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| Registros recuperados: 10 | |
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| Leclerc, Jean-charles; Riera, Pascal; Laurans, Martial; Leroux, Cedric; Leveque, Laurent; Davoult, Dominique. |
| Worldwide kelp forests have been the focus of several studies concerning ecosystems dysfunction in the past decades. Multifactorial kelp threats have been described and include deforestation due to human impact, cascading effects and climate change. Here, we compared community and trophic structure in two contrasting kelp forests off the coasts of Brittany. One has been harvested five years before sampling and shelters abundant omnivorous predators, almost absent from the other, which has been treated as preserved from kelp harvest. δ15N analyses conducted on the overall communities were linked to the tropho-functional structure of different strata featuring these forests (stipe and holdfast of canopy kelp and rock). Our results yielded site-to-site... |
| Tipo: Text |
Palavras-chave: Laminaria hyperborea; Community cascade; Stable isotopes; Biomass; Suspension-feeders; Omnivorous predators. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00226/33747/32161.pdf |
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| Guarini, Jean-marc; Blanchard, Gerard; Bacher, Cedric; Gros, Philippe; Riera, Pascal; Richard, Pierre; Gouleau, Dominique; Galois, Robert; Prou, Jean; Sauriau, Pierre-guy. |
| Microphytobenthos plays an important role as primary producer in shallow embayments subject to a tidal regime. The present paper aims to characterize the spatial patterns of sedimentary chlorophyll a (chl a) biomass in 2 seasons in the wide intertidal mudflats of the Marennes-Oleron Bay (France); furthermore, it provides estimates of total microphytobenthic biomass. Accordingly, a systematic sampling scheme was performed in June 1995 and in January 1996. On average, biomass was higher in June (ca 120 mg chl a m-2) than in January (ca 85 mg chl a m-2). Moreover, the geostatistical analysis revealed that spatial similarities were propagated over larger distances in June (6 km) than in January (2.2 km). In order to account for this result , we suggest that... |
| Tipo: Text |
Palavras-chave: Marennes Oleron; Intertidal mudflat; Geostatistics; Spatial distribution; Chrlorophyll a; Microphytobenthos. |
| Ano: 1998 |
URL: https://archimer.ifremer.fr/doc/1998/publication-3820.pdf |
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| Bacher, Cedric; Blanchard, Gerard; Bougrier, Serge; Cariou-le Gall, Valerie; Delmas, D.; Deslous Paoli, Jean-marc; Dinet, A.; Garet, Marie-josee; Geairon, Philippe; Jonquieres, Gerard; Laisne, A.; Maffei, E.; Montagna, P. A.; De Montaudouin, Xavier; Morin, S.; Richard, P.; Riera, Pascal; Sauriau, Pierre-guy; Vrignaud, N.. |
| Les cartographies annuelles des biomasses microphytobenthiques ont été réalisées pour le bassin de Marennes-Oléron. Parallèlement les cartographies des caractéristiques sédimentaires ont été établies simultanément aux cartes d'abondance et biomasse macrofauniques en portant un effort particulier sur les densités des compétiteurs des huîtres notamment les Crépidules. Simultanément les études des mécanismes contrôlant le réseau trophique sur la vasière de Brouage ont été poursuivies notamment les relations entre les flux de sels nutritifs et le microphytobenthos. L'importance de ce dernier compartiment dans la nutrition de l'huître a été clairement mis en évidence par l'utilisation des traçeurs isotopiques naturels. Enfin, les caractéristiques de filtration... |
| Tipo: Text |
Palavras-chave: Bassin de Marennes Oléron; Microphytobenthos; Physiologie; Crassostrea gigas; Crépidules; Modèle réseau trophique; Cartographie; Charente-Maritime. |
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00102/21294/18911.pdf |
