I think the bigger issue is ocean acidification/global warming. I see the point that collection stresses and already stressed system.

(Warning the below paragraph is very pessimistic....)

I personally feel that many (...most) of the reef species aren't going to make it regardless of any conservation actions that are taken at this point. If global warming is anthropological, I don't see the world making changes that will stop it ...and even if all the countries stopped producing greenhouse gasses today, it may be too late anyways since there is likely latency between the cause and effect of global warming (enough carbon already in the atmosphere to continue to do irrevocable damage). And if you are in the camp that thinks global warming is a natural cycle, then there is also really nothing that can be done about it except to let nature take its course. (If you are still denying global warming even exists, then you haven't been watching the news with all the reports of polar icecaps melting in the past couple months.)

I think there is no doubt that our reef aquariums will have a lot less bio diversity (i.e., available livestock) as global warming continues.