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| Registros recuperados: 51 | |
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| Cochennec-laureau, Nathalie; Bellec, Gwenael; Bizzozero, Lucie; Bonneau, Francoise; Bouget, Jean-francois; Bouvier, Calypso; Collin, Karine; Fortune, Mireille; Gabellec, Raoul; Le Merrer, Yoann; Manach, Soazig; Mellor, Alice; Pierre-duplessix, Olivier; Reboul, Sebastien; Retho, Michael; Roux, Pauline; Schapira, Mathilde; Schmitt, Anne; Souchu, Philippe; Stanisiere, Jean-yves. |
| Activités d’observation, de surveillance de la qualité des eaux littorales du Morbihan, Pays de Loire et Nord Vendée et résultats des projets de recherche 2018 |
| Tipo: Text |
Palavras-chave: Réseaux de surveillance et d’observation; Qualité des écosystèmes marins littoraux du Morbihan; Pays de Loire; Microbiologie; Phytoplancton; Eutrophisation; Ressources exploitées; Huîtres; Moules. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00481/59245/61969.pdf |
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| Collin, Karine; Bizzozero, Lucie; Le Merrer, Yoann; Retho, Michael; Pierre-duplessix, Olivier; Souchu, Philippe; Cochennec-laureau, Nathalie. |
| Ce rapport décrit le contexte hydrologique du littoral côtier du Morbihan, Pays de Loire et Nord Vendée, durant l’année 2018. Il s’appuie sur les suivis environnementaux réalisés dans le cadre des réseaux REPHY et de la DCE, complétés des données acquises en haute fréquence sur la bouée MOLIT et sur le secteur du Bois de la Chaise. |
| Tipo: Text |
Palavras-chave: Hydrologie; DCE; Nutriment; Loire Bretagne; Rephy; Phytoplancton. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00634/74571/74443.pdf |
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| Le Moal, Morgane; Gascuel-odoux, Chantal; Menesguen, Alain; Souchon, Yves; Etrillard, Claire; Levain, Alix; Moatar, Florentina; Pannard, Alexandrine; Souchu, Philippe; Lefebvre, Alain; Pinay, Gilles. |
| Eutrophication is one of the most common causes of water quality impairment of inland and marine waters. Its best-known manifestations are toxic cyanobacteria blooms in lakes and waterways and proliferations of green macro algae in coastal areas. The term eutrophication is used by both the scientific community and public policy-makers, and therefore has a myriad of definitions. The introduction by the public authorities of regulations to limit eutrophication is a source of tension and debate on the activities identified as contributing or having contributed decisively to these phenomena. Debates on the identification of the driving factors and risk levels of eutrophication, seeking to guide public policies, have led the ministries in charge of the... |
| Tipo: Text |
Palavras-chave: Eutrophication; Nitrogen; Phosphorus; Algae bloom; Land-sea continuum; Diffuse pollution. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00456/56734/58551.pdf |
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| Chapelle, Annie; Menesguen, Alain; Deslous-paoli, Jean-marc; Souchu, Philippe; Mazouni, Nabila; Vaquer, André; Millet, Bertrand. |
| An ecosystem model based on nitrogen cycling and oxygen has been developed for the Thau lagoon. It takes into account the specific features of this Mediterranean lagoon, a semi-confined system with watershed inputs and oyster farming. The ecosystem model uses currents calculated by a two-dimensional hydrodynamic model and integrated into a box model. This model is compared with a year survey data and used to estimate nitrogen and oxygen fluxes between the different ecosystem compartments. The yearly simulation shows that the ecosystem behavior is driven by meteorological forcing, especially rain which causes watershed inputs. These inputs trigger microphytoplankton growth, which is responsible for new primary production. During dry periods, nitrogen is... |
| Tipo: Text |
Palavras-chave: Oxygen; Nitrogen; Oysters; Primary production; Box model; Lagoon ecosystem. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-725.pdf |
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| Orsoni, Valerie; Souchu, Philippe; Sauzade, Didier. |
| L'étude porte sur les trois principaux étangs corses (Biguglia, Diana et Urbino), situés à la bordure de la plaine orientale. Ecosystèmes fragiles et productifs, ces étangs supportent des enjeux importants, en tant qu'habitats naturels remarquables et du fait de leur exploitation intensive par la pêche, l'aquaculture et la conchyliculture. Cette étude vise à évaluer leur état d'eutrophisation, en utilisant une méthode de diagnostic spécifique aux milieux lagunaires méditerranéens, développée par l'Ifremer pour l'Agence de l'eau Rhône Méditerranée Corse, et portant sur l'utilisation d'indicateurs caractérisant la colonne d'eau, dont le phytoplancton, le sédiment et les macrophytes. Dans l'eau, les prélèvements ont été réalisés sur une période de 12 mois en... |
