The sea lions camping out on Pier 39 started arriving in January 1990, shortly after the Loma Prieta earthquake. At first they numbered from 10-50, but due to a plentiful herring supply, available dock space and the marina's protected environment, the population grew to more than 300 within a few months. Each winter, the population can increase up to 900 sea lions, most of which are male. During the summer months, the sea lions migrate south to the Channel Islands for breeding season, but in recent years a small group stays year-round. A sea lion statue is located right in front of Pier 39.