Franck Gilbert

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4 2 4 2 Abstract—Pore water and solid phase distributions of oxygen, manganese, and nitrogen from hemipelagic and shelf sediments sometimes indicate a close coupling between the manganese and nitrogen redox cycles. Reaction coupling must be sustained in part by biological reworking of Mn-oxide-rich surface sediments into underlying anoxic zones. Surface(More)
Oil spills threaten coastlines where biological processes supply essential ecosystem services. Therefore, it is crucial to understand how oil influences the microbial communities in sediments that play key roles in ecosystem functioning. Ecosystems such as sediments are characterized by intensive bioturbation due to burrowing macrofauna that may modify the(More)
Patterns of change in the structure of bacterial communities monitored by ribosomal intergenic spacer analysis (RISA) in oil contaminated sediments inhabited or not by the marine polychaete Nereis diversicolor were studied during 45 days under laboratory conditions. Results supported by principal component analysis showed a marked response of the bacterial(More)
Active organisms modify the substratum in which they dwell. This process, called “bioturbation”, affects the way that biogeochemical fluxes are mediated at the substratum–water interface. In the frame of this work, the bioturbation potential of the Asiatic clam Corbicula fluminea was characterized and quantified. We measured the displacement of fluorescent(More)
As part of the ECOMARGE operation (J.G.O.F.S. France), macrobenthic assemblages in the Toulon Canyon were described and quanti"ed on the basis of sampling carried out between 250 and 2000 m depth on the Mediterranean continental slope. Results show that Mediterranean bathyal assemblages are made up mainly of continental shelf eurybathic species. The(More)
The interactions between invertebrates and micro-organisms living in streambed sediments often play key roles in the regulation of nutrient and organic matter fluxes in aquatic ecosystems. However, benthic sediments also constitute a privileged compartment for the accumulation of persistent organic pollutants such as PAHs or PCBs that may affect the(More)
We propose a simple and inexpensive method to determine the rate and pattern of surface sediment reworking by benthic organisms. Unlike many existing methods commonly used in bioturbation studies, which usually require sediment sampling, our approach is fully non-destructive and is well suited for investigating non-cohesive fine sediments in streams and(More)
The heterogeneity of oxygen distribution in a Hediste diversicolor burrow environment was investigated in a laboratory experiment using a 6-mm thick tank equipped with oxygen planar optodes. The two-dimensional oxygen distribution in a complete burrow was monitored every 2 min for 4 h. Oxygen concentrations fluctuated over a scale of minutes in the burrow(More)
  • Rénald Belley, Archambault, Philippe Sundby, Bjorn, Gilbert Franck, Gagnon +6 others
  • 2013
OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible. a b s t r a c t The bottom water in the 4 300 m deep Lower St. Lawrence Estuary (LSLE) is persistently hypoxic in contrast to the normoxic bottom waters in the Gulf of St. Lawrence (GSL). We photographed the seabed at(More)
  • Jenny Hedman, Elisabet, Jonas S Gunnarsson, And Samuelsson, Göran, Gilbert +3 others
  • 2013
Particle reworking and solute transport by the sediment-living polychaetes Marenzelleria neglecta and Hediste diversicolor. OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible. a b s t r a c t This experimental study quantified and compared particle-mixing and solute(More)