宁德海域表层沉积物氧化还原环境特征及其影响因素

The environment characteristics of redox in the surface sediments of Ningde coastal sea area in relation to influence factors

通过2015年8月对宁德海域表层沉积物氧化还原电位(Eh)的现场调查(119.867°E^120.649°E,26.348°N^26.994°N),分析了该海域表层沉积物Eh的分布特征,并从水团性质、盐度、p H、溶解氧等上覆水体特征参数以及硫化物、有机质、底质类型等沉积物特征因子两大方面探讨了Eh的影响因素。结果表明,研究海域表层沉积物Eh的变化范围为-162~110 m V,平均值为-89 m V,基本属于弱还原性-还原性环境,空间分布呈近岸高外海低的特征。相较于20世纪80年代福建沿岸Eh调查结果,本次调查宁德近海表层沉积物Eh明显降低。上覆水体的盐度、DO等参数与Eh表现出一定的相关性,DO与Eh的正相关性极为显著(r=0.729,p<0.01),且空间分布特征也较为相似。表层沉积物中硫化物含量高低直接影响Eh值,并表现出极显著的负相关(r=-0.806,p=0.000)。近年来,受人类活动影响,研究海域表层沉积物氧化还原状态发生了明显改变,这种改变在一定程度上会影响沉积物中生物的生存活动,因此有必要采取相应措施,加强该海域底质环境的监测,在保持地区经济发展的同时也要加强海域环境的保护力度。

Based on the data collected from the oceanographic survey in the Ningde offshore area in August 2015（ 119.867°E ~ 120.649°E,26.348° N ~ 26.994° N）,we analyzed the distribution characteristics of redox potential（ Eh） of the surface sediments in the Ningde coast was in situ_measurement on deck in August 2015,and then analyzed those distribution characteristics.In addition,from the aspects of water mass properties,salinity,p H,dissolved oxygen of the feature parameters in overlying water and sulfide,organic matter,bottom matter type of the characteristics factor in sediments,we deeply studied the influencing factors of Eh.The results showed that the Eh value in the surface sediments varied from- 162 m V to 110 m V with an average of- 89 m V,which were basically in the weak reducibility and reducibility level.The distribution of Eh was higher in the coastal areas than the offshore areas.The Eh value de-creased significantly compared to the results of Eh value in coastal areas in Fujian in 1980 s.There is a certain correlation between the salinity,dissolved oxygen and other parameters of the overlying water and Eh values of the surface sediments,especially dissolved oxygen with an extremely significantly positive correlation（ r = 0.729,p 〈 0.01）,and the spatial distribution are also similar.The sulfide content level of the surface sediments directly affected the Eh value,which showed an extremely significantly negative correlation（ r =- 0.806,p = 0.000）.In recent years,influenced by human activities,the redox status of surface sediments in the Ningde sea areas has changed significantly,which may threaten the biological activities in the sediment in some extent.Therefore,it is necessary to take some measures to strengthen the monitoring of submarine environment quality.At the same time of developing regional economy,we also need to further strengthen the efforts in protecting the marine environment.