Economic Importance for Humans: Negative
Because of their over-aggressive behavior and generalist diet, sea lampreys parasitize many species of fish, contributing to the severe decline of commercial fishing industries, including those on the Atlantic coast of North America and in the Great Lakes region. Each sea lamprey kills more than 18.2 kg of fish each year. This species has parasitized many species of native fish in the Great Lakes region since the early 1800s, leading to the collapse of the Great Lakes commercial fishing industry and costing it millions of dollars. Population declines of native fish in the region have also negatively impacted sport fishing and tourism. In one case, a sea lamprey bit a human, though this is thought to have been accidental.