Interannual and decadal variability in zooplankton communities of the southeast Bering Sea shelf

摘要: The southeastern Bering Sea shelf ecosystem is an important fishing ground for fin- and shellfish, the summer foraging grounds many planktivorous seabirds marine mammals. In 1997 1998, Northern Hemisphere climate anomalies affected physical biological environment of shelf. resulting anomalous conditions provided a valuable opportunity to examine how longer-term change might affect this productive ecosystem. We compared historical recent zooplankton biomass species composition data whether or not there was response atmosphere–ocean–ice 1998. Summer (1954–1994) over did exhibit decline as previously reported oceanic stations. addition, in 1998 appreciably different from other years time series. Spring concentrations numerically abundant copepods (Acartia spp., Calanus marshallae, Pseudocalanus spp.), however, were significantly higher during 1994–1998 than 1980–1981; spring Metridia pacifica Neocalanus spp. consistently between two periods. only taxon have consistent differences stage periods—CV copepodites much more prevalent May 1990s early 1980s. Since relatively high observed prior 1997, we do attribute summers directly acute anomalies. With present it possible distinguish increased production (control below) decreased predation above) explain increase examined.