Verse Corbula gibba en Acanthocardia paucicostata van de Maasvlakte (2)

In 1999 the author reported for the first time on the occurrence of Corbula gibba and Acanthocardia paucicostata on the Maasvlakte-beach, south of the port entrance of Rotterdam (province of Zuid-Holland, the Netherlands). This report explored the assumption that ballast water from ships had introduced those species in this area. During the year 2000, a big supply of sand was deposited to fight erosion of the latter beach. Since that time the beach finds of both species has dramatically decreased.