Baby Bulls!

Finally!

So here they are.

These are this year's first tiny baby Fiji Bulls that are getting the treatment by the volunteers of Projects Abroad. Congratulations to the intrepid fishermen, to Gary who showed them how to do it and to Juerg who found the time to attend and oversee the science.

Lovely album here.

Kudos!

The Nadi Workshop - Spillover!

Top left-to-right: Api, Ben and Tumbee
Middle left-to-right: Ingrid, Colin, Perry, Juerg and Netani
Bottom left-to-right: Gary and Angelo - click for detail!

Apologies - I'm currently simply too busy to blog.

Just this.

Looks like the big Shark meeting has been a great success as told here by Angelo.

And it has had direct repercussions for us.

Several participants have made time to come and say hi, and most have managed to partake in a  stellar Shark dive with plenty of Fiji Bulls and great viz. It just so happens that our dear friends Juerg and Gary are visiting, resulting in the rather epic picture above where the notable absentee is Demian who merely managed to squeeze in a short cameo before gallivanting off to some other remote destination where he's championing the cause of Sharks.

Fortuitous or not, a meeting like that will always have consequences.

Keep watching this space!

Feeding Bull Sharks in Fiji - the Paper!

This pic by Doug is so good that I catch myself using it time after time again - click for detail!

Finally!

Stating that I'm mighty proud would clearly be the understatement of the year!

Opportunistic Visitors: Long-Term Behavioural Response of Bull Sharks to Food Provisioning in Fiji
Juerg M. Brunnschweiler, Adam Barnett

Abstract

Shark-based tourism that uses bait to reliably attract certain species to specific sites so that divers can view them is a growing industry globally, but remains a controversial issue. 
We evaluate multi-year (2004–2011) underwater visual (n = 48 individuals) and acoustic tracking data (n = 82 transmitters; array of up to 16 receivers) of bull sharks Carcharhinus leucas from a long-term shark feeding site at the Shark Reef Marine Reserve and reefs along the Beqa Channel on the southern coast of Viti Levu, Fiji. 

Individual C. leucas showed varying degrees of site fidelity.
Determined from acoustic tagging, the majority of C. leucas had site fidelity indexes greater than 0.5 for the marine reserve (including the feeding site) and neighbouring reefs. However, during the time of the day (09:00–12:00) when feeding takes place, sharks mainly had site fidelity indexes smaller than 0.5 for the feeding site, regardless of feeding or non-feeding days
Site fidelity indexes determined by direct diver observation of sharks at the feeding site were lower compared to such values determined by acoustic tagging. 

The overall pattern for C. leucas is that, if present in the area, they are attracted to the feeding site regardless of whether feeding or non-feeding days, but they remain for longer periods of time (consecutive hours) on feeding days. The overall diel patterns in movement are for C. leucas to use the area around the feeding site in the morning before spreading out over Shark Reef throughout the day and dispersing over the entire array at night. Both focal observation and acoustic monitoring show that C. leucas intermittently leave the area for a few consecutive days throughout the year, and for longer time periods (weeks to months) at the end of the calendar year before returning to the feeding site.

So this is it.

Like we never tire to say, BAD has essentially been established in order to manage a Shark research and conservation project and consequently, everything we do is geared towards those aims whilst generating just enough income to compensate the various stakeholders and ensure our long term survival.

So far so good - touch wood!

But of course the beginning was everything but easy.

I had reached out to Gary Adkison when formulating the Fiji Shark Project, and when Juerg lost his Bull Shark research site in the Bahamas, Gary suggested that he go check out the crazy dude who was trying to set up a Shark MPA in Fiji. I desperately needed to find a conservation-oriented researcher, something that in those times was far from common; and Juerg desperately needed to find a new and and above all, reliable Bull Shark research site for his Bull Shark Tagging Programme. We met, took each other's measure, liked what we saw and decided to give it a try.

Gesagt getan and the rest, as they say, is history.

That was in 2003.

Ten years and countless adventures, discussions and heated debates (!) later, I must really say that it was a match made in heaven. I really, really like and respect Juerg and the feeling is likely reciprocal, the more as we really completely see eye to eye on conservation matters (sometimes less so on research techniques), are completely result-driven and despise  bullshit - and we even share the same degree of incisive humor!

But I'm digressing as always.

