Mollusken van zandopspuitingen op het Noorderstrand (Scheveningen, Zuid-Holland)

Sand suppletions offer an opportunity to collect material from a large volume of sediment, and therefore also species that occur in small numbers at the sample locality. Over a period of decades, several sand suppletions have been carried out to restore and/or broaden the Noorderstrand beach at Scheveningen (Zuid-Holland, The Netherlands). Each suppletion used sand from an area at a different distance from the coast. In this paper first the 2019 suppletion (with sand from 10 km NW of Scheveningen) is described. This is followed by a summary of earlier suppletions (1975 and 1984, using sand from respectively 20 and 4 km NW of Scheveningen). In a table the mollusc faunas from the suppletions are summarised and compared with the fauna known from the Noorderstrand. This highlights changes in the mollusc fauna from beach to offshore. Moreover, during the five decades of observations by the author also the abundance of several well-known species has changed substantially. The main body of the paper is used to describe a selection of the species found, especially those that are rare, show marked changes or are worth a short description. Most of the described specimens are also depicted.