Abstract

Pacific waters transiting northward over the shallow continental shelves of the Bering, Chukchi, and East Siberian seas have a dramatic influence on benthic carbon cycling, biological structure and shelf-basin exchange with the Arctic Basin. Recently the extent and duration of seasonal ice has decreased in this region, coincident with changing hydrographic conditions. The shallow, productive and dynamic nature of the Bering Strait region accentuates its role as a sentinel indicator of global change effects. Changes in both primary and secondary production levels could lead to major impacts for higher-trophic level fauna, including benthic-feeding walrus, bearded seals, gray whales and diving seaducks. Ecosystem change in this region is intimately connected to systems further north. Studies as part of the Western Arctic Shelf-Basin Interactions (SBI) project are investigating the production, transformation and fate of carbon at the shelf-slope interface in the northern Chukchi and Beaufort seas, downstream of these productive western shelves, as a prelude to understanding the impacts of a potential warming of the Arctic. The importance of this Pacific-influenced region in the context of pan-Arctic shelf-basin exchange will be discussed.

Biographical Sketch

Dr. Grebmeier's oceanographic research interests are related to pelagic-benthic coupling, benthic carbon cycling, and benthic faunal population structure in the marine environment. Over the last 20 years, her field research program in both the Arctic and Antarctic has focused on such topics as understanding how water column processes influence biological productivity in Arctic waters and sediments, how materials are exchanged between the sea bed and overlying waters, and documenting longer-term trends in ecosystem health of Arctic continental shelves. Some of her research projects have included analyses of the importance of benthic organisms to higher levels of the Arctic food web, including walrus, gray whale, and diving sea ducks, and studies of radionuclide distributions in sediments and within the water column in the Arctic as a whole. In other work, she has studied the influence of oceanographic processes on benthic communities in Antarctica, chemical exchange at hydrothermal vents systems in the equatorial eastern Pacific Ocean, and the transport and fate of materials in melted snow in Arctic tundra in the Brooks Range foothills.

Dr. Grebmeier has served on a number of advisory committees to the U.S. National Academy of Sciences, Polar Research Board, and the National Science Foundation. She also currently acts as project office director for a National Science Foundation global change research project on Shelf-Basin Interactions (SBI). The SBI project is multidisciplinary, involving a number of different university researchers across the United States, and it is linked to other international scientific research across the circumpolar Arctic. The project goals are to evaluate how projected global changes in temperature, sea ice coverage, and oceanographic processes may influence the exchange of materials between Arctic shelves and deep water basins, and what larger impacts these changes will have on Arctic communities specifically and human society in general.

Academically, Dr. Grebmeier received her Bachelor of Science in Zoology at the University of California, Davis in 1977 and went on to receive Masters Degrees in Biology from Stanford University in 1979, and in Marine Affairs from the University of Washington in 1983, specializing in applications of Arctic science to Arctic resource utilization policy. She received a Ph.D. in Biological Oceanography from the University of Alaska, Fairbanks in 1987. Following service as a postdoctoral associate of the University of Southern California from 1987-1988, she then affiliated with the University of Tennessee in 1989. She was appointed as a member of the United States Arctic Research Commission in 2000.

Light refreshments are served in the Interaction Area (4th floor of the Oceanography/Physics Building) at 4:00 p.m.

All seminars begin at 3:00 p.m. and are held in room 200 of the Oceanography/Physics building.