Sustainable Coastal Defense Concords with Life Below Water

This chapter examines the Netherlands’ challenges in safeguarding its low-lying coastline against rising sea levels and the consequences of coastal defense strategies on marine life, particularly in relation to SDG14. Sea-level rise necessitates increased soft coastal defense strategies, affecting seafloor areas and marine biodiversity through sand extraction and sand nourishments. The use of hard structures for coastal defense contributes to the loss of natural coastal habitats, raising biodiversity concerns. The chapter explores the potential benefits of artificial hard surfaces as marine habitats, emphasising the need for careful design to prevent ecological problems caused by invasive species. Strategies for enhancing biodiversity on human-made hard substrate structures, including material variations, hole drilling, and adaptations, are discussed.
The ecological impact of marine sand extraction is examined, detailing its effects on benthic fauna, sediment characteristics, primary production, and fish and shrimp populations. Solutions proposed include improved design for mining areas, ecosystembased rules for extraction sites, and ecologically enriched extraction areas. The ecosystem effects of marine sand nourishments are also analysed, considering the impact on habitat suitability for various species. The chemical effects of anaerobic sediment and recovery challenges are addressed. Mitigation measures, such as strategic nourishment location and timing, adherence to local morphology, and technical solutions, are suggested. The chapter underscores the importance of education in Nature-based Solutions and
announces the launch of a new BSc programme in Marine Sciences at Wageningen University & Research, integrating social and ecological knowledge to address challenges in seas, oceans, and coastal regions and support SDG14 goals.