by Miranda Spencer
Facts about Florida's most beloved sea mammal, the manatee.
Manatees, also known as sea cows, belong to the order of aquatic mammals, Sirenia. There are four living species in the order Sirenia, including the West Indian manatee, the West African manatee, the Amazonian manatee, and the dugong. The manatees that are seen along the coast of Florida are West Indian manatees. The manatee’s closest relative is the elephant and hyrax (a small furry animal that resembles a rodent). The average adult manatee is 10 feet long and weighs 1,000 - 1,200 pounds. However, manatees can grow to reach a length of 13 feet and a weight of approximately 3,000 pounds. Manatees are vegetarians and they consume about ten percent of their body weight daily, or about 60 to 100 pounds from a variety of submerged, emergent, and floating plants, spending 6-8 hours daily foraging. West Indian manatees have no natural enemies, and it is believed they can live 60 years or more.
The Federal Marine Mammal Protection Act of 1972 and the Endangered Species Act of 1973 protect West Indian manatees. There are approximately 2,500 manatees living in Florida waters based on annual statewide synoptic aerial surveys. Several factors have lead to the decline of manatees. One of the problems manatees face is that their reproductive rate is slow. Scientists believe female manatees don’t become sexually mature until around five years of age. Males are mature at approximately nine years. Manatee females usually bear one calf every two to five years. Because the reproductive rate is so low, the species as a whole adapts very slowly to changing situations or unnatural stress. A second problem elucidated by the Florida Marine Research Institute (FMRI) has shown that human-related activities accounted for 44 percent of all manatee mortalities from 1976 though 2001, where cause of death could be determined. FMRI statistics have also shown that most human-related manatee mortalities occur from collisions with watercraft. Ultimately, however, loss of habitat is the most serious threat facing manatees today.
For more information about manatees:www.savethemanatee.org/manfcts.htm