ABSTRACT
The narrow Bering Strait provides the only gateway between the Pacific Ocean and the Arctic, bringing migrating marine mammals in close proximity to ships transiting the strait. We characterized ship activity in the Bering Strait during the open-water season (July-November) for 2013-2015 and quantified the impact of ship noise on third-octave sound levels (TOLs) for bands used by baleen whales (25-1000 Hz). Peak ship activity occurred in July-September with the greatest overlap in ship noise and whale vocalizations observed in October. Ships elevated sound levels by â¼4 dB on average for all TOL bands combined, and 250-Hz TOLs exceeding 100 dB re 1 µPa were recorded from two large vessels over 11 km away from the hydrophones. Our results show that ship noise has the potential to impact baleen whales in the Bering Strait and serve as a baseline for measuring future changes in ship activity in the region.