Sustain Our Nation's Forests and Grasslands

Controlling invasives in waterways in and around the Chippewa National Forest

MINNESOTA – Survey crews from Itasca County Soil and Water Division recently conducted an invasive species survey at West Winnie campground on Lake Winnibigoshish on the Chippewa National Forest. The survey crew was looking for starry stonewort, and quickly found the invasive macro-algae.

Starry stonewort has been known to be present at the site near the West Winnie boat landing. The crew wore waders as they walked through the cold water, reaching down to grab handfuls of the invasive species.

Starry stonewort was discovered in Minnesota in 2015 and is now found on ten lakes, including Winnibigoshish. It can be identified by the small starry bulbil found at the base of the plant. Clear, root-like filaments extend from the stars and anchor in to the lake bottom sediment. Starry stonewort can produce a thick mat at the water’s surface, interfering with recreation and outcompeting native aquatic plants, including wild rice.

The County Soil and Water Division partners with the Chippewa National to survey 100 lakes in Itasca County. The crew will revisit this West Winnie site a number of times during the summer, removing the starry stonewort. Eric Raitenen, fisheries biologist on the Deer River Ranger District, noted “We have worked with Itasca County to identify invasive species in area lakes for a few years.  It has been a great partnership”.

Crews were surprised to see so much starry stonewort this early in the season. The May 2018 survey also revealed zebra mussels and faucet snails at the site. 

People spread starry stonewort through watercraft and equipment. The small bulbils can be hidden in mud and debris and can stick to anchors, ropes and even footwear. A small bulbil can start a new invasion of starry stonewort on another lake. Minnesota law requires water recreationists to clean all watercraft of all aquatic plants and prohibited invasive species.


Nitellopsis obtusa, commonly known as starry stonewort, is a bushy, bright green macro-algae originally from Eurasia. Starry stonewort has become an invasive species in Minnesota waterways as well as other parts of the Great Lakes. Photo courtesy of Minnesota Department of Natural Resources, Bugwood.org.

Survey crews from Itasca County Soil and Water Division conducting invasive species surveys at West Winnie campground on Lake Winnibigoshish on the Chippewa National Forest. Forest Service photo.