Don’t Feed the Algae


Algae Toxin Thresholds

Toxic green algae outbreaks are increasing in duration and frequency threatening our waterways and our health. The St. Johns River experienced more than 90 days of outbreaks this summer impacting more than 50% of our river. Earlier this year, the Environmental Protection Agency (EPA) issued guidelines for recreational exposure to microcystin and cylindrospermopsin, two of the many potential toxins that could be used for both swimming advisories and new water quality standards.

The Florida Department of Environmental Protection (FDEP) has not made a decision whether or not to add these new water quality standards in their upcoming rulemaking process. FDEP has asked the Governor’s Blue Green Algae Task Force to deliberate the pros and cons of adding this new criteria at its meeting on Tuesday, September 24.

Waterkeepers Florida has urgently requested FDEP and the Blue Green Algae Task Force to adopt the most protective EPA toxin thresholds due to the increased frequency, duration, and severity of blue green algae toxins in Florida waterways.


Please email the Blue Green Algae Task Force Members and ask them to recommend the most protective EPA toxin thresholds to protect our community and our children.

Deadline: Before COB, Monday, September 23

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Sign our Petition

More than 89,000 tons of South Florida’s sewage sludge (more than 80% of all the Class B sewage sludge produced in the state) is being disposed of annually within the Upper Basin of the St. Johns River. Nutrient pollution runoff from the sludge is fueling harmful algal blooms in our river.

Don’t Feed the Algae

Algae bloom season is upon our St. Johns River.  Since mid-April, St. Johns Riverkeeper has received dozens of reports of blooms from Lake George to Jacksonville. Hotter temperatures, warming waters and runoff from frequent rainstorms during the summer could result in even more green muck coating our River.

Nutrients? Aren’t those good for the River?

Algae blooms are visible symptoms of sickness and too much nutrient pollution in our waterways. Nutrients like nitrogen and phosphorus are naturally occurring in our environment.  However, in excess, they can undermine the ecological integrity of our waterways by depleting oxygen from the water, which negatively impacts plankton and causes fish die-offs, and hurting submerged grasses by blocking adequate sunlight. The River’s entire food web becomes severely harmed.

2019 Algae Blooms: reported to us by river citizens like you! 

Impact To Us

Algal blooms can release toxins that can make us and our pets sick. Exposure to toxic algae can cause respiratory and skin irritations.  Long-term exposure can potentially result in nerve or liver damage. If citizens spot what looks like bright green paint-like, scum on the surface of the water, they should steer clear. Do not recreate, boat, swim, or fish near an algae bloom.

So, where are all the excess nutrients coming from?

Some of the major sources of nutrient pollution (phosphorous and nitrogen) in the St. Johns River:

  • The application of sewage sludge (also known as biosolids) on agricultural lands surrounding our River’s Headwaters at Blue Cypress Lake
  • Fertilizer run-off from agricultural, urban, and residential lands
  • Septic tanks
  • Industrial wastewater discharge and sewage spills
  • Aquatic spraying
  • Reclaimed water
  • Atmospheric deposition

Where can I find the locations of recent algae blooms?

Before you get out on the water, visit the Florida Department of Environmental Protection’s website to see an interactive map of algae bloom samples and results in our waterways.

Health Impacts

Toxins produced by algae blooms can cause rashes, stomach cramps, nausea, diarrhea, and respiratory irritation. High exposure to toxins can affect the liver and nervous system. If skin contact occurs, wash off immediately and thoroughly with clean water and soap.



There is no standard duration for a bloom and no way to determine visually whether a bloom is toxic.

  • Report blooms to the Florida Department of Environmental Protection at or call toll free at 1-855-305-3903.
  • Email with photos, time, date and location.
  • To report fish that are either dead or sick, contact the Fish Kill Hotline 1-800-636-0511.


Although the legislative session does not begin until January 2020, we must begin advocating today! Let them know that you are disappointed that the Florida Legislature failed to pass legislation to prevent sewage sludge and other nutrient sources from polluting our waterways. Tell them to get the job done next session by stopping pollution at its source. Find your Legislators

Tell your Mayor, City Council, or County Commissioners that we need to enact stronger fertilizer ordinances and enforce the ones we have! Let’s lead by example in our parks and homes to stop pollutants from reaching our creeks, lakes, canals, and waterways.

Eliminate or reduce your use of fertilizer and reduce your impact on the health of our river. Learn how to live a more River Friendly lifestyle.

EDUCATE yourself and others by attending one of St. Johns Riverkeeper’s educational programs and events

SPREAD the word! Share what you know with your friends and family and encourage them to be more River Friendly. Follow us on Facebook