WHERE DID ALL THE GREAT WHITES GO?

In Jaws, sharkhunter Quint describes shark eyes as black and lifeless… but he was wrong.

“Great whites have beautiful blue eyes," says Toby Rogers, Research Director of Shark Spotters in Cape Town. "They're very pretty." It’s the kind of detail you only discover up close… and Toby has been up close more times than most.

It's one of many surprises his research has thrown up over the years – such as the fact that great whites have been having a tough decade. In 2017, something no one had documented in South African waters before began to happen: two killer whales began predating on great white sharks – taking animals of up to almost five metres. "Everyone sees white sharks as top of the food chain, and no one can compete with them," Toby says. "But we've all been humbled." 

The whites appear to have abandoned the coastal areas where they had traditionally gathered to feed – specific hotspots around seal colonies that had drawn researchers and ecotourists to Cape Town for decades.

Their absence has had an unexpected consequence. The bronze whaler shark – the species Toby studied for his PhD – has moved in to fill the space. "The ecotourism boats never used to see bronze whalers," he says. "Then the whites disappeared and the bronzies filled the void. While they're not a “formidable” white shark, they've basically saved the shark cage diving industry in South Africa."

Video shows Toby and colleagues attaching an external tag

Into the deep

Understanding where sharks go and why is at the heart of Toby's work. As Research Director at Shark Spotters – a shark safety and research organisation in Cape Town – his role spans data analysis, manuscript writing, fieldwork and training. “It is all centred on understanding what these animals are doing and why, so we can try to improve the management and conservation of these enigmatic predators.” The answer depends largely on what the tags tell him.

Two types do the work. The first goes inside the animal; the shark is brought alongside the boat, turned on its back, a small incision made, and a device the size of a AA battery placed inside. These last up to ten years and work by logging the shark's presence as it passes any of the 160 to 200 acoustic receivers deployed along the South African coastline. 

The second type attaches externally and transmits to satellite, recording data at three-second intervals for around 200 days. "This shark we just got the tag back from was swimming down to about 1,000 metres, in water temperatures of about six degrees," Toby says. "You see them at the surface, but once they're subsurface, the habitat use is incredible." He pauses. "We ask one question and ten more come from that. It's the constant why, why, why. That's what keeps us going."

The early warning system that gave Shark Spotters its name runs alongside all of this: spotters on the mountain above Cape Town and Plettenberg Bay, watching the water, radioing down to clear swimmers and surfers when a shark is spotted. It's deceptively simple and, in the South African context, genuinely effective at reducing human-shark conflict. 

There have been other surprises, too. The organisation recently took on the management of Cape Town's baboon population – 600 animals living at the interface of suburban neighbourhoods and Table Mountain National Park, part of the UNESCO-listed Cape Floral Region Protected Areas, requiring daily management to reduce human–baboon conflict. "I did not see myself ever managing monkeys, but it’s been a fascinating challenge," says Toby. “Although in a very different environment, similar principles apply as in shark conservation: understanding species’ movement and motivations so we can better manage conflict and inform conservation strategies.”