Harmful Algal Blooms

Rapid algae overgrowth can result in harmful algal blooms (HABs). Blooms can be both toxic and non-toxic but always have a detrimental effect on marine life in the affected area. Algal blooms most often occur in still or slow-moving water and are brought on by the combination of sunlight and nutrients, such as phosphorus and nitrogen. HABs can have serious health consequences for both animals and humans that come into contact with the impacted water. Reducing the availability of nutrients to the phytoplankton is essential to reducing the occurrence of HABs.


  • Harmful algal bloom monitoring guidance | PDF
  • One Health Harmful Algal Bloom System (OHHABS) | Webpage
  • EPA Information about Exposure to CyanoHABs | Webpage
  • National Preparedness Webinars | Webpage


EPA's CyAN Mobile App & Early Detection of Algal Blooms Webinar

The CyAN App is a mobile application that uses satellite data to map the location of cyanobacteria concentrations in many of the largest water bodies in the country. This information can be used to inform decisions regarding recreational and drinking water safety.

November 2019, slide deck | PDF
Webinar Recording | YouTube

Harmful Algal Blooms & Cyanobacteria Webinar

This webinar includes an overview of monitoring, remote sensing, toxicology, health effects, development of analytical methods and mitigation; an overview of the techniques and methods used a state's laboratory to analyze samples and monitor for harmful algal blooms; and an overview of the activities Florida has implemented to better coordinate cyanobacteria bloom response and provide information to Floridians about steps they can take to protect themselves.

November 2018, slide deck | PDF
Webinar Recording | YouTube