Florida’s deadly manatee crisis could flare again this winter

Starvation has been blamed for a mass die-off. The circumstances that led to this point will linger.
Two dead, emaciated adult manatees recovered from Brevard County are seen before a necropsy in March at the state's Marine Mammal Pathobiology Lab.
Two dead, emaciated adult manatees recovered from Brevard County are seen before a necropsy in March at the state's Marine Mammal Pathobiology Lab. [ Florida Fish and Wildlife Conservation Commission ]
Published Aug. 4, 2021|Updated Aug. 5, 2021

The problems that have caused an unprecedented die-off of Florida manatees in 2021 could linger for years to come, according to state wildlife officials.

The Florida Fish and Wildlife Conservation Commission board on Wednesday heard a blunt assessment of the situation from agency staffers. At least 890 manatees had died as of late July, which means 2021 is already the most lethal year on record for one of the state’s most iconic species.

The numbers are inflated by a crisis on the east coast, centering on the northern Indian River Lagoon, where manatees starved after retreating to their winter homes around warm discharges from power plants. Repeated algal blooms fed by human pollution have killed off tens of thousands of acres of the seagrasses that manatees eat.

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

For as bad as it’s been, state leaders tasked with caring for Florida’s threatened manatee population made clear Wednesday that they are also worried about — and scrambling to prepare for — what could be to come. This die-off, designated an “unusual mortality event,” is different than other problems manatees have faced in the past, said Gil McRae, director of the state Fish and Wildlife Research Institute.

“If it’s a Red Tide, it comes and goes. If it’s a cold kill, it comes and goes,” he said during a meeting in Bonita Springs. “This one we’re uncertain how long the impact’s going to be, but we know this forage is not going to come back overnight or even in a few years.”

Related: Red Tide suspected as manatees deaths pile up in Tampa Bay

A terrible winter

Between December and the end of May, McRae said, 677 dead manatees were found along Florida’s Atlantic coast.

That is nearly one-fifth of all manatees believed to live in the area, according to researchers’ most recent population estimate.

They were dying at about five times the normal rate.

By the time they washed up, McRae said, the manatees were severely emaciated. They were ailing in their muscles, livers and hearts. State scientists took blood samples from some manatees that were rescued and found signs of “end-stage starvation.”

The die-off eased as manatees moved away from their winter homes, swimming up and down the peninsula to places with more seagrasses. But the symptoms of starvation did not always disappear, even after the manatees began to eat again. Those animals could suffer enduring consequences and illness.

“Sometimes it’s tough to bring them back if they’re too far gone,” McRae said.

Particularly troubling were the deaths of many adult manatees. Mothers, McRae said, typically give birth to a single calf every two to five years.

“We lose a 40-year old manatee, we lose a lot of reproductive potential,” he said.

Related: Florida manatees are dying at a worrisome rate. Many appear to be starving.

On the east coast, 13 calves were rescued between December and May, compared to an average of 5 for that period over the last five years. Taking care of orphaned manatees is difficult.

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ZooTampa has two calves, said Cynthia Stringfield, a senior vice president of animal health, conservation and education. Staffers only recently ended bottle feedings at 2 a.m.

“It’s been a rough year,” she told the commissioners.

A manatee swims near a snorkeler by the entrance of Three Sisters Springs in Crystal River in 2014.
A manatee swims near a snorkeler by the entrance of Three Sisters Springs in Crystal River in 2014. [ DOUGLAS CLIFFORD | Tampa Bay Times ]

How healthy are manatees overall?

Florida’s manatee population is believed to have risen since bottoming out decades ago. At least 7,520 manatees were estimated to be alive at last count. But the animals still face many threats.

This summer, attention has turned to the gulf coast, where scientists suspect some manatees have been killed by Red Tide.

One of the leading causes of manatee deaths and injuries in the past has been boaters, according to the Conservation Commission. This year, at least 68 deaths have been blamed on watercraft. McRae noted that 96 percent of adult carcasses recovered bear old boat scars.

Parts of southwest Florida and the Atlantic coast have about a 50-50 chance of seeing manatees decline by 30 percent or more over the next century, according to estimates cited in a version of McRae’s slideshow posted online.

In the middle of the presentation Wednesday, Fish and Wildlife Conservation Commission Chair Rodney Barreto stopped to take issue with what he said are grisly ads from nonprofit manatee advocates showing injured animals. He said such campaigns are meant to “yank at your heart a little bit and your purse strings a little bit,” but that boaters are only one of multiple reasons manatees die.

“There’s certainly no one up here who gets in their boat and says ‘Hey, let’s go run a manatee over,’” Barreto said.

He also said the state’s herd, compared to decades ago, has “come back. It’s very, very healthy.”

Some argue that manatees are not protected enough. The federal government moved the species to a status of threatened, instead of endangered, in 2017.

Related: Manatees no longer classified as an endangered species, but still a threatened one

U.S. Rep. Vern Buchanan, a Sarasota Republican, called earlier this year for regulators to restore the manatee’s endangered listing.

“Manatees are beloved, iconic mammals in Florida, and we should be doing everything in our power to protect them and ensure their continued survival,” Buchanan wrote in a June letter to the principal deputy director of the U.S. Fish and Wildlife Service. “Considering the number of manatee deaths so far this year, redesignating the manatee as endangered, which provides for the highest levels of federal protection and conservation efforts, is critical.”

The congressman’s office said he had not received a reply as Tuesday morning.

The federal government, in 2020, began the process of conducting a comprehensive assessment of the manatee population’s status, said Larry Williams, a U.S. Fish and Wildlife Service ecological supervisor for Florida. The emergency in the Indian River Lagoon has delayed that work.

A manatee and two calves swim off King's Bay in 2018.
A manatee and two calves swim off King's Bay in 2018. [ DOUGLAS R. CLIFFORD | Tampa Bay Times ]

Looking to the future

If next winter proves to be as bad for manatees on the east coast as this year, McRae said the Conservation Commission will have a plan.

State employees, he said, are working with partners at aquariums and other organizations to ramp up their ability to rescue sick manatees. They are also contemplating whether they could bring in food to help sustain manatees through winter. That would be difficult, McRae said, because manatees need a lot to eat each day. And, generally, “supplemental feeding of wildlife often does more harm than good.”

The Florida Legislature allocated about $8 million that can fund priority projects addressing the manatee problem, McRae said. But some obvious work, like replanting seagrasses, may not make sense to pursue until after water quality improves in the Indian River Lagoon. Such an overhaul will take coordination across agencies, including the Department of Environmental Protection.

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

The northern portion of the lagoon has lost more than 46,000 acres of seagrass, according to figures from the St. Johns River Water Management District cited by McRae. It has been altered by heavy development, fertilizer runoff from land and contamination out of leaking septic tanks. Extra nutrients have given fuel to recurring algal blooms that shade the water, blocking light from reaching seagrass beds.

McRae said the state wildlife staff feels a sense of urgency. “We know that winter is right around the corner,” he said.

Mike Sole, vice chair of the Conservation Commission, said the agency has to be vocal and aggressive about pushing water quality improvements in the Indian River Lagoon and beyond.

“It’s very place-based right now, but it doesn’t mean it’s not a similar challenge in other lagoons ... in St. Johns in the river, here on the west coast,” he said. “There’s so much that I think we as a partner agency can do to help push the understanding that our resources are dying because we’re not acting fast enough.”