| Registro completo |
| Provedor de dados: |
ArchiMer
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| País: |
France
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| Título: |
Biogeochemical transformations of dissolved organic matter at the sediment-water interface: results from in situ incubations within benthic chambers
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| Autores: |
Accornero, A
Picon, P
De Bovee, F
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| Data: |
2002-05
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| Ano: |
2002
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| Palavras-chave: |
Interface eau–sédiment
Chambre benthique
Incubation in situ
Marge continentale
Méditérranée nord-occidentale
Sediment-waterinterface
Benthic chamber
In situ incubations
Continental margin
NW Mediterranean
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| Resumo: |
Biogeochemical transformations of dissolved organic matter at the sediment-water interface were investigated by the use of benthic chambers in the western Gulf of Lions. The experimental approach used for this study consisted of in situ incubations of radiolabeled glutamic acid ((14)C-Glu), followed by a sequential extraction allowing the quantification of the radioactivity associated to different chemical fractions, representative of different biogeochemical processes. This technique was devised to simulate the fate of simple dissolved compounds resulting from the degradation of particulate organic matter near the seafloor. In our experiment the substrate underwent both biotic (mineralization, bacterial incorporation) and abiotic (geopolymerization) transformations. Significant spatial variations were put in relation with sediment characteristics (e.g. fine-errained fraction, Eh, CaCO(3) contents) and biological activities, such as bacterial respiration and infaunal bur-rowing. Biologically mediated processes decreased from onshore to deep sites. with mineralization always accounting for the bulk of transformations of the injected (14)C-Glu. Geopolymerization did not display a clear spatial trend and appeared to be a quantitatively important process on the Gulf of Lions margin.
Les transformations biogéochimiques de la matière organique dissoute à l’interface eau-sédiment ont été étudiées à l’aide de chambres benthiques dans le secteur occidental du Golfe du Lion. L’approche expérimentale consistait en une incubation in situ d’acide glutamique marqué radioactivement (14C-Glu). Cette technique a été mise au point pour simuler l’évolution de composés dissous simples issus de la dégradation de la matière organique particulaire près du fond. Cet acide aminé a subi des transformations biotiques (minéralisation, incorporation bactérienne) et abiotiques (géopolymérisation). Des variations spatiales significatives ont été mises en relation avec les caractéristiques du sédiment (ex., fraction granulométrique fine, Eh, contenu en CaCO3) et des activités biologiques telles que la respiration bactérienne et la bioturbation. Les processus biologiques montrent une diminution de la côte vers le large et la minéralisation est responsable de la plus grande partie des transformations du (14C-Glu) injecté. La géopolymérisation ne montre pas de tendance spatiale mais apparaît comme un processus quantitativement important sur la marge continentale du Golfe du Lion.
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| Tipo: |
Text
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| Idioma: |
Inglês
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| Identificador: |
http://archimer.ifremer.fr/doc/00322/43318/42936.pdf
DOI:10.1016/S0399-1784(02)01192-1
http://archimer.ifremer.fr/doc/00322/43318/
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| Editor: |
Gauthier-villars/editions Elsevier
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| Formato: |
application/pdf
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| Fonte: |
Oceanologica Acta (0399-1784) (Gauthier-villars/editions Elsevier), 2002-05 , Vol. 25 , N. 3-4 , P. 171-178
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| Direitos: |
2002 Ifremer/CNRS/IRD/Éditions scientifiques et médicales Elsevier SAS. All rights reserved
info:eu-repo/semantics/openAccess
restricted use
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