Starry Stonewort Action Plan

Starry Stonewort Background

Starry Stonewort (Nitellopsis obtusa) is a fast-spreading aquatic invasive species (AIS) threatening the health of Minnesota’s lakes. If left unchecked, it can:

  • Damage critical fish habitat

  • Block boat navigation and shore access

  • Outcompete native aquatic plants essential for healthy ecosystems

It was first discovered in MN in Koronis Lake near Paynesville in 2015, and confirmed present in the Whitefish Chain on Rush Lake in September 2024.

It’s found in shallow, relatively calm areas of lakes and rivers across a variety of trophic ranges. It favors waters with a high pH and hardness.

It’s identified by its "grass-like" appearance, whorls of 4-6 branchlets off of thin stems, branchlets form asymmetrical forks at the end, clear cells that shallowly anchor it, and antheridia present at all times.

It impacts native species and human recreation. Minnesota Aquatic Invasive Species Research Center research has shown dense growth displaces native species and effects the habitat quality of fish and other animals.

Starry stonewort has never been eradicated once it has infested a waterbody.

Additional Resources:

Support Our Efforts! The fight against invasive species like Starry Stonewort requires significant resources. Please consider supporting WAPOA's ongoing efforts to protect the Whitefish Chain of Lakes through a donation. Your contribution will directly support crucial activities such as expanded surveys, treatment initiatives, and educational outreach. Donate Today

What has WAPOA done?

  • September 5, 2024: Minnesota DNR AIS Specialist, Camden Droppo, confirmed the identification and initiated mapping of the infestation area.

  • September 20, 2024: WAPOA, in collaboration with partner agencies, began developing a short-term containment and notification strategy, including the placement of warning buoys.

  • October 12 & 25, 2024: Chemical treatments were applied within the contained area.

  • Volunteers Help Pull Starry Stonewort Out of Rush Lake Near Crosslake

Starry stonewort has never been successfully eradicated once it has infested a waterbody, but WAPOA is working hard to contain it in its present location in Rush Lake. How will WAPOA do this?

  • Enhanced Lake Surveys in 2025:

    • Increased survey frequency to three times annually.

    • Expanded survey locations based on the 2024 discovery.

    • Comprehensive surveys to include all public access points.

    • Exploration of additional survey locations.

    • Continued training of Certified AIS Detectors

WAPOA's commitment to addressing the Starry Stonewort infestation is demonstrated by the allocation of over $85,000 to the 2025 management and prevention project. We urge all members and users of the Whitefish Chain of Lakes to remain vigilant, adhere to best practices for cleaning watercraft and equipment, and report any suspected sightings of Starry Stonewort or other aquatic invasive species to the Minnesota DNR. Collaborative vigilance and responsible stewardship are essential to safeguarding the ecological health of our valuable lake resources.

What can you do?

We still need your help to protect our lake. You can help by ensuring that any equipment or recreational items that are in the water are cleaned according to DNR regulations. More information on DNR laws and regulations can be found here.

Become educated about starry stonewort and its native look-alikes — learn more here.

Become a Member of WAPOA! Join the Whitefish Area Property Owners Association and become a vital part of our efforts to protect the Whitefish Chain of Lakes! Your membership provides support for our ongoing initiatives to combat invasive species, promote lake health, and advocate for responsible stewardship of our precious natural resources. Become a Member

Images courtesy of Kay Rezanka

Become an Early Detection Volunteer

Help Protect the Lakes We Love

Invasive species like Starry Stonewort threaten everything we treasure about our lakes — from fishing, boating, and swimming to clean water, healthy wildlife, and long-term property values. In 2024, Starry Stonewort was discovered in Rush Lake on the Whitefish Chain. Now is the time to act.

By becoming an Early Detection Volunteer, you’ll be part of a growing community effort to stop the spread before it’s too late. No experience is needed, and free, hands-on training will give you everything you need to:

  • Properly survey aquatic plants around the Chain and nearby lakes

  • Distinguish native aquatic plants from Starry Stonewort and other invasive species

  • Record and report observations, focusing on what to do if you find something suspicious

Whether you live on the lake, visit on weekends, or simply care about preserving these waters, your help matters. The commitment is flexible, and the process is easy, fun, and incredibly important.

Contact Shannon Watters at Shannon@watters-edge.com to join and make a difference.