A very well written book about a very tough subject.Roberts manages to convey the crisis of the oceans that is almost on us with sparkling clarity. He doesn't over complicate the subject, but writes with an urgency and a passion.The chapters are quite gloomy when you consider how bad the seas are. He covers the amount of rubbish, in particular plastics that are in the sea, the steady acidification due to the water absorbing carbon dioxide relentlessly. He covers the scandalous trade in sharks fin, and the devastation that bottom trawling and by catch is having. Grim, very grim.But in all the bad news, there is some hope. More nations are starting to set aside marine reserves, and he details how even a small reserve can have a massive change to a far wider area.A must read for those interested in the state of the largest wilderness on the planet.