The monitoring of benthic diatoms, macrophytes, macroinvertebrates and fish will be the backbone of future water management in Europe. This book describes and compares the relevant methodologies and tools, based on a large data set covering rivers in most parts of Europe. Seven sections on “Stream and River Typologies”, “Linking Organism Groups”, “Macrophytes and Diatoms”, “Hydromorphology”, “Tools for Assessing European Streams with Macroinvertebrates”, “Intercalibration and Comparison” and “Errors and Uncertainty in Bioassessment Methods” with altogether 36 articles provide scientists and water managers with a unique insight into background and application of state-of-the-art monitoring tools.