With a very heavy Heart!

This is a terribly difficult post to write.

But the story needs to be told.
At stake, my personal friendship with some good people who I until now considered to be highly intelligent, honest and ethically irreproachable, for which they had earned my utmost respect; but equally at stake, the credibility of a prominent Shark diving operator with a substantial involvement in Shark conservation, and of the agencies funding that effort.

But first, let me try and put things into perspective.
Watch this.



Yes, I've posted it before.
This is the message of Dr. Erich Ritter distilled to its bare essentials, a collection of moronic platitudes, idiotic truisms and bunk science: pure snake oil!
Patric hits the nail on the head when he claims that these PSAs are factually incorrect, moronic in their simplistic assumptions, and dangerous in their conclusions.

But I fear that we may again be totally wasting our time.
Sadly and after years of trying to set the record straight, Ritter continues to enjoy a loyal following, principally from German speaking Europe where some circles continues to regard him as a messianic visionary. I call that movement Sharkitarianism and if you want to perceive the extent of blind adulation he commands, look no further than the incoherent ramblings of his devotee Pascal Gospodinov in the comments section of this post.

Not so elsewhere.
Despite having long attained pariah status in the established Shark research community, Ritter did enjoy an equally remarkable popularity in the USA and the UK, this largely due to his legendary eagerness to bloviate and showcase himself on numerous television productions. Incidentally, and yes I'm digressing, that has not changed: from Sharkwater to Shark Con (proof that Darwin's Theory is flawed ??? Gotta love the man!!!) all the way to Red Sea Jaws and the brand new Sharkwise, Ritter and Sharkitarianism continue to spread like cancer.

All that did however come to a screeching halt when his harebrained theories were debunked by a Bull Shark in a predatory attack in 2002 that nearly cost Ritter his life.
This is that attack.



The aftermath counts as one of the saddest chapters in the history of Shark conservation.
It completely discredited the perceived conservationist and scientist Ritter and by association, it did untold damage to Sharks, Shark research, the Shark diving industry and the Shark conservation movement.

The principal perpetrator: Ritter himself.
He rescinded his word never to allow the publication of the footage and partook in what remains to this day one of the most ignominious examples of Shark porn ever produced, a Discovery program called Anatomy of a Shark Bite that was aired during Shark Week 2003. He then repeated his feat in a subsequent equally catastrophic Discovery shoot, Bull Shark: World's Deadliest Shark (=great, visionary conservation messaging!) that gave Discovery yet another excuse for airing the gory scene. The attack sequence remains a staple of the Shark Week page and until this day, it is being used to advance anti industry agendas, and to forever heap scorn on anybody trying to intercede on behalf of Sharks.
After all, if the the only professional applied shark-human interaction specialist could get bitten, what hope was there for the rest of humankind!

The Shark researchers and the Shark conservationists have not forgotten this, nor have they forgotten the vitriolic personal diatribes that ensued after the airing of the Discovery programs.

Example?
This is an excerpt from a simply brilliant article that was published after the airing of the second Discovery show.
And I quote.

And what became of the great Yogic Heartbeat Theory? How I miss that!
I also liked how Nigel pointed out that the massive strong powerful shark knocked Erich off balance when it bit. In fact you can see Erich flailing around helplessly as clear as day. But in Anatomy of a Shark Bite Erich tells us what has to be the most idiotic explanation in the history of western thought ever uttered by a supposed scientist. He tells us that when he was bitten he lifted his leg so that he would get the bull shark's head out of the water, its gills would clamp shut and it would have to let go. Of course this baloney is just another attempt by Erich to make him seem like Shark Superhero.

Now we are given two reasons why Ritter got bitten

- "We (note the subtle diffusion of blame...) allowed the shark to come in too close." Excuse me Erich but YOU have been allowing sharks to come in too close over and over again. Not "We". It is what you did whenever you had an audience or film camera pointed at you. And your luck ran out.

- Erich admits that there are food particles in the water wafting around his tasty-looking legs and "sooner or later the shark wants to know what these people are." This is the staggering discovery that Erich presents us with: if you stand among hungry, macro-predatory, chummed-in sharks that are searching for food, sooner or later you will be bitten.

But excuse me Erich: 99.999999999999999% of the planet knew that anyway!

Of interest, Ritter has since once again changed his interpretation of what happened: check out this remarkable interview on Swiss Television - pure genius!

Anyway.
There you have it, this is the context.
Which may help you to better understand what follows.

It has led to this recent post, written by real researchers with no connection to Sharks! Simply hilarious, and didn't I tell you that you were in for a treat - Bangladesh Post Office indeed! :)
It is alas also the context for the following message.

Not All Quiet on the Palauan Front Or; Let Your Principles Be Your Guide

Tonight, 22 March 2011, on the island of Palau, during a presentation at “Shark Week” hosted by Fish N Fins, an unpleasant scene was played out before the participants of the evening lectures.

During the Question and Answer session after 60 minutes of Erich Ritter giving an entertaining presentation entitled: “Shark-Human Interaction as a Tool for Conservation”, Douglas Seifert, World Editor of DIVE Magazine in the UK and a fellow Guest of Honor/Presenter at “Shark Week”, asked a question of Erich Ritter regarding his denouncement of sensationalist “Shark Attack” titled publications in his power point presentation when “he was responsible for the most inflammatory reaction against sharks since the movie Jaws with his own “Anatomy of a Shark Attack” documentary for Discovery Channel” and further challenged Erich Ritter’s qualifications as a “real scientist” by failure to use the scientific method of replicability in his ‘experiments’ or submit to peer review at scientific conferences or in scientific publications.

After portraying Ritter as “not a real scientist” and as a ......, Mr. Seifert further offered to have a forum the following evening where the science and statements behind Ritter’s presentations could be debated.

The question was not answered, the challenge to a debate was not addressed and Mr. Seifert was rightfully asked to leave the venue out of politeness to the speaker.

Mr. Seifert heartily apologizes to his hosts, Tova Harel and Navot Bornovsky of Fish N Fins, their wonderful family and staff, Francis Toribiong, creator Fish N Fins and the paying participants of “Palau Shark Week” for demonstrating such poor manners as confronting a fellow presenter and challenging him in front of the entire audience at a gathering for the appreciation of sharks.

Mr. Seifert will not apologize to Erich Ritter until there is a fair and open forum where a discussion of Ritter’s pronouncements and theories given during the presentation are addressed and discussed including Ritter’s statements claimed to be scientific put to the methods of science, real science.

Douglas David SEIFERT

I understand that Douglas has been declared persona non grata at Fish 'n Fins.
I post this after hearing that he has left Palau and that he is presently spending quality time with mutual friends in Raja Ampat.

What more can I say about Ritter after this.
Maybe, that he just won't go away and that he remains as toxic as ever!

When it comes to Douglas' intervention, Chapeau!
It takes an extraordinary person to do what he has done: to stand up, all alone and amid a throng of hostile Sharkitarians and at risk of embarrassing the hosts who are long term friends, and this with the sole aim of defending the truth and one's principles. With all of my imposing size and arrogant self assurance, I am not at all sure that I would have had the same courage!
But this is Doug: where so many of his peers will say and write anything in exchange for an invitation to a tropical destination and diving dog&pony show, Douglas is beholden to nobody and nothing but his own beliefs and professional and personal integrity.
Brother, I am deeply impressed - and you know what that takes!

And what about Fish 'n Fins?
I must say, I was speechless. I am also deeply saddened.
To me, Tova and Navot were the epitome of Mensch - highly intelligent, always witty, profoundly human. Their love and knowledge of the Ocean knows no bounds. And let's not forget their legendary hospitality featuring Tovas equally legendary home cooked meals - epic stuff!
And now this colossal error both in judgement and ethics- to just throw a close long term friend under of the bus!

But above all, there's this.
Tova and Navot have founded the Micronesian Shark Foundation Palau that is being funded, among others, by the SOSF , to the point that Tova is being prominently showcased in a PSA about their research projects.

Check it out: Tova at 4:10 - and Alison at 0:31, Lesley at 0:22, Mahmood at 3:12, Andrea at 1:02 and Juerg at 0:51!
Just beautiful!


In Awe of the Shark from Save Our Seas Foundation on Vimeo.
But the question for me now is, does Tova still deserve to be featured in that lineup.
How does the image of Fish 'n Fins, the image of the MSFP and ultimately, the image of the donors dovetail with the fact that Tova and Navot

• found it fit to grant a public forum and thus promote the highly controversial and utterly absurd propositions of Erich Ritter
• denied and suppressed the reasonable request for a science-based debate
• ostracized the critic

I say, you got to walk the talk.
There has to be a moment of accountability after a failure of such proportions.

Ritter - appalling!

Damn the guy!

I was actually enjoying my blogging retirement.

But this shit and specifically, his underhanded description of that infamous predatory attack by a Bull Shark cannot remain unanswered.

Here is that attack.

No the attack did not happen because the spotter did not do his job.

It happened because (read it - brilliant!) a stupid self-promoting Sharkitarian who had developed the inane hypothesis that they would not bite him as long as he would lower his heart rate, or whatever, decided to wade around, bare-legged, among a pack of feeding Bull Sharks!

I mean, seriously!

And the worst thing?

Despite of the fact that the Bulls Shark disproved his inane hypothesis, camera running, he continues to spout the same pseudo-scientific drivel til this day - and some poor suckers in Germanic Europe believe him and continue to give him money! Case in point: if you can, you may really want to experience the truly epic masterclass in snake oil salesmanship in the YouTube series prowin- pro nature donates 50 000 U$ for Erich Ritter's SHARKSCHOOL e.g. here.
Simply amazing - both the indisputable craft of Ritter and the naivety of his credulous victims!

Anyway.

There's a sucker born every minute, nobody else cares, and he is and will forever remain the laughing stock and pariah of the Shark research community. I just feel sorry for poor gullible Amin who will inevitably end up like all those other gullible past foundations, sponsors and philanthropists, see below: um teure Erfahrung reicher, and tainted by association!

But back to the spotter.

Here's what he had to say when confronted with the allegations.

What a sad and pathetic little man!
Perception is nine tenths of reality to someone like this guy! Ritter, you have always done your narcissistic "martyr" act far too well!

I think back at the events of that day and see him flexing his muscles in an Arnold Schwarzenegger pose while stating loudly for the two cameras...."We aren't afraid of no stinking sharks"!
This was his response to my telling him he should get out of the water as the tide was slack, too much bait and blood was in the water and we could not control the sharks safely after already having several close calls. He looked at me and laughed! My crew and I exchanged worried looks after his comment.

But the Discovery crew said to Ritter..."we only need 5 more minutes of B roll" and Ritter, who was always a whore to the cameras, said "no problem"!

