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| Registros recuperados: 42 | |
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| Ehrhold, Axel; Auffret, Jean-paul. |
| Grain size trends in relation to net sediment transport pathways are examined, using sorne cornmonly-used grain size pararneters. The results of the model are compared with the net sediment transport pathways established on the basis of the bedfonn asymmetry. The 3 types of trends are calculated using an increasing characteristic distance and differents grids of seabed sediment samples. lt is shown that : (1) the characteristic distance defined by Gao et Collins (maximum spatial sampling interval) changes with these two factors to a maximal value; (2) in an heterogeneous sedimentary environment, the correlations between calculated vectors and observed transport pathways are better by using sand size distributions and (3) the residual pattern rises to sixty... |
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| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00285/39620/38111.pdf |
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| Hamon, Dominique; Ehrhold, Axel; Houlgatte, Eric; Kerdoncuff, Julien; Gaffet, Jean-dominique; Caisey, Xavier; Alix, Anne-sophie; Oger-jeanneret, Helene. |
| Poster présenté aux Journées REBENT Brest les 13 et 14/10/2011 (2ème atelier de restitution Rebent Bretagne. Dans le cadre du programme de surveillance DCE, et en lien avec le projet REBENT, il a été entrepris en 2008-2009 de cartographier et de caractériser les principaux bancs de maërl distribués dans 9 masses d'eaux autour de la Bretagne, et faisant l'objet pour la plupart d'un suivi annuel de leur biodiversité, assuré par l'IUEM (LEMAR). |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00042/15275/12631.pdf |
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| Ehrhold, Axel; Cordier, Celine; Pluquet, Fabrice; Alix, Anne-sophie; Monpert, Coralie; Autret, Elodie; Hamon, Dominique. |
| Les besoins d'inventaires et de suivis des habitats benthiques côtiers, de même que la nécessité de mieux comprendre leur fonctionnement, conduisent depuis plusieurs années à mettre en place des actions à différentes échelles d'observation spatiales et temporelles sur l’ensemble des façades métropolitaines. L’application du Réseau Benthique au pilote breton en est une parfaite illustration. Le Rebent a ainsi soutenu dès 2001 le projet d’une embarcation spécialisée, destinée à relayer dans la frange littorale les moyens acoustiques mis en oeuvre sur les navires côtiers plus au large, et capable d’assurer une investigation des fonds sur de grandes superficies, avec un fort pouvoir de résolution. Ce projet de vedette porté par l’Ifremer a été rendu possible... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00283/39440/37888.pdf |
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| Mazurie, Joseph; Stanisiere, Jean-yves; Bouget, Jean-francois; Langlade, Aime; Leclerc, Emilie; Quinsat, Kevin; Herve, Gilles; Augustin, Jean-marie; Ehrhold, Axel; Sinquin, Jean-marc; Meidi-deviarni, Ika; Goubert, Evelyne; Cochet, Helene; Dreano, Alain. |
| This study (“Risco”), implicating both industry, socio-economic experts and biologists, was funded by the Regional Council of Brittany, for 3 years (2010-2012), to investigate about the causes of oysters (Crassostrea gigas) mortalities in the bay of Quiberon (South Brittany, France). The protocol including both a sonar and video visualization of the bottom, and a monthly survey of 15 experimental oyster structures, allowed to assess the risk due to predation. A clear spatial distribution of the predatory effect was evidenced, with starfish (Asterias rubens and Marthasterias glacialis) predominating in the North-East sector, and boring snails (Ocenebra erinacea and Pterophora inornata) in the South-Center area.. The main mortalities from these predators... |
| Tipo: Text |
Palavras-chave: Baie de Quiberon; Huître; Crassostrea gigas; Risque; Mortalité; Prédation; Étoiles de mer; Bigorneaux perceurs; Risco; Bay of Quiberon; Oyster; Crassostrea gigas; Risk; Mortality; Predation; Starfish; Oyster drills; Risco. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00180/29130/27534.pdf |
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| Ehrhold, Axel; Chevalier, Claire; Alix, Anne-sophie; Autret, Elodie; Caisey, Xavier; Drussel, Benjamin; Gaffet, Jean-dominique; Hamon, Dominique; Houlgatte, Eric; Pluquet, Fabrice; Biscara, Laurie; Choisnet, Justine; Bajjouk, Touria. |
| In 2000 Ifremer launched and coordinated the development of a monitoring strategy for the REBENT network (REseau BENThique) in order to assess the aftermath of the “Erika” oil spill which took place in December 1999. Its aim is to provide consistent baseline knowledge on coastal benthic habitats, as well as to develop a monitoring tool that detects changes at various spatial and temporal scales. Sector-based seabed habitat mapping in shallow water (< 50 m deep), is currently being conducted throughout Brittany's coastal waters using a combination of geoacoustic marine systems together with ground-truthing using biological grab sampling and seabed observations. Due to the extended area, the overlap of soft and rocky bottoms, and contrasting hydrological... |
| Tipo: Text |
Palavras-chave: Rebent; Trégor-Goëlo; Bréhat; Cartographie d’habitats; Sonar latéral; Macrofaune benthique; Peuplements; Crépidule; Maërl; Sédiments; Morphologie; Dynamique sédimentaire; Rebent; Trégor-Goëlo; Bréhat archipelago; Marine habitat mapping; Sidescan sonar; Benthic macrofauna; Communities; Crepidula bed; Maerl; Sediment; Morphology; Bedload transpor. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00280/39161/37724.pdf |
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| Stanisiere, Jean-yves; Mazurie, Joseph; Bouget, Jean-francois; Langlade, Aime; Gabellec, Raoul; Retho, Michael; Quinsat, Kevin; Leclerc, Emilie; Cugier, Philippe; Dussauze, Morgan; Menesguen, Alain; Dumas, Franck; Gohin, Francis; Augustin, Jean-marie; Ehrhold, Axel; Sinquin, Jean-marc; Goubert, Evelyne; Dreano, Alain. |
| The project “Risco”, supported by the “Pôle Mer” and funded by the Regional Council of Brittany, deals with specific risks of mortality of oysters, Crassostrea gigas, cultivated on the bottom, in a subtidal bay of South Brittany : the bay of Quiberon (56, France). Massive mortalities of oysters were reported in summer 2006 in this bay, exclusively located in the deep muddy area with a positive gradient eastward. A validated biogeochemical model was applied in order to simulate the dissolved oxygen over 2000-2006 : it revealed several episodes of hypoxia, more or less intense according to years, but with the same spatial distribution. This approach proved 2006 to be the most hypoxic year since 2000. The hypoxia was due to a rare conjunction of 3 factors :... |
| Tipo: Text |
Palavras-chave: Baie Quiberon; Crassostrea gigas; Huître; Mortalité; Croissance; Hypoxie; Oxygène; Modèle; Upwelling; Loire; Vilaine; Quiberon; Crassostrea gigas; Oyster; Mortality; Growth; Hypoxia; Oxygen; Model; DEB; Upwelling; Loire; Vilaine. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00180/29131/27535.pdf |
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| Bajjouk, Touria; Rochette, Sebastien; Ehrhold, Axel; Cordier, Celine; Laurans, Martial; Tourolle, Julie; Hamdi, Anouar; Tourolle, Julie; Gaffet, Jean-dominique; Caisey, Xavier; Vasquez, Mickael; Populus, Jacques. |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00280/39159/37722.pdf |
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| Registros recuperados: 42 | |
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