Thursday, December 23, 2010

Red Sea - the Experts have spoken!


Did you miss me?
I was marooned in Tonga and no, things there have not improved!

In the meantime, wondrous things have happened!
I’m alluding to my last post about the Red Sea Shark attacks: 28 comments and nobody has hyperventilated or insulted anybody! It’s really a good thread and I invite you to go read it as some highly experienced and intelligent people have shared remarkable insights and entertaining anecdotes.
Very cool indeed!

Also, the experts have published their expert opinions.

Haven’t heard much from Doktor Ritter (hear hear Biminibill!)
All I’ve found is this interview where he has looked at some pics and come to the following spectacular eco-behavioral conclusions

To call this an attack would be wrong. I would call this an accident.
The bite marks I’ve seen on the pictures look like the Sharks were defending themselves. The accident might have happened as follows: first, the Sharks took a bite in order to test the smell
(sic) of that creature – in the same way that we touch something to test its consistence. Then, the victims defended themselves, at which the Sharks took a harder bite because they felt threatened.

Meaning that next time a Shark bites you, let him nibble and do not fight back!
Wow!

But then, as I’m about to post, I find this !
Again: Wow! Talk about armchair sniping from way out there in left field! And no, I’m not gonna waste my time, and yours, in commenting on the content, the arrogance, the bullshit. If by now you haven’t caught on to this particular con, there’s nothing I could possibly say that will sway your mind anyway!

Which leaves the other three musketeers.
Quite honestly, I was looking forward to their statements with considerable trepidation: after all, if the only PhD (this is wrong) has already come up with this kind of rubbish, what was I to expect from the lowly naturalists?

So there.
In a private post, George Burgess says this.

From Sharm El Sheik, Egypt.

….. For those of you disturbed by the unscientific nature of the subject do not read on (or wait until these results appear in a scientific journal). Others may find the results of my investigation of interest. ……...

From Cairo


.....
The attacks were unprecedented in scope – five in five days (two each on Tuesday and Wed., one on Sat.); major trauma, the last a fatality; all from nearby locations; unlikely attackers for shallow-water attacks.
Three of the non-fatal attacks involved major injuries (loss of limbs) and the victims were very fortunate to survive.


Here’s the kicker: two of the attacks were by an oceanic whitetip and two by a mako (likely a shortfin).
Note the use of “an” and “a” – there is conclusive evidence that a single individual whitetip was responsible for two of the attacks, including the fatality, and a single mako almost surely was involved in two separate attacks. The fifth attack was by a carcharhinid - it may have been a whitetip, perhaps even the same one implicated in the other two, but not enough evidence at this time to say for sure.

The whitetip incident is, I believe, the first documented case of multiple attack by a single shark, although others have been suspected.
Will check on this more when I return and can access the ISAF database.
The oceanic whitetip was identified by distinctive color patterns and a bite mark on its upper caudal lobe in underwater photos of the shark taken just before/after one attack and other photos taken from shore during another attack. The attacker also was tracked to other dive locations post-attack via photos taken by divers. It was a big one - 2.5 m – that also threatened other divers prior to its first attack.

The similarly-sized mako first attacked a wader (!) in hip-deep water then bolted back over the top of the reef into blue water only to reappear a minute later and perhaps 10 m away from the first incident, attacking a snorkler.
The first victim got away with some lacerati
ons; the second was not so fortunate, being mauled on both arms, losing one.

All five attacks occurred in depths no more than 20 m deep.
A very strange situation indeed. It appears that the disposal of sheep carcasses by sailors bringing a load of live sheep in through the nearby shipping channel may have played a part in this, as may have unseasonably high water temp’s.


More to come as we sort through some other data.


In the past, I’ve not been very kind to Burgess.
He does come up with some highly speculative and also, irritating statements - but to his credit, like him or not, he is the go-to man when it comes to Shark attacks. And this time, I must really say that I am impressed! This is interesting, refreshingly factual and also, it does not dwell on gratuitous speculation.
Well done!

Which brings me straight over to this.
You may want to notice that the press release is authored by Collier, an amateur US West Coast GW attack investigator and by Levine, a travel agent, plus 3 unknown Egyptian (?) officials - and no Burgess!
There’s much I could say here about professional qualifications, fake academic affiliations, ongoing feuds and jumping guns & stealing shows – but then again, is anybody in the know surprised?
So, for a change, enough said!

Let’s instead focus on the merits of what is being said.
First and foremost: well done for not having tried to whitewash this – these were indeed genuine, and very likely predatory attacks and not accidents or mistakes or the like!
I also like the reference to the increase in the population of aquatic recreationists augmenting the chances of encounters, and to the specific topographical features whereby the water gets very deep close to the shoreline.

