Oslob - bloody Quagmire!

Source - click for detail!

The q being, am I gonna wade straight in?

You betcha I will! :)

But fear not - this is way too complex, inconclusive and also, way too agenda-driven for me to take a strong position and start unleashing.

Just this.

Alessandro Ponzo (che tutt'ora rima con stronzo) and his cohort of Shark huggers are still at it in trying to bring down the Whale Shark feeding industry in Oslob, e.g. here. My pal Mark Meekan and creepy Judi are pushing against it which is essentially a good thing. 

And there sure is a lot of controversy as per eg this thread.

Methinks that the truth lays somewhere in the middle.

Despite of their best efforts, the detractors have so far failed to come up with clear evidence that the Sharks are being harmed, period - and in that respect, invoking the precautionary principle and asking for the reversal of the burden of proof is just unacceptable, especially considering the consequences for the local community.

But that's obviously not the whole story.

The documented non-adherence to the protocols is a cause for concern and needs to be addressed - this especially considering that the financial success of Oslob is already spawning copycat procedures = feeding in other juvenile Whale Shark aggregations across the Coral Triangle. The massive demand for these interactions can easily lead to unchecked development and if so, it is certain to have deleterious consequences if not managed properly - so once again, people get your fucking act together!

And that's it.

Once again it's probably not the WHAT but the HOW - and whereas for now the what appears unproblematic, the how needs urgent attention!

In diesem Sinne.

Let's go Shark diving - responsibly!

Recovery of Sharks within a well enforced MPA - Paper!

Very nice - watch!

Paper here, synopsis here.

I must say that contrary to other papers looking at different aspects of those reefs off Western Australia where I am weary of some of the conclusions, I am quite impressed by this one as the evidence for the rapid recovery of those Sharks appears to be rock solid as e.g. evidenced by the video below.

This is good news indeed.

Provided that there is strict enforcement, MPAs appear to be an effective tool in the protection of at least those comparatively less migratory coastal Sharks - and if so, there is certainly reason for hope.

Of course for us this is nothing new.

But good to see our data (and here!) confirmed by research from other parts of the word.

Enjoy the paper!

The economic Value of Shark-Diving Tourism in Australia!

From the paper - click for detail.

Interesting!

So, in 2014, Shark diving in Australia was worth 25.5m.

This compares to 42.2m for Fiji, 18m for Palau or a whopping 109m for the Bahamas - or maybe not quite as this paper only looks at direct expenditures. This also compares to the value of 2.2 bn dollars attributed to Australia's dive-related spending for marine tourism.

Frankly, I'm not terribly impressed.

Considering the size of Australia's tourism industry but also, the sheer potential bearing in mind Australia's enormous coastline and wide array of marine habitats, and its large number of Elasmobranchs, this is really just a pittance. But it is what it is - and if I were to venture an explanation (which I am not), I would certainly want to explore the effects of Australia's Shark attack phobia but very much also that of its stifling regulatory framework.

But I'm digressing as always.

Enjoy Charlie's paper.

Australia: Reef Shark mediated Trophic Cascade?

Competitors: Grey Reefies and Snappers. Source.

Well well.

Read this.

If I understand it correctly, it shows that several species of mesopredatory Snappers were doing great on reefs where (higher-ranking but equally mesopredatory) Reef Sharks were rare; but on reefs were Reef Sharks were abundant, the Sharks appear to have out-competed, or otherwise influenced the Snappers who had to shift their diet to less nutritious benthic invertebrates and were doing very poorly indeed as a consequence - synopsis here.

The conclusion being that

our findings suggest that overfishing of sharks has the potential to trigger trophic cascades on coral reefs and that further declines in shark populations globally should be prevented to protect ecosystem health.

Really?

Yes to the possibility of top-down effects - but if the Snappers' fitness was being adversely affected by the presence of Sharks, who, exactly, did benefit from it? Obviously not the Snappers - but also not the prey Fishes and Cephalopods that were still being killed; and also not the benthic invertebrates that were being killed on top of that.
So where is the evidence that Sharks help preserve ecosystem health = instead, is this not rather the negation of Healthy Reefs need Sharks?

