Thursday, July 30, 2020

Fiji's Sharks in Peril - Paper!

Remember? It is still happening!

Well well - watch.

And this is the paper.
Shame that it's hidden behind a paywall, the more as it is being hailed as a major achievement which it quite possibly is - but I will leave that determination to others.

What however irritates me is the characterization of Fiji.
The press release has quite obviously been re-worded as the initial version stated that Fiji's Sharks are functionally extinct which is a load of horse manure -  but even after the redaction, we are still being flagged as being particularly problematic which is just not true.
Here's the corresponding graph - click for detail.

Seriously, WTF?
Fiji down at the bottom - and then e.g. Tonga of all places near the top? Lemme tell 'ya that having extensively dived, and lived in both countries, this is just wrong wrong wrong in so many ways - which obviously begs the question, may other data sets be equally faulty?

So what exactly happened?
Having consulted the relevant map for Fiji, I learn that having dropped 382 BRUVs on 14 sites, they only recorded 5 Shark and 7 Ray species, and this only on 28.7% of the videos which is perplexing to say the least. But having asked, it turns out that instead of tapping the available local capacity and know how, they decided to parachute in some dude from New Zealand who I hear may have only sampled the sites of a particular NGO and not a representative cross-section of Fiji's reef ecosystems - and if so I can certainly leave it at that. *

Now compare that fiasco to the data of the GFSC.
Or to the fact that in our little region alone, we harbor at least 10 frequently encountered Sharks = GHH and Zebra, plus our usual Bull, Tiger, Sicklefin Lemon, Tawny, Silvertip, plus Grey, Whitetip and Blacktip Reefies, with several other diving operators and also research papers reporting the same and even more, equally ubiquitous reef-associated species like Scalloped Hammers or Blacktips from many other locations.
And then there's the simply massive data set from the hundreds of  BRUV drops by Projects Abroad that had incidentally been initiated in collaboration with the very same Demian Chapman who is one of the paper's leading authors - surely one should have added those sightings, too?

And the data from Tonga?
They are from a grand total of 24 drops on two sites... see what I mean?

Anyway - it is what it is.
Whereas the situation here is most certainly not remotely as bad as depicted, there is equally clearly room for improvement, see e.g.this old assessment, Kerstin's papers here and especially here, and also the description of Fiji's Elasmobranch fishery here at page 188 ff.
In brief and despite of the reduction in the Asian demand for their fins, our Reef Sharks and the juvenile Sharks in the riverine nurseries are now increasingly being targeted as an alternative source of protein as many of the traditional food Fish stocks are being depleted.
And to top it off, we're now witnessing a massive Covid-19- induced increase of indiscriminate fishing and poaching that is  threatening years of conservation efforts and also indirectly threatening our Shark populations by obliterating their prey.
Talking of which, I really did like reading that
Without an absolute estimate of the abundance of sharks, it is difficult to know how effective the estimated levels of conservation potential might be in restoring shark populations in reef ecosystems that have been degraded by overfishing.
Although research has shown that fully recovered reef fish communities have biomasses between 1,000 kg ha−1 (ref. 27) and 1,500 kg ha−1 (ref. 12), we have no current estimate of the size of the forage base that is required by a recovered shark population, or how the bottom-up effects of prey biomass might influence the recovery potential of reef sharks.
A key question remains as to whether management strategies that only pursue shark conservation can make substantial or limited gains, relative to those that include the restoration of the wider reef ecosystem.
If the restoration of the whole ecosystem is necessary to fully restore shark populations, our results underscore the need for managers to engage with the wider social, economic and cultural drivers of marine exploitation.
Could not agree more!

Long story short, the paper is certainly welcome.
Far from being defeatist, the authors suggest several pathways for improvement that I can only second, albeit with the usual general caveats (= e.g. follow the links here).
The good news is that here in Fiji, there is already some progress, namely the fin ban, the CMM for Sharks by the WCPFC  (incidentally once again courtesy of the simply unequaled Shelley) and an upcoming, WWF-sponsored, long overdue NPOA (Sharks) that will provide a framework for subsequent regulations and pacify the FAO.

And then, hopefully, we will get The Big One.
No, likely not a Shark Sanctuary but instead this comprehensive regulation - and having checked, all appears to be on track for the December deadline at the end of this year!

In any case, we stand ready.
Thanks to Tashi Blue's boundless and also, infinitely endearing passion and commitment, her My Fiji Shark project has been able to accumulate a nice little war chest that will greatly help us assist with the implementation of the regulation.
So fingers crossed and yes, very much to be continued!

But I'm digressing as always.
Enjoy the Shark paper!

