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-Salmon species with shorter freshwater life cycle have shown a higher success rate from hatchery supplementation. They also have less negative impacts on wild/natural populations. Pink and chum salmon supplementation projects in Alaska and BC are examples of this success. -Short-run stocks of salmon and steelhead have responded more positively to supplementation than longer-run stocks. In some cases, it was shown that introducing hatchery stock to a river system a few kilometers closer to the estuary significantly increased rate of adult returns. -Wild/natural fish have higher survival rates than hatchery fish. This has been demonstrated with pink salmon in Alaska, Atlantic salmon in Maine, coho salmon on the coast, and upriver chinook salmon in the Columbia. Where tests were made to compare survival to adult, wild/natural produced fish had higher survival rates than associated hatchery produced fish. -Overstocking of hatchery fish may be a significant problem in a lot of supplementation projects. If hatchery fish are overstocked in a system, the result is decreased performance of both hatchery and wild/natural fish. -Scattering or distributing the supplemented hatchery stock is more successful than single spot techniques which tend to overstock areas of planting and leave unplanted areas understocked. -There is a need to evaluate more supplementation programs. We found 18 projects that were all or partially evaluated out of 26 projects classified as supplementation. In order to do hatchery evaluation work or compare survival, hatchery fish need to Abe identified uniquely from wild/natural stock. There is a need to have a unique visual mark for hatchery produced chinook salmon in the Columbia River. -Successful techniques for establishing, rebuilding, and supplementing sockeye salmon populations have been developed in Alaska and BC. Most of these programs integrate lake fertilization with fry plantings of appropriate stocks. Some of these techniques may prove useful in rebuilding Columbia River sockeye populations. -Hatchery broodstock management for supplementation needs to be stressed. The "Summary of Recommendations Regarding Hatchery Production Principles" in draft form, June 6, 1989, System Planning Oversight Committee, reflect many of the ., concerns with hatchery broodstock management for supplementation. -Genetic considerations should be an initial concern of all supplementation efforts aimed at rebuilding existing runs of anadromous fish. `~~ -Interpretation of genetic studies of hatchery/wild interaction will be difficult, and long- ` term in order to obtain the necessary second and third generation data -maybe 15 to 20 years. Also, the opportunity for documenting the genetic "identity" of many native stocks is already lost. -Overall, conclusions from our review of supplementation show that there are many documented cases of introduced hatchery fish returning as adults to a specific area. However, little data were found on the capability or probability of supplemented 1 hatchery -fish building up and sustaining wild/natural populations. Figure 1 summarizes some of the factors mentioned relative to supplementation success. 38