Or am I missing something here?

PS: great comment by Michael in the comments section - thanks!
 

Scavenging by Tiger Sharks - Paper!

Click for detail!

Very nice!

Watch.

Paper here, press release here.

That's quite a handful of prominent authors - but in essence, this is a re-interpretation of some of the data collected by Richard, Adam and Ian whilst on the venerable Undersea Explorer that have already led to this paper from 2012 I posted about here.

Which is why the authors stress that much of the above is speculation.

The experimental design was aimed at deciphering long-term movements, and the present fine-scale analysis is very much based on inference rather than actual scientific evidence; but having said that, Richard and Adam have logged hundreds of man hours at Raine, and tell me that actual predation events on healthy Turtles are very rare and tend to be confined to the start of the breeding season when there are less Turtles and the Tigers are just arriving hungry. On a busy year, Raine will yield up to 2,000 dead Turtles, meaning that after a while, the Tigers are more than sated and really could not care less about chasing after healthy Turtles.

Like I said, very nice - but now things are changing.

BHP the mining giant is giving a lot of money to the Raine Island Green Turtle Recovery Project, and the island is being made more Turtle-friendly by eliminating features that could kill them and by protecting the nests against inundation. This means that less turtles will have accidents, and that any distressed Turtle will be aided by the turtle lovers and consequently, adult Turtle mortality has already been reduced by 50%.

And the Tigers?

What happens at Raine is part of a system - and if you tinker at one end, it stands to reason that there will be consequences at the other.

Will the Sharks predate more on healthy individuals whilst expending more energy in the process - and if predation increases, will that have an effect on the behavior of the Turtles? Or will the Tiger Sharks gradually stop coming? And what are the effects of this diminishing resource on their population?

Here's what I think - and yes I'm totally speculating.

Research in Hawaii has shown that those Tiger Sharks are able to regularly exploit determined ephemeral resources, and our own observations at Shark Reef indicate the same for our Bulls at Shark Reef. In essence, one of those Sharks will stumbles upon an opportunity, is able to memorize the experience and will henceforth come back to exploit it. This is learned individual behavior, not something that is genetically encoded or communicated by conspecifics or the like.

At the same time, our observations and those of the GWS people indicate that individual Sharks will favor determined strategies, e.g. individual GWS will attack the teaser bait consistently in one determined way; and on Shark Reef where we have a hand feeding and a bin feeding tribe of Bulls with very little overlap, those specialized hand feeding Bulls will gradually stop visiting when we temporarily suspend hand feeding,

Could it be the same for Raine Island?

Could there be always the same Tigers, and could those individuals be specialized scavengers that would not switch to outright predation but instead, would eventually stop coming once there are not anymore enough carcasses to feed on? 

Dunno - but that's certainly testable, or not?

And another thought.

If one believes Domeier -and I certainly do- what happens at Guadalupe is essentially a GWS feeding and mating aggregation. Could the food pulse during the pupping season of the Northern Elephant Seals maybe even trigger mating, and could it be important for the success of the ensuing pregnancies?

And could what happens at Raine Island be the same, meaning that if the Shark aggregation slowly disperses, finding mates would become more difficult and reproduction success would be lower?

Questions questions!

Ain't science a wonderful thing! :)

Reef Shark mediated Trophic Cascades? Not so fast!

Source - click for detail.

Bingo, and I cite,

Resident reef sharks do not sit atop the ecosystem like guardian angels; they dwell among the masses feeding on anything and everything they can.
They’re raccoons, not wolves.

On land, top predators like wolves prey upon large herbivores such as deer and elk, thereby protecting the grass and low-hanging trees from overgrazing. Such knock-on effects through an ecosystem are known as trophic cascades. In this case, those at the very bottom of the food chain—plants—are dependent on those at the top.

