大亚湾西部海域沉积物中生物硅的含量及其分布特征  

Biogenic silica contents and its distribution in the sediments of the west Daya Bay

作　　者：周鹏[1] 李冬梅[1] 李海涛[1] 赵力[1] 赵峰[1] 郑远来[1] 吴梅桂[1] 余汉生[1] ZHOU Peng;LI Dong-mei;LI Hai-tao;ZHAO Li;ZHAO Feng;ZHENG Yuan-lai;WU Mei-gui;YU Han-sheng(South China Sea Environment Monitoring Center,SOA,Guangzhou 510300,China)

机构地区：[1]国家海洋局南海环境监测中心,广东广州510300

出　　处：《应用海洋学学报》2019年第1期109-117,共9页Journal of Applied Oceanography

基　　金：RCA/IAEA(亚太地区核科学技术协议组织/国际原子能机构)资助项目(RAS-7019);国家海洋公益性行业科研专项资助项目(201005015-6;201505005-6)

摘　　要：采用2. 0 mol/dm^3Na_2CO_3溶液5h单点化学提取-硅钼蓝连续分光光度分析法分别测定了大亚湾西部海域13个表层沉积物和1个沉积物岩芯中生物硅的含量.表层沉积物和沉积物岩芯中生物硅含量占比分别为0. 69%～2. 02%和1. 24%～2. 05%,平均值分别为1. 42%和1. 60%.结果证实西大亚湾沉积物中生物硅含量水平与我国南海近岸海域基本一致.在210Pbex测年的基础上,通过分析沉积物岩芯中生物硅、有机物、无机碳等多指标,揭示近百年来大亚湾周边环境变化对海洋环境的影响,证实了上世纪80年代以来西大亚湾周边农业、海水养殖业和工业发展等人类活动加剧了该海域生态环境变化,尤其90年代核电站运行对海洋生态变化造成一定的影响.Thirteen surface sediments and one sediment core were collected from the west Daya Bay (WDB).Biogenic silica (BSi) contents (SiO2%) in the sediments were measured using a single time digestion technique with 2.0 mol/dm^3 Na2CO3 solution and the flow-injection molybdate-blue spectrophotometric method.BSi contents in surface and the core sediments were in the range of 0.69%-2.02% and 1.24%-2.05%,with mean values of 1.42% and 1.60%,respectively.As results,BSi contents in the WDB were basically at the similar level as those of other coastal areas of the South China Sea.The profiles of BSi contents,loss on ignition,total organic carbon (TOC) and other factors in the sediment core dated with 210Pbex method,were analyzed to reveal the impacts of marine environmental change of the WDB in recent 100 years.The marine environment change in WDB was aggravated due to the aquaculture,agricultural and industrial development and the other human activities since 1980s,especially the commercial operation of Daya Bay Nuclear Power Plant in 1990s.

关 键 词：海洋地质学 沉积物 生物硅 沉积记录 人类活动 海洋环境变化 西大亚湾 

分 类 号：P736[天文地球—海洋地质]