Distribution of dimethylsulfide and dimethylsulfoniopropionate in the Yellow Sea and the East China Sea during spring: Spatio-temporal variability and controlling factors

Abstract

Spatial distributions of dimethylsulfide (DMS) and total dimethylsulfoniopropionate (DMSP) were determined in the Yellow Sea (YS) and the East China Sea (ECS) during April–May, 2009. The average concentrations of DMS and DMSP in surface water in the study area were 4.91 (1.18–12.6) and 25.2 (5.47–73.7) nmolL−1, respectively. Significant relationships were observed between the sulfur compounds and chlorophyll a concentrations, suggesting that phytoplankton biomass might play an important role in controlling DMS and DMSP distributions in the YS and the ECS. Zooplankton community and complex hydrographic conditions including the Yangtze River effluent and the Kuroshio water might also influence DMS and DMSP spatial variability. The interannual and seasonal variations of DMS distribution were investigated in the study area by comparing the present results with previous data from the past two decades. Collectively these data suggest that more DMS was released after the 2000s likely because of shifts of phytoplankton population caused by the anthropogenic eutrophication in the YS and the ECS. The average flux of DMS from the YS and the ECS to the atmosphere was estimated to be 13.7μmolm−2d−1, implying a significant relative contribution of continental shelf sea areas to global oceanic DMS emissions.