5 minutes later I was fighting to save his life....and did so thru rapid and definitive means.
I still have the blood stained belt I used to tourniquet his leg. I held him in my arms in the emergency flight I had on standby and kept him from going into shock. I stopped the paramedics in the US from reopening the wound when they wanted to ogle a shark bite by pulling off my clot producing dressing that kept him from bleeding out, and sat the day and night in the waiting room thru his surgery and recovery to make certain that he would be OK. He walks to this day because I saved the hanging torn muscle in his leg when others told me to leave it but I wrapped it into his wound and that muscle was surgically reattached and allows him to walk and run without a limp and continues to work his ankle to this day.

He will never know that I got the Walkers Cay company to give him $10,000 for his recovery and a year later when they decided they wanted repayment of that loan....I fought them hard to back off and leave the man in peace.
They agreed.

So as the "spotter" who you blamed for this horrible misfortune in your "little man's life" I say this.
You should thank me Eric for "giving" you a "war wound" which has been your only meal ticket and the only thing that gives you any credibility among the misguided groupies that you pander to. It certainly has not been your scientific insights in shark behavior or papers full of pseudo scientific drivel that has earned you any acknowledgements.

My crime was that I was loyal to you.
Something you know so little about based on that rambling dissertation I just read! You managed to burn every bridge with every solid individual that wanted to believe in you and who would have launched you into a viable scientific career.

Sadly Ritter....You just can't fix stupid!

Thanks for allowing me to rant!
Mike, feel free to print this if you like. 

Gesagt getan!
 

Ritter and the Enablers

Lookee lookee – the Sharkitarians are on the move!

These are the upcoming trips of Ritter’s Sharkschool – and what is more interesting, the names of the enablers!
Don’t get me wrong, if a bunch of whackos want to go on a dive cruise or book a nice hotel in the tropics, all the power to them and especially, to those who take their money! Whackos are certainly one of the most lucrative market segments and the backbone of entire thriving industries – just think of the New Age movement and its various gurus and quacks or, with all due respect, look at the millions raked in by the global Whale watch industry!

But the Shark diving operators?
There’s really no two ways about this: by whatever metrics one applies, Ritter is just a bad, bad guy and any serious and self respecting operator needs to turn down his business, period!
Or is it once again all about the money, as in pecunia non olet?

But back to Doktor Ritter and his track record.
He has pretty much singlehandedly destroyed a thriving Shark ecotourism operation and conservation project on Walker’s Cay when he decided to take the money and allow Discovery to air the infamous footage of the Shark attack (no that was not an incident!) that cost him his calf. He has also conned several Shark NGOs, namely at least the Shark Foundation and Shark Project (and I suspect, at present, the SRI) of substantial amounts of research money without ever engaging in proper research, let alone publishing a single paper in exchange.
But then, one could argue that the past is the past and that it’s none of our business anyway, and I partly agree.

As for his scientific credentials, or lack of, what can I say.
It just so happens that I’ve studied Biology at the same University of Zurich as he and thus know that Ritter is a Wildbiologe, a very alpine and equally arcane discipline investigating the life history of Mountain Goats and the like. Having then self promoted himself to Shark researcher, he has published a couple of utterly irrelevant papers that few have read and nobody ever remembers, let alone cites.
Apart from that, the bulk of his productions consists in several idiotic little publications intended to educate, or whatever, the public at large that have been authoritatively reviewed as follows, and I cite

The lack of references also detracts from the ability to assess some of the claims and leaves one with the impression that most of the book is pseudoscience.

Finally, the volume is prone to hyperbole. For example, calling overfishing of sharks the largest ecological time bomb of all is absurd given our understanding of global climate change.

Although this book should be of interest to a general audience and is well intentioned, it does not add to our understanding of shark biology, their natural behavior, or their role in marine communities.

Ritter’s absurd non science quickly catapulted him to notoriety, and then to pariah status among his peers, at which he obviously decided to engage into what the Germans call Flucht nach vorne and to start thinking outside of the box – which quickly landed him way out there in left field and consequently, in the maws of a hungry Bull Shark.

Other would call it the ramblings of a lunatic - I call what he teaches Sharkitarianism.
Very much like New Age, it’s a mixture of truisms, pseudoscience, Rousseau-inspired romanticism and pseudo-visionary platitudes (check out the atrocious video!) that purports to breach the confines of petty conventionalism by creating a web of half truths and inane intuitive and always untested hypotheses, abusing scientific insights and language and accusing the perceived other side of being small minded, biased and intolerant - and in case I’m being too intellectually lofty here: it’s total bullshit, baloney, rubbish!
Case in point, the ramblings in the video I’ve posted here - pure snake oil!

The modus operandi is this – and lemme tell you, like all successful charlatans, the guy is crafty!
Having correctly, and cunningly diagnosed the Angstzination (a clever combination of the German world for fear and that for fascination coined by his then mentor and now victim Wegner of Sharkproject) for Sharks of the public at large, he has proclaimed himself to be the world’s foremost expert in Shark-human interaction.
The latter is a conveniently self-invented fusion of amateur psychology and untested, and obviously untestable insights from the Global (and once again, utterly irrelevant) Shark Attack File where he equally conveniently happens to be the resident Shark Behaviorist. And let’s not forget his stints as self-proclaimed Shark attack pathologist and his sanctimonious creation of SAVN, now apparently suspended!
Add to it the serendipitous occurrence, and above all, the survival of a veritable Shark attack and you have all the trappings for the start of a lucrative career as the world’s premier Shark Attack Guru - oh and for the German speakers: as Shark Shaman, too!
Wow - talk about having gone off the deep end!

But back to the topic at hand: this is precisely the insidiousness of Ritter’s proposition.
It’s exactly like Discovery’s recent roll-out. Forget the attempt at greenwashing by proffering Shark conservation sound bites - this is exclusively about making money by exploiting the fear of Shark attacks, pure Shark Porn!
By preaching to his disciples that they will only be able to safely interact with Sharks once they’ve given him their money, attended his seminars and learned his visionary techniques, he directly propagates the image of the ever lurking, man hunting monster.
Can you see that too - or is it once again just me who is blinded by conventionalism and incapable of thinking outside of the aforementioned box? Looks like I'm not alone!

As to the Fiji trip, now we know.
Nothing to add to what I said here – and no, it comes at no surprise!

Ritter - at it again!

Oh for crying out loud!

Read this shit.

A prominent Shark researcher comments,

Rubbish. 
Never even heard of that journal. What's the point??? I don't get it. Ritter must be a lot smarter than me.

But is he?

Yes some Sharks do sneak up on divers.

Big deal. We divers all know that all Fishes, not only Sharks appear to know when you're looking at them and moreover, appear to be wary of occasions when we pay them special attention like when taking pictures or spearfishing. Depending on our behavior and the animal's boldness or lack of, this may lead to close encounters or conversely, to flight behavior. It's complicated because of the countless variables - but if there's one constant, then it is indeed the fact that the animals are very much able to discern whether we see them or not. This is hardly surprising as this faculty is an advantage for both predators and prey and also in other interactions, meaning that evolution would have certainly selected for it.

So far so good.

But then come these remarkable statements.

Since nearly 59% prefer to swim very near—less than 1 m—from the sea floor when approaching the test-subjects, we suggest that the ocean floor is used as a form of camouflage, allowing the sharks to better blend in, whereas a mid-water approach may make them more visible against the lighter background, illuminated by the sky. Approaching close to the bottom to reduce visibility reflects a typical stealth behavior.

Really.

Nothing about currents, and the fact that currents are generally lowest when swimming close to the substrate. Nothing about the fact that on sandy bottoms, most of the potential prey will be either highly camouflaged, or partially to totally buried - meaning that proximity to the sand will enhance detection and chances for predation. Dunno about you - but that's where I would swim too, especially in a stronger current and/or when capturing images of wildlife!

And this?

Such an observation could imply that sharks might categorize humans as a potential form of prey. However, if the shark’s idiosphere does indeed reflect a flight initiation distance, then humans can rather be categorized as some form of predator. Nevertheless, there is also the possibility that sharks assume humans to be neither a prey nor a predator and simply accept them as unfamiliar objects. It, therefore, remains unclear whether and how humans are categorized by sharks, but considering the low yearly incident rates between sharks and humans, there must be some factors that hold sharks back from biting more frequently during encounters with humans.

Really.

Firstly, those are Caribbean Reefies not "Sharks". 

How Sharks behave is species-specific, and there, it varies according to location, situation and individually, the latter based on traits like boldness and/or previous experience etc etc. To in any way try and generalize is just simply stupid, like trying to apply observations made on individual Birds of Paradise to all Birds including Ostriches, Tits, Penguins and Golden Eagles!

Anyway, I can categorically assure you that Caribbean Reefs will never assume that a diver may be prey, as a loud, bubble-spewing 5+-feet person is nothing like anything a Caribbean Reef would ever consume! And for the matter, neither would a Basking Shark, Wobbegong or, say, Epaulette Shark! 

I mean - WTF?

Same-same for the idiosphere!

That's akin to somebody's personal space and like with people, it varies according to the culture (or in animals, the species), the individual and the situation = e.g. the individual's mood or familiarity, or the way it is being approached, etc - meaning that invading it may lead to flight, or avoidance or aggression. Or to a kiss. Or to nothing!

And the explanation of why those Sharks approached the divers?

If completely naive of people (and how likely is that?), those Caribbean Reefies could have indeed investigated those divers as potential predators. Or as generic threats. Or as competitors. Or out of curiosity. Or to better hone their sneaking skills. Or playfully. 

Or because they did in fact know people and had learned that some of them are hunters that will eventually lead them to a feeding opportunity. Or, that some of them are providers of food and/or nose rubs. Or because they wanted a hug. Or as potential partners for kinky sex!
 

The reason why "they" don't bite more people?
What has that got to do with Caribbean Reefies approaching over sand? But ever the Shark pornographer, that's all the dude cares about! They don't bite people because they actually got better things to do, lives to live, prey to catch, babies to make, places to go! They couldn't care less about Ritter's phobia and in most cases when they encounter people, there's no reason for them to strike - see here!

Anyway, who knows. 

Not you, not me and certainly not Ritter, see the crap that follows!

Long story short?

Indeed, what's the fucking point!
And so it goes!

Paper - barf!

Would you hand your money to this man?

Maaaan...

Did you see the headlines - as in here?

And I thought those were only Accidents, as per this pseudoscientific snake oil I've found on the SharkSkool webpage?

Anyway.

Stupid me, I went and got myself the paper.

A friendly researcher writes.

This incredibly poorly-written paper is definitely purely meant to serve as another "tick-mark" under Ritter's name. 

