Shell sand occurrences show areas in the coastal zone with information about shell sand on the seabed, either based on mapping in the field or modeling. Sediments with a calcium carbonate content > 50% and consisting of whole or crushed calcerous shells are described as shell sand or shell gravel.

Distribution of shell sand localities based on modelling. Modelling is based on data collected by NGU, and carried out by NIVA, in the frame of nation program for mapping of biological diversity.

Sampling stations where it is registered minimum 50% content of shell sand or shell gravel in the topmost layer of seabed sediments.