This is Scientific American's 60-second Science, I'm Annie Sneed.Coral reefs are among the most productive ecosystems in the world.They're also in serious danger―climate change and other threats are killing them off.But researchers have come up with an invention they think could help the reefs: 3-D-printed corals.At the heart of reef ecosystems lies a symbiosis between corals and algae."Corals use light, they're photosynthesizing, so they have microscopic algae inside their tissues.And these use light to generate energy, and that energy is then transferred to the coral animal host.And that animal host, in return, transfers certain by-products to the algae, so they have a symbiosis going on."Daniel Wangpraseurt, a coral reef scientist at the University of Cambridge.This tight-knit bond between algae and corals is what makes reefs so incredibly productive.And because of this symbiosis, corals have evolved sophisticated skeletal and tissue structures for collecting sunlight."So usually, you would have this rapid light attenuation.But through the skeleton, light is pumped and guided into deeper, otherwise shaded areas.So there's a lot of tricks that corals use. And in our work, we copied some of them."
