Estimation of selectivity parameters for target and bycatch fishes of the trammel net fisheries in the northern Aegean Sea (eastern Mediterranean Sea)

The size selectivity of trammel nets was investigated in the northern Aegean Sea using 10 different inner-panel mesh sizes ranging from 16 to 70 mm nominal (bar length). Selectivity estimates were made for eight most abundant target and bycatch fish species, namely black scorpionfish, Scorpaena porcus Linnaeus, 1758; annular seabream, Diplodus annularis (Linnaeus, 1758); red mullet, Mullus barbatus surmullet, surmuletus round sardinella, Sardinella aurita Valenciennes, 1847; European hake, Merluccius merluccius greater weever, Trachinus draco blotched picarel, Spicara flexuosum Rafinesque, 1810, which accounted 51.5% by number 42.7% weight caught with sea trials. SELECT method used estimate parameters. Five functions (i.e., normal scale, location, gamma, log-normal, bi-normal) applied bi-normal function providing best fit as it had lowest deviance value all species values dispersion parameter ( D /df). cases retained specimens below at first maturity L m ). 19 seems more appropriate 22 seabream while hake larger than 26 would be appropriate.