Hong Kong's fragile coral reefs boosted by 3D printing

A marine scientist diver from University of Hong Kong's (HKU) School of Biological Sciences swims above a cuttlefish (centre R) protecting her eggs inside an artificial 3D-printed clay seabed, designed to work as an artificial bed for corals, in the waters of Hoi Ha Wan marine park in Hong Kong.

In jade waters off Hong Kong's eastern shoreline, scientists are thrilled to spot a cuttlefish protecting her eggs inside an artificial, 3D-printed clay seabed helping to restore the city's fragile coral reefs. On postcards and in the popular imagination Hong Kong is a byword for urban density, a thicket of towering skyscrapers crammed along the harbour or clinging to the vertiginous hillsides above. Yet it is circled by a surprising array of nature and the small number of coral reefs are some of the city's best-kept secrets. Around 84 species of coral are found in Hong Kong's waters, scientists say, more diverse than those found in the Caribbean Sea.