I think it's about the speed of adaptation or even migration, for that matter. If they had thousands or tens of thousands of years to adapt, sure. But it's more in the 50-100 year range.
See my post above 50 years to regenerate is the only data we have and in that time the Bikini Atolls reef is nothing short of a success story given the fact that it was nuked into oblivion less than 100 years ago.
