Abstract
Climate shifts are key drivers of ecosystem change. Despite the critical importance of Antarctica and the Southern Ocean for global climate, the extent of climate-driven ecological change in this region remains controversial. In particular, the biological effects of changing sea ice conditions are poorly understood.We hypothesize that rapid postglacial reductions in sea ice drove biological shifts across multiple widespread Southern Ocean species. We test for demographic shifts driven by climate events over recent millennia by analyzing population genomic datasets spanning 3 penguin genera (Eudyptes, Pygoscelis, and Aptenodytes). Demographic analyses for multiple species (macaroni/royal, eastern rockhopper, Adélie, gentoo, king, and emperor) currently inhabiting southern coastlines affected by heavy sea ice conditions during the Last Glacial Maximum (LGM) yielded genetic signatures of near-simultaneous population expansions associated with postglacial warming. Populations of the ice-adapted emperor penguin are inferred to have expanded slightly earlier than those of species requiring ice-free terrain. These concerted high-latitude expansion events contrast with relatively stable or declining demographic histories inferred for 4 penguin species (northern rockhopper, western rockhopper, Fiordland crested, and Snares crested) that apparently persisted throughout the LGM in ice-free habitats. Limited genetic structure detected in all ice-affected species across the vast Southern Ocean may reflect both rapid postglacial colonization of subantarctic and Antarctic shores, in addition to recent genetic exchange among populations. Together, these analyses highlight dramatic, ecosystem-wide responses to past Southern Ocean climate change and suggest potential for further shifts as warming continues.
Original language | English |
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Pages (from-to) | 26690-26696 |
Number of pages | 7 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 116 |
Issue number | 52 |
Early online date | 16 Dec 2019 |
DOIs | |
Publication status | Published - 26 Dec 2019 |
Funding
Department of Conservation Permits (OT-25557-DOA, IACUC-18958.00, 32202-FAU, 35682-FAU, 37312-LND, 50437-DOA, 50436-FAU, 50464-DOA, and 38882-RES), NZ Ministry of Primary Industries (2015056535, 2016060908, 2017064905), Permit to Possess Threatened Fauna for Scientific Purposes TFA 15086, DPIWE Permit to Take Wildlife for Scientific Purposes FA05246, Tristan Da Cunha Conservation Department, South African Department of Environmental Affairs, Government of South Georgia and the South Sandwich Islands Restricted Activity Permits (GSGSSI RAP 2018/018, GSGSSI), US NSF Department of Polar Programs ACA permits (ACA 2016-011, ACA 2016-012), Falkland Islands Government (R05/2009, R014/2006), and UK Antarctic Permits. We thank N. Fowke and B. McKinlay for NZ permits. The research was supported by Manaaki Whenua Landcare Research, the University of Otago, Museum of NZ Te Papa Tongarewa, US NSF (Grants OPP-012-8913 and 1443585), Quark Expeditions, The Darwin Initiative, The John Ellerman Foundation, Cheesemans’ Ecology Safaris, Golden Fleece Expeditions, New Island Conservation Trust, Deutsche Forschungsgemeinschaft, The Citadel Foundation, The Dalio Foundation, donations to Penguin Watch, the Institut Polaire Français Paul Emile Victor (Program 109 to P.J. and H. Weimerskirch), The Royal Society of NZ Hutton Fund, The Ornithological Society of NZ, and an Alumni of University of Otago in America Award. T.L.C. was supported by an Otago University Postgraduate Award.
Keywords
- Climate change
- Genomics
- Last Glacial Maximum
- Refugia
- Sphenisciformes
ASJC Scopus subject areas
- General