World Status, Exploitation and Trade - WIDECAST

INDONESIAPOPULATION:Chalonia mydaaNesting sites Nesting by C. mydas . generally regarded as the most commonsea turtle in Indonesia, has been recorded at very many sites distributedvirtually throughout the country. As reported by Salm and Halim (1984),nesting extends from islands off western Sumatra in the west to Irian Jayain the east, and from islands near the border with the Philippines in thenorth to Timor in the south. Known C. mydas nest sites are listed inTable 81, together with estimates of nesting numbers.Nesting numbers Available data on egg production, annual nests andfemale numbers are presented in Table 81 (information from Schulz, 1987 and1989, and sources cited therein). For the vast majority of nest sites, nodirect information on nesting numbers is available; however, the prevalentpractice of harvesting eggs has allowed a useful, if approximate, estimateof nesting numbers to be made, based either on official harvest records, onthe rental value of collection areas, or on unofficial local information.Schulz (1984 and 1987) has visited most of the sites in west and centralIndonesia that had been suspected to hold large nesting populations, and hasprovided nesting estimates for many of them. Surveys have recently beencarried out in more easterly parts of the country, including Sulawesi andthe Moluccas (Schulz, 1989), but full results are not yet available.Nesting numbers at most sites are regarded as low to moderate by Nuitja andAkhmad (1982). This appears to be confirmed by data collected during thelUCN/WWF Marine Conservation Programme undertaken in conjunction with thePHPA (Salm, 1984, cited in Schulz, 1987; Salm and Halim, 1984).Polunin (1975) cited egg collection data relating to west Kalimantan, theBerau region of east Kalimantan, Sukabumi (near Pangumbahan and adjacentbeaches) in west Java, Jember (near Sukomade) in east Java, and the RiauIslands. Very approximately nine million eggs were collected in the1961-1962 period. Polunin calculated (on the basis of mean clutch size andmean renestings per female) that well over 30 000 female turtles, mostlyC. mydas , were nesting annually in western Indonesia (Sumatra, Java, Bali,Kalimantan, and adjacent islands) at that time. Similarly, Polunin andNuitja (1982) concluded that some 25 000 C. mydas nested annually in westernIndonesia.Salm and Halim (1984), on the basis of more extensive survey data, suggestedthat between one quarter and half a million C. mydas may reside inIndonesia, with many more foraging In the country but nesting elsewhere;these authors also suggest that there are between 65 000 and 120 000 nestingC. mydas present. This last estimate would Imply, given a three yearbreeding cycle, that between 21 700 and 40 000 C. mydas nest annually.Schulz's recent fleldwork (1984 and 1987) has allowed realistic estimates tobe made for nesting at sites previously unknown, and has necessitatedrevision of some older estimates for certain sites. The most recentestimate, based on the best available evidence (Schulz, 1987), suggestsbetween 25 000 and 35 000 females nest annually in Indonesia; this isbroadly compatible with Salm and Halim' s figures.Several sites within Indonesia hold sufficiently large nesting numbers thatindividually they would rank among the more important of the known worldnesting beaches. These are, In west-east order:Ieach of the Anambas, South Natuna and Tambelan groups (RiauProvince, South China Sea),239