What causes coral bleaching at the Great Barrier Reef?

Topics Covered: Conservation related issues. What causes coral bleaching at the Great Barrier Reef? What to study? For Prelims:Coral bleaching- causes, effects, concerns and measures to prevent. For Mains: Bleaching in Great Barrier Reef, measures to prevent bleach. Context: Scientists have warned that the Great Barrier Reef will face a critical period of heat stress …