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Registros recuperados: 86 | |
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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 |
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Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00174/28532/26916.pdf |
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Filgueira, Ramon; Grant, Jon; Bacher, Cedric; Carreau, Michel. |
Ecological modeling of dynamic systems such as marine environments may require detailed spatial resolution when the modeled area is greatly influenced by complex physical circulation. Therefore, the simulation of a marine ecosystem must be underlain by a physical model. However, coupling hydrodynamic and biogeochemical models is not straightforward. This paper presents a modeling technique that can be used to build generic and flexible fully-spatial physical-biogeochemical models to study coastal marine ecosystems using a visual modeling environment (VME). The model core is constructed in Simile, a VME that has the capacity to create multiple instances of submodels that can be interconnected, producing a fully-spatial simulation. The core is designed to... |
Tipo: Text |
Palavras-chave: Physical-biogeochemical coupling; Marine spatial planning; Aquaculture; Simile. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00071/18231/15842.pdf |
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Guallar Morillo, Carlos; Chapelle, Annie; Bacher, Cedric. |
En résumé, ce rapport présente les éléments suivants : 1. Identification et inventaire des données environnementales disponibles en relation avec l‟espèce A. minutum et Pseudo-nitzschia sur les côtes bretonnes et atlantiques françaises. 2. Description de la méthodologie développée pour l‟étude de la phénologie des efflorescences et la niche écologique des espèces cibles. 3. Présentation des résultats obtenus sur l‟étude de la phénologie d‟A. minutum. 4. Présentation des résultats obtenus sur l‟étude de la niche écologique d‟A. minutum et Pseudo-nitzschia. 5. Tableau de bord récapitulant les facteurs explicatifs, leur évolution et les risques associés en termes d‟efflorescences des espèces ciblées. |
Tipo: Text |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00315/42640/42019.pdf |
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Leguerrier, Delphine; Niquil, Nathalie; Boileau, N; Rzeznik, J; Sauriau, Pierre-guy; Le Moine, Olivier; Bacher, Cedric. |
Food web modelling is an ideal way to describe ecosystems, because it accounts for the totality of the relationships between its various components. One difficulty of such an approach, however, lies in the lack of data and information about some ecological relationships, resulting in under-defined systems. Inverse analysis can serve to complete steady-state food webs where the number of direct flow measurements is insufficient relative to the actual number of flows. We applied this method to the intertidal mudflat ecosystem of Brouage (eastern Marennes-Oleron Bay, SW France) and estimated the annual average carbon flows between the compartments of a coupled benthic and pelagic trophic food web from primary producers (microphytobenthos and phytoplankton) to... |
Tipo: Text |
Palavras-chave: Network analysis; Food web; Inverse analysis; Carbon flow. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-3134.pdf |
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Heral, Maurice; Bacher, Cedric; Razet, Daniel; Prou, Jean; Deslous-paoli, Jean-marc. |
Le bassin conchylicole de Marennes-Oléron assure 40 % des 100 000 tonnes d ' huîtres commercialisées annuellement en moyenne en France (20 000 emplois, 1 milliard de chiffre d'affaire) . La modélisation des équilibres qui s'établissent entre l es stocks mis en culture , et la production annuelle , réalisée par la station IFREMER de La Tremblade , a mis en évidence les résultats suivants : Lorsque la biomasse augmente : a) La production plafonne vers 40 000 tonnes pour une biomasse de l'ordre de 80 000 tonnes avec l'huître japonaise, ce qui correspond à une biomasse équivalente de 130 000 tonnes d'huîtres portugaises. b) La durée du cycle de production d'une huître de 70 g passe de 2 ans à 4 ans. c) Les mortalités courantes passent simultanément de 20 % à... |
Tipo: Text |
Palavras-chave: Production; Ostréiculture; Biomasse; Modélisation; Marennes Oléron. |
Ano: 1986 |
URL: http://archimer.ifremer.fr/doc/00048/15909/13338.pdf |
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Mongruel, Remi; Prou, Jean; Balle-beganton, Johanna; Lample, Michel; Vanhoutte Brunier, Alice; Rethoret, Harold; Perez Agundez, José A.; Vernier, Françoise; Bordenave, Paul; Bacher, Cedric. |
The contribution of soft institutional change to improve freshwater governance in the coastal zone will be examined. Freshwater management seeks to reduce losses due to overexploitation of the common-pool resources provided by river catchments and their associated ecosystems. Due to the complexity of the governance system, improving the performance of one coastal social-ecological system means searching for the appropriate “soft” institutional change. In the Pertuis Charentais region, increasing scarcity of freshwater in summer threatens the health of the coastal ecosystem and the sustainability of human activities, which depend on the use of natural resources. The allocation of freshwater among competing uses or concerns is a core issue for integrated... |
Tipo: Text |
Palavras-chave: Common-pool resources; Ecosystem services; Freshwater management; Governance; Institutional arrangements. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00055/16665/14158.pdf |
