Washington, 20 Oct 2004
The northern snakehead, an invasive species of fish that can breathe air and move across land for short distances, has been found in a Chicago harbor, officials from the Illinois Department of Natural Resources said this week. This is the first sighting of the fish in the Great Lakes, the world's largest body of fresh water.
Native to China, the snakehead easily outcompetes native fish for food and other resources, and it can decimate native insect populations.
In May 2002, more than 1,000 snakeheads were found in a Crofton, Md. pond, the descendants of two imported fish discarded there by a Maryland man. To eradicate the colony, state officials poisoned the four-acre lake. Snakeheads have also been found up and down the East Coast.
A 2002 report from the National Academies' Board on Agriculture and Natural Resources, Predicting Invasions of Nonindigenous Plants and Plant Pests, divides an invasive species' progress into three distinct stages: arriving, reaching a threshold of survival and thriving through proliferation and geographic spread. The report also offers recommendations for enhancing the science base in this field, improving detection of potential invaders and refining scientists' ability to predict invasive species' impact.