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Auteur Chevrinais, M.; Jacquet, C.; Cloutier, R.
Titre Early establishment of vertebrate trophic interactions: Food web structure in Middle to Late Devonian fish assemblages with exceptional fossilization Type Article scientifique
Année 2017 Publication Revue Abrégée Bull. Geosci.
Volume 92 Numéro 4 Pages (down) 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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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 1214-1119 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2251
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Auteur Mostajir, B.; Amblard, C.; Buffan-Dubau, E.; De Wit, R.; Lensi, R.; Sime-Ngando, T.
Titre Microbial Food Webs in Aquatic and Terrestrial Ecosystems Type Chapitre de livre
Année 2015 Publication Revue Abrégée
Volume Numéro Pages (down) 485-509
Mots-Clés Biodiversity; Biogeochemical cycles; Ecological interactions; Microbial Ecology; Microbial food webs; Microbial loop
Résumé In microbial food webs, different types of interactions occur between microorganisms themselves and with meio- and macroorganisms. After an historical and general introduction, the biological components of the microbial food webs in the pelagic and benthic marine and lake ecosystems, as well as in the terrestrial ecosystems, are presented. The functioning of the microbial food webs in different ecosystems is illustrated and explained, including the trophic pathways and transfer of matter from microbial food webs toward meio- and macroorganisms of the superior trophic levels, the nutrient recycling in the aquatic environments, and the decomposition of organic matter in soils. Finally, the factors regulating microbial food webs, primarily “top-down” and “bottom-up” controls, are described with a special focus on the role of viruses in the aquatic microbial food webs.
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Editeur Springer Netherlands Lieu de Publication Éditeur Bertrand, J.-C.; Caumette, P.; Lebaron, P.; Matheron, R.; Normand, P.; Sime-Ngando, T.
Langue en Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé Environmental Microbiology: Fundamentals and Applications
Volume de collection Numéro de collection Edition
ISSN ISBN 978-94-017-9117-5 978-94-017-9118-2 Médium
Région Expédition Conférence
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Numéro d'Appel MARBEC @ alain.herve @ collection 1394
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Auteur Chouvelon, T.; Brach-Papa, C.; Auger, D.; Bodin, N.; Bruzac, S.; Crochet, S.; Degroote, M.; Hollanda, S.J.; Hubert, C.; Knoery, J.; Munschy, C.; Puech, A.; Rozuel, E.; Thomas, B.; West, W.; Bourjea, J.; Nikolic, N.
Titre Chemical contaminants (trace metals, persistent organic pollutants) in albacore tuna from western Indian and south-eastern Atlantic Oceans: Trophic influence and potential as tracers of populations Type Article scientifique
Année 2017 Publication Revue Abrégée Sci. Total Environ.
Volume 596 Numéro Pages (down) 481-495
Mots-Clés Bioaccumulation; biscay northeast atlantic; enhanced bioaccumulation; feeding ecology; Inorganic elements; Intrinsic markers; marine food webs; mercury concentrations; merluccius-merluccius; Organic contaminants; organochlorine compounds; polychlorinated-biphenyls; stable-isotope analysis; Stable isotopes; thunnus-alalunga; Top predator
Résumé Albacore tuna (Thunnus alalunga) is a highly commercial fish species harvested in the world's Oceans. Identifying the potential links between populations is one of the key tools that can improve the current management across fisheries areas. In addition to characterising populations' contamination state, chemical compounds can help refine foraging areas, individual flows and populations' structure, especially when combined with other intrinsic biogeochemical (trophic) markers such as carbon and nitrogen stable isotopes. This study investigated the bioaccumulation of seven selected trace metals – chromium, nickel, copper (Cu), zinc (Zn), cadmium (Cd), mercury (Hg) and lead – in the muscle of 443 albacore tunas, collected over two seasons and/or years in the western Indian Ocean (WIO: Reunion Island and Seychelles) and in the south-eastern Atlantic Ocean (SEAO: South Africa). The main factor that explained metal concentration variability was the geographic origin of fish, rather than the size and the sex of individuals, or the season/year of sampling. The elements Cu, Zn, Cd and Hg indicated a segregation of the geographic groups most clearly. For similar sized-individuals, tunas from SEAO had significantly higher concentrations in Cu, Zn and Cd, but lower Hg concentrations than those from WIO. Information inferred from the analysis of trophic markers (delta C-13, delta N-15) and selected persistent organic pollutants, as well as information on stomach contents, corroborated the geographical differences obtained by trace metals. It also highlighted the influence of trophic ecology on metal bioaccumulation. Finally, this study evidenced the potential of metals and chemical contaminants in general as tracers, by segregating groups of individuals using different food webs or habitats, to better understand spatial connectivity at the population scale. Limited flows of individuals between the SEAO and the WIO are suggested. Albacore as predatory fish also provided some information on environmental and food web chemical contamination in the different study areas. (C) 2017 Elsevier B.V. All rights reserved.
