Blue-green algae, or cyanobacteria, are a naturally occurring part of the food chain. Although they are most closely related to bacteria, they contain chlorophyll and depend on sunlight to grow, like plants.
Blue–green algae can be found all over the world, and are common throughout the United States. In Florida it is found in freshwater and brackish habitats, such as lakes, rivers and estuaries.
Some, but not all, blue-green algae can produce toxins that can contribute to environmental problems and affect public health. Scientists know little about what causes the algae to produce these toxins. Even those blue-green algae that are known to produce toxins do not always do so. You can find more information on health aspects of blue-green algae from the
Department of Health.
Cyanobacteria blooms have the potential to change very rapidly. Changes in weather, temperature, wind and current can cause dramatic shifts in the physical characteristics of some blooms. Some species of cyanobacteria form blooms that occur mostly at the surface of the water. These blooms can rapidly change from very dilute, widely dispersed blooms to thick scum layers along shorelines due to the effects of wind and changes in atmospheric pressure. If the bloom happens to be producing toxins, these toxin concentrations can change just as rapidly. The occurrence or rate of algal toxin production can change unexpectedly as well.
Blue-green algae has been naturally occurring throughout history. Algal blooms were documented in Florida’s coastal waters as early as the 19th century. To better understand the phenomenon, Florida monitors blue-green algae closely because nutrient (such as nitrogen and phosphorus) pollution appears to intensify blue-green algae outbreaks. The state is taking long-term measures that will reduce nutrient loading and improve water quality.
For more information on state agency partners and algal bloom response and analyses efforts, please visit the
Response and Analyses Page.
To report a bloom in Lake Okeechobee or the St. Lucie or Caloosahatchee rivers, call the toll-free hotline at
855-305-3903 or report online at
To report illnesses or symptoms, please contact the Florida Poison Control Center at
Report fish kills to the Florida Fish and Wildlife Conservation Commission:
To report any other wildlife injuries, call FWC’s Wildlife Alert at
"There are no short term solutions to rectifying the
situation; this is a naturally occurring phenomenon that the
State monitors closely. However, the state is taking
measures that in the long-term will reduce nutrient loading
and improve water quality."