【摘要】 2016年7月在长江口邻近海域5个观测站进行调查,观测了颗粒氮(PN)浓度及其变化.结果显示PN浓度相对稳定,平均值为4.01μmol/L,其中透明度最高的C3站PN浓度高于其他站.研究发现PN浓度与溶解氧(DO)、叶绿素a(Chl-a)呈线性相关,与总悬浮颗粒物(TSP)无显著相关关系,表明调查海域PN大多为生源颗粒物;同时发现PN浓度与磷酸盐(DIP)、溶解无机氮(DIN)、硅酸盐(DSi)相关关系不显著,表明在浑浊水体中,生源PN不受营养盐限制,水体浑浊度制约生物生长,进而影响PN浓度.进一步探讨发现颗粒磷(PP)与TSP间可能存在吸附-解吸作用,造成PP浓度偏高,导致PN/PP比值相对恒定且低于Redfield比值.更多还原

【Abstract】 Continuous observations were carried out at five stations in the Yangtze River Estuary adjacent sea area in July,2016.Particulate nitrogen(PN)and other parameters were observed to study their variations.The concentration of PN was relatively stable at each station with an average value of 4.01μmol/L.PN was the highest at the C3 station,where the transparency was the highest among the five stations.The concentration of PN showed positive correlations with dissolved oxygen(DO)and chlorophyll-a(Chl-a),but it exhibited insignificant correlation with total suspended particles(TSP),which suggested that PN was mainly biogenic particles in the sea area.PN was less significantly correlated with dissolved phosphate(DIP),dissolved inorganic nitrogen(DIN)and dissolved silicate(DSi),which indicated that the biogenic PN was not limited by nutrients in the coastal turbid waters.Biological production was mainly limited by light because of the high turbidity,and thus influenced the concentration of PN.However,the concentration of particulate phosphorus(PP)was relatively high due to adsorption-desorption from TSP,which resulted in the relatively consistent ratio of PN/PP that was slightly lower than the Redfield ratio.更多还原