sea lamprey 
Petromyzon marinus
Image by Lee Emery

Sea Lamprey

Sea Lamprey Map
Image by USGS

Map by USGS on HUC level record of sea lamprey in the United States

Sea Lamprey

Sea lampreys are parasitic pests. They attach to fish with their suction mouth and teeth, and use their tongue to rasp through a fish’s scales and skin so they can feed on its blood and body fluids. A single sea lamprey will destroy up to 18 kgs (40 lbs.) of fish during its adult lifetime. Sea lampreys are so destructive that, under some conditions, only one out of seven fish attacked will survive. Sea lampreys prey on all types of fish, such as lake trout, salmon, rainbow trout (steel­head), brown trout, whitefish, yellow perch, burbot, walleye, catfish, and even sturgeon.

In the 1940s and 1950s, sea lamprey populations exploded as there were no effective control methods and no natural predators. This contributed significantly to the collapse of fish species that were the economic mainstay of a vibrant Great Lakes fishery. [From Sea Lamprey: The Battle Continues to Protect Our Great Lakes Fishery, below]


Sea Lamprey: The Battle Continues to Protect Our Great Lakes Fishery on the Fisheries and Oceans Canada website describes shared responsibility of U.S. and Canada for conditions of the Great Lakes fishery; describes sea lampreys, where they are found, damage they inflict on the fishery, methods of control used in the Great Lakes, their life cycle, and contact information for members of the Great Lakes Fishery Commission.

Sea Lamprey – Factsheet on the NYS Dept. of Environmental Conservation website covers biology, impacts, and control of the species.

Sea Lamprey Species Profile on the USDA National Invasive Species Information Center website provides a brief profile on the species.

Sea Lamprey Fact Sheet on the U.S. Geologic Survery Nonindigenous Aquatic Species website covers identification, nonindigenous occurrences, means of introduction, impact, and management of the species. 

Last updated June 25, 2019