Harbour Porpoise

The Harbour Porpoise (Phocoena phocoena) is found in the northern latitudes of the Pacific and Atlantic oceans mainly in the continental margins. It is the smallest cetacean found in Irish waters.

These porpoises are small cetaceans approximately 1.4 to 1.9 metres long when fully grown. Unusually for cetaceans the females are heavier, with a maximum weight of approximately 76 kilograms compared with the males' 61 kilograms. The body is typically quite stout, dark grey in colour and has a short rounded-beak typical of porpoises. Little is known about breeding but it appears that most calves are born during June and July.

This species is generally the most common cetacean in Irish waters; despite this it can often be difficult to observe due to its small size. Harbour Porpoises are often very wary of human contact and rarely interact with boats unlike many other Irish cetacean species.

Due to its small size and the difficulty in spotting an animal, which spends the majority of its time underwater, this species is very difficult to monitor. Surveys that have been undertaken in Ireland have established that monitoring requires a dedicated vessel during near-calm sea conditions to make a reliable count of Harbour Porpoises. Furthermore, acoustic techniques that can identify the calls of individual porpoises are likely to develop into a reliable monitoring technique during the coming years.

Harbour Porpoise I Harbour Porpoise II
(Photos: IWDG & NPWS)  


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