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Registros recuperados: 16 | |
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Menesguen, Alain; Desmit, Xavier; Duliere, Valerie; Lacroix, Genevieve; Thouvenin, Benedicte; Thieu, Vincent; Dussauze, Morgan. |
Since 1950, increase in nitrogen (N) and phosphorus (P) river loadings in the North-East Atlantic (NEA) continental seas has induced a deep change in the marine coastal ecosystems, leading to eutrophication symptoms in some areas. In order to recover a Good Ecological Status (GES) in the NEA, as required by European Water Framework Directive (WFD) and Marine Strategy Framework Directive (MSFD), reductions in N- and P-river loadings are necessary but they need to be minimal due to their economic impact on the farming industry. In the frame of the “EMoSEM” European project, we used two marine 3D ecological models (ECO-MARS3D, MIRO&CO) covering the Bay of Biscay, the English Channel and the southern North Sea to estimate the contributions of various... |
Tipo: Text |
Palavras-chave: Marine eutrophication; Ecosystem modelling; Nutrient reduction scenario; Linear optimization; Good ecological status; EU policies. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00426/53774/54661.pdf |
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Dussauze, Morgan. |
En 2013/2014, l’étude financée à 50% par l’ONEMA (Ménesguen et Dussauze, 2015)1 avait pour but de déterminer par la modélisation le bassin récepteur marin des 45 principaux bassins versants (ou groupes de bassins versants) français de la façade Manche-Atlantique. Ces différents panaches statistiques calculés pour chaque fleuve ont ensuite été utilisés pour calculer un scénario optimal de réduction différenciée fleuve par fleuve des apports en azote et phosphore dans le but de se rapprocher du Bon Etat Ecologique au regard des critères définis par la Directive Cadre sur l’Eau (DCE) et la Directive Cadre Stratégie pour le Milieu Marin (DCSMM). Ces critères étaient des concentrations marines en NID et PID à ne pas dépasser. Différentes zones cibles ont été... |
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Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00636/74765/75139.pdf |
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Stanisiere, Jean-yves; Mazurie, Joseph; Bouget, Jean-francois; Langlade, Aime; Gabellec, Raoul; Retho, Michael; Quinsat, Kevin; Leclerc, Emilie; Cugier, Philippe; Dussauze, Morgan; Menesguen, Alain; Dumas, Franck; Gohin, Francis; Augustin, Jean-marie; Ehrhold, Axel; Sinquin, Jean-marc; Goubert, Evelyne; Dreano, Alain. |
The project “Risco”, supported by the “Pôle Mer” and funded by the Regional Council of Brittany, deals with specific risks of mortality of oysters, Crassostrea gigas, cultivated on the bottom, in a subtidal bay of South Brittany : the bay of Quiberon (56, France). Massive mortalities of oysters were reported in summer 2006 in this bay, exclusively located in the deep muddy area with a positive gradient eastward. A validated biogeochemical model was applied in order to simulate the dissolved oxygen over 2000-2006 : it revealed several episodes of hypoxia, more or less intense according to years, but with the same spatial distribution. This approach proved 2006 to be the most hypoxic year since 2000. The hypoxia was due to a rare conjunction of 3 factors :... |
Tipo: Text |
Palavras-chave: Baie Quiberon; Crassostrea gigas; Huître; Mortalité; Croissance; Hypoxie; Oxygène; Modèle; Upwelling; Loire; Vilaine; Quiberon; Crassostrea gigas; Oyster; Mortality; Growth; Hypoxia; Oxygen; Model; DEB; Upwelling; Loire; Vilaine. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00180/29131/27535.pdf |
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Menesguen, Alain; Dussauze, Morgan; Lecornu, Fabrice; Dumas, Franck; Thouvenin, Benedicte. |
Nitrate loadings to the French coastal waters of the Bay of Biscay and the English Channel have increased from 5 to 10 times during the four last decades, due to runoff on intensively fertilized agricultural watersheds. Eutrophication of this coastal zone is now a recurrent problem, with wellknown direct impacts (Ulva “green tides” on beaches, excessive phytoplanktonic blooms responsible for “coloured waters” and bottom hypoxia events offshore), but also indirect enhancement of the toxicity of some phytoplankton species, caused for instance by increased N:Si ratio in the coastal sea. In order to better guide the decision makers about nutrient loading reduction, Ifremer uses the so-called ECO-MARS3D biogeochemicalhydrodynamical model to simulate the present... |
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Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00197/30797/29166.pdf |
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Cayocca, Florence; Verney, Romaric; Petton, Sebastien; Caillaud, Matthieu; Dussauze, Morgan; Dumas, Franck; Le Roux, Jean-francois; Pineau-guillou, Lucia; Le Hir, Pierre. |
The rising interest in environmental and ecosystem dynamics have lead coastal oceanographers to not only investigate the “traditional” physical parameters describing the ocean state and its dynamics (e.g. temperature, salinity, currents, water levels in coastal areas), but to also account for the dynamics of parameters describing its biogeochemical components. To that end, MARS3D regional and coastal modelling system has been coupled to ecosystem modules (ECO-MARS3D, ECO3M) as well as sediment dynamics modules (MARS3D-SEDIM): sediment, nutrient and primary production contents can be considered as the lower level environment and ecosystem descriptors of the “biogeochemical” ocean. Early investments into physical and biological analysis at the regional scale... |
