2023-08-28 03:08:38
The Chesapeake Pyre is thought to have inhabited only the lower watersheds of the Susquehanna and Potomac Rivers, and it has not been seen in the Potomac since the late 1930s. Credit: State of Pennsylvania
Researchers point to the heightened urgency to save and restore the river’s population.
A Penn State research team, in conjunction with the Pennsylvania Fish and Boat Commission, has embarked on a mission to rescue a unique darter from the lower Susquehanna River. Their findings revealed that this fish is a unique subspecies found nowhere else, underscoring the urgency of restoring its population.
Characterized by its yellow to olive hue, the Chesapeake bonfire is a member of the darter family with dark patterns often resembling zebra stripes. Usually measuring only a few centimeters, this fish has a small mouth and a short, cone-shaped snout. Historically, its habitat has been restricted to the lower reaches of the Susquehanna and Potomac rivers. However, no sightings have been made in the Potomac since the late 1930s.
To reach their conclusion that the Chesapeake perch, Percina bimaculata, is one of a kind — recently published in Fishes — Researchers have collected thousands of logger specimens using seines, electrofishing units, and electrified benthic trawls in the Allegheny River, tributaries of Lake Erie, and the lower Susquehanna River. They also included in the study specimens from the Mississippi River watershed, collected in Illinois and Minnesota and stored at the Illinois Natural History Survey.
To compare fish from different populations, the researchers performed 18 measurements and seven counts on specimens, quantifying characteristics such as the presence or absence of scales on the nape of the fish, the number of pectoral fin rays, the lateral line scales, and the gill rakers.
“We have concluded that Chesapeake perch found in the lower Susquehanna River and a few of its tributaries are not the same as closely related fish found in other watersheds,” said the chief of team Jay Stauffer, Distinguished Professor of Ichthyology at Penn State. “This makes our project to rescue and reintroduce fish into the river and its tributaries even more urgent. »
To come to the conclusion that the Chesapeake Pyre is one of a kind, researchers collected thousands of Pyre specimens using seines, electrofishing units, and electrified benthic trawls in the Allegheny River, in tributaries of Lake Erie and the lower Susquehanna River. Credit: State of Pennsylvania
Stauffer and his research group at the Penn State College of Agricultural Sciences, in collaboration with Doug Fischer of the Pennsylvania Fish & Boat Commission, have just concluded a four-year effort to restore the perch population in the lower Susquehanna, which has was funded by grants totaling nearly $500,000 from the Pennsylvania Fish and Boat Commission and the Pennsylvania Wild Resources Fund.
For the reintroduction, Stauffer and several graduate students conducted underwater snorkel surveys of sections of the lower Susquehanna and some tributaries, capturing the Chesapeake Bonfire and determining the habitats the fish frequent. They studied and collected fish from the Susquehanna River below Holtwood Dam in Pennsylvania and six tributaries.
In Maryland, researchers collected stingers just below Conowingo Dam and in the Susquehanna Flats at the mouth of the river in Chesapeake Bay.
Researchers then cultured — meaning breeding and rearing in this context — some 2,000 Chesapeake perch at facilities in Penn State and introduced the fish to selected locations with good habitats within their historic range. in the Susquehanna River watershed.
“We tagged all of the Chesapeake pyres that were being raised before releasing them so they could be identified later, and we were able to recapture a few around Columbia,” Stauffer said. “And we also put electronic tags on a whole bunch of fish that we put in Conodoquinet Creek, to see if they migrate to the Susquehanna River. Unfortunately, we haven’t had enough time to see if they return to spawn, so we are continuing some of this work and looking for other funding.
The fish fell victim to past pollution, Stauffer pointed out, but is now threatened by predation from voracious invasive fish, including colonizing northern snakehead, flathead catfish and blue catfish. the lower Susquehanna. Chesapeake perch numbers have dropped significantly in the river and a few of its tributaries.
“Few people realize how serious and pervasive the threat invasive predatory fish pose to native benthic fish fauna is,” Stauffer said.
Already listed as an endangered species in Pennsylvania and Maryland, the Chesapeake perch is about to be added to the federal endangered species list. species list. This could have dire consequences for the lower Susquehanna River, Stauffer warned.
“We don’t want that to happen because having the Chesapeake perch federally listed would cause a lot of development issues in the lower Susquehanna River basin and also in development around the upper Susquehanna. Chesapeake Bay,” he said. “We believe we can restore the Chesapeake perch to its original distribution in the Susquehanna River by culturing it, translocating it, and reintroducing it to its original habitat. But it will take more time and maybe more introductions. »
The effort to save the Chesapeake Pyre is new, Stauffer believes.
“A lot of work has been done over the past decade to try to restore fish to their habitats, but there aren’t many restoration projects of this magnitude with a species that hasn’t been listed. federal,” he said. “Trying to prevent a species from being federally listed is quite unique. »
Why go to so much trouble to save this unimpressive little fish? Stauffer admitted that he asked himself this question. Because the Chesapeake Pyre has no commercial value and no recreational significance, a conventional cost-benefit analysis of fish loss cannot be performed, he admitted.
“If it disappears, we will lose another species that inhabits Earth,” he said. “I think there is something to be said for preserving the biodiversity of our aquatic systems. When a species disappears, it is forever. You don’t get it back.
At one point, Stauffer, 72, considered the just-completed first phase of the Chesapeake perch rescue and reintroduction to be his final research project. But now he wants to finish the job.
“I think I’m going to go all the way and not retire for a while,” he said.
Research contributors were former graduate student Jonathan Freedman; Douglas Fischer, Pennsylvania Fish and Boat Commission; and Robert Criswell, retired from the Pennsylvania Game Commission.
Funding for this research was provided by the Department of the Interior, the U.S. Fish and Wildlife Service, the Wild Resources Conservation Program, and the National Institute of Food and Agriculture of the States Department of Agriculture -United.
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