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| Registros recuperados: 74 | |
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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... |
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| Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/00100/21102/18726.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; 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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| Ropert, Michel; Blin, J.l.; Cornette, Florence; Pacary, S; Pien, S; Leganeur, E; Kopp, Joel; Richard, O. |
| Since 1998, a growth and quality monitoring study of reared molluscs has been developped as part of a close collaboration between the Shellfish Research Laboratory of Normandy (IFREMER Port-en-Bessin, Calvados) and the SMEL (Syndicat Mixte d'Expansion du Littoral) Experimental Centre (Blainville, Manche). REMONOR (REseau MOllusque de NORmandie) is based on the experience gained through the national monitoring network REMORA, which protocol has been entirely applied. Adults and spat of Pacific oysters Crassostrea gigas were placed in 13 stations all along the oysters rearing areas of Normandy. These oysters had the same origin and history (i.e. age and weight) until they were dispatched on the 13 stations. 4 essential criteria were used to monitor rearing... |
| Tipo: Text |
Palavras-chave: REMORA; Quality; Growth; Mortality; Normandy; REMONOR; Crassostrea gigas; REMORA; Croissance qualité; Mortalité; Basse Normandie; REMONOR; Crassostrea gigas. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/rapport-2248.pdf |
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| Soletchnik, Patrick; Le Moine, Olivier; Faury, Nicole; Guilpain, Patrice; Geairon, Philippe; Razet, Daniel; Seugnet, Jean-luc; Robert, Stephane; Ropert, Michel; Simonne, Charlotte; Hugonnet, Virginie; Moal, Jeanne; Pouvreau, Stephane; Huvet, Arnaud; Samain, Jean-francois; Lambert, Christophe; Soudant, Philippe; Frouel, Stephane; Choquet, Gwenaelle; Delaporte, Maryse; Paillard, Christine. |
| Four laboratories are involved in this multidisciplinary study: the Conchological Laboratory of Normandie (LCN), the Invertebrates Physiology Laboratory (LPI), the Université Bretagne Occidentale (LEMAR IHP) and the Conchological Laboratory of Poitou-Charentes (LCPC). The part of the study which is presented here (thematics "Coastal ecology") was produced in collaboration with the LCN. The data on the Bay of Veys was collected by Michel Ropert. This study aims at observing the "sites" effect on mortality and on the general biology of the animal, as well as measuring some environmental elements (e.g. water temperature, etc.). The geographical sites are Gefosse in the Bay of Veys (East Cotentin) and the Ronce bank in the south of the Marennes Oléron Bay. The... |
| Tipo: Text |
Palavras-chave: Immunologie; Physiologie; Paramètres environnementaux; Croissance; Ecologie côtière; Baies des Veys Cotentin; Ronce Charente Maritime; Comparaison sites; Reproduction; Mortalités; Crassostrea gigas; Huîtres. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/acte-3405.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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| Soletchnik, Patrick; Ropert, Michel; Bedier, Edouard; Costil, K. S.; Dubois, Brice; Degremont, Lionel; Bouget, Jean-francois; Martin, Jean-louis; Enriquez-diaz, M.; Faury, Nicole; Le Moine, Olivier; Renault, Tristan; Gagnaire, Beatrice; Huvet, Arnaud; Moal, Jeanne; Samain, Jean-francois. |
| Field characterization of summer mortality was performed in France in the frame of the Morest project. Natural and hatchery spat were compared between three oyster production areas in France. Regardless of the natural or hatchery origin, oysters died during the reproduction period after temperature reaches 19 degree C. Thus, in southern areas, temperature accelerated gametogenesis of small spat (10mm) as well as adults, and mortality appeared for the two age classes. In contrast, sexual maturation proceeded more slowly in northern where spat mortality was lower compared to 18 months old oysters. However, critical gametogenesis and temperature were not sufficient to induce mortalities, as observed in examples with stable environment. Alternatively sediment... |
| Tipo: Text |
Palavras-chave: Seasonal variation; Oyster culture; Mortality causes; Hatcheries; Gametogenesis; Environmental factors; Crassostrea gigas; Oysters. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3348.pdf |
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| Faury, Nicole; Geairon, Philippe; Moal, Jeanne; Pouvreau, Stephane; Razet, Daniel; Ropert, Michel; Soletchnik, Patrick. |
| Proximate biochemical analysis (proteins, lipids and carbohydrates) are performed on a regular basis by the various laboratories fom the Aquaculture Resources Directorate. Methods initially developed to analyse hydrological parameters were firstly transfered to assess meat components.1t appears now important to review and update the commonly used methods (Lowry et al., (1951), Dubois et al.,(l956), Marsh et Weinstein, (1966)), for our specifie purposes. A round table was organized to facilitate discussion among researchers and technicians from both Directorates 'Aquaculture Resources' and 'Product Valorization'and external partners, University of Caen. Several communications reviewing former and recent studies were done. Colleagues from the Directorate... |
| Tipo: Text |
Palavras-chave: Glycogen; Carbohydrates; Lipids; Proteins; Methods comparison; Proximate biochemical composition; Glycogène; Carbohydrates; Lipiedes; Protéines; Comparaison méthodes; Composition biochimique. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/rapport-6378.pdf |
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| Simonne, Charlotte; Pien, S; Hugonnet, Virginie; Le Gagneur, Eric; Ropert, Michel; Kopp, Joel; Richard, O. |
