Demographic Reconstruction of Antarctic Fur Seals Supports the Krill Surplus Hypothesis
Much debate surrounds the importance of top-down and bottom-up effects in the Southern Ocean, where the harvesting of over two million whales in the mid twentieth century is thought to have produced a massive surplus of Antarctic krill. This excess of krill may have allowed populations of other pred...
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MDPI AG
2022-03-01
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| Series: | Genes |
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| Online Access: | https://www.mdpi.com/2073-4425/13/3/541 |
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| author | Joseph I. Hoffman Rebecca S. Chen David L. J. Vendrami Anna J. Paijmans Kanchon K. Dasmahapatra Jaume Forcada |
| author_facet | Joseph I. Hoffman Rebecca S. Chen David L. J. Vendrami Anna J. Paijmans Kanchon K. Dasmahapatra Jaume Forcada |
| author_sort | Joseph I. Hoffman |
| collection | DOAJ |
| description | Much debate surrounds the importance of top-down and bottom-up effects in the Southern Ocean, where the harvesting of over two million whales in the mid twentieth century is thought to have produced a massive surplus of Antarctic krill. This excess of krill may have allowed populations of other predators, such as seals and penguins, to increase, a top-down hypothesis known as the ‘krill surplus hypothesis’. However, a lack of pre-whaling population baselines has made it challenging to investigate historical changes in the abundance of the major krill predators in relation to whaling. Therefore, we used reduced representation sequencing and a coalescent-based maximum composite likelihood approach to reconstruct the recent demographic history of the Antarctic fur seal, a pinniped that was hunted to the brink of extinction by 18th and 19th century sealers. In line with the known history of this species, we found support for a demographic model that included a substantial reduction in population size around the time period of sealing. Furthermore, maximum likelihood estimates from this model suggest that the recovered, post-sealing population at South Georgia may have been around two times larger than the pre-sealing population. Our findings lend support to the krill surplus hypothesis and illustrate the potential of genomic approaches to shed light on long-standing questions in population biology. |
| first_indexed | 2024-03-09T19:47:47Z |
| format | Article |
| id | doaj.art-ee8860b46e3847dbb0299be73bd03b39 |
| institution | Directory Open Access Journal |
| issn | 2073-4425 |
| language | English |
| last_indexed | 2024-03-09T19:47:47Z |
| publishDate | 2022-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Genes |
| spelling | doaj.art-ee8860b46e3847dbb0299be73bd03b392023-11-24T01:19:51ZengMDPI AGGenes2073-44252022-03-0113354110.3390/genes13030541Demographic Reconstruction of Antarctic Fur Seals Supports the Krill Surplus HypothesisJoseph I. Hoffman0Rebecca S. Chen1David L. J. Vendrami2Anna J. Paijmans3Kanchon K. Dasmahapatra4Jaume Forcada5Department of Animal Behavior, University of Bielefeld, P.O. BOX 100131, 33615 Bielefeld, GermanyDepartment of Animal Behavior, University of Bielefeld, P.O. BOX 100131, 33615 Bielefeld, GermanyDepartment of Animal Behavior, University of Bielefeld, P.O. BOX 100131, 33615 Bielefeld, GermanyDepartment of Animal Behavior, University of Bielefeld, P.O. BOX 100131, 33615 Bielefeld, GermanyDepartment of Biology, University of York, York YO10 5DD, UKBritish Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 OET, UKMuch debate surrounds the importance of top-down and bottom-up effects in the Southern Ocean, where the harvesting of over two million whales in the mid twentieth century is thought to have produced a massive surplus of Antarctic krill. This excess of krill may have allowed populations of other predators, such as seals and penguins, to increase, a top-down hypothesis known as the ‘krill surplus hypothesis’. However, a lack of pre-whaling population baselines has made it challenging to investigate historical changes in the abundance of the major krill predators in relation to whaling. Therefore, we used reduced representation sequencing and a coalescent-based maximum composite likelihood approach to reconstruct the recent demographic history of the Antarctic fur seal, a pinniped that was hunted to the brink of extinction by 18th and 19th century sealers. In line with the known history of this species, we found support for a demographic model that included a substantial reduction in population size around the time period of sealing. Furthermore, maximum likelihood estimates from this model suggest that the recovered, post-sealing population at South Georgia may have been around two times larger than the pre-sealing population. Our findings lend support to the krill surplus hypothesis and illustrate the potential of genomic approaches to shed light on long-standing questions in population biology.https://www.mdpi.com/2073-4425/13/3/541<i>Arctocephalus gazella</i>Antarctic fur sealRAD sequencingdemographic modellingbottleneckkrill surplus hypothesis |
| spellingShingle | Joseph I. Hoffman Rebecca S. Chen David L. J. Vendrami Anna J. Paijmans Kanchon K. Dasmahapatra Jaume Forcada Demographic Reconstruction of Antarctic Fur Seals Supports the Krill Surplus Hypothesis Genes <i>Arctocephalus gazella</i> Antarctic fur seal RAD sequencing demographic modelling bottleneck krill surplus hypothesis |
| title | Demographic Reconstruction of Antarctic Fur Seals Supports the Krill Surplus Hypothesis |
| title_full | Demographic Reconstruction of Antarctic Fur Seals Supports the Krill Surplus Hypothesis |
| title_fullStr | Demographic Reconstruction of Antarctic Fur Seals Supports the Krill Surplus Hypothesis |
| title_full_unstemmed | Demographic Reconstruction of Antarctic Fur Seals Supports the Krill Surplus Hypothesis |
| title_short | Demographic Reconstruction of Antarctic Fur Seals Supports the Krill Surplus Hypothesis |
| title_sort | demographic reconstruction of antarctic fur seals supports the krill surplus hypothesis |
| topic | <i>Arctocephalus gazella</i> Antarctic fur seal RAD sequencing demographic modelling bottleneck krill surplus hypothesis |
| url | https://www.mdpi.com/2073-4425/13/3/541 |
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