1
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Tschritter CM, van Coeverden de Groot P, Branigan M, Dyck M, Sun Z, Jenkins E, Buhler K, Lougheed SC. The geographic distribution, and the biotic and abiotic predictors of select zoonotic pathogen detections in Canadian polar bears. Sci Rep 2024; 14:12027. [PMID: 38797747 PMCID: PMC11128453 DOI: 10.1038/s41598-024-62800-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 05/21/2024] [Indexed: 05/29/2024] Open
Abstract
Increasing Arctic temperatures are facilitating the northward expansion of more southerly hosts, vectors, and pathogens, exposing naïve populations to pathogens not typical at northern latitudes. To understand such rapidly changing host-pathogen dynamics, we need sensitive and robust surveillance tools. Here, we use a novel multiplexed magnetic-capture and droplet digital PCR (ddPCR) tool to assess a sentinel Arctic species, the polar bear (Ursus maritimus; n = 68), for the presence of five zoonotic pathogens (Erysipelothrix rhusiopathiae, Francisella tularensis, Mycobacterium tuberculosis complex, Toxoplasma gondii and Trichinella spp.), and observe associations between pathogen presence and biotic and abiotic predictors. We made two novel detections: the first detection of a Mycobacterium tuberculosis complex member in Arctic wildlife and the first of E. rhusiopathiae in a polar bear. We found a prevalence of 37% for E. rhusiopathiae, 16% for F. tularensis, 29% for Mycobacterium tuberculosis complex, 18% for T. gondii, and 75% for Trichinella spp. We also identify associations with bear age (Trichinella spp.), harvest season (F. tularensis and MTBC), and human settlements (E. rhusiopathiae, F. tularensis, MTBC, and Trichinella spp.). We demonstrate that monitoring a sentinel species, the polar bear, could be a powerful tool in disease surveillance and highlight the need to better characterize pathogen distributions and diversity in the Arctic.
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Affiliation(s)
| | | | - Marsha Branigan
- Department of Environment and Climate Change, Government of the Northwest Territories, Inuvik, Northwest Territories, Canada
| | - Markus Dyck
- Department of Environment, Government of Nunavut, Igloolik, NT, Canada
| | - Zhengxin Sun
- Department of Biology, Queen's University, Kingston, ON, Canada
| | - Emily Jenkins
- Western College of Veterinary Medicine (WCVM), Saskatoon, SK, Canada
| | - Kayla Buhler
- Western College of Veterinary Medicine (WCVM), Saskatoon, SK, Canada
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2
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Westbury MV, Brown SC, Lorenzen J, O’Neill S, Scott MB, McCuaig J, Cheung C, Armstrong E, Valdes PJ, Samaniego Castruita JA, Cabrera AA, Blom SK, Dietz R, Sonne C, Louis M, Galatius A, Fordham DA, Ribeiro S, Szpak P, Lorenzen ED. Impact of Holocene environmental change on the evolutionary ecology of an Arctic top predator. SCIENCE ADVANCES 2023; 9:eadf3326. [PMID: 37939193 PMCID: PMC10631739 DOI: 10.1126/sciadv.adf3326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 06/09/2023] [Accepted: 10/06/2023] [Indexed: 11/10/2023]
Abstract
The Arctic is among the most climatically sensitive environments on Earth, and the disappearance of multiyear sea ice in the Arctic Ocean is predicted within decades. As apex predators, polar bears are sentinel species for addressing the impact of environmental variability on Arctic marine ecosystems. By integrating genomics, isotopic analysis, morphometrics, and ecological modeling, we investigate how Holocene environmental changes affected polar bears around Greenland. We uncover reductions in effective population size coinciding with increases in annual mean sea surface temperature, reduction in sea ice cover, declines in suitable habitat, and shifts in suitable habitat northward. Furthermore, we show that west and east Greenlandic polar bears are morphologically, and ecologically distinct, putatively driven by regional biotic and genetic differences. Together, we provide insights into the vulnerability of polar bears to environmental change and how the Arctic marine ecosystem plays a vital role in shaping the evolutionary and ecological trajectories of its inhabitants.
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Affiliation(s)
- Michael V. Westbury
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
| | - Stuart C. Brown
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
- Environment Institute and School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
- Department for Environment and Water, Adelaide, South Australia, Australia
| | - Julie Lorenzen
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
| | - Stuart O’Neill
- Environment Institute and School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Michael B. Scott
- Department of Anthropology, Trent University, 1600 West Bank Drive, Peterborough, Ontario K9L0G2, Canada
| | - Julia McCuaig
- Department of Anthropology, Trent University, 1600 West Bank Drive, Peterborough, Ontario K9L0G2, Canada
| | - Christina Cheung
- Department of Anthropology, Chinese University of Hong Kong, Shatin, Hong Kong
| | - Edward Armstrong
- Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland
| | - Paul J. Valdes
- School of Geographical Sciences, University of Bristol, Bristol, UK
| | | | - Andrea A. Cabrera
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
| | - Stine Keibel Blom
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
| | - Rune Dietz
- Arctic Research Centre (ARC), Department of Ecoscience, Aarhus University, Frederiksborgvej 399, PO Box 358, Roskilde DK-4000, Denmark
- Section for Marine Mammal Research, Department of Ecoscience, Aarhus University, Frederiksborgvej 399, Roskilde DK-4000, Denmark
| | - Christian Sonne
- Arctic Research Centre (ARC), Department of Ecoscience, Aarhus University, Frederiksborgvej 399, PO Box 358, Roskilde DK-4000, Denmark
- Section for Marine Mammal Research, Department of Ecoscience, Aarhus University, Frederiksborgvej 399, Roskilde DK-4000, Denmark
| | - Marie Louis
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
- Greenland Institute of Natural Resources, Kivioq 2, PO Box 570, Nuuk 3900, Denmark
| | - Anders Galatius
- Section for Marine Mammal Research, Department of Ecoscience, Aarhus University, Frederiksborgvej 399, Roskilde DK-4000, Denmark
| | - Damien A. Fordham
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
- Environment Institute and School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Sofia Ribeiro
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
- Glaciology and Climate Department, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, Copenhagen DK-1350, Denmark
| | - Paul Szpak
- Department of Anthropology, Trent University, 1600 West Bank Drive, Peterborough, Ontario K9L0G2, Canada
| | - Eline D. Lorenzen
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
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3
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Kellner A, Atwood TC, Douglas DC, Breck SW, Wittemyer G. High winds and melting sea ice trigger landward movement in a polar bear population of concern. Ecosphere 2023. [DOI: 10.1002/ecs2.4420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Annie Kellner
- Graduate Degree Program in Ecology Colorado State University Fort Collins Colorado USA
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado USA
| | - Todd C. Atwood
