Volume 4 presents the results of the first global indicator-based, comparative assessment of large marine ecosystems, prepared in partnership with IOC-UNESCO (lead), the US National Oceanic and Atmospheric Administration (NOAA), the University of West Indies (Cave Hill) Centre for Resource Management and Environmental Studies (CERMES), the Center for Marine Assessment and Planning (CMAP) University of California Santa Barbara, Dalhousie University, the Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP), the International Geosphere-Biosphere Programme (IGBP), the Tokyo University of Agriculture and Technology (TUAT), the University of British Columbia Sea Around Us (UBC SAU), the UNEP World Conservation Monitoring Centre (UNEP WCMC), and a number of independent experts. An assessment of the Western Pacific Warm Pool, based on a sub-set of the indicators, is included.