[] TL: Sea Turtles (GP)
SO: Greenpeace Factsheet From Greenpeace International
DT: September 18, 1991
Keywords: oceans greenpeace gp factsheets turtles reptiles /

                      SEA TURTLES

Sea turtles have inhabited the earth for over 100 million years.
Today seven species of these ocean dwelling reptiles remain. Once
inhabiting marshes, they evolved and adapted for life in the sea. 
Sea turtles are found throughout the world in tropical and sub-
tropical oceans.

Most species are highly migratory, often passing through
territorial and international waters from nesting to feeding
grounds and back again, exhibiting extraordinary powers of
navigation.  The green turtles feeding off the coast of Brazil,
swim 2000km to nest on Ascension Island, a mere dot on the map in
the middle of the Atlantic Ocean.

Sea turtles are air breathing, varying in size according to
species and maturity.  They are well adapted for life in the
marine environment, being able to dive for long periods, swim
powerfully, and do not need to drink fresh water.  They are
somewhat protected against natural predators in the water by
their size, shell and bony skull.

Sea turtles do not have teeth but their jaws can crush, tear or
bite depending on their diet, which varies between species. There
is little reliable information on their life span but they are
generally assumed to be long-lived, greater than 50 years for the
larger species.  Until maturity is reached it is difficult to
distinguish between male and female turtles.  At maturity, the
male develops a long tail and often a curled and elongated claw
on each fore-flipper.

Generally, the only time sea turtles leave the protective habitat
of the ocean is when the female crawls ashore to nest.  Some sea
turtles return to the same stretch of beach, usually every two to
three years, nesting several times in a season.  (One species,
the olive ridley, has been observed nesting in consecutive
years.)

Under cover of darkness, the female drags her large body by her
flippers, a few inches at a time towards an area above the high
tide mark.  After carefully digging a precisely shaped hole with
her rear flippers, she will deposit between 60 and 200 eggs, the
number varying between species.  Once completed, she covers the
eggs and disguises the nest, throwing sand behind her with her
flippers.  She returns to the ocean leaving the eggs to incubate
in the sand.

Many eggs are lost to predators, inundation and erosion, or are
infertile. After an incubation period of approximately two
months, the hatchlings break out of their shells and over a few
days dig their way to the surface.  Almost always at night under
cover of darkness, they emerge from the nest and guided by the
light of the moon and stars on the water, scramble instinctively
towards the ocean.

A significant number may be eaten by birds, crabs and other
animals.  Upon reaching the sea, little is known about their fate
or destination, or the time it will take before they return as
mature adults to play their part in the continuation of their
species.  It is estimated that only one in a thousand survives to
adulthood.

Where they go is one of the great mysteries of the sea turtle:
juveniles and sub-adults of the olive ridley turtle, for example,
have never been seen even though the major characteristic of this
species is to nest in groups of tens of thousands of turtles.

TYPES OF SEA TURTLES

The seven species of sea turtles are:

1. Flatback (Natator depressa)
2. Loggerhead (Caretta caretta)
3. Hawksbill (Eretmochelys imbricata)
4. Leatherback (Dermochelys coriacea)
5. Olive ridley (Lepidochelys olivacea)
6. Kemp's ridley (Lepidochelys kempi)
7. Green (Chelonia mydas)

FLATBACK (Natator depressor)

The flatback is a sea turtle found only in northern Australian
waters and the Gulf of Papua.  Nesting occurs exclusively in
Australia.

The major feeding grounds, which coincide with major prawn
trawling areas, are the Gulf of Carpentaria and the coastal
waters sheltered by the Great Barrier Reef.  The flatback has a
dark carapace, weighs up to 80kg and feeds on invertebrates.

LOGGERHEAD TURTLE (Caretta caretta)

Loggerheads are also highly migratory animals and nest further
from the tropics than other turtle species.  They grow to a
length of about 1m and weigh up to 180kg.  They have a brown
heart-shaped carapace, a large head and a hard horny beak.
Loggerheads are primarily carnivorous feeding on molluscs, crabs,
jellyfish and crustaceans.

