Dyllan Thieme used to run manatee tours in Dania. For most of his customers, it was their first time encountering the plump herbivorous marine mammals face-to-face, and Thieme says reactions usually fell somewhere between “bewilderment” and “awestruck.’’ Only a few people screamed.
He still remembers one tour in particular, when they came upon a manatee that was acting a little off. “I’d never seen this before,” Thieme says. “He was actually rubbing his nose with his flipper, almost like he was itching.”
The group observed from a responsible distance, in a semi-circle formation, as the manatee drifted closer. “We’re all sitting on the paddleboards with our feet in the water. And the manatee comes up and breaches right between this gentleman’s legs—and he sneezes.”
Thieme had never seen anything like it. It was explosive: “snot 20 feet in the air. And when I say snot, I mean, like, thumb-sized pieces of white phlegm.”
The man’s face took the brunt of it. “Covered,” Thieme says, twice for emphasis.
After a tense second or two—not knowing whether it was OK to laugh—the entire group was cackling. The tour was a success.
Thieme doesn’t do those tours anymore, though he still paddles in Fort Lauderdale when he can and cherishes any manatee sighting. He knows the animal’s future in South Florida is not guaranteed. He’s pragmatic. He’s seen too much trash on the beach, and too many irresponsible boaters, to be anything but.
Thieme is better than most at finding the animals. He’s had lots of practice. But 2021 was a particularly brutal year for manatee mortality rates in Florida. There were a record-breaking 1,101 confirmed deaths in 2021, nearly 15 percent of the entire population. When he looks towards the future, Thieme does not view the possibility of losing manatees, in his own lifetime, as entirely unrealistic.
“If we keep going the way we’re going,” he says, “yeah, I definitely see that happening.”
A brief history of the human/manatee relationship in Florida can be summed up thus: We found them, we (allegedly) mistook them for mermaids, then we ate them for about 8,000 years before we eventually decided to stop doing that in 1893. (That year, Florida lawmakers passed the state’s first manatee preservation legislation, an act that banned hunting them.) Although soon afterwards we found new ways to accidentally kill them in the form of the motorboat, pollution and habitat destruction.
The manatee has no natural predators except for us. And despite our license plates and T-shirts and various manatee-shaped ceramics one can find in coastal gift shops, we’ve proven to be an unbelievably cruel neighbor.
Still, manatees have persisted. They are more durable than their adorably bulbous bodies suggest. And despite our worst efforts, humans have only driven one species of manatee to extinction: the Steller’s sea cow, a humongous 30-foot-long creature that proved too slow and delicious for Russian sailors in the 1700s, who hunted them out of existence in less than 30 years. In 2017, manatees were even taken off the endangered species list and reclassified as threatened.
And then came the winter of 2020. That’s when manatees started dying in alarmingly high, record-breaking numbers. The “Unusual Mortality Event” (UME)—as it was officially termed—was concentrated in central Florida’s Indian River Lagoon, an estuary that takes up 40% of Florida’s east coast, flows through seven counties and is a critical habitat for more than 4,400 species of plants and animals, including a significant portion of Florida’s manatee population. Thousands of them gather there during the winter, huddling around the warm waters of coastal power plants in their annual pilgrimage to avoid potentially deadly cold water.
It was in that region that scientists first started to notice the deeply troubling trend: manatees were starving to death. Their emaciated corpses showed the signs of death clearly.
It was an environmental crisis somehow both shocking and entirely predictable.
“We kind of expected we were going to see this outcome with the loss of seagrasses,” says Duane De Freese, Ph.D., the executive director of the Indian River Lagoon Council, a program established under the Federal Clean Water Act that focuses on restoring and protecting the IRL. “I think some of us were surprised that it took so long to see malnutrition and starvation.”
“Teetering on the Edge”
De Freese has been the IRL Council’s executive director since 2015, although he has worked in various conservation efforts for the estuary since the ’90s. In his career, he has watched “incremental stressors” snowball. Pollution and loss of water quality led to algal blooms, which killed the seagrass, which created—among a growing list of ecological crises—the current manatee famine.
