Identifying Beluga Distribution in the Tarium Niryutait Marine Protected Area using Passive Acoustic Monitoring

Abstract

Arctic estuaries are important summer habitats for beluga whales (Delphinapterus leucus) and many populations form seasonal aggregations at these locations. This study presents the first comprehensive long-term analysis of beluga distribution within the Mackenzie Estuary since the 1970s and 1980s. Leveraging eight years of passive acoustic monitoring data, we assess the consistency of beluga habitat use over time and space by comparing vocalization rates at select monitoring locations annually and providing a benchmark upon which to monitor ecological change in the Tarium Niryutait Marine Protected Area. Findings reveal temporal consistency in beluga distribution and demonstrate site fidelity in alignment with known habitat hotspots; however, results also highlight a degree of inter-annual variability in beluga habitat use, indicating that belugas may alter their distribution in response to environmental and anthropogenic factors. Additionally, we develop a suite of simple univariate metrics to define the timing of belugas movements to and from the estuary. Our data support previous aerial survey findings and Inuvialuit Knowledge that beluga entry into the estuary is closely tied to the timing of ice breakup. Characteristics of the annual beluga aggregation should be considered in the relation to ice breakup date when interpreting indicators of change in habitat use.