On August 12, 2024 Lake Owen Association Vice President Tom Johnson received an email report of a possible sighting of invasive milfoil in Lake Owen near the Two Lakes Campground. In 2005, the Two Lakes Boat Landing was the site of the contamination of the invasive Chinese Mystery Snails. Within minutes Tom Johnson notified the Lake Owen Association’s Ecologist Steve Schieffer, a biologist with 20 years of experience studying Wisconsin lakes who is the lead scientist for the Lake Owen Association since 2018. Minutes after that, Steve Schieffer was in communication with Tom Johnson’s source of information and then communicated with the original source. After thanking the source, Steve explained to all that the most definitive method to identify invasive milfoil is to count the leaflet pairs because native Milfoil has less than 12 leaflet pairs while invasive Milfoil has more than 12 and often approaching 20 pairs, and that he would be out shortly. Steve sent out detail instructions on how to distinguish between the invasive species and the native species and provided the following photos with showing invasive Milfoil on the left, native Milfoil on the right.
As background, in some waterbodies in Wisconsin, invasive Eurasian watermilfoil (MYRIOPHYLLUM SPICATUM) form large, floating mats of vegetation on the surface that impede boat traffic and providing lesser quality habitat for native plants and fish. On one lake in Vermont, the yearly cost of controlling invasive Milfoil went from $5,640 to 6 years later to $48,000 per year.
On August 16, 2024, Steve Schieffer arrived at Lake Owen to examine the milfoil in the area of concern. Steve meandered an extensive path throughout the reported location and other areas with Milfoil and checked every milfoil clump, bed, and even plants floating that had been dislodged from boat traffic. Steve found extensive native milfoil growth, some have red stems but no characteristics consistent with either invasive milfoil or hybrid milfoil. Everything Steve saw was native Milfoil.
The following day, Scientist Steve Schieffer reported to all concerned his finding and thanked everyone for being vigilant in reporting, reaffirmed to all that his inspection was necessary and it is “better to be safe than sorry.”
Please remember, Wisconsin’s invasive species law prohibits the transport of aquatic plants. Before leaving a boat landing with your watercraft, Wisconsin law requires that you must inspect and remove aquatic plants and animals from boats and equipment and remove all water from the boat and equipment. The law further requires that before entering another waterbody with your watercraft, you must either decontaminate you watercraft and equipment by either spraying your boat and equipment with high-pressure hot water or allow the boat and equipment to dry out of water for at least five days. Other invasive species can also be controlled by chlorinated water at 500 parts per million followed by scrubbing and waiting 10 minutes.
The Lake Owen Association maintains professional personnel presence during times of high activity at the Northern Lake Owen Outlet boat landing and the Two Lakes Boat Landing to inspect and decontaminate boats equipment for you. Additionally, self service decontamination spray is available with instructions at those landings and at the Otter Bay Resort private boat landing.
For more information on invasive species, please peruse the Lake Owen Association website pages. For specific further information on Milfoil in Wisconsin Lakes, go to: https://dnr.wisconsin.gov/topic/Invasives/fact/EurasianWatermilfoil