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Registros recuperados: 43 | |
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Le Hir, Pierre; Bassoullet, Philippe; Erard, E.; Blanchard, Michel; Hamon, Dominique; Jegou, Anne-marie. |
Ce rapport en 6 volumes est le résultat d'une étude pluridisciplinaire (6 thèmes correspondant aux volumes du rapport), réalisée sur un secteur géographique bien délimité, présentant des caractéristiques physiques et biologiques particulières (très fort marnage, grande hétérogénéité des fonds, forte production biologique à base de mollusques filtreurs…), et siège d'activités humaines importantes et diversifiées (essentiellement basées sur l'exploitation des ressources du milieu). L'étude fait suite à un Livre Blanc établi en 1982, synthétise les données existantes, et les complète par des travaux originaux sur la connaissance des mécanismes naturels, en particulier de ceux qui ont une relation directe ou indirecte avec les activités humaines (processus... |
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Ano: 1986 |
URL: http://archimer.ifremer.fr/doc/00047/15837/13240.pdf |
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Blanchard, Michel. |
L'élimination de la crépidule est une préoccupation majeure de la part de nombreux ostréiculteurs. Que leurs concessions soient sous 10 mètres d'eau, comme à Cancale, ou sur l'estran, elles sont de plus en plus envahies par ce gastéropode proliférant. Les professionnels sont obligés de procéder à de fréquents nettoyages. Le problème qui se pose alors est le devenir du produit ainsi débarqué. Très peu de solutions intéressantes sont actuellement proposées, en dehors de l'écrasement et de l'enfouissement dans les terrains agricoles, pour la culture des primeurs comme cela se pratique au Vivier-sur-Mer. Le rejet au large, par grande profondeur, est une solution qui fut proposée par des ostréiculteurs charentais. Les crépidules immergées par des fonds de 2000... |
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Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/00102/21312/18931.pdf |
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Blanchard, Michel; Gros, Philippe. |
Three main intertidal macrofauna communities are identified in Saint-Brieuc Bay: a Macoma balthica community, a Tellina tenuis community; and a third community with Cerastroderma and Tellina tenuis. Physiological parameters such as filtration, respiration and excretion are examined, for the filter-feeding molluscs with the highest biomass (the cockle Cerastoderma edule, the tellinid Tellina tenuis, and the blue mussel Mytilus edulis), either through laboratory experiments, or through previous literature. These results are used together to build up an annual energy budget for the complete soft bottom community, and to observe trophic relations. Results show that the mussel population has a negative influence on the cockle beds that lie just above. |
Tipo: Text |
Palavras-chave: ENERGY BUDGET; FLUXES; CERASTODERMA-EDULE; TELLINA-TENUIS; SAINT-BRIEUC BAY. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00100/21132/18752.pdf |
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Blanchard, Michel; Hamon, Dominique. |
The slipper-limpet (Crepidula fornicata) is a marine gastropod which causes serious perturbations in shellfish beds, because of spatial spreading and density rising. Along French coasts, in Northern Brittany, two bays are highly colonized : bay of Saint-Brieuc, centre for scallops fishery, and bay of Mont-Saint-Michel, a famous oyster-farming area, with a total limpet stock about 450 000 metric tons. The association AREVAL was founded in 2001 to manage there, an industrial collect of limpets by a succing-dredge, followed ashore by a treatment for calcareous soil improvement. The scientific survey, contracted to IFREMER, included measurements of long andshort-term dredge's effects on grounds and limpet population, and proposals to set up dredging... |
Tipo: Text |
Palavras-chave: France; Western Channel; Bay of Mont Saint Michel; Bay of Saint Brieuc; Impact; Dredging; Treatment; Crepidula fornicata; Slipper limpet; Manche Ouest; Baie du Mont Saint Michel; Baie de Saint Brieuc; Impact; Dragage; Exploitation; Crepidula fornicata; Crépidule. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/rapport-6301.pdf |
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Blanchard, Michel. |
A population of the invasive slipper limpet (Crepidula fornicata) has been spreading in the Bay of Mont-Saint-Michel (Western English Channel) for 40 years. Sidescan sonar, underwater video and quantitative sampling were conducted in 1996 and 2004 to document the widening geographic spread of the species over the bay. The limpet population grew by 50% during this period, to reach a fresh biomass of about 150 000 t. This local study analyses causes and effects of the spread and provides a typical example of the limpet spreading process. This population increase has significant effects on the environment in the most densely colonized area (modification to the sediment and biodiversity), leading to the emergence of a new benthic community. Anthropic dredging... |
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Palavras-chave: Western Channel; France Crepidula fornicata Sidescan sonar Stock estimation Oyster farming Spread Invasive species. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6351.pdf |
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Pechenik, Jan; Blanchard, Michel; Rotjan, Randi. |
The slipper shell snail Crepidula fornicata forms dense assemblages along much of the European coast, where it co-occurs with oysters. We examined the susceptibility of slipper shell larvae to predation by suspension-feeders, including adults of their own species. In particular, we compared filtration rates on phytoplankton with those on larvae, and determined the extent to which consumption of larvae varied with adult size, larval size, and with the presence of alternative food (phytoplankton). We also examined the ability of competent larvae to metamorphose successfully in the presence of feeding adults. For each experiment, adults were held in plastic jars with seawater or phytoplankton suspension and allowed to graze on larvae (101 larvae per jar) for... |
