10 April, 2013 10 April, 2013

The Great White Shark Debate – Another View

When the video of a great white shark ramming its head between the bars of a shark-diving cage first started going viral on YouTube a couple of weeks back, we were interested to hear the thoughts of someone with a little more knowledge of the ocean’s apex predator.

Long-time Zag scribe Anton Louw has penned many an article on shark cage diving, and has a keen interest in our toothy friends. Below is his opinion on the incident, as well as a few words to catch-up on the work done by Ocearch since their controversial operations in South African waters last year:



I’m not a shark expert. But the creatures do fascinate me and I enjoy listening to people who are experts and then writing about it. I don’t take any pleasure in taking a contrarian viewpoint. I don’t enjoy starting sentences with, ‘well, actually…’ but I do believe in skeptical reasoning over emotive lashing out. Admittedly, it’s with a certain reluctance that I wade into these waters again.


A close-call was filmed and went viral stirring up venom and bile in its wake. At first viewing, the video of the shark lunging through the gap in the cage looked pretty bad, and would seem to confirm that the shark wanted to bite off the face of the cage diver within. Of the million plus who saw the video, there were naturally quite a few concerned surfers – myself amongst them.

But, again, when you’re not a pro, there’s often more to it than meets the eye. It’s a bit like whenever non-surfers portray us in whichever form of media. Surfers see it with an  an expert eye and cringe. We know so much more than the director or the general audience. Similarly when a biologist, who has vast reference of shark behaviour to fall back on, looks at the video they can see way more than teeth lunging at a face.

It would be impossible to gauge everyone’s reaction and responses to them, but on Zigzag’s own posting, a commentator calling herself ‘Sharklady’ had a very measured reaction based on what comes across as extensive experience. There’s little emotion, more reason, and so that sort of response carries more weight with me. In chatting to another shark researcher, she generally agreed with what was posted there, noted some minor factual errors, and also added that there would probably be a few divergent opinions amongst the research community. I still fall back on those who do know more than me. Yet, I’m not aware of any qualified person stating that this is evidence of increased aggression towards humans. I scanned a few websites hosting the video, most had a few witness comments, no-one had an expert opinion. Perhaps they were hoping for something damning and couldn’t find it, perhaps they just didn’t bother. And I’m fairly sure that as this video has been seen around the world by just about everyone who is an expert. Based on this, I accept that the shark was more curious than intent on eating the human within the cage.

Viewing sharks from the safety of a steel cage has proved a tremendously popular (and lucrative) tourist activity in the Cape.

Viewing sharks from the safety of a steel cage has proved a tremendously popular (and lucrative) tourist activity in the Cape.

Yes, the shark hurts itself. And, yes, the diver also could have sustained injuries. These are good reasons to use this event to adjust the cage design to ensure that this does not happen again.

The industry is often called out for not being accountable as it could be, nor making the sharks’ well-being a priority. ‘Finding a Balance’, a 2004 paper, commissioned by the City of Cape Town in partnership with the WWF and DEAT examined a number of possible causes for a spate of attacks. Although it failed to link cage diving (or anything) to attacks, it did make a number of recommendations for the industry. None of these have been implemented. This is a good opportunity for the industry to engage the wider ocean using community and show that they are serious about addressing shark wellbeing and accepting accountability.

Having written about cage diving on a few occasions, I’m well acquainted with the standard objections to it, but won’t discuss them here as they’ve been covered before. I will deal with them as they arise in the comments section. In the end, I’m still undeterred by cage diving. There are still some spots around Gansbaai and the general area that I’m keen to hit this winter. My advice is to surf as you always have, and forget about sharks while you do.

Unless of course, you’ve been surfing some places that show up regularly on:


OCEARCH and the Shark Wranglers caught a fair bit of flack when they were out here. I felt most of it was knee jerk and unjustified. I also felt that it was drummed up by a few figures in particular who were jealous of the scale of OCEARCH’s operation and their ‘intrusion’ into False Bay. The fatal attack that happened during their expedition was tragic, and seemed to vindicate the clamour, but in the end, it was concluded that it was an awful co-incidence – they do happen. In the end, OCEARCH themselves learned a lot about engaging the public and the research resulting from their efforts is impressive.

