Population growth is limited by nutritional impacts on pregnancy success in endangered Southern Resident killer whales (Orcinus orca).
The Southern Resident killer whale population (Orcinus orca) was listed as endangered in 2005 and shows little sign of recovery. These fish eating whales feed primarily on endangered Chinook salmon. Population growth is constrained by low offspring production for the number of reproductive females i...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2017-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC5491047?pdf=render |
| _version_ | 1811336752512630784 |
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| author | Samuel K Wasser Jessica I Lundin Katherine Ayres Elizabeth Seely Deborah Giles Kenneth Balcomb Jennifer Hempelmann Kim Parsons Rebecca Booth |
| author_facet | Samuel K Wasser Jessica I Lundin Katherine Ayres Elizabeth Seely Deborah Giles Kenneth Balcomb Jennifer Hempelmann Kim Parsons Rebecca Booth |
| author_sort | Samuel K Wasser |
| collection | DOAJ |
| description | The Southern Resident killer whale population (Orcinus orca) was listed as endangered in 2005 and shows little sign of recovery. These fish eating whales feed primarily on endangered Chinook salmon. Population growth is constrained by low offspring production for the number of reproductive females in the population. Lack of prey, increased toxins and vessel disturbance have been listed as potential causes of the whale's decline, but partitioning these pressures has been difficult. We validated and applied temporal measures of progesterone and testosterone metabolites to assess occurrence, stage and health of pregnancy from genotyped killer whale feces collected using detection dogs. Thyroid and glucocorticoid hormone metabolites were measured from these same samples to assess physiological stress. These methods enabled us to assess pregnancy occurrence and failure as well as how pregnancy success was temporally impacted by nutritional and other stressors, between 2008 and 2014. Up to 69% of all detectable pregnancies were unsuccessful; of these, up to 33% failed relatively late in gestation or immediately post-partum, when the cost is especially high. Low availability of Chinook salmon appears to be an important stressor among these fish-eating whales as well as a significant cause of late pregnancy failure, including unobserved perinatal loss. However, release of lipophilic toxicants during fat metabolism in the nutritionally deprived animals may also provide a contributor to these cumulative effects. Results point to the importance of promoting Chinook salmon recovery to enhance population growth of Southern Resident killer whales. The physiological measures used in this study can also be used to monitor the success of actions aimed at promoting adaptive management of this important apex predator to the Pacific Northwest. |
| first_indexed | 2024-04-13T17:44:13Z |
| format | Article |
| id | doaj.art-575290141a1f455084b15fdbfecaba66 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-04-13T17:44:13Z |
| publishDate | 2017-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-575290141a1f455084b15fdbfecaba662022-12-22T02:37:03ZengPublic Library of Science (PLoS)PLoS ONE1932-62032017-01-01126e017982410.1371/journal.pone.0179824Population growth is limited by nutritional impacts on pregnancy success in endangered Southern Resident killer whales (Orcinus orca).Samuel K WasserJessica I LundinKatherine AyresElizabeth SeelyDeborah GilesKenneth BalcombJennifer HempelmannKim ParsonsRebecca BoothThe Southern Resident killer whale population (Orcinus orca) was listed as endangered in 2005 and shows little sign of recovery. These fish eating whales feed primarily on endangered Chinook salmon. Population growth is constrained by low offspring production for the number of reproductive females in the population. Lack of prey, increased toxins and vessel disturbance have been listed as potential causes of the whale's decline, but partitioning these pressures has been difficult. We validated and applied temporal measures of progesterone and testosterone metabolites to assess occurrence, stage and health of pregnancy from genotyped killer whale feces collected using detection dogs. Thyroid and glucocorticoid hormone metabolites were measured from these same samples to assess physiological stress. These methods enabled us to assess pregnancy occurrence and failure as well as how pregnancy success was temporally impacted by nutritional and other stressors, between 2008 and 2014. Up to 69% of all detectable pregnancies were unsuccessful; of these, up to 33% failed relatively late in gestation or immediately post-partum, when the cost is especially high. Low availability of Chinook salmon appears to be an important stressor among these fish-eating whales as well as a significant cause of late pregnancy failure, including unobserved perinatal loss. However, release of lipophilic toxicants during fat metabolism in the nutritionally deprived animals may also provide a contributor to these cumulative effects. Results point to the importance of promoting Chinook salmon recovery to enhance population growth of Southern Resident killer whales. The physiological measures used in this study can also be used to monitor the success of actions aimed at promoting adaptive management of this important apex predator to the Pacific Northwest.http://europepmc.org/articles/PMC5491047?pdf=render |
| spellingShingle | Samuel K Wasser Jessica I Lundin Katherine Ayres Elizabeth Seely Deborah Giles Kenneth Balcomb Jennifer Hempelmann Kim Parsons Rebecca Booth Population growth is limited by nutritional impacts on pregnancy success in endangered Southern Resident killer whales (Orcinus orca). PLoS ONE |
| title | Population growth is limited by nutritional impacts on pregnancy success in endangered Southern Resident killer whales (Orcinus orca). |
| title_full | Population growth is limited by nutritional impacts on pregnancy success in endangered Southern Resident killer whales (Orcinus orca). |
| title_fullStr | Population growth is limited by nutritional impacts on pregnancy success in endangered Southern Resident killer whales (Orcinus orca). |
| title_full_unstemmed | Population growth is limited by nutritional impacts on pregnancy success in endangered Southern Resident killer whales (Orcinus orca). |
| title_short | Population growth is limited by nutritional impacts on pregnancy success in endangered Southern Resident killer whales (Orcinus orca). |
| title_sort | population growth is limited by nutritional impacts on pregnancy success in endangered southern resident killer whales orcinus orca |
| url | http://europepmc.org/articles/PMC5491047?pdf=render |
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