If you've been to the Fisherman's Wharf part of San Francisco in the past twenty years, chances are you've seen (and heard) the resident sea lions that call Pier 39 home. I'd spend long stretches of time just observing them and their behavior patterns, and always found them neat.
Since about a month ago, when they collectively slipped into the bay and disappeared, the pier has been quiet and barren.
The sea lions’ disappearance is as strange as their initial colonization of the pier about 20 years ago, in late 1989. They just started showing up one day and as their numbers increased, their traditional hang out, Seal Rocks, became less populated. There are all sorts of theories about why the pier became a favorite haul-out spot for the sea lions, but no one knows for sure why the animals’ behavior changed.
It doesn’t appear that local weather conditions could have influenced the animals. The weather in San Francisco has been normal, according to National Weather Service meteorologist Rick Canaepa. “It’s pretty typical winter conditions,” Canaepa said.
There is also no apparent population increase on Seal Rock; apparently hundreds of them just decided to move on.