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Special Areas of Conservation

1351 Harbour porpoise Phocoena phocoena

Vertebrate species: mammals

Description and ecological characteristics

Harbour porpoise Phocoena phocoena appears to favour the continental shelf and may make seasonal movements to the coast. This inshore movement appears to be connected with the feeding of calves in shallow waters. During this time they have a very intense ‘social’ life. The highest number of births occurs during June and July (although there is, as yet, limited evidence concerning where calves are actually born). The young to adult ratio is at its highest level during this period. As the end of summer approaches, young and adult individuals appear to range more widely together.

Most of the identified areas with most frequent sightings are in coastal waters. These are often areas where there is a high degree of water mixing, sometimes associated with strong tidal streams. Such areas have high biological productivity, and are often associated with important concentrations of small prey fish. There may be offshore areas supporting similar concentrations. However, little is known about these, because of the lack of research effort.

Distribution of SACs/SCIs/cSACs with species 1351 Phocoena phocoena. Click image for enlarged map.

European status and distribution

The harbour porpoise Phocoena phocoena is widespread throughout the cold and temperate seas of Europe, including the North Sea, the Skagerrak, Kattegat, Irish Sea, the seas west of Ireland and Scotland, northwards to Orkney and Shetland and off the coasts of Norway. It was formerly infrequent in the English Channel and southern North Sea, but now appears to be returning to these areas. There is a population in the southern Baltic Sea, but the species is scarce in the remainder of the Baltic Sea, and is infrequent in the Bay of Biscay and off the Atlantic coasts of Spain and Portugal. In the Mediterranean, there is a population in the Aegean Sea, mainly in Turkish waters. There is some DNA evidence that there are distinct populations of porpoises in the Irish Sea, northern North Sea, southern North Sea and Baltic Sea.

UK status and distribution

The harbour porpoise Phocoena phocoena is widespread around the UK, including the North Sea, Irish Sea, the seas west of Ireland and Scotland, and northwards to Orkney and Shetland. Since the 1990s it has become much less common around the Northern Isles, but it appears to be returning to the English Channel and southern North Sea, where it was infrequent in the late 1980s. For reasons not yet fully understood, individuals of the North and Celtic Seas population appear to concentrate in some areas close to the coast between June and September. A portion of the population remains in those regions year-round. The west of Wales, the west of Scotland and the Shetland Islands may be examples of this behaviour.

View UK distribution of this species.

Site selection rationale

Following discussions with experts, the European Commission DG Environment has outlined broad selection criteria for this species. JNCC and the country agencies are currently analysing distribution data for harbour porpoise Phocoena phocoena in UK waters to determine whether any suitable sites for SAC designation can be found.

Site accounts

SACs where this Annex II species is a qualifying feature, but not a primary reason for site selection

Many designated sites are on private land: the listing of a site in these pages does not imply any right of public access.

Please note that the map shows sites where the presence of a feature is classed as ‘grade d’, but these sites are not listed. This is because ‘grade d’ indicates a non-significant presence.