Ocearch's Shark Tracker app has allowed free access to data of tagged great white's movements. (click image to go to app)

Ocearch’s Shark Tracker app has allowed free access to data of tagged great white’s movements. (click image to go to app)

Some things have changed for OCEARCH since their visit. Firstly, they are no longer selling TV rights – they’ve been funded for 3 years and 9 expeditions by Caterpillar. Chris Fischer is stoked as this enables them in a number of ways. Firstly, they don’t have to worry about making ‘good’ TV. “I’ve always been an ocean guy, who then had to do TV, not the other way around”, he admits. Although he maintains they always kept the purity of the mission, in some aspects they were compromised. The most pertinent is they were contractually restricted from interacting with the public as this would ruin the element of suspense needed to keep viewers tuned into their show. Now, they’re freely able to engage where ever they are, and they’ve leapt at the opportunity. Take a look at this video where they surf and chat to locals. “We now like to meet locals in advance, before we arrive. Apart from gaining their support and involving them in solving their own puzzle, they’re often a great source of information.” This was a lesson they learned here. They even check the forecast and if there’s good conditions for surf, they’ll wait or go somewhere else.

In the meantime, the data coming from their trip here is being put to work. Two dozen academic papers are being produced as a result, and the end goal of this is to affect policy. ‘I’m a data driven centrist’, says Chris. “The idea is not to polarise, but to bring people together to be able to make the right decisions for long term benefit of the ocean.” In another year or two, as the results of the study are released, we may begin to see that happening here.

One big question researchers had here, was where do the sharks go? They have protection here and in Namibia, but if they were straying North of Ponto D’ Ouro, and more than 200 Nm offshore they would be fair game.

40 tagged sharks and a lot of animosity later, they began to see what was going on. They also made it freely available here for everyone to keep as up to date as possible. The results are fascinating and discernible trends are beginning to appear. If you haven’t had a look at it yet, you’re missing out.

Ocearch has tagged and released more than 40 sharks during their operations worldwide.

Ocearch tagged and released 40 great white sharks during their operations in SA waters.

But some caution in using it. Firstly, its not a real time shark alert app, as some have been treating it over in the US. For starters, there’s a 2 hour delay between a ping and it hitting the web. Then, they tagged 40 sharks, which is the largest sample of its kind, still reckoned to be a fraction of 1% of the local population, but even then they’re unsure about that. Chris reckons, “The best way to interpret the data is use it to understand the rhythm of the sharks. They move in distinctive ways according to their sex and point in their lifespan. We reckon we’ve found out where they’re mating in SA. Play around with the settings and see if you can find it for yourself.”

From a surfers’ perspective, it is still useful. As the data come in, the ‘rhythms’ will become more apparent. Alison Kock from Shark Spotters suggests, “one can get an idea of general activity in that area and use it as a guide to better understand times of higher activity, and also because it’s in near real time, the kinds of conditions associated with such activity. For example, on the west coast with Maureen (their largest specimen, who gets around) we (the shark spotters) got a lot of responses from ocean users that the water was much warmer than usual, and lots of birds and dolphins were also about. In that case it also created awareness that whites do in fact swim along that shore.”

And there’s lots to see in the data. Curiously, some areas we consider hotspots – like False Bay (Fishhoek and Koeel Bay in particular), Hawston, Plett, East London and some Southern Cape points – look quiet on the map. Alison explains, “We’d hoped to get a representative sample: 10 each in False Bay, Gansbaai, Mossel Bay, and Algoa, but the practical and logistical constraints prevented this.” So the areas we know are probably as sharky as we believe, but the sharks tagged just aren’t the one’s who hang out there. “In False Bay we only managed to tag three large (4.5m+) females, which the data have shown are the ones who move a lot.” False Bay is also beginning to be better understood, thanks to the data being generated by the spotters, and also from studies made using acoustic tags. This article shows interesting seasonal patterns and is worth a look if you surf the Bay regularly.


A close-up look at one of Ocearch’s satellite tracking tags.

The tags themselves also have their limitations. They only link with the satellite when the fin breaks the surface. Some sharks are bigger ‘finners’ than others and this gives more and better data points. Others, like stealthy subs, hang a little deeper. Maureen, disappeared in late January way down south in the roaring forties before popping up again near Lamberts Bay on the 7th of March. At her last check in on March 12th, she surfaced just of Mouille Point in Cape Town, before slipping away. Where she is now, is anyone’s guess. Some other big girls are busy on amazing journeys, but don’t let me tell you about it.

