Whales at 70 north: East Greenland's food web is being rebuilt in one career's span
A new Frontiers in Marine Science study documents fin, humpback and minke whales feeding in numbers along a coast where they were once rare. The consumption estimate is the part managers should read.
The Scientist · Science desk
What happened
- A study in Frontiers in Marine Science reports 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 degrees N, according to Professor Mads Peter Heide-Jorgensen of the Greenland Institute of Natural Resources.
- The change has led to regular mixed feeding frenzies of fin whales, humpback whales and common minke whales, species that historically were only rarely observed in coastal East Greenland.
- Heide-Jorgensen and colleagues in Greenland, Denmark and Iceland documented the findings in a study in Frontiers in Marine Science.
- The authors conducted the first systematic aircraft survey of baleen whales up to 50 km off the East Greenland coast in August 2015 and 2024, added airborne observations from summer 2022, testimony from Inuit hunters between 2023 and 2025, records from ships in North Atlantic Sighting Surveys since 1987, and tracks from 15 satellite-tagged baleen whales collected between 2019 and 2025, then built a mathematical model using historical sea surface temperature, salinity and ice pack concentration.
- Between 1987 and 2024 there was a marked change in the occurrence of baleen whales along the East Greenland coast north of 60 degrees N and west of 29 degrees W.
Why it matters
Researchers in Greenland, Denmark and Iceland report that fin, humpback and common minke whales are now feeding regularly along the East Greenland coast as far north as 70 degrees N, forming mixed aggregations in a region where all three were historically rare [1][2][3]. The relevant number is not the whales but their appetite: during a roughly four-month stay the animals may consume about 1.1 million tons of prey, an amount the authors say could reshape the regional food web [13].
That works out to on the order of 9,000 tons of fish and krill a day [22]. It is being removed from a system that, until recently, was not part of the temperate North Atlantic feeding circuit at all.
The evidence base is unusually broad for a wildlife claim. The team flew the first systematic aircraft surveys up to 50 km offshore in August 2015 and 2024, added airborne observations from summer 2022, testimony from Inuit hunters collected between 2023 and 2025, ship records from North Atlantic Sighting Surveys going back to 1987, and tracks from 15 satellite-tagged whales between 2019 and 2025, then modelled the records against sea surface temperature, salinity and ice concentration [4]. Sightings rose as water warmed and summer ice retreated [28].
The ship-survey series is the clearest signal. No humpback was recorded in the area until 2006; there were seven in 2007, 26 in 2015 and more than 150 in 2024 [6], a more than twentyfold increase across 17 years [24]. Minke encounters were few until 1995 and then ran at 10 to 20 a year after 2001 [7]; fin whale sightings rose sharply across the same period [8]. In August 2025 a ship crew reported up to 50 baleen whales together near 69 degrees N [9], and the 2015 and 2024 flights found an almost continuous distribution of all three species between 60 and 70 degrees N [10].
The mechanism is prey, not temperature preference. Capelin shifted their summer feeding grounds from north of Iceland toward the Greenland Sea after the mid-2000s, and the whales followed [11]; capelin were identified in minke stomachs from the region, while fin whales and humpbacks likely take both capelin and krill [12]. Because all three species avoid ice-covered waters, the post-2000 retreat of coastal pack ice opened the habitat [14][15].
Two numbers deserve caution. The abundance estimate for summer 2024 is reported as 4,000 humpbacks and 6,000 fin whales in both accounts, but 6,000 minke whales in one and 4,500 in the other, a 1,500-animal spread on a 14,500 to 16,000 total [25][26][29]. The warming figure also varies: roughly 2 degrees C since the 1990s in one telling, roughly 1 degree C after the late 1990s in the other, a factor-of-two difference in the headline driver [27][28][30].
There is no commercial capelin fishery in the region, so the authors see no immediate competition with human harvest [21]. That is the current state, not a guarantee. Heide-Jørgensen, who has worked in Greenland for 45 years and said he was surprised by the change [19], describes a major ecological regime shift in which narwhals increasingly share habitat with, or are displaced by, temperate baleen whales [16]; the team calls the process borealization [17]. He expects the system to become "more Atlantic than Arctic in function and species occurrence", and notes tuna already turning up as bycatch in East Greenland mackerel fisheries [18]. He also declines the easy framing, saying that had the ice held, the whales might simply have fed elsewhere in the North Atlantic [20].
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence70
- Adoption
- Not scored
- Hype gap+10
- Incentives35
- Confidence62
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
A study in Frontiers in Marine Science reports 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 degrees N, according to Professor Mads Peter Heide-Jorgensen of the Greenland Institute of Natural Resources.
- [2]
The change has led to regular mixed feeding frenzies of fin whales, humpback whales and common minke whales, species that historically were only rarely observed in coastal East Greenland.
- [3]
Heide-Jorgensen and colleagues in Greenland, Denmark and Iceland documented the findings in a study in Frontiers in Marine Science.