The remainder? Hmmm…

  • The sheep carcasses? Indeed, maybe. But then again, the only confirmed occurrence appears to date back to the end of September which makes for a rather tenuous causal connex to events unfolding two months later. Or not?
  • The depletion of natural prey due to overfishing? First, from everything I hear, the species most targeted and thus depleted in the Red Sea are pelagic Sharks rather than pelagic Fishes, thus leading to the exact opposite conclusions – but granted, I don’t dispose of the numbers and may indeed be wrong. Which of course begs the question whether this assertion is supported by any specific data? Second, I’m hearing the implicit assumption that “Sharks” will go anywhere and eat anything if they are hungry, very much like the proverbial Bears and Wolves are said to approach human dwellings during particularly harsh winters and the like. But Sharks are not Bears and Wolves. With the exception of a few large generalist feeders like Tigers, most Shark species occupy very specific ecological niches where they have evolved to be successful hunters of very specific, in this case pelagic prey. Conversely, individuals that would stray to hunt outside of their ecological niches would be comparatively unsuccessful, meaning that evolution would have selected against this kind of behavior (and incidentally, one could argue that anyway, those Bears and Wolves would still be roaming well within their original habitats from which they were displaced by our invasion). Look at the Med and the North Atlantic: well before the comparatively recent craze for Shark fins and according slaughter of Sharks, fish stocks in those waters were severely depleted - and yet, I don’t remember witnessing any consequent notable increase in Shark attacks. I remain skeptical.
  • Fish feeding attracted the Sharks? Maybe – and if so, I would suspect that the attractant might have been the commotion rather than the fish bait (what was it anyway: bread and the like?). Then again, I have the exact opposite experience here in Fiji. Shark Reef sits on the edge of Beqa Channel that drops down to 300m and where given determined meteorological conditions, there are regular sightings of both Tuna and OWTs – and still, in more than 10 years of baiting with massive amounts of food creating a huge commotion, no OWT has ever visited the reef! See above, reef habitats are simply not the ecological niche of pelagic Sharks, full stop! In brief, way before attracting any pelagic Sharks, the Fish feeding on the coast would have first attracted the local coastal Sharks, among which the ubiquitous Tigers – and obviously, it has not! Again, I am highly unconvinced!
  • Shark feeding? Do I once again hear that Sharks fed by humans will learn to feed ON humans? This is boring – but if you insist: please, do re-read this! Having said this, there is however one caveat: shark feeding does aggregate Sharks and if conducted in the wrong place, e.g. in the vicinity of swimming beaches and the like, it will contribute to increasing the chances of encounters between the Sharks and the aquatic recreationists – and if conducted in the wrong way, e.g. by triggering feeding frenzies, all bets are off anyway! Is this is true and the guys were feeding the Mako, they were really asking for it! As Richard points out, it is very much the responsibility of Shark diving operators to choose the correct locations and procedures, and rogue operators need to be taken to task! Again: snorkeling with large predatory Sharks is just plain stupid - and talk about this having been prophetic! Alas!

This is plenty dangerous enough!
  • Temperature and metabolism? Yes most Sharks are poikilothermic - but it just so happens that the Mako as a Lamnid like the GW is not! Plus, despite the intuitive plausibility of such a hypothesis: are there any data supporting the assertion that Sharks will eat more when ambient temperatures rise, and if so: concerning which species? My personal observations certainly don’t support that hypothesis. Rather, they lead me to the conclusion that instead of falling into a feeding frenzy, Sharks that feel too hot will re-locate to where the ambient temperature is more to their liking, and that different species prefer different ambient temperatures. For instance, in Cocos, the Hammers will always be found just above the thermocline, meaning that in an El Niño year, they will stay deep and during a La Niña, very shallow. Or to take another example, Juerg’s research on the Bulls seems to indicate that they prefer to reside in water between 25 and 27 degrees Celsius. Conversely, our Reef Blacktips seem completely adapted to the much higher temperatures on the reef top. Different Sharks have evolved to function best in different habitats and temperatures and when those parameters change, they just do not behave like mechanical automatons but instead, re-locate to where conditions are best for them. And then, there’s this: many pelagic Fishes like Tuna are highly migratory and fishermen know that both they and the pelagic Sharks that follow them are associated with specific thermoclines, both in terms of depth but also in terms of how warm water expands from the Equator in Summer and contracts back in Winter. With that in mind, would it not be much more plausible to assert that the unusually elevated sea temperatures may have contributed to aggregating both the Sharks and their prey in the Northern Red Sea?
Yes I’m speculating – but so are they!
The fact is that two different species of pelagic Sharks (forget Ritter) have attacked several snorkelers and a wader (!) on the coastline.
This is truly absolutely exceptional and cannot be suitably explained by the usual generalist sound bites about Fish feeding and overfishing – if causal, both would have led to attacks by coastal Sharks first.

So bear with me if I come up with my own set of wild speculations – and let there be no doubt that my guess is as good as anybody’s and that we’ll never know what really went down anyway.
  • An environmental effect, likely the unusually high temperatures, caused pelagic Fishes and the pelagic Sharks that prey on them to wander into the Northern Red Sea
  • An “event” caused the Sharks to approach the coast, the most likely being that their prey went there (think Sardine Run), or that indeed, a Sheep carcass floated there - or the prey dispersed or was consumed and the Sharks approached the coast when swimming one of their typical search patters
  • The stimuli (think splish-splash) sent out by the snorkelers attracted the Sharks who then attacked

And after these simply brilliant deductions (If you can't dazzle them with brilliance, baffle them with bullshit), I herewith end my posts about the Red Sea attacks!
Hopefully!

2 comments:

Shark Diver said...

Well posted sir, yes I did notice the fracturing of experts and the singular press release.

For the record I am staying with the sheep, anecdotally upwards to 1000+ animals were dumped only a few miles away, that's the word at least.

All your other points are on target, as I emailed you when this broke, this was most likely a cascade event, one thing leading to the other.

Unprecedented none the less.

As for Herr Ritter?

He sees everything through the lens of that Discovery Shoot which almost took his leg.

Talk about an "Ahab Complex" but that's a post for another day, week, or month.

DaShark said...

Thanks Patric!

1,000+ is a whole lotta sheep!
One would think that there would be more than just anecdotal evidence and whispers?

Yes agree, this is more than just one simple cause and effect - like incidentally, nearly all major accidents!