But of the 26 key species of sharks on coral reefs, only a few infrequent visitors—namely tiger sharks, bull sharks, and hammerheads—can be placed in the top tier of the food chain. “Shark” isn’t a blanket term for a huge voracious hunter, but a family of fish that encompasses a diversity of diets and lifestyles. The vast majority of species, such as whitetips and grey reef sharks, for example, are more akin to large-mouthed groupers and giant trevally—they are all mesopredators.

Remember this?

There it is suggested that only the adults of a few large-bodied Sharks with vast home ranges truly qualify as apex predators. The reef-associated species among them, like Tigers, Bulls and Great Hammerheads are however mere transients, which is why the evidence for (Reef-) shark-induced trophic cascades that benefit herbivorous fishes is weak or equivocal, or as this paper illustrates

In the absence of suitable long-term empirical studies, comparisons of the trophic structure between protected and fished sites can provide insight into the effects of shark removal on coral reefs. Theoretically, the loss of sharks would result in an increase in mesopredators, with cascading effects towards multiple prey at lower trophic levels. However, a critical evaluation of the available empirical studies finds weak evidence for shark-driven cascades.

Nearly all studies reported simultaneous declines across all trophic levels driven primarily by high levels of fishing pressure in populated and heavily fished locations (bingo again!).

Most studies focused on links between sharks and fish species at the base of the food chain: herbivores. This interest stems from the key ecological role herbivores provide on coral reefs, enhancing coral resilience by consuming fleshy macroalgae that outcompete corals for space. Theoretically, high shark abundance might lead to reduced mesopredator abundance and allow herbivorous fish to escape predation and become more abundant. However, empirical demonstration of trophic cascades involving sharks, mesopredators, and herbivores has proved elusive and nearly all studies find that reductions in shark densities occur in conjunction with reductions in mesopredators and herbivores .
Further, in regions where herbivores are not targeted for fisheries, higher densities of sharks inside marine reserves had no effect on the density or biomass of herbivorous fish.

While a recent study purports to show evidence of a shark-driven trophic cascade following catastrophic reef disturbance, no differences were found in the abundance of lower trophic groups (herbivores, corallivores, or planktivores) among fished and unfished atolls before disturbance, despite mesopredators being more abundant in areas where sharks were depleted by fishing
Increases in herbivore abundance in the area protected from shark fishing were observed only following cyclone disturbance, but the consequences of habitat damage confound interpretation. Because the cyclone caused loss of coral and a concomitant increase in algal resources, food limitation provides an alternative, and perhaps parsimonious, explanation for the positive response of herbivores rather than a shark-driven trophic cascade.

Alas, the last paragraph concerns this paper.

And despite Mark et al having mounted a vigorous rebuttal, I fear that upon reading the riposte by Roff, I remain equally unconvinced.

Alas - because I really liked that paper!

Long story short?

Nah I'm not gonna repeat myself like an old broken record - re-read it here!

Whale Shark tourism in Ningaloo - Paper!

The strobe ban is baloney (and should be exchanged for a ban on self-promoting peroxide piranhas) - but other than that, this is excellent. Source - click for detail.
 

Wonderful!

Love love love the paper!

Great to see longterm monitoring much like we do here and has been done by Avi in Cocos! Also great to see that grouper challenge  winner Rob is being mentored by Shark tourism supremos Jessica and Mark. And finally, great to see yet another piece of evidence that when done correctly, Shark tourism does not harm either the animals or their environment!

This is obviously different, meaning that it is high time for the regulator to step in and step up - re-read this!

But I'm digressing.

Very well done!

Enjoy the paper!

Until a group of Western Environmentalists turned up!

A former fisherman, now a whale shark guide, hand feeds a whale shark as tourists look on, Tan-awan, Oslob Cebu, Philippines, 22 March 2012. © Paul Hilton / Greenpeace - source.

 

The video description reads.

