Preliminary analysis of Pinctada maxima in nature reserves along coastal area in the northern South China Sea

Pinctada maxima, a first class national protected wild animal with high social, economic and ecological value, is a unique pearl oyster species in the South China Sea. The distribution and status of P. maxima resources were investigated by diving section method in Yangpu and Lingao Pearl oyster Nature Reserve and western Leizhou Peninsula Nature Reserve. The results show that frequency of P. maxima was 54. 55% in Lingao waters. Habitat density ranged from0 to 0. 25 indm-2 . Biomass ranged from0 to 70. 31 gm-2 in Lingao waters. Frequency of P. maxima was 15. 38% in Yangpu waters. Habitat density ranged from0 to 0. 10 indm-2 . Biomass ranged from0 to 22. 55 gm-2 . Frequency of P. maxima was 65. 00% in west Leizhou waters. Most stations habitat density ranged from0. 10 to 0. 20 indm-2 and the maximumhabitat density was 0. 30 indm-2. The maximumbiomass was 390 gm-2 in west Leizhou waters. The analysis reveals that the current age structure of P. maxima is relatively unreasonable, which indicates that the stock structure has been destroyed and its recovery ability is weak.