ABSTRACT

The only previous review of photographic identication of sharks (Marshall and Pierce, 2012) considered what was then seen as a relatively new technique that still struggled for acceptance with some peer reviewers and editors. In the years since, the use of photographic identication (henceforth referred to as “photo-ID”) has been widely and rapidly adopted, and photo-ID has become a standard method in studies of elasmobranch population ecology, movement, and social behaviors. A small number of large, semiautomated (and, increasingly, fully automated) collaborative online databases are routinely used to facilitate data sharing among research groups. The ubiquity of underwater camera systems has led to a dramatic increase in the volume of visual data posted online. The continuing development of computer vision and machine learning capabilities means that the use of photo-ID will continue to expand, with articial intelligence systems enhancing, automating, and assuming responsibility for many of the processes and decisions that are currently performed manually.