On a cold winter morning in Florida, the water in the rivers turns chilly and gray, and something remarkable happens in the clear springs. Dozens, sometimes hundreds, of large gray shapes gather in the warm water, drifting slowly just beneath the surface. They are Florida manatees, the gentle giants of the Sunshine State, and they have come to the springs for the same reason people head indoors when the temperature drops: to stay warm and survive the winter.
Manatees are among the most beloved animals in America. They are slow, peaceful, and entirely harmless, spending their days grazing on underwater plants and floating through the shallow waters of Florida’s rivers, bays, and coastal lagoons. They have no natural predators as adults, no teeth for biting, and no interest in anything but food and warm water. Yet these gentle animals have had a hard century. Hunted in the past, struck by boats, and starved when their seagrass food disappeared, they fell to just a few hundred animals in Florida in the 1970s. Today, after decades of protection, they have made one of the great wildlife comebacks in American history, even as new threats keep their future uncertain.
What Is a Florida Manatee?
The Florida manatee is a subspecies of the West Indian manatee, with the scientific name Trichechus manatus latirostris. It is a sirenian, a member of the same order of fully aquatic, plant-eating mammals that includes the dugong and the extinct Steller’s sea cow. Sirenians are the only marine mammals that are entirely herbivorous, and manatees are often called sea cows for good reason: they graze, they move slowly, and they spend much of their lives in shallow water with their heads down in the vegetation.
Florida manatees live in the coastal and inland waters of the southeastern United States, and Florida is the heart of their range. In the warm months, they spread out along both coasts of the peninsula and sometimes wander far beyond it, with animals recorded as far west as Texas and as far north as Massachusetts in summer. But they are tropical animals living at the northern edge of where their kind can survive, and when winter comes, they must return to Florida’s warm water or die. That seasonal movement shapes everything about their lives.
Built for Slow Water
An adult Florida manatee is typically about nine to ten feet long and weighs around 1,000 pounds, with females tending to be slightly larger than males. The largest animals can grow to more than 13 feet long and weigh far more, and the largest Florida manatee on record weighed about 3,650 pounds. Newborn calves are about four to four and a half feet long and weigh roughly 60 to 70 pounds. Manatees are estimated to live 50 years or more in the wild, and one famous captive Florida manatee, Snooty, lived to the age of 69.
Every part of a manatee’s body is adapted to a slow life in shallow water. The broad, paddle-shaped tail powers a gentle, unhurried swim, while the two flippers at the front help the animal steer, hold food, and even embrace a calf. The body is covered in sparse, highly sensitive whiskers called vibrissae, which the manatee uses to feel its way through murky water and to guide plants into its mouth.
Their teeth are one of their strangest features. A manatee’s diet of gritty, sandy vegetation wears its teeth down constantly, so the animal grows new molars at the back of its jaw throughout its life. The old, worn teeth fall out at the front and are replaced by fresh ones moving forward, like a slow conveyor belt. It is a clever solution for an animal that spends up to eight hours a day chewing plants.
A Life Spent Grazing
Manatees are strict herbivores. They feed on more than 60 species of aquatic plants in Florida, with seagrasses making up the bulk of the diet in coastal waters. Turtle grass, manatee grass, and shoal grass dominate in salt water, while hydrilla, eelgrass, water hyacinth, and water lettuce fill the menu in rivers and springs.
An adult manatee can eat up to 10 percent of its body weight in plants each day, which works out to roughly 100 pounds of vegetation for a 1,000-pound animal. Grazing takes up a large part of the day, and manatees are most active in the morning and evening, resting during the heat of the day. Their metabolism is very low, which means they extract energy from their food slowly and need to eat a lot of it. By cropping seagrass beds regularly, manatees encourage new growth and help keep these underwater meadows healthy, which benefits the fish, crabs, and other animals that depend on the same habitat.
Manatees are mostly solitary or travel in small, loose groups. A mother and her calf form the closest bond in manatee life, and calves stay with their mothers for a year or two, learning where the warm-water refuges and feeding grounds are. That knowledge is passed down through generations, and it is one reason why protecting the springs matters so much: a young manatee learns its winter refuge from its mother, and if that refuge disappears, the animal may not know where else to go.
