Fiji Bull Sharks - full Circle!

Kerstin - intrepid and extremely successful!

Finally!

We've detected two of our pregnant Bulls in one of our rivers!

Despite of our best efforts and more than a dozen years of research into the life history of Fiji's Bull Sharks, coming up with concrete evidence linking Shark Reef to one of the putative river nurseries has always eluded us as the tags would come off and the frequent floods would wash away the receiver arrays. But we've persevered, tinkered with the hardware, tagged a dozen pregnant Bulls in October and deployed new receivers in several rivers - and bingo, and this despite of the horrendous weather and floods a fortnight ago! With this having been little more than a small trial run, expect much, much more of the same next year!

And the river are teeming with babies!

This is obviously recruitment time, and Kerstin and her assistants from Projects Abroad and  the USP are reporting impressive numbers from all monitored rivers - the bad news being that absent any management let alone protection, the little Sharks are being obliterated by the local fishermen. 

This may well explain the disappointing numbers later in the year and is of course cause for grave concern, not least because it is also directly impacting on the long-term viability of Fiji's thriving Shark diving industry. But now that we have the evidence, we shall certainly go and speak to the powers that be - so fingers crossed!

To be continued no doubt.

Happy New Year everybody - may 2017 bring many more fantastic adventures!

Tagging GWS in Oz!

Source.

Bingo.

Like I said, nobody is missing out on anything.

Check out the video.

No drama no superheroes - just some information, as it should be.

The fisheries department of WA is continuing to tag those GWS and to perfect its early warning system - and  I know for a fact that excellent, experienced people are standing by should the department decide that it really requires any external assistance.

Story here - and more info here!

Nuff said.

Enjoy!

Australian GWS - extremely well documented!

The shenanigans continue - as expected!

No WA did not miss out on anything!

If you read past the pro-OCEARCH propaganda and Fischer's pathetic demagoguery, you will discover that the Ozzie GWS researchers have been extremely active - and I may add that this has been going on for years (read it!) and not only since the strikes in WA. As a result, the coastal phase (including the nurseries and early life stages) of the life history of those Sharks is extremely well documented - and considering that that is precisely where their trajectories intersect with those of the aquatic recreationists,  Fischer's assertions sound particularly hollow. 

More details here, and I know of trials to link those arrays to the other early warning systems and thus e.g. complement the helicopter patrols.

Think the WA authorities are really as moronic as depicted? Check this out and think again!

The oceanic phase however warrants more investigation.

Ever since Bonfil documented Nicole's epic trip, we know that there is connectivity between WA and South Africa. As far as I know, the purpose of those voyages remains unknown - but that cannot be addressed by telemetry alone and will require additional evidence collection, very much like what has been pioneered by Domeier in the NE Pacific.

Think the Ozzie scientists are too stupid to do that if they wanted to?

Long story short?

Juvenile Bulls in the Everglades!

A juvenile Bull from one of Fiji's rivers, with a Scalloped Hammer pup in the background - click for detail.

Another nice one from the Heithaus Labs!

This is gonna be one of next year's volunteer projects.
Initially, we'll be investigating their usage of the riverine nurseries and later on, when and how they transition to the reef environment.
Interested? You know what to do!

The paper is here.
And here's the video that thankfully needs no further interpreting.

Enjoy!

A self-propelled Shark Tracker?

Source - "tracks killers"?

Hah!

Check this out!

Bingo. 

You may want to go read this old post.

Today's tags are much improved, smaller and often featuring one single attachment, and endowed with heaps of new technology all the way to solar cells to recharge the battery. And see my suggestion to develop a receiver that would follow the tag akin to what is being done with Penguins?

Great to see it put into action!

Really looking forward to those data!

But I remain concerned about some of those real-time tracks and can only repeat my suggestion that they be publicized with much circumspection, on a case-by-case basis!

Anyway, great stuff!

Track your Tiger Shark!

This is way cool!
Gary alerts me to Mahmood's real time Tiger Shark tracks and I am deeply impressed!

From the website.
To understand tiger shark movement behavior in more detail and aid in conservation efforts, the Guy Harvey Research Institute/Guy Harvey Ocean Foundation and their project partners are investigating tiger shark movements in the western and central North Atlantic Ocean in long-term studies based out of Bermuda, the Bahamas, the Cayman Islands and the US Virgin Islands.

