Point Reyes National Seashore

Point Reyes National Seashore

Species Spotlight: Harbor Seal (Phoca vitulina)

April 6, 2009, 1:35 pm

A harbor seal on the beach.These shy, curious creatures call the chilly Pacific waters off the coast of California home. Visitors often catch glimpses of their heads bobbing in the coastal waters or see groups of them sunning themselves on the shores. In addition to the coastal waters of California, harbor seals live in the northern waters of the Atlantic and Pacific Oceans, as well as those of the Baltic and North Seas.

Description: Harbor seals are often grey with either dark or light spots or rings. They grow to be about five to six feet in length and can weigh as much as 250 pounds. Most harbor seals are a grey or silvery color with black spots. Unlike sea lions, harbor seals are “true” or earless seals and do not have external ear flaps--only a small hole where the ear canal is located. They also possess distinctive v-shaped nostrils and whiskery snouts. Their thick layer of blubber allows them to endure the cold Pacific waters.

Park Habitat: In Golden Gate National Recreation Area, harbor seals can often be seen at Fort Baker from the shoreline or the fishing pier at Horseshoe Cove. They also sun themselves on isolated coastal rocks and beaches along the bay shores. Significant harbor seal pupping areas are found in Bolinas Lagoon. Another popular place to see harbor seals is Point Reyes National Seashore. Beyond the park, Harbor Seals are found along temperate and Arctic marine coastlines of the Northern hemisphere.

Diet: Harbor seals are carnivorous, feeding on the fish that inhabit the waters along the shores, including herring, anchovies, sardines, flounder, sole and salmon. They also eat invertebrates such as octopus, squid and even crabs!

Main Predators: White sharks are the primary marine predator of harbor seals, but they are also part of the diet of other large sharks and killer whales. Terrestrial predators such as coyotes, golden eagles and bobcats also occasionally prey on harbor seals, especially pups that are virtually defenseless on land.

The seals are wise to stay near the shore though—the Pacific waters off the coast of the Golden Gate National Recreation Area are part of an area known as the “bloody triangle,” because it has one of the largest concentrations of great white sharks in the world.

Interesting Fact: Harbor seals can’t rotate their pelvis, so they drag their body along the land like an inchworm to move around on beaches and shorelines. In the water they propel themselves with their hind flippers and steer with their front flippers.