Hundreds of sea lions that abruptly blew out of San Francisco Bay's Pier 39 around Thanksgiving have apparently found a new home at another tourist attraction — 500 miles north on the Oregon coast.
Thousands of California sea lions started showing up in December at Sea Lion Caves, a popular tourist draw because of the Stellar sea lions living in the caves.
The California sea lions appear to have made the trip because of an abundance of anchovies at the Oregon site, 11 miles north of the town of Florence.
Scientists say there is no way to say how many of the newcomers came from Pier 39, where the numbers fell from a peak of 1,701 in October to just 20 by the end of November. But it is likely some did, since they easily swim 100 miles a day searching for food between Mexico and Alaska.
Some of the California newcomers came into the cave, but most seem to prefer a nearby rocky beach.
'My gut feeling'
Kim Raum-Suryan, a biologist at the Hatfield Marine Science Center in Newport, noticed the number of California sea lions at Heceta Head had doubled to some 5,000 in December and, like other scientists, figures the simple answer is food.
"My gut feeling is it has something to do with the (ocean warming) El Niño conditions off California, which is driving prey and sea lions up north," she said.
There are fewer herring in San Francisco Bay, and a general decline in sea lion food off California last summer triggered a die-off of young sea lions making the transition from mother's milk to fish.
Meanwhile, anchovies have been plentiful in Oregon waters — so plentiful that brown pelicans that normally winter in California are also hanging around, said Bob Emmett, a fisheries biologist for NOAA Fisheries Service in Newport.
Picking out which of the newcomer sea lions at Oregon Sea Caves are visitors from Pier 39 would be difficult.
Many sea lions are branded, and Raum-Suryan has been recording the brands she sees on sea lions at Heceta Head. But she hasn't found anyone who did the same at Pier 39.
Back at Pier 39, a marketplace and arcade with a view of Alcatraz, public relations director Sue Muzzin was happy to hear a couple dozen sea lions barking Thursday, and hopes any that are in Oregon left their hearts in San Francisco.
"People are taking photos of the dock because it is so atypical," she said. "You don't realize how much you miss them 'til they're gone."