Snakeheads were illegally dumped into a pond in Crofton, Maryland two years earlier. They spread into the Potomac River drainage, eventually making their way into Virginia streams. They finally ...

(Read more: Fishermen battle invasive ‘frankenfish’ snakeheads.) The largest U.S. invasive population lives in the Potomac River drainage of the Chesapeake Bay watershed. In 2002, a snakehead ...