How to Upscale Nature-Based Solutions for Coastal Management, a Coastbusters Showcase
WODCON XXIII - Dredging is changing - The Practice. The Science. The Business.
T. Mascart, T. Sterckx, J. Fordeyn, M. Huygens
"Coastal zones are under duress of climate change and enhanced anthropogenic pressure. Hard and soft conventional coastal protection measures, such as sea walls, dykes, embankments and beach reclamations, are increasingly required to combat flood risks. Stakeholders are currently challenging them as they are seen unsustainable and carry high installation and structural maintenance costs. Hard structures are designed for current sea levels and are incapable of adapting to increasing flood risks. Conventional soft measures will suffer from storm events and require frequent maintenance. As a consequence, current civil engineering approaches can fall short in efficiently and cost effectively protecting the coast. Nature-based Solutions - facilitating natural processes and enhancing biodiversity - induce more resilient solutions towards a more sustainable coastal zone management. Therefore, the public private Coastbusters consortium deployed reef facilitating infrastructures, to kick-start a sediment stabilising blue mussel (Mytilus edulis) biogenic reef on the foreshore and shoreface of the sandy Belgian coast. In order to initiate such a reef, a commercial aquaculture system was adapted to a different objective than seafood harvesting. Results showed the mussel to form a dense uniform mussel reef on the local seabed under the facilitating structure. From the fundamental knowledge and initial operational insights, an upscaling from living lab towards site implementation has been developed. The proof-of-concept passed to the next phase to demonstrate most appropriate technical, spatial and temporal design of the offshore setup; as modularity and scalability of a coastal protection engineering is crucial. Current field observations not only provides further technical engineering insights; but also reveal essential ecological information on biodiversity enhancement and ecosystem services of the mussel bed setup under different hydrodynamic conditions. From here, an integrated business assessment forms the base to implement this Nature-based Solution as a crucial part of future coastal ecosystem management."
Keywords: Biostabilisation, Resilient Coastal Management, Nature-based Solutions, Ecosystem services, Biodiversity