Back then, Shark conservation was very much in its infancy and the exclusive domain of a handful of idealistic and rather clueless loons (and probably still is!), we were both essentially rookies, and progress only happened in baby steps and with plenty of setbacks. This also on the research side where the first generation of PAT tags was rather temperamental and where for ethical reasons, we had burdened ourselves with the challenge of trying to tag the animals underwater, first intra-gastrically and then externally.

But Juerg and Gary did persevere and eventually got it done - and this very much despite the vocal objections of your truly who developed an increasing distaste for the invasive techniques.

Love you guys! :)

At the same time, we started our long term monitoring.

This is a first (and by no means last!) look at our enormous data base where we have so far meticulously recorded close to 10 years, or approx. 4,000 individual baited Shark dives in the Shark Reef Marine Reserve. Over those years, we have named and monitored more and more individual Sharks and have been keeping particularly detailed records of presently approx 150 individual Bulls.

The paper is the comprehensive analysis of only one subset of those observations, i.e. simple presence/absence data, this in comparison to several years' worth of acoustic tagging data of the same 48 individual Sharks.

Thankfully it is open access - read it!

The take-away message as I see it is this.

This particular Shark dive has been operating continuously since 1998 and it is fair to state that if there has ever been a population of conditioned Sharks, it would be the Bull Sharks of Shark Reef.

And yet,

• Our Bulls remain wild animals.
  Once they have discovered Shark Reef, they do come back; but at the same time, it is quite obvious that they continue to roam the area and undoubtedly fulfill their ecological function like any other non-provisioned Bull Shark, much in line with what we postulated years ago - and now we have the peer-reviewed science to back it up!

• Effects at large spatial and temporal scales appear minimal.
  This is consistent with all research into provisioned Sharks, i.e. that there may well be conditioning on site but that typically, the long term migrations and life history in general remain largely unaffected.

• Feeding does not appear to significantly effect the Sharks' diel patterns, this with the only exception that they will spend more time at the feeding site on feeding days - however only to depart and continue their usual daily roaming patterns. Note the observation about night-time foraging at and possibly even within the Navua River - very interesting and eminently testable!

• Same-same for their propensity, or lack of, to approach humans.
  There are obviously pronounced differences at the individual level, something I experience on a daily basis - but despite of the fact that there are Sharks that are decidedly more friendly (or bold), it is equally true that none of them comes begging for food when there is no bait in the water. In fact, the observation that during the time of the day (09:00–12:00) when feeding takes place, sharks mainly had site fidelity indexes smaller than 0.5 for the feeding site, regardless of feeding or non-feeding days may be an indication for the fact that the presence of bait barely compensates for the notorious shyness of this species!

• Long-term exposure to feeding does not appear to cause any conditioning in terms of dependence on that food source.
  One could stipulate such conditioning if the data showed increased presence over the years - but the fact is that the data appear to absolutely negate that hypothesis, as e.g. illustrated by the site fidelity indexes for 2004-2011 of Crook, a friendly old-timer and voracious hand feeder., to wit 0.48, 0.20, 0.16, 0.24, 0.23, 0.22, 0.14 and 0.47  (Table S1), an observation that is consistent for all monitored Sharks.

• The Shark Corridor appears to confer a solid degree of protection.
  Yes the animals do regularly leave that area - but site fidelity indexes that are larger than 0.50 indicate that the protected area is apparently large enough to have a positive effect.

Long story short?

Granted, strictly speaking, this only applies to Fiji Bull Sharks that are being fed in Fiji and not to "Sharks" in general - but after Aleks' paper on Caribbean Reefs and Neil's Tiger Shark paper, we now have one more indication that one cannot simply draw conclusions from other research showing conditioning, and possibly negative consequences for other species: not from those Lemons in Moorea, not from the Southern Stingrays in Cayman - and certainly not from teleost Fishes that appear to have a higher propensity for being conditioned, let alone the proverbial bloody Bears!

On the contrary and with the caveat that this may well be species- but possibly also situation-specific (see the Moorea Lemons where there may be procedural issues), it appears that those larger Sharks may just be a tad too smart for the simplistic cause-effect bullshit spouted by our detractors.

In fact when it comes to the risk they pose to humans, I'm of the strong opinion that provided that those baited dives are conducted responsibly, those "tame" Sharks pose less and not more of a threat! Yes I'm obviously speculating - but after thousands of Shark dives, I've earned myself the right to do so!

