Aarti spoke to Keenan Saiz, who was doing yoga on the edge of the ruins when he saw the otter leap into the water. "Oh it just didn't want to be seen," Saiz said. "For one minute it liked the attention. [Then] it wanted to be away from people as much as possible. I could tell it was a little bit shy. I think the otter is building himself a nest, to take cover from all the spectators."
We could not confirm that the otter is indeed shy, or that his name is actually Sutro Sam. But the Chronicle's Peter Fimrite spoke to Megan Isadore of The River Otter Ecology Project about the creature. "Our best guess is that the otter showed up there and then just quickly swam around the point to Sutro Baths," she said. "This guy could have swum across the Golden Gate. We haven't heard of otters doing it before, but they could."
Isadore also said, "This otter is the first otter recorded in decades and decades in San Francisco, and as far as I know he is the only otter in San Francisco."
(Update: I asked Ms. Isadore via email how she identified the otter as a male. "Anatomy!" she wrote back.)