Which fishes were harmed by sea lampreys in the Great Lakes?

In the Great Lakes, the invasive sea lamprey—a primitive, jawless agnathan—has caused significant harm to native fish populations by acting as a parasite.12

By attaching to hosts with their suction-cup mouths and rasping through flesh to feed on blood and fluids, sea lampreys have devastated several species, most notably the lake trout, which served as the ecosystem's apex predator. Other fish populations that suffered declines due to the lamprey invasion include:12

• Lake whitefish
• Chub
• Cisco
• Walleye
• Northern pike
• Burbot
• Lake sturgeon

Unlike in their native habitats where they often do not kill their hosts, sea lampreys in the Great Lakes kill more than half of the fish they parasitize. These impacts, compounded by overfishing and pollution, led to the collapse of major commercial fisheries in the region.12