【摘要】 于2014年7月—2015年4月对九龙江河口海域的氮、磷营养盐和叶绿素a及环境因子进行了4个航次的调查.结果表明,九龙江口的溶解无机氮平均质量浓度为3.046mg/L,活性磷的平均质量浓度为0.103mg/L,叶绿素a的平均质量浓度为2.92μg/L.无机氮及活性磷质量浓度均比20世纪80年代增加约8倍.氮、磷营养盐在冬、春季高,夏季低;叶绿素a在夏季高,冬季低.氮、磷营养盐随盐度增加而线性降低,呈保守分布.硝酸盐氮在溶解无机氮中占比最高,平均值范围为54.7%～76.9%;氮磷比最高值出现在冬季,四季平均值范围为49.0～94.4,该区域有潜在的磷限制因素.3种溶解无机氮之间及其与活性磷均呈正相关关系,且在夏季最显著;氮、磷营养盐与溶解氧呈显著的负相关关系,冬季叶绿素a与溶解氧呈正相关关系;叶绿素a与悬浮颗粒物存在一定的正相关关系;此外,pH与盐度呈极显著正相关关系,pH与溶解氧呈正相关关系,溶解氧和pH均与水温呈负相关关系,溶解氧与盐度呈显著的正相关关系.更多还原

【Abstract】 Four cruises were carried out in the Jiulongjiang Estuary sea area from July,2014 to April,2015 to investigate nutrients including nitrogen and phosphorus,chlorophyll-a and environmental factors.The results showed that the average mass concentration of dissolved inorganic nitrogen was 3.046 mg/L,the average mass concentration of soluble reactive phosphorus was 0.103 mg/L,and the average mass concentration of chlorophyll-a was 2.92μg/L.The mass concentration of dissolved inorganic nitrogen and soluble reactive phosphorus increased by about 8 times compared with that in 1980 s.The concentration of nitrogen and phosphorus were relatively high in winter and spring,but low in summer.Chlorophyll-a had higher concentrations in summer and lower in winter.The nitrogen and phosphorus decreased linearly with the increase of salinity and had conservative distributions.Nitrate nitrogen accounted for the highest proportion in dissolved inorganic nitrogen,with an average range of 54.7% to 76.9%.The maximum N/P ratio occurred in winter,and the average values of four seasons ranged from 49.0 to 94.4,which appeared to be phosphorus limited.The correlations between the three kinds of dissolved inorganic nitrogen and soluble reactive phosphorus were positive,which were the most significant in summer.There were significant negative correlations between nitrogen and dissolved oxygen and between phosphorus and dissolved oxygen.There was a positive correlation between chlorophyll-a and dissolved oxygen in winter.There was apositive correlation between chlorophyll-a and suspended particle.In addition,there was a very significant positive correlation between pH and salinity,apositive correlation between pH and dissolved oxygen,and negative correlations between dissolved oxygen and water temperature and between pH and water temperature.There was a significant positive correlation between dissolved oxygen and salinity.更多还原