CLEWISTON — The Florida Department of Health in Hendry County (DOH-Hendry) has issued a health alert for the presence of harmful blue-green algal toxins in areas of Lake Okeechobee in Hendry County.

The alert is in response to water samples taken on May 7, 2024. 

According to the Florida Department of Environmental Protection (FDEP),   several samples taken from Lake Okeechobee May 6-8  contained microcystin toxins, but most had barely detectable levels. The World Health Association and Environmental Protection Agency consider levels below 1.0 parts per billion (ppb) to be safe for drinking water and levels below 8.0 ppb to be safe for recreational contact (swimming).

On May 6-8, South Florida Water Management District staff collected six HAB response samples and 28 Lake Okeechobee routine HAB monitoring samples (KISSR0.0, LZ2, NES191, L001, NES135, NCENTER, EASTSHORE, L004, L008, L005, POLESOUT3, POLESOUT2, POLESOUT1, POLESOUT, KBARSE, CLV10A, LZ40, L006, PALMOUT3, PALMOUT2, PALMOUT1, PALMOUT, LZ30, POLE3S, RITTAE2, LZ25A, L007 and PELBAY3.). Dominant algal taxa and cyanotoxin results follow each waterbody name.

C43 Canal - S77 (upstream): Microcystis aeruginosa; no cyanotoxins detected.

C44 Canal - C44S80 (upstream): no dominant algal taxon; no cyanotoxins detected.

C43 Canal - S78 (upstream): Microcystis aeruginosa; no cyanotoxins detected.

C43 Canal - S79 (upstream): Microcystis aeruginosa; trace level (0.26 ppb) microcystins detected.

Lake Okeechobee - KISSR0.0: Microcystis aeruginosa; no cyanotoxins detected.

Lake Okeechobee - LZ2: Microcystis aeruginosa and Dolichospermum circinale co-dominant; no cyanotoxins detected.

Lake Okeechobee - NES191: Microcystis aeruginosa; no cyanotoxins detected.

Lake Okeechobee - L001: Microcystis aeruginosa; no cyanotoxins detected.

Lake Okeechobee - NES135: Microcystis aeruginosa; no cyanotoxins detected.

Lake Okeechobee - NCENTER: Microcystis aeruginosa; no cyanotoxins detected.

Lake Okeechobee - EASTSHORE: Microcystis aeruginosa; trace level (0.26 ppb) microcystins detected.

Lake Okeechobee - L004: Microcystis aeruginosa; trace level (0.60 ppb) microcystins detected.

Lake Okeechobee - L008: Microcystis aeruginosa and Dolichospermum circinale co-dominant; 4.8 ppb microcystins detected.

Lake Okeechobee - L005: Microcystis aeruginosa; trace level (0.30 ppb) microcystins detected.

Lake Okeechobee - POLESOUT3: Microcystis aeruginosa; 1.3 ppb microcystins detected.

Lake Okeechobee - POLESOUT2: Microcystis aeruginosa; 6.3 ppb microcystins detected.

Lake Okeechobee - POLESOUT1: Microcystis aeruginosa; microcystins estimated to be 1.1 ppb.

Lake Okeechobee - POLESOUT: Dolichospermum circinale; no cyanotoxins detected.

Lake Okeechobee - KBARSE: Microcystis aeruginosa; no cyanotoxins detected.

Lake Okeechobee - CLV10A: Dolichospermum circinale; trace level (0.34 ppb) microcystins detected.

Lake Okeechobee - LZ40: Microcystis aeruginosa; no cyanotoxins detected.

Lake Okeechobee - Pahokee Marina: no dominant algal taxon; no cyanotoxins detected.

Lake Okeechobee - L006: Microcystis aeruginosa; 2.3 ppb microcystins detected.

Lake Okeechobee - PALMOUT3: Microcystis aeruginosa; trace level (0.47 ppb) microcystins detected.

Lake Okeechobee - PALMOUT2: Microcystis aeruginosa; trace level (0.35 ppb) microcystins detected.

