Cage aquaculture has grown rapidly during the past decades and is presently undergoing swift changes in response to pressures from globalization and an escalating worldwide global demand for aquatic products. There has been a move toward clustering existing cages as well as toward the development and use of more intensive cage-farming systems. In particular, the need for suitable sites has resulted in cage aquaculture accessing and expanding into new untapped open-water culture areas such as lakes, reservoirs, rivers and coastal brackish and marine offshore waters. This report aims to assess the current situation and the future prospects of cage aquaculture around the globe. It is organized into nine chapters including a global overview and eight reviews covering China, Asia (excluding China), northern Europe, the Mediterranean, sub-Saharan Africa, Latin America and the Caribbean, North America and Oceania. The report recognizes the tremendous importance of cage aquaculture today and its key role for the future growth of the aquaculture sector. Each review, by geographic region, informs about the history and origin of cage aquaculture; provides detailed information on the current situation; outlines the major regional issues and challenges; and highlights specific technical, environmental, socio-economic and marketing issues that cage aquaculture faces and/or needs to address in the future. The global overview discusses trends in cage aquaculture based on the most recent and complete data available; summarizes the information on cultured species, culture systems and culture environments; and explores the way forward for cage aquaculture, which offers especially promising options for multitrophic integration of current coastal aquaculture systems as well as expansion and further intensification at increasingly offshore sites.