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Why great white sharks are disappearing from South Africa’s coastline

Eleven years ago, out in the cool, coastal waters of Gansbaai on the Western Cape’s Atlantic seaboard, Dr Sara Andreotti was awed by how many great white sharks she would encounter in the white shark capital of the world: 15 a day on average.

The Stellenbosch University marine biologist remembers how her research partner, conservationist “Sharkman” Mike Rutzen, told her how he had seen as many as 40 white sharks around the Dyer Island nature reserve near the small fishing town in previous years.

Now, other than a few sporadic sightings, white sharks have vanished from Gansbaai and False Bay, both hotspots for the iconic, mysterious species and lucrative shark ecotourism.

“My research partner [marine biologist] Mary Rowlinson, is happy when she sees two or three great whites in Gansbaai,” Andreotti says. “It’s very sad.”

According to shark specialist and cage-dive operator Chris Fallows, the same disquiet exists in False Bay, about 100km away. 

“We haven’t seen a great white shark at Seal Island for the last two years — we used to see about 200 different animals every season. The great whites are completely missing,” he says. 

The apex predators, which have survived for 400-million years, are in deep trouble. 

“We’re seeing the extinction of [great] white sharks along our coastline, and people are not even blinking an eye, but it’s like tigers, elephants or rhinos disappearing off this planet.”

Why have great whites vanished?

There are two prominent theories. One is the recent appearance of a pod of orcas, or killer whales, in Gansbaai and False Bay, which specialises in hunting large, coastal sharks like white sharks. This has scared off the great whites. 

The other is the decline of white shark food from intensified fishing of small shark species, such as smooth-hound and soupfin sharks. The local shark demersal longline fishery, which sets kilometres of baited hooks on the seafloor, exports smooth hounds to Australia, where they are sold at fish-and-chip eateries as “flake”. These vessels have been caught fishing inside marine protected areas.   

The International Union for Conservation of Nature classifies smooth hounds as endangered and soupfins as critically endangered. The department of environment, forestry and fisheries has admitted both species are overfished. 

Panel of experts

In May, mounting public concern about shark populations and the ensuing conflict between fishers and tourism operators prompted Environment Minister Barbara Creecy to set up an expert panel to formally review the country’s national plan of action for the conservation and management of sharks.

Its report found there is “some evidence for a causative link between the appearances of a pod of orcas that had specialised on preying on white sharks”, spurring their shift from west to east.

Since 2015, this killer whale pair, dubbed Port and Starboard, has been recorded 41 times between False Bay and Gansbaai, preying on sevengill sharks, white sharks and bronze whaler sharks. 

“In 2017 the same pair were suspected of killing at least five large white sharks in Gansbaai. The increased presence of these shark-specialist killer whales may explain why white sharks have remained absent in False Bay and Gansbaai, but present in Mossel Bay, Plettenberg Bay and Algoa Bay,” the report stated.

It cited a 2019 scientific paper showing how white sharks disappeared from an area in the Farallon Islands, California, for up to a year when orcas passed through their hunting grounds.

Shark ecotourism ‘laid to the sword’

Orcas are unlikely to be the main culprit, Andreotti says. 

“The feeling I’ve got from the report is that they’ve been trying to find an excuse for not seeing white sharks that will not necessarily prompt action from fisheries. So it’s not the humans’ fault; it’s not the fisheries fault: ‘We’re doing everything right, and nature just happened to chase the white sharks away from our coast.’

“Some orcas could chase some white sharks out of an area for a short period. But saying two orcas will make the entire population disappear overnight, based on five sharks that in a very short period of time were found in Gansbaai, is a hell of a stretch.” 

Call of the sea: Marine biologist Dr Sara Andreotti says sharks must be managed as a sustainable resource for our blue economy. Photo: Stefan Els/Matie Media

In 2016, the results of Andreotti’s seven-year study revealed only 353 to 522 white sharks are roaming the country’s coastline, comprising one single population with low genetic diversity.

