Freshwater Mussels in Indiana

Freshwater mussels found in Raccoon Creek in The Nature Conservancy’s Green Bluffs Nature Preserve.

I’ve played in creeks my whole life. I was lucky enough to have grown up with one in my backyard where I watched fish, snapping turtles, and crawfish. Maybe I found some shells, but I never thought about mussels.
Did you know we have mussels in Indiana? If not, you are not alone. I didn’t fully understand this until I went on a mussel hunt at Raccoon Creek is south-central Indiana. Although I should have learned this some time ago. 
I had seen information about The Nature Conservancy releasing tagged wavyrayed lampmussels in the Blue River back in September 2015, watched a video about this event, and posted it on social media. However, it didn’t sink in until almost a year later when I got to experience freshwater mussels for myself.
When Cassie Hauswald, Indiana Freshwater Ecologist at The Nature Conservancy, Brant and Joanna from Indiana Department of Natural Resources and I got to Green’s Bluff Nature Preserve in Owen County on a Monday morning, I wasn’t sure what to expect.
As we walked the trail to Raccoon Creek, I started thinking about mussels in Indiana. And once I started thinking about freshwater mussels, I couldn’t stop. They might seem unassuming, but they play a big role in the health of our freshwaters.

Freshwater mussels indicate a stable habitat as most mussels cannot survive in waters that are polluted. If mussels are found in polluted waters, we can determine the water quality issues in the area because contaminants will collect in their shells.

Areas where you find freshwater mussels, are usually areas with clean water. Mussels have a heart, kidneys, a stomach, and a mouth like we do. They also have gills like fish and it is with these gills that mussels act as natural filters and can filter over 30 liters of water in one day!

They are filter eaters which means they depend on water with the right algae content to consume and by keeping these microorganisms and nutrients for food, they expel water that is cleaner than what they took in.
Along with filtering water, freshwater mussels are an important food source for many fish, mammals, and birds. In addition to being food for fish, mussel larvae will hitch a ride on a host fish and once they have developed into juveniles, they will drop off in an area and live out their lives as long as they landed in a suitable habitat. In order for mussels to thrive, the specific fish they depend on must also thrive.

Mussels usually live in one spot their whole lives, though they are able to move themselves a bit with their single foot, which they use to drag themselves across the bottom of a waterbody. Mussels stabilize the bottom of waterbodies and help to mix it as they burrow, increasing oxygen exchange.

There used to be at least 77 native species of mussels found in Indiana. Today, almost half of Indiana’s native freshwater mussel species are no longer found here or are federally listed as endangered or are species of special concern.

Altering the waterways where mussels live by constructing dams, causing erosion, or dredging, along with the introduction of exotic species, and pollution are reasons to be concerned about the well-being and existence of freshwater mussels in Indiana.

In Raccoon Creek, we found evidence of seven types of freshwater mussels. However, these were mostly empty shells that were few and far between. Between four of us and hours of searching, we only found a few live mussels.
So, what is being done to protect freshwater mussels? When the Endangered Species Act passed and was implemented along with the Clean Water Act, some species of freshwater mussels were able to recover in numbers. The Endangered Species Act provides protection for threatened and endangered mussel species. The Clean Water Act has improved water quality which allows mussels to recolonize in some areas.
Please remember, if you find live freshwater mussels or their shells, leave them where they are. It is illegal to take these items from Indiana waterways.
Click here to learn more about freshwater mussels and ways you can help.