Consulta: creatorFacets:"Thomas, Yoann"
Registros recuperados: 31
Data/hora: 16/06/2024 10:55:03

Metazooplankton communities in the Ahe atoll lagoon (Tuamotu Archipelago, French Polynesia): Spatiotemporal variations and trophic relationships
Provedor de dados: 5
Autores: Pagano, Marc; Sagarra, Pascual-boi; Champalbert, Gisele; Bouvy, Marc; Dupuy, Christine; Thomas, Yoann; Charpy, Loic.
Metazooplankton abundance, biomass (&lt;80 mu m, 200-500 mu m and &gt;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

Larval connectivity of pearl oyster through biophysical modelling; evidence of food limitation and broodstock effect
Provedor de dados: 5
Autores: 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

Assessing the sensitivity of bivalve populations to global warming using an individual-based modelling approach
Provedor de dados: 5
Autores: Thomas, Yoann; Bacher, Cedric.
Climate change exposes benthic species populations in coastal ecosystems to a combination of different stressors (e.g. warming, acidification and eutrophication), threatening the sustainability of the ecological functions they provide. Thermal stress appears to be one of the strongest drivers impacting marine ecosystems, acting across a wide range of scales, from individual metabolic performances to geographic distribution of populations. Accounting for and integrating the response of species functional traits to thermal stress is therefore a necessary step in predicting how populations will respond to the warming expected in coming decades. Here, we developed an individual‐based population model using a mechanistic formulation of metabolic processes...
Tipo: Text
Palavras-chave: Benthic species; Biogeography; Climate scenario; Dynamic energy budget; Global warming; Phenology; Population dynamics; Temperature tolerance.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00450/56163/57710.pdf

Spatial and temporal extension of eutrophication associated with shrimp farm wastewater discharges in the New Caledonia lagoon
Provedor de dados: 5
Autores: Thomas, Yoann; Courties, Claude; El Helwe, Yasmin; Herbland, Alain; Lemonnier, Hugues.
Shrimp farming in New Caledonia typically uses a flow-through system with water exchange rates as a tool to maintain optimum hydrological and biological parameters for the crop. Moreover, the effluent shows hydrobiological characteristics (minerals, phytoplankton biomass and organic matter) significantly higher than that of the receiving environment. Separate surveys were carried out in a bay (CH Bay) with a medium-size intensive farm (30 ha) (PO) and in a mangrove-lined creek (TE Creek) near a larger semi-intensive farm (133 ha) (SO). Net loads of nitrogen exported from the semi-intensive farm and the intensive farm amounted to 0.68 and 1.36 kg ha(-1) day(-1), respectively. At CH Bay, discharge effects were spatially limited and clearly restricted to...
Tipo: Text
Palavras-chave: Environmental impact; Shrimp farming; Eutrophication; Flow cytometry; New Caledonia.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00014/12527/9882.pdf

Remote Sensing-Driven Pacific Oyster (Crassostrea gigas) Growth Modeling to Inform Offshore Aquaculture Site Selection
Provedor de dados: 5
Autores: 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

Oysters as sentinels of climate variability and climate change in coastal ecosystems
Provedor de dados: 5
Autores: 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

Oyster (c. gigas) recruitment in Mediteranean lagoons ; new approaches for studying larval connectivity using MARS3D modeling tools
Provedor de dados: 5
Autores: 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
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00248/35905/34427.pdf

Global change and climate-driven invasion of the Pacific oyster (Crassostrea gigas) along European coasts: a bioenergetics modelling approach
Provedor de dados: 5
Autores: 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

Multi-scale distribution and dynamics of bivalve larvae in a deep atoll lagoon (Ahe, French Polynesia)
Provedor de dados: 5
Autores: 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

Estimation of physical and physiological performances of blacklip pearl oyster larvae in view of DEB modeling and recruitment assessment
Provedor de dados: 5
Autores: 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

Impact of environmental variability on Pinctada margaritifera life-history traits: A full life cycle deb modeling approach
Provedor de dados: 5
Autores: 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

Use of satellite data to predict shellfish growth
Provedor de dados: 5
Autores: 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
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00083/19459/17093.pdf

Disruption of amylase genes by RNA interference affects reproduction in the Pacific oyster Crassostrea gigas
Provedor de dados: 5
Autores: 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

Modelling spatio-temporal variability of Mytilus edulis (L.) growth by forcing a dynamic energy budget model with satellite-derived environmental data
Provedor de dados: 5
Autores: 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

Application of a bioenergetic growth model to larvae of the pearl oyster Pinctada margaritifera L.
Provedor de dados: 5
Autores: 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

Revisiting wild stocks of black lip oyster Pinctada margaritifera in the Tuamotu Archipelago: the case of Ahe and Takaroa atolls and implications for the cultured pearl industry
Provedor de dados: 5
Autores: 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

Modeling reproductive traits of an invasive bivalve species under contrasting climate scenarios from 1960 to 2100
Provedor de dados: 5
Autores: 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

Latitudinal drivers of oyster mortality: deciphering host, pathogen and environmental risk factors
Provedor de dados: 5
Autores: 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
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00627/73915/73251.pdf

