Consulta: creatorFacets:"Villeger, Sebastien"
Registros recuperados: 13
Data/hora: 06/06/2024 10:18:07

Coral-associated viruses and bacteria in the Ha Long Bay, Vietnam
Provedor de dados: 5
Autores: Thu Pham, The; Thuoc Chu, Van; Viet Ha Bui, Thi; Thuy Nguyen, Thanh; Huy Tran, Quang; Ngoc Mai Cung, Thi; Bouvier, Corinne; Brune, Justine; Villeger, Sebastien; Bouvier, Thierry; Bettarel, Yvan.
Viruses inhabiting the surface mucus layer of scleractinian corals have received little ecological attention so far. Yet they have recently been shown to be highly abundant and could even play a pivotal role in coral health. A fundamental aspect that remains unresolved is whether their abundance and diversity change with the trophic state of their environment. The present study examined the variability in the abundance of viral and bacterial epibionts on 13 coral species collected from 2 different sites in the Ha Long Bay, Vietnam: one station heavily affected by anthropogenic activity (Cat Ba Island) and one protected offshore station (Long Chau Island). In general, viral abundance was significantly higher in coral mucus (mean = 10.6 +/- 2.0 x 10(7)...
Tipo: Text
Palavras-chave: Viruses; Coral-associated bacteria; Mucus; Symbionts; Coral reefs.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00627/73870/73680.pdf

From current distinctiveness to future homogenization of the world's freshwater fish faunas
Provedor de dados: 5
Autores: Villeger, Sebastien; Blanchet, Simon; Beauchard, Olivier; Oberdorff, Thierry; Brosse, Sebastien.
AimAssessing the consequences of a future increase in non-native species introductions and native species extirpations on taxonomic similarity among fish faunas. LocationWorld-wide. MethodsWe designed 42 scenarios of future species introductions and extirpations to simulate future fish composition for 1054 river basins. Using these simulated future compositions, we computed the change in taxonomic similarity among pairs of fish faunas from historical to future situation at the river basin, biogeographic realm and world scales. ResultsAccording to all our scenarios, taxonomic similarity among fish faunas will strongly increase in the future at the three spatial scales considered. Fish faunas from the Southern Hemisphere, which are currently the less...
Tipo: Text
Palavras-chave: Extirpation; Freshwater fish; Introduction; Non-native species; Taxonomic similarity; Taxonomic uniqueness.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00250/36174/73737.pdf

Mare Incognitum: A Glimpse into Future Plankton Diversity and Ecology Research
Provedor de dados: 5
Autores: Chust, Guillem; Vogt, Meike; Benedetti, Fabio; Nakov, Teofil; Villeger, Sebastien; Aubert, Anais; Vallina, Sergio M.; Righetti, Damiano; Not, Fabrice; Biard, Tristan; Bittner, Lucie; Benoiston, Anne-sophie; Guidi, Lionel; Villarino, Ernesto; Gaborit, Charlie; Cornils, Astrid; Buttay, Lucie; Irisson, Jean-olivier; Chiarello, Marlene; Vallim, Alessandra L.; Blanco-bercial, Leocadio; Basconi, Laura; Guilhaumon, Francois; Ayata, Sakina-dorothee.
With global climate change altering marine ecosystems, research on plankton ecology is likely to navigate uncharted seas. Yet, a staggering wealth of new plankton observations, integrated with recent advances in marine ecosystem modeling, may shed light on marine ecosystem structure and functioning. A EuroMarine foresight workshop on the “Impact of climate change on the distribution of plankton functional and phylogenetic diversity” (PlankDiv) identified five grand challenges for future plankton diversity and macroecology research: (1) What can we learn about plankton communities from the new wealth of high-throughput “omics” data? (2) What is the link between plankton diversity and ecosystem function? (3) How can species distribution models be adapted to...
Tipo: Text
Palavras-chave: Plankton; Macroecology; Species distribution; Functional diversity; Climate change; Habitat modeling.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00625/73739/74755.pdf

Functional biodiversity loss along natural CO2 gradients
Provedor de dados: 5
Autores: Teixido, Nuria; Gambi, Maria Cristina; Parravacini, Valeriano; Kroeker, Kristy; Micheli, Fiorenza; Villeger, Sebastien; Ballesteros, Enric.
The effects of environmental change on biodiversity are still poorly understood. In particular, the consequences of shifts in species composition for marine ecosystem function are largely unknown. Here we assess the loss of functional diversity, i.e. the range of species biological traits, in benthic marine communities exposed to ocean acidification (OA) by using natural CO2 vent systems. We found that functional richness is greatly reduced with acidification, and that functional loss is more pronounced than the corresponding decrease in taxonomic diversity. In acidified conditions, most organisms accounted for a few functional entities (i.e. unique combination of functional traits), resulting in low functional redundancy. These results suggest that...
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00473/58478/62400.pdf

