The Great Lakes Fishery Commission today reported that abundances of destructive, invasive sea lampreys have been knocked down to a 30 year low in Lake Huron, a 20 year low in Lake Michigan, and to below the target level in Lake Ontario.

The commission also reported that although sea lampreys are above the target levels in Lakes Erie and Superior, the trends in both lakes follow a steady five-year decline. Sea lampreys are and always will be a constant battle in the Great Lakes and without lamprey control, the fishery would suffer significant ecological and economic harm.

The sea lamprey is one of the worst human-caused ecological disasters ever inflicted upon the Great Lakes. Sea lampreys invaded through shipping canals and, by 1939, were present throughout the system. They attach to Great Lakes fish with a tooth-filled, suction cup mouth and file a hole through the fishís scales and skin with a razor-sharp tongue. The average sea lamprey will kill up to 40 pounds (18 kg) of fish during its parasitic stage. Sea lampreys prefer trout, salmon, whitefish, and sturgeon, but they also attack smaller fish like walleye and perch.

Sea lamprey control consists of several techniques including lampricides, barriers, and traps. The commission also is experimenting with sex pheromones as a way to disrupt spawning behavior. For more information about sea lampreys and control, visit www.sealamprey.org/sealamp.