Mollusken verzamelen in het benedenrivierengebied: verslag van de excursie van 21 oktober 1999

Results of an inventory made by members of the Dutch Malacological Society in the Nieuwe Menvede and Hollandsch Diep (Rhine delta) are given. Samples were taken with a Van Veen-grab and a mussel-trawlnet in the deeper parts, and a 2 mm mesh-steel handnet in the shallow parts. The bottom of the five locations sampjed (for the location description see table 1) consisted of different mixtures of sand and silt. A list of species found is given in table 2. Results of previous monitoring activities in the same area in 1992 and 1995 are summarised in table 3. Six species were only found during the inventory in 1999.