Tipo: Text |
Palavras-chave: Larvae; Susceptibility; Predation. |
Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/2004/publication-755.pdf |
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Cugier, Philippe; Frangoudes, Katia; Blanchard, Michel; Mongruel, Remi; Perez, Jose; Le Mao, Patrick; Robin, T.; Fontenelle, Guy; Mazurie, Joseph; Cayocca, Florence; Pouvreau, Stephane; Olivier, F.. |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00026/13707/10862.pdf |
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Blanchard, Michel; Pechenik, J; Giudicelli, E; Connan, Jean-paul; Robert, Rene. |
The degree to which larvae of the invasive American slipper limpet (Crepidula fornicata) and the Japanese oyster (Crassostrea gigas) may compete for food was examined during 2003 in the laboratory. Larval microalgae uptake, growth and mortality were compared for larvae fed each of six species of unicellular algae, ranging in length from 2 to 10 mu m. Tested diets included the two flagellates Tetraselmis chui (Prasinophyceae) and Isochrysis affinis galbana (T-ISO, Haptophyceae), one member of the Chlorophyceae (Nannochloris atomus), and three diatom species (Chaetoceros calcitrans forma pumilum, Chaetoceros gracilis, Skeletonema marino). We found that the limpet larvae ingested phytoplankton over a wider range of cell sizes and ate at higher rates on each... |
Tipo: Text |
Palavras-chave: Larvae; Crepidula fornicata; Crassostrea gigas Growth Feeding rate Diet Phytoplankton. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4703.pdf |
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Kostecki, Caroline; Rochette, S.; Girardin, R.; Blanchard, Michel; Desroy, Nicolas; Le Pape, Olivier. |
Coastal bays provide habitats for juveniles and adults of many marine species. Mont Saint-Michel Bay (MSMB, France) hosts a highly diversified fish community and constitutes one of the most important nursery grounds for many commercially exploited marine species, such as sea bass, flatfish, clupeids and rays in the English Channel. Besides, MSMB also suffers from the massive invasion of an exotic mollusc, the American slipper-limpet (Crepidula fornicata, L). This species arrived four decades ago and now represents the main filter-feeder biomass in the bay (150 Mt), an order of magnitude larger than local farmed and natural shellfishes. Recent analyses underlined the impact of this small gastropod on the trophic structure of this bay and its negative... |
Tipo: Text |
Palavras-chave: Spatial competition; Flatfish habitat; Crepidula fornicata; Invasive species; Mont Saint-Michel Bay. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00035/14641/11990.pdf |
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Blanchard, Michel; Blanchet, Aline; Gaffet, Jean-dominique; Hamon, Dominique. |
The limpet (Crepidula fornicata), a gastropod mollusc belonging to the Calyptraeidae, native of the Atlantic coast of northern America, was introduced by accident on the French coasts in different steps (Blanchard, 1995, 1997). The most important, at the beginning of the 1970s, is linked to the massive importation of the Japanese oyster (Crassostrea gigas), in replacement of the Portuguese oyster (Crassostrea angulata), decimated by an epizooty. It is an opportunistic species proliferating in the neighbourhood of the main oyster basins of the English Channel and the Atlantic Ocean. Such is the case of the oyster culture areas of the Norman-Breton Gulf where stock assessments accounted for hundreds of thousands of tonnes of them (Hamon and Blanchard, 1994;... |
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Ano: 2001 |
URL: https://w3.ifremer.fr/archimer/doc/00000/5305/ |
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Quiniou, Francoise; Blanchard, Michel; Bocquene, Gilles; Burgeot, Thierry; Giboire, Louis; His, Edouard; Le Du, Anne. |
La présente étude a pour objectif de sélectionner des méthodes de laboratoire et de terrain les mieux appropriées pour l'évaluation de l'écotoxicité de sédiments dragués : indicateurs biochimiques d'exposition (EROD et AChE), tests de toxicité sublétale (micro-organismes, algues, embryons de bivalve et extrait enzymatiques de poisson), indices physiologiques de bivalve (respiration, excrétion, mouvements valvaires). Une synthèse des résultats est présentée accompagnée, en annexes, des rapports des différents participants à l'étude. |
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Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/00104/21573/19153.pdf |
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Foucher, Eric; Blanchard, Michel; Cugier, Philippe; Desroy, Nicolas; Dreanno, Catherine; Fauchot, Juliette; Fifas, Spyros; Guyader, Olivier; Jean, Frederic; Le Gallic, Bertrand; Riou, Philippe; Schapira, Mathilde; Thiebaut, Eric. |
The King scallop Pecten maximus constitutes the first landed species in terms of tonnage and the second or third one in terms of value for the French fisheries. More than 90% of these landings come from the English Channel indicating that its exploitation is essential to local fleets. The COMANCHE project (Ecosystem Interactions and anthropogenic impacts on King scallops populations in the English Channel) proposed to improve the knowledge of the scallop within the Channel, through an ecosystem-based approach for fisheries, appealing to a wide range of scientific disciplines (physics, chemistry, genetics, ecology, geostatistics, modeling, economics ....). Researches on the spatial location of scallop beds, connectivity by larval dispersal between beds,... |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00251/36236/34797.pdf |
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Registros recuperados: 43 | |
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