Oregon and Washington Department of Fish- 

 eries (1968). 



C. E. Stockiey (1966), commenting on the 

 near disappearance of the chum salmon runs 

 along the coast of North America, reported 

 that some of the many causes are: (1) whole- 

 sale destruction of spawning areas through 

 clear-cut logging, which resulted in compaction 

 of the gravel of spawning riffles by silt; (2) 

 construction of dams, such as Bonneville, which 

 flood lower areas of streams chai'acteristically 

 used by this species; (3) predation by sharks 

 in the open seas; and (4) in general, disturb- 

 ance of its former ecological niche, which has 

 probably increased predation or competition 

 or both. Another important cause for the de- 

 crease in chum salmon may weH be that the 

 larger numbers of yearling coho salmon in 

 the lower Columbia River prey more heavily 

 on chum salmon fry before they move out to sea. 



Future of Chum Salmon Runs 



Runs of chum salmon in the Columbia River 

 have been low in the past several years. The 

 3.8 million kg. caught in 1928 is equivalent 

 to 8.50,000 fish (based on a 4.5-kg. average 

 weight per fish). By comparison only 560 

 chum salmon were caught in the fishery in 1965; 

 497 ascended Bonneville Dam, and the fewest 

 fish in many years were on the principal 

 spawning grounds. 



The type of spawning area used by this 

 species has been the least aflfected by the con- 

 struction of dams as far as passage is con- 

 cerned, but perhaps the more subtle changes 

 in the lower portions of streams such as sil- 

 tation and compaction of gravel have had a 

 more serious effect on the survival of eggs 

 and fry. Chum salmon seem unable to adapt 

 to new spawning areas upstream, as sockeye, 

 Chinook, and coho salmon appear to have done. 



In summary, this species has failed to re- 

 spond to almost complete closure of the fishery 

 since 1959. Chum salmon stocks along the 

 Pacific Coast from Alaska to Oregon are de- 

 clining, indicative of some common adverse 

 factor. At this time the future of this species 

 in the Columbia River is discouraging. 



SUMMARY 



Information about the areas in which steel- 

 head trout and coho, sockeye, and chum salmon 

 spawn in the Columbia River basin is scattered 

 in many detailed, lengthy reports. Because 

 these reports cover many tributaries, it is dif- 

 ficult to draw conclusions on which to base 

 decisions about management of the salmon 

 fisheries or about needs for research. Further- 

 more, many data are not published. Accord- 

 ingly I have summarized relevant publications 

 and uni)ublished data through 1969 in the 

 present report; information on chinook salmon 

 v/as similarly summarized in a previous report 

 (Fulton, 1968). 



In my study of the steelhead trout and the 

 species of salmon reported here, I considered 

 three main aspects of each species; spawning 

 areas, abundance, and the future of the Co- 

 lumbia River runs. 



Steelhead Trout 



Spawning areas. — Steelhead trout have been 

 eliminated from many spawning areas above 

 dams such as Merwin Dam on the Lewis River 

 and Hells Canyon Dam on the Snake River. 

 The chief spawning areas in the tributaries of 

 the Columbia River are located, in order of im- 

 portance, in the following rivers: Salmon, 

 Clearwater, Cowlitz, Washougal, Lewis, Ka- 

 lama, Grande Ronde, John Day, Willamette, 

 Sandy, Hood, Deschutes, and Imnaha. 



Although steelhead trout move throughout 

 the year from the ocean into the Columbia 

 River, they all spawn in the winter or spring. 

 Those entering during the winter November 

 to April) predominantly spawn in the tribu- 

 taries below Bonneville Dam, and those enter- 

 ing during the summer (May to October) pre- 

 dominantly spawn in the tributaries above 

 Bonneville Dam. Some steelhead trout return 

 to the Columbia to si)awn two or more times. 



Abundance. — The early runs of steelhead 

 trout in the Columbia River Basin were large. 

 About 2 million kg. was packed, for example, 

 during the peak year of 1892. The smallest 

 pack— 177,000 kg.— was in 1966. Since 1929, 

 Oregon is the only state in which this species 

 is processed commercially. Large sport catches 

 are taken in Washington, Oregon, and Idaho. 



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