Hawksbill Turtle
Eretmochelys imbricata (Linnaeus 1766)
IUCN Status Category: Critically Endangered
CITES Appendix: I
INTRODUCTION
The hawksbill turtle is a medium-sized cheloniid, usually less than 1m in length and weighs 4060kg. The shell is thin, flexible and highly coloured with elaborate patterns. As the English name
suggests, Eretmochelys imbricata has a narrow pointed beak reminiscent of a bird of prey.
Hawksbill turtles are mainly carnivorous and use their narrow beaks to extract invertebrate prey
from crevices on the reef. Both sessile and mobile animals are consumed, and Eretmochelys
imbricata would seem to be an opportunistic predator, although sponges normally constitute a
major proportion of its diet.
Nesting occurs widely throughout the range, but tends to be more dispersed than in other
species. There are seldom more than a few hundred nests on a single beach and few major
colonial nesting beaches. It has been suggested that this is simply a result of centuries of overexploitation. The hawksbill appears to nest every two to three years and lays 60 to 200 eggs at
a time. Nesting is mainly seasonal and varies with the location of the nesting beach. Yearround nesting has been recorded in some localities. The hawksbill often nests close to coral
reefs, and is often encountered by snorkellers and scuba-divers.
In the past, the hawksbill was thought by many to have a more sedentary life history than the
other species of marine turtle (Hendrickson 1980). However, more recent work involving satellite
telemetry has revealed that the hawksbill does make long distance migrations. In 1994,
Groshens and Vaughan found that all turtles tracked by satellite from Buck Island Reef National
Monument in St Croix, US Virgin Islands moved away after nesting; it is likely they utilise
completely different areas for feeding and breeding.
The carapace of the hawksbill is unusual amongst the sea turtles as the scutes (the hard, bony
plates that constitute the shell) are overlapping. These are often streaked and marbled with
amber, yellow or brown, most evident when the shell material is worked and polished. This
species is the sole source of commercial "tortoiseshell".
DISTRIBUTION
The hawksbill is pan-tropical and has only rarely been recorded outside the tropics. It can be
found in the eastern Atlantic from as far north as the coast of France to the southern tip of
Africa. There are feeding grounds in the Mediterranean. The range stretches from along the
east coast of Africa, the Middle East and India to South Asia and as far north as China. It can
be found in the coastal waters of Australia and Indonesia. In the Americas Eretmochelys
imbricata can be found in the east Pacific, from the United States to Peru, and in the west
Atlantic, from Nova Scotia to Brazil.
Breeding range states: American Samoa, Anguilla, Antigua and Barbuda, Aruba, Australia,
Bahamas, Bangladesh, Barbados, Belize, Brazil, British Indian Ocean Territory, Cambodia,
Cameroon?, Cape Verde?, China?, Colombia, Comoros, Cook Islands, Costa Rica, Cote
d'Ivoire, Cuba, Djibouti?, Dominica, Dominican Republic, Ecuador, Egypt, El Salvador?,
Equatorial Guinea, Eritrea, Federated States of Micronesia, Fiji, French Guyana, French
Polynesia?, Gabon?, Ghana?, Grenada, Guadeloupe, Guam, Guatemala, Guinea?, GuineaBissau?, Guyana, Haiti, Honduras, India, Indonesia, Iran, Jamaica, Japan, Kenya, Kiribati?,
Kuwait?, Madagascar, Malaysia, Maldives, Marshall Islands, Martinique, Mauritania?, Mayotte,
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Mexico, Montserrat, Mozambique, Myanmar, Netherlands Antilles, New Caledonia?, Nicaragua,
Nigeria?, Northern Marianas?, Oman, Palau, Panama, Papua New Guinea, Philippines, Puerto
Rico, Qatar, Reunion (Iles Glorieuses), Sao Tome and Principe?, Saudi Arabia, Senegal?,
Seychelles, Sierra Leone, Solomon Islands, Somalia, Sri Lanka, St Kitts and Nevis, St Lucia, St
Vincent, Sudan, Suriname, Taiwan?, Tanzania, Thailand, Tokelau, Tonga?, Trinidad and
Tobago, Turks and Caicos Islands, Tuvalu?, US Minor Pacific Islands?, United States. United
Arab Emirates?, Vanuatu, Venezuela, Vietnam?, Virgin Islands (British), Virgin Islands (US),
