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| Titel |
Biochemical characteristics and bacterial community structure of the sea surface microlayer in the South Pacific Ocean |
| VerfasserIn |
I. Obernosterer, P. Catala, R. Lami, J. Caparros, J. Ras, A. Bricaud, C. Dupuy, F. Wambeke, P. Lebaron |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 5, no. 3 ; Nr. 5, no. 3 (2008-05-06), S.693-705 |
| Datensatznummer |
250002515
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| Publikation (Nr.) |
 copernicus.org/bg-5-693-2008.pdf |
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| Zusammenfassung |
| The chemical and biological characteristics of the surface microlayer were determined during a
transect across the South Pacific Ocean in October-December 2004. Concentrations of particulate
organic carbon (1.3 to 7.6-fold) and nitrogen (1.4 to 7-fold), and POC:PON ratios were consistently
higher in the surface microlayer as compared to surface waters (5 m). The large variability in
particulate organic matter enrichment was negatively correlated to wind speed. No enhanced
concentrations of dissolved organic carbon were detectable in the surface microlayer as compared
to 5 m, but chromophoric dissolved organic matter was markedly enriched (by 2 to 4-fold) at all
sites. Based on pigment analysis and cell counts, no consistent enrichment of any of the major
components of the autotrophic and heterotrophic microbial community was detectable. CE-SSCP
fingerprints and CARD FISH revealed that the bacterial communities present in the surface
microlayer had close similarity (>76%) to those in surface waters. By contrast, bacterial
heterotrophic production (3H-leucine incorporation) was consistently lower in the surface
microlayer than in surface waters. By applying CARD-FISH and microautoradiography, we
observed that Bacteroidetes and Gammaproteobacteria dominated leucine uptake in the surface
microlayer, while in surface waters Bacteroidetes and Alphaproteobacteria were the major
groups accounting for leucine incorporation. Our results demonstrate that the microbial
community in the surface microlayer closely resembles that of the surface waters of the open
ocean. Even a short residence in the surface microlayer influences leucine incorporation by
different bacterial groups, probably as a response to the differences in the physical and chemical
nature of the two layers. |
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