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| Lienart, Camilla; Savoye, Nicolas; Bozec, Yann; Breton, Elsa; Conan, Pascal; David, Valerie; Feunteun, Eric; Grangere, Karine; Kerherve, Philippe; Lebreton, Benoit; Lefebvre, Sebastien; L'Helguen, Stephane; Mousseau, Laure; Raimbault, Patrick; Richard, Pierre; Riera, Pascal; Sauriau, Pierre-guy; Schaal, Gauthier; Aubert, Fabien; Aubin, Sebastien; Bichon, Sabrina; Boinet, Christophe; Bourasseau, Line; Breret, Martine; Caparros, Jocelyne; Cariou, Thierry; Charlier, Karine; Claquin, Pascal; Cornille, Vincent; Corre, Anne-marie; Costes, Laurence; Crispi, Olivier; Crouvoisier, Muriel; Czamanski, Marie; Del Amo, Yolanda; Derriennic, Herve; Dindinaud, Francois; Durozieri, Maia; Hanquiez, Vincent; Nowaczyk, Antoine; Devesa, Jeremy; Ferreira, Sophie; Fornier, Michel; Garcia, Fabrice; Garcia, Nicole; Geslin, Sandrine; Grossteffan, Emilie; Gueux, Aurore; Guillaudeau, Julien; Guillou, Gael; Joly, Orianne; Lachaussee, Nicolas; Lafont, Michel; Lamoureux, Jezabel; Lecuyer, Eric; Lehodey, Jean-paul; Lemeille, David; Leroux, Cedric; Mace, Eric; Maria, Eric; Pineau, Philippe; Petit, Franck; Pujo-pay, Mireille; Rimelin-maury, Peggy; Sultan, Emmanuelle. |
| In coastal systems, the multiplicity of sources fueling the pool of particulate organic matter (POM) leads to divergent estimations of POM composition. Eleven systems (two littoral systems, eight embayments and semi-enclosed systems and one estuary) distributed along the three maritime façades of France were studied for two to eight years in order to quantify the relative contribution of organic matter sources to the surface-water POM pool in coastal systems. This study was based on carbon and nitrogen elemental and isotopic ratios, used for running mixing models. The POM of the estuary is dominated by terrestrial material (93% on average), whereas the POM of the other systems is dominated by phytoplankton (84% on average). Nevertheless, for the latter... |
| Tipo: Text |
Palavras-chave: Particulate organic matter; Coastal systems; C and N stable isotopes; C:N ratio; Mixing model. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00374/48550/48871.pdf |
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| Leroy, Fanny; Meziane, Tarik; Riera, Pascal; Comtet, Thierry. |
| Recruitment success of marine invertebrate populations not only depends on the number of recruits but also on their quality which affects their survival. In species characterized by a mixed development (encapsulated embryonic development and release of planktotrophic larvae), the offspring quality depends on both maternal provisioning and larval feeding. Here, we investigated potential changes of maternal provisioning over the whole reproductive period in a gastropod with a mixed development: Crepidula fornicata. In its introduction area, C. fornicata reproduces from February to October, which implies that both adults and larvae are exposed to different food availabilities. Maternal provisioning was assessed by measuring the fatty acid (FA) composition of... |
| Tipo: Text |
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| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00374/48498/48825.pdf |
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| Riera, Pascal. |
| This study examined the delta(15)N of suspended and sedimented particulate organic matter, primary sources of organic matter and benthic invertebrates along an estuarine gradient in Marennes-Oleron Bay, France. Particular emphasis was given to the use of delta(15)N as a tracer of the origin of organic matter and as a means of determining the benthic food web structure in estuarine environments. delta(15)N values indicated that there was direct utilisation of benthic diatoms as a food source by oyster Crassostrea gigas near intertidal mudflats but suggested trophic mediation between terrestrial detritus and oysters in the upper estuarine reaches. delta(15)N data showed that the trophic position of oysters may vary in the estuarine bay. The delta(15)N values... |
| Tipo: Text |
Palavras-chave: Nitrogen isotope ratio; Particulate organic matter; Crassostrea gigas; Benthic food web; Estuary; Marennes-Oleron Bay. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00448/55926/57786.pdf |
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| Leroy, Fanny; Comtet, Thierry; Brante, Antonio; Leroux, Cedric; Riera, Pascal. |
