Interactions between small cetaceans and the purse-seine fishery in western Portuguese waters

摘要: Marine mammal interactions with Portuguese purse-seine fisheries operating in four different ports (Figueira da Foz, Sesimbra, Setubal, Sines) were studied (July-October 2003). Observers accompanied commercial fishing vessels and monitored 48 trips. An interview survey of skippers was also carried out (n = 36). Three species marine mammals observed 31 sightings during the commercials trips but only Delphinus delphis category Delphinidae to interact activities. Small cetaceans sink, gather or disperse school fishes damage gear. Mean CPUE effort values did not change significantly presence dolphins (H 0.06 H 0, both p>0.05). Results from Figueira Foz indicate that are attracted grounds a high abundance their prey-species. Fishermen reported three by-catch events off Foz. Compared other fisheries, does seem be among most damaging mammals.