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Leatherback
Turtle
Credit:
Ocean Conservancy
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AquaFacts:
Leatherback Turtles (Dermochelyidae coriacea)
How big
are leatherback turtles?
- Leatherbacks
are the largest of all the sea turtles, measuring up to 2.4m (6 ft)
long and 1.6m (4 ft) wide.
- The average
weight of a leatherback turtle is around 400 kg (880 pounds).
- The maximum
recorded weight of a leatherback is 916 kg (2015 pounds).
Where
do leatherback turtles live?
There are
several populations of leatherback turtles that live in very different
parts of the world:
- Eastern
Pacific leatherbacks nest in Costa Rica and Mexico and travel to both
South America (off Chile and Peru) and California.
- Western
Pacific leatherbacks nest in areas such as Indonesia, Malaysia, and
the Mariana Islands of the South Pacific and travel across the Pacific
Ocean to the west coast of the US and Canada to forage for food.
- Atlantic
leatherbacks nest in places like the southern states of the US, the
Caribbean, Trinidad, French Guyana, Mexico, and Western Africa. They
travel to various locations throughout the Atlantic as far as the Eastern
Coast of Canada even to South Africa and the United Kingdom.
How are
they able to live in the cold water?
Although
most reptiles are cold-blooded, leatherbacks have a special ability that
allows them to change their body temperature -- this means that they can
keep themselves warm to survive in the colder water that other turtles
might not tolerate for very long. They have layers of fat under their
leathery skin that insulate them from the cold, and have a specialized
circulatory system that minimizes heat loss.
What do
leatherback turtles eat?
- Leatherbacks
main source of food are jellyfish (jellies) like the Portugese Man-of-War,
the lions mane, the cannonball jelly and other jelly-like animals.
- Leatherbacks
can eat their body weight in jellies in one day!
Leatherback turtles have many rows of spikes in their throats to help
them hold their slippery food down.
- Unfortunately,
turtles often mistake plastic bags or fishing line for jellies, which
can injure them and can sometimes be fatal.
How do
leatherback turtles reproduce?
- Leatherbacks
dig nests in the sand like other sea turtles, but they often lay many
more eggs in their nests. In one nesting season females can lay 12 clutches
(groups), with 65 to 85 eggs in each clutch.
- Leatherbacks
also lay eggs of various sizes in a single clutch. Small, yolkless eggs
are laid alongside the viable eggs -- they are believed to act as spacers
which allow air to circulate in the nest.
Did you
know?
- Leatherback
turtles do not have a hard shell like other sea turtles. Instead they
have a thick layer of cartilage (like the hard material found in your
ears and nose) strengthened by thousands of tiny bones.
- Leatherbacks
travel the furthest distances (up to 12,000 km) and dive the deepest
(1200m) of all the turtles.
- Leatherback
turtles show an amazing knack for travelling across the oceans. They
dont even use the major ocean currents to swim to where they are
going. In fact, the turtles completely disregard the direction of the
currents.
How many
leatherback turtles are there in the world?
- Leatherback
turtles are listed as endangered on the Species at Risk List in Canada,
and are on the Endangered Species List in the United States.
- There
are an estimated 30,000 leatherbacks left in the world (compared to
115,000 in 1980).
- The Pacific
populations are facing extinction and the Atlantic population is being
caught as bycatch (living things caught unintentionally while fishing)
at an unsustainable rate.
What are
some of the problems leatherback turtles are facing?
- Leatherbacks
are facing extinction mainly due to human impacts on their environment.
- Nesting
sites are disturbed through tourism or commercial development, and poachers
often harvest eggs for food.
Adult turtles are sometimes captured for food and their body parts are
used for various commercial products (like traditional medicines).
- Turtles
are killed and injured in collisions with boats.
Rubbish dumped at sea or from land may be mistaken for food and swallowed
by the turtles, causing severe injuries and death.
- Turtles
become trapped in fishing nets and drown.
What is
being done to help the leatherback turtles?
- The most
important thing you can do to help the turtles is to keep our beaches
and oceans clean. Log on to the Great Canadian Shoreline Cleanup Web
site at www.vanaqua.org to get involved.
- Some fishing
companies are outfitting nets with Turtle Exclusion Devices (TEDs) that
allow turtles to escape the nets when caught accidentally.
- Protection
of nesting sites has been increased in countries like Mexico, Costa
Rica and the United States. National Parks have been created to prevent
further commercial development and the illegal actions of poachers.
- Fitting
turtles with satellite tracking devices has helped to find out more
about where the turtles go and how many there are in the ocean.
Where
can I get more information on leatherback turtles?
There are
many helpful Web sites available to learn more about leatherbacks and
other sea turtles, and to find out what YOU can do to help save them from
extinction. Visit the Vancouver Aquarium's Web site, www.vanaqua.org,
and stay tuned for more leatherback information and activities.
References:
Lutz, Peter
and John Musick. 1996. The Biology of Sea Turtles. Boca Raton, FL: CRC
Press.
Langton, Tom. 1999. Hell for Leatheries. BBC Wildlife, 17(3):
10-17
Schuett, Gordon and Ryan Sawby. 2001. Seaturtles: The Excellent
Fishe in Cyberspace. Fauna, July/August: 38-42.
Spotila, James, et al. 1998. Worldwide Population Decline of Dermochelys
coriacea: Are Leatherback Turtles Going Extinct? www.coas.drexel.edu/environ/leatherback.popdeck.html.
7/16/02.
Waldichuk, Michael. 1987. Sea Turtles -- Endangered Species.
Marine Pollution Bulletin, 18(12): 623-627.
Watt, E.M. 2002. Leatherback Turtles (Untamed World Series). Austin, New
York. Raintree Steck-Vaughn Publishers.
Permission
is granted by the Vancouver Aquarium Marine Science Centre for classroom
teachers to make copies for non-commercial use. This permission does not
extend to copying for promotional purposes, creating new collective works,
or resale.
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