Arctic Biodiversity Climate change Whales and seals

Ice-generated sound and its potential masking effects on bearded seal vocalizations in the western Canadian Arctic

Shajahan, N., Halliday, W., Hart, C., Abeywardhana, R., Frazao, F., Barclay, S., Niemi, A. & Insley, S.

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Key points

• The Arctic is changing rapidly due to climate change, and changing sea ice conditions are leading to a shift in the underwater soundscape.
• Bearded seals actively use sound for advertisement during the mating season, and increased noise caused by ice may impede their ability to communicate.
• We detected and measured the underwater noise caused by ice in the western Canadian Arctic, and assessed how bearded seal vocalizations changed in response to this noise.
• Ice noise was very prevalent in the data, sometimes contributing as much as 40 dB in sound exposure level. Bearded seals responded to this noise by reducing the total time that they were producing sounds.
• These results highlight that a shifting Arctic soundscape can impact bearded seals, even though this noise is caused by ice, which is a natural source of sound. These results also have implications for how bearded seals may respond to human-caused noise if it occurs during their mating season.

Abstract

Quantifying acoustic masking due to noise sources is an important part of marine mammal conservation. This study examines the relative masking of bearded seal vocalizations by ice-generated sounds, using passive acoustic data collected from the western Canadian Arctic. Broadband ice sound events and bearded seal calls were extracted from acoustic recordings, and masking potential was estimated using the listening space reduction (LSR) metric, based on the bearded seal audiogram and propagation loss in an ice-covered environment. Results indicate that bearded seal vocal activity decreased with increasing LSR and ambient sound exposure levels, suggesting a potential behavioural adjustment to elevated ice sound levels that warrants further investigation.

Recommended citation

Shajahan, N., Halliday, W., Hart, C., Abeywardhana, R., Frazao, F., Barclay, S., Niemi, A. & Insley, S. (2025). Ice-generated sound and its potential masking effects on bearded seal vocalizations in the western Canadian Arctic. JASA Express Letters. https://doi.org/10.1121/10.0039964