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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 0048-9697 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2139
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Auteur Espinoza, P.; Bertrand, A.
Titre Ontogenetic and spatiotemporal variability in anchoveta Engraulis ringens diet off Peru Type Article scientifique
Année 2014 Publication Revue Abrégée Journal of Fish Biology
Volume 84 Numéro 2 Pages (down) 422-435
Mots-Clés euphausiids; Humboldt Current system; oxygen; Peruvian anchovy; spatiotemporal variability; trophic ecology
Résumé In this study, historical data available since 1954 were used to get new insight to ontogenetic and spatiotemporal variability in Peruvian anchovy or anchoveta Engraulis ringens diet. Whatever the period, E. ringens foraged mainly on macrozooplankton and the importance of euphausiids in E. ringens diet appears directly related to euphausiids abundance. This bottom-up effect is also observed at smaller scale because the euphausiids fraction increased with E. ringens total length and euphausiids accessibility. Selecting the largest prey, the euphausiids, provides an energetic advantage for E. ringens in its ecosystem where oxygen depletion imposes strong metabolic constraints on pelagic fishes. This study illustrates the plasticity of E. ringens that allows it to cope with its highly variable environment.
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Editeur Lieu de Publication Éditeur
Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0022-1112 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 358
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Auteur Cinner, J.E.; Huchery, C.; MacNeil, M.A.; Graham, N.A.J.; McClanahan, T.R.; Maina, J.; Maire, Eva; Kittinger, J.N.; Hicks, C.C.; Mora, C.; Allison, E.H.; D’Agata, S.; Hoey, A.; Feary, D.A.; Crowder, L.; Williams, I.D.; Kulbicki, M.; Vigliola, L.; Wantiez, L.; Edgar, G.; Stuart-Smith, R.D.; Sandin, S.A.; Green, A.L.; Hardt, M.J.; Beger, M.; Friedlander, A.; Campbell, S.J.; Holmes, K.E.; Wilson, S.K.; Brokovich, E.; Brooks, A.J.; Cruz-Motta, J.J.; Booth, D.J.; Chabanet, P.; Gough, C.; Tupper, M.; Ferse, S.C.A.; Sumaila, U.R.; Mouillot, D.
Titre Bright spots among the world’s coral reefs Type Article scientifique
Année 2016 Publication Revue Abrégée Nature
Volume 535 Numéro 7612 Pages (down) 416-419
Mots-Clés Environmental impact; Sustainability; Tropical ecology
Résumé Ongoing declines in the structure and function of the world’s coral reefs require novel approaches to sustain these ecosystems and the millions of people who depend on them. A presently unexplored approach that draws on theory and practice in human health and rural development is to systematically identify and learn from the ‘outliers’—places where ecosystems are substantially better (‘bright spots’) or worse (‘dark spots’) than expected, given the environmental conditions and socioeconomic drivers they are exposed to. Here we compile data from more than 2,500 reefs worldwide and develop a Bayesian hierarchical model to generate expectations of how standing stocks of reef fish biomass are related to 18 socioeconomic drivers and environmental conditions. We identify 15 bright spots and 35 dark spots among our global survey of coral reefs, defined as sites that have biomass levels more than two standard deviations from expectations. Importantly, bright spots are not simply comprised of remote areas with low fishing pressure; they include localities where human populations and use of ecosystem resources is high, potentially providing insights into how communities have successfully confronted strong drivers of change. Conversely, dark spots are not necessarily the sites with the lowest absolute biomass and even include some remote, uninhabited locations often considered near pristine. We surveyed local experts about social, institutional, and environmental conditions at these sites to reveal that bright spots are characterized by strong sociocultural institutions such as customary taboos and marine tenure, high levels of local engagement in management, high dependence on marine resources, and beneficial environmental conditions such as deep-water refuges. Alternatively, dark spots are characterized by intensive capture and storage technology and a recent history of environmental shocks. Our results suggest that investments in strengthening fisheries governance, particularly aspects such as participation and property rights, could facilitate innovative conservation actions that help communities defy expectations of global reef degradation.
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Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0028-0836 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1628
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