 9% and 15% at 60 μg/mL respectively, with complete susceptibility at the highest concentration (360 μg/mL). This demonstrates markedly higher resistance to Sulfonamides than to Tetracyclines. Ten multidrug-resistant (MDR) isolates were further screened for resistance genes via PCR. All MDR isolates carried the blaTEM gene, associated with β-lactam resistance, whereas the tetA and tetM genes were not detected. These findings indicate the presence of sulfonamide-resistant Salmonella spp. and Shigella spp. carrying the blaTEM gene in the Kelani River transition zone, highlighting the role of freshwater systems as reservoirs of antibiotic resistance. The study underscores the need for enhanced environmental surveillance and improved water management practices to mitigate the spread of AR and protect public health. Keywords: Antibiotic resistance, Kelani river, Transitional zone, Salmonella spp., Shigella spp.
Effects of Repeated Application of Organic Amendments on Water Repellency, Initial Infiltration and Hydraulic Conductivity of Soil Under Field Conditions
The application of various organic amendments is a common practice in agriculture to enhance soil organic matter content. Soil Water Repellency (SWR) is a phenomenon that restricts water movement in soil, which is caused by the presence of organic substances. The application of organic amendments to soil can alter the water-repellent nature of the soil, potentially causing negative impacts on soil hydraulic functions. Comprehensive evidence on the possibility of the development of SWR to detrimental levels through repeated applications of organic amendments and consequent effects on the soil hydraulic dynamics is highly limited. The present study aimed to examine the development of SWR and the impacts on initial infiltration (Ii) and unsaturated hydraulic conductivity (k) of soil through the repeated application of repellent and non-repellent organic amendments. The experiment was conducted as a field experiment with 20 raised bed plots (0.25 m2 area per plot). The 3% (w/w) of compost (COM), cattle manure (CM), paddy husk biochar (BCPH), and casuarina leaf litter biochar (BCCE) were used as three repeated applications per year (4-month interval). SWR was assessed using the water drop penetration time (WDPT) test, while Ii and k were measured in the field using a mini disk infiltrometer. The results indicated that soil remained non-repellent (WDPT<5s) with repeated applications of organic amendments, though extremely water-repellent BCCE showed an increasing trend in SWR. Initially, soils with CM and BCCE had the lowest Ii, while the control had the highest. Over time, Ii increased in CM and BCCE soils with no significant difference between them. The k showed a slightly decreasing trend with the application of COM, CM, and BCCE, where BCCE resulted in a more pronounced decline (a 48% decline compared to the control after 1 year). Results confirmed that the tested application level did not create negative levels of SWR. The loamy sand soil is typically associated with high k, which may lead to the leaching of agrochemicals and nutrients from the root zone. The observed decrease in k with the application of organic amendments may therefore be beneficial by reducing the leaching effect and groundwater contamination. Thus, despite concerns over repeated application of organic amendments, the finding highlights the positive effect of reduced k in soils with initially high hydraulic conductivity. Keywords: Organic amendments, Water repellency, Infiltration, Unsaturated hydraulic conductivity
Occurrence and Prevalence of Antibiotic-Resistant Bacteria in Landfill Leachate
Leachate, the liquid produced when rainwater percolates through solid waste in landfills, often contains a mixture of contaminants, including residual antibiotics and microbial communities. In countries like Sri Lanka, inadequate solid waste management leads to leachate discharge, posing significant public health risks through the dissemination of Antibiotic-resistant Bacteria (ARB) into surrounding environments and water sources. The present study assessed the prevalence of ARB in leachate collected from three landfill sites in Sri Lanka: Karadiyana (urban), Kurunegala (suburban), and Horana (rural). One leachate sample was collected from each landfill site, resulting in a total of three samples for analysis. Four commonly used antibiotics: Augmentin (AUG), Azithromycin (AZT), Ciprofloxacin (CIP), and Gentamicin (GEN), were selected to evaluate resistance profiles. Total viable counts (TVC) and minimum inhibitory concentrations (MIC) were determined following Clinical and Laboratory Standards Institute (CLSI) guidelines. TVC in the leachate samples ranged from 1.24×102 to 3.58×102 CFU/mL. Horana leachate exhibited the highest prevalence of ARB, particularly for CIP and AUG, with MIC values ranging from 60-360 µg/mL for AUG and 60-180 µg/mL for CIP. CIP-resistant isolates constituted 27.9% of the total bacterial load, while AUG resistance was 14%. Resistance to AZT (1.4%) and GEN (1.7%) was comparatively lower. Karadiyana leachate showed moderate resistance, with AZT at 3.9%, AUG at 3.1%, and CIP at 1.8%; no GEN resistance was detected. Minimal resistance was observed in Kurunegala samples, with AUG at 0%, CIP at 1.6%, and both AZT and GEN at 2.4%. These results suggest that Horana landfill leachate represents a significant source of environmental antibiotic contamination, likely due to industrial or municipal inputs, whereas Karadiyana and Kurunegala leachates exhibit lower ARB prevalence. Overall, the study highlights landfills and their leachates as important reservoirs for ARB, emphasizing the need for improved waste management and monitoring to mitigate the environmental spread of antibiotic resistance. Keywords: Landfill, Leachate, Antibiotic resistance, Antibiotic-resistant bacteria, Solid waste
Evaluating the Relationship Between Chemical Oxygen Demand (COD) and Polycyclic Aromatic Hydrocarbons (PAHs) in Kelani River
Polycyclic Aromatic Hydrocarbons (PAHs) are persistent organic pollutants that originate from both petrogenic and pyrogenic sources, with significant ecological and human health risks. Among them naphthalene (NAP) and phenanthrene (PHE) are two low molecular-weight PAHs that are classified as “priority pollutants” by the United States Environmental Protection Agency. Chemical Oxygen Demand (COD) is widely employed in water quality assessments as an indicator of total organic load. This study examined the relationship between COD and PAHs in surface water samples from the meandering part of the Kelani River basin, Sri Lanka. Samples were collected from thirteen locations with triplicate measurements obtained during two distinct seasons to capture spatial and temporal variability. The water samples were collected into amber color glass bottles by dipping the sampler below 10 cm of the water surface to minimize air entrapment and preserved in a refrigerator below 4 ºC until analysis was done. COD was determined using the dichromate oxidation method, while priority PAHs specifically NAP and PHE were quantified by using high-performance liquid chromatography (HPLC) with UV detection following the liquid-liquid extraction using hexane and acetone. HPLC calibration demonstrated excellent linearity with strong correlations between peak area and concentration for PHE (R2=0.999) and NAP (R2=0.991), underscoring the robustness of the standard curves. The concentrations of NAP ranged from 2.499 to 8.414 mg/L in the wet season and 0.005 to 9.658 mg/L in the dry season, while PHE varied between 0.248 mg/L during the wet season and undetectable to 0.329 mg/L in dry season, across sampling sites. COD values spanned from 10.6 to 32.0 mg/L (wet season) while varying from 12.4 to 42.6 mg/L (dry season) with markedly higher loads observed in urban and industrially influenced locations. Seasonal analysis indicated that both PAHs and COD were elevated during the dry season compared to the wet season due to reduced dilution and enhanced accumulation effects. Pearson correlation analysis revealed a significant positive association between COD and PAHs concentrations (wet season: r=0.94; dry season: r=0.98). These findings suggest that COD could serve as a potential surrogate indicator of PAHs contamination providing a rapid and cost-effective screening tool for aquatic pollution monitoring particularly in resource-limited contexts. Keywords: Polycyclic aromatic hydrocarbons, HPLC, Naphthalene, Phenanthrene, COD
Assessment of Hygiene Practices and Water Quality of Commercial Reverse Osmosis Water Filtration Units in Anuradhapura Town Sri Lanka
The demand for commercially filtered Reverse Osmosis (RO) water has risen sharply in urban Sri Lanka due to increasing awareness of water quality and health concerns. In Anuradhapura town, nearly 100 small-scale RO units currently operate along major roads, supplying water to local residents. This study evaluated the physicochemical properties and hygiene practices of 50 selected RO units, distributed evenly across the town, over a twelve-month period from September 2024 to August 2025. Monthly sampling was carried out on Sunday mornings to ensure consistency and reflect routine consumption patterns. Water samples were analyzed for pH, Total Dissolved Solids (TDS), and temperature, while hygiene assessments focused on floor and ceiling cleanliness, tank coverage, bottle-washing procedures, RO membrane maintenance, and overall environmental conditions. All results were compared with National Water Supply and Drainage Board (NWSDB) potable water standards. Findings revealed that most water samples had pH values between 5.0 and 6.0, indicating mild acidity, with only a few units showing slightly higher pH levels of 6.0-7.0. TDS values were generally below 20 mg/L, demonstrating very low mineral content, which could affect long-term dietary mineral intake. Morning water temperatures ranged from 29 °C to 33 °C. Hygiene assessments showed widespread deficiencies. Only 12 units had properly tiled floors, and many ceilings were dusty or covered with spider webs. The majority of storage tanks were left uncovered, leading to dust accumulation. RO membranes were seldom cleaned or replaced according to recommended schedules. Poor bottle-cleaning practices were documented in 15 units, and routine tank disinfection was largely absent. Surrounding environments were often cluttered with dust and waste, increasing the risk of contamination. Only one unit practiced mineral re-addition, which resulted in comparatively higher and more acceptable pH and TDS levels. Overall, the study revealed significant non-compliance with national potable water standards and highlighted potential risks such as microbial contamination, corrosion related to low pH, and mineral deficiencies. The results underscore the need for stronger regulatory oversight, mandatory hygiene protocols, proper maintenance of RO systems, and regular water quality monitoring. This year-long assessment provides a critical baseline for improving the safety, quality, and reliability of commercial RO water in Anuradhapura, contributing to better public health outcomes. Keywords: Commercial reverse osmosis water, Physicochemical parameters, Hygiene, Water quality monitoring
Prevalence and Minimum Inhibitory Concentration Profiling of Ciprofloxacin-Resistant Bacteria in Coastal Waters of the Northern and Southern Provinces of Sri Lanka
Antibiotic resistance is a critical global health threat, with environmental contamination playing a significant but underexplored role alongside clinical misuse. Coastal waters are particularly vulnerable due to inputs of Antibiotic Residues (AR) and Antibiotic-Resistant Bacteria (ARB) from wastewater discharge, agricultural runoff, and aquaculture effluents. This study assessed the prevalence and resistance profiles of ciprofloxacin (CIP) resistant bacteria in coastal waters of Sri Lanka, where such data remain limited. Water samples were collected in triplicate from eleven coastal sites, six in the Northern Province (Karaitivu, Anaikodai, Ponnalai, Dambakola Patuna, Point Pedro, and Dutch Fort-Jaffna), and five in the Southern Province (Polhena, Weligama, Koggala, Unawatuna, and Hikkaduwa). CIP-resistant bacteria were isolated using the standard pour plate method on nutrient agar supplemented with 60 µg/mL CIP. Minimum inhibitory concentrations (MICs) were determined via agar dilution following Clinical and Laboratory Standards Institute (CLSI) guidelines. Total Viable Counts (TVCs) of bacteria were higher in Southern sites (5.07×104-6.75×104 CFU/mL) than Northern sites (1.21×104-1.53×104 CFU/mL), with the highest counts recorded at Hikkaduwa (6.75×10⁴ CFU/mL, South), followed at Ponnalai (1.53×104 CFU/mL, North). Similarly, CIP-resistant bacteria were more prevalent in the South (2.55×104-6.06×104 CFU/mL) compared to the North (1.81×103-1.25×104 CFU/mL). Among 22 isolates, 86% of Southern isolates exhibited MIC values >360 µg/mL, whereas no Northern isolates exceeded this level. Northern isolates displayed MIC distributions of 20% at 180-240 µg/mL and 60% at 240-360 µg/mL, while Southern isolates showed no MIC values below 240 µg/mL, with only 14% falling within the 240-360 µg/mL range. These results reveal a pronounced geographic disparity in ciprofloxacin resistance, with the Southern coastal region identified as a significant hotspot for high-level resistance. While this study offers crucial initial data on CIP-resistant bacteria prevalence and MIC profiles, more extensive research is required for a comprehensive understanding. These results underscore the need for sustained environmental monitoring and targeted interventions to mitigate the spread of antimicrobial resistance in coastal ecosystems. Keywords: Ciprofloxacin resistance, Antibiotic-resistant, Coastal pollution, Southern province
Watershed Management Practices and Their Long-Term Impacts in the Uva Basin, Sri Lanka: A Case Study of the Upper Watershed Management Project
The Uva basin of Sri Lanka, with its unique geomorphology and dominance of Uma Oya and Badulu Oya sub-catchments is identified as one of the most eroded sub-basins in the country. The area imposes considerable sedimentation to the Rantambe Reservoir, which has lost nearly 56% of its original storage capacity. To address these issues, the Upper Watershed Management Project (UWMP) was implemented from 1998-2006 under the Ministry of Environment with financial support from the Asian Development Bank. This study aimed to evaluate the long-term effectiveness of watershed management interventions, community adoption, and their effect on sustainable land productivity in Uma Oya sub-basin's Hibiliagolla Grama Niladari Division. Participatory observation, direct measurements, farmer interviews, and interaction with a social mobilizer were undertaken at Mahagandowa village, which was the project focus area. A total of 25 farmers were interviewed. A combination of qualitative assessment by participatory observation and quantitative measurement of land and terraces were made to determine the effectiveness of conservation. Findings revealed that nearly 60% of the soil and water conservation measures introduced under UWMP are still practiced even after 17 years since project completion. Mechanical, biological, and cultural measures such as terrace farming, stone bunding, block spill drains, grass ridges with Cymbopogon citratus (lemon grass), and wind-controlling tree strips have been effectively sustained by farmers. Terraces widths ranged between 7-13 feet, depending on slope and soil condition, indicating effective design guideline adaptation. Farmers reported increases in vegetables such as carrots, potatoes, and onions following soil stabilization. Besides, regular maintenance of above mountain forest cover and riparian zones increased infiltration and reduced the runoff velocity. The interviews revealed that the reward and participation-based approaches and social mobilizers increased community ownership and long-term sustainability of the project impact. Inadequate post-project impact evaluation and narrow replication of the model in other erosion sites were documented as key weaknesses. Finally, the study concludes that the Upper Watershed Management Project has resulted in concrete environmental and socio-economic benefits and reveals the advantages of participatory watershed management and community-based conservation in sustainable land and water management. Keywords: Uma oya, Uva basin, Soil conservation, Sustainable watershed management
Assessment of Variability of Carbon Stocks, Physicochemical Parameters, Growth Dynamics of Mangrove Soil and Mangrove Ecosystem in Koggala Lagoon, Sri Lanka
Mangrove forests are unique and invaluable ecosystems due to their role in carbon sequestration. This study examined the spatial variability of selected physicochemical parameters of mangrove soil and total soil carbon distribution at the Koggala lagoon. One hundred core samples were selected from 0-10 and 10, 20 cm depths from the surface based on stratified random sampling techniques. Further, a vegetation survey was conducted to identify mangrove species in the same areas. Soil temperature (°C), pH, Oxidation Reduction Potential (ORP), Total Dissolved Solids (TDS), electrical conductivity, and salt as the physicochemical parameters and carbon contents (inorganic and organic) were analyzed using a standard laboratory method as Loss of Ignition (LOI) involving simple gravimetric equations. The results revealed that soil temperature had the greatest impact on changing carbon content, followed by moisture and dry bulk density. That temperature spatially consistent vertical variation from 29.0 °C to 32.0 °C, with the highest temperature recorded in the top layer. The soil pH values for both depth intervals ranged approximately between 5.0 and 7.0 across all plots. The plots dominated by Rhizophora mucronata achieved mean DBH values of 13-16.4 cm and heights of 5.1-5.7 m under low to moderate salinity, higher soil temperatures and more alkaline pH. Bruguiera sexangula exhibited lower DBH (8.6-11.7 cm) and heights (3.0-4.3 m) in high-salinity plots. Finally, the widening of the channel acted as a primary driver of environmental changes in the lagoon, significantly altering carbon content, physicochemical parameters, and ecosystem dynamics. Therefore, long-term monitoring of soil carbon content and its seasonal and spatial variations, using advanced remote sensing tools and field measurements, will improve the assessment of mangrove ecosystems. Additionally, clear awareness about the ecological importance of the Koggala lagoon area and management strategies and policy developments is very urgent to the resilience and sustainability of this valuable mangrove ecosystem in the face of environmental changes and anthropogenic pressures. Keywords: Mangrove soil carbon, Physicochemical parameters, Growth dynamics, Koggala lagoon, Ecosystem resilience
Quantification and Spatial Variability of Soil Organic and Inorganic Carbon in the Intermediate Zone Forests
Soil carbon plays a critical role in regulating ecosystem functions, nutrient cycling, and long-term carbon sequestration. Understanding the dynamics of Soil Organic Carbon (SOC) and Soil Inorganic Carbon (SIC) in tropical forest ecosystems is crucial for developing effective, sustainable forest management strategies. This study quantifies and analyses the spatial variation of SOC and SIC, along with the effects of environmental and human factors on their variability, in the intermediate zone forests of Sri Lanka. Field data were collected using a systematic random sampling approach, where 34 sampling points were selected across representative forest sites in Badagamuwa Conservation Forest and Dikkele Forest Reserve. A total of sixty-eight composite soil samples were extracted with an auger at two depth intervals (0-7.5 cm and 7.5-15 cm) for laboratory determination of SOC and SIC contents. Parallel to this, indices such as Leaf Area Index (LAI), Normalized Difference Vegetation Index (NDVI) Human Disturbance Index (HDI) were derived from hemispherical photographs and Sentinel-2 satellite imagery. In-situ measurements of soil pH, Oxidation-reduction Potential (ORP), temperature, and moisture were taken to capture micro-environmental variability. Laboratory analysis indicated that the average SOC content was 2.26%, while the average SIC content was 1.15%, with both forms of carbon showing depth-dependent variation. The 7.5-15 cm soil layer stored higher SOC (8.9 t/ha) and SIC (5.2 t/ha) compared to the surface layer, which contained 8.0 t/ha and 3.5 t/ha, respectively. Spatial interpolation using the Inverse Distance Weighting (IDW) method revealed a heterogeneous distribution of SOC and SIC across the landscape. Statistical analyses, including regression and Principal Component Regression (PCR), identified soil moisture (p<0.001), canopy light variability (p=0.01), and oxidation-reduction potential (p=0.03) as key predictors of SOC variation, while SIC was primarily influenced by soil moisture (p<0.001). Overall, this study shows the significant role of vegetation structure, soil moisture, and human disturbance in SOC and SIC dynamics in Sri Lanka’s intermediate zone forests. Keywords: Soil carbon stocks, Intermediate zone, Anthropogenic disturbances, Predictors
Hydrological Drivers of Vegetation Zonation in a Sri Lankan Riverine Mangrove
Riverine mangrove ecosystems are strongly influenced by hydrological conditions, particularly tidal fluctuations and seasonal water-level variations. Factors such as groundwater depth, surface water dynamics, and tidal activity shape vegetation structure and zonation. However, in Sri Lanka, studies that examine these ecohydrological drivers remain relatively new. To address this gap, the present study was conducted in the Malgasowitadeniya Conservation Forest, a riverine mangrove ecosystem located in Ittapana South, Kalutara District, Sri Lanka. The objective was to assess how fluctuations in groundwater and surface water levels influence vegetation zonation from the riverbank to inland. From September 2024 to April 2025, groundwater and surface water levels were measured at ten fixed sampling points along three transect lines (each~430 m) using custom-made monitoring setups. Measurements were taken four times per month, aligned with lunar phases to capture tidal influences across wet and dry seasons. Additionally, short-duration tidal and overflow experiments were also conducted to examine immediate hydrological responses. A vegetation survey was conducted along the middle transect, documenting species composition and structural attributes (height, Diameter at Breast Height (DBH), canopy width, and canopy shape). Results showed no significant difference in groundwater depth between wet and dry seasons or between tidal phases across transects. Groundwater depth remained shallow and relatively uniform along Transects 1 and 2, but increased inland along Transect 3. Vegetation displayed clear zonation: true mangrove species (Bruguiera sexangula and Rhizophora mucronata) dominated the river edge, mangrove associates (Cerbera odollum) in the mid-zone, and invasive species (Annona glabra and Dillenia suffruticosa) prevailed inland. Structural attributes were greater closer to the river and declined landward. Although zonation patterns did not statistically correlate with groundwater depth, field-based observations and spatial mapping suggest that the hydrological gradient plays an important role in shaping vegetation structure and distribution. These findings provide baseline evidence of ecohydrological controls on riverine mangrove vegetation in Sri Lanka. The study highlights the need for systematic restoration strategies, strengthened protective regulations, and site-specific restoration standards to safeguard riverine mangrove ecosystems facing hydrological and land-use pressures. Keywords: Groundwater dynamics, Vegetation zonation, Riverine mangrove, Ecohydrology, Sri Lanka
Diversity and Distribution of Lichen and Flora Species in Serpentine Soil in Ussangoda, Sri Lanka
Serpentine soils, which form from ultramafic rocks such as peridotite and serpentinite, are chemically severe environments with low nutrient levels, high magnesium-to-calcium ratio, and high concentrations of heavy metals (nickel, chromium, and cobalt). These conditions preclude most organisms from colonizing but select for the growth of specially adapted plants and microbial life. This research investigates lichen and plant species diversity and their distribution within the serpentine soil ecosystem of Ussangoda National Park, Sri Lanka and their relationship to succession. The study aims to catalog the flora and lichen species, their ecological roles, and the interaction between soil chemistry and biological adaptation in this specialized edaphic habitat. Field surveys were conducted across ten randomly selected 25,000 m2 sampling plots, and 10 composite soil samples, macro-lichen, and macro-floral datasets were collected using standardized ecological and sampling methods. Lichen and plant species were identified to species level based on morphological characteristics using dichotomous keys, while biodiversity indices such as Shannon-Wiener, Margalef's richness, and species evenness were calculated to ascertain ecological diversity. Soil testing was done for phosphorus, potassium, EC, OM and pH. Three macro-lichen species, Pyxine sorediata, Bacidia circumspecta, and an unidentified crustose species, were found to be predominant on serpentinite rock surfaces, indicating their pioneering nature in the colonization of metal-rich substrates. These lichens are significantly involved in the weathering of rocks, soil formation, and bioindication of environmental stress. Similarly, the main serpentine-tolerant plant species such as Fimbristylis falcata (Vahl.) Kunth., Evolvulus alsinoides (L.) L., and Eragrostis ciliaris (L.) R. Br. were encountered, which displayed prominence in the sampled areas. These are adaptive responses that are evolutionary responses to edaphic stress imposed by serpentine. With that newly identified three plant species Chlorophytum sp., Phyllanthus wheeleri, Veronica peregrina were not recorded earlier in the Ussangoda serpentine ecosystem. As soil analysis results, obtained pH:5.47±0.14, OM:3.28%±0.255, P2O5:1.26±0.22 ppm, K2O: 137.76±15.87 ppm and EC as 0.041±0.0095 dS/m. The results emphasize the ecological role played by plant communities in the maintenance of stability and function in serpentine ecosystems. Their roles include nutrient cycling, prevention of erosion, and ecosystem facilitation. Identifying and understanding macro-lichen and flora species offer critical insights for ecological restoration in degraded or metal-contaminated environments. Their physiological resilience and adaptive strategies can guide the selection of species for reforestation and soil rehabilitation in extreme habitats and sustainable land management toward succession. Keywords: Primary succession, Toxic habitats, Serpentine ecosystem, Toxic tolerability, Land degradation
Antibiotic Susceptibility Profiling of Escherichia coli Isolates from Inland Reservoirs Against Selected Antibiotics
Antibiotic resistance is a critical global concern, extending beyond clinical settings into freshwater ecosystems due to improper antibiotic use and inadequate waste management. In Sri Lanka, inland reservoirs play a key role in irrigation but are increasingly contaminated with antibiotic-resistant bacteria through urban runoff, sewage discharge, and agricultural activities. Escherichia coli, a primary faecal contamination indicator, frequently harbors resistance genes, making it a vital target for environmental antimicrobial resistance (AMR) monitoring. This study evaluated the antibiotic susceptibility of E. coli isolates collected from major Sri Lankan reservoirs located in the Central, Western, North Western, Eastern, and North Central provinces of Sri Lanka against seven antibiotics: Amoxicillin, Cloxacillin, Tetracycline, Oxytetracycline, Piperacillin, Cefotaxime, and Ceftazidime. Water samples were collected from 24 sampling sites in triplicates, and E. coli was isolated using standard microbiological and biochemical methods. Antibiotic susceptibility was assessed using the agar dilution method (60-360 μg/ml) in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines, and the Multiple Antibiotic Resistance (MAR) index was calculated to evaluate environmental antibiotic exposure. Results showed complete resistance (100%) to Amoxicillin and Cloxacillin at 360 μg/mL, indicating reduced effectiveness of these β-lactam antibiotics. Resistance to Tetracycline and Oxytetracycline was comparatively lower (15.6% and 6.3%, respectively). Resistance to third-generation antibiotics was moderate at 60 μg/mL (Cefotaxime 18.8%, Ceftazidime 40.6%, Piperacillin 28.1%) and absent at 360 μg/ml. All MAR index values exceeded 0.2 at 60 μg/mL, reflecting significant environmental exposure to antibiotics. The observed resistance patterns suggest the presence of highly resistant E. coli strains, potentially facilitated by horizontal gene transfer. These findings underscore the urgent need for stricter antibiotic regulation, controlled over-the-counter access, and improved wastewater management. They also highlight the importance of establishing a national AMR surveillance system under the One Health framework. Future studies should focus on resistance gene profiling, antibiotic residue quantification, and elucidating mechanisms of resistance dissemination to inform effective mitigation strategies and safeguard public health. Keywords: Escherichia coli, Antibiotic resistance, MAR index, Recreational water bodies, public health.
Β-Lactam and Multi-Drug Resistance Profiling of Salmonella spp. and Shigella spp. Isolated from the Transitional Zone of the Kelani River, Sri Lanka
Salmonella spp. and Shigella spp. are significant enteric pathogens responsible for gastrointestinal infections, and the emergence of antibiotic-resistant strains increasingly compromises treatment efficacy. This study evaluated the β-lactam and multidrug resistance profiles of Salmonella and Shigella isolates from the transitional zone of the Kelani River Basin, a key freshwater resource in Sri Lanka. 27 surface and groundwater samples were collected during the first inter-monsoon season of 2024. Isolation was performed using the standard pour plate method, and bacterial identification was confirmed with five standard biochemical tests. Resistance to three commonly used β-lactam antibiotics amoxicillin (AMOX), ampicillin (AMP), and cloxacillin (CLOX) was assessed by determining Minimum Inhibitory Concentration (MIC) values. The Multiple Antibiotic Resistance (MAR) index was calculated to estimate the extent of multidrug resistance among isolates. Results showed that CLOX exhibited the highest resistance, with 46.9% of isolates resistant at 60 μg/mL and 61.3% at 360 μg/mL. AMX resistance was observed in 28.6% (60 μg/mL) and 32.4% (360 μg/mL) of isolates, while AMP resistance was observed in 24.5% (60 μg/mL) and 6.5% (360 μg/mL). MAR index values ranged from 0 to 1, with 17.2% of isolates exhibiting no resistance and 37.9% resistant to all three β-lactam antibiotics. The elevated MICs and high MAR indices indicate strong selective pressure and widespread antibiotic resistance in this freshwater environment. These findings highlight the urgent need for continuous environmental surveillance and the implementation of strict policy measures to prevent the dissemination of clinically relevant Antibiotic Resistance Genes (ARGs) in the Kelani River Basin. Keywords: Antibiotic resistance, Salmonella spp., Shigella spp., MIC value, MAR Index
Impact of Initial Tilapia (Oreochromis niloticus) Stocking Size on Crop-Fish Yield and Soil-Water Quality in Integrated Rice-Fish Farming Systems
Integrated rice-fish farming (IRFF) is a system of producing fish in combination with paddy cultivation using the same resources in the same unit area. This study aimed to assess the effects of different initial tilapia (Oreochromis niloticus L.) stocking sizes on the growth and yield of rice and fish, economic return, and to evaluate soil fertility and water quality within an IRFF system. A field experiment was conducted using four (T1-T4) stocking sizes: T1:5 g, T2:20 g, T3:35 g, and T4:50 g. Each treatment with three replicates was randomly allocated in a Complete Randomized Block Design. Data were analyzed using ANOVA and Duncan’s post hoc test. Stocking sizes influenced both rice and fish performance significantly. The 35 g and 50 g provided the best balance, supporting high yields for both rice and fish without adverse effects on soil fertility or water quality. The 50 g treatment produced the highest rice yield (5.08 t/ha), presenting a 1.8% increase compared to the average regional rice yield (4.99 t/ha). Soil nutrient levels (N, P, K) and organic matter (OM) significantly increased across treatments, with T4 showing the highest enrichment. Water quality parameters including pH (7.36-7.80), EC (376-383 µS/cm), temperature (29.26-29.40 ºC), DO (4.72-5.08 mg/L-1), NO3- (0.61-0.86 mg/L-1), and NH3 (0.23-0.34 mg/L-1) remained within non-toxic limits. The 50 g stocking size yielded the highest net return (USD 1,047.54 ha-1) and benefit-to-cost ratio (BCR) of 1.44, presenting a 290 % increase in profit and a 19 % higher BCR compared to rice monoculture. In conclusion, this study suggests that 35 g and 50 g tilapia stocking sizes optimize rice-fish yields and enhance soil quality without compromising water quality in IRFF systems. Keywords: Integration, Nutrients, Profitability, Stocking size, Sustainable agriculture
Soil Remediation Potential: Evaluation of Polycyclic Aromatic Hydrocarbon Degradation by a Bacterial Consortium Influenced by Silver (Ag) Stress
Soil contamination with persistent environmental pollutants such as Polycyclic Aromatic Hydrocarbons (PAHs) poses a critical environmental challenge, particularly in areas that have undergone rapid industrialization and accumulation of waste. Compounds such as PAHs are highly resistant to natural degradation and are often co-contaminants alongside heavy metals such as silver. These ubiquitous pollutants pose a significant health risk to organisms due to their carcinogenicity and mutagenicity, threatening soil fertility, groundwater quality, as well as food safety, necessitating sustainable bioremediation strategies. This study aimed to isolate PAH degrading bacteria from four soil samples in dumping sites across Sri Lanka (Colombo, Galle, Jaffna and Kandy) to form a consortium and evaluate its potential for phenanthrene and naphthalene degradation under silver-induced stress. Ten morphologically different bacteria were isolated from soil samples, of which four strains (CHR-J7, CHR-J5, CHR-C15 and CHR-G10) were chosen for the consortium after they showed consistent growth on selective media prepared using BBH agar spiked with PAHs. Spectrophotometric analysis revealed that all four strains showed promising degradation, with CHR-J7 displaying the highest degradation of both PAHs. The optimal degradation of phenanthrene was observed to be at 40 ppm (52.03%) and that of naphthalene was at 30 ppm (38.96%). Antagonistic assays confirmed compatibility among the selected strains, and the strains CHR-J7 and CHR-G10 were identified to be as Glutamicibacter ectropisis (PV942265) and Achromobacter insolitus (PV942243) respectively by 16S rRNA sequencing. Toxicity bioassays with Artemia salina and Vigna radiata revealed low cytotoxic and high phytotoxic effects under the tested conditions. Highest PAH concentrations were observed to be in soil samples from urbanized areas such as Colombo and Jaffna by High Performance Liquid Chromatography (HPLC) analysis. The key degradation assays for four bacterial strain samples were carried out in triplicates to ensure data reliability. These findings suggest that these indigenous bacterial consortia can be used as a potential biological agent in the remediation of soil co-contaminated with PAHs and silver. Biotechnological approaches such as soil remediation with bacterial consortiums hold promises for mitigating the persistence of soil pollutants and contributing to soil and water remediation strategies, restoring contaminated soils and safeguarding the quality of groundwater. Further research around genetic analyses, optimizing the bacterial strain ratios, and different environmental conditions in field-scale applications is recommended for enhancing the effectiveness of this bioremediation approach. Keywords: Polycyclic aromatic hydrocarbons, Bacterial consortium, Bioremediation, Soil contamination, Heavy metals
Temporal Variability of Soil Properties in the Diyawannawa Wetland, Sri Lanka
Wetland soils are highly dynamic and sensitive to seasonal hydrological fluctuations that influence their physical structure, nutrient dynamics, and overall ecological functioning. Understanding these temporal variations is essential for sustainable wetland management and conservation. This study investigated the temporal variability of key soil physical and chemical properties in the Diyawannawa Wetland, Sri Lanka, under varying rainfall conditions. This study examined the temporal variability of major soil physical and chemical properties in the Diyawannawa Wetland, Sri Lanka, across three rainfall-driven sampling periods including July, September, and November 2024. Bulk density, porosity, pH, electrical conductivity (EC), Organic Matter Content (OMC), total nitrogen (TN), and available phosphorus (AP) were assessed. A total of 24 soil samples per period, each with 3 replicates, were analyzed using standard laboratory procedures, and temporal differences were tested using one-way ANOVA. The results revealed that temporal variability in both physical and chemical parameters (p<0.05). Bulk density was lowest in November (0.70±0.22 g/cm³) and highest in September (0.97±0.30 g/cm³), indicating reduced compaction under wetter conditions. Correspondingly, soil porosity peaked in November (57.48±13.82%) and declined during drier months (43.03±14.58% in July; 41.91±17.07% in September), reflecting the influence of soil moisture on structural aggregation. Among chemical properties, soil pH was significantly lower in November (6.15±0.52) compared to July (6.39±0.61) and September (6.57±0.48), suggesting acidification driven by organic acid accumulation under anaerobic conditions. Similarly, EC showed its lowest value in November (0.06±0.01 dS/m) due to leaching of soluble ions during high rainfall, whereas higher EC values occurred in July (0.086±0.02 dS/m) and September (0.113±0.05 dS/m). Organic matter content and total nitrogen followed opposite trends, with peak values recorded in November (70.30±43.77 g/kg and 0.26%±0.09, respectively), associated with enhanced litter input, moisture retention, and reduced decomposition. In contrast, July and September exhibited significantly lower values due to limited rainfall and increased mineralization rates. Available phosphorus showed minimal temporal variation (8.22±7.25-9.81±8.65 mg/kg) and was not significantly affected by rainfall fluctuations (p>0.05), implying that phosphorus availability is more controlled by soil redox and adsorption–desorption processes than by direct hydrological input. Overall, the findings highlight the strong influence of rainfall-driven hydrological variability on wetland soil structure and nutrient dynamics, emphasizing the need for seasonal monitoring to support adaptive management of the Diyawannawa Wetland and similar tropical ecosystems. Keywords: Diyawannawa wetland, Soil properties, Temporal variability, Hydrological fluctuations, Nutrient dynamics
Influence of Rainfall on the Physicochemical Characteristics: A Study of Aththanagalu Oya River Basin, Sri Lanka
The environmental situations and value of the river are intentionally influenced by varying climatic circumstances and social events, and rainfall actions that affect the water quality of the river basins. The objective of the present study was to investigate the changes in the physicochemical characteristics of the Aththanagalu Oya under different rainfall events. The water samples were collected in six locations (Alawala-Up Stream, Aththanagalle Bridge, Weediyawatta water intake, Gampaha Bridge, Kotugoda Bridge, Seeduwa Bridge) per month for three-year periods (2022,2023 and,2024), and composite water samples from two edges and the middle were analyzed. The correlation between the monthly rainfall and a range of physicochemical parameters, such as pH, Temperature, Electrical Conductivity (EC), Turbidity, Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), Chlorides, hardness, phosphate, and nitrate, were investigated. The analytical results were obtained and averaged. The pH values were observed to be neutral. EC showed average levels, with a mean value of 0.14 mS/cm. Turbidity exhibited a wide range of variation from the upper watershed to the downstream areas, averaging 43 NTU (5-85 NTU). COD averaged 13 mg/L (5-25 mg/L), and BOD averaged 3 mg/L (2-5 mg/L). Chloride concentrations showed varied values, with an average of 20 mg/L (4-69 mg/L), and the levels increased noticeably near the river mouth. Total hardness averaged 36 mg/L (15-77 mg/L), while averaged nitrates 0.24 mg/L (0.2-0.98 mg/L) and averaged phosphates 0.045 mg/L (0.01-0.11 mg/L were very low. According to the time-series analysis across the upper, middle, and lower basins of the Aththanagalu Oya, turbidity, total hardness, and chloride showed noticeable correlations with rainfall patterns. In the downstream section of the river basin, turbidity increased significantly, which is carried towards the lower basin during intense rainfall. In general, according to the parameters analyzed, pollution levels are very low. Keywords: Climate, Water quality, Anthropogenic
Sustainable Tourism Pathways in Madampe: Applying the TRO-TOUR Concept for Eco-Cultural and Community Development
Madampe, located in Sri Lanka’s Puttalam District, possesses significant eco-cultural and community-based tourism potential that remains underutilized due to weak infrastructure, fragmented governance mechanisms, and limited local participation. This study aims to examine how the TRO-TOUR Tourism Concept-Trust, Respect, Ownership, Transparency, Opportunity, Unity, Responsibility, Transformation, Uniqueness, and Resilience can be operationalized to promote sustainable tourism development in Madampe. A qualitative Grounded Theory approach was adopted to generate theory directly from community realities. The study employed theoretical sampling and engaged 50 participants across four stakeholder categories: local community members and fishers (n=20), tourism-related micro-entrepreneurs (n=12), public officials and policymakers (n=10), and religious and cultural custodians (n=8). Data were collected through semi-structured in-depth interviews, two focus group discussions, field observations, and document analysis. Each TRO-TOUR principle was examined using context-specific qualitative indicators, including levels of stakeholder trust and collaboration, perceptions of cultural respect, degree of community ownership in tourism initiatives, transparency in decision-making, livelihood opportunities generated, collective action, environmental responsibility, socio-economic transformation, destination uniqueness, and adaptive capacity to environmental and market changes. Data analysis followed open, axial, and selective coding procedures to identify categories and relationships among themes. Findings reveal that eco-tourism initiatives linked to the Pambala Mangrove Reserve, sustainable boating and recreation at Thinipitiya Lake, improved access to the Samadhi Statue and Taniyawallabha Temple, and the revitalization of the Pambala fishing area demonstrate strong alignment with multiple TRO-TOUR principles. Cultural and religious assets such as Senanayake Monastery, Punchi Kataragama Temple, and the Pambala Mangrove Museum further enhance destination uniqueness and resilience. The emergent core theory indicates that sustainable tourism development in Madampe depends on strengthening community trust and ownership while integrating eco-cultural resources with inclusive entrepreneurial opportunities. The study concludes that the TRO-TOUR framework provides a practical, community-centred model for developing resilient and replicable rural tourism pathways in Sri Lanka. Keywords: Madampe tourism, TRO-TOUR, Sustainable tourism, Grounded theory, Community-based tourism
Investigating the Possibilities of Nature-Based Tourism: Adventure Activities, Fish Therapy and Water Sports in Heenatiyanwaththa Dola, Kalutara District
Tourism is increasingly recognized as a key driver of sustainable rural economic development, contributing to livelihood improvement while promoting responsible natural resource management. This study investigates the potential for nature-based and adventure tourism development in Heenatiyanwaththa Dola, located in the Palindanuwara area of the Kalutara District, an area characterized by cascading streams, dense forest cover, and an unspoilt rural landscape. The primary objective of the research is to assess the feasibility of introducing adventure and wellness-oriented tourism activities such as nature hiking, river trekking, kayaking, river tubing, low-impact water sports, and fish therapy using naturally flowing streams, while ensuring environmental sustainability. A case study research design was adopted, using primary data collected through field observations, structured questionnaires administered to 60 local households, and semi-structured interviews with 15 key stakeholders, including community representatives, tourism officials, and local entrepreneurs. Community consultations were conducted to incorporate local perspectives and participatory planning approaches. The study further examines the socio-economic impacts of tourism development, particularly its potential to generate household income, create local employment opportunities, and enhance community involvement. Based on the findings, a community-based eco-adventure tourism development model is proposed, emphasizing environmentally sensitive product development, provision of essential visitor facilities and services, and the integration of conservation and local governance mechanisms to safeguard ecosystem integrity. The results indicate that tourism development in Heenatiyanwaththa Dola has strong potential to diversify the rural economy, improve livelihood opportunities, and strengthen community stewardship of natural resources while minimizing negative environmental and social impacts. The findings offer practical insights for local planners, tourism authorities, and private investors, positioning Heenatiyanwaththa Dola as a viable nature-adventure tourism destination and reinforcing its role in promoting sustainable rural development and eco-tourism growth within the Kalutara District. Keywords: Adventure tourism, Nature-based tourism, Heenatiyanwaththa dola, Rural development, Water sports, Fish therapy, Sustainable tourism, Kalutara district
Exploring Sustainable Ecotourism Practices in Ella, Badulla: A Qualitative Inquiry into Community Perspectives and Environmental Conservation
Sustainable ecotourism is increasingly recognised as an effective approach to conserve natural ecosystems, protect cultural heritage, and enhance the social and economic well-being of local communities. The hill station of Ella in the Badulla District of Sri Lanka has become a popular destination for both domestic and international travellers who are attracted by its scenic beauty and authentic rural experiences. However, the rapid growth of tourism has raised concerns about environmental degradation, overcrowding, and limited coordination among institutions. This study aimed to explore community attitudes towards ecotourism in Ella and to evaluate how these practices contribute to sustainable development goals. A qualitative research approach was adopted, and purposive sampling was used to select 160 participants representing key stakeholder groups. The sample included homestay owners, eco tour guides, local residents, small-scale entrepreneurs, government officers, and private sector representatives engaged in tourism and environmental management. Data were collected through in-depth interviews, field observations, and informal discussions. Thematic analysis was employed to identify, analyse, and interpret recurring patterns within the data. Findings reveal that ecotourism has generated significant positive impacts on local livelihoods by creating new income opportunities and encouraging active community involvement. Many residents are engaged in tourism-related activities such as managing guesthouses, operating small cafés and handicraft outlets, guiding nature trails and waterfall tours, conducting traditional cooking and tea tasting sessions, organising cycling and hiking tours, providing transport services for visitors, and participating in cultural performances. These community-based initiatives are strongly connected with environmental conservation practices including waste management programmes, reforestation projects, biodiversity protection, and plastic-free campaigns. Despite these benefits, challenges such as overcrowding at popular sites like Ella Rock and Nine Arches Bridge, inadequate waste management, and weak governance structures were frequently reported. Participants emphasised the importance of establishing stronger institutional coordination, ensuring continuous government support, and fostering effective collaboration among stakeholders to achieve long-term sustainability. In conclusion, Ella demonstrates strong potential to serve as a model for sustainable ecotourism in Sri Lanka by conserving natural resources, preserving cultural heritage, and empowering rural communities. Insights from the experience of Ella can guide future ecotourism initiatives across other rural and highland regions of the country. Keywords: Sustainable tourism, Ecotourism, Environmental conservation, Community participation, Ella