And their long term life history?
If there there is one constant observation among all papers analyzing Shark provisioning, it is that over the longer term, the animals keep their normal migration and mating/birthing patterns - e.g. think of the GWS in Lupe, the Playa Bulls and the Bimini GHH that are all seasonal irrespective of the fact that they are being fed! This is once again a strong indication that feeding causes no harm, at least not to the Sharks that are being fed.

Anyway - is this cool, or what!

Keep watching this space.

As I said, this is only the beginning, meaning that our data base contains the answers to many more questions. And, we're already conducting and are about to roll out several more new large multi-year projects that will hopefully lead to new important insights - especially about reproductive and possibly even natal philopatry that would greatly assist us in refining local Shark conservation measures.

In the meantime, enjoy Juerg and Adam's paper!

PS thanks Patric!
PS2: thanks Georgina!

Interview with Gary!

Shark men: Rusi, Alex and Gary at Shark Reef

How can I possibly do the man justice.
We will always differ on the finer points of culture vs abject savagery - but peanut butter or no peanut butter, Gary Adkison will always remain one of my heroes for whom I have nothing but the biggest respect and admiration.
Plus a whole lotta Love, with a capital L!

We first met in 2001 when he was running the legendary Shark dives at Walker's Cay and the rest as they say is history.
When first developing the Fiji Shark Project, I reached out to Gary who graciously and enthusiastically agreed to give us a hand in turning a lot of lofty ideas into something tangible. It is he who first introduced us to Juerg with whom he has developed and still manages the Bull Shark Tagging Programme; it is he who has also made the introductions to his former dive shop manager and now BAD shareholder Andrew; and it is he who has been invaluable in helping us define our initial Shark diving procedures and in coaching us through the thousand vagaries of managing a Shark diving operation. They will undoubtedly disagree - but Gary and his wife Brenda have been absolutely crucial in every single step of BADs history and for that, we shall always be indebted to them.
But mon, before you ask: not to the point of sharing my cheese!

Gary met Alex the Sharkman here in Fiji in 2009.
That was the International Year of the Shark and we had invited Alex to witness what we were doing in Fiji, namely organizing Fiji's first national Shark conservation campaign. Shark Reef was really starting to blossom, with healthy corals, scores of Fishes but above all, ever growing numbers of Sharks and I remember those weeks as a time of great conversations, great dives and mutual bonding.

They have been friends ever since.
Alex has finally found the time to re-vamp his website and Gary is the first to sit through one of his legendary interviews - and I must say, fantastic job! This is my Gary: one of the original salt dogs, a pioneer of Shark diving and Shark conservation (!) and above all, just a really nice guy!
Chapeau my friends!

Enjoy Gary's interview!
And if you are as fascinated as I am: start reading Gary's autobiography A Life Underwater here!

PS - Nice comments by David here!

He's baaaaaaaaack!!!

Guadalupe GW with permanent bling - click for detail.

Domeier wants to go and fish for more Great Whites – story here.

Before commenting, let me try and put things into perspective.
Generally speaking, we are very much in favor of research as we deem it essential for providing the data enabling us to devise effective conservation measures. Consequently, as you know, we have always always sponsored research on our Bull Sharks that are the principal attraction of the Fiji Shark Dive. But research is expensive as we devote a lot of resources to this undertaking and depending on what we do, it may also be disruptive to our business as some happens during our regular Shark dives with paying customers. We consequently don’t just blindly embark into new ventures, but have instead developed the following process whereby every project gets thoroughly screened before being implemented – and incidentally, we do something very similar when deciding about the countless film productions that get proposed to us.

The lead researcher is Dr. Juerg Brunnschweiler.
Juerg is one of, if not the foremost expert on this species and everything we do and every request by any other researcher is subject to his vetting and approval. We will also consult with Gary Adkison who brings to the table a lifetime of experience in diving with Sharks, and with Rusi whose understanding of the individual Sharks on Shark Reef is simply unparalleled, and define the framework for a research project. From the very beginning, we have had the understanding that all projects need to be checked against the following two prerequisites:

• There must be a direct link between the project and Shark conservation. Like I’ve said many times before, funding for research (and conservation) is scarce and the inevitable consequence is that it must be prioritized. We believe that the most urgent biological challenges that need to be tackled are habitat degradation and species extinction, and that “nice to know”, let alone blatantly frivolous queries must wait, respectively have no place in our research.
• The method we use must be the least invasive possible, this in order to conform to what we deem ethical (no lethal sampling, ever!), to safeguard the animals but also, to ensure that the Sharks we have worked so hard to attract and befriend are not being spooked by unnecessary rough handling.

