A Quick Guide to the Common Cyanobacteria

of New England

The "Dirty Dozen" represents groups of commonly occuring cyanobacteria in New England. Various genera are grouped together here, due to their similiarity in shape. While there are some organisms that look morphologically similar, they vary significantly by genus and species. This list summarizes associated toxins and taste and odor issues by cyanobacteria noted from the literature. The toxins are not a comprehensive list of all reported toxins and there is some variation in toxin-genetics by colonies and species. The most commonly reported toxins are the microcystins, hepatotoxins that chronically affect the liver and may cause gastrointestinal issues. The taste and odor compounds produced by cyanobacteria have been mainly identifed as "geosmin" and "MIB", organic compounds with a distinctive "earthy" and "musty" taste and smell. Though there is not a clear distinctintion between cyanobacteria species that produce these compounds, taste and odor issues in drinking water supplies have been noted and described (below) from EPA reports. We will continue to research and expand our knowledge of known toxins and taste and odor compounds for these major groups of cyanobacteria as we develop this key further.

Genus Groups

Photo Example

Associated (known) Toxins

Reported Taste & Odor Issues