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Auteur NIEBLAS, A.-E.; DEMARCQ, H.; DRUSHKA, K.; SLOYAN, B.; BONHOMMEAU, S. url  openurl
  Titre Front variability and surface ocean features of the presumed southern bluefin tuna spawning grounds in the tropical southeast Indian Ocean Type Article scientifique
  Année 2014 Publication Revue Abrégée Deep-sea Research Part II-topical Studies In Oceanography  
  Volume 107 Numéro Pages 64-76  
  Mots-Clés Front detection index; Indo-Australian region; Oceanic fronts; Southern bluefin tuna Thunnus maccoyii; Spawning grounds (10 degrees S-20 degrees S 105 degrees E-125 degrees E); Tropical southeast Indian Ocean  
  Résumé The southern bluefin tuna (SBT, Thunnus maccoyii) is an ecologically and economically valuable fish. However, surprisingly little is known about its critical early life history, a period when mortality is several orders of magnitude higher than at any other life stage, and when larvae are highly sensitive to environmental conditions. Ocean fronts can be important in creating favourable spawning conditions, as they are a convergence of water masses with different properties that can concentrate planktonic particles and lead to enhanced productivity. In this study, we examine the front activity within the only region where SBT have been observed to spawn: the tropical southeast Indian Ocean between Indonesia and Australia (10 degrees S-20 degrees S, 105 degrees E-125 degrees E). We investigate front activity and its relationship to ocean dynamics and surface features of the region. Results are also presented for the entire Indian Ocean (30 degrees N-45 degrees S, 20 degrees E-140 degrees E) to provide a background context. We use an extension of the Cayula and Cornillon algorithm to detect ocean fronts from satellite images of sea surface temperature (SST) and chlorophyll-a concentration (chl-a). Front occurrence represents the probability of occurrence of a front at each pixel of an image. Front intensity represents the magnitude of the difference between the two water masses that make up a front. Relative to the rest of the Indian Ocean, both SST and chl-a fronts in the offshore spawning region are persistent in occurrence and weak in intensity. Front occurrence and intensity along the Australian coast are high, with persistent and intense fronts found along the northwest and west coasts. Fronts in the tropical southeast Indian Ocean are shown to have strong annual variability and some moderate interannual variability. SST front occurrence is found to lead the Southern Oscillation Index by one year, potentially linked to warming and wind anomalies in the Indian Ocean. The surface ocean characteristics of the offshore SBT spawning region are found to be particularly stable compared to the rest of the Indian Ocean in terms of stable SST, low eddy kinetic energy, i.e., low mesoscale eddy activity, and low chl-a. However, this region has high front occurrence, but low front intensity of both SST and chl-a fronts. The potential impact of these oceanic features for SBT spawning is discussed.  
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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 (up)  
  ISSN 0967-0645 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1131  
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Auteur Jose, Y.S.; Aumont, O.; Machu, E.; Penven, P.; Moloney, C.L.; Maury, O. url  doi
openurl 
  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  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition (up)  
  ISSN 0967-0645 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel LL @ pixluser @ collection 364  
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Auteur Lezama-Ochoa, A.; Irigoien, X.; Chaigneau, A.; Quiroz, Z.; Lebourges Dhaussy, A.; Bertrand, A. url  doi
openurl 
  Titre Acoustic reveal the presence of Macrozooplankton biocline in the Bay of Biscay in response to hydrological conditions and predator-prey relationships Type Article scientifique
  Année 2014 Publication Revue Abrégée PLoS One  
  Volume 9 Numéro 2 Pages  
  Mots-Clés  
  Résumé Bifrequency acoustic data, hydrological measurements and satellite data were used to study the vertical distribution of

macrozooplankton in the Bay of Biscay in relation to the hydrological conditions and fish distribution during spring 2009.

The most noticeable result was the observation of a &8216;biocline&8217; during the day i.e., the interface where zooplankton biomass

changes more rapidly with depth than it does in the layers above or below. The biocline separated the surface layer, almost

devoid of macrozooplankton, from the macrozooplankton-rich deeper layers. It is a specific vertical feature which ties in

with the classic diel vertical migration pattern. Spatiotemporal correlations between macrozooplankton and environmental

variables (photic depth, thermohaline vertical structure, stratification index and chlorophyll-a) indicate that no single factor

explains the macrozooplankton vertical distribution. Rather a set of factors, the respective influence of which varies from

region to region depending on the habitat characteristics and the progress of the spring stratification, jointly influence the

distribution. In this context, the macrozooplankton biocline is potentially a biophysical response to the search for a

particular depth range where light attenuation, thermohaline vertical structure and stratification conditions together

provide a suitable alternative to the need for expending energy in reaching deeper water without the risk of being eaten.
 
