Ninety years of change, from commercial extinction to recovery, range expansion and decline for Antarctic fur seals at South Georgia
Abstract With environmental change, understanding how species recover from overharvesting and maintain viable populations is central to ecosystem restoration. Here, we reconstruct 90 years of recovery trajectory of the Antarctic fur seal at South Georgia (S.W. Atlantic), a key indicator species in t...
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Online Access: | http://dx.doi.org/10.1111/gcb.16947 https://onlinelibrary.wiley.com/doi/pdf/10.1111/gcb.16947 |
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crwiley:10.1111/gcb.16947 2024-09-15T17:48:30+00:00 Ninety years of change, from commercial extinction to recovery, range expansion and decline for Antarctic fur seals at South Georgia Forcada, Jaume Hoffman, Joseph I. Gimenez, Olivier Staniland, Iain J. Bucktrout, Pete Wood, Andrew G. UK Research and Innovation Deutsche Forschungsgemeinschaft 2023 http://dx.doi.org/10.1111/gcb.16947 https://onlinelibrary.wiley.com/doi/pdf/10.1111/gcb.16947 en eng Wiley http://creativecommons.org/licenses/by/4.0/ Global Change Biology volume 29, issue 24, page 6867-6887 ISSN 1354-1013 1365-2486 journal-article 2023 crwiley https://doi.org/10.1111/gcb.16947 2024-06-25T04:14:19Z Abstract With environmental change, understanding how species recover from overharvesting and maintain viable populations is central to ecosystem restoration. Here, we reconstruct 90 years of recovery trajectory of the Antarctic fur seal at South Georgia (S.W. Atlantic), a key indicator species in the krill‐based food webs of the Southern Ocean. After being harvested to commercial extinction by 1907, this population rebounded and now constitutes the most abundant otariid in the World. However, its status remains uncertain due to insufficient and conflicting data, and anthropogenic pressures affecting Antarctic krill, an essential staple for millions of fur seals and other predators. Using integrated population models, we estimated simultaneously the long‐term abundance for Bird Island, northwest South Georgia, epicentre of recovery of the species after sealing, and population adjustments for survey counts with spatiotemporal applicability. Applied to the latest comprehensive survey data, we estimated the population at South Georgia in 2007–2009 as 3,510,283 fur seals [95% CI: 3,140,548–3,919,604] (ca. 98% of global population), after 40 years of maximum growth and range expansion owing to an abundant krill supply. At Bird Island, after 50 years of exponential growth followed by 25 years of slow stable growth, the population collapsed in 2009 and has thereafter declined by −7.2% [−5.2, −9.1] per annum, to levels of the 1970s. For the instrumental record, this trajectory correlates with a time‐varying relationship between coupled climate and sea surface temperature cycles associated with low regional krill availability, although the effects of increasing krill extraction by commercial fishing and natural competitors remain uncertain. Since 2015, fur seal longevity and recruitment have dropped, sexual maturation has retarded, and population growth is expected to remain mostly negative and highly variable. Our analysis documents the rise and fall of a key Southern Ocean predator over a century of profound ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Fur Seal Antarctic Fur Seals Antarctic Krill Bird Island Southern Ocean Wiley Online Library Global Change Biology 29 24 6867 6887 |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract With environmental change, understanding how species recover from overharvesting and maintain viable populations is central to ecosystem restoration. Here, we reconstruct 90 years of recovery trajectory of the Antarctic fur seal at South Georgia (S.W. Atlantic), a key indicator species in the krill‐based food webs of the Southern Ocean. After being harvested to commercial extinction by 1907, this population rebounded and now constitutes the most abundant otariid in the World. However, its status remains uncertain due to insufficient and conflicting data, and anthropogenic pressures affecting Antarctic krill, an essential staple for millions of fur seals and other predators. Using integrated population models, we estimated simultaneously the long‐term abundance for Bird Island, northwest South Georgia, epicentre of recovery of the species after sealing, and population adjustments for survey counts with spatiotemporal applicability. Applied to the latest comprehensive survey data, we estimated the population at South Georgia in 2007–2009 as 3,510,283 fur seals [95% CI: 3,140,548–3,919,604] (ca. 98% of global population), after 40 years of maximum growth and range expansion owing to an abundant krill supply. At Bird Island, after 50 years of exponential growth followed by 25 years of slow stable growth, the population collapsed in 2009 and has thereafter declined by −7.2% [−5.2, −9.1] per annum, to levels of the 1970s. For the instrumental record, this trajectory correlates with a time‐varying relationship between coupled climate and sea surface temperature cycles associated with low regional krill availability, although the effects of increasing krill extraction by commercial fishing and natural competitors remain uncertain. Since 2015, fur seal longevity and recruitment have dropped, sexual maturation has retarded, and population growth is expected to remain mostly negative and highly variable. Our analysis documents the rise and fall of a key Southern Ocean predator over a century of profound ... |
author2 |
UK Research and Innovation Deutsche Forschungsgemeinschaft |
format |
Article in Journal/Newspaper |
author |
Forcada, Jaume Hoffman, Joseph I. Gimenez, Olivier Staniland, Iain J. Bucktrout, Pete Wood, Andrew G. |
spellingShingle |
Forcada, Jaume Hoffman, Joseph I. Gimenez, Olivier Staniland, Iain J. Bucktrout, Pete Wood, Andrew G. Ninety years of change, from commercial extinction to recovery, range expansion and decline for Antarctic fur seals at South Georgia |
author_facet |
Forcada, Jaume Hoffman, Joseph I. Gimenez, Olivier Staniland, Iain J. Bucktrout, Pete Wood, Andrew G. |
author_sort |
Forcada, Jaume |
title |
Ninety years of change, from commercial extinction to recovery, range expansion and decline for Antarctic fur seals at South Georgia |
title_short |
Ninety years of change, from commercial extinction to recovery, range expansion and decline for Antarctic fur seals at South Georgia |
title_full |
Ninety years of change, from commercial extinction to recovery, range expansion and decline for Antarctic fur seals at South Georgia |
title_fullStr |
Ninety years of change, from commercial extinction to recovery, range expansion and decline for Antarctic fur seals at South Georgia |
title_full_unstemmed |
Ninety years of change, from commercial extinction to recovery, range expansion and decline for Antarctic fur seals at South Georgia |
title_sort |
ninety years of change, from commercial extinction to recovery, range expansion and decline for antarctic fur seals at south georgia |
publisher |
Wiley |
publishDate |
2023 |
url |
http://dx.doi.org/10.1111/gcb.16947 https://onlinelibrary.wiley.com/doi/pdf/10.1111/gcb.16947 |
genre |
Antarc* Antarctic Antarctic Fur Seal Antarctic Fur Seals Antarctic Krill Bird Island Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Fur Seal Antarctic Fur Seals Antarctic Krill Bird Island Southern Ocean |
op_source |
Global Change Biology volume 29, issue 24, page 6867-6887 ISSN 1354-1013 1365-2486 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1111/gcb.16947 |
container_title |
Global Change Biology |
container_volume |
29 |
container_issue |
24 |
container_start_page |
6867 |
op_container_end_page |
6887 |
_version_ |
1810289781832155136 |