This indicator shows the temporal trends in the percentage of important sites for marine biodiversity (i.e. those that contributes significantly to the global persistence of biodiversity) that are wholly covered by designed protected areas. This indicator is calculated from data derived from a spatial overlap between digital polygons for protected areas and digital polygons for marine Key Biodiversity Areas. The value of the indicator at a given point in time, based on data on the year of protected area establishment recorded in the World Database on Protected Areas, is then computed by dividing the total number of KBAs wholly covered by protected areas by the total number of KBAs in each country, and multiplying by 100. The metadata is available here.