Distinguishing the Impacts of Inadequate Prey and Vessel Traffic on an Endangered Killer Whale (Orcinus orca) Population
Managing endangered species often involves evaluating the relative impacts of multiple anthropogenic and ecological pressures. This challenge is particularly formidable for cetaceans, which spend the majority of their time underwater. Noninvasive physiological approaches can be especially informativ...
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ftpubmed:oai:pubmedcentral.nih.gov:3368900 2023-05-15T17:03:38+02:00 Distinguishing the Impacts of Inadequate Prey and Vessel Traffic on an Endangered Killer Whale (Orcinus orca) Population Ayres, Katherine L. Booth, Rebecca K. Hempelmann, Jennifer A. Koski, Kari L. Emmons, Candice K. Baird, Robin W. Balcomb-Bartok, Kelley Hanson, M. Bradley Ford, Michael J. Wasser, Samuel K. 2012-06-06 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3368900 http://www.ncbi.nlm.nih.gov/pubmed/22701560 https://doi.org/10.1371/journal.pone.0036842 en eng Public Library of Science http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3368900 http://www.ncbi.nlm.nih.gov/pubmed/22701560 http://dx.doi.org/10.1371/journal.pone.0036842 This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication. PDM CC0 Research Article Text 2012 ftpubmed https://doi.org/10.1371/journal.pone.0036842 2013-09-04T08:19:41Z Managing endangered species often involves evaluating the relative impacts of multiple anthropogenic and ecological pressures. This challenge is particularly formidable for cetaceans, which spend the majority of their time underwater. Noninvasive physiological approaches can be especially informative in this regard. We used a combination of fecal thyroid (T3) and glucocorticoid (GC) hormone measures to assess two threats influencing the endangered southern resident killer whales (SRKW; Orcinus orca) that frequent the inland waters of British Columbia, Canada and Washington, U.S.A. Glucocorticoids increase in response to nutritional and psychological stress, whereas thyroid hormone declines in response to nutritional stress but is unaffected by psychological stress. The inadequate prey hypothesis argues that the killer whales have become prey limited due to reductions of their dominant prey, Chinook salmon (Oncorhynchus tshawytscha). The vessel impact hypothesis argues that high numbers of vessels in close proximity to the whales cause disturbance via psychological stress and/or impaired foraging ability. The GC and T3 measures supported the inadequate prey hypothesis. In particular, GC concentrations were negatively correlated with short-term changes in prey availability. Whereas, T3 concentrations varied by date and year in a manner that corresponded with more long-term prey availability. Physiological correlations with prey overshadowed any impacts of vessels since GCs were lowest during the peak in vessel abundance, which also coincided with the peak in salmon availability. Our results suggest that identification and recovery of strategic salmon populations in the SRKW diet are important to effectively promote SRKW recovery. Text Killer Whale Orca Orcinus orca Killer whale PubMed Central (PMC) British Columbia ENVELOPE(-125.003,-125.003,54.000,54.000) Canada PLoS ONE 7 6 e36842 |
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Open Polar |
collection |
PubMed Central (PMC) |
op_collection_id |
ftpubmed |
language |
English |
topic |
Research Article |
spellingShingle |
Research Article Ayres, Katherine L. Booth, Rebecca K. Hempelmann, Jennifer A. Koski, Kari L. Emmons, Candice K. Baird, Robin W. Balcomb-Bartok, Kelley Hanson, M. Bradley Ford, Michael J. Wasser, Samuel K. Distinguishing the Impacts of Inadequate Prey and Vessel Traffic on an Endangered Killer Whale (Orcinus orca) Population |
topic_facet |
Research Article |
description |
Managing endangered species often involves evaluating the relative impacts of multiple anthropogenic and ecological pressures. This challenge is particularly formidable for cetaceans, which spend the majority of their time underwater. Noninvasive physiological approaches can be especially informative in this regard. We used a combination of fecal thyroid (T3) and glucocorticoid (GC) hormone measures to assess two threats influencing the endangered southern resident killer whales (SRKW; Orcinus orca) that frequent the inland waters of British Columbia, Canada and Washington, U.S.A. Glucocorticoids increase in response to nutritional and psychological stress, whereas thyroid hormone declines in response to nutritional stress but is unaffected by psychological stress. The inadequate prey hypothesis argues that the killer whales have become prey limited due to reductions of their dominant prey, Chinook salmon (Oncorhynchus tshawytscha). The vessel impact hypothesis argues that high numbers of vessels in close proximity to the whales cause disturbance via psychological stress and/or impaired foraging ability. The GC and T3 measures supported the inadequate prey hypothesis. In particular, GC concentrations were negatively correlated with short-term changes in prey availability. Whereas, T3 concentrations varied by date and year in a manner that corresponded with more long-term prey availability. Physiological correlations with prey overshadowed any impacts of vessels since GCs were lowest during the peak in vessel abundance, which also coincided with the peak in salmon availability. Our results suggest that identification and recovery of strategic salmon populations in the SRKW diet are important to effectively promote SRKW recovery. |
format |
Text |
author |
Ayres, Katherine L. Booth, Rebecca K. Hempelmann, Jennifer A. Koski, Kari L. Emmons, Candice K. Baird, Robin W. Balcomb-Bartok, Kelley Hanson, M. Bradley Ford, Michael J. Wasser, Samuel K. |
author_facet |
Ayres, Katherine L. Booth, Rebecca K. Hempelmann, Jennifer A. Koski, Kari L. Emmons, Candice K. Baird, Robin W. Balcomb-Bartok, Kelley Hanson, M. Bradley Ford, Michael J. Wasser, Samuel K. |
author_sort |
Ayres, Katherine L. |
title |
Distinguishing the Impacts of Inadequate Prey and Vessel Traffic on an Endangered Killer Whale (Orcinus orca) Population |
title_short |
Distinguishing the Impacts of Inadequate Prey and Vessel Traffic on an Endangered Killer Whale (Orcinus orca) Population |
title_full |
Distinguishing the Impacts of Inadequate Prey and Vessel Traffic on an Endangered Killer Whale (Orcinus orca) Population |
title_fullStr |
Distinguishing the Impacts of Inadequate Prey and Vessel Traffic on an Endangered Killer Whale (Orcinus orca) Population |
title_full_unstemmed |
Distinguishing the Impacts of Inadequate Prey and Vessel Traffic on an Endangered Killer Whale (Orcinus orca) Population |
title_sort |
distinguishing the impacts of inadequate prey and vessel traffic on an endangered killer whale (orcinus orca) population |
publisher |
Public Library of Science |
publishDate |
2012 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3368900 http://www.ncbi.nlm.nih.gov/pubmed/22701560 https://doi.org/10.1371/journal.pone.0036842 |
long_lat |
ENVELOPE(-125.003,-125.003,54.000,54.000) |
geographic |
British Columbia Canada |
geographic_facet |
British Columbia Canada |
genre |
Killer Whale Orca Orcinus orca Killer whale |
genre_facet |
Killer Whale Orca Orcinus orca Killer whale |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3368900 http://www.ncbi.nlm.nih.gov/pubmed/22701560 http://dx.doi.org/10.1371/journal.pone.0036842 |
op_rights |
This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication. |
op_rightsnorm |
PDM CC0 |
op_doi |
https://doi.org/10.1371/journal.pone.0036842 |
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PLoS ONE |
container_volume |
7 |
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6 |
container_start_page |
e36842 |
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1766057546109419520 |