Deep sea reef expedition offers rare glimpse of marine ecosystems – video

The Deep Down Under investigation of Osprey Reef in the Coral Sea, north-east of Queensland, studies marine life to a depth of 787 metres. Footage from the expedition includes silvertip sharks 350 metres below the surface. One of the marine species uncovered by researchers is a variety of sponge new to science that uses silicon to create its form. 'They're made of glass,' the lead author of the expedition's study, Dr Rob Beaman, says. 'If you look at them through a microscope " [there's] living flesh embedded with these little glass spicules'