By John Koski
Editor
In terms of size, Lulu Lake isn’t that big. Located about six miles northwest of East Troy, it has a surface area of 95 acres. By comparison, nearby Lake Beulah has a surface area of 834 acres, while Phantom Lake, near Mukwonago, consists of 433 acres.
In terms of ecological importance, however, Lulu Lake ranks high on the list of Wisconsin’s lakes.
The Nature Conservancy, which own 504 acres at Lulu Lake and is actively involved in protecting and preserving the lake and its surrounding watershed, noted on its website:
“Lulu Lake glitters amidst the rich marshes of the upper Mukwonago River watershed. When viewed through the lens of species richness and water quality, the lake and its watershed comprise one of Wisconsin’s highest quality natural areas.”
The lake’s pristine waters, which can reach nearly 50 feet deep, have been recognized as such for more than 150 years. In the days preceding electric refrigeration “Lulu Lake ice was highly prized by breweries and dairies for its pristine clarity,” according to the East Troy Area Historical Society.
Boxcar loads of the ice were taken from a massive six-story icehouse on the shores of Lulu Lake to Milwaukee, Chicago and other areas, according to the society.
Lulu Lake today
In recent years, Eurasian water-milfoil, an unwelcome invasive species that grows underwater, has established itself in Lulu Lake.
Once it takes root, Eurasian Water-milfoil forms thick mats of tangled stems that make recreational activities, such as swimming and fishing, difficult and sometimes impossible. It also impairs the ability of fish to spawn and displaces native aquatic plants that cranes, ducks, geese and other waterfowl need to survive.
“Eurasian water-milfoil was introduced into Lulu Lake on the propellers of recreational boats,” said Jerry Ziegler, southeast Wisconsin land steward with the Nature Conservancy.
“On a typical Saturday or Sunday in the summer, we can have up to 100 pontoon boats and several dozen kayaks and canoes that have traveled to Lulu Lake from Eagle Springs Lake,” Ziegler said.
Over time, he said, those watercraft introduced the fast-growing Eurasian water-milfoil into Lulu Lake.
Dealing with the problem
A snorkeler holds a clump of Eurasian water-milfoil removed from Lulu Lake on July 30. The clumps were placed in large, white tubs in nearby canoes for later disposal. (Photo by John Koski)
To help rid the lake of Eurasian water-milfoil, several times a year The Nature Conservancy mobilizes teams of scuba divers, snorkelers and interns in canoes intent on removing thick clusters of the invasive species.
The scuba divers and snorkelers remove the milfoil and load it into a large, white tub in each of the canoes, which were operated by Nature Conservancy interns.
On Tuesday, July 30, the teams concentrated on a five-acre area of Lulu Lake, removing large masses of Eurasian water-milfoil.
To prevent the invasive species from returning, The Nature Conservancy is utilizing an innovative technology to help native underwater plants establish themselves.
Dr. Timothy Gerber, professor of biology at UW-LaCrosse, working with Ziegler, developed an innovative technology they hope will prevent Eurasian water-milfoil from returning and establish native underwater plants.
Native plants are interwoven into large mats, which are then submerged directly over the areas where Eurasian water-milfoil has been removed.
It’s new technology, so its effectiveness will take time to evaluate.
“We do know that Euarasian water-milfoil harvesting techniques that chop the plants into pieces aren’t the answer, “Zielger said, “because the chopped-up pieces drift and float and reestablish themselves. It’s not a permanent solution.”
Ziegler also noted that using chemical poisons to eliminate the plants is not the answer because of the toll the poisons takes on fish and other living organisms in the lake.
He said that Lulu Lake and the Mukwonago River system are home to nearly 60 species of fish, including several that are endangered or threatened.
“So chemical poisoning is not an option,” Ziegler said. “We need constant maintenance and removal efforts to keeps its growth in check and give native plant species the chance to gain a foothold. And that’s what we’re doing, one area at a time.”
