Callum Roberts is Professor of Marine Conservation at the University of Exeter. His research focuses on threats to marine ecosystems and species and on finding the means to protect them. His team provided the scientific underpinning for a new ocean protection target – 30% by 2030 – which is gaining widespread international support. His latest book, Reef Life: An Underwater Memoir (Profile Books), is on the past and future of coral reefs, the world’s richest marine ecosystem. He was chief scientific advisor for the BBC’s Blue Planet II and is chief scientific advisor to BLUE Marine Foundation, and Ambassador for WWF UK.