Consulta: subjectFacets:"Mudflat"
Registros recuperados: 12
Data/hora: 04/06/2024 08:06:09

Influence of environment factors on bacterial ingestion rate of the deposit-feeder Hydrobia ulvae and comparison with meiofauna
Provedor de dados: 5
Autores: Pascal, Pierre-yves; Dupuy, C; Richard, P; Haubois, A.g.; Niquil, N.
Deposit feeders are able to process a considerable volume of sediment, containing large quantities of associated bacteria. However, conclusions concerning the trophic role played by benthic bacteria in marine sediments are still not fully elucidated. This study deals with bacterivory by the gastropod Hydrobia ulvae, one of the most abundant deposit-feeding species in intertidal mudflats in Western Europe. Ingestion rates of bacteria were determined during grazing experiments using 15N preenriched bacteria. Grazing experiments were performed in order to measure effects of abiotic (temperature, salinity and luminosity) and biotic (bacterial and algal abundances) factors on ingestion rates of bacteria by H. ulvae of an intertidal mudflat (Brouage,...
Tipo: Text
Palavras-chave: Mudflat; Nematodes; Ammonia tepida; Environmental factors; Grazing; Bacteria; Gastropod; Hydrobia ulvae; Deposit feeding.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4781.pdf

Stable isotope analysis position of intertidal of food source and trophic nematodes and copepods
Provedor de dados: 5
Autores: Rzeznik Orignac, J; Boucher, G; Fichet, Denis; Richard, P.
Four dominant nematode species and various copepods from an intertidal mudflat in Marennes-Oleron Bay were analyzed for delta C-13 and delta N-15 ratios together with their potential food source, the microphytobenthos. It was shown that microphytobenthic C is passed to nematodes either by grazing or predation on herbivorous meiofauna by other nematodes. Diatoms of different sizes exhibited different C-13 content, which can be reflected in herbivorous meiofauna, such as the nematodes Daptonema oxycerca and Metachromadora remanei and the bulk of copepods, indicating they can select different sizes of diatoms. Results confirm the need to analyze meiofauna feeding habits at the species or genera level since the delta N-15 and delta C-13 signatures differed...
Tipo: Text
Palavras-chave: Stable isotopes; Marennes Oleron; Mudflat; Food web; Benthic diatoms; Microphytobenthos; Meiofauna; Copepods; Nematodes.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4292.pdf

Dynamique des sédiments fins et mixtes des zones intertidales de la baie de Marennes-Oléron
Provedor de dados: 5
Autores: Kervella, Stephane.
This thesis aims at increasing the general knowledge on sediment dynamics of intertidal flats in the Marennes-Oléron Bay, according to physical, biological and anthropogenic factors.  The conducted research is compound of three complementary studies: (1) a study of sediment behaviour through applied rheophysics on intertidal superficial sediments; (2) a hydro-sedimentary study based on identification of the forcing action (physical, biological or anthropogenic) on the intertidal flat stability over several time scales (from the event to several months); (3) a specific application of the model SiAM-2DH to the Marennes-Oléron Bay.  The surface sediments shows a mechanical behaviour that mainly depends on the fine fraction for a composition that contains up...
Tipo: Text
Palavras-chave: Rhéophysique; Seuil d’écoulement; Sédiments cohésifs et mixtes; Sédimentation; Érosion; Hydrodynamique; Vasière; Zone intertidale; Conchyliculture; ALTUS; SiAM-2DH; Baie de Marennes-Oléron; Rhéophysics; Shear strenght; Cohesive and mixed sediment; Sédimentation; Erosion; Hydrodynamics; Mudflat; Intertidal area; Oyster; ALTUS; SiAM-2DH; Marennes-Oléron Bay.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00004/11534/8117.pdf

Devenir des bactéries dans les réseaux trophiques des vasières intertidales : le cas de brouage (Baie de Marennes-Oléron)
Provedor de dados: 5
Autores: Pascal, Pierre-yves.
Bacteria are highly abundant and productive in intertidal mudflat sediments. By analogy  with pelagic system, it has been suggested that bacteria play an important role in benthic food  web. Due to technical difficulties, numbers of studies dealing with benthic bacterivory are not  numerous and give conflicting results. A method using community of 15N enriched bacteria as  tracer was developed in order to measure grazing of meiofauna and macrofauna. Since enriched  bacteria present characteristics of size, activity and diversity close to natural ones, bias due to  selective bacterial ingestion by grazers are limited. Due to tidal cycles, intertidal mudflat  constitutes highly variable environment at short time scale. Since those variations may influence...
Tipo: Text
Palavras-chave: Stable isotope; Hydrobia ulvae; Foraminifera; Copepod; Nematode; Bacteria; Mudflat; Trophic foodweb; Isotope stable; Hydrobia ulvae; Foraminifère; Copépode; Nématode; Bactérie; Vasière; Réseau trophique.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/these-4778.pdf

Bacterivory in the common foraminifer Ammonia tepida: Isotope tracer experiment and the controlling factors
Provedor de dados: 5
Autores: Pascal, P.y.; Dupuy, C; Richard, P; Niquil, N.
The majority of sediment dweller foraminifera are deposit feeders. They use their pseudopodia to gather sediment with associated algae, organic detritus and bacteria. Uptake of bacteria by foraminifera have been observed but rarely quantified. We measured uptake of bacteria by the common foraminifera Ammonia tepida using 15N pre-enriched bacteria as tracers. In intertidal flats, seasonal, tidal and circadian cycles induce strong variations in environmental parameters. Grazing experiments were performed in order to measure effects of abiotic (temperature, salinity and irradiance) and biotic (bacterial and algal abundances) factors on uptake rates of bacteria. In mean conditions, A. tepida grazed 78 pgC ind-1 h-1 during the first eight hours of incubation,...
Tipo: Text
Palavras-chave: Trophoecology; Prey abundance; Mudflat; Grazing; Foraminifera; Environmental factor; Bacteria.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4298.pdf

