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Manatee
Facts
Description:
West Indian manatees are large, gray aquatic mammals with bodies
that taper to a flat, paddle-shaped tail. They have two forelimbs,
called flippers, with three to four nails. Their head and face are
wrinkled with whiskers on the snout. The manatee's closest land
relatives are the elephant and the hyrax, a small, gopher-sized
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 to the Steller's sea cow,
which was hunted to extinction in 1768. The average adult manatee
is about three meters (9.8 feet) long and weighs between 362-544
kilograms (800-1,200 pounds).
Habitat
and Range: Manatees can be found in shallow, slow-moving
rivers, estuaries, saltwater bays, canals and coastal areas. Manatees
are a migratory species. Within the United States, West Indian manatees
are concentrated in Florida in the winter, but they can be found
in summer months as far west as Texas and as far north as Virginia.
However, these sightings are rare. Summer sightings in Alabama,
Georgia and South Carolina are common. West Indian manatees 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.
Behavior:
Manatees are gentle and slow-moving. 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 in vegetation. 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. When manatees are using a great deal of energy,
they may surface to breathe as often as every 30 seconds. When resting,
manatees have been known to stay submerged for up to 20 minutes.
Lifespan,
Mortality, Population: West
Indian manatees have no natural enemies, and it is believed they
can live 60 years or more. Many manatee mortalities are human-related.
Most human-related manatee mortalities occur from collisions with
watercraft. Other causes of human-related manatee 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 manatees today. There
are approximately 3,000 West Indian manatees left in the United
States.
Breeding
and Reproduction: The reproductive
rate for manatees is slow. Female manatees are not sexually mature
until about five years of age, and males are mature at approximately
nine years of age. On average, one calf is born every two to five
years, and twins are rare. The gestation period is about a year.
Mothers nurse their young for one to two years, so a calf may remain
dependent on its mother during that time.
Legal Protection: West Indian manatees in the United States are
protected under federal law by the Marine Mammal Protection Act
of 1972 and the Endangered Species Act of 1973, which make it illegal
to harass, hunt, capture, or kill any marine mammal. West Indian
manatees are 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." Anyone convicted of violating Florida's
state law faces a possible maximum fine of $500 and/or imprisonment
for up to 60 days. Conviction on the federal level is punishable
by a fine of up to $100,000 and/or one year in prison.
Conservation:
The Florida Manatee Recovery Plan was developed
as a result of the Endangered Species Act. The recovery plan is
coordinated by the U.S. Fish & Wildlife Service (USFWS) and
sets forth a list of tasks geared toward recovering manatees from
their current endangered status. Save the Manatee Club is part of
the Manatee Recovery Team, which carries out the tasks in the plan
under the auspices of the USFWS. In addition, SMC is part of the
Manatee Technical Advisory Council, which makes recommendations
to government officials on manatee protection issues.
In October of 1989, Florida's Governor and Cabinet directed the
Florida Department of Environmental Protection to work with 13 "key"
manatee counties in Florida to reduce injuries and deaths. These
13 counties include: Duval, Volusia , Citrus, Brevard, Indian River,
St. Lucie, Martin, Palm Beach, Broward, Dade, Collier, Lee and Sarasota.
Over 80% of manatee mortalities have occurred in these counties.
The first task of these 13 county governments, working with the
state, is to develop site specific boat speed zones to reduce watercraft
collisions. The second task is to develop comprehensive manatee
protection plans (MPP) at the local level. Twelve of the 13 key
counties have implemented boat speed zones for manatee protection.
Several key counties are currently at work on their MPPs.
Other
conservation measures deemed important to saving manatees include:
research covering the biology, mortality, population and distribution,
behavior, and habitat of manatees; implementation of management
plans; posting of regulatory speed signs and levying of fines for
excess speeds in designated areas; manatee education and public
awareness programs; and public acquisition of critical habitat and
creation of sanctuaries. |