Florida Manatees are dying in record numbers and it's a man-made disaster

Jim Waymer
Florida Today

A sun-bleached skull, scattered ribs and the decaying husks of dozens of manatees sully the smooth tan sand on a handful of mangrove islands north of Manatee Cove Park in Brevard County.

The emaciated remains, reported by waterfront residents or spotted by boaters, have been collected and dumped on the sandy outcroppings by state wildlife officers, turning these idyllic tropical settings into sea cow mass graveyards. 

The smell of death owns the air. Vultures own the sky above as they circle what is quickly becoming an environmental catastrophe.

The manatees are dying by the hundreds

Up and down the Sunshine State, manatees, the gentle giants of the inland waterways, are dying en masse. They are, in fact, starving to death. The mangrove coves and canals that once were havens for the creatures are increasingly empty of them. Decades of conservation success have given way to jumbles of bones and rotting carcasses all around Florida.

"I think it will be the highest (number of manatee deaths) we've ever documented," said Martine de Wit, who runs the Florida Fish and Wildlife Conservation Commission's marine mammal pathology lab in St. Petersburg. 

What is going on? Who or what is responsible for this?

We humans, the residents of and visitors to Florida, own the reasons all this is happening, biologists say. Evidence from the massive die off suggests this is a completely man-made famine. The sewage, detritus and fertilizers we have been dumping into our coastal waters for decades have created blooms of bad plant life while choking to death the seagrass on which the manatees and other marine life depend.

At the same time, our power plants lure manatees to winter farther north than they otherwise would be, increasing their risk of starving before seagrass grows back in the spring.

The damage we have wrought appears to be finally taking its toll. And we, those responsible for the mess, can only watch, helpless as the food web collapses around a fellow mammal.

Money for manatees:Will $8 million more save the manatees this year? The state is hoping

Sad statistics:Brevard leading state in manatee deaths so far this year

Once upon a time, biologists were sure it was mostly speeding boats and their propellers that threatened to wipe out manatees. It was a problem we could fix, and indeed speed limits, manatee crossing signs and fines made a positive impact, biologists say. Manatee numbers rebounded.

This problem — the loss of habitat and food — is not so easily or quickly remedied. 

"Very, very sad," Jacquie Scoggin, of Orlando, said from her paddleboard on an otherwise beautiful recent April day in a paddling paradise that these days looks somewhat lost. She came for the serenity and wildlife but found death and sadness instead.

'Ground zero' is central Florida

While manatees throughout Florida are being impacted by famine, Brevard County hosts the largest population in the state and has become "ground zero" for the tragedy.

Already 696 manatees have died in 2021, triple the average number of deaths for this time of year. That's more than one in 10 of the known manatees counted by biologists. The most deaths by far — 292 or 42% — were in Brevard County and the waters of the Indian River Lagoon.

The lagoon right now looks clear enough for seagrass to grow, but these waters ran out of ecological luck long ago. Decades of runoff from septic tanks and fertilized front lawns, as well as sewage leaks, eventually changed the balance of life in the closed system of the lagoon in such a way that the grasses and microorganisms that supported them died out and didn't come back. 

Manatees are starving. To death. They have nothing to eat.

The bottom — like increasingly more places statewide — is grassless, leaving a desert where once a garden for manatees thrived. And not just for manatees: As the seagrass that anchors the food web of Florida's coastal waters disappears, it impacts the lives of sea turtles, shrimp, fish and crabs too.

The massive dying has not been terrible for all creatures. It's been good for vultures and marine scavengers. Horseshoe crabs now reign supreme in the waters south of NASA's Kennedy Space Center.

But the negative fallout is huge and can be measured in dollars as well as lost animal life. Tens of billions in yearly tourism revenue is at stake. Lush seagrass spawns a lucrative saltwater fishing industry and ecological tourism, including those who come from near and far to see manatees and catch glimpses of mothers and calves grazing or leisurely moving through the waterways.

