Consulta: creatorFacets:"Guillaud, Jean-francois"
Registros recuperados: 28
Data/hora: 07/06/2024 00:52:32

Rejets urbains et contamination fecale
Provedor de dados: 5
Autores: Pommepuy, Monique; Dupray, Elisabeth; Guillaud, Jean-francois; Derrien, A; L'Yavanc, Jacky; Cormier, M.
The behaviour of fecal bacteria was investigated in a turbid estuary which is also a shellfishing area. Sediments are polluted by sewage by the way of settlement, fecal bacteria mixed with estuarine water being able to survive a very long time (T90 are about several days). By measuring the increase of salt tolerance of the strains grown in natural estuarine organic matter, it was demonstrated that Escherichia coli is able to support the salinity of coastal water. Moreover, because light penetration is obstructed by suspended matter, the solar bactericidal effect is very low. A close relationship between T90 and light intensity received by the bacteria is found. These mechanisms can explain the low die-off rate found in turbid areas.
Tipo: Text
Ano: 1991
URL: http://archimer.ifremer.fr/doc/00267/37860/35941.pdf

Nutrient and phytoplankton distribution in the Loire River plume (Bay of Biscay, France) resolved by a new Fine Scale Sampler
Provedor de dados: 5
Autores: Lunven, Michel; Guillaud, Jean-francois; Youenou, Agnes; Crassous, Marie-pierre; Berric, Roger; Le Gall, Erwan; Kerouel, Roger; Labry, Claire; Aminot, Alain.
A new Fine Scale Sampler (FSS) was designed and used in the Loire River plume (Bay of Biscay, France) in order to study phytoplankton distribution in highly stratified water columns. The FSS consists of a linear array of 15 sampling bottles, set horizontally at 20 cm intervals. Data acquired from the CTD and fluorescence probe of the FSS enable it to be precisely positioned at the depth of the highest density gradient or at the chlorophyll a maximum. The FSS made it possible to investigate fine scale vertical distribution of phytoplankton and relationships with water density, nutrient concentrations or light availability, for spring and summer conditions. Under spring conditions, the entire upper layer exhibited a dominant diatom population (Chaetoceros...
Tipo: Text
Palavras-chave: Plankton patchiness; Density discontinuity; Sampling; Thin layer; Nutrients; Phytoplankton.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-533.pdf

New instruments to monitor coastal sea water masses according to European Water Framework Directive, Trophimatique project
Provedor de dados: 5
Autores: Repecaud, Michel; Degres, Yves; Bernard, Nathalie; Allenou, Jean-pierre; Aoustin, Yannick; Arrondeau, Jean-pierre; Bouget, Jean-francois; Bucas, Karenn; Daniel, Anne; Guillaud, Jean-francois; Hamon, Michel; Jegou, Paul; Laes, Agathe; Le Roux, Dominique; Le Piver, David; Quemener, Loic; Rolin, Jean-francois; Rudelle, Tiphaine; Legrand, Jacques; Vuillemin, Renaud.
The automated monitoring of physico-chemical parameters in the coastal zone has been using large buoys and fixed infrastructures. A better understanding of many estuaries is needed in order to fulfil the agenda and requirements of the European Water Framework Directive. In order to address the fluxes of nutrients as well as algal blooms and low oxygen events, the "TROPHIMATIQUE" project has developed a new generation of instruments able to be deployed in sea waters. The smaller size of the new instruments is intended to facilitate the maintenance. A new multi-parameter probe has been developed. The measurements of all nutrients are performed thanks to the CHEMINI flow injection analysers for nitrate, ammonia, silicate and phosphate. A sampler using similar...
Tipo: Text
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00107/21807/20276.pdf

