Atmospheric emissions of volatile organic sulfur compounds (VOSCs) from the marine environment represent an important component of the global sulfur cycle. It is now well established that microbial activity contributes to the production of VOSCs, but the extent of microbial consumption is unknown. This research will test the hypothesis that microbial metabolism of VOSC controls its emission from sediments and seawater. The program will: (1) develop and employ radiotracer methods to determine turnover rates of dimethylsulfide (DMS) in sediments and seawater in a salt marsh; (2) determine microbial control over VOSC fluxes from sediments; (3) study production and consumption of COS and CS2 in sediments; (4) isolate microbes that metabolize VOSC. This research will provide the first direct measurements of VOSC turnover rates in sediments and in the water column.
