Estimation of CPUE and CPUA of pufferfish (Tetraodontidae) caught by the Bottom Trawl Fishery in the eastern Mediterranean Coasts

Abstract

Two indicators of pufferfish communities, catch per unit effort (CPUE) and catch per unit area (CPUA), were used with surveys of bottom trawl fishery to elucidate the level of the catch of each pufferfish species in the Mediterranean coasts of Turkey, comprising the Iskenderun Bay, Mersin Bay, and Antalya Bay. The surveys were conducted seasonally in 2019. The average rate of CPUE for Lagocephalus sceleratus, L. suezensis, L. spadiceus, and Torquigener flavimaculosus were 2.2, 0.8, 0.5, and 0.2 kg km-2, respectively that the highest CPUE values were in winter (8.0 kg km-2) for L. sceleratus and also lowest was in winter (0.08 kg km-2) for L. spadiceus. The highest and lowest CPUE values were at the depth of 20-50 m (2.7 kg km-2) for L. sceleratus and 50-80 m (0.08 kg km-2) for T. flavimaculosus, respectively. The highest CPUE values (3.5 kg km-2) were found at the sandy bottom for L. sceleratus, and the lowest one (0.01 kg km-2) was at the hardy-ground for T. flavimaculosus. The average annual CPUA of pufferfish species at the Iskenderun, Mersin, and Antalya bays was estimated as 15.6, 28.4, and 6.81 kg, respectively, with a mean value of 17.3 kg/day/boat. In multiple correspondence analysis, L. sceleratus showed a great contribution to CPUE and CPUA data. However, T. flavimaculosus revealed contribution, especially in catch numbers which were positively affected by precipitation. L. spadiceus, L. suezensis, and T. flavimaculosus were positively affected by depth, temperature, month, season, and bottom structure.