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| Registros recuperados: 74 | |
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| Ropert, Michel; Mazurie, Joseph; Bedier, Edouard; Le Coz, Florence; Soletchnik, Patrick. |
| L'objectif de ce thème est de préciser les relations entre Mortalités et Environnement, en déclinant cette relation à travers les "risques environnementaux" caractérisés depuis le début du programme MOREST. La température, les bassins versant etlou l'eau douce, la ressource trophique, le compartiment sédimentaire, autant de facteurs impliqués directement ou indirectement dans les processus de mortalités de Crassostrea gigas. Ces facteurs d'influence "externe" sont étudiés à différentes échelles d'espace ("nationale", "régionale", "sites") et de temps (annuelle, mensuelle, bimensuelle, journalière, horaire, infra horaire) en s'appuyant sur des données issues de bases institutionnelles (REMORA', REPHY~, METEO-FRANCE) et sur les résultats de terrain obtenus... |
| Tipo: Text |
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| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00304/41536/40744.pdf |
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| Ropert, Michel. |
| Depuis 1986, une population de l'annélide tubicole Lanice conchilega (Polychète) se développe et prolifère sur le site conchylicole de Grandcamp-Maisy (Baie des Veys), en association avec une accélération des processus de sédimentation liés à la présence des structures tabulaires ostréicoles. La capacité de cet annélide à développer un mode alimentaire suspensivore en fait un compétiteur trophique potentiel de l'huître creuse Crassostrea gigas. L'objectif de ce travail est de réaliser un premier bilan global de l'impact de cette population de Lanice sur l'activité conchylicole du secteur. Dans un premier temps, nous avons pu mettre en évidence et quantifier expérimentalement son activité suspensivore : il est en effet susceptible de retenir des particules... |
| Tipo: Text |
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| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00450/56173/57720.pdf |
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| Ropert, Michel. |
| The trophic competItIon between the Pacific oyster Crassostrea gigas and the polychaete Lanice conchilega was studied by assessing the polychaete suspension feeding activity. Particle size distributions were compared at the input and output of the experimental design so as to estimate the polychaete retention efficiency. Although particles ranging from 4 µm to 12 µm were kept by Lanice conchilega, no upper treshold and maximum retenti on rate were reached. In contrast, Crassostrea gigas showed a retention efficiency starting at 2 µm and reached a 6 to 8 Ilm upper treshold. Based on our results, a trophic competition is likely to occur between Crassostrea gigas and Lanice conchilega. Standardized filtration rates reached 0.27 l.h-1.dmw-1 and 2.41... |
| Tipo: Text |
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| Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/00100/21102/18726.pdf |
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| Degremont, Lionel; Boudry, Pierre; Soletchnik, Patrick; Bedier, Edouard; Ropert, Michel; Samain, Jean-francois. |
| Three successive generations were produced between 2001 and 2003 to assess to what extent genetic variability exists for this trait in juvenile oysters Crassostrea gigas. For each generation, two groups were selected for their high ("R" for resistant) and low ("S" for susceptible) survival. Significant differences of mortality were observed during the first year in Rivière d'Auray (RA) (Brittany-France). However, low and similar mortality were observed for both groups, with no significant difference between groups in the first and second generation in this site, where the first summer is the critical sensitive period with a clear age effect. In Baie des Veys (BDV) (Normandie-France), where mortalities usually mainly affect adults, mortality between... |
| Tipo: Text |
Palavras-chave: Genetic variability; Genetic; Summer mortality; Crassostrea gigas; Pacific oysters. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3442.pdf |
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| Delaporte, Maryse; Moal, Jeanne; Soudant, Philippe; Lambert, Christophe; Pouvreau, Stephane; Enriquez, Martha; Degremont, Lionel; Soletchnik, Patrick; Gagnaire, Beatrice; Ropert, Michel. |
| In the frame of MOREST project, a common biological material, resulting of a mixture of different families produced in experimental hatchery, was reared in two different environmental fields : Normandy and Charente. Concomitantly, a pool was conditioned at the Ifremer Argenton hatchery with three different algae levels : 4%, 8% and 12% of algal dry weight per oyster dry weight. During the experiments, five immune parameters were studied in parallel with survival rate and reproductive status (stages and intensity). Site location, seasonal variations and experimental diet level clearly influenced oyster immune parameters. Haemocyte counts were higher for oysters reared in Normandy than those reared in Charente and in hatchery. Granulocyte percentage was... |
| Tipo: Text |
