North Pacific Ocean sound levels 2018–2022: COVID-19 pandemic impacts on anthropogenic noise

Global economic shifts stemming from sociocultural events drive ocean sound levels. During the COVID-19 pandemic, human health guidelines and manufacturing restrictions led to a global decrease of container ship traffic. Here we examine passive acoustic data to describe resulting impacts to ambient sound levels at four sites in the northeast Pacific and Arctic: Ocean Station Papa, the U.S. Olympic Coast, Axial Seamount, and the Beaufort Sea. We analyzed key frequencies for ship noise to compare pre-, during-, and post-pandemic periods spanning 2018–2022. During spring-summer 2020 sound levels decreased by 1–2 dB (~10–30%) from 2018 to 2019 levels, and returned to pre-pandemic norms by late 2020–2021. From 2021 to 2023, sound levels varied across sites; Ocean Station Papa showed sustained lower levels due to reduced nearby ship traffic, while Olympic Coast saw similar or lower levels despite increased traffic. Compared to previous economic events, pandemic-related sound reductions were less pronounced, likely reflecting different sociocultural contexts.