Foraging insights from whisker isotopic signatures of southern elephant seals around the Antarctic Peninsula
The Antarctic Peninsula is one of the most rapidly warming regions on Earth and is home to a diverse and rich community of life, especially along its continental shelf. The biophysical characteristics that define these regions of highly localised productivity are associated with processes that are d...
Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Pergamon-Elsevier Science Ltd
2018
|
Subjects: | |
Online Access: | https://doi.org/10.1016/j.dsr2.2018.01.006 http://ecite.utas.edu.au/130084 |
id |
ftunivtasecite:oai:ecite.utas.edu.au:130084 |
---|---|
record_format |
openpolar |
spelling |
ftunivtasecite:oai:ecite.utas.edu.au:130084 2023-05-15T13:55:18+02:00 Foraging insights from whisker isotopic signatures of southern elephant seals around the Antarctic Peninsula Gallon, S Hindell, MA Muelbert, MMC 2018 https://doi.org/10.1016/j.dsr2.2018.01.006 http://ecite.utas.edu.au/130084 en eng Pergamon-Elsevier Science Ltd http://dx.doi.org/10.1016/j.dsr2.2018.01.006 Gallon, S and Hindell, MA and Muelbert, MMC, Foraging insights from whisker isotopic signatures of southern elephant seals around the Antarctic Peninsula, Deep-Sea Research. Part 2, 149 pp. 229-239. ISSN 0967-0645 (2018) [Refereed Article] http://ecite.utas.edu.au/130084 Biological Sciences Ecology Marine and Estuarine Ecology (incl. Marine Ichthyology) Refereed Article PeerReviewed 2018 ftunivtasecite https://doi.org/10.1016/j.dsr2.2018.01.006 2019-12-13T22:28:10Z The Antarctic Peninsula is one of the most rapidly warming regions on Earth and is home to a diverse and rich community of life, especially along its continental shelf. The biophysical characteristics that define these regions of highly localised productivity are associated with processes that are driven by climate. Climate changes will therefore potentially alter the oceanographic features and processes on which top predators rely to find their food. Studying the foraging behaviour of apex predators, such as southern elephant seals (SES), Mirounga leonina, is important during this time of rapid change to detect changes in prey availability. Carbon and nitrogen stable isotope (SI) analyses were performed to assess the dietary history (e.g. δ 15N) and infer the foraging habitat (e.g. δ 13 C) on consecutive sections of whole whiskers from 119 southern elephant seals from Elephant Island (6113'S 5523W) from all age and sex classes. Whisker SI values were spread over a large range, with δ 13 C and δ 15 N values varying from -23.21 to -16.34 (a 6.87 difference) and from 8.90 to 15.47 (6.57), respectively. SI analyses also confirmed marked differences in the feeding ecology of southern elephant seals according to sex (e.g. δ 15 N significantly different between sexes in adults, GLMM, p = 0.001) and age group (e.g. δ 13 C related to age classes in females, GLMM, p < 0.001). Results suggest that yearlings foraged more frequently in the sub-Antarctic zone whilst adult seals stayed south of the polar front and, adult and sub-adult males fed on higher trophic level prey than other sex and age classes. We discuss how these differences are likely a result of a combination of intra-specific competition, ontogenetic factors and resource distribution. Studying the degree and the ontogeny of individual specialisation within a population is a first step towards understanding its implications in various dimensions of ecological and evolutionary processes and hence for adapting to climate changes. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Elephant Island Elephant Seals Mirounga leonina Southern Elephant Seals eCite UTAS (University of Tasmania) Antarctic The Antarctic Antarctic Peninsula Elephant Island ENVELOPE(-55.184,-55.184,-61.085,-61.085) Deep Sea Research Part II: Topical Studies in Oceanography 149 229 239 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Biological Sciences Ecology Marine and Estuarine Ecology (incl. Marine Ichthyology) |
spellingShingle |
Biological Sciences Ecology Marine and Estuarine Ecology (incl. Marine Ichthyology) Gallon, S Hindell, MA Muelbert, MMC Foraging insights from whisker isotopic signatures of southern elephant seals around the Antarctic Peninsula |
