Modeling biogeochemical processes in sediments from the Rhone River prodelta area (NW Mediterranean Sea)
| Type | Article | ||||||||||||
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| Date | 2011-05-27 | ||||||||||||
| Language | English | ||||||||||||
| Author(s) | Pastor L.1, Cathalot C.2, Deflandre B.1, 3, Viollier E.1, Soetaert K.4, Meysman F. J. R.4, Ulses C.5, Metzger E., Rabouille C.2 | ||||||||||||
| Affiliation(s) | 1 : Univ. Paris Diderot, Sorbonne Paris Cité, Institut de Physique du Globe de Paris, UMR7154 CNRS, 75013 Paris, France 2 : Lab. des Sciences du Climat et de l'Environ., CEA-CNRS UMR 1572, Av. de la Terrasse, 91198 Gif sur Yvette, France 3 : UMR5805 EPOC – OASU, Université Bordeaux 1 – CNRS, Avenue des Facultés, 33405 Talence cedex, France 4 : NIOO-KNAW, Centre for Estuarine and Marine Ecology, Korringaweg 7, 4401 NT Yerseke, The Netherlands 5 : Laboratoire d'Aérologie, CNRS et Université de Toulouse, 14 avenue Edouard Belin, 31400 Toulouse, France 6 : Laboratoire des Bio-Indicateurs Actuels et Fossiles, UPRES EA 2644, UFR Sciences 2 bd Lavoisier, 49045 Angers Cedex 01, France |
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| Source | Biogeosciences (1726-4170) (Copernicus GmbH), 2011-05-27 , Vol. 8 , N. 5 , P. 1351-1366 | ||||||||||||
| DOI | 10.5194/bg-8-1351-2011 | ||||||||||||
| WOS© Times Cited | 41 | ||||||||||||
| Note | Special issue Biogeochemical fluxes in River-dominated Ocean Margins (RiOMars): the Rhone delta (NW Mediterranean Sea) – river inputs, plume processes, benthic recycling, budgets and models | ||||||||||||
| Abstract | In situ oxygen microprofiles, sediment organic carbon content, and pore-water concentrations of nitrate, ammonium, iron, manganese, and sulfides obtained in sediments from the Rhone River prodelta and its adjacent continental shelf were used to constrain a numerical diagenetic model. Results showed that (1) the organic matter from the Rhone River is composed of a fraction of fresh material associated to high first-order degradation rate constants (11-33 yr(-1)); (2) the burial efficiency (burial/input ratio) in the Rh boolean AND one prodelta (within 3 km of the river outlet) can be up to 80 %, and decreases to similar to 20% on the adjacent continental shelf 10-15 km further offshore; (3) there is a large contribution of anoxic processes to total mineralization in sediments near the river mouth, certainly due to large inputs of fresh organic material combined with high sedimentation rates; (4) diagenetic by-products originally produced during anoxic organic matter mineralization are almost entirely precipitated (> 97 %) and buried in the sediment, which leads to (5) a low contribution of the re-oxidation of reduced products to total oxygen consumption. Consequently, total carbon mineralization rates as based on oxygen consumption rates and using Redfield stoichiometry can be largely underestimated in such River-dominated Ocean Margins (RiOMar) environments. | ||||||||||||
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