Mechanisms leading to the frequent occurrences of hypoxia and a preliminary analysis of the associated acidification off the Changjiang estuary in summer

doi:10.1007/s11430-015-5542-8

	Mechanisms leading to the frequent occurrences of hypoxia and a preliminary analysis of the associated acidification off the Changjiang estuary in summer
	Wei QinSheng 1,2; Wang BaoDong 2,3; Yu ZhiGang 1,3; Chen JianFang 4; Xue Liang 2
刊名	SCIENCE CHINA-EARTH SCIENCES
	2017-02
卷号	60 期号:2 页码:360-381
关键词	Changjiang estuary Hypoxic zone Upwelling Front Nutrient regeneration Biogeochemistry Acidification
ISSN号	1674-7313
DOI	10.1007/s11430-015-5542-8
英文摘要	Based on literature data and shipboard observations, this study investigated the main environmental characteristics of the seafloor topography, current field, front, and upwelling that are closely related to hypoxia occurrence off the Changjiang estuary. The physical processes of the plume front and upwelling off the Changjiang estuary in summer were coupled. The vertical distribution pattern of the plume front was closely related to the upwelling. By reviewing and analyzing the historical summer hypoxia events off the Changjiang estuary, we statistically demonstrated the spatial structure of the horizontal distribution of the hypoxic zone and investigated the location of occurrence zone of the hypoxia. We found that the dissolved oxygen (DO) concentration on the inner continental shelf off the estuary showed a "V" shape in relation to station depth. Therefore, we noted that the hypoxic water on the inner continental shelf mostly occurred on the slopes with steep seafloor topography. Base on the current understanding of the hypoxic mechanisms off the Changjiang estuary, we analyzed the biogeochemical mechanisms that could cause the steep terrain off the Changjiang estuary to become the main areas prone to summer hypoxia and explained the internal relations between the location of the hypoxic zone on the slopes and the plume front and upwelling. The plume front and upwelling off the Changjiang estuary and their coupling were important driving forces of summer hypoxia. The continuous supply of nutrients affected by the interaction of the plume front extension of the Changjiang Diluted Water (CDW) and upwelling and the favorable light conditions were important mechanisms causing the phytoplankton blooms and benthic hypoxia off the Changjiang estuary in summer. By analyzing oxygen utilization, organic carbon mineralization, and nutrient regeneration in the hypoxic zone, we observed that the significant oxygen utilization process off the Changjiang estuary in summer also mainly occurred near the steep slopes with front and upwelling features and confirmed the apparent nutrient loss in the benthic hypoxic zone. Meanwhile, our analysis revealed that the sediment resuspension in the benthic boundary layer in the mud areas off the Changjiang estuary could also affect the oxygen utilization and mineralization of organic carbon and nutrient recycling and regeneration. This study also demonstrated that the steep terrain off the Changjiang estuary was the main location for summer acidification, and the coupling between the plume front and upwelling on the steep slopes was an important physical driving force inducing summer benthic acidification. Finally, we discussed issues to address in future studies of the hypoxic zone and water acidification off the Changjiang estuary.
资助项目	National Project of Comprehensive Investigation and Research of the Coastal Seas of China[908-ZC-I-03]
WOS关键词	EAST CHINA SEA ; YANGTZE-RIVER ESTUARY ; OXYGEN DEPLETION ; DISSOLVED-OXYGEN ; ORGANIC-MATTER ; ADJACENT ; SHELF ; NORTH ; WATER ; EUTROPHICATION
WOS研究方向	Geology
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000394043000014
内容类型	期刊论文
源URL	[http://ir.fio.com.cn:8080/handle/2SI8HI0U/27477]
专题	自然资源部第一海洋研究所
通讯作者	Wei QinSheng
作者单位	1.Ocean Univ China, Key Lab Marine Chem Theory & Technol, Minist Educ, Qingdao 266100, Peoples R China 2.First Inst Oceanog, State Ocean Adm, Qingdao 266061, Peoples R China 3.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Ecol & Environm Sci, Qingdao 266071, Peoples R China 4.Second Inst Oceanog, State Ocean Adm, Hangzhou 310012, Zhejiang, Peoples R China
推荐引用方式 GB/T 7714	Wei QinSheng,Wang BaoDong,Yu ZhiGang,et al. Mechanisms leading to the frequent occurrences of hypoxia and a preliminary analysis of the associated acidification off the Changjiang estuary in summer[J]. SCIENCE CHINA-EARTH SCIENCES,2017,60(2):360-381.
APA	Wei QinSheng,Wang BaoDong,Yu ZhiGang,Chen JianFang,&Xue Liang.(2017).Mechanisms leading to the frequent occurrences of hypoxia and a preliminary analysis of the associated acidification off the Changjiang estuary in summer.SCIENCE CHINA-EARTH SCIENCES,60(2),360-381.
MLA	Wei QinSheng,et al."Mechanisms leading to the frequent occurrences of hypoxia and a preliminary analysis of the associated acidification off the Changjiang estuary in summer".SCIENCE CHINA-EARTH SCIENCES 60.2(2017):360-381.