Harbor seal

(Phoca vitulina)

Habitat and Distribution: Found near piers and beaches along temperate subarctic and Arctic coasts on both sides of the North Atlantic and North Pacific Oceans.

Size: 4.5-6.5 feet; 120-370 pounds. Males are larger than females.

Wild Diet: Fish, crustaceans, squid, octopuses, shrimp, and shelled mollusks.

Predators: Sharks, killer whales, polar bears, and humans.

Life Span: 20-30 years

Reproduction: Harbor seals return to the same breeding grounds every year and usually breed in the water. Males attract females with visual and vocal displays including slapping their bodies on the water, blowing bubbles, and vocalizing. Gestation is 9-11 months with a single pup born each year (twins are rare). Newborn pups weigh about 25 pounds and bond with their mothers within the first hour. They are nursed with high-fat milk that enables rapid growth and weaned after 4-6 weeks.

Behavior: Harbor seals can dive underwater in search of food for 3-5 minutes. They hunt alone but can be found in groups for breeding and when hauled out on land. They may haul out to rest, avoid predators, socialize, molt, nurse, or give birth. They tend to haul out on sandy or rocky beaches that are uncovered at low tide.

Conservation

IUCN Status: Least Concern

Harbor seals are widespread along a great range, but some subspecies (Phoca vitulina stejnegeri and Phoca vitulina mellonae) are on the brink of extinction. The main threats to harbor seals are fishing gear, oil spills, chemical pollution and harassment by humans. They are also hunted for their blubber, meat, fur, and skin. They have been protected by the Marine Mammal Protection Act (MMPA) since 1972.

Did you know?

  • If you see a lone seal pup on a beach, leave it alone and keep your distance. Although pups are able to swim, they can't thermoregulate (maintain body temperature) as well as adults, so they don't spend long periods of time in the water. A mother may leave her pup on shore to go fishing, but she will soon return.
  • They have large eyes with flattened corneas that allow them to take in more light and see well underwater.
  • Their whiskers detect sound waves, which helps them locate prey.