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| Registros recuperados: 37 | |
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| Husson, Berengere; Hernandez Farinas, Tania; Le Gendre, Romain; Schapira, Mathilde; Chapelle, Annie. |
| King scallop contamination (Pecten maximus) by domoic acid, a neurotoxin produced by some species of the diatom Pseudo-nitzschia, is highly problematic because of its lengthy retention in the bivalve tissue, leading to prolonged fishery closures. Data collected within the French Phytoplankton and Phycotoxin monitoring network (REPHY) over the 1995–2012 period were used to characterize the seasonal dynamics and the interannual variability of P.-nitzschia spp. blooms as well as the contamination of king scallop fishing grounds, in six contrasted bays distributed along the French Atlantic coast and English Channel. Monitoring revealed that these toxic events have become more frequent since the year 2000, but with varying magnitudes, frequencies and timing... |
| Tipo: Text |
Palavras-chave: Pseudo-nitzschia spp.; Domoic acid; King scallop; Interannual variability; Seasonal dynamics; Environmental parameters. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00299/40983/40084.pdf |
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| Harzallah, Ali; Chapelle, Annie. |
| The Thau lagoon, located in southern France, suffers episodically in summer from anoxic crises known as 'malaigues'. Such crises mostly occur under warm conditions and low winds. In this paper we investigated effects of local weather conditions (air temperature, wind speed and precipitation over southern France), and two climate oscillations (the North Atlantic Oscillation and the El Ni (n) over tildeo Oscillation) on malaigue occurrences based on 33-year data series and dates when malaigues appeared. The study shows that the probability of occurrence of malaigues increases with increasing temperature and decreasing winds in August both mostly associated to the high phase of an index of North Atlantic Oscillation. Malaigues are found to be frequently... |
| Tipo: Text |
Palavras-chave: Lagoon; Thau; Malaigues; Anoxic crises; Climate variability; Lagune; Thau; Malaïgue; Eutrophisation; Variabilité climatique. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-517.pdf |
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| Plus, Martin; La Jeunesse, I; Bouraoui, F; Zaldivar, J; Chapelle, Annie; Lazure, Pascal. |
| The Soil and Water Assessment Tool (SWAT model, 2001 Version) has been applied to the Than lagoon catchment area in order to simulate water discharges and nutrient inputs into the lagoon over a 10 years period (1989-1999), and to provide routing inflows to a previously developed lagoon ecosystem model. The watershed model has been calibrated and validated using measured data available for the two main rivers. The results indicate that the mean annual nitrogen inputs into the Thau lagoon is 117 +/- 57 tons y(-1), with the two main rivers, contributing for 80% of total annual nitrogen export. The variations of outputs to the lagoon are nonetheless important from 1 year to another. Due to the local agricultural practices and a reduced in-stream natural... |
| Tipo: Text |
Palavras-chave: Thau lagoon; Primary production; Integrated modelling; Lagoon model; Watershed model. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1118.pdf |
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| Chapelle, Annie; Le Bec, Claude; Le Gac, Mickael; Labry, Claire; Amzil, Zouher; Guillou, Laure; Dreanno, Catherine; Pineau-guillou, Lucia. |
| Suite à l’événement de grande ampleur d’efflorescence d’Alexandrium minutum et des toxicités associées en Rade de Brest en 2012, un projet a été monté avec la Région dans le cadre du développement du port de Brest. De juillet à août 2013, l’Ifremer a organisé un échantillonnage serré dans l’estuaire de Daoulas, zone la plus touchée en 2012. De ce suivi et des mesures réalisées au laboratoire à ce jour, ainsi que des résultats du réseau Rephy et Velyger, il ressort que : * Alexandrium minutum s’est développé à nouveau en rade de Brest en 2013 mais à des teneurs inférieures à 2012. * l’épisode de bloom et de toxicité supérieur aux seuils légaux s’est déroulé plus tard qu’en 2012, du 1er juillet jusqu’à 5 août. * les efflorescences et la toxicité ont touché... |
| Tipo: Text |
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| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00191/30230/28644.pdf |
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| Bacher, Cedric; Bioteau, Hélène; Chapelle, Annie. |
