Coral Reefs Provide the best shoreline protection-why even consider a sea wall which only protect the land behind it?

Your idea is right but for the problem of coral bleaching which the scientists have decided NOT to solve because it gives them endless access to grant money for as long as this problem continues to exist. The real solution is very easy and economical: take care of the zoxanthellae then the corals will not bleach and how do you do that, simply by adding Iron chelate to the water which will make all zooxanthellae clades resistant to high temperatures. A scientific demonstration of this could be conclusively done for a few thousand dollars and in a very short amount of time, but that is of course not helping all those who want to bleed the system for as long as they can. I have done this demonstration already 3 times with giant clams and soft corals, but I am not a scientist so it's very easy for them to dismiss my findings. In the meantime coral reefs will continue to bleach everywhere.

Given 80% of reefs in Caribbean are "dead" they have ceased to provide the protection required. Indeed warmer more acidic oceans mean poorer coral recruitment and growth. So the question really is what are we going to do about it?