The dataset contains the polygons of surrounding areas of grasslands or prairies of marine phanerogams. Bounding areas are zones in the sea near the shoreline where there is known to be grassland.

The dataset contains the coastline of Catalonia characterized for reporting the reliability of the grasslands in the 'Herbassars or prairies of marine phanerogams' dataset. If there is not known information in a section the line is not displayed. The degrees of reliability in which the line is classified are: Very high; High; Medium; Low.

The dataset contains the polygons of known grasslands along the coast of Catalonia. The polygons have associated an attribute that indicates the type of community based on the species of phanerogams present: Posidonia oceanica; Cymodocea nodosa; Zostera noltii; Cymodocea nodosa i Caulerpa prolifera; Cymodocea nodosa, Zonstera noltii i Ruppia cirrhosa.