Freshwater mussels are known to help clear the waters they live in.
The Minnesota Department of Natural Resources is looking at a Southeast Minnesota watershed hoping to get a clearer picture of how to use them to help clean waterways.
The Cedar River watershed in Mower County is one of three watersheds in Minnesota selected for research and reintroduction work by the DNR’s Center for Aquatic Mollusk Programs in Lake City along the Mississippi River.
Last year, watershed teamed with CAMPS to release more than 1,500 captive-raised black sandshell mussels in the Cedar River near Austin.
Last month, the DNR placed about 3,300 native mussels — all juveniles — in containers in East Side Lake to grow there to transplant into the Cedar River next year. The three species of mussels native to the area — black sandshell, mucket, threeridge and spike — will be transplanted by DNR officials along in the Cedar River State Water Trail at several sites downstream from the downtown Austin dam as part a few tag-and-release efforts over the next year or so.
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Those mussels were in addition to about 3,300 growing there since last fall that DNR officials plan to tag and place in the Cedar River in late August or September.
The CAMP labs have limited space to propagate mussels. After being propagated in labs in water from the bodies of water where they will eventually be released, juvenile mussels are moved to grow in a natural environment.
Their early growth is slow, said Madeline Pletta, DNR mussel propagation biologist.
However, once placed in a natural environment, they grow quickly and tend to thrive.
Using East Lake, which is a part of Dobbins Creek, to help the mussels grow helps ensure they adjust to their new environment and grow healthy.
Mussels are freshwater mollusks native to Minnesota, and are related to clams and oysters. They have a "foot" that they use to move around and anchor themselves to the bottom of water bodies. Once anchored, they rarely move much, and filter particles such as plankton, fungus, bacteria, and other organic matter and pollutants from the water.
Their shells were widely harvested for making buttons. That harvesting, pollution and dams that prevent migration of fish mussels need to propagate has reduced their populations across the state.
CAMP has been successfully breeding mussels and determining which species of fish certain species of mussels rely on to propagate. Mussels propagate by releasing larvae onto a host fish’s gills, where the larvae feed off the fish until they metamorphose from parasites to organisms capable of living on their own.
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If the body of water no longer supports populations of host fish, the mussel populations also die out and the water quality of that body suffers.
The black sandshell mussels released in the Cedar River last year came from samples of populations still living in the wild downstream in the Cedar River in Iowa.
In addition to the native species introduced there this year by the DNR, Dobbins Creek still supports some native mussels. The DNR will begin studying this month how many and which species thanks in part to a $5,000 grant to the DNR from Friends of the Jay C. Hormel Nature Center.
As CAMP and DNR officials learn more about how to successfully propagate and transplant these mussels in the Cedar River watershed, these tactics could be applied to other watersheds throughout the state to improve water quality.
Will it work? The results should be clearer in the next couple years.
John Molseed is a tree-hugging Minnesota transplant making his way through his state parks passport. This column is a space for stories of people doing their part (and more) to keep Minnesota green. Send questions, comments and suggestions to life@postbulletin.com .