topic_facet |
Biological Sciences Ecology Marine and Estuarine Ecology (incl. Marine Ichthyology) |
description |
The Antarctic Peninsula is one of the most rapidly warming regions on Earth and is home to a diverse and rich community of life, especially along its continental shelf. The biophysical characteristics that define these regions of highly localised productivity are associated with processes that are driven by climate. Climate changes will therefore potentially alter the oceanographic features and processes on which top predators rely to find their food. Studying the foraging behaviour of apex predators, such as southern elephant seals (SES), Mirounga leonina, is important during this time of rapid change to detect changes in prey availability. Carbon and nitrogen stable isotope (SI) analyses were performed to assess the dietary history (e.g. δ 15N) and infer the foraging habitat (e.g. δ 13 C) on consecutive sections of whole whiskers from 119 southern elephant seals from Elephant Island (6113'S 5523W) from all age and sex classes. Whisker SI values were spread over a large range, with δ 13 C and δ 15 N values varying from -23.21 to -16.34 (a 6.87 difference) and from 8.90 to 15.47 (6.57), respectively. SI analyses also confirmed marked differences in the feeding ecology of southern elephant seals according to sex (e.g. δ 15 N significantly different between sexes in adults, GLMM, p = 0.001) and age group (e.g. δ 13 C related to age classes in females, GLMM, p < 0.001). Results suggest that yearlings foraged more frequently in the sub-Antarctic zone whilst adult seals stayed south of the polar front and, adult and sub-adult males fed on higher trophic level prey than other sex and age classes. We discuss how these differences are likely a result of a combination of intra-specific competition, ontogenetic factors and resource distribution. Studying the degree and the ontogeny of individual specialisation within a population is a first step towards understanding its implications in various dimensions of ecological and evolutionary processes and hence for adapting to climate changes. |
format |
Article in Journal/Newspaper |
author |
Gallon, S Hindell, MA Muelbert, MMC |
author_facet |
Gallon, S Hindell, MA Muelbert, MMC |
author_sort |
Gallon, S |
title |
Foraging insights from whisker isotopic signatures of southern elephant seals around the Antarctic Peninsula |
title_short |
Foraging insights from whisker isotopic signatures of southern elephant seals around the Antarctic Peninsula |
title_full |
Foraging insights from whisker isotopic signatures of southern elephant seals around the Antarctic Peninsula |
title_fullStr |
Foraging insights from whisker isotopic signatures of southern elephant seals around the Antarctic Peninsula |
title_full_unstemmed |
Foraging insights from whisker isotopic signatures of southern elephant seals around the Antarctic Peninsula |
title_sort |
foraging insights from whisker isotopic signatures of southern elephant seals around the antarctic peninsula |
publisher |
Pergamon-Elsevier Science Ltd |
publishDate |
2018 |
url |
https://doi.org/10.1016/j.dsr2.2018.01.006 http://ecite.utas.edu.au/130084 |
long_lat |
ENVELOPE(-55.184,-55.184,-61.085,-61.085) |
geographic |
Antarctic The Antarctic Antarctic Peninsula Elephant Island |
geographic_facet |
Antarctic The Antarctic Antarctic Peninsula Elephant Island |
genre |
Antarc* Antarctic Antarctic Peninsula Elephant Island Elephant Seals Mirounga leonina Southern Elephant Seals |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Elephant Island Elephant Seals Mirounga leonina Southern Elephant Seals |
op_relation |
http://dx.doi.org/10.1016/j.dsr2.2018.01.006 Gallon, S and Hindell, MA and Muelbert, MMC, Foraging insights from whisker isotopic signatures of southern elephant seals around the Antarctic Peninsula, Deep-Sea Research. Part 2, 149 pp. 229-239. ISSN 0967-0645 (2018) [Refereed Article] http://ecite.utas.edu.au/130084 |
op_doi |
https://doi.org/10.1016/j.dsr2.2018.01.006 |
container_title |
Deep Sea Research Part II: Topical Studies in Oceanography |
container_volume |
149 |
container_start_page |
229 |
op_container_end_page |
239 |
_version_ |
1766261689994444800 |