Watchable Wildlife: Harbor Seals

By Bob Garrison
Outdoor California - May/June, 1994

Early summer is a great time to travel to the coast in search of the harbor seal. California's most common marine mammal, the harbor seal is often missed at first glance. Unlike their noisy relatives, the California and Steller's sea lions and northern elephant seals, harbor seals make little noise and their mottled fur allows them to practically disappear against the rocks and sand. The key to finding the seals is knowing a little about their lifestyle.

Natural History

Harbor seals spend their entire lives along the same stretch of coastline. To guard against California's cold water temperatures, seals maintain a thick layer of fat beneath their skin, giving them a thick sausage shape. They spend many hours during low tide hauled out on a favorite sandbar or rocky island soaking in the warm sunshine. The seals tend to hunt for fish, crabs, and shellfish during high tide. Harbor seals are the most vulnerable when out of the water and will quickly swim off if you get too close.

Harbor seals give birth to one pup in the spring. The dark-colored pups can be born on land or in the water, and the nursing period lasts about six weeks. After nursing is complete, the adult seals mate. Pregnancy lasts nine months, but the fertilized egg does not begin to develop for three months, aligning birth dates to the same time each year.

Viewing Tips

• Use binoculars from an elevated cliff or pier to scan the shoreline at low tide for groups of seals. Once you spot a group of harbor seals, you can expect to see them at the same location on future visits.
• If the seals are watching you from their haul-out area, you're too close. Back off quietly and watch from a hidden spot.
• Look for group interactions between the seals hauled out on shore. The most dominant seal is usually the one found in the driest (and warmest) spot. Watch what happens as the tide rises.
• Do not approach or touch harbor seal pups that seem to be abandoned. Pups are often left alone on the beach while the female hunts. If you or other humans are too close to the pup, the female will not return to the beach.
• Look for harbor seals silently watching you from the water just beyond the wave line. Seals will magically appear with just their head poking up from the water for a few moments and slip away before you know it.

Other Marine Mammals You May See

The last of the northward bound California gray whales may still be seen off the coast. California and Steller's sea lions also haul out along the shore. Listen for their loud barking calls. The northern elephant seal breeds on the channel islands in Southern California, the Farralon Islands off San Francisco and at Ano Nuevo north of Santa Cruz. Solitary elephant seals can occasionally be seen on mainland beaches near breeding islands.

Harbor Seal Viewing Locations in California

• Lake Earl Wildlife Area
• Patrick's Point State Park
• MacKerricher State Park
• Sonoma State Beach
• San Pablo Bay National Wildlife Refuge
• San Francisco Bay National Wildlife Refuge
• Elkhorn Slough Ecological Reserve
• Montana de Oro State Park
• Carpenteria State Beach
• Crystal Cove State Park