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| Registros recuperados: 14 | |
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| Orvain, Francis. |
| Flume experiments were designed to study how sediment erodibility was modified by the facultative suspension-feeder Scrobicularia plana living at different densities in sediment beds of various degrees of compaction. Two separate erosion phases were identified from the resuspension kinetics: (1) erosion of an unconsolidated surficial layer (i.e. fluff layer) and (2) the subsequent bed erosion. S. plana were found to influence both erosion phases: (1) erosion rates of the fluff layer were controlled by bioturbation activities, the extents of which were influenced by bivalve density and the degree of compaction of the sediments, and (2) critical thresholds of the subsequent bed erosion decreased as clam density increased, likely due to depressions in the... |
| Tipo: Text |
Palavras-chave: Resuspension; Model; Functional groups; Sediment transport; Bioturbation; Scrobicularia plana; Intertidal mudflat. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-3776.pdf |
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| Ouillon, S.; Douillet, Pascal; Lefebvre, J. P.; Le Gendre, Romain; Jouon, Aymeric; Bonneton, P.; Fernandez,; Chevillon, C.; Magand, O.; Lefevre, J.; Le Hir, Pierre; Laganier, R.; Dumas, Franck; Marchesiello, P.; Madani, A. Bel; Andrefouet, S.; Panche, J. Y.; Fichez, R.. |
| The south-west lagoon of New Caledonia is a wide semi-open coral reef lagoon bounded by an intertidal barrier reef and bisected by numerous deep inlets. This paper synthesizes findings from the 2000-2008 French National Program EC2CO-PNEC relative to the circulation and the transport of suspended particles in this lagoon. Numerical model development (hydrodynamic, fine suspended sediment transport, wind-wave, small-scale atmospheric circulation) allowed the determination of circulation patterns in the lagoon and the charting of residence time, the later of which has been recently used in a series of ecological studies. Topical studies based on field measurements permitted the parameterisation of wave set-up induced by the swell breaking on the reef barrier... |
| Tipo: Text |
Palavras-chave: Hydrodynamics; Suspended sediment; New Caledonia; Coral reef lagoon; Sediment; Turbidity; Resuspension. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00014/12526/9401.pdf |
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| Guidi-guilvard, L. D.; Thistle, D.; Khripounoff, Alexis; Gasparini, S.. |
| A continuous high-resolution time-series survey of the hyperbenthic community and local environmental conditions was conducted in the benthic boundary layer (BBL) of the DYFAMED-BENTHOS station (43 degrees 24.61'N, 7 degrees 51.67'E at 2347 in depth in the NW Mediterranean) between January 1996 and April 1998 using bottom-moored sediment traps and a current meter. Sediment traps were set 4 m above the bottom. Hyperbenthos was collected as 'swimmers', i.e. those organisms that are alive when they enter the traps but are not part of the particle flux. Identification of these organisms showed that similar to 90%, were meiobenthic, Copepods dominated and comprised on average 75%, of total swimmers. They were followed by nauplii (12%), annelids (7.8%),... |
| Tipo: Text |
Palavras-chave: Biodiversity; Population growth; Emergence; Resuspension; Benthic storms; Hyperbenthos; Swimmers; Deep sea. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7416.pdf |
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| Kassila, Jawad; Hussenot, Jerome. |
| A study was conducted in seabass (Dicentrarchus labrax) and oyster (Crassostrea gigas) ponds to assess the levels of heterogeneity of sediments and settling particles. The intensity of sampling to estimate with high accuracy some characteristics will depend on the magnitude of the variation within the population under consideration. Several variables, such as total phosphate (Tot-P), total iron (Tot-Fe), total ammonium nitrogen (TAN), organic carbon (Org-C), total nitrogen (Tot-N) and P fractions were analysed during the rearing period. The box-and-whisker plots were used as graphical/statistical tools to visualize the descriptive statistical characteristics of the data. In the fish pond, the sediments have high concentrations of Tot-P, Tot-Fe and TAN in... |
| Tipo: Text |
Palavras-chave: Sampling strategy; Resuspension; Sedimentation; Artificial aeration; Particles; Sediment. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1224.pdf |
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| Savelli, Raphael; Bertin, X.; Orvain, Francis; Gernez, P.; Dale, A.; Coulombier, T.; Pineau, P.; Lachaussée, N.; Polsenaere, Pierre; Dupuy, C.; Le fouest, V.. |
| Microphytobenthos (MPB) resuspension is a key mechanism in the transfer of organic matter from productive intertidal mudflats to terrestrial and marine systems. In this study, we infer on the contribution of physical and biological factors involved in the MPB resuspension. We use a physical‐biological coupled model forced by realistic meteorological and hydrodynamical forcings to simulate chronic (without any concomitant sediment resuspension) and massive (driven by bed failure) resuspension over a year. The model simulates mud surface temperature, MPB growth, and grazing by the gastropod Peringia ulvae. The model suggests that MPB resuspension is the highest in spring tides and at the flood beginning due to high current velocity and low water heights that... |
| Tipo: Text |
Palavras-chave: Microphytobenthos; Mudflat; Resuspension; Physical-biological coupling; Numerical modeling. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00599/71114/69416.pdf |
