The first mass coral bleaching event

1997 CEGreat Barrier Reef

"The summer of 1997-1998 was one of the hottest recorded on the Reef in the 20th century. Mild bleaching began in late January 1998 and intensified by February/March. Extensive aerial surveys of 654 reefs conducted by scientists from the Great Barrier Reef Marine Park Authority (GBRMPA) showed that 74 percent of inshore and 21 percent of offshore reefs had moderate to high levels of bleaching."

"Coral bleaching events", Australian Government: Australian Institute of Marine Science, 2021, https://www.aims.gov.au/docs/research/climate-change/coral-bleaching/bleaching-events.html

Image: Coral bleaching in the Scott Reef (Western Australia), 2016