The Endangered Species Act (ESA) is a far-reaching law that has sparked intense controversies over the use of public lands, the rights of property owners, and economic versus environmental benefits. In this volume a distinguished committee focuses on the science underlying the ESA and offers recommendations for making the act more effective. The committee provides an overview of what scientists know about extinctionâ€"and what this understanding means to implementation of the ESA. Habitatâ€"its destruction, conservation, and fundamental importance to the ESAâ€"is explored in detail. The book analyzes: Concepts of speciesâ€"how the term "species" arose and how it has been interpreted for purposes of the ESA. Conflicts between species when individual species are identified for protection, including several case studies. Assessment of extinction risk and decisions under the ESAâ€"how these decisions can be made more effectively. The book concludes with a look beyond the Endangered Species Act and suggests additional means of biological conservation and ways to reduce conflicts. It will be useful to policymakers, regulators, scientists, natural-resource managers, industry and environmental organizations, and those interested in biological conservation.

The Hiram M. Chittenden Locks, known locally as the Ballard Locks, are an integral part of Seattle's extensive waterways. The busiest facility of their kind in America, the Ballard Locks form the heart of the channel connecting Puget Sound's saltwater with Seattle's main freshwater lakes. When completed in 1917, the locks were second only in size to the Panama Canal and the first of their kind on the West Coast. They function primarily to maintain the lakes" levels and allow the movement of vessels between them and the sea. The Ballard Locks are among Seattle's top tourist attractions; more than one million people visit annually. They watch salmon and other fish migrate through the fish ladder, visit the botanical gardens, and watch the nonstop parade of ships--from working vessels to pleasure craft--as they rise and fall in the locks.