Distribution of Dissolved Inorganic Phosphate in Nansha Islands Sea Area,Southern South China Sea

Based on the survey data from the program Multidisciplinary Expedition to Nansha Islands Sea Area, the distribution of dissolved inorganic phosphate ( PO43--P ) in the sea water of Nansha Islands Sea Area is comprehensively analyzed in this paper. The results show that PO43--P concentration in the sea water of southeastern Nansha Islands Sea Area is commonly higher than that in the other sea areas; the vertical distribution of PO43--P concentration varies inconspicuously in different seasons; the concentration of PO43--P increases with water depth and changes most greatly in the layer of 50 ~ 100 m. The diurnal variation of PO43--P concentration differs in different seasons and at different observation stations. The distribution and variation of PO43--P concentration result from the physical and biological processes together.