Stream fish and altered flow regimes in MO

By Nick Sievert, School of Natural Resources

Nick participated in the event in Montgomery

The small, muddy stream running through a woodlot on a central Missouri farm might not look like a hotbed of biodiversity, but chances are it has over a dozen different species of fish calling it home. Some like the Orangethroat Darter, Longear Sunfish, and Red Shiner look like something you might encounter on a snorkeling trip in the Caribbean Sea.


As a fisheries researcher one of my jobs is to try and gain a better understanding of how these fish survive, grow, and reproduce. Living in a small stream presents unique challenges for the fish that call these areas home. If you take a walk along your neighborhood stream in the spring or early summer shortly after a rain storm you are likely to see a deep, fast-moving body of water, however if you go back to the same place after it’s been dry for a few weeks in the fall and you’ll likely find shallow, still water, and perhaps only water in isolated pools or puddles.

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Fish living in these streams have to find ways to cope with these dynamic systems. Most of the fish in these systems are adapted to both high flow events after rainstorms and late summer and fall drying, however human actions likely impact how much water is flowing through the stream at a given time. Our development of the landscape has caused water to flow into the stream much more quickly than it did in the past causing both higher peaks and longer periods of low stream flow. My research is aimed at identifying how the flow of a stream impacts which fish succeed and which fish struggle under different conditions. For example we might expect larger and more sensitive fish to struggle in streams which have a lot of drying and get drained down to small puddles during the late summer and fall. We also expect that streams which experience high flow events early in the year may wash out the young of fish species which have already bred, and in some case may even remove the adults of species which aren’t good at finding shelter during these conditions.

By gaining a better understanding of how humans impact stream flow and how changes in stream flow impact fish we can take actions in ways that help protect these resources. The ultimate goal of the research I’m conducting is to find ways to better protect these hidden gems that are found right in our backyards.