There seems to be so much wrong with this "experiment" that "getting published again" is the only reason that I can see behind this paper. 

My favorite line is "To better understand the relationship between sharks and humans, additional studies, like the one presented here, are a priority." 

I would really love to hear Ritter's ideas on just how exactly this can help us understand our interactions with sharks, and WHY studies like this one should ever be a priority! 

Sharks like to approach from behind, great, on to the next obvious statement.

Indeed!

This is merely the latest in a whole series of amateurish fluff (shark attack rates huh - my-oh-my...) originating from the cooperation of the world's only and thus most important sharkxpert and self professed guru of pseudoscience human-Shark interactions, or whatever, with this dude and with the Jersey girl who was likely conned into squandering (even more) donor money in exchange for some perceived and urgently needed academic legitimacy - not!

So what can I say about this stupidity.

I was going to review it in detail but quite frankly, it's so bad that it's really not worth the effort - and incidentally, talk about a simply epic failure of peer review!

Only this.

Let's assume for the sake of the argument that this was a credible and rigorous experiment (it was not!), and let's focus on the conclusions that in brief consist in the observation that those tested Caribbean Reefies would preferably approach divers from behind, with older animals being more wary and/or wily.

• Dooh.
  Every single Shark I've ever encountered knew exactly when I was looking at it, and has always established eye contact - and so did every single Fish! Ask any spearo how wily those Fishes are, and how they instantly perceive being at the center of attention  - and ask any Shark diver how easily one can stare away Sharks, and how Sharks trying to sneak in from behind will instantly veer away when one looks at them!
  That's what terrestrial and marine predators and prey do.
  They keep an eye on each other, with the predators trying to catch their prey unawares, and the prey trying not to get surprised - and to depict this trivial observation as a great discovery is quite frankly pathetic!

• And the great unexplained mystery, and I cite?
  

  The way predators stalk their prey or sneak up on them is often linked with the avoidance of visual contact with the quarry.
  Such a theory demands that a predator is capable of locating the prey’s eyes or at least recognizing its viewing direction. Neither can be assumed for sharks—as the stalkers—in the vicinity of humans, especially in our design, since the chosen human position did not resemble any known prey for any shark species. Although it cannot be excluded that sharks might still be able to make a comparison to a prey species and act on it, our results do not offer explanations as to what that clue might be. Ritter and Amin (2012) showed that human presence does affect the swim behavior of sharks and that larger animals seem to be more cautious in the vicinity of humans than smaller animals. Our results are consistent with this interpretation, showing a significant preference of the larger animals to approach test-subjects via their blind areas.
  
  Since sharks are evolutionarily more distant from mammals than birds, can it be concluded that human gaze might not be detectable at all and that something entirely different is used by sharks to comprehend a person’s viewing direction?
  A satisfactory answer cannot be given since the shark’s perception and capability of sensory organs are much different from both birds and mammals. Similarly, the different medium could also be of importance. Characteristics of water as a solvent could facilitate a so far unknown human emission that might not carry as well in air.
  
  Could face masks have an effect in choosing the approach direction?
  As with bubbles, such would not be detectable should the shark be too far away. Likewise, a shark would need to understand where the eyes of a person are located, hence not just to know the body proportions be known but also how to read these proportions when presented in a kneeling object.

  Right.
  A so far unknown human emission.
  Sez the great Shark shaman!
  
  How about this for an explanation.
  These are not naive Sharks that have never seen divers - the location of the experiment is in the Northern Abaco Islands, Bahamas = the famous Walker's Cay where literally thousands upon thousands of divers have interacted with Caribbean Reefies!
  For the newbies among you: this was that dive - much copied but never equaled!

Think that those Sharks don't know divers?
Think that they've not observed us like we've observed them, that they're not able to detect our orientation and what we are doing even from a distance, and that they cannot approach us from behind if they wish to do so - with the older and more experienced ones being more wily whilst the younger ones are still learning the ropes?
Hell, the researchers tell us that their cognitive and above all, their learning faculties are impressive, and the Shark diving operators who interact with them on a daily basis will confirm that they even recognize individual people!
This is so trivial to be painful!

Anyway.

All I really wanted to say was, caveat emptor - whilst global Shark populations are going to shit, Ritter and the SRI continue to squander donor money on amateurish and utterly useless experiments.

And if you're not careful, that money may well be yours!

To be continued no doubt!

Erich Ritter – new spectacular eco-behavioral Insights!

I just love this pic!

Here’s Ritter on Swiss national television!
Otto C. Honegger is one of Switzerland’s most respected producers and documentary filmmakers and as it happens, an old dive buddy of mine

Am I correct in assuming that you may be somewhat befuddled?
Worry not – I speak that stuff and can enlighten you about the long-awaited ultimate explanation of the ominous
attackaccident and above all, the spectacular deciphering of completely novel and hitherto completely (and I may add: criminally negligently) overlooked Shark behavior!

And lemme say this: once again, the visionary man who has singlehandedly devised the experiments that have erased many of the old theories of why Sharks attack, and proposed new ideas, proves that he remains at the very top of the crop!

Not that I'm surprised.
Coming from a world famous Shark researcher (weltberühmter Haiforscher), extremely popular fundraiser, the only professional applied shark-human interaction specialist and holder of a Ph.D. from Zurich University in “Behavioral Ecology”, investigator and Shark Behaviorist of the Global Shark Attack Incident File, Philantropist, Senior Scientist at the Green Marine Institute a leading marine conservation org,, Adjunct Assistant Professor at Hofstra University and possibly, even Shark shaman (!), this is obviously as good as it gets – and screw the blinded, cowardly, hateful and ignorant detractors !
Who’s that guy anyway?

First things first: a big Bravo! for re-broadcasting the fateful scene as, really, it cannot be seen often enough!
This feat alone will undoubtedly turn all Swiss school children into Shark protectors as, like a great thinker once said, you don't protect what you fear!

The accident (see, I’m learning!) was first described by Marie Levine and then, after rigorous analysis, by the great master himself.
Further meticulous and groundbreaking eco-behavioral research (immer schoen nach dem Motto: Wat kümmert mich ming Jeschwätz von jestern?) has led Ritter to the following ultimate analysis of events.

1:43
Oeppis isch total falschgloffe…
Mir haend natuerli e Situation usegfordered, saegemermal, fuer’s Ferseh, damit’s ae chli spektakulaer usgseht ond ich ha gwuesst, wo da die heikle Ecke sind a dem Projaekt..…ond natuerli e Person aagstellt…. ond leider haett die Person ebe noed uufpasst ond de job noed gmacht ond es isch zum Unfall cho.

Something went totally wrong.
Of course, in order to make it look a little (more) spectacular for the TV channel, we had created a challenging situation but I knew which were the problematic aspects… and of course, I had hired a person… and unfortunately, that person did not watch out and did not do the job, and (thus) the accident happened.
Not surprised – the more as the spotter has already been exposed as a total liar!

But now comes the spectacular revelation!

2:20
De erschti Biss isch au noed e so tragisch gsi – aber daenn isch das Tier noed wegcho ond Haie versuechet natuerli immer zerscht “ich muess weg ich muess weg” ond das isch noed gange, also haett es versuecht, dur mis Bei durezbisse.

The first bite was not so tragic – but then the animal could not get away and Sharks obviously always try “gotta get away gotta get away”, and that didn’t work, so it tried to bite itself through my leg.

Bingo!
What a stroke of pure eco-behavioral genius!
It had always been so obvious – but it took a true master of his craft to finally think outside of the petty confines of the oceanic box and to make the totally logical connection to the terrestrial predators: when constrained, like any self respecting trapped Coyote, Sharks will gnaw their way to freedom!
How could everybody else have been so blind!

And if they know how to gnaw their way out… cage diving operators: you have been warned!

Just in case...
Sarcasm from the ancient Greek σαρκάζω (sarkazo) meaning 'to tear flesh' (=Sharkasm?):
A mode of satirical wit depending for its effect on bitter, caustic, and often ironic language that is usually directed against an individual

Otto – saeg nume, Du bisch dem uuf de Lim gangge????

Time for a new Rant?

From a message by a friend.

Just looked at your blog. Doesn't look like you're fighting with anyone lately. ZZZZZ ...

See? Damned if I do, damned if I don't!

What to do?

Should really I post that anonymous message about this plea bargain?

It reads, inter alia

That article is only part of the whole story.
Having a name like Cousteau can get you out of a lot of hot water...what a pathetic ending to what was going to be a blockbuster investigation about a film crew in a National Marine Sanctuary who deliberately caused the killing of a protected whale calf...

C and his team used zodiacs to separate the calf from the mother so the killer whales could kill the calf. THEN they needed close in shots so they grabbed as many pieces of blubber they could to keep the killers around.
Obviously this was outrageous on too many levels to count, and when word got out Ms Blacks house was raided and the images and video of this event with C heard and shown directing the crew became known.

The investigators were told to refocus the entire investigation after C went to his buddies and begged for help - powerful folks indeed.
The deal Ms Black got was part of this fabrication, she would be the fall gal, in return for a light sentence. She gets to keep her boat, her titles and research permits, basically everything she started with.
C got his documentary, made money, and continues to this day to be "Advocate for the Oceans"...so do all his friends.

NO ONE in the oceans community is free from guilt on this.
Complicit in this and was in fact asked to step in and help clear Mr C and his team from wrongdoing?
Sylvia Earle...yes Ms Marine Sanctuary herself!

Or what about the irritating David McGuire.

Should I really re-blog this post and state that quite obviously, something stinks - and that I'm not in the least surprised?

Hardly.

Let others do the dirty work and the investigating!

This is all happening in California that probably boasts the world's highest, and I may add, highly incestuous concentration of marine conservation activists and orgs, from legit all the way to frothy do-gooderism and that toxic mixture of outright liars and cheats, pompous bloviating firemen and outrageous new age whacks.

Let them weed out the rot in their midst and for once show some backbone instead of all that karmic political correctness and collective koombayahing - that baby Whale story literally screams Sea Shepherd and I'm tempted to say, all theirs!
Or how about if Dan Noyes did some real investigative journalism for a change?

But then again... :)

And what about Lupe.

Should I really post that Ritter and his Sharkitarians are mounting a free-diving (= out-of cage) research trip (!) and that this is the inevitable consequence of the shenanigans of the past seasons?
Should I point out that tourists are being abused as guinea pigs for Erich's pseudoscientific BS - notabene unter hoch verantwortungsbewusster, fachmännischer Anleitung, meaning under highly responsible and expert guidance? Of Ritter and this dude? Hah!

Maybe - but then I would probably have to add that a) this is illegal, b) at this rate, somebody will get killed and if so, c) it will be 100% the fault of the operator and that as a consequence d) the Mexican authorities will step in and shut the place down.

