Interesting Manatee Facts
Crystal River Manatee Tours
Do manatees have teeth? Manatees have molars but no front teeth (no incisors or canines). Manatee teeth are unusual among mammals because they are continually replaced throughout the animals’ lives. The teeth are sometimes called “marching molars” because they erupt at the back of the jaw and move slowly forward. As old molars fall out at the front of the jaw, new molars replace them. Scientists believe this is an evolutionary adaptation to a coarse diet of sea grass often mixed with sand.
Do manatees need fresh water to survive? It is unknown whether fresh water is essential for manatees’ survival, but they do like it. Manatees can be found in rivers and springs as well as congregating at fresh water drainage pipes. Some people attract manatees to their docks by letting them drink water from ordinary garden hoses. This is illegal and endangers the mammals because it brings them to areas of high boat traffic.
How big are manatees? The average Florida manatee is about 10 feet long and weighs close to 1,200 pounds. Manatees can reach up to 13 feet in length and weigh 3,500 pounds. Female manatees tend to be larger than the males. Their calves weigh around 66 pounds and are 4 feet long.
How long do manatees live? Manatees in captivity have been known to live for more than 50 years. Distinctly scarred individuals have been known to live for at least 39 years. Dead animals are aged from microscopic examination of growth layer groups (annual layers, similar to the growth rings in trees) in their ear bones.
How many manatees are in Florida waters? As of 2012, the highest number of manatees counted in a statewide survey (in winter 2010) was 5,076. However, this is only the highest count of the number of manatees in Florida and is not a true estimate of the population.
How many types of manatees exist? There are three species of manatees in the world. The West Indian manatee ranges along the coasts and inland waters of the southeastern United States, eastern Mexico, the Greater Antilles, and Central America to as far as northern Brazil. It is comprised of two subspecies: the native Florida manatee is found throughout Florida and neighboring states, and the Antillean manatee found throughout the rest of the species’ range, including Puerto Rico. The other two species include the Amazonian manatee, found only in the fresh waters of the Amazon, and the West African manatee, found in the rivers, estuaries, and coasts of western Africa.
How often do female manatees give birth? After reaching sexual maturity at 4-7 years, female manatees give birth to an average of one calf every two or three years. The calf stays with its mother for up to 2 ½ years.
What is the range of the manatees? Manatees are found throughout rivers, springs, and shallow coastal waters of Florida and nearby states. Manatees have been seen as far west as Texas and as far north as Virginia. Though they like to stay near warm waters, adventurous ones such as “Chessie,” a manatee tagged with a satellite transmitter, was tracked all the way to Chesapeake Bay in 1994. Scientists feared he would not make it back to Florida before the cold weather approached, so they flew him home by plane. The next summer, he journeyed to Rhode Island and returned on his own to the Ft. Lauderdale area. In 1996, he headed north again, losing his transmitter in North Carolina.
What state and federal laws have been enacted to protect manatees? They are protected under two federal laws: the US Endangered Species Act of 1973 lists manatees as endangered; they are also protected under the US Marine Mammal Protection Act of 1972. In response to mounting evidence of the negative effects that boats have upon manatees, the state legislature also passed the Florida Manatee Sanctuary Act in 1978, allowing the state to establish and enforce boating restrictions in important manatee habitats. The responsibility for administering the law now lies with the Florida Fish and Wildlife Conservation Commission.
What threatens manatee survival?
Habitat Loss-Coastal development and pollution can seriously harm manatee habitats by affecting their main food source, seagrass.
Watercraft-Collisions with boat hulls and propellers have caused approximately one quarter of all manatee deaths since 1974 (when record keeping began). Manatees feed on seagrass beds in shallow water where there is little time or room to dive to the bottom to avoid oncoming boats. Death may result from propeller wounds, impact, crushing, or any combination of the three.
Entanglement-Discarded crab traps and fishing gear cause problems for many marine species, including manatees. Manatees can also ingest harmful debris.
Canal Locks and Flood Gates-Manatees are sometimes crushed in gates or killed by asphyxiation.
Poaching-Historically, manatees have been hunted for their meat, hide, bones and fat by Native Americans and European settlers. Manatees were in high demand in the late 1800s. Hunting is now rarely a problem.
Natural Causes-Manatee deaths can result from things like sudden freezes, non-infectious diseases, birth complications, natural accidents, red tide (such as the one in March and April of 1996), and other natural catastrophes.
Why do manatees seem drawn to power plants? During the cooler months, warm water discharge from power plants and other industries attracts the manatees because they can’t survive extended exposure to cold water. When the surrounding water temperature drops below 68° F or 20° C, they move to warmer waters, including southern Florida, power plants, and natural warm water springs. Historically, the manatee population was concentrated around South Florida during the winter months, but the power plants on coastal and inland waterways have made it possible for them to survive winter in northern Florida if they have access to a warm water site.
How fast are manatees? Tracking studies have shown that manatees can travel up to 50 miles or 80 km in a day. Manatees generally swim slowly but have been clocked at speeds up to 15 mph (25 km/hr) for short bursts.
How long can manatees stay underwater without breathing? While time varies with the animals’ level of activity, manatees surface to breathe about every four minutes. When resting, they can stay underwater up to 20 minutes before surfacing for air.
How much do manatees eat? Manatees, feeding between 6 and 8 hours daily, consume about 4 to 9% of their body weight in wet vegetation such as sea grass and other aquatic plants.
For more information, please visit MyFWC.com
M.E.T.A. is the Manatee Eco Tourism Association of Citrus County and strives to ensure that all human/manatee interaction is conducted in safe, non-stressful, and considerate manner. Double J Adventures is proud to be a member of M.E.T.A and serves on the Scientific Committee.