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| Leguerrier, D; Degre, Delphine; Niquil, N. |
| Network analysis was used to analyse steady-state models of the food webs of two intertidat mudflat ecosystems: Aiguillon Cove and Brouage Mudflat, on the South-Western Atlantic Coast of France. The aim was to highlight emergent properties of food-web functioning in these two ecosystems and to compare these properties with other coastal ecosystems. Both ecosystems imported detritus in parallel to a high benthic primary production. They were characterised by a high diversity of resources. Both also exported living material, leading to a high quality production, quantified as export of Exergy. This export was mainly composed of cultivated bivalves during the cold season for Brouage Mudflat, and of the migration of grazing fish in Aiguillon Cove during the... |
| Tipo: Text |
Palavras-chave: Atlantic coast; Intertidal mudflat; Network analysis; Inverse analysis; Ecosystem comparison; Food web. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3696.pdf |
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| Casas, Stellio; Bacher, Cedric. |
| Bioaccumulation of metal within an organism results from interactions between physiological factors (growth, weight loss, absorption and accumulation), chemical factors (metal concentration, speciation and bioavailability) and environmental factors (temperature and food concentration). To account for such interactions in the mussel Mytilus galloprovincialis, we combined bioaccumulation and Dynamic Energy Budget models. Field experiments were conducted to measure uptake and elimination kinetics for two metals (Hg and Pb) in three Mediterranean sites with differences in contamination levels, and to calibrate the models. Metal uptake from water and from food was considered separately. Metal elimination resulted from reproduction and/or from direct excretion.... |
| Tipo: Text |
Palavras-chave: RINBIO; Inverse analysis; Dynamic Energy Budget; Bio indicator. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1965.pdf |
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| Niquil, Nathalie; Kerleguer, G; Leguerrier, D; Richard, Pierre; Legrand, Helene; Dupuy, Christine; Pascal, P; Bacher, Cedric. |
| The presence of herbicides in the run-off water coming over Brouage mudflat (Marennes-Oleron Bay, France) is suspected to cause a loss of primary production by benthic diatom biofilm. Microphytobenthos being the main primary producer of this ecosystem, it was questioned about what could be the effect of such a modification of primary production on the entire food web that depends on it. The probable impacts were investigated through a sensitivity analysis conducted on the steady-state model of the Brouage mudflat, coupling two seasons and trophic-hydrodynamic flows. The loss of benthic primary production had an effect on compartments at a low trophic level, but was buffered at higher levels because of the compensation of herbivory by other pathways and... |
| Tipo: Text |
Palavras-chave: Intertidal mudflat food web; Pollution; Microphytobenthos; Inverse analysis; Sensitivity analysis. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3613.pdf |
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| Leguerrier, D; Niquil, Nathalie; Petiau, A; Bodoy, Alain. |
| We used a carbon-based food web model to investigate the effects of oyster cultivation on the ecosystem of an intertidal mudflat. A previously published food web model of a mudflat in Marennes-Oleron Bay, France, was updated with revised parameters, and a realistic surface area and density of existing oyster cultures on the mudflat. We developed 2 hypothetical scenarios to estimate the impact of oyster cultivation on the food web structure of the ecosystem: one with no oysters, the other with a doubled area devoted to cultivated oysters in the bay. Oysters are direct trophic competitors of other filter feeders, and their presence modifies benthic-pelagic coupling by forcing a shift from pelagic consumers to benthic consumers. Increasing the surface area of... |
| Tipo: Text |
Palavras-chave: Carbon flux; Inverse analysis; Food web; Network analysis; Bivalve culture. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/00000/10816/7583.pdf |
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| Degre, Delphine; Leguerrier, D; Du Chatelet, E; Rzeznik, J; Auguet, Jean-christophe; Dupuy, Christine; Marquis, E; Fichet, Denis; Struski, Caroline; Joyeux, E; Sauriau, Pierre-guy; Niquil, Nathalie. |
| Inverse analysis was used to model the food webs of two intertidal mudflat ecosystems: Aiguillon Cove (AC) and Brouage Mudflat (BM) (south-western Atlantic coast, France). The aim of the present study is to describe and compare the functioning of these two ecosystems. The method of inverse analysis has been adapted in order to take into account, in a single calculation, two seasons: spring/summer (mid-March to mid-October) and autumn/winter (the rest of the year). Gathering all available data on the two sites, the most important gaps in knowledge were identified with the help of sensitivity analyses: they concerned mainly the exports of material by grazing fish (such as mullet Liza ramada), resuspension of microphytobenthos, and fluxes linked to microfauna... |
| Tipo: Text |
Palavras-chave: Atlantic coast; Sensitivity analysis; Tidal flat; Inverse analysis; Steady state; Food web. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1863.pdf |
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| Leguerrier, Delphine; Niquil, Nathalie; Boileau, N; Rzeznik, J; Sauriau, Pierre-guy; Le Moine, Olivier; Bacher, Cedric. |
| Food web modelling is an ideal way to describe ecosystems, because it accounts for the totality of the relationships between its various components. One difficulty of such an approach, however, lies in the lack of data and information about some ecological relationships, resulting in under-defined systems. Inverse analysis can serve to complete steady-state food webs where the number of direct flow measurements is insufficient relative to the actual number of flows. We applied this method to the intertidal mudflat ecosystem of Brouage (eastern Marennes-Oleron Bay, SW France) and estimated the annual average carbon flows between the compartments of a coupled benthic and pelagic trophic food web from primary producers (microphytobenthos and phytoplankton) to... |
| Tipo: Text |
Palavras-chave: Network analysis; Food web; Inverse analysis; Carbon flow. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-3134.pdf |
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