Pelagic longline fishery for albacore (Thunnus alalunga) in the mediterranean sea off Egypt

Özet

This study highlighted the occurrence of a pelagic longline fishery targeting albacore in the Eastern Mediterranean Sea off Egypt. Species selectivity of the fishing method was assessed. Catch per unit effort CPUE , size frequency and lengthweight relationship were estimated for the target species. This fishing method was found to be highly selective for albacore, where its catch represented about 93.5% of the total landed catch. The major by-catch species were swordfish Xiphias gladius (2.5%) and the little tunny Euthynnus alletteratus (2.4%). Skipjack Katsuwonus pelamis, dolphinfish Coryphaena hippurus, Bigeye thresher Alopias superciliosus, and oilfish Ruvettus pretiosus represented collectively, 1.5% of the total landed catch. The fork length of albacore ranged from 54 to 138 cm, with an average of 79.1±7.2 cm. Total weight ranged from 4 t 40 kg with an average of 8.8±7.2 kg. The length-weight relationship was determined to be W = 5.26 x 10-5 L2.75 (W in kg, L in cm). The CPUE for albacore ranged from 7 to 22 fish / 1000 hooks for the different fishing trips, with an average CPUE of 12 fish/1000 hooks (SE±4.4).