Abstract – Dr. William Paton

Hudson Bay, a yet pristine unique northern coastline, provides habitat for whales, seals, polar bears and many migratory birds. The Hudson Bay system is the world’s largest northern inland sea. The watershed that supplies freshwater to this marine ecosystem is extensive, extending to the Rocky Mountains in the far west, receiving waters from the Prairie Provinces, the USA, the province of Ontario, and Nunavut.

The highly eutrophic states of the two major lakes that receive these waters in Manitoba have raised serious concerns about those two large freshwater ecosystems. These lakes eventually drain into Hudson Bay. Major policy and enforcement commitments from governments to address the disastrous state of Lake Winnipeg have been the source of much politics and minimal real science-based legislation or regulations. These Lakes eventually discharge into Hudson Bay, where it has been suggested that nitrogen is the major limiting factor in its potential eutrophication. Nitrogen contributions from the basin together with atmospheric nitrogen deposition could result in disastrous ecosystem decline. However, debate continues with respect to the importance of nitrogen removal from sewage and industrial effluents in the major Manitoba cities. Extremely large cyanobacterial blooms visible on satellite imagery are already contributing large quantities of nitrogen to the Lakes through nitrogen fixation on an annual basis. Efforts to minimize phosphate inputs into the river systems supplying the Lakes lack enforcement and capital to improve the infrastructure necessary to reduce this nutrient. Climate change by way of extremely large precipitation events over short periods of time have overwhelmed existing sewer and wastewater treatment systems resulting in raw sewage discharges into the rivers and increased nutrient loads off the land.

The arctic ecosystem is already being influenced by climate change and extensive hydro dams, which have altered historical freshwater flows into both James Bay and Hudson Bay. The Cree and Inuit peoples are dependent on this marine ecosystem for traditional subsistence foodstuffs which creates a human and social impact in this anticipated decline of this ecosystem if governments fail to seriously address nutrient pollution in the rivers and lakes that feed Hudson Bay.