Minnesota’s newest aquatic invader, an algae with a disarmingly cartoonish name of starry stonewort, didn’t just establish a beachhead in the state. By the time it was discovered last August, the infestation had grown into a massive colony — first estimated at 53 acres but now believed to cover 250 or more — in central Minnesota’s popular Lake Koronis and connected waterways.
For anyone who loves boating or fishing, or whose livelihood is linked to tourism, this is an alarming development. Starry stonewort is notoriously difficult to kill, and its rapidly growing mats crowd out native species and impede recreation. Confirmation of its Minnesota arrival prompted a call for coordinated action to contain it, which is why private and public efforts getting underway this spring to combat it merit praise.
This work also should serve as an early reminder to Minnesota boaters to check, clean off or drain their watercraft, trailers and equipment before entering a lake or exiting one. A starry stonewort fragment or even one of the tiny star-shaped “bulbils” inspiring the algae’s name could be enough to spread the invader to another lake.
Minnesota’s experience combating other invasives has produced partnerships among the state, counties, lake associations and the University of Minnesota. These relationships, which form the foundation for the fight against starry stonewort, give the state an edge.
News that the Department of Natural Resources (DNR) is ramping up the number of hours an inspector will be stationed at a heavily used Koronis boat ramp is a positive. In addition, the agency will again chemically treat the starry stonewort near this launch, and it is working with the U’s aquatic research center to identify best practices to contain the algae.
The Koronis Lake Association also has an energetic blueprint aimed at eradicating the algae more broadly in the lake by using a pioneering integrative approach. It’s aiming to hire a company that pulls out the algae mechanically. Then the association hopes to chemically treat any returning algae. The hope is that the chemicals would be more effective in killing juvenile starry stonewort. The association is working with the DNR to get approval of this plan. The DNR should encourage the association’s energy.
It can’t be said enough how critical boaters are in this fight. With Minnesota’s broad public access to waterways comes the responsibility to prevent the spread of aquatic invaders. Inspecting, draining and cleaning off watercraft before or after each use takes little time and is absolutely critical for the health of Minnesota’s lakes. There’s no excuse for shirking this public duty.