But then again, I've been ranting for years and nobody gives a shit - so why bother!

Decisions decisions...

Shark Conservation and the Holocaust?

Total baloney - and Jupp's totally agrees! Source

Wow.

Out of the blue, Josef Freiherr von Kerckerinck zur Borg has just seen it fit to post a comment on an old post about the Phytoplankton nonsense.

Normally, I wouldn't bother.

Europe is awash in pompous Niederadel, a dime a dozen, and one more messianic Hainarr who has done some Shark dives and now believes that he knows something about something is neither here nor there, totally irrelevant. But Jupp is of course the President of the SRI, and as such, their BS and his assorted platitudes are being regularly  mentioned on this blog, inevitably not in a flattering way.

Case in point, his revamped website.

The Phytoplankton reference is thankfully gone, along with the laudatio of his friend and guru Erich Ritter.
Instead, immer schön frei nach dem Motto I am not a scientist nor am I claiming to be one; but I am not stupid either, we find pearls of erudition like

By the year 2017 nearly 100 of the approximately 500 species of sharks will have been extinct. In the eyes of many scientists, the Great White Shark (Carcharodon carcharias) is already biologically extinct.

And we learn that

They keep water-birds (!!!) and seals (!!!) at viable numbers, that coral reefs without reef sharks will die within one year (repeated in this recent and otherwise charming interview on German television), and that if we humans continue to destroy this controlling factor in the ocean, we will eventually create the largest ecological disaster in the history of mankind - see Ritter here. Yes that would be Shark fishing - not climate change, habitat degradation and pollution!

Whatever - as I said, it's all rather irrelevant.

But this I believe is egregious.

This is the comment by the president of the SRI, re-posted in its entirely lest it gets "accidentally" deleted.

Mike Neumann is a very mean person and a bloody liar. Quoting things out of context, to make me look bad; quoting things I might have said years ago, when I had little or no knowledge about the ocean and the sharks, is typical for him. I don’t believe that I ever used the words he is putting into my mouth.

Maybe he just does not like me because I am a German and he is still living in the bad days of the 1930s. But even in that case he is wrong again. I was a baby then and my mother spoke out publicly against the Nazis. She was even taken to court a few times because of it. Do you, Mr. Neumann, believe in public guilt? So did they.

Now you are trying to make me look like an idiot in order to make yourself look like a hero; or like the self-righteous super brain of all experts on the ocean and the sharks. Mike, I am sure that you are a smart person, who has a very good way with words, much better than I do. However, it is obvious that it does not help you to get over your inferiority complex. Think about it and leave me alone.

No I'm not gonna elaborate.

I trust that everybody understands exactly what's going on here. Thankfully, far from being representative for the Germans, people like that are very much the minority - and time is ticking.

In diesem Sinne.

Guadalupe - the Regulations!

Click for detail!

My bad.

After so much ranting, I've totally missed them!

So here they are, in English and Spanish -  and they could not be clearer!

Do read them and pass them around!

I must really say that I like them.

Yes they are a tad stifling, possibly unnecessarily so - and no I'm definitely not alluding to the ban on going cageless and taking selfies etc which I very much applaud!

But this is after all a biosphere, meaning that the special circumspection is totally warranted. And after all the shenanigans by the shark molesting bimbettes all the way to the adrenaline junkies and their enablers, it is also not unsurprising that the pendulum has swung the other way. The really good news being that it will not at all affect business as instead of being suckered into the Great Slide (we miss you buddy!), the operators will instead be able to continue to offer an awesome, safe and long term sustainable experience with a likely minimal ecological impact, like it should be.

And the dreaded enforcement?

Looks like even there, progress has been remarkable. 

Two completely unrelated sources report that Ritter and his sharkitarians have been prevented from exiting the cage, incidentally much to the dismay of the poor googly eyed suckers that were coldly refused any refund, mind you by Ritter and Wirodive. 

Which begs the question, are they still fans?

And the other perpetrators?

Dunno - but by the same token, for the first time, I am really hopeful. 

And yes, mark this day in your diary! :)

So here's to that - and very well done indeed!

Angry!

Patric is pissed off, and so am I!

The reason for it is this.





There's been quite some brouhaha behind the scenes after somebody posted these two test balloons on YouTube and generally speaking, the condemnation has been universal, especially of these statements.

Sharks are BIG business in adrenaline eco-tourism. And some thrill seekers deliberately pursue close encounters with deadly sharks without the protection of a cage. The bigger and more dangerous the shark, the better. At Mexicos Guadalupe Island, guests (including 5 & 7 year old siblings) come face to face with great whites. In the Bahamas, scuba divers pay big bucks to get up close and personal with tiger sharks.
But have we taken this risky sport too far? Shark advocates Dr. Erich Ritter and Chuck Anderson have grave reservations about how far we are willing to go for a thrill. And they have intimate knowledge of the subject. Both men were brutally attacked by bull sharks. Shark Divers also examines the controversy surrounding a handful of high-profile attacks in 2008, including the first shark tourist killed while on a shark excursion.

Whereas Patric is obviously right in bemoaning that the clips portray a fringe and extreme movement within the Shark diving community without properly mentioning the many positive examples of Shark Ecotourism, methinks Hey, that Guy is right!
Which incidentally, horribile dictu, puts me in the same camp as Mr. Ueber-Charlatan Ritter! Yukk!

But, seriously, is there any disputing that some yahoos out there are pursuing ever more extreme Shark encounters? That they obviously don't understand, or belittle the risks this involves? Just watch the footage of Tigers nuzzling the backs of oblivious and wide-eyed ignoramuses, or the bozos going cageless in Guadalupe!
Shocking!

Thing is, are we to blame those customers, or the shooter of the images?
Shoot the messenger for having said it like it is?

It's same-old-same-old.
Clients will do what clients will do, especially the image hunters. They will never cease to push the envelope in their quest for ever bigger adrenaline rushes and extreme images.
Good on them. They obviously don't know better, and that's their privilege as clients. After all, we the operators know what we're doing and will take good care of them.

But what about those operators and facilitators who enabled those visuals?
Where were they when those Tigers started bumping the customers? Who's that moron who allowed those people to go cageless in Lupe? How can anybody justify that total lack of procedures and that total disregard for the safety of one's clients and the reputation of the Industry?

Mind you, it's always the same people, a small group of greedy, reckless and stupid unprofessional assholes who put the whole Industry at risk and into disrepute. They, and not the shooter of those videos, are the ones "Kicking the Shark Diving Industry"!
Maybe it would be best if the "others" would once and for all finally put them out of their unholy business! And finally slap a code of conduct on those locations!

Did you read the links? See? I'm repeating myself!

And let me repeat this, too.
Dear Client: don't go there!
What those guys do is dangerous and not sustainable and they obviously don't give a rat's ass about your safety! It will all end in tears and you don't want to be anywhere near it when it happens. And it will!
And by that I mean: somebody will get killed, and it could be you!

To the shooter: go for it amigo!
Tell it as it is - but please don't forget to mention that this is the lunatic fringe and that the majority of operators are not like that! Properly organized, Shark Diving is awesome, rewarding and intriguing.

And very very safe!

Morons vs Conservationists?

Source.

Apparently, people like these are disrespectful morons.

Or ecoterrorists!

But this new age clap trap is Shark Conservation!

Whatever - right?

So, how is this any different from the first two clips?

I've actually said what I wanted to say a long time ago - about the self promoting bikini bimbettes, the people that abuse Sharks as underwater scooters, and the fallacy of trying to change people's perception, or whatever, by engaging in those gratuitous stunts in order to "prove" that those large predatory Sharks are harmless .

That's 1:1 Ritter - and we all know how that one ended.

So don't worry, I'm not gonna post another rant.

Instead, read the take of one of the most regarded GWS researchers here and here.

I of course agree with every single word, and so do all responsible GWS dive operators - the exception being the token hippy, stoner version of Dog the Bounty Hunter aka the EcoPirate who has established himself as the el cheapo no-holds-barred enabler of those latest stupidities.

Including the upcoming latest folly of Ritter himself!

I say, bravo Michael Domeier!

As Patric correctly predicted, Act Two is shaping up to be a good one! :)

Red Sea - here come the Scavengers!

Remarkable!

You want to read this - makes me want to puke!

So, as always, the usual vultures are closing in - by invitation, all expenses paid, no less! And on top of that, they've been awarded a grand total of three preemptive PhDs, no doubt in anticipation of their forthcoming spectacular eco-behavioral insights - now that's what I call credentials!
Wow!

As yet another unnamed friend writes
Expect fireworks: Ritter and Levine will try to turn this into a media circus for their own self-promotion as they did previously with the Jamie Daigle case when Ritter hijacked the autopsy (to which George Burgess had been invited by the coroner) and released his wild speculations to the media ahead of the official report.
This really stinks.

Indeed it does - and I say: dive industry beware!
This is a conversation you must get on top of and OWN, or the bureaucrats, self-appointed experts, whacks and charlatans will carry the day, with truly unfathomable consequences - for you!
The authorities are obviously completely overwhelmed, so get in contact with a reputable Shark NGO (Shark Trust!) and let them mediate contacts to reputable researchers and industry professionals.

You need to act right away, join ranks and have a voice.
You need to counter the hysteria (this is pretty good, but where's the follow up?) and the conspiracy theories with reasoned and fact based (!) statements. It also very much looks like you and the other water based tourism operators need to reform and self regulate - or someone else will do that for you.

As to the causes for the attacks, nobody will ever know.
All the theories that have been advanced (the Mossad, no less!) will always remain untestable hypotheses, some of which are certainly plausible. Here's a possible list and here's a remarkable compilation by David - buddy did you just accuse me of being too reserved? Wow, that sure is a first!

All very interesting but let's maybe first stick with Occam's razor.
The simplest and painfully trivial explanation is that due to the massive increase of the tourism infrastructure in that area, there are now heaps of people splish-splashing around in water that incidentally gets very deep very fast, meaning that the chance for attacks by some species of Sharks has increased accordingly. As to why those OWTs (yes David, agree: plural!) have ventured closer to shore, I miss any reference to the usual "big" factors, as in climate, weather, water temperature and currents along with seasonal aggregations of prey, like what happens in South Africa, Florida and Oz.

But I'm digressing and as I said, my guess is as good as anybody's anyway.
The fact is that there are some very negative news out there that need tackling. Leave the initiative to others, especially those guys, and you will end up in an ocean of hurt.

And here endeth the Tuesday sermon!

Shark-Human Interactions – Aggression?

One of the most frequent questions our customers ask is whether our Sharks are aggressive.

