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Auteur Sardenne, F.; Diaha, N.'G.C.; Amande, M.J.; Zudaire, I.; Couturier, L.I.E.; Metral, L.; Le Grand, F.; Bodin, N. doi  openurl
  Titre Seasonal habitat and length influence on the trophic niche of co-occurring tropical tunas in the eastern Atlantic Ocean Type Article scientifique
  Année 2019 Publication Revue Abrégée Can. J. Fish. Aquat. Sci.  
  Volume 76 Numéro 1 Pages 69-80  
  Mots-Clés lipids; top predators; pacific-ocean; thunnus-albacares; stable-isotope analyses; western; vertical movements; bigeye tuna; vinciguerria-nimbaria; yellowfin tuna  
  Résumé In the Gulf of Guinea, bigeye tuna (Thunnus obesus; BET) and yellowfin tuna (Thunnus albacares; YFT) are an important part of commercial fisheries and play a prominent ecological role as top predators. Using fatty acid profiles and carbon and nitrogen stable isotopes, we examined their trophic niche partitioning in this understudied region. Trophic niche overlap was high (> 70%), similar to percentages in other ocean basins. BET occupied a higher trophic position than YFT and fed on deeper prey (high delta N-15 values and high proportions of monounsaturated fatty acids). The trophic position of YFT decreased slightly in the last 15 years (delta N-15 values decreased by similar to 0.5 parts per thousand), suggesting a change in epipelagic communities, as observed in the eastern Pacific Ocean. Ontogenic changes were limited to BET. For both species, the dietary proportion of the diatom marker 20:5(n-3) increased in the seasonal upwelling area, highlighting the influence of seasonal habitat on the diet of tuna. The relatively lipid-rich muscle (similar to 6% dry mass) of Atlantic tropical tuna suggests a richer diet in this region than that of Indian Ocean tropical tuna and (or) differences in energy allocation strategies.  
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  Volume de collection Numéro de collection Edition  
  ISSN 0706-652x ISBN Médium  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2483  
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Auteur Courbin, N.; Besnard, A.; Peron, C.; Saraux, C.; Fort, J.; Perret, S.; Tornos, J.; Gremillet, D. doi  openurl
  Titre Short-term prey field lability constrains individual specialisation in resource selection and foraging site fidelity in a marine predator Type Article scientifique
  Année 2018 Publication Revue Abrégée Ecol. Lett.  
  Volume 21 Numéro 7 Pages 1043-1054  
  Mots-Clés behavior; Behavioural consistency; Calonectris diomedea; diet; ecology; foraging site fidelity; gannets; habitat selection; mediterranean sea; models; movement; resource selection; Scopoli's shearwater; seabirds; strategies; temporal resource dynamic; Western Mediterranean  
  Résumé Spatio-temporally stable prey distributions coupled with individual foraging site fidelity are predicted to favour individual resource specialisation. Conversely, predators coping with dynamic prey distributions should diversify their individual diet and/or shift foraging areas to increase net intake. We studied individual specialisation in Scopoli's shearwaters (Calonectris diomedea) from the highly dynamic Western Mediterranean, using daily prey distributions together with resource selection, site fidelity and trophic-level analyses. As hypothesised, we found dietary diversification, low foraging site fidelity and almost no individual specialisation in resource selection. Crucially, shearwaters switched daily foraging tactics, selecting areas with contrasting prey of varying trophic levels. Overall, information use and plastic resource selection of individuals with reduced short-term foraging site fidelity allow predators to overcome prey field lability. Our study is an essential step towards a better understanding of individual responses to enhanced environmental stochasticity driven by global changes, and of pathways favouring population persistence.  
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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  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2380  
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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 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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  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 0990-7440 ISBN Médium  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2066  
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Auteur Lagabrielle, E.; Allibert, A.; Kiszka, J.J.; Loiseau, N.; Kilfoil, J.P.; Lemahieu, A. doi  openurl
  Titre Environmental and anthropogenic factors affecting the increasing occurrence of shark-human interactions around a fast-developing Indian Ocean island Type Article scientifique
  Année 2018 Publication Revue Abrégée Sci Rep  
  Volume 8 Numéro Pages 3676  
  Mots-Clés coral-reefs; south-africa; florida; western-australia; carcharhinus-leucas; movement patterns; attack; bull shark; la reunion; reunion-island  
  Résumé Understanding the environmental drivers of interactions between predators and humans is critical for public safety and management purposes. In the marine environment, this issue is exemplified by shark-human interactions. The annual shark bite incidence rate (SBIR) in La Reunion (Indian Ocean) is among the highest in the world (up to 1 event per 24,000 hours of surfing) and has experienced a 23-fold increase over the 2005-2016 period. Since 1988, 86% of shark bite events on ocean-users involved surfers off the leeward coast, where 96% of surfing activities took place. We modeled the SBIR as a function of environmental variables, including benthic substrate, sea temperature and period of day. The SBIR peaked in winter, during the afternoon and dramatically increased on coral substrate since the mid-2000s. Seasonal patterns of increasing SBIR followed similar fluctuations of large coastal shark occurrences (particularly the bull shark Carcharhinus leucas), consistent with the hypothesis that higher shark presence may result in an increasing likelihood of shark bite events. Potential contributing factors and adaptation of ocean-users to the increasing shark bite hazard are discussed. This interdisciplinary research contributes to a better understanding of shark-human interactions. The modeling method is relevant for wildlife hazard management in general.  
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  Auteur institutionnel Thèse  
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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 2045-2322 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ alain.herve @ collection 2314  
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