The sharks’ movements are being studied by employing three types of electronic tagging technology that provide complementary information – acoustic tags whose signals are detected by strategically positioned, underwater listening devices (receivers), and two types of satellite tags that relay information on where the tiger shark is and/or its depth in the ocean.

This is a continuation of these studies.
Once again, Tigers are being shown to be highly versatile not only in their diet but also with regards to the habitats they frequent, from coastal to very much pelagic. Also, they are by no means resident but can engage in very wide ranging migrations, this possibly associated with opportunities for predation. Interestingly, this does not appear to be a uniform pattern but rather, it appears that different individuals engage in completely different behavior. As an example, check out the Grand Bahama page and you will see that whereas Nikole and Christina prefer to stay close to the coast, Jamin appears to be way more adventurous - this very much like the Bermuda Tigers that are true pelagic wanderers that visit seasonal hot spots.

Please explore the site and the tracks.
I particularly liked the animated tracks as they feature a running time log which does a great job in depicting time spent in an area or distances traveled.

Enjoy!

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!

Feeding Tiger Shark - 2

This time from Fiji!

Shark Diver have discovered this astonishing document which carries the description this video was shot in February 2008 in Fiji by a guy I know. They throw dead horse and cows in the ocean, so sharks will eat them (Fiji is small so they'd rather have sharks take care of the bodies instead of burying them. Nice video, a bit gruesome. Enjoy!



Difficult to say where it was shot, tho the sizable piece of land in the background may indicate that it was off one of the main islands.
Anyway, very cool!

As per my comment on Underwater Thrills, there's plausible but so far unsubstantiated anecdotal evidence that Fiji's Tiger Sharks have learned to capitalize on the periodic floods during the wet season by aggregating at the river mouths.

2009 is the year where our Bull Shark research is gradually been extended to the principal rivers. It will start with TEK, i.e. obtaining Traditional Ecological Knowledge through interviews with the local population. Promising rivers will then be analyzed to a greater degree, mainly with the aim of identifying the local Bull Shark nurseries. For that, we will selectively deploy acoustic receivers coupled with the tagging of pregnant females.

The Tiger Shark aggregation being a testable hypothesis, we may well decide to go ahead and divert a couple of tags and put them on our Tigers instead. Not decided yet (that's up to Juerg), but I shall keep you posted as things unfold. As always, it's going to be a matter of priorities and of available resources both in terms of money and time. Keep in mind that research money is scarce, Juerg is already mega-busy without having to add yet another species and also, that we're trying to run a dive shop on top of that all.

But I sure would like to do it!
As always, keep watching this space!

Tiger Beach - cool Research!

Hallelujah!

More pro-Shark features in the Florida press!
This time, it's a great article about Guy Harvey's research on Tiger Sharks in the Bahamas.

Yes, that would be "That" Guy, he of the T-shirts!
His bio mentions that Guy Harvey is a unique blend of artist, scientist, diver, angler, conservationist and explorer, fiercely devoted to his family and his love of the sea! And a real nice chap on top of that!

But much more than that, he is also the founder of the Guy Harvey Research Institute that is fiercely committed to the preservation of Fish and particularly, the big game Fish and Sharks. In fact, GHRI conduct some of today's most innovative Shark research and our Juerg often collaborates with them when doing his thing on Shark Reef.

And on top of that, he has done this!



Is this Guy cool - or what?

This time, Guy and his folks have gone to Tiger Beach to tag some Tigers.
It's a cool undertaking which aims at understanding the movements of those animals in the area - much like what we do in Fiji with our small-scale movement research. Whereas we feed the acoustic transmitters and sometimes attach them externally by using a spear gun, they rope in the Sharks and attach the tags internally. Not sure if I like that in terms of the stress they inflict on the animals - but it's fast, really quite harmless and they must have their reasons for believing that it's the best way to go.

And, it's for the best of causes.
Because as I read with great joy, it involves the Bahamian Government and has the aim to eventually have the area declared a Shark sanctuary!

Where did I hear that one before?
Great that things have been set in motion!

PS hat tip to Felix!