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Auteur Maire, Eva; Cinner, J.; Velez, L.; Huchery, C.; Mora, C.; D'agata, S.; Vigliola, L.; Wantiez, L.; Kulbicki, M.; Mouillot, D. doi  openurl
  Titre How accessible are coral reefs to people? A global assessment based on travel time Type Article scientifique
  Année 2016 Publication Revue Abrégée Ecol. Lett.  
  Volume 19 Numéro 4 Pages 351-360  
  Mots-Clés (up) Accessibility; biodiversity; coral reefs; ecological-systems; fish assemblages; fisheries; marine protected areas; market access; population-density; predictors; social<bold>-</bold>ecological; species richness; travel time; vulnerability  
  Résumé The depletion of natural resources has become a major issue in many parts of the world, with the most accessible resources being most at risk. In the terrestrial realm, resource depletion has classically been related to accessibility through road networks. In contrast, in the marine realm, the impact on living resources is often framed into the Malthusian theory of human density around ecosystems. Here, we develop a new framework to estimate the accessibility of global coral reefs using potential travel time from the nearest human settlement or market. We show that 58% of coral reefs are located <30min from the nearest human settlement. We use a case study from New Caledonia to demonstrate that travel time from the market is a strong predictor of fish biomass on coral reefs. We also highlight a relative deficit of protection on coral reef areas near people, with disproportional protection on reefs far from people. This suggests that conservation efforts are targeting low-conflict reefs or places that may already be receiving de facto protection due to their isolation. Our global assessment of accessibility in the marine realm is a critical step to better understand the interplay between humans and resources.  
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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 @ alain.herve @ collection 1626  
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Auteur Giakoumi, S.; Halpern, B.S.; Michel, L.N.; Gobert, S.; Sini, M.; Boudouresque, C.-F.; Gambi, M.-C.; Katsanevakis, S.; Lejeune, P.; Montefalcone, M.; Pergent, G.; Pergent-Martini, C.; Sanchez-Jerez, P.; Velimirov, B.; Vizzini, S.; Abadie, A.; Coll, M.; Guidetti, P.; Micheli, F.; Possingham, H.P. url  doi
openurl 
  Titre Towards a framework for assessment and management of cumulative human impacts on marine food webs Type Article scientifique
  Année 2015 Publication Revue Abrégée Conservation Biology  
  Volume 29 Numéro 4 Pages 1228-1234  
  Mots-Clés (up) acciones de conservación; amenazas múltiples; conservation actions; ecosystem-based management; expert knowledge elicitation; manejo con base en los ecosistemas; multiple threats; obtención de conocimiento de expertos; pastos marinos; seagrass; vulnerabilidad; vulnerability  
  Résumé Effective ecosystem-based management requires understanding ecosystem responses to multiple human threats, rather than focusing on single threats. To understand ecosystem responses to anthropogenic threats holistically, it is necessary to know how threats affect different components within ecosystems and ultimately alter ecosystem functioning. We used a case study of a Mediterranean seagrass (Posidonia oceanica) food web and expert knowledge elicitation in an application of the initial steps of a framework for assessment of cumulative human impacts on food webs. We produced a conceptual seagrass food web model, determined the main trophic relationships, identified the main threats to the food web components, and assessed the components’ vulnerability to those threats. Some threats had high (e.g., coastal infrastructure) or low impacts (e.g., agricultural runoff) on all food web components, whereas others (e.g., introduced carnivores) had very different impacts on each component. Partitioning the ecosystem into its components enabled us to identify threats previously overlooked and to reevaluate the importance of threats commonly perceived as major. By incorporating this understanding of system vulnerability with data on changes in the state of each threat (e.g., decreasing domestic pollution and increasing fishing) into a food web model, managers may be better able to estimate and predict cumulative human impacts on ecosystems and to prioritize conservation actions.  
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  Langue en Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1523-1739 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1330  
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Auteur Goetze, J.; Langlois, T.; Claudet, J.; Januchowski-Hartley, F.; Jupiter, S.D. doi  openurl
  Titre Periodically harvested closures require full protection of vulnerable species and longer closure periods Type Article scientifique
  Année 2016 Publication Revue Abrégée Biol. Conserv.  
