Time for a preliminary
post mortem.
Like everybody interested in Sharks, I’ve been closely following the news tidbits trickling out from Sharm El Sheikh and the various opines in the media and the blogosphere.
There’s much of the usual fluff and idiocy - but there’s also some stellar stuff.
Take the “experts”. Whilst many
prate and pontificate, I found
this remarkable interview with Avi Baranes. Now
THIS is the kind of person you gotta consult, a highly reputable Shark researcher who has been investigating those very waters for a very long time – and accordingly, the interview brims with factual information and quietly addresses and dispels the usual myths. Bravo!
Equally noteworthy are the posts by
Richard, by the
SOSF and by
Michael Scholl - however with some caveats that I’d like to address below.
The way I see it, in this specific case, one needs to try and answer the following queries
- What species are involved. Apparently, the species implicated are Oceanic Whitetip(s) and Mako, both pelagic as opposed to coastal species, which is certainly surprising. I’m particularly surprised to hear about the Mako, because this is very much a specialist predator of fast pelagic Fishes like Tuna and Billfishes, features a very specialized dentition aimed at grabbing rather than cutting, and is exceedingly rarely implicated in attacks on humans. OWTs on the other hand appear to have a much broader feeding spectrum and have the typical generalist dentition of “grabbers” in the lower jaw and “cutters” in the upper jaw, like the equally pelagic and generalist Blues and most Carcharhinids in general. Consequently, OWTs (not Makos) are frequently found feeding on floating carcasses, mainly of cetaceans, where they are able to cut out chunks of meat. They have a well deserved reputation for being highly inquisitive to the point of chasing people out of the water, and have been implicated in a plethora of attacks mainly on shipwreck victims.
- What induced those pelagic Sharks to come close to that coast where the attacks happened. In the Red Sea, OWTs are normally regularly sighted hundreds of miles further south and I would have expected them to move north, if at all, following their preferred temperature gradient, often in line with migrations of their habitual pelagic prey. Yes they are also known to follow ships but with the above in mind, my gut tells me that the most likely explanation might be environmental, as in weather/temperature/currents/movements of prey rather than the much cited paucity of natural food due to overfishing or selected anthropogenic interventions like chumming and baiting that would only draw in Sharks from a much smaller radius. Of note, the cited dumping of sheep carcasses happened at the end of September and cannot be credibly considered to be causal for events occurring in December.
- The cause for the attacks, and their interpretation. This may sound trivial but to me, the immediate causes are obviously location, opportunity and stimulus. Firstly, it has to be noted that the coastline drops off precipitously, meaning that snorkelers and swimmers venturing away from shore quickly find themselves in very deep water indeed. Secondly and due to the massive increase of the local tourism infrastructure, the ocean is teeming with aquatic recreationists, greatly increasing the chances for such an encounter. Thirdly, people splish-splashing at the surface send out the exact stimuli that predatory Sharks will consider worth investigating. As to the interpretation of what happened once the Sharks encountered the victims, see below.
- What can be done so that this will never ever happen again. Barring the complete prohibition to swim and snorkel, or the complete fencing off of areas where people swim and snorkel: nothing at all! As long as people will frequent the Ocean and Sharks will hopefully exist, occasional attacks will continue to occur - but one can certainly minimize the risk by following a set of sensible recommendations, the first one being don't be stupid!
Which leaves the
interpretation of those attacks.
Whilst the mainstream media revel in the image that all Sharks are indiscriminate man hunting killers, the pro-Shark faction claims the exact opposite, that Sharks never prey on humans and that all attacks are the result of mere investigation or mistakes.
Both I believe are wrong.
Shark attacks can be defined as
incidences where Sharks bite people.
The term thus covers a very wide spectrum of species, behaviors, motivations, triggers etc and any generalizations will inevitably lead to mistakes – thus, please correct me if you think I’m wrong!
Also, barring a personal interview with the perpetrators, the exact causes for these specific attacks will never be known, so whatever conclusions will emerge will only be (hopefully) plausible but ultimately always
untestable hypotheses.
In very general terms, Shark attacks can be divided into the following categories.
