In this paper, a general framework for the development of Decision Support Systems (DSSs) for the management of coastal lagoons is presented. The proposed DSS structure integrates the information provided by several models accounting for different characteristics of lagoon ecosystems, including biogeochemical, hydrodynamic, ecological and socio-economic aspects. Outputs and indicators provided by the models are used to accomplish the decision task by the application of multicriteria analysis. Model uncertainty and robustness with respect to uncontrollable factors are addressed. Application of the proposed DSS structure to five lagoons located in the Mediterranean area is discussed, with special focus on the management of clam farming in the Sacca di Goro lagoon (Italy). Thanks to its flexibility, the proposed DSS structure is also applicable in decision problems arising in different fields.
In ecosystem-based management (EBM), the use of knowledge is considered an important means to reach sound decisions. However, EBM approaches typically entail complex decision-making processes, involving multiple actors and policy levels. Hence, it is questionable whether and how knowledge can be used as a means to reach sound decisions. This paper explores and evaluates the knowledge governance employed by decision-makers to successfully implement EBM in a complex setting. Conclusions are drawn from a case study based on 30 qualitative interviews, document analysis, and observational participation in Denmark's second largest river restoration project, the Houting project. Our findings suggest that disjointed knowledge governance, knowledge bases acknowledging different values and interests, and the use of experiments were crucial to the success, but at the same time partly restricted the quality, of decision-making in the project. Several suggestions are made on how to compensate for the shortcomings identified.