Lake Okeechobee - PALMOUT1: Microcystis aeruginosa; 2.0 ppb microcystins detected.

Lake Okeechobee - PALMOUT: Microcystis aeruginosa; trace level (0.55 ppb) microcystins detected.

Lake Okeechobee - LZ30: Microcystis aeruginosa; trace level (0.51 ppb) microcystins detected.

Lake Okeechobee - POLE3S: Microcystis aeruginosa; no cyanotoxins detected.

Lake Okeechobee - RITTAE2: Microcystis aeruginosa; no cyanotoxins detected.

Lake Okeechobee - LZ25A: Microcystis aeruginosa; no cyanotoxins detected.

Lake Okeechobee - L007: no dominant algal taxon; no cyanotoxins detected.

Lake Okeechobee - PELBAY3: no dominant algal taxon; no cyanotoxins detected.

Following the severe weather that impacted North Florida , the FDEP Laboratory lost power for a prolonged duration and was unable to process samples collected after May 8, 2024. Power has been restored at the laboratory, and staff are assessing the equipment to ensure it is functional and able to be calibrated. FDEP is coordinating with partners to continue laboratory services once normal operations at the FDEP Laboratory can be resumed.  

Because it is not possible to tell if toxins are present without laboratory testing, DOH-Hendry advises residents and visitors to take the following precautions:

• Do not drink, swim, wade, use personal watercrafts, or come into contact with waters where there is a visible bloom.

• Wash your skin and clothing with soap and water if you have any contact with algae, or discolored or water that smells unpleasant.

• Keep pets and livestock away from the area to avoid any contact with water. Waters where algae blooms are present are not safe for animals. Pets and livestock should use an alternative source of water when algae blooms are present.

• Do not cook or clean dishes with water contaminated by algae blooms. Boiling the water will not eliminate toxins.

• Eating fillets from healthy fish caught in freshwater lakes experiencing blooms is safe. Rinse fish fillets with tap or bottled water, throw out the guts, and cook fish thoroughly.

• Do not eat shellfish in waters with algae blooms.

The Florida Department of Environmental Protection (DEP) and partners collect algae samples from reported bloom locations. After samples are analyzed at their laboratory, the toxin results can be viewed on the Protecting Florida Together or on DEP’s Algal Bloom Dashboard.

What are blue-breen algae?

Blue-green algae are a type of bacteria that are common in Florida’s freshwater environments. A bloom occurs when rapid reproduction of algae leads to an accumulation of individual cells that discolor water and often produce floating mats.

Blue-green algae blooms can also appear as scum, foam, or paint on the surface of the water in various colors.  

Some environmental factors that contribute to blue-green algae blooms are sunny days, warm water temperatures, still water conditions, and excess nutrients. Blooms can appear year-round but are more frequent in summer and fall. About 25% of species of blue-green algae can produce toxins. Those capable of producing toxins do not always do so. Blue-green algae may not always be visible as a bloom, but it can still be present in the water.

Is blue-breen algae harmful?

Blue-green algae can produce toxins, which can be harmful to human and pets as well as ecosystems, including fish and other aquatic animals. Sensitive individuals (e.g., children, the elderly and those who are immunocompromised) may still be at risk even at low concentrations and should avoid any exposure.

For additional information on potential health effects of algae blooms, visit DOH’s harmful algae blooms webpage.

Where can I report issues related to algae blooms?

• Algae blooms: DEP monitors algae blooms and collects samples for analysis. Blooms can be reported to DEP online or by calling toll-free at 1-855-305-3903.

• Human health impacts: Report symptoms from exposure to a harmful algae bloom or any aquatic toxin to the Florida Poison Information Center by calling 800-222-1222 to speak to a poison specialist.

• Animal health impacts: Contact your veterinarian if you believe your pet has become ill after consuming or having contact with blue-green algae contaminated water.

• Fish kills: Dead, diseased, or abnormally behaving fish or wildlife should be reported to the Florida Fish and Wildlife Conservation Commission online or at 800-636-0511.

If you have other health questions or concerns about blue-green algae, please call DOH-Hendry at 863-674-4041.