The fluctuations in densities or biomass of a number of invading and native polychaete and mollusc species in the S outhwest N etherlands were compared over a period of 20 years. For recent invaders a lag phase of 7–10 years occurred after their first appearance, followed by an exponential increase in abundance or biomass for 2–3 years. High numbers and biomass then continued for about 5 years, followed by a strong decline. Th...

To study the possible environmental impact of hydraulic cockle‐dredging on macrobenthic communities and the environment, a fishing experiment was executed on a tidal mudflat in the Oosterschelde (SW Netherlands) according to a BACI (before‐after‐control‐impact) design. Following the characterization of the initial situation, a part of the mudflat was commercially fished, after which dredged and undredged areas were compared on...