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Fleury, Pierre-gildas; Mazurie, Joseph; Ropert, Michel; Soletchnik, Patrick; Le Coz, Florence. |
The wide range of data from the French Ifremer/REMORA network, collected since 1993 allow a global characterization of mortalities of 1-year old and 2-years old cupped oysters Crassostrea gigas, that are cultivated in the main French oyster areas (Fleury et al, 2003), and thus a better understanding of the causes of these mortalities (Ifremer /MOREST project). The average annual mortalities on intertidal sites range from 10 to 20%. Most of the mortalities take place in Spring and Summer. 1-year oyster mortalities occur in Marennes and several sites in Brittany whilst 2-years oyster mortalities occur in the same sites and in baie des Veys (Normandy). In addition, 2-years oyster mortalities appear more variable according to different annual surveys.... |
Tipo: Text |
Palavras-chave: Meteorolgical factors; Phytoplankton; REMORA; Mortalities; Oysters; Crassostrea gigas. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/acte-4547.pdf |
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Bodoy, Alain; Bougrier, Serge; Geairon, Philippe; Garnier, Jacqueline; Boulo, Viviane; Heurtebise, Serge. |
The flat oyster Ostrea edulis was originally reared in several regions of the European waters. The tidal saline ponds on the Atlantic coasts of France were highly productive before being hit by two consecutive epizooties. Parasitic diseases were described on this species, both of them leading 10 economic losses, as heavy mortalities have usually been recorded before the oysters reach the commercial size. Repeated experiments showed that the two diseases, Marteilia refringens and Bonamia ostreae are still active in this environment. Recently, some evidences were given that haemocytoblasts of Crassostrea gigas had the ability to lyze the Bonamia cells. Therefore, in an experiment of contiguous culture of the two species of oysters, the growth, mortality and... |
Tipo: Text |
Palavras-chave: Molluscs; Mortalities; Growth; Pathology; Crassostra gigas; Ostrea edulis; Marteilia refringens; Bonamia ostreae. |
Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/1991/acte-3049.pdf |
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Burgeot, Thierry; Quirion, Sophie; Quiniou, Francoise; Knoery, Joel; Soletchnik, Patrick; Gagnaire, Beatrice; Renault, Tristan; Osada, M.; Geret, F.; Communal, P. Y.; Jadas-hecart, A.; Gagne, F.. |
In the Atlantic French coast, significant mortalities were observed in oyster communities during gametogenesis. These deaths possibly result from the cumulative effects of various stressors such as seasonal temperature variations, pesticide application and the release of contaminants from the resuspension of sediments. A field survey, based on aquaculture conditions at 15 and 70 cm from the sediment bed with genetically-resistant (R) and -sensitive (S) lines, showed a stress condition. Significant weight loss was observed during May 14th through June 10th for both R and S lines. On one hand, the levels of the egg yolk vitellin in females were decreased at May 14th for both R and S lines. On the other hand, a significant increase in vitellin production was... |
Tipo: Text |
Palavras-chave: Mortalities; Herbicides; Sediment; Biomarkers; Gametogenesis; Crassostrea gigas; Pacific oysters. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3384.pdf |
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Le Deuff, Rose-marie; Renault, Tristan. |
Among the Iridovirus related infections frequently described on many teleosts fish species, Viral Erythrocytic Necrosis (VEN) (Pinto et al., 1989), Epizootic Haematopoietic Necrosis Virus (EHNV) (Langdon et al., 1988) as weil as Lymphocystis Disease Virus (LDV) are not considered to directly cause fatality. Indeed, Lymphocystis outbreaks of farmed fish could be observed in some cases, as a consequence of a bacterial double infection or cannibalism (Ahne ef al., 1991; Moate et al., 1992). Here, we report for the first time a strong LDV infection, and an additional physical stress responsible for mortalities of reared sea bream, Sparus aurata, from Toulon area, on French Mediterranean coast. Although, since the first report of Lymphocystis in sea bream under... |
Tipo: Text |
Palavras-chave: Mortalities; Sparus aurata; Fish; Iridovirus. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/1993/publication-2886.pdf |
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Bodoy, Alain; Garnier, Jacqueline; Razet, Daniel; Geairon, Philippe. |
Mass mortalities of oysters were recorded in the South of the Bay of Marennes-Oleron, during spring 1988. The percentages of mortality averaged 50 % and reached up to 90 % in some areas of bottom culture. The losses were estimated to 7 800 tonnes. This paper present the results of the investigations carried out in several fields. Among them, pathological examination revealed that no pathogenic agent or parasitic infestation could be evoked to explain these mortalities. Analyses of pollutants were either negatives, or the concentrations were far below the toxicity levels. Climatological and hydrological observations showed that rainfalls were twice more abundant then the average, for a period of 6 months preceding the mortalities. The salinity was low and... |
Tipo: Text |
Palavras-chave: Bay of Marennes Oleron; Crassostrea gigas; Oysters; Mortalities. |
Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/acte-3030.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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