Ecological Indicators for Coastal and Estuarine Environmental Assessment

Experience demonstrates that none of the available measures for biological and ecological effects of pollution could be considered ideal. The use of a single approach does not seem appropriate due to the complexity inherent in assessing the environmental quality of a system. Rather, this should be evaluated by combining a set of indicators providing complementary information. A decision key was built with the aim of helping managers and authorities of coastal areas in selecting the most suitable ecological indicators, taking into account the type of disturbance and the data available. It includes numerous indicators, namely based on benthic invertebrate fauna information. This is because in the case of coastal and transitional water ecosystems there is a clear preference for benthic communities, which integrate environmental conditions and changes in a very effective way if we want to monitor long-term responses and site-specific impacts. The decision system development was based not only on theoretical approaches, but also on results from its experimental application using data bases corresponding to different geographical areas.Recommendations are provided with regard to the most adequate application of indicators, as for example, in what situations it is not advisable to use some of them, depending on the type of disturbance or the level of taxonomic identification of the organisms. Finally, it is shown, with examples, how to combine indicators to characterise systems ecological quality status.