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| Registros recuperados: 31 | |
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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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| Thomas, Yoann; Garen, Pierre; Bennett, Auguste; Le Pennec, Marcel; Clavier, Jacques. |
| Bivalve larvae and hydrographic parameters were sampled over a range of spatio-temporal scales in a deep atoll lagoon. Bivalve larvae abundances were very high throughout the year: 18,550 m(-3) in average. Larvae were (i) concentrated at mid-depth with nocturnal ascent and diurnal descent, (ii) heterogeneously dispersed at the lagoon scale, (iii) subject to day-to-day variation in abundance and (iv) transferred between different parts of the lagoon providing evidence of intra-lagoonal connectivity. The primacy of physical factors was seen on large spatial scale with the diluting effect of water renewal and transfers by hydrodynamics. On smaller spatial scale, the primacy of biological processes was recognised, with larval swimming activity leading to dial... |
| Tipo: Text |
Palavras-chave: Bivalve larvae; Distribution patterns; Vertical migration; Pinctada margaritifera settlement; Deep atoll lagoon; French Polynesia. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00101/21200/20690.pdf |
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| Sussarellu, Rossana; Suquet, Marc; Thomas, Yoann; Lambert, Christophe; Fabioux, Caroline; Pernet, Marie Eve Julie; Le Goic, Nelly; Quillien, Virgile; Mingant, Christian; Epelboin, Yanouk; Corporeau, Charlotte; Guyomarch, Julien; Robbens, Johan; Paul-pont, Ika; Soudant, Philippe; Huvet, Arnaud. |
| Plastics are persistent synthetic polymers that accumulate as waste in the marine environment. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Because filter-feeder organisms ingest MP while feeding, they are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (micro-PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 0.023 mg·L−1) for 2 mo during a reproductive cycle. Effects were investigated on ecophysiological parameters; cellular, transcriptomic, and proteomic responses; fecundity; and offspring development. Oysters preferentially ingested the 6-µm micro-PS... |
| Tipo: Text |
Palavras-chave: Microplastic; Reproduction; Energy allocation; Oyster. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00311/42233/41600.pdf |
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| Lemonnier, Hugues; Thomas, Yoann; Legrand, Alexandre; Martin, Jean-louis; Herbland, Alain. |
| In the booming context of shrimp culture in French Caledonia, some research actions need to be considered in order (i) to make sure this production will not impact the quality and biodiversity of the coastal environment it is contingent upon (ii) for the field to highlight, based on objective bases, its good "environmental image", for an efficient commercialization of its products. In the framework of the MOM project, a number of actions have been carried out: Action 1: A bibliographical synthesis of the impact of shrimp culture on coastal environment has been conducted, taking into account the works carried out throughout the world and in French Caledonia in order to draw the main issues the Territory will have to deal with. It seems necessary to start... |
| Tipo: Text |
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| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/rapport-6593.pdf |
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| Sangare, Nathanael; Lo-yat, Alain; Le Moullac, Gilles; Pecquerie, Laure; Thomas, Yoann; Beliaeff, Benoit; Andrefouet, Serge. |
| In French Polynesia black pearl farming represents one of the dominant business sectors. However, it still entirely relies on unpredictable Pinctada margaritifera spat collection success, which is itself conditioned by larval development completion. To assess the relationship between larval development and recruitment success, we studied under controlled conditions the effect of food concentration on development, growth, ingestion rate, survival and metabolic rate at the larval stage. Larvae were exposed to four different phytoplankton densities (2,5; 7,5; 15 and 30 cell.μL−1). Larvae survived equally all over the range of phytoplankton concentration with an average survival rate of 16% at the end of experiments. Food concentration significantly affected... |
| Tipo: Text |
Palavras-chave: Bivalve larvae; Pinctada margaritifera; Physiology; Energetics; Dynamic energy budget theory; Pearl farming; Aquaculture. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00476/58795/61446.pdf |
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| Andrefouet, Serge; Thomas, Yoann; Dumas, Franck; Lo, Cedrik. |
| Spat collecting of the black lip oyster (Pinctada margaritifera) is the foundation of cultured black pearl production, the second source of income for French Polynesia. To understand spat collecting temporal and spatial variations, larval supply and its origin need to be characterized. To achieve this, it is necessary to account for the stock of oysters, its distribution and population characteristics (size distribution, sex-ratio). While the farmed stock in concessions can be easily characterized, the wild stock is elusive. Here, we investigate the distribution and population structure of the wild stock of Ahe and Takaroa atolls using fine-scale bathymetry and in situ census data. Stocks were surprisingly low (∼666,000 and ∼1,030,000 oysters for Ahe and... |
| Tipo: Text |
Palavras-chave: Invertebrate population; Aquaculture; Spat collecting; French Polynesia; Atoll bathymetry; Wild stock assessment. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00343/45412/49287.pdf |
