Under the sea ice: Exploring the relationship between sea ice and the foraging behaviour of southern elephant seals in East Antarctica

• Published in: Progress in Oceanography
• Main Authors: Labrousse, Sara, Sallée, Jean-Baptiste, Fraser, Alexander D., Massom, Robert A., Reid, Phillip, A., Sumner, Michael, Guinet, Christophe, Harcourt, Robert G., Mcmahon, Clive R., Bailleul, Frédéric, Hindell, Mark A., Charrassin, Jean-Benoit
• Other Authors: Institute for Marine and Antarctic Studies Hobart (IMAS), University of Tasmania Hobart, Australia (UTAS), 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), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Hokkaido University Sapporo, Japan, Antarctic Climate and Ecosystems Cooperative Research Centre (ACE-CRC), Australian Antarctic Division (AAD), Australian Government, Department of the Environment and Energy, Centre for Australian Weather and Climate Research (CAWCR), Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Department of Biological Sciences, Macquarie University, Macquarie University, Department of Biological Sciences, University of Sydney Institute of Marine Science (USIMS), The University of Sydney, South Australian Research and Development Institute Australia (SARDI), CNES-TOSCA, European Project: 637770,H2020,ERC-2014-STG,WAPITI(2015)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: [SDE]Environmental Sciences; Antarctic; East Antarctica; Kerguelen; Kerguelen Islands; Antarc*; Antarctica; Elephant Seals; Mirounga leonina; Sea ice; Southern Elephant Seals
• Online Access: https://hal.science/hal-01538931; https://doi.org/10.1016/j.pocean.2017.05.014

International audience Investigating ecological relationships between predators and their environment is essential to understandthe response of marine ecosystems to climate variability and change. This is particularly true inpolar regions, where sea ice (a sensitive climate variable) plays a crucial yet highly dynamic and variablerole in how it influences the whole marine ecosystem, from phytoplankton to top predators. For mesopredatorssuch as seals, sea ice both supports a rich (under-ice) food resource, access to which dependson local to regional coverage and conditions. Here, we investigate sex-specific relationships between theforaging strategies of southern elephant seals (Mirounga leonina) in winter and spatio-temporal variabilityin sea ice concentration (SIC) and coverage in East Antarctica. We satellite-tracked 46 individualsundertaking post-moult trips in winter from Kerguelen Islands to the peri-Antarctic shelf between2004 and 2014. These data indicate distinct general patterns of sea ice usage: while females tended tofollow the sea ice edge as it extended northward, the males remained on the continental shelf despiteincreasing sea ice. Seal hunting time, a proxy of foraging activity inferred from the diving behaviour,was longer for females in late autumn in the outer part of the pack ice, 150–370 km south of the iceedge. Within persistent regions of compact sea ice, females had a longer foraging activity (i) in the highestsea ice concentration at their position, but (ii) their foraging activity was longer when there were morepatches of low concentration sea ice around their position (either in time or in space; 30 days & 50 km).The high spatio-temporal variability of sea ice around female positions is probably a key factor allowingthem to exploit these concentrated patches. Despite lack of information on prey availability, females mayexploit mesopelagic finfishes and squids that concentrate near the ice-water interface or within the watercolumn (from diurnal vertical migration) in the pack ice ...