The areas along the river and the river itself support a great variety of plants and wildlife. Because there is an abundance of natural cover, a good amount of isolation, and food provided by plants such as sedges, pondweeds, and millets, a number of birds flock to the area, especially waterfowl. An estimated eight million ducks, geese, and swans winter in the lower portion of the river, and many more birds use it in their route to Latin America.
The river itself is home to a number of different fish. For example, the most important vareties of fish include several types of catfish, which are used commerically. There are also walleyes and suckers, which are abundant in the middle and lower river and provide the basis for the sport-fishing industry.
Alligators are now becoming rare
in the river, only being found in the most isolated backwaters. Shrimp
and crab fisheries of the waters are in decline.