Beneath the sea ice : exploring elephant seal foraging strategy in Earth's extreme Antarctic polar environment

• Main Author: Labrousse, Sara
• Other Authors: Processus de couplage à Petite Echelle, Ecosystèmes et Prédateurs Supérieurs (PEPS), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris VI, University of Tasmania, Jean-Benoît Charrassin, Mark Hindell, Frédéric Bailleul
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: HAL CCSD 2016
• Subjects: Elephant seals; Marine antarctic ecology; Marine ecosystems; Éléphants de mer du Sud; Glace de mer Antarctique; Océanographie; Polynie; Écologie marine; Télémétrie; [SDV.EE]Life Sciences [q-bio]/Ecology; environment; Antarc*; Antarctic; Antarctique*; banquise; Elephant Seal; Elephant Seals; Mirounga leonina; Sea ice; Southern Elephant Seals; Southern Ocean
• Online Access: https://theses.hal.science/tel-01533383; https://theses.hal.science/tel-01533383/document; https://theses.hal.science/tel-01533383/file/these_archivage_2601538o.pdf

Understanding how physical properties of the environment underpin habitat selection of large marine vertebrates is crucial in identifying how and where animals acquire resources necessary for locomotion, growth and reproduction and ultimately their fitness. The Southern Ocean harbors one of the largest and most dynamic marine ecosystems on our planet which arises from the presence of two majors physical features, (i) the Antarctic Circumpolar Current and (ii) the seasonal sea ice cover region. In the Antarctic, marine predators are exposed to climate-induced shifts in atmospheric circulation and sea ice. However, because these shifts vary regionally, and because much remains to be understood about how individual animals use their environment, it has been difficult to make predictions on how animals may respond to climate variability. Southern elephant seals (Mirounga leonina) are a major consumer of Southern Ocean resources and use two main large scale foraging strategies, (i) feeding in the frontal zone of the Southern Ocean, or (ii) feeding in the seasonal sea ice region. In the present thesis I examined the winter post-moulting foraging strategies of 46 male and female Kerguelen southern elephant seals which utilized the second strategy. Using an eleven year time-series of tracking, diving, and seal-collected hydrographic data (from 2004-2014) I assessed their movements and foraging performance in relation to in situ hydrographic and sea ice conditions. The influence of both the spatio-temporal and inter-annual variability of sea ice around seal locations was investigated, and an investigation on the role of polynya for male elephant seal during winter conducted. Les mammifères marins de l'Océan Austral sont des éléments essentiels des écosystèmes marins antarctiques et des sentinelles de l’état des océans polaires. Comprendre comment les conditions océanographiques déterminent leurs habitats préférentiels est essentiel pour identifier de quelle façon et dans quelle région ces mammifères acquièrent les ...