Brutal, saw the same off the coast. It's all from ocean heatwaves getting worse. The coral gets so stressed it kicks out the algae. Then it turns white and starves. We're losing these reefs fast. Makes you want to scream at the folks in charge.
From my time with rescue groups, putting up shade cloths fast over reefs can cut bleaching by half during heat spikes. We do it from boats when we see hot spots on maps. It's a temporary fix, but it keeps coral alive while we work on climate change. Showing local leaders the proof often gets them to help.