The fish of the Mississippi River are mostly invisible unless we seek them out with a fishing rod. But these water residents play a vital role in the life of all the river’s neighbors, including people. Fish supply food for otters, eagles, humans, and other fish. Some are critical to the life cycle of mussels. Their presence (or absence) says much about water quality. More than 120 species of fish inhabit the river below St. Anthony Falls, a diversity made possible by the many habitats available in currents, pools, and backwaters.
Yet, the river of today is not yesterday’s river. Just 90 years ago, a summer fish survey found only two living fish between St. Paul and Hastings. Sewage, industrial by-products, stockyard waste, and settlement runoff degraded the water quality that once supplied abundant food for generations of Native Americans, white explorers, and early settlers who lived along the river and its tributaries.
Since that low point in fish populations actions by concerned citizens, groups, and government have cleaned up the river. That effort has restored the diversity and quality of the river’s fish, giving us a better place to live and play today. As water quality improved the fish returned and with them came their predators, such as bald eagles, herons, ospreys, cormorants, and river otters.
But the story of the Mississippi River and its fish is not done. The river continues to change as Earth changes. Warming temperatures favor those fish species that can survive on less oxygen. More silt entering the river with Increasing water flow may cover gravel spawning beds, inadvertently choosing winners and losers. Road salt, fertilizers, pharmaceuticals, and even microplastic fibers from synthetic fabrics are altering the water today’s fish must swim through and may have effects on the fish that we treasure.
The choices we make today determine what fish populations will be found in the Mississippi River of the future.
Selected Fish Species
Last updated: December 10, 2018