‘Remarkable’ Story of Recovery: Otters Reclaim the Detroit River

River otters are back in the Detroit River for the first time in a century. That means clean-up efforts are working.

Need to Know

• As seen in a video on Twitter, a river otter was spotted in the Detroit River. There are likely more.
• Otters are native to the region but were driven out by hunting and remained out due to pollution.
• Their century-long homecoming means the river is clean enough for other species too. 

WINDSOR, Ontario—Marine ecology student Eric Ste Marie was audibly astonished as he filmed a moment 100 years in the making. On his morning walking route along the Windsor waterfront, Ste Marie noticed a fury body bobbing its way through choppy waters in the Detroit River.

Muskrat, no. Beaver, no. Ste Marie recognized a river otter, holding its head high as it navigated the water its ancestors were once hunted out of.

Running to keep up, he pulled out his camera and started filming, aware that sights like this didn’t come along every day. What he didn’t know is that there hadn’t been a (confirmed) sight like this in a century.

“A straight-up river otter in the Detroit River,” Ste Marie, a Ph.D. student at the University of Windsor, said in a video he posted online. “Have you ever heard of something so controversial?”

River otters had been prominent in the region until human intervention over many years wiped them out.

Back in the 1600s, settlers new to Michigan traded European goods for animal pelts from Native American tribes. The settlers sent the pelts back to Europe, where high-fashion had created a demand for fur.

The spoils of fur trading soon overwhelmed the local population of otters, however, and by the early 1900s they had vanished from the Detroit River and nearby watersheds. 

As fashion progressed from fur to furnaces in the early 1900s, the toxic pollution dumped into the water by shoreline factories kept native species—including the otter—at bay, even as populations survived in other parts of the state. Since that time, no one has captured evidence of river otters in the Detroit River—not until April 25, 2022.

River otters are particularly recognizable. Growing up to four feet long, much larger than other aquatic mammals, they have webbed feet, a flattened aqua-dynamic head, and whiskers that they perceptively bristle to detect prey. The skilled hunters are notoriously playful and can hold their breath for up to eight minutes.

Though knowledgeable himself, Ste Marie took his evidence to regional scientists to confirm what he saw. On the receiving end of the footage, John Hartig, a visiting professor at the University of Windsor and a leading Great Lakes scientist, had been waiting for this moment for years.

“That is one of the single most remarkable ecological recovery stories in North America, and it’s in our backyard,” Hartig, whose research focuses on environmental cleanup, said to WXYZ in Detroit.

In 1986, the Ohio Department of Natural Resources reintroduced 123 otters to northeastern Ohio, where they had also been extirpated. Transported from Arkansas and Louisiana, the otters and the progeny thrived and began to make their way westward, eventually reaching Ontario’s Point Pelee National Park for the first time in 2019. 

Now with a confirmed sighting in the Detroit River, local ecologists and marine biologists are celebrating. It’s not just good news for river otters, who face little modern threat of extinction, but for the habitat as a whole.

Most important for where river otters live are the quality of water and abundance of food. In the 20th century, the depleted conditions of both made it impossible for otters and other species to survive in the Detroit River. Now, nature is healing.

Work still has to be done to preserve the habitat, Hartig said to The ‘Gander. Residue from the industrial revolution still plagues the river bottom, slowing the ecosystem’s recovery, and climate change is throwing a wrench into rehabilitation.

But there is progress. Scientists are working on softening the shoreline to create natural banks instead of human-created steel or concrete pilings, so that river otters and other riparian species have places to nest.

The best news is that there isn’t an otter without others, scientists suspect. More likely live in the area; they just haven’t had their Kodak moment yet.

“One was seen and photographed, but we suspect there are more,” Hartig said. “Much work is being done to prevent and control pollution.”