Coral reefs are the most biodiverse ecosystem on the planet and the lifeblood of a thriving ocean. Yet without action, 90 percent of coral reefs could die by 2050. Fortunately, reef guardian Theresa Fyffe has a plan. Learn how her team at the Great Barrier Reef Foundation is rolling out a targeted approach to large-scale coral restoration by combining breakthrough science with Indigenous wisdom and global collaboration — giving coral reefs (and our planet) a fighting chance. (This ambitious idea is part of The Audacious Project, TED's initiative to inspire and fund global change.)