Aquatic Invasive Species

Expansion of a Northern Snakehead Population in the Potomac River System

Transactions of the American Fisheries Society 136:1633–1639, 2007 doi: 10.1577/T07-025.1

Northern snakeheads (Channa argus) are illegal to posses in the states of Maryland and Virginia. After finding several of these fish in a Maryland pond in 2004, both states created an initiative in order to quantify and eliminate the snakehead “threat.” By way of electrofishing (a system of creating an electrical blast radius in a water body) and traditional hook and reel fishing, a large number of snakeheads were accounted for. The amount of snakeheads caught increased between the years of 2004 and 2006, either by way of informed anglers, or increased breeding.The study came to several conclusions. The majority (>80%) of the fish caught originated from a single point, showing a central nest location. They then began to migrate downstream in an attempt to find more food and nesting grounds. As the population matured over the years, the average length and mass of captured snakeheads increased. In addition, these fish fed primarily on the local aquatic fauna population, decreasing the amount of game fish for local anglers.