It's true that oceans cover three-quarters of the Earth's surface, but you wouldn't know it from environmental conferences like Rio, which tend to give short shrift to the deep blue sea. That needs to change. The oceans are incredibly valuable to human life, and they're in great peril, facing threats like pollution, overfishing and climate change. The best way to protect them is to protect them and that made Australia's announcement this month that it will create the world's biggest marine reserve so welcome. Little progress has been made on oceans since 1992. Creating true international marine reserves out of this year's summit would be a long overdue change.