L'eutrophisation des eaux marines et saumâtres en Europe, en particulier en France
Provedor de dados: 5
Autores: Menesguen, Alain; Aminot, Alain; Belin, Catherine; Chapelle, Annie; Guillaud, Jean-francois; Joanny, Michel; Lefebvre, Alain; Merceron, Michel; Piriou, Jean-yves; Souchu, Philippe.
In order to be able to count the cases of coastal eutrophication and to propose methods to monitor as well as to reduce these phenomena, first of all it is necessary to precisely define the word eutrophication itself. Instead of the strict etymological definition, that is to say a progression of the enrichment of a medium, we will rather retain the concept of a state enriched at a point such as it causes harmful effects on the ecosystem, and nuisances to man's activities. Based on the average chemical equations of the organic matter synthesis/degradation in the sea, this operational definition thus puts forwards the harmful consequences of enrichment, i.e. the production of an excessive algal biomass, sometimes unbalanced from the point of view of...
Tipo: Text
Palavras-chave: Alexandrium; Phaeocystis; Monostroma; Ulva; Dilution plume; Water trapping; Anoxia; Nitrogen and phosphorus loadings; Red tides; Phytoplankton blooms; Green tides; Eutrophication; Alexandrium; Phaeocystis; Monostroma; Ulva; Panache de dilution; Confinement; Anoxie; Phosphate; Nitrate; Apports terrigènes; Eaux colorées; Blooms phytoplanctoniques; Marées vertes; Eutrophisation.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/rapport-22.pdf

Les rejets urbains en mer
Provedor de dados: 5
Autores: Guillaud, Jean-francois; Romana, Louis-alexandre.
L'amélioration des conditions de rejet en mer des effluents urbains nécessite une approche pluridisciplinaire qui permette de prendre en compte les spécificités de la zone littorale réceptrice dans l'évaluation de l'effort d'épuration à mettre en place.
Tipo: Text
Ano: 1992
URL: http://archimer.ifremer.fr/doc/00177/28853/27335.pdf

Suivi à long terme des apports de matières organiques et nutritives par les effluents urbains de Morlaix
Provedor de dados: 5
Autores: Aminot, Alain; Guillaud, Jean-francois; Le Guellec, Anne-marie.
La qualité des effluents de la station d'épuration de Morlaix a été suivie pendant six mois. Les rendements ont été évalués et comparés à ceux observés précédemment avant réfection du réseau de collecte. Les flux sont comparés à ceux de la rivière en période pluvieuse et en période sèche.
Tipo: Text
Ano: 1990
URL: http://archimer.ifremer.fr/doc/00080/19135/16730.pdf

Satellite and in situ observations of a late winter phytoplankton bloom, in the northern Bay of Biscay
Provedor de dados: 5
Autores: Gohin, Francis; Lampert, Luis; Guillaud, Jean-francois; Herbland, Alain; Nezan, Elisabeth.
A phytoplankton bloom was observed in late winter 2000, on the continental shelf offshore of southern Brittany, in northwestern Bay of Biscay. This bloom appeared initially along the 120-m isobath, in stratified and clear waters, at the interface between the oceanic water and the plumes of southern Brittany rivers (mainly the Loire and Vilaine). The development of the bloom was triggered by favourable meteorological conditions, characterised by solar irradiance reaching the maximum level expected for that period of the year. Outside of the bloom area, the phytoplankton photosynthesis was irradiance limited: inshore, because of the stronger attenuation of the light; offshore, because of the weak stratification. The hydrological conditions at the onset of...
Tipo: Text
Palavras-chave: Bay of Biscay; Coscinodiscus; Algal bloom; Phytoplankton; Ocean colour; Satellite sensing.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/publication-463.pdf

Hydrologie et populations phytoplanctoniques dans le panache de la Loire et en Baie de Vilaine en période estivale : résultats de la campagne VILOIR.
Provedor de dados: 5
Autores: Lunven, Michel; Guillaud, Jean-francois; Crassous, Marie Pierre; Youenou, Agnes; Gohin, Francis; Huret, Martin; Danielou, Marie-madeleine; Kerouel, Roger; Labry, Claire; Aminot, Alain.
Inscrite dans le cadre du Grand Défi Golfe de Gascogne, la campagne VILOIR a été réalisée du 19 au 26 Juin 2003 à bord du Côtes de la Manche avec pour objectif l’étude en période estivale des structures hydrologiques et phytoplanctoniques des panaches de la Loire et de la Vilaine. Elle fait suite, sur la même thématique, à la campagne hivernale NUTRIGAS (2001) et à la campagne printanière GASPROD (2002).
Tipo: Text
Palavras-chave: Surveillance; Littoral; Phytoplancton; Phycotoxines; Bretagne; Pays de Loire.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/00144/25494/23648.pdf

