The underwater acoustic environment used by beluga whales in the Mackenzie River estuary
The underwater soundscape is a critical component of marine mammal habitat, as marine mammals such as beluga use sounds for many aspects of their lives, including for communication and hunting. Ship traffic is increasing throughout the Arctic and may impact marine animals, such as beluga whales, by causing underwater noise that changes the soundscape.
The Tarium Niryutait Marine Protected Area (TNMPA) in the western Canadian Arctic represents important habitat for beluga whales, and understanding the influences of both natural and human activities on underwater sound levels is an important aspect of conservation planning and understanding the influence of underwater noise on belugas within the TNMPA.
Read this open access paper on the Arctic Science website.
We recorded underwater acoustic data at multiple sites within the TNMPA each summer between 2015 and 2018. We measured underwater sound levels in all of the acoustic data, and then used statistical models to examine the influence of environmental variables (wind speed, water current, wave height), beluga vocalizations, and passing ships on underwater sound levels.
Click here to listen to wave sounds and beluga whistles and calls
Wind speed and associated changes in wave height were very important drivers of natural underwater sound levels in low (200 Hz to 1 kHz) and medium (1 to 10 kHz) frequency bands. Beluga whale vocalizations caused large increases to underwater sound levels in the high frequency band (10 to 48 kHz).
Boat noise also increased underwater sound levels, particularly in the low and medium frequency bands, although only for relatively short periods of time. Boat noise was detected in 0 to 5.2% of the acoustic data collected in 2017. Acoustic data should continue to be collected at these sites into the future so that underwater sound levels, and in particular, the influence of boat noise on the soundscape can be tracked as ship traffic increases in the region.
Read the paper — The summer soundscape of a shallow-water estuary used by beluga whales in the western Canadian Arctic by W.D. Halliday, K. Scharffenberg, D. Whalen, S. MacPhee, L.L. Loseto, and S.J. Insley.