Why Winter Means the Springs
The single most important fact about a Florida manatee is that it cannot handle cold water. Manatees have a low metabolic rate and very little insulating body fat for their size, so they lose heat quickly in cool water. Prolonged exposure to water below about 68 degrees Fahrenheit, or 20 degrees Celsius, can cause a condition called cold stress syndrome, in which the immune system weakens, skin lesions appear, and the animal loses weight and eventually dies from infections that follow weeks after the cold exposure. A single cold snap in a Florida winter can kill many manatees.
That is why, from about November to March, Florida manatees gather at warm-water refuges. Florida’s natural springs are the most important of these. Spring water emerges from the aquifer at a steady temperature of about 72 degrees Fahrenheit all year round, providing a warm haven when the surrounding rivers drop into the 60s or lower. The great spring gathering places include Crystal River and the Three Sisters Springs on the Gulf Coast, Blue Spring State Park on the St. Johns River, Homosassa Springs, and Wakulla Springs. On the coldest days, hundreds of animals crowd into a single spring run, waiting out the cold until the surrounding water warms again.
Blue Spring has become the most famous of these refuges. In the early 1980s, only about 35 manatees were counted there. On January 21, 2024, a record 932 manatees were counted in the spring run on a single cold morning, a number that speaks to both the recovery of the population and the importance of the spring itself. Crystal River, meanwhile, is the only place in the United States where people may legally swim with wild manatees, under strict rules designed to protect the animals. Manatees also gather at the warm-water outflows of power plants along the Florida coast, which has created a new problem for conservationists: as old power plants are retired, the artificial warm-water refuges disappear with them, and the natural springs must carry more of the load.
The Comeback Story
Florida manatees were first protected under Florida state law in 1893, and they are now protected by the Florida Manatee Sanctuary Act as well as by the federal Marine Mammal Protection Act and the Endangered Species Act. They were listed as endangered in 1967, when only a few hundred animals remained in Florida. When systematic aerial surveys began in 1991, only 1,267 manatees were counted in the state.
What followed was one of the most successful recoveries in American wildlife conservation. Boat speed zones were established in manatee habitat, floodgates and locks were made safer, springs were protected, and rescue and rehabilitation programs saved injured animals and returned them to the wild. The public played a part too: the Save the Manatee Club, founded in 1981 by former Florida Governor Bob Graham and singer Jimmy Buffett, turned the manatee into a symbol of Florida conservation, and sales of manatee license plates have raised tens of millions of dollars for research and protection.
The recovery was strong enough that in May 2017 the U.S. Fish and Wildlife Service reclassified the West Indian manatee from endangered to threatened under the Endangered Species Act, a change that reflected population growth and habitat improvements while keeping full federal protections in place. The Florida Fish and Wildlife Conservation Commission reports that the Florida manatee population has grown to a minimum of 8,350 animals, and the Marine Mammal Commission cites a most recent statewide abundance estimate of 9,790 manatees from the 2021–22 survey period. The two figures reflect different ways of counting the same growing population, but both tell the same story: from a few hundred animals in the 1970s, Florida manatees have climbed back into the thousands.
The Starvation Crisis of 2020 to 2022
Just as the recovery seemed secure, disaster struck on Florida’s Atlantic coast. For more than a decade, excess nutrients flowing into the Indian River Lagoon had fueled algal blooms that smothered and killed the lagoon’s seagrass beds. The lagoon is vital manatee habitat in every season and sits at the center of manatee migration along the Atlantic coast, so when the seagrass disappeared, the manatees that depended on it began to starve.
Federal and state agencies declared an Unusual Mortality Event in March 2021. Between December 2020 and April 2022, 1,255 manatee deaths were recorded, and in the winter of 2021–22, wildlife officials took the extraordinary step of running a pilot supplemental feeding program, offering donated romaine lettuce to starving animals at a power plant site in the lagoon until warmer weather allowed them to disperse and find other food. The mortality event was officially closed on March 14, 2025, and there are signs that seagrass in the Indian River Lagoon is beginning to recover. But the crisis was a warning: a population that looks healthy on paper can collapse quickly when its food disappears, and the health of Florida’s water is the health of its manatees.
