Hank49
Contributor
I understand coral bleaching, but have not witnessed this in this area.
The cot infestations seem to be concentrated on healthy, shallow corals - cots 'no.1 tasty bite' are shallow tables.
I have seen the 'trails' of cots from the deep to shallow table corals. They move quickly (surprisingly so!) to the shallows.
Then they work down the reef to eat everything (dessert) on the way down.
At Rocky Beach (Tampuan, Gensan), the corals and marine life is - more or less - as it ought to be. It has the natural predators there that are alleged to eat cots.
But, still they come. Why?
Again, more research into this needs to be undertaken. And, we honestly respect to you for your knowledge.
In the meantime, we place ourselves in the firing line of others who regard cot outbreaks as 'natural'. I accept this.
Respect.
"Healthy coral" is a term that needs to be defined. What may appear healthy could in fact be stressed with limited ability to fend off other stresses and or have a breakdown of its normal defense mechanisms (enzyme production for example). I'm sure there is very little work published on this as there are many species with different tolerance levels etc etc.
A case in point. I grow shrimp...shrimp larvae to be exact, by the millions. If I showed you some baby shrimp in a bowl, I'm sure you would determine that they appear healthy. However, using microscope observations and environmental stress tests such as salinity shock, it can be determined that these baby shrimp are NOT really healthy as compared to other populations of the same age, species etc. This could very well be the case with your table corals.
Not every single coral head was bleached on Boracay's west side in 99 but the cots pretty much consumed everything. Because what killed most, almost certainly stressed the others to some point, allowing the full on invasion to occur.