Quigley, M. A. Great Lakes Environmental Research Lab, quigley@glerl.noaa.gov
Berquist, S. J. Great Lakes Environmental Research Lab, berquist@glerl.noaa.gov
Nalepa, T. F. Great Lakes Environmental Research Lab, nalepa@glerl.noaa.gov
Lang, G. A. Great Lakes Environmental Research Lab, lang@glerl.noaa.gov
Eadie, B. J. Great Lakes Environmental Research Lab, eadie@glerl.noaa.gov

 
WHY THE DISPARITY BETWEEN HIGH PRODUCTION OF LAKE MICHIGAN BENTHIC AMPHIPODS AND LIMITED SOURCES OF AVAILABLE CARBON?
 
Long-term production estimates of the Great Lakes benthic amphipod Diporeia sp. in southeastern Lake Michigan have indicated rates (up to 35 gDWm-2y-1; or 17.5 gCm-2y-1) that are markedly higher than those reported elsewhere. However, comparisons of production with corresponding supplies of available carbon (primary production, flux to sediments) suggest that these sources are not sufficient to account for the amphipod's relatively higher production. Results of previous gut fullness studies, and more recent feeding experiments imply that the amphipod adjusts its gut throughput rates in response to nutritional quality of food sources, i.e. high throughput rates for low-quality food, and lower throughput rates for high-quality food. This mechanism enables Diporeia to more fully assimilate available food sources which change seasonally, and may in part explain how populations can maintain relatively higher production despite apparent limitations in available carbon.
 
Day: Wednesday, Feb. 3
Time: 04:00 - 04:15pm
Location: Hilton of Santa Fe
 
Code: SS21WE0415H