The barking colony on Pier 39's west side is San Francisco's most-watched wildlife. The sea lions weren't part of any plan, though. They simply moved in.
How it started
According to Pier 39, a few California sea lions began 'hauling out' on K-Dock shortly after the Loma Prieta earthquake in October 1989. By January 1990 they were arriving in droves and had taken over the dock, to the frustration of the boat owners who rented slips there.
Wikipedia tells it a little differently. It says sea lions first hauled out at Pier 39 in September 1989, before the earthquake, and that they had mostly used Seal Rock off Lands End until then. That makes the popular story that the quake drove them in doubtful. It's more likely that the sheltered bay simply felt safer.
Why they stayed
The marina asked The Marine Mammal Center for advice. Its experts recommended letting the sea lions keep the dock, and the boats were moved. With plenty of food in the bay and protection from predators, the colony grew past 300 within months, according to Pier 39.
By the numbers
- Pier 39 reports an all-time record of more than 2,100 sea lions in May and June 2024.
- Adult males can reach about 850 pounds and 7 feet, and females about 220 pounds and 6 feet. Most of the animals on K-Dock are male.
- Most California sea lion pups are born in June on the Channel Islands off Southern California.
The animals are protected by the Marine Mammal Protection Act, so feeding or harassing them is illegal. Pier 39 also runs a live webcam of K-Dock.