Lamprey control cleared
Staff Report | September 03,2006
WATERBURY — The Vermont Fish & Wildlife Department has received all of the state permits needed to treat sea lampreys in Lewis Creek in Ferrisburgh. Treatment with the lampricide TFM is scheduled to begin in early October.
The sea lamprey is a parasitic fish that kills many other species of fish in Lake Champlain. Attacks on landlocked salmon, lake trout and walleye are unacceptably high, according to fisheries scientists working for the states of Vermont and New York, and the federal government.
Fisheries biologists with the Vermont Fish & Wildlife Department, New York Department of Environmental Conservation, and the U.S. Fish and Wildlife Service are working together as members of the Lake Champlain Fish and Wildlife Management Cooperative in efforts to control the sea lamprey population and restore populations of native fishes in Lake Champlain.
In addition to preying on trout, salmon and walleye, sea lamprey also parasitize the endangered lake sturgeon, as well as channel catfish, lake whitefish and other species.
Scientists believe a single sea lamprey can kill up to 40 pounds of fish and grow from 6 inches to more than 18 inches long during its 12 to 20-month life as a parasite in Lake Champlain.
The lamprey feeds by attaching to the side of a host fish, rasping through its body wall with its sharp toothed tongue, and then sucking blood and body fluids over an extended period of time. Sometimes several lampreys will attach to the one fish at the same time or repeatedly, often resulting in death of the host.
Lewis Creek will be treated with TFM for the fourth time since the beginning of Lake Champlain sea lamprey control efforts in 1990. TFM was developed specifically to target sea lamprey and has been successfully used for more than 50 years in the Great Lakes and more recently in the Finger Lakes and Lake Champlain tributaries in New York and Vermont.
The Lewis Creek treatment will be preceded by scheduled treatments with TFM of four New York streams in late September. TFM targets larval sea lamprey that stay in the soft stream bottom for four years between hatching and migrating out to Lake Champlain where they become parasitic. The adults return to the streams to spawn after one year in the lake and then die.
Stream lampricide treatments are usually conducted once every four years with carefully controlled lampricide applications, each taking about 12 hours to complete. The treatment cycle takes advantage of the species' life history to minimize the use of treatment measures. Because larval sea lamprey remain in streams for four years before becoming parasitic, four years' production of larval lampreys can be killed at once, precluding the need for annual treatments.
All five streams to be treated this fall are on schedule, having been last treated in 2002.
"The Vermont Fish & Wildlife Department has received the Aquatic Nuisance Control Permit and the Threatened and Endangered Species Permit from the Agency of Natural Resources," said Fish & Wildlife Comissioner Wayne Laroche.
"The plan now is to begin treating Lewis Creek in early October," Laroche said. "Stream levels and water temperatures must be within specific ranges to effectively use TFM. This means that there will always remain a risk that weather conditions might make treatment impossible this fall. However, at this time, all systems are GO for this fall's treatment of Lewis Creek."