Coral Bleaching

ocean · climate change · coral reefs · ecosystems

Corals lose color. Corals turn ghostly white when they get stressed and kick out the tiny algae living inside them. Those algae give corals their brilliant colors and also feed them by making food from sunlight.

Warming water is the problem. The biggest reason corals bleach is that ocean temperatures are rising because of climate change. Even a few degrees of extra heat stresses corals so much they abandon their algae helpers.

Bleached corals struggle. When a coral bleaches, it loses its food source and becomes weak and sick. Without the algae feeding them, many bleached corals eventually starve to death.

Reefs matter hugely. Coral reefs support millions of sea creatures and protect coastlines from storms. When big bleaching events kill whole reefs, fish lose their homes and people who depend on reefs for food and tourism suffer.

Ocean acid is another threat. The oceans are becoming more acidic because they absorb carbon dioxide from the air, and this extra acid also harms coral health and makes it harder for them to survive.