With that in mind, here is what has happened lately.
After completing the satellite tagging project that was aimed at identifying the nursery areas but was fraught with technical challenges, we started a new project aimed at exploring the short-range movement patterns of the Sharks with the aim of better defining the area required to ensure their effective protection. For that, we positioned a multitude of receivers on the adjacent reefs and proceeded to equip the Sharks with acoustic transmitters. In line with our beliefs about having to use non-invasive methods, all tags were fed rather than attached, meaning that they would be expelled within only 3 to 7 days. Despite of this impediment, we were able to indentify the likely scope of their range and this has resulted in the establishment of a Shark protected Shark Corridor in 2006.

Our next query was to try and pinpoint the mating areas.
As the Bulls do not feed during the mating period, we had no choice but to attach the acoustic tags externally – and back came the old technical challenges. Our first choice of pole spears proved inadequate as most of the time, the anchors would not penetrate properly and the tags would detach in no time. Using a spear gun was more successful but resulted in veritable hunting expeditions where some of us got the impression that the Sharks quickly caught on to the activity and would split as soon as the hunter would ascend in the water column, to the point that after a few days of spearing, Shark numbers would be noticeably diminished and only recover after several weeks of normal diving.
Long story short – despite of obtaining several stellar results, we have realized that our protocols are sub-optimal and need urgent improvement.

As a consequence, we have not tagged a single Shark in 2010.
Instead, we have sent back all surplus tags that are now being deployed elsewhere and after the last tag had detached itself, we have retrieved all receivers and have instead concentrated on obtaining as many tissue samples as possible for Mahmood’s research on genetic fingerprinting. At the same time, we are scouting the rivers in order to set up a series of research projects there in 2011 where we will re-deploy the receivers.

And what about the tagging?
The current problem we are facing is threefold:

• We know the range of the Bulls and have expanded the protected area accordingly, and we also know where the mating areas are (up to Juerg to explain that in an upcoming paper): thus, in order to invest more resources, we will need to come up with a new, conservation-oriented query. As I said, mere nice to know does not cut it.
• Tagging the Bulls externally is invasive and changes their behavior, albeit only temporarily. On a personal note, it is also profoundly disturbing for both me and Rusi to witness somebody shooting animals to whom we have developed a personal attachment.
• The gizmos are faulty and continuing with the present techniques is going to lead to more frustration.

With that in mind, we will resume tagging only once we have a new, worthwhile conservation-oriented project and above all, only once we have developed a new, secure and non invasive technique for deploying them.
But fear not: we have already agreed upon such a project and have also already successfully deployed a completely new prototype gizmo! Preliminary results look highly promising and we may soon be able to reveal it to the public – after securing it against moochers like the always industrious and formidable BB!

Which brings me straight over to Domeier.
He wants to fish and then tag 13 more GWs, a highly endangered and strictly protected species, and that within a protected marine sanctuary. That fact alone requires a very much heightened level of vigilance and due diligence when determining whether he should be allowed to do so.
It may not surprise you that I believe he should not, and here is why.

I’ve read the draft proposal.
Quite frankly, it is a great piece – in fact, it is so exhaustive and compelling that being my usual skeptical self, I already harbor the suspicion that this is already a done deal and that the public consultation is merely a ploy aimed at preempting any subsequent critique once things will again go pear shaped.
But as I said, it is extremely well written and addresses many grievances head on and with plausible explanations – so good that in fact, I’m stumped that Domeier never deigned to use the same compelling arguments and deflect much of the criticism when the proverbial hit the fan!

What it however does not address are the two prerequisites we postulate here in Fiji.

Cui bono?
Is there really a need to tag more Pacific Great Whites?
I sure hope this is not again a fishing show for Nat Geo! And if not: thanks to TOPP and others, Pacific GWs are without a doubt the most researched and best documented local population of this species: we basically already know where they give birth, where the juveniles migrate, where the adults roam. Also, those GWs are already protected in the USA and in Mexico, however with the caveat that quite a few juveniles perish as they are caught accidentally by small Mexican fishermen when they migrate south to Baja.
What possible new data will Domeier’s project gather for better preserving the species?