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| Walker, Tony R.; Grant, Jon; Weise, Andrea M.; Mckindsey, Christopher W.; Callier, Myriam D.; Richard, Marion. |
| Downward fluxes of organically rich biodeposits under suspended mussel lines can cause benthic impacts such as changes in benthic community structure or microbial mat production. Quantifying sediment erosion in these coastal ecosystems is important for understanding how fluxes of organic matter and mussel biodeposits contribute to benthic–pelagic coupling. Critical shear velocity (u*crit), erosion rates and particle size distributions of resuspended sediment were measured at four stations distributed along a transect perpendicular to a mussel farm in Lagune de la Grande Entrée, Îles-de-la-Madeleine (Quebec, Canada). Stations were selected underneath the outer-most mussel line (0 m) and at distances of 15, 30 m and at a reference station (500 m) further... |
| Tipo: Text |
Palavras-chave: Sediment erosion; Shear velocity; Resuspension; Biodeposits; Particle size; Mytilus edulis. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00202/31287/31925.pdf |
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| Blanchard, Gérard F; Sauriau, Pg; Cariou-le Gall, Valerie; Gouleau, D; Garet, Mj; Olivier, F. |
| Resuspension of the top few sediment layers of tidal mud flats is known to enhance planktonic biomass of microbiota (benthic diatoms and bacteria). This process is mainly controlled by tidal shear stress and cohesiveness of mud, and is also influenced by bioturbation activities. Laboratory experiments in a race track flume were performed to test the interactive effects of these factors on both the critical entrainment and resuspension kinetics of microbiota from silt-clay sediments from the Marennes-Oleron Bay, France. The marine snail Hydrobia ulvae was used to mimic surface bioturbation activities. As expected, the kinetics of microbial resuspension versus shear stress were largely controlled by the cohesiveness of silt-clay sediments. However, our... |
| Tipo: Text |
Palavras-chave: Microphytobenthos; Bacteria; Resuspension; Bioturbation; Hydrobia ulvae; Shear velocity; Sediment cohesiveness; Flume experiment. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00337/44789/44480.pdf |
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| Dupuy, Christine; Mallet, Clarisse; Guizien, Katell; Montanie, Helene; Breret, Martine; Mornet, Francoise; Fontaine, Camille; Nerot, Caroline; Orvain, Francis. |
| Resuspension thresholds in terms of friction velocity were experimentally quantified for the prokaryotes, protists and for the first time, viruses of intertidal mudflat biofilms. Differences in resuspension thresholds could be related to the type, behaviour and size of microorganisms and their association with particles. Free microorganisms (viruses, bacteria and some nanoflagellates) were resuspended by weak flow at friction velocities lower than 2 cm s- 1. Chlorophyll a, some nanoflagellates and attached bacteria were resuspended together with the bed’s muddy sediment, which required friction velocities larger than 3 cm s- 1. Diatoms smaller than 60 μm were resuspended at velocities between 3 and 5 cm s- 1, while those larger than 60 μm were resuspended... |
| Tipo: Text |
Palavras-chave: Viruses; Microorganisms; Resuspension; Benthic-pelagic coupling; Spatial distribution; Mudflat. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00168/27922/26196.pdf |
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| Orvain, Francis; Sauriau, Pierre-guy; Le Hir, Pierre; Guillou, Gael; Cann, Philippe; Paillard, Michel. |
| A portable erosion device (ERIS) was deployed in November 2000 and May 2001 to investigate the spatio-temporal variation of fine-grained sediment erosion over a transect on the intertidal mudflats of Marennes-Oleron Bay, western France. The objective was to relate changes in bed erodability over diurnal emersion periods to bioturbation, rapid changes in sediment characteristics, and microphytobenthos biomass. Macrofaunal assemblages were dominated by the bivalve, Scrobicularia plana, on the upper mudflat, and by the gastropod, Hydrobia ulvae. on the middle mudflat. A power relationship was obtained where tau(cr) was plotted as a function of sediment density. Results from the upper part of the mudflat deviated from this relationship due to bioturbation by... |
| Tipo: Text |
Palavras-chave: EPS; Microphytobenthos; Erodability; Intertidal mudflat; Sediment; Scrobicularia plana; Hydrobia ulvae; Bioturbation; Resuspension; Eris. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3779.pdf |
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| Orvain, F; Sauriau, Pierre-guy; Bacher, Cedric; Prineau, Michel. |
| Laboratory experiments performed in a recirculating flume were designed to quantify the bioturbation influence of the mud snail Hydrobia ulvae, one of the most abundant deposit feeders on European intertidal mudflats. Variations in sediment moisture content that occur between bedforms in shore-normal, ridge and runnel systems of intertidal mudflats were added to the model definition. Sediment erosion thresholds, erosion rates and the microalgal pigment composition of resuspended material were quantified for different H. ulvae densities (0, 1000, 5000, 10 000 and 50 000 snails m(-2)) and applied bed shear stresses. Two different sediment moisture contents were tested. In the absence of macrofauna, recorded turbidities increased up to the maximum applied... |
| Tipo: Text |
Palavras-chave: Model; Flume; Chloropigments; Ridges and tunnels; Mudflat; Sediment; Hydrobia ulvae; Bioturbation; Resuspension. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3774.pdf |
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| Registros recuperados: 14 | |
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