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| Registros recuperados: 86 | |
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| 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 |
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| Guallar, Carles; Bacher, Cedric; Chapelle, Annie. |
| The dinoflagellate Alexandrium minutum is a toxic bloom-forming species distributed worldwide. The mechanisms driving and promoting the species blooms and their toxicity are studied and presented here. Most previously published work focuses on local and/or short-term scales. In this study, a broad temporal and spatial approach is addressed using time series covering several sites over several years and combining environmental variables and A. minutum abundances from the French English Channel − Atlantic coasts. Data were explored by means of phenology and threshold analysis. The A. minutum bloom characteristics are defined. Only one bloom per year is measured and it may reach more than a million of cells L−1. Bloom period extends from April to October and... |
| Tipo: Text |
Palavras-chave: Alexandrium minutum; PSP toxicity; HAB; Bloom phenology; Threshold analysis; Monitoring long time-series. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00390/50130/51076.pdf |
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| Ferreira, Joao Gomez; Aguilar-manjarrez, José; Bacher, Cedric; Black, Kenny; Dong, S.l.; Grant, Jon; Hofmann, Eileen E.; Kapetsky, Jim; Leung, P.s.; Pastres, Roberto; Strand, Oivind; Zhu, C.b.. |
| Attention is presently turning to the processes, methods and tools that allow the principles of the ecosystem approach to aquaculture to be translated into practical implementation. An essential element for this is the use of virtual technology and decision-support tools, particularly if developing nations are to implement the key elements of aquaculture sustainability. We provide an overview of current and emerging issues and trends related to this topic over the past decade, an assessment of progress with regard to the expectations and commitments expressed in the Bangkok Declaration and conclude with some thoughts for the future. |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00086/19747/17387.pdf |
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| Bacher, Cedric. |
| A model coupling biological and hydrodynamical processes is used in order to study the influence of the amount of cultivated oysters (Crassostrea gigas) on growth performance in the Bay of Marennes-Oléron. The model is based on an energetic budget equation of a mean oyster and on a transport equation of particulate organic and inorganic matter through 12 spatial boxes. Sensitivity analysis is performed and allows computation of the impact of the distribution of oysters among the boxes on the growth performance of a mean oyster in each box. Il is shown that, mainly in the south of the bay, individual growth is affected by the increase in the stock. The same approach also shows that the response of individual growth to the amount of natural benthic... |
| Tipo: Text |
Palavras-chave: Modélisation; Modéle croissance; Compétiteurs; Crassostrea gigas; Stocks huîtres. |
| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/1991/publication-3053.pdf |
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| 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 |
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| 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 |
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| Rosland, R; Strand, O; Alunno-bruscia, Marianne; Bacher, Cedric; Strohmeier, T. |
| A Dynamic Energy Budget (DEB) model for simulation of growth and bioenergetics of blue mussels (Mytilus edulis) has been tested in three low seston sites in southern Norway. The observations comprise four datasets from laboratory experiments (physiological and biometrical mussel data) and three datasets from in situ growth experiments (biometrical mussel data). Additional in situ data from commercial farms in southern Norway were used for estimation of biometricalrelationships in the mussels. Three DEB parameters (shape coefficient, half saturation coefficient, and somatic maintenance rate coefficient) were estimated from experimental data, and the estimated parameters were complemented with parameter values from literature to establish a basic parameter... |
| Tipo: Text |
Palavras-chave: Low seston; Modelling; DEB theory; Mytilus edulis; Mussel culture. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6266.pdf |
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| Bacher, Cedric; Baud, Jean-pierre; Bodoy, Alain; Deslous-paoli, Jean-marc; Dreno, Jean-paul; Heral, Maurice; Maurer, Daniele; Prou, Jean. |
| An assessment of the reared stocks of the Pacific oyster (Crassostrea gigas ) has been recently conducted on the major French areas of molluscs culture. The methodology proposed included both estimates of densities obtained by subsampling in the field, and aerial photographs which covered the cultivated, intertidal area. The size and the number of samples were designed to reach a precision of 10% on the final assessment in each area. The field work consisted in weighing and counting the oyster in unit areas of 0.5 m2 for the bottom culture or in trays or bags, for the off bottom technique. These results give a better knowledge of the technique evolution and of the general structures in the cultivated areas. |