1. Attacks associated with feeding events, i.e. predation and scavenging.The most notorious species implicated in this category of attacks are the large predatory Sharks
Great White, Tiger, Bull and Oceanic Whitetip.
Whilst large adult GWs appear to be specialist hunters of mammal blubber, the other species are generalists with a broad spectrum of prey and consequently, hunting techniques. It should thus not come as a surprise that the track record here is unequivocal:
these Sharks will sometimes attack and prey on humans!Granted, these events are exceedingly rare.
It is obvious that humans are not the primary prey of any Shark species and let me spare you the long winded and pathetically trivial explanations as to why evolution could not possibly have selected for it. Also, granted, sometimes the Sharks appear not to
like (whatever that may mean) what they have attacked and either spit it back out or not bother to come back to completely consume the meal. In GWs, this may be linked to the fact that we may indeed be
too lean for a specialized hunter of blubber. In other species, it may be an indication of the fact that the Shark was not very hungry, or that something disturbed it whilst it may have hung off waiting for the victim to stop struggling.
But when limbs go missing and Sharks hang on, those are predatory attacks, period!Which brings me straight over to the whitewashing.
Yes we love Sharks, yes Sharks are much maligned and we need to work at improving their reputation: but the fact is that large
predatory Sharks are dangerous and that they need to be treated with respect and with circumspection!
That makes them neither
bad, nor
good – that just makes them large predatory Sharks! I’ve said it
before –
we need to remain fact based and refrain from creating our own unhelpful stereotypes!The common pattern of predatory Shark attack has been called
Sneak Attack whereby a Shark suddenly turns up (in fact, many survivors claim that they never saw the Shark prior to the attack) and persistently attacks, very much like what happened in Sharm
is being described. This is not surprising and only consistent with most attacks by terrestrial predators who relay on the element of surprise in order to approach their prey.
Great Whites sometimes attack Seals and Sea Lions which are close to the surface by sneaking up close to the bottom and then attacking more or less vertically at high speed, resulting in the much publicized predatory breaches.
Some surfers have been attacked in the same way, leading John McCosker to develop the hypothesis of
Mistaken Identity, meaning that the GWs attacking a silhouette at high speed may have mistaken a surfer for a Pinniped, especially in murky water. This is certainly plausible, the more as GW are being routinely induced to attack decoys in the same manner.
BUT:
this is strictly GW lingo!This cannNOT just simply be applied to other species! Specifically, this is
not how Tigers prey on Turtles (and no film maker goes potting around Hawaii towing Turtle decoys) and it does
not apply to each and every “mistake” a Shark may make! Thus, asserting that most Shark attacks are due to
Mistaken Identity is a fallacy and as such, nothing more than pseudo-science!
The same applies to
Investigative Bites.
Once again,
this is GW lingo, as Great Whites are known to test objects and people by (more or less, see
Rodney Fox) gently nibbling at them. Rather than being a strictly predatory behavior, this is probably linked to testing food when scavenging and may, or may not result in subsequent feeding.
Other species known to investigate people, snorkelers and divers alike, by mouthing are Tigers and I hear, Lemons – yes, as in TB!
Not Oceanic Whitetips!They are the picture child for
investigation via bumping. They will circle ever closer, the frequency of bumps will increase and if not countered vigorously or if the affected person does not leave the water, this will likely result in a predatory attack, sometimes referred to as
Bump and Bite attack. Check out the video
here: this is typical behavior and it is pretty obvious that this Shark would
not suddenly slow down to apply a gentle test bite! The same apparently applies to Bull Sharks.
Of note, this is different from the
ramming with snout mentioned in
Martin 2007 that is related to aggression, not predation. Incidentally, Martin does not cite
ramming with snout as an agonistic display in OWTs, a further confirmation that in this species, that behavior is linked to predation!
Once again, attributing
Investigative Bites to species other that GWs, Tigers and maybe Lemons is mere whitewashing and pseudo-science! It also looks like an attempt to exonerate the Shark from having had
bad intentions or the like, something that I find rather peculiar to say the least!
2. Attacks associated with self defenseYou may want to go and re-read
this: several species of Sharks display behavior that is called
agonistic and is linked to self defense. Failure to identify and adequately react to that behavior may lead to what are generally open-mouthed, slashing bites that result in cuts rather than missing tissue.
