The harbour porpoise is the smallest cetacean found in Icelandic waters and is actually one of the smallest marine mammals in the world. It is also one of the shortest lived, rarely surviving beyond 12 years of age. The maximum age, however, is around 20 years.

The harbour porpoise is not a dolphin but belongs to a family called Phocoenidae (hnísur).

Porpoises look similar to dolphins. The way to distinguish them generally is from their smaller size, rounder body shape and lack of the ‘beak’ of the better-known dolphins.

Porpoises can be found all around Iceland. They are also common elsewhere in the Atlantic Ocean along the coast of North America to Labrador and the west coast of Greenland. They can also be found near the UK, along the coast of Norway, in the Baltic Sea and as far south as the Bay of Biscay.

The harbour porpoise makes a distinctive, explosive noise as it comes to the surface to exhale. It has also been called a “puffin pig”. They are social creatures and are often found in groups of 2–20, though the usual pod size is around 4 animals.