Malin, G. University of East Anglia, 44 1603 507714

In recent years we have gained a much better understanding of the microbial processes which influence the production and turnover of the volatile organic sulfur compound dimethylsulfide (DMS) and related sulfur compounds. However, we still have rather scant knowledge of which pathways will dominate in a given environment, and limited ability to predict the likely magnitude of DMS emissions to the atmosphere. The European Union project ESCAPE (Entangled Sulfur and Carbon Cycles in Phaeocystis Dominated Ecosystems) has provided an opportunity to study DMS biogeochemistry in blooms of the colony forming phytoplankton species Phaeocystis. This organism produces dense almost monospecific blooms, and is thought to be a major source of DMS in some temperate and polar regions. Two field campaigns have been carried out a) in northern Norwegian waters during April 1997, and b) in the southern North Sea during the 1998 spring bloom. During these studies we carried out incubation experiments to investigate the turnover of DMS, dimethyl sulfoxide (DMSO) and dimethylsulfoniopropionate (DMSP) at various stages of the Phaeocystis blooms. Experiments included comparison between light and dark incubations and addition of inhibitors of bacterial DMS and DMSP turnover. Data from some relevant laboratory studies will also be presented.
Day: Friday, Feb. 5
Time: 08:30 - 08:45am
Location: Sweeney Center
Code: SS37FR0830S