Socio-ecological evaluation of estuary-scale interventions: Case study of reopening the Haringvliet, the Netherlands

Estuaries are considered valuable regions, both socio-economically and ecologically. The gradients in physical characteristics like salinity present result in a high biodiversity, while the provision of many ecosystem services have attracted human settlement and activity. Human activities and estuarine biodiversity are often at odds with each others, leading to socio-ecological trade-offs in decision- and policy-making in which the ecological perspective is generally underrepresented. In this study, we implemented a hydrodynamic model to explore the socio-ecological implications of reopening the closed-off Haringvliet estuary in the Netherlands. Our socio-ecological evaluation considers the trade-off between freshwater availability and ecological diversity. In the case of the Haringvliet, we have shown that partially opening the gates enhances diversity in the system against no — or limited — loss of freshwater availability. All in all, the use of representative (non-monetary) performance indicators for the considered stakeholders allowed us to demonstrate the trade-offs in a clear fashion: the Pareto-front resulting from these performance indicators is an intuitive visualization for decision- and policy-makers as well as the communication to the public.