Biogeochemical transformations of dissolved organic matter at the sediment–water interface: results from in situ incubations within benthic chambers
- 作者：Accornero ; Alessandra ; Picon ; Philippe ; de Bové ; e ; Francis
- 关键词：Sediment&ndash ; waterinterface ; Benthic chamber ; In situ incubations ; Continental margin ; NW Mediterranean ; Interface eau&ndash ; sé ; diment ; Chambre benthique ; Incubation in situ ; Marge continentale ; Mé ; dité ; rrané ; e nord-occidentale
- 刊名：Oceanologica Acta
- 出版年：2002
- 期刊代码：65_03991784
- 类别：ear
- 出版时间：May - June, 2002
- 卷：25
- 期：3-4
- 页码：171-178
- 文件大小：381 K
摘要
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 (14C-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-grained fraction, Eh, CaCO3 contents) and biological activities, such as bacterial respiration and infaunal burrowing. Biologically mediated processes decreased from onshore to deep sites, with mineralization always accounting for the bulk of transformations of the injected 14C-Glu. Geopolymerization did not display a clear spatial trend and appeared to be a quantitatively important process on the Gulf of Lions margin.