His sister was ailing, and the man in Maryland remembered that, back home in Hong Kong, there was a fish that was considered a delicacy and a restorative. He would make a fish soup for her. He called an Asian fish market in New York and ordered a couple of northern snakeheads, live. But by the time they arrived, she was well again. He put the fish––also sold as pets––in an aquarium, and started feeding them goldfish. The snakeheads started to grow. Soon they were devouring a dozen goldfish a day. What to do?
Behind a local shopping center was a tree-lined, four-acre pond. An ideal new home? The snakeheads, which turned out to be a mating pair, seem to have found it so.
Two years after they were released there, a fisherman caught a fish with sharp teeth and small eyes atop its flattened snout that he couldn’t identify. He let it go, but not before he took its photo. He showed the picture to the state Department of Natural Resources in Annapolis. They weren’t concerned until a second one was caught in the same spot, and some babies netted. All it would take was one heavy rain to wash some of these fish into a nearby river and from there into Chesapeake Bay. For this is an invader with a vengeance: a top-tier predator with a voracious appetite. A fish that can live out of water for days, cross mud to find new territory, and eat not just fish but frogs, birds, and small mammals. The drastic solution chosen was the fish-killing poison rotenone. The kill revealed over a thousand snakeheads, many recently hatched.
That took care of that particular pond. But despite federal legislation banning the import and transport of all snakeheads, they continue to be found in waterways around the country, the result of illegal introductions by humans. A population of the fish is now so well established in the Potomac Basin that the first Snakehead Tournament was held in 2011. All of the fish analyzed from this system had the same DNA sequence, indicating that the entire population may be the offspring of a single female.
Essential to stopping the spread of the snakehead will be effective law enforcement to stop supply routes, sources, and markets to prevent new introductions. Border surveillance is essential—the Lacey Act profits bringing live snakeheads into the US.
In areas where the snakehead is found, federal officials have been removing them through electrofishing, stunning the fish and removing the invaders. There have been some efforts to start a commercial fishery for the species around DC and Maryland, but why buy what you can catch yourself? Some hunters use a bow and arrow, but bass fishing outfits will work just as well for snakeheads. You can find some tips here.
One study, published in Integrated and Comparative Biology, found that bow fishing has been successful in removing large pregnant females from Maryland waters. Harvests were greatest near full and new moons. Read more about this effort in the New York Times.
