Consulta: subjectFacets:"Estuaire"
Registros recuperados: 36
Data/hora: 09/06/2024 09:45:51

Étude par télédétection de la dispersion en mer des eaux estuariennes issues de la Gironde et du Pertuis de Maumusson
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Castaing, P; Allen, Gp; Houdart, Michel; Moign, Y.
The objective of this study, carried out in the Gironde estuary inlet, was to determine the nature of the seaward dispersion of estuarine water and suspended sediments during a spring tide and high river flow. On June 3, 19(7, three flights were made over the inlet, at mid ebb, low tide and mid flood. The planned flight at high tide was cancelled due to adverse meteorological conditions. During each flight, thermal infrared coverage was obtained, together with black and white photographs. These data were correlated with concomitant ground mesures of current velocity, salinity, temperature and suspended sediment concentration Four types of water masses were identified during the tidal cycle: estuarine "very warm and turbid" water; estuarine "cooler and...
Tipo: Text
Palavras-chave: Hydrodynamique; Suspensions; Télédétection; Eaux côtières; Estuaire; Gironde; Hydrodynamic; Suspended sediments; Remote sensing; Coastal waters; Estuary; Gironde.
Ano: 1979
URL: http://archimer.ifremer.fr/doc/00122/23361/21188.pdf

Impact du barrage d'Arzal sur la qualité des eaux de l'estuaire et de la baie de la Vilaine
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Merceron, Michel.
The Arzal dam upon the Vilaine estuary provokes an aggravation of a recurrent summer hypoxia of the bottom waters in the bay of  Vilaine.
Tipo: Text
Palavras-chave: Suspended sediments; Salinity; Coastal zone; Dam estuary; Oxygen depletion; Matières en suspension; Salinité; Zone côtière; Estuaire; Barrage; Anoxie.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/1989/rapport-2658.pdf

Cycle du mercure en estuaire, baie de Seine et pays de Caux
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Laurier, Fabien.
The Seine estuary and its adjacent region Pays de Caux are two significant sources of mercury for coastal marine environments. It is carried through fluvial means for the Seine bay and through karstic fresh water emergences for Pays de Caux's coastal area.  Mercury cycle in the Seine estuary and bay is affected by additional anthropical activities. The estuary's maximal turbidity area acts like a trap and a chemical reactor for fluvial mercury. Within this area, we can confirm: (i) the non conservative behaviour of dissolved mercury; (ii) mercury enrichment of particles when comparing the Seine's and marine environment and we suggest mercury particle redistribution from the organic fraction to the oxyhydroxydes fraction. A large fraction of mercury is...
Tipo: Text
Palavras-chave: Bay of Seine; Pays de Caux; Estuary; Coastal zone; Speciation; Bioavailability; Mercury; Pays de Caux; Seine; Estuaire; Emergence; Zone côtière; Spéciation; Biodisponibilité; Mercure.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/these-1842.pdf

Spéciation des contaminants métalliques en milieu estuarien : Intérêt de la modélisation et application au cadmium
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
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

Les virus de l'estuaire de la Charente el du bassin de Marennes-Oleron. Dynamiques spatio-temporelles et  interactions avec les communautés bactériennes
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Auguet, Jean-christophe.
This study is divided in two parts; one aim is to evaluate the in situ spalio-temporal dynamics of viral communities  in the Charante estuary in order to define the appropriate seasons to conduct in vitro viral enrichment experiments. These experiments, that constitute the second part of this study, were performed to assess the impact of freshwater viruses carried by the Charante River on the dynamics and composition of coastal bacterial communities. With abundance ranging from 1.4 x 107 to 208 x I07 VLPml-1. viruses are the most abundant component among plankton microorganisms in surface waters of the Charente estuary. Thre temporal dynamics of this component reflects the indirect influence of temperature through the control of bacterial abundance,...
Tipo: Text
Palavras-chave: Richesse spécifique; Composition clonale; Enrichissement vital; Infection lyrique; Structure des communautés; MET; PPGE; Dynamique temporelle; Gradient de salinité; Estuaire; Bactérioplancton; Virioplancton; Species richness; Clonal composition; Viral enrichment; Lytic infection; Community structure; Diversity; TEM; PEGE; Temporal dynamic; Gradient; Salinity; Estuary; Bacterioplankton; Virioplankton.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/these-3071.pdf

