Understanding the relationship between marine mammals and their environment in the Bering Sea.

Abstract

Passive aquatic listening (PAL) instruments were deployed on sub‐surface moorings along the 70‐m isobath of the Bering Sea shelf. 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. Year long time series indicate that marine mammal vocalizations dominate the regional soundscape in the late winter/early spring time period. Species acoustically identified include North Pacific right, killer, beluga, humpback, fin, and bowhead whales, plus bearded seal and walrus. Synoptic measurements of prey abundance with three‐frequency active acoustic sensors, ice cover, and physical oceanographic processes provide vital information for understanding the relationship between marine mammals and their continually changing environment. These data represent important baseline measurements of environmental variability, marine mammal species richness, and temporal distribution of animals in an area of the world that is rapidly transforming due to global climate change. [Research supported by ONR.]