Foraging behaviour of Weddell seals (Leptonychotes weddellii) in connection to oceanographic conditions in the southern Weddell Sea
The region of the Filchner Outflow System (FOS) in the southeastern Weddell Sea is characterized by intensive and complex interactions of different water masses. Dense Ice Shelf Water (ISW) emerging from beneath the ice shelf cavities on the continental shelf, meets Modified Warm Deep Water (MWDW) o...
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Online Access: | http://hdl.handle.net/2263/72331 https://doi.org/10.1016/j.pocean.2019.02.013 |
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ftunivpretoria:oai:repository.up.ac.za:2263/72331 2023-05-15T14:02:58+02:00 Foraging behaviour of Weddell seals (Leptonychotes weddellii) in connection to oceanographic conditions in the southern Weddell Sea Nachtsheim, Dominik A. Ryan, Svenja Schroder, Michael Jensen, Laura Oosthuizen, Wessel Christiaan Bester, Marthan Nieuwoudt Hagen, Wilhelm Bornemann, Horst 2019-04 http://hdl.handle.net/2263/72331 https://doi.org/10.1016/j.pocean.2019.02.013 en eng Elsevier http://hdl.handle.net/2263/72331 Nachtsheim, D.A., Ryan, S., Schroeder, M. et al. 2019, 'Foraging behaviour of Weddell seals (Leptonychotes weddellii) in connection to oceanographic conditions in the southern Weddell Sea', Progress in Oceanography, vol. 173, pp. 165-179. 0079-6611 doi:10.1016/j.pocean.2019.02.013 © 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/). CC-BY Elephant seal (Mirounga leonina) Antarctic ice Antarctic silverfish (Pleuragramma antarcticum) Weddell Sea continental shelf Diving behavior McMurdo Sound Ecology Winter Diet Weddell seals (Leptonychotes weddellii) Marine top predators Foraging metrics Bio-telemetry Weddell Sea Physical oceanography Filchner outflow system (FOS) Dense ice shelf water (ISW) Modified warm deep water (MWDW) Article 2019 ftunivpretoria https://doi.org/10.1016/j.pocean.2019.02.013 2022-05-31T13:25:30Z The region of the Filchner Outflow System (FOS) in the southeastern Weddell Sea is characterized by intensive and complex interactions of different water masses. Dense Ice Shelf Water (ISW) emerging from beneath the ice shelf cavities on the continental shelf, meets Modified Warm Deep Water (MWDW) originating from the Antarctic Circumpolar Current at the sill of the Filchner Trough. These hydrographic features convert the FOS into an oceanographic key region, which may also show enhanced biological productivity and corresponding aggregations of marine top predators. In this context, six adult Weddell seals (Leptonychotes weddellii) were instrumented with CTD-combined satellite relay data loggers in austral summer 2014. By means of these long-term data loggers we aimed at investigating the influence of environmental conditions on the seals’ foraging behaviour throughout seasons, focussing on the local oceanographic features. Weddell seals performed pelagic and demersal dives, mainly on the continental shelf, where they presumably exploited the abundant bentho-pelagic fish fauna. Diurnal and seasonal variations in light availability affected foraging activities. MWDW was associated with increased foraging effort. However, we observed differences in movements and habitat use between two different groups of Weddell seals. Seals tagged in the pack ice of the FOS focussed their foraging activities to the western and, partly, eastern flank of the Filchner Trough, which coincides with inflow pathways of MWDW. In contrast, Weddell seals tagged on the coastal fast ice exhibited typical central-place foraging and utilized resources close to their colony. High foraging effort in MWDW and high utilization of areas associated with an inflow of MWDW raise questions on the underlying biological features. This emphasizes the importance of further interdisciplinary ecological investigations in the near future, as the FOS may soon be impacted by predicted climatic changes. Appendix A: Characterization of demersal and pelagic ... Article in Journal/Newspaper Antarc* Antarctic Antarctic silverfish Elephant Seal Ice Shelf McMurdo Sound Mirounga leonina Weddell Sea Weddell Seals University of Pretoria: UPSpace Antarctic The Antarctic Weddell Sea Austral McMurdo Sound Weddell Filchner Trough ENVELOPE(-36.000,-36.000,-77.000,-77.000) Progress in Oceanography 173 165 179 |
institution |
Open Polar |
collection |
University of Pretoria: UPSpace |
op_collection_id |
ftunivpretoria |
language |
English |
topic |
Elephant seal (Mirounga leonina) Antarctic ice Antarctic silverfish (Pleuragramma antarcticum) Weddell Sea continental shelf Diving behavior McMurdo Sound Ecology Winter Diet Weddell seals (Leptonychotes weddellii) Marine top predators Foraging metrics Bio-telemetry Weddell Sea Physical oceanography Filchner outflow system (FOS) Dense ice shelf water (ISW) Modified warm deep water (MWDW) |
spellingShingle |
Elephant seal (Mirounga leonina) Antarctic ice Antarctic silverfish (Pleuragramma antarcticum) Weddell Sea continental shelf Diving behavior McMurdo Sound Ecology Winter Diet Weddell seals (Leptonychotes weddellii) Marine top predators Foraging metrics Bio-telemetry Weddell Sea Physical oceanography Filchner outflow system (FOS) Dense ice shelf water (ISW) Modified warm deep water (MWDW) Nachtsheim, Dominik A. Ryan, Svenja Schroder, Michael Jensen, Laura Oosthuizen, Wessel Christiaan Bester, Marthan Nieuwoudt Hagen, Wilhelm Bornemann, Horst Foraging behaviour of Weddell seals (Leptonychotes weddellii) in connection to oceanographic conditions in the southern Weddell Sea |