Ecologie larvaire de l'huître perlière (Pinctada margaritifera, L.), croissance et dispersion dans un lagon d'atoll polynésien
Provedor de dados: 5
Autores: Thomas, Yoann.
Understanding key factors determining the bentho-pelagic species larval growth and dispersal remains one of the challenges of marine ecology, notably to understand the adult population structure and dynamics. In the present study, we explore this determinism on the development and dispersal of the black-lip pearl oyster (Pinctada margaritifera var. cumingii, Linné 1758) larvae in a French Polynesian atoll lagoon (Ahe, Tuamotu archipelago). Rearing of the pearl oyster for the production of black pearls takes on a major social and economic place in French Polynesia. However, the supply of pearl oyster seed to the farms depends entirely on the natural collection of wild spat of the only one specie P. margaritifera, and spatial and temporal variability of spat...
Tipo: Text
Palavras-chave: Ecologie larvaire; Hétérogénéité environnementale; Modélisation; Croissance; Dispersion; Huître perlière à lèvres noires; Pinctada margaritifera; Lagon d’atoll; Polynésie française; Larval ecology; Environmental heterogeneity; Modeling; Growth; Dispersal; Black-lip pearl oyster; Pinctada margaritifera; Atoll lagoon; French Polynesia.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00003/11449/7999.pdf

Biological, socio-economic, and administrative opportunities and challenges to moving aquaculture offshore for small French oyster-farming companies
Provedor de dados: 5
Autores: 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

Qualification zoo-sanitaire du naissain de captage 2013 de l'huître creuse Crassostrea gigas (QUALIF) - Détection précoce des maladies en épreuve thermique de laboratoire
Provedor de dados: 5
Autores: 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

Modeling the impact of hypoxia on the energy budget of Atlantic cod in two populations of the Gulf of Saint-Lawrence, Canada
Provedor de dados: 5
Autores: 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

Reply to Lenz et al.: Quantifying the smallest microplastics is the challenge for a comprehensive view of their environmental impacts
Provedor de dados: 5
Autores: Huvet, Arnaud; Paul-pont, Ika; Fabioux, Caroline; Lambert, Christophe; Suquet, Marc; Thomas, Yoann; Robbens, Johan; Soudant, Philippe; Sussarellu, Rossana.
Tipo: Text
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00345/45604/45224.pdf

Oyster reproduction is affected by exposure to polystyrene microplastics
Provedor de dados: 5
Autores: 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

Impact de la crevetticulture calédonienne sur l'environnement : état des lieux, recherche de traceurs des effluents et définition d'un programme de recherche pluriannuel
Provedor de dados: 5
Autores: 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
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/rapport-6593.pdf

Modelling paralytic shellfish toxins (PST) accumulation in Crassostrea gigas by using Dynamic Energy Budgets (DEB)
Provedor de dados: 5
Autores: 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

Larval Dispersal Modeling of Pearl Oyster Pinctada margaritifera following Realistic Environmental and Biological Forcing in Ahe Atoll Lagoon
Provedor de dados: 5
Autores: Thomas, Yoann; Dumas, Franck; Andrefouet, Serge.
Studying the larval dispersal of bottom-dwelling species is necessary to understand their population dynamics and optimize their management. The black-lip pearl oyster (Pinctada margaritifera) is cultured extensively to produce black pearls, especially in French Polynesia's atoll lagoons. This aquaculture relies on spat collection, a process that can be optimized by understanding which factors influence larval dispersal. Here, we investigate the sensitivity of P. margaritifera larval dispersal kernel to both physical and biological factors in the lagoon of Ahe atoll. Specifically, using a validated 3D larval dispersal model, the variability of lagoon-scale connectivity is investigated against wind forcing, depth and location of larval release, destination...
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00197/30843/29210.pdf

Development of in situ hybridisation using 16S rRNA gene to monitor black-lip pearl oyster, Pinctada margaritifera, larvae in plankton samples
Provedor de dados: 5
Autores: Thomas, Yoann; Belliard, Corinne; Garen, Pierre; Gueguen, Yannick; Montagnani, Caroline.
In French Polynesia, the black-lip pearl oyster Pinctada margaritifera has been farmed to produce pearls since the 1980s, forming the basis of a major industry. The sustainability of this activity relies on spat collection in the lagoons. However, pearl oyster spat can be difficult to identify for the evaluation of stock variations. It is especially hard to distinguish Pinctada spp. larvae at a very early stage of development. In the present study, a whole- mount in situ hybridisation (ISH) technique was developed to allow the discrimination of larvae of closely-related pearl oyster species found in the French Polynesian atolls. Using specific ribosomal 16S-DNA sequence data, we were able to successfully differentiate between Pinctada margaritifera and...
Tipo: Text
Palavras-chave: Whole larvae in situ hybridisation; 16S rRNA; Plankton; Species identification; Pearl oyster; Pinctada margaritifera.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00035/14603/11923.pdf

Editorial: Remote Sensing for Aquaculture
Provedor de dados: 5
Autores: Gernez, Pierre; Palmer, Stephanie C. J.; Thomas, Yoann; Forster, Rodney.
Tipo: Text
Palavras-chave: Earth observation; Site selection; HAB risk assessment; Production monitoring; Ecological modeling; Kelp; Fish; Shellfish.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00675/78753/80921.pdf

Stochastic Modeling of Forces on Jacket-Type Offshore Structures Colonized by Marine Growth
Provedor de dados: 5
Autores: 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

Effects of of hypoxia on metabolic functions in marine organisms: Observed patterns and modelling assumptions within the context of Dynamic Energy Budget (DEB) theory
Provedor de dados: 5
Autores: 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
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00473/58466/65967.pdf