The tags are difficult to read from the bluff. Because they are on the flippers, which fold up, the tail has to be displayed such that the tag is visible. Then it has to be readable. Numbers rub off in the abrasive sand. Sometimes the number can be read from a photo, blown up on the computer.
Tags are color-coded to indicate where the animal was born. The white tags on this animal identify Piedras Blancas (White Rocks). Gorda, to the north, get purple tags; Ano Nuevo, green; San Miguel Island, yellow; San Nicolas Island, red; Farallon Islands/Point Reyes, pink; and orange for rehabilitated animals. One of the questions the tags help to answer is how often animals return to the beach where they were born. About three quarters of them do. They are not universally faithful to the beach where they started life.
We see all colors of tags at Piedras Blancas.