DEMA - Speech by Juerg!

You don't want to miss this!

Juerg will be giving a speech as follows

DEMA Show 2013
Friday, November 8
S320A  2:00pm-3:00pm

Feeding Sharks in Fiji: Good or Bad?

A scientific analysis of shark provisioning within the Shark Reef Marine Reserve in Fiji.  Presentation by Dr. Juerg Brunnschweiler, Shark Behaviorist and Marine Biologist.

Quite obviously, it's about our research. 

Juerg has just completed his latest paper about species composition, to be published very shortly indeed, and will be talking about those insights and the results of his other paper about Shark feeding within the SRMR. You will also have the opportunity of meeting the legendary Gary and Brenda Adkison, of Walker's Cay and Shark Rodeo fame.

See you there!

Amazing Shark Behavior!

Involuntary stomach eversion - frequently performed by Shark researchers.

Remember Juerg's paper about intra-gastric tags?
Here it is again, in full length. You may notice that the retention time of the transmitters varied considerably, from less than 24h to 34 days.

The shortest retention times are likely the result of voluntary gastric eversion.
That is the faculty of many (if not all - does anybody know?) Sharks to eliminate indigestible or unwanted items by voluntary turning their stomach inside out through their mouth. The process is very short and consists in relaxing their stomach muscles and using abdominal pressure to prolapse and speedy retraction of the stomach to empty indigestible particles, parasites, or mucus, researchers speculate. This may also aid them in keeping a healthy alimentary tract. This can be accompanied by head shaking and I must confess, always fatally reminds me of that old condom recycling joke - yes you can Google it!

Where was I?

Oh, yes.
It just so happens that Juerg is da man when it comes to gastric eversion in Sharks.
His 2005 paper is a classic and analyzes the voluntary eversion by a Caribbean Reef in, I believe, Walker's Cay, one of the first Shark destinations to seamlessly integrate adventure and Shark conservation. Juerg was extremely fortunate in being able to record the behavior, and this is what he filmed.

Is this totally amazing, or what!
And before the usual Shark slanderer and defamer starts snickering and pointing at Starfish and the like: dude, not that you would ever understand, but I'm talking cool animals, the pinnacle of evolution - not such lowly, utterly useless and creepy stuff!

Now, Juerg has published a new paper about the gastric eversion by a hooked Longfin Mako, likely in an attempt to rid itself of the hook, and proposes a mechanism by which Sharks can perform this amazing (!) feat. It, too, is based on a video that was recorded in 2004 by Frank Nielsen aka MalibuFrank of Sharkfootage.

Here it is - enjoy!

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!

Competitive Exclusion at Shark Reef - the Paper!

Thriving Sharks - still one of my very favorite pics ever, by one of my very favorite people!

Bless Juerg!

Despite of an ever increasing burden of obligations from his other activities, he has found the time to go and mine yet another data set from our monstrous data base.

So here are his latest insights!

Whereas the last paper (read it!) shows that feeding our Bull Sharks has no notable effects at the ecosystem level, this latest one documents the existence of small-scale effects, notably a progressive change in relative species abundance that as he postulates is likely due to a combination of competitive exclusion and gradual change of feeding protocols.

The general observation is this.

Over the past ten years, we've been seeing ever more Bulls (!), Whitetips and Blacktips and about the same number of Greys - but the number of Nurses, Lemons, Silvertips and Tigers has fallen precipitously.

And the possible explanations?

Juerg doesn't speculate, and a research paper is also the wrong forum for digressing into the minutiae of feeding protocols - but as I'm not being constrained by scientific rigor, allow me to elaborate some more.
Yes some of it is speculative and difficult to test - but having logged close to 2,000 Shark dives on Shark Reef, I would argue that it is at least plausible.

• Sharks don't generally like to approach people.
  Hence the necessity of using bait when diving where they don't aggregate naturally. Research has shown that at least the big, long lived species like Tigers are able to memorize the location (and possibly time) of successful feeding events - but the flip side is that they will likely stop bothering to pop by once they are not anymore being adequately rewarded.

• This may in part explain the decline in numbers of those intermediate Sharks.
  They occupy roughly the same depth profile as the Bulls and once the numbers of the latter did increase beyond some tipping point, the risk/reward ratio simply became too unfavorable - this especially for the Lemons and Silvertips who appear positively scared whenever I see them trying to sneak in, this quite possibly because they may well be on the Bull Sharks' menu.

• The Nurses are a different matter altogether.
  There, the principal factor may well be food composition and presentation, along with the fact that we don't feed them much as they create too much of a mess.
  
  Ever since taking on Shark Reef and turning it into a marine reserve, we've been concerned about our influence on the other Fishes. Having noticed an overabundance of small predators and scavengers, we've gradually phased out all Fish scraps and feed nearly exclusively Tuna heads, meaning that the overwhelming majority of bait leaves the reserve in the stomach of a large Shark or gigantic Trevally, as it should be. As a consequence, the Fish biodiversity of Shark Reef has undergone a massive increase from a baseline count of 260 species in 2004 to close to 500 in 2010 which is now highly indicative of a healthy Fish population on a Fijian barrier reef - possibly also because a robust Shark population may favor biodiversity, which would then be a positive small-scale effect!
  
