nu skaisti, eju sportot
HOW GOOD IS GOOD ? EUROPEAN APPROACHES TO LAKE ECOLOGICAL ASSESSMENT

One of the great challenges in ecosystem-based water management is to establish a comprehensive set of ecological assessment tools and related objectives. According to the European Water Framework Directive (WFD), all member states should have developed and harmonized ecological assessment systems before 2006 with the overall aim of reaching at least “good” status by 2015. Nevertheless, the development of indicators and setting of class boundaries has turned out to be one of the most critical and difficult tasks of the WFD implementation and is not completed yet.
The best progress achieved for phytoplankton – most of the EU countries (19) have developed lake assessment systems based on phytoplankton biomass and composition metrics. 12 countries have finalised lake assessment systems using macrophyte metrics, 8 countries - benthic fauna indicators, while development of fish-based lake assessment methods has been considerably slower.
Hence, the stepwise progression of this contribution includes: 1) presentation of the main principles of European lake assessment; 2) overview of the metrics and indices used in the lake assessment for different quality elements; 3) principles and methodologies applied in setting “good” status boundaries; 4) some problems indentified in implementing the WFD.