Balaenoptera musculus

SIZE: Male- 23-26m, Female- 24-27m

Blue whales are the largest animals known to have ever lived on Earth. Although they no longer reach the enormous sizes recorded before commercial whaling, blue whales in the North Atlantic can still reach around 25–26 metres in length.

The largest blue whales once lived in the Southern Ocean around Antarctica, but they were heavily hunted during the industrial whaling era, and their populations remain very low. Blue whales are still considered an endangered species globally and are critically endangered in the Antarctic. Current estimates suggest that around 5,000–15,000 mature blue whales remain worldwide, compared with an estimated population of more than 300,000 before commercial whaling.

Like other baleen whales, blue whales migrate to warmer waters in winter, where they are believed to breed. Their exact breeding grounds remain largely unknown.

Blue whales are also unusual among whales in that they do not always raise their tail flukes when diving, making their dives look quite different from those of some other whale species.

With only a few thousand blue whales estimated to remain in the North Atlantic, encountering one is always a special experience. They are rarely seen on our whale watching tours from Ólafsvík, but they can appear in the area. We have recorded blue whale sightings twice in 2026.

Blue whales feed mainly on krill. When large concentrations of krill occur, blue whales may sometimes appear in the area to take advantage of this abundant food source. These feeding opportunities are difficult to predict, and we never know when blue whales might pass through.

While Ólafsvík was historically known as an important area for blue whale sightings, their presence has changed over time and they are no longer considered a regular sighting. Changes in their distribution may be linked to shifts in food availability and broader changes in the marine environment.