A Study of Community Based Eco-Tourism Practices in Biodiversity Preservation in Forest Areas: Special Reference to Wilpattu National Park
Community based eco-tourism is increasingly recognized as a sustainable approach to balancing biodiversity conservation with the livelihood needs of local communities. In ecologically sensitive regions such as Wilpattu National Park in Sri Lanka, eco-tourism provides an important platform where surrounding communities engage directly in protecting natural resources while benefiting economically from tourism activities. An ongoing concern is whether these practices genuinely support biodiversity preservation or risk creating additional pressure on forest ecosystems. This study investigates the role of community based eco-tourism in biodiversity conservation, with special reference to Wilpattu National Park. The research problem focuses on how community participation in eco-tourism can be organized in a way that ensures long term ecological protection. The study aims to identify existing eco-tourism practices in the Wilpattu region, evaluate their contribution to environmental conservation, assess socio economic benefits to local communities, examine challenges in achieving sustainable management, and propose strategies to strengthen eco-tourism as a conservation tool. A mixed method approach was used. Data were collected from a sample of 50 respondents, including community members and eco-tourism operators selected through simple random sampling. Quantitative data from structured questionnaires were analyzed using descriptive statistical techniques, while qualitative data from interviews and field observations were examined through thematic categorization to identify behavioural patterns and conservation attitudes. The findings show that eco-tourism has enhanced community income, improved environmental awareness, and encouraged local stewardship of forest resources. Respondents reported reductions in unsustainable practices such as poaching and illegal logging due to increased monitoring and eco-tourism related responsibilities. The study also identified weaknesses, including insufficient training for eco-tourism guides, lack of proper infrastructure planning, limited stakeholder coordination, and occasional stress on wildlife habitats caused by uncontrolled visitor activities. The study concludes that community based eco-tourism in Wilpattu holds significant potential for biodiversity preservation if managed more effectively. Strengthening capacity building programs, improving stakeholder collaboration, enforcing regulated visitor numbers, and reinvesting tourism income into conservation projects are essential to ensure long term sustainability and enhanced community engagement in forest protection and empowering local communities via eco-tourism is key to protecting Wilpattu National Park’s ecology. Keywords: Eco-tourism, Biodiversity preservation, Wilpattu national park, Sustainable tourism, Community participation
A Comparative Study of Geo-Spatial Characteristics Influencing Eco-Tourism Development in Sri Lanka and Taiwan: Insights for Sustainable Tourism Practices
Eco-tourism is gaining prominence as an essential approach to sustainable tourism, supporting environmental protection while generating positive outcomes for local communities. It represents a form of travel centered on nature-based experiences that prioritize ecosystem preservation, strengthen community well-being, and encourage awareness of cultural and ecological values through learning and engagement. Despite the ecological richness of Sri Lanka and Taiwan, two island nations with significant biodiversity, there is limited comparative research on how their differing geo-spatial contexts influence eco-tourism development. This study addresses this gap by examining the spatial characteristics that shape eco-tourism trajectories in both countries. Qualitative methodology was adopted, incorporating structured interviews and sample comprises of 32 Sri Lankans at least once visited Taiwan, who were selected under snowball sampling from Sri Lanka. Policy reviews and existing literature to assess geo-spatial distribution, community engagement and sustainable eco-tourism policies based on geo-spatial distribution tailored to island contexts within eco-tourism zones. Both primary and secondary data from Sri Lanka and secondary data from Taiwan were analyzed using thematic analysis in A Qualitative Hypotheses (QHs) to investigate geo-spatial changes and eco-tourism practices. Findings reveal that Sri Lanka’s diverse yet fragmented geo-spatial pose challenges for cohesive eco-tourism planning, while Taiwan’s centralized and technologically managed spatial frameworks facilitate effective conservation-tourism balance and visitor management. Taiwan’s robust transportation infrastructure further enhances site accessibility compared to Sri Lanka’s more isolated eco-tourism regions were evident, while 68% of respondents identified limited infrastructure connectivity as a major constraint in Sri Lanka. Both nations exhibit community-based initiatives, though spatial dispersion and coordination differ markedly. About 74% emphasized the importance of community participation, though uneven due to spatial isolation. Environmental vulnerabilities also display spatial variation, affecting tourism resilience that spatial planning and local context profoundly influence how eco-tourism can be managed sustainably, offering valuable lessons for policymakers and planners aiming to balance conservation with community development. The majority (81%) agreed that integrated spatial planning can improve conservation outcomes if supported by strong policies. The study highlights the significance of geospatial characteristics in shaping tourism resilience across diverse island environments. Drawing lessons from Taiwan’s spatial governance, Sri Lanka should adapt strategies to its ecological diversity and infrastructure limitations. Effective eco-tourism management must address spatial differences and environmental vulnerabilities. These insights provide valuable guidance for policymakers and planners seeking to balance environmental conservation with community development while optimizing eco-tourism to preserve both natural and social environments. Keywords: Communities, Ecotourism, Geospatial, Islands, Sustainability
Tourism and Social Stratification in Weligama, Sri Lanka: A Sociological Analysis of Economic Opportunities and Inequalities
Weligama, a rapidly growing tourism hub on Sri Lanka’s southern coast, has undergone significant socio-economic transformation driven by its expanding surf culture, hospitality sector, and foreign-owned enterprises. While tourism has generated considerable economic activity, its effects on local social stratification and inequality remain insufficiently examined. This study adopts a sociological lens to analyse how tourism reshapes social hierarchies, opportunity structures, and access to resources within the Weligama community. Guided by Conflict Theory and Weberian perspectives on class, status, and power, the research investigates how tourism-generated benefits are distributed across occupational groups, and how structural factors reinforce or challenge existing inequalities. The study employs a mixed-methods design, incorporating 45 semi-structured interviews, including 12 fisher folk, 10 small-scale vendors, 15 resort and guesthouse employees, and 8 local administrative stakeholders along with two focus group discussions representing diverse community demographics. Direct observations of tourist resident interactions and local business practices further enrich the analysis. Findings reveal uneven integration into the tourism economy: while business owners, skilled service workers, and individuals with higher educational capital gain substantial advantages, traditional groups such as fisher folk and informal vendors face barriers to accessing profitable opportunities. These disparities stem from differences in economic capital, vocational skills, social networks, and bargaining power reflecting core Weberian stratification elements. From a conflict-oriented perspective, tensions emerge between groups competing over coastal resources, employment spaces, and market access, contributing to heightened perceptions of social exclusion. The study highlights tourism’s dual role as both a driver of livelihood diversification and a reproducer of inequality. It underscores the need for inclusive tourism development, targeted skill-building, and community-based interventions to ensure equitable benefit distribution and strengthen social cohesion in Weligama. Keywords: Community development, Social stratification, Social inequality, Sustainable tourism
Linking Eco-tourism Practices to Visitor Satisfaction and Future Intentions in Galle, Sri Lanka: An Analytical Approach
A strategic approach to sustainable tourism, eco-tourism promotes socioeconomic benefits for local communities while striking a balance between environmental preservation, cultural preservation, and visitor satisfaction. In Galle, Sri Lanka, a district known for its rich cultural heritage, historical sites, and coastal biodiversity, this study examines the relationship between ecotourism practices, visitor satisfaction, and future behavioral intentions within eco-resorts. Goals of the study are to determine which ecotourism practices have the biggest effects on visitor satisfaction and investigate the degree to which visitor satisfaction mediates the relationship between sustainable practices and travelers’ intentions to return to or recommend eco-resorts. Using Cochran's sample size formula with finite-population correction, a working sample of 110 respondents was selected from an estimated 150 self-declared eco-resorts in Galle. Structured questionnaires were used to gather primary data from both domestic and foreign tourists leaving particular eco-resorts. The instrument assessed four aspects of ecotourism practices: environmental management, social and community engagement, economic sustainability, and educational and experiential offerings. Descriptive statistics were used to profile the respondents, correlation analysis was used to investigate the relationships between the constructs, multiple regression analysis was used to find significant predictors of both behavioral intention and satisfaction, and the Sobel test was used for mediation to look at the indirect effects of satisfaction on the relationship between behavioral intentions and eco-tourism practices. Findings revealed different Galle resorts implemented ecotourism strategies differently. Key predictors of visitor satisfaction were environmental management and educational and experiential offerings; perceived authenticity was positively boosted by social and community engagement; and perceptions of fairness and trust were strengthened by economic sustainability. Satisfaction mediated the effect of eco-tourism practices on behavioral intentions. The study suggests that visitor satisfaction increases the favorable effects of sustainable practices on the likelihood of revisit and recommendation. The framework demonstrated strong predictive power by explaining 81% of the variance in satisfaction and 73% of the variance in behavioral intentions. In order to improve visitor engagement, satisfaction, and loyalty, results highlight the imperative of improved interpretive programs, visible conservation initiatives, community partnerships, and responsible marketing. Intended to match operational plans with guest expectations, practical ramifications include the implementation of standardized eco-certification systems, resort employee capacity building, and strategic communication of sustainability practices. While anonymity and consent upheld ethics, geographic and self-report limits suggest future longitudinal, multi-regional research. The study provides evidence and guidance for Sri Lankan tourism stakeholders to align sustainability with market-driven eco-tourism and enhance visitor experience and stewardship. Keywords: Eco-tourism practices, Visitor satisfaction, Behavioral intentions, Eco-resorts
GIS-Based Assessment of Coastal Tourism Sustainability and Environmental Vulnerabilities: A Case Study of Trincomalee District, Sri Lanka
Coastal tourism is one of the fastest-growing sectors in Sri Lanka, and Trincomalee has become a major destination known for its high-quality beaches, coral reefs, whale-watching tours, and heritage sites. However, the unplanned and unsustainable growth of tourism has increased pressure on ecologically sensitive coastal ecosystems, including coral reefs, mangroves, and seagrass beds, and has worsened issues like coastal erosion and waste management problems. This study aims to evaluate the sustainability of coastal tourism development in Trincomalee using an integrated geospatial (GIS-based) approach. Multi-temporal Land Use and Land Cover (LULC) data from 2010 to 2025 were analyzed through supervised classification to examine patterns of built-up expansion along the coast. Spectral indices and ecosystem vulnerability data were combined with tourism infrastructure records and GPS surveys conducted in the field to map environmental sensitivity layers and tourism activity hotspots. A Multi Criteria Decision Analysis (MCDA) model was used to combine environmental sensitivity, accessibility, infrastructure availability, and socio-economic factors in order to develop a Sustainable Coastal Tourism Suitability Index (SCTSI). The findings show significant built-up growth along Nilaveli and Uppuveli, encroachment near Pigeon Island’s coral ecosystems, and an uneven distribution of tourism infrastructure with limited community involvement. The final suitability map identifies priority areas for eco-tourism development, conservation zones, and regions needing sustainable infrastructure planning, providing a practical spatial decision-support tool for policymakers to balance tourism growth with long-term environmental preservation in Trincomalee. Keywords: Coastal tourism, GIS, Trincomalee, Ecosystem vulnerability, Multi-criteria analysis
Ecotourism as a Pathway to Improve the Living Standards, in Sangilipalama, Kotmale, Nuwara Eliya District
Sri Lanka has significant potential for ecotourism, but a few practice all ecotourism principles adhering to the definition. Most focusing on sustainable tourism rather than comprehensive ecotourism. This research examined the role of ecotourism in supporting rural livelihoods in Sangilipalama, Kotmale, by evaluating community support and positive perception towards developing ecotourism, its impact on living standards, youth employment, local goods and services. It also examined changes in students’ perception through an awareness session. Thus, to develop a sustainable ecotourism model in Sangilipalama, Kotmale, that can serve as a benchmark for the Nuwara Eliya district. Data was collected through field observations and structured questionnaire surveys from June 2024 to September 2024 and were analyzed using the Self-Determination Theory Framework. Sangilipalama, which is in Kotmale, has various landscapes like rivers, forests and historical locations, that help facilitate activities like boating, bird watching and mammal watching. There are multiple species of plants, birds, mammals, reptiles, fish and butterflies; and residents engage in spice cultivation contributing to its agricultural heritage. Two separate questionnaire surveys were designed; one targeting 50 local residents and other for 50 students, including both school and undergraduate students. The students were assessed using the same questionnaire before an awareness session and after on the ecotourism potential of Sangilipalama. The findings from the local respondents indicated that seventy-two percent of them “Agreed” that the community people support the need for ecotourism in Kotmale. Seventy-two percent of “Agreed” regional development raises the level of living standard and strengthens the local community. 68% “Agreed” ecotourism would lower youth unemployment. Seventy percent “Strongly agreed” ecotourism will support the local goods and services of Kotmale. Principal Component Analysis (PCA) revealed that, before the awareness session, the eigenvalues for the statements on community support for ecotourism and its impact on living standards were 0.86 (factor loading1.59) and 0.62 (factor loading 1.05) respectively. After the awareness session, these values changed to 0.91(factor loading 1.373) and 0.22 (factor loading 0.715), indicating a shift in perception among the students. The findings support that Sangilipalama can be positioned as a model for sustainable ecotourism development in Nuwara Eliya district by integrating local involvement, awareness programs and responsible policy measures. In addition, this model can be applied to other locations across Sri Lanka. Key recommendations from the study include involving local communities in ecotourism initiatives, addressing knowledge gaps through targeted awareness programs, and developing policies to promote responsible tourism. Keywords: Awareness impact assessment, Community participation, Ecotourism, Livelihood improvement, Student’s perception
Visitor Perceptions of Birdwatching and Ecotourism Potential at Beddagana Wetland Park, Sri Lanka: A SWOT-Based Assessment
Urban wetlands are vital ecosystems for biodiversity and community well-being, and they offer unique opportunities for specialized ecotourism. This study assesses the potential for high-value birdwatching tourism (avitourism) at the Beddagana Wetland Park (BWP) in Sri Jayewardenepura Kotte, Colombo, Sri Lanka. Using Strengths, Weaknesses, Opportunities, and Threats (SWOT) framework, the research synthesizes perception data from 83 local and international visitors. The questionnaire systematically assessed a wide range of variables, visitor demographics, birdwatching dedication, conservation ethics, the quality of infrastructure (rated on detailed experiences, such as cleanliness, bird diversity, and signage), and interest in guided services. Results show BWP attracts a specialized market of highly educated environmentally literate visitors. Core strengths supporting avitourism include the excellent urban accessibility of the park (67% of respondents) and its capacity to deliver a unique and highly valued asset in its “peaceful and quiet natural setting” (55%) within the surrounding rush-around metropolis. However, operational failures and unmanaged visitor dynamics critically threaten this inherent ecological and recreational value. The primary external threat is the critical failure of “Destination Carrying Capacity,” cited by 48% of respondents as the top discouraging factor, coupled with noise or disturbances (23%). Overcrowding and disturbances from general park visitors currently affect the specialized birdwatching experience. A major internal weakness is park maintenance, with 31% of respondents identifying poor cleanliness as a discouraging factor. Additionally, 27% of visitors noted a lack of guided tours or trained staff to assist them. However, there is a significant opportunity to address these issues through the visitor's interest in supporting the park, where 97% are willing to support conservation financially, and 84% are willing to pay for specialized guided tours. Furthermore, visitor demand underscores the need for a service like “conservation workshops,” which is a top three desired improvement, quoted by 51% of the participants, indicating a clear market for structured educational ecotourism products. In conclusion, while BWP possesses the necessary ecological and recreational assets for birdwatching, reaching its full potential requires specific improvements in infrastructure, visitor education, and site management. Based on these preliminary findings, park management could consider designated access hours to prioritize dedicated birdwatchers during peak times to reduce visitor conflict. There is also potential to develop professional guiding services and conservation-related fees. Revenue from these initiatives could be directed toward improving facilities requested by visitors, such as specialized bird hides and additional rest areas. Keywords: Birdwatching, Ecotourism, Avitourism, Urban wetland, Visitor dynamics
Sustainable Agro-Tourism and Climate Entrepreneurship in Hanguranketha, Sri Lanka
Integrating agriculture and forest conservation into tourism offers a strategic pathway to promote community livelihoods, build climate resilience, and sustainable rural development. The Hanguranketha Divisional Secretariat Division (DSD) in Sri Lanka possesses rich biodiversity and fertile agricultural lands, but faces challenges such as climate variability, socio-natural disasters, and weak rural entrepreneurship which is vital for local development. This study evaluates agro-tourism as a driver for sustainable development in Hanguranketha, examining the challenges and opportunities of related climate entrepreneurship. The research adopted a mixed-method approach, combining primary data from questionnaires, interviews, and field observations with information from government development plans. A total of 28 small and medium enterprises (SMEs) across tourism-related sectors accommodation, food and beverage, tour operations, transport, and agro-based products were selected using stratified random sampling. Quantitative data was analyzed descriptively and examined qualitative insights thematically. The study generated the findings into a SWOT framework to evaluate the strengths, weaknesses, opportunities, and threats of agro-tourism development. Results show that agriculture uses 67.08% of the DSD’s land area, while 23.38% of the forest cover supports agroforestry and related tourism. Based on evidence from 28 respondents, 70% identified wellness tourism particularly herbal spas and Ayurveda based experiences as a key strength for developing integrated agro-tourism packages. However, agro-tourism expansion is constrained by inadequate policy and programmatic support (40%), weak integration into divisional and local development plans (48%), limited industry and community commitment (71%), and insufficient incentives for climate entrepreneurship (64%). Conversely, strong opportunities exist to establish agroforestry tourism clusters (84%), enhance entrepreneurial capacity (89%), and promote public- private partnerships linking agriculture, tourism and climate adaptation (85%). Increasing anthropogenic forest fires over the past five years, mainly damaging grasslands and understory plantations, pose a significant threat to the sustainability of agro-tourism (64%). To overcome these challenges, the study proposes strategic interventions such as developing agroforestry tourism clusters, building local entrepreneurial capacity, and enhancing collaboration between public and private actors. By mobilizing local resources, applying traditional agricultural knowledge, and promoting climate-conscious entrepreneurship, Hanguranketha can position itself as a model for community-centered, environmentally sustainable, and climate-resilient rural tourism in Sri Lanka. Keywords: Sustainable tourism, Agro-tourism, Forest-based tourism, Climate tourism entrepreneurship
Integration of Biodiversity Conservation with Sustainable Ecotourism in Sri Lanka
Sri Lanka's status as a biodiversity hotspot underpins a tourism industry with the symbiotic potential to fund conservation and foster local stewardship. However, translating this model from a theoretical ideal into a successfully implemented practice remains a complex global challenge. The objective of this qualitative study was to find themes for a quantitative survey to further investigate the above mentioned model. Through qualitative analysis of semi-structured interviews with 15 frontline forest and wildlife officers from Hurulu forest reserve of Polonnaruwa, Knuckles conservation forest of Matale, Udawattakele forest reserve of Kandy, Sinharaja world heritage site of Ratnapura, and Wilpattu national park of Puttalam, this research captures the critical perspectives of those responsible for managing this delicate balance. The data reveal six pivotal themes essential for achieving sustainability. Firstly, strengthening governance and enforcement including improved revenue reinvestment and clearer regulatory frameworks can be done by reinvesting revenue generated from park entry fees, guided tours, and accommodations directly into conservation efforts, such as anti-poaching patrols, habitat restoration, and scientific research. Secondly, investing in capacity and infrastructure to address critical gaps in staffing, equipment, and visitor facilities such as well-designed trails, adequate waste disposal systems, and informative signage, can minimize ecological footprints. Thirdly, promoting genuine community partnership to ensure local communities can derive tangible benefits and become active conservation stakeholders. Fourthly, prioritization of education and interpretation for both tourists and locals can be done to foster pro-conservation behavior. Ensuring meaningful stakeholder participation in policy decisions was proposed as the next step for sustainability. Lastly, it was proposed to leverage digitalization for enhanced monitoring, management, and visitor experience. The findings were used as themes for further investigation using a quantitative study to illustrate the synergy between conservation and ecotourism is not automatic but must be consciously built by listening to and empowering its frontline forest officers and wildlife officers, addressing their operational challenges, and building robust partnerships with local communities. This study concludes that the insights of frontline officers are indispensable for formulating effective policies and provides an evidence-based framework for enhancing the sustainability of Sri Lanka's ecotourism sector while safeguarding its unique biodiversity for future generations. Keywords: Biodiversity, Ecotourism, Sustainability, Conservation, Restoration
A Case Study on Bamboo Conservation at Sadaharitha Una Arana, Sri Lanka
This study examines Sadaharitha Una Arana, a garden full of bamboo species (Dendrocalamus giganteus, Dendrocalamus latiflorus, Bambusa oldhamii, etc.), established in 2000 at Arukwatta, Sri Lanka. The garden is managed solely by the owner without additional staff, with the intention of promoting bamboo culture and sustainable tourism. Initially the garden attracted local tourists but is currently experiencing a visitor fatigue and lack of operations, disrupting both conservation efforts and income generation. Thus, the objective of this study was to identify factors hindering the continuous operation of the garden in relation to the owner’s entrepreneurial and strategic knowledge on those outcomes. A qualitative research design was adopted involving an extensive five-hour in-depth interview with the owner, observations during site visits, and analyzing the garden’s literature, including newspaper articles, TV program records, and the garden’s social media managed by the owner. Due to a lack of daily visitors and low community engagement, direct visitor or community interviews were not feasible. Which limits the scope of the study but provides unique insight into the owner’s decision-making. Data was analyzed using qualitative content analysis focusing on finding entrepreneurial and marketing gaps in garden operations. Findings reveal that despite the garden’s significant conservation and cultural value-conserving diverse bamboo species and varieties while supporting local biodiversity, including habitat for the endangered Red slender loris (Loris tardigradus) the garden faces major challenges. The owner initially prioritized bamboo conservation and showcased its potential through cultural festivals, positive media coverage, and educational school visits, but at present he seeks to generate sustainable income but lacks a clear vision, mission, or proper strategic plan. Even though the owner possesses extensive knowledge on bamboo species and culture, the lacks of the awareness on sustainable business models and lacks knowledge on commercializing the garden’s offerings. As he lacks entrepreneurial knowledge and sustainable business management ability, it has led to a vicious cycle, where current financial struggles hinder ongoing conservation efforts. As a conclusion, continuing such conservation efforts becomes challenging without a clear commercial value proposition and strong entrepreneurial and marketing knowledge. Therefore, capacity building and institutional support are recommended to strengthen these conservation efforts by giving the owner the necessary business awareness. Future research is required to explore similar conservation-related properties and expand the study by getting perspectives from local communities and visitors. Keywords: Bamboo gardening, Conservation, Entrepreneurship, Sustainable, Tourism
Eco-Tourism Development Potential in Thannepita: Utilizing Environmental Resources like Natural Streams and Waterfalls for Rural Economic Growth
Thannepita is a rural village situated in the 836C Kapugedara Grama Niladhari Division consisting of approximately 400 families engaged in tea plantation agriculture as their main economic activity. Each family cultivates around one acre of tea and generates a monthly income of about Rs. 50,000. However, this income is often inadequate to cover expenses for fertilizer, education, and daily living, resulting in economic vulnerability. Children’s education has suffered due to financial and socio-economic conditions and there are reports of irregular school attendance, as well as a lack of university-level students from Thannepita. Furthermore, these socio-economic challenges overall indicate the need to develop alternative and additional incomes to assure sustainable development for the community. Thannepita has abundant natural resources that are suitable for eco-tourism, such as Yalamediya Dola, Kaluwala, Oliyamala Ella, Hulankadu Ella, and the newly discovered (2022) ‘Saripota Ella’ waterfall. Kaluwala has clear water suitable for bathing, Gonawala has space for 30-40 guests to camp, nature walks can be developed in Uduwankanda, Maha Ara, Rajakanda, and Heenatiyanwaththa, and where possible, existing adventure casual activities, such as 30-foot jumps and other water-based sports could be expanded to attract additional travellers. This study uses a qualitative case study approach to investigate the viability of eco-tourism development in Thannepita as a means of stimulating economic growth in a rural setting. A purposive sample of 50 participants will be recruited and include local residents, community leaders, and tourism stakeholders. Primary data collection will consist of semi-structured interviews, field observations, and focus group interviews, and secondary data will be gathered from official reports, previous studies on tourism, and socio-economic statistics. The findings generated from the analysis will aim to recommend mechanisms to diversify income streams create greater opportunities for education, and enhance overall quality of life through eco-tourism and community based tourism initiatives. Accordingly, this study proposed eco-tourism activities include guided nature walks and trekking routes, waterfall-based recreational activities such as bathing and swimming in designated safe areas, community-managed camping sites for small groups, nature observation activities including bird watching, and supervised low-risk adventure activities such as stream exploration and cliff jumping. And also, this study further considers community-based eco-tourism developments such as the establishment of basic visitor infrastructure, marked nature trails, small-scale homestays, trained local tour guides, safety facilities, and environmentally responsible waste management systems to support sustainable tourism growth. Keywords: Eco-tourism development, Rural economic development, Tea plantation community, Community-based tourism, Nature trails and waterfalls, Sustainable livelihoods diversification
Green Synthesis of Zinc Oxide Nanoparticles Embedded Microcrystalline Cellulose from Murusi Crown Leaves for Water Hardness Removal by Column Adsorption
Pineapple crown is an abundant agricultural waste in Sri Lanka, usually discarded in landfills during harvesting or processing, despite being a source of lignocellulosic biomass and bioactive phytochemicals. These properties make it a promising resource to synthesize biogenic nanocomposite that acts as an effective adsorbent for removing water hardness, thereby enhancing drinking water quality and mitigating related health issues. This research focuses on the green synthesis of zinc oxide nanoparticles (ZnO NPs) embedded in microcrystalline cellulose (MCC) derived from Murusi pineapple crown leaves (MCL), for effective water hardness removal via column adsorption. The cellulose was extracted through alkaline and bleaching pretreatments, followed by MCC extraction from cellulose using acid hydrolysis under optimized conditions at 2.5 M HCl, 80 °C for one hour, yielding 32.3%. ZnO NPs were synthesized from MCL extract, under optimal conditions at a plant-to-metal ratio of 1:50, zinc acetate concentration 0.01 M, pH 12, and room temperature. UV-Visible spectroscopy demonstrated characteristic ZnO NPs absorption with a blue shift confirming nanoscale dimensions. Characterization by FTIR spectroscopy confirmed the removal of lignin and hemicellulose after chemical treatment and verified the presence of functional groups on ZnO NPs associated with phytochemical capping agents. SEM analysis showed MCC with an average diameter of about 2.50±0.54 µm and ZnO NPs with an average size of approximately 113.75±20 nm, exhibiting hexagonal and flower-like morphologies. The nanocomposite column embedding 10 mg ZnO NPs into 20 g MCC was compared with pure MCC and cellulose columns for filtering synthetic dolomite hard water (1,900 mg/L as CaCO3) at 1.2 mL/min flow rate. All three columns, each with a bed height of 25 cm and a diameter of 2.5 cm were operated in duplicate. The ZnO-MCC composite outperformed, achieving breakthrough after filtering 60 mL, compared to 40 mL and 10 mL for MCC and cellulose, respectively. The ZnO-MCC also exhibited the highest saturation volume of 130 mL, surpassing MCC (120 mL) and cellulose (90 mL). Enhanced adsorption efficiency of ZnO-MCC (~99%) is attributed to synergistic effects of ZnO active adsorptive sites and MCC’s high surface area with hydroxyl groups facilitating effective Ca2+ and Mg2+ binding. ZnO leaching was negligible, confirmed by no precipitate in centrifuged effluent. These findings highlight the sustainable ZnO-MCC nanocomposite synthesized via green methods as a low-cost solution for water treatment, leveraging agricultural waste valorization and environmentally benign synthesis techniques. Keywords: Pineapple, Microcrystalline cellulose, Nanocomposite, Hardness, Adsorption
Environmental Knowledge versus Behavioral Practice: A Case Study on Plastic Waste Disposal in Kamburupitiya, Sri Lanka
The unsustainable disposal of plastic and polythene waste constitutes a critical environmental and public health challenge in Sri Lanka. This study investigates the persistent gap between environmental awareness and actual disposal practices among educated households in Kamburupitiya. Using a pre-tested, structured questionnaire, data was collected from 73 households in the Bibulawela area. Analyses employing descriptive statistics and a paired sample t-test revealed a significant dissonance: while 89% of respondents acknowledged the environmental harm of plastics, 74% demonstrated inadequate knowledge of proper disposal methods or lacked access to formal waste management systems. All households generated plastic waste weekly, primarily disposing of it through open burning (67%) and open dumping (16%); only 6% used recycling centers. The paired sample t-test confirmed a statistically significant disparity (p<0.05) between high awareness and the adoption of harmful practices. The study concludes that awareness alone is insufficient to drive behavioral change. Mitigating plastic pollution requires integrated strategies combining targeted public education on practical waste management with substantial investments in accessible and reliable collection and recycling infrastructure. Keywords: Plastic waste, Polythene disposal, Environmental awareness, Waste management practices, Household behavior
Evaluation of Material Flow for Sustainable Wafer Production by Highlighting Inefficiencies
Rapid industrial growth in the global wafer manufacturing sector has intensified solid waste generation and resource inefficiency, particularly in developing economies such as Sri Lanka, where expansion often outpaces the establishment of robust environmental controls. This study employed process flow mapping, quantitative material balance analysis, and targeted on-site waste auditing across key production stages mixing, baking, creaming, cutting, and packing to systematically identify process inefficiencies and waste hotspots. Findings revealed a total waste generation of approximately 890 kg per day, with the baking and cutting phases contributing over 55% of the total, mainly through plain sheet discards, cutter trims, and oven lumps. These wastes originated from suboptimal thermal management, mechanical misalignment, and insufficient operator oversight, indicating systemic weaknesses in process control and maintenance practices. The absence of Standard Operating Procedures (SOPs) further exacerbated inefficiencies, leading to poor equipment calibration, irregular maintenance, and inadequate process monitoring, resulting in mechanical failures such as oven overheating, sensor malfunctions, and conveyor misalignment. Such operational lapses not only increase material and energy losses but also hinder productivity and sustainability performance. The study recommends strategic interventions including advanced equipment calibration, proactive preventive maintenance, intensive workforce training, and the establishment of comprehensive SOPs to standardize operations. Implementation of these measures supports the achievement of Sustainable Development Goals (SDGs) 9 and 12, promoting industry innovation, resource efficiency, and responsible production practices aligned with waste reduction and circular economy practices as emphasized in the waste management policy in Sri Lanka. Keywords: Wafer manufacturing, Waste flow analysis, Process inefficiency, Workforce training, Standard operational procedures
Role of Material Recovery Facility in Minimizing the Final Disposal: Evidence from Anuradhapura Municipal Council
Improper solid waste management (SWM) remains a pressing environmental challenge in developing countries, leading to open dumping, and associated air, water, and soil pollution. In Sri Lanka, the increasing waste generation due to rapid urbanization has highlighted the need for sustainable solutions that minimize final disposal and promote resource recovery. The research adopted a mixed-method approach involving field observations, structured interviews with municipal officials and waste handlers, and secondary data from the Anuradhapura Municipal Council (AMC) SWM division were used to study the current status of SWM practices. Material Flow Analysis (MFA) was used to assess waste generation, composition, recovery rates, and residual disposal pathways to understand the role of MRF in minimizing the waste disposal. Results indicated that the AMC generates approximately 32.8 tons of waste per day, of which around 62.25% is collected, approximately 42% comprises non-compostable waste directed to the Material Recovery Facility (MRF) for sorting and recovery, and the compostable waste temporally stored in the MRF facility to send for composting. At the MRF facility, non-compostable waste is manually segregated into recyclable and non-recyclable fractions. Recyclable plastics, paper, and cardboard, averaging approximately 140 tons in 2024, are pressed and baled at MRF to optimize space utilization, and ensure convenient handling prior to dispatch to private recyclers. Non-recyclable but combustible waste fractions were baled and transported to cement manufacturing facilities for co-processing, contributing to energy recovery and waste to energy initiatives. Overall, AMC has achieved significant progress in managing MSW through composting, recycling, and energy recovery, thereby reducing dependency on disposal and achieving an impressive 99% of waste diversion rate in terms of collection while, 61.5% as per the generation. The findings emphasize that a well-managed MRF, coupled with effective source segregation and public private collaboration can substantially enhance waste minimization while this approach represents a replicable model for sustainable waste management for the local authorities of Sri Lanka. The MRF facility contributes to achieving Sri Lankan Waste Management Policy targets with respect to waste diversion and supports the United Nations Sustainable Development Goals particularly SDG 11; Sustainable Cities and Communities. Keywords: Material recovery facility, Municipal solid waste, Waste diversion, Recycling and energy recovery, Public-private partnerships
Effect of Poultry Offal as a Substrate for Black Soldier Fly Larvae Production
Feed is the largest expense in poultry production. Black soldier fly larvae (BSFL) can replace soybean and fish meal, lower costs, and offer environmental benefits. Their growth and nutrition depend on the substrate, and broiler processing generates about 25% inedible offal that must be managed to avoid negative impacts. This study investigated the suitability of broiler offal, either alone or in mixtures with manna grass (Cymbopogon nardus), as a substrate for BSFL rearing. A completely randomized design was used with six treatments: Six days old BSFL were introduced into substrates having either food waste (FW) as the control, 100% poultry offal (P100M0), 75% poultry offal+25% manna grass (P75M25), 50% poultry offal+50% manna grass (P50M50), 25% poultry offal+75% manna grass (P25M75), and 100% manna grass (P0M100). Larvae grown on FW, P50M50, and P25M75 reached the prepupal stage within 13 days. Survival rate of BSFL grown on FW (86%) was not significantly different from those on P50M50 (81%), P25M75 (83%), and M100 (88%). Survival rate on Poultry offal alone (3.7%) or even high offal level, P75M25 (40%) was extremely low. However, day 13 weight of larvae on P75M25 (109 g) was similar to those on FW (110 g). Manna alone (14 g) or offal alone (56 g) did not support for good larval growth. Among the offal manna combinations, the best larval weight was reported on P50M50. Larval crude protein content was similar on FW and P0M100. Interestingly, all manna and offal combinations as substrates resulted in higher CP contents (46%-49%). Substrate reduction rate, waste reduction index, bioconversion ratio, and N conversion ratio of larvae on P50M50 were statistically similar to those on FW. The study concludes that broiler offal or Manna grass alone is not a suitable substrate for BSFL production. The P50M50 mixture showed higher CP and similar waste conversion, but further studies are needed to improve survival and growth. Keywords: BSF, Poultry offal, Substrate, Growth, Composition
Organic Carbon Fractions in the Weras River, Sri Lanka, under the Influence of Landfill Leachate Inputs
Organic Carbon (OC) is the key aquatic component that influences contaminant mobility in freshwater ecosystems, yet limited knowledge exists on the distribution of organic carbon fractions in freshwater systems impacted by municipal waste. This study quantified OC fractions in the Weras river system to evaluate the influence of landfill leachate from the Karadiyana open dumpsite with multiple discharge outlets on riverine organic carbon dynamics. Seventeen water samples were collected twice during the dry period in the same locations, with every sample triplicated from upstream reference points, the leachate discharge zone, and downstream locations using a selected sampling technique, and average values were calculated. Total Organic Carbon (TOC), Dissolved Organic Carbon (DOC), and Particulate Organic Carbon (POC) were analyzed using a TOC analyzer. The TOC, POC, and DOC showed upstream: 13.59±0.75, 2.24±0.83, and 11.35±0.57 mg/L, leachate discharge point: 121.68±63.34, 96.20±62.94, and 25.48±0.54 mg/L, and downstream: 21.11±4.27, 7.58±4.85, and 13.53±1.21 mg/L, respectively. The results showed an increased amount of OC fractions in the downstream landfill disposal point compared to the upstream reference sites. Evidenced by a high population of Eichhornia crassipes, reflecting the potential of DOC converted into POC through the plant biomass accumulation while releasing POC fraction through particle trapping and plant decaying. Downstream 34.89% dilution effects were observed, with TOC decreased at 2.30 km from dumpsite, though concentrations remained elevated. Flow velocities ranged from 2.25×10-3 to 2.74×10-4 ms⁻¹ along the sampling locations, and the average velocity was around 2.72×10-3±3.21×10-3 ms⁻¹ between upstream and downstream, suggesting reduced flow conditions in the leachate-influenced zones. The study confirms the significant impact of landfill discharges on the distribution of OC in the Weras river system, considering potential OC deposition in the riverbed, even at low flow rates, thus highlighting the need for improved leachate control and remediation strategies. Keywords: Total organic carbon, Riverine carbon fractions, Karadiyana dumpsite, Landfill leachate, Surface water pollution
Assessment of the Biodegradation Potential of Commercially Available “Biodegradable” Polymers by Microbial Isolates
Biodegradable products are designed to degrade into valuable metabolites under desirable ecological conditions or in municipal and industrial biological waste treatment facilities. Microbial activity plays a major role in biodegradation. The present study investigated the biodegradability of three commercial products: a biodegradable salad plate (SP), a compostable lunch sheet (LS), and an Oxo-degradable garbage bag (GB) using isolated microorganisms. Microorganisms with potential polymer-degrading activity were isolated and screened through a sequential enrichment protocol under aerobic conditions. Equalized inocula of individual bacterial and fungal isolates were separately introduced to each test sample, and biodegradation was analyzed gravimetrically. Four bacterial and four fungal isolates were selected and inoculated into test samples prepared in minimal salt (for bacteria) and Rose Bengal agar (for fungi). Inoculated flasks and plates were incubated at room temperature in the dark for 60 days under sterile conditions. Recovered test samples were weighed to determine mass loss. Chemical changes were analysed by Fourier Transform Infrared (FT-IR) (ATR mode) spectroscopy. Molecular identification was performed using 16S rRNA (for bacteria) and 5.8S-ITS (for fungi) sequencing. The General Linear Model revealed no significant differences in mass loss percentages between test samples regarding microbial isolate (p=0.073) or material type (p=0.089). The highest mass losses observed were 24.73% in SP, 13.01% in LS, and 14.49% in GB, inoculated with F06, B06, and F14, respectively. FT-IR spectra confirmed the absence of notable chemical modifications. Molecular characterization identified bacterial isolates as Bacillus sp. (B06), B. safensis (B12), B. cereus (B29), and B. pumilus (B33), and fungal isolates as Aspergillus sp. (F01), A. fumigatus (F02), Paecilomyces variotii (F06), and A. tamarii (F14). The screened bacterial and fungal isolates exhibited measurable biodegradation potential under laboratory conditions, and the activity of A. tamarii in degrading LDPE (GB) is commendable. However, chemical degradation was not reported. Further investigations are recommended to optimize conditions to enhance the degradability by microorganisms. Keywords: Biodegradable polymers, LDPE, Microbial degradation, Microcosm, Sequential enrichment protocol
