Imagine cooling down 2,300 km of Barrier Reef along the Australian coast using renewable energy. Mind-blowing, right? Dr Brian Von Herzen has such a plan. It's part of a bigger picture that he calls Marine Permaculture - using nature to restore habitat in the oceans. It is a project he has been working towards for over a decade including demonstrations off Hawaii.  Dr Karl discussed Dr Brian's vision in Queensland earlier this year. The audio quality varies as it was recorded on location.