Species composition and temporal variation of trawl by-catch in fishing grounds off northern Andhra Pradesh, western Bay of Bengal

摘要

The by-catch composition, catch rates of major species in by-catch and its seasonal variation was studied from 53 trawl hauls of a commercial shrimp trawler for the period from December 2013 to December 2014. From 330.036 kg of by-catch, 27,854 specimens were obtained belonging to 248 taxa (89 families) from which 216 were identified upto species level. Contribution of teleosts and invertebrates to the total by-catch biomass was 87.49% and 11.48% and to the total number of individuals in by-catch was 86.83% and 13.05%. Portunidae, Carangidae, Penaeidae, Sciaenidae, Apogonidae, Engraulidae, Synodontidae and Leiognathidae were the eight most speciose families accounting for 41 % of the species. Photopectoralis bindus was the most numerically abundant (16.92%). Mean catch rates of total by-catch differed significantly between seasons with higher catch rates in post fishing ban period for biomass and number. Seven teleost and four invertebrate species had mean catch rates higher during post fishing ban period, while one each had higher catch rate during pre fishing ban period.