World Status, Exploitation and Trade - WIDECAST

INDONESIAparts of Riau and in Sulawesi, the Moluccas and Irian Jaya. In general,because of the highly dispersed nesting pattern of E. imbricata . with smallnumbers nesting, sometimes on beaches more heavily used by other species,estimates of Hawlcsbill nesting numbers are likely to be less reliable thanin the case of C. mydas .Nesting numbers at almost all sites are regarded as low to moderate byNuitja and Alchmad (1982). This appears to be confirmed by data collectedduring the lUCN/WWF Marine Conservation Programme undertaken in conjunctionwith the PHPA (Salm, 1984; Salm and Halim, 1984). Schulz (1987) hasmodified earlier figures provided by Salm (1984, not seen) on the basis ofinformation received from turtle traders in Ujung Pandang; however, heconsiders the estimate of around 25 000 Hawksblll nests per year to be toolow, perhaps far too low.Schulz (1987) preferred not to extrapolate from estimates of nests per year,to number of females nesting per year, because less information is availableon E. imbricata wi thin-season re-nesting frequency than for C. mydas . Ifeach female re-nests three or four times a year, between 5 000 and 10 000females may be nesting annually.Sambas-Paloh beachesThese beaches, some 50 km in length, are located in north-west Kalimantanbetween the mouth of the Paloh River and the border with Sarawak. Thebeaches are apparently subject to rapid changes in morphology, due toerosion and deposition caused by wave action. Although large numbers ofHawksbills had been reported to nest in the area, much of the reputednesting by this species is by Olive Ridley Lepidochelys olivacea . Schulz(1987) found that although the small sized eggs of both species areofficially reported as Hawksbill, the local egg collectors admit thatnesting by both species occurs, apparently in the proportion of aboutone-fifth E. imbricata to four-fifths L. olivacea . On this basis, some 200E. imbricata nests were laid annually in 1981-1984 on Selimpai and Mutusanbeaches, and on P. Tua, all near the mouth of the Paloh River.South Natuna IslandsRiau Province, including several Island groups in the South China Searegion, has for some time been regarded as an important turtle area, andfishermen in north-west Kalimantan spoke of concentrations of turtles in theSouth Natuna and Tambelan Islands (Schulz, 1987). Both E. imbricata andC. mydas nest in the South Natuna group, including Serasan, Perhantuan andSempadi , approximately in the proportion of one of the former species toevery eight of the latter. Schulz (1987) considered Sisi beach on SerasanIsland to be one of the finest turtle nesting beaches he had yet seen inIndonesia, along with Pangumbahan and Sukamade. Nesting habitat is good;P. Perhantuan is a typical "Hawksbill island": a small, well-vegetated anduninhabited oceanic island, with a wide coral reef and a high beachplatform. The other South Natuna Islands are similar. Good feeding habitatis thus widespread, and is similarly so in the North Natuna group, althoughhere there is little nesting and the local feeding E. Imbricata aresuspected to nest in the South Natuna group (Schulz, 1987). The mainnesting season for E. imbricata is said to be March-May. Egg harvest dataIndicate a yield of around 125 000 E. imbricata eggs annually, and (giventhe assumption of a mean clutch size of 120) around 7 500 nests (Schulz,1987).252