Giants of the deep: The fight to save Whale Sharks

They're the biggest fish in the ocean - making them one of the biggest targets for fishermen around the world. The whale shark is massive, magnificent and on the brink of extinction. But in a tiny corner of the Philippines, man and shark have come to a unique compromise. Fishermen, who used to hunt this marine giant, now protect it - reaping a financial bonanza from tourists.

And everything had been going swimmingly, until a group of Western environmentalists turned up.

Indeed.

As in Alessandro Ponzo (che rima con stronzo)!

But watch the video, it is great stuff.

First and foremost, Bravo Mark!

Mark Meekan is a heavyweight in Shark research and conservation in general and Whale Sharks in particular, and his statements could not have come at a better time. Ponzo's continuous vociferating is resonating in the conservation community all the way to some of the biggest and most respectable organizations, and the pressure on Oslob is mounting.

I've said it here, the screeching opposition is total bullshit.

If deprived of the tourism income, the fishermen will revert to what they were doing before and kill those Sharks. Instead of throwing the baby out with the bathwater, the solution lays in investing one's energy into reforming, implementing, monitoring and ultimately, enforcing the interaction protocols. 

Not rocket science is it - that is, unless one is driven by some idiotic Shark hugging agenda or even worse, by one's wish to promote their sites XXX and YYY and shut down the poor people in Oslob without giving them a chance to improve, like a prominent Shark conservation advocate writes.
And it's not only the fishermen and the local economy - this is creating thousands of Asian Whale Shark lovers!

We shall keep an eye on this.

For now, huge kudos and a big THANK YOU! to Mark for having lent his authoritative and unambiguous voice to the debate!

Citizen Science is good Science!

Bingo.

Read this - and here is the paper!

Now we finally dispose of some powerful evidence that despite of many critical voices, citizen science really does work.

Of course we knew that already.

We've been employing trained observers to record data on Shark Reef since 2003, and those observations have been the backbone of many of Juerg's papers where they have complemented the data obtained via acoustic and satellite telemetry. In 2012, the concept has been expanded throughout the whole of Fiji where every six months, the majority of preeminent dive operators are participating in the Great Fiji Shark Count where they are counting Sharks, Rays and Turtles with their customers and passing on the data to the project team and ultimately, Christine. On top of that, Projects Abroad are now conducting such counts on every dive and uploading the data to eShark, meaning that Beqa Lagoon is now being monitored year-round.

And the results?

This is long term monitoring, and trends will only become visible over time - but when it comes to the Sharks, anecdotal evidence is already pointing to local declines. My hope is that we may well see an improvement once the authorities will have to increase their monitoring and management effort in line with the looming implementation of CITES.

We shall see.

But that's another story.

Congratulations to the indefatigable Gabe and the dream team from Western Australia for yet again an excellent job.

Bravo! 

Trophic Cascades in Coral Reefs - Paper!

Mean density of trophic groups (±95% confidence intervals) for fished (red) and non-fished (green) reefs.

The density of trophic groups across fished, non-fished, disturbed (stippled bars) and non-disturbed (solid bars) reefs are shown. Figure 4. Mean density of trophic groups (±95% confidence intervals) for fished (red) and non-fished (green) reefs. The density of trophic groups across fished, non-fished, disturbed (stippled bars) and non-disturbed (solid bars) reefs are shown.

Finally!

This is what I've been waiting for!

This paper is simply epic - read it!

So far, the most cited example of Sharks and trophic cascades has been the controversial 2007 paper by Meyer about those exploding Cownose Rays (synopsis here). There are also Ferretti et al that I personally prefer, Sandin et al where the snapshot approach is highly questionable, and then there's a lot of anecdotal evidence that however still requires rigorous testing. All-in-all, it's a lot of interesting stuff - but so far, the findings appear far from being unequivocal, this also owing to the complexity of the investigated food webs.

This however is different.

First, it is not based on meta-analysis but instead, on original and comprehensive long term monitoring over a period of ten years which in itself is rather epic. Secondly and contrary to what happens in most other locations where people are fishing down the food chain and thus inhibiting any postulated mesopredator release, those Indonesian fishermen were selectively targeting Sharks and leaving the other Fishes more or less alone, meaning that any of the detected effects were singularly isolated.

