12 Fun Facts About the Sea Lions at PIER 39

Since 1989, the sea lions of PIER 39 have been charming visitors with their playful antics, hearty barks, and undeniable charisma. Whether you’re a longtime fan or new to these whiskered wonders, here are 12 fun facts to celebrate their 35th anniversary at PIER 39!

1. “We Came, We Barked, We Took Over!”

After the 1989 Loma Prieta earthquake, a few sea lions began hauling out on PIER 39’s K-Dock. By early 1990, hundreds had moved in, much to the dismay of boat owners—who eventually relocated, leaving the dock to its new, flippered residents.

2. “Breaking Records Like a Boss!”

In April 2024, the sea lions reached an all-time high of over 2,100 lounging on the docks! Their previous record was 1,701 in 2009. However, sea lion numbers fluctuate due to migration and food availability, making each visit to PIER 39 a unique experience.

3. “Barking Up a Storm!”

Ever wonder why sea lions are so noisy? Their loud barks help them communicate, claim space, and, in the case of males, establish dominance. With hundreds of sea lions on K-Dock, it’s a non-stop conversation!

4. “The Great Sea Lion Getaway”

In November 2009, after setting a record, nearly all the sea lions suddenly vanished! Where did they go? Experts believe they followed a shifting food source down the coast—but, like clockwork, they returned a few months later.

5. “Winter Wonderland for Sea Lions”

PIER 39 hosts the highest number of sea lions in winter when food is plentiful in the Bay. In summer, many head south to breeding grounds, but a few stay behind, keeping the dock lively year-round.

6. “Global Superstars”

Sea lions at PIER 39 have fans worldwide, thanks to the Sea Lion Webcam! People from across the globe tune in to watch these playful pinnipeds in action, proving their appeal stretches far beyond San Francisco.

7. “Boys Rule the Dock”

Most of the sea lions at PIER 39 are males! You can tell them apart from females by their larger size (up to 850 lbs!) and a noticeable bump on their heads called a sagittal crest, which develops around age 4-5.

8. “Flippers vs. Fins – Know the Difference!”

Sea lions are often confused with seals, but here’s a fun trick: Sea lions have external ear flaps and can “walk” on land using their front flippers, while seals have small ear holes and wriggle on their bellies.

9. “Living Large and Long”

California sea lions can live up to 25 years in the wild! Their strong swimming skills, intelligence, and social nature help them survive along the Pacific coast, from Vancouver to Baja California.

10. “Protected & Adored”

California sea lions are protected under the Marine Mammal Protection Act, which means it’s illegal to feed, harass, or harm them. So, while they might look friendly, it’s best to admire them from a distance!

11. “Plastic Pollution – Their Biggest Threat”

One of the biggest dangers sea lions face today is getting entangled in plastic waste like fishing lines and nets. Organizations like The Marine Mammal Center work tirelessly to rescue and rehabilitate injured sea lions.

12. “A 35-Year Love Story!”

Since 1990, the sea lions have become an icon of PIER 39, drawing visitors from around the world. Celebrate their 35th anniversary by sharing your favorite sea lion moments on social media with #PIER39SeaLions and watching them live on the webcam!

Whether you’re visiting PIER 39 in person or tuning in online, the sea lions are always ready to put on a show. Come see why they’ve been stealing hearts for 35 years and counting!

6 Frequently Asked Questions About the Sea Lions at PIER 39

The sea lions at PIER 39 are some of San Francisco’s most famous (and noisiest) residents! Whether you’re visiting for the first time or a longtime fan, here are answers to some of the most frequently asked questions about these playful pinnipeds.

1. Why do the sea lions stay at PIER 39?

The sea lions found a perfect home at PIER 39’s K-Dock because it offers everything they need: plenty of food (fish like herring and anchovies are abundant in the Bay), no natural predators (great white sharks and orcas don’t usually hunt in the Bay), and a safe, comfy haul-out spot that’s easier to rest on than a rocky shoreline.

2. Do the sea lions stay at PIER 39 all year?

Yes and no. While there are always some sea lions at PIER 39, their numbers change with the seasons. Most leave in the summer (June-July) to migrate to breeding grounds on the Channel Islands, but many return in late July. The highest populations are typically seen from late summer through spring, with hundreds lounging on the docks at any given time.

3. Are the sea lions at PIER 39 wild animals?

Yes! The sea lions are completely wild and not trained or cared for by humans. PIER 39 staff do not feed them or interact with them, and it is illegal to feed, touch, or disturb them under the Marine Mammal Protection Act. However, if a sea lion is injured or sick, The Marine Mammal Center steps in to rescue and rehabilitate it.

4. Why are most of the sea lions at PIER 39 male?

Male sea lions migrate further north after breeding season, while females and pups stay closer to the Channel Islands. Since PIER 39 is a great resting and feeding spot along their route, it’s mostly young and adult male sea lions that take over the docks. You can recognize mature males by the large bump (sagittal crest) on their heads.

5. Do the sea lions ever leave and not come back?

Sometimes their numbers drop dramatically for a short period—like in 2009, when nearly all the sea lions suddenly disappeared in November after setting a record population earlier that year. Scientists believe they left in search of food as fish populations shifted. But don’t worry—they always return!

6. Can I watch the sea lions if I’m not at PIER 39?

Absolutely! You can see the sea lions anytime via the PIER 39 Sea Lion Webcam. Whether you’re across the country or just want a sneak peek before visiting, the live cam lets you watch them bark, nap, and play from anywhere in the world.

Have more questions? The best way to learn about these famous flippered friends is to visit PIER 39 and see them for yourself!