3 minute read
Salt Marsh Development Marconi Delfzijl
Port of Delfzijl, the Netherlands
At the far northeast coast of the Netherlands, in the United Nations Educational, Scientific and Cultural Organisation (UNESCO) World Heritage-listed Wadden Sea, salt marsh development has been underway since 2014 using sediment from the Port of Delfzijl and the Dollard Estuary. The overarching goal of this project is to improve a variety of natural habitats in the Delfzijl region while simultaneously contributing to the region’s economy through improved spatial quality—particularly with regard to recreation and nature viewing. Flood protection was also a high priority, as was building a connector between the city and the estuary. The salt marsh is a valuable natural area and ecosystem that also mitigates the effects of subsidence and sea level rise. This test site will provide EcoShape, the organization executing the work, with important knowledge about the successful development of natural salt marshes. The project was commissioned by the municipality of Delfzijl, and it is part of the “Marconi Buitendijks” regional development effort, which addresses a number of major issues faced by the municipality: a shrinking population, sea-level rise combined with subsidence, and the poor ecological condition of the Dollard.
Article cover: Applying sandy substrate for the salt marshes. (Photo by Petra Dankers)
Producing Efficiencies
The experiment used different percentages of fine sediments and tested various types of wave-attenuation structures, such as semipermeable barriers. Tests are also being conducted with samphire seed—either sowed or supplied naturally—to stimulate development of the salt marshes. The trial will generate knowledge about how salt marshes can be created, developed, or restored under difficult circumstances.
Using Natural Processes
Only a pioneer-stage salt marsh is being created, together with the right abiotic conditions. From that point forward, natural processes are expected to begin playing a larger role in providing sediment. In due time, the pioneer salt marsh is expected to naturally grow into a mature salt marsh.
Broadening Benefits
The goal is to investigate the best way to restore salt marshes by reusing sediment while enhancing nature. The effort is expected to contribute to water quality and coastal defenses, to the attractiveness of the coast and to the local ecology, while also providing recreational opportunities.
Promoting Collaboration
This project came to fruition as a result of extensive stakeholder participation and government commitment. The key collaborating parties met regularly, which germinated firm commitment in all stakeholders. During the fine-tuning of the plans, updates were shared regularly with stakeholders and promising solutions involving Building with Nature were created. EcoShape was appointed by the municipality of Delfzijl to study saltmarsh development. The Wadden Fund provided financial support for knowledge development relating to salt-marsh construction. The remaining amount will be financed by the EcoShape partners themselves, Wageningen University, Royal HaskoningDHV, Deltares, and Arcadis.
