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Blue-green algae updates

Weekly Update from the Florida Department of Environmental Protection (DEP)

March 10 – March 16, 2023 – There were 17 reported site visits in the past seven days with 17 samples collected. Algal bloom conditions were observed by samplers at 10 of the sites.

The most recent usable satellite imagery from 3/16 shows scattered low bloom potential on Lake Okeechobee, primarily along the northern, western and southern shorelines. Satellite imagery from 3/16 for the Caloosahatchee and St. Lucie estuaries shows scattered low bloom and no bloom potential, respectively.

Satellite imagery from 3/16 for the St. Johns River shows scattered low bloom potential on visible portions of Lake George and the mainstem of the river. Please keep in mind that bloom potential is subject to change due to rapidly changing environmental conditions or satellite inconsistencies (i.e., wind, rain, temperature or stage).

On 3/14-3/16, Florida Department of Environmental Protection (DEP) staff collected harmful algal bloom (HAB) response samples at 10 locations. Dominant algal taxa and cyanotoxin results follow each waterbody name.

Tiger Lake – Center: Microcystis aeruginosa; trace level (4.0 parts per billion [ppb]) microcystins detected.

• Wood Lake – E Shore: No dominant algal taxon; trace level (0.22 ppb) microcystins detected.

• Lake Baldwin – Fleet Peeples ParkMicrocystis aeruginosa; trace level (1.1 ppb) microcystins detected.

• Lake Marian – Boat Ramp: Results pending.

• Lake Sue – Fawsett Ramp: Results pending.

• Deep Lake – N Shore: Results pending.

• Louise Lake – NW Lobe: Results pending.

• Lake Howell – NW Shore: Results pending.

• Lake Mann – McQueen Park: Results pending.

• Sunset Lake – W Shore: Results pending.

On 3/16, South Florida Water Management District staff collected one HAB response sample at L8 M Canal – CWPB2S (upstream). Results are pending.

On 3/14-3/16, St. Johns River Water Management District staff collected five routine HAB monitoring samples. There was no dominant algal taxon and no cyanotoxins detected at Doctors Lake – Center (DTL)St. Johns River – Mandarin Point (MP72)St. Johns River – Shands Bridge (20030157); and Lake George – Center (LEO). Results are pending for Crescent Lake – mouth of Dunns Creek (CRESLM).

On 3/16, Highlands County staff collected one HAB response sample at Lake Viola – Boat Ramp. Results are pending.

Last Week

On 3/7-3/9, DEP staff collected HAB response samples at 15 locations, six of which had results pending. Dominant algal taxa and cyanotoxin results follow each waterbody name. DEP continues to monitor the persistent algal bloom in Georges LakeThe Putnam County Health Department’s existing Cyanobacteria Health Alert remains in effect.

• Blue Lake – Lagrow RdMicrocystis aeruginosa; trace level (0.58 ppb) microcystins detected.

• Lake Placid – Boat RampMicrocystis aeruginosa and Cylindrospermopsis raciborskii co-dominant; trace level (0.24 ppb) microcystins detected.

• Georges Lake – Boat Ramp RdMicrocystis aeruginosa; 7.5 ppb microcystins detected.

• Georges Lake – CenterMicrocystis aeruginosa; 2.8 ppb microcystins detected.

• Black Creek – at SR-17: No dominant algal taxon; no cyanotoxins detected.

• Lake Glenada – Boat RampMicrocystis aeruginosa and Microcystis wesenbergii co-dominant; trace level (0.61 ppb) microcystins detected.

blue-green algae map
Blue dots represent recent sampling. Green dots represent past sampling. An interactive version of this mapping of blue-green algae sampling and results for completed analyses is available at FloridaDEP.gov/AlgalBloom.

An interactive version of the above with detailed sampling is available at FloridaDEP.gov/AlgalBloom.


Related Stories


Blue-Green Algae Sampling Maps


Results for completed analysis are available at FloridaDEP.gov/AlgalBloom.

For detailed breakdowns of blue-green algae sampling across the state, visit the state Department of Environmental Protection.


blue-green algae
Blue-green algae bloom. (Photo courtesy St. Johns River Water Management District.)

Blue-Green Algae statewide dashboard — LIVE map prepared by the Florida Dept of Environmental Protection

More from Florida Rambler: The Florida Red Tide Report


Contributing factors to both red tide and blue-green algae.

blue-green algae site 1web final algae red tide inforgraphic Blue-green algae updates
Contributing factors to both red tide and blue-green algae. (Florida Audubon)

Related: Blue-Green Algae and Red Tide Leave Floridians Frustrated, Florida Audubon


Blue-green algae

In water bodies with blue-green algae, if people or animals splash or if boats create wakes, the cyanotoxins in the algae can release into the air. The toxins mix with water droplets and spray—that’s how people and animals can inhale the toxin. These toxins can’t pass through your skin easily so swallowing large amounts of contaminated water is what causes illness. This algae is blue, bright green, brown or red, and can have a strong odor like rotting plants. Pets can become sick from blue-green algae so keep them out of those areas and away from contaminated marine animals and fish.

SYMPTOMS? Stay away from blue-green algae.  For some people, blue-green algae can cause rashes, stomach cramps, nausea, diarrhea and vomiting. People who are very sensitive to smells can have respiratory irritation. Sometimes, high exposures of toxin can affect the liver and nervous system.
If you come into contact with blue-green algae, get out of the area and wash off with soap and water. See your doctor if you think blue-green algae has made you sick.

CONTAMINATED WATER. Water from areas with blue-green algae can make animals and people sick—stay away from these areas.

SWIMMING. Don’t swim in or around blue-green algae.

BLUE-GREEN ALGAE AND FISH.  Fish tested from water with blue-green algae show that cyanotoxins don’t accumulate much in the edible parts — muscle or fillet — of fish, but can in other organs. Rinse fish fillets with tap or bottled water. Throw out guts. Cook fish well.

blue-green algae

Notes from the editor:

The information in this article was accurate when published but may change without notice. Confirm details when planning visits.

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