Attacks on surfers and bathers by small piscivorous Sharks like Blacktips and Spinners (see
Volusia County) or the frequent nips on the feet of waders by subadult Blacktip Reef Sharks are commontly referred to as
Hit & Run attacks and generally result in mere harmless cuts. They, too, are believed to be the result of self defense as the Sharks may simply have been startled and may have wanted to fend off a perceived attack, or may have previously displayed agonistic behavior that was never noticed by the victims.
These are, by far, the most frequent Shark attacks on people.
Finally, there are the
Provoked Attacks, where the people have touched the Sharks, as in the retaliatory bites by Wobbegongs and Nurses that get dragged out from their covers by the tails.
3. Attacks associated with competitionTypically associated with spear fishing, Sharks may bite people when competing for the speared fish. These attacks are thus not aimed at preying on the person but rather, at chasing away a perceived competitor.
Incidentally, the same happens between different Shark species (but apparently
not between individuals of the same species): I’ve personally witnessed a Silvertip biting a Nurse to dislodge him from some bait, and filmed one of our Bulls biting away a Lemon who wanted to approach a feeder.
Consequently, when referring to site fidelity in Sharks, one should always talk about
residency as opposed to
territoriality. The latter implies defense against conspecifics, a behavior that has been observed in many Fishes but apparently, never in any species of Shark!
This is again different from
aggression associated with rank.
Sharks do display behavior that may be interpreted as “posturing” and there are even
anecdotal accounts of actual bites on conspecifics in the context of social interactions.
Yes, it’s complicated!
4. Attacks associated with mistakesSharks
make mistakes.
Considering the impressive array of senses they dispose of, this may seem surprising: and yet, they hunt, attack and bite a vast array of objects like boat propellers, metallic structures, decoys, and ingest completely inedible items like the famous number plates and car tires - and most often and fatally, they will be fooled by fishing bait and lures!
Mistaken attacks on humans are mostly associated with Shark feeding and baiting.
Many species of Sharks (and Fish!) are highly competitive and uncontrolled Shark feeding events can quickly develop into
Feeding Frenzies where the animals get highly agitated and may end up biting other Sharks or the human spectators by mistake. Equally, Sharks may accidentally bite the feeders’ hands during hand feeding shows, etc.
Again, these are genuine mistakes and neither competitive nor predatory in nature – the latter much contrary to the opinion of the anti-feeding lobby.
Talking of which, you may want to check out
these latest statements by Burgess: apparently, the perpetrator of at least two attacks is
one and the same Shark! Amazing!
Plus, there’s this:
"These are open-ocean sharks that are living in an environment that is food-poor," says Burgess. "So when you do find food, you darn well better take advantage of it. Do they remember things? Sure, they remember where the good places to eat were, and they'll come back." Surprise surprise: I happen to totally agree - re-read
this! But... Sharks that may have been
conditioned to come and feed on Tuna heads learn to…
feed on Tuna heads! Not humans!
There you have it I believe - and again, if I'm factually wrong, feel free to correct me!
Long story short:
if we want to be credible Shark advocates, we got to do our homework and first of all, be informed about the animals we love! Science is always in flux and today’s insights may quickly become tomorrow’s fallacies, meaning that we must keep abreast of the latest research results and not base our knowledge on old publications and approximate hearsay. Most importantly, we the amateur naturalists should never make up things on the fly, nor should we idly re-interpret what is considered to be the accepted consensus.
This does not mean that we should not challenge the current
status quo, as that is precisely the process by which knowledge is being advanced!
BUT: the only accepted technique for doing so is the
Scientific Method and as always, let me warn against the siren calls and intellectual shortcuts of the self promoters, quacks and charlatans!
All researchers I’ve ever met have always been eager to engage in informed discussions and to entertain different hypotheses, if adequately supported by according observations. Those researchers are not omniscient and also, not omnipresent and often, observations by common mortals like us have greatly contributed to the advancement of scientific insights - so even if you have no academic background, don’t be shy and speak up!
But do your home work first!
In diesem Sinne!PS read
this brand new report - so, how do you interpret it? :)
