There is very little documentation on the economic importance of locally available marine sponges (Porifera) in north-western Europe. From Iceland and the Faroe Islands there are records of naming and using the so-called mermaid's glove sponge (Isodictya palmata) especially for cleaning purposes. As late as in the 1940s, school children in the Faroe Islands gathered this sponge and used it to clean the slate.