World Status, Exploitation and Trade - WIDECAST

BRITISH INDIAN OCEAN TERRITORIESPOPULATION:Chalonia mvdaaNesting sites Nesting has been reported in the past on Peros Banhos,Salomon, and Diego Garcia (sources cited in Frazier, 1977), and wasconfirmed more recently on Nelson, an atoll in the Great Chagos Bank, byFrazier (1977). The 1978-79 Joint Services Chagos Research Expedition foundsigns of nesting on 11 of 17 islands visited on Peros Banhos, and on 11atolls visited on Salomon Atoll. Of the Peros Banhos nests, nearlyone-third were on Ye Ye, and more than half the Salomon nests were onAnglais (Dutton, 1980). Most of the islands comprising the ChagosArchipelago are little visited, and nesting is likely to be more widespreadthan is currently known (Frazier, 1977).Nesting numbers On present information, the nesting population isrelatively small, probably comprising little more than 300 females (Frazier,1977). The only direct evidence concerns Nelson Island, in the Great ChagosBank, where Frazier recorded two dozen nest pits on 25 July 1970. Frazier'sinformants on Peros Banhos suggested 40-100 turtles could be caughtannually, and on Salomon Atoll, only two or three. The 1978-79 JointServices Chagos Research Expedition found a total of 88 turtle nests on 11of 17 islands visited on Peros Banhos, and 11 nests on 11 atolls visited onSalomon Atoll (Dutton, 1980). Since all turtles actually seen (apparentlyat sea) were E. imbricata . the observed nesting may well have been by thisspecies; however, Frazier (1982, citing information from Dutton) states thatnests and tracks were large and thought likely to be by C. mydas .Trends in nesting numbers No reliable information is available.Nesting season Nesting appears to be concentrated in June-September,during the south-east trades.Foraging sites No details are available. Foraging grounds, comprisingseagrass and algal beds, do not appear to be notably well-developed orwidespread in the Archipelago, although several such sites are known(Frazier, 1977).POPULATION: Eretmochelys imbricataNesting sites Although the species has been reported from Peros Banhosand Diego Garcia, and local informants indicated to Frazier (1977) that thespecies occurs at Salomon and Egmont Atolls, there appears to be very littlerecent confirmed evidence of E. imbricata nesting. Frazier found one neston lie du Coin (Peros Banhos). The past nesting activity recorded in1978-1979 at Peros Banhos, notably on Ye Ye, and at Salomon, notably onAnglais, may have been by E. imbricata . since all the turtles seen inadjacent waters were this species (Dutton, 1980); however, the signs havebeen attributed to C. mydas (Dutton, cited in Frazier, 1982).Nesting numbers Frazier (1977) estimated the annual nesting femalepopulation to be 300; this figure is based mainly on annual numbers said tobe harvested recently and in the past, not on modern field survey.Trends in nesting numbers No reliable information is available.Nesting season Available information suggests that nesting occurs eitherin July-September and/or in November-February (Frazier 1977).104