Western Sahara?, Western Samoa, Yemen [Atlantic (eastern central, north-east, north-west,
south-east, south-west, western central), Indian Ocean (eastern, western), Mediterranean and
Black Sea, Pacific (eastern central, north-west, south-east, south-west, western central)]
POPULATION
Worldwide numbers of sea turtle populations are very difficult to estimate. considering the wide
range of these migratory animals. From the nesting beaches, estimates are possible of adult
females. However, data are not recorded at all nesting sites. Even when data are recorded,
numbers may be confused due to the uncertainty as to how many times an individual nests in a
season. The adult female nesting population is largely unknown but 8000 + ? has recently been
estimated (Euro Turtle 1999). There are only five populations worldwide with more than 1,000
females nesting annually. (Kemf, et al. 2000)
Genetic studies of mitochondrial DNA (mtDNA) taken from Eretmochelys imbricata nesting on
beaches in seven Caribbean countries (Belize, Mexico, Puerto Rico, US Virgin Islands, Antigua,
Barbados, and Brazil) have shown that at least six of these colonies are isolated breeding
populations (Bass et al. 1996). The studies also show that foraging populations are drawn from
many different nesting colonies (Bowen et al. 1996); it is still uncertain whether females always
return to the same feeding ground. The significance of isolated breeding colonies in the
Caribbean is that a depleted population will not be replenished by immigration from elsewhere.
Expiration of a population will result in irreversible loss of genetic diversity.
In northern Australia, there appear to be two separate breeding populations of the hawksbill,
consisting of many nesting beaches. The closer colonies are related and colonies separated by
2,700km are genetically distinct. (Broderick et al 1994).
Major breeding population: There is evidence that a nesting colony on Milman Island in
Queensland, Australia is the largest hawksbill population in the world (Loop 1995).
THREATS
Because of overuse and other threats – including pollution, accidental drowning in fishing nets
or hooking by longline fishing, and habitat loss -- six of the world’s seven marine turtle species
are in danger of extinction. The hawksbill has been classified by the IUCN/SSC Marine Turtle
Specialist Group as “Critically Endangered”. All seven species of marine turtles are listed on
Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and
Flora (CITES), thus prohibiting international trade by more than 140 CITES member nations.
As with other species, Eretmochelys imbricata is threatened by the loss of nesting and feeding
habitats, excessive egg-collection, fishery-related mortality, pollution, and coastal development.
Despite their protection under CITES, as well as under many national laws, there is still a
disturbingly large amount of trade in Eretmochelys imbricata, and this probably constitutes the
major threat to the species.
Hawksbills have been hunted for centuries as a source of tortoiseshell ("carey" or “bekko”) for
jewellery and ornaments. In recent decades eastern Asia, and Japan in particular, has provided
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an eager market for tortoiseshell. Through international conventions and national legislation
some countries have sought with some success to restrict trade. In 1975, the hawksbill was
included on Appendix I of CITES. Many nations ended their shell imports and exports over the
next decade as they became parties to CITES.
Japan filed a reservation to CITES on the listing of the hawksbill on Appendix I and continued to
import enormous quantities of shell. Between 1970 and 1992, Japan imported about 33 tonnes
of hawksbill shell per year, a total equivalent to the deaths of 31,000 turtles annually (Marine
Turtle Newsletter 1994). Between 1970 and 1986, approximately 250,000 hawksbill turtles were
harvested in the Caribbean (Milliken and Tokunaga 1987). Japan withdrew its reservation to
CITES in July 1992, and stopped the import of turtle products in 1993.