And with that in mind, would those resources not be better invested elsewhere?
Just as some examples: could those funds not be better invested in trying to stop the accidental catches by the small Mexican fishermen? Could those tags not be deployed to study the little documented GW in the Mediterranean, or the newly found population in Vietnam?

But much more importantly, those SPOT tags suck!
First, there are notorious connectivity problems that need not be addressed here.
But secondly, the present attachment technique is just simply unacceptable. The tag is supposed to uplink to a satellite and transmit is position whenever the Shark comes to the surface and for that, in its present configuration, it needs to be rigidly attached to the first dorsal fin. This implies catching and immobilizing the Shark in order to drill some holes and attach the tag with bolts and nuts, a fact that condemns the Shark to henceforth carry around some ugly bling that will never ever fall off anymore. Check out the above picture from Lawrence’s blog, and I can only agree with his comment : WTF?

The whole procedure is highly invasive, if not outright cruel.
That alone should be grounds enough for not giving the permit.
In fact, the procedure is so bad that Domeier himself has recognized the problem and apparently (and unsuccessfully) tried to develop a clamp very much in line with what is already being deployed on Whale Sharks. Having failed, he now wants to resort to the old, “proven” (and granted, slightly improved) technique of catching the Sharks with rod and reel, subduing them by having them fight against some buoys and then hoisting them onto a vessel.
That’s just not good enough!

I say: wait til the gizmo is fixed!
Collecting those data is probably neither really necessary, nor urgent. Why not take the time to develop a better tag with a better attachment instead of having the Sharks pay the price for his incapacity to devise a better attachment.
Solutions? Surely, if one can produce a space-age satellite tag, one can also devise something equally sophisticated instead of continuing to resort to those jury-rigged implements? Maybe indeed a clamp that snaps shut and can be applied on the fly? Maybe re-design the tag so that it can be attached anywhere (and thus, on the fly) and equip it with a short line to just a small floating and self-righting antenna? And if everything fails: how about a cool contest among the students of some technical university!

So, there you have it.
It is once again about what’s ethical and whether the need for data warrants mistreating the animals. We believe it does not and consequently, we don’t do it in Fiji - and neither is it OK to do so anywhere else! Yes, improving faulty protocols may be tedious and even expensive - but it needs to be done.

Mind you, just my 2 ¢ - and as I said, I fear that in practical terms, nobody cares anyway.
As always, we shall watch how this venture unfolds.

The Story

Shark men: Gary (right), our iconic Rusi and Alex the Sharkman.

Bless Gary!

Every picture truly tells a story!
After I posted that old picture of Gary and the Tiger Shark, he took the time to write me a moving message about the story behind it - just for me and not meant for public consumption. But having asked, he's granted me permission to post it. I love it as it so eloquently documents the transition from macho Shark killer to passionate Shark advocate, and what a good man my dear friend Gary really is.
Here is Gary's reminiscence of that fateful day.

Dear Mike,

You know that photo of the shark and myself has a story with it that I want to share.
I lived in the Gambier Islands in remote eastern French Polynesia for many months when I was sailing around the world. I would go out with the natives everyday and photograph them free diving black pearls and shooting fish for the village. One day we went out in three dugouts to spear a seasonal schooling fish they called Nanui (like a Bermuda chub) in the lagoon. There were many sharks around due to the amount of fish being shot and large amounts of blood.

I was snapping away at the grey reefs and blacktips with my camera when the tiger showed up.
This is in 1980-81 and most folks knew nothing about shark behavior or how to read it. The tiger was amped up and initially went after a couple of the native free divers, chewing on their fins. The tiger then came at my wife, who kicked her away repeatedly while backpedaling to get away. It even bit one of the outrigger logs on one of the canoes!

I carried a bangstick in the bottom of my dive bag that someone had given me before I left to sail around the world and I had never used it.
However, it was in my dive bag in the canoe that day. I quickly rolled into the outrigger canoe, grabbed it and rolled back in the water just in time to see the tiger turn and charge at me. To this day I really did not know what I was going to do with the bang stick but when she came at me and tried to bite the stick in my hand I rolled over her back and shot her behind the head.

