第四节 海水中的可溶性磷酸盐

CHAPTER 3 SEAWATER CHEMISTRY Section 4 Soluble Phosphate in the Xiamen Harbour Waters

海洋中磷、氮、硅等营养元素对浮游植物(因而对整个海洋食物链)起着重要作用,它们主要来源于岩石风化、火山、热泉和有机物的腐解等。它们在海洋真光层及浅海中的时空变化主要受浮游值物兴衰、海流及季节性的海洋热成对流的影响。在浮游植物旺盛的季节,它们被大量消耗,浓度下降到接近于零;在浮游生物衰亡腐解时,又部分地回到水体中。一般在热成跃层发达的夏季,垂直变化较大;而在热成跃层消失的冬季,垂直变化较小,成垂直均匀分布。在河口港湾区,陆源淡水一般带来丰富的营养盐类,因此它们的时空变化较为复杂。

The soluble Phosphate concentrations ranged between 0.0—2.93μmol·P/L with an average of 0.48μmol/L which is lower than the average phosphate in seawater Its horizontal distribution presented an even trend in summer and relatively large variation with the seasons,Even distribution appeared at various transects The measurent values during December 1980 to February 1981 were high leading large vertical variations with lower values at upper part of the water columm and higher values at the lower layer for most stations,vertical variations from other cruises were small resulting in roughly even distribution The diurnal variation of Phosphate was complex,its daily differences were between 0.12—2.47μmol/L;about 34%of the satations showed some tidal impacts the diurnal variation curve had the form of two peaks and two valleys roughly corresponding to opposite tidal variation,The annual variation presented a trend with one high and one low value,the peak appeared in winter the valley in summer.