There is a growing need for appropriate management of aquatic plants in rivers and canals, lakes and reservoirs, and drainage channels and urban waterways. This management must be based on a sound knowledge of the ecology of freshwater plants, their distribution and the different forms of control available including chemical, physical, biological and biomanipulation. This series of papers from over 20 different countries was generated from the European Weed Research Society symposia on aquatic plant management, this being the ninth. The contributions provide an insight into the complexities involved in managing aquatic systems, discuss control techniques such as biomanipulation using fish and waterfowl and the use of straw, and deal with patterns of regrowth and recovery post-management. Careful consideration is given to the use of chemicals, a practice which has come under scrutiny in recent years. Underpinning the development of such control techniques is a growing body of knowledge relating to the biology and ecology of water plants, including growth responses under different trophic conditions, the impact of pollution, and aspects of photosynthesis. The authorship of the papers represents the collective wisdom of leading scientists and experts from fisheries agencies, river authorities, nature conservation agencies, the agrochemical industry and both governmental and non-governmental organizations.