Consulta: subjectFacets:"Modélisation"
Registros recuperados: 94
Data/hora: 01/06/2024 04:39:07

Modélisation de l'emprise BAST - Modèle 100m de la région de BASTIA. Document I : Construction du modèle aspects opérationnels
Provedor de dados: 5
Autores: Gerigny, Olivia; Coudray, Sylvain.
Document descriptif de la construction du modèle hydrodynamique des eaux de la méditerranée autour de la Région de Bastia (Haute-Corse).
Tipo: Text
Palavras-chave: Modélisation; MARS3D; BASTIA; CORSE; Hydrodynamique.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00154/26489/24598.pdf

Influence du positionnement des filières ostréicoles et mytilicoles dans le Pertuis Breton : Résultats préliminaires
Provedor de dados: 5
Autores: Robert, Stephane; Fillon, Alain.
La mise en place d'une nouvelle zone de filière ostréicole fait actuellement l'objet d'une demande de la Section Régionale Ré Centre-Ouest. L'objectif du projet est de transférer une partie de l'ostréiculture d'estran sur filières, le tout à biomasse constante afin d'obtenir un gain de productivité. Deux sites ont été proposés. La proximité des zones d'élevage (mytilicole et ostréicole) en filières laisse supposer une compétition possible de l'exploitation des ressources alimentaires dans l'ensemble géographique du Pertuis Breton. Par conséquent, le choix du site d'élevage est particulièrement important et doit être sélectionné de façon à minimiser l'impact sur les cultures déjà existantes. Pour cela, l'influence du positionnement des filières a été étudié...
Tipo: Text
Palavras-chave: Filière ostréicole; Modélisation; Courantologie; Bathymétrie; Pertuis Breton; Pertuis Antioche.
Ano: 1996
URL: http://archimer.ifremer.fr/doc/00149/26026/24127.pdf

Application de modèles dynamiques bayésiens aux séries temporelles de Dinophysis à Antifer (Normandie, France)
Provedor de dados: 5
Autores: Soudant, Dominique.
Le Dinophysis est une microalgue toxique à l’origine d’epidémies diarrhéiques. En dépit de nombreuses études, l’écologie et la biologie de ce genre phytoplanctonique restent mal connues. Afin de déterminer les conditions d’apparition de Dinophysis cf. acuminata sur le site d’Antifer (Normandie, France), des prélèvements d’eau de mer ont été effectués quasi-journellement pendant les périodes estivales des années 1987 à 1993. Les séries temporelles résultantes concernent la concentration de la microalgue et les facteurs chimiques, physiques et météorologiques. L’analyse de ces données à l’aide d’outils sta- tistiques classiques (e.g. régression) s’est avérée difficile (e.g. instabilité temporelle des résultats). Une caractéristique commune de ces méthodes...
Tipo: Text
Palavras-chave: Modélisation; Statistique; Dynamique; Séries temporelles; Bayésien; Dinophysis; Baie de Seine.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00015/12576/9446.pdf

Adaptabilité des activités conchylicoles aux modifications de leur environnement : Scénarii et solutions. Le cas du bassin de Marennes-Oléron
Provedor de dados: 5
Autores: Mille, Dominique; Le Moine, Olivier.
Ce travail a été réalisé dans le cadre du programme européen ANCORIM (Atlantic Network For Costal Risks Management) dont la durée est de 3 ans (mai 2009 à avril 2012) et qui est cofinancé par l'Union Européenne dans le cadre du programme INTERREG IV B espace atlantique « Investir dans notre avenir commun ». L'objectif d'ANCORIM est de promouvoir les outils destinés à renforcer les capacités d'action des décideurs du littoral des régions atlantiques afin de faire face aux risques littoraux en matière d'érosion côtière, de submersion ou d'atteinte à la qualité des eaux. L'action privilégie le renforcement des échanges et des connaissances en créant un outil d'échange à l'usage des décideurs. Elle prend la forme d'une intensification des relations entre la...
Tipo: Text
Palavras-chave: Activités conchylicoles; Modèles de production conchylicoles; Recensement des risques côtiers; Méthodologie; Modélisation; Bassin de Marennes Oléron.
Ano: 2011
URL: https://archimer.ifremer.fr/doc/00061/17257/14766.pdf

Amélioration de l'évaluation des stocks de mollusques cultivés en Charente- Maritime
Provedor de dados: 5
Autores: Bacher, Cedric; Deslous-paoli, Jean-marc; Heral, Maurice; Prou, Jean.
The expansion of shellfish culture businesses (oysters, mussels, clams...) gives way to a competition for the use of limited food resources, especially in the Marennes-Oléron basin where water circulation is slow. Increasing the amount of cultivated molluscs leads, from a biological point of view, to:- a drop in growth performances- a rise in chronic mortalities, higher and higher, due to a weakness in the physiological state with a lack of stocks which would have compensated the habitat seasonal shortages (end of winter, etc...)- a greater weakness to diseases, linked to a deficient physiological state and a density rise which increases the proximity rate and thus, parasite propagation speed.For these primary reasons, and for the future of oyster culture,...
Tipo: Text
Palavras-chave: Modélisation; Estimation; Echantillonnage; Mollusques; Marennes Oléron; Evaluation stocks.
Ano: 1986
URL: http://archimer.ifremer.fr/doc/1986/rapport-3841.PDF

Modélisation des turbidités en Bretagne sud et validation par des mesures in situ
Provedor de dados: 5
Autores: Tessier, Caroline; Le Hir, Pierre; Dumas, Franck; Jourdin, F.
A hydrodynamic and sediment model of South Brittany is calibrated with ADCP measurements, which allow to estimate hydrodynamic forcing and concentration of suspended particulate matter. The exercise of comparison between observed and simulated concentrations reveals that turbidity is highly dependant on numerous strongly coupled sedimentary and physical processes.
Tipo: Text
Palavras-chave: Waves; ADCP; Acoustical backscattering; Modelisation; Turbidity; Vagues; ADCP; Rétrodiffusion acoustique; Modélisation; Turbidité.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-6300.pdf

Changements climatiques dans la mer de Barents : interactions glace-océan, formation et variabilité de la masse d'eau
Provedor de dados: 5
Autores: Barton, Benjamin I.
Winter sea ice has declined in the Barents Sea and there is growing evidence that the low sea ice here coincides with cold, winter surface air temperature in Europe and Asia. Atlantic Water (AW) transported into the Barents Sea is warming and its temperature variability is correlated with variability in sea ice extent. As AW extends into the Barents Sea it is modified into a cooler, fresher water mass called BarentsSea Water (BSW). There are limited observations of BSW despite its importance in the Arctic Ocean system, leading to the question, how does the seasonal sea ice impact ocean stratification and mean flow?First, satellite observations are used to find the Polar Front, a water mass boundary between BSW and fresher Arctic Water to the north. The sea...
Tipo: Text
Palavras-chave: Barents Sea Water; Front polaire; Banquise; Satellite; Modélisation; Model; Barents Sea Water; Polar front; Sea ice; Satellite.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00692/80424/83560.pdf

La capacité biotique des bassins ostréicoles
Provedor de dados: 5
Autores: Heral, Maurice; Bacher, Cedric; Deslous-paoli, Jean-marc.
Maurice Héral has been studying, since 1976 at the IFREMER Station of La Tremblade (France), the trophic networks of shellfish-farming ecosystems and, especially, the variability of available food, energy assessment, the ecophysiology of the Japanese oyster; he has set up a comprehensive model of shellfish farming production. He has been managing the Shellfish Farming Ecosystems Laboratory (LEC) since 1980. A specialist of digital models, Cédric Bacher has been working at the LEC since 1985. He invented a strategy of sampling farmed molluscs' biomass and a preliminary, analytic trophic model that combines physical and biological systems. Jean-Marc Deslous-Paoli has been a member of the same laboratory since 1979, where his work focuses on monitoring...
Tipo: Text
Palavras-chave: Modèle analytique; Modélisation; Modéle global; Production; Capacité trophique; Biomasse; Climatologie; Captage naissain; Bassin Marennes Oléron.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/1989/publication-3011.pdf

Spéciation des contaminants métalliques en milieu estuarien : Intérêt de la modélisation et application au cadmium
Provedor de dados: 5
Autores: Gonzalez, Jean-louis; Dange, Catherine; Thouvenin, Benedicte.
In estuarine environment, cadmium has a nonconservative behavior. It can be present under various species: dissolved (mineral and organic complexes), colloidal and particulate forms (adsorbed, precipitated), or integrated by various mechanisms in the organisms. This distribution is the result of processes (physical, chemical and biological) which are controlled by many factors (salinity, pH, Eh, nature and concentration of suspended matter, primary production). Geochemical modeling is a very useful approach to understand the dynamics of this type of contaminant, especially in the complex systems which are the estuaries. A speciation model was used to simulate the measurements taken (dissolved and particulate Cd) during various cruises carried out in the...
Tipo: Text
Palavras-chave: Cadmium; Estuary; Speciation; Modeling; Surface complexation; Cadmium; Estuaire; Spéciation; Modélisation; Complexation de surface.
Ano: 2001
URL: https://archimer.ifremer.fr/doc/00480/59120/61749.pdf

Présélection de sites ostréicoles en pleine eau. Mise au point d'une maquette (version 0) et analyse critique. Application à la bande côtière des Pertuis Charentais
Provedor de dados: 5
Autores: Loubersac, Lionel; Guillaumont, Brigitte; Heral, Maurice; Prou, Jean; Durand, Henri.
Le présent document fait la synthèse et l'analyse critique d'une expérience préliminaire, de mise au point d'un outil et d'un produit d'aide à la décision, faisant appel aux technologies des Systèmes d'Information Géographique et visant la résolution d'un problème d'aménagement littoral. L'objectif fixé par ce travail est principalement, au travers de la réalisation d'une maquette, d'identifier les points d'ordre méthodologique qui demandent un effort de Recherche Développement. La présente étude a été conduite en partenariat entre le groupe transdirectionel SILLAGE de l'IFREMER, concepteur et architecte de la maquette du Système d'Information, et l'IFREMER DRV/RA (M. Héral et J. Prou) pour la validation scientifique du problème posé. Le groupe SILLAGE,...
Tipo: Text
Palavras-chave: Méthodologie; Ostréiculture; Système Informatique géographique; SIG; Modélisation.
Ano: 1994
URL: http://archimer.ifremer.fr/doc/00048/15906/13334.pdf

Modélisation de l'affinage de l'huître Crassostrea gigas alimentée avec la diatomée Skeletonema costatum
Provedor de dados: 5
Autores: Meleder, Vona; Barille-boyer, Anne-laure; Baud, Jean-pierre; Barille, Laurent; Cognie, Bruno; Rosa, Philippe.
The traditional fattening of the oyster Crassostrea gigas in oyster ponds of the French Atlantic Coast is submitted to natural environmental fluctuations. In order to reduce the growth variability of the soft parts of the bivalve, an intensive fattening process was developed, where the conditions of temperature, particulate organic and inorganic matter (POM and PIM) are controlled. This process relies on the production of the diatom Skeletonema costatum, which is then distributed to the oysters at an average concentration of 4–5 mg POM·L–1. An ecophysiological model of the oyster C. gigas, which simulates the evolution of somatic and gonad–reserve compartments, was applied to these conditions in order to analyse the bivalve responses. Experimentation was...
Tipo: Text
Palavras-chave: Modélisation; Affinage; Ecophysiologie; Crassostrea gigas; Skeletonema costatum; Modelling; Oyster fattening; Ecophysiology; Crassostrea gigas; Skeletonema costatum.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/00021/13248/10285.pdf

