Identifying Cyanobacteria Blooms

Cyanobacteria Blooms may produce toxins at a high enough level to affect those using the water for drinking or recreational use. The photos below illustrate what cyanobacteria blooms may look like.  A laboratory analysis of a water sample must be completed to determine if toxins are present.

Harmful Algae Blooms (HABs) Information Sheet 

Examples of Harmful Blue-green Algae Blooms 
Blue-green algae blooms may look like blue, green, or white spilled paint on the water surface.  (Photo: NYS DEC)
Blue-green algae blooms may look like blue, green, or white spilled paint on the water surface.
(Photo: NYS DEC)


Blue-green algae blooms may look like parallel streaks, usually green, on the water surface. (Photo: NYS DEC)
Blue-green algae blooms may look like parallel streaks, usually green, on the water surface.
(Photo: NYS DEC)
Blue-green harmful algae blooms may look like green dots in the water, or green globs on the water surface. (Photo: Ohio EPA)
Blue-green harmful algae blooms may look like green dots in the water, or green globs on the water surface. (Photo: Ohio EPA)

Blue-green Algae Bloom may look like pea soup.  (Photo: NYS DEC)
Blue-green Algae Bloom may look like pea soup.
(Photo: NYS DEC)