The Case of the Disappearing Sea Lions

I spent some time catching up on my RSS feeds last night and was interested and mystified to read this post on the Wired Science blog: the San Francisco Pier 39 sea lions have disappeared! They were a big tourist attraction at the already touristy pier. Whenever anyone came to visit during the year I was at Stanford, we inevitably went to check out the sea lions and laugh as they lazily lounged on the pier, occasionally sounding an “arf arf arf” to their sea lion buddies. The last time I saw them was in 2005 when I was in San Francisco for a work-related conference. The piers weren’t teeming with sea lions at that particular time, as you can see, but there was still a crowd.

They first arrived in 1990 and have been a constant presence, in growing numbers, for 20 years. Last year, they set a new record for the number of sea lions there — and now, just as abruptly, they left! This fascinates me. Did they just get tired of the area? Did the number of fish go down? Did they decide they were tired of fog?? So strange!

The Pier 39 website is optimistic, saying they expect the sea lions to return later this year, but the quotes in the Wired article indicate that marine scientists really don’t know much about them, and can’t promise anything. Maybe they’ll return; maybe they won’t.

And a couple days ago, USA Today reported that the sea lions have been found — 500 miles north in a cove full of anchovies! Of course they don’t know for sure if the sea lions that suddenly showed up in Oregon in December are the same animals that suddenly left San Francisco in November, but it seems highly likely.