Invasive sea lamprey numbers fall in four of five Great Lakes
The gist
Adult sea lamprey counts dropped in four of the five Great Lakes in 2026, with Lake Huron down nearly 15,000.
The parasitic fish kill native fish, so the decline matters for the lakes' fisheries.
How it unfolded
- Oct 29, 2026The Great Lakes Fishery Commission reports adult sea lamprey abundance fell in four of five Great Lakes in 2026: Lake Michigan at 20,211 (down about 1,000), Lake Huron at 29,602 (down nearly 15,000), Lake Superior at 29,767 (down more than 10,000), and Lake Erie up slightly by 120, still within target.
- Oct 29, 2026Using three-year averages from 2024-2026, populations in Lakes Erie and Ontario stayed below target levels, while Lakes Superior, Michigan and Huron remained above their targets.
- Oct 29, 2026FishPass, a selective fish passage project on the Boardman-Ottaway River in Traverse City, is designed to sort and pass certain fish while keeping out invasive species like sea lamprey; construction is due to finish next year.