Sustaining roughly a quarter of all Earth’s marine life is a complex ecosystem characterized by the rigid skeletons of lifeforms we know as hard corals. Corals belong to the phylum Cnidaria, within which there are hundreds of different species, both soft corals and hard corals, that vary in shape, size, biofluorescence, and color. Scleractinia, or hard corals, are composed of calcium carbonate and form most of the coral reef ecosystems as their polyps (singular coral units) cluster in groups.

Lying just below the surface of tropical oceans are some of the largest coral reef ecosystems in the world. Globally, these coral reef systems are valued at up to 2.7 trillion USD annually. Over 500 million people directly depend on coral reef ecosystems for their livelihoods.

Anthropogenic impact has played a huge role in the mass degradation of coral reefs, with leading causes being water pollution, sedimentation, dynamite/poison fishing, irresponsible tourism and climate change.

"From a scientific point of view, the problem is that we have probably missed the opportunity to understand how pristine coral reefs function. We know that coral reefs persisted, in fact thrived, for tens of millions of years. But whether modern reefs—that are degraded to various degrees and have probably lost a lot of their biological and functional diversity and redundancy—can survive in the coming decades of dramatic climate change remains elusive." - Gergely Torda in Pacific Standard