In August of 2018 starry stonewort, an aquatic invasive species was found in a lagoon of Geneva Lake and within a year it was found in Geneva Lake. Initially it was hoped that the isolated population in the lagoon could be eradicated by dredging before it got into the lake, but the attempts failed and two populations were found in the lake during the summer of 2019.
Starry stonewort is a macro-algae that was brought to the United States as a “hitchhiker” from Eurasia. It was first found in the United States in 1978 in the St. Lawrence River, but it is now found in several Great Lake states. It was first discovered in Wisconsin in September 2014, and is now known to be in more than 14 different lakes, including the shore waters of Lake Michigan and Green Bay.
The Wisconsin Department of Natural Resources has tried different approaches to control starry stonewort and has had mixed results. Perhaps the most promising starry stonewort management is to manage the lake’s entire aquatic plant community for biodiversity and community richness, and let the healthy community keep starry stonewort from becoming a nuisance. A healthy aquatic community, strong boater education with the Clean Boats and Clean Waters Program and continual lake plant community monitoring offers the most promising future for our lakes in managing aquatic invasive species.