Coral Reefs: Crisis and Hope

Coral reefs cover less than 0.2% of the ocean but host 30% of all marine life.

Here's what's killing them. When water heats up just 0.5 degrees above normal,

corals kick out their zooxanthellae, the tiny algae living inside them that provide up to 95%

of their food through photosynthesis. It's like evicting your personal chef during a famine.

The coral turns bone white, starves, and dies within weeks.

Ocean acidification makes it worse by dissolving their calcium skeletons like dropping chalk

in vinegar. The Great Barrier Reef has lost half its coral in 27 years.

But there's hope. Some corals in the Persian Gulf survive 35 degree waters. Scientists are studying