Our standard answer is to tell them that in our experience, they are not aggressive as in wanting to bite us but rather, that they may sometimes be assertive, meaning that some will try and barge in to get some food and that in doing so, they may display a degree of posturing.
Granted our definition may be threading a very fine line – but words are powerful and we want to steer the conservation away from the usual stereotypes and towards a more neutral mindset.

In behavioral terms, such assertiveness is called agonism, defined as any behavior related to fighting and competition,including fighting, threat, defense, flight, freezing, avoidance, and appeasement.

Very unfortunately, commercial Shark dives continue to slowly inch towards ever more close and personal encounters even with the biggest, most powerful and consequently most dangerous predatory Sharks.
In that regard, it becomes ever more important to adequately interpret the language of the animals and to adapt commercial diving procedures and one’s individual behavior accordingly, something that unfortunately appears to be missing both on the side of some operators and many clients alike.

Luckily for us, Sharks are far from being misunderstood and unpredictable and reading their state of mind is quite easy.
Equally luckily for us, they appear unendingly and uncomprehendingly tolerant and will generally gracefully overlook our breach of etiquette, meaning that people are likely to only get into trouble if they persist on displaying the most reckless, stupid and persistent of behaviors – which some individuals, being notoriously unpredictable, will undoubtedly manage to achieve!
Case in point!

The following paper is a useful compilation of the agonistic behaviors of several species of Sharks known in 2006. Yes it is long (!) but it’s an excellent reference for any Shark diver and thus, I believe, required reading. This is not the entire paper but merely excerpts that I have chosen for their immediate correlation to Shark diving.
More thoughts below.

A review of shark agonistic displays: comparison of display features and implications for shark-human interactions

Author: R. Aidan Martin
Disclaimer: Sharks are potentially dangerous animals. While the author offers his opinion on actions that may make encounters with sharks less dangerous, neither he nor Taylor & Francis accept any responsibility whatsoever for the safety of those who choose to interact with sharks, regardless of whether or not they follow the author's safety suggestions. Those who seek out interactions with sharks do so entirely at their own risk.

Abstract

Agonistic displays in 23 species of sharks of six families are described and illustrated.
These displays are reviewed in terms of ethological concepts and shark hydrodynamic models. Shark agonistic displays feature many common elements rendering them readily distinguishable from normal swimming and pseudodisplays caused by sharksucker irritation. Shark agonistic displays are most readily elicited by rapid, direct diver approach when food is absent and potential escape routes restricted. Such displays appear to be motivated by defence of self or the immediately surrounding space rather than defence of territory or resources. Costs and benefits of display versus attack in shark-shark and shark-diver contests are evaluated using payoff matrices and optimal strategies are identified. Shark-human interactions are modelled in terms of a system of nested critical approach distances. For divers faced with a displaying shark, responses which may decrease the likelihood of defensive attack are suggested. Recommendations for future work on shark agonistic behaviour are offered.
Introduction

Agonism is a class of behaviour that occurs in competitive contexts and is important to the social dynamics and evolutionary fitness in animals of many taxa (Hall and Halliday 1998).For example, individuals displaced or defeated in agonistic contests often disperse into adjacent habitats that are frequently suboptimal, thus reducing their feeding and reproductive success (Reese 1978). Agonistic behaviour is widespread among animals, including crustaceans, insects, spiders, mammals, birds, reptiles, amphibians, and fishes (see Bradbury and Vehrencamp 1998, for a recent review). Agonistic displays have been recorded in many teleost species, representing numerous families and orders (Fine et al. 1977; Colgan 1993; Guthrie and Muntz 1993; Helfman et al. 1997; Reebs 2001).

Many shark species exhibit a variety of social behaviours, yet agonistic displays have rarely been reported in this group (Bres 1993).
Shark agonistic displays are best known in the grey reef shark (Carcharhinus amblyrhynchos), which exhibits a distinctive, highly stereotyped ‘‘hunch display’’ (named for the characteristic raised snout-arched back posture, resembling a sustained shrug) in response to persistent crowding or oriented pursuit by divers or submersibles ( Johnson and Nelson 1973; Doak 1975; Stark and Anderson 1978; Nelson et al. 1986).
This display features four postural elements,
(1) a prominently raised snout,
(2) bilaterally (to_the same angle) depressed pectoral fins,
(3) arched back, and
(4) lateral flexure of the body, combined with two locomotory elements, (a) laterally exaggerated swimming, and (b) rolling and/or spiral looping ( Johnson and Nelson 1973).

The hunch display of the grey reef shark is a graded response, increasing in intensity with speed and directness of diver approach as well as degree of restriction of the shark’s escape route ( Johnson and Nelson 1973).
If a pursuing diver or submersible persists, the hunch display rapidly escalates to either a rapid withdrawal or a lightning-fast, open-mouthed slashing attack ( Johnson and Nelson 1973; Nelson et al. 1986) Thus, the hunch display of the grey reef shark is an accurate predictor of more intense defensive behaviours (Fellows and Murchison 1967).

Displays evolve from non-communicative source behaviours ritualised via a five-step process shaped by natural selection (Tinbergen 1952). Barlow (1974) proposed that the hunch display of the grey reef shark, like that of other predatory animals, was derived from movements associated with subjugating prey.

Accurate signalling of an animal’s motivation or state (‘‘display honesty’’) can be ensured by being costly, such as handicapping the signaller by diverting resources that would otherwise increase its fitness (Zahavi 1993).
However, accurate signalling must have benefits that exceed the costs for such behaviour patterns to be retained rather than eliminated through natural selection (Krebs and Davies 1993; Cuthill and Houston 1997). Costs and benefits of agonistic displays in the grey reef and other sharks have not been analysed.

The hunch display is most often elicited in situations where food is not present, such as close approach to a shark by an underwater photographer not using bait as a lure, and probably plays a role in normal social encounters among grey reef sharks ( Johnson and Nelson 1973; Nelson and Johnson 1980).
This species is widespread throughout the tropical Indo-Pacific region and, despite its modest size (most individuals are smaller than 1.5m long), is avoided by or actively displaces most sympatric shark species, including solitary heterospecifics larger than itself ( Johnson 1978; Compagno 1984). Myrberg (1991) suggested that distinctive fin markings in whaler and hammerhead sharks (Carcharhinidae and Sphyrnidae, respectively), especially on the relatively mobile pectoral and caudal fins, may serve as species recognition badges and/or accentuate signals, both social (intraspecific) and extrasocial (interspecific). The ventral apices of the grey reef shark’s pectoral fins are dusky and its caudal fin bears a distinct black rear margin (Last and Stevens 1994); in western Pacific and Indian Ocean representatives, the first dorsal fin features a conspicuous pale apex (Compagno 1984). Intriguingly, western Pacific and Indian Ocean grey reef sharks are more timid and less likely to display than those from French Polynesia or Micronesia (personal observation). Whether such regional differences in grey reef shark behaviour and markings are causally related is unknown.

The primary literature contains descriptions of agonistic displays similar in context and execution to that of the grey reef shark in several other shark species, including the bonnethead (Sphyrna tiburo), scalloped hammerhead (S. lewini), and blacktip shark (C. limbatus), but none as overt as that exhibited by the grey reef shark (Myrberg and Gruber 1974; Klimley 1985; Ritter and Godknecht 2000). Putative agonistic displays in several other shark species, including the Galapagos shark (C. galapagensis), Caribbean reef shark (C. perezi , white shark (Carcharodon carcharias), and shortfin mako (Isurus oxyrinchus), have been reported in the popular literature (Hobson 1964; Stoneman 1985; Compagno et al. 1989).

Confounding such anecdotal reports are recent studies showing that striped sharksuckers (Echineis naucrates) can induce behaviours that resemble agonistic displays in the blacktip shark, bull shark (Carcharhinus leucas), Caribbean reef shark (Video clip 4), and possibly other shark species (Ritter 2002; Brunnschweiler 2006).
Blurring the picture further are dissimilar shark behaviours reported under competitive contexts, including tail slapping (whip-like lashing of the tail at or near the surface, hittingor directing splashes toward a receiver), which has been reported in sandtigersharks (Carcharias taurus) and white sharks, and breaching (leaping completely from the.water) and repetitive aerial gaping (RAG: rhythmic, exaggerated opening and closing of the jaws above the surface, apparently as a displacement activity), which have been reported in white sharks (Compagno et al. 1989; Klimley et al. 1996; Strong 1996).

The present work reviews relevant theoretical background issues and putative shark agonistic displays from the literature, augmented and extended with opportunistic observations by the author and collected from experienced, credible divers.
What constitutes an agonistic display is defined and the challenge of differentiating displays from non-displays in sharks is discussed. Previously undescribed agonistic displays or new display elements in six species of sharks are described and illustrated. All known shark agonistic displays are compared and general patterns are identified. Relative costs and benefits of shark agonistic displays in interactions with other sharks and divers are evaluated using payoff matrices. Shark–diver interaction scenarios in which sharks are most likely to exhibit agonistic displays are reviewed. A hierarchy of critical approach distances for sharks is hypothesised and diver responses to an agonistically displaying shark that may reduce likelihood of escalation to full attack are suggested. Recommendations for future work on shark agonistic behaviour are offered.
Methods

Shark measurements and display elements used in this review are:

