冬、夏季长江口海域二甲基硫化物的时空分布及对海水酸化和铁添加的响应  

Spatiotemporal Distribution of Biogenic Dimethylated Sulfur Compounds in the Yangtze (Changjiang) River Estuary and Its Adjacent Area During Summer and Winter and Their Response to Ocean Acidification and Fe Addition

作　　者：孙茂祥 于娟[1,2,3] 杨桂朋 Sun Maoxiang;Yu Juan;Yang Guipeng(College of Chemistry and Chemical Engineering,Ocean University of China,Qingdao 266100,China;Laboratory for Marine Ecology and Environmental Science,Laoshan Laboratory,Qingdao 266237,China;Institute of Marine Chemistry,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中国海洋大学化学化工学院,山东青岛266100 [2]崂山实验室海洋生态与环境科学功能实验室,山东青岛266237 [3]中国海洋大学海洋化学研究所,山东青岛266100

出　　处：《中国海洋大学学报（自然科学版）》2024年第6期108-120,共13页Periodical of Ocean University of China

基　　金：国家自然科学基金项目(41976038);国家重点研究发展计划项目(2016YFA0601301)资助。

摘　　要：本文于2022年2和7月测定了长江口及其邻近海域表层海水及重要断面海水中的二甲基硫(Dimethylsulfide, DMS)、二甲基巯基丙酸内盐(Dimethylsulfoniopropionate, DMSP)浓度;基于DMS生产速率、消耗速率和溶解态DMSP(DMSPd)降解速率,综合评价了DMS的迁移转化速率,并通过船基培养实验探究了二甲基硫化物对海水酸化和Fe添加的响应。结果表明:冬季长江口海域DMS、DMSPd、颗粒态DMSP(DMSPp)平均浓度分别为(1.55±0.96)、(3.55±2.38)和(4.42±3.11) nmol·L^(-1);夏季分别为(8.45±5.76)、(18.90±6.86)和(22.41±15.99) nmol·L^(-1)。冬、夏两季长江口二甲基硫化物高浓度主要出现在远岸,垂直方向上呈现出表层到底层逐渐降低的变化特征。冬季和夏季的DMS海气通量分别为2.23和22.96μmol·m^(-2)·d^(-1)。夏季DMSPd的转化率和DMS生物产率高于冬季,使得夏季DMS浓度较高。微生物消耗是长江口海域DMS的主要去除途径。船基培养实验表明,在pH=7.7、7.9条件下,海水酸化抑制了DMS和DMSP的产生,而Fe的添加促进了它们的释放。因此,未来海水酸化和Fe的输入会对长江口DMS的生物地球化学循环产生重要影响。The concentrations of dimethylsulfide(DMS)and dimethylsulfoniopropionate(DMSP)in the surface seawater and important vertical sections of Changjiang River Estuary and its adjacent area were measured during two cruises in February 2022 and July 2022.The migration and conversion rate of DMS were comprehensively evaluated based on DMS production rate,consumption rate,and dissolved DMSP(DMSPd)degradation rate.Ship-based incubation experiments were conducted to explore the response of dimethyl sulfide to seawater acidification and Fe addition.The results showed that the mean concentrations of DMS,DMSPd and DMSPp in winter were(1.55±0.96)、(3.55±2.38)and(4.42±3.11)nmol·L^(-1),respectively,while those in summer were(8.45±5.76),(18.90±6.86)and(22.41±15.99)nmol·L^(-1).In winter and summer,the high DMS concentrations in the Changjiang Estuary mainly appeared in the open sea,and the dimethyl sulfide concentrations showed a gradual decrease from surface to bottom in the vertical direction.The DMS sea-air fluxes in winter and summer were 2.23 and 22.96μmol·m^(-2)·d^(-1).The conversion rates of DMSPd and the biological yields of DMS were higher in summer than in winter.Microbial consumption is main removal pathway of DMS in the Yangtze River Estuary.Ship-based incubation experiments showed that OA inhibited the production of DMS and DMSP when pH was 7.7 and 7.9.The addition of Fe promoted releases of DMS and DMSP.Therefore,the future acidification of seawater and Fe input will have an important influence on the biogeochemical cycle of DMS in the Changjiang Estuary.

关 键 词：二甲基硫 二甲基巯基丙酸内盐 时空分布 生产消费 海气通量 海水酸化 长江口 

分 类 号：P734[天文地球—海洋化学]