A marine biologist‚ an applied mathematician and a software developer from Stellenbosch University have combined their expertise to develop a custom-made software package‚ called Identifin (view YouTube video)‚ documenting shark profiles.
The lack of a standardised procedure for collecting data about elusive and hard to find species like the great white shark has to date seriously hampered efforts to manage and protect these animals
Dr Sara Andreotti‚ a marine biologist in the Department of Botany and Zoology at the University‚ has collected over 5‚000 photographic images of the dorsal fins of white sharks along the South African coastline as part of her research.
She spent six years building the database with information on where and when individual white sharks are sighted.
“I nearly lost my head. I quickly realised that in the long term updating the database was going to consume more and more of my time. That is when I headed over campus to the applied mathematics division and asked for help‚” said Andreotti.
In those cases where she was able to collect a biopsy from the shark‚ the genetic information was linked to its profile.
The image recognition software they developed‚ Identifin‚ compares a semi-automatically drawn trace of the back edge of the dorsal fin to existing images in the database.
The images in the database are then re-arranged and ranked by probability of match. If there is a match‚ the database photograph in the first position will be the correct one.
“The software had to be capable of quickly matching the fin identification of a newly photographed shark with a possible existing match in the database‚ and to automatically update the sharks’ ID catalogue. The database also had to be user-friendly and structured in such a way so that different researchers can use it over the long term‚” she explains.
She said while there is still room for improvement‚ the success of the first trials boosted their hope that in the near future they will be able to use Identifin to monitor white shark populations on a large scale.