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Auteur Cucherousset, J.; Villeger, S. url  doi
openurl 
  Titre Quantifying the multiple facets of isotopic diversity: New metrics for stable isotope ecology Type Article scientifique
  Année 2015 Publication Revue Abrégée Ecological Indicators  
  Volume 56 Numéro Pages 152-160  
  Mots-Clés biodiversity; Bioindication; communities; diversity indices; food web; Populations; stable isotope analyses; Trophic diversity  
  Résumé Abstract

Stable isotope analyses have emerged as an insightful tool for ecologists, with quantitative methods being developed to analyse data at the population, community and food web levels. In parallel, functional ecologists have developed metrics to quantify the multiple facets of functional diversity in a n-dimensional space based on functional traits. Here, we transferred and adapted metrics developed by functional ecologists into a set of four isotopic diversity metrics (isotopic divergence, dispersion, evenness and uniqueness) complementary to the existing metrics. Specifically, these new metrics are mathematically independent of the number of organisms analysed and account for the abundance of organisms. They can also be calculated with more than two stable isotopes. In addition, we also provide a procedure for calculating the levels of isotopic overlap (similarity and turnover) between two groups of organisms. These metrics have been implemented into new functions in R made freely available to users and we illustrated their application using stable isotope values from a freshwater fish community. Transferring the framework developed initially for measuring functional diversity to stable isotope ecology will allow more efficient assessments of changes in the multiple facets of isotopic diversity following anthropogenic disturbances.
 
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  Langue Langue du Résumé Titre Original  
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  Volume de collection Numéro de collection Edition  
  ISSN 1470-160x ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 1361  
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Auteur Quétel, C.; Marinesque, S.; Ringler, D.; Fillinger, L.; Changeux, T.; Marteau, C.; Troussellier, M. url  doi
openurl 
  Titre Iles Eparses (SW Indian Ocean) as reference ecosystems for environmental research Type Article scientifique
  Année 2016 Publication Revue Abrégée Acta Oecologica  
  Volume Numéro Pages 1-8  
  Mots-Clés Biodiversity sanctuaries; climate change; Environmental research; Iles Eparses; Indian Ocean; Pristine ecosystems  
  Résumé TAAF ensures since 2007 the management of 5 small tropical islands lying in the southwestern Indian Ocean: the Iles Eparses. These islands share an exceptional natural heritage including many marine and terrestrial endemic species. At a regional scale the Iles Eparses are some of the most pristine ecosystems, largely preserved from anthropogenic impacts due to their geographical isolation and a historically very limited human occupation. In this context, TAAF wished that Iles Eparses become unique natural laboratories for earth scientists and environmental process observation – like climate change impacts – but also sustainable biodiversity sanctuaries for which the scientific community should provide baseline ecological data to inform on appropriate conservation tools. An inter-agency research consortium emerged in 2009 to meet this commitment for the Iles Eparses. This program was intended to set a science framework in accordance with France' objectives for Research and Conservation. It enabled between 2009 and 2014 the implementation of 18 cross-disciplinary research projects ranging from geology to ecology and represented by the variety of the proposed articles in this special issue. Altogether research projects have dramatically increased knowledge on the Iles Eparses' ecosystems and have provided the first overview of their diversity, their functions and their dynamics and its determinants. In particular applied research efforts have supplied a significant amount of ecological evidence that is now available to develop optimal conservation strategy to ensure the Iles Eparses' long-term biodiversity value. These findings point out that the continuation of research activity in the Iles Eparses should be considered a priority.  
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  Langue Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Îles Éparses (French Scattered Islands, SW Indian Ocean) as reference ecosystems for environmental research. Titre de collection Abrégé  
  Volume de collection 72 Numéro de collection Edition  
  ISSN 1146-609x ISBN Médium  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1571  
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Auteur Marsac, F.; Galletti, F.; Ternon, J.-F.; Romanov, E.V.; Demarcq, H.; Corbari, L.; Bouchet, P.; Roest, W.R.; Jorry, S.J.; Olu, K.; Loncke, L.; Roberts, M.J.; Ménard, F. url  doi
openurl 
  Titre Seamounts, plateaus and governance issues in the southwestern Indian Ocean, with emphasis on fisheries management and marine conservation, using the Walters Shoal as a case study for implementing a protection framework Type Article scientifique
  Année 2019 Publication Revue Abrégée Deep Sea Research Part II: Topical Studies in Oceanography  
  Volume Numéro Pages 104715  
  Mots-Clés Amended Nairobi Convention; Areas Beyond National Jurisdiction; Benthic biodiversity; Deep-sea fisheries; Deep-sea mining; International Law of the Sea; Marine protected areas; Saya de Malha Bank; South Indian Ocean Fisheries Agreement; Vulnerable Marine Ecosystems  
  Résumé There is a growing interest in the management of seamounts of the Southwestern Indian Ocean (SWIO) both in waters under national jurisdictions and in the Areas Beyond National Jurisdiction (ABNJ). New scientific knowledge has been gathered through various oceanographic cruises during the past decade, and new agreements are under consideration globally to promote conservation and sustainable use of the biodiversity in the ABNJ, where the deep sea ecosystems associated with seamounts are a growing matter of concern. SWIO seamounts have attracted the interests of fishers since the 1960s, and contracts for mining exploration have been granted recently. Seamounts are known to shelter rich, fragile and poorly resilient ecosystems whose important ecological functions are threatened by various anthropogenic pressures. Whereas many seamounts and shoals are located in national waters, many others fall in the ABNJ, with no current legal status per se. To ensure conservation of their habitats and biodiversity, it is essential that protection measures are instigated under an internationally recognized legal and institutional framework. In this paper, we review the current state of such a framework relevant to seamounts, with emphasis on fisheries and conservation in the SWIO. An emblematic seamount, the Walters Shoal, is selected as a case study to discuss how it could become a fully-protected space in the ABNJ. As a large part of the SWIO is under the mandate of the Nairobi Convention (as a Regional Sea under the auspices of UNEP), guidelines are proposed to encourage dedicated seamount governance within the framework of this Convention.  
