Researchers estimate there are 15,000 sea lampreys in Lake Erie–a number that is five times more than fisheries can manage. Despite attempts to control the species’ population, it has been steadily growing in Lake Erie since the mid-1990’s. Mike Steeves is the head of assessment for the Sea Lamprey Control Center in Canada. He says fisheries typically lose 40 pounds of fish for each lamprey in the area.
“They prey upon primarily cold-water fish species—so lake trout, burbot, salmonids in particular—and they rasp a hole in the side of the fish. They drink the blood and the body fluids of the fish, and basically don’t allow it to either grow very well, or, in fact, it typically ends up killing the fish.”
Steeves says researchers have experienced some success taming the lamprey population by creating barrier dams to block migration. He says he also works with a team that kills lamprey larvae.