David Shukman is Environment and Science correspondent for BBC News. He has reported from the Arctic, the Amazon, Antarctica, and the Galapagos Islands, and more than 90 countries. His latest book, Reporting Live from the End of the World, was published this week. Shukman points to the constant battle between the political imperative of helping fishing communities and meeting market demand, and what the science is saying about what’s happening to the oceans. Fishing with modern techniques – with radar, and these huge nets – is the most destructive activity on earth, he says. ‘Over-fishing is changing the world. We don’t see it, because it’s underwater, but if the same went on, on land – imagine if you had a mile of net dragged over the plains of Africa, catching everything – it just wouldn’t be tolerated. But that’s what’s going on underwater.’