Sea lampreys treated in Chippewa River by U.S. Fish and Wildlife Service

What’s happening: From May 23 through June 1, the U.S. Fish and Wildlife Service (USFWS) administered lampricides into the Chippewa River in a coordinated effort to reduce sea lamprey numbers. 

The administration of lampricides in the Chippewa River is part of a larger effort to reduce sea lamprey numbers in all infested tributaries of rivers that empty into the Great Lakes. Lampricides are administered for 12 hours at a time at predetermined sites and are continually monitored by USFWS personnel to ensure the concentration remains at the desired level. Lampricides pose minimal risk to humans or other species, as evidenced by studies conducted by the U.S. EPA and Health Canada Pest Management Regulatory Agency.

Why it’s important: Sea lampreys are an invasive, eel-like species of fish that prey on other aquatic species in a parasitic manner, usually resulting in the death of the host fish. Sea lampreys spawn and go through the larval stage in rivers and streams before migrating to the Great Lakes as juveniles. This has had a detrimental effect on native fish populations in Great Lakes waters. The administration of lampricides is a crucial control method to help prevent further population declines, with sites along the Chippewa River playing a key role in these efforts. 

Population declines in native fish would be damaging to the economic viability of the Great Lakes Fishery, which is currently valued at $7 billion. In a press release, the USFWS said, “Failure to kill the larvae in streams would result in significant damage to the Great Lakes fishery. Infested tributaries must be treated every three to five years with lampricides to control sea lamprey populations.”

A mouth of a sea lamprey (stock image)What they’re saying: The USFWS, in conjunction with the Department of Fisheries and Oceans Canada, has been conducting chemical sea lamprey removal efforts since 1958, under the banner of the Great Lakes Fishery Commission (GLFC). The removal efforts have been widely successful in protecting the Great Lakes from the harmful effects of sea lampreys. 

“The Commission is committed to delivering a sea lamprey control program that practices good environmental stewardship. To support the continued safe use of lampricides the Commission recently conducted a series of studies at a total cost of $6 million to assess the effects of the lampricides on human health and the environment,” says the USFWS. Not just limited to chemical control, the GLFC is also conducting research on other means of sea lamprey removal. “The Commission also is developing a strategy to increase the number of barriers on lamprey-producing streams, and is conducting research into barrier design, traps, attractants, and biological controls.”

What it means for the community: As suggested by the name, lampricides are selectively toxic to sea lampreys, posing little risk to human health at the concentrations needed to control sea lamprey populations. Still, recreators in the Chippewa River are advised to exercise caution and limit unnecessary exposure in the days after lampricides have been administered. The elimination of sea lampreys in the Chippewa River and other infested waters helps to ensure the long-term health of waterways for future generations to enjoy. For additional information about sea lamprey control, call 1-800-472-9212.