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Auteur Chevrinais, M.; Jacquet, C.; Cloutier, R. doi  openurl
  Titre Early establishment of vertebrate trophic interactions: Food web structure in Middle to Late Devonian fish assemblages with exceptional fossilization Type Article scientifique
  Année (down) 2017 Publication Revue Abrégée Bull. Geosci.  
  Volume 92 Numéro 4 Pages 491-510  
  Mots-Clés north-america; bottom-up; body-size; predator; top-down; bottom-up control; coordinated stasis; Devonian; digestive contents; ecomorphology; escuminac formation; foraging ecology; fossil fish; fossil record; pahteoecology; prey size relationships; top-down control  
  Résumé In past and present ecosystems, trophic interactions determine material and energy transfers among species, regulating population dynamics and community stability. Food web studies in past ecosystems are helpful to assess the persistence of ecosystem structure throughout geological times and to explore the existence of general principles of food web assembly. We determined and compared the trophic structure of two Devonian fish assemblages [(1) the Escuminac assemblage (ca. 380 Ma), Miguasha, eastern Canada and (2) the Lode assemblage (ca. 390 Ma), Straupe, Latvia] with a closer look at the Escuminac assemblage. Both localities are representative of Middle to Late Devonian aquatic vertebrate assemblages in terms of taxonomic richness (ca. 20 species), phylogenetic diversity (all major groups of lower vertebrates) and palaeoenvironment (palaeoestuaries). Fossil food web structures were assessed using different kinds of direct (i.e. digestive contents and bite marks in fossils) and indirect (e.g. ecomoiphological measurements, stratigraphic species co-occurrences) indicators. First, the relationships between predator and prey body size established for the Escuminac fishes are comparable to those of recent aquatic ecosystems, highlighting a consistency of aquatic food web structure across geological time. Second, non-metric dimensional scaling on ecomorphological variables and cluster analysis showed a common pattern of functional groups for both fish assemblages; top predators, predators, primary and secondary consumers were identified. We conclude that Devonian communities were organized in multiple trophic levels and that size-based feeding interactions were established early in vertebrate history.  
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  ISSN 1214-1119 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2251  
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Auteur Mellin, C.; Mouillot, D.; Kulbicki, M.; McClanahan, T.R.; Vigliola, L.; Bradshaw, C.J.A.; Brainard, R.E.; Chabanet, P.; Edgar, G.J.; Fordham, D.A.; Friedlander, A.M.; Parravicini, V.; Sequeira, A.M.M.; Stuart-Smith, R.D.; Wantiez, L.; Caley, M.J. url  doi
openurl 
  Titre Humans and seasonal climate variability threaten large-bodied coral reef fish with small ranges Type Article scientifique
  Année (down) 2016 Publication Revue Abrégée Nat Commun  
  Volume 7 Numéro Pages 10491  
  Mots-Clés Biological sciences; Ecology; Oceanography  
  Résumé Coral reefs are among the most species-rich and threatened ecosystems on Earth, yet the extent to which human stressors determine species occurrences, compared with biogeography or environmental conditions, remains largely unknown. With ever-increasing human-mediated disturbances on these ecosystems, an important question is not only how many species can inhabit local communities, but also which biological traits determine species that can persist (or not) above particular disturbance thresholds. Here we show that human pressure and seasonal climate variability are disproportionately and negatively associated with the occurrence of large-bodied and geographically small-ranging fishes within local coral reef communities. These species are 67% less likely to occur where human impact and temperature seasonality exceed critical thresholds, such as in the marine biodiversity hotspot: the Coral Triangle. Our results identify the most sensitive species and critical thresholds of human and climatic stressors, providing opportunity for targeted conservation intervention to prevent local extinctions.  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 1537  
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Auteur Drouineau, H.; Lobry, J.; Bez, N.; Travers-Trolet, M.; Vermard, Y.; Gascuel, D. doi  openurl
  Titre The need for a protean fisheries science to address the degradation of exploited aquatic ecosystems Type Article scientifique
  Année (down) 2016 Publication Revue Abrégée Aquat. Living Resour.  
  Volume 29 Numéro 2 Pages Unsp-E201  
  Mots-Clés climate-change; eafm; Ecology; Fisheries management; fisheries science; individual-based model; Management strategy evaluation; marine ecosystems; marine resources; models; Movement; ocean; Sustainability; uncertainty; vms data  
  Résumé In this introductory paper we highlight key questions that were discussed during the symposium on “Status, functioning and shifts in marine ecosystems” organized by the Association Francaise d'Halieutique (French Association for Fisheries Sciences, Montpellier, France, July 2015). This symposium illustrated that fisheries science is now working at multiple scales and on all dimensions of socio-ecosystems (ecological, political, sociological, and economic), with a great diversity of approaches and taking into account different levels of complexity while acknowledging diverse sources of uncertainty. We argue that we should go one step further and call for a protean fisheries science to address the deteriorated states of aquatic ecosystems caused by anthropogenic pressures. Protean science is constantly evolving to meet emerging issues, while improving its coherence and integration capacity in its complexity. This science must be nourished by multiple approaches and be capable of addressing all organizational scales, from individual fish or fishermen up to the entire ecosystem, include society, its economy and the services it derives from aquatic systems. Such a protean science is required to address the complexity of ecosystem functioning and of the impacts of anthropogenic pressures.  
