夏季中国东海生源有机硫化物的分布及其影响因素研究

Distribution of Biogenic Organic Dimethylated Sulfur Compounds and Its Influencing Factors in the East China Sea in Summer

二甲基硫(DMS)、二甲巯基丙酸内盐(DMSP)和二甲亚砜(DMSO)是海洋中最重要的3种生源有机硫化物.本文系统研究了2013年6月中国东海表层海水中3种硫化物的水平分布规律及其影响因素,并估算了DMS海-气通量.结果表明,表层海水DMS、溶解态DMSPd、颗粒态DMSPp、溶解态DMSOd和颗粒态DMSOp浓度平均值分别为4.70、7.00、27.83、13.66和10.78 nmol·L-1.DMS、DMSP和DMSO与叶绿素a(Chl-a)水平分布规律相似,均呈现近岸高、远海低的趋势.相关性分析结果表明,DMS、DMSPd和DMSOp浓度与Chl-a浓度均有显著的相关性,说明浮游植物生物量是影响东海有机硫化物生产分布的重要因素.此外,研究发现DMS与DMSPd、DMSOd与DMS间分别存在一定的相关性,表明表层海水中DMS主要来源于DMSPd的微生物降解,而DMSOd的主要来源是DMS的氧化过程.此外,夏季东海DMS海-气通量在0.62~33.98μmol·(m2·d)-1之间,平均值为9.71μmol·(m2·d)-1.

Dimethylsulfide( DMS), dimethylsulfoniopropionate( DMSP) and dimethylsulfoxide( DMSO) are the most important biogenic organic dimethylated sulfur compounds in the ocean. The spatial distributions of these three sulfur compounds and their influencing factors were investigated in the East China Sea in June 2013. The mean concentrations of DMS,DMSPd,DMSPp,DMSOd and DMSOp in the surface seawater were 4. 70,7. 00,27. 83,13. 66 and 10. 78 nmol·L-1,respectively. The horizontal distributions of DMS,DMSP and DMSO exhibited the similar patterns to that of chlorophyll a( Chl-a),with high values in coastal regions and low values in the open sea. DMS,DMSPd and DMSOp concentrations were significantly correlated with the levels of Chl-a,indicating that phytoplankton biomass might play an important role in controlling the concentrations of these sulfur compounds in the East China Sea.Moreover,positive relationships were observed between DMS and DMSPd and between DMSOd and DMS in the study area,which implied that the microbial degradation of DMSPd was the main source of DMS and DMSOd came mostly from the oxidation of DMS. The sea-to-air flux of DMS from the East China Sea in summer ranged from 0. 62 to 33. 98 μmol·( m2·d)-1,with an average of 9. 71μmol·( m2·d)-1.