Marine biologists Ross Jones and Ove Hoegh-Guldberg followed the 1998 bleaching event at the One Tree Island Research Station. Hoegh-Guldberg thinks they are getting close to pinpointing the precise mechanism of bleaching. And it's all got to do with how the zooxanthellae process light. It's almost as efficient as higher plants which are the ultimate in this. But this efficiency comes at a cost.
Corals push their biochemical pathways to the limit.
These days, underwater science is getting quite sophisticated. That's actually the energy that ultimately ends up in sugars and the photosynthetic products. Now that turns out to be very interesting because one of the first impacts of thermal bleaching on corals is that the efficiency with which they process photons drops off at a phenomenal rate. But the process is temperature dependent. If the water gets much above 30 degrees, the algae seem to lose their capacity to convert this trapped energy.