Several species of glass sponge are found in relatively high colony densities in deep cold (<2°C) waters. One of the most common species of glass sponge in the Norwegian Sea is Caulophacus arcticus, which is generally found on hard bottom on the lower part of the continental slope.
The demospongian species Chondrocladia gigantea and Cladorhiza sp. are found in cold Arctic waters in the Nordic Seas, normally in low densities. However, north of Iceland, they occur in greater abundances.