Effect of the number of meshes in the protective bag circumference on size selectivity of demersal trawl codends
Makaleler > Tam Makale · 2014
Yazarlar: Celalettin AYDIN, T. Sensurat, Yeliz ÖZDEMİR, Zafer TOSUNOĞLU
Journal of Applied Ichthyology, SCI Expanded İndekslerine Giren Dergi, Uluslararası, Wos, 2014, cilt 30, ss 454-462
DOI: 10.1111/jai.12413
Özet
This study investigated the effect of the number of meshes in the protective bag circumference on size selectivity of a demersal trawl codend. Circumferences of 50-mesh (NMPB50) and 215-mesh (NMPB215) protective bags rigged on the 44 mm diamond mesh codend were tested. Fishing experiments were carried out on the commercial trawler ‘Hapuloğlu’ between 20 and 27 August 2010, using a modified trawl net. Data were collected using the covered codend method and analyzed using the logistic equation with the maximum likelihood method. Mean selection curves were analyzed and compared using the between-haul variations model. The mean L50 values of NMPB50 and NMPB215 were, respectively, 16.4 ± 0.1 mm and 16.5 ± 0.1 mm carapace length for deep-water rose shrimp, 10.7 ± 0.1 cm and 12.2 ± 0.1 cm total length for hake, and 16.0 ± 0.1 cm and 16.7 ± 0.1 cm total length for horse mackerel. In conclusion, increasing the number of meshes around the protective bag resulted in a 14% and 4% increase in the L50 for hake and mackerel, respectively; however, these differences were not statically significant (P > 0.05).