Present status of the seine fishery in Negombo lagoon of Sri Lanka

Abstract

Studies on the seine fishery of Negombo Lagoon in the west coast ofSri Lanka (7°10' Nand 79°50' E) were carried out for a period of one yearfrom May 1989 to April 1990. In the operation of this gear, 2 or 4 standardnets, each with a length of 32 m are used. Each net was made up of 4 or 5vertically joined pieces of nets, with a stretched mesh size of 1.25 em. 3 and 5men are involved in 2 net and 4 net operations respectively. Total productionfrom this gear was estimated to be around 36,000 kg/year. During the presentstudy, 82 species of fish ranging in size from 2.5 em to 130.0 em were encounteredtogether with 6 species of commercially important penaeid prawns. Thecatch and fishing effort were low from August to December. Catch per uniteffort was high from February to May. Salinity and fish catch showed asignificant positive correlation probably due to immigration of allochthonousmarine organisms into the lagoon with increasing salinity. Fishing effortalso showed a significant positive correlation with salinity. Significant differencebetween the catches of 4 net-piece and 5 net-piece nets was not observed(P>0.05). Although the catch and catch per fisherman were significantly higherin 4 net operations than in 2 net operations (P <0.05), significant differencein catch per net between the two operations was not observed (P > 0.05). 2 Netoperations were observed to provide more employment opportunities andbetter distribution of income than 4 net operations. Threat of overexploitationof the resource was observed to be high in 4 net operations.