The two major nesting grounds are in Oman and south-eastern USA.
The track can be recognised by the pattern of alternate flipper
marks, and the nest by the shallow body pit and small amount of
sand thrown back. Hatchlings are 50mm in length and light to dark
brown, with a lighter plastron.

HAWKSBILL TURTLE (Eretmochelys imbricata)

Hawksbills inhabit tropical coastal waters around coral reefs.
They are small turtles, adults commonly weighing around 50kg, are
up to 90cm in length and named after their narrow birdlike beak.
They are omnivorous, consuming a variety of items including
seagrasses, jellyfish, sponges and crustaceans.

The desire to make luxury jewellery out of their highly patterned
shell has been responsible for the death of millions of
hawksbills.  Hawksbills nest high up the beach, often in the
vegetation.  The hatchlings are 40-45mm in length and are dark
all over.

LEATHERBACK TURTLE (Dermochelys coriacea)

The leatherback is the largest of all sea turtles reaching a
length of 1.8m and weighing up to 600kg.  Their track is up to 2m
wide and like the green turtle, create large craters in the sand
when they nest.  This circum-global species inhabits the
Atlantic, Indian and Pacific Oceans and occasionally the
Mediterranean Sea.

The leatherback is ecologically unique among sea turtles.  Unlike
other species, it lacks a hard outer shell but instead has a soft
shell composed of small bones and cartilage which is
characterised by seven long ridges.  Their diet consists mostly
of jellyfish.

OLIVE RIDLEY TURTLE (Lepidochelys olivacea)

The olive ridley is the smallest of the sea turtles, the adults
weighing less than 40kg, measuring 65cm in length and found
mainly in the tropical Pacific and Indian Oceans.  They are
mostly carnivorous, eating crustaceans fish eggs and some
vegetation.

The major nesting sites are in Mexico, Costa Rica and India.
Their major characteristic is the pattern of nesting in huge
congregations called "arribazones" when thousands of turtles will
emerge together over a few nights, often digging up the
previously laid eggs.

KEMP'S RIDLEY TURTLE (Lepidochelys kempi)

The Kemp's ridley is a close relative of the olive ridley and is
the most endangered species of sea turtle.  They are small
carnivorous turtles weighing up to 45kg, grow to a length of 65cm
and have a grey circular shell.  They feed on crabs and molluscs. 
The Kemp's ridley is found only in the Gulf of Mexico and along
the US Atlantic coast.  There is only one important nesting site
in the world, in Mexico.  An estimated 40,000 nesting females in
1947 has decreased to less than 500 and some experts believe that
the species may already be beyond recovery.  This turtle also
nests en masse providing an easy opportunity in the past to over-
exploit the one remaining nesting beach.

GREEN TURTLE (Chelonia mydas)

Green turtles are highly migratory and found in the Atlantic,
Pacific and Indian Oceans, primarily in tropical regions.  Greens
have an oval greenish carapace (shell) with darker streaks and
can weigh up to 230kg with an average length of 1m.
Although hatchlings are mainly carnivorous, greens are
predominantly herbivorous, feeding on sea weed and sea grasses.
This diet is nutritionally limiting, resulting in a slow growth
rate and delayed sexual maturity - estimated at 20-30 years of
age.  The major nesting grounds are in Australia, Indonesia,
Ascension Island and Costa Rica.
The green turtle track is 1m wide, with symmetrical lines made by
the front flippers.  The nest is identified by the deep body pit
and large amount of sand thrown back.  Newly emerged hatchlings
are about 50mm in length and have a black carapace (shell) and
white plastron (belly shell).

                     THREATS TO SEA TURTLES.

