Super-Aggregations of Krill and Humpback Whales in Wilhelmina Bay, Antarctic Peninsula
Ecological relationships of krill and whales have not been explored in the Western Antarctic Peninsula (WAP), and have only rarely been studied elsewhere in the Southern Ocean. In the austral autumn we observed an extremely high density (5.1 whales per km2) of humpback whales (Megaptera novaeangliae...
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ftunivmassboston:oai:scholarworks.umb.edu:envsty_faculty_pubs-1001 2024-06-16T07:34:21+00:00 Super-Aggregations of Krill and Humpback Whales in Wilhelmina Bay, Antarctic Peninsula Nowacek, Douglas P. Friedlaender, Ari S. Halpin, Patrick N. Hazen, Elliott L. Johnston, David W. Read, Andrew J. Espinasse, Boris Zhou, Meng Zhu, Yiwu 2011-04-27T07:00:00Z application/pdf https://scholarworks.umb.edu/envsty_faculty_pubs/2 https://scholarworks.umb.edu/context/envsty_faculty_pubs/article/1001/viewcontent/journal.pone.0019173.pdf unknown ScholarWorks at UMass Boston https://scholarworks.umb.edu/envsty_faculty_pubs/2 https://scholarworks.umb.edu/context/envsty_faculty_pubs/article/1001/viewcontent/journal.pone.0019173.pdf © 2011 Nowacek et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Environmental, Earth, and Ocean Sciences Faculty Publication Series Antarctic krill humpback whales Wilhelmina Bay baleen whale climate change Environmental Health and Protection Marine Biology Oceanography text 2011 ftunivmassboston 2024-05-21T03:20:07Z Ecological relationships of krill and whales have not been explored in the Western Antarctic Peninsula (WAP), and have only rarely been studied elsewhere in the Southern Ocean. In the austral autumn we observed an extremely high density (5.1 whales per km2) of humpback whales (Megaptera novaeangliae) feeding on a super-aggregation of Antarctic krill (Euphausia superba) in Wilhelmina Bay. The krill biomass was approximately 2 million tons, distributed over an area of 100 km2 at densities of up to 2000 individuals m−3; reports of such ‘super-aggregations’ of krill have been absent in the scientific literature for >20 years. Retentive circulation patterns in the Bay entrained phytoplankton and meso-zooplankton that were grazed by the krill. Tagged whales rested during daylight hours and fed intensively throughout the night as krill migrated toward the surface. We infer that the previously unstudied WAP embayments are important foraging areas for whales during autumn and, furthermore, that meso-scale variation in the distribution of whales and their prey are important features of this system. Recent decreases in the abundance of Antarctic krill around the WAP have been linked to reductions in sea ice, mediated by rapid climate change in this area. At the same time, baleen whale populations in the Southern Ocean, which feed primarily on krill, are recovering from past exploitation. Consideration of these features and the effects of climate change on krill dynamics are critical to managing both krill harvests and the recovery of baleen whales in the Southern Ocean. Text Antarc* Antarctic Antarctic Krill Antarctic Peninsula baleen whale baleen whales Euphausia superba Megaptera novaeangliae Sea ice Southern Ocean University of Massachusetts Boston: ScholarWorks at UMass Antarctic Southern Ocean Antarctic Peninsula Austral Wilhelmina ENVELOPE(-62.160,-62.160,-64.642,-64.642) Wilhelmina Bay ENVELOPE(-62.160,-62.160,-64.642,-64.642) |
institution |
Open Polar |
collection |
University of Massachusetts Boston: ScholarWorks at UMass |
op_collection_id |
ftunivmassboston |
language |
unknown |
topic |
Antarctic krill humpback whales Wilhelmina Bay baleen whale climate change Environmental Health and Protection Marine Biology Oceanography |
spellingShingle |
Antarctic krill humpback whales Wilhelmina Bay baleen whale climate change Environmental Health and Protection Marine Biology Oceanography Nowacek, Douglas P. Friedlaender, Ari S. Halpin, Patrick N. Hazen, Elliott L. Johnston, David W. Read, Andrew J. Espinasse, Boris Zhou, Meng Zhu, Yiwu Super-Aggregations of Krill and Humpback Whales in Wilhelmina Bay, Antarctic Peninsula |
