Trends in wind, rain, and ships measured from ambient sound in the Bering Sea

Abstract

Advances in low-cost passive acoustic technology are providing long term, ambient sound time series from which to better understand the complex interactions between marine life, the environment, and mankind in remote, seasonally ice covered areas such as the Bering Sea. Remotely deployed Passive Acoustic Listeners (PALs) operate according to an adaptive sampling protocol as opposed to recording continuously, thus enabling data collection for a full year at a sampling rate of 100 kHz. Adaptive sub-sampling overcomes hardware and power limitations by reducing the amount of data acquired, while maintaining a high probability of detection and classification of targeted signals. Source contributions to the overall soundscape vary in space and time, and are highly dependent on temporal, geographic, and oceanographic factors. The differences observed in the acoustic record over time and between locations reflect changes in both physical and biological dynamics. This study focused only on the changing patterns of seasonal sea ice dynamics, storm frequency and intensity, and human activity in the acoustic record. As polar conditions continue to change due to reductions in sea ice, warming ocean temperatures, and increases in human use, passive acoustic monitoring will be a valuable tool to identify and track weather dynamics.