The fallout of famine

Before the COVID-19 pandemic changed our lives last year, dead manatees would end up with Martine de Wit at the marine mammal pathology lab in St. Petersburg. There the veterinary pathologist would dissect and test to figure out why the creatures were dying. But this year, the vast majority, two thirds, of the dead never made it to de Wit.

COVID-19 rules at FWC's St. Pete lab preclude too many examiners in the lab at once. So FWC biologists examined sea cow carcasses in the field when they could get to them, which wasn't all the time. As of April 23, state wildlife officials hadn't examined 463 (66%) of this year's 696 dead manatees.

The known causes of death this year include 25 from cold stress, 97 from natural causes and 55 that died within a year of birth.

But de Wit and most biologists studying the problem see one harsh and inescapable fact underlying the sad phenomenon: the loss of many tens of thousands of acres of seagrass across the state.

Food source death:Pollution and extreme weather killed vast acres of seagrass along Florida's coastal waters

In the Indian River Lagoon alone, two phytoplankton blooms devastated seagrass in 2011, followed by two years of brown algae blooms, ultimately killing 47,000 acres of seagrass, or about 60% overall in the estuary. Not much has grown back since.

As seagrass withers statewide, manatees have little to eat, leaving them vulnerable to disease, to cold and to starvation. An adult manatee eats 100 to 200 pounds of seagrass per day to survive.

"Of all the events I've gone through myself, this one makes me wonder what are the long-term health effects on manatees with prolonged starvation," de Wit said. "I'm not as optimistic as I was before."

Ironically, the manatees dramatic comeback after boating rules changed may have made things worse in the face of the looming environmental disaster.

As the state's manatee counts doubled over the past two decades, boating advocates like Bob Atkins, of Merritt Island, warned wildlife officials that seagrass growth wasn't keeping pace and manatees faced imminent famine. Boaters for years shouldered too much of the blame for the manatee's plight, Atkins and fellow boating advocates argued.

"This situation is tragic but not a surprise. In fact, we’ve predicted it,"  Atkins, president of the boating advocacy group Citizens for Florida's Waterways, said.

This year's FWC stats show boaters being responsible for just 4.8% of the manatee death toll. They typically cause 20 to 25% of the deaths on any given year. Boats have killed 34 manatees in 2021, just one less death than the state's five-year average. 

Boaters point to power plants, too.

Boating advocates have argued for decades that Florida puts too much emphasis on regulating boat speeds and not enough on protecting seagrass habitats.

Manatees migrate to natural warm water refuges like freshwater springs but also to artificial ones, such as the warm-water discharge zones at power plants. That puts them in areas with scant seagrass during colder months. Before power plants, manatees seldom migrated farther north than Sebastian Inlet on the east coast and Charlotte Harbor on the west coast, fossil records show.

But in Brevard County, hundreds of manatees huddle flipper-to-flipper each winter at Florida Power & Light's plant in Port St. John, keeping them farther north than they'd otherwise be.

"We've been warning the agencies for years that either we eliminate the artificial warm-water outflows (at power plants) and risk some manatees not returning to natural migration and at risk of cold stress mortality, or do nothing and keep stressing the system until the loss of seagrass threatens the life of the IRL (Indian River Lagoon) itself and everything dies including many more manatees," Atkins said.

Someone has made a totem out of a manatee skull and some horseshoe crab shells near Triangle Island in the Indian River Lagoon in Merritt Island.

Manatees die when water temperature dips below 68 degrees Fahrenheit for too long.

A special state and federal task force looked at the issue of warm water discharges at 10 power plants luring manatees too far north in the winter but little concrete action has come thus far from the initial draft plan they put out in 2004.

In October, the task force issued another action plan that includes restoring flow to springs and developing other warm-water habitats not dependent on industry, gradually decreasing manatee dependence and use of power-plant discharges. That way sea cows will have time to adapt to new warm-water networks. 

But the proposals are too late to stop what's happening now. This year's mass starvation is something all levels of government, science and advocacy failed to prevent, despite many millions of dollars spent. But is it something that could have been prevented? And can it be reversed in the future?

