The Lake Where You Live

We teach about Clean Boats, Clean Waters. We volunteer to inspect boats at landings. We post signage at landings. Produce and distribute brochures about stopping aquatic hitchhikers. Give talks to lake groups and school classes. And a great deal more.

And yet, aquatic invasive species continue to spread. That’s true in Wisconsin and in our neighbor states of Michigan and Minnesota. The efforts of many good people and state and local agencies have not been for nothing — imagine how severe the problem would otherwise be. But it’s clear the AIS safety net still has holes.

Let’s cite a few examples. The latest Michigan Lakes and Streams Association newsletter reports that hydrilla, an extremely aggressive invasive plant, has been discovered in two ponds on private property in southwestern Michigan. 

Experts believe that if it were to break out into lakes, hydrilla could be more problematic than Eurasian watermilfoil. It is tough. It can thrive in many environmental conditions. It spreads by plant fragments, seeds, and over-wintering buds called turions. It grows rapidly and forms dense beds and thick mats on the surface. 

Closer to home, I know from a reliable source that Eurasian watermilfoil was recently found in the Turtle-Flambeau Flowage. The 2022 Wisconsin DNR Invasive Species Report lists discoveries of a few unwelcome plants new to the state. 

European frogbit was found in 2021 in Oconto County. The report says this free-floating plant, which invades shallow and slow-moving waters, can out-compete native species, harm wildlife habitat, and keep northern pike from passage upstream to spawning grounds. 

Other newcomers include floating marsh pennywort, found in the Horicon Marsh State Wildlife Area, and water lettuce, detected in a private pond in Milwaukee County. New populations of starry stonewort were found in Marquette, Shawano and Kenosha counties, and this bushy macro-algae is now found in 16 Wisconsin lakes.

Meanwhile, the Minnesota Coalition of Lake Associations newsletter reports continued spread of starry stonewort, zebra mussels and Eurasian watermilfoil. On the plus side, only two new milfoil infestations had been found this year as of September. 

But six new instances of starry stonewort were found since 2015, a 27 percent increase, bringing the state’s total to 28:  “A troubling growth rate for a very troubling species that is still early in its infestation life cycle,” the report says. Zebra mussel infestations as of September were up by 17, to 599 statewide. 

“While waterbody counts may be slowing,” the newsletter says, “you should be aware that most large lakes in Minnesota have one or more AIS, and the percentage of Minnesota’s surface water infested with AIS is very high.”

So it’s clear as we move into winter that now is no time to become complacent about invasive species in our waters. A strong argument can be made that more money and more people power need to be devoted to detection, prevention, and control.

If as taxpayers we are unwilling to dedicate the needed funds for those purposes, then maybe we don’t love our lakes as much as we say we do.