Consulta: subjectFacets:"Microphytobenthos"
Registros recuperados: 40
Data/hora: 01/06/2024 11:41:06

Monthly HPLC measurements of pigment concentration from an intertidal muddy sediment of Marennes-Oléron Bay, France
Provedor de dados: 5
Autores: Cariou-le Gall, Valerie; Blanchard, Gerard.
Chloropigments and carotenoids were measured by HPLC in an intertidal muddy sediment of Marennes-Oleron Bay (France). Concentrations were determined as a function of sediment depth at low tide. The analyses were carried out at monthly intervals over 1 yr. Pigment analysis indicated that the microphytobenthic community was dominated by diatoms throughout the sampling year. Chlorophyll b was not encountered at any time or depth, indicating that no input from macrophytic detritus had occurred at the sampling site. There was a large pool of phaeopigments a, of which phaeophorbides were the major forms (75%). A microphytobenthic bloom occurred between March and June during which phaeopigments significantly increased with a high proportion of phaeophorbides...
Tipo: Text
Palavras-chave: Pigment; HPLC; Intertidal mudflat; Microphytobenthos; Seasonal change.
Ano: 1995
URL: http://archimer.ifremer.fr/doc/00257/36844/36666.pdf

Bacterial Dynamics in a Microphytobenthic Biofilm: a Tidal Mesocosm Approach
Provedor de dados: 5
Autores: Agogue, Helene; Mallet, Clarisse; Orvain, Francis; De Crignis, Margot; Mornet, Francoise; Dupuy, Christine.
In intertidal mudflats, during low tide exposure, microphytobenthos (MPB) migrate vertically through the surface sediment and form, with the heterotrophic bacteria, a transient biofilm. Inside this biofilm, multiple interactions exist between MPB and bacteria. These micro-organisms secrete a wide range of extracellular polymeric substances (EPS), which are major components of the biofilm matrix. In this study, we used a tidal mesocosm experiment in order to decipher the interactions of the MPB-EPS-bacteria complex within the biofilm. We tried to determine if the EPS could control bacterial activities and/or production and/or richness according to the age of the biofilm and to the immersion/emersion period. The dynamics of biomasses of MPB and prokaryotes,...
Tipo: Text
Palavras-chave: Muddy sediment; Microphytobenthos; Bacteria; Extracellular polymeric substances; Interactions; Mesocosm.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00181/29271/27682.pdf

Mapping the Intertidal Microphytobenthos Gross Primary Production, Part II: Merging Remote Sensing and Physical-Biological Coupled Modeling
Provedor de dados: 5
Autores: Savelli, Raphael; Méléder, Vona; Cugier, Philippe; Polsenaere, Pierre; Dupuy, Christine; Lavaud, Johann; Barnett, Alexandre; Le Fouest, Vincent.
Microphytobenthos (MPB) at the sediment surface of intertidal mudflats are known to show a high spatial and temporal variability in response to the biotic and abiotic conditions prevailing at the mud surface. It makes long-term and large-scale monitoring of MPB Gross Primary Production (GPP) difficult to set up. In this study, we developed the first 3D physical-biological coupled model (MARS-3D) that explicitly simulates GPP of intertidal MPB at the mudflat scale, and we compared the outputs with in situ and space remote sensing MPB GPP data. We discuss the sources of discrepancies between the modeling and the remote sensing approach in the light of future developments to be done. For instance, the remote sensing algorithm provides a very synoptic view of...
Tipo: Text
Palavras-chave: Microphytobenthos; Intertidal mudflat; Gross primary production; Remote sensing; Physical-biological modeling.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00654/76612/77764.pdf

Biomasse et production primaire du phytoplancton et du microphytobenthos de deux biotopes sableux (Golfe de Fos, France)
Provedor de dados: 5
Autores: Plante-cuny, Marie-reine; Bodoy, Alain.
The primary production (phytoplankton and microphytobenthos) of a coastaL shallow water ecosystem (0.5 m) was investigated in two sandy areas, differing by their wave exposure. The physical and chemical parameters, the functional chlorophyll and pheopigments as well as the primary production were measured monthly, throughout a two-year study. The bivalve Ruditapes decussatus was the dominant species in the sheltered station (RD), whereas Donax trlmcu/us inhabited the other station (DT) which was exposed to the open-sea waves. Microphytic biomasses were determined after extracting chlorophyll a and pheopigments in 90% acetone. by spectrophotometric measurements before and after acidification. Gross hourly primary production was estimated by measuring the...
Tipo: Text
Palavras-chave: Biomasse; Production primaire; Phytoplancton; Microphytobenthos; Mediterranee; Biomass; Primary production; Phytoplancton; Microphytobenthos; Mediterranean.
Ano: 1987
URL: http://archimer.ifremer.fr/doc/1987/publication-2870.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

