Intra-species variability in migratory movement of hawksbill turtles in the southwest Indian Ocean

• Published in: Endangered Species Research
• Main Authors: Nivière, Manon, Dalleau, Mayeul, Bourjea, Jerome, Jean, Claire, Ciccione, Stéphane, Mortimer, Jeanna A., Didon, Vanessa, Rowat, David, Rocamora, Gérard, Ranaivoson, Ravaka, Mahafina, Jamal, Randriamiharisoa, Lalatiana Odile, Barichasse, Eliott, Bousquet, Olivier, Barat, Anne, Laforge, Antoine, Ballorain, Katia
• Other Authors: CEDTM - Centre d’Etude et de Découverte des Tortues Marines, MARine Biodiversity Exploitation and Conservation - Station Ifremer Sète (UMR Marbec - Station Sète), MARine Biodiversity Exploitation and Conservation - MARBEC (UMR MARBEC ), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Kélonia - Observatoire des tortues marines, University of Florida Gainesville (UF), Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2024
• Subjects: [SDV]Life Sciences [q-bio]; Indian; Antarc*; Antarctique*
• Online Access: https://hal.science/hal-04606335; https://doi.org/10.3354/esr01309

International audience Implementing effective conservation measures to manage migratory populations is challenging, especially in a relatively inaccessible dynamic environment such as the ocean. With limited financial and human resources, efforts must be intelligently prioritized to achieve conservation success and reduce uncertainties of conservation efforts. The southwest Indian Ocean (SWIO) hosts some of the world’s most important breeding grounds for the Critically Endangered hawksbill turtle Eretmochelys imbricata. However, knowledge gaps remain about the movement patterns of this species. Between 2007 and 2022, we deployed 17 satellite tags onto hawksbill turtles from scattered locations in the SWIO: 16 nesting females—Granitic Islands, Seychelles (n = 9); north Madagascar (n = 5); Moheli, Comoros (n = 1); Juan de Nova, Terres australes et antarctiques françaises (n = 1)—and 1 female bycaught in fisheries (east Madagascar). We found strong variability in migratory movements amongst individuals, particularly in terms of distance and movement persistence. Detailed analysis of movement persistence reveals that these individuals behave differently in neritic and oceanic habitats, with a lower movement persistence in neritic habitats. We identified a total of 12 foraging areas scattered throughout the SWIO, both in coastal and open-sea neritic habitats. These results reinforce the need to consider the importance of neritic habitats, for both migration and foraging, in conservation policies. The quantification of the degree of migratory variability is particularly important to developing conservation plans and strategies at both the national and international level, including the delineation of regional management units (RMUs) in the Indian Ocean.