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  ISSN 0990-7440 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2066  
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Auteur Matthews, T.J.; Triantis, K.A.; Rigal, F.; Borregaard, M.K.; Guilhaumon, F.; Whittaker, R.J. url  doi
openurl 
  Titre Island species–area relationships and species accumulation curves are not equivalent: an analysis of habitat island datasets Type Article scientifique
  Année (down) 2016 Publication Revue Abrégée Global Ecology and Biogeography  
  Volume 25 Numéro 5 Pages 607-618  
  Mots-Clés Boosted regression trees; conservation biogeography; fragmentation; habitat islands; island biogeography; island species–area relationship; macroecology; nestedness; species accumulation curve; species–area relationship  
  Résumé Aim The relationship between species number and area is of fundamental importance in macroecology and conservation science, yet the implications of different means of quantitative depiction of the relationship remain contentious. We set out (1) to establish the variation in form of the relationship between two distinct methods applied to the same habitat island datasets, (2) to explore the relevance of several key dataset properties for variation in the parameters of these relationships, and (3) to assess the implications for application of the resulting models. Locations Global. Methods Through literature search we compiled 97 habitat island datasets. For each we analysed the form of the island species–area relationship (ISAR) and several versions of species accumulation curve (SAC), giving priority to a randomized form (Ran-SAC). Having established the validity of the power model, we compared the slopes (z-values) between the ISAR and the SAC for each dataset. We used boosted regression tree and simulation analyses to investigate the effect of nestedness and other variables in driving observed differences in z-values between ISARs and SACs. Results The Ran-SAC was steeper than the ISAR in 77% of datasets. The differences were primarily driven by the degree of nestedness, although other variables (e.g. the number of islands in a dataset) were also important. The ISAR was often a poor predictor of archipelago species richness. Main conclusions Slopes of the ISAR and SAC for the same data set can vary substantially, revealing their non-equivalence, with implications for applications of species–area curve parameters in conservation science. For example, the ISAR was a poor predictor of archipelagic richness in datasets with a low degree of nestedness. Caution should be employed when using the ISAR for the purposes of extrapolation and prediction in habitat island systems.  
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  ISSN 1466-8238 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1559  
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Auteur Meistertzheim, A.-L.; Lartaud, F.; Arnaud-Haond, S.; Kalenitchenko, D.; Bessalam, M.; Le Bris, N.; Galand, P.E. url  doi
openurl 
  Titre Patterns of bacteria-host associations suggest different ecological strategies between two reef building cold-water coral species Type Article scientifique
  Année (down) 2016 Publication Revue Abrégée Deep Sea Research Part I: Oceanographic Research Papers  
  Volume 114 Numéro Pages 12-22  
  Mots-Clés Bacterial communities; Bacterial ecology; Deep-Sea corals; Lophelia pertusa; Madrepora oculata; Mediterranean Sea; Microbe-microbe and microbe-host interactions  
  Résumé Cold-water corals (CWC) are main ecosystem engineers of the deep sea, and their reefs constitute hot-spots of biodiversity. However, their ecology remains poorly understood, particularly, the nature of the holobiont formed by corals with their associated bacterial communities. Here, we analyzed Madrepora oculata and Lophelia pertusa samples, collected from one location in a Mediterranean canyon in two different seasons (autumn and spring), in order to test for species specificity and temporal stability of the host-bacteria associations. The 16S rRNA sequencing revealed host-specific patterns of bacterial communities associated with L. pertusa and M. oculata, both in terms of community composition and diversity. All analyzed M. oculata polyps exhibited temporally and spatially similar bacterial communities dominated by haplotypes homologous to the known cnidarians-associated genus Endozoicomonas. In contrast, the bacterial communities associated with L. pertusa varied among polyps from the same colony, as well as among distinct colonies and between seasons. While the resilient consortium formed by M. oculata and its bacterial community fit the definition of holobiont, the versatility of the L. pertusa microbiome suggests that this association is more influenced by the environmental conditions or nutritional status. Our results thus highlight distinct host/microbes association strategies for these two closely related Scleractinians sharing the same habitat, suggesting distinct sensitivity to environmental change.  
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  ISSN 0967-0637 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1565  
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