corals owe a greateal of their magic and their autiful n between organisms. algae live in the polyps' tissue and provide nutrients to the coral in exchange for protection. but this delicate teamwork is under threat from climate change. co2 emissions dissolve in the seas, making waters more acidic and weakening coral skeletons. and that's not all. aslobal temperatures soar, coral reefs suffer through ever more frequent and tense ocean heat waves. extreme mperatures cause the algae to produce harmful chemicals, prompting the coral polyps to kick them out. exthis is “coral bleaching,” where vibrant polyps turn white from heat stress, a process that can eventually prove fatal. and global warming is already driving vast bleaching eves today. sherry: my son is four, as i told you.y never sea coral reef. it really scares me to think of a world without coral reefs. reporter: sherry constantine of the nature conservancy has established a large-scale conservation project in the eastern caribbean. the goal was to protect corals and other ecosystems, while still enabling some tourism and fishing