Like a vampire, the sea lamprey latches onto its prey and sucks the blood and nutrients out of fish in all five of the Great Lakes. Sea lampreys, an eel-like parasitic fish that’s native to the Northern Hemisphere, but is considered invasive in the Great Lakes, experienced a brief population spike during the COVID-19 pandemic, and authorities have spent the last year removing the lamprey surplus.
The U.S. Fish and Wildlife Service is contracted by the Great Lakes Fishery Commission to apply lampricide to the creeks and tributaries throughout the Great Lakes corridor. The applications of lampricide are applied every three to four years. The treatment is specifically created to target the lamprey larva with minimal effects on other aquatic wildlife. Even though the lamprey control program has been effective, there’s still a chance that anglers may encounter one while fishing on the Great Lakes.
The United States Geological Survey reports that sea lampreys are “an ancient species” that have retained “primitive ancestral characteristics from millions of years ago,” which includes a slim body, two closely spaced dorsal fins, seven gill openings on each side, a large round mouth with curved razor-like teeth and a rasping tongue.