  Those big Tuna heads are rather unattractive to the Nurses who have small mouths and got no means of cutting out adequate portions. And once we shifted to mid-water dumping as opposed to hand feeding in response to the increased numbers of Bulls, the Nurses were less able to monopolize bait on the bottom and may indeed have relocated to Lake Reef where protocols, I hear, are different.

• The Tigers?
  From my observations, they are incredibly persistent to the point of obstinacy - but they like to take their time and certainly don't appreciate the stress of having to contend with those frisky Bulls that have become ever bolder with increasing numbers.
  They certainly don't anymore slink away when the Tiger shows up like in the old times, but instead engage in direct competition to the point of where I dispose of footage of them out-swimming and even shouldering away the much bigger Tigers - meaning that in all likelihood, the latter have simply stopped bothering and prefer to try their luck elsewhere!
  
  And then, there is the fact that recently, the pressure by coastal fishermen on especially the particularly lucrative Tigers has increased substantially.
  If you add that to their risk of running into one of those Tuna longlines during their pelagic migrations, it is quite likely that the Tiger Shark population in Fiji has been depleted by overfishing!

• Not surprised about the Reefies.
  Like Juerg remarks, they nearly never descend to the lower depths and once there, they never attempt to feed, this likely owing to their inexistent chances of competing successfully for the bait but also, the risk of being predated upon by the Bulls. Conversely, we've conditioned the Bulls never to ascend to 10 meters, this also due to our positioning of the clients who obstruct any direct access to the feeder whereas the small Reefies can access him from the reeftop.
  Hence the Reefies are not subjected to competitive exclusion when they stay shallow.

• Generally speaking, resident Grey Reefie populations appear to be comprised of juveniles, subadults and adult females and are usually found at reef passes - but ours are predominantly adult males and thus quite possibly much more transient.
  This appears to be confirmed by the fact that they abscond for months on end in mid year, likely to go and visit one or more resident populations during the mating season, meaning that any newborns would reside there and not in the SRMR. With that in mind and considering the risk posed by the Bulls, they will continue to quickly dash in for a snack during meal times but otherwise remain rather wary and nomadic.

• The Blacktips took forever to accept any bait.
  If memory serves me right, they only started feeding and thus approaching people 6 years ago, and the increase in numbers may well be due to the fact that they are now swimming in from other areas, namely the lagoon side, of Shark Reef during feeding time, to then quickly abscond as soon as the feeding ceases. Like Johann teaches us, they migrate to breed in shallow lagoons, meaning that any juveniles would be found there. But they also disperse, meaning that some may have indeed hopped over from Serua Reef that features similar habitats - but my gut tells me that the majority are resident locals that have simply become bolder.

• And the Whitetips breed on Shark Reef.
  We know that because we've now observed neonates and juveniles on several years, and the population has increased accordingly - no unsolved mysteries there apart from the question of when we will reach carrying capacity and the population will stabilize.

There you have it.

There have been many changes, some of which massive - the question being, is it good or is it bad?

The answer is probably: rather good to indifferent!

Fish stocks are thriving, meaning that I cannot detect any evidence that those increased number of Reefies are having a negative effect - and when it comes to those other larger Sharks with larger home ranges, evidence suggests that they remain well protected within the Shark Corridor, this with the sad exception of those poor Tigers for whom we however carry no responsibility

And in the vicinity?

Yes like Juerg states, we don't quite know
But what we DO know is that the fishermen in Galoa catch more fish, this likely due to overspilling from the SRMR - whereas further away, stocks are grossly overfished and fishing yields have crashed. We also know that our big Sharks are not resident, meaning that we're not subtracting them from elsewhere where they continue to perform whatever functions they are meant to perform..

So with that in mind, how can I not be happy!

And as always, I'm mighty proud - and so thankful to Juerg for yet again a wonderful job in helping us better understand the animals we love and our influence on their life.

Merci Jürg - sisch jo wie immer e super gueti Sach!

Shy-Bold Continuum?

She's smart, she's pretty and she's here!
And yes, having just landed upon our shores, she's way too pasty as well - but we're working on that! :)

Meet Kirsty Richards, Juerg's newest protégée.
She's here to work with our smaller Sharks as part of her master thesis and we very much look forward to reading her posts on Juerg's Fiji blog. Focusing on Sharks other than our flagship Bulls is important and long overdue as it will help round up what we know about the dynamics at play within the SRMR. Juerg is continuing to decipher our huge data base and having been shown some excerpts, I know that the latest Bull Shark abundance paper will soon be followed by an analysis of the other Sharks, something that will undoubtedly dovetail very nicely with Kristy's research.

Anyway, very much looking forward to all of this!
As to the exact meaning of the intra- and interspecific variations along the shy-bold continuum: we shall see shall we not! :)

The Great Fiji Shark Count - Info!

Let me give you some background information here.

