Identifying Areas of Potential Risk Based on Future Genetic Adaptability in Three Arctic Whale Species

AbstractAssessments of adaptive genetic diversity across multiple species are necessary for improving the efficacy of regional management in the context of climate change. Rapid loss of sea ice and rising water temperatures in the Arctic Ocean threaten marine species survival. Beluga whales (Delphinapterus leucas), narwhals (Monodon monoceros), and bowhead whales (Balaena mysticetus) are endemic Arctic whales adapted to cold-water conditions that depend on sea ice for foraging and protection from predators. We forecasted the degree of genetic mismatch these species may experience under future climate change scenarios by the next century using Canadian Arctic genomic samples in genotype-environment association models. When examining local adaptation to different environmental variables, we found that ice thickness was the strongest environmental predictor for bowhead whales, while temperature and chlorophyll concentration, an indicator of primary productivity, carried greater weight for beluga whales and narwhals. Notably, a higher degree of genetic mismatch for all three species was observed in the Canadian High Arctic and Hudson Bay, suggesting that whales in these areas may exhibit the greatest maladaptive risk to climate change. This multispecies assessment of Arctic-adapted whales provides insight into the spatial congruence between three genomic datasets and context for designing ecosystem-wide evolutionarily enlightened conservation strategies.