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| Thomas, Yoann; Cassou, Christophe; Gernez, Pierre; Pouvreau, Stephane. |
| Beyond key ecological services, marine resources are crucial for human food security and socio-economical sustainability. Among them, shellfish aquaculture and fishing are of primary importance but become more vulnerable under anthropogenic pressure, as evidenced by reported mass mortality events linked to global changes such as ocean warming and acidification, chemical contamination, and diseases. Understanding climate-related risks is a vital objective for conservation strategies, ecosystems management and human health. We provide here a comprehensive study of the historical mortality of adult oysters related to observed climate variability along the French Atlantic coast from 1986 to 2015, and we built on this knowledge to develop hindcast and forecast... |
| Tipo: Text |
Palavras-chave: North Atlantic; Weather regime; Oyster; Monitoring network; Mortality risk assessment; Climate models; RCP scenarios. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00461/57255/59281.pdf |
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| Thomas, Yoann; Flye Sainte Marie, Jonathan; Chabot, Denis; Aguirre-velarde, Arturo; Marques, Gonçalo M; Pecquerie, Laure. |
| Hypoxia is a decrease in dissolved oxygen that causes physiological disturbances in marine fishes and invertebrates, including reduced mobility, growth rate and reproductive success, altered phenology and increased vulnerability to diseases. Under pressure from global changes such as warming or eutrophication, ocean and coastal ecosystems worldwide are becoming less oxygenated. In order to better understand the consequences of hypoxia on marine systems, there is a need for predicting hypoxia-induced changes from individual organisms to populations. By combining the effect of several stressors on species metabolic performances and life-history traits across their full life-cycle, the Dynamic Energy Budget (DEB) theory offers a suitable framework for... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00473/58466/65967.pdf |
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| Pousse, Emilien; Flye-sainte-marie, Jonathan; Alunno-bruscia, Marianne; Hegaret, Helene; Rannou, Eric; Pecquerie, Laure; Marques, Goncalo M.; Thomas, Yoann; Castrec, Justine; Fabioux, Caroline; Long, Marc; Lassudrie, Malwenn; Hermabessiere, Ludovic; Amzil, Zouher; Soudant, Philippe; Jean, Fred. |
| As other filter-feeders, Crassostrea gigas can concentrate paralytic shellfish toxins (PST) by consuming dinoflagellate phytoplankton species like Alexandrium minutum. Intake of PST in oyster tissues mainly results from feeding processes, i.e. clearance rate, pre-ingestive sorting and ingestion that are directly influenced by environmental conditions (trophic sources, temperature). This study aimed to develop a mechanistic model coupling the kinetics of PST accumulation and bioenergetics in C. gigas based on Dynamic Energy Budget (DEB) theory. For the first time, the Synthesizing Units (SU) concept was applied to formalize the feeding preference of oysters between non-toxic and toxic microalgae. Toxin intake and accumulation were both dependent on the... |
| Tipo: Text |
Palavras-chave: Alexandrium minutum; Paralytic shellfish toxins (PST); Dynamic Energy Budget (DEB); Modelling; Pacific oyster. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00455/56662/58407.pdf |
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| Thomas, Yoann; Mazurie, Joseph; Alunno-bruscia, Marianne; Bacher, Cedric; Bouget, Jean-francois; Gohin, Francis; Pouvreau, Stephane; Struski, Caroline. |
| In order to assess the potential of various marine ecosystems for shellfish aquaculture and to evaluate their carrying capacities, there is a need to clarify the response of exploited species to environmental variations using robust ecophysiological models and available environmental data. For a large range of applications and comparison purposes, a non-specific approach based on ‘generic’ individual growth models offers many advantages. In this context, we simulated the response of blue mussel (Mytilus edulis L.) to the spatio-temporal fluctuations of the environment in Mont Saint-Michel Bay (North Brittany) by forcing a generic growth model based on Dynamic Energy Budgets with satellite-derived environmental data (i.e. temperature and food). After a... |
| Tipo: Text |
Palavras-chave: Mussel; DEB; SeaWifs; Aquaculture; Site Selection; Resource Management. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00037/14836/14537.pdf |
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| Sangare, Nathanael; Lo-yat, Alain; Le Moullac, Gilles; Pecquerie, Laure; Thomas, Yoann; Lefebvre, Sebastien; Le Gendre, Romain; Beliaeff, Benoit; Andréfouët, Serge. |
| The black-lipped pearl oyster (Pinctada margaritifera) is extensively farmed in French Polynesia to produce black pearls. For a sustainable management of marine resources, studying interactions between organisms and environment, and the associated factors and processes that will impact their life cycle and thus modulate population dynamics is a major research priority. Here, we describe black-lipped pearl oyster energy acquisition and use, and its control by temperature and food concentration within the Dynamic Energy Budget (DEB) theory framework. The model parametrization was based on literature data and a specific laboratory experiment. Model validation was carried out thanks to historical in-situ datasets and a dedicated field survey. Three theoretical... |
| Tipo: Text |
Palavras-chave: Bivalve; Physiology; Bioenergetics; Dynamic energy budget theory; Environmental change; Pearl farming. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00613/72469/71614.pdf |