. Back arching – a sustained dorsal flexure of the back, so that it forms an inverted U, measured or estimated as the angle between the dorsal surface of the head and that of the pre-dorsal back (‘‘nape’’)
. Body length (BL) – estimated total length, from snout tip to upper caudal fin apex
. Body shivering – a quivering or rapid (faster than 5 Hz) shaking of the entire body, usually combined with a lateral display
. Body tilting or rolling – an exaggerated, sustained roll of the body around its longitudinal axis, up to plus/minus 45 degrees from vertical, either as a single action (tilt) or an oscillation (roll) (sensu Johnson and Nelson 1973; Klimley 1985; Ritter and Godknecht 2000)
. Charging – rapid (2 to 3þBL/s) approach toward a receiver, often terminated by veering away on a perpendicular course within a distance of 1–2BL
. Clasper flexion – rotation of a clasper (elasmobranch intromittant organ) anterolaterally, mimicking its erect state during copulation (sensu Myrberg and Gruber 1974)
. Corkscrewing – rapid burst swimming into a tight looping trajectory while rotating the longitudinal body axis through nearly 180 degrees (sensu Klimley 1985)
. Flank displaying – a sustained perpendicular bodily orientation of signaller’s body toward a receiver, displaying its lateral surface
. Follow–give way – an agonistic interaction in which one animal follows another, which deviates from its course, implying social precedence of the following individual (sensu Myrberg and Gruber 1974)
. Gill pouch billowing – a sustained conspicuous, spinnaker-like expansion of the branchial region; equivalent to ‘‘gill-puff’’ of Myrberg and Gruber (1974)
. Give way – an agonistic interaction in which one animal deviates from its course at the approach of another, implying social precedence of the undeviating individual (sensu Myrberg and Gruber 1974)
. Head shaking – rhythmic, exaggerated lateral shaking of the head, usually rapid (faster than 2 Hz) and through an arc of more than 30 degrees
. Jaw closing – a non-forceful bringing together the upper and lower jaws in an agonistic context (as compared to a bite, which is a forceful jaw closure during feeding)
. Jaw gaping – a slow, exaggerated opening of the jaws (30–90 degrees, measured or estimated as the angle formed at the mouth commissure), conspicuously wider than during ram ventilation and in an agonistic context, resembling a yawn
. Laterally exaggerated swimming – sustained , eel-like swimming motion
. Looping – swimming in a spiral loop (sensu Johnson and Nelson 1973)
. Open jawed tooth raking – a forceful strike with the upper jaw teeth causing injury to a receiver
. Palatoquadrate protrusion – forward extension of the upper jaw, causing it to separate from the cranium, and which may bare the upper dentition; categorized as present or not
. Pectoral fin angle (PFA) – is measured or estimated from a horizontal plane perpendicular to the body axis at the level of the chord formed by a straight-line from pectoral fin origin to pectoral free rear tip (which is often easier to discern than the pectoral insertion in free-swimming sharks); equivalent to the ‘‘dihedral angle’’ of Wilga and Lauder (2000)
. Pectoral fin depression – a sustained bilateral lowering of the pectoral fins from their usual position during swimming, quantified as pectoral fin angle
. Ramming with snout – a signaller using its rostrum to forcefully strike a receiver, often causing it to recoil or retreat; synonymous with ‘‘hit’’ of Myrberg and Gruber (1974)
. Rapid withdrawal – movement of a signaller away from a display receiver at _3BL/s.
. Rapid, tight pattern swimming – fast swimming marked by sudden and frequent changes in direction
. Reduced swimming efficiency – conspicuous reduction in forward locomotion, from almost normal swimming speed to nearly stationary in the water column, despite exaggerated swimming movements ( Johnson and Nelson 1973)
. Ritualistic jaw snapping – rhythmic (faster than 1 Hz), exaggerated opening and closing of the jaws, (30–90 degrees, measured or estimated as the angle formed at the mouth commissure)
. Snout elevation – a sustained raising of the snout from the resting position, measured or estimated as the angle between the dorsal surface of the rostrum and that of the epibranchial region (surface of the back above the gill slits) ( Johnson and Nelson 1973)
. Stand back – an agonistic interaction in which two oncoming animals deviate from their courses simultaneously, making it impossible to infer social precedence (sensu Compagno 2001)
. Stiff or jerky movement – a conspicuous reduction or loss of fluidity of body and fin movements during locomotion, probably due to an increase in tonus of associated muscles
. Swimming speed – is measured in BL/s
. Tail depression – a sustained vertical bending of the caudal peduncle, stiffly holding the causal fin downward, below the main body axis .
. Tail flexure – a sustained lateral bending of the caudal peduncle, stiffly holding the causal fin to one side, away from the longitudinal axis ( Johnson and Nelson 1973)
. Tail slapping – a whip-like lashing of the tail at or near the surface, hitting or directing splashes toward a competitor (Compagno et al. 1989; sensu Klimley et al. 1996)
. Torso thrusting – an exaggerated, sustained lateral flexure of the abdominal region into an S-shape, often accompanied by body tilting, sensu Klimley (1985)

Results

Signal logistics and types

The term ‘‘agonism’’ was introduced by Scott and Fredericson (1951) to refer to any behaviour related to fighting and competition.
Agonism embraces a broad spectrum of behaviours related to animal conflict, including fighting, threat, defence, flight, freezing (remaining motionless to avoid detection), avoidance, and appeasement ( Johnson 1972; King 1973; Dewsbury 1978; McFarland 1987).

For all their variety, agonistic behaviours are united by occurrence during conflict situations (Scott 1971).
Conflict denotes a motivational state in which tendencies to perform more than one activity are expressed simultaneously (Manning 1979). Much agonistic behaviour is characterised by motivational conflict between attack and flight, often resulting in vacillation between approach and withdrawal (McFarland 1987).

A ‘‘display’’ is a stereotyped motor pattern involved in animal communication; displays are usually intraspecific and related species often have similar displays (McFarland 1987).
For well-armed contestants, physical combat bears significant risk of injury, which could compromise the feeding or reproductive abilities of both participants (Lorenz 1964). Therefore, in conflict situations, ritualised displays may be more adaptive than combat (Reichert 1982). Due to their conservative structure and the constraints of efficient swimming, sharks have few structures available for signalling. Their only suitable appendages are the relatively highly mobile pectoral and caudal fins (Myrberg 1991) and, in males, the claspers (Myrberg and Gruber 1974; Klimley 1985). Signals are ritualised from non-communicative source behaviours via a process of simplification, exaggeration, decreased performance speed, repetition, and increased stereotypy (Tinbergen 1952). Thus, by definition, shark agonistic displays are conspicuous MAPs elicited in conflict situations, usually between or among conspecifics.

The hunch display of grey reef sharks, however, is not known to be performed toward conspecifics, but is known to be directed toward humans ( Johnson and Nelson 1973; Nelson et al. 1986), great hammerhead sharks (Sphyrna mokarran) and moray eels ( Johnson 1978).
Similarly, blacktip sharks have been documented displaying toward scuba divers before accelerating away (Ritter and Godknecht 2000; Stafford-Deitsch 2000). Since shark agonistic displays are unlikely to have evolved in response to diver encroachment (within the last 50 years), it is likely that shark species perform agonistic displays the same way toward natural predators or competitors as toward humans. This performance conservatism is useful, as it enables scientific study of shark agonistic displays.

Recognising shark agonistic displays

Complex biological structures, such as fins, are often multifunctional (Bock and von Wahlert 1998).
Caudal and pectoral fins of sharks play important and active roles in shark locomotion (Bone 1988). This raises methodological questions about differentiating between use of these fins for locomotion versus signalling.

Use of pectoral fins by sharks for turning is conspicuously different from their use during agonistic displays (Barlow 1974).
Qualitatively, during turning in free-swimming sharks in the wild, the pectoral fins are flexed slowly in a fluid, short-duration (usually shorter than 1 s) motion and PFA of the left and right pectoral fins are unequal, with the fin on the side to which a shark turns usually depressed more strongly than the other, although this is not always the case in slow-moving sharks. This biased pectoral fin depression is contrary to Figure 11 in Wilga and Lauder (2000), which may reflect simplification for clarity or an artefact of inhibited steering in the confines of a laboratory tank. In contrast, during shark agonistic displays, both pectoral fins are held stiffly downward for prolonged periods (usually 5 to 120þs), and bilaterally. Such pectoral fin depression, probably derived from postures assumed by a shark bracing its body in the water column during prey dismemberment would be expected to increase yaw stability and decrease agility. …….

However, sustained bilateral pectoral fin depression, performed in a conflict situation, and accompanied by other common shark agonistic display elements (described subsequently) greatly increase the likelihood of correctly identifying a shark agonistic display.

Species in which displays are known

Agonistic displays are known in at least 23 species of sharks, representing six families.
Sandtiger shark.
This species exhibits a variety of agonistic behaviours not reported by Compagno et al. (1989) in western Indian Ocean individuals. Among the most obvious of these in western North Atlantic individuals is pectoral fin depression accompanied by flank displaying. As in grey reef sharks, pectoral fin depression is elicited in approach–withdrawal conflict situations and is a graded response, with intensity of PFA increasing from 30 degrees to 50 degrees with diver proximity and degree of escape route restriction. This species has attacked divers off South Africa and elsewhere, delivering minimalist bites (not removing flesh) similar to those inflicted on captive conspecifics (Compagno 2001). Another putative agonistic behaviour in this species, often performed in conjunction with pectoral fin depression, is a loud shotgun-like report, generated by exaggerated tail beats during rapid withdrawal that is termed ‘‘tail popping’’ by North Carolina wreck divers (R. Allen, personal communication). Preliminary field tests off North Carolina suggest that likelihood of tail popping increases with speed, directness, and angle of diver approach. Rapid frontal approaches at a downward angle of 30 degrees from the animal’s longitudinal axis seemed to produce the strongest tail popping response. Similar sounds generated by the caudal fin of this species have also been reported from Australia, where groups of sandtigers were observed apparently herding a school of carangids (Cliff 1988). However, it is probable that sound production in this species is caused, at least in part, by cavitation in the wake of its large subterminal lobe), which may make it an artefact of rapid acceleration rather than a display element. Systematic testing of tail popping under agonistic and non-agonistic contexts is needed to resolve this matter. Such testing could include speaker playback of tail popping, which would allow separation of visual and other shark-related cues from the potential stimulus-specific role of popping, analogous to birdsong playback to distinguish mate-attraction from competitor-repulsion functions (e.g. Searcy and Nowicki 2000; Vehrencamp 2000).

White shark.
A variety of named and described agonistic behaviours have been reported in this species, but without supporting evidence (Compagno 2001; Martin et al. 2005). A photo of a white shark hunch display featuring strong pectoral fin depression (PFA¼_70_), was taken off Dyer Island, South Africa in July 2003 (Figure 3i). A possible hunch display by a white shark, apparently contesting access to speared fish and followed by an attack on the spearfisher, was reported in South Africa by Jones (1991), while Collier (2003) identifies four cases in which this species appears to have attacked humans off California in agonistic contexts. Between July 2002 and July 2005, the following agonistic behaviours were performed by white sharks toward conspecifics at Seal Island in False Bay, South Africa: 22 give ways, four follow-give ways, three hunch-give ways, and two stand backs. As these behaviours are well defined and illustrated elsewhere (Myrberg and Gruber 1974; Martin 2003; Martin and Martin 2006), they will not be further described here.. On 27 June 2005, after having been thwarted by the bait handler in repeated attempts to consume the bait, a 3.5m male white shark twice performed RAG displays completely consistent in form and context with those described and illustrated in Strong (1996).

