Rare fish species hasn’t been seen in creek for 20 years — until now. See ‘small victory’

An at-risk species of fish eluded detection in a tributary of the Thames River for over two decades — but now conservationists are celebrating.

The elusive black redhorse was spotted summer 2023 in Fish Creek, a body of water near London, Ontario,, where researchers found a healthy population of the widely threatened species.

“We were thrilled,” aquatic biologist Erin Carroll told Global News. “Looking at the fish, it looked healthy. Had a nice shine, a little bit of, almost iridescence and didn’t see any lesions or tumors or anything that would indicate that it was unhealthy.”

The Upper Thames River Conservation Authority announced in a Feb. 13 news release that the black redhorse was first designated as at-risk in 1988. It was then later reconfirmed in 2019 due to ongoing threats such as pollution, climate change, severe weather, invasive species, and human intrusion.

The rare species has been spotted in other tributaries in Canada, but the black redhorse’s spotting in Fish Creek is a “small victory” for conservationists who have been trying to make the tributary more hospitable to life.

The black redhorse is known as an “indicator” species, according to Global News, meaning it is an animal whose presence in a water body signals hospitality of the water.

The black redhorse’s healthy and abundant presence there tells researchers that Fish Creek is habitable to one of the most at-risk species after decades of environmental work.

“In the last 20 years, the Clean Water Program has funded 85 projects in Fish Creek,” Tatianna Lozier of the Upper Thames River Conservation Authority said in the release.

This story was originally published February 21, 2024 at 1:57 PM with the headline "Rare fish species hasn’t been seen in creek for 20 years — until now. See ‘small victory’."