- Order: Cetacea
- Suborder: Odontoceti
- Family: Phocoenidae
- Genus: Phocoena
- Species: phocoena
Distribution and Habitat
Harbour porpoises are found in the temperate waters of the northern hemisphere in a nearly circumpolar
distribution. They generally inhabit coastal waters with a depth of less than 150 meters, and their
common name is derived from their regular appearance in bays and harbours. Many populations of harbour
porpoises are migratory.
Harbour porpoises are one of the world's smallest cetaceans, growing to an average length of 1.55 m and a
mass of 55 kilograms. Female porpoises are usually larger than males. It is believed that porpoises can live as
long as 20 years. Harbour porpoises become sexually mature between 3 and 5 years of age. After that time,
female porpoises usually produce one calf every year. Porpoises feed on herring (Clupea harengus), capelin
(Mallotus villosus) and gadoid fishes such as pollack (Pollachius virens) and hake (Merluccius bilinearis).
Porpoises also eat squid. Recently weaned porpoises eat euphausiid shrimp. Harbour porpoises are deep
divers, capable of reaching depths in excess of 200 meters.
Status and Protection
Many harbour porpoise populations around the world
have been depleted through bycatch in fisheries. This
has led some countries to afford them special status. In
Atlantic Canada, harbour porpoises are listed as
threatened by the Committee on the Status of
Endangered Wildlife in Canada (COSEWIC). Northwest
Atlantic harbour porpoises are currently designated as
a strategic stock under the U.S. Marine Mammal
Protection Act (MMPA) because current levels of
killing exceed the estimated Potential Biological
Removal (PBR) level for the population. Harbour
porpoises are listed in the IUCN Red List of Threatened
Species as vulnerable throughout their range.
Threats to the Species
Porpoise populations throughout their range continue to
be threatened by incidental mortality in many fisheries.
In North America alone, bottom set gill nets catch hundreds of porpoises yearly. Chemical and noise pollution
may also threaten this species.