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

In this underwater photo taken on February 2, 2021, 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. - AFP

HONG KONG (AFP): 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.