The waters around the remote inhabited island of Tristan da Cunha in the South Atlantic are set to become the world's fourth-largest marine sanctuary.
The big picture: Currently less than 3% of the world's ocean area is fully protected from human activity, compared to 13% of the world's much smaller land mass. With the oceans coming under increasing pressure from fishing, pollution and climate change, expanding true marine sanctuaries is more important than ever.
