The catch characteristics of a set longline fishery in the Foça Special Environmental Protection Area, Turkey

Background. Fisheries activities are rarely documented in the marine and coastal protected areas in Turkey. This study aimed to determine the catch composition of set longline fishery in the Foça Special Environmental Protection Area (Turkey), and to understand the effects of factors (e.g., bait type, hook size, and soak time) on the catch per unit effort (CPUE) and the size of species caught. Materials and methods. Samples were collected by small-scale fishing boats in 2007 at depths ranging from 1 to 50 m. Kruskal–Wallis test was used to understand if the CPUE changes depended on the fishery specific factors (hook size and bait type). Mann–Whitney U test was used to test if CPUE changes depended on sampling seasons (autumn and summer). Chi-square test was used to determine whether hook size influenced the body size of two commonly caught species. Results. The following 25 fish species were caught, Diplodus sargus, Sparus aurata, Diplodus vulgaris, Boops boops, Lithognathus mormyrus, Oblada melanura, Conger conger, Trachurus sp., Spondyliosoma cantharus, Pagellus erythrinus, Pagrus pagrus, Dentex dentex, Sciaena umbra, Scorpaena scrofa, Belone belone, Serranus sp., Myliobatidae gen. sp., Muraena helena, Sarpa salpa, Diplodus annularis, Coryphaena hippurus, Diplodus puntazzo, Chelidonichthys lucerna, Scomber japonicus, and Dicentrarchus labrax. The most commonly caught species were white seabream, Diplodus sargus and gilthead seabream Sparus aurata. The hook size and bait type were important factors that influenced the CPUE. Moreover, the hook size significantly influenced the body size of caught white seabream and gilthead sea bream. Conclusion. The discard level was low in the set longline fishery in the Foça Special Environmental Protection Area. We recommend using 12 sized hooks rather than 13 to reduce the discards of the main target species in the Foça SEPA. Nevertheless, this also needs an economic assessment, and also identification and use any incentives to promote the shift in the use of larger size hooks. Minimum size limits to be set in the fisheries legislation and alternative bait use studies were also recommended.