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Thomas, Yoann; Mazurie, Joseph; Alunno-bruscia, Marianne; Bacher, Cedric; Bouget, Jean-francois; Gohin, Francis; Pouvreau, Stephane; Struski, Caroline. |
In order to assess the potential of various marine ecosystems for shellfish aquaculture and to evaluate their carrying capacities, there is a need to clarify the response of exploited species to environmental variations using robust ecophysiological models and available environmental data. For a large range of applications and comparison purposes, a non-specific approach based on ‘generic’ individual growth models offers many advantages. In this context, we simulated the response of blue mussel (Mytilus edulis L.) to the spatio-temporal fluctuations of the environment in Mont Saint-Michel Bay (North Brittany) by forcing a generic growth model based on Dynamic Energy Budgets with satellite-derived environmental data (i.e. temperature and food). After a... |
Tipo: Text |
Palavras-chave: Mussel; DEB; SeaWifs; Aquaculture; Site Selection; Resource Management. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00037/14836/14537.pdf |
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Bacher, Cedric. |
The interrelationship between the amount of oysters Crassostrea gigas and their scope for growth in the Bay of Marennes-Oleron is studied through a mathematical model. lndividual growth results from the difference between assimilation and respiration , which are related to weight, temperature, seston and available food in the water height. The water height is supposed to be well mixed vertically and biodeposition instantaneously recycled. Besides, an advection-dispersion model allows to predict the food and mineral transport. lt is based on a box structure applied to the oyster production area. The parameters are evaluated from eulerian currents averaged over the tide, tidal excursion and distance between box centers. The more important competitors are... |
Tipo: Text |
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Ano: 1989 |
URL: http://archimer.ifremer.fr/doc/00441/55212/56682.pdf |
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Bacher, Cedric; Goulletquer, Philippe. |
A comparison of trophic relationships for Ruditapes philippinarum in estuarine and oceanic areas: the use of a growth mode!. Trophic relationships in Ruditapes philippinarum were studied in estuarine and oceanic areas of Marennes-Oleron during 1985 and 1986. Principal components analysis (P.C.A.) was used to reveal the fluctuations of the descriptors from the principal axes. Changes in dry weight were predicted in each area through an allometric growth model and were related to the principal axes derived from the P.C.A. The results of the model were used to compare the growth in each area and to point out the descriptors responsible for the discrepancies, such as autumnal blooms or silt resuspension. Attention was paid to the sampling strategy related to... |
Tipo: Text |
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Ano: 1989 |
URL: http://archimer.ifremer.fr/doc/1989/publication-2884.pdf |
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Hernandez Farinas, Tania; Bacher, Cedric; Soudant, Dominique; Belin, Catherine; Barille, Laurent. |
Relating environmental factors to species occurrence is a fundamental step in a better understanding of the community structure, the spatial and temporal dynamics of populations and how species may respond to environmental changes. In this paper, we used phytoplankton occurrence data, from a French national phytoplankton monitoring network, and environmental variables with the aim of characterizing the realized ecological niches of phytoplankton groups. We selected 35 phytoplankton taxa representing the most important taxa in terms of occurrence frequency and abundance along the French coast of the eastern English Channel, the Southern Bight of the North Sea and the Atlantic Ocean. We show that environmental variables such as nutrient concentration, water... |
Tipo: Text |
Palavras-chave: Phytoplankton; Environment; Niche position; Tolerance; Kernel density; Outlying mean index. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00255/36627/35263.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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Hernandez Farinas, Tania; Ribeiro, Lourenco; Soudant, Dominique; Belin, Catherine; Bacher, Cedric; Lampert, Luis; Barille, Laurent. |
Suspended marine benthic microalgae in the water column reflect the close relationship between the benthic and pelagic components of coastal ecosystems. In this study, a 12-year phytoplankton time-series was used to investigate the contribution of benthic microalgae to the pelagic system at a site along the French-Atlantic coast. Furthermore, all taxa identified were allocated into different growth forms in order to study their seasonal patterns. The highest contribution of benthic microalgae was observed during the winter period, reaching up to 60% of the carbon biomass in the water column. The haptobenthic growth form showed the highest contribution in terms of biomass, dominant in the fall-winter period when the turbidity and the river flow were high.... |
Tipo: Text |
Palavras-chave: Co-inertia; Dynamic linear models; Epipelon; Epiphyton; Haptobenthos; Microphytobenthos growth forms; Seasonality; Tychoplankton. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00392/50345/51035.pdf |
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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 |
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Registros recuperados: 86 | |
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