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| Registros recuperados: 31 | |
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| Ameryoun, Hamed; Schoefs, Franck; Barille, Laurent; Thomas, Yoann. |
| The present paper deals with the stochastic modeling of bio-colonization for the computation of stochastic hydrodynamic loading on jacket-type offshore structures. It relies on a multidisciplinary study gathering biological and physical research fields that accounts for uncertainties at all the levels. Indeed, bio-colonization of offshore structures is a complex phenomenon with two major but distinct domains: (i) marine biology, whose processes are modeled with biomathematics methods, and (ii) hydrodynamic processes. This paper aims to connect these two domains. It proposes a stochastic model for the marine organism's growth and then continues with transfers for the assessment of drag coefficient and forces probability density functions that account for... |
| Tipo: Text |
Palavras-chave: Marine growth; Biofouling; Wave loading; Stochastic modeling; Reliability; Jacket structures. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00605/71668/70107.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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| 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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| 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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| 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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| 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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| 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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| Lavaud, Romain; Thomas, Yoann; Pecquerie, Laure; Benoit, Hugues P.; Guyondet, Thomas; Flye-sainte-marie, Jonathan; Chabot, Denis. |
| Like many marine species around the globe, several stocks of Atlantic cod (Gadus morhua) live in increasingly hypoxic waters. In the Gulf of Saint Lawrence (GSL) in Canada, the deep channels traversing the semi-enclosed sea exhibit year-round hypoxia, identified as one of the limiting factor for the recovery of GSL cod in its northern part. While many individuals in the northern GSL are known to venture in deeper, warmer, and more hypoxic waters of the Gulf channels, those in the southern GSL live in a shallower, colder, and more oxygenated environment. In this study, we use the modeling framework of the Dynamic Energy Budget (DEB) theory to disentangle the effects of hypoxia, temperature and food on the life-history traits of these two populations of cod... |
| Tipo: Text |
Palavras-chave: Hypoxia; Dynamic energy budget; Atlantic cod; Growth; Temperature; Gulf of Saint-Lawrence. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00448/55966/57472.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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| 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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| 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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| Petton, Bruno; Riobe, Marion; Koechlin, Hugo; Queau, Isabelle; Mingant, Christian; Ratiskol, Dominique; Le Grand, Jacqueline; Petton, Sebastien; Thomas, Yoann; Alunno-bruscia, Marianne; Pouvreau, Stephane; Pernet, Fabrice; Maurer, Daniele; D'Amico, Florence; Lagarde, Franck; Mortreux, Serge; Roque D'Orbcastel, Emmanuelle; Mille, Dominique; Geay, A.; Bouquet, A.-l.; Cochet, Helene. |
| Depuis 2008, des mortalités massives d’huîtres creuses âgées de moins d’un an sont relevées sur le littoral français dès que la température de l’eau de mer atteint le seuil de 16°C. Ces mortalités de naissains sont associées à la détection du virus OsHV-1 μVar. Des travaux de qualification zoo-sanitaire menés depuis 2010 ont montré qu’un lot de naissains issus du captage naturel sur deux était infecté par le virus bien avant l’apparition des mortalités dans le milieu naturel, mais qu’a contrario les naissains d’écloserie expertisés présentaient un moindre risque de contamination. Dans le contexte de crise sanitaire chronique, l’objectif de notre étude était d’ obtenir une information qualitative relative au statut zoo-sanitaire OsHV -1 μ V ar des... |
| Tipo: Text |
Palavras-chave: Huitre creuse; OsHV - 1μVar; Epreuve thermique.; Maladie; Naissain; Pacific oyster; Spat; Disease; Thermal challenge; OsHV-1 μVar. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00276/38682/37180.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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| 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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| 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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| Registros recuperados: 31 | |
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