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| Registros recuperados: 115 | |
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| Pete, Romain; Guyondet, Thomas; Bec, Beatrice; Derolez, Valerie; Cesmat, Ludovic; Lagarde, Franck; Pouvreau, Stephane; Fiandrino, Annie; Richard, Marion. |
| The decrease of microbial and nutrient inputs from the watershed has long dominated lagoon ecosystem management objectives. Phytoplankton biomass and abundance have drastically decreased for more than a decade and Zostera meadow have gradually recovered, expressing lagoon ecosystem restoration such as Thau lagoon. Do the progressive achievement of the good ecological status of the Thau lagoon possibly threatens the shellfish industry in terms of production and oyster quality, by reducing the carrying capacity? To provide answers about the right balance to be achieved between conservation and exploitation, a new numerical tool was developed to help in decision-making. We hereby propose to incorporate a Dynamic Energy Budget type shellfish production model... |
| Tipo: Text |
Palavras-chave: Shellfish farming; Carrying capacity; Stakeholder implication; Nitrogen and phosphorus inputs; Water frame directive; Ecological indicators; Phytoplankton depletion; Coupled biogeochemical-deb model. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00622/73395/75312.pdf |
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| Thomas, Yoann; Pouvreau, Stephane; Alunno-bruscia, Marianne; Barille, Laurent; Gohin, Francis; Bryere, Philippe; Gernez, Pierre. |
| Aim The spread of non-indigenous species in marine ecosystems world-wide is one of today's most serious environmental concerns. Using mechanistic modelling, we investigated how global change relates to the invasion of European coasts by a non-native marine invertebrate, the Pacific oyster Crassostrea gigas. Location Bourgneuf Bay on the French Atlantic coast was considered as the northern boundary of C. gigas expansion at the time of its introduction to Europe in the 1970s. From this latitudinal reference, variations in the spatial distribution of the C. gigas reproductive niche were analysed along the north-western European coast from Gibraltar to Norway. Methods The effects of environmental variations on C. gigas physiology and phenology were studied... |
| Tipo: Text |
Palavras-chave: Biogeographical range expansion; Crassostrea gigas; DEB model; European coasts; Functional traits; Global change; Individual-based model; Invasive species; Remote-sensing. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00287/39828/38459.pdf |
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| Pouvreau, Stephane; Bernard, Ismael; Le Souchu, Pierrick; Huvet, Arnaud; Talarmain, Eric; Auby, Isabelle; Maurer, Daniele; Barbier, Claire; Tournaire, Marie-pierre; D'Amico, Florence; Rumebe, Myriam; Neaud-masson, Nadine; Bedier, Edouard; Martin, Anne-genevieve; Claude, Serge; Langlade, Aime; Bouget, Jean-francois; Hitier, Benoist; Stanisiere, Jean-yves; Breerette, Stephane; Robert, Stephane; Guilpain, Patrice; Seugnet, Jean-luc; Guesdon, Stephane; Soletchnik, Patrick; Le Moine, Olivier; Dumas, Franck; Quemener, Loic; Barbot, Stephane; Repecaud, Michel; Mille, Dominique; Geay, A; Bouquet, Anne-lise. |
| L’ostréiculture constitue la principale activité aquacole française. Cette activité de quasi-monoculture, basé sur l’élevage de l’huître creuse, Crassostrea gigas, repose en grande partie sur le recrutement naturel de l’espèce qui assure 70% des besoins en jeunes huîtres (naissain). Or, depuis une dizaine d'années, dans les bassins d'Arcachon et de Marennes-Oléron, principaux centres de captage français pour l’huître creuse, la collecte du naissain ou captage devient encore plus variable qu’auparavant: à des années de captage presque nul (par exemple les années 2002, 2005, 2007) succèdent des années où il est surabondant (par exemple les années 2003 ou 2006). En parallèle, et probablement en raison du progressif réchauffement des eaux, la reproduction de... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00054/16489/13995.pdf |
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| Colsoul, Bérenger; Pouvreau, Stephane; Di Poi, Carole; Pouil, Simon; Merk, Verena; Peter, Corina; Boersma, Maarten; Pogoda, Bernadette. |
| The European flat oyster (Ostrea edulis) is an ecosystem engineer that provides important biogenic reef habitat with associated ecosystem functions and services. Most stocks have been commercially exploited and degraded; some are functionally extinct. Ecological restoration now aims to recover these degraded, damaged or destroyed ecosystems. Availability of seed oysters and substrate for successful larval recruitment has been identified as a major limiting factor for restoration projects in Europe. In substrate‐limited areas, restoration approaches have to involve the restoration of suitable substrates. The present study provides an evaluation of such potential substrate types. Various categories were investigated through hatchery and/or field experiments:... |
