|
|
|
| Registros recuperados: 18 | |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| Delmas, Daniel; Herbland, Alain; Maestrini, Serge; Mornet, Francoise; Morand, Philippe; Spano, Anna-maria; Burgeot, Thierry; Margat, Sylvie; Charpentier, Gabriel; Fillon, Alain; Leguay, Didier; Thomas, Gerard; Bacher, Cedric; Heral, Maurice; Prou, Jean. |
| Environmental and species features which lead to increases in cell density of the D.S.P. Dinoflagellate Dinophysis in inshore and offshore waters of the île de Ré - île d'Oléron area, France (cruises "Dinopertuis89"). Four weekly sampling series have been carried out, within 10 May – 31 May 1989, at 24 stations located from inshore to offshore waters of the "île de Ré" - "île d’Oléron" area, with the aim to investigate (i) whether Dinophysis increases in cell density occur first in offshore waters and then, eventually, are pushed to the coast, or develop simultaneously in the whole area, and (ii) whether there are some environmental conditions which are related to Dinophysis blooms. Depths of sampling have been stated on the bas is of STD profiles. All... |
| Tipo: Text |
|
| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00174/28532/26916.pdf |
| |
|
|
| Maggi, Pierre; Truquet, Philippe; Mornet, Francoise; Lassus, Patrick. |
| Une campagne de prélèvements hydrologiques a été réalisée en juillet 1991 en baie de Seine sur le N/O THALIA. Elle visait à connaître la distribution du phytoplancton en fonction des paramètres physicochimiques du milieu et plus particulièrement par rapport à l'extension du panache de la Seine. Bien que les espèces toxiques recherchées (Dinophysis spp.) aient été absentes au cours de cette opération, l'analyse et le traitement des données recueillies sur une radiale côtière située entre le Havre et Antifer ont permis de discriminer les espèces à affinité estuarienne ou marine présentes pendant cette période. Les diatomées étaient largement dominantes, en particulier Skeletonema costatum et Rhizosolenia stolterfothii, alors que les dinoflagellés étaient... |
| Tipo: Text |
|
| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/00064/17535/15053.pdf |
| |
|
|
| Feuillet-girard, Michelle; Heral, Maurice; Sornin, Jean-marc; Deslous-paoli, Jean-marc; Robert, Jean-michel; Mornet, Francoise; Razet, Daniel. |
| The respective influences of the sediment and of oyster (Crassostrea gigas) farming on the accumulation and the recycling of different forms of organic and inorganic nitrogen are described. Fluxes of dissolved inorganic and organic forms of nitrogen were studied between the water column, the water overlying the sediment and the pore waters, while for particulate forms the fluxes were studied between suspended material, the "biodeposits" (faeces and pseudofaeces of Crassostrea) and the sediment. The flux of inorganic nitrogen amounts to 10.5 106 g.m(-2). Yr(-1), while that of organic nitrogen is half this figure. The particulate flux is 15.106 g.m(-2).yr(-1). On the other hand, the phytoplanktonic nitrogen accounts for only 6% of the total particulate... |
| Tipo: Text |
Palavras-chave: Marenne Oleron; Sediment; Pore water; Interface; Crassostrea gigas; Nitrogen; Marennes Oléron; Sédiment; Eau interstitielle; Adsorption; Interface; Crassostrea gigas; Azote. |
| Ano: 1988 |
URL: http://archimer.ifremer.fr/doc/1988/publication-2878.pdf |
| |
|
|
| Hussenot, Jerome; Mornet, Francoise; Le Moine, Olivier; Geairon, Philippe; Guesdon, Stephane. |
| This study aimed to analyse the quality of the sea water flowing into the marine farm of Douhet, a gilthead bream hatchery, from the marsh-seawater reservoir to the entrance of the hatchery. The basin-seawater reservoir is not stratified in the pumping area. As a consequence, the measurements carried out at the surface to the right of the pumping dock give a good evaluation of the quality of the seawater pumped in depth. The high sensitivity of gilthead bream larvae to the water PH during the first two weeks of their larval life, and the values measured in the circuit seem to be an explanatory parameter to the observed mortalities. The water flowing into the hatchery retains, after pre-treatment, a nycthemeral PH variability, with maxima, at the end of the... |
| Tipo: Text |
Palavras-chave: Ammonia nitrogen; PH; Sea bream; Fish hatchery; Reservoir; Water quality; Azote ammoniacal; PH; Daurade royale; Ecloserie; Réserve; Qualité des eaux. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/rapport-6497.PDF |
| |
|
|
| Collos, Y; Descolas Gros, C; Mornet, Francoise. |
| During parallel sampling of seawater samples in bottles and in free water (1000-2000 m(3) clay ponds), we have measured phytoplankton biomass, Ribulose biphosphate carboxylase (Rubisco), phosphoenol pyruvate carboxylase, and phosphoenol pyruvate carboxykinase activities and major nutrients (ammonium, nitrate, phosphate, silicate). This was done in two ecosystems: one with high grazing pressure due to the presence of oysters and another with low grazing pressure (no oysters). In the ecosystem subjected to high grazing pressure, anaplerotic carbon fixation by phytoplankton in free water was higher in the light period and could represent 25% of total carbon fixation. Incubating samples in bottles led to a major increase in Rubisco activity (80% in 3 h)... |