The Threats That Remain
Boat strikes remain the leading cause of human-related manatee deaths in Florida. Manatees are slow swimmers, they rest near the surface, and they cannot get out of the way of a fast boat. Most adult manatees in Florida carry propeller scars on their backs, and researchers can identify individual animals by the pattern of their scars. Boat speed zones, marked manatee protection areas, and public education have reduced deaths, but collisions still kill and injure animals every year.
The loss of seagrass is the second great threat, driven by polluted runoff, algal blooms, and coastal development. Red tide, the toxic algal bloom that periodically strikes Florida’s Gulf Coast, can also kill manatees, as can entanglement in crab trap lines and fishing gear. And the loss of warm-water habitat is a slow-moving problem: as power plants retire, the artificial refuges that generations of manatees have relied on will close, and the natural springs must be protected and restored to take their place. In January 2025, the U.S. Fish and Wildlife Service proposed listing the Florida and Antillean subspecies separately, keeping the Florida manatee as threatened while proposing to uplist the Antillean manatee to endangered, a sign of how differently the two populations are faring.
How to See Manatees Responsibly
Winter, from about November to March, is the easiest time in the world to see manatees, and Florida’s springs are the best places to do it. Blue Spring State Park closes its spring run to swimming during manatee season so visitors can watch from the boardwalk above, and Crystal River offers guided tours where swimmers can float quietly near the animals under strict rules. The Three Sisters Springs, Homosassa Springs, and the Manatee Viewing Center at Apollo Beach near Tampa are also popular winter viewing spots.
The rules for watching manatees are simple and worth following. Give the animals space, move slowly and quietly, and never chase, touch, or ride a manatee. A resting manatee is a manatee saving energy for the cold, and disturbing it can cost the animal the warmth it needs to survive the night. If you are in a boat, slow down in marked manatee zones and watch for the swirl of a surfacing animal. The best manatee encounter is a quiet one: an animal drifting past in clear spring water, unhurried, unbothered, and entirely at home.
Florida manatees have come back from the edge, but their story is not finished. They survived because people slowed their boats, protected their springs, and gave them room to recover. The same choices will decide whether the gentle giants of Florida’s springs keep drifting through the clear water for another hundred years.
Frequently Asked Questions
How many Florida manatees are there?
The Florida Fish and Wildlife Conservation Commission reports a minimum of 8,350 Florida manatees, and the Marine Mammal Commission cites a statewide abundance estimate of 9,790 from the 2021–22 survey period. Both figures reflect a dramatic recovery from the 1,267 animals counted when aerial surveys began in 1991.
Why do manatees gather in Florida’s springs in winter?
Manatees cannot tolerate cold water for long. Below about 68 degrees Fahrenheit, they develop cold stress syndrome, which can kill them. Florida’s springs hold a steady temperature of about 72 degrees all year, so manatees crowd into spring runs and power plant outflows from about November to March to stay warm.
What do manatees eat?
Manatees are herbivores that feed on more than 60 species of aquatic plants in Florida. Seagrasses such as turtle grass, manatee grass, and shoal grass dominate in coastal waters, while freshwater plants fill the menu in rivers and springs. An adult can eat up to 10 percent of its body weight in plants each day.
Are manatees still endangered?
No. The West Indian manatee was reclassified from endangered to threatened under the Endangered Species Act in 2017, reflecting population growth and habitat improvements. Florida manatees remain fully protected under the Endangered Species Act, the Marine Mammal Protection Act, and the Florida Manatee Sanctuary Act.
Where is the best place to see manatees in Florida?
Winter is the best season, and the great spring refuges are the best places: Blue Spring State Park, Crystal River and the Three Sisters Springs, and Homosassa Springs. Crystal River is the only place in the United States where people may legally swim with wild manatees, under strict rules. Always give the animals space and never chase or touch them.