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Auteur Pons, M.; Branch, T.A.; Melnychuk, M.C.; Jensen, O.P.; Brodziak, J.; Fromentin, J.M.; Harley, S.J.; Haynie, A.C.; Kell, L.T.; Maunder, M.N.; Parma, A.M.; Restrepo, V.R.; Sharma, R.; Ahrens, R.; Hilborn, R. url  doi
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  Titre (up) Effects of biological, economic and management factors on tuna and billfish stock status Type Article scientifique
  Année 2017 Publication Revue Abrégée Fish Fish  
  Volume 18 Numéro 1 Pages 1-21  
  Mots-Clés Fisheries management; marine conservation; stock assessment; stock status; Tuna fisheries  
  Résumé Commercial tunas and billfishes (swordfish, marlins and sailfish) provide considerable catches and income in both developed and developing countries. These stocks vary in status from lightly exploited to rebuilding to severely depleted. Previous studies suggested that this variability could result from differences in life-history characteristics and economic incentives, but differences in exploitation histories and management measures also have a strong effect on current stock status. Although the status (biomass and fishing mortality rate) of major tuna and billfish stocks is well documented, the effect of these diverse factors on current stock status and the effect of management measures in rebuilding stocks have not been analysed at the global level. Here, we show that, particularly for tunas, stocks were more depleted if they had high commercial value, were long-lived species, had small pre-fishing biomass and were subject to intense fishing pressure for a long time. In addition, implementing and enforcing total allowable catches (TACs) had the strongest positive influence on rebuilding overfished tuna and billfish stocks. Other control rules such as minimum size regulations or seasonal closures were also important in reducing fishing pressure, but stocks under TAC implementations showed the fastest increase of biomass. Lessons learned from this study can be applied in managing large industrial fisheries around the world. In particular, tuna regional fisheries management organizations should consider the relative effectiveness of management measures observed in this study for rebuilding depleted large pelagic stocks.  
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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 1467-2979 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2079  
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Auteur Garrido, M.; Cecchi, P.; Vaquer, A.; Pasqualini, V. url  doi
openurl 
  Titre (up) Effects of sample conservation on assessments of the photosynthetic efficiency of phytoplankton using PAM fluorometry Type Article scientifique
  Année 2013 Publication Revue Abrégée Deep-Sea Res. Part I-Oceanogr. Res. Pap.  
  Volume 71 Numéro Pages 38-48  
  Mots-Clés diatom, quantum yield, temperature, parameters; PAM fluorescence, Phytoplankton, Temperature Biguglia lagoon; physiological-responses, marine-phytoplankton, oxygen evolution, benthic; rapid light curves, chlorophyll-a fluorescence, in-vivo,  
  Résumé Pulse Amplitude Modulated (PAM) fluorometry is now a widely used method for the assessment of phytoplankton fitness, with an increasing popularity in field assessments. It is usually recommended to carry out measurements swiftly after collection, but the number of samples and analytical procedures needed to obtain valuable datasets sometimes makes immediate analysis impracticable, forcing delays between fluorescence measurements. Conservation conditions of samples before analysis may potentially affect their photosynthetic performances but no formal study documenting such impacts appears available in the literature. The aim of this study was to investigate the effects of storage conditions (temperature, duration) on photosynthetic parameters in different phytoplankton communities (characterized in situ by a BBE fluoroprobe) sampled during summer in different environmental locations in a Mediterranean lagoon (Biguglia lagoon, Corsica, France). PAM-fluorescence parameters were measured after three different conservation durations (2-4 h, 6-8 h and 10-12 h after collection) on samples stored at three different temperatures (15 degrees C, 25 degrees C and 35 degrees C). Results showed that storage at the highest temperature severely impacted photosynthetic parameters, with cumulative effects as storage duration increased. For phytoplankton samples collected in warm or tropical environments, storage at “room temperature” (25 degrees C) only appeared a valid option if measurements have to be carried out strictly within a very short delay. Inversely, cooling the samples (i.e. conservation at 15 degrees C) did not induce significant effects, independently of storage duration. Cooling appeared the best solution when sampling-to-analysis delay goes over a few hours. Long-term storage ( > 8 h) should definitively be avoided. (C) 2012 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 0967-0637 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 552  
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Auteur Boyd, C.; Grunbaum, D.; Hunt, G.L.; Punt, A.E.; Weimerskirch, H.; Bertrand, S. doi  openurl
  Titre (up) Effects of variation in the abundance and distribution of prey on the foraging success of central place foragers Type Article scientifique
  Année 2017 Publication Revue Abrégée J. Appl. Ecol.  