Manatee bones scattered along the shore of the Indian River. Wildlife officials have dragged more than 30 dead manatees to an area just north of Manatee Cove in the Indian River. The manatees have a low body weight and officials believe they have died from a lack of sea grass.

The death toll was so bad that last month, the National Oceanic and Atmospheric Administration declared Florida's manatee die-off an "unusual mortality event," potentially freeing up federal money to look deeper into the matter.

More manatees live, die here

Florida's Space Coast is best known for rockets and sea cows.

Typically, a third of Florida's estimated 6,000 or more manatees reside here, within the 156-mile-long Indian River Lagoon. The most recent statewide sea-cow count, in early 2019, spotted 5,733 manatees.

In the 1970s, biologists believed only a few hundred manatees remained in the wild. So the federal government listed them as an "endangered" species in 1973.

The protection paid off. And manatees had been doing better in the years leading up to March 2017, when the federal government reclassified them from "endangered" to the less serious status of "threatened." The same year, Florida biologists had counted a record 6,620 manatees from land and air.  

The nonprofit Save the Manatee Club battled the reclassification, warning it was too soon to ease boating and other protections.

Most of this year's death toll happened near Kennedy Space Center, but de Wit says the cause is far from rocket science. They're simply starving in a barren, grassless underwater wasteland that resulted from pollutants. 

"We've never seen tissue atrophy like this before," de Wit said of the manatees she sees in her lab.

De Wit pushes back on the boaters' theory that the manatee population explosion is to blame for eating themselves out of habitat and home. To her, it's much more likely too many people living too close to manatees killed all that grass.

She points to the lush seagrass in the Indian River Lagoon 10 years ago. "That seagrass didn't disappear because there were too many manatees," de Wit said.

Disaster decades in the making

Seagrass and sea cows led a balanced coexistence in the Indian River Lagoon but in 2011 algae blooms began to ramp up yearly, blocking light, choking out oxygen and eventually killing off more than half the waterway's seagrass.

"We are witnessing the impacts of a destabilized Indian River Lagoon food web," said Duane DeFreese, executive director of the Indian River Lagoon National Estuary Program. "There are no quick fixes to this problem. If food resources decline, animal population size will adjust to carrying capacity."

Manatees at first adapted to the seagrass loss, shifting their meals to whatever drift algae was left. But that changed the mix of bacteria in their guts, resulting in a bizarre sort of "toxic shock" that caused an acute, fatal cardiovascular syndrome. The manatees drowned as a result, and in 2013, 244 manatees died in Brevard in a record year in which 830 manatee died statewide.

Manatee bones scattered along the shore of the Indian River. Wildlife officials have dragged more than 30 dead manatees to an area just north of Manatee Cove in the Indian River. The manatees have a low body weight and officials believe they have died from a lack of sea grass.

Most biologists predict this year's death toll will far surpass that record.

DeFreese is optimistic the situation can be reversed — and manatees can be saved — if municipalities and residents can manage to improve water quality in the long term. For that to happen, local governments need to get more aggressive in keeping sewage and runoff from Florida's coastal waters, he said.

But for Pat Rose, the executive director of Save the Manatee Club, that's not the first order of business.

"First priority must continue to be given to the rescue and rehabilitation of sick or injured manatees," said Rose.

Rose long has criticized Florida for lack of action on preventing winter manatee deaths near power plants and for removing federal protection from the animals.

"I fear that the FWS is preoccupied with rashly removing the manatee from the endangered species list altogether rather than ensuring that imperiled manatees are truly and fully recovered," Rose said.

Florida Fish and Wildlife Conservation Commission
Manatees huddle in the winter at the warm water discharge of Florida Power and Light's power plant in Port St. John. Observers fly over power plants and other warm-water discharge areas to count manatees every winter. Recent counts put the manatee population at more than 6,000.

