It will only take a few years of back to back bleaching events, and as evidenced with the reefs in the southern Caribbean, you get stressed out corals that are susceptible to infection, and you can lose an entire reef in the matter of months. All the wild collection in the world can't put in dent in the amount that can and most likely will be lost in the coming decades due to global warming/bleaching/disease. Not that I'm supporting going out and raping and pillaging all the corals, but I do think it is imperative that some sort of live genetic bank of corals is set up to document the species and sub-species currently kept in captivity for future assurances of species survival.
I would guess that the water quality in the Southern Caribbean is pretty close to pristine too. Thus making this news that much more of a disheartening message. My exprience diving in Fiji (only a couple dives in one area) is that the reefs are nice, but not pristine, and clearly were much nicer in years past. The dive operators attributed the decline to recent crown of thorns and cyclone events. This was also the case in the Cook Islands, same story. I am going to guess that the bleaching events of '98 and '02 probably had an effect too... But to anyone that is only familiar with Florida Keys or touristy Caribbean reefs, then yes these Pacific reefs look pretty damn nice. However, in the Solomon Islands, I would happily have to say that the reefs there were pristine and very healthy.
I have given some thought to the "well if the waters warm up, why don't the corals just move north (or south in the southern hemisphere)?" question. I am going to hypothesize that just because the waters are warming in the summer, doesn't necessarily mean that the temps will be hospitible in the winter. Further more, once you get off of the existing reefs, it isn't long before you move into bottom habitat that probably isn't ripe for the development of new reefs. But I do think it would be interesting to study some of the freak North/South reefs like Lord Howe Island, Bermuda, and the Flower Garden Banks off Texas to see whether those reefs are being affected by bleaching, or whether they are actually doing better.
Sure, corals have adapated to changing water chemistry and temperatures over the eons, but can they adapt to even a 5 degree F increase over 100 years? I doubt it. If there are some massive corals like Montastrea that are over 800 years old, then adaptation is a moot point for them (although the adpatation of their zooxanthellae is a real possibility). And it is these giants are the important reef builders/ habitat providers. Acroporids would likely be the best candidates for adaptation due to their fast growth. There is definately a lot of room for investigation in this area, and I doubt that there is a lot of funding being provided for it.
If the reefs go, then it will be a domino effect that will effect the entire planet. The reefs will likely be the first major ecosystem to go worldwide, and if they are going to go , they will go fast, and then any tropical island nation of people is good as f***ed without these fisheries to sustain them. I doubt we have the ability to exactly calculate jsut how far reaching the effects will be worldwide, but I doubt that they will be very good. I'm not trying to be doomsayer, but I'm just pulling my head of the sand and looking at the facts and the outcome doesn't look to good.
Go see the reefs now if you want to see them as nice as they ever will be. In the meantime let's keep our chin's up and stay focused. Let's keep up the aquaculture, and collecting responsibly for those species that we haven't yet figured out how to aquaculture.