Low-Cost Sustainable Dye Removal from Textile Wastewater Using Banana Husk-Derived Activated Carbon
The textile sector, particularly Sri Lanka’s Batik industry, produces highly colored wastewater containing reactive dyes that are resistant to degradation and pose significant environmental risks. Small and medium enterprises (SMEs) in this sector often lack access to affordable treatment systems. This study developed a low-cost, sustainable dye removal technology using banana husk (Musa spp.) derived activated carbon and compared its performance with rice husk (Oryza sativa) based activated carbon. Both agricultural wastes were chemically activated with phosphoric acid and characterized using Fourier-Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Adsorption behavior was examined under batch and fixed-bed column conditions. The banana husk adsorbent achieved a maximum dye removal efficiency of 94.6% and a Langmuir adsorption capacity of 82.3 mg g-1, surpassing rice husk (68.4% and 54.1 mgg-1, respectively). The Langmuir model provided the best fit (R²=0.982), confirming monolayer adsorption on a relatively homogeneous surface. Column studies revealed that a bed height of 22 cm and a flow rate of 1.16 mL min-1 produced the longest breakthrough time (175 minutes) and the highest overall removal efficiency, with an equilibrium dye concentration reduction exceeding 90%. FTIR analysis showed hydroxyl and carbonyl functional groups responsible for dye binding, while SEM confirmed enhanced porosity and uniform surface morphology after activation. A preliminary cost analysis revealed that the production cost of banana husk-derived activated carbon was approximately 65% lower than that of commercial activated carbon, mainly due to the use of locally available agricultural waste and low energy input during carbonization. This highlights its potential as an affordable and sustainable adsorbent for decentralized wastewater treatment applications. The results demonstrate that banana husk-derived activated carbon is a high-performance, locally available, and environmentally friendly adsorbent suitable for small-scale textile wastewater treatment. Future work should assess regeneration efficiency, long-term stability, and scalability to strengthen its practical application within Sri Lanka’s Batik SMEs and similar industries globally. Keywords: Banana husk, Activated carbon, Textile wastewater, Adsorption, Batik industry
Analysis of Cytotoxicity and Morphological Effect of Tributyltin (Tbt) Using Brine Shrimps
As an antifouling agent, Tributyltin (TBT) is widely employed in industrial applications. Still, it has been implicated in toxic effects on aquatic life, raising imbalance in the ecosystem, biodiversity loss, and bioaccumulation. Numerous research studies have recently been conducted to analyze the toxicological impact of TBT on marine organisms. Moreover, these studies employed alternative biological assays. The Brine Shrimp Lethality Assay is the most suitable system for assessing the toxicity of compounds, as it provides a wide range of advantages, including availability, simplicity, and rapidness. This study aimed to determine the cytotoxicity and morphological effects of tributyltin (TBT), a persistent environmental organotin pollutant, on brine shrimp (Artemia salina). Nauplii of brine shrimps (n=15) were exposed to increasing concentrations of TBT (3.1 ng. L-1, 6.25 ng. L-1,12.5 ng. L-1,25 ng. L-1,50 ng. L-1, and 100 ng. L-1) and the mortality rates, lethal concentration (LC50) value, and morphological abnormalities were assessed over 24-hour exposure. Triplicate assessments were done for all concentrations. An LC50 value of 54.50 ngL-1 was determined and prominent morphological changes in total length, head width, and abdomen width. Other morphological deformities, including asymmetrical appendages, elongated bodies, shortened antennae, swollen limbs, malformations along the tail, and impaired motility, were observed. A significant correlation was observed between increasing concentrations of TBT and its impact on mortality rates and morphological alterations (p≤0.05). The findings highlight TBT as a highly toxic environmental pollutant with potent cytotoxic effects on brine shrimp. Therefore, there is a need for further analysis of the toxicity of TBT, its impact on ecological systems, and the utilization of brine shrimp A. salina as a model organism for cytotoxicity investigations. Keywords: Tributyltin, Toxicity testing, Morphological abnormality, Brine shrimp, LC50
Institutional Plastic Waste Management in Vavuniya, Sri Lanka: Issues and Opportunities
Rapidly increasing plastic production and low recovery rates have intensified the plastic waste crisis, caused significant environmental and health impacts and highlighted the urgent need for sustainable plastic waste management. This study investigates current institutional plastic waste management practices and explores opportunities for implementing Circular Economy (CE) strategies. A mixed-method approach involving onsite waste audits, stakeholder interviews, focus group discussions, and waste flow analysis visualized through Sankey diagrams was employed to map and evaluate the existing plastic waste flow. Results revealed that the institution generates approximately 16 kg of plastic waste per day, predominantly consisting of low-density polyethylene (LDPE) and polyethylene terephthalate (PET), which together account for nearly 68% of the total. The absence of source segregation severely limits recycling and recovery potential. Canteens were identified as the major sources of plastic waste generation, contributing nearly 89% of the total plastic waste and producing a wide range of materials, including single-use plastics and packaging items. Currently, all the collected plastic waste is transported to an open dumpsite, leading to soil and water contamination, toxic and greenhouse gas emissions from open burning, and micro plastic pollution. Key challenges identified include inadequate source segregation, insufficient bins and storage facilities, limited infrastructure, weak institutional governance, and a lack of partnerships with licensed recyclers. Proposed CE strategies include eliminating single-use plastics, adopting green procurement, establishing segregation at source, forming partnerships with recyclers, and channeling non-recyclables into waste-to-energy initiatives. These measures can significantly reduce environmental pollution, generate economic benefits, and create a replicable, cost-effective model for higher education institutions in Sri Lanka. The findings support the National Policy on waste management and the national action plan on plastic waste management, contributing to Sri Lanka’s transition toward a circular economy. Keywords: Plastic waste management, Circular economy practices, Recycling and recovery, Public-private partnerships
Towards Sustainable Organic Waste Management at the Institutional Canteens in Vavuniya, Sri Lanka
Organic waste generated in institutional settings poses a major environmental challenge due to improper management practices that lead to odour nuisance, pest infestation, and greenhouse gas (GHG) emissions. This study focuses on assessing organic waste management practices in five institutional canteens in Vavuniya, Sri Lanka, aiming to propose sustainable strategies for organic waste valorization. The research was conducted from June to September 2024. The methodology integrated waste audits, on-site field observations, and semi-structured interviews with canteen operators and relevant stakeholders to evaluate existing practices and challenges. The collected data were analyzed using quantitative analysis of waste generation, collection, recycling and disposal rates, supported by qualitative thematic analysis of interview responses to identify behavioral, operational, and policy-related challenges. A detailed waste flow analysis was conducted to trace the movement of organic waste from generation to final disposal and to identify points of inefficiency and resource loss. Results revealed that approximately 450 kg of solid waste is generated daily from all canteens, of which 92.34% was organic, varies from 40 kg to 100 kg per day throughout the canteens, including cooked food leftovers, vegetable and fruit peels, and other biodegradable residues. The absence of source separation at generation points results in inefficient handling and limited opportunities for recycling and resource recovery. All generated waste is collected by the local authority and is directly disposed of at an open dumpsite, creating severe environmental problems such as foul odours, attraction of flies and stray animals, and leachate contaminates the soil and groundwater. Moreover, anaerobic decomposition of this waste emits methane, a potent GHG contributing to climate change. The study identifies the lack of organic waste valorization initiatives and absence of institutional policies as major causes. It recommends introducing composting and biogas units, along with the source segregation programmes, and conducting stakeholder awareness campaigns to convert biodegradable waste into valuable resources and renewable energy. These measures will support Sri Lanka’s National Waste Management Policy (2021), Nationally Determined Contributions (NDCs), and Sustainable Development Goals (SDGs) 11 and, 13 contributing to more sustainable and climate-resilient waste management. Keywords: Organic waste, Source separation, Open dumping, Composting, Biogas production
Growth Pattern of Chlorella variabilis in Untreated and Partially Treated Palm Oil Mill Effluent (POME)
Palm oil extraction process generates a significant waste stream, namely Palm oil mill effluent (POME), which requires mandatory remediation to ensure proper treatment and disposal. The palm oil industry faces considerable challenges in the sustainable management of POME. Microalgae, Chlorella variabilis possess a significant nutrient removal and bio-sorption capacity, thus potential for bioremediation of POME. This study aimed to investigate the growth pattern of C. variabilis in untreated and partially treated POME. C. variabilis cultures were obtained from the Department of Biotechnology and cultivated in untreated (POME-U) and partially treated (POME-T) effluent samples (30% diluted) collected from a commercial palm oil mill in Galle, Sri Lanka. Mass cultures (1.5 L) were maintained under controlled conditions (pH 7.1-7.5,30 °C±1 °C temperature, 2000 lux light intensity, 1.6 L/hr air flow rate) for 35 days. The growth pattern of Chlorella sp. in BG11media indicated a 28 hr lag phase, an exponential phase (28-261 hr), a stationary phase (261-309 hr), and a death phase (309-333 hr). POME-U was characterized with 4.49 pH, 22,272 mg/L Total Suspended Solids (TSS), 0.0819% (w/v) Total Nitrogen (TN), 2,092.11 mg/L Total Phosphorus (TP), 74,170 mgO2/L Chemical Oxygen Demand (COD), and 3.70 mg/L Phenolics while POME-T indicated 9.15 pH, 4164 mg/L TSS, 0.0437% (w/v) TTN, 0.38 mg/L TP, 2580 mgO2/L COD, and phenolics were not detected. The cell density in both untreated and treated POME cultures indicated significant growth with time. After one week of culturing, the cell growth in POME-U was significantly (33.13%) lower than that in POME-T, which could be due to the strong brown color limiting light penetration. However, during the second week, the cell growth rate in POME-U increased in comparison with POME-T. Studies on the biotreatment potential resulted reduction of COD and TP by 84.14% and, 99.97% respectively in POME-U, whereas in POME-T, COD and TP decreased by 10.30% and 63.16% respectively. In both treatments, TN was completely (100%) removed. This research highlights the capacity of C. variabilis for biomass growth and removal of significant pollutants in both untreated and partially treated POME, offering a sustainable approach to managing palm oil mill wastewater. Keywords: Biotreatment, Chlorella sp., Microalgae, Palm oil mill effluent, Wastewater
Integrated Waste Management Control in a Clinical Waste Treatment Facility in Sri Lanka: A Model for Sustainable Operations
The increasing demand for environmentally compliant clinical waste treatment in Sri Lanka highlights the need for integrated approaches that minimize pollution across liquid, gaseous, and solid waste streams. This study was conducted at a licensed clinical waste treatment facility located in the Western Province of Sri Lanka, addressing its operational performance and alignment with national regulatory requirements. Field investigations were carried out from May to August 2025 and included process flow analysis, waste tracking, and detailed on-site observations. These methods enabled the evaluation of waste handling practices, treatment system efficiency, and environmental monitoring procedures. The analyzed data and field insights directly informed the assessment, revealing several key operational characteristics observed during site visits, such as organized waste storage, appropriate housekeeping standards, controlled internal transport, structured documentation, clear effluent discharge pathways, and multi-stage emission control processes. Liquid waste generated from equipment cleaning and ash-bathing operations is systematically collected, treated, and reused within the facility, reducing freshwater demand and preventing discharge-related contamination. Gaseous emissions from incineration are managed through a multi-stage air pollution control system comprising Selective Non-Catalytic Reduction, a cyclone separator, a dry reactor, and baghouse filters, enabling consistent compliance with Central Environmental Authority emission standards. Solid residues, mainly bottom ash, are subject to resource recovery and utilized in manufacturing SLS-certified eco-blocks, supporting national circular economy initiatives. The facility also maintains continuous environmental monitoring, occupational safety training, and comprehensive operational documentation, demonstrating adherence to the National Environmental Act No. 47 of 1980 and related regulatory frameworks. The findings suggest that integrating pollution prevention technologies with systematic waste reuse and structured environmental management enhances operational sustainability, strengthens public health protection, and contributes to Sri Lanka’s progress toward the Sustainable Development Goals (SDGs). Overall, the facility’s management framework presents a replicable model for sustainable clinical waste treatment operations in Sri Lanka. Keywords: Clinical waste management, Pollution control, Incineration facility, Environmental monitoring, Sustainable operations
Evaluation of Soil Bacterial Consortium in the Biodegradation of Polycyclic Aromatic Hydrocarbons Under Iron (Fe) Stress Conditions
Soil is a valuable natural resource supporting a diverse range of organisms, but excessive chemical or substance contamination causes pollution, which harms non-targeted organisms. Polycyclic Aromatic Hydrocarbons (PAHs) are organic contaminants with fused benzene rings produced by both natural and anthropogenic processes. Among them, phenanthrene (Phe) and naphthalene (Nap) are categorized as priority pollutants by the US EPA due to their high toxicity, carcinogenicity, and persistence in the environment. Microbial degradation is an eco-friendly alternative to costly and ineffective traditional methods for PAH removal. This study aimed to isolate and identify an Iron (Fe) tolerant bacterial consortium capable of degrading PAHs. The soil samples were collected from dumping sites (Jaffna, Colombo, Meemure, Galle) in Sri Lanka to isolate bacterial species. Meemure functioned as a control site, signifying low pollution with little impact from industry and cities. Plate assays were used to screen the best PAH degraders and confirmed through UV spectrophotometry. An antagonistic assay assessed strains compatibility for consortium formation. Further, their optimum Iron metal concentration was determined. Molecular characterizations of selected bacterial strains were identified through PCR amplification and sequencing using 27F (AGAGTTTGATCMTGGCTCAG) and 1492R (GGTTACCTTGTTACGACTT) primers. Only five bacterial strains were identified as the best degraders using screening assays, each capable of degrading above 55% of Phe and 35% of Nap. The most efficient were VM6 and VM7, which degraded 64% of Phe and 78% of Nap, respectively. Nap degradation rises significantly to 63% at the maximum Fe concentration of 30×103ppm, outpacing Phe, which reaches 55%, indicating Fe promotes PAH decomposition in a concentration-dependent way. VM6 was identified as Bacillus safensis PV942242, and VM7 was identified as Bacillus subtilis PV9442354; both were found to be spore-forming, gram-positive bacterial species under microscopic observation. According to these findings, B. safensis PV942242 and B. subtilis PV9442354 are promising biological agents for PAH bioremediation, and an appropriate Fe content may improve the microbial breakdown of PAHs. Keywords: Naphthalene, Phenanthrene, Iron, Bacteria, Biodegradation
Study on Odonates as Bioindicator Species of Water Quality in Selected Urban Wetlands
Wetland ecosystems are vulnerable to disturbances that alter their biodiversity. Monitoring is essential to detect pollution levels and trends. Bioindicators provide a simple, reliable, and cost-effective method for assessing water quality. While odonates have been proposed as bioindicators for assessing wetland quality, their assemblages with reference to habitat water quality and the feasibility of using them as bioindicators have not been widely studied in Sri Lanka. The objective of this study was to assess the feasibility of using odonates as bioindicators of water quality. The study was conducted over a six-month period from June 2018 to December 2018 on selected urban wetlands of the Diyawanna canal system. The water quality of the aquatic systems, especially pH, Dissolved Oxygen (DO), Temperature, Conductivity, Salinity, Turbidity, BOD, COD, Nutrient levels (Nitrate/ Phosphate) is a critical determinant of the odonates ecology alongside the structural habitat heterogeneity like flow rate, vegetation cover and the substrate. Sampling locations were selected based on similar surrounding land use, microhabitat conditions, vegetation cover, and substrate characteristics to minimize variation in environmental factors affecting odonate distribution, other than water quality. Species richness, abundance of odonates and the physico-chemical parameters of water (temperature, pH, DO, BOD5, Total Dissolved Solids (TDS), Electrical Conductivity (EC) and Salinity) were recorded in each site. The correlation between the species richness, total abundance, Shannon-Weiner diversity index (SWDI) and the relative abundance of each species with the water quality parameters were analyzed using Pearson Correlation Method by R Analysis Software. According to the findings, species richness and the SWDI of the odonates had positive correlations with pH, Temperature and DO and negative correlations with BOD5, TDS, EC and salinity. Higher relative abundance of dragonflies like Brachydiplax sobrina, Crocothemis servilia, Acisoma panorpoides and Ictinogomphus rapax and Agriocnemis pygmaea damselflies can be considered as bioindicators of higher DO and lower BOD levels. Higher abundance of generalist species who are resistant to polluted water such as Brachythemis contaminata and Ischnura elegans dragonflies can be considered as bioindicators of polluted water especially higher BOD values. The identified generalist species can be used as indicators of good habitat conditions rather than as exclusive indicators of water quality. These results should be interpreted together with overall species richness and diversity to improve accuracy. More reliable and descriptive conclusions can be achieved through long-term monitoring across a wider range of sampling locations, incorporating additional water-quality variables such as turbidity and nutrient levels. Keywords: Wetlands, Monitoring, Water quality, Bioindicators, Odonates
Emerging Contaminants in Waste Management: Plasticizer Release from Sri Lankan Landfill Sites
Plastic waste in open dumpsites has emerged as a significant environmental issue due to its persistence and widespread distribution. Over time, they break down into smaller particles like microplastics and nano-plastics, which can leach out plasticizers into landfill leachate. The quantification of plasticizers in leachate has gained increasing importance, as they migrate into soil, surface water systems, and groundwater, posing potential environmental and health risks such as reproductive difficulties and developmental defects. This study aims to quantify the abundance of three commonly used plasticizers, Bisphenol A (BPA), Benzophenone (BP), and Di (2- ethylhexyl) phthalate (DEHP) in landfill leachates, adjacent waters, and leachate-impacted sediments in municipal solid waste dumpsites in the Western Province of Sri Lanka. A spatially representative sampling design was employed, covering leachate discharge points, downstream surface waters, and leachate-impacted sediments at each dumpsite by collecting eleven leachate samples, eleven sediment samples, and five adjacent water samples from five major dumpsites. Solid phase extraction (SPE) procedure was used to isolate plasticizers from aqueous samples, while sediment samples were subjected to solvent extraction using dichloromethane. Resulting extracts were analyzed using High Performance Liquid Chromatography (HPLC) equipped with a UV detector. The analysis revealed the presence of DEHP, BPA, and BP in all matrices. In landfill leachates, average concentrations were recorded between 0.379-2.236 mg L-1 for BPA, 0.056-0.335 mg L-1 for BP, and 0.059-0.383 mg L-1 for DEHP. Adjacent surface waters exhibited comparatively lower levels, ranging from N/D-0.012 mg L-1 for BPA, N/D-0.030 mg L-1 for BP, and N/D-0.365 mg L-1 for DEHP, indicating dilution and dispersion effects. Sediment samples, however, depicted higher accumulation, with average concentrations varying from N/D-2.609 mg kg-1 for BPA, N/D-0.227 mg kg-1 for BP, and N/D-2.991 mg kg-1 for DEHP, reflecting the hydrophobic nature of plasticizers and their strong sorption to organic-rich solid phases. Statistically, Karadiyana, Kochchikade, and Kelaniya dumpsites recorded the highest contamination levels across all three matrices. The accumulation of plasticizers in sediments highlights their role as long-term contaminant sinks, with potential for remobilization under changing geochemical conditions, posing sustained ecological risks. These findings highlight the widespread contamination of aquatic and sedimentary environments by landfill-derived plasticizers in Sri Lanka, which can be attributed to the lack of engineered leachate collection and treatment systems. Overall, the findings provide critical baseline data to support environmental risk assessment and the development of sustainable leachate management and treatment strategies to mitigate plasticizer contamination in surrounding ecosystems. Keywords: Municipal solid waste, Bisphenol A, Benzophenone, Phthalate, Landfill leachate
Phytoremediation of Zinc and Chromium in Partially Saturated Constructed Wetlands using Typha angustifolia
Heavy metals are persistent pollutants posing ecological and health risks when discharged into the environment. The study focused on the phytoremediation potential of Typha angustifolia for removing Zinc (Zn) and Chromium (Cr) in partially saturated constructed wetlands (PSCWs) treating municipal wastewater from the post-primary leachate treatment stage at the Dompe Sanitary Landfill, Sri Lanka. Three PSCW configurations with partial saturation (PS) layer heights of 70 cm, 50 cm, and 30 cm were operated in triplicate for four months to assess the effect of saturation depth on heavy metal retention and plant uptake. Systems were operated under vegetated and non-vegetated conditions with a hydraulic retention time of six days, using T. angustifolia as the planted treatment. Data were collected monthly, with influent and effluent concentrations monitored, and metal accumulation in plant roots and shoots analysed at the end of the experimental period. The influent contained around 0.518 mg/L of Cr and 0.173 mg/L of Zn. Across vegetated units, Zn and Cr removal ranged from 28.1% to 55.8%, with significantly higher accumulation of the heavy metals in roots (0.283 mg/L) than shoots (0.112 mg/L). Translocation factors (TF) were consistently below 1 for both metals, confirming that T. angustifolia primarily retained heavy metals within the root zone, characteristic of phytostabilisation. Among the PS configurations, the 70 cm system exhibited the highest root accumulation (0.283 mg/L), suggesting that greater saturation depth enhances contact time and promotes metal retention through root–biofilm interactions. While plant accumulation accounted for a substantial fraction of total removal, the contributions of sediment adsorption and precipitation were not measured and warrant further investigation to complete a full metal mass balance. MANOVA and Tukey’s tests indicated significantly lower removal rates in non-vegetated systems (p<0.05), underscoring the role of vegetation in enhancing treatment efficiency. These findings demonstrate the suitability of T. angustifolia as a phytostabilising species in PSCWs for improving effluent quality and mitigating heavy metal pollution, contributing to the long-term stabilisation of toxic metals in constructed wetland environments. Keywords: Heavy metals, Municipal wastewater, Partially saturated constructed wetlands, Phytoremediation
Calculation of Landfill Gas Flux Rates through the Surrounding Soil Profile and the Water Bodies of the Karadiyana Municipal Solid Waste (MSW) Open Dumpsite in Sri Lanka
Open filling of Municipal solid waste has increased rapidly worldwide due to the increase in world waste generation. Numerous investigations on landfill gas generation, emission, and impact have been conducted, but only a small number of studies have documented the calculation of landfill gas flux rates through the surrounding area with the effect of the dumpsite. The current study aimed to investigate flux rates of some selected landfill gases around the Karadiyana landfill, including methane (CH4), ammonia (NH3), hydrogen sulfide (H2S), and Total Volatile Organic compounds (TVOCs), which have been operational for more than 35 years in Sri Lanka. The surrounding area was split into five different cells by considering the land use, and the map was digitised using ArcGIS. The static flux chamber method was used. Chamber volume and surface coverages were 0.1 m3 and 0.2 m2, respectively. The self-designed floating chamber, an air-filled tube fixed to make it floatable, was used when measuring the flux rates from the water bodies. Random sampling method was employed, and three sampling campaigns were done monthly from October to December 2024. Atmospheric pressure, temperature, and relative humidity were measured during the sampling. The results indicate that the highest flux rates of CH4, NH3, H2S, and VOCs through the waterbodies (352.2±310.8, 8.9±9.95, 4.07±4.52, and 5.31±6.35 mg m-2 h-1), while the lowest values were in settlement areas (54.38±36.69, 1.57±1.59, 0.31±0.41, 0.00±0.00 mg m-2 h-1), respectively. Secondly highest values were in free floating hydrohytes ares (233.0±212.5, 6.78±4.44, 3.54±3.76, 3.91±3.68 mg m-2 h-1), and open areas (95±108.1, 2.24±1.53, 0.51±0.64, 0.00±0.00 mg m-2 h-1) and vegetation areas (51.11±44.56, 2.38±1.58, 0.36±0.54, 0.07±0.43 mg m-2 h-1) shows concidarbly low gas emission flux rates. Leachate was directly released to the water canals and Bolgoda river, with higher amounts of dissolved landfill gas and organic matter, resulting in higher flux rates. Lateral gas migration, human and animal activities around the dumpsite, and leachate mixing were the reasons for higher flux rates through the surrounding soil profile. Leachate collection and purification are impactful practices for the mitigation of landfill gas emissions, and site management practices are critical for emission reduction. Keywords: Gases, Flux rates, Calculation, Water bodies, Soil profile
Occupational Exposure and Waste Management Practices of Hazardous Chemicals in Base Hospital Warakapola, Sri Lanka
Healthcare workers routinely handle hazardous chemicals such as disinfectants and laboratory reagents, which pose occupational and environmental risks if managed improperly. Safe handling and adherence to waste management protocols are critical, yet gaps in knowledge and compliance persist among healthcare staff. This study assessed occupational exposure, handling practices, and perceived risks of hazardous chemicals among healthcare workers at Base Hospital Warakapola, Sri Lanka. A descriptive cross-sectional study was conducted among 200 healthcare workers, including nurses, laboratory technologists, pharmacists, supportive staff, and cleaning personnel, selected via stratified random sampling. Data were collected using a pre-tested, structured, self-administered questionnaire adapted from validated tools as WHO Healthcare Waste Management Questionnaire (WHO, 2014) and Occupational Chemical Safety Questionnaire (NIOSH, 2016). The tool contained 35 items across four domains: demographic data, chemical handling, safety practices, and awareness of hazardous waste management. Awareness was assessed using multiple-choice questions and practice components were assessed using a 5-point Likert scale (1=poor to 5=excellent). Composite scores were categorized as inadequate (<60%), moderate (60-79%), and adequate (≥80%) levels of knowledge and safe practice. Ethical approval and informed consent were obtained. Data were analysed with SPSS v25, using descriptive statistics and Chi-square tests to examine associations between knowledge and selected factors. Participants were 60.5% female and 39.5% male, mostly aged 21-30 years (33.5%) and 31-40 years (28%). Educational levels included diplomas (45%), degrees (30%), and secondary education (25%). Nurses (32%), laboratory technicians (25%), and housekeeping staff (20%) formed the majority. Most had 1-5 years of experience (35%), while 27% had over 10 years. Findings revealed that 70% (n=140) handled hazardous chemicals, yet only 55% (n=110) demonstrated adequate knowledge of safe segregation and disposal. Although 60% (n=120) reported available waste segregation systems, only 48% (n=96) consistently used color-coded bins, and 42% (n=84) admitted occasional improper disposal. Formal training was reported by 52% (n=104) and was significantly associated with higher knowledge (χ2=9.34, p<0.05). Environmental monitoring was limited, with only 40% (n=80) maintaining disposal records, and 68% (n=136) expressed concern about pollution and occupational risks from inadequate waste management. The study highlights substantial occupational exposure to hazardous chemicals and gaps in safe handling practices among healthcare workers. Enhancing training programs, enforcing compliance with waste management protocols, and implementing regular environmental monitoring are recommended to improve occupational safety and mitigate environmental risks in healthcare settings. Keywords: Hazardous chemicals, Occupational exposure, Waste management
Assessment of Heavy Metal Concentrations in Avian Feathers at the Karadiyana Solid Waste Disposal Site
Rapid urbanization and poor waste management have increased heavy metal contamination around municipal dumpsites, posing long-term risks to wildlife and surrounding ecosystems. This study aimed to assess heavy metal contamination at the Karadiyana solid waste disposal site using avian feathers as non-destructive biomonitoring indicators and to evaluate bioaccumulation patterns across different bird species. Concentrations of seven heavy metals (Cu, Zn, Cd, Cr, Ni, Mn, and Pb) have been assessed in the feathers of 3 bird species: the house crow (Corvus splendens), feral pigeon (Columba livia), and cattle egret (Bubulcus ibis), from the Karadiyana solid waste disposal site and compared them with the reference sites. Samples were cleaned, dried, and digested using microwave-assisted acid digestion (HNO3 and H2O2), followed by heavy metal analysis through Microwave Plasma Atomic Emission Spectrometry (MP-AES). Bioaccumulation factors (BAF) were calculated using sediment data from previous research, and correlations between metal concentrations and feather dimensions were examined. All these heavy metals were detected in all the bird species, except Cd. Cadmium was below the detection limits for house crow and feral pigeon feathers collected from the Karadiyana dumpsite. The order of concentration of metals in the feathers collected from the Karadiyana dumpsite is Zn>Cu>Mn>Pb>Cr>Ni>Cd. House crow feathers collected from the Karadiyana dumpsite showed higher Zn (505.75±189.97 µg/g), Ni (1.88±0.46 µg/g), Cr (3.26±1.06 µg/g), and Mn (20.57±10.6 µg/g) concentrations compared to the reference site (Dharmapala Park in Galle). The cattle egret feathers also showed elevated concentrations for Zn (109.4±13.62 µg/g), Ni (2.25±0.51 µg/g), and Pb (4.7±1.5 µg/g) at the Karadiyana dumpsite compared to the reference site (Hikkaduwa paddy field), whereas feral pigeon feathers did not show notable differences, possibly due to their more limited exposure and feeding behavior. The BAF values follow the order Zn>Cd>Cu>Mn>Cr. The negative correlation between metal concentration and feather dimension in the house crow and feral pigeon contrasts with the positive correlation in cattle egrets, suggesting species-specific physiological mechanisms of metal accumulation during feather growth. Furthermore, heavy metal content was higher in tail feathers compared to the flight feathers. This study suggests that bird feathers can serve as effective, non-destructive biomonitoring indicators for assessing heavy metal concentrations in municipal solid waste disposal sites. Keywords: Biomonitoring, Heavy metal, Avian feathers, Solid waste
Isolation and Identification of Thermostable Enzyme-Producing Fungi from Compost in Wennappuwa, Sri Lanka
Thermostable enzymes can thrive in extreme conditions, making them highly valuable in industrial biotechnology. They offer environmentally friendly alternatives to chemical catalysts in the production of biofuels, detergents, food processing, textiles, and pharmaceuticals. Compost piles naturally reach high temperatures during decomposition, creating an ideal environment for thermophilic fungi that produce heat-stable enzymes. In this study, thermostable amylase and, cellulase-producing fungi were isolated from compost in Wennappuwa, Sri Lanka. Soil samples were collected from compost piles at 61 °C. Fungal colonies were isolated on potato Dextrose Agar using the spread plate technique. Primary screening for amylase and cellulase enzymes was conducted with starch and carboxymethyl cellulose hydrolysis tests, respectively. The 3,4-dinitrosalicylic acid (DNS) method was used for secondary screening to measure enzyme activity, and temperature and pH optimizations were performed using the same method. Morphological differences in fungal colonies were examined under a microscope, revealing unique hyphal structures. Thirteen fungal isolates (CW 1 to CW 13) with diverse morphologies were obtained, including 8 amylase-producers and 07 cellulase-producers. The fungal isolate CW 3 showed the highest cellulase activity at 60 °C (125.9 U/mL) with an optimal pH of 4, while CW 13 exhibited the highest amylase activity at 60 °C (1,197.07 U/mL) with an optimal pH of 9. These results indicate the presence of thermophilic fungi capable of producing thermostable enzymes suitable for industrial applications in Sri Lankan compost ecosystems. Isolates CW 13 and CW 3, which showed strong potential as producers of thermostable amylase and cellulase, respectively, could be developed for large-scale biotechnological processes requiring stability at high temperatures and extreme pH levels. Future research will focus on molecular identification, protein purification, and further optimization to enhance enzyme productivity and expand industrial utility. Keywords: Thermophilic fungi, Thermostable enzymes, Amylase, Cellulase, Compost
Use of Wastewater for the Mass Growth of Microalgal Species Chloroccoum aquaticum
This study investigates the potential of Chlorococcum aquaticum, a green microalga, for wastewater treatment and biomass production. Although microalgae-based bioremediation is well established, limited studies have comparatively evaluated the performance of C. aquaticum across multiple real wastewater types under identical experimental conditions, particularly using locally available wastewater sources. Four types of wastewater-agricultural, automotive, domestic, and laboratory-were tested to assess algal growth and pollutant removal over 14 days. The experiment was conducted under controlled laboratory conditions, with a standardized initial inoculum concentration adjusted to an optical density (OD750) of 0.1. It was performed under normal daylight conditions with a uniform light regime to ensure comparability among treatments, and at room temperature (30±1 °C). Key parameters analyzed included Chemical Oxygen Demand (COD), Total Dissolved Solids (TDS), Dissolved Oxygen (DO), heavy metal content (lead, Pb), and pH levels. Automotive wastewater supported the highest algal biomass production, yielding 1.89 g of dry weight, followed by agricultural wastewater, which yielded 1.05 g. In contrast, domestic and laboratory wastewater showed lower growth rates, while the control culture (algae+BBM) produced the least biomass at 0.84 g. The study revealed significant reductions in COD across all wastewater types, with automotive wastewater showing the highest COD reduction from 523.2 mg/L to 345.9 mg/L. Lead (Pb) removal was most effective in automotive sewage, with a decrease of 0.305 mg/L, followed by agricultural wastewater at 0.27 mg/L. Dissolved oxygen levels increased due to algal photosynthesis, while pH remained relatively stable, ranging between 7.03 and 8.36 across wastewater types. Total dissolved solids (TDS) showed minor fluctuations, with agricultural wastewater exhibiting the highest TDS at 165 mg/L. The findings demonstrate that Chlorococcum aquaticum can thrive in nutrient-rich wastewater environments while effectively removing pollutants, including heavy metals and organic contaminants. Based on the measured physicochemical parameters, treated agricultural, domestic, and automotive wastewater complied with the permissible limits for land application and irrigation as stipulated by Central Environmental Authority (CEA) guidelines. The harvested algal biomass holds promise for applications such as biofuel production, animal feed, and organic fertilizers. Future research should focus on detailed biochemical characterization of the algal biomass and optimization of cultivation parameters to enhance large-scale wastewater treatment efficiency and resource recovery. This study highlights the sustainable benefits of microalgae-based wastewater treatment systems. Keywords: Chlorococcum aquaticum, Wastewater treatment, Heavy metal removal, Biomass production, COD reduction
Identification of Virulent Gene Clusters (Eae-A and Stx2) in Escherichia coli O157 Isolated from the Bolgoda River
The Bolgoda River, the largest freshwater reservoir in Sri Lanka’s Western Province, flows through the Colombo and Kalutara districts and supports diverse domestic and industrial uses. Rapid urbanisation and industrialisation have contributed to significant pollution, creating conditions that favour the survival and dissemination of pathogenic microorganisms, including Escherichia coli. Among pathogenic strains, E. coli O157 is of particular concern due to its production of Shiga toxins (stx1, stx2) and intimin (eae-A), which can cause severe gastrointestinal disorders such as haemolytic uremic syndrome and haemorrhagic colitis. The present study aimed to detect the virulence genes stx2 and eae-A in E. coli O157 isolated from 16 sites along the Bolgoda River, to assess water quality and public health risk. Water samples were processed to isolate E. coli on Eosin Methylene Blue (EMB) agar, followed by DNA extraction using the freeze-thaw method. PCR amplification with stx2 and eae-A specific primers, followed by gel electrophoresis, was used to identify target virulence genes. Out of the forty DNA samples tested, three isolates were positive for stx2, all originating from the site near the Karadiyana dumpsite, suggesting leachate contamination as a likely source. In contrast, no isolates tested positive for eae-A. These results indicate the presence of pathogenic E. coli O157 in the Bolgoda River, highlighting the potential public health risk and underscoring the need for continuous microbial monitoring and improved wastewater and landfill management to safeguard water quality in this critical freshwater system. Keywords: Bolgoda river, E. coli O157, Virulent genes, stx2, eae-A
Optimization of Color and Turbidity Removal from Batik Wastewater by Coagulation and Flocculation Using Poly-Aluminum Chloride (PAC) with Response Surface Methodology (RSM)
The batik industry is a part of the textile industry, which is one of the largest consumers of water and complex chemicals during various stages of processing. Batik industries generate wastewater containing heavy metals, dyes, and suspended solids, which contribute to environmental pollution. Physical-chemical methods are used for batik wastewater treatment; among these, coagulation-flocculation is one of the simplest and most common methods. Polymeric forms of metal coagulants are often used in batik wastewater treatment; however, the conditions are not well optimized. The effectiveness of polyaluminium chloride (PAC) as a coagulant for turbidity and color removal of batik wastewater was evaluated in this study. The two variables, coagulant dose and pH, were considered for the optimization of color and turbidity removal using PAC. The pH range of 2-12, and PAC dose of 0.5-1 g/L, were selected for the optimization study based on the preliminary experiments. The study ranges were chosen as coagulant dosage 0.5-1 g/L and pH 6-8. Central composite design (CCD) within the response surface methodology (RSM) was used to optimize two independent variables (coagulant dosage and pH), each evaluated at five levels. To obtain the optimum dosage and pH, two dependent variables (turbidity and color removal) were determined as responses. Quadratic models developed for the two responses showed that a coagulant dosage of 0.82 g/L and a pH of 6.3 are the optimum conditions, resulting in turbidity and color removal efficiencies of 88.3% and 84.8%, respectively. The experimental data and model predictions showed good agreement (turbidity, R2=0.9639; color, R2=0.9192). This study demonstrates that PAC effectively removes the colour and turbidity in batik wastewater under optimum conditions. Therefore, it can be concluded that optimizing the coagulation-flocculation process with PAC is an effective approach for treating batik wastewater. Keywords: Coagulation-flocculation, Batik wastewater, Polyaluminium chloride, Response surface methodology, Central composite design
Fractionation and Mobility of Toxic Trace Metals in Soils from E-Waste Processing Sites
The improper processing of E-waste for metal extraction leads to the accumulation of toxic metals in soil, posing long-term environmental and human health risks. The mobilization of toxic metals in soil depends on their binding nature in different geochemical fractions. This study investigates the geochemical fractionation and leaching behavior of Cadmium (Cd), Lead (Pb), and Chromium (Cr) in soils collected from four E-waste processing sites and one uncontaminated control site in Sri Lanka. A sequential extraction procedure that fractionates metals into eight fractions: F1: soluble + exchangeable, F2: easily mobilizable, F3: bound to Mn oxides, F4: bound to soil organic matter, F5: sulfide fraction, F6: occluded into amorphous Fe oxides, F7: occluded into crystalline Fe oxides, F8: residual fractions was used. The potential mobile fraction (PMF) ranged from 0.00%-20.13%, 3.83%-9.50%, and 0.27%-0.63% for Cd, Pb, and Cr, respectively. The mobile fraction was dominant for Pb and Cd, whereas Pb was mainly bound in F3 and F4, and Cr in F8. The leaching potential of toxic trace metals was evaluated using the US-EPA Toxicity Characteristic Leaching Procedure (TCLP). The leaching potential of toxic metal concentrations ranged from 1.56±0.15-30.15±6.93 mg/kg for Cd, 6.31±3.69-47.57±16.56 mg/kg for Pb, exceeding regulatory limits, whereas 0.01±0.00-0.46±0.07 mg/kg for Cr remained below the TCLP standards. Pearson correlation analysis revealed a significant positive correlation between TCLP extractable Cd and its mobile fraction (r=0.833, p=0.001), indicating its risk of leachability. In contrast, Cr showed a moderate, however, non-significant correlation (r=0.539, p=0.348), while Pb exhibited a negative correlation (r=-0.450, p=0.447), suggesting limited leachability due to strong binding with stable soil fractions. The results showed that the percentage of recovery ranged on average between 62% and 101% for Cd, 59% and 106% for Cr, and between 71% and 121% for Pb. The results highlight that the release of toxic metals from E-waste contaminated soil is a serious concern due to their potential for mobilization and environmental risk. Therefore, promoting safe E-waste processing practices is essential to safeguarding environmental and public health. Future studies should evaluate the potential of immobilizing these metals using biochar composites to mitigate long-term environmental risks. Keywords: E-waste, Geochemical fractions, Leachability, Metal mobility Acknowledgement: Financial assistance by the Research council of University of Sri Jayewardenepura
Wastewater Treatment and E. coli Removal Using Biochar Derived from Sugarcane Bagasse
Industrial wastewater has become a major problem for environmental and public health. Among various methods that have been employed to treat wastewater, biochar (BC) provides a promising solution for wastewater treatment. The aim of this study is to evaluate the efficiency of BC produced from sugarcane bagasse in treating aquaculture wastewater. In this study, BC was produced by pyrolyzing sugarcane bagasse at 300 °C. BC was chemically activated using potassium hydroxide (KOH) to improve the surface area and porosity of the BC. Both activated and non-activated BC were separately inserted as a sandwich layer in sand and gravel filters. Raw water samples collected from a brackish water shrimp farm were filtered through each filter unit. The efficiency of E. coli removal by the BC was evaluated using the filtration method. Water quality parameters, including pH, Chemical Oxygen Demand (COD), Ammonia, Nitrate, Nitrite, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Turbidity, and Total Phosphate (TP) were evaluated before and after treatment. Control filters were developed using only sand and gravel layers, excluding BC. Activated and non-activated BC completely removed E. coli from wastewater, whereas the filtrate from the control medium showed the presence of E. coli colonies, indicating ineffective removal in the control filter. The activated treatment system showed a decrease in pH of 12.99%, EC by 5.82%, TDS by 5.51%, and COD by 5.80%. A Turbidity removal of 74.3%, Ammonia removal of 65.9%, TP reduction of 39.4%, Nitrate reduction of 53.8% and Nitrite removal of 96.7% was also achieved. Similarly, the non-activated system showed a decrease in pH by 8.57% and TDS by 6.11%. Turbidity removal was 65.48%, showing 26.30% Ammonia removal, 39.4% TP removal, 22.07% Nitrate removal, and 95.89% Nitrite removal. The activated and non-activated BC systems exhibited higher treatment efficiency compared to the control. The present study suggests that activated sugarcane bagasse BC can be used as a sustainable alternative to other filter materials for wastewater treatment and E. coli removal. Keywords: Biochar, Aquaculture wastewater, Water quality parameters, Sugarcane bagasse, E.coli.
