RESTON, Va. (AP) — Scientists say the invasive northern snakehead fish carries bacteria that could harm other creatures.

The U.S. Geological Survey says some snakeheads caught in Virginia waters of the Potomac River south of Washington were infected with an unknown species of mycobacteria.

Mycobacteria can cause chronic disease in a variety of animals, including mammals. But Virginia state fisheries biologist John Odenkirk said Thursday there is no indication of a health risk to people who eat infected snakeheads that have been cooked.

USGS veterinarian Christine Densmore says more research is needed to determine the potential effects of the bacteria on the snakehead population and other species.

“Thats what we’re trying to get a handle on — is what the disease outlook is for snakehead and where this might fit into it,” Densmore says.

Densmore says people can take steps to help ensure the bacteria isn’t transferred.

“Disinfect your gear when going from one tributary to another or one local area fishing to another,” she says.

The predatory fish can breathe air and survive on land. They’ve been reported in at least nine states since they were discovered in California in 1977.

WTOP’s Megan Cloherty contributed to this report.

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