Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
Sci Total Environ. 2019 Jun 15;669:590-599. doi: 10.1016/j.scitotenv.2019.03.144. Epub 2019 Mar 11.
Field investigations of the Yangtze Estuary and its adjacent sea were carried out from July to August 2011. The distribution, source, transportation and transformation of biogenic silica (BSi) in suspended particulate matter (SPM) and core sediments were comprehensively investigated; dissolved silica (DSi) in pore water was also analyzed in this work. The budgets of reactive silica (RSi) and BSi in the East China Sea (ECS) were initially constructed on the basis of the above survey. The results indicated that the BSi distribution in this area was mainly affected by the input of the Yangtze River and Taiwan Warm Current, which was significantly correlated with SPM. The RSi flux input by rivers accounts for 17.6% of the total source of RSi in the ECS. Thus, these findings combined with the horizontal distribution of BSi in the Yangtze Estuary and its adjacent sea indicate that riverine input has a profound influence on the primary production of diatoms in the euphotic zone. Submarine groundwater exchange accounts for 22.3% of the DSi input, especially in the upwelling region, which will directly affect the euphotic nutrient structure. The DSi benthic flux from pore water to upper water exceeds riverine input by 3-fold, accounting for 11.5% of primary production in the ECS, which can alleviate the Si limiting effect caused by the decrease in DSi flux from the Yangtze runoff in recent years. Approximately 75.5% of BSi is dissolved and re-engaged in the ECS silicon cycle in the settlement process.
2011 年 7 月至 8 月对长江口及其毗邻海域进行了实地调查。综合调查了悬浮颗粒物（SPM）和岩芯沉积物中生物硅（BSi）的分布、来源、输运和转化；还分析了孔隙水中溶解硅（DSi）。在此基础上，初步构建了东海（ECS）反应性硅（RSi）和 BSi 的收支。结果表明，该地区的 BSi 分布主要受长江输入和台湾暖流的影响，与 SPM 显著相关。河流输入的 RSi 通量占 ECS 总 RSi 源的 17.6%。因此，这些发现结合长江口及其毗邻海域 BSi 的水平分布，表明河流输入对真光层中硅藻的初级生产有深远影响。海底地下水交换占 DSi 输入的 22.3%，特别是在上升流区，这将直接影响真光营养结构。从孔隙水到上层水的 DSi 底通量是河流输入的 3 倍，占 ECS 初级生产力的 11.5%，可以缓解近年来长江径流量减少导致的 DSi 通量减少所造成的硅限制效应。BSi 在沉降过程中有 75.5%溶解并重新参与到 ECS 硅循环中。
