Manatees are aquatic mammals that can live in saltwater and freshwater. Manatees live in slow-moving rivers, bays, estuaries and coastal marshes, preferring to stay in water that is about 7 feet deep. Manatees resemble a walrus in some ways but are relatives of the elephant. Manatees are an endangered species, with estimates having no more than 3,000 individuals left in the wild.
Manatees are herbivores, meaning they consume only vegetation. Their role in the ecosystem is as a plant eater, as they feast on over 60 species of water vegetation in the waters they live in. Manatee species are found in the southern coastal waters of the United States, especially the waters off of Florida. Other manatee species are found in limited parts of interior eastern Africa and in South America.
The occasional mollusk and other sea creatures may accidentally be consumed by the manatee as it feeds, but they do not actively pursue any fish or other marine or freshwater animals. Manatees can weigh more than a thousand pounds and have been commonly been known to eat as much as 15 percent of their own body weight in plants each day. Manatees are the watery equivalent of deer, spending many of their waking hours grazing.
Manatees have very few natural predators in their ecosystem. Sharks, alligators, crocodiles and killer whales are the only creatures large enough to handle a manatee, but attacks on them by these predators are rare. They are large enough to be left alone by just about every other animal they encounter except for man. They have been hunted to the edge of extinction for their meat and bones and are extremely vulnerable to being hit by boat propellers, which kill several each year.
Manatees may have an impact on the ecosystem when they repeatedly return to the same beds of sea grass and graze. Manatees most often feed on the edges of sea grass beds, and they remember where these food sources are when they move from spot to spot. Although there is no documented proof, the constant "mowing" of these sea grasses may do them harm in the long run.
Manatees are long-lived animals if they are allowed to be. One manatee in a Florida aquarium was born in the late 1940s and is over 60 years old. Manatees do not tolerate cold water or weather and confine themselves to warmer waters. One was seen as far north as Cape Cod in Massachusetts, but they do not normally reside any further north than Virginia. They migrate back to the warm Florida and Gulf Coast state waters in the winter.