Several local shark scientists disagreed with Andreotti and her team’s “pessimistic” prediction for white sharks. They wrote a rebuttal in the same journal in which her findings were published, stating, “due to the complex stock structure of white sharks and the model assumptions made by Andreotti et al, the conclusions drawn cannot be supported by their methods and data”. 

Andreotti says more analysis was conducted, confirming the initial findings. The panel ignored her findings, she says.

 “Our research in 2012 showed how white sharks have been in a poor state for years because of depleted food resources, fishing by-catch, poaching and legal shark nets and drum lines in KwaZulu-Natal, you name it … We’ve been affecting this population for decades, and now we see the result of poor management,” Andreotti says. 

Fallows concurs. “We’ve had 43 different interactions with orcas and white sharks at False Bay and Seal Island and never noticed any difference in the white sharks’ behaviour and a decline in numbers. I’m not disagreeing with the fact that those two orcas probably did kill a couple of white sharks, but in no instance in nature does one apex predator completely displace another from pretty much an entire coastline just by their presence.”

He says the government hasn’t been prepared to admit to the incredible damage the demersal shark longline fishery is doing. 

“One of the world’s great coastlines and the greatest example of shark ecotourism is being laid to the sword by a fishery that contributes less than 1.5% of what ecotourism contributes, which is about R1-billion,” Fallow says. 

Mossel Bay marine biologist Dr Enrico Gennari adds there is no evidence to show an eastward shift of white sharks from the Western Cape as the panel indicated.

‘No evidence fishing to blame’

There is no scientific evidence indicating demersal sharks, such as soupfin and smooth-hound sharks, comprise a significant portion of white sharks’ diet, the panel’s report states, describing how they feed on 40 different species. “White sharks have not disappeared from Mossel Bay, Plettenberg Bay and Algoa Bay, even though catches of demersal sharks, specifically smooth hounds, by this fishery has been higher.” 

The decline in soupfin shark stock precedes the development of the demersal shark long fishery by 70 years. 

But for Fallows, this fishery is “like allowing a hunter to start a biltong factory with wild dogs and cheetah in the Kruger National Park”.

Gennari says, despite the government’s revelations that soupfin sharks will be commercially extinct by 2055, “Nobody on the panel said maybe it would be a good idea to remove that species from the allowed catches.” 

The panel says permit conditions have been changed to accommodate a reduction in catches. “If they regulate, but do not enforce, there’s no point,” Andreotti says.

Lack of prudent management

Globally, about 100-million sharks are fished each year. “Part of the problem is we know so little about global white shark populations. That’s why it’s imperative to be overly cautious on how we manage the species, their human-caused threats and their environment,” says Andreotti.

Climate change, too, could play a massive and “sinister” role in the distribution of oceanic prey and their predators, says Craig Smith, senior manager of the World Wide Fund for Nature South Africa’s marine programme. 

“The compliance on board these vessels has been atrocious. The observer programme has been defunct for a number of years.”

In the absence of good data, the legislation makes provision for the precautionary approach. “But socioeconomics seems to override the precautionary approach where there’s a lot more emphasis on livelihoods as opposed to sustainability … Sharks don’t vote for politicians, people do,” Smith says. 

Ripple effects and Russian roulette

Great white sharks, which are long-lived and slow to breed, play a critical role in balancing the marine environment. “With their disappearance, that’s where we start playing Russian roulette with ecosystems,” Smith says.

Rowlinson is witnessing this unfold in Gansbaai. The seal population has boomed, as have the numbers of bronze whaler sharks congregating in the bay, which are “eating everything,” she says. 

“The diversity of the entire area has decreased dramatically … When you take the top predator out the food chain, it seems to crash everything else,” Rowlinson says.

Fewer white sharks will increase the number and distribution of other predators, Andreotti says. “This will have drastic consequences for ecotourism activities, local tourism and the fishing industry.”

Sharks are worth more alive. “Unfortunately, this doesn’t seem to be enough to change the policies towards more sustainable uses of sharks, as a resource for our blue economy, rather than for cheap, exported ‘fish and chips’,” Andreotti says.

This week, a white shark was spotted in False Bay. “It goes without saying that one shark sighting is not an indication of population recovery,” Andreotti adds. 

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