Sea lamprey control in the Great Lakes
One sea lamprey can kill up to 40 pounds of fish in its lifetime, but certain programs can reduce the impact of this invasive species in the Great Lakes.
Sea lampreys are native to the Atlantic Ocean, however, they can be found throughout the Great Lakes. They were one of the first aquatic invasive fish that entered the Great Lakes when the Wetland Canal was built to bypass Niagara Falls. When the sea lamprey entered into the upper Great Lakes, they decimated native fish populations. One sea lamprey can kill 20 to 40 pounds of fish in its lifetime.
Michigan Sea Grant and Michigan State University Extension recently held an educational session at the Michigan Fish Producers Association Annual Conference. During the conference, Scott Grunder of the U.S. Fish and Wildlife Service Sea Lamprey Control Program, gave a presentation educating the public on Sea Lamprey Control in the Great Lakes.
Sea lampreys have a very unique life cycle. Lampreys tend to cause the most damage to Great Lake fisheries during the adult parasitic phase of life, which lasts 12-18 months. During the spring, Lamprey’s will die, but not before they spawn in Michigan rivers to continue their destructive legacy. After the eggs hatch, they go through a non-parasitic larval stage that lasts for three to six years. When the larval stage is complete, they begin the adult parasitic phase where they enter the Great Lakes and feed on the fish population. However, during the larval stage sea lampreys are vulnerable to chemical control.
The Great Lakes Fishery Commission, Fisheries and Oceans Canada and control agents of the U.S. Fish and Wildlife have implemented a program to control sea lamprey in the Great Lakes. These programs include both chemical and alternative control methods. The total control program budget exceeds $20 million per year. About $3 million of that is spent on chemicals. These chemicals are registered-use pesticides that are very selective for sea lampreys. They pose no unreasonable risk to public health or the environment and are non-persistent. Over 100 streams are treated annually.
Alternative methods are another important component of sea lamprey control. Physical barriers are used in some streams to block upstream migration of sea lampreys and reduce habitat availability for producing the next generation. Traps are also used near these barriers to capture adults.
The integrated sea lamprey control program has had great success in minimizing damage to Great Lakes fish. Sea lamprey spawning has been reduced by about 90 percent since the onset of the sea lamprey control program.
Without this control program, sea lampreys would have continued to increase in numbers throughout the Great Lakes. Research continues in the areas of genetic manipulation, pheromones, repellents, effects of lampricides on non-target organisms and resistance to lampricides.