This all actually started with Juerg and Christine Ward-Paige.
Christine did publish this excellent open source paper about the value of having recreational divers count elasmobranchs and in the lively discussion that ensued, Juerg proposed and Christine very graciously accepted to test the concept here in Fiji. Christine has currently another job but she will provide for the scientific oversight and analyze the data under the umbrella of eShark, and this completely on her own time and with no incremental funding! Potential donors: hint hint - funding this will make you shine for many years to come!
Christine thank you!

Fiji is of course the ideal destination for this endeavor.
Thankfully and in spite of the recent highly disturbing developments, we do still have a reasonable number of Sharks and Rays, and even Turtles.
Plus, the dive and tourism industry is tight knit and forward looking, as witnessed by the many past initiatives that were able to unite everybody around a common goal.
In 2008, we had the first tourism-based Great Butterflyfish Count that was repeated in 2009 and then alas fizzled out for lack of funding.
In 2009, Fiji organized the only nation-wide initiative to celebrate the Year of the Shark, the Fiji Shark Conservation and Awareness Project with various government departments, the tourism industry and several NGOs contributing to make this Fiji's first country-wide Shark campaign. 2009 also saw the only nation-wide drive to contribute to the Shark Free Marinas Initiative where to this day, Fiji is one of the principal participants.
In 2010 we took a breather to launch our own initiative aimed at protecting vital habitat and Shark nurseries whilst cleaning up our carbon footprint, Mangroves for Fiji, only to announce mission accomplished late last year.
2011 then saw the rolling out of the Fiji Shark Sanctuary Campaign where a plethora of largely unheralded events further contributed to Shark awareness all the way to the local grass-roots level.
Long story short: there sure is track record!

Enter the local project team.
She won't like me saying it but IMO, Helen Sykes of Marine Ecology Consulting is Fiji's most pugnacious, and thus most efficient and strictly (as opposed to agenda- and money-) goal oriented marine conservation professional for which she has all of my respect - and this despite her being dead-set against the feeding of any wildlife inclusive of Sharks, something that will regularly pitch us in super-heated debates where we pull no punches but always end up smiling as we both understand this to be an excellent means of furthering our knowledge! Anyway, it is great news that she has once again accepted to take the lead in this, like she did for the Butterflyfish Count of which this is the logical crescendo - and let's face it, Sharks are way sexier than Butterfly Fishes! :)
Same-same for Stuart Gow of Resort Support who has been our friend and advisor for many, many years. Among many other things, he is the current Chairman of the Dive Commission of the Fiji Hotel & Tourism Association, i.e. the highest representative of Fiji's dive industry. He is also a Director of Matava and in that incarnation, he has been instrumental in making Fiji Shark Free. Stuart is acting as our web- and spin-master, and having him help us behind the scenes is a phenomenal asset indeed!
And then there is Nani, Arthur and our new marine scientist Chris of BADs conservation brand SRMR that will be assisting in a thousand ways when it comes to keeping up the daily dialogue and coordination among the participants - and yes, yours truly will just sit back, continue hiding behind his computer and rant about others as always! :)

Please also check out our partners.
These are the people who are contributing money, or money and lots of passionate work like Samantha Whitcraft of Shark Savers. Sam is the indefatigable! driver of Shark Savers' Sharks Count program and as such, she has been an invaluable team member who has contributed money, leadership and know how but above all, an inordinate amount of work.
Then there are the pillars of reliability and generosity when it comes to sponsoring Juerg's research (blog here!) in Fiji, the unequaled Shark Foundation and Save our Seas Foundation.
And finally, there is Ocean Soaps, a division of Punjas who already greatly assisted in the Butterflyfish Count.
And I also want to mention the great photographers and friends who have donated images!
Thank you all!

And how about you?
If you so wish and decide to come to Fiji in April, you can partake in the first nation-wide Shark count anywhere!

To do that, follow the instructions here.
And before the usual geniuses start whispering that this is just about BAD making a buck: we have been counting Sharks since 2003 and thus your contribution would be most significant elsewhere! As the dive ops and resorts will start confirming their participation, the list of participants will grow and I urge you to go and help them and not us, always by mentioning that you're coming for the Count!
You can then always book a couple of Shark dives at the end as a treat and reward - and if you prove that you've taken part in the Count, we'll throw in a little something extra for you, how about that! :)

Now to be precise.
The aim is not to find out how many Sharks there are in Fiji!
For that, one would have to try and mobilize everybody everywhere, something that is impossible and would be fraught with immense costs, immense logistical problems and a staggering margin of error!
The aim here is to do a first random sampling and to then regularly repeat the exercise in the same locations. This way, we would be able to establish a first baseline and the starting point of long term monitoring via so-called transects (i.e. your dives, snorkeling excursions and even game fishing trips) which is an excellent scientific tool that will enable us to eventually detect a trend.