- U.S. Geological Survey Alaska Science Center Anchorage Alaska USA
| | | | - Stewart W. Breck
- USDA‐WS‐National Wildlife Research Center Fort Collins Colorado USA
| | - George Wittemyer
- Graduate Degree Program in Ecology Colorado State University Fort Collins Colorado USA
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado USA
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4
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Patil VP, Durner GM, Douglas DC, Atwood TC. Modeling the spatial and temporal dynamics of land‐based polar bear denning in Alaska. J Wildl Manage 2022. [DOI: 10.1002/jwmg.22302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Vijay P. Patil
- Alaska Science Center U.S. Geological Survey 4210 University Drive Anchorage AK 99508 USA
| | - George M. Durner
- Alaska Science Center U.S. Geological Survey 4210 University Drive Anchorage AK 99508 USA
| | - David C. Douglas
- Alaska Science Center U.S. Geological Survey 250 Egan Drive Juneau AK 99801 USA
| | - Todd C. Atwood
- Alaska Science Center U.S. Geological Survey 4210 University Drive Anchorage AK 99508 USA
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5
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Pagano AM, Durner GM, Atwood TC, Douglas DC. Effects of sea ice decline and summer land use on polar bear home range size in the Beaufort Sea. Ecosphere 2021. [DOI: 10.1002/ecs2.3768] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Anthony M. Pagano
- U.S. Geological Survey Alaska Science Center Anchorage Alaska 99508 USA
| | - George M. Durner
- U.S. Geological Survey Alaska Science Center Anchorage Alaska 99508 USA
| | - Todd C. Atwood
- U.S. Geological Survey Alaska Science Center Anchorage Alaska 99508 USA
| | - David C. Douglas
- U.S. Geological Survey Alaska Science Center Juneau Alaska 99801 USA
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6
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Lomac-MacNair K, Wisdom S, Pedro De Andrade J, Stepanuk JE, Esteves E. Polar bear behavioral response to vessel surveys in northeastern Chukchi Sea, 2008–2014. URSUS 2021. [DOI: 10.2192/ursus-d-20-00023.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Kate Lomac-MacNair
- CCMAR, Centro de Ciências do Mar, Universidade do Algarve Campus de Gambelas, 8005-139 Faro, Portugal
| | - Sheyna Wisdom
- Fairweather Science LLC, 301 Calista Court, Anchorage, AK 99518, USA
| | - José Pedro De Andrade
- CCMAR, Centro de Ciências do Mar, Universidade do Algarve Campus de Gambelas, 8005-139 Faro, Portugal
| | - Julia E. Stepanuk
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY 11794, USA
| | - Eduardo Esteves
- CCMAR, Centro de Ciências do Mar and Instituto Superior de Engenharia, Universidade do Algarve Campus da Penha, 8005-139 Faro, Portugal
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7
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Pagano AM, Williams TM. Physiological consequences of Arctic sea ice loss on large marine carnivores: unique responses by polar bears and narwhals. J Exp Biol 2021; 224:224/Suppl_1/jeb228049. [PMID: 33627459 DOI: 10.1242/jeb.228049] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Rapid environmental changes in the Arctic are threatening the survival of marine species that rely on the predictable presence of the sea ice. Two Arctic marine mammal specialists, the polar bear (Ursus maritimus) and narwhal (Monodon monoceros), appear especially vulnerable to the speed and capriciousness of sea ice deterioration as a consequence of their unique hunting behaviors and diet, as well as their physiological adaptations for slow-aerobic exercise. These intrinsic characteristics limit the ability of these species to respond to extrinsic threats associated with environmental change and increased industrial activity in a warming Arctic. In assessing how sea ice loss may differentially affect polar bears that hunt on the ice surface and narwhals that hunt at extreme depths below, we found that major ice loss translated into elevated locomotor costs that range from 3- to 4-fold greater than expected for both species. For polar bears this instigates an energy imbalance from the combined effects of reduced caloric intake and increased energy expenditure. For narwhals, high locomotor costs during diving increase the risk of ice entrapment due to the unreliability of breathing holes. These species-specific physiological constraints and extreme reliance on the polar sea ice conspire to make these two marine mammal specialists sentinels of climate change within the Arctic marine ecosystem that may foreshadow rapid changes to the marine ecosystem.
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Affiliation(s)
- Anthony M Pagano
- Institute for Conservation Research, San Diego Zoo Global, San Diego, CA 92027, USA
| | - Terrie M Williams
- University of California, Santa Cruz, Department of Ecology and Evolutionary Biology, Santa Cruz, CA 95060, USA
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8
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Laidre KL, Atkinson SN, Regehr EV, Stern HL, Born EW, Wiig Ø, Lunn NJ, Dyck M, Heagerty P, Cohen BR. Transient benefits of climate change for a high-Arctic polar bear (Ursus maritimus) subpopulation. GLOBAL CHANGE BIOLOGY 2020; 26:6251-6265. [PMID: 32964662 DOI: 10.1111/gcb.15286] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 05/18/2020] [Indexed: 06/11/2023]
Abstract
Kane Basin (KB) is one of the world's most northerly polar bear (Ursus maritimus) subpopulations, where bears have historically inhabited a mix of thick multiyear and annual sea ice year-round. Currently, KB is transitioning to a seasonally ice-free region because of climate change. This ecological shift has been hypothesized to benefit polar bears in the near-term due to thinner ice with increased biological production, although this has not been demonstrated empirically. We assess sea-ice changes in KB together with changes in polar bear movements, seasonal ranges, body condition, and reproductive metrics obtained from capture-recapture (physical and genetic) and satellite telemetry studies during two study periods (1993-1997 and 2012-2016). The annual cycle of sea-ice habitat in KB shifted from a year-round ice platform (~50% coverage in summer) in the 1990s to nearly complete melt-out in summer (<5% coverage) in the 2010s. The mean duration between sea-ice retreat and advance increased from 109 to 160 days (p = .004). Between the 1990s and 2010s, adult female (AF) seasonal ranges more than doubled in spring and summer and were significantly larger in all months. Body condition scores improved for all ages and both sexes. Mean litter sizes of cubs-of-the-year (C0s) and yearlings (C1s), and the number of C1s per AF, did not change between decades. The date of spring sea-ice retreat in the previous year was positively correlated with C1 litter size, suggesting smaller litters following years with earlier sea-ice breakup. Our study provides evidence for range expansion, improved body condition, and stable reproductive performance in the KB polar bear subpopulation. These changes, together with a likely increasing subpopulation abundance, may reflect the shift from thick, multiyear ice to thinner, seasonal ice with higher biological productivity. The duration of these benefits is unknown because, under unmitigated climate change, continued sea-ice loss is expected to eventually have negative demographic and ecological effects on all polar bears.
