Why Florida Manatees Are Addicted to Power Plants

Florida’s enormous gray manatees often swim lazily, their barnacle-covered bodies, close to the surface of the protected channel next to Apollo Beach on the Gulf Coast.

There, the water warms up to the perfect temperature for manatees, which cannot survive below 20°C.

The manatees’ natural habitat is the hot springs found throughout Florida. There, the mammals spend up to eight hours a day grazing among the seagrasses.

But these Apollo Beach manatees don’t feed in these artesian marine springs at the bottom of the ocean, protected by limestone and surrounded by trees covered in old man’s beard. In fact, what exists there is a large coal-fired electricity-producing plant that hovers over the animals. The plant pumps hot water – a byproduct of that industry.

These manatees have become dependent on coal and gas power plants. Their historic place of growth – the natural springs along the Atlantic coastline – has been destroyed by human development, explains conservationist Elizabeth Fleming, a manatee expert with the nonprofit Defenders of Wildlife.

Now this situation is reaching a critical point. As the United States moves to renewable energy, these plants will shut down and the artificial hot water source for manatees will disappear.

“It’s one of the most incredible mysteries of the relationship between humans and wildlife that I’ve ever observed in my life,” says Fleming. “We completely redesigned their entire habitat.”

Manatees have been heading to these plants for years, including the Cape Canaveral plant in the Indian River Lagoon. But energy companies will likely phase out these hot water discharges over the next 30 years as Florida moves toward achieving zero emissions by 2050.

“We destroyed all of its sources on the Atlantic coast,” explains Fleming. “We need to figure out how to get these manatees to go other places.”

In 1997, a power plant frequented by manatees was modified to meet water quality standards. In doing so, it eliminated the hot water discharge, which is produced by using cold water to cool steam and produce electricity.

Accustomed to using warm water to survive the winter months, the manatees did not leave the region and died of hypothermia.

Although power plants provide manatees with the warm water they need, this does not mean there is seagrass there, as they cannot survive in polluted waters.

Between 2011 and 2019, 19,000 hectares of seagrass in the Indian River Lagoon (representing 58% of the total) died due to pollution and nutrient depletion.

Other estimates from the environmental group Save the Manatee, which tracks manatee populations and advocates for stricter protections, put seagrass loss at nearly 90 percent.

The manatees that used to go to the Indian River Lagoon to get artificial hot water did not leave the place – and died of starvation. In 2021 and 2022, 1,900 manatees died.

“This is unprecedented,” says Save the Manatees founder Pat Rose.

“It took a tragedy for people to understand what was happening to the manatees.”

There were so many dead animals that scientists at the Florida Wildlife Commission simply stopped performing necropsies, which are normally done whenever a manatee dies.

The manatee population was in crisis, which led scientists to come up with a desperate plan: If there was no seagrass to eat, they would feed the animals romaine lettuce.

About 272,155 kg of lettuce were offered to the manatee population on the east coast of Florida, mainly around Cape Canaveral, for two years. The program was called Let Them Eat Lettuce (“Let Them Eat Lettuce”) and was supervised by Rose.

The initiative was a success. The manatees have recovered enough that the program can be suspended during the winter of 2023.

But loss of habitat and seagrass isn’t the only threat facing Florida’s manatees — 96 percent of them have some type of scar on their bodies from collisions with boats.

“Virtually all living manatees have come within 5-10 cm of losing their lives,” explains Rose. “The main cause of their injuries and deaths is still collisions with boats.”

Florida’s manatees share the waterways with hundreds of thousands of boats. They suffer severe trauma and cuts caused by the propellers. And collisions account for almost 25% of deaths.

Still, motorized boats remain permitted in many of the natural springs that Florida’s manatees seek for survival.

“The sanctuaries we have for them are simply too small,” Rose continues.

He helped write the Florida Manatee Sanctuary Act of 1978. Under the law, it is illegal for “any person, at any time, intentionally or negligently, to disturb, harass, abuse, or annoy any manatee.”

The law also defined protection zones. It prohibits ships from entering certain areas or establishes speed limits in others.

Despite these protections, at least 104 manatees were killed by human activity in 2023.

“We are far from protecting all the areas we need,” says Rose. “We’ve already made a lot of progress, but we need to try even harder.”

Progress is slow but steady, says Pat Rose.

In 2023, new questions were introduced into the boating safety course, which is required of every person who operates a boat in Florida.

Questions included how to protect manatees to prevent them from being harmed by vessels.

Measures were also taken to recover natural sources. The Florida Fish and Wildlife Conservation Commission (FWC) restored the springs at Warm Mineral Springs late last year, which had been damaged by severe flooding.

From winter through spring, the region is off-limits to allow manatees access to their warm-water refuge undisturbed. But the FWC has not yet published manatee numbers from last winter.

In 2019, Florida allocated more than US$50 million (about R$254 million) to programs dedicated to manatees. And, in 2023, the State recorded the lowest manatee mortality rate since 2017.

Another US$325 million (around R$1.65 billion) was invested in restoring Florida’s hot water sources.

Blue Spring State Park has been investing to restore springs since 1970. In January 2024, the park welcomed a record number of 932 manatees. At the start of restoration work, park administrators had only counted 14 animals.

Some natural springs in the state were dredged to expand access for manatees. But in some places, complete thermal shelters have been built by the U.S. Navy Corps of Engineers.

In 2015, a set of three six-meter-deep basins was built in a 4-hectare area south of Port of the Islands, in the Everglades. It provides the manatees with enough warm water to survive the winter.

The U.S. Fish and Wildlife Service reported that manatees have been using the artificial refuge.

A spokesperson for the FWC, which monitors the refuge, told the BBC that its latest count was 48 manatees. This number is a third lower than previous years, as temperatures outside the refuge are still warm enough for the animals. Basically, the warmer climate has given manatees options for places to spend the winter.

Other ideas still need to be tested, such as solar-powered heaters or installing a mobile heating system that manatees can follow.

In 2011, water heaters were turned on for the manatees, shortly after a power plant was shut down, to help them get through the winter.

In other parts of the state, scientists are experimenting with growing seagrass in large tanks and transplanting it into the Indian River Lagoon.

Florida Atlantic University in the United States is creating a seagrass nursery, which will create a source for transplanting and restoration. They are also researching the genetic diversity of seagrasses and how it would be possible to create strains with faster growth and greater environmental tolerance.

Still, the most optimistic of estimates predict that seagrass recovery could take 12 to 17 years.

Other actions focus on education, such as convincing people who maintain lawns on the shore not to apply fertilizer, to prevent pollution from reaching manatee habitats.

Moving the manatees will be a long and expensive process. The government itself recognizes that it took manatees 50 years to develop their dependence on power plants – and it may take the same period to wean them.

For Elizabeth Fleming, this “is a fascinating wildlife management situation. We have a moral obligation to ensure that these animals can live out their lives in safety.”

Working to save manatees will be beneficial to the entire aquatic ecosystem, according to Rose. After all, to protect manatees, the environment also needs to be protected, especially against development and pollution.

Rose remains optimistic despite the difficulty of weaning animals from power plants. The solution is to find areas where the water table is warming, without necessarily focusing on natural sources.

“We will need a combination of old and new technologies,” he explains. “And it’s not impossible, as we believe we can find a way out of this situation.”