Great Lakes Moment: River otters return to western Lake Erie

Great Lakes Moment is a monthly column written by Great Lakes Now Contributor John Hartig. Publishing the author’s views and assertions does not represent endorsement by Great Lakes Now or Detroit Public Television.

Most people know river otters from zoos or YouTube videos as endearing playful creatures that can put a smile on anyone’s face.

The river otter, once common throughout much of North America, was first reduced by trapping and then displaced from many areas by loss of habitat from urbanization and pollution. But sightings along western Lake Erie at Ottawa National Wildlife Refuge in Ohio and Point Pelee National Park in Leamington, Ontario, and evidence of a return of river otter to Toronto Harbour, raise the prospects that they just might return one day to the Detroit River too.

The river otter makes its home near the water. They live in a den by the edge of a lake, stream, or marsh. One fun fact is that River Otters don’t dig their own dens, they either use a natural hollow or burrow made by another animal. Otter dens feature numerous tunnels with easy access to water, especially for night hunting for fish, amphibians, crayfish and other aquatic delicacies. They can even close their nostrils to keep water out during long dives and stay underwater for up to 8 minutes.

Check out the Detroit Zoo’s live otter cam HERE.

Trail cam photo of a river otter from the Toronto and region watershed. (Photo credit: Toronto Region Conservation Authority).

Historically, river otters were present throughout most of North America, including southeast Michigan and southwest Ontario. One Monroe County, Michigan, creek is even named Otter Creek, a testament to how common they were during the late 1700s. However, that all changed during the Fur Trade Era when river otters were harvested in large numbers for their valuable water-resistant pelts. While hunting and trapping reduced otter numbers in Michigan, Ontario and Ohio, urbanization and water pollution proved to be the final blows. By the early 1900s these semi-aquatic mammals were gone.

In 1986, the Ohio Department of Natural Resources began a 7-year project to reintroduce river otters to areas with clean water and abundant food supply. More than 100 River Otters were captured in Arkansas and Louisiana, where they were still common, and transported to eastern Ohio. They were then released in the Grand River (a tributary of the central basin of Lake Erie) and Killbuck Creek, Little Muskingum River and Stillwater Creek, which flow into rivers that are part of the Mississippi River watershed.

By all accounts the river otter has not only survived but thrived in these watersheds. Monitoring has shown slow but steady growth of the population, and in 2002 it was even removed from Ohio’s list of state endangered species. But as the river otter population grew, individual otters began to adventure out to new watersheds – what scientists call expanding their range.

Some of the adventurous otters have now found a home in western Ohio. River otter sightings have occurred annually for more than 10 years from Cedar Point south to Darby, Ohio, near Columbus. Along the southern shore of western Lake Erie, not only have they been seen in Cedar Point, but Ottawa National Wildlife Refuge located just 15 miles east of Toledo, Magee Marsh Wildlife Area and the Toussaint River. Ottawa National Wildlife Refuge manages 6,500 acres of wetlands, grasslands and woodlands for protection of a wide diversity of waterfowl and other migratory birds, resident wildlife, and threatened and endangered species. Refuge biologists and volunteers have confirmed that they are now reproducing in refuge. What a thrill for conservationists and nature lovers to see them frolicking in the waters of western Lake Erie after an 80-year absence.

In March 2019, a naturalist discovered a set of tracks in the snow at Point Pelee National Park in Leamington, Ontario, on the northern shore of western Lake Erie. The tracks were discovered near the DeLaurier Canal and immediately they knew that they were not the mink tracks often seen in the park. There was a set of mink tracks nearby for comparison, which were much smaller, narrower and of course did not have the “slide” marks characteristic of otters.

Suspected river otter tracks at DeLaurier Canal, 2019. (Photo courtesy of Point Pelee National Park.)

Then in June 2019, two Parks Canada team members were in a boat entering the channel to West Cranberry Pond in the park marsh when an otter swam very close to their boat before diving underneath. Within a couple of weeks of that sighting, another team member working at the marsh boardwalk saw an otter swimming in the open water just to the left of the marsh tower. You can imagine how exciting it would be for a naturalist to see the return of river otters to this revered national park for the first time since it was established in 1918.

Situated on the northern shore of Lake Ontario is Toronto – Canada’s largest city and a key hub of the nation’s commercial, financial, industrial and cultural life. It has long been recognized as a pollution hotspot. In 1985 the International Joint Commission identified Toronto and region as a Great Lakes pollution hotspot and area of concern. Since then, substantial cleanup of pollution and habitat restoration have occurred, resulting in a surprising ecological revival.

More than $80 million alone have been invested in habitat restoration in Toronto and region since 1987. One exciting wetland restoration project has been Corner Marsh at Duffins Creek. For decades it had been in a degraded state, and over 10 years ago it was restored to the point where wetland vegetation, nesting birds and amphibians were flourishing again. Corner Marsh now has the highest population density of muskrats on the north shore of Lake Ontario, which attracted river otters to the area. River otters then spread from Duffins Creek and now occupy the entire Toronto waterfront. It has been over a hundred years since river otters freely inhabited the Toronto waterfront.

Knowing that river otters have returned to the once heavily polluted Toronto Harbour, that they have been successfully reintroduced into eastern Ohio, and that they have now been seen along western Lake Erie in Point Pelee National Park, Ottawa National Wildlife Refuge and other locations, is it possible that they just might return one day to the Detroit River?

I say yes.

Skeptics might say no. But we must all remember that as recently as 1985 there were no bald eagles, peregrine falcons, or osprey reproducing in the Detroit River watershed because of eggshell thinning caused by pesticides like DDT, no lake sturgeon or lake whitefish were reproducing in the Detroit River, and beavers had long disappeared.

Today they are all back. Wouldn’t it be wonderful if we had one more ecological surprise?

Keep up with more Great Lakes Moments at Great Lakes Now:

Great Lakes Moment: Earth Day turns 50

Great Lakes Moment: Decline of bird species should serve as a warning

Great Lakes Moment: One man’s foray into high-tech, long-distance birding

Great Lakes Now Contributor John Hartig is a board member at the Detroit Riverfront Conservancy. He serves as the Great Lakes Science-Policy Advisor for the International Association for Great Lakes Research and has written numerous books and publications on the environment and the Great Lakes. Hartig also helped create the Detroit River International Refuge, where he worked as the refuge manager until his retirement.

Featured Image: River otter family at Ottawa National Wildlife Refuge located just east of Toledo, Ohio. (Photo credit: Jeff Vogelpohl)