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Water Quality Report: Blue-green algae -- learn it, live it, but you don't have to love it


It’s the time of year when warnings about blue-green algae outbreaks will be a regular part of this column as the harmful algae will start popping up everywhere, peaking in August.

However, there is no telling how the hyperactive hurricane season may affect the normal rhythm of the abnormal amount of blue-green algae that Southwest Florida has to contend with yearly.

 There are some rumblings that heavy summer rains or a hurricane may break up the summertime coating of blue-green algae over Lake Okeechobee, which is supposed to be especially bad this year.

Or it won’t. And the water the Army Corps releases down the Caloosahatchee River regularly to control the level of the Big Lake may carry Big Chunks of algae with it.

For now, the Florida Department of Health in Lee County issued its sixth health advisory this year due to blue-green algae in the Caloosahatchee River.

Tom Bayles

The health department detected the presence of harmful blue-green algae toxins in a canal that leads to the Caloosahatchee River West Basin Storage Reservoir, which is under construction and when completed sometime in the next two years it will hold more than 55 billion gallons of water.

Being built on 10,700 acres of former farmland in Hendry County, the reservoir is part of an overall solution to restore the river and estuary, including water quality improvements, storage, and operational changes.

Two weeks ago, the health department found the harmful algae just to the west of the Broadway Street Bridge in the canals next to Sebastian Court in Alva.

Blue-green algae can be dangerous. Do not drink, swim, wade, use personal watercraft, or come into contact with water if you can see a bloom.

The best idea when you can see a visible bloom is to go somewhere else.

If you have any contact with algae, or discolored water that smells unpleasant wash your skin and clothing with soap and water.

Ingestion of a component of toxic blue-green algae called Microcystis may cause vomiting, nausea, headaches, diarrhea, pneumonia, and fever.

Keep your pets away from the water, and do not let them drink the water or get in it. Blue-green algae have killed pets and livestock.

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.

However, do not eat shellfish in waters with algae blooms.

“Blooms have the potential to produce toxins, and what triggers them to do so remains poorly understood,” the health department warns in a statement. "Since bloom conditions can change at any time, it is important to exercise caution as if the bloom were toxic, even if toxin presence has not yet been confirmed.”

Bayles, Tom

Let’s just hope and hope that the blue-green algae outbreaks remain as relatively small as they have been so far this year. We don’t need another coating of the smelly and slimy algae all over everything like the summer of 2018.


The Florida Fish and Wildlife Conservation Commission sampled for any above-normal amounts of the red tide organism, Karenia brevis, and found none. Yippee.

No reports of fish kills suspected to be related to red tide were received over the past week, nor was there any respiratory Irritation reported in Florida over the past week related to the harmful algae bloom.


The agency reminds residents that winds and tides tend to push the components of blue-green algae around, so people in that region should be watchful for the potentially toxic bloom.

Lake Okeechobee shows a high potential for a significant bloom this summer.

The FDEP says it is important to remember the blue-green algae potential is subject to change due to rapidly changing environmental conditions or satellite inconsistencies.

What is red tide?

Red tide is one type of harmful algal bloom caused by high concentrations of the toxic dinoflagellate K. brevis, which is a type of microscopic algae found in the Gulf of Mexico.

Red tide typically forms naturally offshore, commonly in late summer or early fall, and is carried into coastal waters by winds and currents. Once inshore, these opportunistic organisms can use nearshore nutrient sources to fuel their growth.

Blooms typically last into winter or spring, but in some cases, can endure for more than one year.

Is red tide harmful?

K. brevis produces potent neurotoxins that can be harmful to the health of both wildlife and people. Wind and wave action can break open K. brevis cells and release toxins into the air. This is why you should monitor conditions and stay away from beaches where red tide is in bloom.

 People in coastal areas can experience varying degrees of eye, nose and throat irritation during a red tide bloom. Some individuals with chronic respiratory conditions like asthma or chronic lung disease might experience more severe symptoms.

Red tide toxins can also affect the central nervous system of fish and other marine life, which can lead to fish kills.

What causes red tide?

A red tide bloom develops naturally, but recent studies have discovered mankind's infusion of other nutrients into the mix can make the red tide last longer or get stronger. But biology (the organisms), chemistry (natural or man-made nutrients for growth) and physics (concentrating and transport mechanisms) interact to produce the algal bloom. No one factor causes the development of a red tide bloom.

What is blue-green algae?

Blue-green algae, also known as cyanobacteria, are a group of organisms that can live in freshwater, saltwater or brackish water.
Large concentrations, called blooms, can change the water color to blue, green, brown, orange or red. Some cyanobacterial blooms can look like foam, scum, or mats on the surface of freshwater lakes and ponds. As algae in a cyanobacterial bloom die, the water may smell like something with a naturally unpleasant odor has now started to rot, too.

Is blue-green algae harmful?

 Different types of blue-green algal bloom species can look different and have different impacts. However, regardless of species, many types of blue-green algae can produce toxins that can make you or your pets sick if swallowed or possibly cause skin and eye irritation.

The FDEP advises staying out of water where algae is visibly present as specks or mats or where water is discolored. Pets or livestock should not come into contact with algal bloom-impacted water or with algal bloom material or fish on the shoreline. If they do, wash the animals right away.

What causes blue-green algae?

 Blue-green algae blooms occur when the algae that are typically present grow in numbers more than normal. Within a few days, a bloom can cause clear water to become cloudy.

Winds tend to push the floating blooms to the shore where they become more noticeable. Cyanobacterial blooms can form in warm, slow-moving waters that are rich in nutrients. Blooms can occur at any time, but most often occur in late summer or early fall.

If any major type of water quality alert is issued, you can find the details here in WGCU’s Water Quality Report.


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