Attacking the invader

Divers to remove invasive plant from Little Muskego

The state DNR and Little Muskego Lake residents are teaming up to attack starry stonewort, an invasive plant that can resemble an “underwater golf course.”

After the discovery in September of the invasive starry stonewort in Little Muskego Lake, community members and the state Department of Natural Resources are beginning a counter assault on the destructive aquatic plant.

The form of algae was reported for the first time in Wisconsin last year in 506-acre Little Muskego Lake in Waukesha County.

A property owner, Lisa Niles, said she was saddened when she heard about the plant and the effect it has had on other lakes.

“It’s really such a fragile ecosystem,” said Niles, vice president of the Little Muskego Lake Association. “You hate for something like this to happen. It really upsets the apple cart.”

Beginning next month, divers will try to remove all the plants, which are scattered in patches over the 3-acre area of the lake, Niles said.

A hitchhiker from Europe and Asia, it has wreaked havoc on Michigan lakes and prompted an expert on the topic to tell the Milwaukee Journal Sentinel last year that some lakes in Michigan “almost look like an underwater golf course.”

Sarah Lesage, aquatic invasive species program coordinator for the Michigan Department of Environmental Quality, said starry stonewort has spread rapidly since it was found in 1986 in Lake St. Clair near Detroit.

The plant is known to inhabit more than 250 lakes in Michigan.

In Wisconsin, the plant is one of more than 30 invasive aquatic species to attack state waterways. In the case of the starry stonewort, dense mats crowd out native plants, wiping out habitat for juvenile fish.

In June, scuba divers trained by the DNR will start to pick up the plants from the bottom of Wentland Bay on the west side of the lake. Niles said that divers need to make sure they remove the entire plant, including the root system, otherwise it will grow back.

Buoys in the bay with signs will ask boaters to avoid the area. City of Muskego employees and volunteers will staff the busiest boat landing, Idle Isle, on Saturdays, Sundays and Tuesdays — the three busiest days for lake traffic — to inspect boats coming in and out of the lake for signs of the plant.

In August, divers from a commercial company will begin vacuuming plants from the lake bottom.

“We think we really have a good chance of controlling it,” Niles said.

In Michigan, officials say the plant has been hard to eradicate. It can regrow from pieces not harvested.

Lisa E. Huberty, who works on aquatic invasive species for the Michigan Department of Environmental Quality, said the use of mechanical harvesters in Michigan has been counterproductive.

The harvesters seem to be spreading infestations on some lakes.

Because of starry stonewort’s limited distribution in little muske go lake, the DNR thinks hand pulling and vacuuming will be more effective than using chemicals.

The cost of the project will be shared by the city, lake association, DNR and Little Muskego Lake District, Niles said.

In recent years, the DNR and Little Muskego Lake Association have stocked 3,000 young walleye on the lake. Working with the Wisconsin Bowfishing Association, more than 3,500 carp have been removed.