Japan coral protectors race to save reefs from heat 'bomb'

From "heatwave simulators" to ecological bootcamps, scientists and conservationists are trying ways to revive and reinforce the famous coral reefs off Japan's Okinawa, decimated by climate-driven bleaching two summers ago. The subtropical southern Japanese region boasts some of the world's most biodiverse hubs of normally multicoloured coral, but a 2024 marine heatwave -- like elsewhere -- created "graveyards" of ghostly pale or sickly brown organisms.