Assessment of Acute Toxic Effects of Zinc Oxide Nanoparticles in Zebrafish (Danio rerio) Embryos
The extensive application of zinc oxide nanoparticles (ZnO-NPs) in industrial, cosmetic, and pharmaceutical sectors has led to their continuous release into the environment, primarily in wastewater effluent. Excessive dumping has led to the issue of their accumulation and toxicity towards aquatic life. To facilitate effective waste management and pollution control policies, it is necessary to understand the biological responses of such nanoparticles in aquatic organisms. The current research aimed to investigate the acute toxic effects of ZnO NPs on zebrafish (Danio rerio) embryos, a well-established and sensitive vertebrate model in ecotoxicology. Zinc oxide nanoparticles were synthesized using the sol-gel method and characterized before exposure. The average width of the synthesized nanoparticles was in the range of 75-96 nm. The acute toxicity assay was performed in accordance with OECD guidelines, where zebrafish embryos at 2 hours post-fertilization (hpf) were exposed to varying concentrations of ZnO-NPs (0.5-100 ppm) for 96 hours in a controlled laboratory environment. Mortality, hatching, and developmental abnormalities like pericardial edema, yolk sac edema, spinal deformity (bent spine) and reduced eye size were recorded and observed at each 24-hour interval to determine the concentration-dependent effects and the 96-hour LC50 value. The results showed evidence of increased mortality and malformations with higher concentrations of nanoparticles, with the most critical deformities being pericardial edema, yolk sac edema, retardation of hatching, and curvature of the spine. The LC50 value of ZnO-NPs was determined to be 5.721 ppm, showing extremely high acute toxicity to D. rerio embryos. These findings highlight the onset of ecological risks associated with nanoparticle pollution and underscore the need for strict regulation, proper waste management, and the inclusion of nanotoxicity testing within environmental monitoring programs. Strengthening policies for managing nanoparticles is crucial in safeguarding aquatic ecosystems and promoting long-term ecological sustainability. Keywords: Zinc oxide nanoparticles, Danio rerio, Acute toxicity, Environmental pollution, Waste management
Evaluation of Amoxicillin, Cloxacillin, Cefotaxime, Ciprofloxacin, and Erythromycin Resistance in Escherichia coli Isolated from the Transition Zone of the Kelani River Basin
Antimicrobial resistance (AMR) is a global health challenge, reducing the effectiveness of commonly used antibiotics and increasing the risk of untreatable infections. Although AMR is often studied in clinical settings, freshwater ecosystems are increasingly recognized as reservoirs for antibiotic-resistant bacteria. In Sri Lanka, the Kelani River serves as a critical water resource, with its transition zone particularly vulnerable to pollution from untreated wastewater, creating conditions conducive to the proliferation of faecal indicator bacteria such as Escherichia coli. This study evaluated the antibiotic resistance profiles of E. coli isolated from the Kelani River transition zone. Phenotypic resistance was assessed by determining the Minimum Inhibitory Concentration of amoxicillin (AMX), cloxacillin (CLOX), cefotaxime (CEF), ciprofloxacin (CIP), and erythromycin (ERY) using the agar dilution method at concentrations ranging from 60 to 360 ppm. The Multiple Antibiotic Resistance (MAR) index was also calculated. At the lowest tested concentration (60 ppm), all isolates exhibited resistance to CLOX and ERY (100%), while AMX, CIP, and CEF resistance was 94%, 84%, and 50%, respectively. At the highest concentration (360 ppm), resistance decreased, with most isolates showing partial susceptibility. MAR index analysis revealed that at 60 ppm, most isolates had MAR=1 (48%) or 0.8 (28%), whereas at 360 ppm, the majority exhibited MAR=0.6 (58%) or 0.4 (22%), reflecting partial susceptibility. These findings demonstrate that E. coli in the Kelani River transition zone is subjected to significant antibiotic pressure, highlighting the river’s role as a reservoir for resistant bacteria. Continuous environmental monitoring, coupled with public awareness and improved wastewater management, is essential to mitigate the spread of AMR from aquatic environments to human populations. Keywords: Antibiotic resistance, Escherichia coli, Kelani river, Environmental monitoring, Multiple antibiotic resistance index
Plankton Diversity of Selected Waterbodies in Relation to Status of Pollution
Plankton are valuable bioindicators that can be used to evaluate the quality of waterbodies. This study was carried out to correlate plankton diversity and water quality of three lakes in Colombo: Mattegoda-lake, Rukmale-lake, and Olupattawa-lake affected by different pollutant sources. Volumes of 1L of water from nine locations across the lakes were collected in daytime, filtered through a 33 µm plankton sieve, and preserved with 10% formalin. Concurrently, samples were analysed for physicochemical parameters: Dissolved Oxygen (DO), pH, Electrical Conductivity (EC), turbidity, Total Dissolved Solids (TDS), nitrate, and phosphate to calculate biotic indices to evaluate water quality. Microscopic identification of planktons using rose-bengal stain identified a total of 28 genera of plankton across all lakes, including five genera each of Chlorophyceae (phytoplankton), Bacillariophyceae (phytoplankton), Rotifera (zooplankton); eight of Copepoda (zooplankton); three of Branchiopoda (zooplankton); and one genus each of Cyanophyceae (phytoplankton), Zygnematophyceae (phytoplankton), Euglenophyceae (phytoplankton), and Ciliophora (zooplankton). Bacillariophyceae dominated (~63% of total plankton) in Mattegoda and Olupattawa lakes, whereas Zygnematophyceae dominated in Rukmale-lake. Significant differences in EC and TDS were found among the lakes (p<0.05) through a one-way ANOVA test, with Mattegoda-lake showing the highest average EC (140.0 µS) and Olupattawa-lake the lowest average TDS (47 ppm). Several plankton species identified at Mattegoda-lake such as Microcystis, Pediastrum sp., Cyclotella, Ankistrodesmus, Euglena, Eudorina, Pinnularia are known pollution indicators and support its classification for being polluted compared to the other two lakes. This was further supported by Palmer's Algal Genus Pollution Index, which yielded a score of 11 for Mattegoda-lake while neither of the other two lakes received any score. Biodiversity comparisons between zooplankton and phytoplankton revealed no significant differences in Shannon-Wiener diversity (p=0.729) or evenness (p=0.510). The findings highlight the utility of plankton as bioindicators and identify Mattegoda-lake being most impacted due to high-level of EC, a parameter commonly associated with increased ion concentrations due to pollution and the Olupattawa-lake being least affected due to absence of indicator species and having a lower average TDS value. The organic-pollution was caused likely due to past industrial-waste discharge and illegal dumping near Mattegoda-lake, while Olupattawa-lake remains relatively unpolluted due to being in an isolated location. Keywords: Plankton, Bioindicators, Water quality, physico-chemical parameters
Detection of Escherichia coli O157 in Raw and Processed Dairy Products in Colombo District
Escherichia coli O157:H7 is a virulent Shiga toxin-producing strain capable of producing stx1 and stx2 toxins, which can cause severe gastrointestinal illness in humans, including abdominal cramps, bloody diarrhea, vomiting, and in severe cases, hemolytic uremic syndrome (HUS), particularly in children and the elderly. One major route of transmission is through the consumption of contaminated milk and dairy products. This study assessed the presence of E. coli O157 in raw milk, milk products, and commercially available dairy items from the Colombo district. A total of 30 samples including raw cow and goat milk, pasteurized milk, yoghurt, and cheese were collected from 15 locations. Detection methods included microbiological culturing on EMB agar and molecular PCR targeting stx1, stx2, and eae genes. Results showed that generic E. coli was present in all goat milk samples and in two of three cow milk samples, indicating potential fecal contamination at the farm level. However, none of the samples tested positive for E. coli O157. All processed dairy products were free from E. coli and coliforms, highlighting the effectiveness of pasteurization and hygienic processing. These findings confirm that while raw milk can harbor generic E. coli, proper processing effectively eliminates bacterial contamination. The study underscores the need for ongoing microbial surveillance, strict adherence to hygiene protocols at the farm and processing levels, and public education to ensure dairy safety in Sri Lanka. Future studies should include larger sample sizes, seasonal variations, and screening for other virulent E. coli strains to strengthen risk assessment and inform policy development. Keywords: Escherichia coli O157:H7, Dairy products, stx1, stx2, eae gene
Optimization of Extracted Pectin Yield from Discarded Lime (Citrus aurantifolia L.) Peels Using Response Surface Methodology
Pectin is a valuable structural polysaccharide, important as an ingredient in food industry that can be extracted from discarded citrus peels. Extraction of pectin from discarded lime peels and yield optimization open new avenue for waste management in fruit processing industry through giving value for waste in Sri Lanka to develop a green and economically viable waste valorization approach. The current study aims optimization of extraction conditions (pH; 1.5,2.25,3.0, extraction temperature; 80,90,100 ᵒC and extraction time; 0.5,1.0,1.5 hours) in citric acid (0.5 N) assisted pectin extraction using lime (Citrus aurantifolia L.) peels and the optimization was done using three level three factor box-behnken design in response surface methodology. The Minitab 21 statistical software was used for the analysis and 15 different combinations of independent variables were tested. According to the model summary, the predicted yield can be offed by ±2.08% from the actual value and 97.92% of yield variability is explained by the model, exhibiting the excellent model fit. Moreover, the model can predict new data points with an accuracy of 96.33%. According to the analysis of variance (ANOVA), there was a significant (p<0.05) linear (pH and temperature) and interaction effects between temperature and time on pectin yield. Under optimized conditions (pH 2.23,80 ᵒC,1.5 hours), experimentally 42.35±0.15 % of pectin yield was obtained, agreeing with the predicted value (43.15%). The characterization of the extracted pectin was also done using methoxyl content (3.4±0.8%), equivalent weight (319.3±51.6 g/mol), total anhydrouronic acid content (75.1±12.8%), degree of esterification (25.2±2.4%) and emulsifying activity (53.2±2.3%). Moreover, the FTIR spectroscopy confirms the presence of pectin with the characteristic peaks related to pectin. The current study provides insight to maximize the pectin yield using citric acid assisted extraction method by optimizing extraction conditions; pH, temperature and time as a sustainable solution for waste management of discarded citrus peels in the food industry and turn waste into money as an avenue for new industry in Sri Lanka. Keywords: Extraction optimization, Pectin, Response surface methodology, Box-behnken design, Yield
Assessment of Microplastic Fibre Release from Common Synthetic Fabrics During the Washing Process Using Domestic Washing Machines in Sri Lanka
Microplastic fibre (MPF) pollution from synthetic textiles is a growing environmental concern, particularly in regions such as Sri Lanka, where coastal ecosystems are ecologically sensitive and economically important. Limited research has been conducted on the release of MPF from domestic washing in Sri Lanka, making it difficult to assess potential local impacts. Therefore, this study aimed to assess the release of MPFs from two synthetic fabrics as 100% polyester and 100% nylon 6, under different washing parameters using fully automatic top-loading washing machines. Three standard programmes, strong, gentle, and speedy, differing in washing duration and agitation intensity, were tested with 4 replicates per treatment, resulting in 24 washing trials. MPFs were collected from the effluent and the lint filter bag, followed by vacuum filtration and analysis using digital microscopy and Fourier Transform Infrared Spectroscopy (FTIR). Polyester released a higher number of MPFs, with 133,989±24,521 particles/kg fabric, compared to nylon, which released only 32,173±10,490 particles/kg fabric. FTIR spectra showed no major structural changes before and after washing, indicating chemical stability of the polymers, while microscopy revealed surface abrasion across all washing programmes, suggesting mechanical stress during washing. Although nylon released fewer fibres overall, a larger percentage passed through the lint filter into the effluent compared to polyester, due to the lower length-to-width ratio of nylon fibres facilitated their passage through the lint bag. Washing duration influenced total fibre release, with the strong programme of 45 minutes releasing 99,609±63,572 particles/kg fabric, the gentle programme of 28 minutes releasing 87,035±56,013 particles/kg fabric, and the speedy programme of 23 minutes releasing 62,599±44,890 particles/kg fabric. However, the gentle cycle resulted in the highest percentage of fibres entering the effluent, 81.77%±6.31, likely due to reduced water flow through the lint filter during its agitation pattern. Future studies should assess fibre blends, aged fabrics, repeated wash cycles, and the use of different sieves and filter pore sizes to better guide policies and practices that reduce MPF pollution. Keywords: Microplastic fibre, Polyester, Nylon, Domestic washing, Aquatic pollution
LDPE and PP Microplastic-Induced Growth Inhibition in Common Bean (Phaseolus Vulgaris L.) Growth and Soil Alterations
Microplastic (MP) contamination in agricultural soil imposes a global concern, yet the comparative effects of different polymer types and environments remain underexplored. This study aimed to assess the impact of two common MP types, Low-Density Polyethylene (LDPE) and Polypropylene (PP), on the growth of common bean (Phaseolus vulgaris L.) and soil physicochemical parameters. Two independent experiments were conducted using two different local soil sources, incorporating 0% (control), 1%, 3%, and, 5% w/w of dry soil with LDPE and, PP MPs (≤1,000μm and, ≤2,000μm particles). The experimental soil for both was confirmed to be MP-free via Fourier-transform infrared spectroscopy before treatment. Plant growth was monitored for 45 days after sowing seeds. Vine length was recorded daily, while the number of leaves and stem diameter were recorded weekly. Soil moisture content, conductivity, and pH were measured after 45 days of sowing. A regression model/two-way ANOVA followed by a Tukey pairwise comparison test and descriptive statistics were deployed for data analysis. The results revealed a highly significant (p<0.001) and concentration-dependent negative impact on plant growth across both MP types, where plants were most affected at 5% w/w concentration. Both treatments caused substantial reductions in all three growth parameters over the 6-week period. Maximum growth reduction occurred in the number of leaves (up to 56.52% reduction), followed by vine length (up to 44.45% reduction), and stem diameter (up to 25.76% reduction). Vine length and number of leaves showed a reduction in the consistent range of 13-45% and 18-57%, respectively, across the concentration gradient. The observed effects under these elevated MP levels reflect stress-test conditions designed to identify the potential phytotoxicity risk of both MP types. Similar effects were observed on soil physicochemical properties. Both MP amendments caused a concentration-dependent lowering of soil conductivity and reduction of soil moisture content. Soil pH showed a slight alkaline shift with increasing LDPE-MP concentration, whereas a slight acidification occurred with PP-MP. These findings support that both common microplastic types pose a phytotoxicity risk to common bean growth and alter the soil properties. Despite the short experimental duration, the results offer early warning evidence of phytotoxicity risks that may emerge under repeated or long-term MP accumulation in agricultural soils, such as those arising from the progressive degradation of plastic mulches. Given that these findings are influenced by variables such as polymer type, soil particle size, future studies should address these interactions to understand the MP effect on agroecosystems. Keywords: Microplastics, Plant growth, Phytotoxicity, Soil contamination
Varietal-Specific Assessment of Arsenic and Mercury Content and Associated Health Risks in Traditional Sri Lankan Rice
Rice (Oryza sativa L.) provides over 45% of Sri Lanka’s caloric intake; however, concerns remain regarding trace metal contamination. This study presents a varietal-specific assessment of Arsenic (As) and Mercury (Hg) concentrations in traditional rice cultivars to determine contamination levels, identify high-risk varieties, and evaluate dietary exposure against international safety standards. Forty-four certified rice varieties from the Rice Research and Development Institute, Bathalagoda, were analyzed for As and Hg using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) following microwave-assisted acid digestion. Health risk was assessed by calculating the Estimated Daily Intake (EDI), Target Hazard Quotient (THQ), and Hazard Index (HI). Tolerable daily intake values of 2.14×10-3 mg kg⁻¹ bw⁻¹ day⁻¹ for As and 0.57×10-3 mg kg⁻¹ bw⁻¹ day⁻¹ for Hg were applied, assuming an adult body weight of 60 kg and rice intake of 300 g day⁻¹. Arsenic levels ranged from 22.5 µg/kg (Suduru Samba) to 117 µg/kg (Inginimitiya), averaging 57.0 µg/kg, but all below the 200 µg/kg safety limit. Mercury was undetectable (<LOD) in 32 varieties, while the remaining 12 contained 3.45 µg/kg (Hondarawalu) to 18.87 µg/kg (Kolikuttu), within the 20 µg/kg safety limit. The highest THQ values were 0.285 for As (Inginimitiya) and 0.166 for Hg (Kolikuttu), both below the reference threshold of one. Combined HI values ranged from 0.05 (Suduru Samba) to 0.29 (Thatu Wee), indicating no significant non-carcinogenic risk. Overall, the estimated exposure to As and Hg from the consumption of these rice varieties appears to be within acceptable limits under typical dietary intake circumstances. However, some variability in metal accumulation was observed among the different varieties. These results indicate that the traditional rice varieties examined are generally consistent with established safety guidelines for human consumption, while highlighting the importance of continued monitoring. Keywords: Arsenic, Mercury, ICP-MS, Traditional rice, Health risk assessment
Abundance, Seasonal Variation and Human Exposure of Microplastics and Tire Wear in Urban Road Dust from Colombo, Sri Lanka
Urban roads are considered major transport pathways for microplastics (MPs), with tire wear particles (TWP) being identified as a major source of MPs, believed to be a significant cause of MP pollution in the natural environment. Understanding the influencing factors and abundance of MPs and TWP in road dust is important to get an insight into their behavior and spatial distribution. This study emphasizes the influence of both dry and wet seasons on MP abundance and their morphological characteristics to estimate the exposure potential of MPs in road dust in the Colombo district, Sri Lanka. Road dust samples were collected from 15 sampling sites in two sampling events: a dry-season event after an extended dry period and a wet-season event after multiple rainfall occurrences. MPs were extracted using density separation followed by chemical digestion. The results confirmed the presence of MPs in all tested samples. The average abundance of MP was 655±75 particles kg⁻¹ during the dry spell and 214±26 particles kg⁻¹ during the wet season. The Wilcoxon signed-rank test revealed a significant seasonal difference in MP abundance (V=120, p<0.001), with a large effect size (r=0.873), indicating a strong rainfall impact on MP abundance in road dust. Black was the most prominent MP color, accounting for more than 70% in both dry and wet seasons. The dominant shape was found to be fragments, which increased from 79.63 to 81.62% with rain. A clear shift in particle size distribution was observed, as 2-5 mm size MPs were more frequent during the dry season, and 1-2 mm size MPs were more frequent during the wet season. The Fourier Transform Infrared (FTIR) analysis identified Rubber, Polyethylene (PE), Polyethylene Terephthalate (PET), Polypropylene (PP), Polystyrene (PS), Polyamide (PA), and Polyvinyl Chloride (PVC) as the common polymer types in samples. The PP and rubber were detected as the predominant polymer types, 20.99% and 24.44%, respectively, in both dry and wet seasons. The estimated acute ingestion of MPs via incidental road dust for children, in both wet and dry seasons, was approximately three times higher than that for adults, indicating a higher potential exposure in children. These findings conclude a noticeable influence of rainfall on MP abundance, leading to reduced potential human exposure. Keywords: Microplastics, Road dust, Dry-wet seasons, Polymer types, Human exposure
In Vitro Evaluation of Rumen Methane Production in Cattle Feed Supplemented with Effective Microorganisms
Effective microorganisms (EM) are a consortium of beneficial microbes that are used in livestock waste management and as a feed additive to improve animal nutrition. This study was conducted to evaluate the effect of EM supplementation on in vitro methane production using rumen fluid collected from dairy cows. Rumen fluid was collected from freshly slaughtered cows at a local abattoir into prewarmed vacuum flasks and immediately transported to the laboratory. The 200 mL of fluid was filtered through clean cheesecloth and transferred into prewarmed conical flasks. Each flask was assigned either 1 g of feed alone (control) or 1 g of feed supplemented with 1 mL of EM solution (treatment), with six replicates per treatment. The flasks were sealed with rubber stoppers connected to 0.5 M NaOH for gas trapping and incubated in a 39 °C water bath at 70 rpm for 24 hours. Methane volume was measured using the syringe plunge displacement method at 2,4,6,12 and, 24 hours of incubation. Data were analysed using the mixed procedure in SAS software. Results revealed that time had a significant effect on methane production (p<0.05), while the overall treatment effect was not significant (Con: 16.97±0.70 cm3; EM: 18.83±0.70 cm3). However, the treatment-time interaction was significant (p<0.05), indicating that EM affected the temporal pattern of methane production. In the first 2 hours, EM-treated samples produced a higher volume of methane (40.33±1.42 cm3) than the control (27.17±1.42 cm3), whereas at 24 hours later, methane production was higher in the control (18.00±1.42 cm3) than in EM-treated samples (12.50±1.42 cm3). These results demonstrate that EM influenced the kinetics of fermentation rather than the total cumulative methane production. The findings suggest that although EM supplementation does not significantly alter total methane production, it modifies the fermentation dynamics, influencing early and late methane production differently. This time-dependent effect shows the importance of assessing temporal patterns when evaluating feed additives for ruminants. Keywords: Feed additives, Gas kinetics, Methane, Microbial inoculants, Ruminant nutrition
Productivity Analysis of Single Phase and the Dual Phase Biogas Reactors
Biogas is a renewable and clean energy source produced through anaerobic digestion (AD), a process in which microorganisms decompose organic matter in the absence of oxygen. It provides a sustainable solution for energy generation and organic waste management while reducing greenhouse gas emissions. The single-phase biogas system is the most common method of biogas generation. However, dual-phase biogas reactor systems are increasingly adopted in advanced applications because they offer higher productivity and improved process stability. In dual-phase reactors, the hydrolysis and acidogenesis stages are separated from the acetogenesis and methanogenesis stages. This separation allows optimization of operating conditions for the specific anaerobic microorganisms involved in each stage, thereby enhancing overall digestion efficiency and increasing biogas production. This study was conducted at the Sisili Hanaro Encare facility to research on productivity comparison of single-phase and dual-phase biogas reactors. The dual-phase reactor system consists of two plastic shell tanks: T1 (2 m³) and T2 (10 m³). Tank T1 is used for the hydrolysis and acidogenesis stages, while Tank T2 is used for the acetogenesis and methanogenesis stages. The single-phase reactor consists of a single 10 m³ tank in which all four stages of anaerobic digestion occur within the same reactor. Biogas is collected using HDPE polyethylene bags. Stainless-steel agitators are installed to ensure uniform mixing, temperature regulation, and improved reactor productivity. A 3 HP industrial blender is used to reduce the particle size of kitchen waste. Each system is fed daily with 25 kg of blended kitchen waste mixed with water at a 90:10 ratio (water: solids). In the single-phase reactor, the blended kitchen waste is directly transferred into the 10 m³ tank. In the dual-phase system, the blended kitchen waste is first fed into the 2 m³ tank (T1). Once the pH in T1 reaches 4.0-4.5, the slurry is transferred to the 10 m³ tank (T2) for the acetogenesis and methanogenesis stages. After statistical evaluation of the results, it was found that the dual-phase reactor achieved a higher average biogas yield (2.20 m³/day) compared to the single-phase reactor (1.58 m³/day), along with improved total volatile solids removal efficiency (79.52% vs. 74.05%) and productivity (1.4 vs. 1.1). These findings indicate that dual-phase reactors offer higher performance in biogas production, waste stabilization, and overall process efficiency, making them a promising option for sustainable energy generation from organic waste. Further development is in progress to implement automated effluent transfer system within the dual-phase system, from the 2 m³ (T1) tank to the 10 m³ (T2) tank, based on VFA (volatile fatty acid) concentration focusing commercial bio gas plants development in future. Keywords: Biogas, Anaerobic digestion, Single-phase reactor, Dual-phase reactor, Volatile fatty acid
Ethnobotanical Survey of Antidiabetic Medicinal Plants in Chavakachcheri
A growing issue to public health on a global scale is diabetes mellitus and traditional medicinal plants have been used to manage hyperglycaemia. Capturing local knowledge of antidiabetic plants can aid in research of pharmacological activity and conservation. An ethnobotanical survey was conducted in Chavakachcheri, Sri Lanka during January to June 2025 through semi-structured interviews with traditional healers, herbalists and members of the local community with a total sample size of 50 participants. Data was collected on plant species, parts used, methods of preparation and therapeutic indications for managing diabetes. Identification of species followed standard botanical references. A total of 94 medicinal plant species from 55 families were recorded to have antidiabetic uses. Some frequently cited species included Cassia auriculata, Eugenia jambolana, Justicia adhatoda, Gymnema sylvestre, Syzygium cumini, Momordica charantia, and Azadirachta indica. Leaves (45%) and roots (25%) were the most common parts used and were typically prepared as decoctions, infusions, or pastes. Several species including G. sylvestre, C. auriculata, E. jambolana, S. cumini, and M. charantia had high use values and suggest strong reliance on use and may have pharmacological importance. The study has demonstrated that the local population holds a rich knowledge of ethnobotanical information on plants that are antidiabetic in nature. Species with high consensus should be examined via preclinical and clinical studies to confirm their utility, as well as for safety. Keywords: Ethnobotany, Antidiabetic plants, Traditional medicine, Diabetes mellitus, Chavakachcheri
Evaluating the Impact on Water PH on Glyphosate Acute Toxicity Using the Zebrafish (Danio rerio) Embryos
Glyphosate (GLY) is the most widely used herbicide in the world to control weeds. Widespread use of GLY potentially causes health risks to both human and aquatic organisms. GLY can be toxic under different pH, which alters the fish physiology by causing oxidative stress, inflammation, and mitochondrial dysfunction. The present study aimed to assess the acute toxicity of the GLY under acidic, basic and neutral pH using zebrafish embryos focusing on the mortality rate, hatching rate, morphological deformities, and heart rates. Zebrafish is a model organism who depicts the rapid development of embryos, optical transparency, external fertilization and has 70% genetic similarity to humans. Zebrafish embryos were exposed to combination of pH series (5,6,7,8 and, 9) and commercial glyphosate (Anu 71). The pH solutions were prepared using NaOH and HCl, then 0.7 mgL-1 GLY was added into each. Distilled water was used as the control. Twenty embryos were exposed to each solution after 2 hours post fertilization (hpf) and triplicated. Observation was recorded at 24 hour interval, up to 96 hpf. After 1 hour, the mortality of the embryos in GLY at pH 5 was 83.3±0.58%, and within 24 hrs it was 100%. The Mortality rate of embryos in pH 6 was 50.0±1.15% after 1 hr and reached to 100% at 96 hr. GLY at pH 8 and 9 showed delayed embryonic development and recorded 100% mortality after 96 hr. The mortality rate of embryos in pH 7 was 18.2±0.58%, and it was 82.3±0.58% at 96 hr. Yolk sack oedema was observed in more than 30% of the exposed larvae. The hatching rate of the embryos were 18.2±1.74% in pH 7 and the heart rate was 120±10 bpm. No fatalities were reported in the control solution, the hatching rate was 100% and heart rate were 140±4. According to the results, glyphosate toxicity was highly influenced by pH fluctuations as low pH caused acute mortalities and high pH caused delayed growth. Yolk sack oedema represents internal fluid accumulation caused by organ disruption. This can affect embryonic survival in the natural environment and can cause long-term diversity loss in water bodies. Implications regarding the usage and discharge of glyphosate around natural eco-systems have to be critically monitored to overcome this issue in future. Keywords: Glyphosate, Hatching rate, Mortality rate, pH, Zebrafish embryos
Comparative Assessment of Avifaunal Diversity Across Habitat Zones in the Malgasowitadeniya Riverine Mangrove Forest, Sri Lanka
The Malgasowitadeniya Riverine Mangrove Forest represents a critical transitional ecosystem in Sri Lanka’s wet zone, characterized by distinct floristic zonations that support diverse avifaunal assemblages. To assess the ecological importance of these varying habitat structures, this study evaluated bird species richness and community composition across three distinct zones: true mangroves, associated mangroves with invasive flora (primarily Dillenia suffruticosa and Annona glabra), and adjacent terrestrial forest. Bird surveys were conducted from July to August in 2025, using the line transect method along three 500 m transects, with observations recorded during morning (07:00-09:00 h) and evening (16:00-18:00 h) periods. During the survey, 26 species of birds were recorded, belonging to 20 different families. The terrestrial zone exhibited the highest species richness (S=22), followed by the true mangrove zone (S=11). The invasive flora with the associated mangrove zone showed the lowest richness (S=9). Diversity indices revealed significant variation between the habitats. The terrestrial zone displayed the highest species diversity (Shannon-Wiener H=2.90) and the most equitable distribution of species (Evenness J=0.94). In contrast, the true mangrove zone recorded moderate diversity and the lowest evenness (H=2.19, J=0.91), indicating common species Halcyon smyrnensis, Amaurornis phoenicurus, Aegithina tiphia, and Lonchura striata. The invasive flora with the associated mangrove zone displayed the lowest species diversity (Shannon-Wiener H=2.07) due to low species richness, despite having high evenness (J=0.94). These results suggest that although adjacent terrestrial habitats support greater species richness, the core mangrove zone maintains a more stable and evenly distributed avifaunal community, underscoring its conservation importance. Protecting both mangrove and adjacent terrestrial habitats, while managing invasive vegetation, is essential to sustain avifaunal diversity in riverine mangrove landscapes. Keywords: Avifauna, Diversity indices, Riverine mangrove ecosystem, Habitat zones, Conservation
Status of Mangroves and Conservation Requirements in Sarasalai, Jaffna Peninsula
Mangroves are unique and highly productive ecosystems distributed along the intertidal coastlines and riverbanks. They play an important role by providing the link between marine and terrestrial ecosystems. This ecosystem provides several benefits to humans. Mangroves are traditionally used as timber, food, fuel, poles and fish traps. They serve as a source of tannin which is economically important. Sarasalai in the Jaffna peninsula is a vast area of a mangrove ecosystem. It serves as a study area during field trips for students. Research students also visit this area frequently to collect data. Recently the Sarasalai area has been facing various threats, including sand mining, garbage disposal, habitat destruction due to the construction of roads, communication towers etc. The construction activities have fragmented the habitat and blocked the natural lagoon water flow. This is a major danger faced by the completely natural mangrove ecosystem. In spite of its importance as a vital ecosystem and ecotourism spot, the area’s natural biodiversity is at risk due to these anthropogenic activities. Cutting of mangroves and hunting also pose a serious threat to the mangrove vegetation at Sarasalai. Effective conservation measures are not taken continuously by the relevant authorities. Recent studies stress the need for coordinated conservation efforts, better management strategies and increased community participation. The local people who are living close by should be made aware of the danger of over exploitation of mangroves. There is an urgent requirement for collaboration between the relevant government officers and agencies to work towards an action plan to conserve this ecosystem. Keywords: Mangroves, Ecosystem, Conservation
Assessment of The Dynamics of Wetland Fragmentation in Bellanwila-Attidiya Wetland
Wetlands are ecologically sensitive landscapes that provide essential ecosystem services. However, rapid urbanization has accelerated wetland fragmentation, threatening their ecological integrity. This study focuses on assessing the spatial dynamics of wetland fragmentation in the Bellanwila-Attidiya Wetland from 1995 to 2024, emphasizing the temporal evolution of fragmentation patterns. Landsat satellite images from 1995, 2011, and 2024 were analyzed using GIS and remote sensing techniques to identify spatio-temporal changes in wetland fragmentation. Fragmentation indices including Number of Patches, Patch Density, Mean Patch Area, and Edge Density were used to quantify extent of fragmentation in Bellanwila-Attidiya Wetland. Additionally, field observations and household surveys were conducted over a four-month period, and households were selected using a stratified random sampling method to ensure spatial representation across the study area. A total of 55 households and 10 semi-structured interviews with key informants such as the local wildlife officers were included to identify community-observed wetland fragmentation dynamics. Spatial analysis of wetland fragmentation revealed that fragmentation initially occurred along the peripheral zones between 1995 and 2011, followed by expansion towards the central and southern sections by 2024, indicating a clear outward-to-inward pattern of encroachment. Results of the analysis of fragmentation indices revealed a significant reduction in wetland cover, with continuous wetland in 1995 replaced by smaller, isolated patches by 2024. The number of wetland patches increased from 16 in 1995 to 28 in 2011 and 141 in 2024, while mean patch area declined by 91,245.54 m2 between 1995 to 2011 and 38,022.06 m2 between 2011 to 2024. Edge density increased sharply, increasing edge effects and loss of core wetland habitat. The increase in patch number and edge density, along with the reduction in mean patch area, shows a transition from a continuous wetland to a fragmented landscape. Change detection analysis indicated that approximately 105.85 ha of wetland area has been lost, primarily converted into built-up areas such as residential areas, road infrastructure, and commercial establishments due to unplanned urban expansion and encroachment. These findings clearly demonstrate the progressive intensification of wetland fragmentation and loss of spatial connectivity over the past three decades. Effective restoration of fragmented habitats and regulation of urban expansion are urgently needed to protect core wetland areas and maintain the ecosystem integrity of the Bellanwila-Attidiya Wetland. Keywords: Ecology, Fragmentation, GIS, Remote sensing, Wetlands
Influence of Forest Proximity on Species Composition and Diversity of Avifauna in Buffer Zones
Buffer zones play a crucial role in maintaining biodiversity flow and connectivity by providing transitional habitats between natural forests and anthropogenic environments. Understanding the variations in avian diversity within buffer zones is essential for effective conservation planning. This study aims to assess the variations in species composition and diversity of avian communities in proximity to the forest within the buffer area. The Belipola Arboretum, a 45-year-old analog forest situated in the Badulla District of Sri Lanka, was selected as the main forest. The buffer zone consisted of home gardens, agricultural lands, and other anthropogenic settlements. Eight line transects, labeled as T1 to T8, each 100m in length, were deployed, starting from the forest edge and continuing outward from the forest. The Visual Encounter Survey method was employed for data collection, utilizing binoculars. Observations were conducted for 10 minutes at each transect between 06:00 h and 08:00 h, twice a month from April to August 2025. A total of 66 species were observed, including 11 endemic species. The species richness of T1 to T8 were 31,35,31,34,27,23,28, and 31, respectively, while the Shannon-Wiener Diversity Index values were 3.040, 3.043, 3.084, 2.937, 2.576, 2.653, 2.931, and 2.974, respectively. First three transects recorded seven endemic species each, while the last three transects only recorded two endemic species each. Two endangered species were recorded: Picus xanthopygaeus in T3 and Hirundo domicola in T5 to T8. The results revealed a gradual reduction in diversity while species richness remained relatively constant in relation to the increasing distance from the forest. This pattern suggests that even though the number of species does not significantly decrease, species composition and evenness of the avian communities change along with the forest gradient. Transect 3, though located further from the analog forest, was adjacent to a small remnant forest patch, likely contributing to its higher diversity of forest-dependent species. The presence of endemic species concentrated in the transects closer to the forest indicates their sensitivity to habitat degradation. Overall, the results demonstrate that even subtle changes in habitat structure across short spatial scales can influence avian community composition, and that conserving small forest patches within buffer zones can significantly contribute to a higher avian diversity. Keywords: Avian diversity, Buffer zone, Forest gradient, Species composition
Seasonal Changes in Arbuscular Mycorrhizal Fungi Linked to Rhizosphere Characteristics and Soil Properties
This study investigates the seasonal influence of rhizosphere dynamics and soil chemical properties on the distribution, abundance, and diversity of Arbuscular Mycorrhizal Fungi (AMF) in wild plant species. A total of 11 rhizospheric soil and root samples were collected from various host plants during summer and winter seasons of 2024. These included Senna italica, Cyperus laevigatus, Phragmites australis, Pelargonium peltatum, Zygophyllum simplex, Citrullus colocynthis, Malva parviflora, Zygophyllum coccineum, Calotropis procera, Solanum nigrum, and Salsola baryosm. Among these species, Phragmites australis exhibited the highest AMF spore density, with 175 and 124 spores per 100 g dry soil in summer and winter, respectively. In contrast, Calotropis procera had the lowest spore counts (101 in summer and 63 in winter). Eight AMF species were identified: Glomus ambisporum, Rhizophagus intraradices, Claroideoglomus etunicatum, Diversispora globifera, Funneliformis geosporum, Funneliformis mosseae, Rhizophagus fasciculatus, and Gigaspora spp. Moderate variation in AMF diversity was observed among host plants. The Shannon diversity index ranged from 0.692 in Zygophyllum simplex to 0.653 in Salsola imbricata, while Simpson’s index ranged from 0.498 to 0.461. Phragmites australis also exhibited the highest root colonization (90.5% in summer, 84.7% in winter), along with the greatest arbuscule (76%, 69.3%) and vesicle (36%) formation. In contrast, Calotropis procera showed the lowest colonization and symbiotic structure development. Soil chemical analysis indicated a general decline in nutrients Nitrogen (N), Phosphorus (P), Potassium (K), Magnesium (Mg), Calcium (Ca), Sodium (Na), Total Organic Carbon (TOC), and Organic Matter (OM) during summer, with increased levels in winter, likely to reflect seasonal variation in microbial activity and soil temperature. Overall, this study highlights the spatio-temporal patterns of AMF in relation to host plants, rhizosphere conditions, and soil nutrients, enhancing our understanding of plant-fungi-soil interactions across seasons. Keywords: Rhizosphere dynamics, Soil chemical properties, Wild plants, AMF
Activity Pattern of the Sri Lankan Sloth Bear (Melursus ursinus inornatus) in Wilpattu National Park, Sri Lanka
The Sri Lankan Sloth Bear (Melursus ursinus inornatus) is an endangered and endemic subspecies of the Indian Sloth bear. It is a large carnivoran mammal confined to the lowland dry zone forest areas of Sri Lanka. Understanding its activity pattern is vital for effective target species specific conservation planning. This study examined the Activity pattern of Sloth Bears’ in Wilpattu National Park (WNP), the largest and one of oldest protected areas in the country, Study was conducted from September 2024 to July 2025. Twelve passive infrared Browning camera traps were deployed following a systematic-random sampling design across 3×3 km² plots, and relocated every 1.5 months, they were operated continuously over 24 hours during the research period. Camera traps were distributed proportionally according to the percentage availability of each habitat type, ensuring approximately 40% coverage within each of the three dominant habitat types dry mixed evergreen forests, tropical thorn forests, and grasslands representing the dominant ecosystems of WNP. A total of 65 Sloth Bear footage records were obtained and used to analyze diel activity patterns, with time data converted to radians for circular analysis. All the collected data were used to generate the activity graphs by using the activity package in R 4.3.3. According to the graph, short peaks are observed during the daytime, while distinct bimodal peaks occur between 20:30-22:30 and 00:00-03:00 hours, indicating predominantly crepuscular and nocturnal activity (activity level=0.58; 95% CI: 0.31-0.65), with minimal activity during midday. These findings highlight that the Sri Lankan Sloth Bear in Wilpattu National Park is primarily active during crepuscular and nocturnal periods, with limited daytime movement. Understanding this activity pattern provides essential baseline information for improving conservation planning, optimizing monitoring efforts, and minimizing potential human bear encounters during peak activity hours. Keywords: Camera trapping, Activity pattern, R software, Wilpattu national park
Factors Influencing the Abundance and Coverage of Ramalina sp. Lichens on Selected Three Mangrove Species
Mangrove ecosystems are vital and highly threatened coastal habitats, and lichens of the genus Ramalina serve as important bioindicators. However, their distribution in Sri Lankan mangroves remains critically understudied. This study investigated the abundance and coverage of Ramalina lichens on three key mangrove species: Excoecaria agallocha, Rhizophora mucronata, and Lumnitzera racemosa in Rekawa Lagoon to determine the influence of host tree characteristics and microenvironmental conditions. Data were systematically collected over one month (3rd of November to 3rd of December 2024) from a total of 90 randomly selected trees (30 per species), recording lichen abundance, coverage, tree height. Regression analysis revealed that canopy cover was the dominant factor, showing a strong positive correlation (p<0.0001) with lichen abundance across all three species. The regression equations between lichen abundance and canopy cover were: E. agallocha-Number of lichens=6.442+34.15 canopy cover (R2 = 64.0%, p=0.000); R. mucronata-Number of lichens =-2.689+44.98 canopy cover (R2=74.7%, p=0.000); and L. racemosa-Number of Lichens=-23.98+65.12 canopy cover (R2=94.8%, p=0.000). These results suggest that a dense canopy is crucial for creating a stable microclimate, particularly consistent moisture, necessary for the fruticose Ramalina growth form. Tree height, however, exhibited species-specific influences, with the following regression equations: E. agallocha - Number of lichens = 11.65+0.0726 Tree height (R2=63.7%, p=0.000); R. mucronata-Number of lichens=78.87-0.1017 Tree height (R2=66.4%, p=0.000); and L. racemosa-Number of lichens=91.42-0.2129 Tree height (R2=62.6%, p=0.000). Multiple regression analysis further confirmed that canopy cover had a consistent positive effect, while tree height varied by species: E. agallocha-Number of lichens=5.94+0.0425 Tree height +20.32 canopy cover; R. mucronata - Number of lichens=41.9-0.0567 Tree height+24.17 canopy cover; and L. racemosa-Number of lichens=-6.85-0.0368 Tree height +57.99 canopy cover. A one-way ANOVA indicated no statistically significant difference in overall lichen coverage among the three-mangrove species (p=0.270). These findings highlight that the distribution of Ramalina sp. lichens is driven by a combination of overarching environmental factors (canopy cover) and host-species-specific traits (tree height), offering valuable insight for ecological monitoring and conservation of mangrove canopy integrity. Keywords: Ramalina sp., Lichens, Mangrove species, Abundance and coverage, Bioindicators
Effects of Benzophenone-3 (BP-3); an Ingredient of Sunscreen Cream, on a Common Freshwater Fish Model (Poecilia reticulata)
Benzophenone-3 (BP-3) is widely used as a UV filter in personal care products (PCPs) to prevent sunburn, skin damage and as a stabilizer. Due to concerns over endocrine disruption, international regulatory agencies are currently re-evaluating their safety. In this study, the toxic effects of dissolved BP-3 in aquatic environments using a fish model, Poecilia reticulata (Guppy) (0.28±0.09 g/ 2.20±0.19 cm), were studied under laboratory conditions. The tested sunscreen is composed of a water-soluble mixture of ingredients containing BP-3 with a labeled percentage of 6% (w/w %). Around 360 adult male P. reticulata (weight=0.282±0.001 g; length=2.20±0.01 cm) were collected from a natural habitat that was partially influenced by domestic wastewater effluents (pH=7.6,25.2±0.1 °C) and acclimatized in glass aquaria (45×25×15 cm3) filled with de-chlorinated water (pH=7.1,25±0.1) for one week (% mortality 1.398). A concentration series of BP-3 (molecular weight: 228.26 g/mol) (0.000[control], 0.1, 0.5,1.0,2.0,3.0,4.0,5.0,6.0,7.0,8.0 and, 9.0 mg/L) was prepared in triplicate using ethanol (added 2mL, for each tank including 0.28213±0.0862 g control) as a solvent in separate tanks containing 6 L of static water with 10 fish. Mortality, abnormal behavior (back swimming), water pH (7.0±0.1), and temperature (25.8±0.1 °C) were monitored for 24-96 hours. Along with the 96 hour toxicity tests, BP-3 levels in dead fish and in the commercial sunscreen were measured using HPLC analysis. According to HPLC analysis, the sunscreen contained 7.79 % (w/w %) of BP-3, exceeding the labelled percentage. The BP-3 concentrations in the fish body in each exposed group were not significant (p>0.05), with each group even with the elevated exposure concentrations. Notably, fish from the control setup showed pre-existing BP-3 (28.391±0.001 mg/kg dry weight), indicating the exposure of collected fish in their natural habitat. Probit analysis determined LC50 values for 24,48,72 and, 96 hours as 5.51,3.70,1.68, and 1.19 mg/L, respectively. Similarly, EC50 values were 4.71,3.19,2.32 and, 1.42 mg/L, while no observed effect concentrations (NOEC) were 1.04,0.17,0.07, and 0.02 mg/L. The calculated risk ratios (RR) for 24-96 hours were 1.81,4.94,8.37, and 7.92, all of which exceeded the risk level of 1. Hazard Index (HI) values for 48-96 hours of exposure were 1.60,2.09 and, 2.66. These results indicate that BP-3 imposes significant stress and mortality on P. reticulata even at relatively low concentrations. Therefore, BP-3 poses a substantial environmental risk when it is released into aquatic ecosystems and recommends replacing BP-3 in sunscreen cream with sustainable alternatives. Keywords: Benzophenone-3, Hazard index, P. reticulata, Risk ratio
Diversity of Butterfly Species in Urban and Semi-Urban Areas of Sri Lanka
Butterflies, belonging to the order Lepidoptera, are highly sensitive to environmental changes, and both natural processes and human activities have increasingly altered their habitats in recent years. In highly urbanized regions such as Colombo and its surrounding areas where rapid land-use conversion, infrastructure expansion, and population growth continue at an accelerated pace these changes have resulted in extensive habitat loss and fragmentation, posing a significant threat to the survival and diversity of many butterfly species. This study aims to identify the diversity and distribution of butterfly species by selecting Kurunduwatta Grama Niladhari Division as an urban area and Mulleriyawa Grama Niladhari Division as a semi-urban area. The Kurunduwatta Grama Niladhari Division, characterized as an urban environment, consists predominantly of built-up residential and commercial structures with limited green spaces, home gardens, and ornamental vegetation. In contrast, the Mulleriyawa Grama Niladhari Division represents a semi-urban landscape that includes a greater extent of home gardens, scattered agricultural fields, water bodies, and patches of natural vegetation that provide more suitable habitats for butterfly populations. Field observations were conducted in November 2024 during the time periods of 8:30-10:00 a.m. and 4:00-5:30 p.m. on 12 sampling sites. Data were collected on the number of individuals and the habitats of each butterfly species. The guidebook “Common Butterflies of Sri Lanka” was used for species identification. The Shannon diversity index was applied to calculate species diversity and abundance. A total of 5 butterfly species were recorded from Kurunduwatta, while 13 species were recorded from Mulleriyawa. The Shannon diversity index value for Kurunduwatta was 1.45, whereas for Mulleriyawa it was 2.3. According to this study, Mulleriyawa had relatively higher butterfly diversity. The most abundant species in the Kurunduwatta area was the Common Sailer (Neptis hylas), while in Mulleriyawa the most abundant species was Psyche (Leptosia nina). Seasonal changes, particularly the pre and post monsoon periods, have a significant influence on butterfly distribution. The key finding of this study is that semi-urban zones play a decisive role as transitional habitats for butterflies. Keywords: Urban and semi-urban butterflies, Butterfly diversity, Butterfly abundance, Shannon diversity index
Wings Over Wetlands: Diversity, Habitat Utilization, and Risk Assessment of Migratory Shorebirds in Wilpattu National Park
The island nation of Sri Lanka serves as one of the final terrestrial stopover for migratory shorebirds of the order Charadriiformes along the Central Asian Flyway. The most migratory shorebirds arrive in Sri Lanka via north-western route, where Villu ecosystems serve as available habitats, specially in Wilpattu National Park. This study aims to investigate the species diversity, relative abundance, habitat utilization, influence of anthropogenic interventions on migratory shorebirds to identify conservation measures. Satellite imagery between 2023-2025 were used to create a supervised classification for selected Villus to determine the habitat availability with use of NDVI and NDWI indices. To quantify anthropogenic interventions weighted maps were created using Raster Calculator in ArcGIS Pro based on weights determined using Analytical Hierarchy Process (AHP), within a 5 km buffer from the study areas. Pairwise comparisons in AHP were used to assign ordinal values to selected factors based on their relative importance using the 9 point scale. A total of 470 migratory shorebirds of order Charadriiformes belonging to 18 species and 3 families were recorded in the selected Villu ecosystems during the migratory season. The highest species diversity was recorded in Mahapatassa Villu which is Shannon’s Diversity Index (H)=1.803 followed by Kokkara (H=1.532) and Panikkar Villu (H=1.290). In the park, although dense forest represents the dominant habitat, shorebirds predominantly utilized grasslands and mudflats (86.56%), while open water habitats were least used. The all selected Villu sites are in the low risk level according to the risk assessment map account for 74.95% of the landscape, indicating that the majority of the area is subject to relatively low levels of anthropogenic disturbance. Among the contributing factors, agricultural lands and the road networks are the primary sources of risk. Kentish Plover (Charadrius alexandrines) and Little ringed Plover (Charadrius dubius) were also recorded, which are listed as Endangered, and Common Tern (Sterna hirundo) is listed as Critically Endangered at the national level. The findings highlight the Villu ecosystem in the Wilpattu National Park provide vital yet limited habitats for migratory shorebirds. Although anthropogenic risk levels remain relatively low, continued monitoring and sustainable land management are essential to ensure the long-term conservation of these critical stopover habitats. Keywords: Migratory shorebirds, Risk assessment, Habitat utilization, Central asian flyway, Wilpattu national park
Compensation as a Strategy for Mitigating Human-Wildlife Conflict in the North Central Province, Sri Lanka: A Choice Experiment Approach
Human-Wildlife Conflict (HWC) poses an escalating burden on both farmer communities and wildlife conservation in Sri Lanka. There is a great potential for compensation-based mechanisms as an effective strategy for mitigating HWC and promoting coexistence. Therefore, this study aims to assess the total economic loss caused by HWC and farmers' willingness to pay for the attributes of improved HWC mitigation programs in the North Central Province. Data were collected from 310 farmer households using a semi-structured questionnaire. The total economic loss was estimated by aggregating both direct and indirect costs, including crop damage, grain loss, livestock damage, property loss, mitigation costs, and the economic value of human injury and fatality impacts, with the latter quantified using the Value of Statistical Life (VSL). A choice experiment was conducted to elicit farmers' Willingness-To-Pay (WTP), and the responses were analyzed using both the Conditional Logit (CL) and Random-Parameter Logit (RPL) models. Model estimations revealed that farmers significantly valued compensation-based strategies. Farmers expressed the highest marginal WTP for the attribute offering 75% additional compensation for death or injury and 25% relief for crop loss, highlighting their preference for direct relief. Community-based shared patrolling was less preferred (specifically when offered without compensation), indicating farmers' reluctance for collective mitigation lacking direct financial incentives. The overall WTP for a comprehensive mitigation package was estimated as Rs. 1,989.24 per farmer household per month, reflecting a considerable economic value placed on effective compensation-based mitigation approaches. The average total household damage cost was Rs. 478,069 per season, with human fatalities accounting for Rs. 362,049 of the cost. Observation of parallel trends in total economic loss estimation and the choice experiment enhances the real-world significance of stated preference. Results emphasize the need for inclusive, well-targeted, species and location-specific, adequately compensated mitigation programs that align with coexistence for rural, vulnerable farming communities with wildlife. Keywords: Choice experiment, Compensation, Farmer households, Human-wildlife conflict, Mitigation
Study on Butterfly Abundance and Diversity at the Western Boundary of Kanneliya Forest Reserve Edge
Butterflies play an important role in the ecosystem as a good bioindicator for a healthy ecosystem. This study was conducted to quantify the abundance of butterfly species, determine the species diversity and analyze relationships between their abundance and diversity, with habitat characteristics of the western boundary of Kanneliya forest reserve edge (6° 14 '10.14 " N, 80° 20’ 34.95" E) in Sri Lanka. Line transect method was used to conduct the survey in different habitats of the forest edge. The habitats were shrubland, forest patch, household area and tea plantation area. Hundred-meter long transects were established in each area with five meters of perpendicular distance. Thirty minutes were spent on each transect at weekly intervals with eight survey frequencies for two months from March to May, 2025. A total of 278 butterflies belonging to five (Hesperiidae, Lycaenidae, Pieridae, Papilionidae, Nymphalidae) out of the six families in Sri Lanka were recorded. Thirty-five butterfly species were recorded in the study with three endemic species (Idea lasonia, Mycalesis rama, Trades darsius). Species diversity was calculated using Shannon- Wiener index (H), and evenness index for each habitat was also assessed. The high H value was found in the household area (2.596) followed by the tea plantation (2.595) and the lowest in the forest patch (1.753). The lowest evenness was recorded in the household area (0.089) and the highest in the forest patch (0.215). There is no significant difference in butterfly abundance between the four different habitats (One way ANOVA, p>0.05), while the species richness in the forest patch is significantly lower than in other three habitats (One way ANOVA, p<0.05). Forest patch at the western boundary of the Kanneliya forest reserve edge shows less species diversity and richness, and higher species evenness compared to other habitats. This indicates a more uniform distribution of a few species of the butterfly community and necessitates conservation attention. On the other hand, although household areas and tea plantation areas have high diversity, there being highly vulnerable to habitat modification. Keywords: Butterfly abundance, Species richness, Species diversity, Forest edge, Habitats.
