A case history of sea lamprey (Petromyzon marinus) abundance and control in Lake Huron: 2000–2019

Abstract

Beginning with the first lampricide treatments of Lake Huron streams in 1960, applying lampricides and maintaining barriers to migration in Lake Huron tributaries continue to be the primary methods of controlling sea lampreys (Petromyzon marinus). In years leading up to the new millennium, sea lamprey abundance in Lake Huron remained at high levels, yet well below the pre-control adult abundance estimate of 700,000 adults. Two decades later, a variety of sea lamprey control strategies have been developed and employed to further reduce sea lamprey abundance in Lake Huron. In recent years, record low numbers have been achieved and continue to be at or near target levels for sea lamprey abundance. The St. Marys River continues to be one of the largest producers of sea lampreys to Lake Huron and additional actions have been taken to address this challenge. Controlling larval abundance in the St. Marys River along with increasing lampricide treatments throughout the basin and focusing on the largest sea lamprey producing streams have contributed to the decline in sea lamprey abundance. Lake trout (Salvelinus namaycush) restoration efforts along with increased sea lamprey control has facilitated natural reproduction and increase in wild stocks across the basin. The fish community objective for sea lampreys in Lake Huron has not been entirely met and efforts to achieve this objective are ongoing.