1. Fine-scale vertical movements of oceanic whitetip sharks (Carcharhinus longimanus)
- Author
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Paulo Travassos, Laurent Dagorn, Fabien Forget, Pascal Bach, Robert Bauer, Mariana Travassos Tolotti, MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Universidade Federal de Pernambuco [Recife] (UFPE)
- Subjects
0106 biological sciences ,Scale (anatomy) ,WHALE SHARKS ,Mixed layer ,DIEL ,PRIONACE-GLAUCA ,Aquatic Science ,010603 evolutionary biology ,01 natural sciences ,PELAGIC SHARKS ,[SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate Zoology ,NORTH PACIFIC-OCEAN ,14. Life underwater ,Diel vertical migration ,biology ,010604 marine biology & hydrobiology ,Generalized additive model ,Prionace glauca ,Pelagic zone ,biology.organism_classification ,TUNA THUNNUS-OBESUS ,Fishery ,Indian ocean ,Carcharhinus longimanus ,Oceanography ,ARCHIVAL TAGGING DATA ,DOLPHINFISH CORYPHAENA-HIPPURUS ,ISURUS-OXYRINCHUS ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,LONGLINE FLEET ,Geology - Abstract
International audience; Time series of depth data, obtained for 6 oceanic whitetip sharks (Carcharhinus longimanus) tagged with pop-up satellite archival tags, were analyzed in detail. The aim was to improve our knowledge of the vertical behavior of this species. Individuals were tagged in the Atlantic Ocean (n=5) and Indian Ocean (n=1) between 2011 and 2012. Deployment periods for these tags varied from 100 to 178 d. The sharks spent most of their time in the mixed layer, displaying the typical behavior of an epipelagic species. However, analyses revealed complex vertical movement patterns, including marked diel changes that reflect 3 different types of behavior. Results of the generalized additive models indicate that vertical movements were strongly correlated with variations in the depth of the mixed layer. A correlation between vertical movements and sea-surface temperature (SST) was also observed. When SST was above average, oceanic whitetip sharks increased their vertical amplitude, disregarding the reduction of the mixed layer. Thermoregulation likely allows this type of vertical movement.
- Published
- 2017