On the heels of the 2006 Minnesota Ducks Wetlands and Clean Water Rally at the state capitol on April 22, Ducks Unlimited (DU) is celebrating the completion of a project partially funded by participants at last year’s Duck Rally. In partnership with the Minnesota Department of Natural Resources (DNR) and other local partners, DU completed the first step to enhancing Lake Maria, a 425-acre historically important waterfowl lake in north central Murray County.
The project featured the installation of an electric fish barrier and electric pump by DU that will be used by DNR to induce a drawdown to rejuvenate the lake’s aquatic plants and invertebrates. Before this project, Lake Maria’s habitat was in very poor shape. The lake’s high water levels and turbid condition were killing the aquatic vegetation ducks need and allowing problem fish to thrive.
“Chronically high water levels prevented the lake from becoming low enough to allow natural winterkills to reduce problem fish that add to turbid conditions, such as carp, black bullhead, and fathead minnows,” said Jon Schneider, DU manager of conservation programs for Minnesota. Turbid water prevents sunlight from reaching submerged aquatic vegetation on which ducks depend, and fish disturb bottom sediment and eat beneficial aquatic invertebrates that control algae blooms.
Key components of project include the installation an electric (non-lethal) fish barrier in the road culvert separating Lake Maria from downstream Lake Sarah and the installation of a large pump in Maria’s outlet channel. DU provided engineering and construction management oversight for the project as part of its Living Lakes Initiative.
Flooding conditions on the lake have prevented the DNR from using the pump yet this spring, but if the watershed dries out this summer, lake levels can be lowered to produce a summerkill and winterkill conditions. The electric fish barrier will then be activated and normal water levels will return providing improved habitat for migrating waterfowl next year.
The project benefited greatly from the 2005 Rally, which improved both funding and public support for improvement of Lake Maria and many other shallow lakes. In close collaboration, DU and DNR are now poised to enhance several other shallow lakes in southern Minnesota with new outlet water control structures including Geneva Lake in Freeborn County, Rice Lake in Faribault County, Rice Lake in Blue Earth County, and Spellman Lakes in Yellow Medicine County. Meanwhile, DU and DNR continue to manage cooperatively nearly 100 wild rice lakes in northern Minnesota.