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Summary of full report
Captive Breeding and
Marketing of Turtles
by Grahame J.W. Webb, S. Charlie Manolis and Michelle Gray
February 2008
RIRDC Publication No 08/012 RIRDC Project No WMI-3A
Background
Wild sea turtles have a
long history of being harvested for meat, eggs, leather and other products.
But harvesting has often been excessive and unsustainable, causing declines
in wild stocks, and generating conservation problems. Experimentation with
sea turtle farming was initiated at the same time as crocodilian farming,
but commercial incentives to develop these technologies to their full potential
with sea turtles were constrained, largely by the Convention on International
Trade in Endangered Species of Wild Fauna and Flora (CITES). The harvest
of wild eggs (ranching) is considered a safe form of wild harvest because
it relies on, life stages that have little chance of survival to adulthood,
and it also links gains by industry to the maintenance of the natural resource.
Captive breeding is perceived as being the safest form of use because its
impact on wild populations is negligible, and as such, once the techniques
and protocols for captive breeding have been developed and proved, it is
the easiest pathway through CITES for international trade. Unlike other
sea turtle species, there is a high international demand for the valuable
shell of Hawksbill turtles, and meat and other by-products could also be
marketed domestically and internationally.
The high demand for freshwater turtles in Asia for food, particularly in China, has placed great pressure on wild populations. To meet the demand, captive breeding of turtles has expanded greatly over the last 10-15 years, in China and other Southeast Asian countries (eg Vietnam, Malaysia, Thailand, Cambodia, Taiwan). The reasons why certain species are sought over others are unclear, although soft-shelled turtle species dominate the food market. The distinction between food and medicine in Chinese culture is not clear, and certain foods, like freshwater turtles, shark fin and bird's nest, have medicinal properties attributed to them, and are considered "good for your health".
Aims/Objectives
The aim was to advance our
understanding of the captive husbandry of Hawksbill turtles. The primary
objective was to develop and test a prototype pen for captive breeding
of farm-raised E. imbricata. A secondary objective was to advance our understanding
of potential market opportunities for Australian turtle meat and other
products (including freshwater turtle species), and to assess ways in which
access to those markets may be able to be realised.
Methods used
A breeding pen incorporating
water and sandy “beach” areas was built in Darwin, NT. Captive-raised Hawksbill
turtles (hatched March 1996) were placed in different densities and sex
ratios, over one breeding season. Water parameters, growth rates and reproductive
behaviours were monitored over the period of study. Information on the
demand for Australian turtles was sought through literature searches and
communication with wildlife authorities, non-government organisations and
private individuals (eg restaurants, Traditional Chinese Medicine practitioners),
and attendance at meetings (eg CITES 2002, 2004) and sea turtle symposia
(2003, 2004, 2005), and visits to countries in Asia (eg China, Singapore,
Malaysia, Japan, Cambodia, Indonesia, Vietnam and Thailand). In particular,
information on potential differences in quality between different species
was sought.
Results/Key findings
Hawksbill turtles are amenable
to captive raising, display high growth rates and early attainment of maturity
(males as early as 1.5 years, females <6 years). The study spanned one
breeding season, and unforeseen problems occurred when turtles were placed
together. Nonetheless, the development of ovarian follicles by females
and mating behaviour indicated that captive breeding is possible, as demonstrated
with Green turtles (Chelonia mydas) in the Caribbean. Suggested modifications
to the prototype breeding pen include provision of areas of warm water
during the cool season, and mechanisms (eg evaporative cooling) to cool
water during the warmer times of the year.
Domestic trade is the most promising option for a turtle industry in Australia in the short-term, for food and perhaps other products (eg shells) for the growing Traditional Chinese Medicine industry.
The Environment Protection Biodiversity Conservation 1999 Act is an impediment to international trade from Australia, as it prohibits live exports of native species for commercial purposes. A strong market appears to exist for Australian freshwater turtles as pets in Europe and the USA, but their suitability for the Asian market remains unknown. It is unlikely that processed (frozen) turtles from Australia could compete with live turtles that can be obtained readily from farms and other sources in the Asian region. However, with the demand on wild turtle populations in Asia and the increased regulation of trade through CITES, this situation may well change over time.
Implications for relevant
stakeholders
Hawksbill turtles are highly
amenable to ranching and subsequent raising in captivity, and early maturation
in captivity supports their potential for captive breeding. An industry
based on Hawksbill turtles could involve indigenous landowners, who have
shown an interest in this type of wildlife industry over many years. In
Australia, most nesting areas for E. imbricata lie on indigenous land.
Captive breeding provides a shorter route for approval of international trade through CITES, and would be the most logical approach to take in the first instance, rather than ranching. A domestic market for freshwater turtles as food could be developed in Australia, and assessment of other derivatives such as the shell for Traditional Chinese Medicine could be undertaken at the same time.
Ranching of freshwater turtles presents an opportunity for economic development of indigenous landowners, and has already been initiated by one community in Arnhem Land. The sustainable use of wildlife is now recognised as a legitimate tool that can contribute to conservation, thereby indirectly benefiting the wider community as a whole.
Recommendations
Successful nesting of Hawksbill
turtles involves a complex interaction between a suite of social, behavioural,
physiological and environmental factors prior to and during the breeding
season. Further research over a longer period of time would help quantify
optimum conditions for captive breeding of the species. A more detailed
analysis of potential markets for freshwater turtles, with particular emphasis
on species that that are amenable to ranching and/or captive breeding,
would allow costbenefits for domestic trade to be estimated more realistically.
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