"Taste-and-odor producing Cyanobacteria may also produce toxins. Mozingo Lake, Missouri. October 2001. Photo by J. L. Graham.

Freshwater and marine harmful algal blooms (HABs) can occur anytime water use is impaired due to excessive accumulations of algae. In freshwater, the majority of HABs are caused by cyanobacteria (also called blue-green algae). Cyanobacteria cause a multitude of water-quality concerns, including the potential to produce taste-and-odor causing compounds and toxins that are potent enough to poison...