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| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00074/18534/16078.pdf |
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| Cochennec-laureau, Nathalie; Bizzozero, Lucie; Bonneau, Francoise; Collin, Karine; Fortune, Mireille; Le Merrer, Yoann; Pierre-duplessix, Olivier; Schapira, Mathilde; Schmitt, Anne; Souchu, Philippe. |
| Suivi hydrologique L’année 2017 s’est caractérisée par des températures élevées et un déficit en précipitation sur le bassin versant de la Loire, ce qui la classe parmi les années sèches exceptionnelles avec les années 2003, 2011 et 2015. Les débits de la Loire ont été largement déficitaires. L’ensoleillement soutenu en début d’année et en automne a été toutefois plus faible sur les mois de juillet et septembre. Suivi microbiologique Parmi les 41 stations de surveillance, 9 ont présenté une bonne qualité microbiologique, 31 une qualité moyenne, et une seule station est de mauvaise qualité. Comparativement à l'année 2016, le nombre de stations présentant une tendance à l'amélioration est en augmentation : 4 stations présentent une tendance à l'amélioration... |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00461/57312/59406.pdf |
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| Pasqualini, Vanina; Derolez, Valerie; Garrido, Marie; Orsoni, Valerie; Baldi, Yoann; Etourneau, Sabrina; Leoni, Vanina; Rebillout, Patrick; Laugier, Thierry; Souchu, Philippe; Malet, Nathalie. |
| Increases in the intensity of disturbances in coastal lagoons can lead to shifts in vegetation from aquatic angiosperms to macroalgal or phytoplankton communities. Such abrupt and discontinuous responses are facilitated by instability in the equilibrium controlling the trajectory of the community response. We hypothesized that the shift in macrophyte populations is reversible, and that this reversibility is dependent on changes in the pressures exerted on the watershed and lagoon functioning. Biguglia lagoon (Mediterranean Sea, Corsica) is an interesting case study for the evaluation of long-term coastal lagoon ecosystem functioning and the trajectory of submerged macrophyte responses to disturbances, to facilitate the appropriate restoration of... |
| Tipo: Text |
Palavras-chave: Coastal lagoons; Human pressures; Long-term changes; Submerged macrophytes; Community shifts. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00372/48341/48564.pdf |
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| Cochennec-laureau, Nathalie; Bizzozero, Lucie; Bonneau, Francoise; Bouget, Jean-francois; Bouvier, Calypso; Collin, Karine; Fortune, Mireille; Gabellec, Raoul; Le Merrer, Yoann; Manach, Soazig; Pierre-duplessix, Olivier; Retho, Michael; Roux, Pauline; Schapira, Mathilde; Schmitt, Anne; Souchu, Philippe; Stanisiere, Jean-yves; Villedieu, Anouk. |
| Activités d’observation, de surveillance de la qualité des eaux littorales du Morbihan, Pays de la Loire et Nord Vendée et résultats des projets de recherche 2019 |
| Tipo: Text |
Palavras-chave: Réseaux de surveillance et d’observation; Qualité des écosystèmes marins littoraux du Morbihan; Pays de la Loire; Microbiologie; Phytoplancton; Eutrophisation; Ressources exploitées; Huîtres; Moules. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00630/74217/73849.pdf |
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| Collos, Y; Vaquer, A; Laabir, M; Abadie, Eric; Laugier, Thierry; Pastoureaud, Annie; Souchu, Philippe. |
| A monitoring program with a weekly sampling frequency over a 15-month period indicates that urea concentrations above a certain threshold level may trigger the blooms of Alexandrium catenella in Thau lagoon. However, urea concentrations were also sometimes related to ammonium and dissolved organic nitrogen concentrations, indicating that the role of urea may not be a direct one. An original approach is used to assess the relative contribution of several nitrogen sources (nitrate, nitrite, ammonium, urea) to growth of A. catenella by comparing nitrogen uptake rates to nitrogen-based growth rates estimated from dilution experiments during four blooms over a 4-year period (2001-2004) in Thau lagoon. Nitrate and nitrite contributed 0.1-14% and 0.1-5%... |
| Tipo: Text |
Palavras-chave: Uptake kinetics; Ammonium; Urea; Growth; Nitrogen; HAB; Alexandrium catenella. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-6454.pdf |
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| Collos, Yves; Husseini Ratrema, Julie; Bec, Béatrice; Vaquer, André; Hoai, Thong Lam; Rougier, Claude; Pons, Virginie; Souchu, Philippe. |