Ecologie trophique de l'espèce ingénieur Crepidula fornicata et implications pour le fonctionnement de son habitat
Provedor de dados: 5
Autores: Androuin, Thibault.
The slipper limpet (Crepidula fornicata) is an invasive species of European coasts. Protandric hermaphrodite, this gregarious species forms individuals' stacks which accumulate in high density on bottom. For a long time considered as a detrimental invader, the slipper limpet is also an ecosystem engineer, modifying its habitat both physically and biologically. It is model to study how invasive and engineer species can structure and modify the ecosystem that they colonize. In this Ph.D. thesis, these effects have been examined through the trophic functioning of habitats colonized by the slipper limpet, with a special reference to the primary benthic production. Experimental stimulation of subtidal microphytobenthos (MPB) has been demonstrated by the...
Tipo: Text
Palavras-chave: Isotopes stables; Acides gras; Imagerie hyperspectrale; Microphytobenthos; Rade de Brest; Stable isotopes; Fatty acids; Hyperspectral imaging; Microphytobenthos; Bay of Brest.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00679/79121/81610.pdf

Dynamic model of the short-term variability of microphytobenthic biomass on temperate intertidal mudflats
Provedor de dados: 5
Autores: Guarini, Jean-marc; Blanchard, Gf; Gros, Philippe; Gouleau, Dominique; Bacher, Cedric.
In the present paper, we list and document the relevant behavioral and physiological processes controlling primary productivity of epipelic microalgae on intertidal mudflats in order to develop a simplified model. We first propose, in an attempt to characterize the 'photosynthetically active biomass' of the epipelic community, a new approach to describe the photic environment at the sediment surface, by substituting a discrete a-layer model in place of continuous vertical light distribution. This concept thus allows us to build a functional representation of the distribution of the photosynthetically active biomass in the sediment and, by then integrating the light and temperature forcing of the latter biomass, to predict the dynamics of the whole epipelic...
Tipo: Text
Palavras-chave: Microphytobenthos; Intertidal mudflat; Primary production; Dynamic model; Migratory rhythm; Ecophysiological response.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00000/10540/7601.pdf

Dynamics of spatial patterns of microphytobenthic biomass: inferences from a geostatistical analyisis of two comprenhensive surveys in Marennes-Oléron Bay (France)
Provedor de dados: 5
Autores: Guarini, Jean-marc; Blanchard, Gerard; Bacher, Cedric; Gros, Philippe; Riera, Pascal; Richard, Pierre; Gouleau, Dominique; Galois, Robert; Prou, Jean; Sauriau, Pierre-guy.
Microphytobenthos plays an important role as primary producer in shallow embayments subject to a tidal regime. The present paper aims to characterize the spatial patterns of sedimentary chlorophyll a (chl a) biomass in 2 seasons in the wide intertidal mudflats of the Marennes-Oleron Bay (France); furthermore, it provides estimates of total microphytobenthic biomass. Accordingly, a systematic sampling scheme was performed in June 1995 and in January 1996. On average, biomass was higher in June (ca 120 mg chl a m-2) than in January (ca 85 mg chl a m-2). Moreover, the geostatistical analysis revealed that spatial similarities were propagated over larger distances in June (6 km) than in January (2.2 km). In order to account for this result , we suggest that...
Tipo: Text
Palavras-chave: Marennes Oleron; Intertidal mudflat; Geostatistics; Spatial distribution; Chrlorophyll a; Microphytobenthos.
Ano: 1998
URL: https://archimer.ifremer.fr/doc/1998/publication-3820.pdf

How would the loss of production due to an herbicide have repercussions in the food web of an intertidal mudflat? Sensitivity analysis of an inverse model for Brouage mudflat, Marennes-Oleron Bay, France
Provedor de dados: 5
Autores: Niquil, Nathalie; Kerleguer, G; Leguerrier, D; Richard, Pierre; Legrand, Helene; Dupuy, Christine; Pascal, P; Bacher, Cedric.
The presence of herbicides in the run-off water coming over Brouage mudflat (Marennes-Oleron Bay, France) is suspected to cause a loss of primary production by benthic diatom biofilm. Microphytobenthos being the main primary producer of this ecosystem, it was questioned about what could be the effect of such a modification of primary production on the entire food web that depends on it. The probable impacts were investigated through a sensitivity analysis conducted on the steady-state model of the Brouage mudflat, coupling two seasons and trophic-hydrodynamic flows. The loss of benthic primary production had an effect on compartments at a low trophic level, but was buffered at higher levels because of the compensation of herbivory by other pathways and...
Tipo: Text
Palavras-chave: Intertidal mudflat food web; Pollution; Microphytobenthos; Inverse analysis; Sensitivity analysis.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-3613.pdf

Spatio-temporal variations in intertidal mudflat erodability: Marennes-Oleron Bay, western France
Provedor de dados: 5
Autores: 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

Nutrient fluxes on an intertidal mudflat in Marennes-Oleron Bay, and influence of the emersion period
Provedor de dados: 5
Autores: Feuillet-girard, Michelle; Gouleau, Dominique; Blanchard, Gérard; Joassard, Lucette.
Fluxes of nutrients (NH sub(4) super(+), NO sub(3) super(-), PO sub(4) super(3-) and Si(OH) sub(4)) were studied on an intertidal mudflat in Marennes-Oleron Bay, France, at two different seasons and at different times of the emersion period. Fluxes through the sediment-water interface were both calculated from vertical profiles of nutrient concentration in pore-water (diffusive fluxes, JD) and measured in light and dark benthic mini-chambers (measured fluxes, J sub(0)). Results indicate that ammonia was mainly released in summer while nitrate was mainly taken up in late winter. This uptake from the overlying water was probably due to the coupling of nitrification-denitrification within the sediment. The J sub(0) /J sub(D) ratio further indicates that...
Tipo: Text
Palavras-chave: Estran vaseux; Flux de nutriments; Microphytobenthos; Bioturbation; Marennes-Oléron; Intertidal mudflat; Nutrient fluxes; Microphytobenthos; Bioturbation; Marennes-Oleron Bay.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00038/14893/12220.pdf