| Tipo: Text |
Palavras-chave: Coastal; Invertebrates; Restoration; Settlement; Substrates. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00658/77058/78357.pdf |
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| Royer, J; Seguineau, Catherine; Park, K; Pouvreau, Stephane; Choi, K; Costil, K. |
| Two methods were used to estimate the reproductive output of female Pacific oysters reared in Normandy: histology with image analysis and ELISA (Enzyme-Linked lmmunoSorbent Assay) which allowed the quantification of egg protein. Condition indices, gonad area and gametogenetic stages of the oysters were determined in the entire population (males and females) between May and October 2005. All investigations were performed in 3 age classes: oysters in their first, second or third years (corresponding to spat, half-grown and market-sized oysters, respectively). Both quantitative histology and ELISA provided similar results in terms of reproductive effort (illustrated by the gonado-somatic index, GSI) except during the GSI drop, corresponding to spawning, which... |
| Tipo: Text |
Palavras-chave: Reproductive effort; Image analysis; Gametogenetic cycle; ELISA; Crassostrea gigas; Condition index. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4305.pdf |
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| Alunno-bruscia, Marianne; Bourles, Yves; Maurer, Daniele; Robert, Stephane; Mazurie, Joseph; Gangnery, Aline; Goulletquer, Philippe; Pouvreau, Stephane. |
| Many studies based on bioenergetics growth models have investigated the effects of environmental factors on oyster (Crassostrea gigas) growth and physiology. However, most of these models are site-specific and cannot be applied to other culture sites without the re-estimation of parameters or re-formulation of some processes. We aimed to develop a generic growth model suitable for application in contrasting environments, with a constant set of parameters. We tested the oyster-DEB model (Bourlès et al. 2009) for the stimulation of C. gigas growth in different cohorts (spats and adults) at major shellfish culture sites in France, in several years: Arcachon (1993–1994); Marennes-Oléron (2007); Quiberon (1999, 2000, 2001); Rade de Brest (2008); Baie du... |
| Tipo: Text |
Palavras-chave: DEB theory; Modelling; Bivalves; Crassostrea gigas; Phytoplankton; Temperature effect; Coastal environment.. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00043/15403/12762.pdf |
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| Pouvreau, Stephane; Tiapari, Jerome; Gangnery, Aline; Lagarde, Franck; Garnier, Matthieu; Teissier, Hinano; Haumani, G; Buestel, Dominique; Bodoy, Alain. |
| Growth of the black-lip pearl oyster, Pinctada margaritifera var. cumingi, was studied for an annual cycle, from March 1997 to April 1998, in the lagoon of Takapoto atoll (Tuamotu archipelago, French Polynesia). Growth in shell and in tissue were measured every 15 days on three successive age groups of cultivated pearl oysters. At the same time, hydrobiological parameters (temperature, salinity, oxygen concentration, suspended particulate matter), known to have influence on bivalve growth, were followed each week during culture. No seasonal trend was observed in hydrobiological parameters, except for temperature which varied between 26 degrees C and 31 degrees C. The potential food for pearl oysters (particulate organic matter, POM, mg l(-1)) was slightly... |
| Tipo: Text |
Palavras-chave: Pearl culture; Matter in suspension; Biochemical composition; Length weight relations ship; Tropical lagoon; Growth; Pinctada margaritifera. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-381.pdf |
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| Lagarde, Franck; Roque D'Orbcastel, Emmanuelle; Ubertini, Martin; Mortreux, Serge; Bernard, Ismael; Fiandrino, Annie; Chiantella, Claude; Bec, Beatrice; Roques, Cecile; Bonnet, Delphine; Miron, Gilles; Richard, Marion; Pouvreau, Stephane; Lett, Christophe. |
| In the context of increasing demand for environmental recovery, aquatic systems may face the challenge of evolving under oligotrophication. This is the case in Mediterranean lagoons, in particular the shellfish-farmed Thau lagoon in France, where we studied recruitment of the Pacific oyster Crassostrea gigas. Oyster spat and environmental parameters were monitored at several sampling sites for 3 yr (2012 to 2014) using an original method with a temporal overlap deployment of collectors to study pre- and post-settlement processes and to identify the best conditions for recruitment. Contrary to the ‘no Pacific oyster reproduction’ paradigm in Mediterranean lagoons, our study showed that recruitment of this introduced species is possible in the Thau lagoon at... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Oyster spat; Pediveliger; Metamorphosis; Recruitment; Oligo trophication; Larval ecology. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00398/50899/51672.pdf |
