Where does it get its name?
The English word ‘porpoise’ comes from the Latin word for pig – porcus. A nickname for the harbor porpoise used to be the “puffing pig”, because of the sneeze-like puffing sound it makes when it breathes!
Whale SENSE Region Found:
Protected throughout its range
Where to watch:
Harbor porpoises live in northern temperate and subarctic coastal and offshore waters. They are commonly found in bays, estuaries, harbors, and fjords less than 650 feet deep.
What to watch for:
Dorsal fin: Harbor porpoises have a medium-sized triangular dorsal fin.
Body: Their back is dark gray while their belly is white.
Size: Length: 5 to 5.5 feet, Weight: 135 to 170 pounds
Associations: Usually solitary or in groups of two or three
May be confused with: Dall’s porpoise, looks similar to a harbor porpoise at a distance, but Dall’s porpoise tend to be in groups and more comfortable around vessels
Harbor porpoises mainly eat schooling fish, like herring and mackerel and occasionally, they will eat squid and octopus. They are warm-blooded mammals and their small size means they have to feed both day and night to keep their body temperature up in cold water. Each day, harbour porpoises will eat enough fish to replenish as much as 10% of their own body weight!
Mating and Calving
Little is known of harbor porpoise reproductive biology. Females reach sexual maturity at 3 to 4 years and may give birth every year for several years in a row. Most mating occurs in summer and most births occur between May and July. Gestation lasts for 10 to 11 months and calves are weaned after about a year.
Did you know?
Hybrids between Dall’s porpoises and harbor porpoises are also fairly common in the northeast Pacific but can also occur elsewhere
Threats to harbor porpoise
Harbor porpoise’s preference for coastal waters makes them particularly vulnerable to gillnets and fishing traps, pollution, and other types of human disturbance, such as underwater noise.