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Auteur Lett, C.; Barrier, N.; Ourmières, Y.; Petit, C.; Labonne, M.; Bourjea, J.; Darnaude, A.M.
Titre Modeling larval dispersal for the gilthead seabream in the northwestern Mediterranean Sea Type Article scientifique
Année 2019 Publication Revue Abrégée Marine Environmental Research
Volume Numéro Pages 104781
Mots-Clés Biophysical model; Connectivity; Fish; Gulf of Lions; Larvae; Models-hydrodynamic; Otolith
Résumé To investigate dispersal and connectivity between spawning and lagoon nursery habitats of the gilthead seabream, Sparus aurata, in the Gulf of Lions (northwestern Mediterranean Sea), we modeled the potential transport of the species’ larvae between its supposed main spawning site in the region (the Planier Island) and two of its main local nursery areas (the coastal lagoons of Thau and Salses-Leucate). Passive larval drift simulations using a dispersal biophysical model showed a large variability in the possible trajectories from spawning to nursery areas and in the predicted ages for larvae arrival on the two nursery sites. The most common ages at arrival obtained in the simulations (20–60 days) are broadly consistent with previous modeling studies but contrast with the actual ages of the S. aurata post-larvae collected in 2016 and 2017 at time of the lagoon entrances (60–90 days, from otolith readings). The period between 25 and 70 days being critical for gilthead seabream larvae to acquire sufficient swimming, osmoregulatory, and olfactory abilities to enter coastal lagoons, we argue that ontogenic development plays a crucial role in the transport and local retention of S. aurata larvae in the studied region, explaining the discrepancy between simulation results and observed data.
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ISSN 0141-1136 ISBN Médium
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Numéro d'Appel (up) MARBEC @ isabelle.vidal-ayouba @ collection 2613
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Auteur Pommier, T.; Douzery, E.J.P.; Mouillot, D.
Titre Environment drives high phylogenetic turnover among oceanic bacterial communities Type Article scientifique
Année 2012 Publication Revue Abrégée Biol. Lett.
Volume 8 Numéro 4 Pages 562-566
Mots-Clés Biogeography; connectivity; diversity; dynamics; patterns; phylogenetic turnover
Résumé Although environmental filtering has been observed to influence the biodiversity patterns of marine bacterial communities, it was restricted to the regional scale and to the species level, leaving the main drivers unknown at large biogeographic scales and higher taxonomic levels. Bacterial communities with different species compositions may nevertheless share phylogenetic lineages, and phylogenetic turnover (PT) among those communities may be surprisingly low along any biogeographic or environmental gradient. Here, we investigated the relative influence of environmental filtering and geographical distance on the PT between marine bacterial communities living more than 8000 km apart in contrasted abiotic conditions. PT was high between communities and was more structured by local environmental factors than by geographical distance, suggesting the predominance of a lineage filtering process. Strong phenotype-environment mismatches observed in the ocean may surpass high connectivity between marine microbial communities.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1744-9561 ISBN Médium
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Numéro d'Appel (up) MARBEC @ isabelle.vidal-ayouba @ collection 567
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Auteur Dalleau, M.; Kramer-Schadt, S.; Gangat, Y.; Bourjea, J.; Lajoie, G.; Grimm, V.
Titre Modeling the emergence of migratory corridors and foraging hot spots of the green sea turtle Type Article scientifique
Année 2019 Publication Revue Abrégée Ecol. Evol.
Volume Numéro Pages
Mots-Clés aldabra atoll; chelonia-mydas; connectivity; corridors; individual-based model; leatherback turtles; marine turtles; migration; movement; penghu archipelago; population-dynamics; remigration intervals; satellite-tracking; sea turtle; wan-an island
Résumé Environmental factors shape the spatial distribution and dynamics of populations. Understanding how these factors interact with movement behavior is critical for efficient conservation, in particular for migratory species. Adult female green sea turtles, Chelonia mydas, migrate between foraging and nesting sites that are generally separated by thousands of kilometers. As an emblematic endangered species, green turtles have been intensively studied, with a focus on nesting, migration, and foraging. Nevertheless, few attempts integrated these behaviors and their trade-offs by considering the spatial configurations of foraging and nesting grounds as well as environmental heterogeneity like oceanic currents and food distribution. We developed an individual-based model to investigate the impact of local environmental conditions on emerging migratory corridors and reproductive output and to thereby identify conservation priority sites. The model integrates movement, nesting, and foraging behavior. Despite being largely conceptual, the model captured realistic movement patterns which confirm field studies. The spatial distribution of migratory corridors and foraging hot spots was mostly constrained by features of the regional landscape, such as nesting site locations, distribution of feeding patches, and oceanic currents. These constraints also explained the mixing patterns in regional forager communities. By implementing alternative decision strategies of the turtles, we found that foraging site fidelity and nesting investment, two characteristics of green turtles' biology, are favorable strategies under unpredictable environmental conditions affecting their habitats. Based on our results, we propose specific guidelines for the regional conservation of green turtles as well as future research suggestions advancing spatial ecology of sea turtles. Being implemented in an easy to learn open-source software, our model can coevolve with the collection and analysis of new data on energy budget and movement into a generic tool for sea turtle research and conservation. Our modeling approach could also be useful for supporting the conservation of other migratory marine animals.
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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 2045-7758 ISBN Médium
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Notes WOS:000481747800001 Approuvé pas de
Numéro d'Appel (up) MARBEC @ isabelle.vidal-ayouba @ collection 2621
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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 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
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0305-0270 ISBN Médium
Région Expédition Conférence
Notes WOS:000484392300001 Approuvé pas de
Numéro d'Appel (up) MARBEC @ isabelle.vidal-ayouba @ collection 2637
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Auteur PANTE, E.; PUILLANDRE, N.; VIRICEL, A.; ARNAUD-HAOND, S.; AURELLE, D.; CASTELIN, M.; CHENUIL, A.; DESTOMBE, C.; FORCIOLI, D.; VALERO, M.; VIARD, F.; SAMADI, S.
Titre Species are hypotheses: avoid connectivity assessments based on pillars of sand Type Article scientifique
Année 2015 Publication Revue Abrégée Molecular Ecology
Volume 24 Numéro 3 Pages 525-544
Mots-Clés connectivity; marine organisms; molecular systematics; taxonomy
Résumé Connectivity among populations determines the dynamics and evolution of populations, and its assessment is essential in ecology in general and in conservation biology in particular. The robust basis of any ecological study is the accurate delimitation of evolutionary units, such as populations, metapopulations and species. Yet a disconnect still persists between the work of taxonomists describing species as working hypotheses and the use of species delimitation by molecular ecologists interested in describing patterns of gene flow. This problem is particularly acute in the marine environment where the inventory of biodiversity is relatively delayed, while for the past two decades, molecular studies have shown a high prevalence of cryptic species. In this study, we illustrate, based on marine case studies, how the failure to recognize boundaries of evolutionary-relevant unit leads to heavily biased estimates of connectivity. We review the conceptual framework within which species delimitation can be formalized as falsifiable hypotheses and show how connectivity studies can feed integrative taxonomic work and vice versa. Finally, we suggest strategies for spatial, temporal and phylogenetic sampling to reduce the probability of inadequately delimiting evolutionary units when engaging in connectivity studies.
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ISSN 0962-1083 ISBN Médium
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Numéro d'Appel (up) MARBEC @ isabelle.vidal-ayouba @ collection 1121
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