南黄海表层沉积物中生源要素的分布规律及其环境意义

Distribution of Biogenic Elements and their Environmental Implications in the Surface Sediments of the South Yellow Sea

【目的】研究南黄海表层沉积物中生源要素的分布规律及其影响因素。【方法】通过测定南黄海82个站位表层沉积物样品中生源要素的含量及表层沉积物的平均粒径,分析研究区表层沉积物中生源要素和沉积物粒径的分布特征,并从表层沉积物中有机质来源、沉积物粒度、水动力作用和环境等因素探讨其对生源要素分布的影响。【结果】南黄海表层沉积物中生源要素总有机碳(TOC)、总氮(TN)及总磷(TP)的含量与平均粒径存在显著的相关关系,近岸沉积物粒度较大,对应生源要素的含量较低,在南黄海中部海区的沉积物粒度较细,各生源要素的含量较高。【结论】表层沉积物的粒度是影响生源要素含量分布的主要因素,即粒度越细,表层沉积物中生源要素含量越高。同时,有机质来源和水动力作用在一定程度上也影响和控制着表层沉积物粒度及生源要素的分布。生源要素TP分别与TOC、TN之间相对较弱的相关关系和近岸河口等地生源要素的高值表明,可能存在其他外部环境因素也会对其含量造成影响。

【Objective】To study the distribution of biogenic elements and the influencing factors in the surface sediments of the South Yellow Sea.【Methods】Based on the determinationof the biogenic contents and the average grain size compositions of the surface sediments in the samples of the 82 stations in the South Yellow Sea,the distribution characteristics of the biogenic contents and sediment grain size in the surface sediments were analyzed.And the organic matter source,sediment grain size,hydrodynamic effect and environment were explored to get the information of influencing the biogenic elements distribution.【Results】The contents of total or-ganic carbon(TOC),total nitrogen(TN)and total phosphorus(TP)in the surface sediments of the South Yellow Sea were significantly correlated with the average grain size,and the sediment size in the coastal region was larger.The biogenic content is higher in the central clay region and lower in the west coastal region of South Yellow Sea.【Conclusion】The grain size of surface sediments is the main factor affecting the distribution of biogenic elements,that is,the finer the grain size,the higher biogenic elements in the surface sediments.At the same time,the organic matter source and hydrodynamic effect also affect and control the distribution of grain size and biogenic elements of surface sediments to a certain extent.The correlation between the biogenic element TP and the relatively weak correlation between TOC and TN and the high value of the source factors in the near shore estuary indicate that other external environmental factors may also affect its content.