Comparison of different selectivity of the trammel nets have various mesh sizes which are used in Black Sea by using different models

The study was carried out between September 2015 and August 2016 by using gillnets with 32 mm, 36 mm and 40 mm mesh size which are used extensively by fishermen in Sinop region. The selectivity parameters of red mullet and whiting targeted species of gillnet and Solea solea, Arnoglossus laterna, Pegusa lascaris which have not previously been assessed in this region have been calculated using SELECT and Holt methods. In addition, the length – weight relationships of fish caught by gillnets used in this study were calculated. At the end of the study, 429.498 kg of fish and crab species were caught in total. 326.125 kg of total catch is composed of fish species and 103.373 kg is composed of crab species. The optimum catch lengths calculated by Holt method in gillnets with 32 mm, 36 mm and 40 mm mesh size were as follows; 14.82 cm, 16.67 cm and 18.53 cm for Mullus barbatus, 13.67 cm, 15.38 cm and 18.80 cm for Merlangius merlangus, 11.90 cm, 13.40 cm and 14.90 cm for Solea solea, 11.50 cm, 13.00 cm and 14.40 cm for Pegusa lascaris, 12.20 cm, 13.70 cm and 15.30 cm for Arnoglossus laterna, relatively. The optimum catch lengths calculated by SELECT method were as; 14.41 cm, 16.21 cm and 18.02 cm for Mullus barbatus, 13.79 cm, 15.51 cm and 17.24 cm for Merlangius merlangus, 12.22 cm, 13.75 cm ve 5.28 cm for Solea solea, 11.40 cm, 12.82 cm and 14.25 cm for Pegusa lascaris, 12.16 cm, 13.68 cm and 15.20 cm for Arnoglossus laterna, respectively.