Les apports en sels nutritifs dans l'estuaire de la Seine
Provedor de dados: 5
Autores: Guillaud, Jean-francois.
In this report, nutrient concentrations and fluxes are evaluated at the Caudebec station in the Seine estuary; with a mean river flow of 413 m3/s, the values of mean interannual fluxes are 46 300 t per year for silicium, 90 700 t per year for total nitrogen and 11 000 t per year for total phosphorus ; since 1984, there is a decrease of phosphate fluxes (3 % per year) and an increase of total nitrogen fluxes (2 % per year).
Tipo: Text
Palavras-chave: Sels nutritifs; Estuaire Seine; Flux; Nutrients; Seine estuary; Fluxes.
Ano: 1993
URL: http://archimer.ifremer.fr/doc/00425/53660/54499.pdf

Spéciation du phosphore et apports en baie de Seine orientale
Provedor de dados: 5
Autores: Aminot, Alain; Guillaud, Jean-francois; Andrieux, Francoise.
The Bay of Seine receives the French river with the highest nutrient concentrations, especially phosphorus. Dissolved (phosphate) and particulate phosphorus fluxes have been determined from fortnightly serial data collected by the Port Autonome de Rouen. These determinants exhibit behaviour opposite to that of the river flow: phosphate concentration decreases hyperbolically and particulate phosphorus increases linearily. An approach based on the rate of domestic effluent treatment agrees well (20%) with the measured phosphate flux. The determination of the main particulate phosphorus forms (adsorbed, apatite, non-apatite inorganic, organic) was undertaken over the whole estuarine salinity range. The speciation of particulate phosphorus exhibits a great...
Tipo: Text
Palavras-chave: PHOSPHORUS; SPECIATION; FLUX; ESTUARY; SEINE.
Ano: 1993
URL: http://archimer.ifremer.fr/doc/00100/21126/18746.pdf

La baie de Seine : hydrologie, nutriments, chlorophille (1978-1994)
Provedor de dados: 5
Autores: Aminot, Alain; Guillaud, Jean-francois; Kerouel, Roger.
The data of hydrology, nutrients and chlorophyll obtained in the Bay of Seine over the period 1978-1994, from 14 océanographie cruises, are synthetised and illustrated by an atlas. The Bay is a typical example of a coastal area influenced by a large river. In winter, the nutrient input is drained off into the eastern Channel. In spring, nutrients are consumed intensively. Silicate is the first that drops to limiting levels. The spring bloom generally begins in the centre-east of the Bay. Chlorophyll a can reach up to 40-70 µg/l during the year, values typical of eutrophic coastal areas. Despite the regular increase of nitrogen inputs, the biomass (as chlorophyll) has not significantly changed over a fifteen year period.
Tipo: Text
Palavras-chave: Chlorophyll; Nutrients; Hydrology; Bay of Seine; Chlorophylle; Nutriments; Hydrologie; Baie de Seine.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/1997/rapport-1428.pdf

Comprendre, Prédire et Agir sur les efflorescences toxiques. Jusqu'où peut-on aller aujourd'hui dans le cas d'Alexandrium minutum en Penzé ?
Provedor de dados: 5
Autores: Chapelle, Annie; Andrieux, Francoise; Fauchot, Juliette; Guillaud, Jean-francois; Labry, Claire; Sourisseau, Marc; Verney, Romaric.
Tipo: Text
Ano: 2007
URL: http://archimer.ifremer.fr/doc/00105/21651/19232.pdf