Étude de la dynamique du microphytobenthos des vasières intertidales aux latitudes tempérées : approche combinée modélisation couplée physique-biologie et analyse de données satellitales
Provedor de dados: 5
Autores: Savelli, Raphael.
The high primary production (PP) of intertidal mudflats at temperate latitudes is mostly supported by microphytobenthos (MPB), which support both benthic and pelagic food webs. In the present thesis, we use a physical-biological coupled model to investigate the spatial and temporal variability of MPB dynamics on a large temperate intertidal mudflat of the French Atlantic coast. The model explicitly simulates the MPB biomass and the grazer (Peringia ulvae) biomass and density. The outputs provide key findings on MPB dynamics. In winter-spring, optimal light and mud surface temperature (MST) conditions for MPB growth lead to a MPB spring bloom. Light is the most limiting driver over the year. However, a high MST limits the MPB growth 40% of the time during...
Tipo: Text
Palavras-chave: Microphytobenthos; Vasière intertidale; Production primaire; Modélisation physique-biologie; Télédétection; Microphytobenthos; Intertidal mudflat; Primary production; Physical-biological modelling; Remote sensing.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00692/80423/83559.pdf

Are epiphytes a significant component of intertidal Zostera noltii beds?
Provedor de dados: 5
Autores: Lebreton, Benoit; Richard, Pierre; Radenac, Gilles; Bordes, Monique; Breret, Martine; Arnaud, Christophe; Mornet, Francoise; Blanchard, Gerard F.
The role of epiphytes in an intertidal Zostera noltii seagrass bed in Marennes-Oleron Bay was assessed in comparison with the other main benthic primary producers (Z. noltii, microphytobenthos) at two bathymetric levels and on a seasonal basis. Assemblage and biomass of epiphytes were studied using scanning electron microscopy (SEM). Z noltii and its detrital matter followed a typical seasonal pattern: microphytobenthos was present in large quantities throughout the year representing 21% of the total biomass while detrital matter, above-ground parts and below-ground parts accounted for 65, 9 and 5%, respectively. Only two species of epiphytic diatoms, Cocconeis scutellum and Cocconeis placentula, were observed on seagrass leaves. Epiphyte biomass was very...
Tipo: Text
Palavras-chave: SEM; Cocconeis spp.; Epiphyte diatom; Microphytobenthos; Zostera noltii; Intertidal seagrass bed; Primary producer.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6589.pdf

Variabilité spatio-temporelle de la biomasse microphytobenthique en rade de Brest et en Manche occidentale
Provedor de dados: 5
Autores: Sagan, G; Thouzeau, G.
Microphytobenthic biomass was estimated in the Bay of Brest (1994) and the western English Channel (Trezen Vraz, 1993) using spectrophotometry. Best results (42 % difference) were obtained with an instantaneous extraction procedure at room temperature, compared with the cold extraction procedure. Chlorophyll biomass in sediment was higher in the western English Channel (65-215 mg Chl a m(-2)) than in the Bay of Brest (10-113 mg Chl a m(-2)), in contrast to total pigment biomass (Chl a + pheo a : 88-254 mg m(-2) at Trezen Vraz vs. 131-934 mg m(-2) in the Bay of Brest). This study emphasized decreasing pigment biomass from the estuary to the open sea. Low benthic pigment biomass in the Bay, compared to eutrophic ecosystems, agrees with previous studies on...
Tipo: Text
Palavras-chave: Microphytobenthos; Biomasse; Écosystèmes côtiers; Forçage physique; Microphytobenthos; Biomass; Coastal ecosystems; Physical forcing.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00325/43651/43242.pdf

Evaluation de l’état écologique des masses d’eau de transition dans le cadre de la DCE. Etude de la pertinence du suivi des peuplements du microphytobenthos estuarien
Provedor de dados: 5
Autores: Ribeiro, Lourenço; Le Bris, Anthony; Hernandez Farinas, Tania; Buchet, Remi; Dutertre, Mickaël; Metzger, Edouard; Rosa, Philippe; Gernez, Pierre; Lerouxel, Astrid; Barille, Laurent.
In order to establish the ecological status of water bodies, the European Water Framework Directive (WFD) is based on the evaluation of a number of biological quality elements, as well as physical parameters supporting the biology. In estuaries, phytoplankton monitoring was not considered relevant because of the high turbidity characterizing the large metropolitan estuaries and the French overseas departments (Guyana). In this work, we considered the possibility of using microphytobenthos (MPB) as a biological indicator of the ecological status of estuaries. This activity report summarizes the actions undertaken in 2017 under an AFB / Université de Nantes convention, which is structured around two main axes: the first axis is based on the analysis of the...
Tipo: Text
Palavras-chave: DCE; Diatomées benthiques; Diversité; Estuaires; Facteurs naturels; Gradient de perturbation; Loire; Bio-indication; Microphytobenthos; Pressions anthropiques; Télédétection.; Anthropogenic pressures; Benthic diatoms; Bio-indication; Diversity; Estuary; Loire; Microphytobenthos; Natural factors; Perturbation gradient; Remote sensing; WFD.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00446/55725/57376.pdf

