I have tried to explain this here, but they don't want to hear it, if it does not put climate change as the #1 reason. My daughter is in coral research, N:P is the poison, heat increases it's potency, without the N:P the heat alone does not bleach the coral. We see coral bleaching in all areas where agricultural sits above the wetlands and the runoff runs into the wetlands and then over the reefs. It's funny how Australia's wetlands and Florida's everglades are so similar, and sitting right above both of them is large sugar farms using tons of fertilizer pumping tons of N:P into the wetlands and then out and over the reef.