Beached bird surveys in Portugal 1990-1996

Between 1990 and 1996 a large proportion of the Portuguese coast was systematically surveyed for dead seabirds during the winter (October to March). About 5330 Km of beaches were walked during this period and 2660 dead seabirds were recorded. Razorbill Alca torda was the most common species, followed by Gannet Morus bassanus, Yellow-legged Gull Larus cachinnans and Lesser Black-backed Gull L. fuscus. Together, these species accounted for 73.7% of all corpses found. Most casualties were found in the central area of the Portuguese coast. Beaches in these regions face predominant northwesterly winds and are close to an important upwelling area which represents a potentially good feeding zone for seabirds. Oil contamination of the corpses was generally low, especially when compared with those recorded in similar surveys in some northern European countries. Deaths due to entanglement in fishing gear were significantly lower than those reported in previous surveys and they apparently no longer represent a major threat to seabirds in the Portuguese coast