Does the size of the microphytobenthic biofilm on intertidal muflats depend on the available photosynthetic biomass?
Provedor de dados: 5
Autores: Herlory, Olivier; Blanchard, G; Planche, S; Huet, V; Richard, Pierre.
Many scientists consider that the top centimetre of the sediment on intertidal mudflats contains the photosynthetic competent biomass (PCB). Part of this biomass migrates upward to the surface of the sediment during diurnal emersion periods to form a temporary biofilm: the photosynthetic active biomass (PAB). The present study tests the hypothesis that the size of the biofilm (PAB) is functionally dependent on PCB. Therefore, we have plotted PAB as a function of PCB for a range of different environmental conditions: 3 seasons and 5 tidal situations, representing a total of 600 cores. This investigation points out that, in spring and autumn, there was a simple linear relationship between PAB and PCB, thus indicating that the maximum size of the biofilm...
Tipo: Text
Palavras-chave: Functional relationship; Biofilm; Biomass; Intertidal mudflat; Microphytobenthos.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-3622.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

Mapping the Intertidal Microphytobenthos Gross Primary Production Part I: Coupling Multispectral Remote Sensing and Physical Modeling
Provedor de dados: 5
Autores: Méléder, Vona; Savelli, Raphael; Barnett, Alexandre; Polsenaere, Pierre; Gernez, Pierre; Cugier, Philippe; Lerouxel, Astrid; Le Bris, Anthony; Dupuy, Christine; Le Fouest, Vincent; Lavaud, Johann.
The gross primary production (GPP) of intertidal mudflat microphytobenthos supports important ecosystem services such as shoreline stabilization and food production, and it contributes to blue carbon. However, monitoring microphytobenthos GPP over a long-term and large spatial scale is rendered difficult by its high temporal and spatial variability. To overcome this issue, we developed an algorithm to map microphytobenthos GPP in which the following are coupled: (i) NDVI maps derived from high spatial resolution satellite images (SPOT6 or Pléiades), estimating the horizontal distribution of the microphytobenthos biomass; (ii) emersion time, photosynthetically active radiation (PAR), and mud surface temperature simulated from the physical model MARS-3D;...
Tipo: Text
Palavras-chave: Microphytobenthos; Intertidal mudflat; Gross primary production; Remote sensing; NDVI; Modeling.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00643/75531/76429.pdf

Kinetics of tidal resuspension of microbiota: Testing the effects of sediment cohesiveness and bioturbation using flume experiments
Provedor de dados: 5
Autores: 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

Fonctionnement des marais maritimes atlantiques: échanges d'énergie et effets des flux aquacoles diffus
Provedor de dados: 5
Autores: Bel Hassen, Malika.
French estuaries, from the Atlantic coast to the English channel, have been characterized by a poor phytoplankton biomass. The turbidity has always been considered as the limiting factor for phytoplankton. Estuarine ecosystems are situated at the boundary between the land and the sea. Consequently, they are subject to an enrichment by nutrient loadings from upland ecosystems. Although it has been demonstrated that a part of the nutrient loadings support an important benthic production. The part, which escapes to the estuarine benthic and planktonic food web and is exported to adjacent estuarine ecosystems, still remains undetermined. Quantifying the nu trient and particulate matter exchange between a macrotidal Bay, the Fier d'Ars, and the adjacent ocean...
Tipo: Text
Palavras-chave: Aquaculture; Exportation; Matière dissoute; Fiers d'Ars; Systèmes d'Information Géographique; Importation; Usages; Lumière; Micorphytobenthos; Modélisation; Nutriments; Matière organique; Matière particulaire; Phytoplancton; Sédimentation; Aquaculture; Export; Dissolved matter; Fier d'Ars Bay; Geographic Information Systems; Import; Land use; Light; Microphytobenthos; Modelling; Nutrients; Organic matter; Particulate matter; Phytoplankton; Sedimentation.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00450/56185/57738.pdf

Dissolved inorganic nitrogen uptake by intertidal microphytobenthos: nutrient concentrations, light availability and migration
Provedor de dados: 5
Autores: Longphuirt, Sorcha Ni; Lim, Jae-hyun; Leynaert, Aude; Claquin, Pascal; Choy, Eun-jung; Kang, Chang Keun; An, Shu.
The importance of intertidal flats as areas of nitrogen filtering has become increasingly apparent in recent times. TO understand fully the cycling of this nutrient. in these areas of high metabolic activity, it is necessary to elucidate the influence of microphytobenthos (MPB) on stocks of ammonium and nitrate in surface areas. In this study, we aimed to quantity nitrogen uptake and relate it to the in Situ concentrations and environmental conditions to which MPB are exposed. In an estuarine system on the Korean Peninsula, we conducted kinetic experiments using N-15 stable isotopes and core sampling over the tidal cycle to determine the temporal evolution of porewater nutrient concentrations and the migration of MPB. The results revealed a range of K-s...
Tipo: Text
Palavras-chave: N 15 stable isotope; Porewater; Microphytobenthos; Kinetic; Nitrogen.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6622.pdf