  Volume 203 Numéro Pages 67-74  
  Mots-Clés (up) areas; biomass; Fiji; Fisheries management; life-history; Locally managed marine areas; Marine conservation; marine reserves; predatory fish; Recovery; reef fish communities; responses; small-scale fisheries; stereo-video; vulnerability  
  Résumé Periodically harvested closures (PHCs) are small fisheries closures with objectives such as sustaining fisheries and conserving biodiversity and have become one of the most common forms of nearshore marine management in the Western Pacific. Although PHCs can provide both short-term conservation and fisheries benefits, their potential as a long-term management strategy remains unclear. Through empirical assessment of a single harvest event in each of five PHCs, we determined whether targeted fishes that differ in their vulnerability to fishing recovered to pre-harvest conditions (the state prior to last harvest) and demonstrated post-harvest recovery benefits after 1 year of re-closure. For low and moderately vulnerable species, two PHCs provided significant pre-harvest benefits and one provided significant post-harvest recovery benefits, suggesting a contribution to longer-term sustainability. PHCs with a combination of high compliance and longer closing times are more likely to provide fisheries benefits and recover from harvest events, however, no benefits were observed across any PHCs for highly vulnerable species. We recommend PHCs have longer closure periods before being harvested and species that are highly vulnerable to fishing (e.g. large species of; grouper, wrasse and parrotfish) are avoided during harvests to avoid overexploitation and increase the sustainability of small-scale fisheries. (C) 2016 Elsevier Ltd. 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 0006-3207 ISBN Médium  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 1695  
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Auteur Loiseau, N.; Legras, G.; Kulbicki, M.; Mérigot, B.; Harmelin-Vivien, M.; Mazouni, N.; Galzin, R.; Gaertner, J.C. doi  openurl
  Titre Multi-component β-diversity approach reveals conservation dilemma between species and functions of coral reef fishes Type Article scientifique
  Année 2017 Publication Revue Abrégée J. Biogeogr.  
  Volume 44 Numéro 3 Pages 537-547  
  Mots-Clés (up) assemblages; Beta diversity; Beta-diversity; biodiversity; climate; coral reef fish; environmental dissimilarity; functional diversity; global patterns; models; nestedness; null; partitioning; turnover; vulnerability  
  Résumé AimWe applied a multicomponent approach based on the decomposition of taxonomic (both presence-absence and abundance) and functional beta diversity to determine the influence of ecological factors in shaping spatial distribution diversity of coral reef fishes, and the implications for conservation decisions. LocationLagoons of ten atolls characterized by low human pressure but with contrasted geomorphology in the Tuamotu Archipelago, French Polynesia. MethodsWe computed beta diversities and their partitioning components, both at local (inter-transect, from 200m to 10km) and large (among atolls, from 22 to 350km) spatial scales. Null models were applied to test whether the observed beta diversity differed from random expectation. Multiple generalized dissimilarity models were run to test which environmental factors were the best predictors of observed beta diversities. ResultsBeta diversity was indistinguishable from randomness at both spatial scales. Species remained generally interchangeable among transects within an atoll and to some extent among atolls. However, strong deviance explained by models showed that the number of species, the number of individuals and functional traits present in transects and atolls were determined by deterministic factors (i.e. environmental factors). Modelling each beta diversity component separately also revealed partial mismatch among atolls and among species and functional dissimilarities. The influence of environmental variables strongly varied among atolls, species and functional dissimilarities. Main conclusionsBy revealing the spatial scaling of ecological factors and partial congruence among species and functional diversity, assessment of beta diversity provides insight into conservation planning. Our results support the idea that conservation planning applied to protect taxonomic diversity cannot be fully extended to functional diversity. We have addressed the dilemma of which diversity component should be favoured in conservation strategies.  
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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 0305-0270 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ alain.herve @ collection 2117  
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Auteur Villon, S.; Mouillot, D.; Chaumont, M.; Darling, E.S.; Subsol, G.; Claverie, T.; Villeger, S. doi  openurl
  Titre A Deep learning method for accurate and fast identification of coral reef fishes in underwater images Type Article scientifique
  Année 2018 Publication Revue Abrégée Ecol. Inform.  
  Volume 48 Numéro Pages 238-244  
  Mots-Clés (up) Automated identification; Convolutional neural network; density; Machine learning; Marine fishes; neural-networks; system; temperate; Underwater pictures; video stations; visual census; vulnerability  
  Résumé Identifying and counting fish individuals on photos and videos is a crucial task to cost-effectively monitor marine biodiversity, yet it remains difficult and time-consuming. In this paper, we present a method to assist the identification of fish species on underwater images, and we compare our model performances to human ability in terms of speed and accuracy. We first tested the performance of a convolutional neural network (CNN) trained with different photographic databases while accounting for different post-processing decision rules to identify 20 fish species. Finally, we compared the performance of species identification of our best CNN model with that of humans on a test database of 1197 fish images representing nine species. The best CNN was the one trained with 900,000 images including (i) whole fish bodies, (ii) partial fish bodies and (iii) the environment (e.g. reef bottom or water). The rate of correct identification was 94.9%, greater than the rate of correct identification by humans (89.3%). The CNN was also able to identify fish individuals partially hidden behind corals or behind other fish and was more effective than humans to identify fish on smallest or blurry images while humans were better to identify fish individuals in unusual positions (e.g. twisted body). On average, each identification by our best CNN using a common hardware took 0.06 s. Deep Learning methods can thus perform efficient fish identification on underwater images and offer promises to build-up new video-based protocols for monitoring fish biodiversity cheaply and effectively.  
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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 1574-9541 ISBN Médium  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2475  
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