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Auteur (up) Jeanmougin, M.; Leprieur, F.; Lois, G.; Clergeau, P.
Titre Fine-scale urbanization affects Odonata species diversity in ponds of a megacity (Paris, France) Type Article scientifique
Année 2014 Publication Revue Abrégée Acta Oecologica-International Journal of Ecology
Volume 59 Numéro Pages 26-34
Mots-Clés Evenness; Landscape composition; Model averaging; Ponds; Species diversity; Urban ecology; agricultural landscape; comparative biodiversity; conservation; dragonflies odonata; ecology; fresh-water habitat; patterns; richness; selection; urban
Résumé Current developments in urban ecology include very few studies focused on pond ecosystems, though ponds are recognized as biodiversity hotspots. Using Odonata as an indicator model, we explored changes in species composition in ponds localized along an urban gradient of a megacity (Paris, France). We then assessed the relative importance of local- and landscape-scale variables in shaping Odonata alpha-diversity patterns using a model-averaging approach. Analyses were performed for adult (A) and adult plus exuviae (AE) census data. At 26 ponds, we recorded 657 adults and 815 exuviae belonging to 17 Odonata species. The results showed that the Odonata species assemblage composition was not determined by pond localization along the urban gradient. Similarly, pond characteristics were found to be similar among urban, suburban and periurban ponds. The analyses of AE census data revealed that fine-scale urbanization (i.e., increased density of buildings surrounding ponds) negatively affects Odonata alpha-diversity. In contrast, pond localization along the urban gradient weakly explained the alpha-diversity patterns. Several local-scale variables, such as the coverage of submerged macrophytes, were found to be significant drivers of Odonata alpha-diversity. Together, these results show that the degree of urbanization around ponds must be considered instead of pond localization along the urban gradient when assessing the potential impacts of urbanization on Odonata species diversity This work also indicates the importance of exuviae sampling in understanding the response of Odonata to urbanization. (C) 2014 Elsevier Masson SAS. 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 1146-609x ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 602
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Auteur (up) Johnson, K.E.; Perreau, L.; Charmantier, G.; Charmantier-Daures, M.; Lee, C.E.
Titre Without Gills: Localization of Osmoregulatory Function in the Copepod Eurytemora affinis Type Article scientifique
Année 2014 Publication Revue Abrégée Physiological and Biochemical Zoology
Volume 87 Numéro 2 Pages 310-324
Mots-Clés
Résumé The Pancrustacea, which include crustaceans and hexapods, have successfully colonized marine, freshwater, and terrestrial habitats. While members of the class Malacostraca (e.g., crabs, shrimp) often display immense osmoregulatory capacities, more basally branching crustaceans (e.g., copepods, branchiopods) tend to possess less-specialized osmoregulatory structures that have been poorly characterized. Remarkably, some of these more basal taxa have also colonized diverse habitats. For instance, the copepod Eurytemora affinis has recently invaded freshwater habitats multiple times independently but lack obvious osmoregulatory structures. To explore localization of ion exchange, we performed silver staining, immunohistochemical staining, and transmission electron microscopy. Our results revealed localization of ion transport within the maxillary glands and on four pairs of swimming legs. Silver staining revealed ion exchange at the maxillary pores and on the endopods and exopods of swimming legs P1 through P4. Immunohistochemical assays localized ion transport enzymes V-type H+-ATPase and Na+/K+-ATPase in the maxillary glands and swimming legs as well. Finally, transmission electron microscopy identified specialized ionocytes within these anatomical regions. These investigations uncovered novel osmoregulatory structures at the swimming legs, which we designate the “Crusalis organs.” Our findings identified specific tissues specialized for ion transport, potentially enabling this small crustacean to rapidly transition into freshwater habitats.
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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 1522-2152 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 953
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Auteur (up) Joo, R.; Bertrand, A.; Bouchon, M.; Chaigneau, A.; Demarcq, H.; Tam, J.; Simier, M.; Gutiérrez, D.; Gutiérrez, M.; Segura, M.; Fablet, R.; Bertrand, S.
