Can the Cuyahoga River Support Rare Wildlife?

Scientists sort rare freshwater mussels collected on the Grand River for reintroduction on the Cuyahoga.

NPS / Ryan Grzybowski

Imagine the river in Cuyahoga Valley back in the 1970s. Detergent bubbles clogged the bend in Peninsula. Catching a carp near Station Road was considered lucky. On bad days, a funk hung in the air from Akron’s water treatment plant. Fast forward to today when bald eagles, otters, and great blue herons are regularly seen raising their young. Kayakers paddle the Cuyahoga River Water Trail past the site of former dams in Brecksville. Could it get any better?

It just might. In 2021, the National Park Service and its partners began two projects that were unimaginable back in those early days. Both explore whether the river can now support some of Ohio’s rarest forms of aquatic life. The first is looking at freshwater mussels and the second at lake sturgeon.

One of the chambers with mussels that will be placed inside of a concrete silo.

NPS / Demarco

Bringing Back Freshwater Mussels

It’s easy to mistake our native mussels for rocks. However, their unassuming looks belie their importance—they are actually rock STARS. According to the US Fish & Wildlife Service and The Nature Conservancy, North America has the greatest diversity of freshwater mussels in the world. The largest concentration is here in the Midwest. Unfortunately, mussels are also our most imperiled group of animals. The adults are sedentary filter feeders. Most cluster in communities called mussel beds that can support 30 or more species. Mussels can live for decades, and sometimes a century or more. This makes them vulnerable to long-term changes in our waterways.

Because of a quirk in their reproduction, freshwater mussels are also good indicators of how healthy certain fish populations are. A female mussel protects her fertilized eggs in a special gill pouch. When the time is right, she uses a specialized lure to attract a host fish and then squirts the unsuspecting babysitter with tiny larvae. The larvae hitchhike for a few weeks in the fish’s gills or fins and then drop off in a new territory. Mussels are out of luck if the right fish aren’t around, or the water is too polluted, or rapid flows wash away the riverbed where the larvae would attach.

In late July 2021, a team of scientists led by the US Army Corps of Engineers collected a small number of muckets (mussels have the coolest names) from the Grand River and relocated them to the Cuyahoga. This pilot confirmed that mussels can survive in the Cuyahoga.

In 2022, a team released groups of mussels in concrete silos in the river. The mussels are inside of a chamber with mesh ends that allows water to filter through. These silos also allow park staff to monitor these groups of mussels to determine if reintroduction is appropriate in the coming years.

These lake sturgeon, only a few months old, were captured in the St. Clair River which helps connect Lake Huron with Lake Erie.

US Fish & Wildlife Service

Finding a Home for Sturgeon

A second multi-agency team led by the US Fish & Wildlife Service is mapping the riverbed to see if the Cuyahoga has the right habitats to support lake sturgeon. They are looking at the entire lower half, from the Gorge Dam to the mouth in Cleveland. These unusual fish are uncommon in Lake Erie. The most striking thing about them is that they have rows of heavy, bony plates instead of scales. And they can live to be 150 years old and reach up to 300 pounds! Historical records show that lake sturgeon used to be common in Lake Erie and would travel up the Cuyahoga to spawn. These fish need places with a pebbly bottom where females can lay their eggs, as well as sandier spots where young hatchlings can find food.

A national park team learns how to use orange bathyscopes to study whether the Cuyahoga can support young lake sturgeon.

NPS / Ryan Grzybowski

In early spring 2021, US Fish & Wildlife Service staff floated downriver with a side scan sonar. This technology is being used to map the natural materials that make up the Cuyahoga’s riverbed. Over the summer, they trained national park staff and volunteers on how to “ground truth” the sonar images. Basically, we’re helping with the field work to see if underwater patches of sand, gravel, pebble, or bedrock are accurately identified in the sonar data. To do this, team members use an underwater viewer called a bathyscope—think orange safety cone meets snorkeling mask. This habitat study is one of the first steps in determining if the Cuyahoga can support a reintroduction of lake sturgeon. In particular, are there places for reproduction and for newly hatched fish? This would build on projects in the Maumee River near Toledo and in the Big Darby Creek near Columbus.

Healthy Water, Healthy People

Whether you get excited about wildlife or not, consider what this means for Ohio and for Lake Erie. Greening the Rust Belt is a heavy lift. Improving the health of the Cuyahoga River is part of an international effort to restore the most polluted areas in the Great Lakes. Each success shows our strength and commitment to a better future for all forms of life, including people.

US Fish & Wildlife Service scientists caught, tagged, and released this adult lake sturgeon in the Detroit River.

US Fish & Wildlife Service