The Save our Seas Foundation (SOSF) in Cape Town, in partnership with students from Bristol University in the UK, is developing software to aid shark conservation.
The software will allow scientists to auto-identify the dorsal fin of the shark and match it to an existing photograph, much like fingerprinting.
White sharks, also known as great whites, are most commonly found off the coast of Cape Town, surrounding the fur seal colony on Seal Island in False Bay, and have recently been put on the endangered list, according to the WWF.
Alison Kock of SOSF has been studying white sharks since 2004 and says scientists have used sharks' dorsal fins as a way of identification for years, but the photo-tagging process was getting very time consuming, not to mention presenting a large source of error.
With this in mind, Mike Meyer from the Marine Coastal Management and Tilo Burghardt and Ionnis Kaloskampis from Bristol University joined forces to develop the software. Burghardt had previously developed similar automatic identification software for use on African penguins.
According to Cheryl-Samantha Owen, ocean correspondent for SOSF, photo-identification of sharks had already replaced the need for conventional ID tags but these are generally not used on white sharks anymore.
However, she says tagging with acoustic pinging and satellite tags will still be necessary as they collect information photo-IDs cannot, such as fine-scale behaviour. Thirty-five acoustic receivers in False Bay have so far recorded 78 sharks in the area.
SOSF's White Shark Research Programme, Shark Centre, Marine and Coastal Management and University of Cape Town aim to collect a database of white sharks.
This is to record their movements and behaviour around the world, so that through understanding white sharks' ecological needs, protection and management measures are kept up to date and effective, says Owen.
“Another objective is to foster collaboration between scientists from different areas... and with other countries around the world to try their larger-scale movement patterns,” she says.
Photo-ID developments
The need for additional developments of the current system was noted by scientist Michael Scholl of the White Shark Trust at the most recent White Shark Symposium in Hawaii, where automated software was discussed as a necessary technology.
The project itself is based on photo-identification, where the Foundation takes existing photos of the dorsal fins, which are like fingerprints on a shark. The scientists can then enter the photos into the database, matching the fins up to existing photos.
“This specific software and project [is] only for white sharks,” says Owen, but there is other software being used on other species, such as whale sharks.
She adds that the difficulty comes in the analysis, which the SOSF hopes the software will address.
The project can be contributed to by anyone with a digital camera, who can take photos of their white shark sightings and send them to the Foundation, says Owen. “The vision is for anyone to be able to contribute to the project, if willing.”
White sharks are threatened globally, according to the SOSF, and habitat degradation, shark fishing, fear mongering and depletion of food sources are the main causes of the decline in numbers. The white shark population has dropped 90% in the past 20 to 30 years, notes the Shark Coalition.
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