Lampricide Control of Sea Lampreys in the Great Lakes
marinus), an invasive species to the Great Lakes from the Atlantic Ocean. Its parasitic life stage
can have severe impacts upon fish populations. The binational, multi-faceted program is
facilitated by the Great Lakes Fishery Commission and delivered by federal agencies in both the
United States and Canada. These agencies work in cooperation with federal, state, and tribal
partners to ensure Program success. Primary control of sea lampreys within the Great Lakes is
achieved by applying lampricides to infested streams and lentic areas to eliminate larval Sea
Lampreys before they metamorphose and parasitize economically important Great Lakes fish.
Streams targeted for chemical control are selected based on assessments that estimate
abundance of larval Sea Lampreys and identify their stream-specific distribution. Lampricide
treatments began in 1958 and are conducted on a 3-4 year cycle in regularly producing streams.
Stream data (pH, alkalinity, and discharge) play major roles in determining the minimum lethal
concentration (MLC) to effectively eliminate Sea Lamprey larvae from a stream. Alternative
methods of control are continually being researched.