Bald eagles. Blue heron. Rare salamanders. More fish than you can shake a fishing pole at. Wildlife is starting to thrive again in what was once one of the country's most polluted waterways — but there is still plenty of work ahead to heal Greater Cincinnati's Mill Creek.
Members of the Mill Creek Alliance provided data and stories showing the creek's continued comeback at their annual presentation last week — and talked about those challenges.
Mill Creek Alliance Executive Director Dave Schmitt says you can see the health of the creek improving by the birds and fish that are returning to it.
"The proof is what we see every day on the creek," he says. "We're seeing bald eagles up and down the whole length of the creek now. They wouldn't be hanging out here if there wasn't a good fish population for them to eat."
Studies done in 2022 found 63 distinct species of fish in the Mill Creek. University of Cincinnati Biology Professor Emeritus Michael Miller is excited about that — and an unusual salamander sighted in the waterway.
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"Which is an unparalleled number," Miller said of the fish. "They're not all common. And that Necturus is a very rare salamander. That's amazing. It's a first for the Mill Creek and it's rare in the region as well."
Miller helps oversee volunteer sampling of the creek, which measures eight criteria including salinity, turbidity, bacterial content, and the presence of various chemicals at many points along the creek to give the waterway an overall rating of health. Right now, that aggregate rating is right around the federal government's clean water standards. That's a big deal, given the creek's recent polluted past.
"It's right at this dividing line between acceptable and unacceptable," he says. "And we see that in the return of fish and everything else in the river. It's just an amazing story of success."
But Miller cautioned that there are still some trouble spots for the creek, including its salt content. High salt levels can pose problems for fish, a key indicator of a healthy waterway.
"Salt is our big new parameter that we've got to fight," he says. "And it has to be source reduction, because we can't treat it. It goes right through a sewage plant absolutely undisturbed, and that is a big problem."
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Miler says some of that salt is likely coming from treatments municipalities apply to roads in winter months.
You can watch the entire presentation here.