Assessment and Comparison of Commonly Used Eutrophication Indexes

Abstract

Eutrophication is a phenomenon that causes the degradation of the water quality which results in negative impacts on living and non-living environment of the water body. Therefore, monitoring, evaluation and classification of water quality is the utmost importance for policy makers and regional institutions/organizations in order to be able to assess the quality and sustainability of water bodies and take timely and relevant measures for its rehabilitation when and where required. Regional conventions such as the Helsinki Convention, Oslo-Paris Convention, Barcelona Convention – Programme for the Assessment and Control of Marine Pollution in the Mediterranean, Strategic Action Programme and Integrated Coastal Zone Management as well as legislative instruments such as the Water Framework Directive, Marine Strategy Framework Directive, Urban Wastewater Treatment Directive and Nitrate Directive in Europe; the Clean Water Act, Water Quality Act, National Environmental Policy and Coastal Zone Management Act issued by the United State Environmental Protection Agency in the United States, addressed the importance of eutrophication monitoring. The eutrophication indexes have been developed in line with regional requirements by using specific data sets of state variables and parameters, representative of a location. In this study, we reviewed the commonly used eutrophication indexes worldwide within the areas applied, parameters, methods and classification scales and presented trophic level equivalence between the indexes. We expected to provide the researchers with comprehensive approaches related to eutrophication indexes while evaluating the trophic status of a water body.