And the practical application?
As an example, should the Shark Sanctuary eventuate, the trend would provide for a confirmation (or lack of) of its effectiveness and thus be a great educational tool for policymakers. And should the Sanctuary not eventuate, I fear that the trend will document the rapid decline of Shark stocks and the absolute necessity of immediate conservation measures.
But that is then and it will take several years to make those statements, especially considering the fact that the vagaries of the ENSO will add a good amount of variation and unpredictability, like they have done to our own Shark data.

So, please, give it some thought.
I know it's sort of short notice: but it's cool and fun and above all, it's good solid and innovative science!

See you in April!

River Sharks - no Drama!

Bum - very pregnant!

Did I really say tomorrow???
Well, as we all now, Time is relative. Enter Fiji Time, like Tonga Time a hitherto largely overlooked third consequence of Einstein's Theories of Relativity!

But here it is...
Stan and Jone have once again done an outstanding job and delivered a well-rounded and informative piece of pro-Shark media.
You may want to note how real Pacific Islanders perceive Sharks as a natural and unspectacular element of the Marine ecosystem: none of drama and stupid generalizations that are so typical of the various pundits and armchair warriors polluting the blogosphere and the mainstream media. Case in point, check out this evil abomination: mind you, "reporting" about the exact same topic!
And compare it to the hysterical hypocrisy of the so-called "natives" over in Hawaii!

This, and an upcoming spectacular paper by Eroni, Victor and Juerg are the results of our road trip in July where we set out to find Fiji's Bull Shark nurseries. We have found them - and much more!
As always, keep watching this space!

What really blows me is the interview with Rusi..
If anybody deserved the title of Shark Whisperer, it would really be him.
He is normally silent and outright humble - but put him in front of one of his beloved Sharks and his personality changes completely and his understanding of the animals and the way he interacts with them are just simply totally unreal. Over the years, we've hosted our fair share of visiting "experts" - and every single one of them has told us how incredibly impressed they were by how Rusi handles the big Sharks.
I cannot begin to tell you how personally rewarding it is to now see him come out of his shell and talk (!) for minutes (!) about the need to protect them!
Vinaka Rusi, you are simply the best!

Gary is of course one of my heroes.
He has been part and parcel of the Fiji Shark Project since its inception and regularly pops by to inspect its progress and to assist in Juerg's ongoing research projects. His help and his guidance have been invaluable and the Fiji Shark Dive is as much his baby as it is ours - and I may add: much to the contrary of the progress in the help and guidance Juerg and yours truly are trying to extend to Gary! That has been an abject failure!
But we shall persevere!

But as usual, I'm digressing.
So here it is: Enjoy!

Juerg online!

You have to hand it to Juerg: despite the traumatic experience of his recent visit to Florida and despite the jitters about the imminent arrival of his first child, her keeps cranking out the goodies!

His latest creation is a completely re-vamped website where we can finally find all of his scientific papers, along with plenty of useful information about his pet animals, explanations about the methodology and technology involved in his research and obviously, a description of his very favorite Conservation project.

Much much more is in the works.
For some time, Juerg has been studying Whale Sharks in the Indian Ocean and I'm looking forward to his first paper on the subject. And, I hear, there will be a piece on something completely different: gay Sharks!

But most importantly, expect to see the first publications about his most recent research in Fiji: new behavioral observations, the first results from the ongoing radio-tagging small-scale movement study and a first evaluation of our enormous data base where we've recorded every single Shark Dive for the past five years.

And then, finally, there will be a piece about my very favorite topic.
I'm not allowed to spill the beans quite yet - but readers of this Blog will know what I'm talking about.

Keep watching this space!

Old news from Sept 2005

Bula from the folks at BAD!

September has been and gone and what a month it was. BAD was privileged to play host to Juerg Brunschweiller and his research team, Gary & Brenda Adkison and Ron & Valerie Taylor. Last month also saw the return of some familiar faces, Mike & Jo and the arrival of some new faces, Matt & Klaus.

In 2004, Juerg used state of the art pop-up satellite tags on 11 mature female bull sharks to learn more about their annual migration routes. This year was all about localised movements; with the use of listening stations and radio transmitters, Juerg is hoping to uncover the secrets to the bulls? daily movement patterns within the waters of Beqa Lagoon. Mother nature did not make it easy for us.

Torrential rain caused the Qaraniqio River to burst it?s banks, canceling a couple of day?s diving and ultimately creating some sub-optimal visibility. However, after the 2 weeks all the listening stations were positioned and ?Granma?, one of the larger female bulls, is now the proud host to a radio transmitter.

Hopefully we shall get some interesting data from her movements during the time before she headed off on her annual mating/birthing migration.The bull sharks have now departed from Shark Reef Marine Reserve; this now means that we are having more sightings of Silvertips. With all 3 of our named individuals, Madonna, Lady & Joker, already regulars at the site and 3 unnamed individuals already witnessed, it looks to be a good summer in SRMR. Ratu Rua, the resident Queensland Grouper is a common fixture as is Hamilton the Napolean Wrasse.Prior to the freak rains, we were experiencing 20-30m viz out on our soft coral sites in Beqa Lagoon. Some interesting finds this month were Frogfish and Stonefish on Rusi?s Pinnacle and Hawksbill Turtles at Carpet Cove.

