Cost of Fishing on Juveniles of Finfish and Shellfish: Assessment of Economic Impacts of Trawl Juvenile by-Catch along the Coast of North Andhra Pradesh, India

A study was carried out to assess the economic value of juveniles of commercially important species of finfish and shellfish caught as by-catch by multiday commercial trawlers operated off the coast of Visakhapatnam, north Andhra Pradesh from January 2014 to December 2015. Juveniles of twenty species (four species of cephalopods and sixteen species of finfish) were found to dominate the trawl by-catch. The landed juveniles of these 20 species formed 12,757.16 t and 286.86 million numbers per year and their contribution to the total landings of these species in trawl by-catch were 55.30% by weight and 57.03% by numbers. The highest percentage of quantities of juveniles (biomass) was found in trawl by-catch in the months of August and July in, 2014 and 2015 respectively. Among the juveniles, ribbonfish (Trichiurus lepturus) and goatfish (Upeneus vittatus) dominated, contributing together, on an average 11.60% by weight and 33.68% by numbers respectively. Using the bio-economic model, it was estimated that if the juveniles were allowed to grow up to length at first maturity; total annual economic gain would have been Rs. 273.21 crores (42.03 million USD) with biomass gain of 44,493.02 t per annum. The estimated total annual biomass would have increased 3.46 times with an increase in revenue by 4.20 times. Annual average loss due to fishing of juveniles was estimated to be Rs. 209.62 crores (32.25 million USD). The results of the present study suggested that sustainable harvest of these resources would have yielded maximum economic return to the fishers. With the help of stakeholders using a participatory approach, management measures such as increase of cod end mesh size of trawl to 40 mm from the present mesh size of 10–12 mm, use of square mesh for trawl cod ends, fishing effort restriction and awareness campaign on the detrimental impacts of catching juveniles needs to be implemented at the earliest for avoiding growth overfishing