Clough, L. M. East Carolina University, cloughl@mail.ecu.edu
Ambrose, Jr., W. G. Bates College, wambrose@abacus.bates.edu
Sun, M. Y. Univ. of GA, mysun@uga.cc.uga.edu
von Quillfeldt, C. H. UNIS, cecilie@unis.no
Grable, M. Bates College, mgrable@abacus.bates.edu
Deming, J. Univ. of Washington, jdeming@u.washington.edu

 
WILL DECREASING ICE CONCENTRATIONS BENEFIT OR HARM THE ARCTIC BENTHOS?
 
During a 1996 cruise to the Chukchi Sea, we observed increases in benthic microbial and macrofaunal respiration following inputs of algal material, most likely derived from ice algae. We hypothesized that ice algae are an important early-season food for the Arctic benthos, and further tested the idea in June 1998. We used taxonomic and chemical analyses to identify both source and concentration of benthic pigments. As in 1996, pigment concentrations varied significantly (<1 to > 20 micrograms total pigment per ml of sediment). Respiration rates at stations with high pigment concentrations were higher than respiration rates at locations where pigment concentrations were low. In addition to assessing naturally occurring variability in respiration rates, we added ice algae to shipboard sediment cores. Again, addition of ice algae increased benthic respiration. Our results support the hypothesis that ice algae represent an early-season food pulse and are likely to constitute a significant portion of annual carbon input to the benthos of arctic shelves, primarily because pelagic components of the Arctic food web are not consuming the entire ice algae bloom. We suggest that a reduction in ice concentrations as a result of warming may negatively impact the benthos of arctic shelves.
 
Day: Tuesday, Feb. 2
Time: 03:45 - 04:00pm
Location: Eldorado Hotel
 
Code: SS15TU0330E