| The dilution technique was used to estimate chlorophyll and pheopigment, net and gross production as well as zooplankton grazing over a 12-month period in a coastal lagoon in Southern France. Chlorophyll a (Cha) based gross growth rates of phytoplankton ranged from undetectable in February to 2.6 day(-1) in June, corresponding to 3.8 divisions per day. Cha-based grazing rates ranged from undetectable in February to 1.1 d(-1) in June. The seasonal growth pattern of picoplankton was similar to that of the whole community, with a peak in July, corresponding to four divisions per day. Grazing processes represented from 20 to 150% of the phytoplankton daily growth, and the grazing pressure was stronger on small phytoplankton cells than on larger cells. Gross... |
| Tipo: Text |
Palavras-chave: Zooplankton; Ammonium; Pheopigments; Degradation; Growth; Phytoplankton. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-727.pdf |
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| Coignot, Elise; Polsenaere, Pierre; Soletchnik, Patrick; Le Moine, Olivier; Souchu, Philippe; Joyeux, Emmanuel; Le Roy, Yoann; Guéret, Jean-pierre; Froud, Louise; Gallais, Régis; Chourré, Elise; Chaigneau, Loïc. |
| Les zones côtières en raison de leur statut d’interface entre les continents, les océans et l’atmosphère constituent un environnement particulièrement actif et impliqué dans les cycles biogéochimiques. Elles sont le réceptacle de molécules particulaires et dissoutes véhiculées par les rivières et impliquées à la fois dans la chaine trophique et dans les phénomènes d’eutrophisation ou de toxicité. Cette étude a pour objectif d’étudier la dynamique des nutriments et du carbone au niveau d’un continuum terrestre-aquatique formé par le Marais poitevin (MP), la Baie de l’Aiguillon (BA) et le Pertuis Breton (PB). L’étude a été réalisée sur deux années (2017 et 2018) contrastées en terme de pluviométrie. Au total, huit sites (deux estuaires, trois chenaux et... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00618/73003/72077.pdf |
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| 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 |
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| Souchu, Philippe; Vaquer A, André; Collos, Yves; Landrein, Sonia; Deslous-paoli, Jean-marc; Bibent, Bertrand. |
| Thau lagoon is a Mediterranean shellfish ecosystem with large biomasses of oysters growing in waters with high residence time due to low tidal ranges, The influence of filter feeders (oysters and their epibiota) on the spatial distribution of particulate and dissolved compounds in the water column of Thau lagoon was studied through its variation with time, In 1991/1992, daily variations were investigated in pens, corridors and outside shellfish farming zones for nutrients, chlorophyll a and primary production. Salinity, dissolved oxygen, nutrients, organic matter and chlorophyll a were also monitored in surface waters inside and outside shellfish farming zones each week from January 1993 to March 1994. The presence of shellfish farms led to a decrease by... |
| Tipo: Text |
Palavras-chave: Thau lagoon; Carrying capacity; Nutrient cycling; Phytoplankton; Suspension feeding bivalves. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-808.pdf |
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| Souchu, Philippe; Gasc, Anne; Collos, Y; Vaquer, A; Tournier, Henri; Bibent, B; Deslous-paoli, Jean-marc. |
| Physical and chemical characteristics (temperature, salinity, dissolved oxygen), nutrients [dissolved inorganic nitrogen (DIN), soluble reactive phosphorus (SRP) and silicate], dissolved organic nitrogen (DON) and phosphorus and particulate matter [particulate organic carbon (POC) and nitrogen (PON) and chlorophyll a] were measured at a station located in the deepest part of the Thau lagoon (8.5 m), France, during a 10 d period of bottom anoxia in summer 1994. The upper 8 cm of sediment were also analyzed for ammonium (NH(4)(+)) and SRP concentrations in the porewater. The study period was characterized by mean wind speed under 4 m s(-1) which induced an increase of surface temperature from 18 to 29 degrees C with the formation of a thermocline. The... |
| Tipo: Text |
Palavras-chave: Anoxia; Nitrogen; Phosphorus; Eutrophication; Thau lagoon; Mediterranean Sea. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00070/18142/15694.pdf |
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| Collin, Karine; Bizzozero, Lucie; Le Merrer, Yoann; Retho, Michael; Souchu, Philippe; Cochennec-laureau, Nathalie; Schapira, Mathilde; Manach, Soazig. |
| Ce rapport décrit le contexte hydrologique du littoral côtier du Morbihan, Pays de Loire et Nord Vendée, sous l’influence de la Loire et de la Vilaine, durant l’année 2017. Il s’appuie sur les suivis environnementaux réalisés dans le cadre des réseaux REPHY et de la DCE, complétés des données acquises en haute fréquence sur la bouée MOLIT (réseau COAST-HF). |
| Tipo: Text |
Palavras-chave: Hydrologie; DCE; Nutriment; Loire Bretagne; Rephy; Phytoplancton. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00472/58410/60972.pdf |
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| Registros recuperados: 51 | |
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