Wednesday, January 15, 2014

NZ - does Shark Diving endanger the Public?

Have you seen this?
And I cite.
About 10 to 15kg of berley was used in a cage dive, he said, which was less likely to attract sharks than the half-tonne of offal dumped by commercial fishermen.

Fishing operators cleaning their catch at the entrance to Half Moon Bay were more likely to attract sharks into the harbour, he said.
Let me once again cite myself.
Fishermen do not only feed Sharks by presenting them baited hooks; many of them attract and often end up feeding Sharks when they drag in struggling fish and when they subsequently clean their catch and throw the scraps into the ocean. Spear fishermen are notorious for attracting, and even conditioning Sharks when they shoot fish and often find themselves embroiled in a competitive struggle over their prey. These people number in the hundreds of thousands and if anybody should be examined for possibly causing an increase of Shark attacks on the public, it should be them - not the few dozen operators conducting baited Shark dives!
  • Great Whites are fully protected in New Zealand.
    If that protection is to make any sense, one must assume that consequently, less adult GWS are being killed and that the juveniles and subadults have a better chance of reaching the stage where they switch from a fully piscivorous diet to seasonal preying on Pinnipeds. If so, the number of Sharks sighted in the vicinity of those Sea Lion colonies may well be on the increase. As Stewart Island is slowly being recolonized by New Zealand Sea Lions, its attractiveness for GWS may equally be on the rise.
  • Shark feeding appears unproblematic at the ecosystem level
    All present research into those baited Shark dives appears to concur that those dives have little to no effect at large spatial and temporal scales. It appears pretty clear that far from becoming dependent on the handouts, those provisioned Sharks continue to fulfill their ecological roles and also continue to follow their normal life cycles as in e.g. mating, pupping and migrating.
  • There's no correlation between Shark feeding and Shark strikes.
    Re-read this. In brief and with maybe the exception of SA, the vast majority of Shark strikes occurs in locations where there are no Shark feeding operations - which is even more surprising if one considers that most of those dives have been established in locations that are known for their healthy Shark populations!
    And even if there were some correlation, it certainly does not equate causation!
But of course there are some big caveats.
  • There are certainly effects at small spatial and temporal scales.
    Shark feeding often aggregates the animals, and this can have local consequences. As an example, take the increased aggression of those Lemons in Moorea; or the observed competitive exclusion of other Sharks in Fiji and possibly SA and TB; or those postulated local behavioral changes and marginally increased residency in Southern Australia.
  • Conditioning via positive reinforcement does likely happen.
    Those GWS are certainly smart and it is absolutely plausible to assume that they may have learned to associate the boat noise with a subsequent feeding opportunity - and with the food being presented at the surface, it as equally plausible to assume that they could be popping up next to other boats in the area!
    The assertion that they may be following the boats ashore is however likely to be humbug - provided, that is, that nobody throws bait overboard on the way home!
  • Location matters.
    Many Shark dives have been being established where there are already Sharks, meaning that objectively speaking, the risk profile is unlikely to change - but perceptions matter and like in the case of population centers like, say, Cape Town or Playa, the diving activity and associated increased publicity of Sharks can lead to conflicts with the other local ocean users. Consequently, as a rule, the feeding locations need to be as remote as possible and should definitely not be established e.g. right in the middle of population centers or right in front of popular beaches etc.
  • Feeding protocols.
    Like I often state, it is often not about the what but about the how.
    Shark provisioning creates its own risks, and those risks need to be managed - meaning that all protocols should be chosen in function of minimizing the impact on both the animals and the habitat, and on maximizing the safety for the participants but also the public. E.g., everybody will hopefully agree that creating humongous chum trails or dumping indiscriminate amounts of bait to create feeding frenzies is probably a bad idea. Or as another example, we here go to great lengths to condition the Bulls never to come to the surface, lest we get accused of endangering other aquatic recreationists.
    In brief, we need to be in a position to demonstrate that we are always striving to conduct our dives in the most responsible way possible.
And then, there's this
  • Obtaining the required Social license and stakeholder involvement are crucial.
    The local stakeholders need to become an integral part of these projects - and this not only through regular awareness, education and consultations but also by letting them partake in the financial windfall, both indirectly but very much also directly. Only this will ensure crucial local support when the inevitable problems will arise.
  • Get in the research.
    The best argument against many of the intuitively plausible reservations of our detractors are strong scientific data. As an example, when people got bitten by Bull Sharks in Cancun and everybody tried to blame the Shark feeding operations in Playa, the operators there had the data showing that they were only feeding females whereas the Bull Shark population in Cancun was only comprised of males. Or in our case, our Bull Shark data show conclusively that we are neither causing residency nor any dependency on our handouts, see above.
Long story short?
I ignore the precise circumstances of those cage dives in Stewart Island. Intuitively, I am inclined to assume that they are being conducted responsibly, and that the location is sufficiently remote.

But there appears to be a problem of perception.
If I am correct in speculating that the islands may be attracting more GWS, it follows that  the risk for the Pāua divers may be on the increase. With that in mind, it may be wise to engage in some preventative measures, as in increased dialogue and data sharing with the fishing community all the way to maybe helping fund protective gear like Shark shields etc. And it may also be smart to re-engage with the authorities and the stakeholders, and ensure their support by developing a code of practice everybody can agree with!

But again, I don't know the precise circumstances.
Maybe all of that has already happened, and the current blowback is merely some noise by troublemakers.

But if not, some of the above may be useful.
Good luck!

1 comment:

jsd said...

Shark diving critics claim that the dead fish introduced in the feed damages the local ecology. When is the last time such critics considered the impact on the global ecology of the god-knows-how-many thousands (?) of tonnes of dead and dying fish (and other creatures) discarded/discharged back into the oceans by commercial fishing fleets?