“We’re not going to replant our way out of this one,” he says. “People have asked me often, especially recently, how do we save manatees? And it’s not by saving seagrasses. To save manatees, you have to save seagrass, but to save seagrasses, you have to have the water quality.”
But regaining that quality is not an easy task. De Freese believes the Indian River Lagoon has undergone what is called a “regime shift.” It’s a scientific term used to describe an abrupt change in an ecosystem that can happen when too many stressors (leaky septic tanks, algal blooms, climate change) are piled onto the environmental scales. “You go from a place that you are kind of used to seeing to a place that you’re not used to seeing,” he says. “And now it seems we’re living in that new place.”
There are no easy solutions from here on out. Even though water quality in the IRL has shown signs of improvement lately, which De Freese cautiously credits to ongoing efforts, the recovery process will be a long one. And its success will only be achieved, De Freese says, through “a nutrient diet that is aggressive and consistent” with a “level of investment that really pushes transformational change in water quality.”

This could take decades, not a year or two. And—even though Florida’s other subpopulations of manatees aren’t experiencing mortality rates on par with the IRL— there’s nothing about this crisis that suggests it’ll stay that exclusive to the region.
“We’re certainly teetering on the edge,” says Rachel Silverstein, Ph.D., executive director of Miami Waterkeeper, an organization that does advocacy work similar to the IRL Council, except in Miami-Dade and Broward counties.
Silverstein has held her role since 2014 and, prior to that, received a Ph.D. from the University of Miami’s Rosenstiel School for Marine and Atmospheric Science. Over the last decade, she’s watched seagrass levels shrink in South Florida—by as much as 80 to 90 percent in some areas.
“I don’t know that we’re yet at the point where manatees in our region are starving,” she says, “but we’re certainly headed in that direction if we don’t do something quickly.”
De Freese is more than fine with the rest of the state viewing his estuary as a canary in the coal mine. “There’s no question that right now the Indian River Lagoon is an example of how things can go very wrong if you’re not paying attention to water quality all the time,” he says.
Lots of Lettuce, Fewer Answers
The Florida Fish and Wildlife Conservation Commission and the U.S. Fish and Wildlife Service Joint Unified Command expert panel held their final weekly update of the winter season at 10am on April 7. The panel popcorned around from Zoom to Zoom, discussing statistics and giving an overview of that winter’s response efforts. They talked about the unprecedented supplemental feeding trial, during which 202,155 pounds of lettuce were tossed to potentially starving manatees in Brevard County over roughly three months. They discussed findings from hundreds of recent manatee necropsies in the area, the overwhelming majority of which point to “chronic malnutrition and starvation” as a cause of death. They said they were “reviewing our response efforts” in preparation for next year. And they sounded, frankly, exhausted.
“I think we all anticipate the need for a similar level of response next winter,” said Andy Garrett, the FWC’s Manatee Rescue coordinator.
The panel was hesitant to give any sort of sweeping proclamations on what worked and what didn’t. The words “reviewing our response efforts” were used multiple times. If the press was looking for declarative answers to big questions, nobody offered them. We don’t know where we go from here, because we’ve simply never been in this situation before.
“One of the questions to me is: How [is] the manatees’ behavior going to change?” asks Michael Runge, Ph.D., a research ecologist with the United States Geological Survey. Runge, among other things, has been creating population models for Florida manatees since 2000. He forecasts population trends using various data a bit too complicated to explain here.
The question Runge poses is a big one. It’s also sort of impossible to predict since we can’t exactly ask the manatees when they come up for air.

“The understanding is that manatees have a fairly high fidelity to their winter sites,” Runge says. Ideally, manatees loyal to the IRL would disperse to the south and north, finding more hospitable habitats. If that happens, Runge says we could see the mortality rates begin to decline (as long as those other regions don’t suffer the same habitat destruction as the IRL, of course).
“The other possibility is there could be something so attractive about Indian River Lagoon or Brevard County—that whole area—that it keeps drawing in the Atlantic coast manatees, in which case you could see that population continue to decline.”
