MEPS 189:117-123 (1999)  -  doi:10.3354/meps189117

Community reorganization in the Gulf of Alaska following ocean climate regime shift

Paul J. Anderson1,*, John F. Piatt2

1National Marine Fisheries Service, Alaska Fisheries Science Center, 301 Research Court, Kodiak, Alaska 99615, USA
2U.S. Geological Survey, Alaska Biological Research Center, 1011 E. Tudor Rd., Anchorage, Alaska 99503, USA

ABSTRACT: A shift in ocean climate during the late 1970s triggered a reorganization of community structure in the Gulf of Alaska ecosystem, as evidenced in changing catch composition on long-term (1953 to 1997) small-mesh trawl surveys. Forage species such as pandalid shrimp and capelin declined because of recruitment failure and predation, and populations have not yet recovered. Total trawl catch biomass declined >50% and remained low through the 1980s. In contrast, recruitment of high trophic-level groundfish improved during the 1980s, yielding a >250% increase in catch biomass during the 1990s. This trophic reorganization apparently had negative effects on piscivorous sea birds and marine mammals.


KEY WORDS: Shrimp · Capelin · Forage fish · Gulf of Alaska · Groundfish · Climate change


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