title: Dispersal and Diving Adjustments of the Green Turtle Chelonia mydas in Response to Dynamic Environmental Conditions during Post-Nesting Migration.
abstract: In response to seasonality and spatial segregation of resources, sea turtles undertake long journeys between their nesting sites and foraging grounds. While satellite tracking has made it possible to outline their migration routes, we still have little knowledge of how they select their foraging grounds and adapt their migration to dynamic environmental conditions. Here, we analyzed the trajectories and diving behavior of 19 adult green turtles (Chelonia mydas) during their post-nesting migration from French Guiana and Suriname to their foraging grounds off the coast of Brazil. First Passage Time analysis was used to identify foraging areas located off Ceará state of Brazil, where the associated habitat corresponds to favorable conditions for seagrass growth, i.e. clear and shallow waters. The dispersal and diving patterns of the turtles revealed several behavioral adaptations to the strong hydrodynamic processes induced by both the North Brazil current and the Amazon River plume. All green turtles migrated south-eastward after the nesting season, confirming that they coped with the strong counter North Brazil current by using a tight corridor close to the shore. The time spent within the Amazon plume also altered the location of their feeding habitats as the longer individuals stayed within the plume, the sooner they initiated foraging. The green turtles performed deeper and shorter dives while crossing the mouth of the Amazon, a strategy which would help turtles avoid the most turbulent upper surface layers of the plume. These adjustments reveal the remarkable plasticity of this green turtle population when reducing energy costs induced by migration.
authors.affiliation: Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, 23 rue Becquerel, F-67087 Strasbourg cedex 2, France; CNRS, UMR 7178, 23 rue Becquerel, F-67087 Strasbourg cedex 2, France.
authors.forename: Philippine
authors.initials: P
authors.lastname: Chambault
authors.affiliation: Centre d'Études Biologiques de Chizé, UMR 7372 CNRS-Université de La Rochelle, 79360 Villiers-en-Bois, France.
authors.forename: David
authors.initials: D
authors.lastname: Pinaud
authors.affiliation: Laboratoire d'Océanologie et de Géosciences, UMR 8187 CNRS, 28 avenue Foch, BP 80 62930 Wimereux, France; CNRS Guyane, USR 3456, av. Charlery, 97300 Cayenne, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Vantrepotte
authors.affiliation: WWF Guyane, N°5 Lotissement Katoury, F-97300 Cayenne, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Kelle
authors.affiliation: Office National de la Chasse et de la Faune Sauvage-Cellule technique Guyane, Campus agronomique, BP 316, 97379 Kourou cedex, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Entraygues
authors.affiliation: Centre d'Études Biologiques de Chizé, UMR 7372 CNRS-Université de La Rochelle, 79360 Villiers-en-Bois, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Guinet
authors.affiliation: Office National de la Chasse et de la Faune Sauvage-Cellule technique Guyane, Campus agronomique, BP 316, 97379 Kourou cedex, France.
authors.forename: Rachel
authors.initials: R
authors.lastname: Berzins
authors.affiliation: WWF Guianas, Henck Arronstraat 63, Paramaribo, Suriname.
authors.forename: Karin
authors.initials: K
authors.lastname: Bilo
authors.affiliation: Collecte Localisation Satellites, Direction Océanographie Spatiale, 8-10 rue Hermès, 31520 Ramonville, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Gaspar
authors.affiliation: Association Kwata, 16 avenue Pasteur, BP 672, F-97335 Cayenne cedex, France.
authors.forename: Benoît
authors.initials: B
authors.lastname: de Thoisy
authors.affiliation: Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, 23 rue Becquerel, F-67087 Strasbourg cedex 2, France; CNRS, UMR 7178, 23 rue Becquerel, F-67087 Strasbourg cedex 2, France.
authors.forename: Yvon
authors.initials: Y
authors.lastname: Le Maho
authors.affiliation: Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, 23 rue Becquerel, F-67087 Strasbourg cedex 2, France; CNRS, UMR 7178, 23 rue Becquerel, F-67087 Strasbourg cedex 2, France.
authors.forename: Damien
authors.initials: D
authors.lastname: Chevallier
mesh_terms: D025041:Animal Migration; D000818:Animals; D001267:Atlantic Ocean; D004242:Diving; D017753:Ecosystem; D005260:Female; D060434:Herbivory; D057446:Hydrodynamics; D009425:Nesting Behavior; D045483:Rivers; D014426:Turtles / Q000502:physiology*