#Regram #RG @theeconomist: Bleaching is bad for coral. It happens when heat-stressed polyps, the sessile animals that construct coral reefs, eject the photosynthetic algae which usually reside within them. These algae are symbionts, providing nutrients to their hosts in return for shelter, so losing them is harmful to polyps and often results in their death. The higher temperatures brought about by global warming have therefore led to worries that more frequent episodes of bleaching might result in the loss of entire reefs. For the full article search "Protecting coral reefs" at economist.com Credit: Getty Images/cinoby #coral #reef #coralreef #sea #nature #photography #underwater #climatechange #conservation