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Affiliation(s)
- Kristin L Laidre
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
- Greenland Institute of Natural Resources, Nuuk, Greenland
| | - Stephen N Atkinson
- Wildlife Research Section, Department of Environment, Government of Nunavut, Igloolik, NU, Canada
| | - Eric V Regehr
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Harry L Stern
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
| | - Erik W Born
- Greenland Institute of Natural Resources, Nuuk, Greenland
| | - Øystein Wiig
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Nicholas J Lunn
- Environment and Climate Change Canada, University of Alberta, Edmonton, AB, Canada
| | - Markus Dyck
- Wildlife Research Section, Department of Environment, Government of Nunavut, Igloolik, NU, Canada
| | - Patrick Heagerty
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - Benjamin R Cohen
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, USA
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9
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Laidre KL, Atkinson S, Regehr EV, Stern HL, Born EW, Wiig Ø, Lunn NJ, Dyck M. Interrelated ecological impacts of climate change on an apex predator. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2020; 30:e02071. [PMID: 31925853 PMCID: PMC7317597 DOI: 10.1002/eap.2071] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 09/12/2019] [Accepted: 11/11/2019] [Indexed: 05/29/2023]
Abstract
Climate change has broad ecological implications for species that rely on sensitive habitats. For some top predators, loss of habitat is expected to lead to cascading behavioral, nutritional, and reproductive changes that ultimately accelerate population declines. In the case of the polar bear (Ursus maritimus), declining Arctic sea ice reduces access to prey and lengthens seasonal fasting periods. We used a novel combination of physical capture, biopsy darting, and visual aerial observation data to project reproductive performance for polar bears by linking sea ice loss to changes in habitat use, body condition (i.e., fatness), and cub production. Satellite telemetry data from 43 (1991-1997) and 38 (2009-2015) adult female polar bears in the Baffin Bay subpopulation showed that bears now spend an additional 30 d on land (90 d in total) in the 2000s compared to the 1990s, a change closely correlated with changes in spring sea ice breakup and fall sea ice formation. Body condition declined for all sex, age, and reproductive classes and was positively correlated with sea ice availability in the current and previous year. Furthermore, cub litter size was positively correlated with maternal condition and spring breakup date (i.e., later breakup leading to larger litters), and negatively correlated with the duration of the ice-free period (i.e., longer ice-free periods leading to smaller litters). Based on these relationships, we projected reproductive performance three polar bear generations into the future (approximately 35 yr). Results indicate that two-cub litters, previously the norm, could largely disappear from Baffin Bay as sea ice loss continues. Our findings demonstrate how concurrent analysis of multiple data types collected over long periods from polar bears can provide a mechanistic understanding of the ecological implications of climate change. This information is needed for long-term conservation planning, which includes quantitative harvest risk assessments that incorporate estimated or assumed trends in future environmental carrying capacity.
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Affiliation(s)
- Kristin L. Laidre
- Polar Science CenterApplied Physics LaboratoryUniversity of WashingtonSeattleWashington98105USA
| | - Stephen Atkinson
- Wildlife Research SectionDepartment of EnvironmentGovernment of NunavutP.O. Box 209IgloolikNunavutX0A 0L0Canada
| | - Eric V. Regehr
- Polar Science CenterApplied Physics LaboratoryUniversity of WashingtonSeattleWashington98105USA
| | - Harry L. Stern
- Polar Science CenterApplied Physics LaboratoryUniversity of WashingtonSeattleWashington98105USA
| | - Erik W. Born
- Greenland Institute of Natural ResourcesP.O. Box 5703900NuukGreenland
| | - Øystein Wiig
- Natural History MuseumUniversity of OsloP.O. Box 1172BlindernN‐0318OsloNorway
| | - Nicholas J. Lunn
- Environment and Climate Change CanadaCW‐422 Biological Sciences BuildingUniversity of AlbertaEdmontonAlbertaT6G 2E9Canada
| | - Markus Dyck
- Wildlife Research SectionDepartment of EnvironmentGovernment of NunavutP.O. Box 209IgloolikNunavutX0A 0L0Canada
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10
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Jensen EL, Tschritter C, de Groot PVC, Hayward KM, Branigan M, Dyck M, Clemente‐Carvalho RBG, Lougheed SC. Canadian polar bear population structure using genome-wide markers. Ecol Evol 2020; 10:3706-3714. [PMID: 32313629 PMCID: PMC7160183 DOI: 10.1002/ece3.6159] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/23/2020] [Accepted: 02/18/2020] [Indexed: 12/01/2022] Open
Abstract
Predicting the consequences of environmental changes, including human-mediated climate change on species, requires that we quantify range-wide patterns of genetic diversity and identify the ecological, environmental, and historical factors that have contributed to it. Here, we generate baseline data on polar bear population structure across most Canadian subpopulations (n = 358) using 13,488 genome-wide single nucleotide polymorphisms (SNPs) identified with double-digest restriction site-associated DNA sequencing (ddRAD). Our ddRAD dataset showed three genetic clusters in the sampled Canadian range, congruent with previous studies based on microsatellites across the same regions; however, due to a lack of sampling in Norwegian Bay, we were unable to confirm the existence of a unique cluster in that subpopulation. These data on the genetic structure of polar bears using SNPs provide a detailed baseline against which future shifts in population structure can be assessed, and opportunities to develop new noninvasive tools for monitoring polar bears across their range.
