CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, Guangdong, PR China; Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Ministry of Education, Qingdao 266100, PR China.
Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Ministry of Education, Qingdao 266100, PR China; South China Sea Marine Survey and Technology Center, State Oceanic Administration, Guangzhou 510300, PR China.
Sci Total Environ. 2022 Apr 20;818:151819. doi: 10.1016/j.scitotenv.2021.151819. Epub 2021 Nov 24.
In this study, components, concentrations, distribution characteristics, sources of low-molecular-weight organic acids (LMWOAs) and relationships among the annual hypoxia, LMWOAs and seawater acidification were investigated in the Changjiang Estuary and its adjacent sea area in July 2015. Lactic, acetic and formic acids were detected in the seawater samples in the study area, and their total concentrations (ΣLMWOAs) varied from 0 to 262.6 μmol·L, with an average value of 39.2 μmol·L. In the surface seawater, high concentration areas of ΣLMWOAs occurred in the sea area near the Changjiang Estuary and the Hangzhou Bay, and north of study area. In the sampling stations along transect A6, high concentration areas of ΣLMWOAs appeared in the bottom seawater of nearshore stations and middle seawater of offshore stations. The terrigenous inputs, especially the Changjiang runoff, were the dominant sources for LMWOAs in the sampling period. The consistency of hypoxia areas, high concentration areas of ΣLMWOAs and low pH value areas in winter and summer suggested that annual hypoxia could cause the long-term seawater acidification by producing LMWOAs in the Changjiang Estuary and its adjacent sea area.
本研究于 2015 年 7 月调查了长江口及其毗邻海域的低分子量有机酸（LMWOAs）的组成、浓度、分布特征、来源及其与年度缺氧、LMWOAs 和海水酸化之间的关系。在研究区域的海水中检测到了乳酸、乙酸和甲酸，其总浓度（ΣLMWOAs）在 0 至 262.6μmol·L 之间变化，平均值为 39.2μmol·L。在表层海水中，ΣLMWOAs 的高浓度区出现在长江口和杭州湾附近海域以及研究区域北部。在 A6 断面的采样站中，ΣLMWOAs 的高浓度区出现在近岸站的底层海水中和近海站的中层海水中。陆源输入，特别是长江径流，是采样期间 LMWOAs 的主要来源。冬季和夏季缺氧区、ΣLMWOAs 高浓度区和低 pH 值区的一致性表明，长江口及其毗邻海域的年度缺氧可能通过产生 LMWOAs 导致海水长期酸化。
