Sea-level rise, marine storms and the resilience of Mediterranean coastal wetlands: lessons learned from the Ebro Delta

Understanding the effects of sea-level rise (SLR) and marine storms on Mediterranean coastal wetlands is crucial to developing adequate climate change adaptation pathways. Because the majority of these systems are in deltaic areas, integrated river basin management (water and sediment discharge) is a must in the design of such pathways. Rising sea levels will tend to gradually flood coastal lagoons and marshes unless there is enough sediment supplied to compensate for the increasing deficit. Although the relationship between climate change and Mediterranean coastal storms is weak or non-existent, their impacts are expected to grow in the context of SLR and coastal squeezing. For example, the most affected Ebro Delta coastal stretches during the Gloria storm (January 2020), one of the most intense ever recorded in the Mediterranean, were those where the beach was narrower and weaker. Hard engineering solutions, such as the construction of dykes, as a protection measure against marine storms are not sustainable under scenarios of climate change and energy scarcity. A management approach based on soft engineering coastal defences and nature-based solutions is the most cost-effective and sustainable in the long run. The adequacy of implementing this kind of solution along the Mediterranean coast is discussed.