Wis. group raises sturgeon in river water
Published on http://seattlepi.nwsource.com on May 16, 2006
MILWAUKEE -- By raising newborn sturgeon in water taken from the Milwaukee River, a group of volunteers hopes the fish will learn to recognize unique scents in the water that will lead them to return to the river years from now when they spawn.
Lake sturgeon have not spawned in the Milwaukee River in more than 100 years. State officials have released hatchery-raised sturgeon into the river in hopes the fish would recognize it as a future breeding site, but to no avail.
Perhaps that's because those sturgeon were up to 1 year old at the time of release, maybe too old to become sensitive to the unique chemistry of the river, said Brad Eggold, southern Lake Michigan fisheries supervisor for the state Department of Natural Resources.
Enter the volunteers, part of a 25-year commitment to boost sturgeon spawning in the river.
The U.S. Fish and Wildlife Service, with the Wisconsin and Michigan Departments of Natural Resources, is coordinating a program to raise sturgeon in trailers by the Milwaukee and Manitowoc rivers in Wisconsin and the Cedar and Whitefish rivers in Michigan.
Volunteers, such as those at Milwaukee's Riveredge Nature Center, clean the tanks and keep clear the lines that draw water directly from the rivers.
Scientists hope the sturgeon will learn to detect a unique scent in that water - perhaps from a type of soil, dissolved mineral or chemical not found in any other lake tributary - when they seek a breeding spot.
Funding in the first three years comes from a $583,000 grant from the Great Lakes Fishery Trust in Michigan, Eggold said.
After that the Wisconsin DNR plans to pay the costs of running the state's two sturgeon trailers, which are expected to raise 1,500 young sturgeon from eggs every year for 25 years, Eggold said.
The sturgeon population in Lake Michigan is estimated at a few thousand, a precipitous decline from the hundreds of thousands believed to have roamed the lake in the early 1800s.
Researchers know of sturgeon spawning in only eight of Lake Michigan's tributary rivers: the Fox, Oconto and Peshtigo in Wisconsin; the Menominee bordering Wisconsin and Michigan; and the Manistee, Manistique, Muskegon and Kalamazoo in Michigan.