Recognizing individual turtles

Though focused on Hawaiian green turtles (called honu), Turtle Trax explains how to identify individual turtles, which presumably would work for unique identifation of turtles world wide:

One of the first questions that occurs to people hearing about our turtle experiences is, "How do you tell them apart?" This question is of the utmost importance to us. If we could not tell them apart, we could not document the changes in a each turtle's tumors from year to year.

The answer is in the faces. Although some turtles are readily identifiable by some obvious characteristic, such as Noke's missing flipper, many turtles look alike at a casual glance--but not if you examine the turtle's "mug shots" closely.

Like people, turtles have individual faces. Most honu have 15-20 darkish scales on their cheeks, although some have more and some less. Regardless of number, the shape and arrangement is constant and in our experience, unique. This provides a way to tell honu apart.

While we can't prove definitively that no two turtles share the same facial pattern, we have collected plenty of documentation to show that within the Honokowai population, turtle profiles are a reliable way of identifying individual turtles.