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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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Soletchnik, Patrick; Le Moine, Olivier; Faury, Nicole; Razet, Daniel; Geairon, Philippe; Robert, Stephane; Goulletquer, Philippe; Taillade, Sylvie. |
The 1999 monitoring of the C. gigas mortality rates showed a 32 to 40% loss for the on-bottom rearings located on the Ronce-Perquis oyster bank. In 1997, the averaged mortality rate varied between 23 and 29% without significant site effect. These mortality rates were ranging from 17 to 32% in 1998 with significant limited mortality rate on site 4 (17%). However, those rates were underestimated by 7 to 8%, based on our 1999 study, Actually, the spatial distribution for these rates on 2 experimental sites divided into 25 subunits demonstrated a large variability ranging from 17-37% and 22-56% for sites 1 and 2, respectively. In spite this large variability, the mortality rates results were larger on the muddy bottom site. In contrast to site 1, the oysters... |
Tipo: Text |
Palavras-chave: Bay of Marennes Oleron; Crassostrea gigas; Reproductive effort; Biochemical composition; Growth; Sampling strategy; Mortality rates; Bassin de Marennes Oléron; Crassostrea gigas; Effort de reproduction; Composition biochimique; Croissance; Méthodologie d'estimation; Taux de mortalité. |
Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/rapport-1641.pdf |
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Faury, Nicole; Remoue, Sophie; Soletchnik, Patrick; Goulletquer, Philippe; Geairon, Philippe; Le Moine, Olivier; Razet, Daniel; Guilpain, Patrice; Robert, Stephane; Taillade, Sylvie. |
This study aims to assess the broodstock origin and cultural effects on oyster summer mortality rates. Three oyster batches, two originating from the Marennes-Oléron Bay, and one from the Normandy rearing area were deployed in March 2000 on the Ronce Perquis oyster bank, on experimental site since 1996. On bottom cultured oysters were monitored until January 2001. By the end of the experiment, the cumulative mortality ranged from 51 to 58 %. Following on initial mortality rate (8.8 % to 9.3 %), oyster batches showed a critical period early July. In 15 days, mortality rate reached 13.7 %. Over the rearing period, the oyster shell growth ranged between 8.9 g and 12.7 g. The somatic gain represented 0.44-0.48 g of dry meat weight. Spawning event occured in... |
Tipo: Text |
Palavras-chave: Taux de mortalité; Croissance; Composition biochimique; Effort de reproduction; Incorporation du glucose; Crassostrea gigas; Bassin de Marennes Oléron; Charente-Maritime; Mortality; Growth rate; Biochemical content; Glycogen synthase; Crassostrea gigas; Bay of Marennes Oleron; Charente-Maritime. |
Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00031/14235/11511.pdf |
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Le Moine, Olivier; Geairon, Philippe; Soletchnik, Patrick; Faury, Nicole; Goulletquer, Philippe; Robert, Stephane; Razet, Daniel; Heurtebise, Serge. |
Thiis report aims to study the oyster Crwsosrrea gigas growth and production over a 12 years time' s span in the bay of Marennes-DIeron. Results of 12 years of oyster growlh did not show any significant oyster biological productivity decrease, nor trend. ln contrast, annual growth showed a large variability, which will be correlated with environmental conditions. Moreover, annual growth variability was greater than the variability due to site location,. besides the Ronce experimental site. The later, located in the south west part of the bay of Marennes-Dleron, has been the leading oyster growth site since 1989. The annual shell growlh variabiliry was greater than oyster dry meat weight fluctuation . Both 1990 and 1991 years were characterized by the... |
Tipo: Text |
Palavras-chave: Réseau de surveillance; Croissance; Composition biochimique; Mortalité; Crassostrea gigas; Bassin de Marennes-Oléron; Charente-Maritime; Monitoring network; Growth; Biochemical composition; Mortality rate; Crassostrea gigas; Bay of Marennes Oleron; Charente-Maritime. |
Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00031/14244/11520.pdf |
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Goulletquer, Philippe; Le Moine, Olivier. |
France is currently one of the leading shellfish production countries in Europe, harvesting more than 150,000 metric tons of the Pacific cupped oyster (Crassostrea gigas) and 60,000 tons of mussels (Mytilus edulis and M. galloprocincialis) each year. Among rearing areas, the Charentais Sounds and the Marennes-Oleron Bay rank first in Europe, with an annual production of 40,000 and 15,000 tons of oysters and mussels respectively. More than a third of French production is marketed from the Marennes-Oleron area. As natural C. gigas and M. edulis spatfall is limited to the Atlantic coast, the Marennes-Oleron Bay and the Charentais Sounds play a critical role nationally, representing more than half of French oyster and mussel spat production. The stocking... |
Tipo: Text |
Palavras-chave: Stepwise model of agreement; Environment aquaculture management; Conservation; Coastal zone management; Charentais Sounds; Bay of Marennes Oleron. |
Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-481.pdf |
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