Take the long(head) way home
The year Lou Gehrig made his final appearance in a Major League Baseball game, a small freshwater fish made its final appearance in Ohio.
The longhead darter hadn’t been seen in the Buckeye state since 1939. Until last year. Now scientists are seeing these fish in a number of streams in Ohio.
Full disclosure: they’re seeing them because they put them there.
In 2018, Ohio State University, the Ohio Department of Natural Resources Division of Wildlife, and the Pennsylvania Fish and Boat Commission began a collaborative project supported by funding from State Wildlife Grants to reintroduce longhead darter into a few streams in the state where it was found historically.
The motivation for the project was clear. “It was missing, and it wasn’t coming back on its own,” said Brian Zimmerman, a research associate at Ohio State.
But the timing was strategic. The reintroduction of longhead darter builds on previous successes reintroducing bluebreast darter and Tippecanoe darter in the same systems. Systems where scientists felt confident the longhead darter would succeed as well.
The effort to bring this fish back to Ohio is a testament to how well the species is doing in neighboring Pennsylvania — now. Not long ago, the longhead darter was scarce there too. Or at least, it appeared to be scarce.
Robert Criswell, retired from the Pennsylvania Biological Survey, recalled that when he got involved in fish conservation in Pennsylvania in the 1990s, “You could find longhead darter, but never many in one spot.”
On a good day, he said he might collect a dozen in French Creek, a tributary to the Allegheny that now serves as one of the source populations for the longhead darters that have been reintroduced in Ohio.
On a recent visit to French Creek, Criswell said, “I collected 40 of them by myself with a backpack shocker.” That’s not a euphemism — it’s a portable power source with two electrodes that scientists use (with a permit) to deliver electricity into the water to (temporarily) stun fish.
What changed since the 1990s? Experts think there are two forces at work. First, we are getting better at finding fish.
In the early 2000s, the Missouri Department of Conservation designed a trawl system to catch small fish in deep water. Essentially, a big weighted net made with fine mesh. A few years later, Penn State University electrified the trawl, literally amplifying its efficacy. Like a boat-sized “backpack shocker.”
The second thing that’s changed over time? We’re getting better at taking care of fish habitat.
The road to recovery
A little more than a century ago, the curator of invertebrate zoology at Pittsburgh’s Carnegie Museum Arnold E. Ortmann painted a bleak picture of aquatic systems in Pennsylvania. In a paper in the Proceedings of the American Philosophical Society bluntly titled, “The Destruction of the Fresh-Water Fauna in Western Pennsylvania,’’ Ortmann observed, “both the Allegheny and Monongahela are as badly polluted as they could possibly be, and, consequently, it is not astonishing that the Ohio immediately below Pittsburgh is also in a deplorable condition.”
He called the damage done by industries like coal mines, oil refineries, tanneries, glass factories, and saw mills “irreparable,” barring “some radical change in the way of the disposal of the industrial refuse, which at present is generally allowed to run directly into the nearest stream.”
That radical change came 63 years later with the passage of the federal Clean Water Act, which regulates the discharge of pollutants into surface waters, including lakes, rivers, streams, wetlands, and coastal areas.
Scientists are increasingly seeing the positive effects of the act percolate into aquatic systems. “Since I’ve been here, we have made 26 adjustments to our state listings for threatened and endangered species and we currently have a few more in the works,” said Doug Fischer, nongame fisheries biologist who has worked for the Pennsylvania Fish and Boat Commission since 2005.
The vast majority of those 26 adjustments were delistings, including the longhead darter, which was removed from the state-threatened species list in 2008. “Species aren’t removed from the endangered or threatened lists unless they are found to be secure in the Commonwealth,” Fischer explained.
Remember how Ortmann considered the Allegheny River to be as badly polluted as possible in 1909? Fischer said that today, the Allegheny is considered a “reservoir of fish” in the region, including the longhead darter.
Even before the Clean Water Act came into play, the river began to recover from historic industrial pollution thanks to the founding of the Allegheny National Forest in 1923. With significant portions of its watershed forested, the river was protected from sedimentation caused by erosion from agricultural fields and development, which muddies the waters for fish like longhead darter that spawn in gravelly substrate, and feed by nibbling macroinvertebrates from rocks.
Now thanks to regulations and better management practices on farmlands, rivers like the Walhonding in Ohio are catching up in terms of water quality. “This is an area that has seen a lot of recovery without intervention,” Zimmerman said. “We’ve seen other species that are sensitive to pollution returning on their own.”
It was a sign that the time was right to facilitate the return of species like the longhead darter that needed help to get back. Although both the Walhonding and the Allegheny drain into the Ohio River, dams make it impossible for fish to travel between them. And the longhead darter is not a species that migrates long distances, like American shad or Atlantic salmon, anyway.
That’s why this fall, a second cohort of longhead darters will make the five-hour trip from Pennsylvania to Ohio by truck. Before scientists let them go, they give them a visible implant elastomer tag, a silicone-like substance injected under the skin with a needle. “Basically, a tattoo for a fish,” Zimmerman explained.
“If we start seeing fish without tags next spring, we’ll know they’re reproducing.”
For now, a longhead darter that was born in Ohio is still a sight nobody has seen since 1939.
But hopefully, not for long.
The longhead darter joins the ranks of more than 190 others in the eastern U.S. whose populations have been determined to be stable thanks to efforts by federal, state, private and non-governmental partners. The effort to conserve at-risk wildlife and recover listed species is led by the Service and state wildlife agencies in partnership with other government agencies, private landowners, conservation groups, tribes, businesses, utilities and others.
Post written by Bridget Macdonald, public affairs specialist
