More than 1,000 fish to be released in a Susquehanna tributary this fall
By: ad Crable, BayJournal.com
In a mad dash to keep the Chesapeake logperch from being placed on the federal endangered species list, the tiny fish is certainly doing its part.
In an underwater roundup of sorts, 28 logperch were netted in late March from three tributaries to the Susquehanna River in Lancaster County, PA, just north of the Maryland line. In an experiment with plenty of doubts, those 28 have multiplied to about 1,500 in propagation fish tanks in Tennessee and at Penn State University.
The plan is to reintroduce logperch into one southern Pennsylvania stream this fall, with later stockings possible into up to seven lower Susquehanna tributaries in Pennsylvania from the Holtwood Dam to Harrisburg. That’s an area where the fish were once native but have disappeared.
It’s a rare experiment. The relatively recent discovery of the fish as a distinct species caused fisheries agencies in both Pennsylvania and Maryland to reassess its status. Both declared it threatened in their states.
“There has been quite a lot of work done in the last 10 years or so trying to restore fishes to their habitats, but there are not many restoration projects of this magnitude with a species that has not been federally listed,” said Jay Stauffer, a distinguished professor of ichthyology at Penn State. “To try to prevent a species from being federally listed is pretty unique,”
But first, a seed stock was needed. To make the captured fish feel right at home, researchers scooped gravel and sand from the streams where they were found. They even collected rocks that the members of the darter family flip over with their piglike snouts to look for aquatic insects. They are known for flipping rocks. The elements from their home stream were combined in the propagation tanks, where pumps replicated the current.
Apparently, the fish indeed felt right at home. They reproduced so fast that their fecundity had to be cut off after three weeks for fear they would overwhelm their tanks. The fish were divided between Penn State and rearing facilities in Tennessee run by the nonprofit aquaculture group Conservation Fisheries, Inc. so that an unforeseen accident or disease wouldn’t wipe out the entire population.
Ripe with that success, the next phase of the four-year plan has been expedited. This summer, teams will snorkel and scuba dive in candidate streams, checking stream-bottom habitat, flow and water temperatures in search of ideal homes for the juveniles. The effort will be aided by an underwater drone attached to a 300-foot tether that will send back a deepwater video of the terrain.
They’ll also study the logperch themselves, because so little is known about the 4-inch fish that were only identified as a separate species in 2008.
“It’s never been studied,” remarked Doug Fischer, an ichthyologist and nongame fisheries biologist with the Pennsylvania Fish and Boat Commission, which is spearheading the effort. “We don’t know for sure what they eat, how old they get, when they spawn and at what water temperatures, where they spawn or how many eggs they release. This year, to increase the odds, we’re going to study what the fish does to live.”Still, Fischer is “cautiously optimistic” logperch can be reinserted in the streams they once roamed and escape inclusion on the federal endangered species list
As far back as 1842, one man knew the Chesapeake logperch roamed the lower Susquehanna and its feeder streams. He was Samuel S. Haldeman, a naturalist from Lancaster County, who caught and described the fish with its zebralike dark bars to the scientific community.
But the fish was promptly lumped in with other known and similar-looking logperch darters and forgotten. Then, in 2008, DNA testing proved the fish was a separate species. It was named Percina bimaculata Haldeman and given the common name of Chesapeake logperch because it was found only in streams that drain into the Chesapeake Bay.
Historically, the fish was found in the main stem and tributaries of the Lower Susquehanna in Pennsylvania and Maryland, and several streams that drain into the Upper Bay at the Susquehanna Flats. In the Susquehanna, the fish are found in the river and streams between the Conowingo and Holtwood dams. They have not been found above the Holtwood Dam, including where Haldeman discovered them. They are gone from about half of their native range in Pennsylvania.
They also were found in the lower and middle sections of the Potomac River basin but not have not been seen since 1938.
Matters escalated in 2017, when the Center for Biological Diversity, a nonprofit that seeks to protect endangered species, sued the U.S. Fish and Wildlife Service for not taking enough action to protect threatened species. The Chesapeake logperch was one of them.
Fish and Wildlife contacted Maryland and Pennsylvania and to learn about the potential for restoration.
“We fleshed out a dream project for the species,” Fischer said. The Fish and Boat Commission secured $500,000 from Fish and Wildlife for the four-year restoration plan. Funds also came from Penn State and the state. Partners with the Pennsylvania Fish and Boat Commission include Penn State, Pennsylvania Biological Survey, Maryland Department of Natural Resources, Susquehanna River Basin Commission and Conservation Fisheries, Inc.
Although Maryland is participating in the plan, there are no plans to begin stocking the fish in that state’s streams. A conservation plan for the fish in Maryland will be prepared, though.
Living in waterways vulnerable to agricultural runoff is a continued threat to the logperch. The fish spawn over sand, and large rain events could smother fragile eggs with silt. Once researchers learn more about the life history of the logperch and what they need, future stream restoration projects could include creating specific habitat for them.
A more recent threat to logperch is the arrival of invasive fish such as snakeheads and the blue and flathead catfish.
The stocking of about 1,200 logperch this fall will be in a tributary, not the main stem of the Susquehanna. Researchers believe the fish will be more likely to find each other that way. If reproduction is successful, they figure the larvae will reach the river anyway, bolstering the population there as well.
Fischer is buoyed by the initial success of the reproduction and thinks the Chesapeake logperch can escape the sad denouement of a federal listing or even extinction. Fish and Wildlife is holding off until the project is finished before determining whether it needs federal protection in 2023.
“Nobody wants to list anything [on the endangered species list],” he said. “That means something has happened. This is a novelty because we are repatriating fish. Our goal is to increase distribution to the point they are technically secure. We want to put them back to where Haldeman would have found them.”