The Florida manatee, a subspecies of the West Indian manatee, occurs only in the southeastern United States. It occupies the northern limit of the species’ range, which extends south along the eastern coast of the Americas to Brazil. Manatees are slow-moving aquatic herbivores that feed in freshwater systems and the ocean. They rarely venture into near-shore ocean waters except to travel between adjacent rivers or estuaries. Prolonged exposure to water temperatures below 18°C (65°F) can be lethal to manatees. Therefore, during winter, Florida manatees are largely confined to the lower two-thirds of the Florida Peninsula. There they aggregate around warm-water springs and thermal outfalls from power plants, or remain in the Everglades at the southern tip of the state. As water temperatures rise in spring and summer, manatees disperse widely throughout the state, although individual animals rarely move from one coast to the other. A few east coast animals range northward into coastal Georgia and the Carolinas, and west coast manatees occasionally travel westward to Louisiana. Movements beyond those limits are unusual.
Although historical information on manatees in Florida is sparse, scientists believe that their abundance was greatly reduced by commercial and subsistence hunting in the 1800s. In 1893, Florida prohibited the killing of manatees, thus making them one of the first wildlife species in the United States to receive protection. Since passage of the Endangered Species Act in 1973, West Indian manatees, including the Florida manatee, have been listed as endangered.