The girl was with her family on the dock, feeding the sea lion, when it rose from the water toward her face. She then sat on a railing at the edge of the dock, and the animal lunged up, grabbed her by her dress and pulled her into the water.
"Thank goodness, the young lady wasn't hurt, but let it be a warning to everybody: Do not do this," Bob Baziuk, a spokesoman for the Steveston Harbour Authority, told ABC News.
He said it appears that the sea lion in the video was about 1,200 pounds.
A man jumped into the water immediately after the girl was pulled in and rescued her, and people on the dock helped pull the two out of the water. Neither one was seriously uninjured.