Avifaunal Richness and Composition Along the Land-Use Gradient of the Endane Biodiversity Corridor Landscape, Nivithigala, Sri Lanka
Biological corridors are ecologically significant as they reconnect fragmented forests and restore functional connectivity. However, limited studies have assessed avifaunal diversity across land-use gradients in Sri Lanka, particularly within the Endane Biodiversity Corridor (EBC). EBC is an ecological corridor that connects the Iharakanda proposed forest reserve with the Walankanda Forest Reserve (WFR) within Sinharaja Forest Landscape. This study examined whether avifaunal richness and composition significantly vary across four land-use types associated with the EBC: the restored area (RA), home gardens (HG), productive tea lands (PT) and a forested section of the WFR. Field surveys from July 2024 to February 2025 used 21 line transects of 100 m, with direct and indirect (auditory) observations done during peak avian activity. Margalef’s richness index was used to assess the species richness, whereas the linear mixed-effects models were applied to compare the richness index. Community similarity was assessed using the Sørensen similarity index and permutational multivariate analysis of variance (PERMANOVA). A total of 111 avifaunal species belonging to 48 families were recorded, including 101 breeding residents, of which 21 were endemic and 10 migratory species. Loriculus beryllinus was the most abundant species across all land-use types. Highest avifaunal richness was recorded in RA (100 species), followed by HG (79), WFR (71) and PT (69). Forty species were common to all four land-use types, while seventeen species were confined to a single land-use type. Margalef’s richness index varied significantly among land-use types (p<0.05), with PT showing the highest richness (5.74±0.53), followed by HG (5.28±0.44), RA (4.77±0.24), and WFR (3.53±0.49). Sørensen similarity analysis revealed that RA showed high similarity with both HG (0.82) and PT (0.81), and slightly lower similarity with WFR (0.78) suggesting that RA functions as an ecological intermediary, bridging natural and human-modified habitats. PERMANOVA confirmed that species composition differed significantly among the four land-use types (R2=0.50, F=3.66, p=0.004), indicating that each supports a distinct avifaunal community. The high richness, endemism, and distinct community composition highlight the effectiveness of restoration and the importance of habitat connectivity for sustaining avian biodiversity in Sri Lanka. Despite the conservation efforts, threats such as illegal gem mining, encroachment, tree cutting, and poaching are identified as persisting risks for the EBC and WFR. Future studies should integrate seasonal variation and long-term monitoring to better understanding of temporal dynamics within avifaunal communities in the EBC. Keywords: Avifaunal diversity, Community composition, Ecological restoration, Habitat connectivity, Landscape gradient
Integrating UAV- Based Mapping with Soil Organic Carbon and Nitrogen Analysis of Coastal Sand Dunes in Kalpitiya, Sri Lanka
Coastal sand dunes, abundant aeolian landforms shaped by wind-transported sediments along coastlines, are vital ecosystems. They give valuable functions and play a crucial role in understanding aeolian landform evolution. The Kalpitiya coastal sand dune is located on the northwestern coast of Sri Lanka. However, a lack of comprehensive data on the morphology, extent, distribution, and carbon sequestration and nitrogen storage of coastal sand dunes limits knowledge for assessing the dynamics, effective conservation, and management strategies in the country. Therefore, this study integrated UAV-based mapping with elemental analysis of Soil Organic Carbon (TOC) and nitrogen to characterize dune morphology and biogeochemical properties in the Kalpitiya coastal system. The DJI Air 2S drone, equipped with a 20-megapixel camera, captured aerial images at an altitude of 50 m. The Orthomosaic maps and a Digital Elevation Model (DEM) were created using the Drone Deploy website. Dune morphology (mean elevation, slope, aspect, and contour) was analyzed, and spatial data visualized using ArcGIS 10.8 software. For elemental analysis, sand samples were collected by placing four 30 m transects perpendicular to the shoreline. A total of 12 sand samples (40 cm depth) were collected. TOC and nitrogen contents of samples were determined using a CHNS elemental analyzer. The results show that the Kalpitiya coastal sand dune system has a moderate slope (8.30°), southward orientation (mean aspect=180.7°), and low mean elevation (6.17 m) with a mean contour value of 6.2 m. The elemental analysis results indicated 24.15±10.57 Mg C ha⁻¹ of mean TOC content and 1.15±0.21 Mg N ha⁻¹ mean nitrogen content. These results signify a dynamic yet stable aeolian regime, with energy levels sufficient for dune formation but preventing extreme segregation. The observed low organic carbon and nitrogen storage is characteristic of the Kalpitiya dune system. This study thus provides valuable information on dune morphology, distribution, and organic carbon and nitrogen storage, which can aid in the effective conservation and management of the coastal sand dunes in Sri Lanka. Keywords: Coastal sand dunes, Digital elevation model, Morphology, Total organic carbon, Unmanned aerial vehicles
Temporal Variations of Interactions between Endemic Pseudophilautus regius (The Polonnaruwa Shrub Frog) and Two Carnivorous Plants in Sri Lanka
The Polonnaruwa shrub frog, Pseudophilautus regius is an endemic Rhacophoridae species in Sri Lanka whose ecological interactions are crucial for its conservation. This study examined temporal variations in interactions between the Polonnaruwa shrub frog and two carnivorous plants, Sarracenia flava and Nepenthes in an open greenhouse in Polonnaruwa (7.946140N, 81.013930E). Associations of shrub frogs with pitchers of five Sarracenia and ten Nepenthes plants were studied. Focal animal sampling was employed to quantify the behaviour. Observations were conducted from August to November 2024 from 06:00 h to 22:00 h. Mean daytime (06:00 h to 18:00 h) and nighttime (18:00 h to 06:00 h) temperatures during the study were 33 °C and 26 °C, respectively. A total of 36 frogs were observed inside Sarracenia pitchers during daytime, with no observations after 18:00 h. Inside Nepenthes pitchers, frogs were mostly observed between 17:00 h and 19:00 h (2 individuals) and 20:00 h and 22:00 h (4 individuals), with no observations between 07:00 h and 16:00 h. All observed behaviours inside Sarracenia pitchers were resting (100%). In contrast, frogs inside Nepenthes spent 83.33% of the total observation time on foraging and 16.67% on resting. This significant difference in plant use indicates that frogs utilise Sarracenia pitchers for daytime roosting to avoid temperature variations and high light intensity and Nepenthes pitchers as a foraging platform during low light hours. These findings demonstrate the importance of both Sarracenia and Nepenthes for P. regius in terms of foraging, thermoregulation, and adaptability to environmental variations presented by novel plant species. This provides valuable insights into the adaptability of Polonnaruwa shrub frogs to such novel microhabitats. Keywords: Nepenthes, Polonnaruwa shrub frog, Pseudophilautus regius, Sarracenia, Temporal interactions
Assessing Habitat Occupancy of Chevrotains (Moschiola meminna and Moschiola kathygre) in Sri Lanka
Sri Lanka is home to two endemic chevrotain species: the Yellow-striped Chevrotain (Moschiola kathygre), predominantly found in the wet zone, and the White-spotted Chevrotain (Moschiola meminna), primarily inhabiting the dry zone. This study aims to evaluate the habitat preferences of these two species within their natural habitat via occupancy modeling. Wilpattu National Park (WNP) (Sep 2024-Apr 2025) and Sinharaja Forest Reserve (SFR) (Dec 2018-Aug 2019) were selected as study sites to represent Sri Lanka's dry and wet zones, respectively. Camera trapping was used as a sampling technique. A systematic random sampling method was applied to deploy camera traps across the study sites. Each camera trap location served as a sampling point to collect data on species presence or absence, along with associated habitat variables. During the study period, camera trap stations were relocated every 45 days. Each 45-day survey period was divided into 3-day sampling intervals to optimize detection probabilities within each interval. Occupancy analysis was conducted using a likelihood-based approach. Detection histories were developed using binary values, where species presence was recorded as ‘1’ and absence as ‘0’. Data analysis was performed using the PRESENCE software package (version 2.15.9). The highest occupancy probability (0.816) was recorded from SFR based on the top occupancy model which was identified as the null model (ψ (). P ()). In SFR, there was no significant difference between the occupancy levels in different habitats, indicating that the species is both widespread and abundant within SFR. In WNP the occupancy probability was 0.38 having litter cover (LC), Euclidean distance to water (EDW) and relative abundance of leopards (RAILeo) (Total number of independent records/Total trap days×100) as covariates that contributed to the top model. All three covariates exhibited positive effects on occupancy probability. Among the three habitat types sampled in WNP, the highest occupancy probability was observed in tropical thorn forest (0.53) followed by dry mixed evergreen forest with an occupancy probability 0.44. Lowest occupancy probability was recorded in grasslands at 0.1. In SFR, the species shows high occupancy across all habitats. In WNP, occupancy is lower and dependent on habitat features therefore conservation should focus on site-specific management. In SFR, where habitat quality is already high and stable, efforts should aim at sustaining current conditions and preventing human-induced degradation such as illegal logging and trail expansion. In WNP, where habitat degradation and resource scarcity were evident, maintaining understory vegetation and leaf litter is crucial. Keywords: Moschiola meminna, Moschiola kathygre, Camera trapping, Habitat covariates, Occupancy modeling
Habitat Requirements of The Endemic Sri Lankan Green Pit Viper (Peltopelor trigonocephalus) in Sri Lanka
Habitat use of Peltopelor trigonocephalus was studied in the main three climatic zones of Sri Lanka from April 2021 to October 2024. P. trigonocephalus is an endemic viper, locally known as “Palapolaga”. This species shows wide distribution in the island, except in the higher hills and arid zones. Three macro-habitat types were considered during sampling; forest, riparian, and open habitat. Visual encounter surveys were conducted to observe P. trigonocephalus along a 200 m transect searching up to 2 m on either side and up to a height of 6m. The first sighting of P. trigonocephalus was recorded, and the perches used by this species were categorized based on their structural characteristics. The height of the perch was measured. The position of P. trigonocephalus on the branch was categorized into three distinct sections: apical, proximal, and middle. Data on 68 individuals of P. trigonocephalus were recorded. Majority of these individuals (71.42%) were observed in riparian habitats. Most preferred perch height for P. trigonocephalus during the diurnal was within the mid-story range of 3-6 m, making up 42.85% of total encounters. The majority of P. trigonocephalus individuals (60.78%) were found in the apical region of the branches, with 36.4% occupying the middle region. A very strong positive linear relationship was observed between snout-to-vent length (SVL) and branch circumference, with a Pearson correlation coefficient of 0.969. The correlation is statistically significant (p=0.00), suggesting that P. trigonocephalus select branches based on their size. For ambush behavior, trees were the most frequently utilized substrate, with 80% of individuals observed using them for this purpose. This study provides important insights into the conservation and management of P. trigonocephalus by critically evaluating its differing habitat requirements. Preservation of its natural habitats and enrichment of ex situ habitats can be achieved through these findings. Keywords: Climatic zones, Macro-habitat, Perch selection, Peltopelor trigonocephalus
Evaluation of Glyphosate Toxicity Using Artemia salina as an Invertebrate Model
Glyphosate, the active ingredient in numerous commercial herbicides, is widely used globally, raising concerns about its potential impact on aquatic ecosystems. This study evaluated the acute toxicity of glyphosate using Artemia salina (brine shrimp), a widely recognized invertebrate bioassay model for Eco toxicological studies. Brine shrimp nauplii (Instar I) were exposed to a series of glyphosate concentrations (50, 75 and, 100 ppm) prepared in artificial seawater, and mortality was assessed at 24 and 48 hours. Results revealed a clear dose-dependent increase in mortality, with estimated LC50 values of 31 ppm at 24 hours and 54 ppm at 48 hours, indicating time-dependent toxicity. While variations in toxicity levels may reflect experimental conditions such as artificial seawater use, the findings are consistent with previous reports of glyphosate’s harmful effects on aquatic invertebrates. Given the ecological importance of A. salina and its role as a model organism, these results highlight potential biodiversity risks associated with glyphosate contamination, including disruption of aquatic food webs and implications for higher trophic levels. Further research is recommended to investigate chronic toxicity, environmentally relevant concentrations, and long-term ecological consequences of glyphosate exposure. Keywords: Glyphosate, Brine shrimps, LC50 value, Mortality, Aquatic food chain
Diversity Patterns of Early Migratory and Resident Birds in the Beddagana Wetland Park, Sri Lanka
Wetland ecosystems are essential habitats for resident and migratory bird species, contributing significantly to the preservation of ecological balance and avian biodiversity. This study investigates the avian diversity patterns of early migratory and resident birds at the Beddagana Wetland Park (BWP) in Sri Jayewardenepura Kotte, Colombo, Sri Lanka, a globally significant location within the world’s only Ramsar-accredited Capital Wetland City. BWP, characterized by distinct microhabitats including shrubs, woodland, marshy areas, open water bodies bordered by Diyawanna Lake, and canal habitats, serves as a crucial ecosystem for both resident and seasonal bird populations. This study quantifies the species richness, abundance, diversity (Shannon-Wiener index), evenness, and dominance (Simpson index) of early migratory and resident birds from early August to the end of November 2025, representing the initial phase of the migratory season. Bird data were collected using systematic circular plot sampling across 10 fixed plots with a 50 m radius each, strategically distributed across the microhabitats of the park. The point count technique was used, wherein data was collected for a standardized three-minute duration at the center of each plot to mitigate the risk of double-counting and ensure consistent sampling effort. Observations were conducted once a week during two daily windows (6.00 to 9.00 AM and 3.00 to 6.00 PM) on alternating weekdays and weekends, allowing comparisons of temporal and weekly variation and to account for anthropogenic influences on bird distribution and activity. Results revealed that a high avian richness (54 total species), comprising 50 Resident species and 4 Early Migratory species. The resident avifauna showed high diversity (Shannon Index, H´=3.19) and high structural evenness (J´≈0.81), with low dominance (Simpson D=0.08, 1-D=0.92), reflecting a relatively balanced distribution of abundance among species. Dominant contributors to abundance included the Rose-ringed Parakeet and Asian Palm Swift, indicating strong adaptation to heterogeneous urban wetland conditions. The migratory group showed a Simpson Diversity Index (1-D) of ≈0.78. Dominance was pronounced among the migratory species, with the Blue-tailed Bee-eater exhibiting the highest overall proportional abundance (Pi​≈0.32) among all 54 recorded species, indicating a significant reliance on the park’s resources during this early migration window. Overall, the presence of multiple microhabitats supports high resident diversity while simultaneously providing essential resources for early migrant species. This ecological richness highlights the role of the park as a significant urban biodiversity refuge. This rich, and quantifiable avian diversity represents a significant ecological strength that must be strategically connected to promote Beddagana Wetland Park as a premier, conservation-centric birdwatching destination within the high-density urban environment of the Colombo metropolitan area. Keywords: Avian diversity, Urban wetland, Resident birds, Migratory birds, Birdwatching
Determination of Threshold Toxicity of Chloride in Drinking Water Using The Zebrafish as a Vertebrate Animal Model
Chloride contamination in drinking water resulting from natural sources, industrial effluents, and disinfection processes, poses significant risks to aquatic life, particularly during early developmental stages making the evaluation of its ecological impact essential. Although chloride is essential in small amounts, elevated concentrations can adversely affect survival, growth, and physiological processes in aquatic organisms. This study aimed to determine the threshold toxicity of chloride in water and assess acute lethal effects on zebrafish (Danio rerio) embryos. Fertilized embryos at 2 hours post-fertilization (hpf) were exposed to five chloride concentrations (2,4,6,8 and, 10 mgL-1), with tap water and distilled water serving as controls. Twenty embryos per each and duplicated. Toxicological endpoints including mortality, hatching rate, heart rate, and morphological abnormalities, were assessed until 96 hpf. The results demonstrate a clear dose-dependent increase in mortality, with the highest rate of 68.75±0.58% was observed at 10 mgL-1and the lowest rate of 25±0.58% was observed at 2 mgL-1. The hatching rate declined gradually at higher concentrations, showing 50±0.00% at 2 mgL-1, and further decreased to 12.5±1.2% at 10 mgL-1, and heart rate was increased progressively, reaching 192±2 bpm at 10 mgL-1compared to 140±4 bpm in controls. Embryos in tap water exhibited 12.5±0.58 % mortality, 75±1.74% hatching, and a heart rate of 150±2 bpm at 96 hpf. Morphological abnormalities, including spinal curvature at 2 mgL-1 and yolk sac oedema at 8 mgL-1, were observed with an occurrence rate of 20% of the larvae. The calculated LC50 value of chloride is 5.6 mgL-1. These findings emphasize the need to reconsider water quality guidelines to protect vulnerable early developmental stages of aquatic life. Overall, this research demonstrates that even relatively low chloride concentrations can induce significant developmental and morphological effects in zebrafish embryos, supporting their application in environmental risk assessment and guiding safer drinking water management. Keywords: Chloride, Hatching rate, Morphological abnormalities, Mortality rate, Zebrafish
The Effect of Environmental Factors on the Diurnal Activities of a Common Wetland Predator (Aves, Egretta garzetta) in an Urban Wetland Complex in Colombo, Sri Lanka
The little egret (Egretta garzetta) is a common wetland bird in Sri Lanka. These small herons are abundant in many different wetland ecosystems, including marshes, paddy fields and around water bodies. They are also a common sight in many of the urban wetland complexes that have been incorporated around the capital city of Colombo, Sri Lanka. These birds are predators, feeding mainly on fish, and a majority of their day is spent foraging. The environmental parameters of these wetlands are often influenced by their urban surroundings. Hence, the aim of this study was to identify whether these environmental parameters, such as temperature, humidity and sound level, have a significant effect on the major diurnal activities of the little egret at one such urban wetland complex in Sri Lanka, the Kimbulawala wetland complex in Colombo. The proportions of time spent on six major diurnal behaviours (foraging, resting, preening, flying, vigilance and aggression) were recorded through focal sampling with 133 focal observations made across 17 sampling days (between July 2024 and February 2025). A typical sampling day spanned from 6:00 AM to 6.00 PM, divided into six time slots of two hours each. Temperature and relative humidity were measured at 15-minute intervals throughout the day while sound levels were measured at 10-minute intervals using standard data loggers. The associations between the proportion of time spent on each behaviour and the environmental parameters were analysed using Generalized Linear Mixed Models (GLMM’s) in R. The results indicated that foraging and resting were affected by temperature and relative humidity (GLMM; p<0.1), with the proportion of time spent foraging tending to decrease as the diurnal temperature increased while the proportion of time spent resting tended to increase. No significant associations were found between its other behaviours and the environmental parameters, including sound (GLMM; p>0.05). These findings suggest that rising temperatures prompt the little egret to prioritize thermoregulation, reducing strenuous activity with a preference to rest during such times. Vigilance, flying and aggression were prompted by the presence of other factors, including conspecifics, other waterbirds and potential predators. It is possible that other parameters such as prey availability and water depth may have an effect as well. As such, this study was able to confirm how some of the environmental parameters of this urban wetland did have an effect on certain diurnal behaviours of the little egret. Keywords: Little egret, Urban wetland complex, Focal sampling
Behavioral Ecology of a Feral Population of Spotted Deer (Axis axis) in Suburban Lowland Wet Zone of Sri Lanka
The establishment of spotted deer population in the lowland suburban wet zone of Sri Lanka is an example of range expansion by the species into new habitats. A population of 393 individuals was reported in Homagama and Kaduwela in Colombo District in 2021, forming a novel opportunity to study behavioral adaptations to human-altered landscapes. The objective of the study was to investigate the patterns of behavior through the temporal, demographic, and habitat gradients to determine the adaptation mechanisms. Behavioral observations were conducted in six habitat types categorized into Agricultural (coconut, rubber and paddy cultivations), Residential (home gardens) and Natural (grassland and shrubland). Observations conducted during daytime (06:30 h-18:00 h) and nighttime (19:00 h-01:30 h). Systematic instantaneous sampling method was used to record feeding, moving, resting and alert behaviors of males, females and juveniles. Spotlight counts were used in nocturnal observations. In April 2021, observations were made with 1,011 individuals in three nighttime and five daytime counts. Feeding and moving were the most common behavioral patterns, while alert and resting were less common. However, significant temporal shifts in overall behavioral distribution occurred (χ²(3)=58.6, p<0.001). At night compared to daytime, both alert and feeding behaviors increased by 2.64 and 1.28-fold, respectively, while movement decreased by 1.94-fold and resting remained constant. Demographic groups exhibited a similar ranking of common behaviors (Feeding>Moving>Alert>Resting). However, males displayed vigilance levels dramatically higher than females (χ²(3)=22.2, p=0.001), suggesting sentinel behavior patterns. There was a significant difference in behaviors between the habitat types (χ²(6)=44.6, p<0.001) with natural habitats being more active in feeding in comparison with agricultural areas. This indicates that more detailed and habitat specific management may be necessary. The lack of osteophagia suggest that the suburban wet zone has more minerals than the dry zone. The lack of vocalizations could indicate an acclimatization to the noise of the suburbs. Spotlighting showed evidence of bias, as the deer tended to orient toward light source. This might have influenced the actual patterns of observed behaviors during the night, particularly alerted behaviors. These results illustrate plasticity of behavior which enables colonization in the suburbs and temporal and sex-specific variations serve as empirical evidence to the urban adaptation theories. To develop effective management strategies in the suburban setting, long-term monitoring is required to demonstrate the seasonal variability and the dynamics of human-wildlife conflict. Keywords: Urban wildlife, Behavioral ecology, Urban adaptation, Human-wildlife conflict, Suburban habitats
Seasonal and Daily Variations of Mugger Crocodile (Crocodylus palustris) Behaviors in Wilpattu National Park
Out of two crocodile species present in Sri Lanka, the Mugger crocodile (Crocodylus palustris) is a Near Threatened freshwater crocodile species, inhabiting freshwater bodies, ponds, and irrigation canals around the island. These large carnivorous reptiles play a crucial role in maintaining their natural ecosystems. The present study aimed to assess all behaviors of muggers across the dry and wet seasons and times of the day. Areas in and around the Wilpattu national park were selected as study sites. The crocodile survey was conducted from September 2024 to August 2025, covering wet (October-February) and dry (March-September) seasons. Point counts along road transects were conducted using a jeep. An ethogram was created after thoroughly observing the behaviors. All the behaviors were documented at the first site during morning, midday, and evening. Eight different behaviors (basking, feeding, floating, gaping, high walk, resting on land, submerged, swimming) were analyzed to examine the significant differences using the chi-squared test across time of the day and between two seasons. Throughout the year, 231 crocodile sightings were recorded, and wet season sightings (150) were higher than the dry season (81). The reason might be the decline in water levels and the confinement of crocodiles to a small area during the dry season. Activity budget of each behavior was recorded as basking (21.40%), feeding (0.87%), floating (24.89%), gaping (9.17%), high walk (3.06%), resting on land (13.10%), submerged (5.24%), and swimming (22.27%). There was a significant difference (p=0.003) in mugger behaviors during the time of day due to environmental variations, as ectotherms. Behavioral patterns also showed significant seasonal differences (p=0.04). When both seasons and time of the day were considered simultaneously, there was a significant difference (p=0.01) in all behaviors, as they had changed their behaviors with preferable environmental conditions. The results highlight the shifting of behaviors strongly influenced by seasonal changes and times of the day. These findings provide pivotal insights that guide future management and conservation strategies for crocodiles by highlighting how their behavioral responses are shaped by environmental changes. Such knowledge is important for mitigating human-crocodile conflict and safeguarding the crocodile population under changing environmental conditions. Keywords: Mugger crocodile, Behavioral patterns, Wilpattu, Crocodylidae, Activity
Assessing the Habitat Utilization, Occupancy, and Land Use Change for the Conservation of Elephants in Wilpattu National Park, Sri Lanka
Sri Lanka is renowned for its significant population of Sri Lankan elephants (Elephas maximus maximus), an endangered subspecies that represents a keystone component of both ecological systems and its ancient cultural heritage. The coexistence of humans and elephants in shared landscapes presents significant challenges, with conflicts arising due to habitat loss, competition for resources, and human-elephant interactions. The case study was conducted in and around the southern boundary of Wilpattu National Park (WNP) from September 2024 to August 2025 to examine the land use and cover (LULC) change, along with the spatiotemporal habitat use of Sri Lankan elephants. Trail cameras (n=34) equipped with passive infrared sensors were deployed systematically within 3×3 km2 grids in the WNP. Visual encounter surveys were conducted outside the protected area. The Sentinel-2 satellite imagery from 2018 was obtained to evaluate the LULC and change using supervised classification. Ten covariates covering vegetation, physical, and food availability parameters at each camera station were obtained to assess the occupancy (ψ) of elephants within the park. The predicted hotspots and migration of elephants were analysed using the heat map developed by Empirical Bayesian Kriging (EBK) in ArcGIS Pro. A total of 81 footage of elephants was documented inside the park, and 102 sightings were recorded outside the southern boundary during the survey period. Interestingly, the elephants exhibited a higher preference (p) for the grassland (p=0.56±0.13), followed by scrubland and dry mixed evergreen forests inside the park, which satisfied their feeding ecology. The LULC change indicated that land encroachment in the protected corridors occurred moderately over the past years (r²=0.46). The occupancy analysis revealed a significant correlation with food availability parameters. The most important parameters for selecting a habitat for elephants were the distance to grasslands and crop fields, which may be correlated with their tendency to invade paddy crops. Keywords: Conflict, Elephant, Occupancy, Preference, Wilpattu
Human-Monkey Conflict in Sri Lanka: Evidence from Yapahuwa to Guide Feeding Stations as a Mitigation Strategy
Human-monkey conflict has intensified across Sri Lanka, with the endemic Toque macaque (Macaca sinica) frequently raiding crops, damaging property, and threatening human safety. The primary objective of this study was to quantify the extent, economic impacts, and patterns of human–monkey conflict in communities surrounding the Yapahuwa heritage site and to evaluate the potential of managed feeding stations as a short-term mitigation strategy. A community survey and field study were conducted in February 2025, collecting information on human–monkey conflict experienced over previous years, from 20 households in villages of Yapahuwa, Pailigama, Lunupothagama, and Diwullawa. The survey focused on the frequency of monkey incursions, troop size, crop and property damage, yield loss, perceived threats to human safety, and associated economic impacts on household livelihoods. Among the 100 households surveyed, 75% reported daily disturbances, with 50% of farmers losing about half their harvest and 15% experiencing total crop destruction. Property damage was reported by 75% of respondents, while more than half expressed concern over aggressive encounters and health risks. During the field observation confirmed that large macaque groups, typically 20-30 individuals, routinely entered home gardens and farmlands, causing significant economic which is nearly 50% reduction of crop yield and social strain. Based on these findings, the study proposes establishing sustainable monkey-feeding stations within natural habitats as a short-term measure to divert monkeys away from settlements and reduce immediate conflict. These stations, equipped with elevated platforms, controlled food dispensing mechanisms, and monitoring systems, can help restore more natural foraging behavior while improving community safety. However, feeding stations alone cannot resolve the issue in the long run. medium-to long-term solutions will require habitat enrichment to restore ecological balance, combined with population management to reduce pressure on both forests and human settlements. The study demonstrates that conflict mitigation demands both immediate interventions and long-term strategies, linking community welfare with primate conservation in Sri Lanka. Key words: Crop damage, Community survey, Conflict mitigation, Human-monkey conflict
A Novel Approach to Assess Biocapacity, A Case Study from the Pundalu Oya Valley, Sri Lanka
This study evaluates the biocapacity of five distinct land use types: Tea cultivation, abandoned tea land, commercial forest, forest border, and estate bungalow compound gardens, using a novel Ecological Value Score (EVS) framework to address the critical gap in tools for holistically assessing ecosystem health in modified landscapes. Biocapacity refers to the capacity of an ecosystem to regenerate biologically productive resources and absorb waste, essential for sustaining biodiversity and human well-being. Biocapacity evaluation is critical for understanding ecological resilience, conservation priorities, and sustainable land management. Biocapacity assessment was conducted in the Pundalu Oya Valley, which is a part of the Central Highlands of Sri Lanka (Elevation ranges from approximately 1,200 to 1,800 meters above sea level), recognized as a UNESCO World Heritage Site and a biodiversity super-hotspot by the International Union for Conservation of Nature (IUCN). The EVS model integrates 14 weighted ecological parameters, incorporating biodiversity (species richness, evenness, rarity, endemism, uniqueness, conservation status), ecosystem services (water quality), soil health (soil nutrient content, % microbial biomass carbon), land use type (Scenic value) and anthropogenic pressures (invasive species, pesticide use). Each factor was assigned a weight based on its ecological significance with positive contributors enhancing biocapacity and negative factors (e.g., pesticides) diminishing it and normalized on a 0-5 scale, with the final score calculated using the formula EVS=∑(Wi×X_normalized), where Wi is the assigned weight and X_normalized is the value normalized to a 0-5 scale. Results revealed the Forest Border as the highest-value ecosystem (EVS:4.41), functioning as a critical biodiversity ecotone. Estate bungalow compound gardens followed closely (3.75), their structural complexity making them unexpected biodiversity reservoirs. Commercial Forest (2.73) showed a moderate biocapacity, while Tea plantations (2.57) and Abandoned Tea Land (2.52) scored the lowest. The findings highlight the ecological significance of forest edges and compound gardens as key conservation zones, revealing significant variations in biodiversity and ecosystem functions across different land use types. Beyond conservation, the study reveals the valley's untapped potential for nature-based tourism, scientific research, and carbon-offset initiatives. The EVS provides a robust, scientific tool to guide targeted ecological restoration and direct sustainable land-use planning, emphasizing the protection of high-capacity ecosystems to enhance landscape-scale resilience in this critical biodiversity hotspot. Keywords: Biocapacity, Land-use assessment, Biodiversity conservation, Sustainable land management, Ecological restoration
Evaluation of the Neurotoxic Effect of Polycyclic Aromatic Hydrocarbons (PAHs) on Brine Shrimp as an Invertebrate Model
Polycyclic Aromatic Hydrocarbons (PAHs) are a set of organic compounds that are broadly dispersed in the marine habitats. It is released by various sources, such as oil spills or incomplete combustion. In today’s world, the quantity of these pollutants is rapidly increasing, which eventually leads to complex toxic effects on aquatic life. This study aims to evaluate the toxicity of Naphthalene (NAP), Phenanthrene (PHE) and Anthracene (ANT) on the brine shrimp (Artemia salina), which is used as a model organism for this neurotoxicity assessment. The nauplii (Instar I) of A. salina were exposed to increasing concentrations (150, 200 and, 250 ppm) of NAP, PHE and ANT to calculate the mortality percentages and LC50 values. NAP had an LC50 value of 340 ppm after 24 hours and 315 ppm after 48 hours. The LC50 value of PHE was 237 ppm after 24 hours and 241 ppm after 48 hours. Furthermore, ANT had an LC50 of 441.8 ppm after 24 hours, but it reduced to 194.52 ppm after 48 hours. In addition, the morphological abnormalities including body deformations, developmental delays and appendage malformations were observed. The neurotoxic and behavioural effects revealed variations in movement patterns, swimming velocity, and body reflexes. Potassium dichromate was used as a positive control. Real seawater and artificial seawater were maintained as negative controls to give a contrasting result in this experiment. These findings propose that acute PAH exposure causes lethal neurotoxic, morphological and behavioural effects in A. salina, emphasizing the suitability of this invertebrate model for aquatic neurotoxicity testing. Further investigation is needed to evaluate the novel effects of PAHs on the environment. Keywords: Polycyclic aromatic hydrocarbons, Brine shrimps, Mortality rate, LC50 value, Toxicity
DNA Barcoding Confirms the First Record of the Coral Pocillopora acuta in Sri Lankan Reefs, which was Previously Misidentified as P. damicornis
Accurate species delineation is essential for effective coral reef management and conservation. However, phenotypic plasticity and introgressive hybridization in scleractinian corals, particularly in morphologically variable genera like Pocillopora, often obscure species boundaries. As a result, morphological taxonomy alone is insufficient, underscoring the need for molecular approaches. This study aimed to verify the taxonomic identity of P. damicornis-like corals in Sri Lanka using the mitochondrial open reading frame (mtORF) as a molecular marker. Coral fragments (1-2 cm) were collected from 11 sites along northwest, west, south, east and northeast coasts in 2023, maintaining a minimum distance of 5 m between mature colonies to minimise the risk of clonal sampling. A total of 423 samples were successfully amplified and sequenced. Preliminary BLAST searches against GenBank produced ambiguous matches to both P. damicornis and P. acuta. To resolve this, phylogenetic relationships were inferred using maximum parsimony based on a 590 bp alignment of 118 unique haplotypes, together with reference sequences from GenBank of different Pocillopora species verified by skeletal data. Bootstrap statistics were conducted based on 1,000 replicates. In addition, a median-joining haplotype network was constructed to visualise genetic relationships among haplotypes and to complement the tree-based results. In the phylogenetic analysis, none of the Sri Lankan samples clustered with the P. damicornis clade, which had a bootstrap support of 97%. Two haplotypes grouped with the P. verrucosa/P. bairdi clade, while six haplotypes formed a more divergent subclade closely related to that group. Two additional haplotypes did not cluster with any recognised Pocillopora lineage. The remaining 108 haplotypes could be assigned to P. acuta, marking the first confirmed record of this species in Sri Lanka. The haplotype network showed consistent results: two haplotypes grouped with the P. verrucosa/P. bairdi haplogroup, six were more divergent but still associated with that haplogroup, and the remaining 110 haplotypes grouped with P. acuta. This difference illustrates how tree-based and network-based approaches combined can help to resolve ambiguous species identification. Overall, these results indicate that P. acuta is the dominant P. damicornis-like lineage present in Sri Lanka, while P. damicornis itself was not detected. These findings highlight the value of incorporating molecular data for accurate coral taxonomy, which is essential for clarifying species boundaries, understanding their ecology, and informing effective conservation strategies in Sri Lanka. Keywords: Conservation genetics, Coral biodiversity, Cryptic species, Molecular taxonomy, Phylogenetic analysis
Discovery of Fossilized Spenophyllum sp of Permian Period in the Tabbowa Sedimentary Basin: Sri Lanka
Plant fossil bearing mudstones of the Mesozoic era are present at a small and deeply faulted basin within the Precambrian Basement at Tabbowa in the Northwestern Province of Sri Lanka. There is only a limited number of studies available on these plant fossils, particularly on their morphological characterization and their systematic positioning in the plant world. Their palaeo geography, age or prevailing palaeo-climatic conditions have not been clearly established. Weathering on outcrops appeared to have eliminated possibility of a clear undertaking of palaeo-stratigraphic analysis of the exposed strata, though deep subsurface strata may yield clear evidence, even spore-pollen assemblages. So far, only the plant macrofossils are considered means of dating these strata. The present study is on Sphenophyllum; a group of extinct plant species, from the Permian (298-252 MY ago) deposits of the Tabbowa basin. The fossils are well preserved, hence allowing detailed morphological analysis, taxonomy, and palaeo-ecological insights. These fossils are recognized by their jointed stems and leaves arranged in whorls (circlets) at nodes. Leaves row in whorls around the stem at each node and are typically triangular or wedge-shaped with veins branching from the base and multiple veins that are radiated from the base of each leaf and branch repeatedly to the tip. Some taxonomic characters and venations of leaves were studied under the microscope. The observed features are compatible with museum specimens so far recovered from India, Australia and Antartctica and information published in literature Sphenophyllum has fan-shaped lobed leaves attachment for efficient photosynthesis in relation to climate. The leaf Taxonomic features mainly the leaf’s margin, size, shape, texture, petiole and venation density have helped in determining past climate. The results revealed that these species do not show any strong taxonomic or morphological evidence of either arid or humid climates but appear to grow as members of hydrophilous plant communities in shallow waters. The findings propose that this association of species of Lopingian age in the Permian period and are compatible with the fossil floras of Peninsula India. Keywords: Sphenophyllum, Permian plant fossil, Tabbowa basin, Sri Lanka
The Impact of Aquatic Invasive Plant, Pontederia crassipes, on Zooplankton Abundance and Diversity in Muthun Ela Stream, Gampaha, Sri Lanka
The proliferation of aquatic invasive plants can profoundly alter freshwater ecosystems by modifying water quality. Pontederia crassipes, commonly known as water hyacinth, is one of the aggressive aquatic invaders, native to tropical and subtropical South America. This study assesses the impact of P. crassipes on zooplankton abundance and diversity in Muthun Ela stream, Gampaha, by comparing three infested and three non-infested sites. Water samples were collected in triplicate from three infested and three open-water sites over six months. A 300 µm zooplankton net was used for zooplankton sampling. Infested sites had lower dissolved oxygen (4.61±0.14 mg/L), temperature (27.13±0.33 °C), phosphate (0.88±0.09 mg/L) and nitrate (0.72±0.09 mg/L), chlorophyll-a concentrations (0.35±0.04 µg/L) and higher turbidity (5.55±0.14 mg/L), likely affecting primary productivity. The study recorded 24 zooplankton species belonging to the orders Cyclopoida, Cladocera, Ploima, Anomopoda, Podocopida, Oikopleurida, and Appendicularia. Cladocera and Cyclopoida were dominant in both environments, contributing 23.33% and 16.67% in infested areas and 21.35% and 16.39% in open waters, respectively. Families such as Moinidae, Sididae, Lepadellidae, and Cyprididae were evenly distributed between the two habitats, with Lepadellidae and Cyprididae showing slightly higher representation in open-water sites, while rotifers of Lecaneidae and Lepadellidae were also widespread. In contrast, Conochilidae (1.07%) and Appendicularia (0.18%) were recorded only in open-water sites, indicating their preference for less vegetated habitats. Non-infested sites consistently support higher zooplankton abundance (180.00±12.76 ind./L) compared to the infested sites (126.11±7.63 ind./L, p<0.001), especially for families such as Daphniidae and Cyclopidae. In contrast, the infested areas showed comparatively higher richness, suggesting that P. crassipes alters community composition by creating microhabitats while limiting overall population size. Diversity indices analysis revealed higher species diversity in open water (Shannon Wiener mean=1.73±0.01), but greater species richness in infested areas (Margalef’s mean=3.17±0.49). Collectively, non-infested sites supported higher abundance, while infested sites exhibited more variable and microhabitat-driven species richness. The findings suggest that P. crassipes alters habitat conditions, reducing zooplankton abundance and diversity, which may have cascading effects on the aquatic food web. Keywords: Invasive, Abundance, Diversity, P. crassipes, Zooplankton
Mangrove Based Resilience Strategies in Sri Lanka’s Coastal Ecosystems: Addressing Climate Change for Sustainable Environmental Management
Climate change presents increasing threats to biodiversity, natural resources, and livelihoods dependent on Sri Lanka’s coastal ecosystems, particularly mangrove forests. This study evaluates the resilience mechanisms and adaptation capacity of coastal forests under growing climatic threats, such as sea level rise, saltwater intrusion, extreme weather events, and shifting monsoon patterns. A qualitative thematic analysis was conducted using a systematic assessment of nearly 50 secondary sources from 2000 to 2025 obtained from important academic databases, government, non-governmental, and policy publications. The review focused on degradation patterns, institutional responses specific to Sri Lanka’s coastal forests, and adaptive strategies, including indigenous ecological knowledge. Findings reveal that Sri Lanka's mangroves, which once covered over 15,670 hectares, have lost 25-35% of their area since the 1980s due to pollution, aquaculture, and coastal development. Important ecosystem services such as habitat support, carbon sequestration, and coastal stabilization are provided by key mangrove species like Avicennia and Rhizophora. Since the 2000s, restoration efforts covering more than 1,000 hectares have resulted in up to 78% seedling survival in sites that combine significant community involvement with scientific input. There are at least ten different adaptation strategies that have been discovered, such as Integrated Coastal Zone Management (ICZM) initiatives involving local stakeholders, indigenous management of fisheries and harvesting, and community-based conservation. According to climate estimates, sea levels will rise by 0.1 to 0.6 m by 2050, and storm frequency will increase. This endangers the mangrove's health and the stability of the shore. Comparative analysis reveals that while Sri Lanka has similar problems as other tropical coastal countries such as the Philippines and Indonesia, it also benefits from a distinctive form of governance that combines policy-driven adaptation with indigenous expertise. Policy recommendations emphasize strengthening coastal and forestry institutions, filling enforcement and coordination gaps, expanding community-led restoration connected to livelihoods and incorporating climate adaptation into planning. Indigenous practices such as traditional planting aligned with natural flooding and sustainable harvesting require formal recognition to enhance resilience. Future studies should focus on monitoring the long-term outcomes of restoration efforts, assessing the effectiveness of indigenous practices, evaluating governance structures, and conducting socio-economic analyses to strengthen policy and management frameworks. This synthesis presents new perspectives by combining data from multiple disciplines, providing a systematic assessment of degradation and restoration outcomes, and identifying key institutional and knowledge gaps that require attention. The study concludes that ensuring long-term environmental sustainability in Sri Lanka's coastal regions requires adaptive and inclusive management within strengthened institutional frameworks to protect coastal mangrove ecosystems, maintain their services, and enhance community resilience against increasing climate change. Keywords: Climate change, Mangroves, Coastal ecosystems, Resilience, Sri Lanka
Efficacy of Plant Extracts in Controlling Seed Fungal Infections and Enhancing Germination of Annual Wi̇ld Ri̇ce: Oryza nivara in Sri̇ Lanka
Wild genetic resources of rice play a crucial role in improving climate-resilient rice. Among them, Oryza nivara is closely related to the cultivated rice. Poor germination ability, prolonged time for germination followed by fungal infections, uneven germination, and strong dormancy are certain practical constraints in adopting O. nivara seeds in research programs. This study aims to assess the antifungal effects of plant leaf extracts on reducing fungal infections and improving the germination percentage of O. nivara seeds. Four aqueous plant extracts from fresh leaves of Zingiber zerumbet, Guava (Psidium guajava L.), Cinnamon (Cinnamomum verum), and Cassia alata, with the 1:1 (100 g leaf crushed in 100 ml water) and 1:2 (100 g leaf crushed in 200 ml water) in 15 min, standard fungicide solution (S) (2gL-1 of Manganese ethylene-bis-dithiocarbamate), a control using distilled water (C), have been employed with a total of 16 treatments. The experiment was conducted in a completely randomized design with 10 seeds per replicate and 3 replicates for one treatment. Husked and dehusked seeds were treated for 24hr, incubated at 36 °C, and assessed every two days. Optimal germination occurred after 10 days. Data were analysed using one-way ANOVA (p<0.05) and Tukey's HSD test. Seeds with husks failed to germinate and showed no fungal contamination, with all treatments showing that dehusking is compulsory to induce germination. The best germination % was recorded in treatments with both ratios of Zingiber zerumbet (1:1=7.33±0.33cd; 1:2=8.00±0.0d) and Cinnamon 1:2 (7.33±0.33cd) compared to the control (C) and standard (S) (C=5.33±0.33b and S=6.67±0.33c), respectively. The least germination rates (1:1=2.67a±0.33 and 1:2=2.00±0.0a) were observed in C. alata treatments, inferring negative effects on germination. Moreover, Z. zerumbet (1:1 and 1:2), P. guajava L. (1:1), and C. verum (1:1) exhibited the lowest fungal infection, while C. alata (1:1) demonstrated the highest mean fungal seed infection (7.33±0.33d) than the control (C=3.00±0.0c) and the standard (S=1.00±0.58b). Z. zerumbet bioactive compounds, especially zerumbone, enhanced antifungal activity and seedling growth. Additionally, C. alata exhibits allelopathic effects that inhibit seed germination. Previous O. nivara germination studies reported low rates of 23.11% (dehusking) and 15.56% (dry heat). Our study achieved significantly higher rates (73.3-80%). Overall, both ratios of Z. zerumbet could be recommended as the best leaf extract to minimize fungal attack while increasing germination ability of O. nivara seeds. Keywords: Antimicrobial properties, Aqueous extracts, Microbial infection, Sustainable, Wild rice
