In the summer of 2020, marine researchers from the University of Manitoba set up a time-lapse camera overlooking the Churchill River Estuary. Their goal was to study the interactions between beluga whales and marine vessels. However, what they captured was an astonishing and unprecedented sight—a group of bowhead whales, a species never previously documented in this area.
A Rare and Historic Encounter
Bowhead whales are the only baleen whales that reside in the Arctic year-round. In Canadian waters, two key populations exist: the East Canada-Western Greenland (EC-WG) population, which ranges from northern Hudson Bay to Greenland, and the Bering-Chukchi-Beaufort population, which inhabits waters from northwestern Canada to Russia.
Historically, commercial whaling between the 15th and 19th centuries significantly reduced the EC-WG population. Although numbers began to recover after commercial whaling ended in 1915, recent trends suggest a stabilization of their population.
A newly published study by Veronica Coppolaro and colleagues in Polar Biology officially documents the first recorded sighting of a bowhead whale group in the Churchill River Estuary. Based on historical data, such an occurrence is extremely rare.
The Discovery: How It Happened
During a beluga whale monitoring study, Ph.D. candidate Veronica Coppolaro and M.Sc. researcher Emma Ausen first noticed the bowheads while reviewing time-lapse photos. Initially, Ausen mistook the dark figures in an image for a floating log. However, after hearing local tour guides report sightings of a bowhead whale in the estuary, the researchers cross-referenced the dates and confirmed the presence of the species.
Apart from beluga whales, no other whale species is known to frequent the Churchill River Estuary. The estuary itself is shallow, with depths mostly under three meters—an unusual environment for bowhead whales, which can grow up to 18 meters long.
Furthermore, bowhead whales are typically solitary when found outside their usual range. “They generally do not travel in groups,” Coppolaro explains, making this sighting particularly noteworthy.
Why Were the Bowhead Whales There? Possible Explanations
To better understand this phenomenon, the researchers analyzed historical records, anecdotal accounts, and scientific literature on bowhead whale sightings along Manitoba’s coastline. Their research revealed only ten documented sightings of bowhead whales in the region since 1900—all involving solitary individuals.
Several theories may explain why this group of whales ventured into the estuary:
- Climate Change and Habitat Shifts: Rising temperatures and melting Arctic ice may be altering the whales’ migratory patterns, pushing them further south.
- Population Growth and Range Expansion: A gradual increase in the EC-WG population could be leading to a broader distribution of the species.
- Orca Predation Avoidance: Declining sea ice has resulted in more orca sightings in Hudson Bay, potentially prompting bowhead whales to seek refuge in the estuary.
- Rich Feeding Grounds: The estuary’s tidal activity creates an abundant food supply, attracting baleen and toothed whales alike.
- Molting Behavior: Similar to beluga whales, bowheads may use the estuary’s warmer, shallower waters to help shed their skin.
Another possibility is that the observed whales were a mother and calf pair, which would make this sighting even more significant.
Conservation Implications: What Comes Next?
“Since 2000, bowhead whale sightings in the estuary have increased,” Coppolaro notes. However, rising vessel traffic in the region could pose a threat to their presence in the future.
Currently, the EC-WG population is classified as a species of “Special Concern” by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). If the Churchill River Estuary becomes a recurring habitat for these whales, conservation measures—such as regulating vessel size and speed—may be required to protect them.
Coppolaro hopes this research will raise awareness about changing marine ecosystems. “When these whales appear, it’s a significant event for the local community,” Ausen adds. “It’s a reminder of the incredible wildlife in Churchill and the ever-changing dynamics of marine life.”
Further Reading and Research
Veronica L. M. Coppolaro et al., First documented sighting of a group of bowhead whales outside their typical range in Hudson Bay, Polar Biology (2025). DOI: 10.1007/s00300-025-03353-1