Rapport de mesures dans le lagon de Hienghène-Touho - Province Nord - Nouvelle-Calédonie. SPHYNX - Suivi des Paysages HYdrologiques des lagons Nord
Provedor de dados: 5
Autores: Le Gendre, Romain; Soulard, Benoit; Lemonnier, Hugues; Laugier, Thierry; Hubert, Morgane; Desclaux, Terence; Royer, Florence; Le Tesson, Eric; Dumas, Franck; Kayara, Jean-françois.
Ce rapport fait partie du projet de recherche PRESENCE (PRessions sur les Ecosystèmes récifaux et lagonaires de Nouvelle-CalédoniE). L'objectif de ce projet est de mieux appréhender le fonctionnement des lagons de Nouvelle-Calédonie à partir d’observations in-situ, de télédétection et de modélisation hydrodynamique. Ce rapport présente les mesures effectuées sur les lagons de Touho à Pouébo situés sur la côte Est de la Province Nord de Nouvelle-Calédonie, secteur sur lequel les connaissances et observations du fonctionnement hydrodynamique étaient assez parcellaires. Les données seront utilisées par la suite pour mieux appréhender la dynamique de ce grand lagon mais également à des fins de calibration et de validation de modèle...
Tipo: Text
Palavras-chave: Mesures; Hydrologie; Courantologie; Hydrodynamique; Hienghène; Hyehen; Pouébo; Pweevo; Modélisation.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00452/56378/58028.pdf

Dynamique des matières en suspensions minérales des eaux de surface de la Manche observée par satellite et modélisée numériquement.
Provedor de dados: 5
Autores: Rivier, Aurelie.
Study of mineral suspended particulate matter (SPM) is essential to understand ecosystem dynamics. SPM influences light penetration which is closely related to primary production and carries pollutants and nutrients within the water masses. This work aims to study near-surface mineral SPM dynamics in the English Channel using two complementary methods: remote-sensing by satellites and numerical modelling. Firstly, MODIS and MERIS satellite images processed by the IFREMER semi-analytical algorithm and describing non-algal SPM, are analysed to build three statistical models which are able to estimate near-surface SPM using simple variables, e.g., tidal coefficient, significant wave height and mean chlorophyll-a concentration. Secondly, the three-dimensional...
Tipo: Text
Palavras-chave: Matière en suspension; Télédétection; Satellite; Modélisation; Manche; Sédiments; Turbidité; Marée; Houle; Suspended particulate matter; Satellite; Remote-sensing; Modelling; English Channel; Sediments; Turbidity; Tide; Wave.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00157/26783/24884.pdf

A modelling study of the thermohaline circulation of the Mediterranean Sea: Water formation and dispersal
Provedor de dados: 5
Autores: Haines, K; Wu, Pl.
A model of the whole Mediterranean sea at 0.25 degrees x 0.25 degrees resolution has been run for ten years with a mean seasonal cycle of forcing using NMC winds and a relaxation to NODC surface temperature and salinity. The winter season water formation and dispersal in the model thermocline has been studied using isopycnal diagnostics and potential vorticity as a water mass tracer. In the eastern basin Levantine Intermediate Water (LIW) is formed in the cyclonic Rhodes gyre and moves west in a continuous mass, accumulating and mixing in the centre of the Northern Ionian. The LIW spreading path is identified both from the high salinity and low potential vorticity values on the 28.8 isopycnal surface. Some LIW then spreads west and south towards Sicily,...
Tipo: Text
Palavras-chave: PRIMO-O; Circulation thermohaline; Eau levantine intermédiaire; Formation; Modélisation; PRIMO-O; Thermohaline circulation; Levantine Intermediate Water; Water formation; Modelling.
Ano: 1995
URL: http://archimer.ifremer.fr/doc/00323/43387/43113.pdf

Impact des mesures de gestion sur la dynamique de la pêcherie pélagique du golfe de Gascogne : Quelles certitudes ? Quels descripteurs ?
Provedor de dados: 5
Autores: Lehuta, Sigrid.
Quantitative evaluations of management measure impact on resource and fleet viability are required to provide diagnostics and feed decision process. Fisheries are complex systems where numerous dynamics interact at various spatial and temporal scales. This complexity and the difficulty to observe marine systems are responsible for the high uncertainty surrounding fishery functioning that makes it hard to identify adequate management measures. The increasing consideration of uncertainties in diagnostics argues in favor of robust management measures rather than optimal management measures. Identifying robust management measures requires the development of models that account for complexity and uncertainty in the description and prediction of management...
Tipo: Text
Palavras-chave: Modélisation; Pêcherie mixte; Gestion des pêcheries; Incertitudes; Simulation; Analyse de sensibilité; Indicateurs; Gestion spatialisée; ISIS-Fish; Modeling; Mixed fisheries; Fishery management; Uncertainty; Simulation; Sensitivity analysis; Indicators; Spatialised management; ISIS-Fish.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00025/13630/10712.pdf

Devenir de l'atrazine dans le bassin de Marennes-Oléron. Approche par la modélisation hydrodynamique, hydrosédimentaire et biogéochimique
Provedor de dados: 5
Autores: Vanhoutte Brunier, Alice.
Atrazine is the most widely used herbicide on cultured areas. This pesticide is degraded during its transport in rivers and streams, to the coastal area. Marennes Oléron is the main french oyster farming area, receiving the fresh water from the Charente river and ail the drainage coming from the coastal cultivated marshlands. Agriculture is thus claimed to be responsible for shellfish mortality in the aquaculture area. To simulate the changing fate of atrazine in the environment, a modelling strategy has been selected. a) First, using a two-way hydrodynamic model developped by IFREMER, the atrazine dilution trail in the Marennes Oléron area was simulated.Combined with larvae bioassays of Crassostrea gigas (Japanese oyster), the results show atrazine rates...
Tipo: Text
Palavras-chave: Produits phytosanitaires; Atrazine; Cycle biogéochimique; Modélisation; Dynamique sédimentaire; Vasières intertidales; Pesticides; Atrazine; Biogeochemical cycle; Models; Sediment transport; Intertidal muflats.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/00412/52312/53082.pdf

Processus Gravitaires et Évaluation de la Stabilité des Pentes : Approches Géologique et Géotechnique. Application à la marge algérienne et à l'effondrement de l'aéroport de Nice en 1979
Provedor de dados: 5
Autores: Dan, Gabriela.
The present work consists of two areas of interest: the Algerian margin and the area affected by the 1979 Nice slide.  The first scientific survey, MARADJA, took place in 2003 in order to characterize the Algerian margin from a morpho-sedimentary point of view and to map the presence of mass-wasting deposits. Based on other two scientific surveys, PRISMA and MARADJA 2, the mechanical and physical properties of the Algerian sediment were defined. The geotechnical properties were used to identify the triggering mechanisms of the observed mass-wasting deposits and to assess the present-day slope stability. The main results are:  • The sedimentary processes are clearly influenced by the morphology of the margin, which is controlled by the tectonics. The...
Tipo: Text
Palavras-chave: Liquefaction; Slope stability; Nice 1979; Algeria; Modelling; Numerical; Modélisation; Liquéfaction; Stabilité de pente; Processus gravitaires; Nice 1979; Algérie.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/these-3881.pdf

Contributions to the Coordinated Control of Two Robotic Arms for Underwater Manipulation of Deformable Biological Specimens
Provedor de dados: 5
Autores: Leborne, Francois.
The research carried out in the scope of this doctorate degree aims to develop innovative techniques to improve the collection of biological and mineral samples underwater using robotic manipulators. The end goal is to enhance the handling by robotic means in order to maximise sample quality provided to marine scientists. The proposed techniques are based on an in-depth analysis of the robotic arm actuators used in most recent underwater intervention vehicles, in order to improve the accuracy of the positionning of the tools held by the manipulator arms. An instrumented tool has also been developed with the aim to measure the reaction forces and adapt the interaction between the arm's end-effector and its environment to improve samples handling. These...
Tipo: Text
Palavras-chave: Robotique sous-marine; Manipulation; Modélisation; Identification; Mesure d'effort; Underwater Robotics; Manipulation; Modeling; Identification; Force sensing.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00498/60958/64361.pdf

Modélisation bioénergétique de la croissance, du développement et de la reproduction d'un petit pélagique : l'anchois du golfe de Gascogne
Provedor de dados: 5
Autores: Pecquerie, Laure.
Understanding the recruitment variability of fish populations is a major challenge in fishery sciences. In the present work, we explore a new approach to study the potential factors that determine this recruitment in the context of biophysical modelling. The adult spawning pattern might influence the survival of the larvae as it determines the environmental conditions they experience during this critical period. We apply our study to the Bay of Biscay anchovy Engraulis encrasicolus, which is a multiple-batch spawner.  The objective of the study is to understand the effect of the environmental conditions experienced by an individual i) on the energy available for reproduction and ii) on the temporal distribution of the spawning events and its consequences...
Tipo: Text
Palavras-chave: Inter individual variability; Environmental scenarios; Link fish metabolism   otolith; Larval survival; Spawning windows; Engraulis encrasicolus; Dynamic Energy Budget theory; Life cycle; Bioenergetic; Modelling; Variabilité inter individuelle; Scénarios environnementaux; Lien métabolisme   otolithe; Survie larvaire; Fenêtres de ponte; Engraulis encrasicolus; Energy Budget; Théorie Dynamic; Cycle de vie; Bioénergétique; Modélisation.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/these-3505.pdf

Etude de l'impact du stock d'huîtres et des mollusques compétiteurs sur les performances de croissance de Crassostrea ggias, à l'aide d'un modèle de croissance
Provedor de dados: 5
Autores: 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

Hydrologie du Grand Etang de Miquelon. Estimation des flux et renouvellements
Provedor de dados: 5
Autores: Le Moine, Olivier; Geairon, Philippe; Robert, Stephane; Coudray, Sylvain; Fiandrino, Annie; Goraguer, Herle; Goulletquer, Philippe.
This study aims to assess the hydrological fluxes between the ‘Grand Etang’ of Miquelon and the oceanic part. Bathymetric surveys and Doppler current meter data acquisitions were carried out from August 14th, to November 5th, 2014 and from April 1st, to end of July 2015 to allow the following estimates : Total area (227 Ha) and characteristics volumes (total : 6,7 106 m3; oscillating 2,8 106 m3 (40 %); half-tide 5,2 106 m3) Velocity Index of channel to evaluate the average current speed at cross-section channel Fluxes, on flood and ebb tide respectively : Instantaneous flow: maxima at 94,2 et 65 m3/s mean 37.2 et 24.5 m3/s. in 2014 and maxima 85,03 et 73,62 m3/s mean 26,22 et 28,20 m3/s in 2015. Circulating fluxes by tide : maxima 1,06 and 1,09 106 m3,...
Tipo: Text
Palavras-chave: Flux hydrologiques; Courantométrie; Bathymétrie; Grand Etang Miquelon; Modélisation; Hydrological fluxes; Current meter data acquisition; Bathymetry; Grand Etang Miquelon; Modelling.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00332/44325/43904.pdf

Active faulting and deep crustal structure of the Eastern Sicily Margin
Provedor de dados: 5
Autores: Dellong, David.
In the Ionian Sea (central Mediterranean) the slow convergence between Africa and Eurasia results in the formation of a narrow subduction zone. The nature of the crust of the subducting plate remains debated and could represent the last remnants of the Neo-Tethys ocean. The origin of the Ionian basin is also under discussion, especially concerning the rifting mechanisms as the Malta Escarpment could represent a remnant of this opening. This subduction retreats toward the south-east (motion occurring since the last 35 Ma) but is confined to the narrow Ionian basin. A major lateral slab tear fault is required to accommodate the slab rollback.This fault is thought to propagate along the eastern Sicily margin but its precise location remains controversial.This...
Tipo: Text
Palavras-chave: Méditerranée; Ionien; Calabre; Géodynamique; Marge; Faille de déchirure lithosphérique; Sismicité; Sismique; Grand-angle; Bathymétrie; Gravimétrie; Modélisation; Mediterranean; Ionian; Calabria; Geodynamic; Subduction; Margin; STEP fault; Wide-angle seismic; Seismicity; Bathymetry; Gravity; Modelling.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00499/61026/64430.pdf