You can read two excellent synopses here and here.

My take-away message is that contrary to more simplistic statements that the removal of Sharks will ripple down through the food chain and eventually lead to the demise of coral reefs, this paper comes to the conclusion that it is instead the presence of Sharks that may play a critical role in the recovery of coral reefs that have been previously damaged by other factors. The paper also once again confirms that due to the high level of residency of Reef Sharks, even comparatively small MPAs may be highly beneficial.

Long story short?
As it becomes all but inevitable that climate change will further damage our coral reefs, those Reef Sharks may indeed turn out to be one of our best allies in trying to mitigate those effects.

If we stop wiping them out that is.

And that is far from being a certainty!

Reef Sharks - new Papers!

Grey Reef aggregation - likely in Apataki's Trou aux Requins - stellar pic by Chip!

Great stuff!

This first paper is about Grey Reefies.

It's by the authors of the Fiji Shark tourism paper and really a nice piece of research - and kudos to Gabe on the first authorship!

Rather surprisingly, it caused quite a kerfuffle on Patric's blog - but as I said there, Patric's comments are a tad harsh, the more as that particular species is not a frequent target of the long liners. 

But the general gist, i.e. that publishing data about philopatry carries some inherent risks is of course correct. I did blog about it here and came to the conclusion that such data should be used for conservation and management purposes and only be shared widely if there is robust and above all, fully enforced local protection - something that certainly pertains to Palau, especially for the popular and highly visited stretch between Siae's and New Dropoff!

Nice re-cap here

And yes Patric - Palau lays east of the Philippines (not north, south or west)! 

And... ? :)

This paper is about Blacktip Reef Sharks.

Inter alia, this one is by the authors of that Lemon Shark paper who continue their observations and in-depth analysis of the Shark Population of French Polynesia as part of the ORP and CRIOBE.

It investigates the genetic makeup of the Blacktip population in several of those islands and describes that it is highly fragmented, meaning that gene flow (= Sharks traveling between populations) is low. The conclusion it draws is that in order to protect Sharks, it is better to establish Shark Sanctuaries rather than to try and protect them via MPAs.

Well, yes, that is certainly true in general - the bigger the better!

On the other hand, as a staunch lumper, I cringe at the recent trend of splitting everything. There are several ignominious examples from Avian, Amphibian and freshwater Fish taxonomy where the designation of many sub-species hast resulted in a plethora of tiny local populations, and subsequently, in the squandering of scarce public resources in the quest of preserving every single one of them - and this fatally reminds me of those occurrences. 

With Shark conservation being as difficult as it is, I'd be quite happy to see progress at the species-complex level - the more as otherwise, most of those tiny populations would succumb to the requirement of prioritizing one's resources by applying conservation triage!

But yes those Sanctuaries are great - at least for as long as Shark fishing remains so poorly managed!

And what about the implications for us here in Fiji?

The first one is that with such high residency levels, the Shark Corridor offers a substantial degree of protection much like in the case of our Bulls.

Other than that, we don't know - yet!

In Juerg's research, we've so far concentrated almost exclusively on the Bulls. But we have also recorded many observations about the other species, and our data base undoubtedly contains the answers to several of the same questions - that is, if somebody had the time to analyze them! But fear not, Juerg's next paper is already in the works, and it will contain much more info about the other species!

Of interest and contrary to all other Grey Reef aggregation sites I have visited, the SRMR harbors more males than females who however also appear more transient much like the Bulls and also leave for what we believe is the mating season in mid year. 

The Blacktips on the other hand appear to be very much resident, and it will be interesting to explore whether the females go walkabout to some nursery area like those in Moorea - which is highly likely as contrary to the Whitetips that appear to give birth in situ, we see zero small juveniles!

Anyway, I'm digressing as always.

Read the papers - it's great stuff, and kudos to the authors on a job well done!

Shark Diving in Fiji - here are the Numbers!