- [4]
The authors conducted the first systematic aircraft survey of baleen whales up to 50 km off the East Greenland coast in August 2015 and 2024, added airborne observations from summer 2022, testimony from Inuit hunters between 2023 and 2025, records from ships in North Atlantic Sighting Surveys since 1987, and tracks from 15 satellite-tagged baleen whales collected between 2019 and 2025, then built a mathematical model using historical sea surface temperature, salinity and ice pack concentration.
- [5]
Between 1987 and 2024 there was a marked change in the occurrence of baleen whales along the East Greenland coast north of 60 degrees N and west of 29 degrees W.
- [6]
Ship-based surveys did not observe any humpback whales in the area until 2006, while seven sightings were recorded in 2007, 26 by 2015 and more than 150 by 2024.
- [7]
Sightings of minke whales from survey vessels were few until 1995, but 10 to 20 were encountered each year after 2001.
- [8]
Ship-based sightings of fin whales increased sharply from 1987 to the present day.
- [9]
In August 2025 a ship crew reported encountering exceptionally large aggregations of up to 50 baleen whales simultaneously along the east coast around 69 degrees N, north of the Arctic Circle.
- [10]
The systematic airborne surveys documented an almost continuous distribution of all three species at the same time between 60 degrees N and 70 degrees N in 2015 and 2024.
- [11]
The authors found the three species visit the region mainly to hunt capelin, a cold-loving fish that has shifted its feeding grounds since the mid-2000s from the relatively warmer waters north of Iceland toward the Greenland Sea.
- [12]
Researchers identified capelin in the stomachs of minke whales from the region, while fin whales and humpbacks likely feed on both capelin and krill there.
- [13]
During their approximately four-month stay the whales may consume roughly 1.1 million tons of prey, and consumption at that scale could reshape the region's food web.
- [14]
The summer ice edge retracted far to the north after the mid-2000s, dramatically reducing the extent of pack ice along Greenland's east coast.
- [15]
Because all three whale species tend to avoid ice-covered waters, the ice retreat opened more feeding habitat.
- [16]
Heide-Jorgensen said East Greenland is undergoing a major ecological regime shift, with ice-associated species such as narwhals increasingly sharing their habitat with, or being displaced by, temperate baleen whales that generally avoid ice-covered waters.
- [17]
The researchers describe the transition as borealization, meaning species associated with Atlantic waters are becoming more prominent in an Arctic ecosystem.
- [18]
Heide-Jorgensen told Discover: "I believe it will become more Atlantic than Arctic in function and species occurrence," adding that tunas have been caught as bycatch in mackerel fisheries in East Greenland.
- [19]
Heide-Jorgensen has worked in Greenland for 45 years and told Discover: "I was very surprised and also very curious about what was behind the change."
- [20]
Heide-Jorgensen told Discover: "You may say that they are 'winners,' but if the ice situation in East Greenland had remained the same as it was 30 years ago, then the whales may just have found other areas in the North Atlantic to feed."
- [21]
There have never been any commercial capelin fisheries in this region, so competition with humans does not seem likely for now, according to the study coverage.
- [22]
Roughly 1.1 million tons over about four months is on the order of 9,000 tons of prey per day.
- [23]
The Arctic and North Atlantic, apart from a cold blob south of Greenland, are among the fastest-warming regions on Earth.
- [24]
Humpback ship sightings rose from seven in 2007 to more than 150 in 2024, a more than twentyfold increase over 17 years.
- [25]
Heide-Jorgensen and colleagues estimate that no fewer than 4,000 humpback whales, 6,000 fin whales and 6,000 minke whales visited the Greenland Sea in the summer of 2024.
- [26]
For summer 2024 the researchers estimated regional abundances of approximately 4,000 humpbacks, 6,000 fin whales and 4,500 minke whales.
- [27]
Sea surface temperatures east of Greenland have risen by approximately 2 degrees C since the 1990s.
- [28]
Sea surface temperatures along East Greenland rose by approximately 1 degree C (1.8 degrees F) after the late 1990s, the summer sea-ice regime changed after 2000 reducing coastal pack ice, and whale sightings increased as the water warmed and summer ice retreated.
- [29]
The two published accounts of the same study differ on the minke whale estimate by 1,500 animals, giving a summer 2024 three-species total of either 16,000 or 14,500.
- [30]
The two accounts of the warming signal differ by a factor of about two, at roughly 2 degrees C versus roughly 1 degree C.
Sources
2 independent publishers whose own reporting we read for this story.
- discovermagazine.comWhales Once Rare Along East Greenland Now Gather by the Thousands in Feeding Frenzies
1 article · August 19, 2026
- phys.orgWarming waters draw summer 'feeding frenzies' by whales off Greenland
1 article · August 19, 2026
Topics and entities
Topics
- Fisheries and Ecosystem Management
- Arctic Marine Regime Shift
- Whale Distribution Monitoring
- Sea Ice Retreat and Ocean Warming
- Forage Fish Range Shift
Entities
- Frontiers in Marine Science
- North Atlantic Sighting Surveys
- Greenland Institute of Natural Resources
- Mads Peter Heide-Jørgensen