Genus: Microcystis aeruginosa
Cyanobacteria (blue green algae)
A harmful algal bloom capable of producing the toxins microcystins and forming dense surface scums. Microcystis aeruginosa is the most abundant bloom-forming cyanobacterium in the western basin of Lake Erie and is the main microcystin producer. Microcystis colonies have no defined shape or size. Microcystis does not have heterocysts. Microcystis is often colonized by a small rod-shaped cyanobacterium Pseudoanabaena.