The Return (of the Otter)

Amy E Kulesza

Guest Blogger

River otters (Lontra canadensis) are a special kind of animal for many people. They invoke a different kind of wildness, a playfulness, a curiosity. I’ve only seen wild otters in the west. We were camping a few years back in Colorado and behind our campsite was a small, forested river, with lots of larger rocks and boulders. Walking along this picturesque river, my dog Aggie quickly alerted me to the presence of a small group of three or four otters. It was us staring at them, and them staring at us, in one of those magic moments that being out in nature can provide, before we backed away and let the otters continue upstream.

The largest mustelid (weasel family) in Ohio, river otters live a semi-aquatic life, spending time on both land and in the water, eating fish and small vertebrates. Similar to what we learned about the bobcat, the extirpation of river otters in Ohio was mainly due to unregulated trapping and habitat destruction. But with reforestation, water quality improvement, and a little help from the introduction of otters from Arkansas and Louisiana, they have made a successful comeback.

Whereas the bobcats were gone from Ohio by around 1900, extirpation of river otters didn’t occur until the mid-1950s. I was able to speak with Lindsey Krusling, a wildlife communications specialist with the Ohio Division of Wildlife to better understand the reasons behind this. Habitat loss, through the drainage of Ohio wetlands and swamps for farmland and for cities, was one of the key factors in the extirpation of otters. And when it comes to otter habitat, it is important to consider water quality, as otters are susceptible to water pollutants and contaminants, with these impacting their food sources as well.

Poor water quality was a major driver of otter extirpation. There was pollution in the form of polychlorinated biphenyls (PCBs) and other toxins in the water, plus bioaccumulate in fish and other otter prey. So by the time otters consume these prey, they are consuming high levels of toxins. Further, our water ways were at one time extremely polluted. In fact things were so bad that part of the Cuyahoga River near Cleveland caught on fire in 1969 to dramatic effect as a result of the ignition of an industrial oil slick. The Cuyahoga River fire brought national attention to the state of our waterways, which led to legislative action in the form of the Clean Water Act of 1972, resulting in much improvement in the water quality of Ohio rivers.

Because otters don’t stray far from the water, riparian habitat is also a critical component to their survival. These narrow strips of land on the edge of rivers and lakes are often rife with lush vegetation. They provide shelter and food sources for many species of wildlife, including otters. Over time, much of Ohio’s riparian habitat declined. Many of our rivers and streams were straightened, dammed, or stripped of their forested buffers. As a result, otters lost a critical habitat for hunting, as well as cover for protection, especially their young. Like the bobcat, which might be using rivers as dispersal corridors, riparian zones are important for river otters as habitat and ways to find new territories. Having riparian buffers supports aquatic health and also benefits aquatic wildlife such as fish, macroinvertebrates and birds.

In time, wetlands returned, were rehabilitated, and were recreated. Having new quality habitat for animals contributed to the decision by the Ohio Division of Wildlife to reintroduce otters to the state. Between 1986 and 1993, 123 otters were captured from the southern US and then released into eastern Ohio. They now occur throughout Ohio (in 84 of the 88 Ohio counties) but the highest number are near the original release watersheds: Grand River, Killbuck Creek, Little Muskingham River, and Stillwater Creek.

From that initial reintroduction, the otter population grew successfully, and they thrived. They started moving throughout the rest of Ohio, and today the population is estimated to be over 6,500. They have done so well that they were removed from Ohio’s list of endangered species in 2002. A regulated trapping season was opened for otters in 2005-2006.

Today, the otter population of Ohio otters is surveyed using a bridge monitoring method that focuses on looking for signs of otters such as scat and tracks. These are typically conducted in January and February, because it is easier to look for the signs of otter presence after snow or rain. The Division of Wildlife also looks at harvest results from the trapping season to track the population, in addition to a wildlife report system on their website where the public can submit sightings. In speaking with Lindsey, many of the public’s reports come from trail cameras. As we learned about with bobcats, trail cameras can be a helpful tool in the animal monitoring process. Trail cameras are not a typical tool used by ODNR for monitoring at this time, due to the otter population’s current success.

This past April, I attended a talk on “River Otter Monitoring within Cleveland Metroparks” at the North Chagrin Nature Center. I learned from their wildlife management coordinator that for their monitoring program, trail cameras are a key tool. After the reintroduction of otters to Ohio, they began to show up in Cleveland Metroparks around 2021. By using targeted trail cameras, the team has been able to learn more about the population of otters in that park system.

All together, these survey methods give us a better understanding of the presence and absence of otters in different areas, and to think about otter movement throughout the state. From the distribution maps on ODW’s website, we can see that otters are prevalent throughout the state of Ohio, but with areas of more and fewer sightings. But, because Ohio’s water systems have been rehabilitated throughout the state, there’s lots of opportunity for their dispersal. Additionally, reintroductions took place in our neighboring states, except for Michigan, so those could also be aiding in Ohio’s population growth.

Keep on the lookout along your local waterways for otters, especially in eastern Ohio, where you’re more likely to see them. Dawn and dusk are more likely times to see them in the wild. It might be possible at some of our local Columbus Metro Parks as well. Battelle Darby Creek and Highbanks Metro Parks have excellent river habitat that otters might utilize, although they may be difficult to spot. Keep that in mind as you round the next bend of the trail or on the river. You too might have your magic moment.