Attempts to Control Invasive Species Grow
September 28, 2007 -- Two invasive species have become a menace in the nation's waterways -- the northern pike, which is troubling California’s lakes and rivers, and the sea lamprey, which threatens to overrun the ecosystem of the Great Lakes. Currently millions of dollars each year are spent in an attempt to control these species.
States and the government are employing many different tactics in order to hold back the tide of these species. In the case of the northern pike, these include nets, traps, electric shocks, explosives, and most recently poison. If left alone, the northern pike could take over Lake Davis and possibly escape to the Sacramento River system, devouring trout and salmon all the way to San Francisco Bay, biologists say.
Sea lampreys likely invaded the Great Lakes in ship ballast water, becoming the scourge of these freshwater bodies. Using conventional methods, officials managed to knock the sea lamprey population down from 3 million to about 433,000, but they realized that an entirely different weapon needed to join their arsenal for battling the species. At a U.S. Geological Survey research station in Millersburg, Mich., on the shores of Lake Huron -- where the largest sea lamprey population lives -- workers now feed roughly 1,200 male sea lampreys per day into a machine that gives each a shot to leave it sterile. The fish are then released back into the ecosystem where they compete for mates. If a female mates with a sterile male, the result is a nest of infertile eggs. The sterilization method seems to be working, since the Lake Huron population has dropped to one-fourth of what it was at its peak, and officials hope to close the gap and finally overwhelm the breeding pools of the sea lamprey in the Great Lakes.
A number of National Research Council reports have examined issues related to invasive species. NEON: Addressing the Nation's Environmental Challenges identifies invasive species as one of the main environmental and ecological challenges facing the nation and recommends moving forward with the development of the National Ecological Observatory Network as a means to help study and track the problem.