| The national REMORA network is targeted on the studies of growth, flesh quality and mortality of a sample of cupped oyster Crassostrea gigasdistributed on 9 stations along the coast of Normandy. As a better precision is needed for regional purpose, 7 new stations have been added. A total number of 16 stations is now sampled from Chausey to Meuvaines. Weak rates of mortality have been noticed in 2002 on both adults (7%) and spat (6 %). These rates are the weakest ever seen. The mortality rates in the Baie des veys were less than 10 %. This rearing area shows usually a much higher mortality level. Growth rates were noticed weaker than usual. They slowly decline from 1999. From Mach to December, the growth rate of adults has been computed to 0,21 %/day (for a... |
| Tipo: Text |
Palavras-chave: REMORA; Quality; Growth; Mortality; Normandy; REMONOR; Crassostrea gigas; REMORA; Qualité; Croissance; Mortalité; Basse Normandie; REMONOR; Crassostrea gigas. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/rapport-2247.pdf |
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| Degremont, Lionel; Boudry, Pierre; Bedier, Edouard; Ropert, Michel; Soletchnik, Patrick; Huvet, Arnaud; Moal, Jeanne; Samain, Jean-francois. |
| In the scope of the Morest program, 3 series of bi-parental families of cupped oyster consisting of full and half-sib have been created in 2001, and then studied on a regular basis on several sites over the summer period. In October, major survival differences had been demonstrated between the 3 families. The average survival rate for the half-sib families monitored on the three sites varies from 17 to 97 %. Some of them showed high mortality for the three sites, indicating a strong genetic basis (h2 = 0.81 - 0.29) to the variations observed regarding survival. To a lesser extent, growth differences between the studied half-sib families indicate a weaker heritability for this character. .... |
| Tipo: Text |
Palavras-chave: Physiologie; Génétique; Naissain; Sélection; Croissance; Survie; Huîtres; Crassostrea gigas. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3490.pdf |
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| Degremont, Lionel; Bedier, Edouard; Soletchnik, Patrick; Ropert, Michel; Samain, Jean-francois; Boudry, Pierre. |
| The French project "Morest", coordinated by IFREMER, aims to a better understanding of the causes of summer mortalities in juvenile oysters by a multidisciplinary approach. Within this program, a first generation (G1) was bred in 2001 to assess to what extent genetic variability exists for this trait in French populations. 17 half-sib families (HSF) including 44 full-sib families (FSF) were obtained in the G1, and each FSF was reared in three sites along the French coast during the summer period. Significant differences in survival were observed among HSF, clearly indicating a genetic basis for survival. Estimation of heritability for survival was very high: 0.81  0.29. In 2002, 3 "good" HSF and 3 "bad" HSF were selected on their survival... |
| Tipo: Text |
Palavras-chave: Selection; Genetic; Mortalities; Crassostrea gigas; Oyster. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3439.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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| Ropert, Michel; Rauflet, Fabienne; Soletchnik, Patrick; Geairon, Philippe; Bedier, Edouard; Bouget, Jean-francois. |
| Temperature affects undoubtedly the 3 working sites where, systematically, the observation of the first abnormal mortalities coincides with a water temperature of around 19°C. The nature of the processes implied could have a "cumulative" effect, affecting the physiology (this phenomenon has been observed with other marine species) or a "threshold" effect, acting only as a trigger. The question has not been answered yet. The kinetics of the thermic evolution around the mortality period has to be studied in depth in order to understand if this temperature acts more as an "associated factor", during a chronic stress period, or during an acute stress, as suggested by the "on-bottom/off bottom" mortality model of the Marennes Oléron Bay [12]. |
| Tipo: Text |
Palavras-chave: MOREST; Mortalité; Stress; Température; Risque thermique; Physiologie; Crassostrea gigas; Huîtres. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/acte-3408.pdf |
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| Simonne, Charlotte; Pien, S.; Hugonnet, Virginie; Le Gagneur, Eric; Ropert, Michel; Kopp, Joel; Richard, O.. |
| The network named REMONOR (REseau MOllusqueNORmandie) aims to assess mortality, growth and tissue quality of the Pacific oyster, Crassostrea gigas, cultivated in Normandy over an annual cycle. This local network relies on the same material and methods as the national one named REMORA (REseau Mollusques Ressources Aquacoles). The study was carried out in 17 sites, which were distributed in the four basins where oyster rearing occurs in Normandy (West and East coast of Cotentin, Baie des Veys and Meuvaines). In 2003, a new site was added, which was located in the area of Ver-Sur-Mer (Calvados). The results obtained in 2003 showed a low annual mortality for adults (8%) as well as for juveniles (10%). Growth was also low for the two age classes of oyster... |
| Tipo: Text |
Palavras-chave: REMORA; Quality; Growth; Mortality; Normandy; REMONOR; Crassostrea gigas; REMORA; Qualité; Croissance; Mortalité; Basse Normandie; REMONOR; Crassostrea gigas. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/rapport-2246.pdf |
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| Soletchnik, Patrick; Ropert, Michel. |
| 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 et/ou l'eau douce, la ressource trophique, le compartiment sédimentaire, autant de facteurs impliqués directement ou indirectement dans les processus de mortalité. Ces facteurs d'influence "externes" sont étudiés à différentes échelles d'espace (du national au régional) et de temps (Interannuel à saisonnier) en s'appuyant à la fois sur des données issues de bases institutionnelles (REMORA, REPHY, METEO-FRANCE) mais également sur les résultats de terrain observés depuis le début du programme MOREST sur les 3 sites... |
| Tipo: Text |
Palavras-chave: Mortalité estivale; Huîtres creuses; Crassostrea gigas; Bassin de Marennes Oléron; MOREST. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/00164/27551/25716.pdf |
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| Registros recuperados: 74 | |
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