Minto Inlet 2019 Passive Acoustic Monitoring Data

We collected seven months of passive acoustic data from February to September 2019 in Minto Inlet, Northwest Territories, Canada, using an acoustic recorder (SoundTrap ST500) attached to a bottom-mounted oceanographic mooring. The acoustic recorder recorded five minutes of audio every hour. We processed the acoustic data to examine the seasonal presence of four species of marine mammals and unidentified fish species, examine drivers of underwater sound levels, and quantify underwater noise from vessel traffic. This dataset includes hourly sound pressure levels (dB re 1 uPa) in the 20-1000 Hz, 1-10 kHz, and 10-24 kHz bands, and daily bioacoustics results, including the daily presence and daily proportion of files examined with bowhead whale (Balaena mysticetus), beluga whale (Delphinapterus leucas), ringed seal (Pusa hispida), bearded seal (Erignathus barbatus), and fish (likely Arctic cod, Boreogadus saida) vocalizations. Bearded seals were vocally present from mid-March to early July. Ringed seals were present in every month. Beluga whales were present from early July until September. Bowhead whales were detected from April to August, and fish were detected from February to July. Underwater sound levels were highest during the open water period (July - September) and lower during the ice covered period (February - June). The only vessel detected was the research vessel that recovered the acoustic recorder, therefore levels of anthropogenic noise were quite low. Underwater sound levels were much lower in Minto Inlet compared to other areas in the region, and it appears to be an important site for many marine mammals where forage fish species, primarily Arctic cod, are abundant at depth. These results are in line with Minto Inlet being identified as an important area by the community of Ulukhaktok. This area appears to be currently facing very low anthropogenic impacts, but further monitoring is required to determine if any management measures are necessary to maintain the low levels of anthropogenic pressure.