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Auteur CASINI, M.; ROUYER, T.; BARTOLINO, V.; LARSON, N.; GRYGIEL, W.
Titre Density-Dependence in Space and Time: Opposite Synchronous Variations in Population Distribution and Body Condition in the Baltic Sea Sprat (Sprattus sprattus) over Three Decades Type Article scientifique
Année (down) 2014 Publication Revue Abrégée Plos One
Volume 9 Numéro 4 Pages
Mots-Clés
Résumé Spatio-temporal density-dependent processes are crucial regulatory factors for natural populations. However, there is a lack of studies addressing spatial density-dependence in fish growth. A previous investigation has suggested spatio-temporal density-dependence in body condition of Baltic sprat. Here, we used different techniques, such as centre of gravity, distance, and homogeneity indices, to better characterize the spatial and temporal variations in sprat density and body condition in the Baltic Proper. Our results evidenced a negative spatio-temporal co-variation between the centres of gravity of density and maximum condition. In the 1980s-early 1990s both centres were located in the middle of the Baltic Proper. From the mid 1990s the centres progressively separated in space, as the sprat population moved towards the north-eastern Baltic Proper, and the centre of maximum condition towards the south-western areas. Moreover, at low abundances, sprat density and condition were homogeneously distributed in space, whereas at high abundances both density and condition showed pronounced geographical gradients. The ecological processes potentially explaining the observed patterns were discussed in the light of the Ideal Free Distribution theory. We provide evidence that the shift in the spatial distribution of cod, the main predator of sprat, has been the main factor triggering the overall spatial changes in sprat density, and thus condition, during the past thirty years. The spatial indices shown here, synthesizing the spatio-temporal patterns of fish distribution, can support the implementation of the EU Marine Strategy Framework Directive.
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ISSN 1932-6203 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 374
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Auteur Parravicini, V.; Villeger, S.; McClanahan, T.R.; Arias-Gonzalez, J.E.; Bellwood, D.R.; Belmaker, J.; Chabanet, P.; Floeter, S.R.; Friedlander, A.M.; Guilhaumon, F.; Vigliola, L.; Kulbicki, M.; Mouillot, D.
Titre Global mismatch between species richness and vulnerability of reef fish assemblages Type Article scientifique
Année (down) 2014 Publication Revue Abrégée Ecology Letters
Volume 17 Numéro 9 Pages 1101-1110
Mots-Clés Vulnerability; biodiversity; biodiversity loss; conservation; coral-reefs; extinction; fisheries; functional diversity; hotspots; macroecology; marine; patterns; protected areas; risk assessment; sensitivity
Résumé The impact of anthropogenic activity on ecosystems has highlighted the need to move beyond the biogeographical delineation of species richness patterns to understanding the vulnerability of species assemblages, including the functional components that are linked to the processes they support. We developed a decision theory framework to quantitatively assess the global taxonomic and functional vulnerability of fish assemblages on tropical reefs using a combination of sensitivity to species loss, exposure to threats and extent of protection. Fish assemblages with high taxonomic and functional sensitivity are often exposed to threats but are largely missed by the global network of marine protected areas. We found that areas of high species richness spatially mismatch areas of high taxonomic and functional vulnerability. Nevertheless, there is strong spatial match between taxonomic and functional vulnerabilities suggesting a potential win-win conservation-ecosystem service strategy if more protection is set in these 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 1461-023x ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 630
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Auteur Le Pape, O.; DELAVENNE, J.; VAZ, S.
Titre Quantitative mapping of fish habitat: A useful tool to design spatialised management measures and marine protected area with fishery objectives Type Article scientifique
Année (down) 2014 Publication Revue Abrégée Ocean & Coastal Management
Volume 87 Numéro Pages 8-19
Mots-Clés
Résumé The delineation of essential fish habitats is necessary to identify, design and prioritize efficient marine protected area (MPA) networks with fishery objectives, capable, in addition to other possible objectives and functions of MPAs, of sustaining the renewal of marine living resources. Both the methods available to map essential fish habitats and the usefulness of these maps are discussed in this paper. Generally, the first step to obtain maps of essential fish habitats consists in choosing one of the numerous existing statistical approaches to build robust habitat suitability models linking relevant descriptors of the marine environment to the spatial distribution of fish presence or density. When these descriptors are exhaustively known, i.e. maps are available for each of them, geo-referenced predictions from these models and their related uncertainty may be imported into Geographic Information Systems for the quantitative identification and characterization of key sites for the marine living resources. The second part of this paper deals with the usefulness of such quantitative maps for management purposes. These maps allow for the quantitative identification of the different habitats that are required for these marine resources to complete their life cycles and enable to measure their respective importance for population renewal and conservation. The consequences of anthropogenic pressures – not only fishing but also land reclamation, aggregate extractions or degradation of habitat quality (e.g. nutrient excess or xenobiotics loadings, invasive species or global change) – on living resources, may also be simulated from such habitat models. These quantitative maps may serve as input in specific conservation planning software based on the systematic conservation approach. Fish habitat maps thus may help decision makers to select relevant protection areas and design coherent MPA networks which objectives are to sustain fishing resources and fisheries.
