Most research on the Columbia and Snake Rivers in recent years has been directed to downstream migrant salmon (Oncorhynchus spp.) losses at dams. Comparatively little attentions has been given to adult losses. Recently an estimated 378,4000 adult salmon and steelhead (O. mykiss) were unaccounted-for from Bonneville Dam to terminal areas upstream. It is now apparent that some of this loss was due to delayed mortality from wounded by marine mammals. This report reviews the recent literature to define predatory effects of marine mammals on Columbia River salmon.

Return to the River will describe a new ecosystem-based approach to the restoration of salmon and steelhead populations in the Columbia River, once one of the most productive river basins for anadromous salmonids on the west coast of North America. The approach of this work has broad applicability to all recovery efforts throughout the northern hemisphere and general applicability to fisheries and aquatic restoration efforts throughout the world. The Pacific Northwest is now embroiled in a major public policy debate over the management and restoration of Pacific salmon. The outcome of the debate has the potential to affect major segments of the region's economy - river transportation, hydroelectric production, irrigated agriculture, urban growth, commercial and sport fisheries, etc. This debate, centered as it is on the salmon in all the rivers, has created a huge demand for information. The book will be a powerful addition to that debate. A 15 year collaboration by a diverse group of scientists working on the management and recovery of salmon, steelhead trout, and wildlife populations in the Pacific Northwest Includes over 200 figures, with four-color throughout the book Discusses complex issues such as habitat degradation, juvenile survival through the hydrosystem, the role of artificial production, and harvest reform