There are also limitations on the accuracy. The fins need a short while above to get a good fix on position. “We’ve noticed that in warmer, productive waters like the Cape, the tags get more algae fouling and so take longer to get an accurate fix,” explains Alison. Thats why some sharks appear to be inland. Others have their paths running overland, and this is just a straight line between points – Maureen being an example of this, but there are plenty who vanished off the Cape only to reappear in Mozambique some time later, apparently via Lesotho.

As suspected, sharks were ranging beyond our waters and into Mozambique and even further. What is quite chilling is that two of them have met their end one in Mozam, another in Natal’s shark nets, with a 3rd suspected in Mozam. With two or three out of forty sharks dead, that implies a 5% – 7.5% mortality rate within a year. If this is representative of the general population, it’s a serious problem. The researchers aren’t alarmist about it, but it’s something to consider.

The SPOT tags have a 5 year lifespan, so we’ll be able to learn loads more. The sharks also have internal tags good for 10 years which can be picked up by positioned receivers should they swim by. Apart from the suspected mating area, they’re hoping to get clues as to where the pupping ground might be. And the more time you spend on it, the better you’ll understand them. But, if there’s a ping off your local, you can probably relax. The odds are there have been plenty of sharks a lot closer to you that you didn’t know about.

This is Mary Lee, one of the biggest white sharks caught, tagged and released by the Ocearch team.

This is Amy, one of the bigger white sharks caught, tagged and released by the Ocearch team. She measured just short of five metres long, and weighed over one and a half tons.

To wrap up here, I’ll say that despite attacks, we need sharks. You would rather accept the small risk of an attack, than surf in what the sea will become if there are no sharks. For this we need researchers to do their job – there’s still a lot we don’t know, and they’ll admit it. Their aim is not to make cash while surfers die, but to understand the sharks so as to affect policy change and conserve them for our oceans’ future. In meeting with policy makers, they need to back up their positions. To do otherwise, would be to look foolish.

They are far from being unsympathetic towards the surfing community. Many surf themselves, almost all of them dive recreationally. They recognise fellow ocean users as the key to helping the wider public gain an empathy for what we all hold dear. Yes, some of what they do is not pretty and quite invasive, but in the absence of better methods, their choice is either that, or not do the work and remain ignorant.

As for cage diving, I don’t have a huge issue with it, but I believe there is room for them to improve on their service – both in terms of shark and human safety, and in offering more emphasis on education focussing on conservation. I have a much bigger issue with shark nets, but that’s a topic for another occasion.

I’m sure there’s plenty written here that many will disagree with, and I’m happy to discuss this in the comments below. If you want to call me out on something, please do. If you want to raise your own points, go for it. Whatever you say, be able to back it up. Let’s just keep it civil. Just like guys arguing about whose wave it was, by the time it gets to pointing and shouting, no one’s going to win. Both parties just leave thinking the other is just a dick.


For more white shark reading, you can also check out: http://www.surfermag.com/features/east-coast-shark-tracking/


  1. Robin Mousley
    10 April, 2013 at 11:26 am · Reply

    Great article Anton!

    “You would rather accept the small risk of an attack, than surf in what the sea will become if there are no sharks”

    I completely agree. But are there any articles around that describe the probable consequences of wiping out an apex predator?

    • Anton
      10 April, 2013 at 12:42 pm · Reply

      Hi Robin

      Good question. One of the defining moments in this field was when wolves were reintroduced to Yellowstone NP in Wyoming. Until then, research had been focussed on the way predators limit prey numbers. But when an apex predator was reintroduced to the forest it altered the behaviour of prey, and consequently the entire ecosystem in ways that were far beyond prediction. It becomes very complex very quickly, but I know of research going into seal behaviour at Dyer Island.

  2. Gina S
    10 April, 2013 at 11:29 am · Reply

    I would have liked you to delve more into the research done on the correlation between cage diving and shark attacks. Both sides of the debate seem to tout research proving their point…I wonder which side is skewing the data? Or if we simply don’t know enough? Maybe next time you can get into that more. Thanks!

