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The West Indian manatee was
discovered in the 1500s by Spanish explorers that hunted
them for their meat, hide, and oils. Hunted almost to
extinction, Florida banned the hunting of manatees in
1893. The official "season" for Florida Manatee
is October 15th to March 31st. But there are Manatee that
stay in certain areas all year. In warmer months manatees spend most of their time at sea and out of harm's way, but from October they 15th to March 31st, the colder weather drives them inland to places where can find warm water. Florida's Crystal River National Wildlife Refuge supports the largest concentration. During the summer months the best time to catch them is in the morning when they are frolicking and sunning. They usually stay in one area when they are in the "morning mode" and can be approached quite easily. In the afternoon, when the sun is hot they stay mainly on the bottom or are on the move for food. When the air temperature drops below the water temperature of 72 degrees (72 degrees is the year round temperature for Crystal River) for several days, hundreds upon hundreds of manatee are in river. Best sightings are on the coldest days of the year. The West Indian manatee (Trichechus manatus latirostris) is a large, gray-brown, aquatic mammal with a body that tapers to a flat, paddle-shaped tail. It has two flippers with 3 to 4 nails on each, and it's head and face are wrinkled, with whiskers on the snout. The manatee's closest relatives are the elephant, hyraxes, and aardvarks than any other marine mammal. Manatees are believed to have evolved from a wading plant-eating animal. The West Indian manatee is related to the West African manatee, the Amazonian manatee, the dugong and the Steller's sea cow, which was hunted to extinction in 1768, just 27 years after it was discovered in 1741. The average, adult manatee is about 10 feet long and weighs about 1000 pounds. They can reach up to 13 feet in length and weigh up to 3,000 pounds. Manatees belong to the order Sirenia. The word "Sirenia" came from the word "siren." "Sirens" are legendary Greek sea beauties that lured sailors in to the sea. It is thought that old-time mermaid sightings were actually sirenians rather than mythical half women, half fish. Manatees are a migrant species, concentrated in Florida in the winter, but can be found as far west as Louisiana and as far north as Virginia and the Carolinas in the summer months. The Manatee lives in warm, shallow rivers, bays, estuaries and coastal waters. Because manatee have an unusually low metabolic rate, they usually don't live in waters that are below 68 degrees Fahrenheit. They often live in the warm run off water of power plants. They prefer shallow waters (3 to 6 feet deep) that produce the salt and fresh water plants that they eat. During the winter months as many as 500 manatees can be found in the Crystal River area. During the summer as few as 35 remain in the river. The West Indian manatee can also be found in the coastal and inland waterways of Central America and along the northern coast of South America, although distribution in these areas may be spotty. Manatees
are gentle, slow-moving graceful swimmers. Most of their
time is spent eating, resting and in travel. Manatees are
completely herbivorous. They eat aquatic plants and can
consume 10-15% of their body weight daily. Upon occassion
they will consume shell fish. They graze for food along
water bottoms and on the surface. They may rest submerged
at the bottom or just below the surface, coming up to
breathe on the average of every three to five minutes and
twenty minutes and longer when asleep. Manatee bones are
very dense, lacking marrow. Because of this, manatees are
negatively buoyant and can lie on the sea bottom without
exerting any energy to stay down. The less energy they
use, the longer manatees can remain submerged between
breaths making feeding more efficient. Manatees have the
ability to control the volume of air their lungs,
enabling them to rise to the surface, take a breath, and
return to the bottom with no noticeable effort. Manatees have no natural enemies, and it is believed they can live 60 years or more. Most human related manatee mortalities occur from collisions with watercraft. Other causes of human related mortalities include being crushed and/or drowned in canal locks and flood control structures; ingestion of fish hooks, litter and monofilament line; entanglement in crab trap lines; and vandalism. Ultimately, however, loss of habitat is the most serious threat facing the manatee today. There are approximately 3000 West Indian manatees left in the United States. In 2001 Florida recorded 325 manatee deaths. In 2002, 305 have perished. Scientists from the Florida Fish and Wildlife Conservation Commission’s Florida Marine Research Institute suspect that 27 manatee carcasses brought in from four southwest counties between March 15 and April 16 2002 died as a result of exposure to red tide. The 2003 count, counted only 2, 568 manatess, down 17.5% from last year, a loss of 545 manatees. The Florida Fish and Wildlife Conservation Commission and the Florida Marine Research Institute have submitted a report envolving a complex scientific process that included compiling the best available data on the manatee and developing a population viability analysis model to project the probability of a population decline and extinction in the next 45 and 100 years. Among the data incorporated into the model were survival rates, age of maturity, age of first reproduction, and potential catastrophic events such as red tide and cold weather. Eighteen FMRI and other FWC staff contributed to the 151-page report. It represents the most comprehensive analysis of manatee population data to date. The
manatee is protected under federal law by the Marine
Mammal Protection Act of 1972 and the Endangered Specials
Act of 1973, which make it illegal to harass, hunt,
capture or kill any marine mammal. The manatee is also
protected by the Florida Manatee Sanctuary Act of 1978,
which states: "It is unlawful for any person, at any
time, intentionally or negligently, to annoy, molest,
harass or disturb any manatee."
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