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Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00194/30572/29015.pdf |
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Dussauze, Morgan. |
Le modèle hydrodynamique/biogéochimique ECO-MARS 30 est appliqué à la Baie de Bourgneuf (mailles des 500 mètres) afin d'une part, de modéliser la production primaire et d'autre part, d'introduire le modèle de croissance de l'huître Crassostrea gigas (Bari lié et al, 1997). Le modèle n'étant muni ni d'un module de remise en suspension du sédiment, ni d'un module permettant de représenter le compartiment microphytobenthique, une approximation (forçage d'une climatologie pour la matière en suspension, utilisation d'un terme source dans la couche de fond pour la chlorophylle) a été effectuée afin de représenter de manière schématique le gradient Nord-Sud de turbidité, les rapides changements de turbidité qui sont mesurés au niveau des bancs ostréicoles au... |
Tipo: Text |
Palavras-chave: Baie de Bourgneuf; Production primaire; Croissance de l'huître; Modèle mathématique. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00446/55746/57401.pdf |
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Dussauze, Morgan. |
Cette étude financée à 50% par l’Agence de l’Eau Loire/Bretagne avait pour but de modéliser la production primaire et l’oxygène dissous dans la zone Loire/Vilaine au moyen du modèle Ifremer ECO-MARS 3D. Après validation des résultats à l’aide de données in situ et satellitaires, elle a permis de déterminer la classification DCE des différentes masses d’eaux de la zone suivant les critères ‘biomasse phytoplanctonique’ et ‘oxygène dissous’. Elle a également donné pour la première fois une idée de l’étendue de la zone potentiellement sensible à l’hypoxie. Différents scénarios de réduction des apports azotés et phosphorés (-20%, -50% et +20%) ont été réalisés. En voici les principales conclusions : -les diatomées sont assez peu sensibles aux différentes... |
Tipo: Text |
Palavras-chave: Zone Loire/Vilaine; Modélisation 3D; Production primaire; Oxygène dissous; Classement DCE. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00061/17207/14713.pdf |
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Dussauze, Morgan; Menesguen, Alain; Dumas, Franck. |
Two techniques of tracking are compared for delineating the marine area impacted by a river plume. The first one uses a simple conservative tracer released in the river during a several year long period: the probability density function of the tracer concentration in each mesh of the model is used to map 3 characteristic descriptors of the freshwater influence (10%, 50% and 90% percentiles). The second one uses a signature of the river attached to a state variable of a biogeochemical model (e.g. the Dissolved Inorganic Nitrogen components), which can be followed in space and time in the various nitrogenous state variables. Departure between the two methods increases when tracking of nitrogen is considered in biogeochemical forms more and more distant from... |
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Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00068/17892/15423.pdf |
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Menesguen, Alain; Dussauze, Morgan; Dumas, Franck; Thouvenin, Benedicte; Garnier, Valerie; Lecornu, Fabrice; Repecaud, Michel. |
European directives (Water Framework Directive - WFD and Marine Strategy Framework Directive - MSFD) require a regular survey of several descriptors of the Environmental Status of coastal waters of the North-east Atlantic Ocean. Especially for the MSFD, which may concern large continental shelf areas where measurements are scarce, realistic ecological models can help assessing the Environmental Status. The ECO-MARS3D model of the pelagic ecosystem of the Bay of Biscay and English Channel continental shelf (NE Atlantic) has been developed for these applied purposes and validated against various types of historic data. This first paper deals with the basic biogeochemical version, which contains inorganic nutrients (NH4, NO3, PO4, Si(OH)4), three... |
Tipo: Text |
Palavras-chave: Ecological 3D model; Continental shelf; Bay of Biscay and English Channel; Surface chlorophyll; Dissolved oxygen; MSFD. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00469/58098/60510.pdf |
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Desmit, Xavier; Lacroix, Geneviève; Thieu, Vincent; Menesguen, Alain; Dulière, Valerie; Campuzano, Francisco; Billen, Gilles; Neves, Ramiro; Lancelot, Christiane; Gypens, Nathalie; Dussauze, Morgan; Garnier, Josette; Silvestre, Marie; Passy, Paul; Lassaletta, Luis; Guittard, Gabriel; Théry, Sylvain; Thouvenin, Benedicte; Garcia, Carla; Pinto, Ligia; Sobrinho, Joao; Mateus, Marco; Ascione Kenov, Isabella. |
One of the leading challenges in marine science and governance is to improve scientific guidance of management measures to mitigate eutrophication nuisances in the EU seas. Too few approaches integrate the eutrophication process in space (continuum river-ocean) and in time (past, present and future status). A strong need remains for (i) knowledge/identification of all the processes that control eutrophication and its consequences, (ii) consistent and harmonized reference levels assigned to each eutrophication-related indicator, (iii) identification of the main rivers directly or indirectly responsible for eutrophication nuisances in specific areas, (iv) an integrated transboundary approach and (v) realistic short term and long term nutrient reduction... |
Tipo: Text |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00292/40301/38750.pdf |
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Registros recuperados: 16 | |
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