Hi-tech vision zeroes in on sharks lurking off Cape Town beaches

12 February 2019 - 10:59 By DAVE CHAMBERS
Shark Spotter Monwabisi Skweyiya on the mountain, high above Fish Hoek beach.
Shark Spotter Monwabisi Skweyiya on the mountain, high above Fish Hoek beach.
Image: Halden Krog

Technology is coming to the aid of Cape Town's Shark Spotters.

The organisation has teamed up with experts in computer-aided vision to develop an automatic shark-detection algorithm.

Field work has begun on Fish Hoek beach, where footage of sharks is being collected for analysis and development of the software.

"While footage of live sharks is collected where possible, a decoy shark is also being used due to the sporadic and unreliable nature of shark sightings," said a statement on Tuesday from the City of Cape Town, which funds the Shark Spotters with the Save Our Seas Foundation.

The research is expected to see fixed cameras deployed above beaches within 18 months, but they won't mean the end of human shark spotters equipped with binoculars and walkie-talkies.

"The automated system will not replace the spotters employed in Cape Town, but rather assist them with more reliable and accurate shark detection," said the statement.

Since 2004, the Shark Spotters have recorded more than 2,500 shark sightings. "The development of the automated shark-spotting system will build upon this strong foundation and help to overcome some of the limitations the programme currently experiences including the need for natural elevation [mountains] and the potential for human fatigue and error."

Marian Nieuwoudt, the mayoral committee member for the environment, said environmental and experimental variables were being recorded during the data collection to assess their impact on the software's ability to detect sharks, and to compare results to the effectiveness of the human-based spotting system.

"Shark Spotters has been at the forefront of sustainable shark-bite mitigation measures worldwide since it started in 2004," said Nieuwoudt.

"We are excited by the new possibilities that this automated shark spotting research project presents and hope it will result in a system that enhances shark safety at beaches across the city."

The team working on the algorithm includes the Institute for Communities and Wildlife in Africa at the University of Cape Town (UCT), and PatternLab SaRL, a Swiss research and development company specialising in data science and computer-aided vision.

The research is being funded under the Eurostars programme, an international scheme that supports innovative projects led by research and development.

In SA, the funding for Shark Spotters and UCT is administered via the department of science and technology, while PatternLab’s involvement is financed by Innosuisse, the department’s Swiss counterpart.