Trotline hook selectivity for the Atlantic Bonito (Sarda sarda Bloch, 1793) fishery in the Canakkale Strait (northern Aegean Sea, Turkey)

This study was conducted to determine the selectivity of hooks (galvanized, tin, carbon, nickel) used for Atlantic bonito (Sarda sarda Bloch, 1793) in the Gallipoli Peninsula and the Dardanelles during the 2015 and 2018 fishing seasons (spring and autumn). The Atlantic bonito was fished with hooks of size 1/0, 2/0, 3/0, and 4/0. A total of 604 bonitos were caught, including 201 individuals using a galvanized hook, 194 individuals using a tin hook, 158 individuals using a nickel hook and 51 individuals using a carbon hook. A lower catch was obtained with hooks of size 4/0 (42 in total). The highest catch (100 total) was obtained with hooks of size 1/0 and a lower catch (19 in total) was obtained with hooks of size 4/0 in the case of tin hooks. In the case of nickel hooks, the highest catch (63 in total) was obtained with hooks of size 1/0 and a lower catch (eight in total) was obtained with hooks of size 4/0. The optimum catch length and curve width were calculated in relation to the size of hooks. It was determined that all hooks used in the experiments catch below the length allowed for fishing. It was therefore concluded that the use of the largest hooks would be preferable, with size 4/0 being the most suitable for maintaining the continuity of the species.