World Status, Exploitation and Trade - WIDECAST

INDONESIAnesting populations is inevitable if exploitation remains at the intensitythen prevailing. One additional factor is that nesting populations inIndonesia will to some extent be buffered against over-exploitation becausea significant, but unknown, proportion of the turtles caught at sea will beindividuals that forage in Indonesian waters but use distant nestingbeaches, outside Indonesian territory (see Migration section, below).Nesting season At some sites, such as Enu in the Aru group (Compost,1980) and the Sambas-Paloh beaches in north-west Kalimantan - perhaps atmost sites - some level of nesting persists throughout the year; at thelatter, nesting is concentrated in June-September, with a peak. inJuly-August. At Pangumbahan, nesting occurs all year round, with lowestactivity in January-March. Nesting in the South Natuna Islands and in theBerau Turtle Islands is concentrated in August-October, and in the Tambelangroup, in May-August (Schulz, 1984 and 1987).Foraging sites Foraging habitat, including seagrass and algal pastures,coral reef flats and marine shallows, appears to be very widespread inIndonesia, with the probable exception of certain areas where large riversflow into the sea, such as parts of the Sunda and Arafura shelves (parts ofKalimantan, Sumatra, Java and Irian Jaya) (Salm and Halim, 1984).Migration No long-term tagging programmes have been undertaken inIndonesia, and migratory movements of Indonesian nesting turtles areunknown. However, several female C. mydas tagged on distant beaches havebeen recovered in Indonesian territory, again demonstrating that migrant seaturtle populations are often a resource shared by more than one country.Countries known to provide nesting grounds for turtles foraging in Indonesiainclude: Australia (tagged in Queensland, recaptured in Ambon, Aru and IrianJaya) (Limpus and Fleay, 1983), Papua New Guinea (tagged on Long Island, 5of 14 recaptures from north-west Irian Jaya) (Spring, 1983), Sabah (tworecaptures, at Cempedek Island, south-east Sulawesi, and Kai Kechil, easternMoluccas) (de Silva in press, 1986), and, reportedly, Sarawak. Turtlesbearing tags said to be from the Sarawak turtle islands have, according tolocal informants reported by Schulz (1987), been recaptured on nestingbeaches in the South Natuna Islands and on mainland north-west Kalimantan.POPULATION: Eretmochelys imbricataNesting sites This appears to be the second most common sea turtle inIndonesia, and, as with C. mydas , nesting has been recorded at very manysites distributed virtually throughout the country. As reported by Salm andHalim (1984), nesting extends from islands off western Sumatra in the west,to Irian Jaya in the east, and from northern Sulawesi and northernKalimantan, to Timor, in the south. Known E. imbricata nest sites arelisted in Table 88, together with estimates of nesting numbers.Nesting numbers Available data on egg production, annual nests andfemale numbers are presented in Table 88 (information from Schulz, 1987, andsources cited therein). For the vast majority of nest sites, no directinformation on nesting numbers is available; however, the prevalent practiceof harvesting eggs has allowed a useful, if approximate, estimate of nestingnumbers to bo made, based either on official harvest records, on the rentalvalue of collection areas, or on unofficial local information. Schulz (1984and 1987) has visited several of the sites in west and central Indonesiathat had boon suspected to hold large nesting populations, and has providednesting estimates for many of them. Surveys are still required in some249