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  Langue eng Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition (up)  
  ISSN 1932-6203 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel LL @ pixluser @ collection 365  
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Auteur Lefevre, S.; Domenici, P.; McKenzie, D.J. url  doi
openurl 
  Titre Swimming in air-breathing fishes Type Article scientifique
  Année 2014 Publication Revue Abrégée Journal of Fish Biology  
  Volume 84 Numéro 3 Pages 661-681  
  Mots-Clés acid-base; aerobic metabolism; amia-calva; bimodal respiration; dicentrarchus-labrax; european sea-bass; exercise; exhaustive exercise; gar lepisosteus-platyrhincus; megalops-cyprinoides; pacific; partitioning; rainbow-trout; recovery; respiratory; tarpon; trout oncorhynchus-mykiss  
  Résumé Fishes with bimodal respiration differ in the extent of their reliance on air breathing to support aerobic metabolism, which is reflected in their lifestyles and ecologies. Many freshwater species undertake seasonal and reproductive migrations that presumably involve sustained aerobic exercise. In the six species studied to date, aerobic exercise in swim flumes stimulated air-breathing behaviour, and there is evidence that surfacing frequency and oxygen uptake from air show an exponential increase with increasing swimming speed. In some species, this was associated with an increase in the proportion of aerobic metabolism met by aerial respiration, while in others the proportion remained relatively constant. The ecological significance of anaerobic swimming activities, such as sprinting and fast-start manoeuvres during predator-prey interactions, has been little studied in air-breathing fishes. Some species practise air breathing during recovery itself, while others prefer to increase aquatic respiration, possibly to promote branchial ion exchange to restore acid-base balance, and to remain quiescent and avoid being visible to predators. Overall, the diversity of air-breathing fishes is reflected in their swimming physiology as well, and further research is needed to increase the understanding of the differences and the mechanisms through which air breathing is controlled and used during exercise.  
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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 (up)  
  ISSN 0022-1112 ISBN Médium  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 877  
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Auteur LAGABRIELLE, E.; CROCHELET, E.; ANDRELLO, M.; SCHILL, S.R.; ARNAUD-HAOND, S.; ALLONCLE, N.; PONGE, B. url  openurl
  Titre Connecting MPAs – eight challenges for science and management Type Article scientifique
  Année 2014 Publication Revue Abrégée Aquatic Conservation-marine And Freshwater Ecosystems  
  Volume 24 Numéro Pages 94-110  
  Mots-Clés coastal; conservation evaluation; Fishing; Marine Protected Areas; ocean; spatial modelling  
  Résumé Connectivity is a crucial process underpinning the persistence, recovery, and productivity of marine ecosystems. The Convention on Biological Diversity, through the Aichi Target 11, has set the ambitious objective of implementing a ‘well connected system of protected areas’ by 2020. This paper identifies eight challenges toward the integration of connectivity into MPA network management and planning. A summary table lists the main recommendations in terms of method, tool, advice, or action to address each of these challenges. Authors belong to a science–management continuum including researchers, international NGO officers, and national MPA agency members. Three knowledge challenges are addressed: selecting and integrating connectivity measurement metrics; assessing the accuracy and uncertainty of connectivity measurements; and communicating and visualizing connectivity measurements. Three management challenges are described: integrating connectivity into the planning and management of MPA networks; setting quantitative connectivity targets; and implementing connectivity-based management across scales and marine jurisdictions. Finally, two paths toward a better integration of connectivity science with MPA management are proposed: setting management-driven priorities for connectivity research, bridging connectivity science, and MPA network management. There is no single method to integrate connectivity into marine spatial planning. Rather, an array of methods can be assembled according to the MPA network objectives, budget, available skills, data, and timeframe. Overall, setting up ‘boundary organizations’ should be promoted to organize complex cross-disciplinary, cross-sectoral and cross-jurisdiction interactions that are needed between scientists, managers, stakeholders and decision-makers to make informed decision regarding connectivity-based MPA planning and management.  
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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 (up)  
  ISSN 1052-7613 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1133  
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