Blog about "The World's best Shark Dive" by Beqa Adventure Divers.
Featuring up to eight regular species of Sharks and over 400 different species of fish, Shark diving doesn't get any better!
Showing posts with label Richard Fitzpatrick. Show all posts
Showing posts with label Richard Fitzpatrick. Show all posts
Huge congratulations, and best wishes to our pals Richard, Adam, Kátya, Christian and the rest of the team - may the future bring many more exciting common projects!
What an amazing group of researchers, conservationists and industry professionals! From L2R, back row: Peni, Gauthier, Wase, Richard, Ian, Charlie and Re; front row Chris, Christian, Manoa and Adam - click for detail!
We're finally analyzing our impact on the Whitetip Reefies - and with the original authors having graciously flown in to supervise but also document our experiments, I'm highly confident that we will shortly dispose of solid evidence, the more as the gizmos we are deploying are truly amazing - and totally non-invasive, too!
And like I said back then, I'm equally highly confident that our Sharks are not being harmed.
But we will see won't we.
And should the results indicate that we need to implement changes, we certainly will - and that's a promise.
Much of it depicts the situation at Raine - including the Turtle lovers, Turtle tagging, Tigers scavenging and finally, Tigers attacking Turtles, and the Turtles' defensive maneuvering.
Overall, I was rather underimpressed - but my favorite scenes were the aerial shot of a GWS catching a Sea Lion, and then the chapters with the reef-walking Epaulette Shark and the aggressively mimic Tasseled Wobbegong. Turns out that the latter two were both filmed by Richard Fitzpatrick who on top of being an excellent researcher is also a top notch multi-awarded underwater shooter with his own production house, Biopixel - and as with all truly exceptional people, nobody could be more knowledgeable, professional and yet humble!
Here is his 2015 Shark portfolio.
This is real natural history imaging, requiring heaps of skills, perseverance, patience, knowledge and yes, plenty of luck too. Compare that to the contrived and pedestrian fare that is regularly being dished out by Shark Week and you'll understand why I love the former and rather loathe the latter!
That's quite a handful of prominent authors - but in essence, this is a re-interpretation of some of the data collected by Richard, Adam and Ian whilst on the venerable Undersea Explorer that have already led to this paper from 2012 I posted about here.
Which is why the authors stress that much of the above is speculation.
The experimental design was aimed at deciphering long-term movements, and the present fine-scale analysis is very much based on inference rather than actual scientific evidence; but having said that, Richard and Adam have logged hundreds of man hours at Raine, and tell me that actual predation events on healthy Turtles are very rare and tend to be confined to the start of the breeding season when there are less Turtles and the Tigers are just arriving hungry. On a busy year, Raine will yield up to 2,000 dead Turtles, meaning that after a while, the Tigers are more than sated and really could not care less about chasing after healthy Turtles.
Like I said, very nice - but now things are changing.
BHP the mining giant is giving a lot of money to the Raine Island Green Turtle Recovery Project, and the island is being made more Turtle-friendly by eliminating features that could kill them and by protecting the nests against inundation. This means that less turtles will have accidents, and that any distressed Turtle will be aided by the turtle lovers and consequently, adult Turtle mortality has already been reduced by 50%.
And the Tigers?
What happens at Raine is part of a system - and if you tinker at one end, it stands to reason that there will be consequences at the other.
Will the Sharks predate more on healthy individuals whilst expending more energy in the process - and if predation increases, will that have an effect on the behavior of the Turtles? Or will the Tiger Sharks gradually stop coming? And what are the effects of this diminishing resource on their population?
Here's what I think - and yes I'm totally speculating.
Research in Hawaii has shown that those Tiger Sharks are able to regularly exploit determined ephemeral resources, and our own observations at Shark Reef indicate the same for our Bulls at Shark Reef. In essence, one of those Sharks will stumbles upon an opportunity, is able to memorize the experience and will henceforth come back to exploit it. This is learned individual behavior, not something that is genetically encoded or communicated by conspecifics or the like.
