The species composition, abundance and the distribution of seagrass communities in Puttalam lagoon

Abstract

The species composition, abundance and the distribution of different seagrassbeds of Puttalam lagoon have been investigated. Eight species belonging to sixgenera were recorded during the investigation i.e., Enhalus acroida (I. F..)RoyleThalassia hemprichif (Ehrenb.) Aschers., HaIodule uninervis (Forsk.) Aschers inBossiser, Syringodium isoetifolium (Aschers.) Dandy, Cymodocea rotundataEhernb. et Hempr. ex Aschers., Cymodocea serrulata(R. Br.) Aschers, and Magnus,Halophila ovalis (R. Br.) Hook. F. and Halophila decipiens Ostenfeld. Twovarieties of Halodule uninervis (narrow and wide) were also recorded during thisinvestigation. The distribution pattern of the different species of seagrass bedsshowed a close association with different salinity values of the lagoon. It wasfound that the narrow variety of Halodule uninervis covered 75% of the potentialareas of the lagoon. It was also observed that Enhalus acroides, Cymodoceaserrulata and Thalassia hemprichii play a major role as substrata lor manyimportant epiphytic forms of macro and micro algae. It was also discussed thaitraditionalfishing methods prevailing in this lagoon show til great threat to the'survival of the seagrass communities.'