This edition describes the fishways and fish facilities used around the world to assist the passage of fish over dams and other obstructions to their migration. It focuses on the protection of fish (mainly young fish) from the hazards encountered on their downstream migration, and emphasizes the need for both biologists and engineers to collaborate in the design of fishways. It also discusses the benefits such collaboration can bring to fisheries conservation in the future. The text is intended for fisheries scientists, environmental engineers, conservation managers and ecologists.