Samenvatting

Coastal soft-sediment habitats are some of the most valued ecosystems due to their high productivity, sustaining coastal food webs. However, coastal soft-sediment habitats are under pressure due to human activity and sea level rise. To preserve or restore soft-sediment habitats different management strategies are tested, like tidal flat nourishments and groins. The tidal flat of Knuiterhoek located in the Westerschelde (The Netherlands), has eroded till an un-erodible peat layers low in benthic life. Groins were constructed to reduce flow velocities stimulating sedimentation in order to creating a mud layer full of benthic species which serve as food for waders. This research describes the ecological state of this tidal flat just after implementation of the groins. Benthic samples were taken at the area under influence of the groins (project area) and a reference area. At this stage, a lower species richness, abundance and biomass is expected in the project area compared to the reference area just after completion of the groins. Monthly low water bird counts are executed to give insight in changes in habitat use. The research showed that the current ecological state of the project area harbours less benthic macrofauna, has a lower diversity, and lower abundance. This is reflected in less waders foraging in this area. No relations between benthic macrofauna and abiotic parameters and benthic macrofauna and wading birds were found. Long-term monitoring is needed to test if groins can improve the quality of the tidal flat in terms of macrofaunal community and feeding ground for waders.