Comparison of trawl catch compositions in Saros and Gökova bays

In this study, the trawl catch data were analysed collected from Saros and Gökova Bays. Four bottom trawl surveys were conducted in Gökova Bay in May 2001, January 2002, October 2002 and January 2003 with R/V. K.Piri Reis while only two surveys were carried out in Saros Bay in May 2001 and January 2002. A total of 49 bottom trawls (33 in Gökova Bay and 16 in Saros Bay) were hauled at depths ranging from 57 m to 72 m. Altogether 91 species were obtained, which contained 1 echinoderm, 7 crustacean species, 13 cephalopod species (5 cuttlefishes, 4 squids and 4 octopuses), 6 cartilaginous fish species (4 sharks and 2 rays) and 64 bony fish species. Bony fishes constituted more than 90 % of total catch by weight, while their share ranged between 40-70 % in Saros Bay of the catch. The total estimated biomasses based on the swept area method varied between 479.71-799.69 kg/km2 for Gökova Bay and 858.02-1135.33 kg/km2 for Saros Bay. While the similar species diversity and richness values observed for both bays, the structures of demersal resource assemblages were seemed to be slightly different. Sampling area is found as main factor determining the structure of demersal resource assemblages. However, the main species that the effective in discrimination regional differences were Pagellus erythrinus, Upeneus moluccensis, Scyliorhinus canicula, Uranoscopus scaber, Boops boops and Diplodus annularis.Keywords: Gökova Bay, Saros Bay, trawl catch composition, biomass.