Harbour porpoise

The harbour porpoise is the smallest species of cetacean found in Scottish waters, being less than two metres long. It weighs about 45 kilos and is usually seen in small groups or schools. A porpoise breathes between 4 and 5 times every minute. As it surfaces to do breathes you may hear the breath as the first part of the back is seen at the surface, followed by the dorsal fin and then the last part of the back. It gives the visual impression that it is twisting. There is no protruding nose ‘beak’ and the teeth are small and squared off. You may see grey seals feeding in the vicinity of harbour porpoises which eat fish and squid.

They tend to stay in coastal waters in the summer and can be quite close to shore. In winter, they  spend more time out at sea. Porpoises are shy creatures and rarely associate with boats, however are quite common in certain areas. You are unlikely to see harbour porpoises in the vicinity of bottlenose dolphins as porpoises tend to keep well out of their way!
Found out to sea and closer inshore right around the coasts of Scotland travelling into sea lochs and up into river estuaries.
In a recent study of harbour porpoises found dead in the Moray Firth, there was evidence that over a hundred had died after being attacked by the much larger bottlenose dolphin. This mortality rate is however dwarfed by the estimated number of 8000 harbour porpoises killed by gill nets set in the North Sea by the European sand eel fishing fleets every year.
Bottlenose dolphin

Bottlenose dolphin

Tursiops truncatus

The Scottish bottlenose dolphins are considerably larger than their cousins living in the warmer waters off Florida, USA. These dolphins can be between 3 and 4 metres in length and are normally to be seen in pods (groups) of up to ten animals. Pods can fo...