Effect of encrusting corals on live rock's surface area

So I been pondering lately. Various encrusting corals, as they cover the live rock, do they effectively reduce the surface area of the live rock that hosts denitrifying bacteria in our tanks?

In theory, if all of your live rock was covered by encrusting green cap, does it mean you effectively have no live rock left? I realize coral itself has some bacteria on it's surface, but since that surface does not have cracks and deep crevices like live rock, the surface area has to be greatly reduced. Plus there would be no anaerobic areas.

Hmm...

 

Isn't the bacteria also "in" the rock too, not just in the surface?

Another thought that came to mind is that you only light one side of the rock, so in theory you'll still have 50% that can't grow most corals due to no light and or contact with sand/other rocks.

 

I doubt it's a significant loss of surface area and I would be willing to guess, that like humans and other animals, coral are covered in bacteria as well. Live rock is really porous and encrusting coral doesn't create a rubber sealant, so to speak. Water is still seeping into cavities, be it from underneath the coral or through another opening.

 

You forgot to say, it's like a sponge you can't squeeze.