The study area (Figure 1) is comprised of 118 provincial quality monitoring points from the Government of Ontario found along streams within the northern Lake Erie watershed of Ontario, Canada. These fall within the quaternary watersheds of: Essex Region, St. Clair Region, Lower Kettle Creek, Catfish Creek, Upper Thames River, Long Point Region, and the Grand River (Government of Canada, 2018).
The Lake Erie watershed is inhabited by over 11 million people with drainage from the province of Ontario, and the states of Michigan, Indiana, Ohio, Pennsylvania, and New York (Government of Canada, 2018; Erie County, 2019). The Canadian portion of the Lake Erie watershed has two significant tributaries that drain into the eastern basin, the Thames River which flows in Lake St. Clair and the Grand River as well as the Sydenham River which discharges into the central basin (Government of Canada & Ontario, 2017). The land-use within the watershed is extensively farmed and highly industrialized, approximately 75% of the Canadian portion of the Lake Erie watershed is agriculture, with 12% urban cover and 13% natural (Government of Canada, 2018). Lake Erie is the shallowest of the Great Lakes, with an average depth of 62 feet, making it the warmest and most biologically diverse (DCNR, 2010). These combined factors make the Lake Erie watershed a critical concern for nutrient loading of nitrogen and phosphorous, the main drivers for eutrophication (Government of Canada, 2018).
Figure 1. Study area illustrating the Lake Erie watershed, the Ontario Provincial Water Quality Monitoring Points, and associated stream network.