La gestion de l'eau douce en Seudre
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Masson, Daniel.
Suedre River, a small river in Charente-Maritime, is 45 km long and drains a 380 km2 river basin. Its flow rate is about 20 m3.s(-1). Beyond the Saujon agglomeration, the river extends to the sea via a 25-km long estuary which, through the action of tides, becomes a sea arm reaching 1 km in width. Freshwater and salt marshes line the banks of the Seudre River. Freshwater marshes are occupied by large cattle farms and intensive, irrigated crops. Salt marshes are used for oyster finishing—the final, fattening process in oyster farming. The coexistence of both types of activity is sometimes problematic, particularly in terms of water management, a frequent source of conflict. The climate in Charente-Maritime is characterised by dry summers and rainy winters,...
Tipo: Text
Palavras-chave: Ostréiculture; Agriculture; Eau douce; Gestion eau; Seudre; Charente Maritime; Estuaire.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/1997/acte-3211.pdf

Géochimie du mercure dans le continuum de la retenue de Petit-Saut et de l'estuaire du Sinnamary, Guyane française
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Muresan Paslaru, Bogdan.
The mercury cycle was explored in the Petit-Saut reservoir / Sinnamary Estuary continuum in French Guiana. Main processes involve (i) photo-induced reduction, (ii) adsorption and desorption at the particle surfaces, (iii) methylating bacterial activity, (iv) precipitation and dissolution of iron oxyhydroxides and sulfides. Sources of mercury to the Petit-Saut reservoir consist of the partly impacted river-tributaries, the atmospheric deposition and the flooded soils or vegetation. Once into the reservoir, divalent mercury undergoes a large spectrum of transformations including speciation and phase changes. We, here, probe these processes and demonstrate that the Petit-Saut reservoir behaves as a privileged site for atmospheric recycling and in situ...
Tipo: Text
Palavras-chave: Atmosphere; Estuary; Reservoir; French Guiana; Methylmercury; Mercury; Atmosphère; Estuaire; Retenue; Guyane française; Methylmercure; Mercure.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/these-1508.pdf

Impact du régime du barrage d'Arzal sur la stratification a l'embouchure de la Vilaine : étude par modélisation numérique
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Le Hir, Pierre; Duchene, C.; Merel, A; De Nadaillac, G.; Merceron, Michel; Breton, Marguerite.
The rate of flow of the fresh water releases at the Arzal Dam into the Vilaine is likely to influence the haline structure of Vilaine Bay. In order to determine the rate of flow that causes a minimum downstream stratification, a vertical two-dimensional mathematical modelling of the Vilaine's estuary was undertaken. We obtain very similar stratification flows for different fresh water release scenarios, in spite of the rather different desalinisations and currents.
Tipo: Text
Palavras-chave: Water release; Stratification; Estuary; Numerical model; Vilaine; Rejet de barrage; Stratification; Estuaire; Modèle numérique; Vilaine.
Ano: 1986
URL: https://archimer.ifremer.fr/doc/1986/rapport-2654.pdf

Incidence du débit de la Charente sur la capacité biotique du bassin ostréicole de Marennes-Oléron
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Ravail, Brigitte; Heral, Maurice; Maestrini, Serge; Robert, Jean-michel.
The estuary of Charente can be considred as a vast natural zone of mixing brackish waters and marine waters of Marennes-Oleron. One part of the cruises engaged from October 1985 to November 1987, allowed to dfine the main hydrobiological features of the estuary and to estime the input of the river Charente. Cruises permitted to establish the general hydrobiological schema of the estuarine bay and showed that the river Charente does play a part in the salinity and nitrogen inputs on marine waters.
Tipo: Text
Palavras-chave: Estuaire; Charente; Marennes-Oléron; Panache de dispersion; Eaux douce; Impact.
Ano: 1988
URL: http://archimer.ifremer.fr/doc/00015/12663/9552.pdf

