As state and federal resource managers revealed that the northern snakehead has spread into the Upper Potomac River, a local angler provided yet more evidence that these exotic predatory fish grow larger here than anywhere else in the world. That's a potential double whammy for bass and other native species.
"Part of the reason we should be worried about it is we don't really know what the impacts are going to be," said Joe Love, tidal bass program manager for the Maryland Department of Natural Resources (MDNR). "We do know that, in some cases, invasive species cost millions of dollars in damage to the ecosystem."
With the population of snakeheads in the tidal Potomac now an estimated 20,000, one concern is that aggressive snakeheads will outcompete bass for food, a fear that is heighted by the fact that they are growing to world-record proportions. In late June, Dan Moon boated the latest giant, which weighed 18.8 pounds on an uncertified scale. The official world record checked in at 17-12, and was caught last year within two miles of where Moon caught his fish.
With both adult snakeheads and fry confirmed in the C&O canal above Great Falls, it seems almost certain that the invaders will spread up the non-tidal Potomac, as well as into its tributaries.
"Eradication is not possible once these fish become established in an open river system such as the Potomac," said MDNR biologist John Mullican. "We expect that these fish will eventually become a permanent part of the Upper Potomac fish community. Confronting snakeheads in the canal system is the best way to mitigate their emigration into the Upper Potomac.
Consequently, Maryland is working with the U.S. Fish and Wildlife Service and the National Park Service to develop control strategies.
MDNR emphasized that the snakehead can be caught legally in any season and at any size. "We'd like it to be harvested if anyone catches it," Love said. "We'd like it if they took it home and possibly ate it. Anglers and archers enjoy fishing for them, which is great. And they enjoy eating them, which is great."