Mestre, J and Authier, M and Cherel, Y and Harcourt, R and McMahon, CR and Hindell, MA and Charrassin, J-B and Guinet, C, Decadal changes in blood 13C values, at-sea distribution, and weaning mass of southern elephant seals from Kerguelen Islands, Proceedings of the Royal Society of London. Biological Sciences, 287, (1933) Article 20201544. ISSN 0962-8452 (2020) [Refereed Article]
Copyright © 2020 The Author(s) Published by the Royal Society.
Changes in the foraging environment and at-sea distribution of southern elephant seals from Kerguelen Islands were investigated over a decade (2004–2018) using tracking, weaning mass, and blood δ13C values. Females showed either a sub-Antarctic or an Antarctic foraging strategy, and no significant shift in their at-sea distribution was detected between 2004 and 2017. The proportion of females foraging in sub-Antarctic versus Antarctic habitats did not change over the 2006–2018 period. Pup weaning mass varied according to the foraging habitat of their mothers. The weaning mass of sub-Antarctic foraging mothers' pups decreased by 11.7 kg over the study period, but they were on average 5.8 kg heavier than pups from Antarctic foraging mothers. Pup blood δ13C values decreased by 1.1‰ over the study period regardless of their sex and the presumed foraging habitat of their mothers. Together, these results suggest an ecological change is occurring within the Indian sector of the Southern Ocean with possible consequences on the foraging performance of southern elephant seals. We hypothesize that this shift in δ13C is related to a change in primary production and/or in the composition of phytoplankton communities, but this requires further multidisciplinary investigations.
|Item Type:||Refereed Article|
|Keywords:||seals, foraging ecology, foraging habitat, stable isotopes, bio-logging, population strategies, decadal change, Indian sector of the Southern Ocean|
|Research Division:||Earth Sciences|
|Research Field:||Biological oceanography|
|Objective Division:||Environmental Management|
|Objective Group:||Terrestrial systems and management|
|Objective Field:||Assessment and management of terrestrial ecosystems|
|UTAS Author:||McMahon, CR (Dr Clive McMahon)|
|UTAS Author:||Hindell, MA (Professor Mark Hindell)|
|Web of Science® Times Cited:||2|
|Deposited By:||Ecology and Biodiversity|
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