Modélisation écologique tridimensionnelle (3D) de la baie de Seine (Manche, France)
Provedor de dados: 5
Autores: Cugier, Philippe; Ménesguen, Alain; Guillaud, Jean-francois.
A three dimensional (3D) ecological model is developed and applied to the "baie de Seine" area. It consists of a 3D model for hydrodynamics and port (SiAM3D) coupled to an ecological model simulating nutrient cycles (nitrogen, phosphorus, silicon) and two phytoplanktonic classes (diatoms and flagellates). The model is validated by confronting simulations with nine year long series of measurements and then used to better understand the ecosystem functioning. It especially allows to show the role of the proportion of silicon with regard to nitrogen and phosphorus in the summer loadings of the Seine river on the more or less strong presence of flagellates in the river plume. The model was also used to test various hypotheses of reduction of nitrogen loading...
Tipo: Text
Palavras-chave: Modèle 3D; Éléments nutritifs; Diatomées; Flagellés; Baie de Seine; 3D model; Nutrients; Diatoms; Flagellates; Baie de Seine.
Ano: 2001
URL: https://archimer.ifremer.fr/doc/00479/59101/61739.pdf

Two- or three-layered box-models versus fine 3D models for coastal ecological modelling? A comparative study in the English Channel (Western Europe)
Provedor de dados: 5
Autores: Menesguen, Alain; Cugier, Philippe; Loyer, Sophie; Vanhoutte Brunier, Alice; Hoch, Thierry; Guillaud, Jean-francois; Gohin, Francis.
The general trend in ecosystem modelling is to improve the spatial resolution by shifting from rough box-models to fine 3D models. Despite the continuous speeding-up of computing, 3D models involving numerous state variables may remain intractable, especially for parameter calibration, when processes with long half-life periods (i.e, from years to decades) are introduced, such as the behaviour of organic matter in sediment and population dynamics of benthic species. In these cases, a first approach can be provided by fast-running box-models, if they take into account the most crucial hydrodynamic properties of the system. In a macrotidal shelf sea such as the English Channel, the long-term horizontal transport can be summarized by the tidal residual...
Tipo: Text
Palavras-chave: English Channel; Stratification; Diatom/dinoflagellate succession; 3D model; Layered box model.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2315.pdf

Modélisation sur vingt ans (1976-1995) de la production phytoplanctonique en baie de Seine
Provedor de dados: 5
Autores: Guillaud, Jean-francois; Menesguen, Alain.
This paper presents an ecological modelling of the Bay of Seine (Eastern Channel) over the last twenty years, chosen as a typical case of eutrophication in a river plume. In the physical sub-model, the Bay is divided into 42 boxes and water fluxes between them are calculated automatically using Ifremer's "Elise" software. A two-layer, vertical thermohaline model is then linked with the horizontal circulation scheme in order to take vertical stratification into account. The biological submodel deals with two chemical elements, nitrogen and silicon, and splits phytoplankton into diatoms and flagellates. Results from this ecological model point out the spatial concordance of highest phytoplanktonic concentrations with the river plume spreading in the bay....
Tipo: Text
Palavras-chave: Eutrophication; Flagellate; Diatom; Bay of Seine; Two layer model; Eutrophisation; Diatomée; Diatomée; Baie de Seine; Modèle bicouche.
Ano: 1998
URL: https://archimer.ifremer.fr/doc/1998/publication-842.pdf

Modèlisation des transferts de nutriments dans le continuum "Seine, Seine Aval, Baie de Seine"
Provedor de dados: 5
Autores: Billen, Gilles; Cugier, Philippe; Garnier, Josette; Menesguen, Alain; Guillaud, Jean-francois; Durand, I.
Le processus d'eutrophisation des milieux marins côtiers, et le développement épisodiques de dinoflagellés qui en est une des manifestations, dépend de manière complexe de l'équilibre des flux d'azote, de phosphore et de silice en provenance des milieux terrestres du bassin versant. Ceux ci sont déterminés par la manière dont les activités humaines sur le bassin versant interagissent avec les processus naturels. La possibilité de prévoir l'effet sur l'eutrophisation marine des mesures prises pour l'amélioration de la qualité des eaux continentales dépend donc à la fois de notre connaissance du fonctionnement des milieux marins et de celui des bassins versants. En vue de développer les outils de modélisation nécessaire pour prévoir l'Etat de la Baie de...
Tipo: Text
Ano: 2003
URL: http://archimer.ifremer.fr/doc/00106/21695/19274.pdf

