Odeh (Conte Anadromous Fish Research Center) presents 13 contributions which explore the technical possibilities of constructing effective fish bypass systems for hydroelectric dams, especially those that are due for relicensing in the context of new regulations. The articles consist of case studies in the effectiveness of such techniques as surface bypass systems, modular inclined screens, hydroacoustic evaluation of fish entrainment patterns, surface collection, surface spill gates, and radio-tagging and radar tracking behavior evaluation strategies. Annotation c. Book News, Inc., Portland, OR (booknews.com).

The focus of this report is technologies for fish passage around hydropower generation facilities and protection against entrainment and turbine mortality. Emphasis is given to Federal Energy Regulatory Commission (FERC)-licensed hydropower projects where fish protection is a subject of controversy and congressional interest due to the Federal Power Act (FPA) and the Electric Consumers Protection Act (ECPA). Thus institutional issues related to FERC-relicensing are also discussed. (Major points of controversy are high-lighted in box 1.1).

Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 0.05%. These environments differ from marine conditions in many ways, the most obvious being the difference in levels of salinity. To survive fresh water, the fish need a range of physiological adaptations. 41.24% of all known species of fish are found in fresh water. A fish is defined as an aquatic or marine animal with vertebrae. All fish have vertebra, except sharks and rays that have cartilage. Cartilage is more flexible than bone, but strong enough to support the body. They usually possess gills in the adult stage and have limbs in the form of fins. Fishes also include the jawless vertebrates such as the lamprey and hagfish; and the shark, ray, chimaera, lungfish, and bony fishes. The bony fishes are the most common. A bony fish has jaws that are well developed, formed by true bone rather than cartilage. Fish are very different in appearance, size and shape. This all depends on the environment that it lives in. Fish are part of the ecosystem entering the flux of energy at different levels of the food chain. This book introduces the ecology of fishes by describing the inter-relationships between fishes and the aquatic habitats they occupy. Sequential reading, chapter by chapter, covers the main themes of ecology, including habitat use, species interactions, migration, feeding, population dynamics and reproduction in relation to the major habitats occupied by fishes.

Many fish species, like salmon and sturgeon, undertake extended migrations as part of their basic behavior, and other fish and invertebrates also undertake short-term or small-scale migrations at certain phases of their life cycles. Activities such as dam construction for water supply and power generation, channelization for navigation and flood control, land drainage and wetland reclamation for agricultural and urban use all have profound impact on the aquatic ecosystem and thus on natural fish populations. Fish passes are often the only way to make it possible for aquatic fauna to pass obstacles that block their up-river journey. Based on knowledge and experience from mainly Europe and North America, this book describes the various types of fish passes, with special emphasis to "close-to-nature" solutions.

Countless millions of fish disappear into water abstractions used for power generation, water supply, irrigation and other uses. As fish stocks become depleted, increasingly, countries around the world see this as a threat to sustainability and are seeking to minimise these losses through legislation and introduction of best practice guidance on fish screening. In March 2011 the Institute of Fisheries Management, in the United Kingdom, organised a two-day conference which attracted international experts from the UK, Europe and the USA. Presenting key papers from the meeting this book will be of interest to academics, students, practitioners and environmental regulators everywhere.