    • Anton
      10 April, 2013 at 12:56 pm · Reply

      Your best resources, that i’m aware of are the finding a balance report: http://awsassets.wwf.org.za/downloads/23_finding_a_balance__white_shark_conservation_and_recreational_safety_in_the_inshore_wa.pdf

      and then a recent paper from South Australia: ftp://ftp.marine.csiro.au/pub/Bradford/Hayden/Bruce_Bradford_Effects_of_Berleying_2011.pdf

      This last one is often quoted as evidence the cage diving is leading to attacks, or more correctly, but ambiguously ‘changing behaviour’. Yes, behavioural changes are seen, but not in a way that would lead them to become more aggressive, although this is mentioned – once, briefly.

      It’s not so much that data is being skewed by the camp opposing cage diving, but that they misinterpret information. You’ll often hear “Attacks have increased since…” but do so without working through the figures themselves.

      I’m not aware of anyone with qualifications who believes that that there is a link. And there’s a lot of international scrutiny in the scientific community. If our researchers were releasing bogus results, the odds are someone would call them on it.

      In the end, yes, there is a lot we still don’t know. But in carefully examining everything that we do know, and not cherry picking ‘facts’ that suit us or using oversimplified metaphors, we can be confident enough to say that there is no link.

      • ROB
        12 April, 2013 at 10:43 am · Reply

        Thoughts : I would like to think that(and i am sure we do not need to be qualified), the mere fact there is such a thing as Shark Cage Diving, it has created an influence on their behaviour. An adjustment to natural behaviour could bring out the best in anything, however has it been proved not to bring out the worst.

  3. Jonesy PE
    10 April, 2013 at 12:14 pm · Reply

    I pray for a Shark alarm system intergrated into your board that bleeps,flashes and goes MAL everytime one of these big Aunties or her smaller cuzzies are

    within a 1 km range of me/you.

    But I guess I’m a dick thinking that way …..cause technology just can’t do that yet heh ? Like a car you by with ABS ……buy a board with HFSA huge flippin shark alarm.

    Ag what ever !!!!!!!There is no money to be made in saving surfers limbs or lives .


    • Anton
      10 April, 2013 at 1:00 pm · Reply

      Part of the research Ocearch did was swabbing the bacteria from the shark’s mouths in the hope of developing an antibiotic for victims. So, someone is spending money and time that might save our lives and limbs. I doubt that there’s money to be made off it, and it won’t save anyone from blood loss, but it just could spare you an amputation or life ending infection.

  4. CT Surfgirl
    10 April, 2013 at 6:10 pm · Reply

    Great article Thank you! Only thing I’d like to add is there is no way of knowing why that particular person in that cage attracted the sharks attention……Maybe it was a smell, a hormone, an emotion the shark was sensing, something about the cage….just the same as why do sharks sometimes attack swimmers and surfers but mostly not…I don’t think it is any indication of sharks suddenly becoming aggressive towards humans. Although who would blame them with what humans are doing to sharks globally.

    • jemfrim949
      11 April, 2013 at 2:16 am · Reply

      It may appear the shark just went for the cage on some sort of cue you mentioned but typically when you see a shark run into a cage it is referred to as a “bait handler error”. In other words, the shark went for the surface bait at the wrong angle and was led into the cage. With low visibility and various other factors this happens, more often than not, by accident. However, just as in the bush a lion does not see individual humans sitting on the truck a shark does not discern between the humans and the boat/cage.

      Just to provide some credibility to my claim, I work on a cage diving boat and a white shark research institution I’m also an avid surfer and diver.

    • Anton
      11 April, 2013 at 4:55 pm · Reply

      When I look at the video, it looks like the shark goes for an exploratory bit of the buoy on the corner and in turning its head to do this, it puts it through the bars. But, Jemfrim probably has a better perspective of things like this.

      If you do go cagediving, the different personalities of sharks becomes immediately apparent. This may have something to do with why some sharks are more aggressive – to anyone or anything. Still, most attacks do appear to be inquisitiveness or mistaken identity.

      And, yes if they realised what we’re doing to them, we’d be in big trouble. Though, I’m more afraid of dolphins working that out.

  5. Jamii Hamlin
    11 April, 2013 at 8:49 am · Reply

    Great article!

    I have always been fascinated by sharks, growing up I read every National Geographic article I could to understand a little more about them as I felt the best way to demystify sharks was to educate myself about them.

    Some 12-13 years ago a few mates & I went cage diving in Gans Baai to realise these beasts are graceful, curious, and apart from young “teenage” 3m GW that still needed to learn lesson and prove themselves, the 4m+ are very caution about humans as they mature and far different from what the general public understanding is.

