Size: 1.5 – 1.7m
Key feature: Smallest European Cetacean
The harbour porpoise is the smallest cetacean and the only porpoise to be found in European waters. It has a dark brown to grey colouration on its back and a white belly. Its head is small and round, with no beak. The dorsal fin is also recognisable, in the centre of the animal, with a short triangular shape.
Harbour porpoises are slow, unobtrusive swimmers and can be unobvious to an observer, particularly in stormy weather. They tend to surface gently 3 or 4 times and then dive for a few minutes. They are shy, unlike many of their dolphin relatives and will avoid boats where possible. Harbour porpoises travel alone, or in small groups of up to 6. Unlike dolphins the harbour poropise rarely breaches fully out of the water. They are typically seen on their own or in small pod sizes.
Harbour porpoises have a large distribution over cold temperate and subarctic waters in the northern hemisphere. They are found in shallow and coastal areas. They are often encountered in the western English Channel, along Welsh and Irish coasts and the Brittany coast. They are easily seen from many headlands around the British Isles. Specific locations include Flamborough Head (Yorkshire), Strumble Head (Pembrokeshire), Porthgwarra (Cornwall), and Sumburgh head (Shetland). They are also encountered frequently on ferry trips towards the Bay of Biscay, Isles of Scilly, Isle of Man and in the North Sea. The harbour porpoise is listed under Annex II of the EU Habitats Directive. In September 2016 the Inner Hebrides and Minches was designated a Special Area of Conservation (SAC) this is the largest protected area for harbour porpoises in Europe and supporting a population of over 5,000 individuals. Five more sites are currently being considered for SACs in England, Wales and Northern Ireland.
There have been significant declines in the European population of harbour porpoises over the last 40 years. Due to its preferred habitat of shallow, coastal zones, the harbour porpoise is under threat from high levels of chemical pollution, vessel traffic, underwater noise and the depletion of prey by overfishing. But, the primary threat for the harbour porpoise is the accidental capture in fishing nets.
If you would like to find out more about the harbour porpoise in European waters check out ORCA's State of European Cetaceans report.