Algal Toxins

Algal toxins are chemicals that are produced by algae during its life cycle. The algal toxins are released from the cell into the surrounding water. Algal toxins may have an increased potential of concern when an algae bloom is in effect. Some algae blooms are harmful to animal life, and those algae blooms are called harmful algae blooms (HABs).
Depending on the type of algae, HABs can cause serious health effects and even death. HABs that occur in freshwater, like the Great Lakes and other drinking water sources, are dominated by the cyanobacteria Microcystis. This organism produces a liver toxin that can cause gastrointestinal illness as well as liver damage.

As with many environmental exposures, children and the elderly may be especially sensitive to HAB toxins. Populations that rely heavily on seafood are also at risk of long-term health effects from potentially frequent, low-level exposures to HAB toxins.