In Michigan, they have been found in the Au Sable, Boardman, Grass, Pere Marquette, Pine, and Upper Manistee river systems, all up north, since 2015. Invaded river systems in Michigan, to date.

While residents enjoy Michigan's Great Lakes, invasive species may be, too. During Aquatic Invasive Species Awareness Week ...

An invasive algal species native to Lake Superior has been found in upper Manistee River in Kalkaska County. This is the first time that the species, didymo, nicknamed ‘rock snot,’ has been ...

Those out in the Manistee River may continue to notice a brown gunk clinging to rocks or trees under the surface. Didymo, most commonly referred to as rock snot is a kind of algae that continues ...

The Manistee River detection suggests didymo’s distribution in Michigan waters may be more widespread than previously expected. A microscopic diatom, ... drain and dry waders, ...