SETTLEMENT OF MACOMA-BALTHICA ON AN INTERTIDAL SANDFLAT IN THE WADDEN SEA

Settlement of Macoma balthica was investigated at 4 stations on an intertidal sandflat in the Wadden Sea. The stations were characterized by differences in sediment structure, tidal elevation and macrobenthic community. The supply of planktonic larvae was compared with the abundance of the early benthic stages and their length-frequency distribution. Most of the settlement occurred at the station with the lowest tidal elevation, characterized by mixed sediments. No limiting effects of adult M. balthica or a dense assemblage of the filter-feeding bivalve Mya arenaria on settlement could be observed. From the temporal course of abundance and the length-frequency distribution of M. balthica at the different stations, it was concluded that the higher part of the flat was colonized by post-larvae. Settlement and subsequent post-larval transport are discussed in detail.