Sand mining removes benthic habitat from the seabed and thus it impacts the local ecosystem. It is known that the removal of the substrate will typically impact the local benthic system (and by extension demersal fish) for a few years, but given time, if the particle size distribution of the bed is similar to that before dredging, the ecosystem will rejuvenate (see Cooper, 2013, for a review of this extensive pool of research). But how can the morphology of the bed of a sand mining pit be designed, so that it maximises the recolonisation of benthic and demersal species and perhaps even enables higher productivity than before the dredge?

Research into the recovery of borrow pits excavated for the Maasvlakte2 project, has identified that for that particular situation, landscaping a sand pit to include ridges rather than just a flat bed, promotes the process of recolonisation and can create higher species diversity (De Jong, 2016). Figures 1 and 2 illustrate how the troughs between ridges increase in biomass.