Aggregate indicators in coastal policy making: potentials of the Trophic Index TRIX for sustainable considerations of eutrophication

Sustainable development is one of the key concepts in coastal management, and indicators are widely considered to be suitable communicative and easy-to-use tools in providing environmental information for management. However, the applicability of aggregate indicators still needs examination and discussion. In this study the Trophic Index TRIX was applied in the northern Baltic Sea, an environment different from where it has been elaborated (the NW Adriatic Sea). The results of TRIX were in accordance with the general classification scheme of Finnish coastal waters. The results indicate that TRIX, like other aggregate indicators, is site dependent and needs to be calibrated to the conditions of the area in question. TRIX can provide useful information for decision-making, but needs to be linked with other sources of information to draw a broader picture that is needed in adaptive management of coastal waters. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment.