Great white critical status could put an end to shark cage diving

2016-07-21 20:00 -
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Cape Town - Conservation tour operators in Gansbaai have had the great white's back for the longest time - to the extent that spin-off activities such as Shark Cage Diving have become a bucket-list item of note. 

But the latest study released from the Department of Botany and Zoology at Stellenbosch University (SU) indicates the poor genetic stream of South Africa's great white sharks continue to put the local shark population is severely at risk.

In the latest update the research concludes that the great white’s chances of survival are even worse than what was previously thought.  

If the situation stays the same SA’s great white sharks could vanish completely, the university has said.

Traveller24 previously reported on the study looking at white sharks and their DNA along the South African coastline, conducted by researchers from the evolutionary genomics group in the Department of Botany and Zoology at Stellenbosch University (SU) and involved over 302 genetic samples and 5 000 photographs.

New Research: SA's sharks facing serious genetic threat

Dr Sara Andreotti, who collected genetic samples as part of her doctoral research at SU, had to rely on the expertise of well-known shark conservationist, Mike Rutzen, to track down white sharks along the South African coast line. The field work kept them busy for four years, sometimes for up to two months at a time.  

The findings are based on six years of fieldwork conducted at Gansbaai and along the country’s coastline.

According to the latest release from Stellenbosch entitled “South Africa’s great white sharks heading for extinction”, this local population has the lowest genetic diversity of all great white shark populations internationally and is limited to between 353 and 522 individuals. 

Of these, only 350 are breeders able to continue the lineage.

'Extremely low, possible extinction'

“The numbers in South Africa are extremely low. If the situation stays the same, South Africa’s great white sharks are heading for possible extinction.”

Reasons for the decline include impact of shark nets and baiting, poaching for the honour of owning a shark jaw; habitat encroachment and depletion of their food sources.

Shark behaviour specialist Michael Rutzen stated that in the 90s, if he’s gone out to his usual spot close to Dyer Island, he would have between 20 and 48 sharks around his boat; if he went out today, he’d have three.

Rutzen said also states that no one really knew the exact number of great white sharks left in the oceans.

Alison Towner of the Dyer Island Conservation Trust working in partnership with Marine Dynamics Tours says, “The national estimate for great white sharks is under way using data from each respective aggregation site from False Bay to Port Elizabeth,” says

“This will help form a collective from scientists and will provide a more precise dataset and not just a regional snapshot.

“The great white shark is migratory animal and collaboration is key to understanding its population dynamics. Our team continues to monitor and collect data on a daily basis which will be used in collaboration with other scientists,” says Towner.

Apex predators’ massive drawcards for conservation tourism

While the decline of great whites would be detrimental for the ecological stability of the marine environment, these apex predators are also massive drawcards when it comes to shark diving tours – which often aid in funding conservation efforts and in creating awareness of the situation.  

"If better measures won't be put in place to protect white sharks, it is likely that the cage diving industry could collapse in the near future," says Rutzen. 

Enver Duminy, CEO Cape Town Tourism says, “ Shark Cage Diving adds an extensive contribution to the tourism economy and supports families and communities across Cape Town, especially those who live and work close to the sea.”

“While part of the thrill for visitors in seeing these apex predators up close is related to the wildly exaggerated legends, the knowledge shared during shark diving tours includes environmental awareness tips, and a broader perspective on responsible tourism, especially within our sensitive marine environment.”

“It’s essential that tour operators subscribe to ethical practices aligned with conservation so that this incredible experience remains available to visitors, and, more importantly, so that all forms of the marine ecosystem are protected,” says  Duminy.

“The great white shark is one of the oldest shark lineages with an evolutionary origin dating back about 14 million years – they won’t vanish overnight – but as tourism professionals we have a responsibility along with other stakeholders and citizens to act as custodians of our planet.”

Fallows: Capturing wildlife at its greatest

Critical of the state of great whites is Chris Fallows, a renowned wildlife photographers based in Cape Town who has been pioneered the research and photography of the breaching Great White Sharks of False Bay, Cape Town

 “These latest findings certainly push home the fact that it is farce to call this animal protected when we have the world’s largest great white shark killing machine, The Natal Sharks Board, killing between 11 - 60 great whites annually, a staggering 10-15% of the population,” says Apex Shark Expeditions and renowned wildlife photographer Chris Fallows.

“Add to this South Africa also issues permits to legally long line sharks and so it is little wonder that the species is in such a dire state. Over the course of the past 20 years we have noticed a steady decline in False Bay.”

What to read next on Traveller24:

- SHARK ALERT - Be cautious along Southern Cape coastline

-#ShockWildlifeTruths: Dwindling SA sharks in focus on World Oceans Day

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