Rejets urbains. Volet Manche - Atlantique - Site de Morlaix - Etudes sédimentologique et Bathymétrique de l' estuaire de Morlaix
Provedor de dados: 5
Autores: Bassoullet, Philippe; L'Yavanc, Jacky; Guillaud, Jean-francois; Loarer, Ronan; Breton, Marguerite.
In order to increase our knowledge about sediment transport in the bay and maritime part of the River of Morlaix (Finistère), measurernènts have been perforrned on site. This report gives the granulometrical and physical parameters of the sediments as weIl as the hydrodynamics, used for a model of particulate transport in the area. The rnodel and its application will be published later
Tipo: Text
Palavras-chave: Rejet urbain; Sédiment; Granulométrie; Hydrodynamique; Modèle de transport particulaire; Sable; Vase; Estuaire de Morlaix.; Urban wastes; Model; Sediment; Granulometry; Hydrodynamics; Sand; Mud; Sedimentary transport model; Morlaix estuary.
Ano: 1987
URL: http://archimer.ifremer.fr/doc/00345/45658/45293.pdf

Vers une modélisation opérationnelle du devenir des nutriments dans la bande côtière bretonne
Provedor de dados: 5
Autores: Pénard, Cédric; Ménesguen, Alain; Dumas, Franck; Guillaud, Jean-francois.
Eutrophication of French Brittany coastal shelf is a recurrent problem, more and more worrying. This eutrophication exhibits two main forms :– “green tides”, which are constituted by local proliferations and strandings of green macro-algae (particularly the Ulva species) in nitrogen-enriched areas.– phytoplanktonic blooms, which are responsible of coloured water events. Toxic species can be present (Pseudonitzschia, Alexandrium, Dinophysis), and induce banning of shellfish consumption.Several programs and directives compel authorities to initiate actions in order to diminish these problems. (WFD, OSPAR). This implies a better understanding of these phenomena.This work deals with the influences of the plumes of Loire, Vilaine and bay of Brest rivers (Elorn...
Tipo: Text
Ano: 2007
URL: https://archimer.ifremer.fr/doc/00480/59153/61782.pdf

Extension du port du Legue (St Brieuc) étude d'impact sur l'environnement marin
Provedor de dados: 5
Autores: Merceron, Michel; Manaud, Francois; Guillaud, Jean-francois; Monbet, Yves.
The commercial port of the city of St-Brieuc currently has a limited capacity. It is only accessible for low-tonnage ships, and for this reason, cargo is not allowed, which is a contributing factor to its current traffic being limited to 450,000 tonnes per year.  A significant silting-up of the port is diminishing even more its potential for accepting ships. Its future seems, therefore, threatened. Several studies conducted by the Côtes-du-Nord Chamber of Commerce and Industry have concluded that it is necessary to develop a port with greater capacity, which would stimulate the regional economy. Cargo traffic would then reach 1 million tonnes per year, and St-Brieuc would be accessible to heavier-tonnage coasters and would then follow the current growth of...
Tipo: Text
Ano: 1981
URL: http://archimer.ifremer.fr/doc/1981/rapport-2835.pdf