Etude et modélisation des mécanismes impliqués dans la croissance de l'huître perlière, Pinctada margaritifera, au sein de l'écosystème conchylicole du lagon de l'atoll de Takapoto (Polynésie Française)
Provedor de dados: 5
Autores: Pouvreau, Stephane.
L'huître perlière, Pinctada margaritifera (Linné, 1758) var. cumingi (Reeve), productrice de perles noires, fait l' objet d'une aquaculture florissante en Polynésie Française. Afin de pérenniser cette activité, un programme de recherche (le PGRN) a été lancé, en 1990, sur l' atoll de Takapoto. L' un des thèmes de ce programme réside dans l'étude de la capacité trophique d'un lagon soumis à une activité de perliculture. A cet égard, un modèle déterministe expliquant la croissance et la reproduction de P. margaritifera à partir des paramètres du milieu (notamment la nourriture disponible) a été mis au point. La construction de ce modèle a impliqué : ( 1) l'analyse de l'hydrobiologie du lagon; (2) l'étude de la physiologie de P. margaritifera; (3) le sui vi...
Tipo: Text
Palavras-chave: Bivalves; Huîtres perlières; Pinctada margaritifera; Physiologie; Croissance; Reproduction; Hydrobiologie; Atoll; Lagon; Écosystème; Réseau trophique; Modélisation; Capacité trophique; Polynésie française; Bivalves; Pearl oyster; Pinctada ma rgaritifera; Physiology; Growth; Reproduction; Hydrobiology; Atoll; Lagoon; Ecosystem; Trophic web; Modelling; Carrying capacity; French Polynesia.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/00034/14558/11856.pdf

3D modelling of seasonal evolution of Loire and Gironde plumes on Biscay Bay continental shelf
Provedor de dados: 5
Autores: Lazure, Pascal; Jegou, Anne-marie.
A 3D model of the Atlantic shelf has been developed and applied to study shelf dynamics and evolution of hydrology. The model takes the combined effects of tide, wind, river discharges and surface heat flux into account. Time scales vary from 1 day to several years. Following a brief description of the model and forcing variables, the behaviour of the Loire and Gironde plumes is described, first for winter and spring, then over a period of several years, under realistic forcing. The results show that plume evolution depends on the high Variability of river runoff and winds. Model simulations performed over 7 years (1990 to 1996) have highlighted several features of these plumes: 1) In early winter and periods of high river runoff, plumes usually spread...
Tipo: Text
Palavras-chave: Panache; Modélisation; Dynamique du plateau continental; Golfe de Gascogne; River plume; Modelling; Shelf dynamics; Bay of Biscay.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/1998/publication-847.pdf

Rapport final projet Liteau II. Modélisation intégrée des transferts de nutriments depuis les bassins versants de la Seine, la Somme et l'Escaut jusqu'en Manche-Mer du Nord
Provedor de dados: 5
Autores: Lefebvre, Alain.
The main aim of the project was to produce quantitative assessment elements on past and future consequences of nutrient inputs from French and Belgian coastal rivers (Seine, Somme, Escaut) with regards to eutrophication status in the English Channel – North Sea. This project will reinforce implementation of the Water Framework Directive (2000/60/CE), in the context of the 2.1. axis (Definition of ecological status) from APR LITEAU II. This project implements and generalizes to the whole eastern English Channel and the southern bight of the North Sea the results from LITEAU I Programme which allowed the development of this application on the Seine watershed and the Baie de Seine estuary. The method consists in : (i) the simulating the Nitrogen, the...
Tipo: Text
Palavras-chave: OSPAR; WFD; Watershed – coastal zone continuum; Modelisation; Eutrophication; Southern bight of the North Sea; English Channel; OSPAR; DCE; Continuum bassin versant – zone côtière; Modélisation; Eutrophisation; Baie sud de la Mer du Nord; Manche.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/rapport-6298.pdf

ECOSCOPA. Evaluer la qualité des écosystèmes conchylicoles en lien avec les pressions climatiques et anthropiques. Rapport annuel campagne 2015
Provedor de dados: 5
Autores: Fleury, Elodie.
Le réseau ECOSCOPA, co-financé par la DPMA, a pour objectif de développer un outil permettant de mesurer, à plusieurs échelles, des paramètres environnementaux et biologiques en lien avec la croissance et la survie d’huîtres creuses en élevage. Sur l’année 2015 et afin de préparer de façon concertée ce projet, il a été proposé dans un premier temps de renforcer la synergie existante entre les réseaux RESCO et VELYGER afin de disposer d’un suivi proactif du cycle complet de production de l’huître (incluant le captage, la croissance, la reproduction, les éventuelles mortalités) à partir d’animaux communs sur différents sites ateliers, en lien avec l’acquisition de descripteurs environnementaux et physiologiques susceptibles d’influencer chacune de ces traits...
Tipo: Text
Palavras-chave: Observation; Modélisation; Explication; Anticipation; Communication.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00334/44511/44204.pdf

Development of shellfish production models
Provedor de dados: 5
Autores: 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

Étude du comportement non-linéaire d'une colle dans un assemblage
Provedor de dados: 5
Autores: Cognard, Jean-yves; Sohier, Laurent; Davies, Peter; Gineste, Bernard.
The objective of this study is to define a reliable tool for dimensioning of adhesively bonded assemblies, particularly for marine and underwater applications. A modified “Arcan” fixture, suited for the study of the behavior of bonded metal-metal assemblies, was developed in order to focus on the analysis of the behavior of the adhesive in thin films. To analyze the kinematics of the deformation of the adhesive joint non-contact extensometry techniques were employed. Thus various characteristics of the non-linear behavior of the adhesive were observed. The first results obtained for mixed assemblies (steel, aluminium, composite substrates) show similar behaviour of the adhesive using the proposed procedure. Furthermore, quality controls by DSC, and studies...
Tipo: Text
Palavras-chave: Ssemblages collés; Modélisation; Essais; Comportement non-linéaire; Composites; Adhesive bonding; Model; Tests; Non linear behaviour; Composite.
Ano: 2006
URL: https://archimer.ifremer.fr/doc/00480/59156/61785.pdf

États de mer et agitation sur le fond. Sous-région marine Méditerranée occidentale. Evaluation initiale DCSMM.
Provedor de dados: 5
Autores: Ardhuin, Fabrice; Accensi, Mickael.
Tipo: Text
Palavras-chave: Méditerranée; Etats de mer; Agitation sur le fond; Modélisation.
Ano: 2012
URL: https://archimer.ifremer.fr/doc/00330/44112/43683.pdf

Méthodologie pour une simulation des transformations granulométriques de sables de la zone d'avant-côte
Provedor de dados: 5
Autores: Barusseau, Jp; Diouf, Mb; De La Bardonnie, M; El Ghandour, N.
The grain-size of mature coastal sands changes rapidly in response to the variation of the energy regime which provokes either erosion or deposition of fractions of the textural assemblage. Whatever the dynamic conditions, questions of paramount importance such as the size of grain populations transported simultaneously, the most common size of the grains in movement and the grain-size range of the sediment fraction involved ape still poorly understood. The present paper deals with an attempt to describe this fraction without any consideration of the processes responsible for the observed changes. A major problem results from the fact that the distribution of the mobilized fraction cannot be known and described by direct comparison between the initial and...
Tipo: Text
Palavras-chave: Granulométrie; Fraction mobile; Modélisation; Simulation; Grain-size; Mobile fraction; Modelling; Simulation.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/00325/43619/43919.pdf

Ecosystème estuarien et système économique régional : faisabilité d’une intégration par modélisation Input-Output. Application au cas de l'habitat halieutique dans l’estuaire de la Seine
Provedor de dados: 5
Autores: Cordier, Mateo.
Mateo Cordier’s PhD addresses the interactions between the economic system and the ecosystem of the Seine estuary, an ecosystem deeply modified by human activities. His work aims at a holistic perspective and targets, among others, the destruction of nursery habitats and the subsequent impact on fish stocks in the Seine estuary. The hybrid input-output model developed in the PhD manuscript brings a quantitative insight on stakeholders and natural resources impacted by the modifications of ecosystem services (modifications caused by economic activities, political measures or restoration programs).
Tipo: Text
Palavras-chave: Input-output; Services écosystémiques; Processus participatifs; Gestion intégrée des zones côtières; Science Post-Normale; Aide à la décision; Économico-écologique; Modélisation; Prospective; Input-Output; Ecosystem services; Participative process; Integrated coastal zone management; Post-Normal Science; Decision-support; Ecological-economics; Modelling; Foresight.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00048/15926/13351.pdf

Simulation of a coastal jet retention process using a barotropic model
Provedor de dados: 5
Autores: Penven, Pierrick; Roy, Claude; Colin De Verdiere, Alain; Largier, John.
In the southern Benguela, sardine and anchovy spawn on the Western Agulhas Bank. Eggs and larvae are transported to the West coast nursery ground by a! coastal current. Once the larvae reach the West coast, retention within the favorable coastal domain is key to larvae survival and recruitment. The Cape Columbine-St Helena Bay area is the main nursery ground along the West Coast. In this area, the interaction between upwelling and topography results in the formation of an upwelling plume. The plume, and the associated circulation patterns, is thought to be the mechanism providing retention within the coastal domain. The dynamics of the plume are studied using a set of:numerical experiments. It is shown that an equatorward wind forcing produces a cyclonic...
Tipo: Text
Palavras-chave: Benguela; Effets de cap; Modélisation; Rétention; Recrutement; Benguela; Cape effects; Modeling; Retention; Recruitment.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00323/43385/42826.pdf

Evaluation des ressources démersales du plateau insulaire martiniquais
Provedor de dados: 5
Autores: Froehlicher, Hermione; Pawlowski, Lionel; Weiss, Jerome; Reynal, Lionel; Thouard, Emmanuel.
Cette étude a pour but de déterminer l’état des ressources ciblées par les pêcheries démersales, majoritairement artisanales, exerçant sur le plateau insulaire martiniquais. Les espèces ciblées par ces pêcheries sont nombreuses (56 groupes d’espèces) et principalement capturées à la nasse. Cette étude se focalise sur les 12 groupes d’espèces principaux en termes de volume débarqué, valeur et nombre de marées effectuées. La courte série temporelle (11 années d'échantillonnage) et les données disponibles (CPUE et volumes de captures) imposent d'utiliser les méthodologies associées aux stocks à données limitées : tendance sur indices de biomasse et modèle de production. Ces deux méthodes sont confrontées dans cette évaluation. L’approche globale est avec un...
Tipo: Text
Palavras-chave: Martinique; Évaluation de stock; Stock à données limitée; Modélisation.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00595/70677/71784.pdf

Rapport d'activité 1990 de l'Unité de Recherche Ecosystèmes Aquacoles (UREA) La Tremblade
Provedor de dados: 5
Autores: Heral, Maurice.
Rapport d'activités 1990 de l'Unité de Recherche Ecosystèmes Aquacoles (UREA) La Tremblade
Tipo: Text
Palavras-chave: Aquaculture; Conchyliculture; Croissance; Biochimie; Estimation biomasse; Hydrobiologie; Modélisation; Bassin de Marennes Oléron.
Ano: 1990
URL: http://archimer.ifremer.fr/doc/00072/18281/15851.pdf

Devenir de l'atrazine dans le bassin de Marennes-Oléron (France) - Approche par la modélisation hydrodynamique, hydrosédimentaire et biogéochlmique
Provedor de dados: 5
Autores: Vanhoutte Brunier, Alice.
Atrazine is the most widely used herbicide on cultured areas. This pesticide is degraded during its transport in rivers and streams, to the coastal area. Marennes Oleron is the main french oyster farming area, receiving the fresh water from the Charente river and all the drainage coming from the coastal cultivated marshlands. Agriculture is thus claimed to be responsible for shellfish mortality in the aquaculture area. To simulate the changing fate of atrazine in the environment, a modelling strategy has been selected, a) First, using a two-way hydrodynamic model developped by IFREMER, the atrazine dilution trail in the Marennes Oleron area was simulated.Combined with larvae bioassays of Crassostrea gigas (Japanese oyster), the results show atrazine rates...
Tipo: Text
Palavras-chave: Produits phytosanitaires; Atrazine; Cycle biogéochimique; Modélisation; Dynamique sédimentaire; Vasières intertidales.; Pesticides; Atrazine; Biogeochemical cycle; Models; Sediment transport; Intertidal muflats.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/00306/41764/40977.pdf