Palavras-chave: Defense mechanisms; Nutrition; Seasonal variations; Physiology; Crassostrea gigas; Pacific oysters. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3500.pdf |
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| Degremont, Lionel; Boudry, Pierre; Ropert, Michel; Samain, Jean-francois; Bedier, Edouard; Soletchnik, Patrick. |
| This study investigated the effects of age (first or second summer of life) and environment (three study sites on French coasts) on summer mortality in Crassostrea gigas, using three generations of oysters produced during the Morest project. For each generation, two groups of oysters, selected either as 'resistant' (R) or 'susceptible' (S) to summer mortality at the age of 6 months in Rivière d'Auray (RA, South Brittany), were evaluated. In Ronce (Marennes-Oléron Bay) and RA, R oysters had low mortality during their first and second summers, while mortality was higher during the second summer in Baie des Veys (BDV, Normandy). In RA, S oysters exhibited higher mortality during their first summer than during their second, while the opposite result was found... |
| Tipo: Text |
Palavras-chave: Summer mortality; Age; Environment; Genetic; Crassostrea gigas. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6972.pdf |
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| Degremont, Lionel; Boudry, Pierre; Soletchnik, Patrick; Bedier, Edouard; Ropert, Michel; Samain, Jean-francois. |
| Three successive generations were produced between 2001 and 2003 to assess to what extent genetic variability exists for survival in juvenile oysters Crassostrea gigas. For each generation, two groups were selected for their high ("R" for resistant) and low ("S" for susceptible) survival. Significant differences in mortality were observed during the first year in Riviere d'Auray (RA) (Brittany-France). However, low and similar mortality were observed for both groups, with no significant difference between groups in the first and second generation in this site, where the first summer is the critical, sensitive period with a clear age effect. In Baie des Veys (BDV) (Normandie-France), where mortalities usually mainly affect adults, mortality between groups,... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Spat; Spatial variations; Survival; Rearing; Mollusc culture; Marine molluscs; Environmental factors; Nursery grounds; Mortality causes; Biological age; Aquaculture techniques. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3385.pdf |
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| Ropert, Michel; Kopp, Joel. |
| The Shellfish Laboratory of Normandy (LCN : Laboratoire Conchylicole de Normandie) observed unusual hydrologic anomalies associated with important oyster mortalities during the winter of 1999. These anomalies were described as sudden salinity variations during the lidal cycle, particularly on the rising tide. Starting in 1996 a multi-parameter probe was used to monitor salinity, temperature and depth every 10 to 20 minutes in the inter-tidal zone. Alter data processing and filtering, two criteria concerning low salinity were chosen : amplitude and duration. Application of a cumulative function (Ibanez et al., 1993) to this time series data treatment showed the 3 year trend (1996-1999). Salinity variation data and climatic data were used in a multivariate... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Mortalités; Salinité; Baie des Veys; Suivi; Crassostrea gigas; Mortality; Salinity; Baie of Veys; Monitoring. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00102/21310/18928.pdf |
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| Degremont, Lionel; Boudry, Pierre; Bedier, Edouard; Ropert, Michel; Soletchnik, Patrick; Huvet, Arnaud; Moal, Jeanne; Samain, Jean-francois. |
| The French project "Morest", coordinated by IFREMER, aims to understand the causes of the summer mortalities in Crassostrea gigas. In 2001, three sets of families were bred following a nested half-sib mating design. 17 half-sib families (HSF) were obtained in this first generation (G1) and reared in 3 sites. Significant differences in survival were observed among HSF, and some HSF showed high levels of mortality in all sites, clearly indicating a genetic basis for survival. In 2002, a second generation (G2), including divergent selection and inbred lines, was constituted. Monitoring of survival and growth of G2s were the same as in 2001. Significant differences in survival were found between the offspring of the "high" and "low" selected groups and between... |
| Tipo: Text |
Palavras-chave: Summer; Oyster culture; Juveniles mortality; Genetics; Commercial species; Breeding. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3346.pdf |
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| Samain, Jean-francois; Degremont, Lionel; Soletchnik, Patrick; Haure, Joel; Bedier, Edouard; Ropert, Michel; Moal, Jeanne; Huvet, Arnaud; Bacca, Helene; Van Wormhoudt, A; Delaporte, Maryse; Costil, K; Pouvreau, Stephane; Lambert, Christian; Boulo, Viviane; Soudant, Philippe; Nicolas, Jean-louis; Leroux, Frederique; Renault, Tristan; Gagnaire, Beatrice; Geret, Florence; Boutet, Isabelle; Burgeot, Thierry; Boudry, Pierre. |
