d3 



Raising Pacific salmon in a hatchery environment holds the potential to alter their natural 

 life history traits and to decrease the genetic diversity of the population. This, too, can 

 decrease the chances of "restoration" salmon "fitting" back into the natural environment and 

 producing a viable population. One answer to these concerns is to be able to monitor changes 

 and take corrective action. Life history traits are extremely difficult to monitor because of the 

 nature of their expression. These traits result from a combination of the impacts of the 

 environment which the salmon experience and their genetic composition. We have learned 

 much about the genetic detennination of a number of these traits (e.g., timing of maturation, 

 timing of smoltification, precocious maturation, and spawning and return timing) and can 

 estimate the relative importance of genetic factors and the environment Avoidance of genetic 

 changes can be accomplished by attention to reproductive and rearing practices. However, 

 monitoring can only be achieved by keeping complete records and noting the occurrence of 

 changes in a population. Such information is not routinely kept in most hatcheries. 



The best approach to eliminating potential problems with life history changes is to 

 reproduce and raise fish without introducing selective changes or diminishing variability. 

 While this easier said than done, it is important to make the attempt The importance of this 

 factor can be illustrated by the fact that historically, there were probably salmon migrating in 

 and out of the Columbia River almost the entire calendar year. Currently, due to changes in the 

 river and to the procedural operations of the hatcheries on the river, most salmon move out of 

 the river during a 6-8 week time frame. This overloads both marine and freshwater systems 

 and causes interactions that previously did not occur. 



Objective measurement of genetic diversity can be a bit more easily accomplished. 

 Although the tools for analysis of genie variability in salmon were developed relatively 

 recendy, there are now a variety of techniques available and more are being developed. Protein 

 electrophoresis is currently used to genetically identify and characterize populations of Pacific 

 salmon. This technique has provided information to define population structures in Pacific 

 salmon species, to identify problems with hatchery breeding procedures, and to define the 

 population composition of harvested salmon. The Washington Department of Fisheries now 

 operates a laboratory dedicated to the electrophoretic analyses of Pacific salmon populations 

 within the state to assist in the management of these species. Molecular techniques utilizing 

 nuclear and mitochondrial DNA have been very limitedly employed to this point but they 

 promise to yield important additional information. Each of these provides a "snapshot" of the 

 genetic variability within and between populations and each has been utilized to monitor genetic 

 change. However, more consistent long-term and extensive use of available genetic analyses 

 need to be employed to provide a basis for determining the meaning of genetic change in 

 Pacific salmon populations. 