Diagnostic étendu de l'eutrophisation (DIETE). Rôle des sédiments dans le cycle des nutriments et impacts sur l'eutrophisation de la baie de Vilaine (2014-2017)
Provedor de dados: 5
Autores: Souchu, Philippe; Cochennec-laureau, Nathalie; Ratmaya, Widya; Retho, Michael; Andrieux, Francoise; Le Merrer, Yoann; Barille, Laurent; Barille, Anne-laure; Goubert, Evelyne; Plus, Martin; Laverman, Anniet.
Le projet DIETE a exploré les données hydrobiologiques (paramètres physico-chimiques, nutriments, phytoplancton) acquises depuis les années 80 dans les eaux côtières au large de la Loire et de la Vilaine, parallèlement à celles des deux fleuves. L’augmentation des concentrations de nitrates dans les eaux de la Loire, appuyée par les réserves sédimentaires de phosphates et de silicate ont entraîné de profonds bouleversements dans la dynamique du phytoplancton de la baie de Vilaine ces deux dernières décennies avec 1) une augmentation substantielle de la biomasse, 2) une modification importante de l’évolution saisonnière, 3) un changement dans les proportions entre diatomées et dinoflagellés au profit des diatomées. Ces résultats ouvrent tout un champ...
Tipo: Text
Palavras-chave: Eutophisation; Azote; Phosphore; Silicium; Sédiments; Modélisation.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00425/53695/54593.pdf

Simulation des trajectoires de matière organique dans le Pertuis Breton. Couplage de l'hydrodynamisme et d'un modèle écophysiologique de M. edulis
Provedor de dados: 5
Autores: Pallas Sanz, Enric.
The "Pertuis Breton" is a macrotidal estuary with an important mollusc exploitation of the inter-tidal zones. The main cultivated specie is M.edulis. In 1991, 250 long lines have been immersed in the centre of the bay. It will be able to extend the concession on the basis of the studies results about the trophy capacity of the "Pertuis Breton". Two deterministic models have been developed for to determining the geographical origin of the matter organic sources for the long line mussels culture, and the destine of this matter in the culture park: a) a model of trajectories of the organic matter particles, b) a coupled model of the hydrodynamic conditions and a ecophysiological model of the mussel growth. The result's simulations of the trajectories model...
Tipo: Text
Palavras-chave: M. edulis; Potentialité mytilicole; Déplétion; Trajectoires; Modélisation; M. edulis; Trophy capacity; Depletion; Trajectories; Modelling.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/00449/56098/57634.pdf

Études des interactions entre la bactérie bioprotectrice Lactococcus piscium et Brochothrix thermosphacta et Listeria monocytogenes dans la crevette tropicale
Provedor de dados: 5
Autores: Fall, Papa-abdoulaye.
The bioprotective potential of Lactococcus piscium CNCM I-4031 towards a specific spoilage organism, Brochothrix thermosphacta, was studied on tropical cooked peeled shrimp packed under modified atmosphere. In co-culture, the growth of this spoilage bacterium was inhibited by 4 log ufc/g by L. piscium and the sensory quality of the product was improved during 31 days. The inhibition could not be attributed to lactic acid or nutritional competition for amino acids. The growth modelling of L. piscium and B. thermosphacta was performed in different conditions of temperature, pH and NaCl concentrations. The optimal growth values of these two bacteria are quite similar, however L. piscium seemed to be more psychrotolerant than B. thermosphacta but twice less...
Tipo: Text
Palavras-chave: Biopreservation; Inhibition; Modélisation; Lactococcus piscium; Flore d’altération; Analyse sensorielle; Produits de la mer; Co-cultures; Biopreservation; Inhibition; Modelling; Lactococcus piscium; Spoilage microflora; Sensory analysis; Seafood products; Co-cultures.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00050/16164/13649.pdf

Recherche de l'origine des sources de contamination microbiologique en rivière de Pénerf. Partie 2, Hiérarchisation des flux et modélisation de la contamination
Provedor de dados: 5
Autores: Treguier, Cathy; Hitier, Benoist.
Dans le cadre de la recherche de l’origine des contaminations en rivière de Penerf, une étude a été menée en partenariat entre l’Ifremer et le SIAGM de juillet 2010 à décembre 2011. Des échantillons d’eau douce aux 8 principaux exutoires, ainsi que des coquillages ont été prélevés à une fréquence bimensuelle afin de dénombrer les indicateurs de contamination fécale Escherichia coli. Le calcul des débits au niveau du bassin versant a permis de reconstituer les flux de bactéries fécales provenant des exutoires étudiés. La contamination des points de prélèvement coquillages situés plus en amont s’avère être supérieure, en moyenne, à la contamination des points REMI situés en aval. Cependant, aucune relation statistique significative n’a pu être mise en...
Tipo: Text
Palavras-chave: Contamination fécale; Escherichia coli; Bassin versant; Pénerf; Flux; Qualité des zones de production conchylicoles; Modélisation.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00140/25174/23280.pdf

Modélisation du transport particulaire dans le Golfe du Lion en vue d'une application au devenir des traceurs radioactifs issus du Rhône
Provedor de dados: 5
Autores: Dufois, Francois.
Among the contaminants introduced into the environment, the artificial radionuclides appear particularly important to take into account because of their chemical toxicity and/or of their radiotoxicity. Some radionuclides present a high affinity with particles so that the study of the sediment dynamics is a useful preliminary to the study of their dispersion on the open sea. This thesis is focused on the fate of sediments in the Gulf of Lions (NW Mediterranean) and in particular on the impact of the Rhone River, which is the main source of particulate matter in the Gulf of Lions. In order to study the sediment transport mechanisms on various space and time scales, this thesis is based on mathematical modelling. The hydro-sedimentary model set up in the Gulf...
Tipo: Text
Palavras-chave: Waves; MARS 3D; Hydrodynamic; Radionuclides; Modelling; Sediment; Rhône prodelta; Gulf of Lions; Vagues; MARS 3D; Hydrodynamique; Radioéléments; Modélisation; Sédiment; Prodelta du Rhône; Golfe du Lion.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/these-6308.pdf

Bassin de la Charente et Baie associée de Marennes-Oléron
Provedor de dados: 5
Autores: Bacher, Cedric; Fillon, Alain; Prou, Jean; Heral, Maurice.
Les modèles d'apports de nitrates par le fleuve Charente, les modèles de productivité de production primaire et les modèles de croissance des huîtres développés précédemment ont été adaptés pour préciser l'impact de la Charente en période d'étiage sur la productivité des huîtres. L'impact de la construction éventuelle du barrage de la Charente a été évalué en fonction de son dimensionnement et de ses modalités de gestion.
Tipo: Text
Palavras-chave: Bassin de Marennes-Oléron; Modélisation; Crassostrea gigas; Charente; Trézence.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00077/18796/16373.pdf

Mortalités estivales de l'huître creuse (Crassostrea gigas) dans le bassin de Marennes-Oléron (France). Etude de la variabilité spataile des caractéristiques environnementales de croissance et de production par un Système d'Informations Géographiques (GIS)
Provedor de dados: 5
Autores: Soletchnik, Patrick; Le Moine, Olivier; Razet, Daniel; Geairon, Philippe; Faury, Nicole; Goulletquer, Philippe; Robert, Stephane.
The Marennes-Oléron Bay is the first cupped oyster production site (35,000 tons/year). For more than 10 years, this species has suffered chronic mortality episodes. A research program has been developed since 1994 in association with the professional sector, in order to try and explain these mortalities.
Tipo: Text
Palavras-chave: Production; Croissance; Modélisation; GIS; Système d'Informations Géographique; Crassostrea gigas; Huîtres; Mortalités estivales.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/1999/acte-3377.pdf

Etude du comportement des éléments traces en milieu estuarien : approche expérimentale et modélisation : Application à l'étude de la spéciation de Cd, Co et Cs dans les estuaires majeurs français (Seine, Loire, Gironde, Rhône)
Provedor de dados: 5
Autores: Dange, Catherine.
Most of trace elements have a non conservative behavior in estuarine environments. It is the case of cadmium, cobalt and caesium for which the fate in estuarine and coastal zones is largely controlled by their distribution between water and suspended particles, which generally have high residence times or can be definitely deposited in these areas. Metallic contaminants and radionuclides can be present under various species : dissolved (mineral and organic complexes), colloidal and particulate forms (adsorbed, precipitated) or integrated by various mechanisms in the organisms. Such distributions are the result of processes (physical, chemical, biological) which are controlled by many factors (ionic strengh, pH, Eh, major cations concentration, nature and...
Tipo: Text
Palavras-chave: Modeling; French estuaries; Caesium; Cobalt; Cadmium; Radionuclides; Trace metals; Speciation; Modélisation; Estuaires français; Cesium; Cobalt; Cadmium; Radionucléides; Métal trace; Speciation.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/2002/these-183.pdf

Etude des apports en herbicides et en nutriments par la Charente : Modélisation de la dispersion de l'atrazine dans le bassin de Marennes-Oléron
Provedor de dados: 5
Autores: Munaron, Dominique.
Our study aims at making progress the estimate of herbicide and nutrient inputs to the Marennes-Oleron bay which could influence summer oysters mortalities, and to bring by modeling a better understanding of the dynamics of these compounds in the shellfish-farming area. The development of a strategy adapted to the Charente river and its estuary reveals that agricultural activity on the catchment area is omnipresent, as well on the level of the nitrogen and herbicides contributions. It is thus necessary to specify Charente fluxes, which is the main tributary of the Marennes-Oleron bay, in order to better characterize its impact on shellfishfarming activity. Use of a dispersion model will constitute an invaluable help in the risk assessment with respect to...
Tipo: Text
Palavras-chave: Atlantic coast; Marennes Oléron Bay; Modelisation; Estuary; Geochemistry behaviour; Charente River; Flux; Nutrient; Herbicide; Littoral Atlantique; Bassin de Marennes Oléron; Modélisation; Estuaire; Comportement Géochimique; Charente; Flux; Nutriments; Herbicides.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/these-2266.pdf

Mécanismes sous-jacents du contrôle bottom-up des populations de sardines dans le Golfe du Lion : enseignements tirés des expériences et de la modélisation
Provedor de dados: 5
Autores: Queiros, Quentin.
The Gulf of Lions has faced a sharp drop in the catches of its two main small pelagic exploited species, the sardine Sardina pilchardus and the anchovy Engraulis encrasicolus since the mid-2000s, despite both population abundances remaining high. This situation has been due to a severe decrease in individual body condition and size as a result of both lower growth and the disappearance of the oldest and largest individuals. While overfishing, predation or disease outbreaks have been refuted to explain this situation, one major hypothesis remained to be investigated. A potential shift in sardine and anchovy diet towards smaller planktonic prey indeed suggested bottom-up control as the main driver of these populations in the Gulf of Lions. The first aim of...
Tipo: Text
Palavras-chave: Poissons petits pélagiques; Expérience; Processus bottom-up; Modélisation; Traits d'histoire de vie; Small pelagic fish; Experiment; Bottom-Up processes; Modeling; Life history traits.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00692/80420/83556.pdf

