BIG HEAT and BIG Chill: Impact on the Timing and Magnitude of Primary Production in Lake Superior
Environmental Engineering Graduate Seminar
Marcel L. Dijkstra, Assistant Professor of Environmental Engineering Technology, University of Wisconsin Oshkosh
The thermal regime, particularly the duration, depth and strength of stratification, plays a governing role in dictating the time course of primary production in phosphorus poor systems like Lake Superior. Further, climate change may impart a high degree of inter-annual variation to the lake’s thermal regime. We sampled a transect extending offshore from Michigan’s Keweenaw Peninsula in Lake Superior bi-weekly from May through October for an average (2011), a record breaking warm (2012; “BIG HEAT”) and an extremely cold year (2014; “BIG CHILL”). Markedly differing thermal regimes and nutrient-plankton dynamics were observed between years: specifically, the time course of stored phosphorus content and biomass accrual in the phytoplankton and manifestation of an upper mixed layer and the degree to which summer-long primary production was maintained, i.e. the presence of a summer desert with respect to production. The potential impact of the climate-driven summer desert on the lower food web is discussed and future plans for model simulation of the phenomenon and coupling with regional climate models is considered.
After finishing his doctorate in environmental engineering at Michigan Tech Dr. Dijkstra was hired by the University of Wisconsin Oshkosh as an assistant professor to strengthen the newly formed Department of Engineering Technology. There he teaches classes concerning air and water quality, sustainability and water resources. His research is focused on developing kinetics for ecosystem models in support of lake management. He has determined the spatial distribution of the fraction of bioavailable phosphorus for Lake Decatur, Carlyle Lake and Lake Shelbyville, Il and is currently determining the impact of zebra mussels on the phosphorus cycle of Lake Winnebago, WI to support TMDL development. His lab has obtained certification by the WDNR to measure low concentrations of phosphorus (detection limit for SRP is 0.2 μg/L). He is a board member for the Fox-Wolf Watershed Alliance and collaborates with NGRREC, SLU, MTU and the WDNR.
Monday, September 24, 2018 at 3:00 pm to 4:00 pm
Great Lakes Research Center (GLRC), 202
1400 Townsend Drive, Houghton, MI 49931