High diversity of skin-associated bacterial communities of marine fishes is promoted by their high variability among body parts, individuals and species
Provedor de dados: 5
Autores: Chiarello, Marlene; Villeger, Sebastien; Bouvier, Corinne; Bettarel, Yvan; Bouvier, Thierry.
Animal-associated microbiotas form complex communities, which are suspected to play crucial functions for their host fitness. However, the biodiversity of these communities, including their differences between host species and individuals, has been scarcely studied, especially in case of skin-associated communities. In addition, the intraindividual variability (i.e. between body parts) has never been assessed to date. The objective of this study was to characterize skin bacterial communities of two teleostean fish species, namely the European seabass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata), using a high-throughput DNA sequencing method. In order to focus on intrinsic factors of host-associated bacterial community variability,...
Tipo: Text
Palavras-chave: Sparus aurata; Dicentrarchus labrax; Skin microbiome; Next generation sequencing; Phylogenetic diversity.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00277/38801/37547.pdf

Disentangling the pathways of land use impacts on the functional structure of fish assemblages in Amazon streams
Provedor de dados: 5
Autores: Leitao, Rafael P.; Zuanon, Jansen; Mouillot, David; Leal, Cecilia G.; Hughes, Robert M.; Kaufmann, Philip R.; Villeger, Sebastien; Pompeu, Paulo S.; Kasper, Daniele; De Paula, Felipe R.; Ferraz, Silvio F. B.; Gardner, Toby A.
Agricultural land use is a primary driver of environmental impacts on streams. However, the causal processes that shape these impacts operate through multiple pathways and at several spatial scales. This complexity undermines the development of more effective management approaches, and illustrates the need for more in-depth studies to assess the mechanisms that determine changes in stream biodiversity. Here we present results of the most comprehensive multi-scale assessment of the biological condition of streams in the Amazon to date, examining functional responses of fish assemblages to land use. We sampled fish assemblages from two large human-modified regions, and characterized stream conditions by physical habitat attributes and key landscape-change...
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00420/53101/75002.pdf

Coral Reef Fish Detection and Recognition in Underwater Videos by Supervised Machine Learning: Comparison Between Deep Learning and HOG plus SVM Methods
Provedor de dados: 5
Autores: Villon, Sebastien; Chaumont, Marc; Subsol, Gerard; Villeger, Sebastien; Claverie, Thomas; Mouillot, David.
In this paper, we present two supervised machine learning methods to automatically detect and recognize coral reef fishes in underwater HD videos. The first method relies on a traditional two-step approach: extraction of HOG features and use of a SVM classifier. The second method is based on Deep Learning. We compare the results of the two methods on real data and discuss their strengths and weaknesses.
Tipo: Text
Palavras-chave: Support Vector Machine; Feature Vector; Coral Reef; Deep Learn; Convolutional Neural Network.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00387/49860/74458.pdf

Skin microbiome of coral reef fish is highly variable and driven by host phylogeny and diet
Provedor de dados: 5
Autores: Chiarello, Marlene; Auguet, Jean-christophe; Bettarel, Yvan; Bouvier, Corinne; Claverie, Thomas; Graham, Nicholas A. J.; Rieuvilleneuve, Fabien; Sucre, Elliot; Bouvier, Thierry; Villeger, Sebastien.
Background: The surface of marine animals is covered by abundant and diversified microbial communities, which have major roles for the health of their host While such microbiomes have been deeply examined in marine invertebrates such as corals and sponges, the microbiomes living on marine vertebrates have received less attention. Specifically, the diversity of these microbiomes, their variability among species, and their drivers are still mostly unknown, especially among the fish species living on coral reefs that contribute to key ecosystem services while they are increasingly affected by human activities. Here, we investigated these knowledge gaps analyzing the skin microbiome of 138 fish individuals belonging to 44 coral reef fish species living in the...
Tipo: Text
Palavras-chave: Tropical; Teleost; Microbiota; Phylogenetic diversity; Phylosymbiosis; Phylogenetic signal.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00454/56565/74934.pdf

Interspecific differences in the effect of fish on marine microbial plankton
Provedor de dados: 5
Autores: Villeger, Sebastien; Fouilland, Eric; Argenty, Jeremy; Bouvier, Corinne; Carre, Claire; Bouvier, Thierry.
The productivity of most marine ecosystems is limited by the availability of dissolved nitrogen (N) and phosphorus (P). Nutrient recycling is therefore a key process for ecosystem functioning. Fish recycle nutrients through the excretion of ammonia and phosphate and can influence the abundance and community structure of primary producers such as phytoplankton. However, the effect of fish on other plankton compartments, and whether all fish species have similar effects, is largely unknown. We used a tank experiment to test how 2 Mediterranean fish species, gilthead seabream Sparus aurata and golden mullet Chelon auratus, with distinctly different N and P excretion rates, can affect the abundance and community structure of 3 plankton compartments:...
Tipo: Text
Palavras-chave: Marine fish; Nutrient excretion; Protozooplankton; Phytoplankton; Bacteria.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00584/69659/67585.pdf

