The green algae-infested waters lapping Florida’s Treasure Coast like watery guacamole over the last few weeks have angered residents, disgusted visitors and drawn the sort of national media attention that can cripple a region’s tourist-driven economy.
There are a lot of questions, including this big one: how far will it spread?
Sign Up and Save
Get six months of free digital access to the Miami Herald
The epicenter of slime remains the waterways branching from the St. Lucie River near Stuart, a rich estuary contaminated by a steady flow of foul, nutrient-laden water from Lake Okeechobee. Marinas, waterfront homes and even Atlantic beaches near the St. Lucie Inlet have been hit by waves of rank goo. A handful of samples from the area taken by the Florida Department of Environmental Protection also have contained concentrations of toxic algae that pose public health risks.
Now, scientists and the state are keeping an eye on a few other potentially vulnerable areas. At the top of the list: the Caloosahatchee River, which serves as the western relief valve for excess water from Lake Okeechobee. State samples already have shown isolated blooms but any dry spells combined with summer heat potentially could mean more green muck for the southwest coast in coming months.
“We don’t see algae typically in flowing river water — it’s more so in sitting water,” said Steve Davis, an ecologist with the Everglades Foundation. For this reason, he said, it will be a delicate balancing act to reduce the flow of the nutrient-rich lake water fueling the algae explosion. If water volumes are reduced too much, that, too, can fuel algae growth.
For now, the algae has been particularly thick in east-side estuaries flushed with lake water that contains high concentrations of nutrients, much of it from farms and cattle pastures. The dumping, primarily aimed at protecting the lake’s dike, has produced bright green waters that have fueled headlines and prompted Gov. Rick Scott to declare a state of emergency in four counties: Martin, St. Lucie, Palm Beach. Lee, on the southwest coast, is also under a state of emergency.
So far, the damages remain largely confined to the lake and its inland waters near its two major rivers but blooms have also fouled beaches from Stuart north to Fort Pierce. Some algae was found as far south as the Intracoastal waterway in Lake Worth in Palm Beach County, but the DEP said that by July 5 whatever was there had dissipated. While it’s still unclear how far this bloom might push, previous dumps from the lake over the last few decades have not affected the inland waters and beaches of Broward or Miami-Dade counties.
Further south, Florida Bay off the Florida Keys also could be at high risk — but not because of anything to do with the Lake O-fueled blooms. With the soaring summer heat, high salinity levels and recent widespread sea grass dieoffs in the bay, Davis said the conditions are prime for an algae bloom. The dead grass would provide the perfect kind of nutrients to fuel an algae explosion.
Davis, like many scientists and critics, say the long-term solution is to move more Lake Okeechobee water south through the Everglades and eventually into Florida Bay — a goal of multibillion-dollar but often delayed Everglades restoration efforts.
For now, the DEP is working to train additional staff to ramp up state water testing operations. The agency is roping in extra helping hands from its field staff at the Indian River Lagoon Aquatic Preserves, Charlotte Harbor and Estero Bay Aquatic Preserve.
At midweek, the state focused its water testing efforts on several spots: Fort Pierce Inlet Beach, Blind Creek Park North, Jensen Beach, Bathtub Beach, Hobe Sound Beach and Coral Cove Beach, and portions of the St. Lucie River..
The state said the testing efforts, which date to the agency’s first observations of algae blooms on May, have mostly shown low levels of toxicity. However, the state’s tracking data isn’t anywhere close to real-time, with the latest samples available Thursday dating back to June 30 — before a Fourth of July holiday weekend that largely shut down the coastal areas of Martin and St. Lucie counties from the stench of algae. The state, however, has established a toll-free hot-line for residents to report blooms: 855-305-3903.
In samples taken through June 30, the state had confirmed algae blooms in at least 44 locations, with the worst conditions in Martin and St. Lucie County. Algae has also been detected as far west as the Fort Myers area along the Caloosahatchee River. State survey teams have sampled blooms in at least nine spots in Lake Okeechobee and the explosion of green is massive and vivid enough that a NASA Landsat 8 satellite captured it in a photo during a flyover last week.
Just about half the samples, 21 of them, have contained toxic varieties of blue-green algae that can be a public health risk, mostly in Martin County. While there are no state standards for toxic algae in recreational waters, county health departments typically ban swimming in areas with high concentrations of any sort. A handful state’s samples have exceeded concentrations considered safe by the World Health Organization. One recorded five meters off Bathtub Beach in the Atlantic Ocean on June 30 contained more 40 times that limit.
Toxicity is an issue of concern because the algae blooms produce toxins that can cause sickness in humans if they touch, or even breathe near, the green water.
The Florida Army Corps of Engineers responded last week to Scott’s declaration of a state of emergency by reducing the flow of water from Lake Okeechobee, the primary source of the algae contagion- into surrounding waterways. Doing so reduces the flow of nutrient-heavy water that fuels algae growth, and allows salt water to naturally flow back into estuaries where fresh and salt water mix. The algae causing the problem is a fresh-water species, so an excess of fresh lake water in bay areas can cause unnatural algae blooms.
Davis said that the issue of controlling water flows from the lake was not a solution in itself, but rather meant to “provide temporary relief.” He pointed to the possibility of heavy rains during hurricane season, saying it would require the state to once again release high volumes of nutrient-rich lake water, which could in turn fuel another algae bloom.
Dee Ann Miller, spokeswoman for the state Department of Environmental Protection, said that prediction and prevention were both difficult tasks.
“The nature of most freshwater algal bloom events makes it difficult to predict where and when a bloom will occur or how long it will last,” she said. “However, lessening the negative effects of algal blooms is possible through restoration work to improve water quality by reducing nutrients. By reducing nitrogen and phosphorous levels, we can help decrease the intensity and duration of algal bloom events.”