The streams and rivers of the Mississippi Alluvial Valley were once teeming with life. In the early 1800s, naturalist John J. Audubon described beautiful waters “covered with thousands of geese and ducks, and filled with fish.” Now, after more than a century of human activity, many of these waterways are struggling. Read More
The Fish and Invertebrate Ecology Team of the US Army Corps of Engineers recently examined how agriculture and flood-control practices have reshaped the Mississippi Alluvial Valley, and offer practical strategies to restore ecosystems. The team has worked together for over 30 years measuring habitat conditions at hundreds of sites throughout the alluvial valley. With over 100 species of fish, the streams and rivers include paddlefish, sturgeon and gar, as well as colorful, tiny darters and minnows, and of course, bass and bream which everyone likes to catch.
The researchers explain that farming itself isn’t the problem – it’s the way floodplains were converted and streams were engineered without accounting for the ecological consequences. Dams, levees, drained wetlands and deforested riverbanks have all taken a toll on water quality and fish diversity. Streams that once flowed steadily now fluctuate between flooding and drying up. The water is often warmer, muddier, and lower in oxygen, which favors hardy species over sensitive ones that are vital to healthy ecosystems.
Although widespread restoration of the Mississippi Alluvial Valley is unlikely given the region’s agricultural importance, the team proposes three practical conservation strategies substantiated by their research, that can benefit both ecosystems and working farms.
Firstly, they recommend protecting forested strips along streams, reforesting large parcels of land, and promoting soil conservation. These efforts will help to stabilize stream banks, filter pollutants, cool the water, and provide critical habitat for fish. Reforestation doesn’t mean removing productive farmland, as trees can be planted on marginal lands and along the riverbanks that are difficult to cultivate. The team highlights agroforestry as a promising way to integrate trees into working farms for mutual benefit.
Secondly, the team suggests sediment management and improved stream connectivity. Sediment runoff from farmland can smother habitats, especially for bottom-dwelling fish. Removing excess sediment in targeted areas and preventing future accumulation – through drop pipes and smart land-use practices – can bring back fish that rely on clean gravel beds and sandbars. Preserving connections between streams, wetlands and backwaters is equally important for fish spawning, refuge, and water quality.
Finally, the researchers recommend helping streams to maintain their flow during dry spells. In many areas, irrigation and drought have led to lower groundwater levels, causing streams to dry up when rainfall is scarce. To keep water flowing year-round, the team recommends the strategic use of groundwater wells to supplement surface flows and diversions from nearby perennial rivers.
The researchers emphasize that even modest conservation measures, when applied at the right locations, can make streams more hospitable to a wide range of fish species. These actions support biodiversity, improve water quality, bolster resilience to climate change, and help sustain agriculture for future generations.
