Dimethylsulfide and the algaPhaeocystis pouchetii in antarctic coastal waters

The concentrations of dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP) and dimethylsulfoxide (DMSO) were measured in water collected from the Southern Ocean 10 km offshore from Davis Station, Antarctica, during the period May 1987 to January 1988, inclusive. During winter and spring, when the sea-ice was up to 1.9 m thick, DMS, DMSP and DMSO concentrations were low (0.2 to 1.5 nM), as were phytoplankton numbers. The maximum concentration of the sulfur compounds generally occurred in the top 10 m of the water column. DMS levels rose dramatically from early December onwards, reaching a peak of 290 nM at a depth of 15 m in January. This concentration is higher than reported elsewhere in the ocean. These high concentrations occurred at the same time as a bloom of the algaPhaeocystis pouchetii. A significant correlation occurred between DMS concentration and cell numbers of the alga. The ratio of DMS concentration to the number of cells of the alga was considerably higher than reported for blooms of this species elsewhere in the ocean. Up to 10% of the total global flux of DMS to the atmosphere may emanate from antarctic seas.