Status of Sea Lamprey

Part of a successful sea lamprey control program is understanding how many adult sea lampreys are in the lake and where they are. For fifty years, sea lamprey assessment crews have been monitoring adult sea lamprey migrations in spring and early summer. Mechanical traps and nets are used to capture the sea lampreys and biological information is recorded to understand population characteristics. A mark-recapture study is conducted on each stream to develop stream and lake-wide population estimates.

Chart showing sea lamprey abundance, wounds on lake trout and laketrout abundance for each great lake

The links below show the lakewide population estimates over time for each lake, beginning with an estimate of adult sea lamprey abundance before the control program began, and then estimates from 1980 to the present.