A big congratulations goes out to Seema, Claire and Alan on completing their PADI Open Water Diver Course, may you have many years of happy diving ahead of you.

Finally to all those who came diving with us, the team at BAD say Vinaka Vakalevu and we hope to see again soon.

Andrew and the crew

Not hard to stomach!

Well worth clicking on! Bravo Lill!

Juerg is cranking them out as always.
This time, it's a methodological paper about our acoustic telemetry data collection.

As you may remember, any research within Shark Reef Marine Reserve has to fulfill two preconditions:
- Is it contributing directly to Conservation?
- Is the method employed the least invasive possible?

There are several methods for deploying acoustic tags and many of them involve catching the animals, after which the tags get attached via a loop around the caudal peduncle, or via tie wraps through a hole drilled into the dorsal fin or even implanted via a small subcutaneous incision.
Here's an example with satellite tags - not for us!



We don't do any of that as we try to avoid any undue stress to the animals and also, because we don't want to "punish" them for having trusted us.
Until very recently, we have resorted exclusively to hand feeding our tags after having hidden them in fish heads or wrapped them into strips of fish loin. It's quite funny as the Sharks do clearly detect the tags' pinging and have to be "conned" into swallowing the bait by quickly switching the pieces once they are committed to taking them. This method is quite wasteful as the tags get excreted (often via stomach eversion) and thus lost after a relatively short time.

Last September, we started to attach some tags externally by using pole spears or spearguns.
The Sharks don't seem to mind much and have all come back - and still, every time, I cringe when I see happen. The reason why I have OKd it is that we want to track the animals during their mating season when they generally refuse to feed. As a added advantage, Juerg is now getting some very useful long-term data as the tags will stay on for several months.

Juerg's paper is titled Tracking free-ranging sharks with hand-fed intra-gastric acoustic transmitters and deals with the abovementioned hand-feeding technique. You can read an excerpt on his blog or purchase and download the whole paper right here.

More papers very shortly indeed!

SRMR - Accolades by Juerg!

Great pic by Klaus!

 

Check this out!

No not because of the personal accolades.

They are certainly nice but irrelevant. But what is really impressive is the sheer number and scope of Juerg's papers so far - and more are in the making as we speak! I should have posted that list a long time ago - but we're currently revamping our website and will certainly add them there!

Interesting to say the least is also the fact that on top of having retracted their support for the GFSC, the SOSF has obviously also ceased to fund Juerg. WTF!

I could comment but choose not to - but it's certainly their loss not ours!

Anyway - very nice!

Thanks buddy!

 

Cool Stuff by Juerg!

Juerg is busy!

He's back in Switzerland and analyzing the latest crop of data - and driving poor Eroni crazy with ever new projects!

I can't tell you too much yet but we're about to see some ground-breaking papers on behavioral stuff and more conclusions from our ongoing radio tagging exercise.
At the same time, after 6 years and close to 2,000 data sets, we're completely re-wamping our trusted database to make place for the many newcomers: who would have ever thought that we would once have 42 named Bulls, along with 4 Tigers, 3 Lemons, 6 Silvertips, and 8 Greys - and mind you, that's just the individuals with a name (for which they need to feature a distinctive permanent imperfection), putting the total population at comfortably double those numbers!
Yes we love our Sharks and name them, very much like an increasing number of other Shark Diving operators worldwide - and we think that that's a good thing (well said Felix!) that contributes to their Protection!

New projects will focus on Fiji's principal rivers, which we suspect of being Bull Shark nurseries, on finding their mating grounds, on some very cool and cutting-edge tissue and DNA analysis, on Shark Diving Tourism and on substantially expanding our current push for better Shark protection. Oh and of course there's the ever-expanding Year of the Shark - Fiji - lots of fun but boy, talk about invested man-hours, especially by Eroni!
As always, watch this space!

And should you wish to delve in Juerg's publications, go to his website as usual or go to SOSFs website where you can find a cool synopsis of what's going on pretty much real-time!

Have fun!

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........

Dr. Juerg Brunnschweiler !

Finally!

Remember last November's post about our intrepid shark man Juerg from, of all places, frigid land-locked and mountainous Switzerland?

Well, he ain't no student no more!

Having delivered a whopping thesis about several aspects of Shark Biology, many of which have been researched on Shark Reef and my new home base in Tonga, he has brillianty survived a thorough cross-examination and now sports a fanciful Doctorate title!
And an own fancy website!

Along with having invented such useful linguistic weapons as the formal and informal "you", we Central Europeans are quite particular about such things and I already dread our next meeting in December! Will we all be clobbered into subservient adulation?

Juerg has just informed us that he plans to spend the prime Bull Shark season, January to March on Shark Reef. Planned experiments include wrapping up the ongoing small-scale movement study along with researching the Bull Shark mating grounds, general ethograms, dominance studies, food preferences and analyzing our huge data base. We're obviously eager to help and will piggyback by offering Shark Weeks, Shark Biology Courses and possibly, even Volunteer Research Assistance Programs.
There will be plenty of attractive options, so watch this space or drop us a line, whether you plan to come for a single day or for a longer stay!