Benthic microalgal communities in the inner part of the Bahia Blanca estuary (Argentina): a preliminary qualitative study
Provedor de dados: 5
Autores: Parodi, Er; Barria De Cao, S.
The intertidal zone of the inner part of the Bahia Blanca estuary, Argentina is characterised by the presence of muddy tidal flats and salt marshes, habitats for burrowing crabs and halophytic plants. The surface layer of the sediments is composed of silt and clay. The sediments are substrate for the proliferation of benthic microalgal communities. The aim of this study was to analyse qualitatively the species composition of these communities and their role in the stabilisation of the sediments. Samples came from two stations: Puerto Cuatreros and Villarino Viejo. Puerto Cuatreros is an old pier without harbour activities closer than Villarino Viejo to the harbour zone affected by dredging. Both stations showed similar physical and chemical parameters. In...
Tipo: Text
Palavras-chave: Microphytobenthos; Stabilisation des sédiments; Benthic microalgal communities; Microbial mats; Sediments stabilisation.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/00322/43311/42963.pdf

Assessing Alternative Microscopy-Based Approaches to Species Abundance Description of Intertidal Diatom Communities
Provedor de dados: 5
Autores: Ribeiro, Lourenço; Brotas, Vanda; Hernandez Farinas, Tania; Jesus, Bruno; Barille, Laurent.
Diatoms usually dominate microphytobenthic biofilms in coastal and estuarine intertidal environments. Yet, functional studies on biofilms often skip species analysis because benthic diatoms are notoriously difficult to extract from sediments and challenging to identify at that taxonomic level. Valid, less time-consuming alternatives would surely be welcomed and increase the inclusion of community structure information in microphytobenthos (MPB) ecophysiological studies. Starting with an original 181-species abundances matrix (OSM), obtained during a 2-year spatial–temporal survey in a Tagus Estuary intertidal flat with contrasting sediment textures, the current study assessed the effectiveness of several approaches to species abundances analysis. The...
Tipo: Text
Palavras-chave: Diatoms; Community structure; Intertidal flats; Microphytobenthos; Multivariate analysis; Taxonomic sufficiency.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00610/72187/70963.pdf

Microstructure of microphytobenthic biofilm and its spatio-temporal dynamics in an intertidal mudflat (Aiguillon Bay, France)
Provedor de dados: 5
Autores: Herlory, Olivier; Guarini, Jean-marc; Richard, Pierre; Blanchard, Gerard.
The spatio-temporal dynamics of the microphytobenthic biofilm was analysed at microscale over a complete day-time emersion period in an intertidal mudflat. The structures of the biofilm were monitored by analysing the variability of the epipelic diatom cover in the horizontal dimension and the kinetics of biomass dispersion in the vertical dimension. Colonisation of the sediment surface by diatoms was rapid (within 15 min); 75% of the biomass contained in the top 1 mm was concentrated in the upper 200 mum, but the cover never reached 100%. This biomass had a higher chlorophyll a/pheopigment ratio than deeper in the sediment, suggesting a better physiological state and a higher photosynthetic potential. The dynamics of the biomass in the upper 200 mum...
Tipo: Text
Palavras-chave: Microphytobenthos; Biofilm; Intertidal mudflat; Spatio temporal dynamics; Microscale.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/00000/10905/7580.pdf

Trophic importance of diatoms in an intertidal Zostera noltii seagrass bed: Evidence from stable isotope and fatty acid analyses
Provedor de dados: 5
Autores: Lebreton, Benoit; Richard, Pierre; Galois, Robert; Radenac, Gilles; Pfleger, Camille; Guillou, Gael; Mornet, Francoise; Blanchard, Gerard F.
A current predominant paradigm emphasizes the role of epiphytic algae for invertebrates in most seagrass food webs. However, in some intertidal Zostera noltii beds, epiphyte biomass is very low compared to microphytobenthos and seagrass biomasses. We assessed the role of microphytobenthos in a temperate intertidal Z. noltii bed by combining stable isotope and fatty acid (FA) analyses on primary producers, composite sources suspended particulate organic matter (SPOM) and sediment surface organic matter (SSOM) and the main macrofaunal consumers. Z. noltii showed high delta C-13 (-9.9 parts per thousand) and high 18:2(n-6) and 18:3(n-3) contents. Microphytobenthos was slightly more C-13-depleted (-15.4 parts per thousand) and had high levels of diatom...
Tipo: Text
Palavras-chave: Food web; Intertidal seagrass bed; Microphytobenthos; Zostera noltii; Stable isotope ratio; Fatty acid profiles; European Atlantic coast.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00035/14640/12051.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

Trophic ecology of juvenile flatfish in a coastal nursery ground: contributions of intertidal primary production and freshwater particulate organic matter
Provedor de dados: 5
Autores: Kostecki, Caroline; Roussel, J. M.; Desroy, Nicolas; Roussel, G.; Lanshere, J.; Le Bris, H.; Le Pape, Olivier.
Coastal and estuarine nurseries are essential habitats for juvenile flatfish. These small but productive areas provide food supply and sustain adult fish populations. The Mont-Saint-Michel Bay (MSMB) supports an important flatfish nursery ground but differs from many other nursery habitats due to limited freshwater inputs. The objectives of the present study in the MSMB were to (1) use gut content analysis to identify prey of the 2 most abundant flatfish species (common sole Solea solea and plaice Pleuronectes platessa) for different juvenile age-classes (0-group and 1-group for sole, 0-group for plaice), (2) use C and N stable isotope analysis to model the production sources sustaining juvenile flatfish production, and (3) compare these results with...
Tipo: Text
Palavras-chave: Microphytobenthos; Organic matter origin; Benthic food web; Coastal nursery ground; Juvenile flatfish.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00073/18438/15976.pdf

