The influence of grain size on the ecological effects of nourishments is important to consider in future nourishment projects. Several studies indicate that the nourished sediment characteristics must be similar as closely as possible to the original sediment to prevent large ecological effects. Another important aspect to consider in predicting the ecological effect of future sand nourishment is the spatial (i.e. ecological zones) and temporal distribution of nourished sand in relation to ecological recovery times. Furthermore, bio-engineers can significantly influence the morphodynamics of a nourishment. In order to predict this stability, the site-specific species composition should therefore be known, including the response of the species composition to a change in physical parameters. Field experiments should be conducted to get real insight into the biogeomorphological interactions which determine the stability of nourishments. During these field experiments it is recommended to monitor the recovery of benthos, the change in physical parameters (and corresponding habitat) and the behaviour of the nourishment itself. Ecologically relevant abiotic parameters within nourishment projects are grain size, layer thickness, oxygen level, geochemical effects, turbidity/SPM (Suspended Particulate Matter), depth and distance to the shore (see Baptist et al. 2008).