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• In extreme measures to prevent the immediate extinction of unique stocks of 

 fish. 



Supplementation is the hatchery production of fish from selected stocks which are 

 then placed back with the progeny of naturally spawning fish. Successful 

 supplementation requires the application of fish culture practices to minimize the 

 domestication of fish as they pass through the hatchery and are returned to their 

 natural habitat. The role of supplementation in slock restoration is to add needed 

 numbers to declining stocks of fish. In some instances, this may ensure the existence 

 of that stock until habitat is restored and resource management is adjusted so that the 

 stock becomes self-sustaining. Supplementation is also used to enhance self-sustaining 

 stocks to support increased harvest. 



There are also situations when hatchery programs can be designed to add fish to 

 traditional common-property fisheries. These programs provide a tool for resource 

 management and divert fishing pressure from selected naturally spawning stocks of 

 concern. In order for this strategy to be successful, the hatchery fish must not alter 

 or significantly compete with the wild stocks. At harvest, the hatchery fish must be 

 separated from the wild fish by either space or time. A secondary benefit of this 

 strategy is maintenance of selected fisheries and associated economics while, at the 

 same time, diminished populations of naturally spawning salmon are protected. 



We have far greater control of hatchery-produced fish than of naturally spawned fish. 

 Hatchery fish are used in controlled situations to help fisheries scientists understand 

 and identify ^ose things tJtat affect the survival of naturally spawning salmon. 

 Identifying factors detrimental to wild salmon as well as modeling the optimal 

 situation for the survival of members of a given slock of fish is critical to the 

 restoration of naturally spawning salmon stocks. In Alaska, we have determined such 

 things as the specific relationship of yearling sockeye salmon smolt size, or the liming 

 of smolt migration to the sea, with the chance the fish will survive to return as adults. 

 This knowledge is used to evaluate the health of a wild population. It can also be 

 used to predict the impact of habitat alteration, eiUier correction or degradation, 

 associated with the activities of man on wild salmon stocks. 



Hatcheries can be used to sustain severely threatened salmon stocks until sufficient 

 numbers of fish and appropriate habitat are available. The hatchery may be used to 

 "bridge over" life history voids: too few aduh spawners to sustain a slock in natural 

 conditions, inaccessible or altered spawning ground.s, impassible migration corridors, 

 or inaccessible or altered freshwater rearing habitat. In the summer of 1990, only 

 one female sockeye salmon successfully migrated up the Columbia and Snake Rivers 

 to Redfish Lake in Stanley Basin, Idaho. There was virtually no chance this single 

 female could have naturally spawned and produced a sufficient number of offspring to 

 perpetuate the Redfish Lake sockeye, Extreme fish culture practices, including 

 developing a hatchery-reared, captive brood stock, were used to perpetuate this stock 

 that had been reduced to several thousand eggs in a single female. 



In summary, it is my opinion that there is no single, best way that hatcheries can 

 assist and speed the restoration of naturally spawning populations of fish. As many of 



