Changes in sea-ice dynamics are affecting polar bears Ursus maritimus across their circumpolar range, which highlights the importance of periodic demographic assessments to inform management and conservation. We used genetic mark-recapture-recovery to derive estimates of abundance and survival for the Baffin Bay (BB) polar bear subpopulation — the first time this method has been used successfully for this species. Genetic data from tissue samples we collected via biopsy darting were combined with historical physical capture and harvest recovery data. The combined data set consisted of 1410 genetic samples (2011–2013), 914 physical captures (1993–1995, 1997), and 234 harvest returns of marked bears (1993–2013). The estimate of mean subpopulation abundance was 2826 (95% CI = 2284–3367) in 2012–2013. Estimates of annual survival (mean ± SE) were 0.90 ± 0.05 and 0.78 ± 0.06 for females and males age ≥2 yr, respectively. The proportion of total mortality of adult females and males that was attributed to legal harvest was 0.16 ± 0.05 and 0.26 ± 0.06, respectively. Remote sensing sea-ice data, telemetry data, and spatial distribution of onshore sampling indicated that polar bears were more likely to use offshore sea-ice habitat during the 1990s sampling period compared to the 2010s. Furthermore, in the 1990s, sampling of deep fjords and inland areas was limited, and no offshore sampling occurred in either time period, which precluded comparisons of abundance between the 1993–1997 and 2011–2013 study periods. Our findings demonstrate that genetic sampling can be a practical method for demographic assessment of polar bears over large spatial and temporal scales.
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Acknowledgements. We dedicate this paper to the memory of our dear colleague and co-author Markus Dyck, a polar bear biologist who was tragically killed in a helicopter accident in April 2021 during a polar bear survey in Lancaster Sound, Canada. Markus flew over 300 hours on Baffin Island collecting genetic biopsies from polar bears for this and other studies of the Baffin Bay subpopulation. He provided important contributions to the work of the Scientific Working Group, resulting in advice to the Canada−Greenland Joint Commission on Polar Bear on sustainable use of Baffin Bay and Kane Basin polar bears (SWG 2016). Markus was both a friend and colleague whose dedication to the conservation of polar bears will be long remembered. He will be greatly missed by us all. We thank M. Akeeagok, D. Andriashek, A. Apak, I. Egede, C. Elverum, P. Frame, B. J. Hainnu, P. Hegelund, J. Jaypoody, M. Jensen, J. Kalliktee, R. Kautak, J. Kigutak, B. Koonoo, J. Kooneloosie, B. Koonoo, G. Koonoo, J. Kruse, K. K. Kruse, J. Kuksiak, R. Kullualik, J. Neely, J. Noble Jr., T. Petersen, A. J. Pitseolak, Qaernaq Nielsen, Timothæus Petersen, T. Ross, V. Sahanatien, H. C. Schmidt, G. Szor, and M. Therkelsen for assistance with field data collection. G. C. White reviewed our mark−recapture modeling approach and interpretations of the analysis. Benjamin Cohen assisted with maps. We thank pilots Sebastian Holst and Geir Akse from Air Greenland. Permits and authorizations to undertake this work were issued by: Danish Transport and Aviation Authority, Environment Canada National Wildlife Areas research permit (Nun-NWA-13-07), Greenland Aviation Authority, Greenland Department of Environment (Nuuk), Greenland Department of Fisheries, Hunting and Agriculture (DFHA), Greenland Department of Health, Greenland Home Rule Government, Government of Nunavut Wildlife Research Permits (2011-041, 2012-010, 2012-015, 2013-011, 2013-0292014-007), Nunavut Impact Review Board screening (13YN017 — exemption from environmental assessment screening), Parks Canada Research and Collection Permit (ANP-2011-8533), Qikiqtani Inuit Association (authorization Q13X009 — permission to access Inuit-owned lands). The Animal Use and Care Committee at the University of Minnesota (Protocol number 1403-31404A), and the relevant Greenland wildlife, environment, and veterinarian authorities approved the methods used in our research (the Greenland Government’s Department of Fishery, Hunting and Agriculture protocol number: 2012-060324. Document number: 807844). Financial, logistical, and in-kind support were provided by Air Greenland, Applied Physics Laboratory (University of Washington), Avannaa Resources Inc. (Copenhagen), Niels Berthelsen (Upenavik), Bureau of Mineral and Petroleum (Nuuk), Canada Department of National Defense, Environment and Climate Change Canada, Environmental Protection Agency (Ministry of Environment and Food of Denmark) -DANCEA Programme, Government of Nunavut, Greenland Department of Fisheries, Hunting and Agriculture (DFHA), Greenland Institute of Natural Resources, Greenland Pharmaceutical Authority (Nuuk), the Hospital in Upernavik — Peqqik, KNAPK (Greenland Hunters and Fishermen Organization), Kullorsuaq School, Lasø ApS (Upernavik), Mitteqarfik airports in Qaarsut and Upernavik, the Mittimatalik Hunters and Trappers Organization, the National Aeronautical and Space Agency (NASA) Development and Testing of Potential Indicators for the National Climate Assessment program (grant NNX13AN28G), NASA Climate and Biological Response (grant NNX11A063G), the Namautaq Hunters and Trappers Organization, the Nativak Hunters and Trap- pers Organization, Nunavut Wildlife Management Board, Parks Canada Agency, Polar Continental Shelf Project, Polar Science Center (University of Washington), Qaanaap Kom-munia, Qikiqtaaluk Corporation, Quantum Murray LP, School of Aquatic and Fishery Sciences (University of Washington), Thule Air Force Base (Base Commander, US Air Force and Danish Liaison Officer, Danish Navy), Universal Helicopters, University of Oslo, Upernavik Seafood, Uummannaq Sundhedscenter — Peqqik, Vetlesen Foundation, and World Wildlife Fund. Two reviewers improved the manuscript.
© The authors 2021. Open Access under Creative Commons by Attribution Licence. Use, distribution and reproduction are unrestricted. Authors and original publication must be credited.
- Baffin Bay
- Genetic mark-recapture-recovery
- Polar bear
- Ursus maritimus