Blue Green Algae

There are a variety of blue green algae (or cyanobacteria) species in Florida that produce natural toxins harmful to humans, pets and livestock.  Usually these toxins only reach harmful levels when there is a “bloom” or overgrowth of algae in slow moving or stagnant surface water.  Blue green algae can appear as thick mats of what some refer to as “pond scum,” or can be dispersed through the water, turning it various intense colors of green, brown, or even red.  Blue green algae blooms can produce a bad smell, although not necessarily. 

People exposed to blue green algae toxins when swimming or boating sometimes report an itchy rash or stomachache and diarrhea within hours of being exposed.  Rinsing off with fresh water and immediately removing clothing can reduce or prevent symptoms.  It is very important that pets, livestock and small children be kept out of water suspected of having a blue green algae bloom, since there have been many reported cases of animals dying after drinking highly contaminated water.  Anyone experiencing symptoms after contact with algae should consult with their doctor immediately. 

It is unclear why blue green algae bloom and produce these toxins, although it appears that reducing fertilizer use near waterways may help prevent blooms.  For more information online on blue green algae toxins and their health effects, please go to www.myfloridaeh.com and select “Aquatic Toxin Health Concerns” or contact the Florida Department of Health at 850 245 4299. 

Image: Greenwater Laboratories/CyanoLab Palatka, FL