A lot of what hobbyists might not realize at first is the fact that coral are colonies of many many tiny organisms each performing their role, like zooxanthellae. These structures are enabled by entire ecosystems of ancillary bacteria on adjacent rock and the water column that maintains the equilibrium. A lot of the acute die off we see is not just warming waters or pollutants harming the coral itself, but primarily the damage to the unseen symbiotes, food sources, and bacterial colonies that are part of the coral's life cycle.

With few exceptions if you have a piece of coral in your tank and it dies, it's your fault. They're immortal otherwise when left undisturbed. Some common pet store coral like pulsing xenia, green star polyps or zooanthids will grow in spite of the worst conditions to the point where they become invasive. All you need is a single polyp and most coral specimens we're familiar with will eventually grow and spread as far as the ecosystem will allow.

Deep deep layered sand beds, areas of stagnant water and high flow water, macroalgae, various gas exchange areas, copepods, amphipods, all of it is part of a holistic picture that is needed for these bacteria to be happy. This process can take years of what I call 'strategic neglect' by not messing with the deeper darker anoxic layers of sand and algae. If those bacteria are happy the coral has no choice but to thrive.

I hope this new effort to get the coral to spawn without subdivision succeeds so that future generations can see the same things we once saw, and the life it creates below.