monitoring STORMvloedkering nieuwPOORT (STORMPOORT)

A flood barrier in the port channel of Nieuwpoort is being implemented in the context of the Coastal Safety Master Plan to protect the city and the hinterland against high water levels during severe storm events. In the MER project, which relates to the new storm surge barrier in the port of Nieuwpoort (construction started in 2018), the implementation of an ecological monitoring programme is included. ILVO should also establish which community of seabed-dwelling animals is found in this area (T0 situation). 

In order to be able to evaluate the ecological effects of the flood barrier, we collect the ecological data in an integrated and targeted manner. Among other things, we take into account the historical approach, the applicable standards and the characteristics of the bottom fauna. We sample the "natural" gradient of the harbour gully and the potential disturbance gradient as a function of distance to the flood barrier location, both along the sea and land side: in the subtidal area, we spread the samples along the channel from the seaward side of the harbor channel to the most landward side of the nature reserve. 

On the basis of this T0 measurement, we noticed that our sampling design gave us a good insight into the seabed-dwelling animals in the intertidal and subtidal habitat in the harbour channel. If we compare this T0 with the previous sampling, we  see that the situation varies considerably from year to year. Higher mud concentrations were observed at the more inland locations, and in the intertidal the tidal gradient had sometimes changed significantly (compared to 2001-2004). However, the intertidal fauna was still dominated by Corophium volutator, Oligochaeta spp. and Hediste diversicolor. The harbour channel was very strongly dominated by Lanice conchilega aggregations, which had a positive effect on biodiversity. Future monitoring will now have to evaluate whether the construction and exploitation of the barrier will change the sedimentation and erosion patterns of the ecosystem.