Polar Bears in Canada’s High Arctic Are the Most Vulnerable to Climate Change, According to New Genetic Analysis

Newswise — Bozeman, Montana – August 7, 2024 – Researchers from leading institutions including Polar Bears International, Environment and Climate Change Canada, the San Diego Zoo Wildlife Alliance, the University of Manitoba, and MacEwan University have analyzed all of Canada’s polar bear populations and found that the most northern polar bears, those in Canada’s High Arctic, are less likely to be able to adapt to a rapidly warming Arctic. Published today in Ecology Letters, the report “Assessing the risk of climate maladaptation for Canadian polar bears” includes a map with hotspots of polar bear vulnerability and resilience across Canada, home to two-thirds of the world’s polar bears. With the Arctic warming up to four times faster than the rest of the planet, and polar bears reliant on sea ice to reach their seal prey, the authors find that many polar bears are genetically unsuited for future warming. This cutting-edge research represents a breakthrough in wildlife conservation technology, as pinpointing polar bears’ vulnerability will help guide conservation and management efforts. 

“This research is a first look at the genetics behind the vulnerability of polar bears in warming climates, and we found that while polar bears in the high Arctic face the most challenges to climate change, those at lower latitudes may be more robust to continued warming,” says lead author Dr. Ruth Rivkin, postdoctoral research fellow with Polar Bears International, University of Manitoba, and the San Diego Zoo Wildlife Alliance, adding “Our work analyzing the adaptive potential of polar bears is crucial, as it will continue to inform conservation efforts of polar bears that are most sensitive to climate change, and offers glimmers of hope in understanding which polar bears may be more resilient.”  

Key takeaways:

• High Arctic (>68 °N) polar bears (including parts of northern Nunavut and the Northwest Territories): These subpopulations have lower genetic diversity, which reduces their potential to adapt to climate change.
• The subpopulations with the largest genetic mismatch to climate change are Norwegian Bay, and M’Clintock Channel
• Low Arctic (55-68 °N) and sub-Arctic (<55 °N) polar bears (based in Ontario and Manitoba – including Churchill, Canada, the polar bear capital of the world): While polar bear populations in the Hudson Bay area have significantly declined, for example Western Hudson Bay’s polar bears decreased 27% between 2016-2021, they may be more genetically suited to climate change thanks to their extensive exposure to warm temperatures – whereas High Arctic bears haven’t experienced the same conditions. This will require further research, as will questions surrounding whether these polar bears can adapt quickly enough to match the rapid pace of Arctic warming. 
• The more genetically resilient subpopulations are Southern Hudson Bay, Western Hudson Bay, Foxe Basin, and Davis Strait
• The researchers found five genetic clusters of polar bears. One cluster includes three subpopulations within Hudson Bay (Southern Hudson Bay, Western Hudson Bay, and Fox Basin), suggesting that the bears are moving around Hudson Bay and encountering each other. 

“Our past emissions have committed the planet to ongoing warming in coming centuries. The extent to which populations might respond adaptively to warming is an open and important question for conserving biodiversity,” notes Dr. Colin Garroway, co-author and Associate Professor at the University of Manitoba, adding, “Forecasting where environments will cause the most evolutionary pressure for multiple warming scenarios will help guide management and understand ecological change in the Arctic.”

“Climate change is putting enormous pressure on species across the globe, perhaps nowhere more so than in the Arctic,” says Dr. Aryn Wilder, co-author and Scientist in Conservation Genetics at the San Diego Zoo Wildlife Alliance, “Genomic approaches like these are becoming increasingly important for identifying populations that may need conservation intervention, such as additional protections or genetic rescue, to ease pressure and facilitate adaptation to their changing environment. 

This study uses genetic data and machine learning to predict how polar bears will need to evolve under climate change, offering a future look to inform conservation, management, and policy-making organizations. The study looked at 13 of the world’s 20 polar bear subpopulations, analyzing 411 samples in total. Researchers used the 8K genotyping chip, called the Ursus maritimus V2 SNP chip, which they developed to identify hybrids (results were published in a June 2024 paper) and maladaptation to climate change. The genetic tool reads the polar bear samples in a lab, allowing rapid and reliable genome analysis. The researchers analyzed the environmental factors of sea ice thickness, sea ice cover, and temperature across four different climate forecasting models and predicted polar bear genetic changes to map their resilience and vulnerability to future climate change across the Canadian Arctic. 

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About Polar Bears International

Polar Bears International’s mission is to conserve polar bears and the sea ice they depend on. We also work to inspire people to care about the Arctic, the threats to its future, and the connection between this fragile ecosystem and our global climate. Polar Bears International is the only nonprofit organization dedicated solely to wild polar bears and Arctic sea ice, and its staff includes scientists who study wild polar bears. The organization is a recognized leader in polar bear conservation. For more information, visit www.polarbearsinternational.org.

About Environment and Climate Change Canada

ECCC is the lead federal department for a wide range of environmental issues, including taking action on clean growth and climate change. The Department is also engaged in activities aimed at preventing and managing pollution, conserving nature, and predicting weather and environmental conditions. 

About MacEwan University

Founded in 1971, MacEwan University inspires its students with a powerful combination of academic excellence and personal learning experiences. Offering more than 90 programs including undergraduate degrees, applied degrees, diplomas, certificates, continuing education and corporate training, the university provides a transformative education in a creative, collaborative and supportive learning environment where creativity and innovation thrive. Located in Edmonton, Alberta Canada, MacEwan University offers a unique student experience that opens up diverse pathways for achievement and growth.

About the University of Manitoba 

The University of Manitoba is recognized as Western Canada's first university, with more than 29,000 students, 5,000 academic staff, 3,900 support staff and more than 188,000 alumni. It is part of the U15, ranking among Canada’s top research-intensive universities and is Manitoba’s only medical-doctoral post-secondary institution. The University provides exceptional liberal arts, science and professional programs of study, inspiring undergraduate and post-graduate students to positively impact their communities as globally engaged citizens. UM campuses are located on the original lands of Anishinaabeg, Ininiwak, Anisininewuk, Dakota Oyate and Dene, and on the National Homeland of the Red River Métis. We respect the Treaties that were made on these territories, we acknowledge the harms and mistakes of the past, and we dedicate ourselves to move forward in partnership with Indigenous communities in a spirit of Reconciliation and collaboration. For more information, please visit umanitoba.ca. 

About San Diego Zoo Wildlife Alliance

San Diego Zoo Wildlife Alliance, a nonprofit conservation leader, inspires passion for nature and collaboration for a healthier world. The Alliance supports innovative conservation science through global partnerships. Through wildlife care, science expertise and collaboration, more than 44 endangered species have been reintroduced to native habitats. Annually, the Alliance reaches over 1 billion people, in person at the San Diego Zoo and San Diego Zoo Safari Park, and virtually in 150 countries through media channels, including San Diego Zoo Wildlife Explorers television programming in children’s hospitals in 14 countries. Wildlife Allies—members, donors and guests—make success possible.