Scientists Hope Sterile Males Will Reduce Lamprey Population

ANN ARBOR (AP) — Scientists will release sterile sea lampreys into several Michigan rivers in the continuing quest to control the aquatic parasites that threaten fish in the Great Lakes region.

Crews this month will put about 4,000 sterile males into the Pigeon, Sturgeon and Maple rivers in the northern Lower Peninsula.

The idea is to drastically outnumber the small population of fertile males and reduce their odds of mating successfully with females.

Eel-like sea lampreys attach themselves to fish with a suction-cup mouth and feed on the hosts' body fluids.

The sterile lampreys have passed the point in their life cycle when they would feed.

Scientists have reduced the Great Lakes lamprey population with a specially designed poison, but it's expensive. If the sterile-male plan works, fewer lampricide river treatments will be needed.