| The Thau lagoon (France) is an important site for the cultivation of Crassastrea gigas. The relationship belween the oyster population and the environment was assessed through a model of trophic relationships. The results represent the initial step lowards a more precise assessment of the biological fluxes in the lagoon. This preliminary model was based on the nitrogen dynamics among the following compartments: phytoplankton, zooplankton. oysters. detritus and dissolved inorganic nitrogen in the water column. Two other compartments were also considered in the sediment: detritus and dissolved nitrogen. The model considered the watershed input and seawater exchange belween the lagoon and the open sea . The parameters were estimated from experiments on oyster... |
| Tipo: Text |
Palavras-chave: Oyster; Crassostrea gigas; Nitrogen dynamics; Impact. |
| Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/00039/15069/12403.pdf |
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| Hermabessiere, Ludovic; Fabioux, C.; Lassudrie, Malwenn; Boullot, F.; Long, Marc; Lambert, Christophe; Le Goic, N.; Gouriou, Jeremie; Le Gac, Mickael; Chapelle, Annie; Soudant, P.; Hegaret, Helene. |
| This study investigated the effect of gametogenesis pattern and sex on levels of paralytic shellfish toxins (PST) accumulated by triploid oysters Crassostrea gigas exposed to a natural bloom of the toxic dinoflagellate Alexandrium minutum in the Bay of Brest (Western Brittany, France), over the summer 2014. Toxin accumulation in oysters was proposed to be influenced by the proportion of energy allocated to reproduction versus other metabolisms, as proposed by Haberkorn et al. (2010). Thus, we hypothesized that triploid oysters with different gametogenesis patterns (α or β, producing respectively numerous gametes or rare gametes) could result in differences in toxin accumulation. Toxin level could also be different according to the gender of the oysters. To... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Alexandrium minutum; Harmful algal bloom (HAB); Paralytic shellfish toxin (PST); Gametogenesis pattern; Triploid. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00307/41801/41010.pdf |
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| Chapelle, Annie. |
| The Bay of Vilaine (South-Brittany, France ) has been affected for many years by eutrophication process . Discoloured waters, oxygen depletion in bottom waters occured, being sometimes so drastic as in July 1982 that several ten tons of fishes and invertebrates were killed by anoxia. This coastal ecosystem is studied using a box model simulating the nitrogen cycle, oxygen and salinity. The model takes into account river inputs and exchanges with the ocean. It is calibrated and validated against several year measurements. The understanding of primary production and oxygen budget is improved. Phosphorus cycle simulation is then added in the model. The impact of different reductions of river nutrients on chlorophyll concentration and on hypoxia in the Bay are... |
| Tipo: Text |
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| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00015/12611/9490.pdf |
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| Le Gac, Mickael; Metegnier, Gabriel; Chomerat, Nicolas; Malestroit, Pascale; Quere, Julien; Bouchez, Olivier; Siano, Raffaele; Destombe, Christophe; Guillou, Laure; Chapelle, Annie. |
| Understanding divergence in the highly dispersive and seemingly homogeneous pelagic environment for organisms living as free drifters in the water column remains a challenge. Here, we analyzed the transcriptome wide mRNA sequences, as well as the morphology of 18 strains of Alexandrium minutum, a dinoflagellate responsible for Harmful Algal Blooms worldwide, to investigate the functional bases of a divergence event. Analysis of the joint site frequency spectrum (JSFS) pointed toward an ancestral divergence in complete isolations followed by a secondary contact resulting in gene flow between the two diverging groups, but heterogeneous across sites. The sites displaying fixed SNPs were associated with a highly restricted gene flow and a strong... |
| Tipo: Text |
Palavras-chave: Dinoflagellates; Harmful algal blooms; Populations Genomics; Pseudocryptic species; Speciation. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00347/45857/45529.pdf |
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| Chapelle, Annie; Bacher, Cedric; Duarte, P; Fiandrino, Annie; Galbiati, L; Marinov, D; Martinez, J; Norro, A; Pereira, A; Plus, Martin; Rodriguez, S; Tsirtsis, G; Zaldivar, Jm. |
| Tipo: Text |
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| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/00348/45930/45622.pdf |
