Our environmental awareness is steadily increasing, albeit very slowly. This process began when we started to address obvious and visible problems. As a result, our streets, beaches, fields and forests became cleaner, industrial emissions decreased, and our chimneys produced less and less air pollution. When we see that there is a problem and there is scope for advocacy, we take action. The oceans, however, are vast and largely inaccessible, and our awareness and understanding of them are correspondingly small. What’s more, they have hardly any advocates or lobby to represent their interests. This is especially remarkable when we consider that the seas crucially influence our climate and are an increasingly important source of food. The Fourth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC) in 2007 and the Stern Review, published in 2006, created an unprecedented level of awareness worldwide of the problems and impacts of climate change. This sparked the idea of producing a similar type of report for the oceans, which cover three-quarters of the Earth’s surface, thus focusing attention on some of the most urgent issues facing us today. To that end, the publishing house mareverlag in Hamburg set up the non-profit company maribus two years ago. This was motivated not by commercial interest but by the desire to focus maximum possible attention on the state of the world’s oceans. Partners were sought to support the pursuit of this objective, and the International Ocean Institute (IOI) and the non-profit Ocean Science and Research Foundation (OSRF) – both founded by Elisabeth Mann Borgese – joined the project. The IOI provides logistical support, its close association with the work of the United Nations playing an important role in this context. The OSRF provides financial backing for the project. The key scientific partner is the Cluster of Excellence “The Future Ocean” – a research group made up of more than 250 scientists investigating climate and ocean change at a number of research institutions in Kiel. Drawing on their outstanding expertise and applying an interdisciplinary approach, more than 40 scientists within the Cluster have authored this first World Ocean Review (WOR). The primary purpose of this first review is not to focus on spectacular new findings or launch high-profile appeals. Rather, with its judicious combination of well-researched and substantive content presented in a clear and accessible style – thanks to the cooperation with mareverlag – the World Ocean Review aims to paint a clear and compelling picture of the complex state of the world’s oceans and underline the urgent need for action. It is up to us to act on this knowledge. We hope that as we look to the future, the World Ocean Review will inspire advocacy to protect and preserve our blue planet.