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| Gasmi, Sonia; Bernard, Ismael; Pouvreau, Stephane; Maurer, Daniele; Schaal, Gauthier; Ganthy, Florian; Cominassi, Louise; Allain, Gwenhael; Sautour, Benoit; David, Valerie. |
| In macrotidal coastal ecosystems, spatial heterogeneity of the water column properties is induced by both oceanic and continental influences. Hydrodynamic processes generate a land-sea gradient of environmental conditions, affecting the biological performances of sedentary organisms. The aim of the present study is to establish an extensive spatial assessment in the reproductive investment of the wild Pacific oyster Crassostrea gigas in Arcachon Bay. This is done by looking for a relationship between the Lawrence and Scott condition index (LSCI) and two tidal processes: the immersion level (IL) and the local oceanic flushing time (LoFt). The LSCI of C. gigas was assessed, just before gamete release, at 68 sampling stations in Arcachon Bay. Oyster... |
| Tipo: Text |
Palavras-chave: Reproductive investment; Crassostrea gigas; Macrotidal lagoon; Immersion level; Oceanic flushing; Environmental variability. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00357/46803/46670.pdf |
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| Mérou, Nicolas; Lecadet, Cyrielle; Pouvreau, Stephane; Arzul, Isabelle. |
| Environmental DNA approaches are increasingly used to detect microorganisms in environmental compartments, including water. They show considerable advantages to study non‐cultivable microorganisms like Bonamia ostreae, a protozoan parasite inducing significant mortality in populations of flat oyster Ostrea edulis . Although B. ostreae development within the host has been well described, questions remain about its behaviour in the environment. As B. ostreae transmission is direct, seawater appears as an interesting target to develop early detection tools and improve our understanding of disease transmission mechanisms. In this context, we have developed an eDNA/eRNA approach allowing detecting and quantifying B. ostreae 18S rDNA/rRNA as well as monitoring... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00636/74800/75174.pdf |
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| Gonzales, Arriagada; Bernard, Ismael; Maurer, Daniele; Auby, Isabelle; Gasmi, Sonia; Pouvreau, Stephane; David, Valerie. |
| Arcachon Bay is one of the most important spat-supplying area for the French oyster production. During the last 16 years, the local economic activity of spat production has been threatened recurrently by a high interannual variability of seed harvesting. This threatened spat production was attributed to reproductive problems highlighted by both a delay in oyster spawning and a decrease of small larvae abundances since 1995. Recent works showed that these two reproduction indices seem closely related to climate change that might controls the phytoplankton communities of the Bay. Food availability in term of quantity and quality appears thus as a serious track to understand the reproductive problems of oyster in the Arcachon Bay. The aim of this work was... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00257/36828/35454.pdf |
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| Ubertini, Martin; Lagarde, Franck; Le Gall, Patrik; Mortreux, Serge; Pernet, Fabrice; Fiandrino, Annie; Pouvreau, Stephane; Roque D'Orbcastel, Emmanuelle. |
| The aquaculture of the oyster Crassostrea gigas is largely based on natural recruitment of the species on spat collectors along the french Atlantic coast, the remaining spat being provided by hatcheries and nurseries. Due to an increase in the climate/meteorological variability, during the last twenty years, the natural spat collection has become variable, from null to overabundant depending on the year. Since 2008, the oyster spat mortalities worsen the situation, reducing the available spat and increasing the cost of the latter. However, the temporal variability of the natural recruitment modalities in the Mediterranean do not allow the aquaculture industry to rely on native spats, making the understanding of natural recruitment in the Mediterranean a... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00248/35894/34422.pdf |
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| Lagarde, Franck; Richard, Marion; Bec, Beatrice; Roques, Cecile; Mortreux, Serge; Bernard, Ismael; Chiantella, Claude; Messiaen, Gregory; Nadalini, Jean-bruno; Hori, Masakazu; Hamaguchi, Masami; Pouvreau, Stephane; Roque D'Orbcastel, Emmanuelle; Tremblay, Rejean. |
| Reproduction and recruitment of benthic invertebrates are influenced by the climate and by the ecological structure of marine ecosystems, along with local anthropogenic pressures such as eutrophication or oligotrophication. Using the Pacific oyster Crassostrea gigas as a biological model, we tested the hypothesis that the variability in prodissoconch II (PII) size (i.e. size at metamorphosis) depends on ecological functioning. Settlement and recruitment were assessed at 5 sampling sites on the French Mediterranean shellfish farmed Thau lagoon during the main summer recruitment events in 3 consecutive years (2012-2014). Hydrobiological and planktonic analyses were conducted at 3 sampling sites. Our results showed that recruitment was extremely... |