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| Chapelle, Annie. |
| The Vilaine bay (South Brittany) has been showing for many years eutrophication troubles (red tides, anoxia, toxic blooms...). Facing these biological and economical problems, scientific studies have been performed and the results are joined in an ecological box model of the bay. It simulates the primary production through nitrogen cycle, dissolved oxygen, and salinity, used to calibrate the advection-dispersion fluxes of the physical submodel. The model is running several years to bring out the seasonal characteristics of this site. A special attention is reported on the oxygen balance sheet. Simulations try to quantify the oxygen demand and to recognize the major cause of anoxia. These results are applied to reproduce the July 1982 anoxia, which caused... |
| Tipo: Text |
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| Ano: 1990 |
URL: https://archimer.ifremer.fr/doc/00480/59124/61752.pdf |
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| Chapelle, Annie. |
| Le programme de recherche Oxythau a pour but l'étude des relations concyliculture - milieu dans l'étang de Thau. Dans ce contexte, l'interface eau-sédiment apparait comme une structure majeure intervenant dans les cycles de la matière et dans les problèmes de dysfonctionnement de l'écosystème (malaïgues). Un modèle en azote et en phosphore simule les étapes de transformation de la matière organique sédimentée jusqu'au relargage de sels nutritifs, ainsi que la concentration en oxygène qui intervient dans les cinétiques de dégradation. L'ensemble de ces réactions est simulé au moyen d'un modèle vertical. La colonne d'eau est scindée en cinq boîtes de 1m superposées et le sédiment en deux boîtes de 5 cm. Ce modèle est mis au point en situation d'équilibre... |
| Tipo: Text |
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| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00060/17091/14604.pdf |
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| Chapelle, Annie; Le Bec, Claude; Amzil, Zouher; Dreanno, Catherine; Guillou, Laure; Klouch, Khadidja; Labry, Claire; Le Gac, Mickael; Pineau-guillou, Lucia; Siano, Raffaele; Abernot, Chantal; Andrieux, Francoise; Caradec, Florian; Destombe, Christophe; Dia, A.; Doner, Anne; Duval, Julia; Gouriou, Jeremie; Lazure, Pascal; Le Brun, Luc; Le Gal, Dominique; Malestroit, Pascale; Petton, Sebastien; Plus, Martin; Quere, Julien; Savar, Veronique; Schmitt, Sophie; Terre, A.; Youenou, Agnes. |
| Suite à l’événement de grande ampleur d’efflorescence d’Alexandrium minutum et des toxicités associées en Rade de Brest en 2012, un projet a été élaboré avec la Région Bretagne dans le cadre du développement du port de Brest. L’Ifremer a organisé un échantillonnage dans l’estuaire de la rivière de Daoulas, zone la plus touchée en 2012, au cours des printemps-été 2013 et 2014. Un suivi de la présence d’A. minutum dans les sédiments a également été réalisé en hiver 2014. De ces suivis, des mesures réalisées au laboratoire à ce jour, des simulations du modèle Prévimer ainsi que des résultats du réseau Rephy et Velyger, il ressort que: * La rade de Brest peut aujourd’hui être considérée comme une zone à risque pour Alexandrium minutum. En effet, depuis 2012... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00254/36487/35029.pdf |
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| Plus, Martin; Chapelle, Annie; Lazure, Pascal; Auby, Isabelle; Levavasseur, G; Verlaque, M; Belsher, Thomas; Deslous-paoli, Jean-marc; Zaldivar, J; Murray, C. |
| A three-dimensional model coupling physical and biological processes for the whole Than lagoon (Mediterranean coast of France) was developed in order to assess the relationships between macrophytes and the oxygen and nitrogen cycles. Ten species have been inserted as forcing variables in the model. Plankton dynamics, shellfish cultivation impact and mineralization of organic matter are also considered, as well as nutrient and oxygen exchanges between the sediment and the water column. Simulations with and without the macrophytes have shown that the system can be characterized as having a highly structured pattern involving lagoon nitrogen and oxygen cycles. This pattern is created by the combined influence of macrophytes, watershed and oyster farming.... |
| Tipo: Text |
Palavras-chave: Thau lagoon; Biogeochemical cycles; Ecological modelling; Macrophytes. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/2003/publication-459.pdf |
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| Registros recuperados: 37 | |
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