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| Barillé, Laurent; Bris, Anthony Le; Goulletquer, Philippe; Thomas, Yoann; Glize, Philippe; Kane, Frank; Falconer, Lynne; Guillotreau, Patrice; Trouillet, Brice; Palmer, Stéphanie; Gernez, Pierre. |
| Oyster production has historically taken place in intertidal zones, and shellfish farms already occupy large extents of the French intertidal space. The expansion of French shellfish aquaculture within intertidal areas is therefore spatially limited, and moving production to the subtidal offshore environment is considered to be a possible solution to this problem. Finding new sites along the French Atlantic coast was studied here from the perspective of small oyster companies run by young farmers, who are interested in offshore bivalve aquaculture expansion compatible with their investment capacity. In assessing the feasibility of such offshore production, we considered three main issues: (1) bivalve growth potential and (2) technical feasibility and... |
| Tipo: Text |
Palavras-chave: Pacific oyster; Site selection; Off-shore aquaculture; Remote sensing; Dynamic energy budget (DEB) model. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00606/71819/70593.pdf |
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| Bacher, Cedric; Thomas, Yoann; Alunno-bruscia, Marianne; Mazurie, Joseph. |
| The advent of remote sensing in biological oceanography in the 1990s offers a very powerful tool able to capture temporal and spatial changes of chlorophyll-a concentration and temperature at several temporal scales (decadal, inter annual and seasonal), and at local as well as at the oceanic scale. Such data have the advantage over traditional measurements of being inexpensive, spatially extensive, automatically repeated in time and validated. They have been very useful for phytoplankton monitoring in relation to eutrophication in coastal waters and the number of applications in the field of coastal zone management is growing. We present here a real case application to shellfish aquaculture. We assessed the potential for mussel aquaculture in Mont Saint... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00083/19459/17093.pdf |
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| Huvet, Arnaud; Beguel, Jean-philippe; Pereira Cavaleiro, Nathalia; Thomas, Yoann; Quillien, Virgile; Boudry, Pierre; Alunno-bruscia, Marianne; Fabioux, Caroline. |
| Feeding strategies and digestive capacities can have important implications for variation in energetic pathways associated with ecological and economically important traits, such as growth or reproduction in bivalve species. Here, we investigated the role of amylase in the digestive processes of Crassostrea gigas, using in vivo RNA interference. This approach also allowed us to investigate the relationship between energy intake by feeding and gametogenesis in oysters. Double-stranded (ds)RNA designed to target the two α-amylase genes A and B was injected in vivo into the visceral mass of oysters at two doses. These treatments caused significant reductions in mean mRNA levels of the amylase genes: −50.7% and −59% mRNA A, and −71.9% and −70.6% mRNA B in 15... |
| Tipo: Text |
Palavras-chave: Alpha-Amylase; DsRNA; Gametogenesis; Marine bivalve; Dynamic energy budget. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00271/38239/36422.pdf |
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| Fleury, Elodie; Barbier, Pierrick; Petton, Bruno; Normand, Julien; Thomas, Yoann; Pouvreau, Stephane; Daigle, Gaétan; Pernet, Fabrice. |
| Diseases pose an ongoing threat to aquaculture, fisheries and conservation of marine species, and determination of risk factors of disease is crucial for management. Our objective was to decipher the effects of host, pathogen and environmental factors on disease-induced mortality of Pacific oysters (Crassostrea gigas) across a latitudinal gradient. We deployed young and adult oysters at 13 sites in France and we monitored survival, pathogens and environmental parameters. The young oysters came from either the wild collection or the hatchery while the adults were from the wild only. We then used Cox regression models to investigate the effect of latitude, site, environmental factors and origin on mortality risk and to extrapolate this mortality risk to the... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00627/73915/73251.pdf |
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| Pagano, Marc; Sagarra, Pascual-boi; Champalbert, Gisele; Bouvy, Marc; Dupuy, Christine; Thomas, Yoann; Charpy, Loic. |
| Metazooplankton abundance, biomass (<80 mu m, 200-500 mu m and >500 mu m) and community structure in the Ahe atoll were studied together with their relationships with environmental factors (temperature, salinity, wind) and trophic factors (phytoplankton, bacteria, heterotrophic nanoflagellates (HNF) and ciliates) during three periods in 2008-2009. Meroplankton, mainly bivalve and gastropod larvae, was dominant. Holoplankton was dominated by copepods, the main species being Oithona spp., Paracalanus parvus, Clausocalanus spp., Corycaeus spp., Acartia fossae and Undinula vulgaris. The results suggest a clear wind influence on the structure and horizontal distribution of the zooplankton communities. The metazooplankton appeared to be controlled mainly... |
| Tipo: Text |
Palavras-chave: Metazooplankton; Spatio-temporal patterns; Trophic relationships; Pearl oyster; Atoll lagoon; French Polynesia. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00101/21207/19419.pdf |
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| Registros recuperados: 31 | |
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