topic_facet |
Antarctic krill humpback whales Wilhelmina Bay baleen whale climate change Environmental Health and Protection Marine Biology Oceanography |
description |
Ecological relationships of krill and whales have not been explored in the Western Antarctic Peninsula (WAP), and have only rarely been studied elsewhere in the Southern Ocean. In the austral autumn we observed an extremely high density (5.1 whales per km2) of humpback whales (Megaptera novaeangliae) feeding on a super-aggregation of Antarctic krill (Euphausia superba) in Wilhelmina Bay. The krill biomass was approximately 2 million tons, distributed over an area of 100 km2 at densities of up to 2000 individuals m−3; reports of such ‘super-aggregations’ of krill have been absent in the scientific literature for >20 years. Retentive circulation patterns in the Bay entrained phytoplankton and meso-zooplankton that were grazed by the krill. Tagged whales rested during daylight hours and fed intensively throughout the night as krill migrated toward the surface. We infer that the previously unstudied WAP embayments are important foraging areas for whales during autumn and, furthermore, that meso-scale variation in the distribution of whales and their prey are important features of this system. Recent decreases in the abundance of Antarctic krill around the WAP have been linked to reductions in sea ice, mediated by rapid climate change in this area. At the same time, baleen whale populations in the Southern Ocean, which feed primarily on krill, are recovering from past exploitation. Consideration of these features and the effects of climate change on krill dynamics are critical to managing both krill harvests and the recovery of baleen whales in the Southern Ocean. |
format |
Text |
author |
Nowacek, Douglas P. Friedlaender, Ari S. Halpin, Patrick N. Hazen, Elliott L. Johnston, David W. Read, Andrew J. Espinasse, Boris Zhou, Meng Zhu, Yiwu |
author_facet |
Nowacek, Douglas P. Friedlaender, Ari S. Halpin, Patrick N. Hazen, Elliott L. Johnston, David W. Read, Andrew J. Espinasse, Boris Zhou, Meng Zhu, Yiwu |
author_sort |
Nowacek, Douglas P. |
title |
Super-Aggregations of Krill and Humpback Whales in Wilhelmina Bay, Antarctic Peninsula |
title_short |
Super-Aggregations of Krill and Humpback Whales in Wilhelmina Bay, Antarctic Peninsula |
title_full |
Super-Aggregations of Krill and Humpback Whales in Wilhelmina Bay, Antarctic Peninsula |
title_fullStr |
Super-Aggregations of Krill and Humpback Whales in Wilhelmina Bay, Antarctic Peninsula |
title_full_unstemmed |
Super-Aggregations of Krill and Humpback Whales in Wilhelmina Bay, Antarctic Peninsula |
title_sort |
super-aggregations of krill and humpback whales in wilhelmina bay, antarctic peninsula |
publisher |
ScholarWorks at UMass Boston |
publishDate |
2011 |
url |
https://scholarworks.umb.edu/envsty_faculty_pubs/2 https://scholarworks.umb.edu/context/envsty_faculty_pubs/article/1001/viewcontent/journal.pone.0019173.pdf |
long_lat |
ENVELOPE(-62.160,-62.160,-64.642,-64.642) ENVELOPE(-62.160,-62.160,-64.642,-64.642) |
geographic |
Antarctic Southern Ocean Antarctic Peninsula Austral Wilhelmina Wilhelmina Bay |
geographic_facet |
Antarctic Southern Ocean Antarctic Peninsula Austral Wilhelmina Wilhelmina Bay |
genre |
Antarc* Antarctic Antarctic Krill Antarctic Peninsula baleen whale baleen whales Euphausia superba Megaptera novaeangliae Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Krill Antarctic Peninsula baleen whale baleen whales Euphausia superba Megaptera novaeangliae Sea ice Southern Ocean |
op_source |
Environmental, Earth, and Ocean Sciences Faculty Publication Series |
op_relation |
https://scholarworks.umb.edu/envsty_faculty_pubs/2 https://scholarworks.umb.edu/context/envsty_faculty_pubs/article/1001/viewcontent/journal.pone.0019173.pdf |
op_rights |
© 2011 Nowacek et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
_version_ |
1802008642454552576 |