However, illegal seizures of tortoiseshell at Japanese airports since 1994 include: 24 kg of
tortoiseshell from the Dominican Republic in 1994 (TRAFFIC 1994); 3,000 kg of tortoiseshell
from Indonesia in 1995 (TRAFFIC 1996); 115kg of tortoiseshell from Singapore in 1995
(TRAFFIC 1996); 66kg of tortoiseshell from Singapore in 1998 (TRAFFIC 1998).
Hawksbills are among the small juvenile turtles collected and stuffed for sale as tourist curios.
Although many countries have banned this trade, it still occurs. For example, stuffed hawksbill
turtles were openly on sale at Hanoi’s international airport in 1998. Harvest for domestic trade
still occurs in many countries, including Cuba, the Dominican Republic, Indonesia, Cambodia,
the Solomon Islands, and Fiji.
The hawksbill turtle is also subjected to many environmental threats. An unknown quantity of
turtles (some estimates are as high as 200,000 to 300,000 annually) are killed as "bycatch" (i.e.
incidentally), particularly in trawling nets. Decline was set in motion hundreds of years ago and
accelerated in this century by decades of egg-collecting and the killing of females; then it was
continued by trawler mortality. Longlines for tuna and swordfish are also responsible for killing
leatherback and loggerhead turtles, which are attracted to the baited hooks. The turtles either
become snared or tangled in the line and are then unable to reach the surface and drown (or in
some cases lose a limb). Turtles that have swallowed hooks almost certainly die as well,
although they may be released alive. This problem is particularly acute because these two
species feed on planktonic organisms that are found in highest concentrations along oceanic
fronts, areas that also support the highest densities of pelagic fish.
Beachfront lighting is also a problem that affects all turtle species. For example, a study in
Barbados found that of 55.6 per cent of nests, 100 per cent of the hatchling hawksbills crawled
inland instead of to the sea, distracted by the artificial illumination (Horrocks et al. 1989).
CONSERVATION AND RESEARCH ACTIVITIES
Trade ban on hawksbill products: Demand for tortoiseshell remains high in Japan and other
parts of East and Southeast Asia. In 2000, Cuba and Dominica have proposed to CITES
member nations to reopen international trade in tortoiseshell, and WWF has rejected their
proposal. (See the CITES Website at: http://www.cites.org and WWF's Website at:
http://www.panda.org)
Monitoring trade in turtles: TRAFFIC, the wildlife trade monitoring arm of WWF and IUCN,
documents the extent of the illegal international trade and is working to bring violations of
international treaties to the attention of government authorities. Such violations appear to be
widespread: there is still a substantial underground trade in tortoiseshell, leather boots, whole
turtles, meat, and eggs. For example, customs officials made a number of seizures of illegal
turtle shells from Indonesia at European Union borders between 1990 and 1995. In September
1998, police officers in Japan arrested five people attempting to smuggle 66kg of tortoiseshell
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into the country. In the United States, a number of arrests have been made recently at
international airports in Florida, New York, and California, where people have been caught
smuggling turtle eggs and meat in their luggage. The contraband finds its way to "ethnic"
restaurants, where it is sold as a delicacy at high prices. As the trade in sea turtle eggs appears
to be on the increase, TRAFFIC is stepping up its efforts to collect and disseminate information
on its extent, so that more effective protection and management can be implemented.
TRAFFIC is also working with governments to improve protection of species threatened by
trade, even where that trade is largely internal and legal. TRAFFIC North America has just
completed a review and legal analysis of the fisheries and primarily commercial trade in marine
turtles in the Bahamas, Cuba, Dominican Republic, Haiti, Jamaica, Mexico, Puerto Rico, Turks
and Caicos Islands, British Virgin Islands, and US Virgin Islands.