| Summer mortality of Pacific oysters is known in several countries. However no specific pathogen has been systematically associated with this phenomenon. A complex combination of environmental and biological parameters has been suggested as the cause and is now starting to be identified. A high genetic basis was found for survival in oysters when a first generation (G1) was tested in three sites during summer. This paper presents a synthesis on physiological characteristics of two selected groups ('R' and 'S', from families selected for resistance and susceptibility to summer mortality respectively), of the second and third generations. R and S showed improvement or reduction of survival compared with the control in both field and laboratory trials... |
| Tipo: Text |
Palavras-chave: ROS; Temperature; Stress; Hemocytes; Reproduction; Genetic selection; Resistant oyster; Crassostrea gigas; Pacific Oyster; Summer mortality. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2809.pdf |
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| Andral, Bruno; Cambert, Harold; Turquet, Jean; Ropert, Michel; Duval, Magali; Vermenot, Coralie; Boissery, Pierre; Talec, Pascal. |
| Les efforts engagés en matière de lutte contre la pollution domestique au cours des vingt dernières années ont permis de réduire de façon significative les rejets directs et non épurés à la mer. Malgré cela, les rejets urbains des agglomérations côtières constituent encore de nos jours l'une des principales contributions à la pollution tellurique du littoral réunionnais. Les eaux urbaines, et en particulier les eaux usées rejetées bien que traitées, peuvent générer des pollutions ou des nuisances dans l’environnement. L’impact de ces apports doit être apprécié au regard de la vie marine et des usages littoraux, notamment lorsqu’ils sont situés à proximité de récifs coralliens très sensibles à toute modification du milieu. Afin d'homogénéiser les pratiques... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00123/23471/21299.pdf |
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| Buestel, Dominique; Ropert, Michel; Prou, Jean; Goulletquer, Philippe. |
| The history of French oyster culture consists of a succession of developmental phases using different species, followed by collapses caused by diseases. The indigenous species Ostrea edulis was replaced first with Crassostrea angulata, then C. gigas. France is now the top producer and consumer of oysters in Europe, producing around 120,000 t of the cupped oyster C. gigas annually, and an additional 1500 t of the flat oyster O. edulis. Cupped oysters are produced all along the French coast from natural and hatchery spat. Various structures are used to collect spat from the wild. After a growing-on period, oysters are Cultivated by three main methods: (1) on-bottom culture in the intertidal zone or in deep water, (2) off-bottom culture in plastic mesh bags... |
| Tipo: Text |
Palavras-chave: Cupped oyster; Flat oyster; Ostrea edulis; Crassostrea gigas; French production; Aquaculture. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7396.pdf |
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| Soletchnik, Patrick; Ropert, Michel; Grangere, Karine; Munaron, Dominique; Struski, C.. |
| The role of freshwater is more difficult to comprehend. It might act as a detrital organic matter "vector" (during floods) or an anthropic waste "vector" (toxic molecules from agriculture or other industries; nutritive salts from leaching...). Its effect has been demonstrated in the Bay of Veys (Ropert and Kopp, 2000; Misko, 2003), and especially its intense but transient action, presenting high freshenings, as recorded by high-frequency multiparameter probes since 1996 [15]. On this oyster culture site, mortality could then result from osmotic shocks. The "mortality-flow" relationship, demonstrated in 2003 in the Bay of Veys (Misko 2003), has to be specified. It is found in a more sustained way in the Marennes Oléron Bay (R2 = 0.40). This result also... |
| Tipo: Text |
Palavras-chave: MOREST; Impact; Physiologie; Pluviométrie; Apport eau douce; Mortalités; Crassostrea gigas; Huîtres. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/acte-3409.pdf |
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| Bedier, Edouard; Fleury, Pierre-gildas; Langlade, Aime; Haure, Joel; Le Roux, A.; Ropert, Michel; Rauflet, Fabienne; Soletchnik, Patrick. |
| The "sedimentary risk" has been identified since the mid-nineties in the Marennes Oléron Bay. The proximity of the sediment (from 0 to 15cms) increases the mortality rate. Depending on the year, mortality can be 10 to 20 % higher than in "high" conditions (50 to 70cms). These zootechnic results, gathered since 1996 on the working site of Ronces Perquis, lead to the research of a pathogenic agent or a toxic substance released by the sediment. Studies conducted between 2002 and 2003 [12, 18] did not allow the identification of any pathogenic agents and ruled out the infectious risk. In 2004, the chemical risk (sulphides, ammoniacal nitrogen) was studied on 4 sites (3 working sites + Quiberon). In 2004, the "on-bottom/off bottom" mortality model of the... |
| Tipo: Text |
Palavras-chave: MOREST; Hydrologie; Zootechnie; Sédimentologie; Mortalités; Crassostrea gigas; Huîtres. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/acte-3411.pdf |
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| Registros recuperados: 74 | |
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