Progress is steadily being made to suppress the Sea Lamprey population in the Great Lakes.
The Great Lakes Fishery Commission announced on Monday that Lakes Superior, Michigan, Huron, and Ontario all saw the population decrease in 2026 and that the populations in Lake Erie and Lake Ontario remained below the target level.
"Sea lamprey control remains one of the Great Lakes' greatest fisheries management success stories," said commission chair Earl Provost. "This year's results demonstrate that continued investment in control is reducing sea lamprey abundance and protecting fish populations across the basin."
Sea lampreys are invasive parasitic fish that attack and kill a wide variety of local fish species by feeding on their blood and body fluids.
Currently, the commission uses lampricides and barriers to control the population, though new and supplemental methods are being evaluated.
The latest data on the Sea Lamprey population for each Great Lake is as follows:
Lake Erie
Management target - 3,263
2025 level - 803
2026 level - 923
Lake Huron
Management target - 31,274
2025 level - 44,591
2026 level - 29,602
Lake Ontario
Management target - 14,065
2025 level - 11,584
2026 level - 7,281
Lake Michigan
Management target - 20,526
2025 level - 21,273
2026 level - 20,211
Lake Superior
Management target - 10,421
2025 level - 40,610
2026 level - 29,767
The Great Lakes Fishery Commission was established by Canada and the United States more than 70 years ago to support fisheries research, control invasive species, and facilitate cross-border management.