Moorea Lemons - one more Piece of the Puzzle!

 (A) Map of the study location. (B) The genetic network of adult lemon sharks. Each individual is indicated by a node labelled by shark ID. Circles and squares indicate females and males respectively and symbol size is indicative of the body length of the shark. Node colour corresponds to the three defined residency groups. Dyads sharing a first-order genetic relationship are connected by a line, with line thickness indicating the strength of the genetic relationship (proportional to R values). (C) Genetic degree (number of first-order genetic relationships an individual has) distribution within the population - click for detail!

Very nice!

Remember the Lemon feeding paper?

I was somewhat underwhelmed, and said so - which led to a personal visit by the very charming Eric Clua, and to a real interesting ongoing dialogue with Johann Mourier. And despite of a toothy (!) public debate between Juerg and Jon and the authors, everybody remains on best terms and is eager to share and discuss. That's how science advances and as Eric stated, everybody agrees that nous jouons dans la même équipe and that everybody profits by sharing ideas and engaging in spirited discussions.

And here is strike two - read it!

The feeding paper did raise the concern that the observed increased residency of some Lemons might lead to increased inbreeding - and from what I understand, this paper comes to the conclusion that it probably does not.

Whereas there are only about two dozen resident adult Lemons in Moorea, the species has evolved patterns to mitigate the according risk of inbreeding insofar as the Sharks will travel to both mate and pup (= migration), and that some individuals will travel to take residence in other islands (= dispersal), all of which is conducive to gene flow. Having said that, the degree of inbreeding of the Lemons in French Polynesia remains never the less relatively high, this likely due to small overall numbers and the relatively high isolation between islands and between archipelagos.

And the take away message after this rather epic 5y investigation?

I believe it boils down to this - and I trust that Johann will correct me if not.

• Like Juerg's Fiji paper, it once again confirms that provisioned Sharks appear to disperse normally, or as Juerg puts it, that
  Chumming and food provisioning are unlikely to fundamentally change movement patterns at large spatial and temporal scales, and seem to only have a minor impact on the behaviour of large predatory sharks; hence, the creation of behavioural effects at the ecosystem level seems unlikely.
  Obviously, this is the one aspect I'm most concerned about - and I sure hope that Johann will agree with this conclusion!

• That said, Lemons are not Bulls and French Polynesia is not Fiji.
  There remain some local effects that are a possible cause for concern, foremost of which the observed increased residency that could eventually result in lower numbers of Lemons dispersing which in this generally small population might have a significant negative effect on gene flow and thus the fitness of that local population.

• The second possibly negative effect is the observed increased aggression.
  I continue to question whether the observed increased brawling among male Lemons is really relevant in view of the animals' quasi magical healing powers. But what is certainly worrisome are the reports of increased strikes on humans, see the testimony by  Moorea Natural Diver Lover in the comments section here.
  To me, they are the direct result of poor procedures, foremost of which the surface feeding mentioned here. However Johann tells me that there's only one remaining operator that feeds the Sharks, so maybe that problem has been resolved - that is, provided that the operator is taking the necessary precautions which is not necessarily a given and certainly worth keeping an eye on!

All-in-all, a really brilliant job, and big kudos to everybody involved!

In German!

Actually, not quite!

Juerg has a blog on the SOSF website where he's posted a short piece on his research in the SRMR. The link brings you to the website of MTW, the Swiss Television's scientific program, with a feature they ran in 2007. When you click on the pic with the diver and the Shark, you will get a pop-up window with the actual footage.

The gibberish are Swiss Standard German and Juerg's Swiss German. Or to be precise, his Zurich dialect, a local variation of High Alemannic (Wikipedia rocks!). If yer from anywhere North of Stuttgart, you will snicker at the first - and when it comes to the second, I wish you the very best of luck!

Anyway, it's a nice piece showcasing Juerg's work with huge and small Sharks and featuring some footage from Fiji. For me, the most remarkable scene is the video of our village ceremony in 2004 where we formally established the Marine Park.

Viel Spass beim Anschaun!
(No, this is the real deal!)

Meet Juerg Brunnschweiler, our resident Bull Shark specialist

Juerg M. Brunnschweiler is a PhD student at the Department of Ecology, Institute of Zoology, University of Zurich, Switzerland. His main research interests are behavioural and ecological aspects of sharks. In 2003 he initiated the Bull Shark Tagging Programme with the long-term goal of understanding movement patterns, habitat use and population dynamics of bull sharks.

Learn more about Juerg's studies here...

New Research - no Bull!

First things first!

Juerg has published the sat tagging paper!

I say, finally! And very well done!
But then, having been very much involved in the Fiji portion, I’m of course fatally biased!

Lemme tell ’ya: it has been challenging!
Talk about the new shiny hammer failing spectacularly! Not that he really had a choice, but Juerg took the decision not to take the easy way and to try and catch the Sharks, drag them to a boat and then drill holes into them. Instead, Gary Adkison armed himself with pole spears and spear guns and proceeded to try and attach the tags on the fly at the end of the Shark feeds – and that was the easy part!

