Villain to Rising Star: Strange Odyssey of the Snakehead
This once-reviled fish is now winning fans among the public―even biologists― as it finds a quiet niche in our Potomac River environment
The northern snakehead is a very slippery fish, both literally and in the sly way it’s changed public opinion.
Just eight years ago, this native of China made headline news when it showed up at a local pond, and then in the Potomac River. Environmentalists and many biologists issued dire warnings: This “Frankenfish,” with its vicious teeth and belligerent personality, would devastate the river’s bass population and otherwise destroy the “ecology.”
Something must be done!
In fact, something was done: We began to change the way we think about this once-reviled fish. Today, the snakehead is winning growing acceptance and even admiration among fishermen and others who know it―including at least one respected fisheries biologist.
“The more I work with snakeheads, the more I see them as beautiful,” John Odenkirk, told group of fishermen at a recent meeting of the Potomac Smallmouth Club. “They’re very neat fish, they really are.”
Not long ago, the Virginia Department of Game and Inland Fisheries, which employs Odenkirk, and its Maryland counterpart were waging an all-out crusade against the snakehead. They vowed to poison the fish to oblivion, and urged anyone who caught one to freeze it solid or bleed it to death.
Then the tide began to turn in the tidal Potomac.
Snakeheads get their green card
As it turned out, the snakehead won a decisive victory in its battle for resident alien status. The war of extermination is over. “We saw that these fish are going do what they’re going do,” Odenkirk recalled.
Today, snakeheads are everywhere in the lower Potomac. In spawning season, many follow their migratory instinct upstream as far as Great Falls. During spring floods, they take advantage of the lowered salinity to swim far down the estuary.
Reaching the Chesapeake Bay, they have taken a left turn to colonize creeks on the western shore. Odenkirk expects that they will soon take a right turn and appear in the Rappahannock as well.
Will we be seeing them soon at Old Anglers and Pennyfield locks? Maybe so. They will get around the Great Falls barrier either with the help of a human dispersal agent, or by following the C&O Canal.
Odenkirk has already found snakeheads right in front of the canal’s tidewater lock in Georgetown. He’s convinced that they’re already in the canal itself. But the Park Service won’t let him prove it, because the boat he uses for electrofishing uses a motor, which is prohibited.
Just as the authorities could not destroy the snakehead, it turned out that the snakehead did not destroy the “ecology.” True, its numbers initially increased rapidly, as is the case with many introduced species. But 2011 saw a slight dip, leading Odenkirk to speculate that the population has begun to stabilize.
In the meantime, the largemouth bass (also an introduced species) appears to have thrived. Electrofishing surveys yield some eight snakehead an hour vs. 80-100 largemouth bass an hour―an order of magnitude.
For all their ferocious looks, snakeheads prefer rather boring diets. They lie silently in their sluggish, weed-choked backwaters, and mostly dine on a minnow called the banded kilifish. They also eat some sunfish, and yes, an occasional bass.
Interestingly, the fearsome teeth aren’t for eating, Odenkirk said. Rather, the snakehead captures his prey by inhaling them with a powerful whoosh of water, like an aquatic vacuum cleaner.
‘A really pretty fish’
Something else quite remarkable is that the snakehead is an obligate air breather. In other words, unlike other fish that can also breathe air, the snakehead doesn’t have a choice.
So the fish must rise up to the surface, take a gulp of air, descend, up and down, all day long. “Really damn neat,” Odenkirk said. “If the snakehead can’t breathe air, it will drown.”
Just like us.