COMMERCIAL EXPLOITATION

The history of commercial exploitation of sea turtles is one of
depletion and decline of sea turtle populations all over the
world.  The colonisation of the Caribbean by the European powers
was built in large part on the plunder of the numerous green
turtle colonies for their meat and eggs.  This was carried out to
such excess that a number of the largest populations had become
commercially extinct by the early 1800s.
The hawksbill has been killed for thousands of years for its
beautiful shell. The factor that has saved many populations from
a similar fate to the green turtle has been its pattern of
nesting singly or in small numbers in isolated bays.  Thus no
large aggregations have formed easy targets, but to satisfy the
principal market in Japan many thousands are nevertheless caught
each year in their feeding grounds.

In Mexico, from 1964-1969, 2,000,000 olive ridleys were killed
for their skin, following the decreasing supply of crocodile
skins in world trade.  Not unexpectedly the populations crashed,
and today only one major "arribazon" of olive ridleys remains,
with drastically reduced numbers.

Human consumption of sea turtle eggs can be equally damaging to
sea turtle populations.  In the Malaysian state of Trengganu,
massive collection of eggs has decimated one of the largest
nesting beaches of the leatherback in the world.  In 1987, only
100 females nested, a decline from over 1700 females in the
1950s.  In neighbouring Indonesia, almost every sea turtle egg
laid is collected and every sea turtle sighted is captured for
the meat or shell.

INTERNATIONAL TRADE/CITES

In 1975, the Convention on International Trade in Endangered
Species of Wild Fauna and Flora came into force.  Designed to
prevent wildlife from becoming endangered through international
trade, it has now been signed by 96 countries.  Together with
such species as the tiger, leopard and giant panda, all sea
turtle species have been listed on Appendix I, which means
international trade in those species is prohibited.

However for a number of complex reasons, CITES has not lived up
to its potential.  Sea turtle products, especially hawksbill
shell, continue to be traded in greater volume than any other
Appendix I species, due mainly to Japan having adopted a
reservation to their protected status.  This means that Japan is
not bound by CITES' prohibition on their trade, and Japanese
dealers, therefore, continue to import sea turtle shell and skin
from around the world. From 1970-1988, Japan alone imported shell
from more than 650,000 adult hawksbills.  If Japan were to lower
its imports of hawksbill shell, it would ease the pressure on
most of the remaining hawksbill populations in the world.
The other major importers of hawksbill shell are Singapore, Hong
Kong, China and Taiwan, and exporters are Indonesia, the
Maldives, Fiji, the Solomon Islands, Cuba, Haiti and Jamaica.
Many of these are also laundering points for shell collected from
neighbouring areas.

HABITAT DESTRUCTION

Human activities have been increasingly intrusive on both nesting
and foraging habitats of sea turtles.  In many areas of the
world, coastal development is a large and ever-growing threat to
sea turtles, causing severe impact on the nesting beaches.
Artificial lighting from such development can result in reduction
in the numbers of females coming ashore to nest and in
disorientation of the hatchlings.  After emerging from the nests
under natural conditions, hatchlings focus on the brighter light
horizon over the sea in their scramble to reach the water.  On
many beaches, artificial light attracts the hatchlings away from
the water which increases the risk from predators, and can result
in death if they cross coastal roads or from dehydration in the
heat of the following day's sun.

Other impacts on nesting beaches are the construction of concrete
walls to prevent erosion; the permanent erection of umbrellas for
tourists; and planting trees for shade, which will affect the
temperature of the nests and thus the sex ratio of the hatchlings
as their sex is temperature dependent.
The foraging habitats too are threatened.  In parts of the world,
the illegal use of chlorine for catching lobster is widespread
and has damaged many reefs, the feeding grounds of the hawksbill
turtle.

