Ecosystem services in estuarine systems: Implications for management

Abstract

Estuaries can be considered strategic locations for human settlement, supporting many anthropogenic activities. These pressures are then added to the naturally occurring ones, resulting in many cases in eutrophication processes and water pollution. The integrity of ecosystems functioning, especially concerning the benefits that attain human well-being, can come easily under pressure if not properly managed. Assuming that human well-being relies on the services provided by well-functioning ecosystems, changes in the ecological functioning of a system can have direct and indirect effects on human welfare. However, many of the interrelations between ecosystem functioning and the provision of services still require quantification in estuarine ecosystems. Therefore, it becomes fundamental to understand the complex and intricate relations in estuarine ecosystems, among ecological, social and economic factors, which are fundamental in designing and implementing management policies. Hence, this chapter tries to explore the interrelations between ecosystem functioning and services provision in estuaries, highlighting that linear relationships between biodiversity and services provision are unlikely to occur. A general overview of several pressures influencing biodiversity, functioning and integrity of estuarine systems, as well as their associated services, is also provided. Furthermore, an illustrative example is provided based on the evaluation of the trade-offs among the services provided by the Mondego Estuary (Portugal). Limitations of the methodologies used to assess estuarine services are discussed. The use of this knowledge on natural resources governance is assumed to be the key to attain the sustainable use of these systems.