Climate Change, Agriculture, and Economy: Evidence from a CGE Analysis for Sri Lanka
Agriculture has a significant influence on the Sri Lankan economy through its substantial contributions to Gross Domestic Product (GDP), foreign exchange earnings, and government revenue. However, rising climate change conditions such as high temperatures, erratic rainfall, and extreme weather events are increasing the vulnerability of the sector, thereby threatening the productivity and economic stability of the country. The broader macroeconomic and sectoral impacts of climate change have been assessed globally, especially in agriculture-dependent economies. In Sri Lanka the economy-wide impacts of climate induced agricultural productivity decline have been evaluated in only a limited number of studies. Hence, this study aims to address that gap by applying a static multi-sector Computable General Equilibrium (CGE) model. A Social Accounting Matrix (SAM) for 2021 was used to calibrate the CGE model. Prices, exports, household income and consumption, welfare, factor prices, and GDP composition were captured endogenously within the model through a set of behavioral and market clearing equations. Two distinct climate shock scenarios were simulated in the study as 5%, 10% and 20% productivity shocks across the agriculture sector in the first case and paddy- specific shocks of 5%, 18%, and 31% in the second case. Results indicate that agricultural productivity shocks generate sharp declines in exports and sectoral GDP contributions. Under the high shock scenario, vegetable exports declined by 47.2%, while GDP contributions from paddy, coconut and livestock also dropped significantly. Non-agricultural sectors showed negligible reductions indicating their weaker ties to agriculture. Factor price analysis indicated that labor prices drop more than capital prices. This highlights the labor intensity of the agriculture sector in Sri Lanka. At the macroeconomic level, welfare, household income and GDP at factor cost declined, with welfare falling by 1.08% at the high shock (20%) scenario. Similarly, targeted shocks on paddy showed considerable declines in welfare, income, and GDP. These findings highlight the urgent need for proactive and climate-resilient strategies to safeguard the long-term economic stability of the country. Keywords: Climate change, GAMS, General equilibrium, SAM, Static CGE
Sediment Organic Carbon and Nitrogen Storage Potential in Kalpitiya Lagoon Seagrass Meadows, Sri Lanka
Seagrass meadows are productive coastal ecosystems that provide important ecosystem services, including primary productivity, habitat provision, carbon sequestration, sediment stabilization, and nutrient cycling. Seagrasses have an ability to trap and bury organic matter within their sediments for long periods, making them effective coastal blue carbon ecosystems, with strong potential to contribute to global climate change mitigation. Although there is increasing global attention on seagrass-associated carbon dynamics, such research remains limited in Sri Lanka. Identifying this gap, this study aims to quantify the Sediment Organic Carbon (SOC) and nitrogen content in seagrass meadows of Kalpitiya Lagoon, to assess their role in the long-term storage potential of carbon and nitrogen. Sediment samples were collected by placing three 20 m transects perpendicular to the lagoon shoreline. A total of 12 sediment core samples (30 cm depth) were collected and subsampled into three depth intervals: 0-10 cm, 10-20 cm, and 20-30 cm. The SOC and nitrogen contents of samples were determined using a CHNS elemental analyzer. Enhalus acoroides and Halophila ovalis were the identified seagrass species within the study area. The results indicated a mean SOC content measured at 32.900±14.535 Mg C ha⁻¹ and a mean nitrogen content measured at 21.567±2.424 Mg N ha⁻¹. These values highlight the substantial accumulation of organic matter in Kalpitiya seagrass sediments, demonstrating the high potential of these ecosystems for carbon sequestration and nutrient retention. The findings provide a better understanding of the contribution of Sri Lankan seagrass meadows to global carbon dynamics. The observed SOC values are comparable to those of other seagrass ecosystems in Sri Lanka, and this is the highest seagrass-associated SOC value recorded in Sri Lanka, according to current literature. Seagrass ecosystems in sheltered lagoon environments often store large amounts of carbon due to restricted water movement, which facilitates sedimentation and the burial of organic matter over time. Additionally, the presence of considerable nitrogen content in sediment emphasizes potential environmental stress, likely due to excess nutrient input from pollution, which can lead to eutrophication and harmful algal blooms. Thus, regional conservation and restoration efforts are essential to protect these ecosystems in Sri Lanka. Keywords: Carbon sequestration, Conservation, Restoration, Sediment organic carbon, Seagrass meadows
Identification of Landslide Susceptible Zones of Nuwara Eliya District Using Geospatial Technologies
Landslides constitute a significant natural hazard in Sri Lanka, particularly prevalent in the Nuwara Eliya District where 1,560 individuals were affected and caused severe property damages in 2018. Identifying high susceptible zones in landslide-prone areas is crucial for effective disaster mitigation and management. This study employs a geospatial methodology based on freely accessible satellite and open data, with ArcGIS software utilized for advanced spatial analysis and cartographic representation. Determinant parameters for landslide susceptibility, identified through literature and applied in this study, includes slope, elevation, topographic wetness index, vegetation cover, and annual average rainfall. Weighted overlay analysis of these rasters indicated that 1,707.94 km² of the area in Nuwara Eliya District is high and moderate susceptible to landslides with the Nuwara Eliya Divisional Secretariat Division (DSD) exhibiting highest susceptibility, covering 81.48 km². Other highest susceptible zones include Ambagamuwa, Kothmale, Hanguranketha DSDs. The findings of this geospatial approach provide a basis for decision-making in developing structural mitigation strategies in high susceptible zones. The proposed approach offers a cost-effective, open-source solution that supports the development of proactive, non-structural mitigation measures in disaster management, aimed at preventing potential impacts from landslide hazards. Keywords: Landslide, Susceptibility, Geospatial analysis, Weighted overlay
Comparative Carbon Storage of Common Tree Species: A Study at University of Kelaniya Sri Lanka
Vegetation helps to combat climate change through the process of carbon dioxide sequestration. Different species of trees have different rates of growth resulting in significant differences in carbon sequestration potential. The objective of the present study was to assess the carbon storage potential in commonly occurring trees in the University of Kelaniya premises in Sri Lanka. Diameter and height of 269 trees were used as the basis of field data collection. For each tree, trunk Diameter at Breast Height (DBH) was measured at approximately 1.3 m above the ground, and the tree height was determined using a clinometer. Trunk mass was calculated by assuming the dry weight of the stem as 50% of the wet mass and the carbon content as 50% of the dry weight. Allometric equations were used to assess the carbon content. To determine the key carbon storage species, the Pareto Principle was applied. The findings provide evidence that Terminalia bellirica, Dypsis lutesenes, Ficus benghalensis, Delonix regia, Terminalia catappa, Artocarpus heterophyllus, Swietenia macrophylla, Azadirachta indica, Carallia brachiata, Filicium decipiens, Delonix regia, Mangifera indica, Pterospermum subcritolium, Syzygium cumini, Bridelia retusa from 44 tree species contribute up to ~80% of the cumulative carbon stock. Terminalia bellirica depicted the highest value of 2.4 kg C/m for the carbon per diameter unit followed by F. benghalensis (1.7 kg C/m), T. catappa (1.5 kg C/m), S. macrophylla (1.4 kg C/m), and A. heterophyllus (1.3 kg C/m). Therefore, identifying key carbon storage species and estimating carbon per diameter unit for tree species helps to determine which species contribute most efficiently to carbon sequestration across different size classes. It offers important implications for land-use systems where space is constrained. By integrating the species that demonstrate an ability to pack greater carbon with smaller size classes into urban forestry, it is possible to enhance carbon sequestration efficiency, contribute to climate change mitigation, and simultaneously promote biodiversity conservation within multifunctional landscapes. Keywords: Carbon sequestration, Climate change mitigation, Forestry, Keystone species
Unprotected Coastal Shrub Vegetation in the Eastern Coast of Sri Lanka: Impacts of Anthropogenic Disturbances and Predicted Sea Level Rise
A resilient coastal shrubland along the eastern coast of Sri Lanka remains unprotected due to human disturbance and jurisdictional gaps. This vegetation type was mislabeled as “bare land” by the Land Use Planning Department. It is vulnerable to human disturbance and sea-level rise. This study establishes a baseline to characterize vegetation dynamics and assess anthropogenic disturbances and rising seas. The study covered Batticaloa District. The vegetation was identified through ground-truthing and supervised classification, then mapped using GPS and GIS. 104 belt transects (10 m wide) were sampled at one-kilometer intervals, perpendicular to the coastline, lengths varied from 450 m to 4,750 m. Transect was divided into 50x50 m blocks, recorded: species composition, patch height, diameter, disturbance, and soil pH, EC, and salinity. GPS coordinates were logged at each sampling point. Across 71 study sites, 2,818.91 ha of coastal shrub vegetation was identified, supporting 1,849 types of patches. It is dominated by highly branched woody perennials that form clumped patches, with a mean height and diameter of 1.5m and 5m respectively. The vegetation is developing at a mean distance of 645 m from the high tide. Its distribution is constrained by soil pH, EC and salinity. Growth is limited when values exceed pH 8.18, EC 6.81 mS/cm, and salinity 3.26 ppt. The favorable ranges for survival are pH 3.85-8.18, EC 0.00-6.81 mS/cm, and salinity 0.0-3.26 ppt. Human disturbance was observed at all sites, averaging 61% per block. A projected 1 m rise in sea level is expected to push the vegetation landward by 45 m. This shift would result in the loss of 107 ha (4%) of shrubland across 34 sites (48%). Human disturbance and predicted sea-level rise threaten this century-old ecosystem. Given its ecological importance, urgent conservation measures and sustainable resource guidelines through stakeholder participation are essential. Keywords: Sea-level, Coastal, Vegetation, Disturbance
Influence of El Niño Southern Oscillation (Enso) Variation on Main Paddy Cultivation Seasons in Sri Lanka
The El Niño Southern Oscillation (ENSO) is a major climate driver that influences global weather patterns, with extensive effects on seasonal rainfall variability. Sri Lanka is a monsoon rainfall dependent country majorly for its paddy production as the staple food which is vulnerable to the influences of ENSO variation. The objective of this study was to understand the influences of ENSO events on the weather patterns in main paddy cultivation seasons (“Maha”- October to March and “Yala”- April to September) across major climatic zones of Sri Lanka which is Dry Zone (DZ), Wet Zone (WZ) and Intermediate Zone (IZ). This study analyzed the relationship between sea surface temperature-based ENSO Index (EI) at Niño 3.4 region, seasonal rainfall anomaly in the climatic zones and seasonal temperature anomaly over the period of 1980-2024. During the El Niño (ENSO positive) phase, first three-month (October to December) rainfall of Maha season (MS) exhibited a significant positive correlation with EI in DZ (r=0.58, p=0.001) and IZ (r=0.50, p=0.001), suggesting that El Niño conditions are associated with enhanced rainfall (DZ-18% and IZ-32%) in these regions during the 45-year period. However, during the La Niña years (negative phase), MS rainfall has decreased by 11%, 8%, and 24% in the DZ, WZ, and IZ respectively. Additionally, El Niño phases have reported a significant negative correlation (r=-0.33, p=0.02) with Yala season (YS) rainfall in the WZ, leading to a 10% decrease, while no significant relationship exists with rainfall in the other zones. Furthermore, the temperature exhibited a significant positive correlation between the EI and YS temperature (r=0.59, p=0.000), indicating that El Niño phases are associated with increased temperature during YS in Sri Lanka. Overall, these findings emphasize the strong influence of ENSO variability on seasonal climate associated with paddy cultivation, and its value for early agricultural planning and water resource management to strengthen climate resilience in Sri Lanka. Keywords: El Niño southern oscillation, Rainfall, Temperature, Paddy cultivation seasons, Climate resilience
Comprehensive Greenhouse Gas Emissions Assessment at the University of Sri Jayewardenepura: Establishing an Evidence Based Framework for Carbon Neutral Campus Operations
Universities worldwide face mounting pressure to quantify and reduce environmental impacts, yet comprehensive ecological footprint assessments remain scarce in South Asian institutions. The University of Sri Jayewardenepura, recognised as Sri Lanka's first carbon neutral university following the Centre for Sustainability Initiative (2019-2022), undertook an expanded greenhouse gas assessment to establish a framework for ongoing sustainability management aligned with Sri Lanka's Nationally Determined Contributions and institutional commitments. This study applied Greenhouse Gas Protocol standards to quantify Scope 1 (direct), Scope 2 (purchased energy), and Scope 3 (indirect) emissions for the main Nugegoda campus, serving approximately 15,000 students and 1,500 personnel during 2022-2025. The assessment adopted biocapacity accounting methodologies adapted from York University's Ecological Footprint Initiative, incorporating primary data on stationary combustion, electricity, fleet operations, waste, water, business travel, and commuting. Data sources included electricity billing records from multiple meters (2022-2024), generator diesel records showing 7,456 L consumed in 2025, solid waste data revealing annual generation of 520-614 collection cubes (approximately 780-920 t), water monitoring, fleet maintenance records, and travel expenditure. Preliminary quantification identified purchased grid electricity as the dominant Scope 2 source, contributing approximately 189 tCO2e annually based on 2023 consumption of 269,547 kWh and Sri Lanka's grid intensity of 0.7 kgCO2e/kWh. Solid waste generation was a significant Scope 3 contributor at approximately 391-461 tCO2e annually, whilst backup generators contributed 20 tCO2e in 2025. Partial quantification yielded 1,907 tCO2e from measured sources; however, excluding substantial Scope 3 categories like commuting, procurement, and food services suggests total emissions significantly exceed this figure. Recommendations include implementing renewable energy to reduce grid dependence, enhancing waste segregation and composting to divert organic waste, optimising backup generators through improved maintenance, establishing systematic commuting surveys, and developing procurement emission tracking. The assessment positions USJ to establish evidence-based reduction targets, maintain sustainability leadership in South Asia, and contribute methodological advances for tropical university carbon accounting. Keywords: Greenhouse gas emissions, Carbon accounting, Ecological footprint, Sustainable universities, Campus sustainability
Vertical Distribution of CO2 in Village, Urban, and Forest Environment: A Case Study from Gampaha, Sri Lanka
Understanding local variations in atmospheric Carbon Dioxide (CO2) concentrations is essential for climate research, urban planning, and ecological studies. This study investigates the vertical distribution of CO2 across three contrasting land-use types in Gampaha, Sri Lanka: village, urban, and forest environments. Measurements were conducted using CO2 concentrations were measured at six vertical heights: 0 m (ground), 1,2,3,4 and, 5 m. A portable HT2000 CO2 data logger (CO2 Accuracy +70 ppm or +3% of reading in 400 ppm-2000 ppm) was used for consistency across all sites within each land-use type. Results indicate clear land-use dependency, with the highest CO2 concentrations observed in traffic-heavy urban areas (up to ~606 ppm at ground level), intermediate levels in villages, and the lowest, more stable profiles in forested environments. The findings highlight the role of vegetation in buffering CO2 levels and the contribution of anthropogenic activities to near-ground accumulation. These results provide insights for urban design, microclimate management, and climate adaptation strategies in tropical regions. Results revealed that urban traffic areas exhibited the highest CO2 concentrations near the ground (up to 606 ppm), with a marked decline in concentration with increasing height, indicating localized emission hotspots and limited vertical dispersion. In contrast, forested environments demonstrated stable and lower CO2 levels across all heights, reflecting their role as carbon sinks. Village environments showed mixed trends, with residential areas displaying decreasing CO2 with height and paddy fields showing slight increases with the height, microbial activities in the muddy areas and the wind. The findings underscore the critical role of green infrastructure in moderating near-surface CO2 concentrations and improving air quality in tropical urban environments. This study contributes new empirical data to the under-researched area of vertical CO2 dynamics in South Asia and highlights the importance of integrating vegetation into urban planning to support climate adaptation and public health. Keywords: Carbon dioxide gradients, Vertical distribution, Land-use impacts, Urban-rural-forest comparison, Gampaha
Antimicrobial Properties of Mycelium Based Leather Producing Fungal Species Against Bacterial and Fungal Isolated from Leather Products
Leather is an expensive material with high susceptibility to microbial biodeterioration. Mycelium Based Leather (MBL) is a green alternative to animal-based leather. This study investigates fungal species with pre-evaluated potential to produce MBL, as a green alternative for inhibiting microorganisms isolated from deteriorating leather products. Cotton swab method isolated 5 fungal and 4 bacterial colonies from three leather products with visible microbial growth. Morphological and biochemical characteristics of the pure cultures were evaluated using Gram and Lacto Phenol Cotton Blue staining, microscopic imaging and Urease, Catalase and Cellulase tests. The antimicrobial efficacy of two MBL producing fungal species (T-1 and T-2) were evaluated against 4 bacterial (Suggestive Genera: Neisseria, Micrococcus, Staphylococcus and Acinetobacter) and 2 selected fungal species (Suggestive Genera: Penicillium and Geotrichum). Agar plugs method and dual culture assay were carried out to evaluate antibacterial and antifungal potential of T-1 and T-2. Chloramphenicol and Clotrimazole were used as the positive controls for anti-bacterial and anti-fungal assays, respectively. All tests were carried out in triplicates and statistical analysis was done using R software version 4.2.2. T-1 species demonstrated significant anti-bacterial effects against all 4 bacterial species with the highest average zone of inhibition (1.58±0.02 cm) against S5C1B (Micrococcus spp.) colony and showed significant anti-fungal activity with an average inhibition percentage of 58.84±3.3% against S5C2F (Geotrichum spp.) colony (p<0.05). Conversely, T-2 species did not show any significant antimicrobial activity against any of the tested colonies (p>0.05). The results of the study are suggestive of T-1 species as an excellent candidate for MBL production as it carries significant antimicrobial activities, which may contribute in excluding synthetic, hazardous, and expensive anti-microbial agents in mycelium culturing stages and post-material processing in mycelium-based leather industry. Keywords: Mycelium based leather, Anti-fungal, Anti-bacterial, Biomaterial
Variation of Foliage Chlorophyll Content with Maturity of Three Mangrove Species: Rhizophora mucronata, Bruguiera gymnorhiza, and Sonneratia caseolaris
Mangroves are highly productive coastal ecosystems whose primary productivity is governed by leaf-level photosynthetic activity, closely linked to chlorophyll concentration. Leaf chlorophyll is strongly associated with nitrogen allocation and serves as a reliable indicator of plant physiological status and stress. Accurate assessment of chlorophyll content is therefore essential for evaluating mangrove health and monitoring ecosystem degradation under changing environmental conditions. This study aimed to assess maturity-related variation in leaf chlorophyll content in dominant mangrove species. The study was conducted in the Malgasowitadeniya Mangrove Conservation Forest Reserve, Kalutara District, Sri Lanka, where Rhizophora mucronata (RM), Sonneratia caseolaris (SC), and Bruguiera gymnorhiza (BG) are the most abundant species. Three trees per species were selected across three circular plots. Leaf sampling and tagging were carried out during the rainy season in August 2024. Leaves within each whorl were labelled sequentially from the most mature (L1) to the youngest. Leaf morphological characteristics were recorded, and leaf colour was measured using a ‘Lovibond’ handheld spectrocolorimeter. Leaf chlorophyll content was quantified using a ‘CCM-2000 Plus’ portable chlorophyll meter and expressed in chlorophyll content index (CCI) units. Younger leaves exhibited higher chlorophyll concentrations compared to older, senescent leaves. Higher chlorophyll concentrations were recorded in the youngest leaves of BG (45.35±5.87 CCI), RM (33.36±8.93 CCI), and SC (32.57±2.32 CCI). In contrast, senescent leaves showed comparatively reduced chlorophyll levels, with values of 25.91±9.36 CCI in BG, 30.35±8.31 CCI in RM, and 28.85±3.73 CCI in SC. These findings demonstrate clear age-related patterns in leaf chlorophyll dynamics among mangrove species. The study provides valuable insights into mangrove physiological responses to environmental variability and contributes to the development of effective monitoring frameworks for assessing mangrove forest productivity and resilience under climate change. Keywords: Productivity, Young, Senescent, Monitoring, Stress, Physiology
Extraction and Characterization of a Red Pigment from Talaromyces verruculosus Isolated from Kalpitiya Lagoon, Sri Lanka
Colours play crucial roles in various aspects of life on Earth. Despite the inherent colouring capability of nature, synthetic dyes are being applied in almost every industry in the world, contributing to a diverse array of environmental and health issues. Therefore, there is a significant demand for top-notch alternatives capable of effectively replacing synthetic dyes. When considering sustainable alternatives, the dyes of fungal origin have been frequently highlighted over other plants or animal-based natural pigments. However, research on fungal pigments in Sri Lanka remains limited, with only a few studies reported to date. The prime goal of this present study was to investigate an effective method for the extraction of fungal pigment and characterization of the novel pigment product. Firstly, fungal cultures already preserved in the Department of Plant Sciences, University of Colombo, were screened for pigmented cultures (n=150). The selected pigmented fungus, Talaromyces verruculosus, was isolated from the lichen Rocella montagnei collected at the Kalpitiya Lagoon, Sri Lanka. Liquid state fermentation in a Potato Dextrose Broth medium was used to facilitate the synthesis of pigments. A metabolite was purified from culture broth with the aim of isolating an economically viable novel pigment. Following optimization of physical parameters of submerged fermentation, the pigment was extracted using ethyl acetate and purified by Thin-Layer Chromatography (TLC). The optimum fermentation conditions for achieving the highest pigment yield were determined to be a pH of 6.5 and a temperature of 32 ºC. Based on the results of the ANOVA test followed by Tukey's HSD post hoc test, the pigment exhibits remarkable thermal stability between 40 ºC and 80 ºC, with noticeable degradation beginning at temperatures above 90 ºC. Based on the Kruskal-Wallis rank sum test, the pigment remains stable across a pH range of 2 to 12. According to the UV-vis, FTIR, and NMR analyses, the pigment was chemically characterized as austrocortirubin which is a deep red, bioactive pigment from fungi, part of the anthraquinone aromatic polyketide family, with potential application in natural dyeing, pharmaceutical research, and bio-sustainable pigment production. Keywords: Red pigment, Submerged fermentation, Chemical characterization, Sustainability
Effectiveness of Assisted Natural Regeneration in Revitalizing Soil Carbon Stocks in Former Chena Lands
The global climate crisis highlights the critical role of forests as vital carbon sinks, with deforestation being a major driver of climate change. In Sri Lanka, a significant reduction in forest cover has threatened biodiversity and ecological stability, prompting the government to increase forest coverage. Assisted Natural Regeneration (ANR) has been promoted as a cost-effective, sustainable technique to restore degraded ecosystems, such as abandoned Chena cultivation, by facilitating natural succession. However, the long-term effectiveness of ANR in restoring key ecosystem functions, particularly carbon sequestration and soil carbon storage (SCS), compared to natural forests, remains inadequately studied. This research aimed to address this gap by investigating whether forest carbon dynamics differ across various restoration stages of ANR at IFS-Pophum Arboretum, Dambulla, and adjacent natural dry mixed evergreen forests. The study assessed how forest maturity influences carbon sequestration and compared the carbon sequestration capacity of natural forests with ANR plots (representing partial restoration and rehabilitation of abandoned chena cultivation) and naturally regenerated forests (no action). The study tested two null hypotheses that stated there is no difference in soil carbon content and sequestration capacity across different forest types: Natural Forest, old-growth restored forest, mid-growth restored forest, and naturally restored forest. Soil samples were collected from two depths (0-0.15 m and 0.15-0.30 m), and Total Organic Carbon was determined using a CHN elemental analyzer. SCS was calculated incorporating the Bulk density measurements obtained by Soil Core method. The results demonstrated that the natural forest had a significantly higher (One-way ANOVA: p<0.05) mean soil carbon stock (305.9±103.6 Mgha⁻¹) than all restored forest types, confirming its superior role as a carbon sink. Contrary to expectations, ANR forests (172.93±42.69 Mgha⁻¹) did not show a significant advantage in carbon storage over naturally regenerated forests (188.6±35.9 Mgha⁻¹); this suggests that human-assisted restoration in this dry zone context has not yet augmented carbon sequestration beyond natural recovery. Results have explained no significant difference between soil layers. Though the upper layer has a higher stock (218.3±73.3 Mgha-1) than the below layer (187.0±80.3 Mgha-1). Among the restored forests, old-growth stands (196.3±58.5 Mgha⁻¹) had higher carbon storage than mid-growth stands (164.09±28.05 Mgha⁻¹), indicating that maturity within restored plots positively influences carbon accumulation. These findings are crucial for informing Sri Lanka's forest policy and restoration strategies, highlighting that while ANR is a valuable tool, natural forests remain irreplaceable carbon reservoirs. Keywords: Carbon sequestration, Assisted natural regeneration, Soil carbon stock, Forest restoration, CHN analyzer
Cracking Plastic: Molecular and AI Driven Insights into Enzymatic PET Breakdown
Microplastic pollution, particularly from polyethylene terephthalate (PET), poses a growing environmental challenge. Among various mitigation strategies, enzymatic degradation has emerged as a promising and sustainable approach. However, the molecular mechanisms governing enzymatic PET breakdown remain poorly understood, limiting our ability to optimize or engineer more efficient biocatalysts. A deeper mechanistic understanding is essential not only for advancing plastic biodegradation technologies but also for enabling scalable, targeted interventions in real-world environments where conventional recycling methods fail. In this study, we computationally investigate the molecular-level interactions between PET and two key plastic-degrading enzymes: PETase and MHETase. Using molecular docking, we explore the binding conformations and interaction profiles of these enzymes with PET oligomers of defined lengths and monomeric compositions. Our analysis reveals stable enzyme–substrate complexes mediated by secondary-level interactions. Despite strong binding affinities, the catalytic degradation mechanisms remain partially unresolved. To further elucidate these mechanisms, we incorporate deep learning-based reaction prediction models trained on organic chemistry reaction data to identify plausible bond cleavage pathways and intermediate states. The AI-driven predictions suggest stepwise hydrolysis of monomer linkages, consistent with mechanistic features observed in similar hydrolases. This integrative computational framework offers new insights into the structural and mechanistic basis of PET biodegradation and supports the rational design of improved enzymatic systems for plastic waste management and removal of oil pollutants. Keywords: Microplastic, PET, Degradation, Modeling, Artificial intelligence
A Study on Estimating the Carbon Sequestration Effects of Wood Use in Japanese Buildings
Removing carbon from the atmosphere is crucial as a climate change mitigation strategy. Forests, in particular, have a significant carbon sequestration effect, and promoting wood utilization is expected to enhance this effect. This study estimates the carbon sequestration effect of wood utilization in Japanese buildings, which have a large volume of wood use. In Japan, seismic-related laws have been revised multiple times. Few buildings currently meet the standards required to comply with the latest regulations. Many structures require seismic retrofitting. Structural components like columns can extensively utilize wood, enabling long-term carbon sequestration. This study estimates the amount of carbon that can be sequestered when wood is used for seismic retrofitting in Japan. It also evaluates the extent to which this can sequester atmospheric carbon. Beyond structural components, wood can be used in furniture such as desks and shelves. This is also one method capable of long-term carbon sequestration. This study verifies how much atmospheric carbon can be sequestered through wood utilization in Japanese buildings-specifically, by using wood for both structural materials and furniture. The average Japanese home has an area of approximately 100 m², and a wooden home uses about 30 to 40 cubic meters of timber. This equates to roughly 50 to 70 logs of cedar or cypress. Japan has a total of approximately 65,000,000 housing units. Assuming 50% are wooden structures, and that 40% of these meet the old seismic standards, it is estimated that 13,000,000 homes require seismic retrofitting. Adding 30% more timber for reinforcement in these homes would sequester an estimated 151,666,667 cubic meters of carbon fix in Japan. Keywords: Carbon sequestration, Wood utilization, Seismic retrofitting, Japanese buildings, Climate change mitigation
Assessment of the Natural Durability of Timber Species Through Graveyard Method
The natural durability of timber may be defined as inherent resistance of timber to attack by wood deterioration agents such as wood decaying fungi and wood destroying insects. Classification of wood durability can be done using different test methods and durability classes of the tested timbers can be differed due to the tested materials, applied test, assessment, and calculation method. Wood durability and the effectiveness of wood preservatives are determined using graveyard method according to BS EN 252 standard. In the present ongoing study, four natural durability classes were identified as very durable class (>10 years), durable class (5-10 years), moderately durable class (2-5 years) and not durable class (0-2 years). With the purpose of durability classification, selected 48 timber species were tested by using the graveyard test at the State Timber Corporation, Kaldemulla Timber Complex (Latitude: 6.8059614, Longitude: 79.8758562) to test wood durability. Two adjacent plots were used to conduct research with 5 replicates in each species. Those were 240x240 cm2 and 180x240 cm2 in size. A test stake was considered to have reached the end of its useful service life when 50% of its cross-sectional area was destroyed. These results may vary due to environmental factors such as the type of soil, rainfall, and weathering condition which may affect the biodegradation activities on the test specimens according to previous research data. According to the results from 10-year observation period, only one species falls under very durable class, it was Diospyros ebenum (Ebony). Whilst 17,23 and, 8 species were categorized as durable, moderately durable, and not durable (Perishable) accordingly. The data indicates that less durable timber species such as Ahu, Albizia, Lunumidella, and Pinus began to decay within four months of being buried, whereas durable and very durable species such as Kahata, Kaluwara, and Kumbuk required more than three years to exhibit signs of decay. It shows that graveyard test requires longer period (more than 3 years) to conclude the durability classes of timber species. Keywords: Field test, Graveyard method, Natural durability, Wood decay
Phytochemical Composition and Antioxidant Potential of Gracilaria verrucosa and Gracilaria multipartita
Red algae play a significant role in free radical scavenging due to their abundance of phenolics and flavonoids, which contribute to cosmeceutical benefits. Such natural compounds support the development of bio-based products while aligning sustainable goals for environmental conservation. Also, there are very limited studies on Sri Lankan red algal species. In this study, two algal species, Gracilaria verrucosa (Trincomalee) and Gracilaria multipartita (Weligama, Matara), were collected with the permission from the Department of Wildlife Conservation (Permit No: W/3/2/113/2024) to evaluate their potential as natural antioxidants. Samples were shade-dried for three days, ground, and extracted using 80% methanol. The total phenolic content (TPC) was quantified using the Folin-Ciocalteu method with a gallic acid standard curve (r²=0.9905). Antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay with each sample triplicated (n=3) and incubated for 30 minutes before absorbance was measured at 517 nm. The TPC of G. verrucosa and G. multipartita was found to be 4.94±0.13 and 3.43±0.23 mg GAE/g extract, respectively. G. verrucosa showed a stronger antioxidant response with 82.9±0.9% DPPH radical scavenging activity at 2 mg/mL compared to 61.5±1.3% in G. multipartita. Trolox was used as the positive control, which results in 93.44±0.45% scavenging activity. G. verrucosa demonstrated a significantly higher scavenging activity value among two algal extracts (p<0.05), reflecting higher antioxidant efficiency. The methanol extract of G. verrucosa exhibited higher phenolics than G. multipartita (p<0.05). The results revealed that both algae species contain notable levels of phenolics and bioactive constituents. This suggests that phenolic compounds may play a more dominant role in the radical scavenging capacity of these extracts. Beyond the bioactivity of these red algae, this research increases the significance of utilizing biological materials for value-enhanced, sustainable innovations. Keywords: Red algae, Gracilaria sp., Antioxidant activity, Total phenolic content, Sustainable biological materials
Impact of Intra Specific Competition on Carbon Stock Accumulation in Lumnitzera racemosa: A Case Study Using the Hegyi Index
Mangrove ecosystems are highly efficient natural carbon sinks, playing a critical role in climate change mitigation by sequestering and storing large amounts of atmospheric carbon. Lumnitzera racemosa had formed a monospecific stand in a regenerated area of Rekawa Lagoon, Sri Lanka, which regenerated over 12 years. Intraspecific competition is a critical ecological factor influencing biomass accumulation and carbon storage in mangrove ecosystems. This study aimed to evaluate the impact of intraspecific competition on carbon stock accumulation in L. racemosa using the Hegyi Competition Index (HCI). Fieldwork was carried out across 15 systematically established plots of 5×5 m, with all individual trees measured for diameter at breast height and height. Biomass components, including stem, leaf, root, above ground, and total biomass were estimated using species-specific allometric equations, and carbon stocks were calculated using a standard conversion factor. The Hegyi index was calculated for each tree based on the proximity of neighboring conspecifics to determine competition intensity. Regression analysis results indicated a generally negative, but not statistically significant relationship between competition intensity and total carbon stocks of L. racemosa. Total carbon ranged (574-1,732 Mg C ha⁻¹), with stem carbon (40.79-256.67 Mg C ha⁻¹) contributing most, followed by root carbon (30.59-193.20 Mg C ha⁻¹), leaf carbon (25.41-198 Mg C ha⁻¹), and above-ground carbon (100.20-621.51 Mg C ha⁻¹). Specifically, total carbon (Coef=14,074; p=0.104), stem (-1,919; p=0.147), root (-1,417; p=0.141), leaves (-198; p=0.139), and above-ground (-4,649; p=0.136) all decreased with higher competition. These findings indicate that intraspecific competition showed a negative but non-significant effect on carbon accumulation. These insights can guide mangrove restoration and management practices, such as optimizing tree spacing and density, to enhance carbon sequestration, coastal ecosystem resilience, and climate change mitigation. Keywords: Lumnitzera racemosa, Mangrove, Carbon stock, Intra-specific competition, Hegyi Index
Effectiveness of Assisted Natural Regeneration in Revitalizing Soil Microbial Communities in Former Chena Lands
Restoration of abandoned lands such as old Chena cultivations in the dry zone, enhances soil quality by revitalizing microbial communities. Microbial biomass carbon is the most active part of soil organic matter, and it is a good indicator of soil health as increased Microbial activity correlates with enhanced potential of carbon storage. Current study quantifies Microbial Biomass Carbon (MBC), as a percentage of total Soil Organic Carbon (SOC) in both restored and natural forests. NIFS-Dambulla Arboretum, once an abandoned Chena site restored using Assisted Natural Regeneration (ANR), including old-growth plots (62 years), mid-growth plots (35 years) and naturally regenerated plots (35 years), compared to adjacent natural forest were sampled adopting a randomized design. Only the upper soil layer (0-15 cm) was analyzed, given the rapid decline in microbial biomass and rate of microbial activity with soil depth. Five composite samples were taken from each plot. It was hypothesized that the Microbial Biomass Carbon content of Natural Forest (NF) was higher than the restored forests (H1). Soil microbial biomass carbon percentage (MBC%) was quantified using the chloroform fumigation and extraction method. Moreover, Soil Moisture was determined using a gravimetric method to correlate with MBC%. One-Way ANOVA for MBC% (p<0.001) indicated a significant difference between the five groups, accepting the alternative hypothesis (H1). Tukey HSD grouped Old-growth restored forest (Mango dominant) (0.1755±0.22), Old-growth restored forest (Rehabilitated without Mango Plants) (0.1506±0.01), and Natural forests (0.1359±0.01) together, depicting no significant difference between those three forest types. The Mid-growth restored forest (0.0575±0.04) and the naturally regenerated forest (0.0770±0.01) showed significantly lower MBC% than the Old-growth forests and NF. There was a strong, significant positive correlation between soil moisture content and MCB% (Pearson's Correlation: R= 0.870, p<0.001). Soil moisture content is important as microbial activity is directly influenced by soil moisture content. It can be inferred that the long-term ANR can effectively rehabilitate soil microbial communities, allowing them to return to their natural state. Keywords: Soil carbon, Assisted natural regeneration, Chena restoration, Revitalizing soil microbes, Microbial biomass carbon, Soil moisture
Development of An Indigenous Bacterial Consortium for Cellulase Production in Sri Lanka: A Step Towards a Greener Economy
Cellulase is one of the most important enzymes which are broadly utilized in different industrial settings including the food industry, paper and pulp industry, textile industry, brewing and wine industry. However, in Sri Lanka the cellulase demand completely relies on the imported cellulase enzyme. Therefore, the present study focuses on the development of locally isolated novel bacterial consortium to produce cellulase enzymes. For the study cellulase producing bacteria were isolated from the two types of compost samples which include municipal solid waste compost in Nagoda and homemade compost collected from Alawwa. For the study, two different types of fresh compost samples were used including municipal solid waste compost and homemade compost which had the pH 6.5±0.1, 6.9±0.2 and temperature 28.5±0.1 ºC and 29±0 ºC respectively. The isolation of bacteria was carried out following the standard pour plate and streak plate assay on the nutrient agar medium and the screening of cellulase positive bacteria was carried out using Carboxymethyl Cellulose (CMC) agar medium. The best potential isolates were used to prepare the bacterial consortia (n=10) followed by the antagonistic assays and the total crude enzyme production of each consortium were evaluated based on the standard 3,5-dinitrosalicylic acid (DNS) assay. The best potential isolates were identified following the standard biochemical tests, including catalase, urease, starch hydrolysis and Gram staining to preliminary identification of the bacterial genera. Based on the results, 20 morphologically different bacterial colonies were isolated from compost samples and out of those, 6 were cellulase positive. Out of all prepared consortia (n=10), the highest cellulase activity (0.0682 U/mL) was recorded by a consortium comprising the bacteria Actinomycetes spp., Cytophaga spp. and Cellulomonas spp. However, commercial bacterial cellulase activity levels were ranged between 1 U/mL to 5 U/mL. Therefore, optimization of the prepared consortium for cellulase enzyme production will be carried out as a further study. Based on the statistical analysis conducted using linear regression, it was revealed that the synergistic cellulase activity in which isolates are combined was significantly (p=0.00147) greater than the single cellulase production by isolates. In contrast, the cellulase enzyme produced by this consortium is potentially suitable for the fabric and food industry in Sri Lanka as a greener approach towards the circular bio economy. Keywords: Bacterial consortium, Cellulase activity, DNS method, CMC agar method
Assessment of Timber Seasoning Practices and Challenges in Furniture and Joinery Manufacturing Industries: A Survey-Based Study in Western Province, Sri Lanka
Timber seasoning is a vital process that influences the quality, durability, and performance of timber-based end products in furniture and joinery manufacturing that produces end products such as dining furniture, bedroom sets, and living room products. This study examined existing timber seasoning practices, monitoring methods, and operational challenges faced by furniture and joinery manufacturers in the Western Province of Sri Lanka. A structured questionnaire survey was conducted among timber-based manufacturing companies located in the Colombo, Gampaha, and Kalutara districts, covering company profiles, commonly used timber species, seasoning methods, kiln types, monitoring techniques, drying schedules, challenges, and seasoning defects. Data were analysed using graphical methods to identify trends and prevalence rates. The results showed that medium-scale enterprises dominated the sector, representing 43.3% of respondents, while 33.3% had operated for 11-20 years. Traditional boiler-type kilns were the most used seasoning method (70.0%), followed by air seasoning, with limited adoption of modern dehumidifying or electric kilns. Monitoring relied mainly on manual methods, with moisture meters used by 86.7%, while 76.7% followed specific drying schedules. Major challenges included lack of skilled operators, high energy costs, poor schedules, inadequate monitoring, equipment shortages, and rushed drying, resulting in common defects such as bow warping (56.7%), cup warping, and end checks. The study concludes that inadequate seasoning practices, absence of national standards, and limited technical capacity contribute to quality issues, highlighting the need for operator training, standardized schedules, energy-efficient technologies, waste wood utilization, and national timber drying standards to improve product quality and export competitiveness. Keywords: Timber seasoning, Kiln drying, Drying defects, Furniture industry, Joinery manufacturing, Western province, Sri Lanka
Survey on the Usage of Forest Wood in Paediatric Ailments by Residents in Polikandy, Jaffna
Traditional health practices are strongly rooted in rural communities, where forest wood is widely used in paediatric care. In Polikandy, Jaffna, caregivers rely on fumigation, decoctions, and topical preparations, yet systematic documentation of prevalence and socio-cultural factors is limited. This study assessed patterns, determinants, and caregiver awareness, with secondary aims of identifying ailments treated. A community-based cross-sectional survey was conducted from March to August 2025 among caregivers of 98 children under 12 years using a pre-tested questionnaire. Overall, 95% of households reported forest wood use. Six species were identified: Aquilaria agallocha, Cedrus deodara, Pterocarpus santalinus, Coscinium fenestratum, Santalum album, and Tinospora cordifolia. All were perennial, comprising two large trees, two small trees, and two climbers. One-third belonged to Menispermaceae, while others were from Thymelaeaceae, Pinaceae, Leguminaceae, and Santalaceae. About half showed diuretic activity, while diaphoretic, stimulant, and alterative effects were also noted; essential oils and berberine were frequent constituents. Applications included fumigation for respiratory illness, decoctions for digestive, febrile, genitourinary, and ear conditions, and ash for skin infections. Usage was highest among low-income families, larger households, and those with limited access to modern healthcare. Caregivers cited accessibility, cultural beliefs, and affordability as primary reasons for use. Awareness of potential risks, including smoke inhalation and improper dosage, was limited (3% of respondents). This study concluded that there are six forest woods which are used in Siddha system for various Siddha formulations. Further scientific studies about forest woods should be performed in future. Keywords: Forest wood, Paediatric ailments, Traditional medicine, Siddha formulations, Pharmacological action
Exploitation of Spirogyra sp. as an Alternative Raw Material for Sustainable Paper Production