Relation concentration-débit et évolution temporelle du nitrate dans 25 rivières de la région Bretagne (France)
Provedor de dados: 5
Autores: Guillaud, Jean-francois; Bouriel, Luc.
The study of the twenty-five largest rivers of Brittany showed that nitrate concentrations are positively correlated with river flow, in 90 % of the cases. The hydrogeological characteristics of the watersheds had an influence on these relationships. In this respect, river basins characterized by prevalent surficial water runoff exhibited higher correlation coefficients and lower lag times between river flow sequences and nitrate concentrations.  The multi-year trend in riverine nitrate concentrations indicated a fourfold increase over 30 years. Nevertheless, 80% of rivers exhibited a recent decrease in nitrate concentrations, independent of inter-annual river flow fluctuations. The highest annual rates of nitrate decrease corresponded to river basins for...
Tipo: Text
Palavras-chave: Eutrophication; River flow; Multiple regression analysis; Multi year trend; Nitrate; Brittany; Eutrophisation; Débit fluvial; Régression multiple; Évolution pluriannuelle; Nitrate; Bretagne.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2568.pdf

Principes de gestion zonale des estuaires français
Provedor de dados: 5
Autores: Allen, G.p.; Guillaud, Jean-francois; Berquin, A.; Poupinet, P.
In numerous countries, estuaries are the site of important urban and industrial implantations. These activities provoke numerous effluents, as well as modifications of the channels and geometry (by dredging, filling, etc ...) which have entrained important perturbations in environmental quality.
Tipo: Text
Palavras-chave: Histoire Ifremer.
Ano: 1979
URL: http://archimer.ifremer.fr/doc/1979/publication-6011.pdf

Rejets urbains en mer. Chloration des effluents urbains avant rejet en mer. Synthèse bibliographique
Provedor de dados: 5
Autores: Abarnou, Alain; Batt, A.; Guillaud, Jean-francois; Miossec, Laurence.
This literature'review presents chemical and microbiological aspects of waste water chlorination, and also effects of chlorinated sewages on marine organisms.
Tipo: Text
Palavras-chave: Chloration; Effluents urbains; Bibliographie; Chlorination; Urban waste water; Bibliography.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/00138/24925/23018.pdf

Biogeochemical modelling in the Bay of Seine (France): an improvement by introducing phosphorus in nutrient cycles
Provedor de dados: 5
Autores: Guillaud, Jean-francois; Andrieux-loyer, Francoise; Menesguen, Alain.
As part of the French National Programme for Coastal Oceanography, this paper focuses on improvement of biogeochemical modelling in the: Bay of Seine (Eastern Channel), by introducing phosphorus in nutrient cycles. The Bay of Seine receives the Seine river, which exhibits very high nutrient concentrations, and this coastal zone constitutes a typical case of eutrophication in a river plume area. In terms of analyses, sequential extraction and analysis of sedimentary phosphorus were used in order, to measure various forms of particulate phosphorus in suspended matter and sediment (calcium-bound phosphate, Fe/Al-bound phosphate, exchangeable phosphate and organic phosphorus). In the modelling approach, the Bay is divided into 42 boxes and a two-layer,...
Tipo: Text
Palavras-chave: Bay of Seine; Phytoplankton; Phosphorus; River plume; Biological two layer box model.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-462.pdf

Apports de nutriments et développement phytoplanctonique en baie de Seine
Provedor de dados: 5
Autores: Aminot, Alain; Guillaud, Jean-francois; Andrieux Loyer, Francoise; Kerouel, Roger; Cann, Philippe.
As part of the Programme National d'Oceanographie Cotiere, the nutrient dynamics of the Bay of Seine were studied between 1992 and 1994 in order to complement work on ecological modelling. Firstly, the River Seine's nutrient fluxes were established: 80 000-130 000 t a(-1) of dissolved inorganic nitrogen, 6 400-8 400 t a(-1) of dissolved phosphorus and 20 000-77 000 t a(-1) of dissolved silicium. Estuarine processes were taken into account. Consequences of nutrient loading for the bay were then evaluated at the pelagic level (nutrient and chlorophyll enrichments) and the benthic level (distribution of various phosphorus fractions in superficial sediments). The large continental inputs always induce concentration gradients in the water from the mouth of the...
Tipo: Text
Palavras-chave: Baie de Seine; Rapport de consommation; Chlorophylle; Nutriment; Bay of Seine; Uptake ratio; Chlorophyll; Nutrient.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/1998/publication-844.pdf

