Wednesday, September 17, 2014

Oslob - the Data!

Remember the despicable Ecoterrorists? Source.


Read this.
I must say that is a great collection of important data, and kudos to the authors for having invested all that energy and time into collating them. I must equally say that the conclusions are rather lousy.

Correct me if I'm wrong, but this is what I read.
  • All whale sharks come and go.

  • All but a very few are males = the females are likely somewhere else = maybe more pelagic?

  • All but a very few that don’t feed are immature, which in combination with the above is consistent with observations made elsewhere = immature male WS form natural aggregations.

  • Some feed, some don’t = this is voluntary behavior, hence the statements that the results of the present study show a significant difference in residency patterns between provisioned and non-provisioned individuals suggesting behavioural modification is quite possibly only partly correct. The increased residency may simply be an individual trait = some immature WS may be simply more resident than others, and since they choose to stay there anyway, they also choose to feed. 

  • The increase in daily individuals is consistent with observations elsewhere, i.e. here in Fiji  where it is however not an indicator for increased residency. Methinks that eventually, the number of daily WS will stabilize as over a determined density, some WS will start feeling uncomfortable and/or start missing out on handouts and leave. And I equally speculate that they will leave once they become adult, see below.

  • Those WS that reside longer are smaller (= younger?) and

  • Those that feed stay longer = possibly conditioning - or may younger WS simply be more resident anyway?

  • I cannot see any evidence that provisioned WS are faring worse than the control group = no difference in propeller strikes. The difference to the WS in Holbox may be due to the fact that the Holbox ones may be more pelagic and thus encounter less vessels? 
Long story short? 
So far, this paper alone does not constitute compelling evidence that provisioning those Sharks is a bad thing. The provisioned Sharks are not being described as having more propeller scars, and there are no statements that they may be otherwise physically impaired.

Leaves the increased residency.
Should it become 100% AND permanent, then those Sharks would be likely prevented from mating = the feeding would have a negative effect at the ecosystem level.
But this is way to early to make that assumption. In fact, methinks that like any other Sharks, those WS will eventually leave what appears to be their immature aggregation site once they become adults, migrate normally and eventually join the females at their mating sites. The latter has certainly been shown for all other places where Sharks are being provisioned. If so, it will be then very interesting to see whether any Sharks will return after the mating season!
But so far, we simply don't know - meaning that we'll have to wait before making any ultimate pronouncements!

The provisioning?
Per se, it appears to have little to no effect - but of course the poor interaction protocols where too many people are being poorly monitored and where, maybe, the total interaction time is too long, see here, need to be reformed. But again, that's a consequence of the protocols, not the feeding - re-read this!
Not easy - but certainly not impossible either!

Or am I missing something here?

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