Caractérisation de la contamination microbiologique d'origine fécale de l'estuaire de la Seudre en période sèche
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Piquet, Jean-come; Fillon, Alain; Thomas, Gerard.
L’estuaire de la Seudre est situé dans le bassin de Marennes-Oléron, au cœur de l’écosystème des Pertuis Charentais. L’estuaire alimente la majorité des surfaces de claire de la région, qui elle même, assure plus de la moitié de la commercialisation nationale. La contamination microbiologique de l’estuaire de la Seudre est donc un enjeu majeur pour l’ostréiculture. L’estuaire possède un bassin versant de faible dimension et dont le fonctionnement hydrologique est particulier. Il est relié à un très important ensemble de zones humides, et les débits d’eau douce sont dépendants de la gestion d’ouvrages hydrauliques. Les périodes d’étiage sont sévères et longues, et les apports d’eau douce à l’estuaire sont quasiment nuls en fin d’été et en début...
Tipo: Text
Palavras-chave: Microbiologie; Contamination microbiologique; Bactériologie; Estuaire; Seudre; Charente Maritime.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00129/24048/22011.pdf

Complexity in trophic structure and stability in a modelled West African estuary
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Villanueva, Ching-maria; Diouf, P.s.; Albaret, J.-j.; Moreau, J.
Un modèle Ecopath de l'estuaire du Sine-Saloum (Sénégal) comportant au total 37 groupes fonctionnels a été appliqué dans la présente étude en vue de déterminer les faits essentiels de ce système aquatique. La grande biodiversité spécifique des poissons de l'écosystème peut y jouer un rôle en assurant son intégrité, spécialement en présence de facteurs de stress, bien qu'il ait été observé que ce n'est pas entièrement le cas. Les résultats montrent qu'un autre facteur de mitigation est le niveau des forces d'interaction entre les groupes fonctionnels. La stabilité est accrue par des relations plus faibles et des pyramides plus courtes et plus larges. Bien que différentes questions se posent concernant les facteurs conduisant à la stabilité d'un système, les...
Tipo: Text
Palavras-chave: Stabilité des systèmes; Sénégal; Omnivorie; Estuaire; Ecosystème côtier; Ecopath; Biodiversité; Afrique de l'Ouest; West Africa; System Stability; Senegal; Omnivory; Estuary; Ecopath; Coastal Ecosystem; Biodiversity.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-2554.pdf

Phytoplankton production in the Tagus estuary (Portugal)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Cabecadas, L.
Biomass and phytoplankton photosynthetic response were studied in the lower Tagus estuary weekly, and related to environmental conditions in February, March and April 1994. The Photosynthesis-Irradiance ((P-I)-I-B) relation was studied based on the light-saturated photosynthesis rate (P(B)m) and the light-limited initial slope (a(B)). The nutrient concentrations observed were high enough to be considered as not limiting phytoplankton growth. Tagus estuary phytoplankton seems, to a certain extent, adapted to high turbid conditions, being able to utilize the low light levels more efficiently, which was translated by high values of a(B) [0.10-0.20 mg C (mg Chl a)(-1) h(-1) (W m(-2))(-1)]; however, light seems to limit phytoplankton production in the water...
Tipo: Text
Palavras-chave: Production primaire; Phytoplancton; Estuaire; Biomasse; Turbidité; Primary production; Phytoplankton; Estuary; Biomass; Turbidity.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/00325/43621/43310.pdf

Modélisation mathématique de l'oxygène dissous dans l'estuaire de la Loire. Première phase
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Thouvenin, Benedicte; Romana, Louis-alexandre.
Depuis plusieurs années, on observe en période post-estivale un très important déficit en oxygène dissous dans l'estuaire de la Loire, accompagné par une mortalité élevée de certaines espèces halieutiques migratrices. L'origine de cette anoxie est imputée au stock de matière organique particulaire biodégradable qui est piégée dans la zone de turbidité maximale. A la demande de l'Association pour la Protection de l'Environnement de l'Estuaire de la Loire, un modèle mathématique a été mis en place pour décrire les mécanismes hydrodynamiques et hydrosédimenraires dans l'estuaire, ainsi que l'évolution de l'oxygène dissous et la dégradation de la matière organique. Dans une première phase, ce modèle reproduit l'évolution longitudinale et temporelle de...
Tipo: Text
Palavras-chave: Modèle mathématique; Estuaire; Loire; Oxygène dissous; Matière organique.
Ano: 1992
URL: http://archimer.ifremer.fr/doc/00439/55039/56471.pdf