| Many marine gastropod species brood their embryos in thin-walled capsules to protect them during development. Despite its beneficial effects, encapsulation has two major constraints, nutrition and oxygen supply, which affect embryo development and larval survival. Developing embryos usually rely on intracapsular food sources provided by the mother, in the form of yolk, nurse eggs and intracapsular fluid. However, it is still not clear if they are able to feed on extracapsular sources that may cross the capsule wall. We investigated this possibility in the calyptraeid species Crepidula fornicata. In this species, the internal capsule wall thickness sharply decreases during embryonic development, which might change wall permeability to small organic... |
| Tipo: Text |
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| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00374/48507/48774.pdf |
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| Kostecki, Caroline; Le Loc'H, F.; Roussel, J. -m.; Desroy, Nicolas; Huteau, D.; Riera, Pascal; Le Bris, H.; Le Pape, Olivier. |
| Estuaries are essential fish habitats because they provide nursery grounds for a number of marine species. Previous studies in the Bay of Vilaine (part of the Bay of Biscay, France) have underlined the estuarine dependence of juvenile common sole (Solea solea, L) and shown that the extent of sole nursery grounds was positively influenced by the variability of the river flow. In the present study, stable carbon and nitrogen isotopes were used to describe the trophic network until the young-of-the-year sole and to compare interannual variations in the dominant trophic pathways in the sole nursery areas in this bay. Particulate organic matter (POM), sediment organic matter (SOM), microphytobenthos, benthic invertebrate sole prey and young-of-the-year common... |
| Tipo: Text |
Palavras-chave: Juvenile Common Sole; Stable Isotopes; Estuarine Nursery Grounds; Food Web; Eastern Atlantic. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00008/11923/8641.pdf |
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| Le Pape, Olivier; Moderan, J.; Beaunee, G.; Riera, Pascal; Nicolas, Delphine; Savoye, N.; Harmelin-vivien, M.; Darnaude, A. M.; Brind'Amour, Anik; Le Bris, H.; Cabral, H.; Vinagre, C.; Pasquaud, S.; Franca, S.; Kostecki, Caroline. |
| Coastal and estuarine nursery grounds are essential habitats for sustaining flatfish stocks since only these shallow and productive areas provide the high food supply that allows maximizing juvenile growth and survival in most flatfish species. However, the main organic matter sources at the basis of benthic food webs might differ drastically between estuarine nursery grounds under strong freshwater influences, where food webs are mainly supported by continental organic matter, and coastal ecosystems under limited freshwater influence, where the local marine primary production is the main source of carbon for the benthos. To better understand the links between continental inputs to the coastal zone and stock maintenance in the highly prized common sole,... |
| Tipo: Text |
Palavras-chave: Nursery ground; Flatfish; Organic matter origin; Stable isotopes; Mixing model SIAR. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00118/22889/20796.pdf |
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| Riera, Pascal; Montagna, Pa; Kalke, Rd; Richard, Pierre. |
| The trophic dynamic Links of migratory juvenile brown shrimp Penaeus aztecus were investigated along the South Texas coast from the Aransas Pass to Corpus Christi and Nueces Bay and to the nursery ground in the Nueces Delta. Shrimps and their potential food sources were measured for delta(13)C and delta(15)N ratios between December 1995 and July 1996. During this period, shrimp length increased from 10 to 11 mm, when the animals entered Corpus Christi Bay as larvae, to 80-90 mm, when they returned to Mexico Gulf as sub-adults. Brown shrimp exhibited spatial and temporal delta(13)C variation (from -25.2 to 12.5 parts per thousand), indicating a high diversity of food sources throughout their migration. From delta(13)C values, the main sources used as food... |
| Tipo: Text |
Palavras-chave: Penaeus aztecus; Food sources; Migration; Nursery area; Delta C 13 and delta N 15. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00000/10496/7604.pdf |
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| Registros recuperados: 10 | |
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