Upriver sightings of beluga whales ( Delphinapterus leucas ) follow storm surges and high water in the Mackenzie Delta, Northwest Territories, Canada

Each summer, Eastern Beaufort Sea beluga whales (Delphinapterus leucas (Pallas, 1776)) form a large congregation in the Tarium Niryutait Marine Protected Area (TNMPA) in the Mackenzie River estuary, a behaviour thought to be linked to warm, freshwater conditions. In 2018, >50 belugas were obs...

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Bibliographic Details
Published in:Arctic Science
Main Authors: Scharffenberg, Kevin C., MacPhee, Shannon A., Loseto, Lisa L.
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 2021
Subjects:
General Earth and Planetary Sciences
General Agricultural and Biological Sciences
General Environmental Science
Arctic
Northwest Territories
Mackenzie River
Canada
Mackenzie Delta
Aklavik
Beaufort Sea
Beluga
Beluga*
Delphinapterus leucas
Mackenzie river
Online Access:http://dx.doi.org/10.1139/as-2020-0010
https://cdnsciencepub.com/doi/full-xml/10.1139/as-2020-0010
https://cdnsciencepub.com/doi/pdf/10.1139/as-2020-0010
Description
Summary:Each summer, Eastern Beaufort Sea beluga whales (Delphinapterus leucas (Pallas, 1776)) form a large congregation in the Tarium Niryutait Marine Protected Area (TNMPA) in the Mackenzie River estuary, a behaviour thought to be linked to warm, freshwater conditions. In 2018, >50 belugas were observed upriver near Aklavik in the Mackenzie River Delta. Community members noted that this upriver occurrence of belugas was unusual and suggested that wind-driven high water levels in the Mackenzie River were a primary driver. We investigated this explanation by searching past communications and reports for documentation of beluga sightings upriver and identifying storm surges and water-level changes at six hydrometric stations in the Mackenzie River Delta. We found three previous occurrences of belugas upriver dating back to 2000, all of which followed prominent surges in river level attributable to coastal storms. Although acknowledging a small sample size, we suggest that upriver occurrences of beluga whales warrant further investigation through extension of the TNMPA beluga monitoring program. As climate-driven changes cause more frequent and intense Arctic storm surges, we expect storm events to increasingly overlap with the annual summer beluga congregation. This may cause upriver movements to become more common, and population-level implications are not known.

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