1. Archive

When will Red Tide on Florida's west coast go away? It's anyone's guess.

SCOTT KEELER | Times Workers clean up thousands of small, stinky fish on North Redington Beach earlier this week.
Published Sep. 14, 2018

ST. PETERSBURG — Now that Red Tide has reached Pinellas County's popular beaches, chasing away tourists and depositing tons of dead marine life, the big question is when it will end.

The short, unsatisfying answer, 10 months after the current bloom cropped up off the Southwest Florida coast, is no one can predict when it will break apart and float away.

"It's certainly something we'd like to know about," said Vincent Lovko, a scientist at Mote Marine Laboratory in Sarasota.

Humans have little control over when Red Tide stops or starts. But, there are three ways that waterfront hotels, restaurants and property owners could finally get some relief from the noxious fumes, say scientists.

Problem is, none of them are happening now.

The way the current bloom reacted to Tropical Storm Gordon last month offers a clue about the first solution. The storm's winds pushed it away from land for a while, lessening the effects and making people feel like things were getting back to normal.

"Sustained winds can push a bloom offshore, and then that's when it can disappear," said Kate Hubbard, a research scientist with the Florida Fish and Wildlife Institute in St. Petersburg.

But once Gordon moved on, the bloom came back to shore again, Lovko said. So in this case, it didn't work.

The second thing to root for is for the algae bloom to end itself, said Edward J. Phlips, an aquatic sciences professor at the University of Florida.

To keep growing, a Red Tide algae bloom needs a steady flow of nutrients, not unlike a crop that requires repeated fertilization. That's why a Red Tide bloom, which starts up to 40 miles offshore, can be prolonged when it moves inshore and is fueled by leaky septic tanks and sewage systems, as well as fertilizer in stormwater runoff.

But if the bloom reaches a certain density, Phlips said, it could pass the point where there are enough nutrients to keep it going "and then it collapses."

Scientists are doing research now on a similar phenomenon known as "programmed cell death," Hubbard said.

Something happens within the cells of the algae themselves that trips a sequence of events that kills the whole bloom. So far scientists have been unable to pinpoint just what sets off the sequence, but if found, that could be the key to ending blooms like the one going on now.

Finally, algae blooms do have predators.

"Sometimes you have organisms that will graze on and eat algae," said Phlips.

The predators include shellfish, which filter the water as it flows through; zooplankton, the tiny animals at the base of the ocean's food chain; and even, in some cases, a fungus. However, Hubbard said, no one has confirmed that fungi feed on the type of algae in Red Tide.

The current outbreak has been particularly unusual, making a forecast on when it will end even harder.

Normally, a Red Tide bloom begins in the late summer or early fall and lasts through the winter until February or March, when it dissipates on its own, Lovko said.

But the current Red Tide, first detected last November, has persisted far beyond when a normal one would sputter out, he said.

Scientists have labeled it the worst in a decade as it's stretched across 125 miles of coastline and, this past week, even showed up off the Panhandle. It's grown more intense over the summer. Its toxins are suspected of killing hundreds of sea turtles, as well as scores of manatees and dolphins.

Because Red Tide routinely lasts through the winter, the traditional Florida lore that says cold water can make Red Tide go away is clearly untrue.

A drop in the temperature of the Gulf of Mexico would have no effect on the continued growth of the algae, according to Hubbard, the Fish and Wildlife Institute scientist.

"They can occur across a whole range of temperatures," Hubbard said.

Rather than wait on an uncertain natural process to kill the Red Tide bloom, Mote has been working on a mechanical device that could strain Red Tide out of the water.

The Sarasota-based lab has been running a test on the device in Boca Grande, according to Mote spokeswoman Hayley Rutger.

"It works like a water purifier," Rutger said. So far, she said, it appears to work — but only in a small waterway such as a canal.

In the meantime, other scientists continue studying the long, long Red Tide bloom and trying to figure out how it will end. At this point, though, Hubbard said, "there's no way to predict when that will be."

Contact Craig Pittman at Follow @craigtimes


  1. Tampa Mayor Jane Castor (far right) and her dog Alcaldesa joined students from Rampello K-8 Magnet School on a Nov. 14 walk across the school's newly-painted crosswalk, located at the intersection of Jefferson and Washington streets in downtown Tampa. CITY OF TAMPA  |  City of Tampa
    Hundreds of transportation and public safety advocates from across the country brought their ideas to Tampa for the Safe Routes to School National Conference.
  2. Sally Carlson of Seminole talks to her newly adopted 5-year-old miniature poodle held by Hillsborough County Pet Resource Center volunteer Mary Claire Streator. Potential owners browsed some of the 300 puppies that were put up for adoption Sunday in the gymnasium at All People's Life Center in Tampa. The designer-breed dogs had been rescued from Trish's All Breeds Pet Grooming in Tampa, where they were found sick and malnourished. Prospective owners were chosen out of thousands who applied during a lottery-type system and were able pick out a dog. LUIS SANTANA   |   TIMES  |  Tampa Bay Times
    The animals were found in deplorable conditions at a grooming business in September. Their new owners had 15 minutes to make a selection.
  3. Check for the latest breaking news and updates. Tampa Bay Times
    The fire destroyed one business and damaged others inside a strip mall at the corner of 49th Street South and 1st Avenue South
  4. Chief Veterinarian Mallory Offner examines a female rescue puppy at the Hillsborough County Pet Resource Center in Tampa. MARTHA ASENCIO-RHINE  |  Times
    With 250 of the pooches ready for adoption, each potential puppy parent has a 1-in-4 shot at getting picked in today’s drawing.
  5. Hillsborough Community College solicited "non-binding letters of interest or intent” last month from developers interested in purchasing the Dr. Gwendolyn W. Stephenson District Administration Center on Davis Islands. OCTAVIO JONES  |  Times
    Developers have eyed the 3.7 acre waterfront parcel for years, but recent interest has prompted the college’s trustees to finally start the conversation.
  6. Check for the latest breaking news and updates. Tampa Bay Times
    Pasco firefighters said the blaze broke out at a home in the 3000 block of Thistledown Lane.
  7. Four, six-week old puppies rescued from inadequate breeding conditions, wait to be checked by veterinary staff at the Hillsborough County Pet Resource Center. Over 300 small-breed dogs were rescued from a breeder on Monday, Sept. 23, 2019. MARTHA ASENCIO-RHINE  |  Times
    To qualify for a Hillsborough County lottery, apply in person Sunday and pass a background check.
  8. Hillsborough County Commissioner Sandra Murman was behind the push for a ban on teenage vaping. [CHRIS URSO   |   Times]
    The change makes it illegal to sell products to under-age customers and bans minors from possessing vaping paraphernalia.
  9. April Griffin
    The former Hillsborough County School Board member will compete against longtime agency employee Nancy Millan for the Constitutional office. The deadline for qualifying is June 12, 2020.
  10. Check for the latest breaking news and updates. Tampa Bay Times
    The first happened at about 4:30 p.m. in North Ybor and left one man wounded. At 5 p.m., a man was fatally shot in Sulphur Springs.