The global paper industry relies predominantly on wood-based cellulose, resulting in substantial environmental burdens associated with deforestation, chemical-intensive pulping, and the discharge of polluted effluents. This study evaluates Spirogyra sp., a rapidly growing filamentous green alga, as a lignin-free alternative raw material for sustainable paper production within a green chemistry framework. The objectives were to culture and optimize the growth of Spirogyra sp., minimize the use of toxic chemicals in processing, produce algal paper sheets, and evaluate their physicochemical and mechanical properties. Spirogyra sp. cultures were optimized using three growth media, CHU 10, BBM, and 3N BBM over a 6-day period (initial inoculum ~10 mg). Growth in 3N BBM produced the highest biomass increase (10.2±0.1 mg to 12.7±1.2 mg), whereas CHU 10 supported minimal growth, declining to 3.1±1.0 mg by day 6. ANOVA indicated significant differences among treatments (p<0.05). Further optimization using a 100 mg inoculum (n=16) showed maximal biomass accumulation at 72-96 h (137.9±4.9 mg), defining the optimal harvest window. Scaling cultures to 500 mL was successful, with dissolved oxygen identified as a limiting factor. Pigment removal using hot saturated salicylic acid solution and fibre softening with dilute fabric softener solution enabled lignin-free paper sheet formation using a deckle and mould process. The resulting sheets exhibited a grammage of 182.4±1.6 g/m2, thickness of 0.32±0.01 mm, moisture content of 11.48±0.47%, density of 0.563 g/cm3, and bulk of 1.776 cm3/g. Long filament lengths (up to 5 cm) contributed to high grammage, although tensile strength remained low (0.4416 N; 29.44 N/m). Blending Spirogyra sp. fibres with softwood pulp improved mechanical properties, demonstrating the potential of algal biomass as a supplementary resource for sustainable paper manufacturing. Keywords: Spirogyra sp., Algal cellulose, Sustainable paper production, Alternative fibre, Environmental impact
Effect of Timber Seasoning Practices on Occurrence of Seasoning Defects in Sri Lankan Furniture Manufacturing Industry
Wood is a primary natural raw material used in Sri Lanka’s established furniture manufacturing industry for producing value-added products such as tables, chairs, cabinets, and flooring due to its aesthetic appeal, strength, and durability. However, wood is a hygroscopic material, and fluctuations in moisture content (MC) cause dimensional changes that can lead to instability and increased susceptibility to decay, particularly at high MC levels. Timber seasoning is therefore essential to reduce MC to an acceptable range of 8-12% through air seasoning or kiln seasoning under controlled conditions of temperature, relative humidity, and airflow. Improper seasoning practices can result in defects such as checks, splits, and warping, which reduce product quality and economic value. This study evaluated the occurrence of seasoning defects in three commonly used furniture timber species in Sri Lanka, namely teak (Tectona grandis), mahogany (Swietenia macrophylla), and pine (Pinus caribaea), under different seasoning practices. Timber planks measuring 1800×150×25 mm3 were subjected to five seasoning practices, including air seasoning and four different kiln seasoning methods. Defects were qualitatively assessed through visual inspection to determine the presence or absence of surface and end checks, surface and end splits, and warping defects such as cup and bow. Pearson Chi-square and Likelihood Ratio tests were conducted using Minitab to assess the association between seasoning practices and defect occurrence. The results revealed a significant association between seasoning practice and defect occurrence (Pearson χ² (4, N=900)=144.337, p<0.001; Likelihood Ratio χ² (4)=157.456, p<0.001), indicating non-independence. The highest defect presence was observed in one kiln practice (31.85%), while air seasoning showed the lowest defect presence (5.22%) and the highest defect absence (30.95%). The findings highlight the strong influence of seasoning practices on defect distribution and emphasize the need for optimized kiln control, standardized seasoning schedules, and improved technical training to enhance timber quality in Sri Lanka’s furniture manufacturing industry. Keywords: Timber, Moisture content, Wood quality, Timber seasoning, Kiln drying, Air seasoning, Seasoning defects, Furniture industry, Sri Lanka
Carbon Sequestration Potential of Medicinal Plants Used in Siddha Pharmacology: A Dual Role in Healing and Climate Mitigation
Traditional medicine systems like Siddha medicine offer untapped potential for climate change mitigation through their reliance on carbon sequestering medicinal plants, yet this dual environmental therapeutic benefit remains largely unquantified. This study quantified the Above Ground Biomass (AGB), carbon stock, and CO2 sequestration potential of twelve commonly used Siddha medicinal plants in Trincomalee, Sri Lanka, comparing carbon storage capacity among growth forms to identify priority species for climate-smart herbal cultivation. Field data collection was conducted over four weeks (June-July 2025), measuring Girth at Breast Height (GBH), Diameter at Breast Height (DBH), and tree height for five tree species (Terminalia arjuna, Azadirachta indica, T. bellirica, Phyllanthus emblica, and Strychnos potatorum), five shrub species (Caesalpinia bonducella, Ricinus communis, Adhatoda vasica, Cassia alata and C. auriculata), and three herbaceous species (Alpinia galanga, Zingiber officinale and A. officinarum). AGB was calculated using standard allometric equations, carbon stock estimated at 50% of AGB, and CO2 sequestration potential determined using molecular weight ratios. Statistical analysis revealed significant differences in carbon sequestration among species (F11,48=42.73, p<0.001) and growth forms (F2,9=156.8, p<0.001). T. arjuna demonstrated the highest individual sequestration potential (340.2±25.1 kgCO2eq per plant), followed by A. indica (219.8±75.6 kgCO2eq per plant). Tree species exhibited superior individual performance (mean: 175.6±89.4 kg CO₂eq per plant), while area-based calculations revealed competitive sequestration rates: trees (52.7-136.1 tCO2eq ha⁻¹), shrubs (41.7-92.0 tCO2eq ha⁻¹), and herbs (17.6-46.2 tCO2eq ha⁻¹). Compared to previous studies on medicinal plants, these sequestration rates are comparable to or exceed those reported for Andrographis paniculata (0.8-2.1 tCO2eq ha⁻¹) and approach conventional agroforestry systems (40-150 tCO2eq ha⁻¹), demonstrating the significant climate mitigation potential of medicinal plant cultivation. This study provides scientific evidence supporting the integration of Siddha medicinal plant cultivation into climate mitigation strategies while maintaining traditional therapeutic practices, establishing a framework for climate-smart cultivation that serves dual purposes in healthcare delivery and environmental conservation. Keywords: Carbon sequestration, Climate mitigation, Environment, Medicinal plants, Siddha pharmacology
Comprehensive Study of Functional, Biochemical and Antibiotic Resistance Profile of Endophytic Bacteria in Nymphaea stellata
Nymphaea stellata, the blue water lily, is an ecologically and culturally significant aquatic macrophyte native to South and Southeast Asia. Despite its well documented medicinal and phytochemical properties, the endophytic bacterial communities within its root and stem tissues remain largely unexplored. Endophytes, nonpathogenic microorganisms inhabiting plant tissues, play crucial roles in promoting plant health, enhancing stress tolerance, and producing bioactive metabolites. This study aimed to isolate and characterize culturable endophytic bacteria from surface sterilized root and stem tissues of N. stellata. The isolates underwent morphological, gram staining, and biochemical characterizations, including enzymatic assays (cellulase, amylase, catalase, and urease) and antibiotic susceptibility testing against ciprofloxacin, erythromycin, and azithromycin. Based on results, thirteen bacterial strains were isolated and identified predominantly as members of the genera Cytophaga, Cellulomonas, Bacillus, Clostridium, Enterococcus, and Curtobacterium. Notably, Cellulomonas spp. showed the highest cellulolytic activity, with a cellulase halo diameter of (7.37±0.06 cm) and strong amylase production with (9.07±0.15 cm) halo diameter, alongside other potent amylase producers within the Enterococcus and Cytophaga taxa. Catalase activity was weakly expressed, primarily among Bacillus related strains, whereas urease activity was negligible across all isolates. Conversely, Cytophaga spp. exhibited pronounced resistance, with minimal inhibition zone diameters of (0.75±0.01 cm) and (1.60±0.06 cm) against erythromycin and azithromycin, respectively, while Bacillus subtilis group isolates showed complete resistance to erythromycin. Comparatively root derived bacterial endophytes exhibited greater enzymatic diversity and stronger polysaccharide degrading capabilities than stem derived bacterial endophytes, which in turn displayed more pronounced antibiotic resistance patterns. These contrasting profiles suggest functional specialization driven by their respective microenvironments, the sediment exposed root versus the submerged stem. Overall, the results reveal that N. stellata hosts metabolically versatile bacterial endophytes capable of producing industrially relevant enzymes, such as cellulase and amylase, while simultaneously exhibiting significant resistance to commonly used antibiotics. The high cellulolytic and amylolytic activity of Cellulomonas spp. and the multidrug resistance of Cytophaga spp. and Bacillus spp. isolates highlight their dual potential as bioresource candidates for biotechnological applications and as important indicators in environmental antimicrobial resistance surveillance. These findings provide a valuable insight on the prevalence and ecological dynamics of endophytic bacterial communities in N. stellata along with their antibiotic resistance propagation in aquatic ecosystems. Keywords: Nymphaea stellata, Endophytic bacteria, Aquatic microbial community, Antibiotic susceptibility
Optimizing Shoot Proliferation in Musa acuminata (Suwandel Banana) Via Short-Term Benzylaminopurine (Bap) Treatment for Efficient Micropropagation
The Suwandel banana (Musa acuminata, AAB group) is a unique traditional Sri Lankan cultivar, highly valued for its nutritional and aromatic qualities. Its conventional propagation leads to low rates of multiplication, vulnerability to diseases, and limits large-scale production. Micropropagation provides an efficient and reliable approach for the rapid multiplication and conservation of this valuable local banana variety. Therefore, the present study aims to evaluate the effects of BAP treatments on in vitro shoot multiplication of Suwandel banana. One-month-old in-vitro banana clumps (1 cm2) were used as explants and cultured on MS media series, supplemented with a constant 0.5 ppm of L-Ascorbic acid and varying concentrations of BAP (0,0.5,1.0,1.5,2.0,2.5 and, 3.0 ppm). After the first bud appeared, explants were transferred to MS medium with constant 1.0 ppm of Indole-3-Acetic Acid (IAA) and varying concentrations of BAP (0,1.0,2.0,3.0,4.0,5.0 and, 6.0 ppm). The experiment followed a completely randomized design with three replicates per treatment, and each replicate consisted of four explants. Data were analyzed using one-way ANOVA followed by Tukey’s post-hoc test at a significance level of p≤0.05 in SPSS. Results showed that the first shoots emerged from the explant within three weeks on 1.5 ppm BAP initiation medium, and others took more than four weeks. After six weeks, shoot proliferation increased significantly with rising BAP concentrations, with 4 mg/L BAP producing the highest response. This treatment resulted in an average of 4.50±0.8 buds per explant and a shoot height of 4.40±0.75 cm, with a 100% survival rate, which was significantly higher compared to all other concentrations. These findings indicate that short-term BAP treatment is an effective strategy for rapid in-vitro shoot induction of Suwandel banana, which is essential for fast mass propagation. Further optimization of growth regulator regimes and acclimatization protocols is recommended to enhance plantlet quality, field establishment, and large-scale propagation efficiency. Keywords: Musa acuminata, Micropropagation, N6-benzylaminopurine, In-vitro culture, Plant growth regulators
Ethnobotanical Study of Siddha Medicine in Kokkavil, Sri Lanka
Traditional systems of medicine, such as Siddha, rely heavily on medicinal plants as core therapeutic resources. Shaped by ecological availability, cultural beliefs and centuries of empirical knowledge, these practices link biodiversity with human health. In regions like the Northern Province of Sri Lanka, documenting ethnobotanical knowledge is essential for preserving traditional practices and evaluating ecological sustainability and pharmacological potential. This study explored the ethnobotanical characteristics, therapeutic applications and ecological implications of medicinal plants used in Siddha Medicine in Kokkavil, Kilinochchi District. Data were collected through belt transect sampling (five 500 m10 m plots) and semi-structured interviews with local healers and knowledgeable community members. Plant specimens were identified and information recorded on local names, morphology, life span, plant parts used, therapeutic actions and targeted physiological systems. A total of 79 species from over 30 families were documented. Fabaceae (15.19%) and Euphorbiaceae (11.39%) were the most represented among the 30 reminded families. Herbs (34.18) were the dominant life form and perennials (71.79%) indicated ecological stability. Leaves (22.36%) were the most frequently used part, suggesting sustainable harvesting, while roots (17.39%) and whole plants (12.42%) raised ecological concerns. Common therapeutic actions included diuretic (8.23%), astringent (7.82%) and tonic (7.41%) mainly targeting the gastrointestinal (21.17%), cardiovascular (16.99%) and nervous (13.65%) systems. The findings highlight a rich Siddha knowledge system that integrates biodiversity and pharmacological insight. Whereas most practices are sustainable, some destructive harvesting practices do occur, underlining the need for conservation. This calls for ethnobotanical research for health, medicine, and environmental stewardship. Keywords: Kokkavil, Sri Lanka, Medicinal plants, Siddha medicine, Sustainable harvesting
Proximate composition, fatty acid and mineral profiles of Trichadenia zeylanica Thwaites nuts: from traditional use to scientific validation
Trichadenia zeylanica Thwaites is a plant endemic to Sri Lanka, belongs to the family Achariaceae. It’s commonly known as “Tholol” among the rural communities, and nuts are traditionally consumed as a delicacy. Despite its ethnobotanical uses, this species remains underexplored, and studies evaluating its nutritional potential have not yet been conducted. This study aimed to assess the nutritional composition of T. zeylanica nuts by analysing their proximate composition, fatty acid profile and mineral content. Samples were collected from Weddagala, Kalawana, Sri Lanka (6.4387719 °N, 80.4082348 °E), and subjected to proximate analysis with standard protocols. Fatty acid methyl esters (FAME) were prepared and analysed through gas chromatography-mass spectrometry (GC-MS). Inductively coupled plasma–mass spectrometry (ICP-MS) was utilized to evaluate mineral composition. Proximate analysis showed, nuts are rich in lipids, with a high crude fat content of 56.66±1.36%. These nuts also accounted for 17.53±0.12% of crude protein in their dry weight, serving as a notable plant-based protein source. The carbohydrate content was relatively low at 5.26±1.62%, complemented by a crude fibre content of 5.31±0.09%. The moisture content was 15.12±4.27% and the ash content was 2.55±0.28%. The fatty acid profile showed a composition dominated by saturated fatty acids (SFAs), which constituted over 62% of the total fat content. Palmitic acid was the most prominent SFA. Nuts also consisted 37% of unsaturated fatty acids, most abundantly with linoleic acid. The complex lipid profile warrants further investigation into its health implications. The mineral composition revealed a distinctive and complex profile. The seeds were rich in certain trace elements, such as Rubidium (31.5±0.339 µg/g) and Vanadium (27.4±0.189 µg/g), which are rarely reported in common edible nuts. Essential minerals such as Zinc (7.83±0.574 µg/g) and Copper (3.54±0.135 µg/g) were present at moderate levels. However, the analysis detected presence of heavy metals, including Arsenic, Cadmium, and Lead at trace levels which are below the recommended values. In conclusion, T. zeylanica seeds represent a promising, nutrient-dense wild food source, characterized by high levels of fat and protein, a unique mineral profile, and a complex fatty acid composition. The study scientifically validates nutritional composition and emphasizes the potential for developing of T. zeylanica seeds into a functional food or nutritional supplement through further studies including toxicity assessments. Keywords: Fatty acid profile, Mineral analysis, Nutritional potential, Proximate composition, Trichadenia zeylanica.
In Vitro Analysis of Synergistic Anti-Inflammatory Effect of Ipomoea pes-caprae (Binthaburu) and Scaevola taccada (Thakkada) Methanolic Leaf Extract as a Polyherbal Preparation
Diverse flora in coastal biomes not only protects shorelines from erosion, supporting biodiversity, but also possess medicinal value. These plants are often neglected, removed for coastal development, or undervalued. To advocate on conservation, it is vital to validate the said medicinal properties and cultural significance, demonstrating value to society. Ipomoea pes-caprae and Scaevola taccada are abundantly found in coastal areas of Sri Lanka, with individually documented anti-inflammatory properties. To add to the limited scientific work on synergistic anti-inflammatory potential, of the said two species, this study was conducted to analyse, combined anti-inflammatory and phytochemical properties of methanolic leaf extracts. Leaves were collected from the coastal area of Gampaha district and methanolic leaf extracts were prepared as A (I. pes-caprae), B (S. taccada), with three combinations, as C (A:B;1:1), D (A:B;1:2), E (A:B;2:1). Dilution series of 0.04×10-1 g/mL-0.04×10-5 g/mL were prepared using all 5 preparations. Egg albumin denaturation assay for anti-inflammatory analysis and phytochemical tests (Phenolic, Terpenoids, Flavonoids, Alkaloids and Tannins) were conducted. All tests were done in triplicates and statistical analysis was done using via R version 4.4.3 software. Significantly higher anti-inflammatory activity percentages of all 5 extracts (A- 86.8%; B-102.5%; C-63%; D-86.2%; E-62.3%) were demonstrated at 0.04×10-1 g/ml, compared to the positive and negative controls (p<0.001). Of the tested preparations, S. taccada demonstrated the highest anti-inflammatory potential individually, whereas I. pes-caprae individually and mixed preparation of 1:2 ration showed similar second highest anti-inflammatory properties. Presence of flavonoids and phenolics was demonstrated in all five extracts. There was no significant increase of anti-inflammatory activity compared to the individual extracts, due to synergistic activities, of the tested ratios. However, further research on investigating different extracting procedures, and different ratios of the two extracts, may yield more potent compounds with anti-inflammatory effects, leading to potential drug leads. The study emphasises the ecological and pharmacological significance of these coastal plant species by confirming their pharmacological relevance, promoting conservation and stimulating further research for sustainable drug discovery. Keywords: Ipomoea pes-caprae, Scaevola taccada, Anti-inflammatory activity, Synergistic effect, Coastal medicinal plants
A New Distribution Record of Acrotrema dissectum Thwaites (Dilleniaceae); A Critically Endangered Endemic Plant Species in Sri Lanka
Acrotrema dissectum Thwaites (Dilleniaceae) is a Critically Endangered (CE) endemic plant from Sri Lanka according to the National Red List, 2020 which last recorded in 1969. We aimed to rediscover A. dissectum from selected habitats in Sri Lanka to enrich the National Herbarium collection for the future Red List assessment and to develop ex-situ conservation protocols. Explorations were conducted for selected forest areas based on herbarium data, botanical literature and personal communications in the Kaluthara district in November 2022. We recovered about 15-20 individuals at a previously undocumented location. The population was restricted to a moss-covered, steep rock surface adjacent to a stream in a small, disturbed forest patch. Specimens were photographically documented and identified using existing records in the National Herbarium collection, historical botanical illustrations and literature. Photograph vouchers were deposited at the National Herbarium, Peradeniya. The original location where the species was described, Hewesse (1855) “Hellesse, Pasdun Korle”, Gualanawatta forest (1969) and the newly discovered locality fall within the same geographical area, suggesting the species has a restricted distribution. Ecological niche modelling based on these localities may help identify additional populations. Attempts to establish individuals in National Botanic Garden nurseries were unsuccessful, indicating that propagation methods require optimization before effective ex-situ conservation can be implemented. This rediscovery provides crucial baseline data for conservation planning and highlights the need for habitat protection and further population surveys in the Kalutara region. Keywords: New record, Acrotrema dissectum, Critically endangered, Endemic species, Conservation
Toxicological and Ecological Assessment of Cerebera manghas in the Eastern, Northern Provinces of Sri Lanka
Cerebera manghas, commonly known as the Sea mango, Tangena, and Bintaro is a small evergreen tree growing up to twelve metres. It is a coastal plant in Sri Lanka which is primarily found in Eastern Province such as Batticaloa, Trincomalee, and Ampara districts. Additionally, it is also found in Northern, Southern and Western Provinces. Despite its ornamental use, the plant is highly toxic, containing cardiac glycosides similar to those found in Nerium oleander. Accidental or intentional ingestion can lead to severe cardio toxic effects and death. The aim of the study has been previously documented yet is limited in Sri Lanka with regard to the toxic properties of C. manghas. The objective of this study is to identify the distribution of C. manghas in selected coastal areas and to assess the toxic compounds present in different parts of the plant. The methodology of this study was carried out by combining field surveys and laboratory analysis. A cross-sectional field survey was conducted at twenty selected places across the Eastern and Northern Provinces in Sri Lanka. At each site “Vegetation data were collected using standardized 10×10 m quadrats (Quadrat Sampling Technique) established at each site to assess the density and ecological characteristics of C. manghas.” From each site, representative plant materials were collected for phytochemical profiling and toxicity assays. Ecological risk was assessed by integrating toxin levels, plant abundance, and exposure potential. The results revealed that, densities ranging from 2-9 plants per 100 m² (mean 5.8), with taller and larger trees observed in lagoon and estuarine habitats. Leaves, fruits, and seeds were present at all sites, whereas flowers were observed at 60% of locations. Phytochemical analysis reflected that, alkaloids, flavonoids, saponins, tannins, terpenoids, and phenolics, with cardiac glycosides detected in 95% of plant parts, particularly in seeds and fruits. The conclusion reveals that C. manghas pose a latent toxicological threat in the Eastern and Northern provinces of Sri Lanka. While ecologically valuable, its presence near residential areas necessitates urgent awareness campaigns, labelling, and potential removal in high-risk zones. Further research is needed to explore its role in the ecosystem and possible medicinal uses under controlled conditions. Keywords: Cerebera manghas, Sea mango, Cardiac toxicity, Eastern province, Northern province
Macroscopic Identification of Fungi in Beddagana Wetland Ecosystem, Sri Lanka
Beddagana Wetland Park is an 18-hectare urban wetland reserve located in Sri Jayewardenepura Kotte, bordering Diyawanna Lake to the west, and supports high wetland plant and animal diversity as well as fungi populations. The present study seeks to accurately identify fungal species present at Beddagana Wetland Park by documenting their key macroscopic features. It also examines fungi present in areas subject to regular human disturbance, particularly in commonly accessed and crowded zones. Field surveys were carried out on four separate days, five days apart from each other. A different group of students performed the survey during each visit, minimizing observer bias while allowing greater coverage for the wetland. Weather conditions varied as follows: the first survey day was rainy, while the remaining three days were dry and sunny. Fungi presented at each site were clearly photographed, the cap and the under-cap. The field records were made on the morphological aspects: colour, shape, gill structure, and habitat. The fungi were identified to the genus level using scientific literature. Among the fungi recorded during the study, the most observed genera were Neofavolus and Pycnoporus. Other fungal genera, including Ganoderma, Polypore, Auricularia, Peniophora, Ternitomices, Fonus, Pleurotus, Favolus, Trametes, Chlorophyllum and Mycena were seen on various decaying substrates. This reflected active fungal colonization and ongoing decomposition processes within the wetland ecosystem, even within human-used areas. Most fungal growths within Beddagana Wetland Park were in moist, shaded locations where decaying organic matter, such as leaf litter, logs, and old branches, were present. It appeared that fungal blooming was significantly higher following rainy days compared to sunny days. Colour changes or wilting were evident in most of the fungal bodies as the days became drier. By the fourth day of observation, most of the fungal growth that had appeared earlier had dried up, except for those areas that remained consistently wet. Therefore, the wetland ecosystem at Beddagana supports high fungal diversity. Yet, this richness stands under threat of household waste dumping, poor waste management, and visitor-induced habitat disturbance. Strengthening waste control, improving public awareness, and protecting sensitive microhabitats are essential to conserve fungal communities and maintain wetland ecosystem health. Keywords: Beddagana wetland, Fungi, Ecosystem, Biodiversity, Conservation
First Record of the Critically Endangered Vandeleuria nolthenii from Hakgala Botanical Garden, Central Highlands of Sri Lanka
Rodents of the genus Vandeleuria are small, nocturnal, arboreal members of the family Muridae, distinguished by partially opposable digits and flat nails on the first and fifth toes. Sri Lanka hosts two species: the widespread V. oleracea and the Critically Endangered, montane-endemic V. nolthenii. During a citizen science survey in urban and semi-natural habitats, we recorded V. nolthenii for the first time from Hakgala Botanical Garden (1,700-1,800 m Above Sea Level), adjacent to Hakgala Strict Nature Reserve. The objective of this study was to document and verify the occurrence and nesting-site characteristics of V. nolthenii within human-modified montane habitats. On May 5, 2023, during an opportunistic survey, a dead Cupressus macrocarpa tree (Girth at breast height=135 cm) near the botanical garden exit gate was examined for nesting activity. The trunk had two oval-shaped openings: the lower at 90 cm above ground (28×44 mm) and the upper 40 cm above it (24×17 mm). The lower cavity was covered with dead cypress leaves and other plant matter. Examining it led to the sequential emergence of five small, brownish, long-tailed mice from the upper opening. Based on their external morphology and behaviour, the individuals were identified as V. nolthenii. Previous studies reported females with four half-grown young occupying bird nests in early April; the present observation of five similarly sized individuals in early May is consistent with a mother accompanied by nearly grown offspring. This record highlights the value of citizen science in documenting elusive small mammals and indicates that V. nolthenii can utilize exotic vegetation and persist in modified habitats. The finding extends the known distribution of the species within the montane zone and unveils the biodiversity present in human-managed landscapes. Continued collaboration among visitors, naturalists, and researchers can support monitoring and conservation of Sri Lanka’s lesser-known mammals. Keywords: Vandeleuria nolthenii, Citizen science, Distribution record, Sri Lanka
Preliminary Survey of Avifaunal Diversity at Horizon Campus
Horizon Campus is located in the Kaduwela divisional secretariat of Sri Lanka and provides habitats for diverse flora and fauna. However, biodiversity within university environments often receives limited scientific attention compared to natural forests and protected areas. Therefore, this preliminary survey was conducted within the premises of Horizon Campus to identify and record the bird species present in the area and to assess its potential as an urban wildlife habitat. Eight observation points were randomly established representing different habitats within the campus premises, with surveys conducted in 10 m radius. Point counts were performed for 10 to 15 minutes per point, twice weekly (one morning session from 6.00 AM to 8.00 AM and one evening session from 4.00 PM to 6.00 PM on two separate days) over a 12-week period from September to November. A total of 51 bird species were recorded, with greater species activity observed during morning, presumably attributable to increased foraging behaviour and cooler ambient temperatures. The highest species richness was recorded at a pond habitat, with a Shannon-Wiener diversity index of 3.4, which provided optimal foraging opportunities and vegetative cover. Frequently observed species included the White-rumped Munia (Lonchura striata) and the Red-vented Bulbul (Pycnonotus cafer). Endemic species recorded were the Sri Lanka Lesser Flameback (Dinopium psarodes), Sri Lanka Swallow (Cecropis hyperythra) and Yellow-fronted Barbet (Psilopogon flavifrons). Migratory species such as the Brown-breasted Flycatcher (Muscicapa muttui), Asian Brown Flycatcher (Muscicapa dauurica), Blue-tailed Bee-eater (Merops philippinus), and Asian Paradise-Flycatcher (Terpsiphone paradisi) which is also both resident and migratory, were observed. In addition, two nearly threatened bird species, the House Sparrow (Passer domesticus) and Indian Cuckooshrike (Coracina macei), were observed. These findings highlight that Horizon Campus supports a diverse bird community, including common, endemic, migratory, and a few nearly threatened species. This emphasizes the ecological value of maintaining green spaces within urban areas and the importance of promoting awareness and continued monitoring to ensure the long-term conservation of such landscapes. Keywords: Biodiversity, Horizon campus, Urban habitat, Endemic species, Migratory birds
Greening The Bench: The Role of Public Interest Litigation in Fostering Environmental Consciousness: A Socio-Legal Inquiry in South Asia
In South Asia, Public Interest Litigation (PIL) has emerged as a transformative legal tool that has expanded access to justice while reshaping the landscape of environmental protection. PIL has acted as a catalyst for raising ecological awareness among institutions, citizens, and policymakers in addition to securing judicial remedies. This study focuses on the judicial innovation and public engagement of PIL in advancing sustainability and strengthening environmental consciousness, environmental protection as an integral component of the constitutional right to life and state responsibility, with particular emphasis on Sri Lanka and comparative insights from India, Pakistan, and Bangladesh. With black letter statutes and a qualitative case study approach and comparative analysis of similar jurisdictions, the study examines landmark judgments, such as Bulankulama v Secretary, Ministry of Industrial Development (Eppawala case, Sri Lanka), the Chunnakam Case, the Indian Supreme Court’s environmental rights jurisprudence under Article 21, and Pakistan’s Shehla Zia v WAPDA. These cases demonstrate this transformation for instance, in Bulankulama v. Secretary, Ministry of Industrial Development, the Court halted the Eppawala phosphate project to protect long-term resource sustainability, and in the Chunnakam case, judicial intervention compelled the shutdown of a pollution causing power plant, while in Shehla Zia v. WAPDA, the Pakistani Supreme Court held that environmental hazards violate the fundamental right to life. The study shows how PIL helps to promote environmental citizenship by bridging the gap between public activism and legal standards while offering insights valuable for policymakers, activists, and environmental practitioners across the region. For example, the Eppawala case sparked nationwide public debate in Sri Lanka. In India, through the Indian Article 21, civil society mobilization, such as environmental NGO participation in litigation. The study identified that South Asian courts have progressively broadened environmental rights through PIL through media coverage, civil society involvement, and court interventions, transforming litigation into a kind of public education. However, challenges remain, such as judicial overreach, procedural delays, and inconsistent enforcement, which often reduce the transformative potential of PIL. The findings demonstrate that PIL has produced tangible legal outcomes, including the suspension of environmentally harmful development projects, judicially mandated pollution controls, and the recognition of precautionary and public trust principles. Beyond legal remedies, the analysis shows that PIL contributes to heightened environmental consciousness by amplifying public discourse through media attention and civil society engagement. However, the study also finds that the long-term effectiveness of these judicial interventions is constrained by inconsistent enforcement, administrative inertia, and delays in compliance, indicating that PIL’s transformative potential depends heavily on institutional follow-through. By linking PIL to the development of environmental citizenship, the study addresses an underexplored socio-legal dimension in South Asian scholarship. Keywords: Constitutional rights, Environment, Public interest litigation, Sustainability, Law
Awareness and Behavioural Contribution of Consumers Towards Fast Fashion and Carbon Footprint
Fast fashion is one of the fastest-growing phenomena in the world apparel industry, marked by affordable and fashion-forward apparel at high speed. Conversely, with the continued surge in popularity, the resultant environmental impact has spurred concerns about carbon emission, textile waste, and microplastic pollution; hence, the need to understand consumer awareness and behaviour becomes relevant. This study explores consumer awareness, perceptions, and their behavioural contribution toward fast fashion and carbon footprint. A total of 256 respondents of varying age groups and academic and professional backgrounds participated in a structured quantitative survey. The survey assessed knowledge of the environmental impacts of fast fashion, their purchase and disposal practices, and their willingness to adopt sustainable alternatives. The majority of 63.7% respondents were between 18-22 years and predominantly female at 72.3%. More than half of the responses came from science or technological disciplines. Results showed that conceptual awareness was limited to only 27.3% of participants who had previously heard the term "fast fashion." Awareness of the environmental impacts of fast fashion was moderate; 43.4% reported being somewhat aware, and 14.1% very aware. While the majority acknowledged that fast fashion contributes to carbon emissions globally, the sustainability factor in purchasing choices was seldom considered, at 1.9%. Further evidence of the environmental gaps in behaviour was seen in the fact that 62.9% never purchased items second-hand or thrifted, while 37.1% did not check if the items contained sustainable or recycled materials. However, 64.5% were willing to support university or community initiatives that promoted sustainable fashion, and 80.9% felt individual choices could mitigate carbon emissions. There is significant potential for change in consumer behaviour with appropriate interventions. It is evident that the knowledge of the participants about fast fashion and its impact is limited. Textile consumption is driven more by the cost of the clothes, quality, and trendiness rather than sustainability concerns. Targeted education and awareness, together with better availability of sustainable clothing, will make a considerable difference in environmentally friendly behaviour. It is recommended that sustainability education be scaled up at the university level, public campaigns be run to raise awareness of carbon emissions related to fashion, eco-friendly clothes be made more available at affordable prices, and policy measures be taken to enhance textile recycling and waste reduction. Keywords: Fast fashion, Consumer awareness, Carbon footprint, Sustainable consumption, Consumer behaviour
Public Participation in the Environmental Impact Assessment Process in Sri Lanka: A Case Study of Selected Projects
Public Participation is a key aspect of the Environmental Impact Assessment (EIA) process in Sri Lanka. However, existing literature on the level and effectiveness of public engagement in the EIA process of Sri Lanka is limited. Addressing this gap, this study focuses on evaluating public participation during the public review stage of the EIA process in Sri Lanka. The objectives include studying the level of public participation, examining the importance of public participation, and proposing suitable recommendations for effective public participation. Secondary data were collected from the Central Environmental Authority of Sri Lanka for fourteen development projects spanning seven sectors: industrial, irrigation, mixed development, power & energy, sewerage, solid waste management, and transportation. Public comments received for each project during the public review period were collected and analyzed. Public comments submitted for each project were collected and examined to identify patterns of engagement, the types of participants, and the nature of issues raised. The varying degrees of public engagement, types of public and types of issues highlighted by the public are identified for each sector. The results reveal considerable variation in participation of the fourteen projects reviewed, five from the industrial, mixed development, sewage and solid waste management sectors received no public comments. Five projects in the power & energy, sewerage, and transportation sectors received between 1 and 10 comments. One power & energy project received 49 comments, while three projects in the irrigation and solid waste management sectors received more than 100 comments. The types of the public identified are residents in the area, non-governmental organizations, local organizations, non-residents, experts, and environmental organizations. The issues raised by the public can be categorized as environmental concerns, socio-economic matters, incomplete or inadequate reports, requests for public hearings, cultural & aesthetic issues, and other comments. The findings indicate that the current engagement of the public in the EIA process of Sri Lanka is unsatisfactory. To improve the effectiveness of public participation, measures such as increasing public awareness, providing accessible feedback platforms, and ensuring transparency are essential. By addressing these challenges, Sri Lanka can promote the effectiveness of the EIA process, leading to sustainable development outcomes and a socially accepted and environmentally responsible decision-making process in the country. Keywords: Public participation, Environmental impact assessment, Sri Lanka, Sustainable development
Landscape-Level Degradation Mapping of Invasive Plant Species in the Central Highland Cloud Forest of Bopaththalawa, Sri Lanka
Montane cloud forests in Sri Lanka’s Central Highlands are among the most threatened ecosystems due to various anthropogenic activities, including the spread of Invasive Alien plant Species (IAS), forest fires, illegal tree felling, gem mining, and poaching. This study assesses the spatial variation of invasive plant species in the Bopaththalawa cloud forest landscape, in relation to native species composition. This study aimed at developing a landscape-level degradation map quantifying the spatial extent both through field-based citizen science observations and aerial mapping (remote sensing). Drone-derived orthomosaics were integrated with Sentinel-2 satellite imagery processed in Google Earth Engine (GEE) to derive vegetation indices. Field observations and geo-tagged photographs compiled over 120 ground-truth points for supervised classification. The classification model combining spectral, textural and topographic variables achieved an overall accuracy of 82% in distinguishing invasive-dominated areas from the present native vegetation. Eight invasive plants (Solanum mauritianum, Dicranopteris linearis, Koenigia mollis, Cymbopogon nardus, Austroeupatorium inulifolium, Ludvigia peruviana, Cenchrus purpureus and Tithonia diversifolia) dominated the landscape, while 15 invasive plants were found within the location. The resulting degradation map reveals that approximately 67% of the 32-hectare degraded landscape remains under moderate to severe invasion. These invasions spread across irrigation channels, forest fire-affected land, slopes and abandoned farming sites regardless of the previous vegetation presence. Forest fires accelerated the encroachment of invasive species into previously undisturbed areas, thereby threatening the natural regeneration potential of native vegetation. Overdominance of invasives such as S. mauritianum was primarily due to seeds dispersed by birds, resulting in approximately 0.8 ha spread with a mean height of 3 m recorded over an 11-month period. Such degradation continues to impair montane ecosystem integrity and often remains undetected without field validation. These findings highlight the need for prioritizing invasive removal, replanting, and ecological restoration. Citizen science actions demonstrated that low-cost drones, open satellite data, and community ground validation can provide scalable information to guide nature-based restoration strategies in Sri Lanka’s high-elevation ecosystems. Keywords: Invasive species, Remote sensing, Landscape degradation, Cloud Forest, Bopaththalawa
Community Willingness and Structural Barriers to Incentive Based Recycling in Sri Lanka
Solid waste management remains a growing environmental challenge in Sri Lanka, as public awareness has not translated into effective participation due to structural limitations. This study aims to understand public waste disposal practices and assess community willingness to engage in an incentive-based waste-to-money system. The Data were collected through a structured questionnaire survey administered to 174 respondents across multiple districts, mainly Colombo (25.3%), Gampaha (46.6%), and Kalutara. The survey examined household waste generation sources, disposal frequency, waste composition, existing segregation practices, perceived barriers, and awareness of incentive-based recycling initiatives. The majority of participants were aged between 18 and 35 years. Findings showed that while 73% demonstrate positive environmental intentions, consistent waste separation remains irregular and time consuming. Only occasional practice was reported by 17.2% participants. Structural constraints such as the absence of a proper municipal collection system, limited space for segregation within households, and time constraints were identified as the main obstacles, emphasizing infrastructural rather than attitudinal shortcomings. Household waste generation was around 48% with most households producing 1-3 kg of waste per day, predominantly consisting of food waste and plastics, and disposal commonly occurring every two to three days. Awareness of existing paid recycling initiatives was comparatively low by 32.7%. However, willingness to participate in a waste to money system was notably high by 83.9%, if accessible collection points were established near supermarkets or public areas etc. Respondents (83.3%) illustrate a clear preference for contributing plastic waste, followed by glass, paper, and organic waste, in exchange for financial or material incentives. Overall, this particular study highlights a strong alignment between public enthusiasm and incentive-based recycling models, indicating that a well and properly designed waste-to-money system could effectively bridge and minimize the gap between environmental intention and everyday practice, contributing to a more sustainable and community driven waste management framework in Sri Lanka. Keywords: Incentive recycling, Community engagement, Community willingness, Sustainable behavior, Solid waste management, Waste to money
Development of Efficient Microbial Consortia for the Production of Bioethanol Using Rice Straw as the Low-Cost Substrate; A Step into the Circular Bio Economy
Energy crisis is one of the major concerns in the globe, which is driven by urbanization and industrialization-related anthropogenic activities. Therefore, the world is looking for alternative energy sources as a green and sustainable strategy in the circular bio-economy. Since second-generation bioethanol has a comparatively smaller environmental effect, it is seen as a possible alternative energy source. Therefore, the present study focuses on developing a microbial consortium under various chemical pretreatment and fermentation conditions to create an efficient saccharification technique for rice straw, a lignocellulosic agricultural by-product. For the study, cellulase-positive bacteria were isolated from compost, soil, and cow dung samples. The primary screening of bacteria was carried out using the Congo red-CMC agar assay, and the DNS method was used for the secondary screening of cellulose-positive bacteria. After evaluating their antagonistic effects, the best potential isolates were combined to create four microbial consortia, and the effectiveness of their saccharification was determined using the DNS. Moreover, the Rice straw was subjected to alkali and acid pre-treatments, including 4% NaOH (66.7%), 2% NaOH (80.0%), 0.5% H2SO4 (54.3%), 1% H2SO4 (81.2%), and 2% H2SO4 (44.7%) to facilitate the accessibility of cellulose for enzymatic saccharification under nutrient rich media and 50 mM sodium citrate buffer. The starved commercial Saccharomyces cerevisiae was used to ferment hydrolysates in a medium that was rich in nutrients, and the final bioethanol yield was quantified by the GC-FID method. Based on the results, 29 morphologically different bacterial isolates were isolated from compost, cow dung, and agricultural soil, and out of those, six potential isolates were selected by secondary screening. The highest ethanol yield was recorded by the consortia D, in 2% H2SO4 pre-treatment in nutrient media (3.96±0.5% v/v), followed by the consortia A in 2 % H2SO4 pre-treatment in nutrient media (2.95±0.4%), and consortia C in 4% NaOH pre-treatment in buffer (2.43%). The biochemical identification confirms that the bacteria in the best consortia D belong to the genus Bacillus spp. and Lactobacillus spp. Further, the findings of the present study provide a valuable insight into the production of bioethanol from waste rice straw using native bacterial consortia as a sustainable approach. Keywords: Bioethanol production, Microbial consortia, Rice straw, Cellulolytic microorganism, Circular bioeconomy
Assessing the Effectiveness of Sustainable Climate Finance: An Integrated Framework of Stakeholder Engagement, Risk Management, Innovation, and Ethical Responsibility in a Developing Country Context
Sustainable climate finance plays a pivotal role in addressing climate change while supporting economic development in developing countries. This study examines the effectiveness of sustainable climate finance mechanisms by analyzing the integration of stakeholder engagement, risk management, innovation adoption, and ethical responsibility. The research adopts a quantitative, work-based approach focused on organizations actively engaged in climate finance-related activities. Primary data were collected through a structured questionnaire administered to ten organizations, including private companies, government institutions, non-governmental organizations, and academic and research institutes. Responses were measured using a five-point Likert scale and analyzed using descriptive statistics, sectional mean analysis, and SWOT analysis to evaluate organizational performance across the four key dimensions. The findings reveal that stakeholder engagement and ethical responsibility are perceived as relatively strong contributors to sustainable climate finance, fostering transparency, trust, and collaboration. However, risk management and innovation adoption demonstrate moderate performance, indicating gaps in institutional capacity, systematic frameworks, and resource allocation. The study highlights the necessity of an integrated approach that aligns these four dimensions to enhance the overall effectiveness of climate finance initiatives. The research offers practical insights and strategic recommendations for strengthening sustainable climate finance frameworks in Sri Lanka and provides valuable implications for climate finance institutions operating in similar developing-country contexts. Keywords: Sustainable climate finance, Stakeholder engagement, Risk management, Innovation adoption, Ethical responsibility, Climate governance
User Preferences of Plastic, Wooden, and Bamboo Forks: A Comparative Survey Analysis
