Passive acoustic monitoring to identify drivers of beluga whale habitat use in the Mackenzie Estuary

Abstract

Understanding drivers of habitat use of mobile species is critical for understanding the impacts of climate change and formulating management plans. Eastern Beaufort Sea (EBS) beluga whales (Delphinapterus leucas), an important subsistence food source for Inuvialuit, are known to form large aggregations in the Mackenzie Estuary each summer; however, environmental drivers of this habitat use are not understood. Passive acoustic monitoring was used to record beluga presence during this aggregation at key locations in the Mackenzie Estuary, while simultaneously recording environmental and oceanographic data. Belugas moved further into the estuary during cold oceanic influxes and did not use locations which typically see high use during high-speed winds. In an extreme case, a large storm prevented belugas from using the area for five days and negatively affected the subsistence beluga hunt. This information can inform decisions by northern communities and policy makers, aiding in management of the EBS beluga population.