the efforts of State and Federal 

 agencies. It is anticipated that the 

 Willamette block will be eliminated 

 by 1954. However, sawmill and 

 mining wastes, as well as warm wa- 

 ters from atomic-energy plants on 

 many streams have tended to de- 

 crease the suitability of the waters 

 for salmon, as well as for humans. 



Early logging operations were 

 detrimental to salmon. All cover 

 was removed from the hills, logging 

 debris was dumped into streams, 

 and logging dams were constructed 

 wherever convenient. The net re- 

 sult was extremely harmful to anad- 

 romous fish. Kapid runoff waters 

 fi"om the bare hills silted streams 

 and spawning beds, high- and low- 

 water periods were accentuated, wa- 

 ters often became too warm for sal- 

 mon survival, and dams blocked up- 

 stream migration. Only in recent 

 years have our forests been managed 

 on the basis of sustained yield. 

 Many of the heavily logged water- 

 sheds have now developed good sec- 

 ond-growth cover, and present-day 

 logging practices and laws are more 

 conducive to preservation of salmon 

 habitat. 



A large-scale salmon-salvage i)ro- 

 gram was undertaken on the upper 

 Columbia River in 1939, when 

 construction of Grand Coulee Dam 

 blocked salmon from hundreds of 

 miles of spawning area. This pro- 

 gram transferred the runs of salm- 

 on that formerly ascended to 

 the areas above Grand Coidee to 

 tributaries below the dam. As part 

 of the salvage program, several 

 salmon hatcheries were constructed. 

 The chinook and silver salmon as- 

 cending the river to Grand Coulee 



Dam have been maintained in pre- 

 dam numbers, and the populations 

 of red salmon have shown tremen- 

 dous increases (Fish 1948). The 

 hatchery production and release of 

 fingerling red salmon can definitely 

 be correlated with the return of the 

 adult fish to the fishery 3 years later. 

 On the Sacramento River in Cali- 

 fornia, the construction of Shasta 

 Dam stopped salmon from ascend- 

 ing to the major spawning areas of 

 the watershed. A hatchery (fig. 1) 

 was constructed on Battle Creek, a 

 tributary below the dam, and adult 

 salmon ascending to Keswick Dam 

 immediately below Shasta were 

 trapped and transferred to Battle 

 Creek. This operation has resulted 

 in maintenance of the salmon in the 

 Sacramento River — ^liatchery oper- 

 ations have provided necessary 

 stock, and cooler waters issuing 

 from the reservoir have made the 

 river below the dam more suitable 

 for salmon spawning. The hatch- 

 ery operation has resulted in defi- 

 iiite and substantial contributions 

 to the fishery in the San Francisco 

 Bay area, as well as in the coastal 

 waters as far north as Vancouver 

 Island. The improvement of con- 

 ditions for spawning of salmon be- 

 low Shasta Dam has not been dupli- 

 cated in connection with the con- 

 struction of any other major dam. 



To mitigate the losses of salmon 

 expected to result from the con- 

 struction of additional dams in the 

 Columbia Basin, the Fish and 

 Wildlife Service, together with the 

 fishery agencies of Idaho, Oregon, 

 and Washington, evolved in 1947 a 

 plan known as the lower Columbia 

 liivei- tislicries develoi^ment pro- 



18 