Food source of intertidal nematodes in the Bay of Marennes-Oleron (France), as determined by dual stable isotope analysis
Provedor de dados: 5
Autores: Riera, P; Richard, P; Gremare, A; Blanchard, G.
Nematodes living on an intertidal mudflat of the Marennes-Oleron Bay (France) were assayed for delta(13)C and delta(15)N ratios together with their potential food resources between July 1992 and May 1993. Results suggest that nematodes do not exploit all the components of the sedimented organic matter (SOM) pool at the same rate. Furthermore, based on coefficients of average trophic enrichment found in the literature for both C and N, the enrichment of nematodes in C-13 and their depletion in N-15 relative to SOM suggest that microphytobenthos constitutes their main food source in this particular environment.
Tipo: Text
Palavras-chave: Nematodes; Microphytobenthos; Food sources; Stable isotope ratios.
Ano: 1996
URL: http://archimer.ifremer.fr/doc/00282/39288/43132.pdf

Dynamique spatiale et temporelle de la production primaire de l'estuaire de la Seine
Provedor de dados: 5
Autores: Morelle, Jérôme.
The estuaries play an important ecological role and are the site of many human activities because of their strategic position at the interface between continental and marine waters. Seine estuary is characteristic of large anthropized estuaries. Long-term management requires better knowledge of the spatial and temporal dynamics of the estuarine food webs. Phytoplankton and microphytobenthos are the main contributor of primary production (PP) in these ecosystems and are at the basis of trophic food webs. These compartments are often reduced to the chlorophyll concentration and their productivity has never been measured along the Seine estuary. The objective of this study was to estimate the PP of these compartments along the salinity gradient. In order to...
Tipo: Text
Palavras-chave: PAM; ETR; 13C; TEP; EPS; Exopolymeric substances; Phytoplankton; Microphytobenthos; Transparent Exopolymeric Particles.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00498/60965/64373.pdf

Cadmium pathways in an exploited intertidal ecosystem with chronic cadmium inputs (Marennes-Oleron, Atlantic coast, France)
Provedor de dados: 5
Autores: Pigeot, J; Miramand, P; Guyot, T; Sauriau, Pierre-guy; Fichet, D; Le Moine, Olivier; Huet, V.
The Marennes-Oleron Bay is subject to chronic pollution by cadmium (Cd) from the Gironde watershed. An ecosystem approach was used to study the fate of cadmium in the different biological compartments. The median Cd concentration was 0.4 mu g g(-1) dry weight for the 63 benthic species measured. When combined with the respective biomasses for the different species studied, we estimated that 7 kg of Cd is partitioned into the soft tissues of the benthic species in the bay. The majority of this cadmium was distributed between primary producers, mainly microphytobenthos (40 %), and suspension-feeders, mainly oysters (40 %). All other benthic species measured were associated with negligible masses of Cd. Two trophic levels contained 98 % of the Cd: 3 kg was...
Tipo: Text
Palavras-chave: Marennes Oleron Bay; Trophic food web; Bioaccumulation; Cadmium; Macrofauna; Microphytobenthos; Macrophytes.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-3615.pdf

Dynamics of spatial patterns of microphytobenthic biomass: inferences from a geostatistical analysis of two comprehensive surveys in Marennes-Oleron bay (France)
Provedor de dados: 5
Autores: Guarini, Jean-marc; Blanchard, Fabian; Bacher, Cedric; Gros, Philippe; Riera, P; Richard, P; Gouleau, D; Galois, R; Prou, Jean; Sauriau, Pg.
Microphytobenthos plays an important role as primary producer in shallow embayments subject to a tidal regime. The present paper aims to characterize the spatial patterns of sedimentary chlorophyll a (chl a) biomass in 2 seasons in the wide intertidal mudflats of the Marennes-Oleron Bay (France); furthermore, it provides estimates of total microphytobenthic biomass. Accordingly, a systematic sampling scheme was performed in June 1995 and in January 1996. On average, biomass was higher in June (ca 120 mg chi a m(-2)) than in January (ca 85 mg chi a m(-2)). Moreover, the geostatistical analysis revealed that spatial similarities were propagated over larger distances in June (6 km) than in January (2.2 km). In order to account or this result, we suggest that...
Tipo: Text
Palavras-chave: Microphytobenthos; Chlorophyll a; Spatial distribution; Geostatistics; Intertidal mudflat.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00447/55852/58117.pdf

