August 24, 2010
Snakeheads... Here to Stay?
Photo credit: AP
Some of you may be aware that the Snakehead, Channa argus, made headlines back in 2002 when they were discovered to have taken up residence in a pond in Crofton, MD. It was another old story: folks with captive Snakeheads let them go in the wild... This was a frightening specter (see Lionfish), and local and federal agencies moved to erradicate the animal.
But, the efforts were not swift enough. These fish are ravenous, rapid-growing, and apparently able to move across land to new territories. From the original pond, (or from other unknown, additional locations), it didn't take long for the Snakeheads to invade streams. From there they found their way into the Potomoc River. Bad news indeed. The Potomoc River empties into the Chesapeake Bay - an enormous body of water with a huge watershed. Oh, did I mention that Snakeheads breed?
It was initially believed that they would be confined to the Virginia side of the Potomoc, and that salinity and current would act as barriers to keep them there. Again, the experts were wrong. They've now been found on the Maryland side of the Potomoc. The salinity in the Bay fluctuates with the amount of rainfall in its watershed. More rainfall in the watershed means lower salinities in the major tributaries. This in turn means that the Snakehead may just jump from one river mouth to another, hop-scotching its way into other Chesapeake tributaries.
Well, if the Lionfish is the Starling of our reefs, it would appear that the Snakehead is the Starling of the Bay.
(Sidebar: this fish was not on the original list of species I was to illustrate for Fishes of Chesapeake Bay. But Jack Musick of VIMS , one of the authors on the project, has added it. So, I've illustrated it, and it will be 'in the book'. That's not a good thing...)