This article was originally published on Lancaster Online.
In the summer of 2018, anglers fishing Octoraro Creek in southern Lancaster County started catching a foreign, ugly, prolific and ever-hungry tooth-filled fish commonly known as “Frankenfish.”
If you have been worried since then that the appearance of the invasive Asian fish with no natural predators is not good news for Lancaster County waters, your fears have been warranted.
The first before-and-after study of northern snakehead populations in two rivers on Maryland’s Eastern Shore has found that of 21 species of fish captured before snakeheads were introduced by humans seven years ago, 17 have declined since then — by 30% to 97%, according to the study by Maryland and U.S. Fish & Wildlife Service scientists.
Particularly hard hit by the snakeheads are white perch, brown bullhead catfish and black crappie — all game fish. The fish apparently declined because snakeheads, which can grow up to 3 feet long, either ate them, devoured their food or muscled them out of preferred habitat.
The study doesn’t rule out that other factors may have caused the fish declines but notes that habitat did not change over the period.
The disturbing results have sent shivers down the spines of fish managers in Pennsylvania, where snakeheads have been found in many tributaries of the Delaware River, in the lower Susquehanna drainage in Lancaster County and, most recently, in the Monongahela River in western Pennsylvania.
Though there is no evidence snakeheads have yet gotten established in the Susquehanna above the Conowingo Dam below the state line in Maryland, fish biologists worry a snakehead population could mean bad news for the river’s prized smallmouth bass and other fish.
“They could wipe out some things we hold dear,” says Geoff Smith, Susquehanna River biologist for the Pennsylvania Fish & Boat Commission.
Moreover, snakeheads have been shown to prefer American eels and American shad, two migratory fish states are trying to reestablish in the river.
In the Delaware River tributaries, studies by The Academy of Natural Sciences of Drexel University indicate snakeheads are negatively affecting native fish. Examinations of snakehead stomachs have found sunfish, American eels, a turtle and other items. There are concerns they are eating and impacting eels, striped bass, American shad and other popular fish, according to the academy.
More bad news
A downright ugly face, as if stitched together by a mad scientist, and a maw of sharp triangular teeth is bad enough. But snakeheads have bad behavior habits that have put them on a most wanted list, such as the ability to survive out of water for up to four days and for juveniles to wiggle over land for short distances.
The discovery of snakeheads in the Octoraro in Solanco was another bit of bad news. Snakeheads prefer backwater pools with slow water and silty bottoms. But they seem to be thriving in the fast-flowing, gravel-bottom Octoraro.
“Obviously, they don’t just live in backwater areas if they’re surviving in the Octoraro. The unknowns with the snakehead is the scary part of it,” says Tyler Grabowski, an area fisheries biologist with the Fish & Boat Commission.
Snakeheads, which look a lot like bowfin fish found in Pennsylvania, first appeared in the United States in California in 1977. They were first found in the mid-Atlantic region in the Chesapeake Bay watershed in 2002. They have since spread to every major tributary up and down the bay. Snakeheads are common in the tidal reaches of the Potomac watershed around Washington, D.C.
The first appearance of the predator in Pennsylvania was in 2004, when they were found in a tidal lagoon near a sports stadium complex in South Philly.
How did they get here?
Originally, it is believed snakeheads were brought to the country for sale in live food fish markets catering to ethnic markets and restaurants and as part of the exotic pet trade. They either escaped or were intentionally released.
Since then, anglers have aided the spread. DNA testing showed the snakeheads in the study area on the Eastern Shore of Maryland came from the Delaware watershed.
Like the invasive flathead catfish that have multiplied in the Lower Susquehanna, snakeheads have garnered the attention of anglers.
“They’re very popular on topwater lures,” notes Grabowski, who was stunned one day seven years ago when he was bass fishing on a lake in Bucks County and hooked a snakehead. “They hit anything a bass does. They do a lot of thrashing with big head shakes at the surface. They are really muscular and dense.”
Some fishing guides are offering snakehead trips.
But the goal of fisheries managers is to kill, not catch, snakeheads. In Pennsylvania, it is illegal to possess, sell, buy or trade live snakeheads or release them in any waters. “We shouldn’t be playing bucket biologists,” says Grabowski in a plea for anglers to avoid helping the fish spread.
Last summer, Maryland and federal officials held a snakehead “derby” on the state’s Eastern Shore. Anglers were invited to take the snakeheads home to eat or kill them on the spot. About 25 snakeheads, up to more than 10 pounds, were taken out of the ecosystem.
But an aggressive catch-and-kill campaign in the Potomac River basin has not dented the population.
On the Susquehanna, it is hoped a gauntlet of four hydroelectric dams will keep snakeheads at bay. But they are knocking at the door.
This past spring, 81 snakeheads were caught in fish lifts at the downriver-most Conowingo Dam that are used to help shad and eels upriver. None had been found last year and only one in 2017. All were killed.
Many more studies are needed to assess how harmful snakeheads could be to Pennsylvania’s waterways.
“We’ll see what happens when and if they get here,” Smith says. “Hopefully they won’t.”