Last week, levels of blue green algae – or, as it is more accurately called, cyanobacteria – in the upper part of the Caloosahatchee River got so high that the Army Corps of Engineers shut down the beach at the Franklin Lock Recreation Area, declaring it a health hazard and creating a public outcry over the images of slick, fluorescent green toxic slime floating on the surface of the river and washing onto the shores. There’s no question as to the source of the stuff, either, as Lake Okeechobee has been covered in as much as 30 miles of it for weeks. Now, with the Corps announcing on Thursday that water releases from the lake will nearly double in anticipation of the coming rainy season, the Sand Paper wanted to know how all of this will affect our beach and back bay estuary.
Cyanobacteria can produce several types of toxins, the most common of which is called Microcystis, part of a group of hepatoxins – called this because they affect the liver. These are the toxins most responsible for poisoning animals and humans. According to the Florida Fish and Wildlife Commission (FWC), cyanobacteria are most closely related to bacteria, but they contain chlorophyll and depend on sunlight to grow, like plants. They are common throughout the United States and occur naturally in Florida’s freshwater and brackish habitats, such as lakes, rivers and estuaries. Problems occur when the organism ‘blooms’ – something that happens in nutrient-rich bodies of water like Lake Okeechobee. Earlier in May, the South Florida Water Management District noticed a large fish kill on the lake, and a water sample test led to the determination that it was caused by a Microcystis bloom. Another bloom was spotted last week in the Caloosahatchee River, along the shorelines of LaBelle, Olga and Alva – prompting the closure of the Franklin Lock recreation area.
These blooms are relatively easy to spot because the natural buoyancy of the bacteria causes it to float on the surface – forming a bright green oily ‘film’ or scum several inches thick.
“Recreational exposure by direct contact with a cyanobacteria bloom from activities such as jet-skiing, boating, and swimming have been reported to cause hay fever-like symptoms (itchy eyes, sore throat, congestion) and dermal reactions (skin rashes, blistering) at high concentrations,” the FWC’s website – myfwc.com – reads. “Ingesting contaminated water can cause gastrointestinal distress (diarrhea, abdominal pains, nausea, vomiting).”
When blooms are reported, multiple state agencies respond as a team, with Florida’s Department of Environmental Protection in charge of collecting samples to analyze. On May 23, 2016, DEP staff members took water samples at Moore Haven (S77) where Lake O water is released into the Caloosahatchee River. No cyanobacteria were found on the lake side or the canal side. Last Thursday, media reported that the bloom is moving downstream and that underwater sensors had detected it west of Interstate 75.
On the other coast of Florida, a 100-foot wide swath of bright green spreads along the Indian Street Bridge in Palm City and a thick gooey mess coats the marina shoreline in downtown Stuart.
Water sampled last Monday from the lake side of the Port Mayaca lock on the eastern side of Lake Okeechobee contained 24.4 micrograms per liter of the toxin microcystin. Water sampled on the canal side had 5.1 micrograms. The World Health Organization says 10 to 20 micrograms per liter is considered a moderate level, with 20 to 2,000 considered high.
Last Friday, the Army Corps of Engineers announced an increase of 420 million gallons per day in water being released down the St. Lucie River and a 1.3 billion gallon increase for the Caloosahatchee River.
Lt. Col. Jennifer Reynolds, who is the Corps’ deputy district commander for South Florida, said in a press conference last Thursday that she can’t predict how the algae bloom will be affected by the increases in discharges from the lake.
“There is a chance that the algae will be disrupted by turbulence in the water created by the discharges,” she said. “They grow better in fresh water conditions, but turbulent water tends to suppress their reproduction rate so we’re not entirely sure what is going to happen. Where blooms will appear and become problematic, we don’t have a good way to predict that.”
Dee Ann Miller, Deputy Press Secretary of the Florida Department of Environmental Protection, said the water district and DEP works with the Florida Department of Health, the FWC and the Florida Department of Agriculture and Consumer Services to monitor algal blooms.
“Since May 13, 2016, when the South Florida Water Management District (SFWMD) first observed an algal bloom on Lake Okeechobee during their routine sampling, DEP and the SFWMD have regularly responded and sampled observed and reported algal blooms on Lake Okeechobee, in the St. Lucie River and Estuary and the Caloosahatchee River and Estuary. Although a majority of our testing shows very low toxin in the blue-green algae, we will continue to work with SFWMD to monitor the algal blooms to keep Floridians and visitors informed and safe.”
Blue-green algae blooms along with dead, diseased or abnormally behaving fish or wildlife can be reported to the FWC’s Fish and Wildlife Research Institute (FWRI) Fish Kill Hotline at 800-636-0511. Callers are asked to leave contact information and a detailed report. Report any illness from exposure to harmful algae to the toll-free Aquatic Toxins Hotline: 1-888-232-8635.
Keri Hendry Weeg