Ask a Scientist: Can you explain coral bleaching?

Coral bleaching happens when corals, which seem like rocks, actually become stressed due to rising ocean temperatures. This stress causes them to expel tiny algae called zooxanthellae that provide food and color, leaving corals white and vulnerable. Without these algae, the corals struggle to survive, affecting the entire marine ecosystem, including fish and other marine life that depend on corals. Coral bleaching events are becoming more frequent due to climate change, threatening not just marine life but also the livelihoods of people in regions like the Philippines, where reefs support fishing and tourism.