La Charente, un estuaire conchylicole
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Thomas, Gerard; Kantin, Roger; Heral, Maurice.
A coastal river 380 km long, the Charente river has a catchment area of about 10,000 km2, flowing through the departments of Charente and Charente-Maritime, as well as a small part of the border departments: Dordogne, Deux-Sèvres, Haute-Vienne and Vienne. Its main affluents are the Tardoire, the Seugne and the Boutonne rivers. The highest part of the catchment area is located in Dordogne, at a height of 496 m, whereas the river itself originates from a spring located at a height of 250 m to the south-east of Rochechouart, in the Haute-Vienne. The average height of the catchment area is quite low. In its downstream part, from the Saint-Savinien dam to the ocean, the Charente is influenced by a dynamic tide. The actual estuarine part begins in...
Tipo: Text
Palavras-chave: Charente Maritime; Gestion eau; Qualité eaux; Conchyliculture; Capacité trophique; La Charente; Estuaire.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/1999/publication-6289.PDF

Sulfate-reducing bacteria [rom mangrove swamps II : Their ecology and physiology
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Bharathi, Pal; Oak, S; Chandramohan, D.
Sulfate-reducing bacteria (SRB) have been enumerated and physiologically characterized in three mangrove stations along the Zuari estuary. The substrates for counting were lactate, acetate, propionate, butyrate and benzoate. Benzoate oxidizing SRB were widespread and occurred in numbers up to 6.62 x 10(3)/g dry sediment. The next highest in number were lactate utilizing SRB. On an average there were more propionate and butyrate utilizers than acetate utilizers. While Agasaim at the mouth of the estuary harboured highest number of lactate oxidizers, none were detected at Mirabaug upstream during the samplings. The SRB shared many characteristics with Desulfovibrio desulfuricans, D. desulfuricans aestuarii, D. salexigens, Desulfotomaculum orientis, D....
Tipo: Text
Palavras-chave: Bactéries; Sulfato-réductrices; Estuaire; Sédiments; Mangrove; Mangrove-Bacteria; Sulfate-reducers; Estuary; Sediments.
Ano: 1991
URL: http://archimer.ifremer.fr/doc/00323/43395/43103.pdf

Evolution de la température et de la salinité dans l'estuaire de la Charente de juin à novembre 1999
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Robert, Stephane; Razet, Daniel; Goulletquer, Philippe; Soletchnik, Patrick; Geairon, Philippe; Le Moine, Olivier; Faury, Nicole; Mineur, Frederic; Seugnet, Jean-luc.
L'aménagement du fleuve Charente constitue un enjeu particulièrement important tant au niveau des activités de la bande côtière que pour le bassin versant. Au niveau du littoral charentais, et en particulier pour la conchyliculture, le fleuve Charente représente le principal apport d'eaux douces, et donc d 'éléments nutritifs, essentiels au développement de la production primaire et des larves d'huîtres. Ainsi, les apports d'eau douce sont importants pour le développement du phytoplancton (printemps, été, automne), le développement des larves d'huîtres en période estivale qui requiert une dessalure, et la qualité des huîtres en fin d'année. Les suivis des caractéristiques de la Charente sont par conséquent particulièrement importants et ont déjà fait...
Tipo: Text
Palavras-chave: Salinité; Température; Evolution temporelle; Estuaire; Paramètres hydrologiques; Charente; Bassin de Marennes Oléron.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00072/18363/15935.pdf

La contamination de la Gironde par le cadmium : origine, extension, importance
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Boutier, Bernard; Chiffoleau, Jean-francois; Jouanneau, Jean-marie; Latouche, Claude; Philipps, Isabelle.
In 1979, the French monitoring program RNO (Réseau National d'Observation de la qualité du milieu Marin) pointed out a dramatic cadmium contamination in the oysters from the Gironde estuary (up to 100 ug -1, dry weight). The wild oyster-beds upstream the estuary were shown to be the most contaminated. This result tends to point to the river as the source of the cadmium contamination. At the same rime, uncontaminated oysters from Arcachon were transplanted in the Gironde estuary (La Fosse, Dau). This ex periment confirmed the importance and proved the permanence of the contamination. Very high concentrations of dissolved cadmium (400 ng. 1-1) were measured in the estuarine mixing zone. This phenomenon can be explained by the desorption of cadmiumfrom...
Tipo: Text
Palavras-chave: Cadmium; Désorption; Estuaire; Bilan géochimique; Contamination des huîtres; Cadmium; Desorption; Estuary; Geochemical budget; Oyster contamination.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/00167/27820/26013.pdf