| Tipo: Text |
Palavras-chave: Modeling; Estimation; Stocks; Crassostrea gigas; Oysters. |
| Ano: 1986 |
URL: http://archimer.ifremer.fr/doc/1986/acte-2864.pdf |
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| David, Valerie; Ryckaert, Mireille; Karpytchev, Mikhail; Bacher, Cedric; Arnaudeau, Vanessa; Vidal, Nadia; Maurer, Daniele; Niquil, Nathalie. |
| Spatial and interannual variations of phytoplankton diversity were characterized along the French Atlantic Coast in relation to physical factors and large-scale climatic indices using phytoplankton surveys conducted from 1993 to 2010 in four geographical areas. This study relates phytoplankton diversity to oyster recruitment success by comparing a 'specific' versus a 'functional' diversity approach. Functional diversity was represented by functional groups of different phytoplanktonic functional traits (size, shape, toxicity), relevant for oyster feeding during growth, reproduction and larval development. Phytoplankton diversity patterns along the French Atlantic coast corresponded to a geographical distribution mainly driven by a latitudinal gradient and... |
| Tipo: Text |
Palavras-chave: Phytoplankton; Long-term variation; Spatial variation; Climate; Atlantic coast. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00093/20376/19677.pdf |
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| Bacher, Cedric. |
| The residence time of the water in different parts of the Marennes-Oléron Bay is one important characteristic of the biological system (Raillard, 1990). For instance, the primary production potentiality of a given area depends on the local turbidity and the residence time of the waters in that area. Further, global assessments of the nitrogen flow between the biological compartments and inflows from the ocean or the Charente river derived from the ecosystem model by Raillard (1990), showed the predominance of the latter term onto the former. A new hydrological model of the Marennes-Oléron Bay yielded two dimensional velocity fields for sorne standard tidallevels: neap-tide, spring-tide, mean tide (Lazur, unpub.). These computations were the basis for the... |
| Tipo: Text |
Palavras-chave: Ecosystem modelling; Box model; Marennes Oleron Bay; Charente Maritime. |
| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/00102/21306/18919.pdf |
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| Bacher, Cedric. |
| The first definition we could give to model is quite general : a model is any representation of the real world or what it is supposed to be at a given moment ; it clearly depends on the knowledge about reality or part of it ; as an abstraction it is necessary based on concepts and assumptions. This paper deals with mathematical modls only and among them, those which try to simulate biological mechanisms (for about 15 years however, other mathematicial approaches have been developping such as adaptative strategies, adapted from economics). Simulation alloxs to study dynamical behaviour of the elements of the ecosystem (which we denoted the real world) defined by the modeliser. Then two main purposes may be reached by the model : - prediction and management... |
| Tipo: Text |
Palavras-chave: Mathemical model; Ecosystem; Management; Aquaculture. |
| Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/00015/12635/9523.pdf |
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| Bacher, Cedric. |
| Mathematical models for biological processes are presented as a set of tools for research, which ilave been created for specifie tasks impact studies, energy budget, test of hypothesis. Before using it, the mecanisms involved must be analysed, depending upon wether a whole ecosystem or one animal is studied (biological scale), physical conditions are taken into account (physical scale), with a predetermined scale for time. The no general method for analysis can be, as conditions of studies are so different, but sorne typical cases can show the approach of the modelizer and the recent developments of its tools. |
| Tipo: Text |
Palavras-chave: Shellfish; Test of hypothesis; Energy budget; Impact studies; Mathematical models; Conchyliculture; Validation hypothèse; Bilan énergétique; Etude d'impact; Modélisation. |
| Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/1985/acte-6220.PDF |
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| Bacher, Cedric; Sochard, S.; Freissinet, C.; Sauvaget, P.. |
| Le but principal du projet OPCOM (OPerational modelling for COastal zone Management - Mast 3 - site Web: htpp://www.hydromod.de/projects/opcom/opcom.html) consiste à améliorer les méthodes de prévision en milieu côtier en évaluant essentiellement la capacité d'outils existants à répondre à des besoins de type opérationnel dans quatre sites sur lesquels ces outils ont été développés et testés par les partenaires du projet. Il s 'agit de l' estuaire de l'Elbe (Allemagne), du bassin de Marennes-Oléron (France), de l'estuaire du Tage (Portugal) et de l'Archipelago Sea (Finlande). Les objectifs, les modèles et leur application sont spécifiques à chacun des sites mais leur évaluation répond à une démarche commune basée sur des enquêtes auprès des utilisateurs... |
| Tipo: Text |
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| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00391/50192/50816.pdf |
