南海北部沉积物间隙水中营养盐研究

Studies on nutrients in sediment interstitial water in northern South China Sea

通过2004年9月对南海北部6个站位的采样分析,探讨了间隙水的营养盐含量及其空间分布特征,估算了沉积物-海水界面营养盐的扩散通量。结果表明,NH4-N含量为8.9—142.3μmol.L-1,是南海北部间隙水中营养盐的主要组分,占溶解态无机氮的比例范围为49.1%—75.2%。在平面分布上,NH4-N含量表现为近海高于远海,PO4-P则差别不大。NH4-N、NO3-N、NO2-N和PO4-P在沉积物-海水界面的平均通量分别为7.08、-0.61、-0.51、0.14μmol.(m2.d)-1。NH4-N、PO4-P主要是从沉积物向上覆水扩散,是底层水体营养盐的来源之一。

The concentrations and spatial distribution characteristics of NH1-N, NO1-N, NO2-N and PO1-P in sediment interstitial water in the northern South China Sea have been analyzed. The results showed that the concentration of NH,-N was 8.9 142.3μmol·L^-1, accounting for 49. 1% 75.2% of dissolved inorganic nitrogen. The concentration of NH1-N showeda trend of being higher along the coast than in the open sea, while that of PO4-P showed little difference. According to Fick＇s First Law, the average diffusion flux across sediment-water interface was 7.08μmol · （m^2 · d）^-1 for NH1-N, -0.61μmol · （m^2·d）^-1 for NO3-N,-0.51μmol· （m^2 · d）^-1 for NO2-N, and 0.14μmol · （m^2 · d）^-1 for PO1-P. The resuits indicated that NH1-N and PO4-P mainly diffused from interstitial water to overlying water, and may be one of the nutrient sources for bottom water.