DIMETHYLSULFIDE, ALGAL PIGMENTS AND LIGHT IN AN ANTARCTIC PHAEOCYSTISSP BLOOM

Dimethylsulfide (DMS) concentrations in sea water were found to be hig h (0.19 to 390 nM) in an Antarctic bloom of Phaeocystis sp. during Oct ober and November 1990. DMS concentrations were positively correlated with algal pigments, particularly 19'-hexanoyloxyfucoxanthin, a prymne siophyte pigment. Concentrations of DMS varied diurnally, possibly due to effects of sunlight, although the exact mechanism is unknown. Sinc e oceanic DMS production has been linked to the global albedo through the formation of cloud condensation nuclei, light-mediated changes in DMS concentrations may affect the global climate. The flux of DMS from this bloom into the atmosphere is calculated to be 67 +/- 55 mu mol m (-2) d(-1).