长江口邻近洋山港工程海域无机氮和磷的时空变化特征

Temporal and spatial characteristics of inorganic nitrogen and phosphate in the Yangtze Estuary adjacent to Yangshan habour

根据2004～2008年间2月和8月的营养盐监测资料,分析了长江口邻近洋山港工程海域无机氮和磷浓度的时空变化特征,结果表明:亚硝酸盐和氨氮浓度呈波动特征。硝酸盐和无机氮浓度很高,均超过四类海水水质标准;硝酸盐占无机氮总量的90.2%以上。活性磷酸盐浓度较高且基本稳定,其浓度均值处于四类海水水质标准范围。水体氮磷比值为48～70,存在磷限制现象。硝酸盐和活性磷酸盐浓度8月高于2月,而亚硝酸盐和氨氮浓度2月高于8月。营养盐浓度表层高于底层,由近岸向外海浓度递减。

Based on the nutrient monitoring data of February and August during 2004-2008, the temporal and spatial characteristics of inorganic nitrogen and phosphate were analyzed in the Yangtze Estuary adjacent to Yangshan habour. The results showed that the concentrations of nitrite and ammonia were fluctuant. The concentrations of nitrate and inorganic nitrogen were extremely high, surpassing those of the fourth rank of standard seawater quality. Nitrate occupied more than 90.2%of inorganic nitrogen. The concentration of phosphate was high and steady, which belonged to the fourth rank of standard seawater quality. The ratio of nitride to phosphate was 48-70, so that phosphorus was a limiting factor for phytoplankton growth. The concentrations of nitrate and phosphate in August were higher than in February, but the concentrations of nitrite and ammonie in February were higher than those in August. The concentrations of nutrients in the surface were higher than those in the bottom. The concentration of inorganic nitrogen and phosphate decreased from seashore to outer sea.