  Volume 54 Numéro 5 Pages 1362-1372  
  Mots-Clés allocation; ecosystem; fisheries; Guanay Cormorant; guano-producing seabirds; Humboldt Current system; impact; indicators; marine spatial planning; Peruvian Booby; Phalacrocorax bougainvilliorum; predator-prey interactions; prey availability; seabird competition with fisheries; small pelagic fish; Sula variegata; upwelling system; variability  
  Résumé 1. Seabirds and pinnipeds are vulnerable to reductions in prey availability, especially during the breeding season when spatial constraints limit their adaptive capacity. There are growing concerns about the effects of fisheries on prey availability in regions where large commercial fisheries target forage fish. 2. For breeding seabirds and pinnipeds, prey availability depends on a combination of abundance, accessibility, patchiness and distance from the colony. An understanding of the aspects of prey availability that determine foraging success is essential for the design of effective management responses. 3. We used a mechanistic individual-based foraging model based on observed data for two sea-bird species, the Peruvian Booby Sula variegata and Guanay Cormorant Phalacrocorax bougainvilliorum, to simulate the foraging patterns of seabirds feeding on schooling fish. We ran the model over simulated prey fields representing eight possible combinations of high or low prey abundance, shallow or deep prey, and broadly distributed or spatially concentrated prey. 4. The results highlight the importance of the accessibility of prey. Depth distribution was the primary factor determining modelled foraging success for both species, followed by abundance, and then spatial configuration. 5. Synthesis and applications. The individual-based foraging model provides a spatially explicit framework for assessing the effects of fisheries on the foraging success of seabirds and other central place foragers, and for evaluating the potential effectiveness of marine-protected areas and other fisheries management strategies for safeguarding central place foragers in dynamic ecosystems. Our analysis indicates that broad-scale fisheries management strategies that maintain forage fish above critical biomass levels are essential, but may need to be supplemented by targeted actions, such as time-area closures, when environmental conditions lead to low prey abundance or reduce prey accessibility for seabirds or pinnipeds of conservation concern. The individual-based foraging model is adaptable and could be reconfigured for application to other species and systems.  
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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 0021-8901 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2192  
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Auteur Arnaud-Haond, S.; Aires, T.; Candeias, R.; Teixeira, S.J.L.; Duarte, C.M.; Valero, M.; Serrao, E.A. doi  openurl
  Titre (up) Entangled fates of holobiont genomes during invasion: nested bacterial and host diversities in Caulerpa taxifolia Type Article scientifique
  Année 2017 Publication Revue Abrégée Mol. Ecol.  
  Volume 26 Numéro 8 Pages 2379-2391  
  Mots-Clés Algae; australia; Caulerpa; Chlorophyta; clonal diversity; dna; endophytic communities; genetic diversity; holobiont; invasion paradox; marine invasion; Mediterranean Sea; microsatellite markers; parasites; plant invasions; polymorphism  
  Résumé Successful prevention and mitigation of biological invasions requires retracing the initial steps of introduction, as well as understanding key elements enhancing the adaptability of invasive species. We studied the genetic diversity of the green alga Caulerpa taxifolia and its associated bacterial communities in several areas around the world. The striking congruence of alpha and beta diversity of the algal genome and endophytic communities reveals a tight association, supporting the holobiont concept as best describing the unit of spreading and invasion. Both genomic compartments support the hypotheses of a unique accidental introduction in the Mediterranean and of multiple invasion events in southern Australia. In addition to helping with tracing the origin of invasion, bacterial communities exhibit metabolic functions that can potentially enhance adaptability and competitiveness of the consortium they form with their host. We thus hypothesize that low genetic diversities of both host and symbiont communities may contribute to the recent regression in the Mediterranean, in contrast with the persistence of highly diverse assemblages in southern Australia. This study supports the importance of scaling up from the host to the holobiont for a comprehensive understanding of invasions.  
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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 0962-1083 ISBN Médium  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2143  
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Auteur Escalle, L.; Pennino, M.G.; Gaertner, D.; Chavance, P.; Delgado de Molina, A.; Demarcq, H.; Romanov, E.; Mérigot, B. url  doi
openurl 
  Titre (up) Environmental factors and megafauna spatio-temporal co-occurrence with purse-seine fisheries Type Article scientifique
  Année 2016 Publication Revue Abrégée Fish. Oceanogr.  
  Volume 25 Numéro 4 Pages 433-447  
  Mots-Clés cetaceans; Eastern Atlantic Ocean; generalized additive models-boosted regression trees; marine conservation; purse-seine fishery; residual autocovariate; Western Indian Ocean; whale sharks  
  Résumé Tropical tuna purse-seine fisheries spatially co-occur with various megafauna species, such as whale sharks, dolphins and baleen whales in all oceans of the world. Here, we analyzed a 10-year (2002–2011) dataset from logbooks of European tropical tuna purse-seine vessels operating in the tropical Eastern Atlantic and Western Indian Oceans, with the aim of identifying the principle environmental variables under which such co-occurrence appear. We applied a Delta-model approach using Generalized Additive Models (GAM) and Boosted Regression Trees (BRT) models, accounting for spatial autocorrelation using a contiguity matrix based on a residuals autocovariate (RAC) approach. The variables that contributed most in the models were chlorophyll-a concentration in the Atlantic Ocean, as well as depth and monsoon in the Indian Ocean. High co-occurrence between whale sharks, baleen whales and tuna purse-seine fisheries were mostly observed in productive areas during particular seasons. In light of the lack of a full coverage scientific observer on board program, the large, long-term dataset obtained from logbooks of tuna purse-seine vessels is highly important for identifying seasonal and spatial co-occurrence between the distribution of fisheries and megafauna, and the underlying environmental variables. This study can help to design conservation management measures for megafauna species within the framework of spatial fishery management strategies.  
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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 1365-2419 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1587  
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