Ecologie alimentaire de l'huitre Crassostrea gigas : dynamiques des compositions isotopiques naturelles
Provedor de dados: 5
Autores: Malet, Nathalie.
Trophic transfers of particulate organic matter sources to the Pacific oyster Crassostrea gigas were investigated in the oyster farming bay of Marennes-Oléron for two years. Stable isotope ratios of carbon and nitrogen were used to trace the origin and fate of primary production and organic matter inputs into the bay, and to depict trophic transfers to oysters that were experimentally reared according to traditional methods. Characterizing particulate organic matter sources available for oysters utilized a combination of hydrobiological parameters and stable isotope ratios. Processes of food incorporation by oysters were described for five organs such as gills, digestive gland, mantle, muscle and gonads, and were interpreted taking into account...
Tipo: Text
Palavras-chave: Microphytobenthos; Phytoplankton; Organs; Trophic discrimination; Tissue turnovers; Particulate organic matter; Marennes Oléron Bay; Pertuis Charentais; Stable isotopes; Pacific oysters; Crassostrea gigas; Microphytobenthos; Phytoplancton; Hydrologie; Organes; Enrichissement trophique; Renouvellement tissulaire; Matière organique particulaire; Bassin de Marennes Oléron; Pertuis Charentais; Isotopes stables; Crassostrea gigas; Huître creuse.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/these-2089.pdf

Interacting effects of Hydrobia ulvae bioturbation and microphytobenthos on the erodibility of mudflat sediments
Provedor de dados: 5
Autores: Orvain, Francis; Sauriau, Pierre-guy; Sygut, A; Joassard, Lucette; Le Hir, Pierre.
Microphytobenthos-macrofauna sediment interactions and their effects on sediment erodability were examined in laboratory experiments. Sediment beds were manipulated in a tidal mesocosm to produce diatom mats in exponential or in stationary phases of development after 6, 8 or 11 d of culture. These sediment beds were used in flume experiments to investigate the influence of bioturbation by the gastropod Hydrobia ulvae on both sediment and pigment resuspension as a function of the physiological state of the microphytobenthic mats. In most experiments, only a surface layer was resuspended. A model was used to analyse in detail the contribution of each variable to this surface-layer erosion. Bioturbation was the major factor controlling resuspension, and its...
Tipo: Text
Palavras-chave: Sediment; Bioturbation; Erosion; Model; Hydrobia ulvae; Physiological state; Microphytobenthos; Resuspension.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/publication-3780.pdf

Réseau trophique du bassin de Marennes-Oléron (rapport 1996). Région Poitou-Charentes
Provedor de dados: 5
Autores: Bacher, Cedric; Blanchard, Gerard; Bougrier, Serge; Cariou-le Gall, Valerie; Delmas, D.; Deslous Paoli, Jean-marc; Dinet, A.; Garet, Marie-josee; Geairon, Philippe; Jonquieres, Gerard; Laisne, A.; Maffei, E.; Montagna, P. A.; De Montaudouin, Xavier; Morin, S.; Richard, P.; Riera, Pascal; Sauriau, Pierre-guy; Vrignaud, N.
Les cartographies annuelles des biomasses microphytobenthiques ont été réalisées pour le bassin de Marennes-Oléron. Parallèlement les cartographies des caractéristiques sédimentaires ont été établies simultanément aux cartes d'abondance et biomasse macrofauniques en portant un effort particulier sur les densités des compétiteurs des huîtres notamment les Crépidules. Simultanément les études des mécanismes contrôlant le réseau trophique sur la vasière de Brouage ont été poursuivies notamment les relations entre les flux de sels nutritifs et le microphytobenthos. L'importance de ce dernier compartiment dans la nutrition de l'huître a été clairement mis en évidence par l'utilisation des traçeurs isotopiques naturels. Enfin, les caractéristiques de filtration...
Tipo: Text
Palavras-chave: Bassin de Marennes Oléron; Microphytobenthos; Physiologie; Crassostrea gigas; Crépidules; Modèle réseau trophique; Cartographie; Charente-Maritime.
Ano: 1996
URL: http://archimer.ifremer.fr/doc/00102/21294/18911.pdf

Inhibition of microphytobenthic photosynthesis by the herbicides atrazine and diuron
Provedor de dados: 5
Autores: Legrand, Helene; Herlory, Olivier; Guarini, Jean-marc; Blanchard, Gerard; Richard, Pierre.
Atrazine and diuron are two herbicides present in sediments of the intertidal mudflats in the Pertuis Charentais (Atlantic coast, France). They may negatively affect photosynthesis processes in microphytobenthos, the most productive primary producer in these environments. The impact of these herbicides on benthic diatoms was investigated using PAM fluorimetry on natural microalgal communities, once extracted from sediment, by following the variations of the effective quantum yield of PSII (Phi(PSII)) during exposure to atrazine and diuron concentrations in a range 0.1 mu g L-1 (.) 10 mg L-1. No significant effect was noticed for 0.1 mu g L-1 concentrations, but progressive reduction in photosynthetic efficiency, always occurring within 15 min, was...
Tipo: Text
Palavras-chave: Diuron; Atrazine; PAM; Chlorophyll fluorescence; Microphytobenthos.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-3614.pdf

