Where Do Manatees Go in Winter? Florida Springs and Warm Water

Why do manatees need warm water?

For such big animals, manatees are surprisingly sensitive to cold. The West Indian manatee has a very low metabolic rate, so its body produces little heat, and despite its rounded shape it has only a thin layer of insulating fat compared with whales or seals. Sirenians evolved in the tropics, and Florida is the northernmost place where any of them live today.

When the water cools below about 20 °C (68 °F) for days at a time, manatees can develop cold stress syndrome. They stop feeding properly, lose weight, develop skin sores and infections, and may die. Young manatees, with their smaller bodies, are the most at risk. In a long cold spell in early 2010, about 280 Florida manatees died from the cold.

The Antillean manatee, the other subspecies, lives in the warmer waters of the Caribbean, Central America and South America, where the sea stays warm all year, so it does not need special winter refuges.

When do manatees move to warm water?

As the water cools in late fall, usually from November, Florida manatees start heading to their winter sites. The biggest gatherings happen in December, January and February, especially on cold mornings after a winter front has passed. On mild afternoons, many leave the warm water to feed in nearby rivers and bays, then return when it gets cold again.

By March or April, as coastal waters warm up, the crowds break up and the manatees disperse. Manatees are creatures of habit. Calves spend one to two years with their mothers and learn where the warm-water sites are, and adults return to the same refuges winter after winter.

Natural springs

Florida has more than 1,000 known springs, and the larger ones pour out groundwater at about 22 °C (72 °F) all year round. In winter, that water feels warm compared with the surrounding rivers, and the spring runs become crowded with manatees.

• Blue Spring State Park, near Orange City on the St. Johns River, is one of the most famous refuges. Only a small group wintered there in the 1970s, but numbers have since grown to hundreds, and in January 2024 park staff counted a record 932 animals in a single day.
• Kings Bay and Crystal River, on the Gulf coast north of Tampa, are fed by dozens of springs and host one of the largest winter gatherings in Florida. The Crystal River National Wildlife Refuge was created there in 1983 to protect the manatees, and Three Sisters Springs has a boardwalk for viewing.
• Homosassa Springs, a little farther south, has a state park with an underwater observatory, and wild manatees use the river outside it in winter.
• Manatee Springs, on the Suwannee River, is named for the animals that winter there.

Springs face their own problems. Pumping of groundwater for farms and towns has reduced the flow of some springs, nutrient pollution clouds the water, and dams and other structures block manatees from some springs they once used.

Power plants and other warm-water sites

Power plants that cool their machinery with seawater or river water release that water several degrees warmer than the surrounding sea. Since the mid-20th century, Florida manatees have learned to gather in these outflows, and a large share of the population now spends the winter at industrial sites. Well-known examples include Tampa Electric’s Big Bend Power Station at Apollo Beach, where a free viewing center overlooks the discharge canal, the Florida Power & Light plant at Riviera Beach with its Manatee Lagoon education center, and Manatee Park in Fort Myers, next to a power plant outflow on the Orange River.

This dependence worries scientists. Older plants are being replaced or modernized, and some may stop releasing warm water altogether. If that happens suddenly, many manatees could lose the winter refuge they have relied on for generations. Wildlife agencies and power companies are working on long-term plans, including restoring natural springs, so that manatees can shift back to natural warm-water sites over time.

Some manatees also use “passive” refuges: deep, dredged canals, harbors and basins that cool more slowly than shallow bays. In some of these, a layer of warm, salty water stays trapped near the bottom under cooler fresh water, giving manatees a pocket of warmth during cold snaps.

Where do manatees go in summer?

When the water warms, Florida manatees spread out across their summer range. Many stay in Florida’s bays, rivers and lagoons, but some swim north along the Atlantic coast to Georgia, the Carolinas and Virginia, or west along the Gulf coast to Alabama, Louisiana and Texas.

A few travel much farther. In 1995 a manatee nicknamed Chessie, fitted with a satellite tag, swam from Florida past New York City to Rhode Island and then returned south before winter. Others have been spotted as far north as Cape Cod, Massachusetts. Manatees that linger too far north as the water cools in the fall sometimes have to be rescued and moved back to Florida.

How to watch manatees in winter

The best time to see manatees is a cold morning between December and February. Boardwalks at Blue Spring and Three Sisters Springs, the observatory at Homosassa Springs and the viewing platforms at Apollo Beach, Riviera Beach and Fort Myers let you see them without disturbing them.

Manatees are protected by federal and Florida law, and winter is when they are most vulnerable. Follow these rules:

• Look, but do not touch, chase, surround or ride a manatee.
• Never feed manatees or give them fresh water from a hose, which teaches them to approach people and boats.
• Never come between a mother and her calf.
• Stay out of posted manatee sanctuaries and obey slow-speed and no-wake signs.
• Report injured, cold-stressed, orphaned or dead manatees in Florida to the Florida Fish and Wildlife Conservation Commission’s Wildlife Alert Hotline at 888-404-3922.

Cold weather affects other Florida animals too: green iguanas can become so chilled that they lose their grip, as explained in Why do iguanas fall from trees? To learn how winter refuges fit into the manatee’s wider conservation story, see Are manatees endangered?