Transformation de la phase solide à travers l’estuaire de la Loire en relation avec son environnement chimique et biologique
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Thibault De Chanvalon, Aubin.
Before reaching the ocean, riverine particles from the Loire watershed undergo important chemical transformations in the estuary. This study aims to identify and characterize main processes involving iron (and to a lesser extent Al, Mn, PO4 3- and rare earths elements). Suspended particulate matter data show that 15% of their iron is lost through the estuary. Reductive iron dissolution during deposition periods is likely to explain most of this loss. However, estuarine sediments are characterized by high spatial heterogeneity due to macrofaunal activities. To overcome this difficulty, new methodologies of high resolution and two-dimensional analyses and calculation of pore water, sediment and benthic meiofauna were developed. These developments enable to...
Tipo: Text
Palavras-chave: Estuaire; Fer; Phosphore; Nitrate; Foraminifère benthique; Diagenèse précoce; Loire; Bioturbation; Estuary; Iron; Phosphorus; Nitrate; Benthic foraminifera; Precocious diagenesis; Loire; Bioturbation.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00498/60932/64325.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: Institutional Archive of Ifreme (ArchiMer)
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

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: Institutional Archive of Ifreme (ArchiMer)
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

Etat de la pollution par les hydrocarbures dans l'Aber Benoit
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Allen, G.; D'Ozouville, Laurent; L'Yavanc, Jacky.
The Aber Benoît, a small estuary on the North West coast of Brittany was polluted by oil from the Amoco Cadiz oil spill. Preliminary results from water and sediment samples taken in the estuary in May 1978, show that two months after the initial spill, high concentrations of hydrocarbures existed in the water and sediments of the estuary. The Aber Benoît shows a well developed salt wedge and upstream increasing suspended sediment concentrations. Oil was dispersed more or less evenly throughout the water column, in the entire length of the estuary. In the bottom sediments, oil had accumulated to depths of 30 cm. Sand bars appear to induce a trapping of oil in the estuary channel.
Tipo: Text
Palavras-chave: Estuaire; Sédiment; Pollution Hydrocarbures; Estuary; Sediment; Oil spill.
Ano: 1978
URL: http://archimer.ifremer.fr/doc/00306/41721/40932.pdf

The effect of tidal range on the flushing of ammonium from intertidal sediments of the Tagus estuary, Portugal
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Cabrita, Mt; Catarino, F; Vale, C.
The time-course evolution of ammonium concentration has been examined in the flood water during the first 25 min of tidal inundation. The way this transport fluctuates with the tidal ranges and wind conditions was investigated. Flood water was collected at three sites, located along a transect from the lower to the upper intertidal area of the Tagus estuary. At spring and intermediate tides, the periods of air exposure vary slightly along the transect due to the high tidal amplitude and the flatness of the area, but the upper site remains uncovered at neap tide over the entire tidal cycle. At each site, sampling was performed at different tidal ranges covering the neap-spring tidal cycle and wind conditions. Ammonium was determined in the flood water at...
Tipo: Text
Palavras-chave: Extraction par la marée; Ammonium; Sédiment intertidal; Estuaire; Tidal flushing; Ammonium; Intertidal sediments; Estuary.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/00325/43611/43908.pdf

Biologie et pêche traditionnelle des crevettes pénéides dans l'embouchure d'un fleuve en milieur semi-aride (sud-ouest de Madagascar)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Laroche, Jean; Benoely,; Siaviri, A.
Traditional fishing using beach seines was studied over a period of one year at the mouth of the Onilahy river. The catches/efforts were recorded on a daily basis, biological sampling and the measurement of hydrological parameters being carried out twice a month. The moderate variations of salinity and temperature (14 &lt; salinity &lt; 35; 25 degrees C &lt; temperature &lt; 30 degrees C) which were observed in the estuary can be explained by the semiarid climate of the area. Four species of penaeid shrimps are to be found on the Onilahy: Metapenaeus monoceros, Panaeus indicus, Penaeus monodon and Penaeus japonicus, which were mainly caught at the subadult/adult stage with a Carapace length between 10 and 50 mm. The presence of these important sizes at the...
Tipo: Text
Palavras-chave: Pêche; Estuaire; Dynamique population; Croissance; Taille corporelle; Cycle évolutif; Zone semi aride; Madagascar; Penaeus japonicus; Penaeus monodon; Penaeus indicus; Metapenaeus monoceros; Rivière Onilahy; Afrique; Milieu saumâtre; Macrura; Decapoda; Crustacea; Arthropoda; Invertebrata; Fishing; Estuaries; Population dynamics; Growth; Body size; Life history; Semi arid zone; Malagasy Republic; Penaeus japonicus; Penaeus monodon; Penaeus indicus; Africa; Brackish water environment; Macrura; Decapoda; Crustacea; Arthropoda; Invertebrata.
Ano: 1995
URL: http://archimer.ifremer.fr/doc/00097/20828/42822.pdf

