[Distribution of biogenic organic dimethylated sulfur compounds and its influencing factors in the east China Sea in summer].

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 x 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 micromol x (m2 x d)(-1), with an average of 9.71 micromol x (m2 x d)(-1).