El Niño’s warm water devastates coral reefs in Pacific ocean

Researchers visited Christmas Island, the world’s largest coral atoll, to measure the effects of El Nino. Eighty percent of the coral is dead, they report. Corals are communities of animals that have tiny photosynthetic algae living inside them in a mutually beneficial relationship. Corals are very temperature-sensitive. A rise of just 1-1.5 degrees Celsius can stress coral enough to evict the algae until the heat stress subsides.