Disposing of stockpiles: The government of the Seychelles has taken a different approach to
marine turtle conservation. In 1988, it burnt its 2.5 tonne stockpile of tortoiseshell. Although the
Seychelles once a huge source of tortoiseshell, recently the government has begun to take very
strong action against this illegal activity. (Associated Press 1998) An artificial substitute to
tortoiseshell has been developed, but goods manufactured from it have yet to acquire the same
desirability as real shell.
LEGAL STATUS
The hawksbill turtle is listed on Appendix I of CITES; thus, member nations of the Convention
are prohibited from international trade in this species and its parts.
Turtles are ideally matched to the aims expressed by the Convention on the Conservation of
Migratory Species of Wild Animals (known also as the Bonn Convention or CMS). The text of
the CMS includes many of the concepts fundamental to regional conservation of migratory
marine animals and their habitats. With the exception of the flatback (Natator depressus), all
species of sea turtles are listed in both Appendix I and Appendix II of the Bonn Convention. The
Inter-American Convention for the Protection and Conservation of Sea Turtles (IAC) is the only
major international treaty dedicated exclusively to sea turtles and their habitats, formally setting
standards for their conservation.
The IAC recognizes that sea turtles migrate and that they are resources shared by the peoples
of many nations. Hence, the IAC has been vigorously supported by many members of the
international community of sea turtle biologists and conservationists, particularly specialists from
Latin America.
WHAT WWF IS DOING FOR MARINE TURTLES
Mediterranean
In 1998, WWF published recommendations for a new approach to conserving the
Mediterranean’s turtles.These set out a number of urgent measures to reduce mortality of adult
and sub-adult turtles, including: reduction of deliberate killing, especially in Egypt; reduction of
bycatch in bottom trawls, especially in the eastern Mediterranean, longline fisheries and a
variety of small coastal fisheries; and education aimed at reducing mortality of turtles
accidentally caught by all kinds of fisheries. Efforts must continue to protect nesting beaches in
Greece, Turkey, and Cyprus, to limit damage by urban and tourist developments, and to reduce
predation by dogs and foxes.
WWF is working to establish a fully representative network of protected areas. As part of its
"Out of the Blue" programme for the conservation of the Mediterranean, WWF has started to
place observers on Italian longline fishing fleets to monitor fish catches and document the extent
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of sea turtle and shark bycatch and mortality. To date, the monitoring programme has been
hampered by the unwillingness of many fishing captains to allow observers on board.
Indo-Pacific
In 1999, WWF together with a network of NGOs and governments participated in the 2nd
Association of Southeast Asian Nations (ASEAN) sea turtle meeting, 15-17 July in Sabah,
Malaysia. Coordinating measures for marine turtle protection on a regional basis is a priority for
marine turtle conservationists. The region's marine turtles and other species are threatened by
coastal development, sand and coral reef mining, pollution, unsustainable egg-collection, and
entanglement in fishing nets or accidental killing by longline fisheries. In Malaysia alone, the
numbers of four species of marine turtles have fallen dramatically in recent decades with
leatherbacks in critical danger. Despite government and WWF efforts over the past 30 years,
sea turtles are in a state of decline not only in Malaysia but also throughout the region. The
creation in 1996 of the Turtle Islands Heritage Protected Area, a group of nine islands shared by
the Philippines and Sabah, Malaysia offers some hope for the future.
Western Indian Ocean
In November 1995, WWF co-sponsored an MTSG-IUCN regional meeting in the Western Indian
Ocean to identify priority activities for marine turtle conservation. WWF is following up on the
recommendations of the MTSG’s Marine Turtle Conservation Strategy and Action Plan for the
Western Indian Ocean and is working to strengthen the network of turtle biologists in the region.
Since 1996, WWF has sponsored regional scientists to attend international marine turtle
meetings, and in 1997, co-sponsored a workshop on Turtle Excluder Device (TED) technology
for resource managers and fishermen from Kenya, Tanzania, Eritrea, Madagascar, and
Mozambique.