Dynamics and sources of suspended particulate organic matter in the Marennes-Oléron oyster farming bay: Insights from stable isotopes and microalgae ecology
Provedor de dados: 5
Autores: Malet, Nathalie; Sauriau, Pierre-guy; Ryckaert, Mireille; Malestroit, Pascale; Guillou, Gael.
The aim of this study was to distinguish between sources of the complex variety of Marennes-Oléron Bay suspended particulate organic matter (SPOM) contributing to the tropho-dynamics of the Marennes-Oléron oyster farming bay. Basic biomarkers (Chl a, C/N and POC/Chl a ratios), carbon and nitrogen stable isotopes from SPOM were analyzed and the microalgae community was characterized. The sampling strategy was bimonthly from March 2002 to December 2003; samples were taken from an intertidal mudflat. Four main sources contributed to the SPOM pool: terrigenous input from rivers, neritic phytoplankton, resuspended microphytobenthos and periodic inputs from intertidal Zostera noltii meadows. Seasonal fluctuations were observed in both years of the study period:...
Tipo: Text
Palavras-chave: Heatwave; Zostera noltii; Mudflat; Microphytobenthos; Phytoplankton; Suspended particulate organic matter; Marennes Oléron Bay.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4313.pdf

The influence of sediment cohesiveness on bioturbation effects due to Hydrobia ulvae on the initial erosion of intertidal sediments: A study combining flume and model approaches
Provedor de dados: 5
Autores: 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

Impact of Chronic and Massive Resuspension Mechanisms on the Microphytobenthos Dynamics in a Temperate Intertidal Mudflat
Provedor de dados: 5
Autores: 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

Spatio-temporal differentiation in the population structure of Hydrobia ulvae on an intertidal mudflat (Marennes-Oleron Bay, France)
Provedor de dados: 5
Autores: Haubois, Anne-gaelle; Guarini, Jean-marc; Richard, Pierre; Blanchard, Gerard; Sauriau, Pierre-guy.
Spatio-temporal changes in density, breeding cycle, growth and population structure of Hydrobia ulvae (Gastropoda: Prosobranchia) were studied by monthly sampling of a wide bare mudflat in Marennes-Oleron Bay. Four stations, located along a cross-shore transect and characterized by different geomorphological structures, were investigated from March 2000 to February 2001. Hydrobia ulvae was mainly distributed in the upper half part of the mudflat and no individuals were found in the lower part. The breeding cycle extended from March to December and showed two annual peaks, in spring and in autumn. Three cohorts were recruited during the year and showed high growth rates during summer; the parameters of the von Bertalanffy model describing the growth curves...
Tipo: Text
Palavras-chave: Gastropoda; Mudflat; Spatio temporal change; Population dynamic.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/2002/publication-598.pdf

Sequential resuspension of biofilm components (viruses, prokaryotes and protists) as measured by erodimetry experiments in the Brouage mudflat (French Atlantic coast)
Provedor de dados: 5
Autores: 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

Bacterivory of a mudflat nematode community under different environmental conditions
Provedor de dados: 5
Autores: Pascal, P.y.; Dupuy, C; Richard, P; Rzeznik-orignac, J; Niquil, Nathalie.
The fate of the benthic bacterial biomass is a topic of major importance in understanding how softbottom environments function. Because of their high abundance, production and nutritional value, benthic bacteria may constitute an important food resource for benthic fauna. The trophic role of bacteria for a nematode community on the Brouage mudflat (Marennes-Ole´ron-France), dominated by three species: Chromadora macrolaima (64% of the abundance), Daptonema oxycerca (15%) and Ptycholaimellus jacobi (8%), was determined in grazing experiments using 15N pre-enriched bacteria. On intertidal flats, seasonal, tidal and circadian cycles induce strong variations in environmental conditions. Grazing experiments were performed in order to measure the effects of...
Tipo: Text
Palavras-chave: Mudflat; Environmental factor; Grazing; Bacteria; Nematode.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4295.pdf

A new snapping shrimp (Crustacea Decapoda, Alpheidae, Alpheus) from the estuarine mudflats of Kuwait
Provedor de dados: 16
Autores: Anker, A.; Grave, S. De.
A new snapping shrimp, Alpheus lutosus spec. nov., is described from the intertidal mudflats of Bubiyan Island, northern Kuwait, south of the vast Shatt-Al-Arab delta. The new species appears to be closely related to Alpheus hoplocheles Coutière, 1897 from similar estuarine habitats in China and Japan, differing mainly in the absence of a sharp distolateral tooth on the palm of the major chela, the less marked rostral carina, and the number of spines on the propodus of the third pereiopod. Both A. lutosus spec. nov. and A. hoplocheles are unique within the A. edwardsii species group in having a strong sharp distomesial tooth on the palm of the otherwise typical edwardsii-type major chela. At the type locality, A. lutosus spec. nov. is often associated with...
Tipo: Article / Letter to the editor
Palavras-chave: Caridea; Alpheidae; Snapping shrimp; Alpheus; New species; Mudflat; Kuwait; Persian Gulf; Facultative association; Goby; 42.74.
Ano: 2009
URL: http://www.repository.naturalis.nl/record/315878