World Status, Exploitation and Trade - WIDECAST

THAILANDHistorical trends Historical data on the levels of egg harvest have beenreviewed by Polunin and Nuitja (1982), who concluded that the harvest haddeclined since the 1950s. The most complete data are available for Pha NgaProvince (Table 200), which show a significant (as tested by Spearman's RankCorrelation Co-efficient) decline in the decade preceding 1973 (Polunin andNuitja, 1982). Another major egg collection site is Ko Khram Island, in theGulf of Thailand, where average annual egg yields reported for thethree-year periods 1955-57 and 1963-65 and the two-year period 1972-73 wererespectively 171 402, 185 000 and 50 850. In 1987, 26 000 eggs were laid atKo Khram (J. Mortimer in litt. , 12 May 1988).Official statistics for the reported egg harvests for the whole of Thailand,compiled by the South East Asia Fisheries Development Centre in theirFishery Statistical Bulletins for the South China Sea Area between 1978 and1983 (Table 201) do not show any discernible trend, but it is not known howreliable these figures are. Polunin (1975) estimated that the reportedfigures should be increased by 50% to take account of the local consumptionof eggs, and said that statistics were lacking for many areas.Table 200. Reported egg yields from three districts in Pha Nga Province.Data for some years are lacking or Incomplete (Polunin, 1975).