Saturday, July 31, 2021

Bronze for Fijiana!

 
Toso Viti - together we can!
 

Wednesday, July 28, 2021

Gold for Fiji!

 
 
Huge congrats to the team.
And to fellow Shark divers Gareth and Danielle!  
 
Toso Viti! 
 

Monday, July 12, 2021

Shark Rescue - Video!

Silio: when he doesn't rescue Sharks or retrieve stolen cameras, he models for My Fiji Shark!

 
Behold!
 
 
So, was that Shark asking for help?
Who knows - but it sure looks that way, especially considering that she tried twice! And she definitely chose to come to the right person as Silio was personally trained by none other than our unforgotten Rusi, speaks Shark and knew exactly what to do!
 
Be it as it may, it was a really remarkable interaction.
This is a completely wild, large alpha predator choosing freely to peacefully interact with a human - which has incidentally also spared her weeks of pain, as the weighted line would have cut deeply into her mouth and left her permanently disfigured like Crook or Granma!
Seriously - how cool is that! 

And before you ask - yes that's a known individual.
Judging from her distinctive crooked smile, she appears to be a habitual raider of fishing lines, and we've accordingly named her Double Crook aka DC - for the smile but also for the petty thievery. 
Bold and friendly, she's prime adoption material, and I would not at all be astonished if Tashi Blue decided to add her to the lineup sooner rather than later - so keep watching this space!

Anyway, this is what we do!
Stay safe everybody - right now it's pretty grim, but we're all getting vaccinated and will definitely see you next year!
 

Monday, July 05, 2021

Grenzenlos - Video!

Toothy Bull by Ozzie Sam-  click for detail!
 
Behold!
 
This was filmed just before the pandemic hit.
I happened to be away, and it never made it to the blog - so there, as a memento of much happier times.
 
Enjoy!
 
 
 

Sunday, June 27, 2021

Do Bull Sharks have Friends? New Paper!


Spoiler: maybe yes maybe not!

In brief, I opined that as their prey is comparatively scarce, evolution would select for large predatory Sharks to be solitary in order not to have to share their kills. 
But whereas that appears to be largely correct for Tigers and Whites, anecdotal evidence and some papers (and here) indicate that Bull Sharks appear to mostly travel in pairs or small groups, and I was eager to see whether our enormous data base could help shed further light on the issue. Yes our Shark feed is obviously an artificial aggregation - but I speculated that if certain individuals would preferentially turn up together, this might be a strong indicator that they might also be traveling together when not attending our dive.

The initial findings were promising.
The data showed some unequivocal, albeit rather weak long-term associations as illustrated e.g. in the following sociogram.
 

Sociogram depicting the social ties between individual bull sharks observed on the study site on ≥34 dives for the time period from 2011 (C). Only GAI values in the highest 30% were included to highlight the strongest associations between dyads, with thicker edges indicating higher GAIs for both individuals observed throughout the entire sampling period (red nodes), and individuals which were not observed throughout the entire sampling period (blue nodes) - click for detail.
 
Impressed? 
Me too, initially - but then came the crux with the bloody interpretation!
Did those Sharks really turn up together because they like each other? Or was it because their core ranges overlap with the Shark Reef Marine Reserve = they just happen to live in the vicinity? Or because they share some behavioral trait that makes them bolder/more curious/more opportunistic/weaker hunters = more prone to visit our feed? Or are they maybe the remnants of a cohort of siblings who stayed together in the river nursery and have traveled together ever since? Questions questions!
Short answer: who knows - which is kinda disappointing!

But, we now have a starting point.
Those numbers in the sociogram all correspond to known individual Sharks, and somebody could now invest some time into observing how they actually interact during the dive - and assuming that the visual observations confirm the initial evidence, one could then try and equip selected individuals with adequate sensors like cameras and/or say, business card tags to see what happens once the Sharks leave Shark Reef and/or take tissue samples to determine their relatedness, etc.
Yes that's a lot of work - but that's what we do, so keep watching this space!

Long story short, so far so good!
Enjoy the new paper
 
PS - Juerg here, courtesy of Tom.
IMO the semantics are a lot of splitting of hairs (= do we KNOW that they're not friends?), the more as I believe that some are, and that some (like Blunt and Maite) are very much the contrary - but then again who am I to say!
So thanks for the publicity, much appreciated!

PPS - another really nice piece here - well done!

Friday, June 18, 2021

Surfing Reefies - Paper!

Source
.
 
Very cool.
But first, watch.


 
This is DV footage from 2005, from an old edit.
I was staying at Sané and Annabelle's epic Tetamanu Village and was fortunate to catch the magic moment when the sun reflects off the Sharks on an early morning incoming tide - and for you insiders, the first two clips are from the challenging trou aux requins in Apataki.

Notice how the Sharks are barely moving? 
They are literally surfing the current - and here's the according paper courtesy of Yannis, Johann, Serge, Charlie et al, inclusive of how they use a conveyor-belt positioning system to ensure that the groups remain stationary over the most advantageous spots.
Story here.
 
Enjoy! 
 

Saturday, May 08, 2021

Shark Reef - Video!

BRAT, way back then when life was easy
.
 
Behold!
 
The virus is on the loose.
Government is doing a truly fabulous job in containment and contact tracing - but as we all must play our part, we've all decided to home isolate, meaning that I've had plenty of extra time on my hands. 
 
So there.
Filmed in 4K and down-sampled to ProRes 1080 due to my measly upload speed of 242 kbps  - and it still took me nearly five full days to post!
 
Oh and.
There's a reason why ours has been called The Best Shark Dive in the World - and this is why. 
The dive keeps on changing, and we keep on learning and adapting, too - but after literally thousands of dives I for one continue to find it as mesmerizing as on day one!

Watch in 1080 - enjoy!


Feeding and Conditioning Sharks - Video!


Bingo.
 
Remember this
And I cite,
Let's not forget the impact of the thousands upon thousands of people who feed and condition Sharks and other Fishes on a daily basis, i.e. the fishermen and spearos!
Case in point:

 
And this is being repeated, mutatis mutandis, countless times wherever there are fishermen = all the time and everywhere!
Do you really believe that the incremental effect of a few dozen Shark feeding operators is in any way relevant to the health of Elasmobranch populations? 
Now watch, and listen = it's exactly like I said back then, and the impact of our industry is absolutely irrelevant.


Story here.
Just gotta love it how they then complain about a problem they themselves have created! 
And, here's another one- see what I mean?
 
Anyway.
Let's go Shark diving - sustainably!