Late Pleistocene and Holocene occurrence of bowhead whales (Balaena mysticetus) along the coasts of Norway

The present study aims at an improved understanding of the origin and distribution of bowhead whales (Balaena mysticetus) along the Norwegian coast during Late Pleistocene/Holocene. We used ancient DNA methodology to identify the species of 52 large whale bones found along the coast of the Norwegian mainland. Nucleotide sequence variation of the mitochondrial control region (CR) was determined and subsequently screened against GenBank for species identification. Thirty-one bones (60%) yielded informative nucleotide sequences for the targeted mitochondrial CR. Of these, 24 matched with bowhead whale. Two additional bones were identified to bowhead whale based on morphology. Thus, 26 of the bones were identified to be from bowhead whales. The ages of the bowhead bones ranged from 15,084cal years BP to present, with most bones older than 10,000cal years BP. We suggest that our results show a change in distribution of bowhead whales from the very southern Norwegian Sea in the Heinrich Stadial 1 (19,000-14,600years BP) to a distribution reaching 64 degrees N in the BOlling-AllerOd Interstadial (14,600-12,900years BP), while the species probably was absent along the Norwegian coast during the cold Younger Dryas (12,900-11,700years BP). During the Holocene, the species most likely has had only a northern distribution. The present study does not contribute new knowledge to solve the question if North Atlantic bowhead whales originated from a refugium in the southeast Atlantic during the Last Glacial Maximum or originate from the Pacific.