Growing as long as 3 feet with large mouths full of sharp teeth, invasive northern snakeheads were described Tuesday as apex predators that could become a problem for native fish species.
And for the first time, state waterway officials have proof that snakeheads — also called frankenfish — have established themselves in a section of the Susquehanna River that flows through Lancaster County.
“This is the first time we’ve documented snakeheads above the Conowingo Dam,” said Mike Parker, communications director with the Pennsylvania Fish and Boat Commission.
Now, commission officials are telling anglers to kill and report any snakeheads they catch. It’s actually unlawful to release them back into local waterways, Parker said.
Parker spoke Tuesday, just days after commission officials announced that 35 snakeheads had been found in the Susquehanna's waters between the Holtwood and Conowingo dams — a stretch of the river that divides southern Lancaster and York counties.
The invasive fish were identified in mid-May during an annual observation of shad migrations, which send shad traveling upstream through the dams to spawn.
The snakehead sightings confirmed numerous unofficial reports from anglers, who had previously claimed they pulled frankenfish from that stretch of the river, Parker said.
“It’s not supposed to be here,” said Parker, who confirmed snakeheads have also been found in parts of Octoraro Creek, a Susquehanna tributary that flows through Lancaster County.
‘A lot of unknowns’
Northern snakeheads are native to China, Russia and Korea. There, they are considered a food-fish and eaten, said Isaac Ligocki, an assistant professor of biology at Millersville University.
According to officials at the U.S. Geological Survey they may have been released into American waters by “aquarium hobbyists or those hoping to establish a local food resource.” They were first discovered in the United Stated in 2002, when a pair was found in a Maryland pond.
That’s a problem because fish native to Pennsylvania have not evolved alongside the “apex predator,” Ligocki said. That means, native predators and the snakeheads will now be competing for the same, limited food supply, he said.
However, Parker said it’s not yet clear exactly how snakeheads will interact with or impact native species.
“There are a lot of unknowns,” he said. “When an invasive species is introduced into a new waterway, they tend to thrive.”
Moving forward, commission biologists will be working to find and remove snakeheads, Parker said, explaining it would be exceedingly difficult to remove them all.
“We are going to do as much as we can knowing that it’s an uphill battle,” he said.
For that reason, commission officials also are calling on anglers who catch snakeheads to kill and report them by calling 610-847-2442 or sending an email to firstname.lastname@example.org.