The Arctic is changing rapidly, leading to changes in the environment and increased human activities. It is crucial to monitor the distribution of different animal species as these changes occur. Arctic marine mammals are difficult to monitor using traditional methods because they live in remote areas around sea ice.
Passive acoustic monitoring (PAM) is a method that provides long-term records of species that make sounds, and is an excellent tool for monitoring marine mammals in remote locations. We used PAM to monitor marine mammals near Sachs Harbour, Northwest Territories, over 15 months. We examined how the presence of different marine mammals changed through time and with patterns of sea ice. We heard both bowhead and beluga whales from late April through August (belugas) and October (bowheads). Both whales migrated into the region as ice broke up in the spring, and migrated out before ice formed in the autumn.
We heard bearded seals from October through June, and heard them 24 hours a day from April through June. Bearded seals generally only called when sea ice was present. We heard ringed seals occasionally in all months, but they were generally quiet. Since the ice-free season is supposed to lengthen in the future because of climate change, with ice breaking up earlier and forming later in the year, there may be large shifts in migration timing for whales and timing of calling for bearded seals. It will be important to continue monitoring these regions to determine how sea ice loss affects these species.