Optimisation de procédés innovants pour l'obtention de phycocolloïdes
Provedor de dados: 5
Autores: Vauchel, Peggy.
Alginates are polysaccharides which are naturally present in the cell wall of brown algae and extracted because of their rheological properties. The alginate industry uses an extraction protocol, which central step, the carbonatation, is conducted in batch reactors. It is a high water, reagent and time demanding process. The main objective of this thesis is to optimize the alginate extraction process. A study of the existing process, focused on carbonatation step, enabled to highlight points which could be enhanced to optimize the extraction yield and the quality of extracted alginates. Stirring intensity and algae pieces size have been identified as parameters having an influence on the carbonatation reaction kinetics. A specific analysis on medullar and...
Tipo: Text
Palavras-chave: Alginate; Extraction; Laminaria digitata; Extrusion réactive; Optimisation; Modélisation; Distribution des temps de séjour; Cinétique; Rendement; Propriétés rhéologiques; Alginate; Extraction; Laminaria digitata; Reactive extrusion; Optimization; Modeling; Residence time distribution; Kinetics; Extraction yield; Rheological properties.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/00002/11364/7937.pdf

Typology of individual growth in sea bass (Dicentrarchus labrax)
Provedor de dados: 5
Autores: Gardeur, J; Lemarie, Gilles; Coves, Denis; Boujard, Thierry.
The individual growth variability of passive integrated transponder tagged sea bass was studied using data sets from two different experiments. In experiment 1 (n = 485), fish submitted to different photoperiod regimes were held in fourteen groups of individual weight of 88 ± 13 g (mean ± SD). In experiment 2 (n = 748, initial weight 243 ± 30 g) fish were held in fifteen groups and had either free or restricted access to diets with three lipid levels. After adjustment for treatment and tank effects, individual growth curves were analysed using multivariate analysis (principal component analysis and clustering) and were modelled using the summary statistics technique. Different growth profiles where characterized. All of them appeared to be curvilinear....
Tipo: Text
Palavras-chave: Variability; Typology; Sea bass; Modelling; Growth curves; Variabilité; Typologie; Bar; Modélisation; Courbes de croissance.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/publication-548.pdf

VIBRance : éValuation des Impacts Bactériologiques dans l'Estuaire de la Rance. Hiérarchisation des flux de contamination microbiologique dans le cadre de l’élaboration du profil de vulnérabilité conchylicole du secteur Rance et baie de Saint-Malo
Provedor de dados: 5
Autores: Cheve, Julien; Le Noc, Sandrine.
Le projet VIBRance (éValuation des Impacts Bactériologiques dans l’estuaire de la Rance) a fait suite à l’observation d’une nette dégradation de la qualité microbiologique des eaux dans l’estuaire de la Rance (Rance maritime &amp; baie de Saint-Malo) au milieu des années 2010, présentant un risque pour la pérennité des activités tributaires : pêche à pied de loisir et professionnelle, conchyliculture, algoculture et à plus long terme la baignade. La situation revêt un caractère multi-sources (nombreux exutoires) et complexe (hydrodynamisme d’un estuaire découpé et contrôlé par un barrage marémoteur). La problématique posée est quelles sont les sources de contamination microbiologique dans l’estuaire de la Rance et leurs impacts associés ? Le projet...
Tipo: Text
Palavras-chave: Impact; Bactériologique; Microbiologique; Estuaire; Rance; Baie de Saint- Malo; Profil; Vulnérabilité; Conchylicole; Baignade; Pêche; Pied; Escherichia coli; Diagnostic; Courantologie; Modélisation; Dispersion source; Contributeur; VIBRance.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00442/55363/56879.pdf

Les outils géomatiques pour des applications de gestion du secteur ostréicole. CoastGIS'97
Provedor de dados: 5
Autores: Populus, Jacques; Loubersac, Lionel; Prou, Jean; Kerdreux, Michel; Le Moine, Olivier.
In Marennes-Oléron, Héral (1986) described the relationship between the annual production and the oysters' biomass over a century. His conclusion is that the drop in the growth of oysters was caused by an "overstorage" considering the trophic capacity of the basin. Moreover, the large intertidal spaces, though providing a great opportunity for mollusc culture, suffer from a large bio-deposition (Sornin 1983) which tends to intensify the sedimentation of the basin. The spatial management of oyster culture could be a key factor for its long-term development. In collaboration with the French Marine Affairs, in charge of the cadastral management, the IFREMER has developed a geographical information system enabling the gathering under the same geographic...
Tipo: Text
Palavras-chave: Bathymétrie; Cartographie; Modélisation; Conchyliculture; SIG; Système d'Informations Géographique.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/1997/acte-3323.pdf

Vers une modélisation déterministe des écoulements de surface en Nouvelle-Calédonie. Implémentation du code GR4H sur quatre bassins versants du Grand Nouméa
Provedor de dados: 5
Autores: Desclaux, Terence; Pischedda, Marine; Lemonnier, Hugues; Soulard, Benoit; Le Gendre, Romain.
Ce rapport fait suite au stage de Marine Pischedda (Master 2 La Rochelle) réalisé au sein de l’unité de recherche "Lagons, Ecosystèmes et Aquaculture Durable en Nouvelle-Calédonie" (LEAD/NC) de l’Ifremer entre février et juillet 2016. Cette étude a été conduite sur quatre bassins versants du Grand Nouméa : la Coulée, la Dumbéa Est, la Dumbéa Nord et la Couvelée. L’objectif principal était de démontrer la pertinence de l’utilisation de modèle pluie-débit au pas de temps horaire (GR4H en l’occurrence) sur les bassins versants calédoniens. Le cadre plus général de ce travail était d’aboutir à une représentation affinée du continuum terre-mer par le couplage des modèles GR4H et MARS3D développés pour simuler la circulation côtière. Les périodes d’étiages ayant...
Tipo: Text
Palavras-chave: Continuum Terre-Lagon; Nouvelle-Calédonie; Rivières; GR4H; Bassins versants; Grand Nouméa; Modélisation; Débits; Land-lagoon continuum; New Caledonia; River; GR4H; Watershed; Nouméa; Model; River Flow.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00388/49969/50545.pdf

Adaptative responses of E-coli to marine environmental stresses. a modelling approach based on viability and dormancy concepts
Provedor de dados: 5
Autores: Martin, Y; Troussellier, Marc; Bonnefont, Jl.
In an attempt to synthesize conceptual and experimental information on the behaviour of enteric bacteria in seawater, a mathematical model has been developed. This model is based on changes in intracellular metabolisable components depending an physiological responses of the cell when subjected to nutrient starvation, salinity stress and solar radiation. Following a strategy which takes into account short- and mid-term physiological adaptation and reversal processes, the cells can develop in different states: culturable (B-1), viable and definitively nonculturable (B-2), and reversibly dormant (B-3) cells. Model parameters were deduced either from original microcosm experiments, from literature data or calibration procedures. Validation of the model was...
Tipo: Text
Palavras-chave: Escherichia coli; Eau de mer; Stress; États cellulaires; Modélisation; Escherichia coli; Seawater; Stress; Cellular states; Modelling.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00325/43646/43224.pdf

Surfaces de mer et dissipation d'énergie
Provedor de dados: 5
Autores: Veras Guimaraes, Pedro.
Stochastic wave formulations and models are the most common tools for the assessment and forecast of sea surface conditions. Their ability to account for some of the processes encountered by waves during their evolution remains however a central question. Among other processes, the wave dissipation is for instance still poorly quantified and traditional methods for wave measurements fail to proper insight into its physics in a wide range of conditions. In this context, the work presented in this PhD aims to explore available observation techniques for their application to several quantitative aspects of the dissipation of wave energy, and particularly for short wave modulated by strong tidal currents, for short wave modulated by longer waves. This work...
Tipo: Text
Palavras-chave: Vagues; Stéréo-vidéo; Bouée dérivante; Modélisation; Interaction vague-courant; Modulation; Déferlement; Breaking; Ocean waves; Stereo video; Drifting buoy; Wave modeling; Wave-current interaction.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00498/60967/64375.pdf

Modélisation de la production de l'huître Crassostrea gigas du bassin de Marennes-Oléron (France). Etude de l'influence des apports de nitrates du fleuve Charente sur la production primaire et ostréicole
Provedor de dados: 5
Autores: Raillard, Olivier; Menesguen, Alain.
Oyster production of the Marennes-Oléron Basin is simulated using a model integrating phytoplankton growth, oyster growth and horizontal transport of suspended matter. Firstly the simulations are compared to the measurements. At season scale, the phytoplankton and nitrates evolution are well predicted by the model. In compensation, the model does not simulated well the spring/neap tidal variability of the phytoplankton. Secondly, the phytoplancton and oyster productions are calculated as a function of the nitrates river inputs. Biotic capacity of the basin appears to be particulary influenced by these nutrients during summer. On the other hand, spatial variability of the impact of the nitrates variation is clearly shown, the primary productions of the...
Tipo: Text
Palavras-chave: Croissance; Production; Marennes Oléron; Crassostrea gigas; Huîtres; Modélisation.
Ano: 1991
URL: http://archimer.ifremer.fr/doc/1991/acte-3042.pdf

Pattern formation in models of plankton dynamics. A synthesis
Provedor de dados: 5
Autores: Malchow, H; Petrovskii, S; Medvinsky, A.
The history of modelling plankton dynamics is already quite long and has been initiated by fishery science in the early 20th century. The main aim of modelling population dynamics is to improve the understanding of the functioning of food chains and webs and their dependence on internal and external conditions. Hence, mathematical models of biological population dynamics have not only to account for growth and interactions but also for spatial processes like random or directed and joint or relative motion of species as well as the variability of the environment. Early attempts began with physicochemical diffusion, exponential growth and Lotka-Volterra type interactions. These approaches have been continuously refined to more realistic descriptions of the...
Tipo: Text
Palavras-chave: Modélisation; Schémas de formation; Agrégation du plancton; Auto-organisation; Modelling; Pattern formation; Plankton patchiness; Self-organization.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/00322/43344/42882.pdf

Testage de souches d'huîtres plates Ostrea edulis tolérantes à Bonamia ostreae: élevage contrôlé, écophysiologie et modélisation de la croissance
Provedor de dados: 5
Autores: Haure, Joel.
Since the 1960's, breeding of the flat oyster Ostrea edulis has been under threat from two protozoan parasites, one of which is Bonamia ostrea. Several attempts have been made to introduce flat oysters of the Ostrea genus on the French coast, without much success. The IFREMER genetics laboratory. at Ronce les Bains has used selective pressure with Bonamia ostrea to obtain bonamiosis-resistant strains of the flat oyster, Ostrea edulis. The growth and physiology of these animaIs was studied in an intensive breeding system in which the algae Skeletonema costatum was used as fodder. The growth performance of the tolerant animals was compared with that of non-selected controls over a period of three years (1994,1995,1996). An analysis of the results showed the...
Tipo: Text
Palavras-chave: Ostrea edulis; Skeletonema costatum; Ecophysiologie; Modélisation; Elevage intensif; Bonamia ostreae; Ostrea edulis; Skeletonema costatum; Ecophysiology; Modelisation; Intensive culture; Bonamia ostreae.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/00108/21961/19555.pdf

Modélisation de la production ostréicole à Marennes-Oléron : introduction d'un modèle de croissance phytoplanctonique
Provedor de dados: 5
Autores: Raillard, Olivier.
La complication d'un modèle déterministe est une action qui ne peut être envisagée sans raisons impérieuses. En plus des mécanismes nouveaux qu'il importe de connaître précisément pour les formaliser correctement, l'introduction de nouveaux paramètres, dont la valeur exacte n'est jamais connue, accroit l'incertitude du modèle (Klepper et Scholten, 1988) et affecte ainsi sa robustesse (Swartzman et Kaluzny, 1987). A Marennes-Oléron, l'introduction d'un modèle de production primaire doit permettre d'aborder les problèmes suivants : Quelle est véritablement l'impact des débits de la Charente sur la production ostréicole? ou plus précisément : les nutriments d'origine charentaise contrôlent-ils la production phytoplanctonique du bassin et par voie de...
Tipo: Text
Palavras-chave: Modélisation; Croissance; Phytoplancton; Modèle biologique; Bassin de Marennes Oléron; Charente Maritime.
Ano: 1991
URL: http://archimer.ifremer.fr/doc/00102/21313/18932.pdf

Evolution et état du cheptel ostréicole dans le bassin de Marennes-Oléron: intérêt d'une régulation
Provedor de dados: 5
Autores: 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

