This new textbook of marine conservation takes a whole-systems approach, covering major advances in marine ecosystem understanding and providing a guide for marine conservation practice. Its premise is that conservation must be informed by the natural histories of organisms together with the hierarchy of scale-related linkages and ecosystem processes. The reader is first introduced to the broad range of overlapping issues and the conservation mechanisms that have been devised to achieve marine conservation goals. Attention is called to emergent and unexpected phenomena that are rapidly changing coastal and marine systems, for example, climate change, ocean acidification, dead zones, and loss of biodiversity, that challenge the resilience of coastal-ocean systems, and cause problems in governance and human wellbeing. Next follow chapters on marine ecosystem science and the natural histories of marine organisms, which provide a basic background for achieving consideration of conservation goals. Seven international case studies are presented by scientists that are directly involved in coastal and marine conservation in action.  Each study illustrates a central marine conservation issue or issues in the context of its own biogeographic and social setting. Finally, a synthesis chapter looks to the future, encouraging innovative thinking about how coastal and marine conservation can be transformed from traditional, fragmented, protection and management of the past to the ecosystem-based approach, intertwined in a social-ecological system of the future. Overall, this book is an attempt to provide students and conservation practitioners with a framework for thoughtful, critical thinking in order to incite innovation in the 21st century.