The Pahokee marina was clear of toxic algae as of May 2, according to tests by the Florida Department of Environmental Protection.

In early April, Florida Department of Health issued public warnings about toxins at the marina after water sampling of a visible bloom there had microcystin toxin levels of 12 parts per billion. The World Health Organization (WHO) considers toxin levels above 8.0 ppb to be unsafe for human recreational contact (swimming) and levels above 1.0 ppb to be unsafe for drinking water.

The City of Pahokee treated the area with algaecide and worked with South Florida Water Management District (SFWMD) to improve water circulation at the marina. FDEP testing on April 16 showed a microcystin toxin level of 2.4 ppb. The May 2 test found no detectable toxins.

FDEP continues to test reported algae blooms statewide. Algae and cyanobacteria (commonly called blue-green algae) are found in lakes, streams, canals and ponds. They are part of the natural ecosystem. Under certain conditions – warm weather, lack of water movement and availability of nitrogen and phosphorus for fuel – these microscopic organisms may reproduce rapidly into a visible “bloom.”

About 25% of the 28 cyanobacteria species documented in the Lake Okeechobee Waterway (Caloosahatchee River, Lake Okeechobee, St. Lucie Canal and St. Lucie River) are capable of producing toxins. Cyanobacteria that can produce toxins do not always do so. Research by Florida Atlantic University found higher toxin levels in areas with higher nitrogen levels in the water. Some cyanobacteria can pull nitrogen from the air, but others – like Microcystis aeruginosa – need nitrogen in the water to thrive. Septic tank runoff was linked to algal blooms in coastal waterways.

Laboratory testing is required to determine what species of algae or cyanobacteria are present and whether any toxins are present in a bloom. FDOH advises the public to stay out of water and keep pets and livestock away from the water if an algal or cyanobacterial bloom is visible.

The week of April 26-May 2, FDEP conducted 21 site visits in areas algal blooms were reported statewide. Algal bloom conditions were observed by samplers at five of the sites. FDEP staff collected 14 response samples. Dominant algal taxa and cyanotoxin results follow each waterbody name.

• Lake Breckenridge - South Lobe: No dominant algal taxon; no cyanotoxins detected.
• St. Lucie Canal - Army Corps Campground: No dominant algal taxon; no cyanotoxins detected.
• St. Lucie Canal - 96th Street Bridge: No dominant algal taxon; no cyanotoxins detected.

• Lake Marian - Pavilion: Microcystis aeruginosa; 3.8 parts per billion (ppb) microcystins detected.
• St. Lucie River - at Palm City Bridge: No dominant algal taxon; no cyanotoxins detected.
• Lullwater Lake - Northeast Lobe: Dolichospermum circinale and Woronichinia naegeliana co-dominant; no cyanotoxins detected.
• Crystal River - Canal: No dominant algal taxon; no cyanotoxins detected.
• St. Lucie River - at Four Rivers: No dominant algal taxon; no cyanotoxins detected.
• St. Lucie River - Harborage: No dominant algal taxon; no cyanotoxins detected.
• C-23 Canal - SW Citrus Boulevard: No dominant algal taxon; no cyanotoxins detected.
• Blanton Lake - South Lobe: Microcystis aeruginosa and Microcystis wesenbergii co-dominant; no cyanotoxins detected.
• Lake Weir - Hampton Beach: Planktolyngbya lacustris and Botryococcus braunii co-dominant; no cyanotoxins detected.
• Apopka Beauclair Canal - near Lake Jem Road: No dominant algal taxon; no cyanotoxins detected.
• Desoto Lakes - Lake Shore Drive: Results pending.

April 29-May 2, South Florida Water Management District (SFWMD) staff collected six algal bloom response samples. Dominant algal taxa and cyanotoxin results follow each waterbody name.
• C43 Canal - S-77 (Moore Haven Lock): Microcystis aeruginosa; trace level (0.73 ppb) microcystins detected.
• C44 Canal - S-308C (Port Mayaca, inside the water control structure): Microcystis aeruginosa; 2.4 ppb microcystins detected.
• C43 Canal - S-78 (Ortona Lock, upstream): Microcystis aeruginosa; trace level (0.58 ppb) microcystins detected.
• C43 Canal - S-79 (W.P, Franklin Lock, upstream): Microcystis aeruginosa; no cyanotoxins detected.
• C44 Canal - S-80 (St. Lucie Lock, upstream): No dominant algal taxon; no cyanotoxins detected.
• Lake Okeechobee - Pahokee Marina: Microcystis aeruginosa; no cyanotoxins detected.