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| Bodoy, Alain; Martin, Jean-louis; Bacher, Cedric; Haubois, Anne-gaelle; Sauriau, Pierre-guy. |
| 1.This report presents the results of a field study conducted in the ECASA test site nOS in the Pertuis Breton, France. The site is located on the Atlantic West coasts. It is open to the bay of Biscay, but is slightly protected against westerly winds. The bay has been exploited by intertidal mussels culture for centuries. 2. Within the bay, mussels (Mytilus edulis) are cultivated either by the traditional pole technique, around the bay or on longlines in the centre of the bay. The area occupied by these longline s represents 250 ha, and the resulting annual production is 1 000 tonnes of mussels. The average depth at mid tide is of 13.8 m. The sediment is sandy, with a small fraction of mud. 3. The site is subject to several regular monitoring through the... |
| Tipo: Text |
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| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00304/41516/40724.pdf |
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| Gangnery, Aline; Le Gendre, Romain; Picoche, Coralie; Petton, Sebastien; Bacher, Cedric; Alunno-bruscia, Marianne; You, Junyong; Hageberg, Anne; Strand, Oivind. |
| La conchyliculture représente une activité importante en Normandie et doit faire face à de sérieuses difficultés (mortalités, diminution de la qualité des produits). Un enjeu actuel concerne la réorganisation des zones d’élevage existantes afin d’optimiser les performances. A contrario, la pisciculture marine est très peu présente dans cette région et il existe un réel enjeu de développement économique. Dans ce contexte, les décideurs (services de l’Etat) et les professionnels ont besoin d’identifier des sites propices à la réalisation de ces activités qui soient également compatibles avec les nombreux autres usages du littoral. Au sein du projet SISQUONOR, un démonstrateur sous Système d’Information Géographique, nommé AkvaVis et développé originellement... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00307/41773/40988.pdf |
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| Bacher, Cedric; Thomas, Yoann; Alunno-bruscia, Marianne; Mazurie, Joseph. |
| The advent of remote sensing in biological oceanography in the 1990s offers a very powerful tool able to capture temporal and spatial changes of chlorophyll-a concentration and temperature at several temporal scales (decadal, inter annual and seasonal), and at local as well as at the oceanic scale. Such data have the advantage over traditional measurements of being inexpensive, spatially extensive, automatically repeated in time and validated. They have been very useful for phytoplankton monitoring in relation to eutrophication in coastal waters and the number of applications in the field of coastal zone management is growing. We present here a real case application to shellfish aquaculture. We assessed the potential for mussel aquaculture in Mont Saint... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00083/19459/17093.pdf |
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| Lavaud, Romain; La Peyre, Megan K.; Casas, Sandra M.; Bacher, Cedric; La Peyre, Jerome F.. |
| We present a Dynamic Energy Budget (DEB) model for the eastern oyster, Crassostrea virginica, which enables the inclusion of salinity as a third environmental variable, on top of the standard foodr and temperature variables. Salinity changes have various effects on the physiology of oysters, potentially altering filtration and respiration rates, and ultimately impacting growth, reproduction and mortality. We tested different hypotheses as to how to include these effects in a DEB model for C. virginica. Specifically, we tested two potential mechanisms to explain changes in oyster shell growth (cm), tissue dry weight (g) and gonad dry weight (g) when salinity moves away from the ideal range: 1) a negative effect on filtration rate and 2) an additional... |
| Tipo: Text |
Palavras-chave: DEB theory; Bioenergetics; Filtration; Maintenance; Growth; Estuary; Louisiana. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00400/51137/53773.pdf |
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| Bodoy, Alain; Bacher, Cedric; Geairon, Philippe. |
| Une estimation du stock d' huîtres creuses en élevage dans le bassin de Marennes-Oléron a été effectuée en août 1986 . Le stock s'élevait alors à 90 000 tonnes, avec une précision de 8,4 %. Ce stock se répartit en 30 300 tonnes pour l'élevage à plat et 59 700 tonnes pour l'élevage en surélevé. Il s'est donc produit une augmentation des tonnages en élevage qui est de 9,4 % entre 1985 et 1986. L'augmentation de tonnage concerne surtout l 'élevage en surélevé, et plus particulièrement les huîtres fixées sur collecteurs. La séparation des classes d'âge au niveau des collecteurs a permis d'améliorer la précision des estimations. Elle a également permis de montrer l'importance de la classe d'âge de 1 an (16 900 tonnes), qui correspond au captage particulièrement... |
| Tipo: Text |
Palavras-chave: Ostréiculture; Stocks; Croissance; Production; Huîtres creuses. |
| Ano: 1987 |
URL: http://archimer.ifremer.fr/doc/00048/15903/13331.pdf |
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| Registros recuperados: 86 | |
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