Sea lamprey are parasitic animals that feed by attaching themselves to fish species, including lake trout, walleye and other species sought after by Lake anglers. Although most everyone agrees sea lamprey are a serious nuisance, there is some debate as to whether they are native or nonnative. Some people believe they are a nonnative species that entered Lake Champlain through the Champlain Canal, which connects to the Hudson River via the Poultney River. But, others believe that sea lamprey may be a native species leftover from the Champlain Sea.

Sea lamprey became a noticeable problem in the 1970's when stocking programs for Atlantic salmon, lake trout and other species were not yielding expected results in the Lake. Attacks by sea lamprey on these species have limited the full development of a Lake Champlain fishery and restricted recreational and economic opportunities.

During 1990-1997, New York, Vermont and the U.S. Fish and Wildlife Service worked together through the Lake Champlain Fish and Wildlife Management Cooperative on an eight-year experimental sea lamprey control and fish stocking program designed to reduce sea lamprey and enhance sport fish populations.

Chemical lampricides were applied to streams to reduce the number of lamprey larvae before they grew into adults and moved into the Lake. Results from the program showed that the number of sea lamprey wounds found on lake trout decreased, as shown on the Sea Lamprey Wounds graphic. In addition, the average number of sea lamprey wounds on landlocked Atlantic salmon decreased, and the number of salmon and lake trout caught increased. Non-chemical control methods including barrier dams built on some tributaries, which prevent lamprey from spawing upstream, were also part of the program.

In 2001, a new Sea Lamprey Control Program by the U.S. Fish and Wildife Service was approved by the National Environmental Policy Act. Several lamprey controls, including lampricides, barrier dams and trapping are being used. Lampricides have been applied to some creeks in the Lake Champlain Basin during the fall. For example, the Salmon River, AuSable River and Little AuSable River in New York were treated during 2002. The lamprey treatment program is a joint project among the Vermont Fish and Wildlife Department, New York State Department of Environmental Conservation, and the US Fish and Wildlife Service.

Barrier dams are an alternative to chemical control of sea lamprey. In the Lake Champlain Basin, two barrier dams received funding through the Lake Champlain Basin Program. On the Great Chazy River in New York, $15,000 was provided to make the existing waterworks dam inpenetrable to sea lamprey. This effort alleviated the need for TFM chemical treatment on 14 miles of the river. In Vermont, an old barrier dam was repaired on Lewis Creek.

The New York State Bond Act has also supported sea lamprey control by providing $226,500 to build a barrier dam on the Little AuSable River. The Little AuSable is one of the largest producers of sea lamprey in the Basin. The dam, which will be constructed by NYSDEC's Bureau of Fisheries (pending the receipt of additional construction funds), will also incorporate a jump pool to allow desirable species to migrate upstream.

• Sea Lamprey Assessment and Control (USFWS Lake Champlain Ecosystem Team)
• Sea Lamprey (Minnesota Sea Grant)
• Sea Lamprey Control (Great Lakes Fishery Commission)
• Sea Lamprey Control Alternatives in the Lake Champlain Tributaries: Poultney, Hubbarton and Pike Rivers and Morpion Stream. Leigh R. Walrath, Environmental Analyst and Katherine M. Swiney, Environmental Analyst, New England Interstate Water Pollution Control Commission. August 2001. LCBP Technical Report #37A.
• Assessment of Sea Lamprey Habitat and the Sea Lamprey Population of the Pike River and Morpion Stream, Quebec, Canada. Micah Dean and Adam Zerrenner, Lake Champlain Fish and Wildlife Resources Office, United States Fish and Wildlife Service. September 2001. LCBP Technical Report #37B.