Kemp's Ridley
Sea Turtle
by Sharon LaPlante
The
Kemp's Ridley sea turtle, Lepidochelys
kempi, is one of the most endangered sea turtles.
It is also one of the smallest. The
adults generally weigh 100 pounds or less, with a straight carapace length of
approximately 2 feet. Adults are
gray-olive above (carapace) and cream or yellow below (plastron). Hatchlings are gray-black above and below.
They
are named after a Key West resident, Richard Kemp, who sent two
The
adults diet consists of crabs, jellyfish, fish and
mollusks. The juveniles diet
consists mostly of seaweed.
The
Kemp's Ridley, as with all sea turtles, lives exclusively in the ocean.
The only time they are not in the ocean is when they lay their eggs on
the beach, and when as hatchlings they emerge from the nest. Sexual maturity is reached at ten to twelve years of age.
Nesting occurs, during the day, from April to August.
When digging the nest the female uses her front flippers to dig a 'body
pit' which she gets into and then with her hind flippers scoops out a cavity for
the hundred or so eggs she will deposit. Many
eggs are lost to natural causes, such as prolonged flooding of the nest, beach
erosion, & predators. The
surviving eggs hatch in approximately two months.
Emerging hatchlings are inundated by predators on their journey to the
water and many do not survive.
Almost
all Kemp's Ridleys nest on a 20 mile stretch of beach at Rancho Neuvo in
Tamaulipas, Mexico (about 200 miles south of Brownsville, Texas).
A film taken there in 1947 shows an estimated 40,000 female turtles on
the beach. These mass nestings are
known as "arribadas" and are believed to be a reproductive strategy.
Today the number of female turtles in an arribada rarely exceeds 200, and
many females nest singly. In 1977
Rancho Neuvo was declared a Natural Reserve and programs were implemented to
protect the nesting beach in order to reduce the poaching of adults and eggs for
human consumption and reduce losses to predators.
The efforts have been successful, but the population is still declining
because of other threats.
Until
recently it was unheard of for a Kemp's Ridley to nest anywhere except in Rancho
Nuevo, but in 1989 a successful nesting did occur on Madeira Beach in Pinellas
County, and four non-nesting excursions occurred in Palm Beach County. In 1994 a nesting occurred in Clearwater Beach, and in 1996 a
nesting occurred on Sanibel Island and in Volusia County.
The occurrence of Florida nesting may be attributed to a
"head-start" program initiated in the late '70's.
The head-start program seeks to reduce the high mortality rate of
hatchling turtles by raising them in captivity until they have outgrown many of
their predators, then releasing them into their natural environment.
The
greatest threat to the Kemp's Ridley sea turtle today is drowning in shrimp
trawls. One of the most recent
conservation efforts is the requirement that owners of shrimp boats install
TED's, or Turtle Exclusion Devices. The
TED is fitted into the neck of the shrimp trawl to prevent large animals from
going into the net and drowning. TED's
are effective at excluding up to 97% of sea turtles with a minimal loss of
shrimp. It is believed that the
breeding population of Kemp's Ridleys is down to about 350 mature females,
so a single turtle that dies in a shrimp trawl is a significant loss.
Other human threats include commercial exploitation for luxury products,
disturbance of nesting beaches & feeding areas, pollution, and
non-degradable debris in the ocean. Support
for continued conservation efforts for this species has never been more
important.
Ashton,
Ray E., Jr. and Patricia Sawyer-Ashton. Handbook
of Reptiles and Amphibians: Part Two: Lizards, Turtles & Crocodilians.
Winward Publishing, Inc.: Miami, FL
1988
Caribbean
Conservation Corporation
Moler,
Paul E., editor. Rare and
Endangered Biota of Florida: Vol. 3: Amphibians & Reptiles.
University Press of Florida: Gainesville,
FL. 1992
Van Meter, Victoria B.. Florida's Sea Turtles. Florida Power & Light Company: Miami, FL. 1992
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