Marine biologist and film-maker, Ellen Husain studied the Great Barrier Reef for her Masters degree thirteen years ago. Today she's back to dive with her old supervisor. The picture is grim. So much of the life she remembers has gone, wiped out by the great coral bleaching events caused by rising sea temperatures.

Some who love the reef are in despair, others who once chose to ignore the signs are finally energised, determined to do what they can to slow or even reverse the decline. Ellen meets the people of the reef- tour operators, aboriginal Sea Rangers and coral scientists- to discover if one of the great natural wonders of the world really can be saved.

Producer: Alasdair Cross.