WWF is involved in a number of marine protected areas on the east coast of Africa, including
Mafia Island in Tanzania, the Kiunga Reserve in Kenya, and the Bazaruto Archipelago in
Mozambique. A prime objective in all these areas is to ensure that marine resources are used
sustainably by local communities and that critical habitats for coral fish, marine turtles, and
dugongs are protected.
Central American Region
Annually, more than 80,000 turtles, mainly greens and hawksbills, are still captured off the
coasts of Central America. WWF is working to encourage local communities and fishermen to
protect turtles through the use of TEDs. Other initiatives include campaigns to keep trash, such
as plastic bags and twine from banana plantations, out of rivers and oceans. WWF is also
encouraging the establishment of wildlife refuges and sanctuaries and supporting patrols on
turtle beaches. In addition, WWF is supporting measures to reduce the harmful effects of street
lighting near beaches. A major effort to conserve marine turtles in the Central American region
is being made through the Central American Environment Programme (Programa Ambiental
Centroamericano -- PROARCA), which seeks to promote integrated coastal management and
protected areas programmes.
Western Atlantic - The Wider Caribbean
Within the wider Caribbean, WWF has addressed threats to the region’s six endangered
species of marine turtles. One of the first steps taken by WWF was the co-sponsoring of a
meeting in November 1999 on Marine Turtle Conservation in the Wider Caribbean: a Dialogue
for Regional Management. Recommendations arising from this meeting will be used to
implement regional consensus on marine turtle conservation by identifying actions needed for
their recovery, and examining ways governments could cooperate to undertake these actions.
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Other WWF initiatives include measures to develop a network of protected areas within the
MesoAmerican Caribbean Reef Ecoregion to protect critical habitat (mangroves, seagrass beds,
and coral reefs) for hawksbill and green turtles.
Guyana Shield Ecoregion
WWF has been supporting marine turtle conservation in the Guyanas since the 1960s. This
biologically rich area comprising Guyana, Suriname, French Guyana, and parts of Venezuela,
Colombia, and Brazil has many important turtle nesting beaches along its coasts. Suriname is
host to four species
Anguilla
WWF has supported the Anguilla National Trust in managing its sea turtle conservation
programme, which included a survey of turtle nesting beaches. Anguilla imposed a five-year
moratorium on harvesting of both adult turtles and eggs in 1995, but the number of nesting
turtles is still declining. In the last few years, more young hawksbills and greens have been seen
in Anguillan waters, but the conservation effort will have to continue for many more years before
populations begin to recover.
Venezuela
WWF’s associate in Venezuela, FUDENA, has worked for two decades on sea turtle
conservation on the Isla de Aves and the Laguna de Tacarigua National Park. The
organisation's activities on Isla de Aves include yearly monitoring and tagging of females during
their nesting period. FUDENA’s "Adopt a Sea Turtle" campaign helps to support this
programme. In Laguna de Tacarigua, FUDENA collaborates with several partners to involve
local communities in the protection of sea turtle nests.
Eastern Atlantic
Mauritania
The Banc d’Arguin National Park, an important nesting and feeding ground for green and
loggerhead turtles, has been supported by WWF since 1976. Observers estimate that several
thousand turtles are killed each year as bycatch in the offshore shark fisheries. It is hoped that
WWF’s work on fisheries management will help to turn this situation around and have a positive
impact. Tag recoveries show that the Banc d’Arguin’s green turtles come from as far away as
Florida, although others originate in the Archipelago dos Bijagos in Guinea-Bissau.
References
Associated Press. 1998. Destruction of Turtle Shell Stockpile. In Marine Turtle Newsletter
83: 22—23.
Bass, A L, Good, D A, Bjorndal, K A, Richardson, J I, Hillis, Z M, Horrocks, J A, and B W
Bowen. 1996. Testing models of female reproductive migratory behaviour and population
structure in the Caribbean hawksbill turtle, Eretmochelys imbricata, with mtDNA sequences.
Molecular Ecology. 5: 321-328.