Modélisation de la dynamique du microphytobenthos des vasières intertidales du bassin de Marennes-Oléron. Effets des synchroniseurs physiques sur la régulation de la production
Provedor de dados: 5
Autores: Guarini, Jean-marc.
The study aimed at quantifying the spatio-temporal evolution of microphytobenthic biomass in intertidal mudflats of Marennes-Oléron Bay. To reach this goal, a dynamic model has been proposed, including processes of primary production, active migration of epipelic diatoms and biomass lasses due to mortalities on one hand and resuspension in the water column during submersion on the other hand. The spatialisation is given by a hydrodynamic madel which calculates the water height everywhere. The photic environment of microphytobenthos is described in a discrete way, by means of two layers: the biofilm of epipelic algae « S »on the top of the sediment and the fust centimeter of the mud « F ». The endogenous vertical migration rhythm of epipelic algae controls...
Tipo: Text
Palavras-chave: Microphytobenthos; Vasière intetidale; Modélisation; Dynamique de la biomasse; Expérimentation; Ecophysiologie; Couplage physique/biologie; Microphytobenthos; Intertidal mudflat; Modelling; Dynamics of the biomass; Experimentation; Ecophysiology; Physics/biology coupling.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00439/55029/56462.pdf

Dynamics of phytoplankton productivity and exopolysaccharides (EPS and TEP) pools in the Seine Estuary (France, Normandy) over tidal cycles and over two contrasting seasons
Provedor de dados: 5
Autores: Morelle, Jerome; Schapira, Mathilde; Claquin, Pascal.
Exopolysaccharides (EPS) play an important role in the carbon flux and may be directly linked to phytoplankton and microphytobenthos production, most notably in estuarine systems. However the temporal and spatial dynamics of estuarine EPS are still not well understood, nor how primary productivity triggers this variability at these different scales. The aim of this study was to investigate the primary productivity of phytoplankton and EPS dynamics in the Seine estuary over a tidal cycle in three different haline zones over two contrasted seasons. The other objectives was to investigate the origin of pools of soluble carbohydrates (S-EPS) and transparent exopolymeric particles (TEP) in phytoplankton, microphytobenthos or other compartments. High frequency...
Tipo: Text
Palavras-chave: Phytoplankton; Microphytobenthos; PAM fluorometer; Electron transport rate.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00400/51132/51898.pdf

Temporal variability of benthic-pelagic coupling in shallow enclosed environment: A case study with eutrophying shrimp ponds
Provedor de dados: 5
Autores: Hochard, Sébastien; Royer, Florence; Hubert, Morgane; Lemonnier, Hugues.
The evolution of benthic pelagic coupling was followed in two semi-intensive shrimp ponds in New Caledonia, with a special emphasis on the role of microphytobenthos (MPB). Three distinct periods could be identified. During the first period, MPB activity led to relative decoupling between the water column and the sediment, both compartments being autotrophic with low nutrients exchanges. During the second period, the sediment operated at the edge of a functional switch between autotrophy and heterotrophy. The amplitude of nutrient fluxes depended of the pool considered (DIN, DIP) and showed light dark variation. In the last period, sediment switched to heterotrophy with the establishment of benthic-pelagic coupling concomitantly to a massive sediment...
Tipo: Text
Palavras-chave: Tropical aquaculture; Shrimp; Eutrophication; Benthic-pelagic coupling; Microphytobenthos; Bioturbation.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00485/59681/62754.pdf

Seston dynamics and bivalve feeding in the Bay of Marennes-Oléron (France)
Provedor de dados: 5
Autores: Zurburg, Wouter; Smaal, Aad; Heral, Maurice; Dankers, Norbert.
Within the framework of an investigation into the carrying capacity of the Bay of Marennes-Oléron (France) for bivalve culture, the in situ uptake of suspended particulate material by oysters (Crassostrea gigas) and mussels (Mytilus edulis) was determined in experiments with benthic ecosystem tunnels. Very high fluctuations in seston quantity and quality were observed within and between tidal cycles. The percentage of organic carbon was inversely related to seston quantity at low concentrations. Organic carbon was diluted by resuspension of material rich in inorganic matter. At high seston concentrations a constant level of about 2% organic carbon was found. The CIN ratio was relatively constant throughout the seasons and fairly low (6.5 to 8.4). Owing to...
Tipo: Text
Palavras-chave: Microphytobenthos; Chlorophyll; Feeding; Mussel; Oyster; Seston quality; Seston load.
Ano: 1994
URL: http://archimer.ifremer.fr/doc/1994/publication-6843.PDF

Short-term changes and longitudinal distribution of carbon metabolism in the Piauí River estuary (Sergipe, Brazil)
Provedor de dados: 57
Autores: SOUZA,M. F. L. de; COUTO,E. C. G.
Net pelagic metabolism (NPM) and net ecosystem metabolism (NEM) were assessed by sigmaCO2 changes in three sampling stations along Piauí River estuary. At the upper estuary station, sampling was carried out over 48 h. Samples exhibited high DIN:DIP ratios. Chlorophyll-a ranged from 0.2 to 2.5 mug.l-1, being higher at the upper estuarine station than marine ones. Net pelagic metabolic rates ranged from -13.2 to 61.2 mgC.m7-2.d-1. Presence of mucilaginous algal material can explain the net mineralization. In the photic period, NPM ranged from-0.05 to 3.04 mgC.m-2h-1. NEM ranged from -7.77 to 6.65 mgC.m-2.d-1. Bottom ressuspension due to microphytobenthic flotation and a high turbidity plume inside de estuary reflected in negative metabolic rates...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Estuary; Short-term changes; Primary production; Mineralization; Microphytobenthos.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71081999000200003