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Auteur (up) FROMENTIN, J.-M.; REYGONDEAU, G.; BONHOMMEAU, S.; BEAUGRAND, G. url  openurl
  Titre Oceanographic changes and exploitation drive the spatio-temporal dynamics of Atlantic bluefin tuna (Thunnus thynnus) Type Article scientifique
  Année 2014 Publication Revue Abrégée Fisheries Oceanography  
  Volume 23 Numéro 2 Pages 147-156  
  Mots-Clés ecological niche model; longline fisheries; Migration; synergistic effects; Thunnus thynnus; time series  
  Résumé Atlantic bluefin tuna (ABFT) has always displayed spectacular changes in its spatial distribution, but the underlying mechanism of such variations still remains obscure. This study focuses on this challenging issue by scrutinizing the intriguing ‘Brazilian episode’ during which a large quantity of ABFT (a temperate species) was caught during the 1960s in the equatorial Atlantic. To investigate this event, we applied a niche model to an extensive data set of catch and environmental variables from 1960 to 2009. ABFT exhibited a remarkably large ecological niche, which matches well with our current knowledge of ABFT. Our results also depicted a high probability of ABFT occurrence in the South Atlantic and, more interestingly, favorable environmental conditions in the western equatorial Atlantic during the 1960s, but not later. ABFT could thus have migrated from their northern spawning grounds to the South Atlantic during the 1960s through the western equatorial Atlantic, playing the role of an ‘ecological bridge’. We argue that the rarity of ABFT in the southern Atlantic during the last four decades would result from the interaction of several processes, particularly oceanographic conditions, migratory behavior, density-dependence, exploitation levels and population structure. Examination of the catch data further indicated that the fish caught in the equatorial Atlantic were from the western stock and we concluded that the lack of rebuilding of this stock could result from a regime shift due to the combination of oceanographic changes in the equatorial Atlantic and overfishing in the North Atlantic in the 1960s and 1970s.  
  Auteur institutionnel Thèse  
  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 1054-6006 ISBN Médium  
  Région Expédition Conférence  
  Notes <p>The following values have no corresponding Zotero field:<br />Author Address: Ifremer Inst Francais Rech Exploitat Mer, UMR EME 212, F-34203 Sete, France.<br />Author Address: IRD, UMR EME 212, F-34203 Sete, France.<br />Author Address: CNRS, UMR LOG 8187, F-62930 Wimereux, France.<br />PB – Wiley-blackwell</p> Approuvé pas de  
  Numéro d'Appel LL @ pixluser @ collection 340  
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