Les prises accessoires de la pêcherie de civelles (Anguilla anguilla) dans l'estuaire de la Loire en 1987
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Guerault, Daniel; Desaunay, Yves; Bellois, Pierre; Grellier, Patrick; Robin, Jean-paul; Robineau, Brigitte.
A survey of the glass-eel fishery in the Loire estuary in 1987 (265 boats, 117 tons gasseel, 13733 fishing trips) showed that 16 fishery species constitute the by-catch (49,3 million individuals, mainly juveniles, among which 98 % consist in flounder, sprat and brown shrimp). The analysis of catches in space and time leads to proposaIs for Iimiting the impact during the last fishing weeks. Taking into account the naturai mortality rates of the concerned juveniles, an attempt is made to estimate the actuai impact of the glasseel fishery, after a delay. Only 10 % of the caught brown shrimps wouid have been recruited in the summer shrimp fishery. Up to 85,5 to 97,6 % of juvenile fishes would have disappeared during the following year by natural mortality.
Tipo: Text
Palavras-chave: Anguille; Pêcherie; Prises accessoires; Estuaire; Loire; Eel; Fishery; By catch; Estuary; Loire.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/00120/23102/20951.pdf

Influence de l'apport de la Charente sur la qualité bactériologique des eaux de l'estuaire - Campagnes 1988 et 1989
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Masson, Daniel; Faury, Nicole; Ratiskol, Jacqueline.
Le bassin de Marennes Oléron, comme toutes les zones conchylicoles, est susceptible d'être touché par les apports pollués. Dans ce domaine, le vecteur potentiel que constitue la Charente méritait d'être étudié plus particulièrement, la qualité bactériologique des eaux pouvant affecter par la suite la salubrité des coquillages. L'étude précédente (Masson et al. 1988) a fait apparaître que la pollution bactérienne apportée par la Charente (particulièrement en étiage) sédimentait rapidement, la quantité de germes devenant très faible à la sortie de l'estuaire. Toutefois, comme l'enjeu économique est important (perspectives européennes) il était nécessaire de confirmer ce résultat avec un système de suivi identique à celui utilisé en 1987. De plus, un certain...
Tipo: Text
Palavras-chave: Bactériologie; Qualité eaux; Salubrité coquillages; Pollution bactérienne; Estuaire; Charente; Charente Maritime Dep.
Ano: 1990
URL: http://archimer.ifremer.fr/doc/00087/19827/17469.pdf

Mortalites de poissons en baie de Vilaine (Juillet 1982) Causes - Mécanismes - Propositions d'action
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Merceron, Michel.
The massive number of fish mortalities that occurred in July of 1982 in Vilaine Bay is due to a very pronounced oxygen depletion in the bay's bottom waters. This loss was caused by the chronic fragility of this area, associated with an abnormal weather pattern. The endemism of partial oxygen depletion has been brought to light. The latter could be economically more significant than the anoxia of 1982. Preventative and warning actions have been proposed.
Tipo: Text
Palavras-chave: Brittany; Dam; Estuary; Meteorological factors; Stratification; Phytoplankton; Oxygen depletion; Coastal waters; Fish kill; Estuaire; Facteurs météorologiques; Stratification; Prolifération planctonique; Déficit en oxygène; Eaux côtières; Mortalité de poisson.
Ano: 1987
URL: http://archimer.ifremer.fr/doc/1987/rapport-2836.pdf

