Harbour porpoise  (Phocoena phocoena)

Found in sub-Arctic and cool temperate waters of the North Atlantic and North Pacific (5), the harbour porpoise is typically a species of coastal areas, although it also occurs over most of the European continental shelf (4). In the UK, seasonal concentrations occur between July and October off western and south-western Ireland, west Wales, the west of Scotland, around Shetland and Orkney as well as around north-east Scotland (4). This species used to occur in the south coast of England and southern parts of the North Sea, but it is now rare in these waters (4).

Favours shallow, cold coastal waters (4). Most sightings have been made within ten kilometres of the land. It frequents relatively shallow bays, estuaries, and tidal channels under about 200 kilometres in depth, and will swim a considerable distance up river (6).