Thursday, June 27, 2013

Shark Feeding - Part deux!

Helen and Fiji Bull Shark - pic by Michael Sealey of Biodiversidad Ibérica

Bless Helen!

Here is the second installment of her post.
I could not agree more - including the fact that there is a local effect, this however not so much precipitated by the bait that is actually all being eaten and mostly leaving Shark Reef in the stomach of the Bulls.which do not reside there. For them, those Tuna heads are just a snack, and not very nutritious at that, and I have no doubt that they continue to prey naturally and fulfill their ecological role in their habitat.
Like I said elsewhere, we are very mindful of our impact and have completely stopped any indiscriminate dumping of bait a long time ago. As a consequence, the composition of the Fishes has changed from a rather low species count of 260 that was being dominated by small scavengers and predators, to now 480+  that is highly representative of any (non-fished) fringing reef along one of Fiji's principal islands.

The effects I detect are more behavioral.
Juerg is writing a paper on the subject, so I don't want to preempt his findings on the subject, the more as I'm yet to see any draft. 
But apart from the obvious conditioning whereby we are actively teaching our Sharks to behave in certain ways, I believe that I'm observing inter-specific aggression all the way to competitive exclusion among the various Sharks. And also believe that we've interfered with the diel patterns of at least the Whitetips that are usually crepuscular but on Shark Reef, leave their hidey holes to come and feed at midday. 
But at this stage, I'm obviously speculating, and Juerg will also need to answer the question of so what - even if there's an effect, does that necessarily mean that it is bad?

Anyway, thank you Helen!
Her endorsement is far from trivial.
For years, Shark provisioning has been the target of much skepticism from researchers and NGOs alike, and only recently do I detect a slight shift in positions away from outright hostile to at least benevolently intrigued. This is largely due to the realization that baited Shark tourism, whilst certainly presenting its specific challenges (especially when conducted poorly!) is never the less  years ahead of the alternative = Shark fishing. 
And recent research is also showing that whilst local, hitherto unqualified and unquantified effects persist, effects at large temporal and spatial scales are negligible. 

Sharks, it appears, are just different.
Whilst bony Fishes show all the typical negative effects of conditioning that lead to the well known numerous bites by Groupers, Moray Eels all the way to those notorious swarms of pesky Sergeant Majors, Sharks simply don't do that - that is, provided that who feeds them does so responsibly, see the reports about beggar Sharks from, say, Tiger Beach!

Long story short?
Come and see for yourselves - this is still the top season for high numbers!

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