Low trophic level diet of juvenile southern elephant seals Mirounga leonina from Marion Island : a stable isotope investigation using vibrissal regrowths
Insight into the trophic ecology of marine predators is vital for understanding their ecosystem role and predicting their responses to environmental change. Juvenile southern elephant seals (SES) Mirounga leonina are considered generalist predators within the Southern Ocean. Although mesopelagic fis...
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Online Access: | http://hdl.handle.net/2263/62235 https://doi.org/10.3354/meps12240 |
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ftunivpretoria:oai:repository.up.ac.za:2263/62235 2023-05-15T16:05:36+02:00 Low trophic level diet of juvenile southern elephant seals Mirounga leonina from Marion Island : a stable isotope investigation using vibrissal regrowths Lubcker, Nico Reisinger, Ryan Rudolf Oosthuizen, Wessel Christiaan De Bruyn, P.J. Nico Van Tonder, Alet Pistorius, P.A. Bester, Marthan Nieuwoudt 2017-09-12T08:26:18Z http://hdl.handle.net/2263/62235 https://doi.org/10.3354/meps12240 en eng Inter Research http://hdl.handle.net/2263/62235 Lübcker, N., Reisinger, R.R., Oosthuizen, W.C., De Bruyn, N.P.J., Van Tonder, A., Pistorius, P.A. & Bester, M.N. 2017, 'Low trophic level diet of juvenile southern elephant seals Mirounga leonina from Marion Island: A stable isotope investigation using vibrissal regrowths', Marine Ecology Progress Series, vol. 577, pp. 237-250. 0171-8630 (print) 1616-1599 (online) doi:10.3354/meps12240 © Inter-Research 2017 Pinnipedia Mirounga leonina Mammalia Euphausiacea Euphausia superba Cephalopoda Vibrissae Stable isotopes Pinnipeds Marine mammals Diet Crustaceans Southern elephant seals (SES) Southern elephant seals (Mirounga leonina) Whiskers Postprint Article 2017 ftunivpretoria https://doi.org/10.3354/meps12240 2022-05-31T13:31:19Z Insight into the trophic ecology of marine predators is vital for understanding their ecosystem role and predicting their responses to environmental change. Juvenile southern elephant seals (SES) Mirounga leonina are considered generalist predators within the Southern Ocean. Although mesopelagic fish and squid dominate their stomach lavage samples, the stable isotope profile captured along the length of sampled vibrissae of young SES at Macquarie Island, southwest Pacific Ocean (54.5° S, 158.9° E) recently emphasized the contribution of crustaceans to their diet (likely Euphausia superba). Herein, we used the stable isotope values of sampled vibrissal regrowths with known growth histories to assess the diet of juvenile SES at Marion Island, southern Indian Ocean (46.8° S, 37.8° E) on a temporally integrated basis. We specifically aimed to quantify the possible contribution of crustaceans to the diet of juvenile SES. Sequentially (chronologically) sampled vibrissal regrowths of 14 juvenile SES produced fine-scale dietary information spanning up to 9 mo. The depleted stable isotope signatures of nitrogen (δ15N) (8.5 ± 0.6‰) and carbon (δ13C) (−20.3 ± 0.1‰) measured during the period of independent foraging suggested the use of a lower trophic level diet within the Polar Frontal Zone. A mixing model predicted that up to 76% of juvenile SES diet comprised crustaceans, consisting of 2 crustacean groups, each contributing 26% (credible interval, CI: 13−39%) and 50% (CI: 35−64%) to their diets, presumably representing subantarctic krill species. This first utilisation of the isotopic signature captured along the length of vibrissal regrowths confirms the inclusion and importance of crustaceans in the diet of juvenile SES. The South African Department of Science and Technology (DST) and National Research Foundation (NRF), grant number 93071. http://www.int-res.com/journals/meps/meps-home 2018-08-30 hj2017 Jurisprudence Article in Journal/Newspaper Elephant Seals Euphausia superba Macquarie Island Marion Island Mirounga leonina Southern Elephant Seals Southern Ocean University of Pretoria: UPSpace Southern Ocean Pacific Indian Marine Ecology Progress Series 577 237 250 |
institution |
Open Polar |
collection |
University of Pretoria: UPSpace |
op_collection_id |
ftunivpretoria |
language |
English |
topic |
Pinnipedia Mirounga leonina Mammalia Euphausiacea Euphausia superba Cephalopoda Vibrissae Stable isotopes Pinnipeds Marine mammals Diet Crustaceans Southern elephant seals (SES) Southern elephant seals (Mirounga leonina) Whiskers |
spellingShingle |
Pinnipedia Mirounga leonina Mammalia Euphausiacea Euphausia superba Cephalopoda Vibrissae Stable isotopes Pinnipeds Marine mammals Diet Crustaceans Southern elephant seals (SES) Southern elephant seals (Mirounga leonina) Whiskers Lubcker, Nico Reisinger, Ryan Rudolf Oosthuizen, Wessel Christiaan De Bruyn, P.J. Nico Van Tonder, Alet Pistorius, P.A. Bester, Marthan Nieuwoudt Low trophic level diet of juvenile southern elephant seals Mirounga leonina from Marion Island : a stable isotope investigation using vibrissal regrowths |