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Affiliation(s)
- Evelyn L. Jensen
- Department of BiologyQueen’s UniversityKingstonONCanada
- Present address:
Department of Ecology and Evolutionary BiologyYale UniversityNew HavenCTUSA
| | | | | | | | - Marsha Branigan
- Department of Environment and Natural ResourcesGovernment of the Northwest TerritoriesInuvikNTCanada
| | - Markus Dyck
- Department of EnvironmentGovernment of NunavutIgloolikNUCanada
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11
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Pagano AM, Atwood TC, Durner GM, Williams TM. The seasonal energetic landscape of an apex marine carnivore, the polar bear. Ecology 2020; 101:e02959. [DOI: 10.1002/ecy.2959] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 10/22/2019] [Accepted: 11/12/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Anthony M. Pagano
- U.S. Geological SurveyAlaska Science Center4210 University Drive Anchorage Alaska99508USA
- Department of Ecology & Evolutionary Biology University of California Santa Cruz 130 McAllister Way Santa Cruz California95060USA
| | - Todd C. Atwood
- U.S. Geological SurveyAlaska Science Center4210 University Drive Anchorage Alaska99508USA
| | - George M. Durner
- U.S. Geological SurveyAlaska Science Center4210 University Drive Anchorage Alaska99508USA
| | - Terrie M. Williams
- Department of Ecology & Evolutionary Biology University of California Santa Cruz 130 McAllister Way Santa Cruz California95060USA
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12
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Watson SE, Hauffe HC, Bull MJ, Atwood TC, McKinney MA, Pindo M, Perkins SE. Global change-driven use of onshore habitat impacts polar bear faecal microbiota. ISME JOURNAL 2019; 13:2916-2926. [PMID: 31378786 DOI: 10.1038/s41396-019-0480-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 07/04/2019] [Accepted: 07/11/2019] [Indexed: 12/16/2022]
Abstract
The gut microbiota plays a critical role in host health, yet remains poorly studied in wild species. Polar bears (Ursus maritimus), key indicators of Arctic ecosystem health and environmental change, are currently affected by rapid shifts in habitat that may alter gut homeostasis. Declining sea ice has led to a divide in the southern Beaufort Sea polar bear subpopulation such that an increasing proportion of individuals now inhabit onshore coastal regions during the open-water period ('onshore bears') while others continue to exhibit their typical behaviour of remaining on the ice ('offshore bears'). We propose that bears that have altered their habitat selection in response to climate change will exhibit a distinct gut microbiota diversity and composition, which may ultimately have important consequences for their health. Here, we perform the first assessment of abundance and diversity in the faecal microbiota of wild polar bears using 16S rRNA Illumina technology. We find that bacterial diversity is significantly higher in onshore bears compared to offshore bears. The most enriched OTU abundance in onshore bears belonged to the phylum Proteobacteria, while the most depleted OTU abundance within onshore bears was seen in the phylum Firmicutes. We conclude that climate-driven changes in polar bear land use are associated with distinct microbial communities. In doing so, we present the first case of global change mediated alterations in the gut microbiota of a free-roaming wild animal.
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Affiliation(s)
- Sophie E Watson
- School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff, UK. .,Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all' Adige, TN, Italy.
| | - Heidi C Hauffe
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all' Adige, TN, Italy
| | - Matthew J Bull
- School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff, UK.,Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all' Adige, TN, Italy
| | - Todd C Atwood
- United States Geological Survey (USGS), University Drive, Anchorage, AK, USA
| | - Melissa A McKinney
- Department of Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, QC, Canada
| | - Massimo Pindo
- Department of Genomics and Biology of Fruit Crops, Research and Innovation Centre, Fondazione Edmund Mach, S. Michele all' Adige, TN, Italy
| | - Sarah E Perkins
- School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff, UK.,Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all' Adige, TN, Italy
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13
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Hamilton SG, Derocher AE. Assessment of global polar bear abundance and vulnerability. Anim Conserv 2018. [DOI: 10.1111/acv.12439] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- S. G. Hamilton
- Department of Biological Sciences University of Alberta Edmonton AB Canada
| | - A. E. Derocher
- Department of Biological Sciences University of Alberta Edmonton AB Canada
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14
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Laidre KL, Stern H, Born EW, Heagerty P, Atkinson S, Wiig Ø, Lunn NJ, Regehr EV, McGovern R, Dyck M. Changes in winter and spring resource selection by polar bears Ursus maritimus in Baffin Bay over two decades of sea-ice loss. ENDANGER SPECIES RES 2018. [DOI: 10.3354/esr00886] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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15
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Laidre KL, Born EW, Atkinson SN, Wiig Ø, Andersen LW, Lunn NJ, Dyck M, Regehr EV, McGovern R, Heagerty P. Range contraction and increasing isolation of a polar bear subpopulation in an era of sea-ice loss. Ecol Evol 2018; 8:2062-2075. [PMID: 29468025 PMCID: PMC5817132 DOI: 10.1002/ece3.3809] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 11/26/2017] [Indexed: 11/10/2022] Open
Abstract
Climate change is expected to result in range shifts and habitat fragmentation for many species. In the Arctic, loss of sea ice will reduce barriers to dispersal or eliminate movement corridors, resulting in increased connectivity or geographic isolation with sweeping implications for conservation. We used satellite telemetry, data from individually marked animals (research and harvest), and microsatellite genetic data to examine changes in geographic range, emigration, and interpopulation connectivity of the Baffin Bay (BB) polar bear (Ursus maritimus) subpopulation over a 25-year period of sea-ice loss. Satellite telemetry collected from n = 43 (1991-1995) and 38 (2009-2015) adult females revealed a significant contraction in subpopulation range size (95% bivariate normal kernel range) in most months and seasons, with the most marked reduction being a 70% decline in summer from 716,000 km2 (SE 58,000) to 211,000 km2 (SE 23,000) (p < .001). Between the 1990s and 2000s, there was a significant shift northward during the on-ice seasons (2.6° shift in winter median latitude, 1.1° shift in spring median latitude) and a significant range contraction in the ice-free summers. Bears in the 2000s were less likely to leave BB, with significant reductions in the numbers of bears moving into Davis Strait (DS) in winter and Lancaster Sound (LS) in summer. Harvest recoveries suggested both short and long-term fidelity to BB remained high over both periods (83-99% of marked bears remained in BB). Genetic analyses using eight polymorphic microsatellites confirmed a previously documented differentiation between BB, DS, and LS; yet weakly differentiated BB from Kane Basin (KB) for the first time. Our results provide the first multiple lines of evidence for an increasingly geographically and functionally isolated subpopulation of polar bears in the context of long-term sea-ice loss. This may be indicative of future patterns for other polar bear subpopulations under climate change.
