Spawning Areas and Abundance of Chinook Salmon 



(Oncorhynchus tshawytscha ) in 



The Columbia River Basin— Past and Present 



By 

 LEONARD A. FULTON, Fishery Biologist 



Bureau of Commercial Fisheries Biological Laboratory 

 Seattle, Washington 98102 



ABSTRACT 



Chinook salmon, the most abundant species of salmon in the Columbia Basin, 

 formerly spawned in nearly all tributaries of the Columbia River and in many areas 

 of the main river. Over the past 60 years, the construction of dams has inundated, 

 impeded, or blocked access to spawning areas. 



Despite these heavy losses, large areas of spawning grounds in the middle and 

 lower portions of the drainage are still available to chinook salmon. Stream im- 

 provements by State and Federal fishery agencies have rehabilitated some areas 

 and have -brought others into production for the first time. 



Important spawning areas are listed and charted in this report according to 

 their past use (before 1965) and present use (1966). Estimates of recent spawning 

 populations in major tributaries and in segments of the main stem are also given. 

 Former and present levels of abundance are listed according to three major runs-- 

 spring, summer, and fall. 



INTRODUCTION 



Chinook salmon ( Oncorhynchus tshawytscha ) 

 formerly spawned in the main stream and in 

 nearly every accessible tributary of the Colum- 

 bia River. 



This species is the most important of the 

 area in total poundage harvested and in value 

 to the commercial and sport fisheries. Com- 

 mercial production reached an alltime high 

 of nearly 19.5 million kg. (kilograms) in 1883 

 (fig. 1). Evidence of impending decline ap- 

 peared as early as 1889, when only 8.2 million 

 kg. were taken. Catches fluctuated between 

 7.7 and 16.8 million kg. in 1890-1920, and 

 gradually declined during 1921-66. The average 

 annual catch during 1962-66 was about 2.3 

 million kg. 



The decline in catch has been attributed 

 to the advance of civilization in the Pacific 

 Northwest. Irrigation, logging, mining, dam 

 construction, and other activities reduced 

 the size and capacity of spawning areas. 

 Resolution of the problems of safely passing 

 migrating salmonids - -particularly of young 

 downstreann migrants- -has not kept pace with 

 dam construction in the Columbia River drain- 

 age. 



The Bureau of Commercial Fisheries began 

 intensive research in 1961 on problems offish 

 passage; the work was closely coordinated 



between State and other Federal agencies. To 

 plan research effectively and to aid manage- 

 ment of the remaining runs of Columbia River 

 chinook salmon, it was necessary to review 

 the many reports available on spawning of 

 salmonids . 



Evermann (1896) reported on the salmon 

 runs in Idaho during the early 1890's. He 

 listed information from local residents and 

 observed the extent of salmon migrations into 

 the upper Snake River and tributaries. 



The Pacific Salmon Investigations of the 

 U.S. Bureau of Fisheries and its successor 

 agency, the Fish and Wildlife Service, sur- 

 veyed the Columbia River Basin from 1934 

 to 1946. The data were published in the Special 

 Scientific Report series of the Service, en- 

 titled "Survey of the Columbia River and its 

 Tributaries" in eight parts by the following 

 authors: Rich (1948); Bryant (1949); Park- 

 hurst, Bryant, and Nielson (1950); Bryant and 

 Parkhurst (1950); Nielson (1950); and Park- 

 hurst (1950a, 1950b, and 1950c). These re- 

 ports contain information on the past spawning 

 areas, size of runs, location and amount of 

 spawning gravel, location of obstructions, and 

 estimates of the capacity of part of the streams 

 to support successful spawning. These reports 

 have been valuable aids in locating spawning 

 areas, so that imiprovements could be made 

 at the nnost desirable locations. 



