Unique Freshwater Ecosystem
Estuaries are unique ecosystems where rivers meet lakes, or seas and oceans, commonly with highly productive plant, animal and fish commuities, Estuary water itself can be a mixing zone and often has characteristics setting it apart from both river water, and lake water. As the National Oceanic and Atmospheric Administration puts it “Estuaries are among the most productive ecosystems in the world,” providing sheltered nursery habitat for fish, migration stopovers for birds and functions helpful to humans, like filtering stormwater entering the lake.
The St. Louis River Estuary is an example of such a unique Lake Superior ecosystem, located at the mouth of the St. Louis River between Duluth, Minnesota and Superior, Wisconsin. It is the largest estuary on Lake Superior. For those from “away,” the waters of the St. Louis River estuary are essentially all the waters visible as one crosses the high Blatnik Bridge (linking Duluth and Superior). On the “lake side,” the estuary is limited only by the Minnesota Point/Wisconsin Point sand spit providing a narrow border to the open waters of Superior. What is the inland extent of the estuary? According to the Lake Superior National Estuarine Research Reserve, the inland extent is the same as the extent of Lake Superior’s seiche, which flows miles inland up the lower St. Louis River.
Explore the Estuary
For well over a hundred years the estuary has been bounded almost entirely by urban and industrial pressures, with their attendant impacts. As such, in 1987, the estuary was declared one of over 40 Great Lakes areas of environmental concern for which cleanup, or remedial action plans, were required. A mapping tool, embedded above and hosted by the National Oceanic and Atmospheric Administration, provides a fascinating way to explore the estuary online. The system is focused on habitat and provides information about:
- priority issues
In addition to beautiful photographs of the estuary, problems and projects, the locations of individual cleanup projects are mapped and each project explained. These projects range from removing 115,000 cubic yards/ of wood debris from Radio Tower Bay through restoring dune and shoreline habitat on Wisconsin Point.
Unlike Areas of Concern on the Canadian side of Lake Superior, which typically work with public advisory committees comprised of a cross-section of community members, the St. Louis River Area of Concern has no such committee. Instead, the St. Louis River Alliance focuses on implementing cleanup actions. In 2013, a framework was produced mapping out all restoration actions necessary for estuary environmental restoration. This framework is a roadmap for all concerned.
Minnesota Pollution Control Agency, U.S. Environmental Protection Agency, the Fond du Lac Band of Lake Superior Chippewa, National Oceanic and Atmospheric Administration, U.S. Army Corps of Engineers, U.S. Fish and Wildlife Service, U.S. Geological Survey, Minnesota Department of Natural Resources and Wisconsin Department of Natural Resources all cooperate to restore environmental quality in the St. Louis River.
See a similar mapping tool for Thunder Bay.