The harbor porpoise is a small, stocky animal.The dorsal side
is brown or dark grey, converging to a lighter grey on the
flanks. The triangular dorsal fin is located in the middle
of the back (Minasian et al, 1984). The average length is
1.5 m. with a maximum size of about 2 m. Females are slightly
larger than males. They weigh 45-65 kg, with a maximum of
90 kg (Evans, 1987; Peet et al., 1992).
The harbor porpoise is a coastal species, limited to the cold
temperate and subarctic waters of the Northern Hemisphere.
In the Eastern North Atlantic it ranges from the Kara Sea
south to Senegal, Africa, including the North Sea, the Baltic
Sea and the Western Mediterranean. There is an isolated population
in the Black Sea. In the Western North Atlantic, this species
ranges from southern Greenland to North Carolina, USA. and
there is also a population around Iceland. In the Eastern
Pacific, it ranges from Alaska (up to Point Barrow) south
to California. In the Western Pacific, the species ranges
from the Bering Sea to northern Japan (Klinowksa, 1991). There
is no clear migration. Most of the travelling seems to be
related to movement of food resources.
The maximum age for harbor porpoises is about 17 years. The
mean age at sexual maturity for females is 3.1 to 3.4 years.
Pregnancy lasts about 10.6 months, followed by 8 to 12 months
of lactation (Palka et al, 1996).