Invasive Species

Starry stonewort is an aggressive aquatic invasive species that was first identified in the St. Lawrence River but has since spread as far west as Minnesota. It is now known to be in 13 waterbodies in Wisconsin, including Lake Geneva, and was confirmed in three new Waukesha County lakes – Okauchee Lake, Pewaukee Lake, and Lower Nemahbin Lake – this summer. At this time, there are no known effective eradication measures for starry stonewort. Water users can learn to identify starry stonewort so that it can be reported to the DNR if they come across a new population. Boaters and fisherman can help prevent the spread of aquatic invasive species like starry stonewort by performing the following prevention steps:

  • INSPECT your boat, trailer, and equipment.
  • REMOVE any attached aquatic plants or animals (before launching, after loading, and before transporting on a public highway)
  • DRAIN all water from boats, motors and all equipment
  • NEVER MOVE live fish away from a waterbody

The most up to date list of waterbodies with starry stonewort can be found on the DNR website here:

https://dnr.wi.gov/lakes/invasives/AISLists.aspx?species=STARRY_STONEW [links.govdelivery.com]

More information about all invasive species and what you can do to help can be found here: