The following selected quotes come from "The Great Coral Grief" by Iain McCalman, Scientific American, May 2014 (also see The Reef: A Passionate History, by Iain McCalman, Scientific American Books, 2014):
"The next major spate of mass bleaching, between 1997 and 1998, hammered reefs in more than 50 countries, even among the hot-water corals of the Arabian Sea. On the Great Barrier Reef, the bleaching coincided with the warmest sea temperatures ever recorded. In an even worse mass-bleaching event in 2001-2002, the global damage also confirmed a close connection with El Nino weather cycles. Catastrophic global warming had arrived. Peculiarly susceptible to increases in heat and light, corals were now alerting scientists to climatic changes.
Charlie's research told him that during El Nino weather cycles, the surface seawaters in the Great Barrier Reef lagoon, already heated to unusually high levels by greenhouse gas-induced warming, were being pulsed from a mass of ocean water known as the Western Pacific Warm Poll onto the reef's delicate living corals."
The SSTA off the eastern coast of Australia is already anomalously high, and if our current fledgling El Nino gains strength in the coming months, the situation for coral around the world will likely become much worse.