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| Registros recuperados: 31 | |
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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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| Thomas, Yoann; Dumas, Franck; Andrefouet, Serge. |
| The black-lip pearl oyster (Pinctada margaritifera) is cultured extensively to produce black pearls, especially in French Polynesia atoll lagoons. This aquaculture relies on spat collection, a process that experiences spatial and temporal variability and needs to be optimized by understanding which factors influence recruitment. Here, we investigate the sensitivity of P. margaritifera larval dispersal to both physical and biological factors in the lagoon of Ahe atoll. Coupling a validated 3D larval dispersal model, a bioenergetics larval growth model following the Dynamic Energy Budget (DEB) theory, and a population dynamics model, the variability of lagoon-scale connectivity patterns and recruitment potential is investigated. The relative contribution of... |
| Tipo: Text |
Palavras-chave: Pearl oyster; Lagoon; Biophysical modelling; Connectivity; Population dynamics; DEB model. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00321/43192/42926.pdf |
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| Palmer, Stephanie C. J.; Gernez, Pierre M.; Thomas, Yoann; Simis, Stefan; Miller, Peter I.; Glize, Philippe; Barillé, Laurent. |
| Aquaculture increasingly contributes to global seafood production, requiring new farm sites for continued growth. In France, oyster cultivation has conventionally taken place in the intertidal zone, where there is little or no further room for expansion. Despite interest in moving production further offshore, more information is needed regarding the biological potential for offshore oyster growth, including its spatial and temporal variability. This study shows the use of remotely-sensed chlorophyll-a and total suspended matter concentrations retrieved from the Medium Resolution Imaging Spectrometer (MERIS), and sea surface temperature from the Advanced Very High Resolution Radiometer (AVHRR), all validated using in situ matchup measurements, as input to... |
| Tipo: Text |
Palavras-chave: Satellite image; Time series; Bivalve; Dynamic energy budget; Growth modeling; MERIS; AVHRR; Marine spatial planning. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00605/71722/70185.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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| Ubertini, Martin; Fiandrino, Annie; Bernard, Ismael; Thomas, Yoann; Dumas, Franck; Pouvreau, Stephane; Roque D'Orbcastel, Emmanuelle; Lagarde, Franck. |
| The Thau lagoon, located at the South of France, provides 10% of the French pacific oyster Crassostrea gigas production (Robert et al., 2013). Despite this intensive shellfish production, the larval recruitment of this species within the Thau lagoon is still misunderstood and spat collection remains highly variable; as a consequence, shellfish farmers rely mostly on hatchery's spat. In 2012, the PRONAMED II project was launched, aiming to improve our understanding of the C. gigas reproductive cycle within Mediterranean lagoons and to explore the feasibility for oyster-spat collecting. In addition to an extensive sampling work encompassing both spatial and temporal features of larval recruitment, we tried to understand the contribution of larval dispersal... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00248/35905/34427.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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| 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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| 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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| 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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| 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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| 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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| Thomas, Yoann; Garen, Pierre; Pouvreau, Stephane. |
| We applied, for the first time, a dynamic energy budget (DEB) growth model to the larval phase in the pearl oyster Pinctada margaritifera var. cumingii (Linnaeus, 1758) to evaluate the impact of spatio-temporal variation in the atoll lagoon environment on its capacity for development. The specific parameters of the model, which represent ingestion, temperature effect and the relationship between length and biovolume of the larvae, were determined from experiments or taken from the literature. The interpretation of the values of these parameters allowed us to identify the underlying adaptive character trait: P. margaritifera larvae have a good capacity to exploit low food concentrations and a narrow range of thermal tolerance restricted to hydrobiological... |
| Tipo: Text |
Palavras-chave: Growth Model; Dynamic Energy Budget; Larva; Pinctada Margaritifera; Atoll Lagoon. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00048/15919/13346.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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| Gourault, Melaine; Petton, Sebastien; Thomas, Yoann; Pecquerie, Laure; Marques, Goncalo M.; Cassou, Christophe; Fleury, Elodie; Paulet, Yves-marie; Pouvreau, Stephane. |
| Identifying the drivers that control the reproductive success of a population is vital to forecasting the consequences of climate change in terms of distribution shift and population dynamics. In the present study, we aimed to improve our understanding of the environmental conditions that allowed the colonization of the Pacific oyster, Crassostrea gigas, in the Bay of Brest since its introduction in the 1960s. We also aimed to evaluate the potential consequences of future climate change on its reproductive success and further expansion. Three reproductive traits were defined to study the success of the reproduction: the spawning occurrence, synchronicity among individuals and individual fecundity. We simulated these traits by applying an individual-based... |
| Tipo: Text |
Palavras-chave: DEB model; IPCC scenarios; Reproductive traits; Crassostrea gigas; Bay of Brest. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00440/55188/56794.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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| 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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| Registros recuperados: 31 | |
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