Silvertip shark.
Encroachment by underwater photographers and pursuit by a submersible elicited a partial agonistic display in this species. This display featured slightly stiff-bodied swimming and brief pectoral fin depression (Eibl-Eibesfeldt and Hass 1959, Nelson et al. 1986). Diver pursuit elicited a more elaborate, highly stereotyped agonistic display in at least five different individuals (1.4–1.8mBL) in eight out of 28 (28.6%) trials on non-feeding animals at several offshore reefs on the Great Barrier Reef, Australia. In each successful trial, when a distance of about 2BL was broached by a diver, the test subject accelerated away to a distance of about 15 m. Each shark then turned sharply and charged toward the observer at 3BL/s. When the shark reached a distance of about 2 BL, it strongly depressed its pectoral fins, turned broadside, vertically depressed its caudal peduncle, and —while holding this posture and moving at greatly reduced speed (slower than 0.5BL/s)— gaped its jaws rhythmically (at approx.1 Hz) and vibrated its entire body in a shiver-like motion. This shiver accentuated the white fin markings characteristic of the species and was maintained until the posterior margin of the animal’s pectoral fin base passed the observer’s mid-line. The shark then ceased shivering, raised its caudal fin and accelerated away at 3BL/s with both its pectoral fins strongly depressed . In one trial, a 1.7m female silvertip shark attacked before fleeing; the observer was uninjured but the nose-cone of the DPV was raked by the shark’s upper teeth. Repeated attempts to approach this species for photographic purposes in the Chagos Archipelago, central Indian Ocean, elicited essentially the same display Emery, personal communication).
Galapagos shark.
Aspects of an agonistic display, featuring laterally exaggerated swimming, have been reported in this species (Hobson 1964). During this display, the shark’s head swung through an arc of >90 degrees, which Hobson (1964) interpreted as an attempt by the animal to increase its visual field to maintain visual contact with the diver following it. Sustained diver pursuit elicited a more extreme version of this display on four occasions in non-feeding subadult Galapagos sharks (1.5–2mTL) at Lord Howe Island, Australia. This display was elicited when the observer repeatedly approached from behind to within 2BL of the shark. It featured laterally exaggerated, sub-anguilliform swimming movements, strong bilateral pectoral fin depression (PFA¼ 40 to 60_), gill pouch billowing, and exaggerated jaw gaping at about 0.5 Hz .The display was terminated when all postural and locomotory behavioural elements ceased, except bilateral pectoral fin depression, which was sustained during rapid withdrawal at _3BL/s. A partial agonistic display by a juvenile Galapagos shark, featuring flank displaying and strong pectoral fin depression (PFA¼_70_) was photographed in October 2003 at Bassas da India Atoll, Mozambique Channel (Figure 3l), which may be a nursery area for this species (Hammerschlag and Fallows 2005).

Caribbean reef shark.
Stoneman (1985) reported more than 450 observations of agonistic behaviour, some of which (fraction cannot be determined, since full data are not available) resulted in attacks, in what he identifies as Carcharhinus limbatus (blacktip sharks). However, Stoneman seems to consistently mistake Caribbean reef sharks for this species (Meltzoff 1988; Gruber 1993). Unfortunately, Stoneman has not published his observations, so they are unavailable for independent analysis. Consultation with Stoneman’s scientific advisor indicated that the displays they attributed to C. limbatus featured brief, 1 to 1.2-second pectoral fin dips, punctuated by frequent changes in direction (A. Emery, personal communication). Diver-acclimatised Caribbean reef sharks in the Bahamas were observed in the presence and absence of bait by the author using scuba. Despite high concentrations of sharks (approx. 60 animals in an area smaller than 2500m2), no clear agonistic behaviour was observed without baits, but repeated brief pectoral fin dips (PFA= approx -15 degrees, period=1 Hz) followed a second or so later by 90-degree changes in direction were evident when bait was present, supporting the proposition that the behaviours attributed by Stoneman (1985) to C. limbatus were performed by Caribbean reef sharks. Scharfer (2003) reported similar agonistic behaviour patterns in Caribbean reef sharks at another long-term shark feeding site in the Bahamas, noting that frequency of agonistic acts by sharks depended on feeding technique and that female sharks bumped camera ports (a possible agonistic behaviour) more frequently than males. Systematic observations, preferably of less diver-acclimatised sharks, are needed to verify agonistic behaviour patterns in Caribbean reef sharks.

Sandbar shark.Agonistic displays have not previously been reported in this species, which is a congener of the grey reef shark and ten other species from which such displays have been reported. Partial agonistic displays by subadult sandbar sharks (1.2–1.5mBL), in mixed aggregation with Galapagos sharks (1.8–2mBL), and in the presence of baits, were observed from a shark cage off the north shore of Oahu, Hawaii. This display appeared to be directed toward the observer/cage and featured partial flank display combined with moderately strong pectoral fin depression, increasing from an initial PFA of 5 degrees to a final PFA of 60_ degrees. In more intense versions of this display in Hawaiian waters, subadult sandbar sharks charged toward a diver in the presence of bait at 2–3BL/s. During such charges, the pectoral fins were strongly depressed and, at a distance of 1.5 BL, males veered away from the diver on a perpendicular course, while females continued toward the diver and sometimes rammed him with the snout tip before withdrawing rapidly (D. Fleetham, personal communication).

None of the preceding six species exhibited palatoquadrate protrusion as a component of agonistic displays.

Discussion

Sensory channels of communication

Sharks are endowed with a battery of well-developed senses, responsive to mechanical, chemical, visual, and electrical stimuli (see Hueter et al. 2004, for a recent review).
In theory, any or all of these sensory channels are available for communication (Dusenbery 1992). However, the marine operating environment imposes signal attenuation and limits signal functional range, ability to go around obstacles, transmission speed, and persistence as well as receivers’ ease of locating signal source (Bradbury and Vehrencamp 1998).

Visual signals propagate at the speed of light within limits set by the optical properties of the transmission medium, are directional and non-persistent (McGregor 2005).
Sharks possess a high order of visual sensitivity and acuity, with pupillary dilation and tapetal plates affording some ten times greater photic sensitivity than human eyes under scotopic conditions and at least some species exhibit a well-developed Purkinje shift and true colour vision (Gruber and Cohen 1978; Hueter et al. 2004). There is no reason to believe that sharks cannot see to the limit of underwater visibility which, depending upon habitat, may be as far as 30m (Hueter and Gilbert 1991).
………………

Thus, pending further data, it is provisionally suggested that vision may be the primary sensory channel employed by sharks for agonistic signalling.

What information is conveyed?

Agonistic encounters are framed by uncertainties between or among the combatants.

Agonistic displays provide information about the likely intent and level of commitment of the signaller and may provide information on relative fighting ability.
For example, agonistic displays may emphasise body size, weapons, or status badges, and may also include a tactical element, placing the signaller in a better position to attack or flee (Bradbury and Vehrencamp 1998). Agonistic displays are stabilised by natural selection if the costs are borne by the signaller, in what are termed ‘‘vulnerability handicaps’’ (Vehrencamp 2000). Size is a good indicator of fighting ability, such that competitors of grossly dissimilar size rarely need to fight or display (Krebs and Davies 1993). If, however, combatants are similar in size, ritualised agonistic displays are likely to occur (Bradbury and Vehrencamp 1998).

In assessing the validity of an agonistic display, two sources of uncertainty arise, (1) receiver estimation of signal magnitude, and (2) degree to which a display indicates the likely outcome of combat (Bradbury and Vehrencamp 1998).
Agonistic displays performed at close range to the receiver are likely to be more effective, but they also bear greater risk (Zahavi 1977). Intention movements are incomplete initial phases of behaviour patterns and many threat displays, such as jaw gapes, are ritualized from attack or defensive behaviours (McFarland 1987; Hauser and Nelson 1991). Frontal and lateral agonistic displays occur as a result of motivational conflict between attacking and fleeing, with frontal displays indicative of a tendency toward attack and lateral displays of a tendency toward escape (Fine et al. 1977). Broadside or lateral agonistic displays are widespread among vertebrates (Thomas et al. 1965; Carpenter 1978; Hinde 1982), probably because they emphasise size by presenting the largest possible aspect; such displays also place the signaller at elevated risk of attack, which could signal the sender’s confidence in its fighting ability. Complicating these issues further, individual combatants may recognise a degree of relatedness or have prior experience of one another, but researchers are rarely privy to such parameters (especially in wild or free-ranging subjects), introducing much uncertainty into interpreting isolated agonistic interactions among study subjects

Motivation

Clear agonistic displays are difficult to elicit in sharks, because they require sustained (several minutes) oriented pursuit.
Drawing on visual and possibly other cues, sharks in the wild use their superior swimming ability to set the preferred minimum distance between themselves and divers; if a diver attempts to approach, most simply swim away to avoid contact. However, in some cases, a shark that is approached by a diver will not retreat and will attack instead.

Traditionally, it was thought that shark attacks on humans were motivated by hunger. Baldridge and Williams (1969) were the first to suggest that the character of many shark attacks seemed more consistent with fighting than feeding. Analyses of 1165 case histories archived in the International Shark Attack File concluded that 50–75% of shark attacks on humans were motivated by something other than a desire to feed (Baldridge 1974b, 1988).

The hunch display of the grey reef shark appears defensive in nature and often precedes a rapid, slashing attack with little or no removal of flesh (Fellows and Murchison 1967; Johnson and Nelson 1973; Nelson et al. 1986).
Agonistic displays by sharks have preceded attacks on humans in at least five other species: sandtiger (Compagno et al. 1989; Compagno 2001; and present study), white shark (Jones 1991; Collier 2003), silvertip (Nelson et al. 1986; and present study), Caribbean reef (Stoneman 1985), and smooth hammerhead (Sphyrna zygaena) (Miller and Collier 1981; Collier 2003).

Yet the majority of agonistic displays do not result in an all-out attack.
Nelson (1981, 1983) suggested that sharks may sometimes attack humans because they are regarded as competition for food or another resource. Shark agonistic displays are rarely elicited during feeding or in the presence of bait, which suggests that access to a food resource is not usually a precipitating factor and that divers are not regarded by sharks as competitors. However, in two attacks on divers involving white sharks and one involving a smooth hammerhead, agonistically displaying sharks appeared to contest access to speared fish ( Jones 1991; Collier 2003).

One often-raised possibility is that a displaying shark is defending a geographic area and its resources (territory) for its exclusive use (Baldridge and Williams 1969; Johnson and Nelson 1973; Nelson 1981, 1983).
Defining territoriality in a way that all ethologists agree upon is difficult because different workers emphasise different attributes to different degrees, depending upon their specific research questions. For purposes of the present review, territoriality will be defined following Wittenberger (1981) as more or less exclusive control of a geographic area by an individual or group of individuals by means of implied or overt aggression.

