Harbor Porpoise

Maximum longevity: 20.4 years (captivity) Observations: These animals rarely live more than 13 years in the wild (Ronald Nowak 1999). One captive specimen was still alive at 20.4 years of age (Richard Weigl 2005).

Harbour porpoises live either solitarily or in groups, normally of three to five individuals, although sometimes more. Normally individual porpoises or couples (mother and calf) are observed and high numbers can be seen during migrations. Like dolphins, the harbour porpoise orientates itself by means of echo-sounding or ‘sonar’. It has a particular way of swimming with a ‘rolling’ movement (imagine a turning wheel); part of the back, including the dorsal fin surfaces briefly before re-entering the water giving the appearance of a rotating motion. This movement will normally be repeated three to four times, prior to a long dive.

The diet of an adult harbour porpoise is made up of various pelagic and demersal fish, as well as invertebrates. In the Southern North Sea, it consists mainly of small benthic fish, herring, cephalopod, whiting and cod. A daily meal would normally consist of about 5 kilos fish (around 10% of the body

Variety of inshore and offshore fish, herring, mackerel, and anchovy. Krill when young.

East Pacific; Eastern Atlantic Ocean; Indo-West Pacific; Western Atlantic Ocean

cool temperate and subpolar, mostly in shallow water

inshore and offshore

Least Concern (LC)

Subpopulation Baltic Sea harbour porpoise : Critically Endangered (CR)

Distinguishing characteristics: Dives without lifting tail. Blow not readily visible. Triangular dorsal fin. Spoon-shaped teeth. Blunt snout. Colour is grey above with white belly.

The head is blunt. Depending on the light, the back may appear black, grey or brown). The flanks are grey and the underside is white. The pectoral fins are black. A dark line runs from the corner of the mouth to the flipper. The more or less triangular small dorsal fin is positioned in the centre of the back. The upper back and dorsal fin are the only features one normally gets to see of a swimming harbour porpoise. The chief characteristics are its small size, the blunt head and the small triangular dorsal fin.