World Status, Exploitation and Trade - WIDECAST

FRENCH POLYNESIAPOPULATION:Chelonia mydasNesting sites The most important known site is Scilly (Manuae) atoll,situated at Ib^AO'S, 15A°40'W, in the Leeward Islands sector of the SocietyIslands group (Anon., 1979; Lebeau, 1985; Hirth, 1971). Mopelia, Tupai andBellinghausen, also in the Leeward Islands, appear to be of lesserimportance, and there is reportedly some sparse nesting in the Marquesas andon most atolls in the north of the Tuamotu group (Lebeau in litt . 1986).Nesting on Scilly is concentrated on the three islets in the south-east ofthe atoll; Motu Papai (Rahi), Motu Otue Oia and Motu Honu (Anon., 1979).Nesting numbers Department of Fisheries staff recorded 8-13 sets oftracks per night along about 3.5 km of beach on Motu Papai (= Rahi) and MotuOtue Oia, and 8-10 tracks/night on Motu Honu decreasing to 1-3 tracks/night(Anon., 1979). Surveys were made in 1972, 1973 and 1979, but the length andtiming of each visit is not clear, nor is the percentage of tracks thatended in nesting.Lebeau (1985) reported on three visits to Scilly in 1983-1984. Total numberof tracks observed and mean number of emergences per night on the threesouth-east islets are shown in Table 66. Table 67 shows the estimated totalfor the three south-east islets, estimated total for all of Scilly, and themean emergences per night on Scilly.Lebeau (1985) concluded that around 400 females were nesting annually onScilly at the time of his visits, with a total of around 800 nests and80 000 hatchlings a season. There are suspected to be 10-15 nests annuallyat several sites in the northern Tuamotu group and the Marquesas (Lebeau1986, in litt . ) , and the total nesting number in the Tuamotu and Marquesasgroups combined is suspected to be approximately equal to the number onScilly alone.Trends in nesting numbers Local informants, reported in Anon. (1979),stated that in 1940-1950 it was not unusual to be able to turn 100-150females a night on the Scilly nesting beaches; if correct, this indicates avery substantial decline in nesting numbers. Such decline appears to havecontinued into recent years (although it is unknown to what extent this isan artefact of natural seasonal fluctuations); Anon. (1979) recorded 8-13emergences a night on Motu Papai (= Rahi), while Lebeau in 1983-84 recordedthree at most. There are similar figures for the remaining two of the threesouth-east islets, which between them hold most nesting in Scilly. Declineis attributed by Anon. (1979) to excess harvest of adults for food.Nesting season According to Anon. (1979) there is some nestingthroughout the year, but with a well-defined peak season between Septemberand December. Lebeau (1985), however, found most signs of nesting duringhis October visit, fewer signs in February, but least in December-January.Foraging sites Little specific information is available. Lebeau (1986,in litt .) reports that juvenile C. mydas . greater than 1-2 years of age, arefrequently seen over the outer reef slope of many atolls in Polynesia.Migration While some C. mydas appear to be present throughout the yearat Scilly, long distance movements to possible foraging grounds, mainly inthe Melanesian region of western Oceania, have been demonstrated by tagreturns (summarised in Table 68).195