Trawl Bycatch Diversity of Bivalves (Mollusca: Bivalvia) in Neendakara Fishing Harbour, Kollam

In India, the fishery exploits species that widely vary in their life history traits and habitats. About 800 species of elasmobranches, teleosts, crustaceans, molluscs and echinoderms are taken by the trawls, and at least 300 species are the target species to the fishery (Vivekanandan, 2013). In the Neendakara harbour, molluscan species are the dominant species landed as by catch during the study period. From the collected samples, the bivalve species were sorted and recorded. Bivalves are the most diverse group of marine invertebrates and they include morphologically diverse group of organisms. The diversity of bivalves landed at the Neendakara fishing harbour, one of the major fish landing centers at Kollam, Kerala is included in this paper. The study period was for one year from August 2013 to May 2014. Altogether 46 species of bivalves were recorded during the study period. These 46 species belong to 13 orders, 16 families and 27 genera. The species composition data showed that the species of the family Arcidae have maximum species composition (21 %), followed by family Glycymeridae, Pinnidae, Pectinidae, Dimyidae however, had less species composition (less than 1 %). The collection represented the economically important species such as Perna viridis, Perna perna, Anadara indica, Anadara inequialis and Anadara gibbosa. Results also revealed that majority of the species identified belonged to sand dwelling or bottom dwelling animal category. Majority of these species belong to the non target species and hence they are discarded into the sea after the target group are selected. It is already known that the bottom trawling affects the natural habitat of bivalves and also inversely affects the diversity of bivalve fauna. This paper focus on the species diversity of bivalves landed as trawl bycatch, the number and species come under the discards and the impact of trawling on these bivalves.