A Brief History of the Sea Lamprey Problem in Michigan Waters

Abstract

The life history of the sea lamprey is briefly outlined. Mature adults are anadromous, spawning chiefly in May and June and dying shortly thereafter. The larvae pass 4 to 5 years in the sand, gravel, and silt banks of the spawning stream before transforming into the parasitic stage. After becoming fitted for a parasitic life, they live as free-swimming adults, parasitic on fish, from 1 1/2 to 3 1/2 years before becoming sexually mature and ready to spawn and die. The sea lamprey spread into the upper Great Lakes within the period 1921–1936, and is firmly established in Lakes Erie, Huron, Michigan, and Superior, and possibly in some of the larger inland lakes. Experiments of 1944 and 1945 on the Ocqueoc River in northeastern Michigan involving the operation of a sea lamprey trap were described. Although the trap failed to take a portion of the run each year, 3,366 lampreys were destroyed in 1944 and 4,608 lampreys were caught and killed, in 1945. Most of the upstream movement (95 percent or more) occurred between the hours of midnight and noon and over half took place between midnight and 6:00 a.m. The total length of the Ocqueoc River sea lampreys ranged from 14.1 inches to 30 inches. Males appeared to precede the females to the spawning grounds. The peak of the run came when the average daily water temperature was from 51° to 60° F. Conservation officers of the Michigan Department of Conservation in all counties bordering the Great Lakes questioned commercial fishermen during June and July 1946 concerning the sea lamprey problem. Their records indicated that: (a) sixty-eight spawning streams or areas were reported; (b) depending on the locality fished and the species of fish sought, from 0 to 100 percent of the catch was lamprey-scarred. Lake trout were most affected, followed by white-fish, suckers, yellow pikeperch, and carp; commercial fishermen, except those fishing from ports in northern Lake Michigan and northern Lake Huron, suffered almost no loss due to scarring of fish by sea lampreys (in the affected areas, the loss was reported to vary from 5 to 75 percent of the normal value of the fish). Any program for the eradication of sea lampreys through attempts to block off and trap all lamprey spawning runs would be exceedingly costly but the operation of traps on the more important spawning streams might control the pest. Further research on the life history and possible economic utilization of the sea lamprey is suggested.