Alaska Species Explorer

Harbor Seal

Common Name: Harbor seal
Scientific Name: Phoca vitulina

One of the most abundant pinnipeds in the Northern hemisphere. They have a circumpolar range.  In the Atlantic Ocean they range as far south as Florida but are mostly concentrated in the north Atlantic from Greenland south to Massachusetts.  In Europe they range from Norway to France. North Pacific animals can be found from California to Nome, Alaska including the Aleutian, Pribilof and Commander Islands.

Conservation Status:

Harbor seal populations are relatively stable worldwide, but have shown   declines of around 80% over the past 30 years in the arctic regions. Their population in Alaska is considered depleted.    The ASLC has been a part of various research projects to find answers for these declines.

Average Length: Males: 4-6ft, Females 4-5ft
Average Weight: Males: 220-330lbs, Females 120-250lbs
Diet in the Wild: Salmon, rockfishes, squid, octopus, walleye pollock, herring, atka mackerel, pacific cod, flatfishes (e.g. halibut), sculpins
Reproduction Period:

Harbor seals pup at about the same time every year, between mid-May and June.  The female chooses a male to mate with, and her single egg is fertilized at this time, but does not implant in the uterine wall until about three months later. This process is called delayed implantation, and allows harbor seals birth at the same time every year.


Found in both fresh and salt water environments and temperate and subarctic regions. They frequent estuaries and intertidal zones and will haul out on sandbars, rocky shores, mudflats, log rafts, piers and ice floes.

Life History:

A female gives birth to one pup a year. Pups can swim very quickly after birth, grow rapidly and within about 6 weeks are usually weaned and on their own.  Males and females reach sexual maturity at 3-6 years.  Seals in aquariums tend to live longer lives and are documented to live into their 30’s where wild counterparts don’t live as long.

Threats in the Wild: Humans, sharks, Steller sea lions, and killer whales
Did you know?:
  • There are six sub species of Phoca vitulina
  • During the winter the blubber layer makes up 27-30% of its total body mass
  • Vibrissae (whiskers) are highly sensitive and are used to navigate, hunt for prey, and detect vibrations in the water
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