| Tipo: Text |
Palavras-chave: Grazing; Carboxylases; Carbon assimilation; Anaplerotic; Ammonium. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-6437.pdf |
| |
|
|
| Raimonet, Melanie; Guillou, Gael; Mornet, Francoise; Richard, Pierre. |
| Although nitrogen stable isotope ratio (delta N-15) in macroalgae is widely used as a bioindicator of anthropogenic nitrogen inputs to the coastal zone, recent studies suggest the possible role of macroalgae metabolism in delta N-15 variability. Simultaneous determinations of delta N-15 of dissolved inorganic nitrogen (DIN) along the land sea continuum, inter-species variability of delta N-15 and its sensitivity to environmental factors are necessary to confirm the efficiency of macroalgae delta N-15 in monitoring nitrogen origin in mixed-use watersheds. In this study, delta N-15 of annual and perennial macroalgae (Ulva sp., Enterommpha sp., Fucus vesiculosus and Fucus serratus) are compared to delta N-15-DIN along the Charente Estuary, after... |
| Tipo: Text |
Palavras-chave: Nitrogen isotopes; Nitrate; Ammonium; Primary producers; Indicators; Land-sea continuum. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00134/24558/23645.pdf |
| |
|
|
| Heral, Maurice; Bacher, Cedric; Razet, Daniel; Prou, Jean; Deslous-paoli, Jean-marc; De Pontual, Helene; Raillard, Olivier; Ravail, Brigitte; Maestrini, Serge; Mornet, Francoise; Menesguen, Alain; Sautour, Benoit; Robert, Jean-michel. |
| Les termes du contrat passé entre le Fond de la Recherche et de la Technologie et l'IFREMER précisent qu ele programmer a pour objectif une gestion rationnelle du milieu conchylicole avec notamment une mise au point de modèles (voir notification de l'aide en annexe). Un premier modèle appelé modèle global par analogie avec les modèles de pêche met en évidence la limite de la capacité trophique du bassin de Marennes-Oléron pour les huîtres cultivées. Un modèle analytique avec un modèle physique simple permet dans un premier temps de développer un modèle de croissance des huîtres en fonction de la nourriture disponible et d'effectuer des simulations qui confirment l'influence du stock sur les performances de croissance des bivalves. Un troisième approche... |
| Tipo: Text |
Palavras-chave: Modélisation; Production; Biomasse; Huîtres creuses; Crassostrea gigas; Capacité biotique; Bassin de Marennes Oléron. |
| Ano: 1989 |
URL: http://archimer.ifremer.fr/doc/00048/15904/13332.pdf |
| |
|
|
| Heral, Maurice; Bacher, Cedric; Razet, Daniel; Prou, Jean; Deslous-paoli, Jean-marc; De Pontual, Helene; Raillard, Olivier; Maestrini, Serge; Mornet, Francoise; Menesguen, Alain; Sautour, Benoit; Robert, Jean-michel. |
| Les termes du contrat passé entre le Fond de la Recherche et de la Technologie et l'IFREMER précisent qu ele programmer a pour objectif une gestion rationnelle du milieu conchylicole avec notamment une mise au point de modèles (voir notification de l'aide en annexe). Un premier modèle appelé modèle global par analogie avec les modèles de pêche met en évidence la limite de la capacité trophique du bassin de Marennes-Oléron pour les huîtres cultivées. Un modèle analytique avec un modèle physique simple permet dans un premier temps de développer un modèle de croissance des huîtres en fonction de la nourriture disponible et d'effectuer des simulations qui confirment l'influence du stock sur les performances de croissance des bivalves. Un troisième approche... |
| Tipo: Text |
Palavras-chave: Modèle production; Biomasse; Huître creuse; Crassostrea gigas; Modèle énergétique; Croissance; Modèle multiboîte; Marennes Oléron; Modèle trophique; Marennes Oléron. |
| Ano: 1986 |
URL: http://archimer.ifremer.fr/doc/00048/15908/13337.pdf |
| |
|
|
| Blanchard, Gerard F.; Guarini, Jean-marc; Richard, Pierre; Gros, Philippe; Mornet, Francoise. |
| A mathematical expression is proposed to describe the relationship between the photosynthetic capacity (Pmax) of natural assemblages of motile benthic diatoms and temperature. Experiments were performed in 2 different seasons to document the response of Pmax to a rapid increase in temperature (3*C h-1). In both cases, there was a progressive increase in Pmax up to an optimum temperature (Topt), beyond which Pmax declined rapidly. Topt did not change from September to December 1995, but the maximum photosynthetic capacity (PMAX, i.e. Pmax at Topt) was twice as high in September as in December. |
| Tipo: Text |
|
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00013/12397/9183.pdf |
| |
|
|
| 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 |
| |
|
|
| Chouvelon, Tiphaine; Violamer, L.; Dessier, Aurelie; Bustamante, Paco; Mornet, Francoise; Pignon-mussaud, Cecilia; Dupuy, Christine. |