| Tipo: Text |
Palavras-chave: Larval ecology; Recruitment; Prodissoconch II; Crassostrea gigas; Oligotrophication; Cryptophytes; Thau lagoon. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00454/56613/58334.pdf |
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| Lambert, C.; Moal, J.; Pouvreau, Stephane; Le Moullac, Gilles; Samain, Jean-francois. |
| Les mortalités apparaissent toujours très rapidement après le passage de la température de l'eau à 19°C. II a bien été montré que ce n'était pas la valeur absolue de la température qui était associée à la mortalité, puisque des années très chaudes comme 2003, peu de mortalités étaient enregistrées. II s'agit plutôt d'un seuil à partir duquel le risque devient réel. La température affecte tous les processus de la physiologie et c'est un facteur clef de la distribution géographique des espèces. Les espèces se maintiennent dans les conditions environnementales qui ont permis leur adaptation. Les mortalités traduisent donc une rupture de l'adaptation ou une modification brutale de l'environnement qui peut affecter les équilibres qui se sont installés entre... |
| Tipo: Text |
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| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00304/41537/40745.pdf |
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| Dauphin, Yannicke; Ball, Alexander D.; Castillo-michel, Hiram; Chevallard, Corinne; Cuif, Jean-pierre; Farre, Bastien; Pouvreau, Stephane; Salome, Murielle. |
| Cultivation of commercial oysters is now facing the possible influence of global change in sea water composition, commonly referred to as "ocean acidification". In order to test the potential consequence of the predicted environmental changes, a cultivation experiment was carried out. The left and right valves of the oyster shell Crassostrea gigas differ in their structure; moreover, lenses of non compact layers are irregular. The shell layers of juvenile C. gigas are studied using a variety of highly spatially resolved techniques to establish their composition and structure. Our results confirm the presence of three different calcitic structural types. The role of the lenses of chalky layers is not yet deciplered. Despite a common mineralogy, the... |
| Tipo: Text |
Palavras-chave: Biomineral; Mollusc shell; Infrared spectroscopy; Laser confocal Microscope; Micro-XANES. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00118/22890/20797.pdf |
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| Fournier, Jonathan; Dupuy, Celie; Bouvy, Marc; Couraudon-reale, Marine; Charpy, Loic; Pouvreau, Stephane; Le Moullac, Gilles; Le Pennec, Marie-annick; Cochard, Jean-claude. |
| In atoll lagoons of French Polynesia, growth and reproduction of pearl oysters are mainly driven by plankton concentration. However, the actual diet of black-lip pearl oysters P. margaritifera in these lagoons is poorly known. To fill this gap, we used the flow through chamber method to measure clearance rates of P. margaritifera in Ahe atoll lagoon (Tuamotu Archipelago, French Polynesia). We found : (i) that pearl oysters cleared plankton at a rate that was positively related to plankton biovolume, (ii) that nanoflagellates were the main source of carbon for the pearl oysters, (iii) that the quantity and origin of carbon filtrated by pearl oysters was highly dependent on the concentration and composition of plankton. These results provide essential... |
| Tipo: Text |
Palavras-chave: Pinctada margaritifera; Clearance rates; French Polynesia; Phytoplankton; Protists. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00078/18888/16599.pdf |
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| Bernard, I.; Massabuau, J. -c.; Ciret, P.; Sow, M.; Sottolichio, Aldo; Pouvreau, Stephane; Tran, D.. |
| The precise environmental conditions under which broadcast spawners spawn in the field remain largely unknown. We investigated this issue in the oyster Crassostrea gigas using three different methods at different time scales in two traditional oyster farming areas of the French Atlantic Coast, the Bay of Arcachon and Marennes-Oléron. We directly recorded spawning at high temporal resolution using high-frequency non-invasive (HFNI) valvometry from 2007–2014 and measured the dry mass and oyster larvae abundance in 2008 and 2009. We analyzed a 29-yr series of oyster D-larvae numbers in the Bay of Arcachon (1982–2010). By combining these three approaches, we demonstrated that during the summer months at both sites, spawning in C. gigas occurs in the morning or... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00312/42335/41666.pdf |
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| Registros recuperados: 115 | |
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