topic_facet |
Elephant seal (Mirounga leonina) Antarctic ice Antarctic silverfish (Pleuragramma antarcticum) Weddell Sea continental shelf Diving behavior McMurdo Sound Ecology Winter Diet Weddell seals (Leptonychotes weddellii) Marine top predators Foraging metrics Bio-telemetry Weddell Sea Physical oceanography Filchner outflow system (FOS) Dense ice shelf water (ISW) Modified warm deep water (MWDW) |
description |
The region of the Filchner Outflow System (FOS) in the southeastern Weddell Sea is characterized by intensive and complex interactions of different water masses. Dense Ice Shelf Water (ISW) emerging from beneath the ice shelf cavities on the continental shelf, meets Modified Warm Deep Water (MWDW) originating from the Antarctic Circumpolar Current at the sill of the Filchner Trough. These hydrographic features convert the FOS into an oceanographic key region, which may also show enhanced biological productivity and corresponding aggregations of marine top predators. In this context, six adult Weddell seals (Leptonychotes weddellii) were instrumented with CTD-combined satellite relay data loggers in austral summer 2014. By means of these long-term data loggers we aimed at investigating the influence of environmental conditions on the seals’ foraging behaviour throughout seasons, focussing on the local oceanographic features. Weddell seals performed pelagic and demersal dives, mainly on the continental shelf, where they presumably exploited the abundant bentho-pelagic fish fauna. Diurnal and seasonal variations in light availability affected foraging activities. MWDW was associated with increased foraging effort. However, we observed differences in movements and habitat use between two different groups of Weddell seals. Seals tagged in the pack ice of the FOS focussed their foraging activities to the western and, partly, eastern flank of the Filchner Trough, which coincides with inflow pathways of MWDW. In contrast, Weddell seals tagged on the coastal fast ice exhibited typical central-place foraging and utilized resources close to their colony. High foraging effort in MWDW and high utilization of areas associated with an inflow of MWDW raise questions on the underlying biological features. This emphasizes the importance of further interdisciplinary ecological investigations in the near future, as the FOS may soon be impacted by predicted climatic changes. Appendix A: Characterization of demersal and pelagic ... |
format |
Article in Journal/Newspaper |
author |
Nachtsheim, Dominik A. Ryan, Svenja Schroder, Michael Jensen, Laura Oosthuizen, Wessel Christiaan Bester, Marthan Nieuwoudt Hagen, Wilhelm Bornemann, Horst |
author_facet |
Nachtsheim, Dominik A. Ryan, Svenja Schroder, Michael Jensen, Laura Oosthuizen, Wessel Christiaan Bester, Marthan Nieuwoudt Hagen, Wilhelm Bornemann, Horst |
author_sort |
Nachtsheim, Dominik A. |
title |
Foraging behaviour of Weddell seals (Leptonychotes weddellii) in connection to oceanographic conditions in the southern Weddell Sea |
title_short |
Foraging behaviour of Weddell seals (Leptonychotes weddellii) in connection to oceanographic conditions in the southern Weddell Sea |
title_full |
Foraging behaviour of Weddell seals (Leptonychotes weddellii) in connection to oceanographic conditions in the southern Weddell Sea |
title_fullStr |
Foraging behaviour of Weddell seals (Leptonychotes weddellii) in connection to oceanographic conditions in the southern Weddell Sea |
title_full_unstemmed |
Foraging behaviour of Weddell seals (Leptonychotes weddellii) in connection to oceanographic conditions in the southern Weddell Sea |
title_sort |
foraging behaviour of weddell seals (leptonychotes weddellii) in connection to oceanographic conditions in the southern weddell sea |
publisher |
Elsevier |
publishDate |
2019 |
url |
http://hdl.handle.net/2263/72331 https://doi.org/10.1016/j.pocean.2019.02.013 |
long_lat |
ENVELOPE(-36.000,-36.000,-77.000,-77.000) |
geographic |
Antarctic The Antarctic Weddell Sea Austral McMurdo Sound Weddell Filchner Trough |
geographic_facet |
Antarctic The Antarctic Weddell Sea Austral McMurdo Sound Weddell Filchner Trough |
genre |
Antarc* Antarctic Antarctic silverfish Elephant Seal Ice Shelf McMurdo Sound Mirounga leonina Weddell Sea Weddell Seals |
genre_facet |
Antarc* Antarctic Antarctic silverfish Elephant Seal Ice Shelf McMurdo Sound Mirounga leonina Weddell Sea Weddell Seals |
op_relation |
http://hdl.handle.net/2263/72331 Nachtsheim, D.A., Ryan, S., Schroeder, M. et al. 2019, 'Foraging behaviour of Weddell seals (Leptonychotes weddellii) in connection to oceanographic conditions in the southern Weddell Sea', Progress in Oceanography, vol. 173, pp. 165-179. 0079-6611 doi:10.1016/j.pocean.2019.02.013 |
op_rights |
© 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/). |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1016/j.pocean.2019.02.013 |
container_title |
Progress in Oceanography |
container_volume |
173 |
container_start_page |
165 |
op_container_end_page |
179 |
_version_ |
1766273421220511744 |