摘要
根据1999—2012年5月对长江口及邻近海区的环境调查数据,分析了该海域近十几年来春季溶解无机氮、磷酸盐的分布变化特征及影响因素。结果表明,溶解性无机氮(Dissolved Inorganic Nitrogen,DIN)包括硝酸盐、亚硝酸盐及铵盐,其中,硝酸盐是主要组成部分,占DIN的70.91%~96.51%,表、底层硝酸盐浓度有相似的变化特征,且表层均高于底层,硝酸盐最高值及最低值分别出现在2012和2011年,硝酸盐在调查海区的平均浓度主要受输送通量影响,其平面分布主要受径流影响;亚硝酸盐含量很低,仅占DIN的0.87%~2.72%;铵盐垂向分布均匀,最高值及最低值分别出现在2011和2012年,其在河口的浓度受长江输送影响明显。调查海区底层磷酸盐浓度多高于表层,最高值及最低值分别出现在2001和2007年,磷酸盐分布受径流及悬浮颗粒物双重影响。除个别站位外,调查海区氮磷比均高于16∶1,说明浮游植物生长主要受磷限制,氮磷比高值区位于最大浊度带附近,最低值位于外海区及叶绿素a高值区。
Based on the environmental survey data in the Yangtze River Estuary and its adjacent waters in May from 1999 to 2012,the distribution features and its influencing factors of dissolved inorganic nitrogen(DIN)and phosphate were analyzed.The results showed that DIN were composed of nitrate,nitrite and ammonium,and nitrate was the major component,which accounted for 70.91%~96.51% of DIN.The interannual variation of nitrate in surface and bottom were quite similar,while the surface concentrations were higher than the bottom,and the highest and the lowest values of nitrate appeared in 2012 and 2011,respectively.The average concentration of nitrate in the investigation waters affected mainly by the transport flux,and its distribution was mainly affected by runoff.The content of nitrite was very low,accounting for only 0.87%~2.72% of DIN.Ammonium had little difference vertically,and the highest and the lowest values were present in 2011 and 2012,respectively.The concentration of ammonium in the Yangtze River Estuary was significantly affected by transport flux.The bottom phosphate concentration were generally higher than the surface,and the highest and the lowest values presented in 2001 and 2007,respectively.The distribution of phosphate was affected by runoff and suspended particulate matter.Apart from individual stations,the ratios of nitrogen and phosphorus(N:P)were higher than 16:1in the investigate area,indicating that phytoplankton growth was mainly restricted by phosphorus in this area.The low values of N:P were located near the maximum turbidity zone,and the maximum values were located off the coast and in the area with high chlorophyll a.
出处
《中国海洋大学学报(自然科学版)》
CAS
CSCD
北大核心
2016年第3期82-90,共9页
Periodical of Ocean University of China
基金
国家自然科学基金面上项目(41176138
31272663)
国家基金委-山东省联合基金项目(U1406403)
国务院三峡工程建设委员会项目(JJ 2012-2013号)资助~~
关键词
长江口
无机氮
磷酸盐
营养盐结构
Yangtze River Estuary
dissolved inorganic nitrogen
phosphate
nutrient structure