Decision support systems for environmental management: A case study on estuary management

In situations to do with the management of natural resources in the public domain there are often many ‘interested and affected parties’. The opinions of how a given resource should be managed are as diverse as the parties themselves. Debates are frequently unproductive. We argue that in these situations the development of a decision support system (DSS) is a constructive way forward towards sound management practices. This approach enables existing knowledge to be integrated into a form that can be used immediately in decision-making. Furthermore, research can be optimally prioritised should greater accuracy or improvement in the initial DSS be required. We illustrate this approach by considering the problem of determining the freshwater requirements of estuaries. The pattern of freshwater flow into an estuary of a river that has been impounded is a management decision. This inflow pattern influences the state of an estuary. This in turn affects the fish that use the estuary. In this illustration we focus on these fish in developing a DSS. The DSS is then applied in a case study of the Krom River in the Eastern Cape.