Seasonal acoustic ecology of beluga and bowhead whale core-use areas in the Pacific Arctic

Abstract

The acoustic ecology of Arctic marine mammals is driven by anthropogenic, biotic, and abiotic factors each of which may influence the behavioral ecology of each species. The acoustic environment of bowhead (Balaena mysticetus) and beluga (Delphinapterus leucas) whales in three core-use regions of the Pacific Arctic was examined during the months in which both species occur in these regions. The Anadyr Strait region in winter was dominated by the signals of bowhead whales, walrus and bearded seals. In Bering Strait in late fall and winter, wind noise predominated in November but once the region was ice-covered, bowhead and walrus were the main sources of noise. Barrow Canyon in late summer and fall was the only region in which anthropogenic sources overlapped with both whale species. Overall, ambient noise levels were low in the Pacific Arctic when compared to other ocean basins in which anthropogenic noise dominates low frequencies. However, climate change-driven increases in open water are leading to rising noise levels from increased human use of the Arctic, increased storminess, and increased presence of vocal subarctic whales. These “new” sources of sound may be altering the underwater soundscape and possibly influencing the acoustic ecology of Pacific Arctic cetaceans.