Red Tide is still floating out there and could return. But when?

The fish kills have receded, but toxic algal blooms are still floating off the Pinellas shore.
Dead fish lie on the sand at Indian Shores Beach in St. Petersburg on June 10. The massive fish kills have receded, but Red Tide is still floating off the Pinellas coast. Scientists say it's hard to forecast when it could return to afflict the shore.
Dead fish lie on the sand at Indian Shores Beach in St. Petersburg on June 10. The massive fish kills have receded, but Red Tide is still floating off the Pinellas coast. Scientists say it's hard to forecast when it could return to afflict the shore. [ ARIELLE BADER | Times ]
Published Aug. 27, 2021|Updated Aug. 27, 2021

The fish kills and murky air are no longer problems for the Pinellas coastline, but that doesn’t mean Red Tide is gone.

The patchy blooms are still floating miles off the county’s western coastline. They don’t currently pose a threat to Pinellas County, but experts say that could change if the currents and winds bring it back to shore.

They just don’t know if that could happen now — or in the fall.

“I was actually quite shocked at how close the Red Tide is,” said Pinellas County Public Works Director Kelli Hammer Levy during a Wednesday meeting with the mayors of Pinellas’ beach cities. “It’s actually sitting right off of our coast right now, so it’s still there.”

No high concentrations of Karenia brevis, the microorganism that causes Red Tide, were detected in state water tests taken Friday, according to the Florida Fish and Wildlife Conservation Commission’s Red Tide online locator map. Medium concentrations were detected off Clearwater Beach and Treasure Island. Low concentrations were found off Madeira Beach, Pass-a-Grille Beach, Redington Shores and Sand Key.

Related: Here’s how climate change could make future Red Tide blooms worse

A sign that the Red Tide situation has improved since the fish kills inundated the coastline this past summer is that the amount of dead sea life and debris picked up has declined considerably. The week of Aug. 9, the county said crews had picked up a total of 1,823 tons. But in the weeks since, just 13 more tons have been recovered as of Monday, according to the county.

The total waste collected now stands at 1,836, which nears the total of 1,860 tons the county collected during the 2018 Red Tide outbreak that afflicted Florida’s west coast. But this year, much of that sea life was killed in Tampa Bay itself, where the blooms resided for several weeks while poisoning fish off St. Petersburg and Tampa.

Blooms have moved north to Hernando and Citrus counties, according to Kate Hubbard, a research scientists leading the conservation commission’s Red Tide monitoring and research. The agency said it received eight reports of fish kills along the Pinellas coast from Belleair Shore to Dunedin.

It’s a stark contrast from a month ago, when Red Tide afflicted Tampa Bay and the Pinellas coastline and left buried in dead fish. Crews worked nonstop to remove the smelly debris.

Here’s why experts can’t say for sure that those days are gone.

Period of uncertainty

“Variability” is a word Hubbard uses a lot this time of year. It’s why researchers can only surmise what the Red Tide situation will look like one week into the future.

Red Tide naturally occurs off the gulf coast every year, where they’re affected by natural and manmade conditions.

Wind patterns affect how much the blooms move each day. Ocean currents can merge already-existing blooms, bring an offshore bloom in or move patches of Red Tide up and down Florida’s gulf coast. Nitrogen strengthens already-existing patches, and that fuel source can grow as the runoff from fertilized lawns ends up in the water. Some parts of the coast jut out to the west and create “convergence zones” that concentrate blooms.

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Put it all together, and it’s difficult to predict how those factors will affect Red Tide.

“So it’s maybe not the best term, but it slips in on us,” said National Centers for Coastal Ocean Science oceanographer Richard Stumpf. “Because it’s difficult to find any patches offshore, and because it does tend to pile up on the beach when it comes in, that makes it difficult to try to forecast ... an additional wave of it.”

