42 



THE POTENTIAL ROLE FOR HATCHERIES IN THE RESTORATION OF 

 NATURALLY-SPAWNING SALMON POPULATIONS 



Hatcheries have been a part of fisheries management since the 

 1870' s. However, it has been in the Pacific Northwest, and 

 especially the Columbia River, that they have been used most 

 widely. The State of Washington alone has 121 major public 

 hatcheries. By some estimates, this number is greater than any 

 other state or province in North America and perhaps the world. 

 The impetus for the rapid growth in the number of hatcheries is 

 largely related to two ideas: (1) hatcheries can be used to 

 mitigate the effects of habitat loss due to human activities; and 

 (2) in addition to mitigation, hatcheries can improve upon nature 

 and increase the number of salmon available for harvest. 



The construction of dams, timber harvest, and agricultural water 

 diversion were the major human activities that used hatcheries to 

 mitigate the loss of salmon habitat. It was assumed that by 

 building hatcheries to replace the amount of natural salmon 

 production, there would be no decrease in the number of salmon. 

 In many cases, this has not proved to be true. Despite an ever 

 increasing number of juveniles released from hatcheries, the 

 number of returning adults has continued to decline. These 

 trends indicate that many hatcheries have not been able to 

 mitigate for man-made activities in many watersheds. 



In addition, hatchery practices themselves have been implicated 

 in the decline of salmon populations. In the words of one 

 fisheries biologist, "hatchery production. . .creates fat and 

 stupid juvenile fish". These "fat and stupid" salmon have been 

 reared in increasingly artificial hatchery facilities. In these 

 hatcheries, they learn habits that do not serve them well in the 

 wild. Juvenile fish from hatcheries are not- as well adapted as 

 "wild" salmon for avoiding predators, foraging in the wild, or 

 using natural resting sites in their run downstream. Because of 

 this, their survival rate upon release is low when compared with 

 wild stocks. In spite of their decreased ability to survive in 

 the wild, they can compete with wild populations of juvenile 

 salmon for food and habitat. So, not only are hatchery fish less 

 able to survive in the wild, they may decrease the survivability 

 of wild populations of salmon that would survive better in the 

 absence of hatchery fish. 



Hatchery reared fish also have problems with disease. When 

 rearing salmon in extremely concentrated conditions, diseases 

 often crop up. Upon release, disease carrying hatchery salmon 

 may infect wild populations and thus, further diminish the number 

 of wild salmon. 



The most recent area of concern for reforming hatcheries lies in 

 the field of population genetics. Individual populations of 

 salmon are the result of natural selection. The end result is a 



