Dimethylsulfide and the algaPhaeocystis pouchetii in antarctic coastal waters

Abstract

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 riM), 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 alga Phaeocystis 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.

Marine microbial production of dimethylsulfide from dissolved dimethylsulfoniopropionate

“…Significantly elevated concentrations are reported in the waters around mainland Britain (143), in the vicinity of blooms of the prymnesiophyte Phaeocystis pouchetii (15,65,66), and in some upwelled waters (11). These studies straddle or fall into one of two broad categories:…”

“…This has been attributed to, varously, the uneven relationship between algal production and chlorophyll, algal speciation, physiological state of the phytoplankton, and different rates of removal for chlorophyll and DMS. Effort to correlate DMS with specific phytoplanton taxa (15,29,65,66,75,95,96,143) DMS from its algal source. These include both consumption and production processes, as detailed below.…”

Oceanographic context of the First Aerosol Characterization Experiment (ACE 1): A physical, chemical, and biological overview

“…are rich sources of the DMS precursor, dimethylsulphoniopropionate (DMSP) [Keller et al, 1989;Malin et al, 1993]. Blooms of E. huxleyi and Phaeocystis have been associated with high DMS concentrations [Gibson et al, 1990;Malin et al, 1993]. Gymnodinium spp was the only abundant, DMSP-rich species found during the ACE 1 intensive experiment ].…”

Amundsen Sea sea-ice variability, atmospheric circulation, and spatial variations in snow isotopic composition from new West Antarctic firn cores

“…DMS is oxidized in the 49 atmosphere to MSA, which is deposited onto the ice sheet in snow [Gibson et al, 1990]. 50…”

“…Changes in brine volume associated with increased permeability of sea-ice cover as it warms and thins have been shown to directly affect DMS and DMSP migration through the brine network in Antarctic sea ice, significantly contributing to the atmospheric sulfur budget [Tison et al, 2010]. DMS is oxidized in the atmosphere to MSA [Ravishankara et al, 1997], which is then deposited by solid precipitation onto the adjacent ice sheet [Saigne and Legrand, 1987;Gibson et al, 1990]. While oxidation of MSA is greatly reduced during polar darkness, the process has still been shown to occur year-round, depending primarily on the BrO oxidation pathway [Jourdain and Legrand, 2001;Breider et al, 2010].…”