Other Common Names
Common porpoise, herring hog, puffing pig (Newfoundland and New England), Pourcils (Quebec), harbour porpoise.
Description
The harbor porpoise is the smallest cetacean species in the western North Atlantic Ocean, reaching a maximum overall length of about 5 feet (1.5 m). Its most distinctive identifying features in encounters at sea are 1) the small, chunky body; 2) the coloration, dark brown or gray on the back, fading to lighter grayish brown on the sides, often with speckling in the transition zone, and white on the belly extending farther up on the sides in front of the dorsal fin; 3) the small rounded head, lacking a distinctive beak; 4) the small, triangular dorsal fin; and 5) the shallow, inshore northerly distribution.
Natural History Notes
As the name implies, the harbor porpoise inhabits bays, harbors, river mouths, and all the relatively shallow inshore water between. Though it may travel in schools of nearly a hundred individuals, it is more often seen in pairs or in small groups of from 5 to 10 individuals. It often swims quietly at the surface. It will not ride the bow wave and is very difficult to approach closely by boat.
May Be Confused With
The harbor porpoise is not known to associate with dolphins but is sometimes seen in close proximity to fin whales and humpback whales off the Canadian coast in spring and summer. Because of its northern inshore habitat, the harbor porpoise is not likely to be confused with any other cetacean.
Distribution
Harbor porpoises are restricted to the colder waters of the western North Atlantic Ocean. They have been reported from North Carolina north to the Davis Straits and the waters of southwestern Greenland. Within this range they are probably most common in the Bay of Fundy and off southwest Greenland.