A “voracious predator,” the Northern snakehead, is being examined in the waters of the John Heinz Refuge in Tinicum, writes Frank Kummer for The Philadelphia Inquirer.
Snakeheads eat native fish, and the Pennsylvania Fish and Boat Commission sees them as an environmental threat. It is illegal to transport them live in the state.
“They are a prized food fish. They were brought here mainly for people to eat. And they’ve been liberated into waters around the area,” said Geoff Smith, a PFBC biologist.
Smith and his PFBC team, along with Pennsylvania State University student Matt Chotlos, are studying the snakehead invasion of local lakes, ponds, and wetlands.
They found 21 species of fish in the stomachs of captured Northern snakeheads. They particularly like killifish, sunfish, and eels.
Darby Creek had the highest concentration of Northern snakeheads in the region.
“It’s a top predator, and has spread very quickly,” said David Keller, fisheries section leader for the Academy of Natural Sciences at Drexel University.
At the Heinz refuge, the snakeheads have also been feasting on frogs, reducing that population.
Part of the Heinz Wildlife study is also looking at the levels of contamination of synthetic per- and polyfluoroalkyl chemical compounds found in the snakeheads.
Read more about the Northern snakehead invasion in The Philadelphia Inquirer.
Editor’s Note: This post first appeared on DELCO Today in September 2025.
