"Coral reefs are a microcosm of our planet: wondrously diverse, deeply interconnected, and critically imperiled. They sustain entire ecosystems and protect vulnerable coasts. But corals across the planet are in the middle of an unprecedented die-off, beset by warming oceans, pollution, human damage, and their own devastating pandemic. Even under stress, they are out-of-this world gorgeous, sending out warning flares in fluorescent bursts of yellow,...