La chloration des effluents urbains avant rejet en mer
Provedor de dados: 5
Autores: Abarnou, Alain; Guillaud, Jean-francois; Miossec, Laurence; Batt, Agnes.
Chlorination of wastewater prior to effluent discharge into the sea is used as disinfecting treatment to preserve salubrity of the coastal marine environment wich is necessary for such activities as shellfish-farming and nautical sports. The disinfecting capacity of chlorine results from its oxydizing property which gives rise to various chemical reactions with constituents present in wastes. ln wastewaters, highly loaded with organic matter and ammonia, monochloramine is the main active chlorine species. Due to organic matter oxydation, thèse active chlorine species rapidly disappear by transformation into non toxic chloride. However, a very sm ail part of the initial chlorine dose can be found as stable and toxic chloroorganics. Monochloramine is also...
Tipo: Text
Ano: 1990
URL: http://archimer.ifremer.fr/doc/00173/28438/26772.pdf

Etude hydrobiologique de l'estuaire de la Seine - Etude des ses nutritifs
Provedor de dados: 5
Autores: Guillaud, Jean-francois.
Cette étude, engagée à la demande de l'Agence Financière de Bassin Seine-Normandie dans le cadre du SAUM de l'estuaire de la Seine, a deux objectifs principaux qui sont : - de définir les flux et le cycle des sels nutritifs dans l'estuaire de la Seine, ainsi que leurs variations, dans le temps et dans l'espace, en fonction des conditions hydrologiques. - d'évaluer les principaux facteurs chimiques, physiques et biologiques, régissant la distribution de l'oxygène dissous dans l'estuaire et ceci en vue de l'établissement d'un modèle mathématique de l'oxygène dissous.
Tipo: Text
Ano: 1980
URL: http://archimer.ifremer.fr/doc/00104/21520/19101.pdf

Vertical distribution of phytoplankton communities and relationships with physico-chemical parameters resolved by a fine scale sampler
Provedor de dados: 5
Autores: Lunven, Michel; Guillaud, Jean-francois; Youenou, Agnes; Crassous, Marie-pierre; Berric, Roger; Le Gall, Erwan; Kerouel, Roger; Labry, Claire; Aminot, Alain.
Many studies in coastal areas have shown the existence of thin chemical and biological layers. Their thickness and vertical extension are mainly controlled by hydrological and physical forcing. An accurate description of the phytoplankton communities growing within these layers is difficult to obtain without a well-adapted sampling system. A new Fine Scale Sampler (FSS) has been designed in Ifremer in order to study phytoplankton distribution and associated dissolved properties in high stratified water column. This FSS consists in a vertical array of 15 sampling bottles, horizontally laid with 20 cm intervals. Data acquired from a CTD and Fluorescence probe provide a precise FSS positioning at the depth of highest density gradient or at chlorophyll a...
Tipo: Text
Palavras-chave: Surveillance; Littoral; Phytoplancton; Phycotoxine.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/00144/25493/23647.pdf

Seasonal variation of riverine nutrient inputs in the northern Bay of Biscay (France), and patterns of marine phytoplankton response
Provedor de dados: 5
Autores: Guillaud, Jean-francois; Aminot, Alain; Delmas, Daniel; Gohin, Francis; Lunven, Michel; Labry, Claire; Herbland, Alain.
Seasonal variations in nutrient inputs are described for the main rivers (Loire and Vilaine) flowing into the northern Bay of Biscay. The river plumes are high in N/P ratio in late winter and spring, but not in the inner plume during the summer. Conservative behavior results in most nutrients entering the estuary and eventually reaching the coastal zone. Temporal and spatial aspects of phytoplankton growth and nutrient uptake in the northern Bay of Biscay distinguish the central area of salinity 34 from the plume area. The first diatom bloom appears offshore in late winter, at the edge of the river plumes, taking advantage of haline stratification and anticyclonic "weather windows." In spring, when the central area of the northern shelf is...
Tipo: Text
Palavras-chave: Northern Bay of Biscay; Phytoplankton; Continental shelf; Riverine inputs; Nutrients.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2007/publication-2354.pdf