What Is Coral Bleaching And Why Does It Happen?

Coral bleaching is when corals release the algae that live in their tissues causing the coral to turn white. This isn’t just a color change, it’s a sign of stress. These algae, called zooxanthellae, give corals up to 90% of their energy from photosynthesis. Without these algae, the corals lose their primary food and energy source, and they risk starving and dying.