Red Tide suspected as manatees deaths pile up in Tampa Bay

Manatees were already dying in record numbers in Florida this year. Now Red Tide threatens them.
Red Tide is suspected in the deaths of eight of nine manatees recently found off the coasts of Pinellas and Hillsborough counties, according to data from the Florida Fish and Wildlife Conservation Commission.
Red Tide is suspected in the deaths of eight of nine manatees recently found off the coasts of Pinellas and Hillsborough counties, according to data from the Florida Fish and Wildlife Conservation Commission. [ DOUGLAS R. CLIFFORD/TAMPA BAY TIMES | Tampa Bay Times ]
Published July 24, 2021

Red Tide is suspected in the deaths suffered by a vulnerable species that has already suffered greatly this year: The manatee.

The brevetoxins released by Red Tide are suspected in the deaths of eight of nine manatees recently found off the coasts of Pinellas and Hillsborough, according to data from the Florida Fish and Wildlife Conservation Commission.

The carcasses were found over a seven-day span starting July 15 through Thursday, when the last two were discovered. One carcass in Pinellas was discovered by a ranger about 10:30 a.m. Thursday in Fort De Soto Park. An hour later, another dead manatee was found on the other side of the bay near Riverview. That cause of death is still pending.

The manatee deaths are the latest sign of the toll Red Tide has taken on Tampa Bay’s marine ecosystem. Crews have removed more than 1,518 tons of dead sea life and debris from St. Petersburg and the Pinellas beaches, including goliath grouper and tarpon, with reports of afflicted dolphins and turtles also being found.

Related: Manatee deaths reach record-breaking yearly numbers in just 6 months

The Tampa Bay manatee deaths are part of a grisly situation developing on the west coast: According to state data, more than 30 manatee deaths linked to Red Tide have been discovered in an area that the FWC defines as “Red Tide Bloom Boundary.” That means the waters off the southwest coast of Florida that have shown high concentrations of Red Tide, including Tampa Bay.

Each death has been designated as either Red Tide “positive” or “suspect,” which is determined by the levels of toxins detected.

Red Tide is exacerbating what has already been a catastrophically deadly year for manatees, which in 2017 was reclassified as a threatened, not endangered, species. The state says 866 manatee deaths were recorded this year through July 16 — already surpassing the record 830 that died in all of 2013.

Most of the 2021 manatee deaths are blamed on starvation because of the lack of food sources along their Atlantic migration route, especially the loss of seagrass in the Indian River lagoon.

“The more recent mortality is shifting to a higher incidence on the west coast,” said Patrick Rose, an aquatic biologist and executive director of the environmental protection nonprofit Save the Manatee Club. He also said boat collisions have also returned as a leading cause of manatee deaths.

Related: Red Tide’s return raises fears about the health of Tampa Bay

There are two ways that Red Tide toxins can harm manatees, Rose said.

Manatees can inhale the toxins while swimming through a bloom. They could also be sickened after consuming the toxins that settle in seagrass, which is their food source.

Red Tide blooms can threaten manatees in another way, by blocking the sunlight that seagrass need to grow, shrinking that food source, said J.P. Brooker of the Ocean Conservancy.

Keep up with Tampa Bay’s top headlines

Subscribe to our free DayStarter newsletter

We’ll deliver the latest news and information you need to know every morning.

You’re all signed up!

Want more of our free, weekly newsletters in your inbox? Let’s get started.

Explore all your options

The algal bloom currently afflicting Tampa Bay and the Pinellas beaches floated north into the bay from Lee County earlier this year, and manatees appear to have died along a similar track. The last Red Tide-linked death found in Lee County was on June 8, according to state data. The first Red Tide-related manatee death in Tampa Bay was found June 17.

Related: Red Tide adds urgency to Clearwater Marine Aquarium manatee rehab center

The manatee situation prompted Clearwater Marine Aquarium officials to announce Wednesday their plans to spend up to $2 million to build a manatee rehab center at Fred Howard Park in Tarpon Springs. The facility will be upgraded to house up to six manatees at a time in the big pool, which measures 40 feet across and is 8 feet deep.

“I’ve never seen it this bad after 50 years of study,” aquarium director James Powell told the Tampa Bay Times earlier this week.

He said the rehab center is needed as the species suffers from a “perfect storm” of threats: lack of seagrass in the Indian River lagoon, reckless boat drivers and now Red Tide.

• • •

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