Four centuries of commercial whaling eroded 11,000 years of population stability in bowhead whales.

Abstract

Bowhead whales were heavily exploited during commercial whaling between the 16th and 20th centuries. Current and near-future climate warming poses a new threat. Assessing bowhead vulnerability to climatic change remains challenging due to insufficient knowledge regarding responses to past climates and pre-whaling population dynamics. We integrate paleogenomics and stable isotopes (δ¹³C and δ¹⁵N) from 206 bowhead fossils from the Atlantic Arctic with paleoclimate and ecological modeling based on 823 radiocarbon-dated fossils, including 140 from this study. We find long-term resilience of bowheads to Holocene environmental perturbations, with no detectable changes in genetic diversity or population structure. Simulated commercial-whaling-driven genetic and fitness changes indicate that population subdivision and loss of genetic diversity are unlikely to be fully realized, despite nearly a century since whaling ceased. Furthermore, even in simulated complete population recovery scenarios, overall fitness did not return to pre-whaling levels, potentially compromising the future resilience of bowhead whales.