INTRODUCTION 



The following report is the result of a study made jointly by the 

 Fish and Wildlife Service and the War Department, Corps of Engineers 

 to determine (l) the mortality of adult fish above and below Bonneville 

 Dam, and (2) the extent of visible injuries to adxilt fall chinook salmon 

 at Big White Salmon Hatchery above the dam and at Bonneville Hatchery 

 just below the dam, 



Bonneville Dam and related facilities were constructed by the Corps 

 of Engineers, for improvement of navigation and the development of 

 hydroelectric power. It was built across the Columbia River about 140 

 miles upstream from its mouth and about 40 miles east of the City of 

 Portland. 



On the following pages will be found the summary and conclusions 

 of the investigators on the studies conducted. A description of the 

 problem, the methods of investigation, and the data collected during 

 the study are presented in Sections I and II, Section III is an appendix 

 showing tables of pertinent data and maps illustrating the areas and ori- 

 enting the studies in the preceding sections. 



The investigation was under the general supervision of J, T. Barnaby, 

 In Charge, North Pacific Fishery Investigations, Fish and Wildlife Servicei 

 Harry A, Hanson of the Service directed the work in the field. He was 

 assisted by Paul D, Zimmer, Russell L, Bagwell, Eugene M. Maltzeff and 

 Curtis P. Jensen of the Service, and Ivan J. Donaldson of the Corps of 

 Engineers. Other members of the Corps of Engineers and local residents 

 contributed information and services which measurably facilitate.d the 

 progress of the investigation. Personnel of the Columbia River Packers 

 Association stationed at Ellsworth cannery graciously made available their 

 dock and moorage facilities for operations at that point. 



With the building of Bonneville Dam several problems arose concerning 

 the runs of anadromous fishes in the Columbia River and its tributaries. 

 The first problem was to provide safe passage for adult fish on their 

 journejr upstream to spawn. This was accomplished by building an elaborate 

 collection system, together vrith fish ladders and fish locks which enable 

 the fish to swim up around the dam or to be "looked" through the locks. 

 Secondly, and of equal importance, was the installation of fish screens 

 and bypass channels to facilitate the downstream movement of the seaward 

 mi grants . 



Since the earliest mention of plans for a dam at Bonneville, there 

 has been considerable speculation about its effect on salmon, steelhead, 

 and other fish. Soon after completion of the dam and its component parts, 

 many commercial fishermen and anglers reported seeing dead salmon and 



