Previously on the Bayblab:
I was informed that sunscreen was bad for coral reefs. However no explanation was given.
Very recently a lucky group of researchers in Italy who presumably get sunburned and get to snorkel around coral reefs have figured out at least part of the story.
It appears that exposure to common active ingredients in sunscreen activate latent lytic viruses within the symbiotic algae of coral reefs inducing the observed coral bleaching.
Heres the open access paper.
Embarrassingly I ran across this on digg.com Not surprisingly the comments suck there, as usual. The best being, " Why does science hate us?"