Harbour porpoises are the smallest cetacean in UK waters. They reach a maximum length of 1.9 m, live between 12 and 20 years and reach breeding age at 3-4 years. They have a plump body with a short blunt head, no beak and a small wide-based triangular fin in the centre of their backs. They can dive for as long as six minutes down to 220 m to forage before surfacing to take a breath. They generally occur in small groups or singly.
They are found around areas of open coast, shallow bays, estuaries, sea lochs, tidal channels and occasionally up rivers. Important calving grounds have been identified in the North Sea. Recorded in all waters around Scotland.
In addition to the layer 'Annual distribution & relative abundance of Harbour porpoise (Phocoena phocoena) (1979 - 1997)' (JNCC data) there are an additional 7 layers: 'Data layers to support 2016 SAC consultation' (based on data collected by DTU, HW&DT, JNCC, SMRU and SWF.
- West Scotland Shelf analysis persistent top 10% density harbour porpoise
- West coast shelf analysis survey effort (1994 to 2011) for harbour porpoise modelling
- West coast shelf analysis model confidence for summers (1994 to 2011)
- West Scotland shelf analysis visual corrected harbour porpoise count data (summer 1994 to 2011)
- Areas of predicted high density of harbour porpoise (acoustic) (2003 - 2010)
- Areas of predicted high density of harbour porpoise (visual) (2003 - 2010)
- Hebridean Whale and Dolphin Trust harbour porpoise calf/ juvenile sightings