US Long-Term Ecological Research Network

Eutrophication of surface waters is of increasing concern worldwide, and is the most significant water quality issue in Lake Mendota, WI. Water quality in Lake Mendota, WI has implications for human health, aquatic organisms, and recreation.

My research is about prediction of water quality. In order to predict future water quality (chemistry and biology) in Lake Mendota, we must first predict physics. One major physical feature of Lake Mendota, WI, is thermal stratification, shown above (a). Predictions shown are for the whole water column (surface to sediment) at the middle of the lake, during summer stratification. We tested our ability to predict water column thermal stratification for the summer of 2008 using a one-dimensional hydrodynamic model.

Potentially toxic Cyanobacteria proliferate in Lake Mendota as a result of eutrophication. We tested our ability to predict Cyanobacterial biomass for summer 2008 (b), using a biogeochemical model coupled to the hydrodynamic model. Our model predicted long-term (average) chlorophyll-a (chl-a) in the surface water for the summer of 2008, but did not reproduce shorter-term variability observed in the lake (hot spots from mid-July through mid August). Here, chlorophyll-a is a proxy for phytoplankton biomass, which is dominated by Cyanobacteria.

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