Disposable forks are used as eating aids and discarded in large quantities especially in the urban and semi-urban areas in Sri Lanka. It is necessary to find sustainable alternative resources as raw materials for making forks and those alternatives should be accepted by the end users. The aim of this research was to establish the preference of consumers among plastic, wooden, and bamboo forks through a structured survey based on main factors: the frequency of use, taste, tactile comfort, environmental impact, and purchase intention. A sample of 200 subjects drawn from different age categories of young people was surveyed using a questionnaire for qualitative and quantitative responses. Participants rated each material based on comfort of use, effect on the environment after usage, fork curviness, fork smell, and cost. Chi-square and Kruskal-Wallis tests were used to find significant differences in the preference for the materials. Plastic forks were found to be the most frequently used and rated very high on the comfort factor among participants (p<0.05) and were also considered fairly inexpensive, with 75% willing to pay up to Rs.2.00-12.00. On the other hand, bamboo and wooden forks scored significantly high on environmental friendliness compared with plastic (p<0.05). There has been little variation in taste perception among participants, while significant differences were observed in comfort and design preferences, particularly among young groups who rated these factors higher (p<0.05). The findings suggested that, while plastic forks are much cheaper and comfortable, urban users have a growing preference for bamboo and wood-based products, mainly due to environmental issues. The survey underlines that alternatives to forks should be provided in such a way as not to reduce the level of comfort for and affordability by users. In this respect, bamboo appears to be the best option for those who stress the problems of environmental effects, although plastic remains more convenient and cheaper. Keywords: Bamboo, Fork, Plastic, Wood
Environmental Life Cycle Assessment for Solid Tire Manufacturing: A Case Study from Sri Lanka
The global solid tire market is valued at USD 6.81 billion in 2024, with Sri Lanka contributing 28.6% of world exports. Despite this industrial significance, literature regarding the specific environmental implications of solid tire manufacturing, which involves specialized molding and energy-intensive curing remains limited. This research assesses the environmental impacts of Sri Lankan solid tire manufacturing following the ISO 14040/44 framework. A cradle-to-gate approach was implemented, defining the functional unit as the manufacturing of one metric ton (1 MT) of industrial solid tire, explicitly excluding downstream product use and end-of-life phases. The assessment utilized SimaPro (v10.2) and the Ecoinvent (v3.9) database, employing the ReCiPe 2016 Midpoint (H) method with calculation setup CML-IA baseline V3.11 / EU25 to analyze 18 distinct impact categories. Results indicate that producing 1 MT of solid tires generates a Global Warming Potential of 2,770 kgCO2-equivalent. However, significant burdens were also identified in Marine Aquatic Ecotoxicity (the highest impacted category), abiotic depletion (fossil fuels), and human toxicity. Raw material production accounts for 58% of total lifecycle impacts, driven largely by synthetic rubber (13%) and carbon black (18%), which are heavily concentrated in supply chains from China and India. Conversely, manufacturing operations are the primary driver for climate change impacts (45%), specifically due to energy consumption in curing operations. The study concludes that while renewable energy adoption can mitigate climate impacts by 30-50%, it must be paired with material circularity strategies. Recommendations include prioritizing bio-based synthetic rubber and recovered carbon black to address toxicity and depletion hotspots, alongside immediate supplier engagement. Keywords: E-LCA, Solid tire, Sri Lankan industries, Environmental hotspots,Cradle-to-gate
Sustainable Machining through Minimum Quantity Lubrication Using Green Cutting Fluids as an Alternative to Mineral Oils
Machining operations have traditionally depended on conventional flood cooling with mineral-based emulsions to improve tool life and surface quality. However, these cutting fluids are costly to produce, difficult to dispose of, and pose considerable environmental and health hazards. Minimum Quantity Lubrication (MQL) has emerged as a cleaner alternative, significantly reducing fluid consumption while maintaining or enhancing machining performance. The use of green cutting fluids offers additional advantages by lowering environmental risks and providing economic benefits. Despite these potentials, only limited research has investigated the application of MQL with green cutting fluids for specific tool-workpiece combinations, particularly regarding surface roughness. This study evaluates the effect of MQL with green cutting fluids on the surface finish of machined components. Through literature review, three environmentally friendly oils sunflower oil, coconut oil, and waste cooking oil were identified for testing. Turning experiments were carried out on AISI D2 steel workpieces using carbide-coated tools under MQL with the selected oils. For comparison, additional trials were conducted under dry cutting, conventional flood cooling with emulsions, and MQL with emulsions. The results revealed that coconut oil and sunflower oil under MQL achieved superior surface finishes, surpassing conventional methods, while waste cooking oil performed poorly due to its degraded properties. These outcomes highlight the potential of green cutting fluids as sustainable substitutes for mineral-based emulsions in machining. Further studies with varied machining parameters and tool-workpiece combinations are recommended to strengthen and generalize these findings for broader industrial adoption. Keywords: Green cutting fluids, MQL, Surface roughness, Sustainable machining
Development of Bio-based Water-repellent Wood Treatment
The significance of effective water-repellent treatments is crucial for withstanding moisture induced degradation, which compromises the durability and longevity of exterior hardwood applications. Conventional synthetic coatings such as polyurethane, varnishes, lacquers, and chemical preservatives offer effective protection against moisture degradation. However, they raise environmental-health concerns, emphasizing the importance of sustainable and non-toxic bio-based substitutions. This study focused on developing a bio-based water-repellent wood treatment employing local natural oils and waxes. This material selection was based on their major fatty acid components, which provide hydrophobic properties. Accordingly, bitter-melon seed oil with -eleostearic acid was extracted using the Soxhlet apparatus. Castor oil with ricinoleic acid was dehydrated (280 °C) to improve its hydrophobicity by converting hydroxyl groups into unsaturated bonds. Beeswax was chosen due to its high myricyl-palmitate ester content hydrocarbon-rich structure, which enables water repellency by filling pores and forming a continuous protective film on wood substrate. The melted beeswax was combined with the two oils (wax-to-oil 1:3) at 60 °C and the coated samples were allowed to reach a dry-to-touch level for 72hours under controlled environmental conditions. Then the formulation was evaluated through an extensive set of characterization techniques, including static water contact angle, liquid and vapor water absorption, dimensional stability and Scanning Electron Microscope (SEM) imaging for both treated and untreated mahogany wood samples. Results showed that treated samples exhibited 58±0.8% and 55±1.2% reductions in liquid and vapor water absorption, respectively, compared to untreated samples, with static water contact angles ranging from 148° to 159°. Moreover, the treatment also reduced volumetric swelling of samples by 58±0.55%, compared to untreated samples, demonstrating a substantial enhancement in the dimensional stability. Obtained SEM images revealed that the untreated wood surfaces were highly porous with open cell lumens, while treated samples displayed a continuous, uniform film that filled and sealed these pores indicating an effective surface coverage. Thermal stability was assessed by cooling the coating solution from 85 °C to 35 °C. According to the results, the coating solution remained stable up to 50 °C, despite the melting point of beeswax being 65 °C demonstrating improved stability of the oil-based coating formulation. All these characterization techniques were performed multiple times under steady controlled conditions for intensified reliability and validity of the results. The developed bio-based wood treatment offers strong practical potential as a safe, locally sourced, and eco-friendly alternative for protecting exterior hardwoods in construction, furniture, and outdoor structures. Keywords: Water-repellent, Wood treatment, Bio-based, Castor oil, Bitter-melon seed oil, Beeswax
Environmental Life Cycle Assessment of Selected Drinking Water Treatment Plants in Kurunegala District
Population growth in Sri Lanka has significantly increased the demand for clean drinking water, requiring expansion of water sources and well-purified water delivery. Conventional water treatment plants rely on continuous 24-hour pump operation and the use of chemical processes that generate residuals or by-products, which may pose risks to both environmental sustainability and human health. This study compares the environmental impacts of three drinking water treatment plants, Kurunegala (Daduru Oya), Nikaweratiya (Magalla Wewa), and Narammala (bore holes), using Life Cycle Assessment across river, tank, and groundwater sources. The study employed a gate-to-gate approach with 1 m³ of treated drinking water as the functional unit, meeting Sri Lankan standards (SLS 614:2013). Data collection included site observations, daily and monthly reports from January-December 2024 and discussions with field personnel from each treatment plant. Life Cycle Inventory quantified inputs and outputs per functional unit. Emission modeling followed IPCC 2006 Guidelines. Environmental impact assessment used ReCiPe 2016 Endpoint and midpoint methods in SimaPro 10.2.0.1, evaluating 18 impact categories. Results indicate that Narammala demonstrated the best performance in most midpoint categories, achieving reductions of approximately 11% in global warming, terrestrial acidification, and ecotoxicity compared to Nikaweratiya, primarily due to the absence of alum coagulation and associated sludge generation. Mineral resource scarcity was also lower for Narammala, reflecting minimal chemical usage in groundwater treatment. At the endpoint level, Narammala exhibited the lowest human health damage, and 10% lower resource depletion compared to Nikaweratiya. Kurunegala consistently demonstrated intermediate performance across all categories. Treatment complexity, particularly chemical coagulation intensity, significantly influenced environmental performance. These findings indicate opportunities for optimization through energy efficiency, reduced chemical dosing, and the integration of renewable energy sources. Keywords: Life cycle assessment, Drinking water treatment, Environmental impacts, Water sources
Sustainable Water-Based Transportation in the Colombo Area
Water-based transportation in Sri Lanka has existed since ancient times, serving as an essential mode for trade and travel. During the early kingdoms, rulers constructed canals to transport goods and passengers between rural areas and major ports, supporting economic and cultural exchange. With the arrival of the British in the nineteenth century, transportation priorities shifted toward road and rail development, leading to the gradual decline of inland water transport. However, Colombo still possesses a valuable network of waterways, including Beira Lake, Hamilton Canal, and the Kelani River, which remain underutilized despite their potential. This study aims to assess the feasibility of introducing sustainable water-based transportation in the Colombo area as a modern solution to traffic congestion, pollution, and energy inefficiency. Particular attention is given to the Kelani River, which offers a direct corridor connecting eastern suburban areas to the city center, and the Hamilton canal, which provides potential feeder and eco-friendly transport routes linking northern urban areas. The research is based on literature review, field observations, and spatial analysis of existing canal systems to identify opportunities and challenges in implementing a passenger boat service. The findings highlight that revitalizing these waterways could significantly reduce urban traffic, enhance eco-tourism, and contribute to sustainable urban mobility. Nevertheless, barriers such as poor canal maintenance, waste accumulation, and lack of policy coordination need to be addressed. The study concludes that integrating water-based transport within Colombo’s urban planning framework can promote environmental sustainability, economic efficiency, and cultural heritage preservation. Keywords: Water-based transport, Sustainable mobility, Colombo, Canal network, Eco-transport
Eco-Innovation for Enhancing the Performance of Metal Roofing Sheets
The demand for metal roofing sheets has declined due to issues such as excessive heat and noise generation. An eco-friendly roofing layer is made from environmentally sustainable materials, contributing to a more comfortable living environment. The objective of this study is to utilize natural materials to develop a roofing layer as an eco-innovative solution to mitigate the excessive temperature and noise, ultimately enhancing industrial performance. To implement the proposed eco-innovative concept, Deluxe roofing sheets was selected as the target industry due to its relevance and suitability for sustainable material integration. A performance evaluation was conducted using four treatments, including a control. The experimental treatments consisted of natural materials: Caryota urens fiber, coir dust, Agave sisalana fiber. Each treatment, including the control, was tested using three replicates to ensure reliability and statistical validity. Each roofing material layer was attached to the Deluxe roofing sheet using rubber latex as a binding agent ensuring proper adhesion. Each treatment unit (76.2×76.2 cm2) was prepared by first applying a thin coat of coagulated rubber latex onto a Deluxe roofing sheet. Different fibre layers were then placed individually on the coated surface, followed by a second latex coating and compression to achieve a thickness of 10 mm. A uniform layer of sawdust was subsequently applied to fill surface gaps, and the composite was pressed again to obtain a final thickness of 15 mm. The performance of composite roofing layers was assessed based on key parameters such as thermal insulation and noise reduction capabilities. The outdoor temperature was maintained between 70 °C and 80 °C, and the indoor temperature was measured at a distance of 125 cm from the sheet using a dual-laser video IR thermometer. The audible sound level was measured at three distances from the sheet (15,30 and, 45 cm) using a sound level meter under standardized testing conditions. All collected data were statistically analyzed using SAS Software and Dunnett’s t test was employed to compare each treatment against the control. According to the changes in indoor temperature values and sound intensity levels, all three fiber based treatments showed a significant difference (40% reduction in indoor temperature and 10.5% reduction in sound level) compared with control test. All three treatments resulted in lower temperature and lower audible sound intensity level than control, indicating their effectiveness in temperature and sound insulation. Fiber from C. urens and A. sisalana showed better results compared to coir dust for temperature and sound insulation. These findings suggest that all three materials are suitable for use as a layering material on Delux roofing sheets. Keywords: Eco innovation, Excessive heat, Excessive noise, Metal sheets, Roofing layer
Application of Life Cycle Assessment to Evaluate Environmental Impacts of Municipal Solid Waste Management: A Case Study of Karadiyana, Sri Lanka
Municipal solid waste management in developing countries faces the dual challenge of minimizing environmental impacts while operating with limited resources. In Sri Lanka, large waste treatment facilities and open dumpsites are associated with growing environmental concerns, but detailed environmental assessments remain limited. The Karadiyana Waste Management Facility processes a substantial share of municipal waste from the Western Province and has significant impacts on nearby ecosystems. This study presents the first Life Cycle Assessment (LCA) of the Karadiyana facility, providing insights to support future improvements in waste management. The main objective of this study is to assess the environmental impacts of municipal solid waste treatment options using a gate-to-gate LCA framework using a functional unit of treatment of one tonne of municipal solid waste. The assessment focuses on waste treatment processes within the facility, from waste reception to treated outputs. Primary data on waste quantities, composition, and facility operations were collected from the waste management facility and the Waste Management Authority through operational records, site observations, and interviews with facility personnel. Secondary data and emission factors were obtained from IPCC guidelines and relevant literature. Environmental impacts were assessed using the ReCiPe 2016 Midpoint method in SimaPro across 18 impact categories, and the results were normalized to support comparative interpretation. Normalization results indicate clear differences among the evaluated midpoint impact categories. Global warming exhibits the highest normalized value. Freshwater eutrophication, freshwater ecotoxicity, and human carcinogenic toxicity show comparatively higher normalized values relative to other impact categories. The characterization results indicate that the global warming potential is primarily driven by untreated waste within the municipal solid waste management system boundary, due to Methane (CH4) emissions generated during waste degradation. These findings highlight that current municipal solid waste management practices in Sri Lanka are linked to significant environmental impacts and underscore the need for targeted improvements to mitigate these effects. Keywords: Environmental life cycle assessment, Impact categories, Municipal solid waste, Waste management, Simapro, ReCiPe 2016
Enhancing Sustainability of Concrete with Bamboo Fiber Reinforcement and Sawdust Substitution
Concrete is the key building material in the construction industry and its continuous demand contributes to the excessive use of natural resources. This study investigates the effectiveness of adding sawdust as a partial substitute for fine aggregate and bamboo fibers as reinforcement in cement mixtures to improve the mechanical properties and sustainability of concrete. The experiments were developed to examine compressive strength, split tensile strength, and workability while assessing the environmental benefits of incorporating these natural by-products. Various proportions of bamboo fibers (0.5-1%) and sawdust (15-40%) were included in mix designs prepared in accordance with BS standards. The specimens were tested after 7, 14, and 28 days of curing. The results from slump tests indicated that sawdust increased workability, with the slump rising up to 86 mm at 40% sawdust and 1% bamboo fiber, which is considered medium workability. In contrast, the addition of bamboo fibers reduced slump due to their water absorption capacity. Compressive strength increased gradually with curing age. Although sawdust replacement alone reduced strength, the optimal combination of 40% sawdust and 1% bamboo fiber achieved 27 N/mm2 at 28 days, which is acceptable compared with the control mix at 30 N/mm2. Split tensile strength also improved with increasing curing age, with a maximum of 2.97 N/mm2 at 40% sawdust and 1% bamboo fiber. These results demonstrate that bamboo fibers enhance tensile strength while sawdust contributes to reduced weight and improved sustainability. The study concludes that the inclusion of sawdust and bamboo fibers in concrete offers a practical approach to addressing raw material depletion and disposal issues of wood waste and agricultural by-products. Proper proportions are essential to obtain desired strength and durability. While the present results confirm the potential of bamboo and sawdust concrete as a sustainable alternative, further studies on flexural strength, fire resistance, and durability under environmental exposure are recommended. Keywords: Saw dust, Bamboo fiber, Concrete compressive strength
Quantification of Internal Trunk Decay in Urban Trees using Ground Penetrating Radar (TRUTM): A Case Study in Colombo, Sri Lanka
Internal trunk decay is one of the least visible defects influencing the structural stability of urban trees, particularly in tropical urban environments such as Colombo, where trees frequently experience compacted soils, dense infrastructure, and mechanical injuries. Conventional Visual Tree Risk Assessment (VTRA) often fails to reveal internal structural conditions, creating uncertainty in estimating true failure risk. To address this gap, this study employed Ground Penetrating Radar (GPR) using the Tree Radar Unit (TRU™) to detect and quantify internal trunk decay in urban trees at two selected locations: Viharamahadevi park and Keppetipola road. Thirty trees (15 per site) previously categorized into low-, moderate-, and high-risk groups using VTRA were scanned circumferentially at breast height (1.3 m). Radar data were processed in TreeWin Pro to generate cross-sectional images, and decay zones were quantified using ImageJ to calculate proportions of advanced (hollow), incipient, and near-surface decay relative to total trunk area. At Viharamahadevi park, 8 of 15 trees exhibited internal decay ranging from 0.67% to 51.72%, while at Keppetipola road, 9 of 15 trees showed decay ranging from 1.13% to 78.60%. All low-risk trees showed no detectable decay, whereas moderate- and high-risk trees displayed varying degrees of internal deterioration. Although decay was more prevalent in trees with higher VTRA categories, the presence of decay did not consistently correspond to elevated failure risk, highlighting the need for a multi-parameter approach. Decay percentages were interpreted in relation to structural integrity thresholds whereas 25%,50%,75%,100% decay were identified as mild, moderate, severe and extreme risk-causing conditions. This study being the first application of TRU™ in Sri Lanka, demonstrates its potential for non-destructive decay detection under tropical field conditions. However, the limitations of GPR technology must be acknowledged, including high equipment cost, the need for trained and experienced operators and sensitivity to moisture content that can influence radar signal interpretation. To overcome these constraints, the accuracy of the machine can be compared and validated with other diagnostic tools. During the study, the TRU machine used was validated with real cross sections of trees to produce a more holistic and reliable assessment. The findings further emphasize practical implications for urban tree management, including improved prioritization of high-risk trees, optimized monitoring schedules, and stronger support for evidence-based municipal policies aimed at proactive tree risk mitigation and long-term urban forest sustainability. Keywords: Urban trees, Ground penetrating radar, Tree radar unit, Internal decay, Risk assessment
Fire Risk in the Built Environment: Towards Sustainable Urban Resilience in Colombo City Area
Ensuring fire safety in commercial buildings is a vital yet frequently neglected component of sustainable urban development in the Colombo City area. Rapid urbanization and the increasing prevalence of high-rise, multi-occupancy buildings have intensified fire-related risks, particularly in densely built environments such as the Colombo City area. Despite the existence of national regulations, widespread non-compliance and inadequate enforcement have heightened vulnerabilities, threatening lives, property, and urban resilience. Fire incidents disrupt economic activities, increase disaster exposure, and undermine sustainable land-use and environmental planning. This study evaluates the fire risk levels of ten representative commercial buildings in Colombo using a semi-quantitative, checklist-based fire risk assessment tool specifically developed for the Sri Lankan context. Unlike conventional assessments that primarily focus on structural or technical provisions, the proposed tool adopts an integrated approach encompassing passive and active fire protection systems as well as fire safety management practices throughout the building life cycle. The tool, validated across over 50 prior facilities and published studies, was systematically applied to ten purposively selected commercial buildings in the Colombo City area, differing in age, height, and construction type. Based on data gathered through field inspections and interviews, fire risk was assessed using the newly developed tool, which applies the Relative Importance Index (RII) method and a four-tier scoring system across five key domains: means of escape, structural fire protection, detection systems, suppression systems, and fire safety management. Findings reveal alarming deficiencies in compliance. Active fire protection systems showed less than 35% compliance, while fire safety management practices fell 59% below required standards. Overall, commercial buildings achieved only 43% compliance with local Construction Industry Development Authority (CIDA) fire regulations and 44% alignment with British Standards and best practices. None of the evaluated buildings met the “low risk” classification; 50% were categorized as high risk and 40% as moderate risk, with older structures performing significantly worse. The results highlight an urgent need to transition from prescriptive regulatory frameworks toward integrated fire risk management approaches that combine engineering design, maintenance, and administrative control measures. Weak enforcement, fragmented legislation, and limited technical capacity remain major challenges. Strengthening regulatory frameworks, implementing systematic compliance monitoring, and promoting investment in modern fire protection systems are essential to safeguard lives and enhance urban resilience. The study contributes a locally adaptable, resource-efficient assessment tool that embeds fire safety within sustainable urban design and climate-resilient development strategies. Keywords: Fire risk assessment, Built environment, Fire safety management, Sustainable infrastructure, Sri Lanka.
Comparison of Environmental Impacts of Orthodox and CTC Tea Processing Methods Using Life Cycle Assessment: Gate-to-Gate Approach in Pasgoda DS Division, Sri Lanka
Sri Lanka is the fourth largest tea producer in the world, with tea serving as the country's main export agricultural crop. In Sri Lanka, black tea is processed primarily through two distinct factory level methods, Orthodox and Crush-Tear-Curl (CTC), which differ in their leaf handling and energy requirements. Orthodox processing accounts for about 90% of production, while CTC represents around 9%. Low-country tea (cultivated up to 600 m elevation), characterized by its blackish appearance and strong cup color and taste, contributed approximately 61% of the national output in 2023. Tea processing however generates significant environmental impacts and analysis of environmental impacts of different tea processing methods in Sri Lanka remain limited. This study therefore conducted a gate-to-gate Life Cycle Assessment to compare the environmental impacts of orthodox and CTC tea processing within factory boundaries. The assessed processing stages included withering, rolling or CTC, fermentation, drying, sorting and grading, and packaging. Primary data related to these processing stages were collected from five tea factories in Pasgoda DS Division, Matara District. The functional unit was defined as 1 t of processed tea at the factory gate. Eight environmental impact categories were evaluated using the CML-IA Baseline method in SimaPro: Global Warming Potential (GWP), Abiotic Depletion (Fossil Fuels and Elements), Acidification, Human Toxicity, Eutrophication, Terrestrial Ecotoxicity, and Freshwater Aquatic Ecotoxicity. Results show that Orthodox processing exhibited higher environmental impacts than CTC across all eight impact categories assessed. Overall, the GWP from Orthodox processing was approximately 1.25 times higher than that from CTC. Withering was identified as the largest GWP hotspot in both methods, contributing nearly half of the total impact, with Orthodox showing a slightly higher share. Abiotic depletion of fossil fuels under the Orthodox method was approximately 1.5 times higher than that of CTC, while human toxicity potential was around 1.4 times higher for Orthodox. The study identifies energy efficiency improvements in withering and drying as key mitigation opportunities, with recommendations including waste-heat recovery, optimized air circulation, and lower-carbon energy sources. Keywords: Tea, Life cycle assessment, Orthodox, CTC
Harmonizing Forest Certification and Deforestation-Free Legislation: Advancing Sustainable Forest Management in Slovakia Under the EUDR
The European Union Deforestation Regulation (EUDR), adopted in 2023, represents a major transformation in global forest governance, requiring that products entering the EU market be both legally harvested and demonstrably deforestation-free. This paper explores the harmonization of voluntary forest certification standards with this new legal framework through the case of the Slovak Forest Certification System (SFCS) operating under the Programme for the Endorsement of Forest Certification (PEFC). The international benchmark standard, PEFC ST 1003:2024 Sustainable Forest Management-Requirements, was revised to incorporate explicit clauses on legality, prohibition of conversion and degradation, and mandatory geolocation of forest management units. In response, PEFC Slovakia revised its national standards TD SFCS 1001 and TD SFCS 1003 in 2025 to ensure full alignment with both the updated PEFC benchmark and the EUDR. A clause-by-clause comparative analysis and validation against the PEFC International Public Assessment Report confirmed that the Slovak standards integrated all new definitions such as agricultural plantations, forest degradation, and geolocation while maintaining compatibility with the national Act on Forests. The revision reinforced operational controls on conversion, enhanced traceability, and established clear legal cross-references, strengthening compliance assurance within certified forest operations. The Slovak experience demonstrates how national certification systems can act as bridging instruments between voluntary sustainability mechanisms and binding legislative frameworks. It illustrates an applicable approach to achieving deforestation-free value chains and contributes to the broader understanding of sustainable forest management as an evolving intersection of policy, legality, and certification practice. Keywords: Sustainable forest management, PEFC, EUDR, Forest certification, Deforestation free legislation
Optimization of Fungal Extract Based Inoculation for Agarwood Induction in Aquilaria crassna
Agarwood is a highly valued non-timber forest product formed as a defense response in Aquilaria species following biotic or abiotic stress. Fungal based biological solid media inoculation is constrained by contamination and sterilization challenges, while liquid spore suspensions require precise timing and are difficult to prepare and transport at large scale. This study aimed to identify effective fungal extracts and determine optimal dosages for agarwood induction using Aquilaria crassna, to develop an inoculation protocol, and to evaluate agarwood yield and oil content over short and medium term periods. Four fungal species; Trichoderma sp., Lasiodiploidea sp. (01), Lasiodiploidea sp. (02), and Aspergillus sp. were selected based on their abundance, toxicity and extract producing potential to induce resin formation. Fungal extracts were prepared using Yeast extract Glucose Broth and Czapek Dox Broth and produced at three volumes of 25, 50 and, 100 mL via dichloromethane extraction. Field experiments were conducted in a 3 ha Aquilaria crassna plantation in Galle District, Sri Lanka, using 10 to 12 year old trees. Extracts were inoculated at different stem heights (top, bottom, middle) as four inoculation points per level using a drilled-hole method. Resin samples were collected after 3 and 6 months through tissue chiselling and later tree felling. Inoculation with 100 mL of Trichoderma sp., extract resulted in the longest resin formation (235.0 cm) after three months, indicating rapid resin development. Incontrast 100 mL of Lasiodiploidea sp. (01), extract resulted in the highest resin length, at six months (180.0 cm), indicating slower, but robust development. Statistical analysis confirmed that both fungal extract type and inoculation volume influenced the induced resin formation length. Furthermore, resin length varied significantly between harvesting intervals of three and six months, with greater development observed at six months (p=0.0023). The relative resin formation area varied with fungal extract type, inoculation volume, and tree diameter. The extract of Lasiodiploidea sp. (01) showed the highest effectiveness at all tested volumes (26.81% at 25 mL, 32.63% at 50 mL, and 38.71% at 100 mL). Extract of Lasiodiploidea sp. (02), consistently yielded the highest oil content, with slight increases observed from three to six months for 25 mL (3.70% to 3.81%) and 50 mL (3.26% to 3.29%) treatments. Accordingly, the application of 25 mL and 50 mL of Lasiodiploidea sp. (01) and Aspergillus sp. is recommended to achieve higher resin yields in A. crassna within six months. Further, it is recommended to increase inoculation points from 6 to 8 for trees with diameter at breast height between 16 cm to 25 cm for optimal yield. Keywords: Optimal dosage, Fungal extracts, Defense response, Yield, Protocol
Application of Geospatial Technology to Urban Tree Risk Assessment for Sustainable Urban Green Space Management: Special Reference to Colombo Municipal Area
Urban trees play a vital role in environmental quality, urban resilience, and human well-being within rapidly growing cities like Colombo, Sri Lanka. However, an increased frequency of urban tree failure, particularly during extreme weather events, indicates the need for an efficient tree risk assessment and management process within urban green spaces. This research intends to fill the gap in the use of geospatial technologies to assess the risk of urban trees in the Colombo Municipal Area. The primary aim is to evaluate and manage urban tree risk in an urban environment utilizing geospatial technology. The specified objectives are to identify and map the location of risky trees, to assess the level of risk and contributory factors, and to develop strategies to improve equity and sustainability relating to urban green space management. Data collection was completed along the examined main roads of the Kurunduwatta and Thimbirigasyaya Grama Niladhari Divisions within the Colombo Municipal Area, purposely sampled based on tree density and activity in the urban area. The methodology used involved mapping the location of trees and canopy characteristics through a combination of observation on the ground, GIS, and LiDAR data. A range of geospatial analysis techniques, including weighted overlay, buffer analysis, hotspot and kernel density mapping, and correlation and regression analysis, were used to assess risk. Risk scoring and indexing techniques were used to rank hazardous trees, along with Multi-Criteria Decision Analysis to identify sustainable urban tree management techniques. The results indicate a high concentration of hazardous trees along examined roadways and around buildings that may pose risks to public safety and infrastructure. The main risk factors were related to tree characteristics, tree defects, and often, various environmental conditions. Overall, there were a total of 75 trees identified as high risk, 29 trees classified as moderate risk, and 19 trees determined to be low risk. The results reveal that an active geospatial framework improves tree risk assessment, enhances public safety, and improves sustainable tree management of urban green space in the Colombo Municipal Area. Keywords: Colombo municipal area, Geospatial technology, Spatial analysis, Urban tree risk, Sustainable tree management
Vegetation Cover Change in Ella Sepa Using Prefire-Postfire NDVI Supported by Supervised Land-Use Classification and NASA Fire Data
Vegetation cover in the Central Highlands of Sri Lanka, particularly in fire-prone areas such as Ella in the Uva Province, is increasingly vulnerable to disturbance. This study assessed vegetation cover change in the Ella Special Environmental Protection Area (SEPA), identified under the Ella Development Plan 2021-2030. Vegetation change was analysed using a prefire-postfire approach with the Normalised Difference Vegetation Index (NDVI) and supervised land-use classification, supported by NASA FIRMS VIIRS Active Fire Data to identify fire-affected areas. NDVI values were derived from 30 m Landsat 8/9 OLI/TIRS Level 2 imagery for prefire conditions in December 2024 and postfire conditions in February 2025. NDVI layers were reclassified into three vegetation classes: non-vegetated, sparse, and moderate, and change detection analysis quantified vegetation loss. Supervised land-use classification validated spatial patterns of change. Results showed that non-vegetated areas increased by 85 ha, from 1.7% to 21.3% of the landscape, largely aligning with active fire detections near Ella Rock and Ella Rock viewpoint. Fire occurrence appears linked to anthropogenic ignition sources, facilitated by human access along the Ella-Wellawaya main road and secondary roads near tourist areas, and further exacerbated by the high flammability of pine-grassland mosaics and dry seasonal conditions. The SEPA core has limited settlements, while the surrounding areas are moderately populated, with a population density of ~400 persons/km2 in the Ella Divisional Secretariat, potentially elevating fire risk along accessible forest edges. Moderate vegetation patches were more resilient, likely due to topographic sheltering and reduced fire intensity. The study demonstrates that integrating NDVI, supervised classification, and active fire data is effective for monitoring vegetation dynamics, supporting conservation, and guiding fire risk mitigation. Keywords: Ella, NDVI, NASA fire data, Supervised land-use classification, Vegetation change
Cultural Justice in Sustainable Forest Management: A Case Study of Fa-Hien Cave, Sri Lanka
Forest heritage sites represent a unique intersection of ecological, cultural, and social values, yet management practices often prioritize environmental conservation over the inclusion of local communities and recognition of traditional knowledge. An integrated strategy that includes ecological preservation, cultural heritage, and community involvement is required for sustainable forest management. Located in Sri Lanka's Pahiyangala Forest Reserve, Fa-Hien Cave is a culturally significant archaeological site that houses the earliest known human skeletal remains in South Asia. It is also an ecologically significant habitat that supports endemic species. This study examines the incorporation of cultural justice principles into sustainable forest management at Fa-Hien Cave, analyzing the impact of power dynamics, governance frameworks, and community engagement on ecological sustainability and cultural conservation. The study aims to examine the degree of local community engagement, evaluate the acknowledgement of traditional ecological knowledge, discern patterns of inclusion and exclusion, and investigate strategies for attaining comprehensive sustainability that harmonizes ecological conservation with cultural heritage. A qualitative case study approach was used, employing document analysis of governmental and archaeological reports, policy frameworks, media articles, and historical records. Semi-structured interviews with 25 purposely selected participants including local elders, knowledge holders, tourism operators, and forest officials were also conducted. Field observations of ecological and culturally significant sites provided context for participant narratives and an assessment of the interaction between human activity and ecological integrity. Thematic analysis based on Braun and Clarke’s six-phase framework allowed for the identification of major themes related to governance, cultural inclusion, community participation, ecological sustainability, and social implications. Findings reveal a pronounced power imbalance, with decision-making dominated by institutional actors, resulting in limited recognition of local traditions, rituals, and heritage practices. Exclusion from governance contributes to cultural harm, marginalization, and diminished community stewardship, even as ecological conservation objectives are pursued. Informal community initiatives, such as volunteer-led monitoring and ritual practices, demonstrate the potential of local knowledge and participatory engagement to enhance ecological outcomes and strengthen social cohesion. Integrating cultural justice principles into forest governance can, therefore, improve both ecological and social sustainability. To achieve holistic sustainability that simultaneously preserves biodiversity, cultural heritage, and human well-being, the active participation of local communities, recognition of indigenous knowledge, and culturally sensitive management strategies are essential. These findings emphasize the necessity of multidisciplinary approaches in heritage forest management, offering actionable insights for policymakers, conservation practitioners, and tourism stakeholders. Keywords: Cultural justice, Sustainable forest management, Community participation, Heritage conservation, Fa-hien cave
Land Use Changes and Challenges in Achieving Effective Regional Development Planning in the Jaffna Divisional Secretariat Division
Land use plays a vital role in achieving effective regional development planning, particularly in areas experiencing rapid socio-economic transformation and environmental change. In the Jaffna Divisional Secretariat Division, land use patterns have undergone notable shifts due to post-war resettlement, urban expansion, migration, and changing agricultural practices. These transformations have created several land-use planning challenges, including the loss of agricultural land, illegal coastal settlements in Navanthurai, unregulated land reclamation, widespread encroachment, and poor drainage particularly Kurunagar and in Aanaikoddai J/88 GN Division. Waste-filled canals along the Sandilipay-Jaffna border, polluted mangroves, illegal tree cutting, and rapid, unplanned building expansion, together with four decades of population pressure from island-to-mainland migration and in-migration for services like education, employment, have further intensified these challenges. The study uses a mixed-methods approach combining GIS-based mapping, descriptive statistics, and thematic analysis to assess land use changes from 2010 to 2024. This period was selected due to the availability of continuous secondary data and its relevance for capturing post-war resettlement impacts. Secondary data from the Divisional Secretariat Statistical Handbooks provided annual land use types and extents for the analysis. GIS digitization was conducted to identify changes across major land categories, while qualitative insights were derived from field observations, stakeholder interviews, and photographic documentation. Quantitative findings from secondary records show that most land categories including built-up areas (87 ha), gardens (567 ha), and coconut/plantation areas remained largely unchanged from 2012-2024. The only substantial shift observed was the sharp decline in paddy extent, dropping from 52 ha during 2012-2019 to only 4-5 ha after 2020, indicating the conversion or abandonment of agricultural lands. Total mapped land area also decreased from 1,092 ha (2012-2019) to about 1,045 ha (2020-2024), a change attributed to boundary adjustments and updated digitization. These findings align with observed issues of agricultural land encroachment, unregulated reclamation, weak institutional coordination, and outdated land use plans. Based on the findings, the study recommends updating existing land use plans using accurate GIS baselines, strengthening enforcement against illegal coastal settlements and land reclamation, restoring blocked drainage and polluted mangrove areas, and protecting the remaining agricultural lands through clear zoning and monitoring. Improved coordination among planning authorities and active community participation are essential to address the documented challenges and support sustainable regional development in the Jaffna Divisional Secretariat Division. Keywords: Challenges, Jaffna DSD, Land use change, Regional development planning
Monitoring Vegetation and Land Cover Changes in Galle District, Sri Lanka Using NDVI-Based Time Series Analysis (2008-2024)
Vegetation cover plays a crucial role in maintaining ecological balance and supporting biodiversity. In Sri Lanka, rapid urbanization and land-use pressures have altered vegetation patterns, particularly in the Galle District, where both ecologically and economically significant. This study analyzed vegetation changes using the Normalized Difference Vegetation Index (NDVI) derived from Landsat imagery for 2008, 2016, and, 2024. This study aims to assess changes in forest cover in Galle district over time and to identify spatial and temporal patterns of deforestation within that region. Because these data driven insights support sustainable forest management and policy development. The years 2008,2016 and,2024 were selected because they represent regular 8-year intervals that allow for consistent long-term comparison of land surface changes. Using high quality satellite images spaced across such intervals helps capture meaningful environmental trends, comparability in spatial resolution and sensor characteristics. The images were selected due to their availability, seasonal comparability, and consistent acquisition during the dry period. Landsat data, with a 30 m spatial resolution, visible-NIR spectral bands essential for NDVI computation (TM Band 3/4; OLI Band 4/5), and 12-bit radiometric resolution (Landsat 8), ensured sufficient detail for long-term vegetation monitoring. NDVI values were reclassified into six land-cover categories: water bodies, built-up areas, barren land, sparse vegetation, moderate vegetation, and dense vegetation. Results indicated that in 2008, dense vegetation expanded significantly from about 658.3 km2 to over 1,000 km2 in 2016, representing a 55% increase likely caused by natural regeneration and targeted reforestation programs. By 2024, dense vegetation declined by nearly 15% to under 900 km, implying with a near doubling of built-up areas from 14km2 to 30 km2 and a significant reduction in water bodies by approximately 43%. To validate the classification 99 random points were generated across NDVI classified layers using ArcGIS. These points were verified against high resolution satellite images from Google Earth Pro. Vegetation changes detected through the study reflect rapid urban expansion and land conversion pressure mainly in low-lying and peri urban areas. Continuous monitoring through remote sensing and GIS is essential to support sustainable development and ensure ecological resilience in the district. Keywords: NDVI, Vegetation dynamics, Remote sensing, Land-use change, Urbanization
Assessing the Synergy of Rooftop Agriculture, Solar Energy, and Rainwater Harvesting in Sri Lanka's Land Use Policy
Rapid, unplanned urbanization and increasing population pressure in Sri Lanka have intensified competition for limited land availability, necessitating a novel, law-backed approach to land use planning to mitigate environmental degradation and improve food security. This study addresses the critical challenge of deriving maximum ecological and economic benefit from minimal urban land area by evaluating the synergy between vertical gardening, photovoltaic (solar) power generation, and rainwater harvesting systems, specifically within the context of applicable and effective implementation of Environmental Law. The main aims of the study are to: 1) design a flexible "vertical land use" model integrated into urban master plans through regulatory requirements, 2) quantify the impact of the technologies proposed on localized food supply and carbon reduction, and 3) recommend necessary legislation for their wide-scale diffusion. A sequential mixed-method approach had been followed, that includes, among others, 1) a desktop review focusing on existing land-use legislation and spatial analysis of areas of conflict, 2) development of a localized modelling and scenario framework, and 3) targeted stakeholder engagement with legal and planning bodies for validation. Key findings demonstrate that the adaptation of the balcony gardening concept of a "vertical land use" model has significantly increased functional green area coverage by an average of 180% per residential unit, thereby directly reducing land-sprawl. Crucially, the integration of solar photovoltaic (PV) panels powering the cultivation units resulted in a net-positive energy system that supplies 115% of the required electricity. The enhanced green coverage, besides a per-square-meter increase in local crop yield of 45% for key leafy vegetables, is a viable pathway for localized food production. Furthermore, this achieves a measurable carbon sequestration rate of 0.75 metric tons of CO2 per building annually. In conclusion, this research postulates that developmental sustainability is only possible not just with technological innovation but also with the compulsory integration of green building standards into revised Integrated Land Use Planning and enactment of specific regulations mandating such vertical ecological enhancement. Keywords: Environmental law, Rainwater energy, Rooftop agriculture, Solar energy, Vertical land use