Co-Sponsored by ICES
Co-Convenors: Hidehiro Kato (Japan), Begoña Santos (ICES, Spain) and William J. Sydeman (U.S.A.)
In many marine ecosystems from tropical to arctic waters, marine mammals are showing considerable changes in abundance. In general, cetaceans, recovering from historical exploitation, are increasing, whereas some pinniped species are declining regionally, while others are increasing. Models of marine mammal prey consumption indicate that ~20-60% of secondary production may be taken by these top consumers. Therefore, marine mammals may exert «top-down» control on food webs, as well as functioning as competitors to fish, seabirds, and humans for mid-trophic level food resources. One of the goals of PICES and ICES science is to enhance forecasts of ecosystem change attributable to climate and anthropogenic forcings. Given this goal, the workshop will review and assess rates of marine mammal population and prey consumption changes in the North Pacific and North Atlantic. Presentations are invited on changes in marine mammal abundance, distribution, diet, and prey consumption. Discussion will focus on how to best integrate this information into models of ecosystem dynamics, with and without climate change and fishing impacts.