This polygon shapefile represents World Wildlife Fund (WWF) global marine ecoregions. Ecoregions are defined as relatively large areas of land or water in the world containing a characteristic set of natural communities that share a large majority of their species, dynamics, and environmental conditions. This data set contains the marine ecoregions of the Global 200. Global 200 ecoregions are a collection of the Earth's most outstanding and diverse terrestrial, freshwater, and marine habitats where the Earth's biological wealth is most distinctive and rich, where its loss will be most severely felt, and we must protect if we are to preserve the web of life. This layer is part of the 2014 ESRI Data and Maps collection for ArcGIS 10.2. World Wildlife Fund Marine Ecoregions provides a global view of marine ecoregions defined by the World Wildlife Fund Conservation Science Program 2001, and can be used for geographic display. World Wildlife Fund; ESRI. (2014). World Wildlife Fund Marine Ecoregions, 2001. ESRI. Available at: http://purl.stanford.edu/wr575bc8479