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Affiliation(s)
- Kristin L. Laidre
- Polar Science CenterApplied Physics LaboratoryUniversity of WashingtonSeattleWAUSA
- Greenland Institute of Natural ResourcesNuukGreenland
| | - Erik W. Born
- Greenland Institute of Natural ResourcesNuukGreenland
| | - Stephen N. Atkinson
- Wildlife Research SectionDepartment of EnvironmentGovernment of NunavutIgloolikNUCanada
| | - Øystein Wiig
- Natural History MuseumUniversity of OsloOsloNorway
| | | | - Nicholas J. Lunn
- Environment and Climate Change CanadaUniversity of AlbertaEdmontonABCanada
| | - Markus Dyck
- Wildlife Research SectionDepartment of EnvironmentGovernment of NunavutIgloolikNUCanada
| | - Eric V. Regehr
- Polar Science CenterApplied Physics LaboratoryUniversity of WashingtonSeattleWAUSA
| | - Richard McGovern
- Polar Science CenterApplied Physics LaboratoryUniversity of WashingtonSeattleWAUSA
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Environmental and behavioral changes may influence the exposure of an Arctic apex predator to pathogens and contaminants. Sci Rep 2017; 7:13193. [PMID: 29038498 PMCID: PMC5643432 DOI: 10.1038/s41598-017-13496-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 09/25/2017] [Indexed: 11/29/2022] Open
Abstract
Recent decline of sea ice habitat has coincided with increased use of land by polar bears (Ursus maritimus) from the southern Beaufort Sea (SB), which may alter the risks of exposure to pathogens and contaminants. We assayed blood samples from SB polar bears to assess prior exposure to the pathogens Brucella spp., Toxoplasma gondii, Coxiella burnetii, Francisella tularensis, and Neospora caninum, estimate concentrations of persistent organic pollutants (POPs), and evaluate risk factors associated with exposure to pathogens and POPs. We found that seroprevalence of Brucella spp. and T. gondii antibodies likely increased through time, and provide the first evidence of exposure of polar bears to C. burnetii, N. caninum, and F. tularensis. Additionally, the odds of exposure to T. gondii were greater for bears that used land than for bears that remained on the sea ice during summer and fall, while mean concentrations of the POP chlordane (ΣCHL) were lower for land-based bears. Changes in polar bear behavior brought about by climate-induced modifications to the Arctic marine ecosystem may increase exposure risk to certain pathogens and alter contaminant exposure pathways.
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Pagano AM, Rode KD, Cutting A, Owen MA, Jensen S, Ware JV, Robbins CT, Durner GM, Atwood TC, Obbard ME, Middel KR, Thiemann GW, Williams TM. Using tri-axial accelerometers to identify wild polar bear behaviors. ENDANGER SPECIES RES 2017. [DOI: 10.3354/esr00779] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Atwood TC, Marcot BG, Douglas DC, Amstrup SC, Rode KD, Durner GM, Bromaghin JF. Forecasting the relative influence of environmental and anthropogenic stressors on polar bears. Ecosphere 2016. [DOI: 10.1002/ecs2.1370] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- Todd C. Atwood
- Alaska Science CenterU.S. Geological Survey Anchorage Alaska 99508 USA
| | - Bruce G. Marcot
- Pacific Northwest Research StationU.S.D.A. Forest Service Portland Oregon 97208 USA
| | - David C. Douglas
- Alaska Science CenterU.S. Geological Survey Juneau Alaska 99801 USA
| | | | - Karyn D. Rode
- Alaska Science CenterU.S. Geological Survey Anchorage Alaska 99508 USA
| | - George M. Durner
- Alaska Science CenterU.S. Geological Survey Anchorage Alaska 99508 USA
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York J, Dowsley M, Cornwell A, Kuc M, Taylor M. Demographic and traditional knowledge perspectives on the current status of Canadian polar bear subpopulations. Ecol Evol 2016; 6:2897-924. [PMID: 27069588 PMCID: PMC4804000 DOI: 10.1002/ece3.2030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 01/21/2016] [Accepted: 01/23/2016] [Indexed: 11/05/2022] Open
Abstract
Subpopulation growth rates and the probability of decline at current harvest levels were determined for 13 subpopulations of polar bears (Ursus maritimus) that are within or shared with Canada based on mark-recapture estimates of population numbers and vital rates, and harvest statistics using population viability analyses (PVA). Aboriginal traditional ecological knowledge (TEK) on subpopulation trend agreed with the seven stable/increasing results and one of the declining results, but disagreed with PVA status of five other declining subpopulations. The decline in the Baffin Bay subpopulation appeared to be due to over-reporting of harvested numbers from outside Canada. The remaining four disputed subpopulations (Southern Beaufort Sea, Northern Beaufort Sea, Southern Hudson Bay, and Western Hudson Bay) were all incompletely mark-recapture (M-R) sampled, which may have biased their survival and subpopulation estimates. Three of the four incompletely sampled subpopulations were PVA identified as nonviable (i.e., declining even with zero harvest mortality). TEK disagreement was nonrandom with respect to M-R sampling protocols. Cluster analysis also grouped subpopulations with ambiguous demographic and harvest rate estimates separately from those with apparently reliable demographic estimates based on PVA probability of decline and unharvested subpopulation growth rate criteria. We suggest that the correspondence between TEK and scientific results can be used to improve the reliability of information on natural systems and thus improve resource management. Considering both TEK and scientific information, we suggest that the current status of Canadian polar bear subpopulations in 2013 was 12 stable/increasing and one declining (Kane Basin). We do not find support for the perspective that polar bears within or shared with Canada are currently in any sort of climate crisis. We suggest that monitoring the impacts of climate change (including sea ice decline) on polar bear subpopulations should be continued and enhanced and that adaptive management practices are warranted.
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Affiliation(s)
- Jordan York
- Department of Geography and the Environment Lakehead University 955 Oliver Road Thunder Bay ON P7B 5E1 Canada
| | - Martha Dowsley
- Department of Geography and the Environment Lakehead University 955 Oliver Road Thunder Bay ON P7B 5E1 Canada
| | - Adam Cornwell
- Department of Geography and the Environment Lakehead University 955 Oliver Road Thunder Bay ON P7B 5E1 Canada
| | - Miroslaw Kuc
- Miroslaw Kuc PH 205-942 Yonge Street Toronto ON M4W 3S8 Canada
| | - Mitchell Taylor
- Department of Geography and the Environment Lakehead University 955 Oliver Road Thunder Bay ON P7B 5E1 Canada
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Sahanatien V, Peacock E, Derocher AE. Population substructure and space use of Foxe Basin polar bears. Ecol Evol 2015; 5:2851-64. [PMID: 26306171 PMCID: PMC4541990 DOI: 10.1002/ece3.1571] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 05/11/2015] [Accepted: 05/18/2015] [Indexed: 11/19/2022] Open
Abstract
Climate change has been identified as a major driver of habitat change, particularly for sea ice-dependent species such as the polar bear (Ursus maritimus). Population structure and space use of polar bears have been challenging to quantify because of their circumpolar distribution and tendency to range over large areas. Knowledge of movement patterns, home range, and habitat is needed for conservation and management. This is the first study to examine the spatial ecology of polar bears in the Foxe Basin management unit of Nunavut, Canada. Foxe Basin is in the mid-Arctic, part of the seasonal sea ice ecoregion and it is being negatively affected by climate change. Our objectives were to examine intrapopulation spatial structure, to determine movement patterns, and to consider how polar bear movements may respond to changing sea ice habitat conditions. Hierarchical and fuzzy cluster analyses were used to assess intrapopulation spatial structure of geographic position system satellite-collared female polar bears. Seasonal and annual movement metrics (home range, movement rates, time on ice) and home-range fidelity (static and dynamic overlap) were compared to examine the influence of regional sea ice on movements. The polar bears were distributed in three spatial clusters, and there were differences in the movement metrics between clusters that may reflect sea ice habitat conditions. Within the clusters, bears moved independently of each other. Annual and seasonal home-range fidelity was observed, and the bears used two movement patterns: on-ice range residency and annual migration. We predict that home-range fidelity may decline as the spatial and temporal predictability of sea ice changes. These new findings also provide baseline information for managing and monitoring this polar bear population.
