Barney Harwood and Gemma Hunt discover the world of Australia's Barrier Reef. Coral reefs are the cities of the reef – thriving, busy places where our fishy friends live, eat and hang out. And just like in any other communities, they have to work too. Everyone has a job to do – from ocean public transport to cleaning and building... or even waste disposal. Time to polish that résumé – get ready for coral career time!