Big problem number one were the animals themselves.
No, not because they are pumped with testosterone (see below) and aggressive as a consequence: but boy, are those Bull Sharks tough to pierce – and not for lack of trying!
Suffice to say that the success ratio was dismal, and at the cost of a rapidly diminishing supply of supposedly unbreakable stainless steel shafts, anchors and leaders. What should have been a walk in the park quickly morphed into a logistical and also, motivational nightmare requiring that the team take several trips to Fiji instead of the planned single one.

And then, the gizmos!
All detached prematurely and happily floated away prior to uplinking.
The most spectacular fail sent an e-mail from no less than north of Cairns, prompting a premature Heureka! that quickly morphed into abject depression once Juerg started looking at the depth data that displayed an endless and disheartening series of zeros.
With all that in mind, the results are truly spectacular and a testimony to what somebody with a brain can do even when he basically gets fatally skunked.

My take on the adventure: nothing comes easy and above all, beware of those hi tech gizmos and the panache that goes with them!
Like I said in another context, those things require some major retro engineering, especially when it comes to the attachment! And before you ask: the SPOT tags are at least as unreliable, if for different reasons linked to the problems of establishing adequate connectivity.
But having said that: we may have an idea – keep watching this space!

So, without further ado, here are excerpts from Juerg’s paper.
Enjoy!


ABSTRACT

Adult bull sharks Carcharhinus leucas were monitored with electronic tags to investigate horizontal and vertical movements in the Atlantic and Pacific Oceans.
In both locations, C. leucas showed some fidelity to specific coastal areas with only limited horizontal movements away from the tagging sites after tag attachment. Fish tagged in the Bahamas were detected mostly in the upper 20 m of the water column in water 25–26° C, whereas C. leucas tagged in Fiji spent most of their time below 20 m in water usually >26° C. The results highlight the importance of coastal inshore habitats for this species.

DISCUSSION

Ninety per cent of the 20 deployed PSATs uplinked to the Argos satellite system resulting in a cumulative total of 235 days on C. leucas depth and ambient water temperature occupancy and some limited information on movements away from the tagging sites.
These first such data available for large C. leucas expand the knowledge about the ecological niche of this species. In both the Atlantic and Pacific Oceans, C. leucas showed some fidelity to specific coastal areas and did not move away from these shallow habitats at large scale during the time of tag attachment. Fish in both locations used the water column from the surface down to c. 200 m, but in the Bahamas the species spent most of the time in shallow waters while in bathymetrically less constraining Fijian coastal habitats C. leucas were usually found deeper than 30 m. The results highlight the importance of coastal inshore habitats for this species. Reliable satellite tag performance still faces many challenges (Hays et al., 2007), with premature pop-off being one of the prime reasons for obtaining shorter than planned tracks from marine vertebrates (Chapman et al., 2007; Arrizabalaga et al., 2008). In most cases, it is difficult to identify reliably the reasons for premature detachment (Hays et al., 2007). The tag attachment method chosen in this study to attach pop-off tags to C. leucas from a platform (Bahamas) or by scuba (Fiji) might have resulted in insufficient tag anchoring and consequently a higher rate of premature tag loss. For example, environmental factors such as currents or the fact that the fish to be tagged could move around freely in the water column pose difficulties to the diver when approaching the animal or might affect the accuracy of tag placement.
Nevertheless, data sets obtained via satellite telemetry that span days rather than months or years can still provide meaningful insight into horizontal and vertical movement patterns and behaviour of sharks (Dewar et al., 2004; Chapman et al., 2007; Pade et al., 2009).

HORIZONTAL MOVEMENT AND SITE FIDELITY

Previous research has shown that large-scale movements tend to be comparatively limited in C. leucas with pronounced site fidelity in coastal and continental shelf waters (Kohler et al., 1998; Kohler & Turner, 2001; Tremain et al., 2004; Curtis, 2008).

Resightings and the admittedly limited horizontal movement data obtained from this study support this proposition.
It remains, however, largely unknown why C. leucas show fidelity to certain coastal inshore habitats. A plausible factor that might explain a certain degree of site fidelity in this study is that at both tagging sites, Walker’s Cay and in the Shark Reef Marine Reserve, C. leucas have been attracted with food for the purpose of sightings by tourists. This might have affected the behaviour of the tagged C. leucas in that, for example, fish would not leave the tagging sites on large-scale movements, but remain in the area. The majority of the tagged C. leucas in this study were resighted at the tagging sites indicating indeed some level of site fidelity. None of the C. leucas tracked for >17 days (B1, B4, F4, F6, F9, F11 and F12) with the exception of F11, however, was resighted more than twice (mean = 0・8) in the weeks following tagging, despite the fact that the means of attracting the C. leucas to the site continued. Carcharhinus leucas F11 was resighted most during tag attachment (Table III), but all seven appearances at the tagging site occurred in a relatively narrow time frame (18 October to 3 November 2004) of its entire 53 days track. This, together with results from other studies (Kohler et al., 1998; Kohler & Turner, 2001; Tremain et al., 2004; Curtis, 2008), indicates that tagged C. leucas in this study showed specific horizontal movements.