Interactions vagues-banquise en zones polaires
Provedor de dados: 5
Autores: Boutin, Guillaume.
Sea ice, which covers most of the ocean near the poles, is a key component of the climate system. Global warming is driving its massive melting, especially in the Arctic. Where sea ice cover decreases, fetch increases leading to more energetic sea states. This means potentially enhanced wavesice interactions effects in the future. The quick evolution of sea ice extent and volume combined with the intensification of human activities in polar regions urge us to improve our understanding of waves-ice interactions.Sea ice attenuates waves. They can however propagate through it and break it far into the ice cover. Attenuation depends on ice properties such as floe size, thickness, etc. Once broken, resulting floes are more likely to drift and melt. In addition,...
Tipo: Text
Palavras-chave: Vagues; Banquise; Modélisation; Zone Marginale de Glace; Waves; Sea ice; Model; Marginal Ice Zone.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00498/60968/64376.pdf

Les pêches maritimes : un terrain d’expérimentation de la géoprospective
Provedor de dados: 5
Autores: Tissière, Laurie; Mahévas, Stephanie; Michel, Charlotte; Trouillet, Brice.
A prospective approach can be used to establish management and environmental protection options to stimulate discussion and bring different scenarios for the future into perspective. This future-oriented process incorporates spatial dimensions with the development of a geoprospective approach. Indeed, a geoprospective approach highlights geographical dynamics and integrates spatial perspectives into the debate. A participatory framework for analyzing the marine fisheries sector has two main advantages. The first is academic, in that it helps to establish a methodological and epistemological corpus based on geoprospective. The method proposal allows, on the one hand, to discuss the purpose of the models and, on the other, to explore the role of researchers...
Tipo: Text
Palavras-chave: Géoprospective; Modélisation; Participation; Méthodes mixtes; Démocratie et gouvernance environnementales; Pêches maritimes; Geoprospective; Modeling; Participation; Mixed methods; Environmental democracy and governance; Marine fisheries.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00664/77597/79611.pdf

Approche théorique du comportement de suspensions d'élevage de moules dans le courant
Provedor de dados: 5
Autores: Bompais, Xavier.
Les suspensions d'élevage de moules sur filières (ou long-lines) sont décrites et modélisées ainsi que les efforts hydrodynamiques qui s'y appliquent. Le rapport présente ensuite une modélisation de leur comportement dans le courant, s'attachant à décrire les déformées statiques, les effets de masque et les phénomènes vibratoires qui peuvent survenir. Deux sites d'implantation sont traités en application, chacun avec différents cas de chargement. Le rapport conclut en conseillant de choisir une orientation des filières d'élevage dans le courant différente de celle retenue pour les deux sites étudiés.
Tipo: Text
Palavras-chave: Long-lines; Mytiliculture; Mer ouverte; Modélisation.
Ano: 1990
URL: https://archimer.ifremer.fr/doc/00469/58036/60454.pdf

Amélioration de la mytiliculture dans la Baie de l'Aiguillon - Rapport général - Tome I : Campagne de mesures sur le site
Provedor de dados: 5
Autores: LCHF - Laboratoire Central d'Hyraulique de France; IFREMER - LABEIM Laboratoire de Biologie et d'Ecologie des Invertébrés Marins.
Dans un même secteur d'élevage de la baie de l'Aiguillon, vraisemblablement à cause de certaines inégalités de nutrition, un déséquilibre du développement des mollusques a été constaté depuis plusieurs années.  Soucieux d'apporter une solution à ce problème de première importance pour la région, et conscient de ce que cette solution doit passer par une recherche de l'amélioration de la circulation des eaux dans la zone des bouchots, IFREMER (Institut Français de la Mer) a confié au Laboratoire Central d'Hydraulique de France (LCHF) une étude courantologique dans la baie de l 'Aiguillon.  Cette étude comporte les trois phases suivantes :  - une campagne de mesures devant permettre de préciser les caractéristiques de la courantologie dans la zone des...
Tipo: Text
Palavras-chave: Modélisation; Courantologie; Baie de l'Aiguillon; Mytiliculture; Bouchots; Modèle mathématique; Département Charente-Maritime.
Ano: 1985
URL: http://archimer.ifremer.fr/doc/00143/25441/23594.pdf

Bilan des actions MOREST 2004 du Laboratoire Envrionnement et Ressources du Poitou-Charentes (LERPC)
Provedor de dados: 5
Autores: Soletchnik, Patrick; Le Moine, Olivier; Geairon, Philippe; Faury, Nicole; Razet, Daniel; Robert, Stephane; Prou, Jean.
The objectives for 2004: - Continuation of the study of the "on-bottom/off-bottom" mortality south of the Marennes Oléron Bay with a study of acute stress (sequel to Dynamo &amp; DynamoR studies) (WP 2.2.8). - Continuation of the laboratory analysis of the dynamoR 2003 samples (biological material) and data (WP 2.2.3). - Analysis of the data on the characterisation of summer mortality (WP 2.2.1) in relation to the environment. Through these tasks, the objectives are: (1) understanding the "on-bottom/off-bottom" mortality model of C. gigas in the Marennes Oléron Bay and underlining the environmental causes of summer mortality, (2) bringing a regional answer to this issue, (3) widening the study of the mortality / environment relationship to all the French...
Tipo: Text
Palavras-chave: Ecosystèmes conchylicoles; Modélisation; Bassin de Marennes Oléron; MOREST; Mortalités; Crassostrea gigas; Huîtres.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/acte-3388.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

Evaluation des ressources démersales du plateau insulaire guadeloupéen
Provedor de dados: 5
Autores: Pawlowski, Lionel; Robineau, Victoire; Guyader, Olivier; Laurans, Martial; Weiss, Jerome; Baudrier, Jerome; Thouard, Emmanuel.
Cette étude a pour but de déterminer l’état des ressources ciblées par les pêcheries démersales, majoritairement artisanales, exerçant sur le plateau insulaire guadeloupéen. Les travaux se focalisent sur les 13 groupes d’espèces principaux en volumes et valeurs débarquées. La courte série temporelle (9 années d'échantillonnage des débarquements) et les données disponibles (CPUE et volumes de captures) font appel aux méthodologies d’évaluation développées pour les stocks à données limitées. Ces methodologies visent à estimer les tendances récentes de la biomasse ainsi que les niveaux relatifs de la biomasse et la pression de pêche par rapport à des points de reference au RMD (Rendement Maximal Durable). L’approche suivie repose sur l’usage du modèle de...
Tipo: Text
Palavras-chave: Guadeloupe; Système d’Informations Halieutiques (SIH); Évaluation de stock; Stock à données limitées; Modélisation.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00689/80098/83161.pdf

Emergence of biodiversity research and main progress from Ifremer
Provedor de dados: 5
Autores: Desbruyeres, Daniel; Goulletquer, Philippe.
Research needs and interests on biodiversity have drastically increased since the Rio Conference (1992). The main conclusions from the Millennium Ecosystem Assessment (MEA, 2001) carried out by the UN and the demonstration of the critical role of biodiversity in maintaining ecosystems services have strengthened research interests on biodiversity. Moreover, the systemic approach generalization, complex system modeling, confluence of thematic prompting new scientific concepts, and multi-scalar – multifunctional approach have induced significant changes to the scientific context. A review of major advances on biodiversity monitoring and research resulting from Ifremer programs will be presented considering deep sea as well as coastal ecosystems and associated...
Tipo: Text
Palavras-chave: Modelisation; Operational monitoring; Benthic habitat mapping; Ecosystem; Research; Marine biodiversity; Modélisation; Surveillance opérationnelle; Cartographie; Ecosystèmes; Recherche; Biodiversité marine.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/acte-6829.pdf

Rapport d'activité 1989 du Laboratoire National Ecosystèmes Conchylicoles (LEC) - La Tremblade
Provedor de dados: 5
Autores: Heral, Maurice.
Tipo: Text
Palavras-chave: Rapport activité; Conchyliculture; Estimation biomasse; Hydrobiologie; Physiologie; Crassostrea gigas; Modélisation; Bassin de Marennes Oléron.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/00077/18838/16413.pdf

La cinématique de l'Atlantique Nord : la question de la déformation intraplaque
Provedor de dados: 5
Autores: Fidalgo González, Luis.
The main features of geodynamic evolution in the North Atlantic and the lithospheric plates surrounding it have been known for a quarter of a century now.  However, a number of questions raised by the first models published have still not been clearly answered in detail. Among them, the difficulty in adjusting the domain to the north and the south of the Faeroe-Iceland-Greenland ridge should be highlighted. This study addresses the issue by using fracture zones as the main data for our reconstructions. We show that they accurately bound the kinematical reconstructions. They also enable kinematical reorganisation periods to be studied on the scale of oceans, as well as their duration.  Reconstructions carried out on these bases confirm the existence of...
Tipo: Text
Palavras-chave: Europa; Africa; North Atlantic; Modelling; Fracture zone; Magnetic anomaly; Ocean crust; Deformation; Plate tectonic; Europe; Afrique; Atlantique Nord; Modélisation; Zone Fracture; Ouverture; Anomalie Magnétique; Croute Oceanique; Déformation; Tectonique Plaque.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/these-1205.pdf

Amélioration de la mytiliculture dans la Baie de l'Aiguillon - Rapport général - Tome IIA : Mise au point du modèle mathématique
Provedor de dados: 5
Autores: LCHF - Laboratoire Central d'Hyraulique de France; IFREMER - LABEIM Laboratoire de Biologie et d'Ecologie des Invertébrés Marins.
Dans un même secteur d'élevage de la baie de l'Aiguillon, vraisemblablement à cause de certaines inégalités de nutrition, un déséquilibre du développement des mollusques a été constaté depuis plusieurs années.  Soucieux d'apporter une solution à ce problème de première importance pour la région, et conscient de ce que cette solution doit passer par une recherche de l'amélioration de la circulation des eaux dans la zone des bouchots, IFREMER (Institut Français de la Merl a confié au Laboratoire Central d'hydraulique de France (L.C.H.F.) une étude courantologique dans la baie de l'Aiguillon.  Cette étude comporte les trois phases suivantes :  - une campagne de mesures devant permettre de préciser les caractéristiques de la courantologie dans la zone des...
Tipo: Text
Palavras-chave: Modélisation; Courantologie; Baie de l'Aiguillon; Bouchots; Modèle mathématique; Département Charente-Maritime.
Ano: 1987
URL: http://archimer.ifremer.fr/doc/00143/25440/23593.pdf

Ecologie larvaire de l'huître perlière (Pinctada margaritifera, L.), croissance et dispersion dans un lagon d'atoll polynésien
Provedor de dados: 5
Autores: Thomas, Yoann.
Understanding key factors determining the bentho-pelagic species larval growth and dispersal remains one of the challenges of marine ecology, notably to understand the adult population structure and dynamics. In the present study, we explore this determinism on the development and dispersal of the black-lip pearl oyster (Pinctada margaritifera var. cumingii, Linné 1758) larvae in a French Polynesian atoll lagoon (Ahe, Tuamotu archipelago). Rearing of the pearl oyster for the production of black pearls takes on a major social and economic place in French Polynesia. However, the supply of pearl oyster seed to the farms depends entirely on the natural collection of wild spat of the only one specie P. margaritifera, and spatial and temporal variability of spat...
Tipo: Text
Palavras-chave: Ecologie larvaire; Hétérogénéité environnementale; Modélisation; Croissance; Dispersion; Huître perlière à lèvres noires; Pinctada margaritifera; Lagon d’atoll; Polynésie française; Larval ecology; Environmental heterogeneity; Modeling; Growth; Dispersal; Black-lip pearl oyster; Pinctada margaritifera; Atoll lagoon; French Polynesia.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00003/11449/7999.pdf

