The Mississippi River Basin is the largest watershed in North America, draining 41% of the continental United States and discharging into the Northern Gulf of Mexico.

Aquatic ecosystems, and national and local economies, depend on healthy, oxygen-rich Gulf waters, which can be negatively impacted by excess nutrients (eutrophication). In 1997, a coalition of federal, state, and tribal agencies established the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force to understand the causes and effects of eutrophication in the Gulf of Mexico and to coordinate activities to help reduce the area of oxygen-depleted water in the Gulf, also known as the hypoxic zone.