topic_facet |
Pinnipedia Mirounga leonina Mammalia Euphausiacea Euphausia superba Cephalopoda Vibrissae Stable isotopes Pinnipeds Marine mammals Diet Crustaceans Southern elephant seals (SES) Southern elephant seals (Mirounga leonina) Whiskers |
description |
Insight into the trophic ecology of marine predators is vital for understanding their ecosystem role and predicting their responses to environmental change. Juvenile southern elephant seals (SES) Mirounga leonina are considered generalist predators within the Southern Ocean. Although mesopelagic fish and squid dominate their stomach lavage samples, the stable isotope profile captured along the length of sampled vibrissae of young SES at Macquarie Island, southwest Pacific Ocean (54.5° S, 158.9° E) recently emphasized the contribution of crustaceans to their diet (likely Euphausia superba). Herein, we used the stable isotope values of sampled vibrissal regrowths with known growth histories to assess the diet of juvenile SES at Marion Island, southern Indian Ocean (46.8° S, 37.8° E) on a temporally integrated basis. We specifically aimed to quantify the possible contribution of crustaceans to the diet of juvenile SES. Sequentially (chronologically) sampled vibrissal regrowths of 14 juvenile SES produced fine-scale dietary information spanning up to 9 mo. The depleted stable isotope signatures of nitrogen (δ15N) (8.5 ± 0.6‰) and carbon (δ13C) (−20.3 ± 0.1‰) measured during the period of independent foraging suggested the use of a lower trophic level diet within the Polar Frontal Zone. A mixing model predicted that up to 76% of juvenile SES diet comprised crustaceans, consisting of 2 crustacean groups, each contributing 26% (credible interval, CI: 13−39%) and 50% (CI: 35−64%) to their diets, presumably representing subantarctic krill species. This first utilisation of the isotopic signature captured along the length of vibrissal regrowths confirms the inclusion and importance of crustaceans in the diet of juvenile SES. The South African Department of Science and Technology (DST) and National Research Foundation (NRF), grant number 93071. http://www.int-res.com/journals/meps/meps-home 2018-08-30 hj2017 Jurisprudence |
format |
Article in Journal/Newspaper |
author |
Lubcker, Nico Reisinger, Ryan Rudolf Oosthuizen, Wessel Christiaan De Bruyn, P.J. Nico Van Tonder, Alet Pistorius, P.A. Bester, Marthan Nieuwoudt |
author_facet |
Lubcker, Nico Reisinger, Ryan Rudolf Oosthuizen, Wessel Christiaan De Bruyn, P.J. Nico Van Tonder, Alet Pistorius, P.A. Bester, Marthan Nieuwoudt |
author_sort |
Lubcker, Nico |
title |
Low trophic level diet of juvenile southern elephant seals Mirounga leonina from Marion Island : a stable isotope investigation using vibrissal regrowths |
title_short |
Low trophic level diet of juvenile southern elephant seals Mirounga leonina from Marion Island : a stable isotope investigation using vibrissal regrowths |
title_full |
Low trophic level diet of juvenile southern elephant seals Mirounga leonina from Marion Island : a stable isotope investigation using vibrissal regrowths |
title_fullStr |
Low trophic level diet of juvenile southern elephant seals Mirounga leonina from Marion Island : a stable isotope investigation using vibrissal regrowths |
title_full_unstemmed |
Low trophic level diet of juvenile southern elephant seals Mirounga leonina from Marion Island : a stable isotope investigation using vibrissal regrowths |
title_sort |
low trophic level diet of juvenile southern elephant seals mirounga leonina from marion island : a stable isotope investigation using vibrissal regrowths |
publisher |
Inter Research |
publishDate |
2017 |
url |
http://hdl.handle.net/2263/62235 https://doi.org/10.3354/meps12240 |
geographic |
Southern Ocean Pacific Indian |
geographic_facet |
Southern Ocean Pacific Indian |
genre |
Elephant Seals Euphausia superba Macquarie Island Marion Island Mirounga leonina Southern Elephant Seals Southern Ocean |
genre_facet |
Elephant Seals Euphausia superba Macquarie Island Marion Island Mirounga leonina Southern Elephant Seals Southern Ocean |
op_relation |
http://hdl.handle.net/2263/62235 Lübcker, N., Reisinger, R.R., Oosthuizen, W.C., De Bruyn, N.P.J., Van Tonder, A., Pistorius, P.A. & Bester, M.N. 2017, 'Low trophic level diet of juvenile southern elephant seals Mirounga leonina from Marion Island: A stable isotope investigation using vibrissal regrowths', Marine Ecology Progress Series, vol. 577, pp. 237-250. 0171-8630 (print) 1616-1599 (online) doi:10.3354/meps12240 |
op_rights |
© Inter-Research 2017 |
op_doi |
https://doi.org/10.3354/meps12240 |
container_title |
Marine Ecology Progress Series |
container_volume |
577 |
container_start_page |
237 |
op_container_end_page |
250 |
_version_ |
1766401497109626880 |