Marine Mammals
of the Pacific Northwest
The waters of the Pacific Northwest, including the inland waterways known as the Salish Sea, are rich with marine life. Just take a walk or a boat ride for a preview!
This diverse habitat supports over 30 species of marine mammals – creatures great and small.
Photo credit: Lynn Shimamoto | Banner image: Robin Lindsey
Meet the
Marine Mammals
of Puget Sound
Pinnipeds, which include harbor seals and sea lions, are the most common mammals to see along our beaches.
Harbor seals spend their whole lives in the Sound without migrating, but, as their name implies, California Sea Lions travel annually between breeding grounds further south and the northern waters of the Northwest.
We often also see Cetaceans (suh-tay-shnz), which include harbor porpoises (pictured), whales, and dolphins.
Harbor porpoise
Photo credit: Marine Mammal Center
Photo credit: Jeffrey Kurtz
Harbor Seals
The most common marine mammals in Puget Sound, harbor seals are frequently seen as a small, smooth head bobbing out of the water. Adults and pups can spend half of their time resting out of the water on beaches or rocks above the waterline.
Seal moms spend 4 to 6 weeks with their pups, after which they are on their own. By the time they are weaned, pups have doubled their birth weight (18-30 lbs), but remain vulnerable to environmental conditions and predation - only 50% survive their first year. Protecting seal pups on the beach helps increase their chances of survival.
Adult male and female California sea lions show distinct profiles
Photo credit: Robin Lindsey
California Sea Lions
Highly social, sea lions are easily recognized by their boisterous barking and playful behavior, both in the water and on buoys, docks, and rocky shorelines.
They reside in the Puget Sound from fall through spring, following salmon runs. We usually only see males here, while female sea lions stay near breeding grounds further south to care for pups until they are weaned.
How can I tell the difference between a harbor seal and a sea lion?
Behavior
Sea lions are very vocal with distinctive barking; harbor seals are mostly quiet except as nursing pups
Sea lions are social and gather in clusters; harbor seals are usually alone
In the water, you might see a seal's smooth head popping up, or you may see a sea lion “sailing” (see photo)
Physical traits
Sea lions have external ear flaps and larger flippers; seals have internal ears and small flippers with short tails (it may be difficult to see physical traits in the water).
WHAT’S THAT IN THE WATER?
It’s a sea lion, and this normal behavior is called "sailing", when they raise their flippers out of water to help regulate their body temperature (thermoregulation).
From a distance, this can sometimes be mistaken for an injured animal or even a dorsal fin of a whale. When you see this, the sea lion is simply relaxing - no cause for concern!
Photo credit: David Hutchinson
Less Common Species
These other marine mammals are less common, but not surprising to see in our area:
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A large, near-threatened species that can be found in the coastal marine habitats of the Pacific Northwest.
These mammals have attracted considerable attention due to significant (and largely unexplained) declines in their numbers.
You would be fortunate to see one of these giant & very vocal pinnipeds.
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The largest pinniped in the Pacific Northwest, elephant seals spend nearly all of their time in the water, except when gathering in large rookeries during mating season.
They are not commonly seen in Puget Sound, though they have become more frequent in recent years.
Orcas
Orcas, or killer whales, swim in every ocean on Earth. But Puget Sound’s Southern Resident killer whales have an unusually beloved place in human hearts and culture.
DID YOU KNOW
These iconic animals are actually dolphins and not whales?
Because of their size–more than 30 feet and up to 10 tons for males–they are also considered whales. They are called killer whales because they can eat other types of whales.
After decades of capture for display at marine parks, Southern Resident populations declined to dangerously low numbers. Despite conservation efforts, J, K, and L pods remain threatened.
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Porpoises are often seen in groups swimming around Puget Sound. They are busy fish finders, and have rounded faces without a prominent beak.
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These Orcas are more plentiful in the Sound than the Southern residents.
Unlike the fish-eating residents, transients prey on marine mammals such as seals and sea lions. We sometimes see more seals up on the beach when Biggs are nearby!
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We are occasionally graced with a visit from a few of the true whales that frequent the waters of the Pacific Northwest.
The two most common species are humpbacks (shown above) and grays, though we don’t see them often.
Illustrations: NOAA Marine Mammals of the U.S. West Coast Poster
Ecology of Puget Sound
Puget Sound is part of the Salish Sea, one of the world’s largest and most biologically rich inland seas.
Its name pays tribute to the first inhabitants of the region, the Coast Salish.
The Salish Sea extends from south Puget Sound in Olympia, WA, up through the San Juan Islands, north to the Campbell River in British Columbia, and west to Neah Bay on the Pacific Ocean.
It is home to 37 species of mammals ,172 bird species, 261 species of fish, and an estimated more than 3,000 species of macro-invertebrates, according to the SeaDoc Society.
Reference Map for the Salish Sea Bioregion
Credit: Dr. Aquila Flower, 2020, Salish Sea Atlas
Protecting our sacred shores
Development around the Sound has disrupted its ecological balance, and the SeaDoc Society reports that 135 species are currently listed as threatened, endangered, or are candidates for listing.
Pollution, shoreline development, boat traffic, and declining water quality all degrade the ecosystem.
Public education and advocacy is crucial for rehabilitating Puget Sound waters and wildlife. Seal Sitters is proud to be part of the regional effort to protect this special resource.
From our volunteers:
“By being a source of data collection, we are contributing to a large body of evidence that can help to shape future policy for protecting the entire ecosystem of Puget Sound.”