Giant whales move into Greenland waters as ice disappears

As East Greenland's sea ice recedes, an extensive study reveals that massive whales, including humpbacks, minke, and fin whales, are now frequenting previously inaccessible coastal waters to feed. Scientists, observing from boats, have documented this phenomenon, marking a significant ecological shift.

Historically, these marine mammals were absent from these coastal areas due to ice barriers. However, as climate change warms the ocean and melts the ice, these whales have adapted, leading to what scientists describe as seasonal Arctic "feeding frenzies." This represents a major transformation in the East Greenland ocean environment.

The change is stark: ship-based surveys in the region recorded no humpback whale sightings until 2006. By 2007, seven humpbacks were observed, and by 2024, a remarkable 150 ship-based sightings of these colossal whales were reported.

Researchers conducted the first systematic aerial surveys of baleen whales off the East Greenland coast in the summers of 2015 and 2024. This data, combined with the tracks of 15 satellite-tagged whales and accounts from Inuit hunters, paints a clear picture of what lead researcher Prof. Mads Peter Heide-Jørgensen termed a "major ecological regime shift."

In the summer of 2024, an estimated 4,000 humpback whales, 6,000 fin whales, and 6,000 minke whales visited the Greenland Sea. Prof. Heide-Jørgensen, from the Greenland Institute of Natural Resources, informed BBC News that these regional changes are "probably the most radical we can see anywhere in the subarctic."

This shift is primarily driven by rising sea temperatures and increased food availability, as the whales appear to be preying on fish that have migrated into East Greenland's warming waters. The researchers estimated that these three whale species would consume at least 800,000 tonnes of fish and krill during a single summer feeding season.

While some whales are benefiting from these warmer waters, the study does not definitively indicate whether this change reflects an overall increase in these whale populations or merely a redistribution from other areas. Other experts expressed concern to the BBC that the study might suggest an influx of animals from West Greenland, a sensitive topic in Greenland, where some whales are hunted.

However, the scientists suggest that these "opportunistic" baleen whales are adapting and potentially thriving due to these environmental changes. Conversely, Prof. Heide-Jørgensen noted that other Arctic species, such as narwhals and belugas, are "in trouble now," as they are sharing or even being displaced from their habitats by these other whales.

"For some species, climate change is not necessarily a problem – it opens up new opportunities," said Prof. Heide-Jørgensen, "but other species are losing their habitat."

The findings of this study have been published in the journal *Frontiers in Marine Science*.