Dynamique sédimentaire et évolution holocène d'un système macrotidal semi-fermé : l'exemple de la rade de Brest
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Gregoire, Gwendoline.
The bay of Brest is a tide-dominated, semi-enclosed coastal basin, which is connected with two rivers (Aulne and Elorn). Its jagged shoreline and seabed morphology constitute an ideal setting to understand sedimentary transfer at the land-sea interface. In this aim, this study is divided in two different time scale. The first (a) focuses on the present-day sedimentary bedload dynamic and the second (b) on the reconstruction of the Holocene infilling, during the last marine transgression. (a) A analyse combining a sedimentology approach and numerical has highlighted the major control of the tidal currents. Swells and rivers have a minor impact, because the inherited morphology accentuates and promotes tidal currents. There are responsible of a shelly sandy...
Tipo: Text
Palavras-chave: Dynamique sédimentaire; Holocène; Paléo-vallée; Estuaire; Système côtier; Rade de Brest; Carottages; Sismique-réflexion; Imagerie; Bathymétrie; Seismic reflection; Coastal system; Bay of Brest; Coring; Paleo-valley; Estuary; Sedimentary dynamic; Backscatter imagery; Bathymetry.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00498/60920/64282.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: Institutional Archive of Ifreme (ArchiMer)
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

Température et salinité dans l'Aber Benoît et l'Aber Wrach été 1991, rapport de mesures
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Merceron, Michel; Gaffet, Jean-dominique.
This report displays the data of temperature and salinity from the records performed in the Aber Wrach and Aber Benoît estuaries during the summer 1991. This work was decided after a massive oyster kill in the Aber Benoît estuary.
Tipo: Text
Palavras-chave: Brittany; Estuary; Salinity; Temperature; Bretagne; Estuaire; Salinité; Température.
Ano: 1991
URL: http://archimer.ifremer.fr/doc/1991/rapport-2659.pdf

Etude des nourriceries de la Baie de Seine orientale et de l'estuaire de la Seine
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Morin, Jocelyne; Riou, Philippe; Bessineton, Christophe; Vedieu, Christophe; Lemoine, Michel; Simon, Serge; Le Pape, Olivier.
This study, carried out from 1995 to 1997, within the framework of "Le Havre" harbour extension project, concerned halieutic populations and the characterization of a coastal nursery in the oriental part of the Seine bay and the Seine estuary . The main objective was to describe the specific and demographic composition of marine populations and their spatio-temporal distribution, and so assess the biological and halieutic role of this area. This study also included a research about the dietary needs of fish juveniles living in the estuary.  Autumn and winter surveys results show that the estuary and area under direct influence are the richest from a biological and halieutic point of view. The mouth estuary isthe richest area in terms of diversity of...
Tipo: Text
Palavras-chave: Bay of Seine; Estuary; Food; Trophic; Juvenile; Nursery; Baie de Seine; Estuaire; Alimentation; Trophique; Juvénile; Nourricerie.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/1999/rapport-1507.pdf

Eléments nutritifs limitant la biomasse phytoplanctonique d'une lagune tropicale de Côte d'Ivoire. Comparaison des méthodes d'estimation
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Dufour, P.; Cremoux, Jl.; Slepoukha, M.
"In vitro" enrichment experiments on natural populations have been used to determine the nutrients controlling the potential biomass of phytoplancton in the Ebrié coastal lagoon. The limiting nutrients were generally nitrogen, phosphorus and carbon, in this order ; in three cases out of eleven, P and N act simultaneously ; in an extreme eutrophication case, N, P and C were all limiting. No effect was observed following addition of metals, vitamins or chelators. The limitations deduced from the enrichment experiments show a. good agreement with the elementary composition of the external medium ; in waters potentially limited by N alone, the dissolved inorganic nutrients have a N : P ratio lower than 25. The agreement is poorer when the sestonic N : P ratio...
Tipo: Text
Palavras-chave: Lagune; Estuaire; Zone tropicale; Phytoplancton; Biomasse; Eléments limitants; Tests biologiques; Composition chimique; Coastal lagoon; Estuary tropical zone; Phytoplankton; Biomass; Limiting nutrients; Bioassay; Chemlcal composition.
Ano: 1979
URL: http://archimer.ifremer.fr/doc/00306/41689/40898.pdf

