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Conserving the Nature of America

The mission of the U.S. Fish and Wildlife Service is working with others to conserve, protect and enhance fish, wildlife, plants and their habitats for the continuing benefit of the American people.


Larval Population Assessment

A Service employee electrofishing
Electrofishing the Rock River in Michigan. Photo by Lynn Kanieski/USFWS.

The Sea Lamprey Control Program assesses the presence, distribution, abundance and size structure of larval sea lampreys in Great Lakes tributaries and lentic or still water areas. In wadeable streams we use backpack electrofishers to assess larval sea lamprey populations. Larval populations in streams and lentic areas greater than 1.0 m in depth are assessed using a granular lampricide.

Lampricide Control

A Service employee ensuring an accurate lampricide application rate
Ensuring an accurate lampricide application rate. Photo by Kasia Mullett/USFWS.

Larval sea lamprey populations are controlled by applying federally registered lampricides to infested streams and lentic areas in the Great Lakes. Prior to each treatment we collect water discharge and chemistry data. We use this data to determine the appropriate concentration of lampricide to apply. Lampricide concentrations are closely monitored in each stream to ensure larval sea lamprey populations are destroyed and non-target species mortality is minimized.

Adult Population Assessment

Service biologists check sea lamprey traps
Biologists remove adult sea lamprey from a trap on the Manistique River. Photo by Lynn Kanieski/USFWS.

The Sea Lamprey Control Program operates traps and nets in about 40 tributaries in the Great Lakes during the spring and early summer to capture adult sea lampreys. A small proportion of trapped sea lampreys are marked and released as a method of estimating lake wide abundance. A small proportion of trapped sea lampreys are marked and released as a method of estimating an index of sea lamprey abundance for each Great Lake.


A Service employee inspects a barrier
An employee inspects a sea lamprey barrier. Photo by Mara Koenig/USFWS.

There are more than 30 barriers on U.S. Great Lake streams that block migrating sea lampreys.The Program works with partners to maintain and implement barrier structures in streams to provide control when other options are not feasible, excessively expensive or ineffective.

Risk Management

The Risk Management Team addresses environmental and non-target issues related to the implementation of sea lamprey control in the United States. This involves coordination with many federal, state and tribal agencies and working with others to minimize risk to non-target organisms. Section 7 of the Endangered Species Act mandates that the Sea Lamprey Control Program consult with the U.S. Fish and Wildlife Service’s Ecological Services to ensure that federally funded actions authorized, permitted or otherwise carried out will not jeopardize the continued existence of any federally listed (endangered, threatened and candidate) species or adversely modify designated critical habitat. Endangered species reviews are conducted annually to discuss:

  • Proposed lampricide applications and electrofishing surveys
  • Assess the potential risk of these actions to listed species
  • Develop procedures to protect and avoid disturbance for each listed species
  • Studies are conducted to determine the effect of an action on a species of concern when information is lacking.


The program supports research designed to increase the efficiency of current methods or to advance new methods of controlling sea lampreys, such as:

  • Use of attractants and repellents to guide sea lamprey towards traps or away from suitable habitats
  • Environmental and physiological determination of sea lamprey sensitivity to lampricides
  • Novel barrier designs that can block sea lampreys while addressing fish passage and human safety objectives
  • Improving selective fish passage by exploiting behavioral and physiological traits of desired and undesirable species
  • Identifying supplemental control techniques that can be deployed to reduce or eliminate the use of lampricides