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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 0964-5691 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 375
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Auteur Dias, M.S.; Oberdorff, T.; Hugueny, B.; Leprieur, F.; Jezequel, C.; Cornu, J.F.; Brosse, S.; Grenouillet, G.; Tedesco, P.A.
Titre Global imprint of historical connectivity on freshwater fish biodiversity Type Article scientifique
Année (down) 2014 Publication Revue Abrégée Ecology Letters
Volume 17 Numéro 9 Pages 1130-1140
Mots-Clés Alpha diversity; Beta diversity; Biogeography; Quaternary climate changes; africa; climate changes; contemporary; diversity patterns; endemism; evolution; freshwater fish; global; history; north-america; richness; river systems; scale; sea-level changes; species turnover; species-richness
Résumé The relative importance of contemporary and historical processes is central for understanding biodiversity patterns. While several studies show that past conditions can partly explain the current biodiversity patterns, the role of history remains elusive. We reconstructed palaeo-drainage basins under lower sea level conditions (Last Glacial Maximum) to test whether the historical connectivity between basins left an imprint on the global patterns of freshwater fish biodiversity. After controlling for contemporary and past environmental conditions, we found that palaeo-connected basins displayed greater species richness but lower levels of endemism and beta diversity than did palaeo-disconnected basins. Palaeo-connected basins exhibited shallower distance decay of compositional similarity, suggesting that palaeo-river connections favoured the exchange of fish species. Finally, we found that a longer period of palaeo-connection resulted in lower levels of beta diversity. These findings reveal the first unambiguous results of the role played by history in explaining the global contemporary patterns of biodiversity.
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Auteur institutionnel Thèse
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 1461-023x ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 631
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Auteur Cresson, P.; Fabri, M.-C.; Bouchoucha, M.; Brach Papa, C.; Chavanon, F.; Jadaud, A.; Knoery, J.; MARCO-MIRALLES, F.; Cossa, D.
Titre Mercury in organisms from the Northwestern Mediterranean slope: Importance of food sources Type Article scientifique
Année (down) 2014 Publication Revue Abrégée Science of The Total Environment
Volume 497-498 Numéro Pages 229-238
Mots-Clés Continental slope; Depth; Sharks; Stable Isotopes; Teleosts; Trophic webs
Résumé Mercury (Hg) is a global threat for marine ecosystems, especially within the Mediterranean Sea. The concern is higher for deep-sea organisms, as the Hg concentration in their tissues is commonly high. To assess the influence of food supply at two trophic levels, total Hg concentrations and carbon and nitrogen stable isotope ratios were determined in 7 species (4 teleosts, 2 sharks, and 1 crustacean) sampled on the upper part of the continental slope of the Gulf of Lions (Northwestern Mediterranean Sea), at depths between 284 and 816 m. Mean Hg concentrations ranged from 1.30 ± 0.61 to 7.13 ± 7.09 μg g− 1 dry mass, with maximum values observed for small-spotted catshark Scyliorhinus canicula. For all species except blue whiting Micromesistius poutassou, Hg concentrations were above the health safety limits for human consumption defined by the European Commission, with a variable proportion of the individuals exceeding limits (from 23% for the Norway lobster Nephrops norvegicus to 82% for the blackbelly rosefish Helicolenus dactylopterus). Measured concentrations increased with increasing trophic levels. Carbon isotopic ratios measured for these organisms demonstrated that settling phytoplanktonic organic matter is not only the main source fueling trophic webs but also the carrier of Hg to this habitat. Inter- and intraspecific variations of Hg concentrations revealed the importance of feeding patterns in Hg bioaccumulation. In addition, biological parameters, such as growth rate or bathymetric range explain the observed contamination trends.
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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 0048-9697 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel LL @ pixluser @ collection 376
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