Taryn Foster believes Australia’s dying coral reefs can still be rescued—if she can speed up efforts to save them. For years, biologists like her have been lending a hand to reefs struggling with rising temperatures and ocean acidity: They’ve collected coral fragments and cut them into pieces to propagate and grow them in nurseries on land; they’ve crossbred species to build in heat-resistance; they’ve experimented with probiotics as a defense against deadly diseases.