THIS book has been written in the hope that it will be of service to all those concerned with the problems of water pollution, but who are not specialists in freshwater biology. It is hoped that it will explain to such people as River Board officials, industrial managers and scientists, sewage works managers, civil engineers and fishermen the biological aspects of a problem which has become of nation-wide importance in Britain during recent decades, and which is also causing great concern in many other parts of the world.

By H.B.N. HYNES