91 



temporary until the environmental constraints on the population(s) are removed and it can be 

 safely placed back into its natural environment A lot of current hatcheries should be able to 

 meet this role, but special needs of handling and maturing adult fish must be considered. 



The second situation v^here hatcheries can be particularly effective is where a population 

 exhibits "under-escapement" (less than the optimum number of adults return to freshwater to 

 spawn) due to diminished production of young fish. This is often due to water quality 

 deterioration (e.g., siltation) that negatively impacts the incubation of eggs in the gravel or the 

 viability of young fish after hatching. The population may not be at the level of being 

 threatened or endangered, but should be augmented before that stage is reached. Hatcheries 

 can be most effective and have the greatest variety of approaches that can be employed. The 

 job a hatchery can perform best is to increase the survival of eggs and young fish above that in 

 the natural environment. This can be accomplished by a very high technology hatchery, or by 

 a very simple streamside incubation box. Thus, in this case the needs of the population can be 

 addressed with hatchery technology that best suits the situation until the constraints on natural 

 production are removed. 



The final scenario is where there is under-escapement due to over-fishing. The most 

 obvious and, perhaps, the best way to address such a problem is to decrease the fishing 

 pressure by limiting catch, season, number of fishermen, or any number of other approaches. 

 However, this can present many economic and sociological problems. An alternative might be 

 to utilize hatcheries to produce salmon that do not interfere/interact with the naturally- 

 reproducing population of interest and will relieve some of the fishing pressure from the 

 population(s) of interest Although notable success has been achieved with this type of 

 "enhancement" of localized salmon fisheries in Alaska and Washington by use of specialized 

 hatchery technology, this approach is the one most fraught with potential problems in regard to 

 interaction with natural populations. Consequendy, very careful control and monitoring are 

 required. 



All of these situations are commonly encountered problems with naturally-reproducing 

 Pacific salmon populations and each can be addressed by use of hatchery technology. The 

 common denominator among all of these is the need for an understanding of what has led to the 

 problem noted. This makes it possible to identify and formulate a solution that will maximally 

 benefit the population. Hatcheries should work, in many ways, like a research and 

 development enterprise. That is, the problems should be identified, potential solutions 

 formulated and conducted, and the work accomplished in a manner to enable evaluation of the 

 results. The most apparent deficit in current hatchery operations is a lack of follow-up to 

 assess and evaluate the results of the operation. 



