Composition and abundance of pelagic shark by-catch in the eastern Mediterranean Sea

During the period 1998-2001, a survey to study the incidence of the drift longline fishery on shark populations was carried out in the eastern Mediterranean Sea. A total of 8 different pelagic shark species were recorded in the catches of the Greek swordfish (Xiphias gladius) and albacore (Thunnus alalunga) longline fisheries. Among them, the blue shark, Prionace glauca, was the most common species in the catches while the bigeyed sixgill shark, Hexanchus nakamurai, was reported for the first time in the area. Shark bycatches were noteworthy in the swordfish fishery reaching a 3.8% in number and 3.6% in biomass of the total catch. The higher abundance indices were observed in the Levantine Basin (CPUE = 0.74 sharks/1,000 hooks). Catches in this area consisted of much larger specimens than those measured in other areas of the Mediterranean Sea.