Nouveau modèle analytique pour une meilleure estimation des flux nets annuels en métaux dissous. Cas du cadmium dans l’estuaire de la Gironde
Provedor de dados: 5
Autores: Pougnet, F.; Blanc, G; Mulamba-guilhemat, E.; Coynel, A.; Gil-diaz, T.; Bossy, C.; Strady, E.; Schäfer, J.
Despite major management efforts initiated in 1987 and 2007 and decreasing emissions in the Gironde watershed, cadmium (Cd) levels in oysters from the downstream Gironde estuary are still higher to the consumption limit (5 mg/kg, dw, EC). Dissolved Cd concentrations were measured in surface water collected in the Gironde estuary during nine cruises (2014 – 2015). The obtained theoretical (Cdd0) concentrations and the daily net Cdd fluxes, using the Boyle’s method, confirm a decadal stepping decrease of the Cd pollution corresponding to that observed in the oysters from the long term national monitoring for priority contaminants at the estuary mouth. As this observation invalidates the previous estimating methods for estimating annual net Cdd fluxes, we...
Tipo: Text
Palavras-chave: Estuaire; Cadmium dissous; Modélisation; Flux nets; Estuary; Dissolved cadmium; Computation; Net fluxes.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00485/59713/62808.pdf

Comprendre la structure et la dynamique du phytoplancton en réponse aux forçages naturels et anthropiques, et contribuer au développement des outils d’analyses automatisées. Vers un Système Intégré d’Observation.
Provedor de dados: 5
Autores: Lefebvre, Alain.
Les écosystèmes marins sont soumis à des pressions d’origine anthropique très importantes depuis ces dernières décennies. Parmi ces pressions, les apports excessifs de nutriments vont impacter directement le phytoplancton et indirectement d’autres niveaux trophiques compromettant ainsi les biens et services écosystèmiques. On parle alors d’eutrophisation, phénomène répandu à l’échelle mondiale. La Manche orientale et la baie sud de la mer du Nord ne font pas exception. La partie française de cette zone est marquée par des proliférations massives de la Prymnésiophycée, Phaeocystis globosa, qui aboutiront au développement d’une mousse abondante et nauséabonde sur le littoral comme à des dysfonctionnements au sein des habitats benthique et pélagique. C’est...
Tipo: Text
Palavras-chave: Manche; Baie sud de la mer du Nord; Eutrophisation; Habitat pélagique; Phytoplancton; Abondance; Diversité; Hydrologie; Climat; Observation; Surveillance; Écologie numérique; Modélisation; Haute fréquence; Systèmes automatisés; Stations instrumentées; Ferry Box.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00360/47103/47027.pdf

Modélisation des écosystèmes conchylicoles : bassin de Marennes-Oléron - Rapport de fin de Contrat
Provedor de dados: 5
Autores: 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

Programme coordonné Ecotron sur le site d'Arcachon (Aquitaine, France) : contrôle de la production biologique marine dans un écosystème lagunaire aménagé (réservoirs à poissons) - Bilan, synthèse et perspectives
Provedor de dados: 5
Autores: Lasserre, Pierre.
Coordinated ECOTRON Program on the Arcachon Basin (Aquitaine, France) : Control of marine biological production in a man-modified lagoon ecosystem (fish ponds). Results, synthesis and prospects. The "fish reservoirs" of the Arcachon Basin consist of eutrophic lagoon ecosys­tems, empirically exploited for extensive amphihaline fish culture (grey mullets, sea bass, eels, sea breams). The 1000 hectares of exploited farms, well integrated in a traditional socio-economic context, are presently not adapted for various reasons.The coordinate researches, which have been developed at Arcachon since 1974, within the ECOTRON (CNEXO) Program, show that these highly productive man modified ecosystems are well adapted for the development of semi-intensive aqua­culture....
Tipo: Text
Palavras-chave: Lagunes côtières exploitées; Réservoirs à poissons; Bassin d'Arcachon; Fonctionnement écosystème; Contrôle productivité; Modélisation; Développement potentiel; Exploited coastal lagoons; Fish ponds; Arcachon Bay; Ecosystem functioning; Productivity control; Modelling; Potential development.
Ano: 1979
URL: http://archimer.ifremer.fr/doc/00306/41676/40885.pdf

Modélisation de la détoxication de mollusques bivalves contenant des phycotoxines paralysantes ou diarrhéiques
Provedor de dados: 5
Autores: Gueguen, Marielle.
The purpose of this study is to implement models to describe detoxification kinetics of Pacific oysters Crassostrea gigas and Blue mussels Mytilus edulis containing paralytic and diarrheic phycotoxins respectively. First, experimental trials made it possible to complement data from the literature regarding the understanding of processes involved in mollusc detoxification. In particular, they pointed out a difference in the mollusc capacity to degrade cellwalls of phycotoxin-producing dinoflagellates, according to their en cystement capacities. It was observed that paralytic phycotoxins reached the various oyster tissues whereas diarrheic toxins were mainly sequestred in the digestive gland of mussels. The latter seem to be retained by lysosomes localized...
Tipo: Text
Palavras-chave: Modélisation; Mytilus edulis; Crassostrea gigas; Phycotoxines; Détoxication; Acide okadaïque; Toxines paralysantes; Modelling; Mytilus edulis; Crassostrea gigas; Phycotoxins; Detoxification; Okadaix acid; Paralytic toxin.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00003/11473/8032.pdf

Les besoins écophysiologiques des larves d'huitres creuse Crassostrea gigas en conditions contrôlees : effet de la température, de la nourriture et modélisation de la croissance
Provedor de dados: 5
Autores: Rico Villa, Benjamin.
Nowadays, spat production of Pacific oyster Crassostrea gigas relies on rearing techniques under controlled conditions in hatchery. In this context, an extensive research in aquaculture is necessary because larval development and metamorphosis are critical for hatchery management. Firstly, a diet consisted in a Haptophyceae: Isochrysis affinis galbana (clone T-ISO) and a Bacillariophyceae: Chaetoceros calcitrans forma pumilum demonstrated its efficiency to supply the nutritional needs throughout the whole larval rearing. Then, a flow-through rearing system was developed and coupled with a continuous hydrobiological data recorder to provide basic information for ecophysiology research through different trophic levels and/or temperature throughout larval...
Tipo: Text
Palavras-chave: Crassostrea gigas; Larve; Huître; Croissance; Ecophysiologie; Microalgues; Température; Système d’élevage; Modélisation; Crassostrea gigas; Larvae; Oyster; Growth; Ecophysiology; Microalgae; Temperature; Rearing System; Modelling.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00012/12308/9102.pdf

Modélisation et analyse numérique du couplage filet-écoulement hydrodynamique dans une poche de chalut
Provedor de dados: 5
Autores: Pichot, Geraldine.
We are interested in the numerical simulation of the catch process at the end part of a trawl. The study of previous works emphasizes the lack of a convincing flow model. The need of a physical understanding of the flow leads us to perform experimental campaigns around a rigid cod-end net model, whose results are given in the manuscript. We propose a model based on the Navier-Stokes/Brinkman equations coupled to an equation for the turbulent kinetic energy by the means of an eddy viscosity, with appropriate boundary conditions. Existence of a weak solution to our coupled problem is proved in dimension 2. Then, we present the axisymmetric code we developed, called SeaNet. We set the parameters of the model and validate the code by comparison with the...
Tipo: Text
Palavras-chave: Finite Element Method; Numerical simulations; Variational formulations; Modelling; Fluid/structure interactions; Turbulence; Fluid mechanics; Selectivity of fishing gear; Méthode des éléments finis; Simulations numériques; Formulations variationnelles; Modélisation; Intéractions fluide/structure; Turbulence; Mécanique des fluides; Sélectivité des engins de pêche.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/these-3350.pdf

Endommagement mecanique de materiaux composites. Role sur les proprietes hygrothermiques
Provedor de dados: 5
Autores: Perreux, D; Suri, C; Varchon, D; Oytana, C.
The mechanical behaviour of polymer based glass fibre composites depends on the damage level and the amount of moisture present. Two anelastic damage models, both adapted to the mechanical properties of epoxy and polyester matrix polymers, are proposed. A coupling effect between the kinetics of damage and moisture level is shown.
Tipo: Text
Palavras-chave: Moisture; Damage; Modelling; Ship technology; Mechanical properties; Composite materials; Humidité; Endommagement; Modélisation; Comportement; Matériau composite.
Ano: 1992
URL: http://archimer.ifremer.fr/doc/1992/acte-1062.pdf

Structure spatiale et cartographie des peuplements benthiques du bassin de Marennes- Oléron : première approche par la méthode du krigeage
Provedor de dados: 5
Autores: Bacher, Cedric; Sauriau, Pierre-guy.
Les peuplements benthiques du bassin de Marennes-Oléron  ont été échantillonnées au printemps 1984 dans le but d'étudier le stock des compétiteurs  des populations de filtreurs cultivés (huître Crassostrea  gigas et moule Mytilus edulis). 370 échantillons ont été prélevés sur une surface d'étude de 18Okm2 en utilisant un plan aléatoire stratifié. Les résultats ont été regroupés en deux groupes d'espèces ayant des stratégies nutritionnelles différentes (mollusques déposivores ou suspensivores).  Ces deux groupes trophiques ont été cartographiés, après une transformation logarithmique en utilisant la technique du krigeage. Pour chaque groupe  trois modèles de structure spatiale ont été utilisés: covariance généralisée, semi-variogrammme unidirectionnel ou...
Tipo: Text
Palavras-chave: France; Estimation stocks; Structure spatiale; Stratification; Peuplement benthique; Bassin Marennes Oléron; Cartographie; Modélisation.
Ano: 1995
URL: http://archimer.ifremer.fr/doc/1995/acte-6863.pdf

État de mer et agitations sur le fond. Sous-région marine Golfe de Gascogne. Evaluation initiale DCSMM.
Provedor de dados: 5
Autores: Ardhuin, Fabrice; Accensi, Mickael.
Tipo: Text
Palavras-chave: Golfe de Gascogne; Etats de mer; Agitation sur le fond; Modélisation.
Ano: 2012
URL: https://archimer.ifremer.fr/doc/00329/44004/43576.pdf

Optimisation des conditions hydrobiologiques pour la conservation de l'huître creuse Crassostrea gigas en système re-circulé
Provedor de dados: 5
Autores: Buzin, Florence.
The maintenance of bivalve commercialisation du ring periods when sales are prohibited represents a major economic issue for shellfish-farming. To ensure their survival and to preserve the oyster Crassostrea gigas quality, their storage in land-based systems has been studied i) out of water in a cold room at 3°C with controlled humidity, enabling the bivalve sensory quality to be retained for 15 days, and ii) in recirculating systems in immersed conditions for 30 days. For the latter, the oysters were stored at 167 kg.m3 density in a tank equipped with an air-lift system, with water treated with UV and thermoregulated. A minimum of food was supplied to avoid mass tissue loss. A temperature of 16°C was defined as optimal to limit mortality and to avoid...
Tipo: Text
Palavras-chave: Crassostrea gigas; Huître Pacifique; Système re-circulé; Ecophysiologie; Sauvegarde; Modélisation; Crassostrea gigas; Pacific oyster; Recirculating system; Ecophysiology; Safeguard; Modelling.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00092/20350/17995.pdf

Modélisation hydrosédimentaire du bassin de Marennes-Oléron
Provedor de dados: 5
Autores: IFREMER - Laboratoire LABEIM La Tremblade; CETIIS - Aix en Provence.
La modélisation de la dynamique sédimentaire est conduite en conformité avec les objectifs susmentionnés. L'étude est scindée en deux parties. En considérant une maille égale à 500 m (au lieu de 1000 m) et la même implantation géographique du maillage, le premier chapitre a pour objectif de valider le calcul hydrodynamique et de diagnostiquer le calcul hydro-sédimentaire dans sa ' nouvelle configuration. Sur la base des résultats précédemment acquis, des choix sont réalisés et appliqués au niveau de la calibration du modèle (chapitre 2). Pour des raisons indépendantes de notre volonté et de nos compétences, le chapitre de l'agitation (houle, clapot) n'a pu être abordé dans le cadre de cette étude.
Tipo: Text
Palavras-chave: Modélisation; Hydro-sédimentologie; Bassin de Marennes Oléron; Modèle hydro-sédimentaire.
Ano: 1994
URL: http://archimer.ifremer.fr/doc/00144/25478/23631.pdf

