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Avoid Algal Blooms

Avoid Algal Blooms Credit: Dr. Gerry Pinto, Doctors Lake in Clay County

Nutrient overload, or eutrophication, from too much nitrogen and phosphorous is one of the most serious water quality problems facing the St. Johns River and its tributaries.

Blue green algae, also called cyanobacteria, are tiny organisms naturally found in all types of water.

Excessive nutrients feed the algae, causing uncontrolled algal blooms that deplete oxygen in the water needed by fish, reduce light that is essential to submerged vegetation, and threaten the health of both humans and aquatic life.

The St. Johns suffers from an excess of nutrients from wastewater treatment plants, industrial discharges, failing septic tanks, storm water runoff, and fertilizers that regularly wash into the river.

  • Blooms can look like a thick mat or foamy green scum and can give off an unpleasant odor.
  • Blue green algae sometimes produce toxins that can result in ear, eye, or skin reactions and hay fever-like or flu-like symptoms.
  • Do not swallow, swim, or wade in water where blooms are present.
  • Do not eat fish caught in the vicinity of a bloom.
  • Wash your skin and clothing with soap and water if you come into contact with a bloom.
  • Keep pets away from blooms.

For more helpful information about algal blooms and how to avoid exposure to potentially harmful toxins, visit the following website:

Top 10 Blue Green Algae Facts from the Florida Department of Health

Aquatic Toxins - Florida Department of Health

Algae and Cyanobacteria - GreenWater Laboratories

Blue-Green Algae - Florida Fish and Wildlife Conservation Commission

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