Ultimately I got a rope on her tail and towed her back to the village behind the outrigger canoe.
There was a great celebration in the village and they feasted on the tiger shark that night. I was the honored guest because I had slayed this magnificent beast. In Polynesian fashion the celebration was done out of respect for the valiant shark. Never in a boastful way.
The chief of the village presented me with a tooth from each side of the jaw of the tiger shark and those are the same teeth I have worn around my neck now for 30 years!

They are a reminder to me of how we fear what we do not understand.
It is a symbol of man's ignorance. That photo of the tiger and I..... is like another person. A person who did not understand that the tiger shark was only doing what it was meant to do. That day in the lagoon.....we created that seemingly dangerous encounter by our spearfishing for the village. In retrospect, I have relived that day a thousand times in my head and early on realized that all we really had to do was get out the water and let her enjoy another day of life in her world.
We were the intruders...and not the other way around.

I would say that that one experience with the tiger shark set the tone of how I would dedicate the rest of my life to understanding and helping others understand this misunderstood creature.
Hopefully she did not die in vain.

All of us old timers in this business of sharks have similar experiences.
Most of us just did not know how limited the ocean and its resources were when we were young. It was a path of ignorance....to knowledge most of us walked. We saw the changes ourselves first hand. We did not read about it. We lived it and saw it each time we went underwater in our work and travels around the world. At least we were wise enough to see the damage for what it was and try and change the tidal flow as best we could with education of others.

Take care old man!

Love 'ya mon!

Honoring Alex

Shark people: Alex (center) with Gary and Klaus (yes this is a link!)

The good guys of MaiLife have done it again!

Please click on the images below: this month's issue features an hommage to our friend Alex the Sharkman who sat down for an interview with Jone during his recent visit. It's the story of how a small boy from the island of Malta became one of the most authoritative and passionate advocates of Sharks.

Thank you Alex!
And Sharkman is now on the list! (:

Enjoy!

Shocking!

Yes Andrew is disgusted!

There's days when I despair.

Like today.
I discovered a veritable cheesemaking masterpiece in a local supermarket.
The iconic Caprice des Dieux is a recipient of the coveted Golden Cup of the Bon Goût Français and and a global ambassador of Gallic savoir vivre. To stumble upon such a treasure in Suva, Fiji can only be called miraculous. Never did an exiled gourmet exclaim Hēurēka (literally!) with more joy, gratitude and fervor!

Life in the islands quickly teaches you that when presented with such serendipitous and unique opportunities, one has to act decisively.
I cleaned out the whole stash.

I also decided to share this epicurean trouvaille with a good friend.
Well, I guess one could say that no good deed goes unpunished.

Enter Gary Adkison.
Gary is like a brother and in many ways, one of my heroes.
He also happens to be the object of an idealistic, and i now realize, hopelessly naive long-term rehabilitation (or should I say: habilitation?) project by Juerg and myself aimed at exorcising him from his fatal addiction to American junk food.

An initial shock therapy in Florida ended in a spectacular failure.
Equally spectacular were the results of a subsequent detoxification program where we availed ourselves of the complicity of his loving and endlessly patient wife Brenda. As time went by, she managed to gradually habituate him to periodic ingestions of unpatriotic fare like Weisswurst and Gravlax. A particularly promising milestone was reached as recently as August 2 when he managed to imbibe, and then pronounce Château Margaux without biting his tongue.

Upon his arrival in Fiji, we sequestered him in Andrew's house and kept him on a strict and wholesome diet of local delicacies like dhal soup, kokoda, dalo and tavioka from the lovo and above all, yaqona and Vegemite sandwiches. His habitus quickly improved to that of a happy, albeit marginally rubicund Hulkster lookalike.

Looks like we overlooked a jar of contraband chunky peanut butter.

Yes, you better believe it: that would be a peanut butter - Caprice des Dieux sandwich!
The sacrilege has been reported to the Quai d'Orsay and sources within the DGSE confirm that should he ever have the audacity to set foot onto French soil, he will will be apprehended and marched straight over to the next available, and preferably rusty guillotine.


Oh well.
Love'ya big mon!

Sex on Shark Reef

Where do they do it?

Indeed, that is the question!
"They" being our Bull Sharks and "it", well, ya know, IT!

When we started analyzing the patterns in 2003, the only thing that was clear is that our Bulls were leaving around October and started to come back in December. Common wisdom had it that they were leaving in order to give birth and mate.

