A remarkable change is taking place off the east coast of Greenland. Fin whales, humpback whales and minke whales, which used to be relatively rare in these waters, now appear in their thousands every summer. A new study shows just how drastically the marine ecosystem has changed within a few decades.
Systematic surveys from 2015 and 2024, as well as other observations, show a significant increase in the number of baleen whales. Researchers estimate that several thousand animals use the waters off East Greenland as a feeding ground during the summer. Large gatherings are now even being observed north of the Arctic Circle. In August 2025, groups of up to 50 whales at a time were reported.
The decline in summer sea ice plays a crucial role in this. Since the late 1990s, the waters off East Greenland have warmed significantly, whilst the summer pack ice has continued to retreat. This has opened up coastal areas that were previously blocked off by ice for long periods of time for these whale species.
However, the whales are primarily following their food. Capelin, small schooling fish and an important prey source for many marine mammals, have increasingly shifted their summer feeding grounds from Iceland towards East Greenland. Fin, humpback and minke whales appear to have followed this trend. Together, the baleen whales could consume around one million tonnes of prey annually during their approximately four-month stay off East Greenland.
The trend is particularly striking among humpback whales. Ship-based surveys recorded not a single humpback whale until 2006. In 2007, there were seven sightings; by 2015, this had risen to 26; and by 2024, more than 150. Fin and minke whales are also being observed much more frequently.
Scientists speak of an increasing ‘borealisation’ of East Greenland: species from warmer, sub-Arctic waters are spreading northwards and encountering typical Arctic species there. This could also alter competitive relationships and food webs. Ice-bound animals such as narwhals are increasingly having to share their habitat with large baleen whales.
The large numbers of whales off East Greenland are therefore not just a spectacular natural spectacle. They are also a visible sign of just how rapidly one of the Arctic’s ecosystems – previously strongly influenced by sea ice – is changing.
Rosamaria Kubny, PolarJournal