Impact of purse seine operations on traditional fishery with special reference to oil sardine in Kerala during 1980 and 1981

There has been a marked decline in the landings of oil sardine in 1980, compared to the previous two Years. A study was undertaken to examine the reasons for this decline and to determine whether the Purse seine operations which started in 1979 has any influence on the treiditional fishery. For this purpose The data on catch, effort, age and length composition of oil sardine collected by this Institute during 1978-81 period pertaining to indigenous gears and purse seines and the data on socio-economic cispects Gathered through a special survey in 1981 in the coastal villages of Kerala were considered. The purse seiners have started operations in Cochin area during the latter half of 1979 with about 10 units, which increased to about 40 and 60 in 1980 and 1981 respectively. The purse seiners operated are of about 13 m. In length with nets measuring 500-600 m in length and 50-60 m in depth with the meshes ranging from 13 to 20 mm in size