LANCASTER COUNTY, Pa. — In an effort to prevent an invasive species of fish from traveling up the Susquehanna River, environmental regulators are closing fish lifts at two dams in Lancaster County.
Holtwood Dam in Martic Township and Safe Harbor Dam in Manor Township will not operate their fish lifts this spring. The lifts are intended to help migratory fish travel upstream to breed, but have not been in use for two years due to the threat of invasive species also moving upstream.
The operator of both dams, energy company Brookfield Renewable, wrote in a statement,
“Since May of 2020, there have been requests from federal and state regulating agencies to suspend the usage of migratory fish lifts on the Susquehanna River in an effort to not allow invasive species to pass the fish lifts. At the request of PADEP and USFWS, we are not operating the fish lifts to prevent the movement of invasive species like the northern snakehead through the lift. By not operating the fish lifts, no invasive species are moving through the lift to further access upstream reaches of the Susquehanna River.”
The invasive species in question is the northern snakehead fish, a long, eel-like fish with sharp teeth that originates in Asia but were first discovered in Maryland in 2002.
“They could potentially pose a risk to all native species,” said Aaron Henning, fisheries biologist with the Susquehanna River Basin Commission (SRBC). “They're voracious predators. They will pretty much eat anything that gets in front of it or poses a risk to their young.”
Closing the lifts, however, has already taken a toll on native fish populations such as American shad and river herring.
“It's a balance. It's a tradeoff. It's not the ideal situation,” Henning said.
Pa. Fish and Boat Commission officials said they would like fish lift operations to resume but need to further assess how to prevent invasive species from entering the lifts. That may require some new technology.
“In some cases, for instance, down at the Conewingo Dam in Maryland, they're able to collect the shad and any other invasive species that come along with them, sort out the invasives and only the shad get past. They put them into trucks and they drive them upriver up above the dams,” said Mike Parker of the Fish and Boat Commission.
Currently, though, Holtwood and Safe Harbor dams don’t have that technology. So for now, no fish will be swimming upstream.