Department of Environmental Conservation

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Sea Lamprey Impacts

Lake Champlain
Sea Lamprey Control

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What are the impacts on the Ecosystem, the Fishery, and the Economy of Lake Champlain?

Sea lamprey have a major detrimental impact on the Lake Champlain fish community, the Lake Champlain Basin ecosystem, the anglers that fish Lake Champlain, and the many people throughout the watershed whose livelihood is directly or indirectly supported by the fishing and tourist industry.

Lake Trout with Sea Lamprey Attached

Ecosystem Impacts

Sea lamprey attach to a host fish, rasp and puncture its skin, and drain its body fluids, often killing the host fish. Their preferred hosts are salmon and lake trout, however they also feed on other fish species, including lake whitefish, walleye, northern pike, burbot, and lake sturgeon. The lake sturgeon is listed as a threatened species in New York and an endangered species in Vermont and it is likely that sea lamprey are affecting their survival.

Most sea lamprey hosts are native fish species that have been part of the Lake Champlain Basin ecosystem for thousands of years. Additionally many of these fish species are important sportfish, highly prized and sought after by local and visiting anglers.

Native salmon and lake trout had been exterminated from Lake Champlain by early 1900s. In the late 1950s and 1960s New York State began experimental stockings of lake trout and salmon with some limited success. It became clear that one of the factors limiting the success of the stocking effort was predation by sea lamprey.

Fishery Impacts

Prior to any control measures, angler catches of lake trout and salmon in Lake Champlain were a fraction of catches in similar lakes, despite intensive stocking efforts. High wounding rates indicated that sea lamprey were having a significant impact on the lake trout and salmon populations, and were preventing the restoration of these native fish species to Lake Champlain.

A Wound a Sea Lamprey Inflicted

Studies on the Great Lakes show a 40 to 60 percent mortality rate for fish attacked by sea lamprey. Other studies found that a single sea lamprey can kill 40 or more pounds of fish during its adult life. Fish that survive a sea lamprey attack expend more energy on healing than on producing eggs and mating, causing declines in fish populations. The abundance of sea lamprey is obviously having a significant detrimental impact on Lake Champlain's fishery and ecosystem.

Economic Impacts

Poor fishing has caused many anglers to seek fishing opportunities elsewhere. It has been estimated that 29.4 million dollars in economic benefits to businesses and residents of the Lake Champlain Basin are lost due to the impacts of sea lamprey.


Due to the severity of the impacts that sea lamprey have on the Lake Champlain fishery and ecosystem, and the social and economic impacts on the people who live in the Lake Champlain Basin, it has been determined that sea lamprey populations should be controlled. The federal and state governments, the agencies that manage Lake Champlain, the various organizations that are concerned with Lake Champlain and the people that live in the Lake Champlain Basin generally agree that it would be irresponsible not to control the sea lamprey population.