The gathering of predators around the sea-cage fish farms in the Aegean Sea

A total of 48 randomly selected fish farms from the coasts of Izmir and Mugla, Aegean Sea, were visited to face-to-face interviewing with fish farmers in the sea-cage fish farms between July 2015 and July 2017. Data were collected concerned mainly the following two aspects in the area: (i) actual problems on the sea-birds and other predators such as sharks, dolphins, monk seals, fishes; (ii) interactions between sea-cages and predator attacks. Around the sea-cage fish farms, 3 sea birds, Phalacrocorax carbo, Egretta alba and Larus michahellis, 2 marine mammals, Tursiops truncatus and Monachus monachus, 3 fish species, Pomatomus saltatrix, Thunnus thynnus and Prionace glauca, and one sea turtle, Caretta caretta, were declared as predators. The cormorant P. carbo had the highest ratio (24.3%) for being seen as a potential problem by fish farmers, followed by T. truncatus, T. thynnus and M. monachus. Great white egret, yellow-legged gull and cormorant were continuously observed by fish farmers. Seasonally, there were significant different incidences of the species (p < 0.05). Monk seal and bluefish were observed continuously, while blue shark had only been appeared during the collecting dead fish around the sea-cage fish farms.