INCIDENTAL KILLS/TEDS

Many sea turtles drown in the nets of fishing fleets around the
world, or are caught on the hooks of long liners.  It is
estimated that over 47,000 sea turtles are caught each year by
the US shrimp fleet of which approximately 12,000 die.  When a
turtle is in the path of a trawl, it generally tries to swim
faster than the trawl, instead of swimming out of its way.  As
the turtle tires, it is overtaken and finally caught in the
trawl.  If the turtle is not pulled out of the trawl after a
short period of time, it will drown.  A turtle that is exhausted
from one capture may not survive a later capture if it occurs
soon after the first.

Although sea turtles are also killed in driftnets, it is shrimp
nets that account for the majority of incidental deaths.  This
problem is not restricted to the USA, but mortality estimates
from other nations are unregulated and difficult to obtain.  For
example, the severe decline in olive ridley numbers in Surinam is
attributed to high incidental catch in shrimp trawlers operating
off the coasts of Surinam, French Guiana and Venezuela.

The major obstacle to the recovery of the Kemp's ridley has also
been attributed to continuing mortalities in shrimp trawlers.
Fortunately a solution to this problem exists.  The US National
Marine Fisheries Service (NMFS) has developed a device which is
97% effective in releasing sea turtles caught during shrimping
operations.  Turtle Excluder Devices (TED) are installed inside
and just forward of the end of the net.  Turtles caught in the
net strike a set of bars which force them upward and out through
a slit cut in the top of the net.

Experienced use of the TED will not significantly reduce shrimp
catch, and will also exclude unwanted catch such as jellyfish and
fin fish species.  This results in a cleaner catch with less
damage to the shrimp.  However, there has been a problem
convincing the fishermen to use the TED.  In the USA, regulations
for the mandatory use of TEDs came into force in 1989.  The
problem remains in many other parts of the world where education
and technology transfer is needed.

MARINE DEBRIS/POLLUTION

Ingestion of plastic is a major problem for sea turtles,
especially the more pelagic species.  Many turtles eat plastic
which resembles jellyfish and becomes clogged in their
intestines.  It is estimated that almost half of the oceanic
turtles are affected by plastic.  While evidence is lacking to
directly link plastic with mortalities, many dead sea turtles
recovered have consumed enough plastic to have contributed to
their deaths.  In one instance, a dead turtle had ingested enough
plastic to cover an area of 12 sq. metres.

Sea turtles are also extremely vulnerable to oil and toxic
chemical pollution. Numerous immature turtles have been found
dead with their throats and jaws obstructed by tar.

RANCHING AND FARMING

There have been a number of attempts to ranch and farm sea
turtles, none of which have gained international acceptance at
CITES.  Ranching of sea turtles entails taking turtle eggs or
hatchlings from the wild and rearing them in captivity until they
reach a suitable size to slaughter.  Farming is taking adults and
eggs from the wild and breeding them in captivity in a closed
cycle operation which should not need continuous replenishment of
wild caught animals.  However, sea turtles have shown themselves
to be particularly unsuitable animals for keeping in captivity,
requiring massive capital investment for the equipment needed and
being prone to disease.  Attempts to breed second generation
turtles in captivity have also failed completely.

The principal reason why the CITES Parties have rejected ranching
and farming proposals is the problem of stimulation of trade. The
ranches will never be able to meet and therefore, replace the
demand for sea turtle products.  The unit cost of ranched or
farmed products will always be higher than from wild caught
turtles, and to achieve economic success, the ranch or farm will
have to continually open up new markets. This in turn will
increase the pressure on the wild populations.

INEFFECTUAL LEGISLATION/IUCN RESOLUTION

The fundamental problem for sea turtle conservation is that most
countries do not have the will or the resources to adequately
protect sea turtles.  Where legislation is in place, it has
mostly followed the pattern of traditional fishery protection and
attempted to protect the younger age classes.  However, the most
valuable members of the population are the adult sea turtles
which have survived to breeding age.

Thus where laws regulate the size of sea turtles allowed to be
caught, a MAXIMUM size limit should be set above which all
turtles are protected.

