This volume provides a comprehensive overview of environmental aspects of the Sava River, which is the greatest tributary to the Danube River and the major drainage river system of South Eastern Europe. Hydroelectric power plants, river traffic, intensive agricultural activities, heavy industry and floods have considerable influence on the environment and biota in the basin. Summarizing the results that were gathered in the course of EU, bilateral and national projects, the book highlights the most important stressors and helps readers to better understand the impact of anthropogenic activities on the function of river basins. Topics include: transboundary water cooperation between the riparian countries; climate change projection, including its impact on flood hazards; evaluation of anthropogenic pollution sources; pollution of sediments, metal bioavailability and ecotoxicological and microbiological characterization of the river. The biological part also addresses quality aspects related to wildlife in river aquatic ecosystems (algae, macrophytes, zooplankton, macroinvertebrates and fish) and riparian ecosystems (amphibians, reptiles, birds and mammals). The general state of biodiversity and pressures caused by invasive aquatic species are also discussed.