Baleen whales are increasingly congregating in the Arctic Circle for feeding frenzies, a phenomenon linked to warming waters and declining sea ice, according to new research.
Scientists have observed fin whales, humpback whales, and common minke whales, species that were historically rare in coastal East Greenland, now regularly participating in mixed feeding events in the Greenland Sea. The study, published in Frontiers in Marine Science, suggests that while many species are negatively impacted by global warming, some are benefiting from these environmental shifts.
"We show that rising ocean temperatures and declining sea-ice cover have facilitated the widespread occurrence of baleen whales along the East Greenland coast, as far north as 70°N," said Professor Mads Peter Heide-Jørgensen of the Greenland Institute of Natural Resources. "This has led to regular mixed ‘feeding frenzies’ of fin whales, humpback whales, and common minke whales – species which historically were only rarely observed in coastal East Greenland."
The Arctic and North Atlantic regions, excluding a specific cold area south of Greenland, are experiencing some of the most rapid warming on Earth. Sea surface temperatures east of Greenland have risen by approximately 2°C since the 1990s, and summer sea ice extent has significantly reduced along Greenland's east coast.
To study these changes, researchers conducted systematic aerial surveys off the East Greenland coast in August 2015 and again in 2024. They supplemented this with airborne observations from the summer of 2022, testimonies from Inuit hunters between 2023 and 2025, and records from ship-based surveys dating back to 1987. Data from 15 satellite-tagged baleen whales between 2019 and 2025 were also analyzed.
A mathematical model was developed to identify patterns in the data, correlating whale occurrence with historical measurements of sea-surface temperature, salinity, and icepack concentration. This combined dataset provides a comprehensive record of baleen whale abundance changes in the Greenland Sea over the past three decades.
The findings reveal a marked increase in baleen whale activity along the East Greenland coast north of 60°N and west of 29°W between 1987 and 2024. For instance, humpback whale sightings were absent until 2006 in ship-based surveys, but increased to over 150 sightings by 2024. Similarly, minke whale sightings, initially few, became a regular occurrence after 2001, and fin whale sightings also showed a sharp rise.
In August 2025, a ship crew reported encountering exceptionally large aggregations of up to 50 baleen whales simultaneously along the coast around 69°N, north of the Arctic Circle. Aerial surveys in 2015 and 2024 documented a near-continuous distribution of all three species between 60°N and 70°N.
Researchers estimate that in the summer of 2024, approximately 4,000 humpback whales, 6,000 fin whales, and 6,000 minke whales visited the Greenland Sea. The primary reason for these visits is feeding, specifically on capelin, a cold-water fish that is a key prey species for these whales. Recent studies indicate that capelin have shifted their feeding grounds from waters north of Iceland towards the Greenland Sea since the mid-2000s, and the whales appear to have followed this prey.
The research team noted the absence of commercial capelin fisheries in the region, suggesting that human competition for this food source is unlikely in the near future. However, they concluded that East Greenland is undergoing a significant ecological regime shift. Ice-associated species like narwhals are increasingly sharing their habitat with, or being displaced by, temperate baleen whales that typically avoid icy waters. This change in species composition underscores how climate-driven shifts are reorganizing the East Greenland marine ecosystem, with potentially lasting consequences.