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Auteur Leroy, B.; Dias, M.S.; Giraud, E.; Hugueny, B.; Jezequel, C.; Leprieur, F.; Oberdorff, T.; Tedesco, P.A.
Titre Global biogeographical regions of freshwater fish species Type Article scientifique
Année 2019 Publication (down) Revue Abrégée J. Biogeogr.
Volume Numéro Pages
Mots-Clés actinopterygians; biogeographical regions; biogeography; bioregionalization; bioregions; connectivity; dispersal; diversity; evolution; freshwater fish; history; homogenization; network; patterns; richness; transition zones; vicariance; world; zoogeographical regions
Résumé Aim To define the major biogeographical regions and transition zones for freshwater fish species. Taxon Strictly freshwater species of actinopterygian fish (i.e. excluding marine and amphidromous fish families). Methods We based our bioregionalization on a global database of freshwater fish species occurrences in drainage basins, which, after filtering, includes 11,295 species in 2,581 basins. On the basis of this dataset, we generated a bipartite (basin-species) network upon which we applied a hierarchical clustering algorithm (the Map Equation) to detect regions. We tested the robustness of regions with a sensitivity analysis. We identified transition zones between major regions with the participation coefficient, indicating the degree to which a basin has species from multiple regions. Results Our bioregionalization scheme showed two major supercontinental regions (Old World and New World, 50% species of the world and 99.96% endemics each). Nested within these two supercontinental regions lie six major regions (Nearctic, Neotropical, Palearctic, Ethiopian, Sino-Oriental and Australian) with extremely high degrees of endemism (above 96% except for the Palearctic). Transition zones between regions were of limited extent compared to other groups of organisms. We identified numerous subregions with high diversity and endemism in tropical areas (e.g. Neotropical), and a few large subregions with low diversity and endemism at high latitudes (e.g. Palearctic). Main conclusions Our results suggest that regions of freshwater fish species were shaped by events of vicariance and geodispersal which were similar to other groups, but with freshwater-specific processes of isolation that led to extremely high degrees of endemism (far exceeding endemism rates of other continental vertebrates), specific boundary locations and limited extents of transition zones. The identified bioregions and transition zones of freshwater fish species reflect the strong isolation of freshwater fish faunas for the past 10-20 million years. The extremely high endemism and diversity of freshwater fish fauna raises many questions about the biogeographical consequences of current introductions and extinctions.
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Langue English Langue du Résumé Titre Original
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ISSN 0305-0270 ISBN Médium
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Notes WOS:000484392300001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2637
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Auteur Letessier, T.B.; Mouillot, D.; Bouchet, P.J.; Vigliola, L.; Fernandes, M.C.; Thompson, C.; Boussarie, G.; Turner, J.; Juhel, J.-B.; Maire, E.; Caley, M.J.; Koldewey, H.J.; Friedlander, A.; Sala, E.; Meeuwig, J.J.
Titre Remote reefs and seamounts are the last refuges for marine predators across the Indo-Pacific Type Article scientifique
Année 2019 Publication (down) Revue Abrégée PLoS. Biol.
Volume 17 Numéro 8 Pages e3000366
Mots-Clés biodiversity; coastal; consequences; hotspots; mortality; ocean; patterns; protected areas; shark sanctuary; tracking
Résumé Since the 1950s, industrial fisheries have expanded globally, as fishing vessels are required to travel further afield for fishing opportunities. Technological advancements and fishery subsidies have granted ever-increasing access to populations of sharks, tunas, billfishes, and other predators. Wilderness refuges, defined here as areas beyond the detectable range of human influence, are therefore increasingly rare. In order to achieve marine resources sustainability, large no-take marine protected areas (MPAs) with pelagic components are being implemented. However, such conservation efforts require knowledge of the critical habitats for predators, both across shallow reefs and the deeper ocean. Here, we fill this gap in knowledge across the Indo-Pacific by using 1,041 midwater baited videos to survey sharks and other pelagic predators such as rainbow runner (Elagatis bipinnulata), mahimahi (Coryphaena hippurus), and black marlin (Istiompax indica). We modeled three key predator community attributes: vertebrate species richness, mean maximum body size, and shark abundance as a function of geomorphology, environmental conditions, and human pressures. All attributes were primarily driven by geomorphology (35%-62% variance explained) and environmental conditions (14%-49%). While human pressures had no influence on species richness, both body size and shark abundance responded strongly to distance to human markets (12%-20%). Refuges were identified at more than 1,250 km from human markets for body size and for shark abundance. These refuges were identified as remote and shallow seabed features, such as seamounts, submerged banks, and reefs. Worryingly, hotpots of large individuals and of shark abundance are presently under-represented within no-take MPAs that aim to effectively protect marine predators, such as the British Indian Ocean Territory. Population recovery of predators is unlikely to occur without strategic placement and effective enforcement of large no-take MPAs in both coastal and remote locations.
