A woman dressed as Eurasian water milfoil, in the Lac du Flambeau 4th of July parade
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Aquatic Invasive Species Still Threaten Lakes
By Ann-Elise Henzl
July 17, 2009 | WUWM | Milwaukee, WI
For years, people who live on lakes in northern Wisconsin have been on the lookout for invasive species. The aquatic invaders can change the very ecosystem of the lakes, one of the state’s most valuable resources.
Most of the foreign plants and creatures originally came to the Great Lakes on ocean-going vessels. As Ann-Elise Henzl reports, the invaders' progress appears to have slowed, but the concern is far from over.
Wisconsin's lakes are a perfect habitat for about a dozen types of pesky invaders. Those foreign plants, mussels, and fish have no natural predators here. So they can quickly establish themselves in a lake, and choke out native species.
Adam Collins is spokesman for the state Department of Natural Resources. He says most aquatic invaders work their way to inland lakes, by hitchhiking on boats and trailers that picked them up elsewhere.
"We've worked very hard on public outreach efforts and public education efforts to inform the public about some of the different dangers that are faced, and some of the relatively easy steps that can be taken, such as draining live wells when you're exiting one waterway, making sure that you're not transporting aquatic plants from one waterway to another," Collins says.
Volunteers are keeping watch for invasive species at nine public boat launches in the town of Lac du Flambeau in Vilas County. Roberta Gast is chair of the town’s lakes committee. She says it’s particularly on the lookout for signs that boaters may be transporting Eurasian water milfoil. It’s a thick, rapidly growing, seaweed-type plant that's taken hold in nearby lakes.
"The plants come up and they get long and they sort of float on the water. You try to boat through it, props get tangled, and actually you can't -- it'll stop a motor. The lake can look completely green, and covered with weeds," Gast says.
Gast says the plant is impossible to eradicate. You can only use chemicals to reduce its growth, or carve out channels so boats can pass through a lake.
In order to raise public awareness of the problem, the lakes committee created a float for this year's 4th of July parade. A woman atop was dressed as Eurasian water milfoil. Gast says the woman’s son designed the costume, which made her look like a seaweed monster.
"It's on a net background, a mesh background, and he used long ropy fibers that hang down, I mean it looks like a dripping, my goodness, like somebody just had vines covered all over them, dripping down," Gast says.
The milfoil creature held up a sign. One side read, "do you care enough to stop me?" The other, "is your lake next?"
Jake Vander Zanden is encouraged by the growing concern over invasive plants, fish and other creatures. He’s a professor at UW Madison's Center for Limnology. Vander Zanden says in worst case scenarios, foreign species can transform ecosystems in dramatic, irreparable ways.
"It only takes a few people to continue to cause these invasive species to spread, and as the invasive species spread to more and more lakes, then it becomes easier for them to spread to more lakes, because there's more source populations from which they can invade. So it gets harder and harder to deal with the problem as time goes on," Vander Zanden says.
The good news is that there’s been progress in the battle against aquatic invasive species in Wisconsin, according to the DNR’s Adam Collins. The troublesome plants and creatures have been documented in fewer than 1,000 of the state's 15,000 lakes. And most are free of two of the worst invaders: Eurasian water milfoil and the zebra mussel.
"This report that we have out here shows that there is reason for optimism, and it's been our experience that anglers and boaters have been very willing to take these simple steps to help prevent the spread of aquatic invasive species," Collins says.
Still, the state is urging residents not to become complacent about prevention.
 This story is part of a group. Click for more.
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