Approx 2,000 data sets later, the pattern is this.

Mid-December sees the arrival of an ever increasing population of all of the large adult females, a few known males like "Whitenose" and "Jaws" and quite a number of sub-adults of both sexes.
Some females display fearsome fresh mating scars that completely heal within a few days literally in front of our eyes.
Some other females are completely emaciated and have an awful skin condition ranging from fungus infestation to algae overgrowth, a clear indication that they have been subjected to fresh water. Bull Sharks are freshwater-tolerant and I may add: "barely", as the freshwater environment clearly strains their metabolism and yes, precipitates the urgent need for a good dermatologist on top of that.

During the course of the year, the numbers increase to an apex in March/April where it is not uncommon to see 30 and more individuals. The females that turned up with scars slowly get bigger and bigger, like "Second" in the picture above (shot this August by Sasha - but that's another story) and the second half of the year features the arrival of an increasing number of sub-adults and some other males like "Blackbeard" and most notably, "Long John" who never arrives before August.
By September, the females are best described as being "fickle": one day they're in yer face and ravenous, the next they barely turn up and keep well to the outskirts whilst the males and the sub-adults are having a feast.
And by mid-October, everybody kind of sneaks off whilst the Grey Reefs and Silvertips move in assertively.

So, what is going on?
Why are the Sharks leaving "home" -the place they have chosen for obviously offering some advantage- in order to expend energy and swim to some other place which is obviously not good enough to be "home"?
In other words, why has Evolution selected for such a wasteful behavior?

The mating scars/pregnant/absent female story seems pretty straightforward: the pregnant females leave to give birth in the nursing areas.
Such areas have been well researched in Florida's Indian River and Australia's Brisbane River. In Fiji, we have well documented reports of seasonal Bull Shark catches in Viti Levu's Rewa river and a big river in Vanua Levu. Interestingly, whereas small Sharks are caught on line, all large Bull Sharks are caught exclusively in nets, as would be expected from otherwise cannibalistic species developing a feeding inhibition towards the end of pregnancy.

Those nursing areas offer clear advantages to the newborn Sharks in that they don't harbor any major predators of Sharks, notably large Sharks and Groupers (except for -how could it be otherwise- the beautiful but always deadly land of Oz, that is) and also feature a large population of suitable prey.
Hence, the disadvantage of leaving "home" is offset by the advantage of an increased chance of successful procreation, and thus passing on one's genes (and notably, the instruction to go walkabout) to the next generation.

But what about the mating?

Mating aggregations and mass spawning are well known for many Fishes.
The disadvantage of having to leave "home" is offset by, to name but a few, the advantages of finding suitable partners; optimizing gene flow; large numbers protecting the Fish and their spawn from annihilation by predation; location and timing -typically, the peak tides at Full and New Moon- optimizing the dispersion of the fertilized eggs.

Carcharhinid Sharks however are not spawning Fish: fertilization is internal, the eggs remain protected inside the body and the need to form schools in order to avoid predation is typically nil. Thus, there seems to be no need for forming mating aggregations.

But how about the need to meet partners and gene flow?
Some Sharks, as Grey Reefs, Silvertips and maybe Scalloped Hammers seem to feature resident populations of mature females and sub-adults whereas the mature males appear to be transient and only turn up in order to perform the dirty deed.
Others, like Whitetip and Blacktip Reefs, feature mixed populations where gene flow may be ensured by the occasional migration of individuals.

When it comes to our Bull Sharks, the jury is still out.
Are the big females resident or even territorial? Probably yes to the former and no to the latter, but we're still determining the range of their small-scale movements in our research with acoustic tags and analyzing aggression patterns that may offer insights into possible territorial behavior.
And what about the males? Here, the difficulty lays in the fact that maybe with the exception of "Whitenose" and "Blackbeard", all regular males appear to be quite small. Is that the normal sexual dimorphism in Bull Sharks or are all of those other males sub-adults?
Are we thus witnessing the Whitetip Reef or the Grey Reef model?

But with that in mind, why do the non-pregnant Bull Sharks leave at all?

The answer may be that strictly speaking, Shark Reef is not really "home".
"Home" may be the lower reaches of Beqa Channel from which the Bulls typically ascend when we prompt them to come in for a snack.

Thus, the story may be this.

