What We Do
Sea lampreys are native to the Atlantic Ocean. In the 1800s sea lampreys entered into the Great Lakes system via manmade locks and shipping canals. Sea lampreys were first observed in Lake Ontario in the 1830s. Niagara Falls served as a natural barrier preventing sea lampreys from entering the other Great Lakes, but modifications to the Welland Canal in the early 1900s provided sea lampreys a path to invade the other lakes. In 1921 sea lampreys were first observed in Lake Erie and quickly spread into Lakes Michigan, Huron and Superior.
Sea lampreys prey on most species of large Great Lakes fish such as lake trout, salmon, lake sturgeon, whitefish, burbot, walleye and catfish. The Great Lakes experienced a drastic decline in lake trout, whitefish and chub populations in the 1940s and 1950s brought on by overfishing, habitat degradation and the invasion of parasitic sea lamprey.
Sea lampreys are naturally anadromous meaning they live in saltwater before migrating to freshwater to spawn. In the Great Lakes, sea lampreys have adapted their life cycle to live entirely in freshwater. Spawning adults deposit eggs in nests in Great Lake tributaries and once the eggs are hatched, the larvae burrow into the sediment where they spend anywhere from 3-7 years filter feeding on detritus, macroinvertebrates and dissolved organic material. After reaching sufficient size, larvae undergo a metamorphosis, growing eyes and an oral disk containing razor sharp teeth and a digestive system capable of feeding on fish blood and absorbing nutrients for growth. The newly transformed lamprey migrate downstream, heading for one of the Great Lakes in search of a host. Once in the lake, they will spend 12-18 months parasitizing fish and feeding on their blood and body fluids. In that short amount of time, each parasitic lamprey is capable of destroying 40 pounds of fish. Sea lampreys prey on all large Great Lakes fish species including lake trout, salmon, rainbow trout, whitefish, walleye and catfish. At the end of their parasitic phase, they undergo another, less drastic transformation in preparation to spawn and head back upstream where they die after spawning.
Management and Conservation
Larval Population Assessment
Assessments are conducted to determine the presence, distribution, abundance and size structure structure
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Learn more about structure of larval sea lampreys in Great Lakes tributaries and lentic or still water areas. In wadeable streams backpack electrofishers are used to assess larval sea lamprey populations. Larval populations in streams and lentic areas greater than one meter in depth are assessed using a granular lampricide.
Lampricide Control
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.
In the 1950s, the U.S. Fish and Wildlife Service sought to identify a chemical compound effective in controlling sea lampreys without significantly impacting other species. Scientists tested nearly 6,000 compounds in their research and discovered two compounds that were effective at controlling sea lampreys: one called TFM (3-trifluoromethyl-4'-nitrophenol), and the other Bayluscide (2', 5-dichloro-4'-nitrosalicylanilide). The lampricides have been used successfully for more than 60 years to suppress sea lamprey populations in the Great Lakes. By the early 1960s, the abundance of sea lampreys was reduced by 90%. This effort paved the way for the rehabilitation of a healthy Great Lakes ecosystem including the recovery of self-sustaining populations of native fish, such as lake trout, in portions of the Great Lakes.
Adult Population Assessment
Traps and nets are operated in about 40 tributaries in the Great Lakes during the spring and early summer to capture adult sea lampreys. A proportion of trapped sea lampreys are marked and released as a method of estimating an index of sea lamprey abundance for each Great Lake.
Barriers
There are more than 30 barriers on U.S. Great Lake streams that block migrating sea lampreys. Agents work 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
Risk management activities are conducted to address environmental and non-target issues related to the implementation of sea lamprey control in the United States. Coordination with many federal, state and tribal agencies and working with others is critical to minimize risk to non-target organisms. Section 7 Section 7
Section 7 Consultation
The Endangered Species Act (ESA) directs all Federal agencies to work to conserve endangered and threatened species and to use their authorities to further the purposes of the Act. Section 7 of the Act, called "Interagency Cooperation," is the mechanism by which Federal agencies ensure the actions they take, including those they fund or authorize, do not jeopardize the existence of any listed species.
Learn more about 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 Program to ensure that federally funded actions authorized, permitted or otherwise carried out will not jeopardize the continued existence of any federally listed species, including those that are endangered, threatened or candidates, or adversely modify designated critical habitat.
Endangered species reviews are conducted annually to:
- Discuss the 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
- Conducted studies to determine the effect of an action on a species of concern when information is lacking
Research
The program also 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 fish passage
Fish passage is the ability of fish or other aquatic species to move freely throughout their life to find food, reproduce, and complete their natural migration cycles. Millions of barriers to fish passage across the country are fragmenting habitat and leading to species declines. The U.S. Fish and Wildlife Service's National Fish Passage Program is working to reconnect watersheds to benefit both wildlife and people.
Learn more about 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