UC San Diego

Bearded seals (Erignathus barbatus) and walrus (Odobenus rosmarus) are Arctic species that rely on sea ice for essential life functions such as mating, pupping, and foraging. Inuit have extensive knowledge of these animals in the waters of Nunatsiavut, Canada, but there is a paucity of information regarding their seasonal distribution and behavior in the northernmost areas of the region, particularly off the Torngat Area of Interest (TAOI). Both species produce distinctive underwater sounds that are readily detected and identified, making them ideal for studies using passive acoustic monitoring (PAM). This study provides observations of the seasonal acoustic presence and behavior of walrus and bearded seals using underwater recordings collected 20 km east of Saglek Bay in the TAOI, from October 2022 to September 2023. Analyses of acoustic data were conducted to detect bearded seal and walrus vocalizations at a temporal resolution of one-hour. Relationships between acoustic presence and environmental factors, such as sea ice concentration and time of day are examined. Bearded seal trills associated with male mating displays were detected from November through June, increasing with sea ice formation and continuing weeks after sea ice retreat and open water. Walrus knocks were detected primarily during ice cover from mid-January to early May, with vocal activity also peaking during 100% ice-covered period. Bearded seals exhibited diel patterns in vocalization with significantly fewer vocalizations detected during daylight hours during November to March. These findings contribute to a baseline understanding of the acoustic presence and behavior of walruses and bearded seals in the TAOI and provide valuable insights for marine spatial planning in the waters of Nunatsiavut.