* PS - Demian informs me that there was no parachute science as the vast majority of drops was effected over several years by that local NGO - which obviously begs the question, what went wrong?
Wrong habitat/site selection? Lousy bait?
Anyway, it is what it is.

Saturday, July 18, 2020

GWS vs Humpback - Video!


Pretty awesome ain't it.
Story here - enjoy!

Monday, June 29, 2020

Selective Removal of Problem Sharks - Paper!

Click for detail!


Remember this paper?
Now Eric et al have doubled down with this further publication that specifies possible techniques for first, a) establishing a data base of potential perpetrators and then, b) identifying and removing individual problem Sharks after they have attacked a person.

Well what can I say.
Like I've already stated here, I am absolutely convinced that problem individuals do indeed exist, much like what has been shown with large terrestrial predators. And I'm equally of the opinion that removing them selectively (whatever that means) would ultimately be vastly preferable over indiscriminate broadcast culling - though having said that, there are obviously other solutions (like eg hazing, etc) that would need to be exhausted beforehand!

But that's the theory.
In general terms I remain unconvinced that individual profiling and selective removal is a practicable solution for large geographical areas featuring thousands of potentially dangerous Sharks, like, say, the USA or Australia. There methinks that one will need to continue trying to reduce the risk and mitigate the consequences - but by the same token, one will have to accept that the odd Shark bite is ultimately just simply inevitable and part and parcel of coastal living.

And in comparatively small areas?
Interesting to see Cocos and Reunion mentioned in the paper!
I've said what I wanted to say about both situations back then and really got nothing to add - maybe with the exception that Reunion looks like an ideal testing ground, the more as there is already an adequate scientific infrastructure allowing for the proposed broadcast DNA sampling and visual identification. So by all means, go for it - tho bon courage trying to establish a feeding station like suggested! :)

Anyway, all very interesting indeed!
Knowing Eric, something is likely brewing - and if so, godspeed, Fair Winds and Following Seas and all!

To be continued no doubt!

Wednesday, June 17, 2020

Kleptoparasitism in Sharks - Paper!

Click for detail!

Very nice!

Read this.
Following their epic dives in Tetamanu and the many experiments they have made, the team around Laurent Ballesta have published their observations about the interactions between the Grey and Whitetip Reefies when nailing that Grouper spawning aggregation.
Here's what Johann has posted.

Not surprised about the kleptoparasitism by the Grey Reefies
They are just that bit bigger and bolder than the other reefies, and will thus tend to dominate any competitive exchange, much like described in this paper from Osprey Reef.
And here in the Reserve, they will equally try to dominate the other reefies during the shallow feeds, something we try and counteract by hand feeding selectively so that the Blacktip and Whitetip Reefies always get their fair share.

Anyway, all really very interesting.

Monday, June 15, 2020

Feeding Frenzy!

Click for detail! Source.

And here's another great one.

Great story by MPO right here!

Sunday, June 14, 2020

Mega Mouse!


A Mega Mouse has arrived in the wave of the left coast of the wave!
The size is 6 M strong, and it is simply surprising! It's a deep-Sea Shark, so I stocking up immediately after the record, but I swam to the deep place and went to the deep place! 
Movie-by F

Translation by Google! :)
From what I can discern, this is from Tateyama, Bōsō Peninsula, Japan  - apparently the Megamouth was trapped in a net and released.

Not quite an epic natural encounter like this - but still!
What a great animal - I hope she makes it!

Friday, June 12, 2020

More Sharks in Pacific Harbour?

Well well.
Somebody has apparently seen a Shark or two in front of Nanuku Resort and now there's a bit of a kerfuffle, with various quarters offering their opinions.

Thing is, opinions are like assholes: everybody got one. 
Look no further than Dunning Kruger and you will quickly discern that that's just simply not good enough. If you wish to be taken seriously, you really got to inform yourself before making public pronouncements - and no, educated guesses and random unrelated factoids do not qualify!

With all due respect, the premise of this posting is just simply 100% incorrect!
Tashi Blue has valiantly attempted to rectify the story with the media but apparently with little effect, the more as Fijjivillage has only published excerpts of her entire statement.

So there.
We look back on more than 15 years of scientific research into these specific Sharks, and our findings = the actual evidence unequivocally shows that.
  • The big sharks are neither resident to the feeding sites, nor are they "territorial" = they have never only been hanging around Shark Reef or for the matter, Pac Harbour but instead, they have been visiting sporadically but have otherwise roamed all across Fiji, e.g. we have tracked them all the way to the Rewa, the Yasawas, Ba and even Vanua Levu. In fact, those mentioned Tiger Sharks are known to make astonishing trips of hundreds of miles that take them into open ocean where they then fall victim to the long liners = and you have all seen those jaws, and those of the Mako Sharks at the Suva handicraft market!
    But I'm digressing. In brief, nothing whatsoever has changed and our Sharks continue to roam the entire archipelago completely unperturbed, like they always have!
    Paper here, blog post with explanations here.

