Nutrient bioavailability and primary production in Lake Simcoe

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The research program that this application will support is the examination of nutrient bioavailability and primary production in Lake Simcoe. Lake Simcoe is the largest inland lake in Ontario and the ice-fishing capital of Canada. It is also the source of drinking water to 8 municipalities and is under the threat of increased nutrient inputs. To date, primary production has never been measured on Lake Simcoe, and there has been no assessment of the microbial food web. Algae, or phytoplankton, form the base of the food web in lakes and understanding their primary production will determine the possible fish production in the lake. The main objective of this research program is to determine the limiting nutrient(s) to the phytoplankton communities in Lake Simcoe and the differences in primary production. This is being assessed with a thorough, year-round examination of microbial biomass, physiology and metabolism. If we can understand what controls the cycling of C, perhaps we can predict and mitigate the seasonal hypoxia and restore the cold-water fisheries to Lake Simcoe. This program currently involves 7 highly qualified personnel (HQP) including a postdoctoral fellow, 2 masters students, 2 undergraduate summer students and 2 technicians. This application is for four independent pieces of equipment required for the proposed research. The YSI Sonde is a field instrument used to profile the water column of lakes and it was selected due to its use in large lakes such as Simcoe where profiling is needed to deep depths under adverse weather conditions. The Water PAM is a specialized fluorometer used to assess the variable fluorescence of phytoplankton communities in water and is used to examine phytoplankton physiology and provide estimates of production. The isotope analyzer is a specialized, inexpensive and efficient tool to measure stable isotopes. The spectrophotometer will be used to measure dissolved nutrient concentrations in water.