Titre Ecosystem scenarios shape fishermen spatial behavior. The case of the Peruvian anchovy fishery in the Northern Humboldt Current System Type Article scientifique
Année 2014 Publication Revue Abrégée Progress in Oceanography
Volume 128 Numéro Pages 60-73
Mots-Clés
Résumé A major goal in marine ecology is the understanding of the interactions between the dynamics of the different ecosystem components, from physics to top predators. While fishermen are among the main top predators at sea, almost none of the existing studies on ecology from physics to top predators contemplate fishermen as part of the system. The present work focuses on the coastal processes in the Northern Humboldt Current System, which encompasses both an intense climatic variability and the largest monospecific fishery of the world. From concomitant satellite, acoustic survey and Vessel Monitoring System data (∼90,000 fishing trips) for a ten-year period (2000–2009), we quantify the associations between the dynamics of the spatial behavior of fishermen, environmental conditions and anchovy (Engraulis ringens) biomass and spatial distribution. Using multivariate statistical analyses we show that environmental and anchovy conditions do significantly shape fishermen spatial behavior and present evidences that environmental fluctuations smoothed out along trophic levels. We propose a retrospective analysis of the study period in the light of the ecosystem scenarios evidenced and we finally discuss the potential use of fishermen spatial behavior as ecosystem indicator.
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Volume de collection Numéro de collection Edition
ISSN 0079-6611 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 321
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Auteur (up) Jose, Y.S.; Aumont, O.; Machu, E.; Penven, P.; Moloney, C.L.; Maury, O.
Titre Influence of mesoscale eddies on biological production in the Mozambique Channel : several contrasted examples from a coupled ocean-biogeochemistry model Type Article scientifique
Année 2014 Publication Revue Abrégée Deep-Sea Research Part II.Topical Studies in Oceanography
Volume 100 Numéro No spécial Pages 79-93
Mots-Clés Chlorophyll; Cyclonic and anticyclonic eddies; Mozambique Channel; Nutrients; Ocean physical-biogeochemical coupling
Résumé The impact of mesoscale activity on phytoplankton and nutrient distribution in the Mozambique Channel was simulated by coupling a biogeochemical model (PISCES) with a regional oceanic model (ROMS). Examples of the effects of eddies on the biogeochemistry of the Mozambique Channel are presented to illustrate the complexity of the system. In the model, several cyclonic eddies were found with low concentrations of chlorophyll at their cores, which contrasts with previous studies in the open ocean. In addition, several anticyclonic eddies were simulated with high concentrations of chlorophyll at their cores. Phytoplankton growth within these mesoscale features (both cyclonic and anticyclonic eddies) occurred in response to nutrient injection into the euphotic zone by advection, and subsequent retention of surrounding nutrient-rich waters within eddies. Offshore nutrient distributions depended strongly on lateral advection of nutrient-rich water from the coastal regions, induced by eddy interaction with the shelf. The environmental conditions at the locations where eddies were generated had an important effect on nutrient concentrations within these structures.
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Editeur Lieu de Publication Éditeur Barlow, R.; Marsac, F.; Ternon, J.-F.; Roberts, M.
Langue 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 LL @ pixluser @ collection 364
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Auteur (up) Kaplan, D.; Chassot, E.; Amande, J.M.; Dueri, S.; Demarcq, H.; Dagorn, L.; Fonteneau, A.
Titre Spatial management of Indian Ocean tropical tuna fisheries: potential and perspectives Type Article scientifique
Année 2014 Publication Revue Abrégée Ices Journal of Marine Science
Volume 71 Numéro 7 Pages 1728-1749
Mots-Clés Bycatch; conservation; Indian Ocean; Marine protected areas (MPAs); pelagic; spatial management of fisheries; tropical tuna fisheries
Résumé Effective use of spatial management in the pelagic realm presents special challenges due to high fish and fisher mobility, limited knowledge and significant governance challenges. The tropical Indian Ocean provides an ideal case study for testing our ability to apply existing data sources to assessing impacts of spatial management on tuna fisheries because of several recent controversial spatial closures. We review the scientific underpinnings of pelagic MPA effects, spatio-temporal patterns of Indian Ocean tuna catch, by catch and fish movements, and the consequences of these for the efficacy of spatial management for Indian Ocean tropical tuna fisheries. The tropical Indian Ocean is characterized by strong environmental fluctuations, regular seasonal variability in catch, large observed tuna displacement distances, relatively uniform catch-per-unit-effort and bycatch rates over space, and high fisher mobility, all of which suggest significant variability and movement in tropical tuna fisheries that are simply not well adapted to static spatial closures. One possible exception to this overall conclusion would be a large time/area closure east of Somalia. If closed for a significant fraction of the year it could reduce purse-seine bycatch and juvenile tuna catch. Dynamic closures following fish migratory patterns are possible, but more focused information on fish movements will be needed for effective implementation. Fortunately, several recent improvements in conventional fishery management and reporting will likely enhance our ability to evaluate spatial and non-spatial management options in the near future, particularly as pertaining to bycatch species.
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Volume de collection Numéro de collection Edition
ISSN 1054-3139 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1199
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