adult migrants to die before spawning. Higher 

 than optimum temperature during spawning 

 probably caused loss of eggs deposited in the 

 beginning of the season. 



It is not possible to predict the future of 

 this species in the Columbia River basin be- 

 cause of the discontinuance of artificial propa- 

 gation at Leavenworth National Fish Hatchery, 

 the impounding of most of the river, and the 

 presence of the other potentially adverse con- 

 ditions cited above. 



CHUM SALMON 



Chum migrate into the lower tributaries 

 of the Columbia River; they enter the Co- 

 lumbia River from October through December 

 and spawn shortly after entering fresh water. 



Chum salmon mature predominantly in 

 their fourth year, although 87 and 5-year-old 

 fish are common. In the Columbia River, age 

 4 fish weigh 3.6 to 5.4 kg. and average about 

 4.5 kg. Chum salmon are principally taken 

 in the river gill net fishery. Because chum 

 salmon do not usually take a lure, they are 

 not part of the si^ort catch, nor are they usually 

 caught by commercial trollers. 



The spawners are grayish green on their 

 dorsal surface with blotches of pink, grey, and 

 green laterally and are sometimes referred to 

 as calico color. The young emei'ge from the 

 gravel upon hatching, soon start on their sea- 

 ward migration, and grow rapidly after they 

 reach the ocean. 



The flesh of chum salmon is pale pink and 

 is regarded as inferior to the other species of 

 salmon, ranking as the lowest grade of canned 

 salmon along the Columbia River. One of the 

 more common methods of processing this spe- 

 cies is smoking. 



Spawning Areas 



Chum salmon spawn in the lower tributaries 

 of the river (map 11). Table 9 lists the pro- 

 ducing areas, length of stream in kilometers, 

 and distance from the mouth. 



This species spawns in the lower portions 

 of tributaries (map 11); the principal tribu- 

 taries are: Grays, Elokomin, Lewis, and 

 Washougal Rivers and Big, Mill, Abernathy, 

 Germany, Milton, Hardy, and Hamilton Creeks. 



Most of the chum salmon that enter the 

 Columbia River spawn in tributaries below The 

 Dalles Dam, 309 km. above the mouth. An 

 average of 27 chum salmon passed through the 

 fishways at The Dalles Dam in 1957-63, where- 

 as an average of 801 passed Bonneville Dam 

 during the same period. Most of these fish 

 probably spawned in tributaries between the 

 two dams, as the fishery was closed. 



Former spawning areas were located in the 

 Kalama River, lower portions of Little White 

 Salmon River and Hamilton, Rock, and Herman 

 Creeks, and areas along margin of river banks 

 in the main Columbia River (the latter four 

 areas were inundated in 1938 by the pool cre- 

 ated by Bonneville Dam). The areas lost are 

 not extensive, however, and made up only a 

 small portion of the total available spawning 

 areas. Many of the spawning riffles in the 

 lower portions of tributaries of the lower Co- 

 lumbia River, however, received heavy layers 

 of silt when the area was logged many years 

 ago and are now unsuitable for spawning. 



Abundance 



Chum salmon were also formerly much 

 more abundant in the Columbia River. Craig 

 and Hacker (1940) stated that it is not po.s- 

 sible to draw conclusions on their relative 

 abundance from data on commercial canning 

 because this species fluctuates in abundance 

 and the annual catch often depends on the 

 market for cheaper grades of salmon. Never- 

 theless, the canning and commercial catch — 

 the only available indexes of relative abundance 

 (fig. 6) — show some production over the entire 

 period of the fishery. 



Maximum and minimum productions of 

 chum salmon in the Columbia River were 

 3,854,000 kg. in 1928 and 3,000 kg. in 1965. 

 The low catches since 1957 was partially due 

 to curtailment of the fishery. For the most 

 part, chum salmon are currently protected 

 from the commercial harvest in the Columbia 

 River by closures in October and all of No- 

 vember. Chum salmon are not taken by off- 

 shore fisheries. Reduced fishing, however, has 

 not produced the expected increase in spawners 

 in the Columbia River. A similar decline of 

 this species occurred along the entire Pacific 

 Coast according to the Fish Commission of 



29 



