Floating among these reef systems, a pair of Scottish scientists discover what might be the key to saving the world's coral reefs.
It is this little piece of coral called the corallith that is unique in that it does not stay in the same place.
A coral larvae settles on a small pebble or a dead piece of coral rubble and then it will encrust it and then grow and grow and grow
and at this point, it will be a mobile coral, so just like this one and it will be tissue and skeleton all around
and it can be moved by the waves and roll around and even when fish come and graze on it, it will move.
And because of that movement, coralliths can help expand the range of a coral reef.
They roll around and they get bigger and bigger and bigger and at some point, they'll be so big that they will stop being mobile.
They'll stop being blown about by the waves and they'll be stable.
At this point, a part of the corallith may die
and then this bare substrate, this bare piece of rock is then perfect for other coral species to come in, land on and then grow.
But coralliths are also important because they're tough
and might be able to withstand the rising temperatures and acidification that is killing the world's coral reefs so quickly.
They might not be so pretty to look at, but they are incredibly resilient to things like changes in the light environment, changes in temperature.
The proof of their toughness shows up in the fossil record.
So these coralliths have been around for many many years and we find them throughout the fossil record
and because they're so resilient to environmental change and so resilient to processes such as coral bleaching.
They're one of the survivors when we see these catastrophic events.
But it is not clear if even the coralliths can withstand the speed of change being brought about by global warming.
But now everything is happening much quicker, so the ocean temperature and the ocean acidification,
everything like that is happening a much much faster events than ever before.
The researchers are now working to see how they respond to events like coral bleaching.
Kevin Enochs, VOA news