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Affiliation(s)
- Vicki Sahanatien
- Department of Biological Sciences, University of AlbertaEdmonton, Alberta, T6G 2E9, Canada
| | - Elizabeth Peacock
- Department of Environment, Government of NunavutIgloolik, Nunavut, X0A 0L0, Canada
| | - Andrew E Derocher
- Department of Biological Sciences, University of AlbertaEdmonton, Alberta, T6G 2E9, Canada
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Peacock E, Sonsthagen SA, Obbard ME, Boltunov A, Regehr EV, Ovsyanikov N, Aars J, Atkinson SN, Sage GK, Hope AG, Zeyl E, Bachmann L, Ehrich D, Scribner KT, Amstrup SC, Belikov S, Born EW, Derocher AE, Stirling I, Taylor MK, Wiig Ø, Paetkau D, Talbot SL. Implications of the circumpolar genetic structure of polar bears for their conservation in a rapidly warming Arctic. PLoS One 2015; 10:e112021. [PMID: 25562525 PMCID: PMC4285400 DOI: 10.1371/journal.pone.0112021] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 09/19/2014] [Indexed: 11/18/2022] Open
Abstract
We provide an expansive analysis of polar bear (Ursus maritimus) circumpolar genetic variation during the last two decades of decline in their sea-ice habitat. We sought to evaluate whether their genetic diversity and structure have changed over this period of habitat decline, how their current genetic patterns compare with past patterns, and how genetic demography changed with ancient fluctuations in climate. Characterizing their circumpolar genetic structure using microsatellite data, we defined four clusters that largely correspond to current ecological and oceanographic factors: Eastern Polar Basin, Western Polar Basin, Canadian Archipelago and Southern Canada. We document evidence for recent (ca. last 1–3 generations) directional gene flow from Southern Canada and the Eastern Polar Basin towards the Canadian Archipelago, an area hypothesized to be a future refugium for polar bears as climate-induced habitat decline continues. Our data provide empirical evidence in support of this hypothesis. The direction of current gene flow differs from earlier patterns of gene flow in the Holocene. From analyses of mitochondrial DNA, the Canadian Archipelago cluster and the Barents Sea subpopulation within the Eastern Polar Basin cluster did not show signals of population expansion, suggesting these areas may have served also as past interglacial refugia. Mismatch analyses of mitochondrial DNA data from polar and the paraphyletic brown bear (U. arctos) uncovered offset signals in timing of population expansion between the two species, that are attributed to differential demographic responses to past climate cycling. Mitogenomic structure of polar bears was shallow and developed recently, in contrast to the multiple clades of brown bears. We found no genetic signatures of recent hybridization between the species in our large, circumpolar sample, suggesting that recently observed hybrids represent localized events. Documenting changes in subpopulation connectivity will allow polar nations to proactively adjust conservation actions to continuing decline in sea-ice habitat.
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Affiliation(s)
- Elizabeth Peacock
- Alaska Science Center, US Geological Survey, Anchorage, Alaska, United States of America
- Department of Environment, Government of Nunavut, Igloolik, Nunavut, Canada
- * E-mail:
| | - Sarah A. Sonsthagen
- Alaska Science Center, US Geological Survey, Anchorage, Alaska, United States of America
| | - Martyn E. Obbard
- Ontario Ministry of Natural Resources and Forestry, Peterborough, Ontario, Canada
| | - Andrei Boltunov
- All-Russian Research Institute for Nature Protection, Moscow, Russian Federation
| | - Eric V. Regehr
- US Fish and Wildlife Service, Marine Mammals Management, Anchorage, Alaska, United States of America
| | | | - Jon Aars
- Norwegian Polar Institute, Tromsø, Norway
| | | | - George K. Sage
- Alaska Science Center, US Geological Survey, Anchorage, Alaska, United States of America
| | - Andrew G. Hope
- Alaska Science Center, US Geological Survey, Anchorage, Alaska, United States of America
| | - Eve Zeyl
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Lutz Bachmann
- Natural History Museum, University of Oslo, Oslo, Norway
| | | | - Kim T. Scribner
- Department of Zoology, Michigan State University, East Lansing, Michigan, United States of America
| | - Steven C. Amstrup
- Polar Bears International, Bozeman, Montana, United States of America
| | - Stanislav Belikov
- All-Russian Research Institute for Nature Protection, Moscow, Russian Federation
| | - Erik W. Born
- Greenland Institute of Natural Resources, Copenhagen, Denmark
| | - Andrew E. Derocher
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Ian Stirling
- Science & Technology Branch, Environment Canada, Edmonton, Alberta, Canada
| | - Mitchell K. Taylor
- Faculty of Science and Environmental Studies, Lakehead University, Thunder Bay, Ontario, Canada
| | - Øystein Wiig
- Natural History Museum, University of Oslo, Oslo, Norway
| | - David Paetkau
- Wildlife Genetics International, Nelson, British Columbia, Canada
| | - Sandra L. Talbot
- Alaska Science Center, US Geological Survey, Anchorage, Alaska, United States of America
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Rode KD, Regehr EV, Douglas DC, Durner G, Derocher AE, Thiemann GW, Budge SM. Variation in the response of an Arctic top predator experiencing habitat loss: feeding and reproductive ecology of two polar bear populations. GLOBAL CHANGE BIOLOGY 2014; 20:76-88. [PMID: 23913506 DOI: 10.1111/gcb.12339] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 07/20/2013] [Indexed: 06/02/2023]
Abstract
Polar bears (Ursus maritimus) have experienced substantial changes in the seasonal availability of sea ice habitat in parts of their range, including the Beaufort, Chukchi, and Bering Seas. In this study, we compared the body size, condition, and recruitment of polar bears captured in the Chukchi and Bering Seas (CS) between two periods (1986-1994 and 2008-2011) when declines in sea ice habitat occurred. In addition, we compared metrics for the CS population 2008-2011 with those of the adjacent southern Beaufort Sea (SB) population where loss in sea ice habitat has been associated with declines in body condition, size, recruitment, and survival. We evaluated how variation in body condition and recruitment were related to feeding ecology. Comparing habitat conditions between populations, there were twice as many reduced ice days over continental shelf waters per year during 2008-2011 in the SB than in the CS. CS polar bears were larger and in better condition, and appeared to have higher reproduction than SB bears. Although SB and CS bears had similar diets, twice as many bears were fasting in spring in the SB than in the CS. Between 1986-1994 and 2008-2011, body size, condition, and recruitment indices in the CS were not reduced despite a 44-day increase in the number of reduced ice days. Bears in the CS exhibited large body size, good body condition, and high indices of recruitment compared to most other populations measured to date. Higher biological productivity and prey availability in the CS relative to the SB, and a shorter recent history of reduced sea ice habitat, may explain the maintenance of condition and recruitment of CS bears. Geographic differences in the response of polar bears to climate change are relevant to range-wide forecasts for this and other ice-dependent species.