• only the pregnant females leave to give birth in the river mouths
• all other Sharks may develop some feeding inhibition as the non-pregnant females get into heat, this maybe triggered by the female pheromones and maybe developed in order not to start devouring each other when they bite and latch on during copulation. Hence, they don't turn up but may remain deep down in Beqa Channel instead. That is where mating occurs and hence, that would account for the freshness of the scars when they turn up again. Yes, that's a whole heap of "maybes" but it's at least a viable initial Hypothesis.

And here is where Juerg and Gary (yes, he of the french cheese) come in.

Recent visitors to Shark Reef were graced by the sight of a speargun-toting Hulk Hogan look-alike nailing a dozen Bull Sharks that subsequently reappeared carrying small acoustic tags. In view of the hunger strike during the mating season, we had no choice but to deploy some tags externally, this specifically to test the local mating Hypothesis.
The tags will remain active for up to one year but typically fall off well before that time, likely in the first months of 2009.
Should the Sharks be hiding in Beqa Channel, a wide array of receivers spanning all the way from the Navua River to Serua Reef will finally give away their little dirty secret.

Intrigued?
So am I - keep watching this space!

Bon Appetit?

Commercial Shark Diving is quickly morphing into a global industry and as always in such cases, the transition doesn't come easy.

Whereas the anti-Shark-diving lobby, scientific and not, continues to successfully pester us with their allegations, we just seem to be unable to get our act together, circle the wagons and mount a credible common defense.

Granted, selling Sharks to the public at large will always be a challenge.
The opposition's arguments feed on our primeval fears and convey the illusion of intuitive plausibility. Very hard to refute as in order to do so, we would need hard and unequivocal scientific data. And those are so far lacking. Having said this, I know of at least two papers, one from South Africa and one from Australia, that postulate that what we do has no discernible behavioral consequences. Actually, make it three, as Juerg's recent research on Shark Reef may well come to the same conclusions.

I'm thus highly confident that in the end, people will come to realize that our large predatory Sharks are just as fascinating and worth protecting as any other alpha predator. It has taken decades of dedicated research and marketing to dispel the myth that wolves, grizzly bears, lions and tigers are nothing more than man-hunting vermin that needs to be eradicated, so I guess we must be patient and persevere.
Let's just hope that by then, it won't be too late.

The real challenge right now however seems to be our incapacity to work together.
Keep in mind that until quite recently, diving was considered a dangerous sport reserved for the passionate few. The Shark Diving pioneers were regarded as, and probably were, a special breed of entirely self-taught, adventuresome, thrill-seeking and death-defying macho warriors and equally intrepid amazons and were consequently accorded Hero status.
Talk about an eclectic collection of unique and charismatic individuals with strong opinions and huge egos!

But now, Shark Diving has gone mainstream and is firmly nested within the entertainment industry. As in: I shall pay for a trip to Guadalupe Island and I shall see Great White Sharks - or else!

In the process, the original Heroes are gradually being replaced by media-savvy, nimble and business-minded service providers. Personality cult is being replaced by client service. Adventure and discovery, by interactive and notabene, guaranteed ecological encounters. Roughing it out on the High Seas, by aircon, en suite bathrooms and warm towels. Individuality, by the need for a uniform global product. And alas, sometimes, excitement by bored indifference.

On top of the historical and ever-present personal animosity between the original silverbacks, this has created substantial resentment against what is perceived as a territorial invasion by parasitic upstarts. Having been at the receiving end, but also, having had to dish out my fair share of aggro myself, I know what I'm talking about.

Thus, to finally make my point, getting everybody to sit at the same table, to share our passion, experiences, visions and research in order to devise a common approach supported by unified procedures remains a gargantuan challenge. Once again, we will have to be patient and persevere.

Plus, there is the cultural gap - we may all be one species but sometimes, one has to wonder.

I didn't quite think about that particular aspect until presented with the shocking document below.
It depicts my European friends Juerg and charming Marlen desperately trying to wean Gary Adkison, one of our Heroes, off his addiction to Kraft cheese spread and other all-American junk delicacies. To witness, Juerg is displaying a beautifully ripened original Brie de Meaux and Marlen has obviously contributed a lovingly arranged and simply delicious Assiette de Fromages.

As to Gary - well, what can I say.


Anyway, a belated Bon Appetit - or whatever.
We shall be patient and persevere........