Pioneered in the late 1980s, the concept of macroecology—a framework for studying ecological communities with a focus on patterns and processes—revolutionized the field of ecology. Although this approach has been applied mainly to terrestrial ecosystems, there is increasing interest in quantifying macroecological patterns in the sea and understanding the processes that generate them. Taking stock of the current work in the field and advocating a research agenda for the decades ahead, this book draws together insights and approaches from a diverse group of scientists to show how marine ecology can benefit from the adoption of macroecological approaches. Divided into three parts, the book first provides an overview of marine diversity patterns and offers case studies of specific habitats and taxonomic groups. In the second part, chapters focus on process-based explanations for marine ecological patterns. The third part presents new approaches to understanding processes driving the macroecolgical patterns in the sea.