Sperm whale (Physeter macrocephalus)
10-18 m, 40-60 tonnes
The sperm whale is the largest toothed whale. The whales living in the Norwegian waters have an average size of about 14-16m. All the sperm whales found in these waters are males; females and calves rest in more temperate waters in the northern/middle antlantic (50ºS- 40ºN).
They are very often seen in summer in the Bleiksdjupet under-water-canyon because it coincides with the ending of the continental shelf, which mixes waters of different streams producing an area very rich in food. Sperm whales feed on squids (Gonatus sp. here) and deep-sea fishes, including some species of small sharks. It has been estimated that an adult can eat 1 ton of food per day. Usually they dive between 500-700m deep to hunt their preys, however dives deeper than 3000m have been deduced from analysing stomach contents. They stay at the surface for about 7 minutes on average, followed by a 20-35 minutes dive. The maximum dive duration can be up to two hours.
The sperm whale is very easy to distinguish because it has a big head and its blow is inclined 45º forward and to the left, due to the anterior left position of the blowhole.
The reproduction rate is very slow. A female can have a calve every 3-5 years. But they seem to have a lifespan of 60 – 70 years.