 |
| Titel |
Differential response of planktonic primary, bacterial, and dimethylsulfide production rates to static vs. dynamic light exposure in upper mixed-layer summer sea waters |
| VerfasserIn |
M. Galí, R. Simó, G. L. Pérez, C. Ruiz-González, H. Sarmento, S.-J. Royer, A. Fuentes-Lema, J. M. Gasol |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 10, no. 12 ; Nr. 10, no. 12 (2013-12-06), S.7983-7998 |
| Datensatznummer |
250085462
|
| Publikation (Nr.) |
 copernicus.org/bg-10-7983-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| Microbial plankton experience short-term fluctuations in total solar
irradiance and in its spectral composition as they are vertically moved by
turbulence in the oceanic upper mixed layer (UML). The fact that the light
exposure is not static but dynamic may have important consequences for
biogeochemical processes and ocean–atmosphere fluxes. However, most
biogeochemical processes other than primary production, like bacterial
production or dimethylsulfide (DMS) production, are seldom measured in
sunlight and even less often in dynamic light fields. We conducted four
experiments in oligotrophic summer stratified Mediterranean waters, where a
sample from the UML was incubated in ultraviolet (UV)-transparent bottles at
three fixed depths within the UML and on a vertically moving basket across
the same depth range. We assessed the response of the phyto- and
bacterioplankton community with physiological indicators based on flow
cytometry singe-cell measurements, fast repetition rate fluorometry (FRRf),
phytoplankton pigment concentrations and particulate light absorption.
Dynamic light exposure caused a subtle disruption of the photoinhibition and
photoacclimation processes associated with ultraviolet radiation (UVR), which
slightly alleviated bacterial photoinhibition but did not favor primary
production. Gross DMS production (GPDMS) decreased sharply
with depth in parallel to shortwave UVR, and displayed a dose-dependent
response that mixing did not significantly disrupt. To our knowledge, we
provide the first measurements of GPDMS under in situ
UV-inclusive optical conditions. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|