长江口海域营养盐的形态和分布特征

The Distribution and Species of Nutrient in the Yangtze River Estuary

利用2007年4月对长江口海域航次的调查结果,对该海域营养盐的形态和分布特征进行了探讨,并对其主要控制过程进行了讨论。结果表明:长江口海域营养盐的浓度变化范围较大,整体分布趋势是由近岸向外海逐渐降低,且明显受水文状况影响。在长江口海域,磷主要以磷酸盐的形式存在,其余依次是溶解有机磷、颗粒态磷;氮主要以硝酸盐的形式存在,其余依次是溶解有机氮、颗粒态氮、氨氮、亚硝酸盐。硝酸盐和硅酸盐的行为是保守的,其行为主要受咸淡水混合过程控制;磷酸盐、溶解有机磷、颗粒态磷、亚硝酸盐、氨氮和溶解有机氮的行为是非保守的。

Concentrations and species of nutrient were determined in the Yangtze River estuary and its adjacent area in April 2007. Concentrations of nutrients displayed obviously variability in the Yangtze River estuary and its adjacent area, with higher levels in the shallow coastal waters. The nutrients distribution of Yangtze River estuary and its adjacent coastal area are influenced by several water masses. Yangtze River diluted water carries abundant N, P, Si nutrients to the surface layer, Taiwan Warm Current mostly affects the bottom layer and in the upwelling area adjacent to the Yangtze River estuary, and that Subei Coastal Water and Minzhe Coastal Water mainly influence the inshore area. Nitrate is the predominant species of dissolved inorganic nitrogen （DIN）. DIN is the predominant species of dissolved total nitrogen （DTN） in the Yangtze River estuary and its adjacent coastal area, while dissolved organic nitrogen （DON） is the predominant species in the Taiwan Warm Current area. Phosphate is the predominant species of dissolved total phosphorus in the Yangtze River estuary and its adjacent coastal area, while dissolved organic phosphorus （DOP） is the predominant species in the Taiwan Warm Current area. The data indicated that silicate and nitrate behave conservatively, but silicate and phosphate did not behaved conservatively.