This is rather worrisome, coming right on the heels of my post about poor farmers in India allowing migratory geese to coexist with them!
“We have no idea where they moved on to or why,” said Shelbi Stoudt, who manages a team that helps stranded animals in the San Francisco Bay from the Marine Mammal Center in Sausalito, California.
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.
Stoudt averred that the officials at the Marine Mammal Center weren’t worried about the animals’ disappearance from their standard location. The sea lions are migratory animals, after all, and it’s natural for them to move around.
The disappearance is unusual, though. The animals’ numbers usually peak in late fall and many stick around during the winter months before heading south for the summer. According to the Marine Mammal Center’s FAQ on the animals, “from late summer to late spring, 150 to 300 sea lions haul out here,” though their numbers can run much higher.
This year saw a massive influx of sea lions. In fact, a Marine Mammal Center survey conducted in the fall found 1,585 mammals hauled out on the spot, an all-time high. Some of them invaded a neighboring area, the Hyde Street Pier, where they may have been scared away by an itinerant fisherman’s dog.
Apparently some of the fishermen aren’t as enamored of the sea lions as us urbanites:
One recently told a local radio station, “They’re cute when they’re in here lying on the docks by Pier 39, but they’re not too cute out in the ocean when they’re stealing your livelihood.”
So it appears that at least one fisherman, and his pit bull/golden retreiver mix dog, managed to scare off the sea lions from Hyde Street Pier (which does not provide the exclusive protected docks that Pier 39 does, and therefore doesn’t normally get large numbers of these animals hanging out there), apparently to the relief of some there, the Marine Mammal Protection Act notwithstanding. While Pier 39 remained protected and far enough from that dog (or any others) hassling the beasts, one is still left with the nagging feeling that they may have decided that they’d had enough of this tenuous relationship with this human habitat. After all, this wouldn’t be the first time that a dog has contributed to local extinction of some species.
“It’s exactly opposite of what we’ve seen over the last 10 years,” said Sheila Chandor, Pier 39’s harbor master. “I think it’s food. Usually this time of year, we have a lot of herring coming through.”
Chandor said that some sea lions tagged by the Marine Mammal Center had been located south of Monterey but cautions that the link to the sea lions’ food supply is just “guesswork.”
A quick check on the Webcam mounted at the Pier 39 Restaurant proves the sea lions are definitely gone from Pier 39’s K Dock. A dozen or so remain on J Dock, according to Chandor.
The population of human sea-lion watchers remained steady.
Stoudt and her team aren’t sending out a search crew. The sea lions are, after all, migratory, she told Wired.com.