As in countless other areas, the diversity, frequency, and scale of human activity are having devastating effects on our oceans and their ecosystem. Whilst overfishing, pollution, and climate change are severely damaging to coral reefs around the world, we remain largely ignorant of – or blind to – the importance of healthy underwater life for our own well-being. Terry Hughes is Director of the Australian Research Council (ARC) Centre of Excellence for Coral Reef Studies, headquartered at James Cook University, Australia. His research focuses on the links between the ecology of reefs and their impact on societies and economies. A recent study led by Terry con-firms that reefs are deteriorating at an alarming rate. It identifies that ever more frequent ‘bleaching’ events not only threaten the lives of a huge number of marine species, they also affect the livelihood and food security of more than half a billion people. As a vocal advocate of swift action to prevent existential damage, Terry has shown true leadership in responding to this global challenge. At Falling Walls, he explains how  a combination of strong policies and innovative management strategies that improve the resilience of reefs could reverse the negative trend and help to ensure the long-term vitality of our oceans.