Analyse des tendances des séries temporelles de la concentration en azote minéral dissous dans les trois principaux estuaires de la façade Manche-Atlantique
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Gailhard, Isabelle.
Estuaries are areas which, from their structure, their fonctioning, and their localisation, are subject to significant contribution of nutrients. One of the objectif of the RNO, the French network for coastal water quality monitoring, is to assess the levels and trends of nutrient concentrations in estuaries. A linear model was used in order to describe and to explain the total dissolved nitrogen concentration evolution in the three most important estuaries on the Chanel-Atlantic front (Seine, Loire and Gironde). As a first step, the selection of a reliable data set was performed. Then total dissolved nitrogen evolution schemes in estuary environment were graphically studied, and allowed a resonable choice of covariables. The salinity played a major role...
Tipo: Text
Palavras-chave: Nutriments; Estuaire; Loire; Seine; Gironde; Schéma de dilution; Modèle linéaire; Tendance; Nutrients; Estuary; Seine; Loire; Gironde; Dilution schema; Linear mode1; Trend.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00079/19070/16665.pdf

Les polychlorobiphenyles ( PCB ) en Baie de Seine
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Abarnou, Alain.
PCB contamination and i ts relationship wi th suspended particulate matter (SPM) have been studied in water from the Seine estuary and the baie de Seine, in July 1985 and February 1986. PCB chromatograms are very similar and characterize a chronic contamination. PCB concentrations vary from 2 ng/l in the marine zone up to 210 ng/l in the estuary. SPM and PCB concentrations are weIl correlated. Highest PCB concentrations are measured in February due to higher SPM inputs mainly made of finer particles.
Tipo: Text
Palavras-chave: PCB; Seine; Fleuve; Estuaire; Baie; Matières en suspension; PCB; Seine; River; Estuary; Bay; Suspended particulate matter.
Ano: 1988
URL: http://archimer.ifremer.fr/doc/00138/24924/23020.pdf

Bilan des connaissances sur la Rive Droite de la Gironde
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Jouanneau, J. M.
Ce mémoire a pour objet de faire très succinctement le point des connaissances acquises à la fin de 1973 sur la rive droite de la Gironde. L'étude traite essentiellement des données de la géologie générale ; de la sédimentologie, de l'hydrologie et de la géochimie. Il y a été ajouté un chapitre sur l'écologie; cette discipline est en effet liée à plus d'un titre aux précédentes. C'est donc un bref résumé des données scientifiques rassemblées sur le milieu naturel.
Tipo: Text
Palavras-chave: Géologie; Morphologie; Estuaire; Gironde; Sédimentologie; Hydrologie; Géochimie.
Ano: 1973
URL: http://archimer.ifremer.fr/doc/00080/19155/16755.pdf

Contamination du milieu marin par les micropolluants (résultats du RNO de 1979 à 1994). 3 : L'estuaire de la Gironde
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Cantin, Christian.
After a quick presentation of the observation national network of the marine environment quality (RNO), the different metallic and organic Micropollutants measured in the gironde estuary are described (origin, eventual toxicity). The results of the contamination measurements in the living tissue (oysters) are presented on graphics, based on a sample every three months from 1979 to 1994, and means are compared to those obtained during the same period on the others points of the Manche-Atlantique coast.  
Tipo: Text
Palavras-chave: Micropolluants; Estuaire; Gironde; Huîtres; Micropollutants; Estuary; Gironde; Oyters.
Ano: 1996
URL: http://archimer.ifremer.fr/doc/00422/53310/54148.pdf

Phytoplankton spring bloom of the Gironde plume waters in the Bay of Biscay: early phosphorus limitation and food-web consequences
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Herbland, Alain; Delmas, Daniel; Laborde, P; Sautour, B; Artigas, F.
During the spring 1995 (2-25 May), a cruise was carried on the RV Poseidon (Germany) on the continental shelf of the south Bay of Biscay. The objective was a comprehensive study of the planktonic food web within the Gironde plume waters. In these waters phosphate was present at very low concentrations (undetectable to &lt; 0.1 mu mol.L-1), whereas nitrate, silicate and ammonium concentrations were much higher (several mu mol.L-1 for nitrate and silicate and 0.5 to 1.0 mu mol.L-1 for ammonium). The size distribution of the phytoplankton biomass (estimated from chlorophyll a measurements by high performance liquid chromatography) and primary production (measured by C-14 in situ method) showed a great proportion of small (40 to 70 % &lt; 3 mu m) and active...
Tipo: Text
Palavras-chave: Phosphate; Phytoplancton; Facteur limitant; Estuaire; Eau côtière; Phosphate; Phytoplankton; Limiting factor; Estuarine water; Coastal water.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/1998/publication-850.pdf