Understanding the processes that drive nutrient processing, delivery, and connectivity from coastal systems to the open waters of the Great Lakes allows managers to better restore coastal ecosystems to a healthier state while managing open water production to maintain desired ecosystem services. The USGS-GLSC is working to assess coastal production and transport dynamics in the Great Lakes to improve predictive models of eutrophication and hypoxia. These predictive models can be used to forecast future occurrences, which will assist managers in making critical decisions to positively influence the Great Lakes.
Recent improvements in geostatistical data interpolation have led to the reanalysis of historical hypoxia cruise data for the Gulf of Mexico (Obenour et al. in prep) and Lake Erie (Zhou et al. in press), resulting in new time series of hypoxic extent with improved accuracy and quantified uncertainty. The reanalysis for the Gulf of Mexico revealed that at least some of the historically recognized hypoxia sensitivity changes in the original data-set can be explained by an instrument artifact (Obenour et al. in prep) and prior hypoxia estimates for Lake Erie did not include a consistent measure of extent. There is thus a pressing need to revisit models, conclusions, and management recommendations based on the historical data-set in light of this reanalysis. An accurate understanding of these systems is important both because they are each the subject of management concern in their own right and because they provide a basis for developing general indicators of hypoxia sensitivity to nutrient loading that can be applied to other systems.