Harbor Seal

Identification

Harbor seals are stocky, medium-sized pinnipeds with rounded heads, short bodies, and short flippers. Adults reach lengths of up to 1.85 m (6.1 ft) and weigh between 55 and 168 kg (120–370 lb), with females generally smaller than males. Their coloring varies from brownish-black to tan or grey, with distinctive spot patterns that are unique to each individual—either dark spots on a light background or light spots on a dark one. Their underparts are typically lighter in color. The most distinctive feature is their V-shaped nostrils. Like all true seals, they lack external ear flaps, though an ear canal may be visible behind the eye. Their streamlined body is covered with blubber that helps maintain body temperature in cold marine waters.

Range & Habitat

Harbor seals are the most widely distributed pinnipeds in the Northern Hemisphere, found along temperate and Arctic coastlines of the northern Atlantic and Pacific oceans, as well as in the Baltic and North seas. They prefer to remain relatively close to shore in subtidal and intertoral zones, often venturing into bays, estuaries, and even swimming up coastal rivers. They feed in shallow littoral waters and are not typically seen as pelagic forms far from land.

Harbor seals are faithful to familiar resting spots called haulout sites, which are typically rocky areas though ice, sand, and mud may also be used. These sites provide protection from adverse weather and predation while remaining near foraging areas.

Behaviour & Diet

Harbor seals are carnivorous marine feeders, consuming herring, flounder, hake, anchovy, codfish, and sculpin in shallow waters. As top-level feeders, they enhance species diversity and productivity in their ecosystems. They are preyed upon by killer whales and white sharks. Males compete for mates both underwater and on land, while females bear a single pup after a nine-month gestation and care for it alone. Pups are remarkably precocial, able to swim and dive within hours of birth and weighing up to 16 kg (35 lb) at birth. They develop rapidly on their mothers' fat-rich milk and are weaned after four to six weeks.

Best Time & Places to See It

The global harbor seal population is estimated at 350,000–500,000 individuals. In California, breeding occurs from March to May, with pupping between April and May depending on local populations. Haul out sites in California include urban beaches throughout San Francisco Bay (including Richmond, Oakland, and the greater San Francisco area), the Greater Los Angeles area (including Santa Barbara, Long Beach, and the city of Los Angeles), and San Diego Bay, with particularly notable sightings near La Jolla. Populations are also found along the Pacific Coast in Oregon, Washington, British Columbia, and Alaska, with large populations moving seasonally and wintering on islands in Washington and Oregon.

Photography Tips

When photographing harbor seals, maintain a minimum distance of at least 50 m (164 ft) from hauled-out seals, especially pups. Mother seals will abandon their young if disturbed by excessive human activity nearby. Look for the seals' unique spot patterns—each individual is identifiable by their distinctive markings, making them rewarding subjects for behavioral documentation. In San Francisco Bay, some harbor seals display unusual reddish coloration, possibly caused by trace element accumulation, which can create striking photographic opportunities. Early morning or late afternoon light will enhance the detail and texture of their fur and surrounding rocky haulout sites.