Danube River (image) Helmholtz Centre for Environmental Research - UFZ Caption Rivers such as the Danube are fascinating ecosystems. They provide important ecosystem functions and services such as recreation, fishing and drinking water for millions of people. Unfortunately, these ecosystems are subject to chemical inputs from adjacent urban areas, agriculture and industry. This leads to a chemical cocktail that adversely affects algae and freshwater animals and carries potential risks for humans. Credit Photo: André Künzelmann, UFZ Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.