In January 1990, two months after the Loma Prieta earthquake, sea lions started migrating to Pier 39. The Marine Mammal Center advised allowing them to make a habitat on these floating barges and since then the pinnipeds have done just that, returning almost regularly the first of every year. They swim a little, bark a lot and lounge about like 850 pound pashas (male). The females generally run to 220 pounds.Their pups are born down in the Channel Islands off Santa Barbara. Stop by and see their lolling frolicking now. Free.