There is world‐wide concern about the effects of bottom‐dredging on benthic communities in soft sediments. In autumn 1988, almost a third of the 50‐km² intertidal system around the island of Griend in the western Dutch Wadden Sea was suction‐dredged for edible cockles Cerastoderma edule and this study assessed subsequent effects. An adjacent area not directly touched by this fishery and an area from which the mussel Mytilus edulis beds were removed, served as reference areas.

Sediment characteristics, together with the total stock size and settlement densities of Cerastoderma, Baltic tellin Macoma balthica and soft‐shelled clam Mya arenaria, were documented during 11 successive autumns before (August–September 1988) and after (August–September 1989–98) the suction‐dredging event in fished and unfished areas. Four other areas in the Dutch Wadden Sea, where changes in densities of …