World Status, Exploitation and Trade - WIDECAST

INTRODUCTIONthe main source but some Green Turtle skins are traded. Immatures andsub-adults, particularly Hawksbills, are frequently traded as curios,stuffed and varnished.6. Historically, the international trade in Green Turtle meat developedbetween European countries and their colonies in the tropics. An estimated15 000 Green Turtles were imported into England in one year in the late 19thcentury, and very large numbers were taken during the 20th century, mainlyfrom the Caribbean and the western Indian Ocean. There is little evidencefor continuing international trade in Green Turtle meat; this can beattributed largely to effective implementation of CITES. Some meat has beenexported from Cayman Turtle Farm and from the ranch on Reunion. Domestictrade is very extensive in some countries (e.g. Indonesia and Mexico) and iscausing serious decline in Green Turtle populations.7. A market for tortoiseshell derived from the carapace and marginal scutesof Eretmochelys ("bekko" in the Japanese trade) has existed for manycenturies. A single turtle yields between 0.75 and 1.5 kg of tortoiseshellin the form of 13 carapace scutes, with an average of around 1 kg; the 27small marginal scales are less in demand. After a brief period of declinein demand owing to the introduction of plastic substitutes, demand has beenvery high in recent decades. Japan is the destination of most rawtortoiseshell in international trade, although the Republic of Korea andTaiwan are also major importers. Customs data indicate that in 1986 Japanimported shell from around 26 000 large Hawksbills, and about 8 000 smallerstuffed Hawksbill. The American and European trade is now insignificant incomparison, although some tortoiseshell is still used in France andF.R. Germany.8. Mortality is highest in eggs and hatchlings and lowest in adults; largersub-adults and adults are of greatest reproductive value to the populationand exploitation of these classes, together with juveniles, must be avoidedwhenever possible. Regular exploitation of adult females on the nest beach,and of adults in inter-nesting habitat, can lead to severe and rapid declinein the nesting contingent of the target population (e.g. C. mydas in PacificMexico); egg harvesting has a less rapid effect on population size, butwherever good long-term records are available (e.g. Burma, Sarawak)continual intense egg harvesting has been shown to lead to severe populationdecline, albeit over decades rather than years. Exploitation of turtles onfeeding grounds will affect both sexes and various age classes, and inprinciple, if practised In moderation, would be expected to constitute aless acute threat to turtle populations than nest beach exploitation.However, tracing the causal connection between turtle numbers on the nestingbeach and turtle harvest on distant foraging grounds is difficult; wheresuch harvesting is Intense serious concern is justifiable (e.g. Indonesia,where there is much evidence of population decline).9. It Is likely that the type of low-intensity exploitation of Green Turtlethat was in the past practised in remote places by certain littoral peoples(e.g. the Seri and Nahuatl In Mexico) is ever less likely to persist at lowintensity. Any restraint that was exercised was probably due not to anintuitive understanding of turtle population dynamics, but to low humandensity, technological limitations to the processes of turtle harvesting,transport and storage, and limited opportunity for trading. There are nowmany more people Inhabiting tropical coasts than there were at the turn ofthe century; more beaches and foraging grounds are easily accessible due tothe construction of roads; fishing communities have aluminium boats.