Trichechus manatus latirostris is one of the most commonly known marine mammals. The Florida manatee is also historically important in that it was the first animal to be considered endangered. In 1967, the Florida Fish and Wildlife Conservation Commission (FFWCC) listed the Florida manatee as endangered nearly six years before the Endangered Species Act of 1973 and listed certain areas as critical manatee habitat. This was one of the first designations of critical habitat for any endangered species or marine mammal.The Florida manatee became an endangered species due to both environmental and anthropogenic causes. Habitat loss due to increasing population growth, watercraft collisions, entrapment in flood gates and canal locks, entanglement in fishing gear, and susceptibility to minute changes in climate have all contributed to the manatee's endangered status. According to the Florida Fish and Wildlife Research Institute, today nearly 25% of manatee deaths are caused watercraft injury. Boating education and regulation are the main areas were the Federal government and the FFWCC have focused on in order to protect the manatee. Starting in the 1980's a federal recovery plan initiated and in 2006, the FFWCC downlisted the Florida Manatee from Endangered to Threatened. Manatee populations have slightly increased since the start of the recovery plan but their downlist by the FFWCC was due to the fact that they changed their definition of "endangered." Even though the Florida manatee is no longer an endangered species, laws that protect these creatures are constantly under attack from boaters and the boating industry. Florida manatee populations have grown over the last couple of decades, but protecting these creatures is a continuous process.
The Florida manatee is rather easy to identify. They typically are large creatures growing as large as 14 feet. Manatees are gray in color and have massive bodies and a fusiform shape. Some people think that the Florida manatee looks like large seal. Other noticeable features are stiff whiskers on their faces, a round, flat tail that is used for movement and control in the water, and rounded forelimbs.
There are actually two species of manatees, the Florida manatee and the West Indian Manatee. All manatees belong to the phylum Chordata. Chordates are defined as having a notochord, dorsal hollow nerve chord, pharyngeal slits, and a post-anal tail. Additionally, most chordates, except for tunicates and lancelets, are vertebrates. Manatees more specifically fall into the class Mammalia. Mammals all have mammary glands, hair coving their bodies, and relatively large brains. They also are all vertebrates, give birth to live young, and breath air. There are more than 100 different mammals that depend on the ocean directly for survival. Marine mammals are divided into three separate orders: Carnivora (seals, sea otters, and polar bears), Cetaceans (whales, dolphins, and porpoises), and Sirenia which include dugongs and manatees.
The Florida manatee is not just constricted to Florida. In the summer, Florida manatees can be found in Georgia and the Carolinas. They have been found as far north as New York and Rhode Island. In the winter months, Florida manatees retreat to their winter thermal areas in south Florida. Florida manatees typically are inshore species found in inland, brackish rivers, lagoons, estuaries, mangroves, and even freshwater rivers. Their diet typically consists of almost any kind of marine vegetation. They are voracious eaters consuming 8% of their body weight and feeding 6-8 hours a day.
Florida manatees are social creatures, but not to the extent as other marine mammals such as dolphins or porposies. Breading can occur during all times of the year, but manatees have low reproductive rates. A female usually produces one calf every two to three years and the gestation period averages about 12 months. The mother then raises that calf for another one to two years before the calf can survive on its own. It takes another five years before the calf reaches sexual maturity. This low rate of reproduction is another reason why it is so hard for manatee populations to recover. Rebuilding Florida manatee populations depends on the survival of mature adults.
Interesting manatee facts: the Florida manatee can hold its breath for over 20 minutes. Florida manatees can live to be more than 60 years old. Florida manatees typically travel between 40-50 miles a day. On average, a Florida manatee weighs about 1,000 pounds. Manatees are closely related to elephants.
References: "Oceanography." Office of Naval Research Home Page. Web. 16 Jan. 2011. <http://www.onr.navy.mil/focus/ocean/life/mammals1.htm>.; "Manatee Facts." Save the Manatee Club. Web. 16 Jan. 2011. <http://www.savethemanatee.org/manfcts.htm>.; "Florida Manatee." Smithsonian Marine Station at Fort Pierce. Web. 16 Jan. 2011. <http://www.sms.si.edu/irlspec/trichec_manatu.htm>
