EPA guidance describes cyanobacterial blooms that may resemble green paint, scum, mats or streaks. Color and appearance vary, and only appropriate testing can determine what organisms or toxins are present.
Avoid contact with suspicious water, keep pets away and follow current public-health advisories. Do not draw a safe conclusion because a bloom is thin or dispersed.
Western Lake Erie bloom location can change with wind and currents, so consult current monitoring and forecast products before recreation.