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Affiliation(s)
- Karyn D Rode
- Marine Mammals Management, U. S. Fish and Wildlife Service, 1011 E Tudor Road, Anchorage, AK, 99502, USA
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24
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McKinney MA, Iverson SJ, Fisk AT, Sonne C, Rigét FF, Letcher RJ, Arts MT, Born EW, Rosing-Asvid A, Dietz R. Global change effects on the long-term feeding ecology and contaminant exposures of East Greenland polar bears. GLOBAL CHANGE BIOLOGY 2013; 19:2360-72. [PMID: 23640921 DOI: 10.1111/gcb.12241] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 03/31/2013] [Indexed: 05/04/2023]
Abstract
Rapid climate changes are occurring in the Arctic, with substantial repercussions for arctic ecosystems. It is challenging to assess ecosystem changes in remote polar environments, but one successful approach has entailed monitoring the diets of upper trophic level consumers. Quantitative fatty acid signature analysis (QFASA) and fatty acid carbon isotope (δ(13) C-FA) patterns were used to assess diets of East Greenland (EG) polar bears (Ursus maritimus) (n = 310) over the past three decades. QFASA-generated diet estimates indicated that, on average, EG bears mainly consumed arctic ringed seals (47.5 ± 2.1%), migratory subarctic harp (30.6 ± 1.5%) and hooded (16.7 ± 1.3%) seals and rarely, if ever, consumed bearded seals, narwhals or walruses. Ringed seal consumption declined by 14%/decade over 28 years (90.1 ± 2.5% in 1984 to 33.9 ± 11.1% in 2011). Hooded seal consumption increased by 9.5%/decade (0.0 ± 0.0% in 1984 to 25.9 ± 9.1% in 2011). This increase may include harp seal, since hooded and harp seal FA signatures were not as well differentiated relative to other prey species. Declining δ(13) C-FA ratios supported shifts from more nearshore/benthic/ice-associated prey to more offshore/pelagic/open-water-associated prey, consistent with diet estimates. Increased hooded seal and decreased ringed seal consumption occurred during years when the North Atlantic Oscillation (NAO) was lower. Thus, periods with warmer temperatures and less sea ice were associated with more subarctic and less arctic seal species consumption. These changes in the relative abundance, accessibility, or distribution of arctic and subarctic marine mammals may have health consequences for EG polar bears. For example, the diet change resulted in consistently slower temporal declines in adipose levels of legacy persistent organic pollutants, as the subarctic seals have higher contaminant burdens than arctic seals. Overall, considerable changes are occurring in the EG marine ecosystem, with consequences for contaminant dynamics.
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Derocher AE, Aars J, Amstrup SC, Cutting A, Lunn NJ, Molnár PK, Obbard ME, Stirling I, Thiemann GW, Vongraven D, Wiig Ø, York G. Rapid ecosystem change and polar bear conservation. Conserv Lett 2013. [DOI: 10.1111/conl.12009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Andrew E. Derocher
- Department of Biological Sciences, University of Alberta; Edmonton; AB T6G 2E9; Canada
| | - Jon Aars
- Norwegian Polar Institute, Fram Centre; 9296; Tromsø; Norway
| | | | | | - Nick J. Lunn
- Wildlife Research Division, Science and Technology Branch, Environment Canada,; 5320 122 Street; Edmonton; AB T6H 3S5; Canada
| | - Péter K. Molnár
- Ecology and Evolutionary Biology, Eno Hall, Princeton University; Princeton; NJ; 08544-1003; USA
| | - Martyn E. Obbard
- Wildlife Research and Development Section, Ontario Ministry of Natural Resources, DNA Building, Trent University; 2140 East Bank Drive; Peterborough; ON K9J 7B8; Canada
| | | | - Gregory W. Thiemann
- Faculty of Environmental Studies, York University; Toronto; ON; M3J 1P3; Canada
| | - Dag Vongraven
- Norwegian Polar Institute, Fram Centre; 9296; Tromsø; Norway
| | - Øystein Wiig
- National Centre for Biosystematics, Natural History Museum, University of Oslo; PO Box 1172; Blindern 0318 Oslo; Norway
| | - Geoffrey York
- Arctic Species Conservation, WWF Global Arctic Programme; 30 Metcalfe Street; Suite 400; Ottawa; ON K1P 5L4; Canada
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MacCracken JG, Garlich-Miller J, Snyder J, Meehan R. Bayesian belief network models for species assessments: An example with the Pacific walrus. WILDLIFE SOC B 2012. [DOI: 10.1002/wsb.229] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Vongraven D, Aars J, Amstrup S, Atkinson SN, Belikov S, Born EW, DeBruyn TD, Derocher AE, Durner G, Gill M, Lunn N, Obbard ME, Omelak J, Ovsyanikov N, Peacock E, Richardson E, Sahanatien V, Stirling I, Wiig Ø. A circumpolar monitoring framework for polar bears. URSUS 2012. [DOI: 10.2192/ursus-d-11-00026.1] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Stirling I, Derocher AE. Effects of climate warming on polar bears: a review of the evidence. GLOBAL CHANGE BIOLOGY 2012; 18:2694-706. [PMID: 24501049 DOI: 10.1111/j.1365-2486.2012.02753.x] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 04/09/2012] [Accepted: 04/09/2012] [Indexed: 05/25/2023]
Abstract
Climate warming is causing unidirectional changes to annual patterns of sea ice distribution, structure, and freeze-up. We summarize evidence that documents how loss of sea ice, the primary habitat of polar bears (Ursus maritimus), negatively affects their long-term survival. To maintain viable subpopulations, polar bears depend on sea ice as a platform from which to hunt seals for long enough each year to accumulate sufficient energy (fat) to survive periods when seals are unavailable. Less time to access to prey, because of progressively earlier breakup in spring, when newly weaned ringed seal (Pusa hispida) young are available, results in longer periods of fasting, lower body condition, decreased access to denning areas, fewer and smaller cubs, lower survival of cubs as well as bears of other age classes and, finally, subpopulation decline toward eventual extirpation. The chronology of climate-driven changes will vary between subpopulations, with quantifiable negative effects being documented first in the more southerly subpopulations, such as those in Hudson Bay or the southern Beaufort Sea. As the bears' body condition declines, more seek alternate food resources so the frequency of conflicts between bears and humans increases. In the most northerly areas, thick multiyear ice, through which little light penetrates to stimulate biological growth on the underside, will be replaced by annual ice, which facilitates greater productivity and may create habitat more favorable to polar bears over continental shelf areas in the short term. If the climate continues to warm and eliminate sea ice as predicted, polar bears will largely disappear from the southern portions of their range by mid-century. They may persist in the northern Canadian Arctic Islands and northern Greenland for the foreseeable future, but their long-term viability, with a much reduced global population size in a remnant of their former range, is uncertain.
