The northernmost sightings of Humpback whales (Megaptera novaeangliae)

The decrease in sea ice coverage impacts the accessibility of marine areas especially in the Arctic. Areas further north than previously reported can be accessed by marine mammals which are usually restricted by the sea ice. We report sightings of several humpback whales north of 81º North. This is a previously unknown habitat expansion. The recent decrease in Arctic sea ice cover is likely to increase accessibility of marine areas for cetaceans, potentially resulting in northward expansions of species habitat ranges. Here, we report multiple sightings of humpback whales (Megaptera novaeangliae) north and west of Jackson Island in the Franz Josef archipelago in July 2016. The observations are north of 81º North, significantly increasing the northernmost observation of humpback whales. The sea ice loss in the summer of 2016 was larger than previous recorded. Changes in population dynamics, especially increase of population size, might be the most important driver for the habitat expansion, but climate change is opening up new marine habitats in the Arctic. Our observations suggest that cetaceans are already expanding their ranges into ice-free areas.