The incidental capture of seabirds by Spanish drifting longline fisheries in the western Mediterranean Sea

The western Mediterranean Sea is an important fishing area for the Spanish drifting longline fleet, targeting swordfish (Xiphias gladius), bluefin tuna (Thunnus thynnus) and albacore (T. alalunga). Some seabird species can be captured incidentally as bycatch marine fauna. From July 1999 to August 2000 information on 554 surface longline sets was collected by onboard observers of the Spanish Oceanographic Institute (IEO) on 18 longline fishing boats working within the Spanish Mediterranean fishing area. Eleven yellow-legged gulls (Larus cachinnans), 9 Cory´s shearwaters (Calonectris diomedea) and 1 Northern gannet (Morus bassanus) were captured incidentally. Bycatch rates ranged from 0.002 to 0.023 birds/1000 hooks.