HR: 0800h
AN: OS41A-0462    [Abstracts]
TI: The Northern Bering Sea: An Arctic Ecosystem in Change
AU: * Grebmeier, J M
EM: jgrebmei@utk.edu
AF: University of Tennessee, Marine Ecology and Biogeochemistry Group, Dept. of Ecology & Evolutionary Biology, 10515 Research Dr Suite 100, Knoxville, TN 37932 United States
AU: Cooper, L W
EM: lcooper1@utk.edu
AF: University of Tennessee, Marine Ecology and Biogeochemistry Group, Dept. of Ecology & Evolutionary Biology, 10515 Research Dr Suite 100, Knoxville, TN 37932 United States
AB: Arctic systems can be rich and diverse habitats for marine life in spite of the extreme cold environment. Benthic faunal populations and associated biogeochemical cycling processes are influenced by sea-ice extent, seawater hydrography (nutrients, salinity, temperature, currents), and water column production. Benthic organisms on the Arctic shelves and margins are long-term integrators of overlying water column processes. Because these organisms have adapted to living at cold extremes, it is reasonable to expect that these communities will be among the most susceptible to climate warming. Recent observations show that Arctic sea ice in the North American Arctic is melting and retreating northward earlier in the season and the timing of these events can have dramatic impacts on the biological system. Changes in overlying primary production, pelagic-benthic coupling, and benthic production and community structure can have cascading effects to higher trophic levels, particularly benthic feeders such as walruses, gray whales, and diving seaducks. Recent indicators of contemporary Arctic change in the northern Bering Sea include seawater warming and reduction in ice extent that coincide with our time-series studies of benthic clam population declines in the shallow northern Bering shelf in the 1990's. In addition, declines in benthic amphipod populations have also likely influenced the movement of feeding gray whales to areas north of Bering Strait during this same time period. Finally a potential consequence of seawater warming and reduced ice extent in the northern Bering Sea could be the northward movement of bottom feeding fish currently in the southern Bering Sea that prey on benthic fauna. This would increase the feeding pressure on the benthic prey base and enhance competition for this food source for benthic-feeding marine mammals and seabirds. This presentation will outline recent biological changes observed in the northern Bering Sea ecosystem as documented in a 20-yr environmental time-series in the Bering Strait region.
UR: http://arctic.bio.utk.edu
DE: 4207 Arctic and Antarctic oceanography
DE: 4215 Climate and interannual variability (3309)
DE: 4283 Water masses
DE: 4540 Ice mechanics and air/sea/ice exchange processes
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting