Environment & Science
10:59 am
Thu August 16, 2012

New barrier to keep blood-sucking parasite under control?

Michigan is taking ownership of a dam on the Manistique River in the Upper Peninsula.

That will allow the federal government to build a new barrier there to keep sea lampreys from breeding in the river. Managers of the fishery expect that will bring the lamprey problem under control in Lake Michigan.

For more than fifty years Canada and the U.S. have been battling the eel-like creature across the Great Lakes. Sea lampreys are parasites that drill holes in fish to feed on blood and body fluids. They often kill the fish. The sea lamprey was one of the first invasive species to arrive in the lakes, and it’s the only invasive to be successfully controlled by humans.

The Manistique is one of the largest watersheds in the Upper Great Lakes. Wildlife officials were caught off guard about a decade ago when it was discovered sea lamprey were passing an old dam near the river mouth and spawning upstream. That was one reason the lamprey population in Lake Michigan surged around 2007.

And today, sea lampreys are still more numerous than fisheries biologists would like. Lamprey keep lake trout from recovering and also attach to white fish and salmon. The U.S. Army Corps of Engineers is ready to build a new barrier on the Manistique River and Michigan’s willingness to own the dam could allow that to happen by 2014.

-Peter Payette for the Environment Report

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