  • But more importantly, their food intake on the Shark dives has always been negligible = they have never depended on our handouts and they have never stopped hunting and are not now having to change their behavior, let alone venture out of their nonexistent "territory" because we feed less and they are "going hungry" or such nonsense. In fact, we note no different behavior and/or increased aggression, or the like during our dives.
    Paper here, blog post with explanations here.
Again, this is scientific evidence = fact.
In brief, there is no factual basis for speculating that any increased Shark sightings on the beach are due to changes in the Shark feeding schedules - and please don't comment that you disagree as there really is nothing to disagree about = you may, possibly, be entitled to your opinion but you are certainly not entitled to your alternative facts unless backed by solid evidence!

And this?
Sorry, nope, that's not correct, either!
Shark populations reproduce slowly and take a long, long time to recover = a single year since the export ban is just too short to have had any notable effect. But more importantly, recent research shows unequivocally  that fishermen are targeting smaller Reef Sharks and also the riverine Shark nurseries  - not for the fins but for the meat!
Especially the latter bodes really ill for Shark populations = in fact, for what it is worth, over the past few years we've experienced less and not more Sharks!

So what about those mysterious Shark sightings.
  • Firstly, that big blue expanse in front of the Nanuku Resort is called "Ocean". That happens to be where Sharks live, and an occasional sighting is only normal and should be no cause for alarm but rather, for joy as Sharks are an indicator for healthy marine ecosystems!
    In fact, the beach in front of the resort is a nursery for tiny baby Blacktip Reef Sharks that are actually very cute and perfectly harmless. Is that what the staff have seen? If so, go have a look as they are adorable! And in the past, there have also been reports of Tiger Sharks patrolling the shallows in front of the Pearl at early dawn.
    All that is normal and part of living on the coast, and it behooves us to act accordingly, see below.
  • Secondly, it is important for a aquatic recreationists to make responsible decisions.
    The ocean can pose many dangers, from currents, waves, and undertow to encounters with species that can cause injury to humans, whether they be sea urchins, cone snails or even Sharks. Learning how to swim (!), not swimming in rough seas, not swimming early morning or at dusk and not swimming alone are some considerations. This is especially important now that the schools are closed and many children go to the beach = perhaps instead of being unduly alarmist, it would be a better idea to explore hiring/training life guards to monitor the most popular beaches?
But there could also be cause for concern.
I ignore whether there is really any actual increase in sightings, and if so, whether it means that there is a higher influx of Sharks  - or whether it simply means that there are more observations due to more people being on the beach.
And, are those Sharks small and harmless or big and potentially dangerous?

Anyway, let's assume the former = that there are more Sharks.
If it's not the Shark feeding dives: what may have changed to trigger such a phenomenon?

IMO look no further than Covid-19!
  • When we did our tagging, one surprising result was that the bulls would aggregate in front of the Navua river (= receiver # 12) in the early evening, and this irrespective of tide. Only later did we discover the reason, i.e. people trying to avoid paying the rates by dumping their trash into the river, and that the Sharks had learned to take advantage of the windfall much like a pack of stray dogs would raid unsecured garbage bins.
    May this be an increasing phenomenon as money is tight, also with respect to the Qara-ni-Qio? And what about all the trash that is notoriously being left behind by the beachgoers, and then gets washed out to sea by the high tide? May this be attracting Fish and consequently, their predators, too?

  • Have you noticed the many pop-up Fish vendors on the side of the road, and the many ads for fresh Fish in the social media, etc?
    All along the coast, many, many more people than before are fishing - for fun, for kanakana but also in order to supplement their income by legal small-scale commercial fishing but unfortunately, also by illegal commercial fishing and poaching in the MPAs including Shark Reef. We know the perpetrators, we know who fills the tanks of the gang of scuba diving spear fishermen, we know who sells them the spear guns etc - but tackling these things take time and for now, the shenanigans continue unabated.
    Anyway, all this massive ubiquitous fishing, spear fishing and cleaning the catch directly on the coast is bound to attract Sharks, like it does everywhere else.
    And if you spear fish and are not careful, you may well end up having one of those close encounters described by Jonathan - not because of us but because that is what happens everywhere around the world, see here and here among many, many such examples!

    Anyway, where I'm coming from is that fishing and spear fishing close to, or directly at the picnic beaches is just simply unconscionable, and must stop. You have all seen it with your own eyes  - next time, do something about it!
And there you have it.
More facts and action - and less opinions, speculation and idle claptrap!

Have a great day everybody!