Greenpeace prepared a resolution which was submitted to the
General Assembly of the International Union for the Conservation
of Nature and Natural Resources (IUCN) in 1988 calling for such
maximum size limits to be set where it is culturally
inappropriate to protect sea turtles altogether.  Further
sections called for the protection of the eggs, nesting beaches
and foraging habitats, and for the use of TEDs by shrimp trawlers
to minimise incidental catch.  The final clause called on
countries to cease all commercial international trade in sea
turtle products.  The resolution was passed unanimously.

GREENPEACE GOALS AND ACTIONS

Greenpeace is working towards greater protection of sea turtles
and their habitats.  This combines improving awareness of coastal
people and their governments of the dangers facing sea turtles,
combating international trade in sea turtle products, promoting
the use of TEDs, opposing damaging beach front developments on
critical nesting beaches, urging the shielding of existing beach-
front lighting to prevent it shining on the beach; establishing
beach patrols to protect nests and relocate the eggs into
protected hatcheries where necessary; and working within CITES to
ensure that no ranching or farming proposals will be allowed to
stimulate international trade.

In the USA, beach patrols covering 240km of north-east Florida
have been established to monitor the beaches every day during the
nesting season, and relocate the eggs into protected hatcheries
when the nests are laid too close to the water-line or in front
of brightly lit buildings.  These patrols have also been vital in
the collection of data on the number of dead sea turtles that
have drowned in the shrimp nets and washed up on the beaches.

This information has contributed to the successful campaign by
Greenpeace and other conservationists for the compulsory use of
TEDs in US waters.

The beach at Les Hattes in French Guiana has one of the largest
nesting colonies of leatherback sea turtles in the world.
Greenpeace organises an annual project there composed of
volunteers from around the world to protect the eggs, minimise
the disturbance to the nesting females from the many tourists and
rescue turtles stranded in the mud off the nesting beach.
In Costa Rica, Greenpeace has been working with fishermen to
develop economic alternatives to catching sea turtles and
supplying them with materials needed.  An annual Sea Turtle
Festival was established to promote awareness in the coastal town
of Limon whose fishermen have caught sea turtles for many years.

In the Mediterranean, Greenpeace has been involved in attempts to
find a solution to the incidental catch problem of the long line
fishing fleet.  It is estimated that 17,000 sea turtles are
caught on their hooks off Spain, although it is not known how
many mortalities result.

From Australia, Greenpeace is investigating the trade of
hawksbill shell in the Pacific region and encouraging better
monitoring of sea turtle mortalities in Australian waters,
particularly from incidental catches of the prawn fleets.
Greenpeace has donated TEDs in an effort to determine which kind
of TED is most suitable for Australian conditions.


In a number of countries in the Caribbean and elsewhere in the
world, Greenpeace is undertaking investigations into illegal
trade and the general consumption of sea turtles to determine if
alternatives can be developed to ease the continuing and
decimating pressure on the sea turtle populations.

WHAT YOU CAN DO

*  Never buy sea turtle products and encourage your friends to do
likewise.

*  Do not throw plastic litter into the sea or coastal waterways.
If you live near the sea, organise plastic clean-up campaigns.

*  When on sea turtle nesting beaches, do not disturb the adults
or hatchlings.  Avoid the use of white light: cover flashlights
with red plastic and do not take photographs until the females
have actually begun to lay their eggs.

*  If you live in a coastal state with sea turtle populations,
ask your government to pass legislation protecting sea turtles
and to implement the IUCN sea turtle resolution, especially the
establishment of maximum size limits to protect the breeding
adults.

*  In states with shrimp fleets, urge the shrimp fishermen to use
TEDs.

*  Urge people living next to sea turtle nesting beaches to shade
their lights to prevent them from shining on to the beach.

*  Write to the Japanese embassy in your country and ask Japan to
reduce the level of its imports of hawksbill shell.

*  Write to Greenpeace to request more information if any of the
above points are of particular interest to you.


Greenpeace International
176 Keizersgracht
1016 DW Amsterdam
The Netherlands
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