摘要:
根据1998年7月和1999年1月两个航次的调查资料,对南海水体中磷的含量分布以及夏、冬季变化规律进行了探讨.结果表明,南海表层水体中磷酸盐夏季含量明显低于冬季,夏季平均含量为0.004μmol/dm3,而冬季为0.35 μmol/dm3;有机磷含量夏季高于冬季,含量分别为0.12,0.04 μmol/dm3;总磷含量的季节变化与无机磷酸盐类似,夏、冬季含量分别为0.22,0.61 μmol/dm3.在垂向分布上表层50 m水柱中PO43--P,总溶解态磷和总磷含量最小,随水深增加基本上呈线性快速增加,至500 m增加减缓,1 000 m左右为最大含量,然后随着水深略有下降.在夏季垂直分布比较典型,不同站位在一水深的含量离散性小,而冬季PO43--P,总溶解态磷和总磷的垂直分布则显得离散性大,尤其是PO43--P分布在200 m左右出现最大值,说明当年冬季南海各区域存在着较大水文、生物差异,很大的影响了化学环境的变化.在南海表层水中通常以有机磷占优势,在150 m深处以下的水中则以无机磷为主.深水中溶解的有机磷含量一般随水深减少.夏季的有机磷明显高于冬季,表明夏季的生物作用强烈.
Abstract:
According to tw o cruises investigation information in summer and winter during 1998 and 1999,the phosphorous concentration distribution and changes of summer and winter were discussed primarily in the South China Sea.The results show that the phosphate concentration of surface seawater in summer is distinct lower than that in winter,and average 0.04 μmol/dm3 in summer and 0.35 μmol/dm3 in winter.The organic phosphorous concentration of surface seawater in summer is higher than that in winter,and average 0.12 μmol/dm3 in summer and 0.04 μmol/dm3 in winter respectively.The season change of total phosphor us is similar to phosphate,and average 0.22 μmol/dm3 in summer and 0.61 μmol/dm3 in winter respectively.In vertical direction,phosphate, TDP,and TP content is lowest in the upper 50 m water column,and increases linearly rapidly with water depth, increases slowly under 500 m,reaches to maximum about 1 000 m,then decreases slightly with water depth increasing.The vertical distribution is typical in summer,and there is small dispersion for phosphorus concentration for the same depth of different stations.However,in winter there is a large dispersion for phosphate,TDP,and TP,specifically for phosphate at 200 m at which the concentration is maximum.This result indicates that there is large difference in hydrology and biology condition that affect largely on the chemical environment of the South China Sea.The organic phosphorus is the predominant in the surface seawater of the South China Sea,but the inorganic phosphorus is the predominant in layers more than 150 m.The organic phosphorus concentration in deep water usually decreases with water depth increasing.The organic phosphorus in summer is distinct more than that in winter because of the strong biology activities in summer.