There is no record of reef-dwelling sharks agonistically displaying toward conspecifics — which, having most similar resource needs and exploitation capabilities, constitute the most intense ecological competitors (Nelson et al. 1986).
Direct, rapid approaches by divers are most likely to elicit shark agonistic displays, especially if potential escape routes are restricted or absent. This observation is consistent with the hypothesis (Fellows and Murchison 1967; Johnson and Nelson 1973; Nelson et al. 1986) that these displays signal defensive threat. The open-mouthed, slashing attack that sometimes follows persistent movement toward a displaying grey reef shark, as well as the rapid withdrawal that terminates the agonistic display, are likewise consistent with self-defence rather than feeding.

Pending further evidence on the issue of site-dependent aggression, it seems likely that, in most cases, an agonistically displaying shark is motivated by defence of self rather than of a food resource or territory.

Common features of shark agonistic displays

Agonistic displays of a few shark species exhibit unique elements (e.g. body shiver in the silvertip or corkscrewing in the scalloped hammerhead, S. lewini ), but a number of elements appear common to the agonistic displays of most . The seven most common features (with percentage occurrence in parentheses) include:
(1) stiff or jerky movements (100%),
(2) sustained bilateral pectoral fin depression (100%),
(3) rapid withdrawal (83%),
(4) jaw gaping (70%),
(5) reduced swimming efficiency (52%),
(6) flank displaying (48%),
(7) laterally exaggerated swimming movements (13%).

All these elements are found in the hunch display of the grey reef shark, indicating that its highly overt agonistic display represents an extreme along a continuum of agonistic behaviours in sharks, which range from subtle (in the Caribbean reef shark) to overt (in the grey reef, silvertip, and Galapagos sharks).

Intriguingly, agonistic behaviours that resemble those of sharks in form (arched back, lowered flippers, ritualised jaw gaping, and flank displaying) and context have been reported in at least three species of cetaceans, the spinner dolphin (Stenella attenuata), the bottlenose dolphin (Tursiops truncatus), and the humpback whale (Megaptera novaeangliae) (Overstrom 1983; Connor and Peterson 1994; Johnson and Norris 1994).

Agonistic displays of many unrelated species exhibit convergent properties that honestly inform rivals about the size and fighting capacity of the signaller (Parker 1974).
Whether these cetacean agonistic display elements represent behavioural mimicry of sharks, shared hydrodynamic and morphological constraints, or some other form of convergence is not clear. But in the agonistic displays of both sharks and cetaceans, presentation of offensive weapons and the largest possible aspect come at the cost of decreased swimming ability.
Shark–human interactions

Human pursuit and proximity are sign stimuli known to elicit agonistic displays in sharks.However, intensity of agonistic responses by sharks is context dependent. Johnson and Nelson (1973) found the likelihood that a grey reef shark performs an agonistic display increased with speed and directness of diver approach as well as with degree of escape route restriction. This pattern appears to hold true for most species of actively swimming (i.e. non-benthic) sharks (personal observation).

Almost any object in the environment – bottom features, divers, other sharks, or possibly a boat – can restrict a shark’s escape route and may render it more likely to perform an agonistic display (personal observation).
For example, while swimming near the bottom, individual sharks of most species appear agitated by any diver that maintains position a few metres above the animal’s back, a situation in which diver proximity and pursuit, a suboptimal view of the diver, and restriction of escape routes by the bottom combine to increase the animal’s stress and the likelihood to perform an agonistic display (personal observation; C. Harvey-Clark, personal communication). A tightly packed group of scuba divers more readily provokes agonistic display in solitary sharks than does a single diver or dispersed group of divers and thus may be considered a supernormal stimulus (Bolhuis and Giraldeau 2005).

Use of bait is well known to induce sharks to approach divers more closely than they do without such provisioning (Nelson 1977; Stafford-Deitsch 2000), although use of bait to stage ‘‘feedings’’ for diving tourists is highly controversial (Brylske 2000; Carwardine 2004).
Single-species groups of sharks that have become acclimatised to being fed individually by taking bait impaled on the end of a feeding pole appear relaxed and—despite close proximity of divers and conspecifics—rarely, if ever, display agonistically. In contrast, shark agonistic displays may be elicited toward divers during mixed species feeding events, especially when food is thrown or scattered into the water. Under such conditions, proximity of the bottom and nearby sharks may restrict escape route of an agonistically displaying shark and increase risk of attack against a nearby diver.

Interpreting the significance of these differences is hampered by general lack of data on the extent of learning from past inter- or intraspecific encounters among individual sharks, including the effects of previous agonistic wins and losses.
However, as with any wildlife encounter, ability to anticipate and avoid shark–human encounter scenarios known to agitate sharks, such as those described here, can help reduce the inherent risks of such encounters. Shark–diver interactions are inherently risky but the level of danger can be limited by a diver’s ability to recognise signs that a shark is becoming agitated and respond appropriately (personal observation).

Under unbaited conditions, most sharks simply avoid divers.
However, some individuals, particularly of relatively large and actively predatory species, appear curious about divers and may approach closely. It is probably safest for a diver to allow a shark to approach on its own terms; attempts to approach it will likely cause the animal to flee. A mildly agitated shark may accelerate away for a few body lengths and then resume a more relaxed cruising pace. As a shark becomes moderately agitated by diver encroachment, it often changes course frequently, using short, jerky movements. With increasing agitation, common elements of shark agonistic displays begin to appear.

Most conspicuous of these are rapid, jerky movements and sustained, bilateral pectoral fin depression.
The more agitated the shark, the more stiff and jerky its swimming movements and the more strongly its pectoral fins are depressed. These signs typically escalate in the regular – and thus predictable – patterns outlined here. Intensity of shark agitation increases with diver proximity, speed and directness of diver approach, and the number of sharks. However, in the vast majority of encounters, shark agonistic displays and signs of shark agitation reduce in frequency and intensity with diver withdrawal.

Thus, to a certain extent, an experienced diver can mediate the intensity of shark encounters through his own actions.
It is, however, absolutely vital that divers maintain visual contact with all sharks in the immediate vicinity throughout an encounter. Should a diver be unable to see all sharks in the vicinity at all times, prudence dictates leaving the water as quietly and efficiently as possible. Based on results presented here, it seems likely that a shark performing an agonistic display is signalling that it is in a highly agitated state and on the verge of either attacking or fleeing; if the receiver persists, the shark will attack rather than flee. Such ritualized threats appear to be mostly bluff (the shark usually flees without attacking), but prudence dictates that one should not depend on this. This comparative behavioural review identifies common elements in shark agonistic displays that could assist divers and other ocean users to recognise whether a shark is becoming agitated and may inform human responses to an agonistically displaying shark.
Critical approach distances and diver safety

The best defence, when faced with a shark that appears to be agitated is to avoid exacerbating the situation. If a shark appears agitated (exhibits stiff, jerky movements and/or frequent direction changes) but has not yet begun to display, maintaining visual contact with the animal and withdrawing are likely to reduce signs of the animal’s agitation and stimulate it to withdraw from the area (personal observation).

For divers faced with an agonistically displaying shark, the outcomes of the present review and model suggest that the following safety recommendations may be of assistance:
(1) Face the displaying shark and maintain eye contact
(2) Do not touch, approach, or photograph a displaying shark
(3) If carrying speared fish or collected marine animals, surrender them immediately
(4) Back away from the displaying shark, using smooth purposeful movements; the shark will most likely seize the opportunity to withdraw
(5) Remain on the bottom, with your back toward a reef, wreck, or – if nothing else is available – your dive buddy
(6) Return to, or immediately below (if boat diving), your pre-planned exit point and exit the water unhurriedly but efficiently
(7) During surfacing in open water and while at the surface, check water around and beneath in case the shark follows
(8) If the shark follows, be ready to fend it off with any available object; avoid using your bare hands, if possible, as the shark’s rough skin and teeth may cause injury.

It is clear that much remains to be learned about shark agonistic displays and also about their perception of and interactions with humans. Further study of agonistic behaviour in sharks is likely to pay dividends not only in a richer understanding of shark social dynamics but also in increased safety in shark–human interactions. With knowledge and care, sharks can be approached in their natural habitat and observed at close range in relative safety and with minimal observer impact. Such direct observations are likely to provide new insights into subtler aspects of shark social behaviour.

Are you still with me?
Here’s what I learn from reading this.

• Remember: it seems likely that, in most cases, an agonistically displaying shark is motivated by defense of self rather than of a food resource or territory. Thus, rule number one is to avoid any behavior that a Shark may interpret as being threatening.

• Learn to interpret Shark behavior by being alert to any of the tell-tale displays described above: Sharks are highly transparent and predictable if you know what to look for – and that includes accepting that predatory Sharks are predatory Sharks, and not some romantic figment of your imagination! Of interest, on top of the species-specific behavior described above, the paper contains a table describing the following agonistic display elements for Tigers: stiff or jerky movements; pectoral fin depression; jaw gaping; flank displaying; reduced swimming efficiency; ramming with snout and rapid withdrawal – and for Bulls: pectoral fin depression; snout elevation and jaw gaping, to which I would add head shaking; jaw closing and above all, ramming with snout (!). If in doubt, back off!

• Avoid getting too close to the animals. Apart from the painfully trivial and yet apparently often forgotten simple fact that in order for there to be an incident, a human and a Shark need to be in the same place at the same time, Sharks have a personal space which in scientific terms is called idiosphere, defined as the volume immediately surrounding an individual animal (of any species) that it will defend if broached without appropriate signalling or permission. Learn to identify that space by observing the Shark’s reaction and retreat if you have breached its confines. Also, since that space is likely to vary with the degree at which an individual Shark is habituated to divers, always let the Shark swim to you (keep eye contact) by remaining stationary.

• Related but not identical: avoid crowding the animals. What a Shark may interpret as being an obstacle impeding its withdrawal may not be readily discernible to you, as in another group of divers or, as exemplified by the paper, swimming above it whilst it is close to the bottom (Tiger Beach anybody?). By the same token, do not assertively swim towards, let alone chase any Shark, ever.

• Do not touch. Sharks are not pets, reefs are not petting zoos and Sharks are never, ever, underwater scooters!

• Selected baiting is better than indiscriminate dumping. This is totally in line with what we do in Fiji, as we always keep control of the food and can discontinue feeding as soon as we sense (and we sometimes do) that the situation is becoming tense.

• Avoid creating competitive feeding situations. Remember: There is no record of reef-dwelling sharks agonistically displaying toward conspecifics, but still, mistakes do happen and excited Sharks may bite each other, and you, by accident. Moreover, a Shark may regard you as a competitor and act aggressively assertively!

• If in trouble, push back. Our rule for image hunters: as long as you keep your camera between the mouth of the Shark and yourself, you're OK!

Easy – right?
Which once again begs the question, what are those operators thinking who facilitate those unsupervised interactive encounters with large predatory sharks?
Not much it appears - it's always the same combo: ignorance and greed!

Let’s hope that this post will contribute to eliminating the former!