This 3-year study will elucidate the historical response of the lower Great Lakes to nutrient enrichment and abatement, and provide a basis for monitoring changes in trophic state variables in other large, deep-water lakes. Data collected will calibrate existing proxy indicators to modern conditions and develop new techniques for estimating past, present and future changes in the trophic state of the Great Lakes. The field program will include data collection from the water column, sediment traps and cores from Lake Ontario and Erie. Laboratory experiments will determine the effects of nutrient enrichment on the carbon and nitrogen isotopic signature of organic matter produced by phytoplankton.
Biogeochemical Response of the Lower Great Lakes to NutrientLoading and Climate: Past, Present, and Future Trends in Tropic State Variables