Defining a Methodology for Selecting Identification Techniques

Individual identification of marine turtles through flipper tags, PIT tags and photo-identification is essential for monitoring or estimating populations using capture-mark-recapture approaches. It allows key demographic parameters such as survival, abundance and remigration intervals to be quantified, while also reducing bias linked to double counting.

In 2025, TOTM supervised a civic service project dedicated to developing a decision-support tool for individual identification techniques in marine turtles, with the goal of improving data quality. This work was carried out in collaboration with Claire Jean, a specialist in identification methods and TOTM board member, as well as with the Kelonia team, the Sea Turtle Observatory of Reunion Island.

One of the project’s objectives is a scientific literature review, which will soon be submitted for publication, covering the different identification methods such as external tagging, internal tagging, photo-identification and genetics, and analyzing their advantages, limitations and contexts of use. In parallel, a detailed technical report was produced, including a decision tree and comparison tables to help managers, researchers and field practitioners choose the most appropriate methods according to their objectives and constraints.