VISAKHAPATNAM : About 70 to 90 per cent of the by-catch is of the economically important juvenile fish. Lack of proper technology and restrictions followed by the fishermen in the trawler nets, the by- catch percentage is growing high.
To control it, Central Institute of Fisheries Technology (CIFT) has designed a square-shaped mesh in trawl nets which is diamond-shaped now. Along with it, they are now designing a Juvenile and Trash Extrude Device (JTED), a device followed by the South East Asian countries, for the escape of juvenile fish into water.
“The fishermen who are using small mesh like 10-15 mm net is resulting in the catch of eggs and even juvenile fish which cannot escape. Once they catch, the fishermen open the cod end every three hours and throw the unwanted fish into water.
By changing the configuration of mesh size to square shape, once you drag the net, all juveniles can escape in live condition,” said G Rajeswari, the principal scientist at the CIFT. For the fish, hatching from egg to its full developed stage, it requires a lot of time. If the fish is allowed to grow, they weigh up to 30 kg, but these are captured in 1-2 gram stage.
“With marine resources of 3.59 million tonnes, we have exploited shallow water up to a depth of 50 metres.
While Tuna fish has a lot of export value with 2,80,000 tonne potential and myctophids fish with high potential available in 102 million tonnes in Eastern Indian Ocean, they are found indepth. Under remote sensing project, we are giving details to the fishermen to find those fish,” she added. Under the project, assessment of Deep Sea Resources, CIFT scientists have found about 155 species in the deep sea.