Meeting Abstract
S7.3 Tuesday, Jan. 5 Evidence for a Benthic Food Bank in West Antarctic Peninsula Sediments: Radiochemical and Benthic Biological Approaches DEMASTER, David J.*; SMITH, Craig R.; THOMAS, Carrie J.; North Carolina State University; University of Hawaii, Honolulu; North Carolina State University demaster@ncsu.edu
Primary production and organic carbon export flux along the Antarctic continental shelf commonly are characterized by intense boom-bust seasonality. The FOODBANCS Project (FOOD for Benthos on the Antarctic Continental Shelf) conducted 5 cruises between December 1999 and March 2001 to the West Antarctic Peninsula (WAP) Shelf to determine the seasonal variability in organic matter flux to the seabed and to examine the fate of this organic matter on the seafloor and in benthic food webs. Sediment traps, time-lapse bottom photography, video surveys, a variety of coring efforts (mega-, box, and kasten), bottom trawls, and flux core measurements (oxygen, DIC, and nutrients) all support the hypothesis that the near-surface Antarctic sediments are acting as a “food bank”, with sedimentary processes (e.g., particle flux, bioturbation intensity, detritivore food availability, organic matter regeneration) exhibiting substantially less variation than the associated primary production rates in the overlying waters. In 2008 and 2009, FOODBANCS2 explored many of the same biogeochemical and benthic biological processes along an expanded N/S sampling grid on the WAP Shelf extending from 63oS to 68oS. This new project is using the gradient in ambient temperatures and ice cover to examine and predict the effects of climate change on Antarctic benthic ecosystem structure and function. The seabed integrates many of the short-term variations occurring in the water column and thus provides a unique perspective of integrated climate change effects in the Antarctic.
