三门湾海域4、7月营养盐分布及其稀释效应  

Nutrient distribution and dilution effect at the Sanmenwan Bay of Zhejiang Province,China,in April and July

作　　者：王奎[1] 金明明[1] 陈建芳[1] 金海燕[1] 卢勇[1] 李宏亮[1] 

机构地区：[1]国家海洋局第二海洋研究所国家海洋局海洋生态系统与生物地球化学重点实验室,浙江杭州310012

出　　处：《海洋学研究》2007年第1期10-22,共13页Journal of Marine Sciences

基　　金：国家自然科学基金(青年基金)资助项目(40403013);浙江省自然科学基金资助项目(M403032)

摘　　要：利用2005年4、7月三门湾海域26个站位的两次水化学要素调查资料,描述了表层盐度和营养盐平面分布特征,对营养盐和盐度进行相关分析,并探讨了24 h连续站的营养盐变化规律,结果表明:(1)表层硝酸盐、硅酸盐浓度基本呈东低西高分布,磷酸盐的分布规律不明显。(2)7月硝酸盐、磷酸盐平均浓度比4月低,而硅酸盐、亚硝酸盐平均浓度比4月高,氨平均浓度在4、7月无显著变化。(3)4、7月表、底层的硝酸盐、硅酸盐、亚硝酸盐浓度均为湾内高湾口低,且与盐度呈显著的负相关,表明在调查时间内受强潮汐作用的三门湾海域呈现出硝酸盐、硅酸盐的保守稀释效应,磷酸盐稀释效应则表现不明显。(4)7月25-26日连续站(29°06′33″N、121°39′03″E,三门湾中部猫头山嘴附近,水深为27-34 m)24 h盐度变化与潮汐变化几乎一致,硝酸盐、硅酸盐浓度与盐度变化呈显著负相关。硝酸盐、硅酸盐的浓度变化可以指示海水与淡水的稀释与混合效应。In April and July, the data of salinity and nutrients which we collected at the Sanmenwan Bay of Zhejiang Province, China, was used to describe their distribution feature, analyze their correlation between surface salinity and nutrients concentration, discuss the nutrients changes during the period of 24-hour at the mooring station （29°06′33＂ N, 121°39′03＂E, at the middle southwestern position of the Bay, depth of 27-34 m; on 25-26, July）. The results show： （1） The surface nitrate and silicate concentrations increased from east to west, and the phosphate distribution was irregular （2） The average concentrations of nitrate and phosphate in July were 4.4 umol/dm^3 and 0.03 umol/dm^3 lower than that in April, whereas silicate and nitrite in July were 3.2umol/dm^3 and 1.6 umol/dm^3 higher than that in April, respectively, and there was little difference in ammonium between April and July （3） The nitrate, silicate and nitrite concentration were high inside the bay but low in the mouth of the bay and they were significantly reverse correlation with salinity. Because the Sanmenwan Bay was affected by strong tide, these demonstrated the conservative dilution effect of nitrate, silicate, nitrite among the waters during the 2-day investigation in both April and July. There was no apparent dilution effect for phosphate （4） While the 24-hour variation of tide height at Station Jiantiao was almost consistent with the 24-hour variation of salinity observed at the mooring station in July, the variation of nitrate and silicate was contrary to salinity. This 24-hour variation of nitrate and silicate can be used to indicate the dilution and mixing effect of seawater and freshwater.

关 键 词：三门湾海域 营养盐 盐度 稀释效应 

分 类 号：P734.44[天文地球—海洋化学]