Annual cycle of the production and fate of DMS and DMSP in a marine coastal system

Abstract

The production of DMSP by phytoplankton and the fate through the marine system of both DMSP and DMS were followed for a period of 21 rno in the natural environment by studying a Wadden Sea tidal inlet. The major production and emission of DMS appeared to be limited to a period of only 2 mo, which was closely linked to the presence of phytoplankton blooms. The production of DMS in the water column was not well correlated with chlorophyll a concentrations or plankton species composition. It was however, found to be closely related to the start of a Phaeocystis bloom early in spring. Contrary to our expectations, the senescence phase of this Phaeocystis bloom did not result in high DMS accumulation. It is postulated that this phenomenon could be the result of a bacterial consumption which increased with time in combination with a decreasing DMSP-lyase activity of Phaeocystis. A slmple model, into which the overall DMSP consumption could be introduced, could very well ~mitate the measured concentrations of DMS In the water column of the natural system studied.

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

“…As previously shown by van Duyl et al (1998), the DMS peak coincided with the Phaeocystis bloom and DMSP maxima rather than following it, as a result of the fast growth of DMS-consuming bacteria after the bloom, and emission to the atmosphere preventing accumulation of DMS in water. The maximum DMS concentrations we report (255 nmol L − 1 ) were similar to maximum values reported by other studies in coastal near-shore areas of the North Sea (Kwint and Kramer, 1996;van Duyl et al, 1998) and were higher than those reported in the deeper and seasonally stratified northern North Sea, with maximum DMS values of 5 nmol L − 1 reported during a bloom of coccolithophores (Archer et al, 2002). Overall, the DMS maximum concentrations in the near-shore coastal areas of the North Sea are one to two orders of magnitude higher than the seasonal maxima typical of open oceanic waters, as compiled and reviewed by Lana et al (2011).…”

“…5d) followed the same pattern than DMSP with spatially averaged concentration of 180 nmol L − 1 in May (with local maximum up to 250 nmol L − 1 ). The timing of the DMS peak was closely linked to the DMSP peak suggesting that DMS was formed from the transformation (cleavage) of DMSP (mainly during the Phaeocystis bloom), a typical interpretation of seasonal DMS(P) cycles (Kwint and Kramer, 1996), in line with the general understanding of DMSP-DMS dynamics (Stefels et al, 2007), based for instance on the study of sulfur isotopes of DMSP and DMS (Kiene and Linn, 2000b). Phaeocystis is known for its high DMSP production (Keller et al, 1989) and DMSP-lyase activity (Stefels et al, 1996) than can cleave DMSP into DMS.…”

“…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.…”

Physical and biological variables affecting seabird distributions during the upwelling season of the northern California Current

“…DMS is released as algal cells are crushed in the process of being grazed (Dacey and Wakeman, 1986;Daly and DiTullio, 1996); however, grazing on microzooplankton that have ingested DMS-containing algae may also increase DMS prevalence . On the other hand, though elevated concentrations of DMS have been associated in some regions with productive plumes (Hatton et al, 1998), blooms (Kwint and Kramer, 1996;Gabric et al, 1999) and upwelling (Anderson et al, 2001), this is not always the case. While some studies report a connection between the release of DMS in the water column and phytoplankton senescence (Kwint and Kramer, 1995), other studies determined that DMS was not well correlated with chlorophyll a concentration (Kwint and Kramer, 1996) or distributions of phytoplankton, microzooplankton or mesozooplankton .…”

“…On the other hand, though elevated concentrations of DMS have been associated in some regions with productive plumes (Hatton et al, 1998), blooms (Kwint and Kramer, 1996;Gabric et al, 1999) and upwelling (Anderson et al, 2001), this is not always the case. While some studies report a connection between the release of DMS in the water column and phytoplankton senescence (Kwint and Kramer, 1995), other studies determined that DMS was not well correlated with chlorophyll a concentration (Kwint and Kramer, 1996) or distributions of phytoplankton, microzooplankton or mesozooplankton . Given these contradictory findings, and without direct measurements of DMS relative to plankton abundance in this study area, we can only speculate regarding the possible relationship between DMS or related olfactory cues and abundance of seabird prey in our study area.…”