Florida's Mild-Mannered Manatee

The waters of northeast Florida have been inhabited by a unique, prehistoric creature for many
thousands of years. The Florida manatee (Trichechus manatus latirostris), also referred to as a
"sea cow", is now an endangered species and is the topic of many research efforts throughout the
state of Florida. The manatee can be observed in the ocean and intracoastal waters around Amelia
Island. Manatees range as far north as Long Island Sound during the summertime; however, with
the onset of cold temperatures in the fall, they are drawn back to south Florida or to the warm
water discharges at natural springs and power plant or industrial plant outfalls. Manatees, which are
warm-blooded animals, don't have a high tolerance for extreme temperature changes and can
succumb to "cold stress" if they remain in cold water for extended periods of time. Therefore, it is
unlikely that you will spot a manatee near Amelia Island in the wintertime; however, beginning with
the onset of spring, sightings become much more common.

Though manatees are usually solitary animals, this photo shows that they can sometimes
be found in groups.
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The manatee is a large, slow-moving marine mammal with no natural predators. Because they have no predators and they don't hunt for food, they do not have to band together for protection and are therefore fairly solitary animals. They have a bizarre appearance, including a wrinkled,
whiskery face; small, beady eyes; and a large, round fluke that they use to propel themselves through the water. The average adult manatee is 10 feet in length and weighs approximately 1,200 pounds. They can reach 13 feet in length and 3,000 pounds. The large size of the manatee is not surprising considering the fact that its closest

relative is the elephant! The grey roughened skin and nails found on manatee flippers are similar to elephant features. Manatees are mammals and must come to the surface to breathe air. They can remain underwater without taking a breath for up to 20 minutes.
Manatees give birth once every three to five years, and although twin births have been
documented, they are very rare. Newborn manatee calves average four feet in length and weigh
between 60 and 70 pounds. They remain with their mother for approximately two years, at which
time they embark on their own. Manatee mating behavior can be an interesting sight. Typically, a
single female is followed by numerous male admirers, and this cavorting group of manatees can
cause quite a scene, thrashing about in shallow water. The gestation period for the manatee is
approximately 13 months.
Seagrass beds and floating aquatic vegetation are very appealing to the manatee's herbivorous
feeding habits. Manatees require a large amount of vegetation to sustain themselves and therefore
spend much of their day feeding. In addition, they spend a large amount of time resting, either
floating at the surface of the water or lying on the bottom. Manatees can also be observed
traveling, cavorting or playing. Although manatees appear to be fairly idle animals, they do have the
ability to migrate long distances. "Chessie," a manatee whose name is short for Chesapeake Bay,
where he was rescued in 1994, has since been documented as far north as Rhode Island. Chessie,
who can be identified by scar patterns and a freezebrand on his back, hasn't been sighted in a
number of years. However, the last sighting occurred in Jacksonville. The wandering nature of this
manatee appears to be fairly rare, though each individual animal exhibits unique behaviors.

The best place in the area to get a good look at a manatee in the wild is Blue Springs State Park during the wintertime. The 72° water in the spring is very appealing to the manatees, and every winter as many as 110 animals return to the spring to live until the water in the St. John's River increases to a comfortable temperature. Due to the murky water we have in northeast Florida, it's
rare to get more than a glimpse of a manatee nose as the animal surfaces to breathe; however, the crystal clear water in the spring allows visitors to get a

Arial view of manatees in the St. John's River
south of Jacksonville.
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good look at the entire body of a manatee. Scar patterns allow park rangers to individually identify manatees that return each winter.
The most recent minimum population estimate for the manatee, resulting from a statewide survey
in January 2001, is 3,276. Manatees are an endangered species and are protected under State and
Federal law. However, despite years of protection for the manatee, the species is still experiencing
many adverse affects of cohabitating with man. One-third of all manatee mortality is human-related,
resulting from boat strikes, fishing gear entanglements, and being crushed in lock structures. State
and Federal researchers and managers are continually working towards finding solutions to help
man and manatee coexist more peacefully. As the population of Florida continues to increase
dramatically, this effort becomes more and more difficult. We should not forget the important lesson
of the Stellar's Sea Cow, which was a relative of the manatee living in the Bering Sea. This creature
was hunted to extinction within 27 years of its discovery in 1741. Although our effect on the Florida
manatee is not as dramatic, we need to ensure that the outcome is not repeated.
Researchers throughout Florida have many projects underway in an effort to increase knowledge
and awareness of the species. If you're interested in learning more about the Florida manatee and
what you can do to help protect and enjoy this species, please visit the website of the Florida
Marine Research Institute Endangered and Threatened Species Section (www.fmri.usf.edu/).