These explosives kill fish and shatter the coral skeletons resulting in depletion.

The sediments contain an element, barium, that is incorporated into coral skeletons as they grow.

What's left behind by the sea star is the leftover coral skeleton.

Some such as Lithophaga are parasites that weaken the coral skeleton.

The coral skeleton is ground into small particles, but cannot be digested.

The calcium carbonate, from which coral skeletons are made is just over 60% carbon dioxide.

They are often very slow growing, and may occur on rock, coral skeletons, shells, other algae or seagrasses.

So the reef turns whiter as the coral skeletons become visible.

The distinction between the two suborders was based on the structure of the coral skeletons.