Research conducted by Chloe Lew, PhD student, Ocean Sciences, UC Santa Cruz, in collaboration with Alex Whiting, Environmental Program Director, Native Village of Kotzebue

Spectrograms of the ocean soundscape in Kotzebue Sound in Western Alaska’s Chukchi Sea visualize the vocalizations of various marine mammals, including bearded seals, beluga whales, and bowhead whales. The recordings used for the spectrograms were collected between 2022 and 2024 in collaboration with the Native Village of Kotzebue. The vocalizations of marine mammals are analyzed by researchers to locate species and their habitats, to study behaviors, and to learn which areas are vital to their survival—knowledge that informs marine area management. 

As the spectrograms reveal, each species has a unique vocalization style, differing in frequency, modulation, and acoustic pattern. Many marine mammals live in deep ocean waters, which are dark and turbid, making sound crucial for survival. The vocalizations of marine mammals are used for navigation, locating food, finding other animals, and avoiding predators. They are also crucial to the social and reproductive lives of marine mammals, used to advertise breeding.

Acoustic conditions and the relationships they sustain are threatened by sea ice loss caused by warming temperatures. Sea ice protects waters from large vessels; it also has a dampening effect on other environmental sounds. This function is vital given the impacts of underwater noise pollution from commercial shipping, which can drown out or interfere with the natural soundscape of the ocean—a phenomenon called acoustic masking.  

The acoustic data collected for this study is being utilized by the Native Village of Kotzebue to bolster local advocacy efforts.