Perhaps the most surprising thing about self-proclaimed “coral nerd” Zack Rago, is that he grew up in the land-locked US state of Colorado.

Coral reefs around the world are vanishing at an unprecedented rate, as highlighted at the UN Ocean Conference in early June.

As part of an effort to find out why - and to reveal the underwater mystery of coral reefs to the world – Mr Rago took part in the new documentary Chasing Coral, which was screened recently at UN Headquarters in New York.

Shot over three years and involving 650 hours underwater, the film directly speaks to Sustainable Development Goal 14, on preserving life below the water.

Zack told Liz Scaffidi just how he got “hooked” on the sea.

Duration: 5’57”