At the same time, our observations and those of the GWS people indicate that individual Sharks will favor determined strategies, e.g. individual GWS will attack the teaser bait consistently in one determined way; and on Shark Reef where we have a hand feeding and a bin feeding tribe of Bulls with very little overlap, those specialized hand feeding Bulls will gradually stop visiting when we temporarily suspend hand feeding,
Could it be the same for Raine Island?
Could there be always the same Tigers, and could those individuals be specialized scavengers that would not switch to outright predation but instead, would eventually stop coming once there are not anymore enough carcasses to feed on?
Dunno - but that's certainly testable, or not?
And another thought.
If one believes Domeier -and I certainly do- what happens at Guadalupe is essentially a GWS feeding and mating aggregation. Could the food pulse during the pupping season of the Northern Elephant Seals maybe even trigger mating, and could it be important for the success of the ensuing pregnancies?
And could what happens at Raine Island be the same, meaning that if the Shark aggregation slowly disperses, finding mates would become more difficult and reproduction success would be lower?
"Best practice" among cage diving operations apparently consists in just
teasing, but never actually handing any bait to the Sharks.
Were I a Shark hugger, I would immediately object that letting the
Sharks waste precious energy on fruitless "hunts" is to be rejected as
it is likely harmful to the animals.
And this example from the Coral Sea?
It's actually very similar: the paper reveals that the metabolism of those provisioned Whitetips increases by about 6.5% on feeding days compared to non-feeding ones, and that the according incremental energy expenditure is not likely to be offset by the feeding as the dominant Grey Reefies consume the bulk of the (calorically inferior) bait.
Click for detail!
Like I said, very interesting!
The authors postulate that even if the Whitetip Reefies were to compensate by hunting more, this would come at a cost to other activities like resting or reproduction, and that consequently, the Shark feed at Osprey is likely to negatively impact their health and fitness, albeit only minimally.
In fact, what is actually being bemoaned is that the Whitetips are NOT being fed but only inconvenienced and teased - think about those caged GWS dives where feeding is illegal, and draw the inevitable conclusions! :)
Not good, and certainly warranting further investigation!
And our own feed?
I'm not so concerned about the other Sharks as they don't usually rest during the day - but our Whitetip Reefies are certainly equally at risk. What however makes me slightly more optimistic, is that our visual observations indicate that they wake up and remain active for a far shorter time frame; and that contrary to Osprey where the operators dump the food, we do hand feed and have always made sure that all the Sharks get a fair share of the handouts.
But we will certainly investigate!
And on top of that, we will also consider handing them calorically superior food like maybe Sardines or the like!
He's the researcher who was featured in the late Mike deGruy's epic documentary Mysteries of the Shark Coast where he tagged and tracked Reef Sharks at Osprey Reef (paper here!) and then moved on to Raine Island to work on Tigers and Turtles.
This dude.
Even this video is actually surprising.
Like in the above documentary, he suggests that Tigers will roam for hundreds, if not thousands of kilometers like they do in Hawaii and the Northern Atlantic (and here) but then aggregate at Raine Island for the Turtle mating season - very much in line with what has been shown for the Tigers/Albatrosses in French Frigate Shoals.
Correct me if I'm wrong - but the way I read it and contrary to the preliminary findings suggested in deGruy's documentary whereby they would be following the Turtles when they leave for their foraging grounds in the Torres Straight, it comes to the conclusion that the Tigers concentrate around Raine Island year-round and merely switch diet when the Turtles are absent. From what I understand (but then maybe I don't), there appears to be enough Tiger Shark food around Raine for them not to have to expend energy on lengthy walkabouts.
If so, it's just another reminder that we should not generalize.
Those large long lived Sharks are obviously not hard wired but instead, they have the capability to develop individual preferences resulting in a high degree of behavioral and trophic plasticity, thus allowing them to best adapt to specific circumstances - as amply demonstrated by the amazing learning potential and vast personality differences between our individual Bulls here at Shark Reef!
Talking of which.
We shall shortly capitalize on precisely those different character traits to run out yet another cool project.