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Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1544-9173 ISBN Médium
Région Expédition Conférence
Notes WOS:000483408500011 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2638
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Auteur McLean, M.; Mouillot, D.; Lindegren, M.; Villeger, S.; Engelhard, G.; Murgier, J.; Auber, A.
Titre Fish communities diverge in species but converge in traits over three decades of warming Type Article scientifique
Année 2019 Publication (down) Revue Abrégée Glob. Change Biol.
Volume 25 Numéro 11 Pages 3972-3984
Mots-Clés biodiversity; biotic homogenization; climate change; climate-change; community ecology; consequences; ecological traits; ecology; ecosystem functioning; fisheries; functional diversity; north-sea; patterns; plant traits; regime shift; shelf seas; spatio-temporal dynamics
Résumé Describing the spatial and temporal dynamics of communities is essential for understanding the impacts of global environmental change on biodiversity and ecosystem functioning. Trait-based approaches can provide better insight than species-based (i.e. taxonomic) approaches into community assembly and ecosystem functioning, but comparing species and trait dynamics may reveal important patterns for understanding community responses to environmental change. Here, we used a 33-year database of fish monitoring to compare the spatio-temporal dynamics of taxonomic and trait structure in North Sea fish communities. We found that the majority of variation in both taxonomic and trait structure was explained by a pronounced spatial gradient, with distinct communities in the southern and northern North Sea related to depth, sea surface temperature, salinity and bed shear stress. Both taxonomic and trait structure changed significantly over time; however taxonomically, communities in the south and north diverged towards different species, becoming more dissimilar over time, yet they converged towards the same traits regardless of species differences. In particular, communities shifted towards smaller, faster growing species with higher thermal preferences and pelagic water column position. Although taxonomic structure changed over time, its spatial distribution remained relatively stable, whereas in trait structure, the southern zone of the North Sea shifted northward and expanded, leading to homogenization. Our findings suggest that global environmental change, notably climate warming, will lead to convergence towards traits more adapted for novel environments regardless of species composition.
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Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1354-1013 ISBN Médium
Région Expédition Conférence
Notes WOS:000482780600001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2639
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Auteur Cucherousset, J.; Villeger, S.
Titre Quantifying the multiple facets of isotopic diversity: New metrics for stable isotope ecology Type Article scientifique
Année 2015 Publication (down) 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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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 Donati, G.F.A.; Parravicini, V.; Leprieur, F.; Hagen, O.; Gaboriau, T.; Heine, C.; Kulbicki, M.; Rolland, J.; Salamin, N.; Albouy, C.; Pellissier, L.
Titre A process-based model supports an association between dispersal and the prevalence of species traits in tropical reef fish assemblages Type Article scientifique
Année 2019 Publication (down) Revue Abrégée Ecography
Volume Numéro Pages
Mots-Clés biodiversity; body-size; dispersal; diversification; diversity; extinction rates; genetic-structure; geographic range size; global patterns; latitudinal gradient; mechanistic models; propagule dispersal; reef fish; speciation; traits
Résumé Habitat dynamics interacting with species dispersal abilities could generate gradients in species diversity and prevalence of species traits when the latter are associated with species dispersal potential. Using a process-based model of diversification constrained by a dispersal parameter, we simulated the interplay between reef habitat dynamics during the past 140 million years and dispersal, shaping lineage diversification history and assemblage composition globally. The emerging patterns from the simulations were compared to current prevalence of species traits related to dispersal for 6315 tropical reef fish species. We found a significant spatial congruence between the prevalence of simulated low dispersal values and areas with a large proportion of species characterized by small adult body size, narrow home range mobility behaviour, pelagic larval duration shorter than 21 days and diurnal activity. Species characterized by such traits were found predominantly in the Indo-Australian Archipelago and the Caribbean Sea. Furthermore, the frequency distribution of the dispersal parameter was found to match empirical distributions for body size, PLD and home range mobility behaviour. Also, the dispersal parameter in the simulations was associated to diversification rates and resulted in trait frequency matching empirical distributions. Overall, our findings suggest that past habitat dynamics, in conjunction with dispersal processes, influenced diversification in tropical reef fishes, which may explain the present-day geography of species traits.
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Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0906-7590 ISBN Médium
Région Expédition Conférence
Notes WOS:000487946300001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2647
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