| Small pelagic fish represent an essential link between lower and upper trophic levels in marine pelagic ecosystems and often support important fisheries. In the Bay of Biscay in the north-east Atlantic, no obvious controlling factors have yet been described that explain observed fluctuations in European sardine Sardina pilchardus and European anchovy Engraulis encrasicolus stocks, in contrast to other systems. The aim of this study was therefore to investigate to which extent these fluctuations could be trophodynamically mediated. The trophic ecology of both fish species was characterised over three contrasting periods (spring 2010 and 2011 and autumn 2011) in the area, in relation to potential variation in the abundance and composition of the... |
| Tipo: Text |
|
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00247/35859/34381.pdf |
| |
|
|
| Dessier, Aurelie; Bustamante, Paco; Chouvelon, Tiphaine; Huret, Martin; Pagano, Marc; Marquis, Elise; Rousseaux, Frederic; Pignon-mussaud, Cecilia; Mornet, Francoise; Breret, Martine; Dupuy, Christine. |
| Mesozooplankton can be considered the most important secondary producers in marine food webs because they hold an intermediate position between the phytoplankton assemblage and the upper trophic levels. They also are a robust indicator of climatic and hydrological conditions. We conducted an analysis of the interannual variability of the spring mesozooplankton assemblage, as sampled by the PELGAS fisheries survey in the southern part of the Bay of Biscay (Northeast Atlantic Ocean) between 2003 and 2013. We examined hydrology and trophic drivers to explain the variability. Our results revealed that the subsurface temperature, the subsurface salinity, the biomasses of subsurface pico-, nano-, and microphytoplankton, and the copepod assemblage exhibited a... |
| Tipo: Text |
|
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00439/55010/56428.pdf |
| |
|
|
| Hubans, Barbara; Chouvelon, Tiphaine; Begout, Marie-laure; Biais, Gerard; Bustamante, Paco; Ducci, Lillian; Mornet, Francoise; Boiron, Anne; Coupeau, Yann; Spitz, Jerome. |
| In the north-eastern Atlantic, meagre (Argyrosomus regius) is one of the largest fish living on the shelf and this species has important commercial interest. Over the past two decades, large variations in meagre abundance have been observed with pluri-annual cycles but the factors involved in such variations are still unclear. Trophic interactions between meagre and other species (both prey and competitors) might be one explanatory variable of the observed variations in meagre recruitment and abundance. In the present study, we described the diet of commercial-size meagre in the Bay of Biscay from stomach content and stable isotope analyses, and explored its dietary ontogeny. We found that commercial-size meagres were mostly piscivorous with a diet... |
| Tipo: Text |
Palavras-chave: Diet; SIAR; Ontogeny; Marine top predators; Sciaenidae. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00384/49531/50028.pdf |
| |
|
|
| Chouvelon, Tiphaine; Chappuis, A.; Bustamante, Paco; Lefebvre, Sebastien; Mornet, Francoise; Guillou, G.; Violamer, L.; Dupuy, Christine. |
| European sardine (Sardina pilchardus) and European anchovy (Engraulis encrasicolus) are two species of economical and ecological significance in the Bay of Biscay (north-east Atlantic). However, the trophic ecology of both species is still poorly known in the area, and more generally, few studies have considered the potential trophic overlap between sardines and anchovies worldwide. This study aims to highlight the trophic links between the mesozooplankton and adults of these two pelagic fish in the Bay of Biscay, through carbon and nitrogen stable isotope analysis (SIA). Mesozooplankton and individuals of sardines and anchovies were collected during one season (spring 2010), over spatially contrasted stations within the study area. First, the potential... |
| Tipo: Text |
Palavras-chave: Plankton preservation; Plankton delipidation; Pelagic fish; Trophic interactions; Spatial variability; Isotopic mixing model. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00176/28741/27280.pdf |
| |
|
|
| 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 |
| |
|
|
| Dessier, Aurelie; Dupuy, Christine; Kerric, Anais; Mornet, Francoise; Authier, Matthieu; Bustamante, Paco; Spitz, Jerome. |
| To explore some aspects of mesozooplankton functional diversity, this study quantified energy density during the springtime in the Bay of Biscay both between different species and between different size-classes. Energy densities of copepod species (Centropages typicus, Anomalocera patersoni, Calanus helgolandicus, and Labidocera wollastoni), as well as anchovy eggs (Engraulis encrasicolus) ranged from 0.5 to 6.7 kJ/g wet weight (ww). Considering size-classes, energy densities varied from 0.74 to 1.26 kJ/g ww. Energy density of C. helgolandicus exhibited a spatial pattern with the highest values in the plume of the Gironde estuary. In contrast, no spatial pattern of energy density has been detected considering size-classes. Our results showed that the... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Profitability; Copepods; Prey-predator relationship; Fisheries. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00407/51835/52434.pdf |
| |
| Registros recuperados: 18 | |
|
|
|
