This volume of the ILEC/UNEP guideline book series offers a general introduction to the role of biomanipulation in lake management with emphasis on the control of excessive algal growth in lakes suffering from eutrophication. Contents: 1) Biomanipulation: Bases for a Top-down Control. 2) Objectives of Biomanipulation. 3) Food Web Alterations by Physical Changes: Eutrophication and selective fisheries. 4) Manipulation of Fish Population for Lake Recovery from Eutrophication in the Temperate Region. 5) Management of Eutrophication of Lakes to Enhance fish Production. 6) Manipulationof Aquatic Plants. 7) Modelling and Biomanipulation. 8) Case study: Lake Candia (Northern Italy). 9) Food-chain Manipulation as a Tool in Management of Small Lakes in the Netherlands: The Lake Zwemlust Example. 10) Case studies: Lake Balaton (Hungary). 11) Long Term (1970-1990) Whole Lake Biomanipulation Experience Case Study: Lake Kinneret (Israel). 12) Management by Food Chain Manipulation of Lake Biwa (Japan). 13) Reservoir Management Using Food Chain Manipulation.