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Affiliation(s)
- Ian Stirling
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9
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Aderhold A, Husmeier D, Lennon JJ, Beale CM, Smith VA. Hierarchical Bayesian models in ecology: Reconstructing species interaction networks from non-homogeneous species abundance data. ECOL INFORM 2012. [DOI: 10.1016/j.ecoinf.2012.05.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Gilg O, Kovacs KM, Aars J, Fort J, Gauthier G, Grémillet D, Ims RA, Meltofte H, Moreau J, Post E, Schmidt NM, Yannic G, Bollache L. Climate change and the ecology and evolution of Arctic vertebrates. Ann N Y Acad Sci 2012; 1249:166-90. [DOI: 10.1111/j.1749-6632.2011.06412.x] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Rode KD, Peacock E, Taylor M, Stirling I, Born EW, Laidre KL, Wiig Ø. A tale of two polar bear populations: ice habitat, harvest, and body condition. POPUL ECOL 2011. [DOI: 10.1007/s10144-011-0299-9] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Ledee OE, Karasov WH, Martin KJ, Meyer MW, Ribic CA, Van Deelen TR. Envisioning the future of wildlife in a changing climate: Collaborative learning for adaptation planning. WILDLIFE SOC B 2011. [DOI: 10.1002/wsb.62] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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34
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Robinson R, Smith TS, Kirschhoffer BJ, Rosa C. Polar bear (Ursus maritimus) cub mortality at a den site in northern Alaska. Polar Biol 2011. [DOI: 10.1007/s00300-011-1013-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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35
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Hunter CM, Caswell H, Runge MC, Regehr EV, Amstrup SC, Stirling I. Climate change threatens polar bear populations: a stochastic demographic analysis. Ecology 2011; 91:2883-97. [PMID: 21058549 DOI: 10.1890/09-1641.1] [Citation(s) in RCA: 171] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The polar bear (Ursus maritimus) depends on sea ice for feeding, breeding, and movement. Significant reductions in Arctic sea ice are forecast to continue because of climate warming. We evaluated the impacts of climate change on polar bears in the southern Beaufort Sea by means of a demographic analysis, combining deterministic, stochastic, environment-dependent matrix population models with forecasts of future sea ice conditions from IPCC general circulation models (GCMs). The matrix population models classified individuals by age and breeding status; mothers and dependent cubs were treated as units. Parameter estimates were obtained from a capture-recapture study conducted from 2001 to 2006. Candidate statistical models allowed vital rates to vary with time and as functions of a sea ice covariate. Model averaging was used to produce the vital rate estimates, and a parametric bootstrap procedure was used to quantify model selection and parameter estimation uncertainty. Deterministic models projected population growth in years with more extensive ice coverage (2001-2003) and population decline in years with less ice coverage (2004-2005). LTRE (life table response experiment) analysis showed that the reduction in lambda in years with low sea ice was due primarily to reduced adult female survival, and secondarily to reduced breeding. A stochastic model with two environmental states, good and poor sea ice conditions, projected a declining stochastic growth rate, log lambdas, as the frequency of poor ice years increased. The observed frequency of poor ice years since 1979 would imply log lambdas approximately - 0.01, which agrees with available (albeit crude) observations of population size. The stochastic model was linked to a set of 10 GCMs compiled by the IPCC; the models were chosen for their ability to reproduce historical observations of sea ice and were forced with "business as usual" (A1B) greenhouse gas emissions. The resulting stochastic population projections showed drastic declines in the polar bear population by the end of the 21st century. These projections were instrumental in the decision to list the polar bear as a threatened species under the U.S. Endangered Species Act.
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Affiliation(s)
- Christine M Hunter
- Department of Biology and Wildlife, Institute of Arctic Biology, University of Alaska, Fairbanks, Alaska 99775, USA.
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Kirk CM, Amstrup S, Swor R, Holcomb D, O'Hara TM. Hematology of southern Beaufort Sea polar bears (2005-2007): biomarker for an Arctic ecosystem health sentinel. ECOHEALTH 2010; 7:307-320. [PMID: 20617361 DOI: 10.1007/s10393-010-0322-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Accepted: 05/08/2010] [Indexed: 05/29/2023]
Abstract
Declines in sea-ice habitats have resulted in declining stature, productivity, and survival of polar bears in some regions. With continuing sea-ice declines, negative population effects are projected to expand throughout the polar bear's range. Precise causes of diminished polar bear life history performance are unknown, however, climate and sea-ice condition change are expected to adversely impact polar bear (Ursus maritimus) health and population dynamics. As apex predators in the Arctic, polar bears integrate the status of lower trophic levels and are therefore sentinels of ecosystem health. Arctic residents feed at the apex of the ecosystem, thus polar bears can serve as indicators of human health in the Arctic. Despite their value as indicators of ecosystem welfare, population-level health data for U.S. polar bears are lacking. We present hematological reference ranges for southern Beaufort Sea polar bears. Hematological parameters in southern Beaufort Sea polar bears varied by age, geographic location, and reproductive status. Total leukocytes, lymphocytes, monocytes, eosinophils, and serum immunoglobulin G were significantly greater in males than females. These measures were greater in nonlactating females ages ≥5, than lactating adult females ages ≥5, suggesting that females encumbered by young may be less resilient to new immune system challenges that may accompany ongoing climate change. Hematological values established here provide a necessary baseline for anticipated changes in health as arctic temperatures warm and sea-ice declines accelerate. Data suggest that females with dependent young may be most vulnerable to these changes and should therefore be a targeted cohort for monitoring in this sentinel.
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Affiliation(s)
- Cassandra M Kirk
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
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