Long road to recovery

During a recent kayaking trip on the lagoon, there were no live manatees visible along the vast shallows south of the space center. There was only the dead. The carcasses look alien. Shriveled hulks of parched-brown skin and bones resemble sticks wrapped tightly in plastic garbage bags. 

Donna Kirk, of Winter Park, had no idea just how bad it was until she explored these islands by paddle board with friends.

"I had heard they were starving but I didn't know it was to this degree," Kirk said, standing beside a manatee skull propped up on a stump in this islands shallows. Someone made a makeshift, pagan-like shrine with the manatee skull.

Their remains should be left alone. Anyone caught taking manatee bones could face a 2nd degree misdemeanor for possessing parts of a federally protected species. Penalties can be severe.

Manatee bones scattered along the shore of the Indian River. Wildlife officials have dragged more than 30 dead manatees to an area just north of Manatee Cove in the Indian River. The manatees have a low body weight and officials believe they have died from a lack of sea grass.

And despite the ongoing famine, biologists warn against feeding manatees. Doing so keeps them lingering in grassless areas, when they could otherwise be expending their scant energy to find greener underwater pastures.

Green shoots of hope reign eternal for both seagrass and sea cow, among those who study and love them most. 

But de Wit said their road to recovery will be long.

"When you go through prolonged starvation, it is sometimes impossible to turn the body around, even when you start eating again," she said. 

The hope is that nature will find a way.

Jim Waymer is environment reporter at FLORIDA TODAY.

Contact Waymer at 321-242-3663                                         

or jwaymer@floridatoday.com.

Twitter: @JWayEnviro

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Florida's withering seagrass

It's unknown how many seagrass acres exist or once existed statewide but is thought to be much less than it was in the 1950s in some estuaries. Reports by Florida Fish and Wildlife Conservation Commission in 2016 and 2018 documented: 

  • Statewide: An estimated 2.5 million acres. Since 2012, storm runoff fed algae blooms that harmed seagrass beds in the Panhandle, the Big Bend, southwest Florida, a. nd along the east coast from Biscayne Bay to the northern Indian River Lagoon.
  • Florida’s east coast: Seagrasses expanded to 58,300 acres since 2013, but these increases followed huge losses in 2010, as the result of widespread algae blooms, especially in the northern Indian River Lagoon. 
  • Northern Indian River Lagoon: Poor conditions from 2009 to early 2017 led to the loss of 39,634 acres of seagrass or 56% of the acreage mapped in 2009.
  • Southern Indian River Lagoon: In 2017, seagrasses covered 7,606 acres of the bottom, 2,688 acres (26%) less than the 10,294 acres mapped using imagery acquired in 2015.
  • South Florida: Estimated 1.6 million acres. Grass remained stable until the summer of 2015 when as many as 10,000 acres died in western Florida Bay, due to hot, very salty conditions.
  • Big Bend and Springs Coast region: Estimated 618,000 acres. Big Bend lost seagrasses due to a prolonged period of poor water clarity from 2012 through 2014; Springs Coast grasses are generally stable.
  • Western Panhandle: Estimated 40,500 acres. Some estuaries have increased acreage while in others declined.
  • Florida's west coast: In recent years, seagrass increased from Pinellas County – Tampa Bay to the Charlotte Harbor – and is estimated to be 143,000 acres. 

Source: Florida Fish and Wildlife Conservation Commission

Florida Manatee Warm-Water Habitat Action Plan

A state and federal task force has met for years to find a way to wean manatees off warm water discharges from power plants that lure manatees too far north in the winter but not much has come of the endeavor. The task force released plans in 2004 and again in October. Their ideas include developing other warm-water habitats not dependent on industry and gradually decreasing manatee dependence and use of power plant discharges. That way sea cows will have time to adapt to new warm-water networks.

Power plants will phase out warm water discharges in the next 30 years, the task force notes, as they implement newer technologies. That leaves it to the state to "train" manatees with "site fidelity" to those power plants.

Source: Florida Fish and Wildlife Conservation Commission