Shark diving - not only fun but extremely valuable, too!

Well it was about time!
After keeping it a closely guarded secret, Pew have decided to finally publish the study they commissioned last year and I must say that I am impressed and also mighty proud!

Executive Summary

We quantified the economic revenues generated by shark diving and the distribution of these revenues to the principal local stakeholders involved with the industry, including businesses, government and local community.

Shark-diving contributed US $42.2 million to the economy of Fiji, a sum composed of revenues generated by the industry combined with the taxes paid by shark-divers to the government.

This estimate was based on self-administered questionnaires designed to collect information on the costs and benefit of the shark-diving industry. We conducted the study in August/September 2011 and distributed questionnaires on the islands of Viti Levu (including the islands of Nananu-i-Ra and Beqa), Vanua Levu, Taveuni and Kadavu, the Yasawa and Mamanuca groups. Questionnaires were answered by 289 divers, 18 dive operators, six resort managers (surveyed at Pacific Harbour and Coral Coast only), 14 dive guides and nine local subsistence fishers from villages that regularly received payment from shark-diving operators for the use of the reef of which they are the traditional owners.

We took a conservative approach to all calculations in order to reduce the risk of over-estimating the value of shark-diving to the Fijian economy We calculated the economic revenue of shark-diving to Fiji based on three key pieces of information:

• (1) Total number of divers visiting the country and the proportion of tourists engaged in dive activities from the Fiji International Visitor Survey 2009

• (2) All expenditures of the divers visiting Fiji primarily to engage in shark-diving activities(“dedicated shark-divers”) as revealed by our surveys;

• (3) The expenditures of divers who visited Fiji for reasons other than diving with sharks, but chose to engage in shark-diving while in the country (“casual shark-divers”) as revealed by our surveys.Expenditures of these divers were allocated as the proportion of their trip spent shark diving, rather than for their entire visit.

In 2010 we estimated that approximately 49,000 divers were engaged in shark-diving activities in Fiji accounting for 78% of the 63,000 divers visiting the country. Dedicated and casual shark-divers accounted for 24% and 54% of all divers we interviewed respectively.

The shark-diving industry contributed US $17.5 million in taxes to the government, a sum composed of corporate taxes from shark-diving (US $11.6 million) and the direct taxes from shark-divers (US $5.9 million).

A minimum of US $4 million was generated annually by shark-diving for local communities. This revenue consisted of salaries paid by the industry to employees (US $3.9 million annually) and community levies paid by dive operators to traditional owners in villages for access to reefs (US $124,200 annually). Employees of the dive industry were predominantly Fijian (13 of 14 dive guides who responded to surveys).

Community levies from shark-diving have played a significant role in promoting the conservation of reefs through systems of traditional ownership.

Viti Levu hosted the largest number of dedicated and casual shark-divers (17,000) with Pacific Harbour accounting for around 50% of the shark-divers, or approximately 8,600 tourists. The Mamanuca/Yasawa group also hosted a large number of shark-divers (11,000) while Vanua Levu/Taveuni hosted approximately 3,600. Kadavu had only 17% of divers identified as casual shark divers and no dedicated shark-divers interviewed during our survey.

Shark-diving generated approximately US $10.2 million on Viti Levu (63% of business revenues from diving) and US $3.2 million (40% of the business revenues) in the Mamanuca/Yasawa groups.

Yes I'm obviously biased.
But having witnessed the enormous effort and acribic number crunching of Gabe Vianna and Mark Meekan when they came to Fiji to collate the data I say, this is as good as it gets - and the real figures are probably even higher!
As a reminder, here is our own back-of-the envelope calculation for the contribution by BAD, once again probably too conservative.

Plus, this only looks at Shark diving.
Like I said e.g. here, I personally believe that the value of Sharks extends far wider, by preserving the health of Fiji's marine habitats and thus having a crucial importance for not only tourism in general but also local fisheries and the well being of our coastal communities.

You can find the entire paper here.
Required reading!