Abstract
Southern Hemisphere humpback whales breed in tropical waters and migrate to Antarctica to forage. While the breeding grounds are well defined, the population structure on Antarctic feeding grounds is poorly described. The Western Antarctic Peninsula (WAP) is of particular interest, where rapidly changing environmental conditions could alter prey distribution or migration pathways. To examine changes in the population of whales around the WAP, we used mitochondrial DNA (mtDNA) and 15 microsatellite loci. We compared our WAP dataset to a dataset collected 18 years earlier, and identified new haplotypes for the region, but found no significant difference between the datasets. We compared whales from the WAP to breeding populations in Oceania, Colombia, and Brazil. We used an Analysis of Molecular Variance to confirm significant genetic differentiation between the WAP and each breeding ground (overall F ST = 0.035/0.007 mtDNA/microsatellite, p < 0.001) except Colombia. Bayesian mixed-stock analyses showed a large apportionment to Colombia (mtDNA 93.0%; CL 91–99%; microsatellites 86%; CL 72–93%) and a small apportionment to French Polynesia/Samoan Islands (mtDNA 2.9%; CL 0.0–11.5%; microsatellites 8.9%; CL 0–22%), supporting the strong connection between Colombia and the WAP. Assignment tests allocated 81 individuals to Colombia and two to French Polynesia/Samoan Islands. No other breeding grounds had significant apportionments. Direct connectivity of French Polynesia to the WAP was confirmed with the first genotype match of French Polynesia to a feeding area. Continued genetic monitoring will highlight the complex patterns of humpbacks in this rapidly changing climate. Our results serve as a baseline for humpback whale population structure, illustrate mixed-stock analysis as a useful tool for migrating wildlife, and aid in future management considerations for humpbacks.
| Original language | English |
|---|---|
| Pages (from-to) | 323–340 |
| Number of pages | 18 |
| Journal | Polar Biology |
| Volume | 41 |
| DOIs | |
| State | Published - Feb 1 2018 |
Bibliographical note
Publisher Copyright:© 2017, Springer-Verlag GmbH Germany.
Funding
For field collection for the WAP2014 dataset, the authors thank members of the Multi-scale and Interdisciplinary Study of Humpback and Prey field team, including D. Waples, P. Halpin, M. Zhou, Y. Zhu, J. Warren, E. Hazen, and B. Espinasse as well as the crew and marine technicians of the RVIB ‘Nathaniel B Palmer’ and ARSV ‘Laurence M Gould’ for their efforts. Sample collection for the WAP1996 dataset was supported primarily by the Instituto Antarctico Chileno (Projects INACH 08-93, 163 and G-02-07). Funding for the collection and genetic analyses of samples from Oceania was provided to the South Pacific Whale Research Consortium by the International Fund for Animal Welfare (IFAW) and the Regional Natural Heritage Program, Department of Environment and Heritage, Government of Australia. Research in French Polynesia was conducted under permits issued by French Polynesia’s Ministry of the Environment, who also provided additional funding. Oregon State University’s Institutional Animal Care and Use Committee approved a protocol for collection of biopsy samples. For access to data from the Oceania breeding grounds, we thank members of the South Pacific Whale Research Consortium for access to the data and sample collection, especially David Mattila, Juney Ward, Alden Tagarino, and Marc Oremus, for assistance with laboratory analyses. For work at American Samoa, we thank the American Samoa Department of Marine and Wildlife Resources, the National Marine Sanctuary of American Samoa, the Hawaiian Islands Humpback Whale National Marine Sanctuary, and the U.S. National Park Service. Research was conducted under National Marine Fisheries Service permits 774-1714 and 14097 (held by Southwest Fisheries Science Center) and the permission of the Government of American Samoa. We thank colleagues at Instituto Baleia Jubarte for collecting samples in Brazil, and colleagues of the Laboratorio de Biologia Genomica e Molecular/PUCRS for their help with laboratory analyses in Brazil. Brazilian biopsy samples were collected off Brazil under permit SISBIO 21489-1. We thank Chris Lundeberg for the photo-identification matching of the WAP2014 dataset to the French Polynesia dataset. In addition, we thank John McClung for reconciling the photos from the French Polynesia archipelagos outside the Society Islands to the main French Polynesia humpback whale catalog. Lastly, we thank the three reviewers who provided thoughtful comments to improve the manuscript. The 2014 research in the Antarctic Peninsula was conducted under National Marine Fisheries Service Permit 808-1735 and 13583-01, Antarctic Conservation Act Permit 2009-014, and Duke University Institutional Animal Care & Use Committee A049-112-02. Research in the Antarctic Peninsula for the 2014 field season was supported by National Science Foundation, Office of Polar Programs Grant ANT-07-39483. All applicable international, national, and institutional guidelines for the care and use of animals were followed.
| Funders | Funder number |
|---|---|
| Instituto Antarctico Chileno | INACH 08-93, G-02-07, 163 |
| National Science Foundation | |
| Office of Polar Programs | ANT-07-39483 |
| International Fund for Animal Welfare | |
| National Foundation for Science and Technology Development |
ASJC Scopus Subject Areas
- General Agricultural and Biological Sciences
Keywords
- Antarctic Peninsula
- Climate change
- DNA markers
- Humpback whales
- Mixed-stock analysis
- Population structure