Bowen, B W, Bass, A L, Garcia-Rodriguez, A, Diez, C E, van Dam, R, Bolten, A B, Bjorndal, K
A, Miyamoto, M M and R J Ferl. 1996. Origin of hawksbill turtles in a Caribbean feeding area as
indicated by genetic markers. Applications. 6 (2): 566-572.
Broderick, D, Moritz, C, Miller, J D, Guinea, M, Prince, R I T and C J Limpus. 1994. Genetic
studies of the hawksbill turtle Eretmochelys imbricata: evidence for multiple stocks in Australian
waters. Pacific Conservation Biology. 1(2): 123-131.
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6
Dominguez, T G and Villalba, A A, 1994. Trade of hawksbill carapaces in Santo-Domingo,
Dominican Republic. In: Bjorndal, K A, Bolten, A B, Johnson, D A and P J Eliazar (compilers).
Proceedings of the Fourteenth Annual Symposium on Sea Turtle Biology and Conservation.
NOAA Technical Memorandum NMFS-SEFSC-351, 323pp: 34-35.
Euro Turtle. 1999. Species distribution: hawksbill turtle--Eretmochelys imbricata.
http://www.ex.ac.uk/NEDASSET/dhawks.htm
Groshens, E B, Vaughan, M R. 1994. Post-nesting movements of hawksbill sea turtles from
Buck Island Reef National Monument, St. Croix, US Virgin Islands. In Schroeder, B A and
Witherington, B E (compilers). Proceedings of the Thirteenth Annual Symposium on Sea Turtle
Biology and Conservation. NOAA Technical Memorandum. NMFS-SEFSC-341. US Dept. of
Commerce, Miami, FL, USA. 278 pp.
Hendrickson, J R. 1980. The ecological strategies of sea turtles. American Zoology. 20: 597-609
(original not seen, quoted from Eckert, K L Hawksbill Sea Turtle, Eretmochelys imbricata. In
Plotkin, P T (ed). 1995. National Marine Fisheries Service and U.S. Fish and Wildlife Service
Status Reviews for Sea Turtles Listed under the Endangered Species Act of 1973. National
Marine Fisheries Service, Silver Spring, Maryland, USA.
Kemf, E, Groombridge B, Abreu A, Wilson, A. 2000. Wanted Alive! Marine Turtles in the Wild,
WWF International, Gland, Switzerland.
hLoop, K. 1995. Hawksbill nesting on Milman Island, Great Barrier Reef, Australia JanuaryMarch 1991. Pp. 73-76. In Richardson, J I and Richardson, T H (compilers). Proceedings of the
Twelfth Annual Workshop on Sea Turtle Biology and Conservation. NOAA Technical
Memorandum. NMFS-SEFSC-361. US Dept. of Commerce, Miami, FL., USA. 274pp.
Marine Turtle Newsletter. 1994. Tortoiseshell trade: end of an era? Marine Turtle Newsletter
66: 16 -17.
Meylan, A B. 1999a. International movements of immature and adult hawksbill turtles
(Eretmochelys imbricata) in the Caribbean region. Chelonian Conservation & Biology 3(2189194.
Meylan, A B. 1999b. Status of the hawksbill turtle (Eretmochelys imbricata) in the Caribbean
region. Chelonian Conservation & Biology 3(2):177-184.
Meylan, A B. and Donnelly, M. 1999. Status justification for listing the hawksbill turtle
(Eretmochelys imbricata) as Critically Endangered on the 1996 IUCN Red List of Threatened
Animals. Chelonian Conservation & Biology 3(2): 200-224.
Milliken, T and Tokunaga, H. 1987. The Japanese Sea Turtle Trade 1970-1986 A Special
Report. Prepared by TRAFFIC (Japan). Funded by Center for Environmental Education,
Washington, D.C. 171 pp.
TRAFFIC Bulletin. 1999. 17 (3): 120
TRAFFIC Bulletin. 1996. 16 (2): 75
TRAFFIC Bulletin. 1994. 14 (3): 116
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