It begs the question whether or not the feeding trial could potentially encourage manatees to return to a habitat that’s no longer suitable for their survival. Ron Mezich, the FWC’s Imperiled Species Management section leader, says that question, among many others, is one they’ll be assessing this summer. The FWC will take a hard look at potential effects of the trial, although Mezich says they do not see initial signs that the feeding had a harmful influence on manatee behavior.
“Long term, we’re thinking that manatees are still doing what they should be doing,” Mezich says. “As soon as we discontinued they were off, back to foraging in the wild and moving to other places.”
Regardless, it’s hard to see an immediate future where Brevard County does not go through a similar ordeal. The FWC would not commit to relaunching the supplemental feeding when manatees return to the IRL next winter, although they certainly didn’t rule it out either. Just because a manatee survived this past winter doesn’t mean they’ll make it through another challenging year. There’s a harmful domino effect to a vulnerable manatee population and a severely damaged habitat like the IRL.
“Manatees are migratory,” explains Tim Gowan, a research scientist at the FWC. “They make long distance movements.”
Gowan says that even manatees in Broward could very well use the IRL as a sort of rest stop during their migration patterns. “So if they lose food in those areas, it’s going to affect those manatees that ultimately might be seen in other parts of the state. And we did see that, particularly last winter. We had high mortality and a high number of rescues farther south in Broward and Miami-Dade. And it was likely because those manatees also still rely on the IRL system.”
Dr. Martine de Wit, a veterinarian who necropsies manatees for the FWC, also touched on the domino effect during the FWC press conference.
“We are seeing a continuum of disease in these animals,” she said. “So animals that survived last year are building those effects of not getting the appropriate nutrition, and because of that we’re seeing some animals looking worse than last winter.”
In 2022, the FWC verified 457 manatee carcasses from December 1 through March 31. The number was lower than those four months the previous year, although de Wit said that might be due to a milder winter in 2022 or a number of other distribution factors.
Still, in Brevard County—what de Wit called “the central hot zone for these issues with manatees not finding good forage”—the number of carcasses was 316. That’s 19 more dead manatees than last winter.
Manatee in the Coal Mine
The reason the FWC started doing these weekly press conferences in the first place was because the public demand for information was intense.
“Manatees have really changed the volume of media attention,” De Freese says. “And not just locally. It’s international.”
Few other animals in Florida can grab headlines like the manatee. And over the last year, this story has been written up in the New York Times, The Guardian, just about every local publication in Florida, and dozens and dozens more news clips that fill pages and pages of Google search results.
People want answers. They want to know how we got here and what happens now. And while we have a pretty good answer with respect to the former question, it’s difficult to provide a satisfying response for the latter. Still, the desire for such answers is fair. These questions feel big, because they are.
To understand the current state of Florida’s climate—to see it nakedly, in all its unpredictable instability—is a feeling akin to hearing footsteps behind you. It’s falling asleep on the beach and waking up with the waves at your shins. It’s Jimmy Buffett’s “Margaritaville” in the key of D minor.
This moment could be the start of many moments, the first in a man-made blitz of slow-moving ecological disasters we helped create and then tried to ignore. Sure, this year, the confluence of pollution, habitat destruction, overfishing, burst sewer pipes, irresponsible boaters, waterfront construction, fertilizer runoff, climate change and nosediving water quality has manatees in its crosshairs. But what’s next?
“You have to think,” Rachel Silverstein says, “if we’re losing animals like manatees, what else are we losing that is less visible?”
It’s impossible to know what happens next, but that doesn’t mean the concern isn’t valid. Because what happens next—and what we do about it—that’ll say a lot. It’ll say a lot about what Floridians can do to get ourselves out of this mess. And it could also say a lot about the opposite too: what’s already out of our hands. The damage done.
“I think people are very interested in the fact that the state is feeding lettuce to manatees because we don’t have enough seagrass,” Silverstein says. “But I think we really have to stop and think just how dire the situation is that we are having to even think about that.”