    During my dive experience, the younger male displayed aggression towards me in the cage in a way to intimidate me from competing with him for the food source, he only appeared after the big ones had lost interest to repeatedly scrape the cage and come nose to nose in mock attack! Yet the older wiser females showed no interest in us in the cage and took long intervals between returning to the bait after missed passes. The females didn’t display any aggression, almost seemed shy and nervous about our discharging bubbles, so much so that I wanted to free dive with them, but in no way considered it safe with the younger male.

    Sharks are part of the sea and should be celebrated every time you see one.

    I am careful in their presence and have rarely felt threaten by them, yet I don’t take unnecessary chances and leave the water if I “feel unsafe or realize there is high risk”. Easy enough whilst surfing a beach break however sometimes being 4-5 km out to sea paddling a surfski gives you little option but to respect them and hope the feeling is mutual!

    It is nearly a year since David’s attack at Kogel Bay, it appears now to be a case of bad luck, as the weeks prior to the fatal attack there was high sea life activity in the bay. We witnessed numorous sighting in Strand/Kogel Bay even a small GW breach kill a small seal at caves 3 weeks prior, yet most continued surfing even if only a few took a 5 min break before going back out. We know there are risks and often don’t read them such as the tell tail signs of birds circling in the air etc, and then often want to blame others when things go wrong…..best advise is educate yourself and realize the sea is almost a safer place to be than driving your car home after a few cold ones!

    I do accept to some degree that ‘cage diving’ can distract sharks from their normal feeding patterns and associate chumming with humans, but it is no different in my opinion from fishermen gutting their catch and chumming the water as they chug back into Kalk Bay or any other harbour near a surf or swimming beach!

    Shark dive operators get a lot of negative credit for their practice and the ‘educational’ role they offer, my sentiments are that they need stay well away from surfing & swimming beaches and a portion of their income should be given to the Shark Spotters or into a trust for shark attack victims.

    • Anton
      11 April, 2013 at 5:01 pm · Reply

      Some good ideas there.

      Research is beginning to show a correlation between water temperature and shark presence – possibly related to prey movements. The difference between 14 and 18 degrees at Muizenberg means 8x the likelihood of a shark being sighted, and 5x at Fishhoek. Also, when Maureen was on the West coast, ocean users noted warmer waters and much more bird and dolphin activity.

      • Jamii Hamlin
        12 April, 2013 at 9:10 am · Reply

        In the weeks preceding the Ocearch and David’s attack, there was a massive mount of baitball activity, to the extend that Tuna was being caught inside the bay and apparently they were followed by Orca Whales!

        One observation that stuck out from a cage diver operator who got to Kogel Bay within hours and reports from those whom witnessed the attack, was the enormous presence of sea life.

        The s/d operator noted the high bird activity as a quick indication to them following the pelagic fish, which are follow by game fish, which are followed by dolphins, seals and other apex predators.

        The surfers accounted on the day the dolphin activity was so great at times that they struggled to paddle out….whether they were warning the surfers or just playing in the waves it is unknown!

        Bottom line is, as important to checking wave quality as well as looking for tell tail signs of fish activity.

        Fishermen above Caves have often told us that we are crazy to surf there, due to the amount of fish activity they have seen off there for many years. Just like Fishhoek, Muizenberg, the Hoek and along with Caves with the Shark Spotters now doing duty, these beaches have numerous warnings during season & are being closed on a regular bases….not because there are more sharks, but because we have become more awareness of them.

        Just a comment on the water temp, would it be beneficial for Shark Spotters to record this on a daily bases for the researchers to correlate this to movement and activity?

  6. Shark Raving Mad (man)
    1 May, 2013 at 10:01 am · Reply

    Justanother (sigh) well-written pro-cage dive article. Is the author receiving kickbacks 😉
    ‘Sharklady”s measured comment from experience is rather subjective as
    ‘she’ is one of the biggest chum-based cage dive operations, standing to
    lose alot of money should negative press like aggravated sharks nearly
    biting off customers faces get too much press.

    Why has nothing
    been done to improve safety since recommendation in 2004 paper? Because
    they are making too much money to care until forced to do so by law.
    concede OCEARCH’s research data is valuable, but the methods of
    extraction are not something animal-lovers can be too proud of. Bating
    (chum), hooking, removing from Ocean environment, mutilating

    But i’m an unqualified non-scientist so my two cents not worth much hey..;)

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