Ecophysiological deterministic model for Crassostrea gigas in an estuarine environment
Provedor de dados: 5
Autores: Barille, Laurent; Heral, Maurice; Barilleboyer, Al.
An ecophysiological deterministic model of growth, reproduction and interactions between the bivalve and its estuarine environ ment was established for the Japanese oyster Crassostrea gigas. The environmental variables used in the model are: total particulate matter, particulate organic matter, particulate inorganic matter, chlorophyll, phaeopigments, proteins, lipids and carbohydrates. Rates of clearance, filtration, ingestion, absorption and respiration along with efficiencies of retention, selection and absorption are modelled with endogenous (dry weight of the animal, energy allocation between growth and reproduction) and exogenous variables (temperature, food quality and quantity). The model simulate the temporal evolution of two compartments: somatic...
Tipo: Text
Palavras-chave: Crassoslrea gigas; Croissance; Écophysiologie; Modélisation; Turbidité; Crassostrea gigas; Ecophysiology; Growth; Modelling; Turbidity.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00038/14892/12219.pdf

Comportement du cadmium et du mercure lors de la diagenèse précoce et flux à l'interface eau-sédiments en zone littorale
Provedor de dados: 5
Autores: Gonzalez, Jean-louis.
The early diagenesis of Cd and Hg has been studied in different coastal areas (vasière Ouest-Gironde, Pertuis d'Antioche, baie de Marennes-Oléron). For these two metals, the fluxes at the sediment-water interface have been calculated. Considering only molecular diffusion, the diffusionnal fluxes of Cd and Hg to the colurnn water are negligible with regard to both the particular fluxes to the sediments and the inputs of the "Gironde" and "Charente" ·,estuaries. The take into account of the different processes which affect the ex changes at the interface (erosion, bioturbation) permits more realistic an estimation of the role of sediments in the geochemical cycle of Cd and Hg. The results show that up to 50% of particular Cd and Hg which are integrated into...
Tipo: Text
Palavras-chave: Cadmium; Mercure; Eaux intrstitielles; Diagenèse précoce; Flux; Interface eaux-sédiments; Bioturbation; Modélisation; Cadmium; Mercury; Pore waters; Early diagenesis; Fluxes; Sediment-water interface; Bioturbation; Modelling.
Ano: 1992
URL: http://archimer.ifremer.fr/doc/00442/55402/56920.pdf

The influence of variability in larval dispersal on the dynamics of a marine metapopulation in the eastern Channel
Provedor de dados: 5
Autores: Ellien, Celine; Thiebaut, Éric; Barnay, Anne-sophie; Dauvin, Jean-claude; Gentil, Franck; Salomon, Jean-claude.
In the English Channel, the polychaete Pectinaria in koreni forms isolated populations confined in bays and estuaries. To determine the influence of larval dispersal variability on the observed stock fluctuations of the three major Pectinaria koreni populations reported along the French coasts of the eastern Channel, larval dispersal was simulated using a 2D hydrodynamical lagrangian model integrating both the tidal residual and the wind-driven circulation. Year-to-year fluctuations of adult stocks were established from benthic surveys carried out between 1973 and 1998. Larval dispersal patterns vary between populations according to the relative importance of tidal advection and eddy diffusion so that local larval retention is maximal where tidal advection...
Tipo: Text
Palavras-chave: Pectinaria koreni; Metapopulation; Modelling; Recruitment; Larval dispersal; Pectinaria koreni; Métapopulation; Modélisation; Recrutement; Dispersion larvaire.
Ano: 2000
URL: https://archimer.ifremer.fr/doc/2000/publication-535.pdf

États de mer et agitation sur le fond. Sous-région marine Mers celtiques. Evaluation initiale DCSMM.
Provedor de dados: 5
Autores: Ardhuin, Fabrice; Accensi, Mickael.
Tipo: Text
Palavras-chave: Mers celtiques; Etats de mer; Agitation sur le fond; Modélisation.
Ano: 2012
URL: https://archimer.ifremer.fr/doc/00328/43926/43499.pdf

Modélisation du transport sédimentaire et des interactions morphodynamiques par les courants de turbidité dans les canyons sous-marins. Application à la Méditerranée Occidentale
Provedor de dados: 5
Autores: Payo Payo, Marta.
Turbidity currents in submarine canyons are the main contribution for sediment transfer across the continental margins. Geological studies of submarine canyons and associated turbiditic systems for more than 30 years led to an extraordinary breakthrough in the understanding of how turbidite systems evolve. However, these studies remain limited to a posteriori interpretations, based on the distribution of deposits and morphological evidences. The overarching aim of this thesis is to apply a 2DH process-based model to simulate large-scale turbidity currents on two different submarine canyons in the western Mediterranean coast.The work in La Fonera canyon, in the Catalan margin, focuses on the modelling of sediment transport and accumulation resulting from...
Tipo: Text
Palavras-chave: Canyons sous-marins; Chalutage; Courants de turbidité; Forces de Coriolis; Hydrodynamique; Modélisation; Sédimentologie; Submarine canyons; Trawling; Turbidity current; Modelling; Hydrodynamics; Sedimentology; Coriolis forces.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00498/60919/64280.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

Cartographie du marais salé de Charente Maritime
Provedor de dados: 5
Autores: Le Moine, Olivier; Geairon, Philippe; Razet, Daniel.
Our objectives can be broken down into two main axes: -Mapping of the swamp and of its use - Thematic mapping of the trophic availability of the hydraulic units. Data acquisition has been continued throughout the year 2003 To do so, a number of technical adjustments have been necessary. In this final phase of the contract, a new point of view has been tackled: that of modelisation. Indeed, considering the complexity of the calculations used, the evaluation of the trophic availability in the different hydraulic units requires the use of such techniques and software. Spatial analyses have been continued, and a number of models aimed at simplifying measurement acquisitions have been created.
Tipo: Text
Palavras-chave: Modélisation; Traitement spatiaux; Cartographie; Charente Maritime; Zone littorale; Marais.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/rapport-6377.PDF

Rapport d'activité 2002 du Laboratoire Conchylicole de Poitou-Charentes de La Tremblade
Provedor de dados: 5
Autores: Le Moine, Olivier; Soletchnik, Patrick; Robert, Stephane; Prou, Jean; Guilpain, Patrice; Geairon, Philippe; Razet, Daniel.
La compétence géographique assurée par le laboratoire dans ses fonctions concerne l'ensemble des Pertuis Charentais depuis le Sud-Vendée jusqu'à l'embouchure de la Gironde. Ce rapport d'activité tient compte de ces faits et présente par ailleurs les programmes de recherche selon la nomenclature établie dans le cadre du Plan Stratégique de l' IFREMER, des grands défis et dans la définition des mandats de laboratoires.
Tipo: Text
Palavras-chave: Rapport activité; Réseaux surveillance; Bactériologie; Microbiologie; REMORA; REMOULA; Ecosystème conchylicole; Modélisation; Marennes Oléron.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/00074/18555/16106.pdf

Modèle énergétique uniboite de la croissance des huîtres (Crassostrea gigas) dans le bassin de Marennes-Oléron
Provedor de dados: 5
Autores: Bacher, Cedric; Heral, Maurice; Deslous-paoli, Jean-marc; Razet, Daniel.
The growth of oysters (Crassostrea gigas) is modeled in order to study the trophic capacity of the Bay of Marennes Oléron. Total seston and amount of protids, lipids, and carbohydrates converted to energy are the environmental factors taken into account. Time series of these variables are derived during 2 yr with a daily time step from a linear regression including the tidal velocity, the height of the water column, and the wind velocity. A model of the energetic budget based on assimilation and respiration terms and depending on the previous time series is run to simulate the individual growth of an oyster. The knowledge of the number of oysters, the flow of water entering the bay, and the volume of the bay allows us then to estimate that 7% of the...
Tipo: Text
Palavras-chave: Marennes Oléron; Crassostrea gigas; Huîtres; Croissance; Modélisation; Marennes Oleron bay; Crassostrea gigas; Oysters; Growth; Modelisation.
Ano: 1991
URL: http://archimer.ifremer.fr/doc/1991/publication-3051.pdf

États de mer et agitation sur le fond. Sous-région marine Manche - Mer du Nord. Evaluation initiale DCSMM.
Provedor de dados: 5
Autores: Ardhuin, Fabrice; Accensi, Mickael.
Tipo: Text
Palavras-chave: Manche; Mer du Nord; Etats de mer; Agitation sur le fond; Modélisation.
Ano: 2012
URL: https://archimer.ifremer.fr/doc/00327/43822/43396.pdf

Implantation sur le modèle courantologique Oko des lois de remise en suspension
Provedor de dados: 5
Autores: Raillard, Olivier.
Cette étude a pour but d'introduire dans le modèle de production globale du bassin de Marennes-Oléron une nouvelle source de variabilité des teneurs de la colonne d'eau en éléments particulaires par la prise en compte des échanges verticaux à l'interface eau-sédiment. Dans la précédente formulation du modèle les biodépots, alors la seule source d'alimentation du fond, sont instantanément remis en suspension. Toutefois la faible bathymétrie ainsi que des régimes de courants et de vents variables déterminent des variations importantes dans les concentrations du matériel particulaire (Bacher, 1989) susceptibles d'influer sur la production biologique primaire et secondaire (fig. 1). Ces échanges conditionnent en partie les fluctuations de quantité de lumière...
Tipo: Text
Palavras-chave: Courantologie; Modélisation; Erosion; Sédimentation; Marennes Oléron; Département Charente-Maritime.
Ano: 1990
URL: http://archimer.ifremer.fr/doc/00146/25741/23844.pdf

Etude de déploiement d'un réseau LoRa en mer
Provedor de dados: 5
Autores: Damour, Valentin.
This report is about the work realized during a part time training at Ifremer. The subject discussed in this paper will associate the maritime field and the computer science field. It proves that computer science is really a  multipurpose domain. In a context of global warming and human pressure (pollution and ressources over-exploitation), the marine ecosystem is jeopardized. In order to have a better understanding of the situation of this habitat and to stem these brutal changes, it is important to observe and gather information about it. It is exactly the goal of the project I took part in. This project mainly deals with observing sea turtles in their natural habitat. Thoses observations are realized thanks to LoRa equiped tags which are implanted on...
Tipo: Text
Palavras-chave: Réseau tolérant au délai; Océan Indien; Tortues marines; Modélisation; Delay-tolerant network; Indian Ocean; Sea turtles; Modeling.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00612/72364/71279.pdf

Application de la Programmation Stochastique Discrète à l’évaluation de l’impact de la contrainte de crédit sur le revenu et la production agricoles dans la basse vallée de l’Ouémé
Provedor de dados: 31
Autores: Kpadonou,   Rivaldo A.B.; Adegbola,   Patrice Ygue; Tovignan,   Silvere D.
Malgré la mise en oeuvre des différentes politiques d’ajustement structurels découlant de l’option du libéralisme économique, l’économie béninoise peine toujours à décoller avec une agriculture à dominance familiale et traditionnelle, subvenant difficilement aux besoins des populations sans cesse croissantes. Les ménages agricoles ruraux vivent toujours dans des situations contraignantes de crédit qui sont souvent considérées comme faisant partie des contraintes majeures au développement agricole du pays. Ainsi, au regard de l’importance accordée au crédit dans les programmes de développement, cette étude s’est proposée d’analyser la vulnérabilité des exploitations agricole à la contrainte de crédit d’une part et, d’autre part, de faire une évaluation ex...
Tipo: Conference Paper or Presentation
Palavras-chave: Programmation linéaire; Modélisation; Production; Revenu agricole; Bénin; Agricultural Finance.
Ano: 2010
URL: http://purl.umn.edu/96824