The Florida Department of Health in Lee County canceled five health warnings due to harmful algal blooms in the Caloosahatchee River and its watershed. The cancelations are a reversal of the one-after-another trend of red tide or blue-green algae outbreaks in Southwest Florida that began days after Hurricane Ian slammed into Lee County in late September 2023.
Right after Hurricane Ian, land-based nutrients like fertilizers were washed into the Gulf of Mexico by the hurricane’s massive volume of rainwater and storm surge. The first red tides were found offshore of Sarasota County, and as the months went by, dozens of more blooms of the toxins, often airborne, were detected throughout Southwest Florida offshore seas.
The red tides dissipated as the Gulf of Mexico got warmer heading into this summer.
Then more than a dozen masses of blue-green algae — another harmful algae bloom — were discovered by testing in the Caloosahatchee River from June through August, which prompted state officials to issue health advisories from the upper Caloosahatchee River to the lower, warning of the presence of the toxic organism throughout.
Skin rashes, gastrointestinal turmoil, and respiratory distress are potential outcomes of contact with algae-filled water. Blue-green algae have also killed family pets who played in infected areas, as well as entire flocks of birds who landed in lakes covered in the slimy, green algae.
In addition to health effects, harmful algae blooms cause significant economic losses when they take hold, keeping tourists and residents alike away from saltwater beaches due to the acrid odors and dead fish lining the shore that are the hallmark of red tide, and the rotten-egg smell and slimy blue-green algae that look like bad toupees gone rotten in freshwater lakes and rivers.
Despite the five canceled health warnings issue in June and July for the waters around Jaycee Park, Overiver Drive, Whitecap Circle, Horton Park, and the end of Canal Circle along the Caloosahatchee River, several more health warnings for the floating, toxic algae remain, and not in places that can so easily be defined because many of the piles of algae float around with the winds and tides.
“It is important that the public exercise caution and good judgment,” the health department said in a press release. “Blue-green algae blooms can move around or subside and then reappear when conditions are favorable again. Residents and visitors are advised to avoid contact with the water if blooms are observed.”
Economic impacts
The after-effects of Hurricane Ian continue to be felt in the Southwest Florida economy. As rebuilding continues in Fort Myers Beach and other coastal areas, Lee County continues to experience a larger effect on tourist tax revenues.
Lee County saw an average year-to-year decrease of 52.5 percent in the past quarter, according to the Florida Gulf Coast University’s Southwest Florida Economic Outlook published in August.
Real taxable sales have also followed this downward trend since Hurricane Ian, the outlook said.
Hurricane Irma, a powerful Category 5 storm five years before Ian, also caused significant damage across the state, including in South Florida. The storm's impact on the environment and coastal areas was substantial, highlighting the need for resilient infrastructure and climate adaptation measures.
Like Ian, Irma kicked up nutrients from the bottom of Lake Okeechobee as well as the surrounding watershed of the lake and the Caloosahatchee River, leading to the blue-green algae outbreaks on the Caloosahatchee: thick, green, slimy and smelly, that resulted in day trips and entire vacations ruined.
More blue-green algae?
Hurricane season is in the midst of its most dangerous weeks, and despite the billions of dollars spent on the restorations of the Florida Everglades, and despite the recent cancellations of the five blue-green algae outbreaks in the river, the history behind the harmful algae blooms have yet to be undone.
More than a century ago, the Army Corps of Engineers linked the Caloosahatchee River to Lake Okeechobee by digging a canal through the river’s swampy headwaters west of the lake.
These days, that waterway is the most common one the Army Corps uses to release water from Lake Okeechobee when levels are high.
"Areas previously unaffected by toxic algal blooms or waterborne diseases because of cooler water temperatures may face these hazards in the future as increasing water temperatures allow the organisms that cause these health risks to thrive."U.S. Global Change Research Program
The problem is that the lake water is hopelessly polluted with nitrogen and phosphorus that’s flowed into it from more than a century of fertilizer use by industrial-sized agriculture operations and people wanting the grass to grow around their homes.
In 2018, heavy releases of lake water into the river are believed responsible for the massive blue-green algae outbreak that fouled the greater Caloosahatchee River estuary all summer. That summer was also the first after a big Hurricane Irma churned up the lake bottom in 2017.
Also called cyanobacteria, blue-green algae has already bloomed in the lake this spring and many are still worried that conditions are shaping up for a repeat of 2018 in the river this summer if another hurricane like Irma and Ian comes this way.
Government agreement
Red tide was detected at every beach in Sarasota County soon after Hurricane Ian made landfall near Fort Myers in late September. At one point, the Florida Fish and Wildlife Conservation Commission found the red tide organism, Karenia brevis, in nearly 100 samples throughout Southwest Florida.
Florida Department of Health officials in Manatee, Sarasota, Charlotte, Lee, and Collier counties began issuing health alerts daily warning of the real and present danger to humans and animals.
Blue-green algae, scientifically known as cyanobacteria, are minuscule organisms that inhabit freshwater bodies across the nation. These organisms, a natural part of aquatic ecosystems, hold the potential for beauty but also for peril when they overstay their ecological welcome and become slimy, smelly leftovers.
Once again, facets of climate change are exacerbating red tide and blue-green algae in Southwest Florida.
Nutrient pollution, larger and more frequent hurricanes, sea-level rise, and overall changes to the ocean are becoming recognized even by federal agencies once skeptical of the connection.
The Pew Center surveys show that fewer than half of all Americans reject that humans are major contributors to climate change, or say addressing the issue is not too important for the country. Even smaller shares take the most skeptical views and say the Earth is not warming at all and that no action should be taken, the enter reports.
Just less than half of Americans say human activity is the primary reason why the Earth is warming. By contrast, 26% say warming is mostly caused by natural patterns in the environment and another 14% do not believe there’s evidence the Earth is warming at all, according to Pew Center surveys.
But mainstream federal agencies say they accept that climate change is a phenomenon that would not be happening otherwise, at least not at the rate it is, and an over-arching agency called the U.S. Global Change Research Program has been formed to help deal with the ramifications, which include harmful algal blooms.
“With climate change, the frequency, severity, duration, and location of weather and climate phenomena—like rising temperatures, heavy rains and droughts, and some other kinds of severe weather—are changing," the agency says on its website.
"Areas previously unaffected by toxic algal blooms or waterborne diseases because of cooler water temperatures may face these hazards in the future as increasing water temperatures allow the organisms that cause these health risks to thrive. Even areas that currently experience these health threats may see a shift in the timing of the seasons that pose the greatest risk to human health.”
WGCU is your trusted source for news and information in Southwest Florida. We are a nonprofit public service, and your support is more critical than ever. Keep public media strong and donate now. Thank you. Environmental reporting for WGCU is funded in part by VoLo Foundation, a non-profit with a mission to accelerate change and global impact by supporting science-based climate solutions, enhancing education, and improving health.
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