Confronting species aesthetics with ecological functions in coral reef fish
Provedor de dados: 5
Autores: Tribot, Anne-sophie; Carabeux, Quentin; Deter, Julie; Claverie, Thomas; Villeger, Sebastien; Mouquet, Nicolas.
The biodiversity crisis has spurred scientists to assess all facets of biodiversity so that stakeholders can establish protection programs. However, species that are perceived as beautiful receive more attention than less attractive species. This dynamic could have tremendous consequences on people's willingness to preserve biodiversity. Coral reefs might be particularly affected by this issue as they are key ecosystems that provide many services, such as aesthetic and cultural benefits attracting millions of tourists each year. Here we show the results of an online photographic questionnaire completed by 8,000 participants whereby preferences were assessed for a set of 116 reef fishes. Based on these preferences, we compared the functional richness, i.e....
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00454/56573/75113.pdf

Taxonomic and functional diversity increase the aesthetic value of coralligenous reefs
Provedor de dados: 5
Autores: Tribot, Anne-sophie; Mouquet, Nicolas; Villeger, Sebastien; Raymond, Michel; Hoff, Fabrice; Boissery, Pierre; Holon, Florian; Deter, Julie.
The aesthetic value of landscapes contributes to human well-being. However, studies which have investigated the link between biodiversity and ecosystem services have not taken aesthetic value into account. In this study we evaluated how the aesthetics of coralligenous reefs, a key marine ecosystem in the Mediterranean, is perceived by the general public and how aesthetic preferences are related to biodiversity facets (taxonomic, phylogenetic and functional diversities). We performed both biodiversity measures and online-surveys of aesthetic perception on photographic quadrats sampled along the French Mediterranean coast. Our results show that species richness and functional richness have a significant positive effect on aesthetic value. Most of the...
Tipo: Text
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00354/46564/74442.pdf

Unexpected high vulnerability of functions in wilderness areas: evidence from coral reef fishes
Provedor de dados: 5
Autores: D'Agata, Stephanie; Vigliola, Laurent; Graham, Nicholas A. J.; Wantiez, Laurent; Parravicini, Valeriano; Villeger, Sebastien; Gerard Mou-tham,; Frolla, Philippe; Friedlander, Alan M.; Kulbicki, Michel; Mouillot, David.
High species richness is thought to support the delivery of multiple ecosystem functions and services under changing environments. Yet, some species might performunique functional roles while others are redundant. Thus, the benefits of high species richness in maintaining ecosystem functioning are uncertain if functions have little redundancy, potentially leading to high vulnerability of functions. We studied the natural propensity of assemblages to be functionally buffered against loss prior to fishing activities, using functional trait combinations, in coral reef fish assemblages across unfished wilderness areas of the Indo-Pacific: Chagos Archipelago, New Caledonia and French Polynesia. Fish functional diversity in these wilderness areas is highly...
Tipo: Text
Palavras-chave: Coral reef fish; Wilderness areas; Redundancy; Baseline functional vulnerability.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00366/47680/68025.pdf

Community-wide scan identifies fish species associated with coral reef services across the Indo-Pacific
Provedor de dados: 5
Autores: Maire, Eva; Villeger, Sebastien; Graham, Nicholas A. J.; Hoey, Andrew S.; Cinner, Joshua; Ferse, Sebastian C. A.; Aliaume, Catherine; Booth, David J.; Feary, David A.; Kulbicki, Michel; Sandin, Stuart A.; Vigliola, Laurent; Mouillot, David.
Determining whether many functionally complementary species or only a subset of key species are necessary to maintain ecosystem functioning and services is a critical question in community ecology and biodiversity conservation. Identifying such key species remains challenging, especially in the tropics where many species co-occur and can potentially support the same or different processes. Here, we developed a new community-wide scan CWS) approach, analogous to the genome-wide scan, to identify fish species that significantly contribute, beyond the socio-environmental and species richness effects, to the biomass and coral cover on Indo-Pacific reefs. We found that only a limited set of species (51 out of approx. 400, = approx. 13%), belonging to various...
Tipo: Text
Palavras-chave: Ecosystem functioning; Biodiversity; Fish community; Key species; Ecosystem services; Coral reefs.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00452/56388/68019.pdf