Related: Red Tide isn’t just bad for fish, as a Tampa Bay man learned in the ER

Pinellas is in a “period of uncertainty,” said Hubbard. Offshore patches were moving north this week, resulting in fish kills between 2.5 and 42 miles off the Hernando County coast. Meanwhile, onshore patches are causing fish kills further south, off the coast of Sarasota County.

What’s unusual about this recent bloom is that Karenia brevis typically forms off the Pinellas coast in late summer or early fall. But this Red Tide outbreak started in June, which Stumpf said is “doubly unusual.”

But there was also an unusual event in April: the release of 215 million gallons of polluted wastewater into the bay from the old site of the Piney Point fertilizer plant in Manatee County. The state authorized the release, fearing a leaking reservoir could have caused a collapse that would have flooded the surrounding community.

Scientists say the nitrogen-rich wastewater could have exacerbated the Red Tide bloom that was already in the bay when the release took please.

Now, as conditions improve, all eyes turn to the gulf coast, where blooms typically form during the late summer.

“Conditions have been significantly better over the last several days, and that’s because the currents and winds have been working in our favor,” Pinellas County spokesperson Tony Fabrizio wrote in an email. “But there are still significant blooms offshore and south of us that could become problematic. If they do, the county and our municipalities stand ready to respond with cleanup efforts.”

New forecast models

One reason officials say they’ll be ready to respond is a research team from the University of South Florida College of Marine Science.

USF’s Ocean Circulation Group created an online map that tries to predict how blooms could move about 3½ days in advance.

The National Centers for Coastal Ocean Science recently launched a new online tool, the Harmful Algal Bloom forecast, that offers a real-time forecast of blooms across the country, including the Gulf of Mexico, based on bloom locations and wind conditions. Its models forecast on bloom intensification, areas that could suffer respiratory issues and conditions on local beaches.

Related: Florida’s deadly manatee crisis could flare again this winter

Those models can help local governments and residents cope with Red Tide, Stumpf said. He works on the bloom forecast tool, and said the agency is testing a model that could predict conditions two weeks out, which he hopes will be released next year.

For now, Stumpf sees the Red Tide situation for the rest of 2021 unfolding like this: The current bloom could last into the fall, and at some point it could also get pushed back to shore.

“But that doesn’t mean it will be intense,” he said. “That depends on how much more growth there is or how much more Karenia (brevis) comes to shore.

“So it’s a very long winded answer to say no, we can’t tell you what’s going to happen in October.”

• • •

Red Tide coverage

Tampa Bay has Red Tide questions. Here are some answers.

Is it safe to eat seafood? Here’s how Red Tide affects what you eat.

Can I go fishing? The state is limiting saltwater fishing.

Piney Point: The environmental disaster may be fueling Red Tide.

Red Tide resources

• The Florida Fish and Wildlife Conservation Commission has a website that tracks where Red Tide is detected.

• Florida Poison Control Centers have a toll-free 24/7 hotline to report illnesses, including from exposure to Red Tide: 1-800-222-1222

• To report dead fish for clean-up in Tampa Bay, call the Florida Fish and Wildlife Conservation Commission at 1-800-636-0511 or file a fish kill report online.

• In St. Petersburg, call the Mayor’s Action Center at 727-893-7111 or use St. Petersburg’s seeclickfix website.

• Visit St. Pete/Clearwater, the county’s tourism wing, runs an online beach dashboard at

How to stay safe near the water

• Do not swim around dead fish.

• Those with chronic respiratory problems should be careful and stay away from places with a Red Tide bloom. Leave if you think Red Tide is affecting you.

• Do not harvest or eat mollusks or distressed and dead fish from the area. Fillets of healthy fish should be rised with clean water, and the guts thrown out.

• Pet owners should keep their animals away from the water and from dead fish.

• Residents living near the beach should close their windows and run air conditioners with proper filters.

• Beachgoers can protect themselves by wearing masks.

Source: Florida Department of Health in Pinellas County