Singers of the high Arctic; Seasonal acoustic presence of bowhead whales (Balaena mysticetus) around Svalbard, Norway

The bowhead whale (Balaena mysticetus) is an Arctic endemic cetacean that spends its entire life in Arctic waters, living in tight association with sea ice. In this study, passive acoustic data recorded between 2017 and 2022 at six locations around the Svalbard Archipelago, Norway, were analysed for the seasonal and spatial vocal occurrence of this endangered bowhead whale stock, using a combination of Long-Term Spectral Averages and visual/auditory verification. The results were subsequently correlated to seasonal patterns in environmental conditions. Bowhead whale vocalizations were detected at all study sites, but there was significant variation between locations and years in acoustic presence and singing behaviour. Consistent, high detection rates of singing west and east of Svalbard suggest that these sites serve as key areas for overwintering and breeding. The lower and fluctuating detection rates north of Svalbard suggest that this area serves as a movement corridor between regions. Significant positive correlations between bowhead whale acoustic activity and high sea ice concentrations emphasizes their ice-affiliated nature. This study provides novel information on the distribution and habitat use of bowhead whales in the Svalbard area and raises concern for the future of this population, in an Arctic that is experiencing rapid sea ice habitat loss.