Size selectivity of sorting grid for eight fish species in the Gulf of Antalya, Northeastern Mediterranean Sea

Abstract

Selectivity of sorting grid for eight fish species were studied under commercial conditions in the trawl fishery of Antalya Bay, in the eastern Mediterranean Sea. Trawling’s were operated from October to December 2012, using a traditional bottom trawl net. The fish totally retained in upper codend (catchees), and bottom codend (escapes) were used to estimate the selectivity parameters. Selectivity data analyzed as covered codend method by means of a logit function of Maximum Likelihood Method. The Kolmogorov-Smirnov test was applied in order to determine the difference between size groups of escapes and catchees codends. Fifty percent retention lengths ( L 50 ) of Spicara flexuosa (Picarel), Boops boops (Bogue), Mullus surmuletus (Surmullet), Mullus barbatus barbatus (Red mullet), Upeneus moluccensis (Goldband goatfish), Trachurus mediterraneus (Mediterranean horse mackerel) Trachurus picturatus (blue jack mackerel) and Saurida undosquamis (Brushtooth lizardfish) were calculated as 13.31; 13.47; 15.58; 12.07; 13.52; 18.49; 17.81 and 20.3cm, respectively. Results showed that sorting grid installed trawl nets provided high selectivity for all fish species