Restoring Freshwater Mussels

For many of us, mussels are mostly out-of-sight and out-of-mind.  But native mussels are important for healthy rivers and lakes. Sadly, freshwater mussels are the most at-risk group of animals in the United States. In Minnesota, 25 of our 48 remaining native mussel species are listed as endangered, threatened, or of special concern by the Minnesota Department of Natural Resources (DNR). The Minnesota Zoo is working with the Minnesota DNR to help mussel populations by conducting research and rearing mussels for release into the wild.

Make a donation to support mussel conservation

Why are mussels in trouble?

Native mussel species were once abundant throughout our rivers and lakes, helping to keep these ecosystems healthy and vibrant. Historic overharvesting of mussels for the pearl button industry caused major declines, along with the construction of dams which can alter water flow and quality, and negatively impact mussels. Runoff from chemicals and silt also threatens mussel populations.

More recently, mussels have been threatened by the introduction of zebra mussels, an invasive mussel species that is native to eastern Europe. The invasive zebra mussels colonize the shells of native mussels, intercept food, and take over their habitat – eventually killing them – and degrading aquatic communities important for fish populations.

A fat mucket mussel, native to Minnesota, entirely covered by invasive zebra mussels.

Why are mussels important?

These tough little filter-feeding animals are critical to a healthy ecosystem. Mussel beds help to filter the water and stabilize riverbeds, much like a freshwater coral reef. This improves water quality and helps create habitat for fish, turtles, birds, and other aquatic animals. Mussels are also an important food source for animals including otters, muskrats, ducks and gulls.

Native mussels just prior to being released into the Mississippi River.

What is the Minnesota Zoo doing to help?

The Minnesota Zoo is joining the Minnesota DNR’s efforts to restore native mussel populations in Minnesota. At several locations across the Zoo campus we’re rearing mussel species including the Plain pocketbook, Black sandshell, Muckets (a state-threatened species), and the Higgins’ eye pearly mussel (a federally endangered species).

Zoo researchers are developing protocols on rearing mussels and studying how they interact with and impact each other in a controlled setting. In addition, the Zoo partners with the Minnesota Aquatic Invasive Species Research Center (MAISRC) to study control methods for the invasive zebra mussel.

The Minnesota Zoo also coordinates the “Show Us Your Mussels” Challenge, a statewide education initiative. Each year, Minnesota middle and high school students create original digital media campaigns educating the public about the importance of native freshwater mussels. The school groups who reach the most people in combination with receiving the most votes win a free field trip to the Minnesota Zoo.

What can you do to help?

Mussel Conservationist Ben Minerich.

  • Boating & Fishing, Clean in Clean Out
    If you use a boat, you can help prevent the spread of zebra mussels by removing all aquatic plants from the boat and trailer, draining all of the water from your boat and bait bucket, and allowing your boat and trailer to dry in the sun for at least five days before using them in other waters.
  • Pet Waste
    Pet waste that washes off lawns and parks during rain and snow melt events contributes to harmful bacteria and nutrient contamination of our river water leading to harmful bacterial blooms (like those that can be toxic to your pets!). Help prevent this by always promptly picking up after your pet and disposing of it properly in the trash.
  • Fertilizer
    Reduce or eliminate your use of fertilizers. Avoid applying fertilizer before it rains and make sure to sweep off any excess fertilizer from the pavement to minimize the amount being washed away into our local waterways and contributing to harmful algal blooms.
  • Road salt  
    Help freshwater mussels and all of our aquatic ecosystems by learning “smart salt” application methods. Salt applied to roads and sidewalks permanently pollutes our freshwater. Manually remove snow frequently and don’t oversalt. One coffee cup of salt is enough for a 20-foot driveway or 10 sidewalk squares.

Blogs from the Field

Key Zoo Staff:
Ben Minerich, Mussel Conservation Specialist, Minnesota Zoo
Seth Stapleton, Director of Conservation and Research, Minnesota Zoo
Liz Gilles, Education Curator, Minnesota Zoo

Key Partners:
Minnesota Department of Natural Resources
Minnesota Aquatic Invasive Species Research Center

Funding and Support: