The seasonal variation of dimethyl sulfide and dimethylsulfoniopropionate concentrations in nearshore waters1

Abstract

Concentrations of biogenic dimethyl sulfide (DMS) in seawater around mainland Britain in winter and summer (1985) ranged from 1 to 1,100 ng S (DMS) liter-'. The mean winter DMS concentration was 4 ng S (DMS) liter-' compared with the mean summer concentration of 220. Analyses of phytoplankton species composition in summer indicate that the main sources of DMS were coccolithophores, various dinoflagellates including the bloom species Gyrodinium aureolum, and certain unidentified taxa of small flagellates. Concentrations of dimethylsulfoniopropionate (DMSP), the precursor of DMS, were measured in 53 of the summer samples, and its mean concentration was about an order of magnitude greater than that of DMS. Particulate (>0.2 pm) and dissolved fractions of DMSP were operationally resolved, with the latter showing the stronger correlation with DMS.Preliminary estimates for the areal and temporal average flux of sulfur (DMS) from the North Sea to the atmosphere during summer are of the order of lo3 pg S m-2 d-l, a 60-fold increase over winter flux. Biogenic emission in summer is equivalent to about 16% of the spatially averaged anthropogenic emission from Europe.

Changing concentrations of CO, CH 4 , C 5 H 8 , CH 3 Br, CH 3 I, and dimethyl sulfide during the Southern Ocean Iron Enrichment Experiments

“…During SOFeX the response of DMS inside the patch was very similar to what was found previously for IronExII (48), although that experiment was conducted in the warm equatorial environment and observations lasted only 8 days. DMS is an important sulfurcontaining trace gas (49) produced by phytoplankton (50,51) and during the grazing of phytoplankton by microzooplankton (52). Emission of DMS from ocean waters is a major source of cloud condensation nuclei in the unpolluted marine environment.…”

Annual cycle of dimethylsulfoniopropionate (DMSP) and dimethylsulfoxide (DMSO) related to phytoplankton succession in the Southern North Sea

“…Seasonal variations DMSP and DMS have been previously studied in the Southern North Sea (SNS) based on field measurements and model applications (Turner et al, 1988;Kwint and Kramer, 1996;van den Berg et al, 1996;Stefels et al, 1995;van Duyl et al, 1998;Archer et al, 2002;. All of these studies reported a marked seasonal cycle in DMS(P) with a maximum in spring (April-May) corresponding to the Phaeocystis bloom followed by a decrease to low winter values.…”

The CLAW hypothesis: a review of the major developments

“…Dimethylsulfoniopropionate (DMSP) is the precursor compound to DMS [10] and DMSP is synthesised by phytoplankton, and the amount of DMSP is highly dependent on the species of plankton present. [11] Although direct emission of DMS from plankton in the laboratory has been observed, [12] it has not been observed in the oceans and more typically it is the action of grazers and viruses on the plankton community that results in significant levels of DMSP in the water column; [13,14] typically, the highest levels of DMSP and DMS are associated with the senescence of a plankton bloom.…”