The finding of tag B2, which was attached to a female C. leucas, floating on the surface in the Stuart Inlet, Florida, at the entrance to the Indian and St Lucie Rivers is noteworthy.
The Indian River Lagoon system is considered a nursery area for different shark species including C. leucas (Snelson & Williams, 1981; Snelson et al., 1984; Curtis, 2008). The light-based longitude estimates indicate that fish B2 moved away from the tagging site in the Bahamas in a westward direction and the tag popped off in waters off the east coast of southern Florida (Fig. 4). Given the lack of accurate geolocation and the fact that this tag was floating on the surface for several days before starting to transmit its position, it is unknown how close to the coast this tag detached from the animal. Despite this finding, it therefore remains unknown whether or not female C. leucas from the Bahamas move to nursery grounds in Florida.
The possibility of such a migratory link to reproductive areas in Florida could be tested conclusively in the future using, for example, acoustic telemetry methods.

VERTICAL DISTRIBUTION

Clear diel vertical migration patterns known from other shark species (Weng & Block, 2004; Sims et al., 2005; Weng et al., 2007; Andrews et al., 2009) were not identified in C. leucas in this study. Although diel patterns were found in some C. leucas from the Bahamas and Fiji, the relatively small differences between day and night mean depths are unlikely to be of biological significance.


Fig. 3. Histograms of mean + s.d. per cent time spent at (a) depth and (b) temperature for Atlantic ( ) and South Pacific ( ) Carcharhinus leucas tagged with pop-off satellite archival tags (PSAT).


The general notion that C. leucas spend the majority of their time in water shallower than 30m (Compagno, 1984) was confirmed for individuals tagged in the shallow waters of the Bahamas, but not for C. leucas tagged in Fiji, where they were recorded below 30 m for most of the time.
Most depth data collected to date come from studies looking at the behaviour of immature C. leucas in estuarine habitats (Simpfendorfer et al., 2005; Curtis, 2008); data on depth preferences of adult C. leucas away from shallow habitats are limited.

The data from this study provide the first evidence that adult C. leucas preferably stay between 30 and 100 m in bathymetrically non-constraining habitats with frequent visits to the surface and only occasionally dive to below 100 m. Dives below 200 m would have been possible in both locations. Defining the northern edge of the Little Bahama Bank, Walker’s Cay is part of the Abacos and the northernmost island of the Bahamas. The shallow waters of the Bahama Banks surrounding the island descend into deep Atlantic Ocean waters a few km north-east of Walker’s Cay. This is contrary to the situation on the southern coast of Viti Levu where the ocean-facing sides of the fringing reefs immediately drop to well below c. 250 m deep waters. Depth and location records obtained from PSATs and direct observation indicate that C. leucas tagged in the Bahamas stayed in shallow waters close to the tagging site, but showed increased diving activity in deeper waters off the Bahama Banks. Such behaviour is similar to what was found for C. leucas tagged on Shark Reef in Fiji where fish spend the majority of their time in the deeper waters just off the fringing reefs on the southern coast of Viti Levu.

MANAGEMENT AND CONSERVATION

The fact that adult C. leucas show a certain degree of site fidelity punctuated by limited migratory movements up and down coastlines makes this apex predator an important species of coastal ecosystems and underpins the need for local and possibly national or even international co-operation.
Estuarine habitats have been determined to be habitats of great concern for coastal sharks, in that these areas continue to suffer from dramatic anthropogenic environmental interactions and destruction. Identifying the movement corridors between or along coasts will therefore help when devising conservation strategies for C. leucas.

And now, to the aforementioned testosterone.
While I was, and still am battling issues of connectivity, Patric has issued a challenge that was accepted and, I believe, brilliantly met by Christie Wilcox of Observations of a Nerd.
Having heard (and believed!) it a thousand times, I consider this an absolute must read! Very, and I mean: VERY well done!

And indeed Patric: thanks Nigel and Discovery for having propagated this stupidity to millions of viewers!

And talking of Bull.
The myth goes one step further, that is, to claim that because of the testosterone, Bull Sharks are particularly aggressive. Certainly not in my experience: among the species I’ve dived with, I consider them among the most circumspect and timid, orders of magnitude less assertive than, say, Silvertips and Galapagoses!
Apparently and contrary to popular myth, the postulated link does not even exist in humans and may even be actually quite the opposite! Like always, it’s probably way more complicated and direct causality can be safely ruled out.

Plus: why, exactly, do bodybuilders dope themselves with testosterone?
Is it because they want to be more aggressive? Just look at how Bull Sharks are built – would it not have been much more plausible to assume that testosterone in Bulls is linked to their spectacular muscle mass?

Anyway, I’m digressing as usual.
All I wanted to say is Bravo Juerg and Bravo Christie!