Description: The body is short and rounded – adults are usually between 1.5 and 1.9 m long. The back is dark grey/black and the belly is pale/white. The pale markings extend up the sides above the flippers. A dark line runs from the mouth to the flippers. The head is small and rounded, there is no beak. There are numerous spade-shaped teeth present in the upper and lower jaw. The small, triangular dorsal fin is in the middle of the back.

The blow is short and usually not visible but can often be heard, giving rise to the name ‘puffing pig’.

Habitat: The best places to see harbour porpoises are headlands and bays when the sea is calm. Feeding seabirds may help pinpoint their location.

Distribution: Harbour porpoises are seen regularly in the seas around Northern Ireland. No evidence of porpoise breeding in Northern Irish waters, aside from some anecdotal accounts. A 1994 survey of small cetaceans in the North Sea, English Channel and Celtic sea (SCANS) estimated the population of harbour porpoise to be around 350,000. SCANS II carried in in 2005 estimated the North Sea block to be around 216,415 individuals, and the Irish Sea population was estimated to be around 15,000. Current population estimates are not known. European population listed as 'stable' on IUCN but no detailed information available for Britain and/or Ireland.

Similar Species: Unlikely to be confused with any other species due to their small size. There is less surface activity than with dolphins – usually only the back and dorsal fin is seen and there is very little splashing. Porpoises are slow swimmers, tend to avoid boats and do not bow ride.

Key Identification Features:

• Small dark, grey/black coloured overall with a pale belly.
• Small rounded head.
• Small triangular dorsal fin.

Distribution Map from NBN: Phocoena phocoena at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Phocoena phocoena at iNaturalist World Species Observations database.

GBIF data for Phocoena phocoena

WoRMS: Phocoena phocoena at World Register of Marine Species. Accepted name: Phocoena phocoena (Linnaeus, 1758). AphiaID: 137117.

Classification: Biota; Animalia; Chordata; Vertebrata; Gnathostomata; Tetrapoda; Mammalia; Theria; Cetartiodactyla; Cetancodonta; Cetacea; Odontoceti; Phocoenidae; Phocoena