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  Langue en Langue du Résumé Titre Original  
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  Volume de collection Numéro de collection Edition  
  ISSN 0967-0645 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2689  
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Auteur Mérigot, B.; Frédou, F.L.; Viana, A.P.; Ferreira, B.P.; do Nascimento Costa Junior, E.; Beserra da Silva Júnior, C.A.; Frédou, T. url  doi
openurl 
  Titre Fish assemblages in tropical estuaries of northeast Brazil: A multi-component diversity approach Type Article scientifique
  Année 2017 Publication Revue Abrégée Ocean & Coastal Management  
  Volume 143 Numéro Pages 175-183  
  Mots-Clés Diversity indices; Double principal coordinate analysis; ecosystem-based fisheries management; Estuaries; Fishes; monitoring; taxonomic diversity  
  Résumé Biodiversity in estuarine ecosystems suffers from the impact of environmental changes and human activities. This mainly involves changes in temperature, salinity, pollution, habitat degradation or loss and fishing activities. The diversity of species communities is traditionally assessed on the basis of their species richness and composition. However, there is growing interest in taking into account complementary components dealing with species differences (e.g. taxonomic relatedness). In spite of their social, ecological and economic importance, the diversity of tropical estuarine fish assemblages has rarely been monitored by means of a multi-component approach under different human pressure and environmental conditions. We analysed the diversity of exploited fish communities (both target and non-target species) sampled during scientific surveys within four estuarine complexes in the state of Pernambuco, Brazil: Itapissuma, Suape, Sirinhaém, and Rio Formoso. A total of 122 species were collected within 34 samples. Overall, diversity indices and species models fitting dominance-evenness profiles mainly revealed differences between assemblages from Itapissuma, being the largest estuary with wide areas of mangrove, and the other estuaries. While assemblages from Itapissuma generally encompassed more species and individuals than the other estuaries, species were more closely related from a taxonomic point of view. In addition, a Double Principal Coordinate Analysis (DPCoA) established a typology of assemblages, useful for management purposes, and linked to particular fish families: it highlighted differences between Itapissuma, Suape, Sirinhaém and Rio Formoso. This method combines matrices of species abundances and differences (here taxonomic distances according to the Linnean classification). It was particularly accurate with a first factorial plane explaining 73% of the total inertia, while only 17% was achieved by a traditional Principal Component Analysis (PCA). Overall, this study provides an assessment of the state of fish assemblage diversity in Pernambuco estuaries where contrasted human and environmental conditions occur. It underscores the accuracy of using a multi-component diversity approach, with a multivariate analysis that is not yet widely used, for monitoring the diversity of estuaries for ecosystem-based fisheries management purposes.  
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  Éditeur de collection Titre de collection The challenge of developing policies and management strategies under changing baselines and unbounded boundaries Titre de collection Abrégé  
  Volume de collection 143 Numéro de collection Edition  
  ISSN 0964-5691 ISBN Médium  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2137  
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Auteur Catherine, A.; Selma, M.; Mouillot, D.; Troussellier, M.; Bernard, C. url  doi
openurl 
  Titre Patterns and multi-scale drivers of phytoplankton species richness in temperate peri-urban lakes Type Article scientifique
  Année 2016 Publication Revue Abrégée Science of The Total Environment  
  Volume 559 Numéro Pages 74-83  
  Mots-Clés Lake- and catchment-scale; Phytoplankton; Productivity–diversity relationship; Random forest; Residuals analysis; species richness  
  Résumé Local species richness (SR) is a key characteristic affecting ecosystem functioning. Yet, the mechanisms regulating phytoplankton diversity in freshwater ecosystems are not fully understood, especially in peri-urban environments where anthropogenic pressures strongly impact the quality of aquatic ecosystems. To address this issue, we sampled the phytoplankton communities of 50 lakes in the Paris area (France) characterized by a large gradient of physico-chemical and catchment-scale characteristics. We used large phytoplankton datasets to describe phytoplankton diversity patterns and applied a machine-learning algorithm to test the degree to which species richness patterns are potentially controlled by environmental factors. Selected environmental factors were studied at two scales: the lake-scale (e.g. nutrients concentrations, water temperature, lake depth) and the catchment-scale (e.g. catchment, landscape and climate variables). Then, we used a variance partitioning approach to evaluate the interaction between lake-scale and catchment-scale variables in explaining local species richness. Finally, we analysed the residuals of predictive models to identify potential vectors of improvement of phytoplankton species richness predictive models. Lake-scale and catchment-scale drivers provided similar predictive accuracy of local species richness (R2 = 0.458 and 0.424, respectively). Both models suggested that seasonal temperature variations and nutrient supply strongly modulate local species richness. Integrating lake- and catchment-scale predictors in a single predictive model did not provide increased predictive accuracy; therefore suggesting that the catchment-scale model probably explains observed species richness variations through the impact of catchment-scale variables on in-lake water quality characteristics. Models based on catchment characteristics, which include simple and easy to obtain variables, provide a meaningful way of predicting phytoplankton species richness in temperate lakes. This approach may prove useful and cost-effective for the management and conservation of aquatic ecosystems.  
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  Langue Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0048-9697 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1566  
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