World Status, Exploitation and Trade - WIDECAST

THAILANDthe third (Table 200). L. olivacea is said to be more common than C . mydasin Pha Nga and Phuket Provinces (J. Mortimer in litt. . 12 May 1988).Nesting season Polunin (1975) reported that most sea turtle nesting onThailand's west coast, facing the Andaman Sea, takes place inDecember-March, during the north-east monsoon, but peak nesting on the eastcoast (Gulf of Thailand/South China Sea) is in March-September, roughlycorresponding to the south-east monsoon period. In Tarutao National Park(west coast) C. mydas starts nesting in late September and continuessporadically from January to late March, the peak being in late October(Ginsberg, 1981).POPULATION : Eretmochelys imbricataNesting sites Species-specific information is scarce, but E. imbricatais reported to nest at Ko Klang and Ko Kai in Tarutao National Park, Ko Kraand Ko Rung in the Ko Kut/Ko Chang group (near the Thai -Kampuchea border),Ko Kra (in the Gulf, off the Thai Peninsula), Similan Islands, SulinIslands, Songkhla Province, Pattani Province, and Narathiwat Province (Bainand Humphrey, 1980; Polunin, 1979; J. Mortimer in litt. , 12 May 1988).Nesting numbers Few details are available. The C. mydas : Eretmochelysnesting ratio was said to be around 4:1 at Ko Khram and 5:3 at Ko Kra (thesouthern of the two islands with the name) in 1956 (sources cited byPolunin, 1975). Some 171 000 eggs were harvested under licence at Ko Khramat this time, around 34 000 E. imbricata eggs may have been laid, perhapsindicating about 100 females a season. However, as noted for C. mydas(above), nesting on Ko Khram (as measured by egg yield) has declined by 70%between 1955 and 1973, and is likely to have declined further since.Mortimer ( in litt. , 12 May 1988) reported that on Ko Khram there were 70E. imbricata and 200 C. mydas nests in 1988. The estimated egg yield at KoKra was put at 10 000 by Polunin (1975); this could suggest some 3750Eretmochelys eggs and perhaps ten females a season. Only six nests werefound during beach surveys (not covering all beaches) in the 1981-1982season in Tarutao National Park (Saisorn, 1983). Fewer than 550 clutches(all species) are now laid annually on the west coast, and in 1987 250-270were laid at Ko Khram, where most east coast nesting occurs (Mortimer,1988b). Assuming three clutches per female, this corresponds to an annualnesting complement of around 180 and 80 females on the west and east coastrespectively. The majority will probably be C. mydas with some L. olivaceaand fewer Eretmochelys .Trends in nesting numbers The species is said to have become rare by1980 in Thailand (1980), and sea turtles in general have reportedly declined(Polunin, 1980; Piyakarnchana, 1985); however, little quantitativeinformation is available. A particularly rapid decline in turtles nestingin Tarutao National Park, where numbers had been high, had occurred by 1980(Ginsberg, 1981).Nesting season Little specific information for Eretmochelys . At TarutaoNational Park (west coast) Hawksbills are said to begin nesting afterC. mydas at the same site have passed their peak, possibly in January(Ginsberg, 1981).Foraging sites The species appears to be widely but sparsely distributedin Thai waters, but no information is available on favoured foraging sites.516