Abstract 993 – Assessing the risk of climate maladaptation for Canadian polar bears

Ruth Rivkin, Evan Richardson, Colin Garroway

The Arctic is warming four times faster than the rest of the world, threatening the persistence
of many Arctic species. It is uncertain if Arctic wildlife will have sufficient time to adapt to such
rapidly warming environments. We used genetic forecasting to measure the risk of
maladaptation to warming temperatures and sea ice loss in polar bears (Ursus maritimus)
sampled across the Canadian Arctic. We found evidence for local adaptation to sea ice
conditions and temperature. Forecasting of genome-environment mismatches for predicted
climate scenarios suggested that polar bears in the Canadian high Arctic had the greatest risk of
becoming maladapted to climate warming. While Canadian high Arctic bears may be the most
likely to become maladapted, all polar bears face potentially negative outcomes to climate
change. Given the importance of the sea ice habitat to polar bears, we expect that
maladaptation to future warming is already widespread across Canada.