Publications

Pacific salmon (Oncorhynchus spp.) are organized into distinct populations because of homing behavior (Rich and Holmes 1939, Ricker 1972). The alternative to homing is straying, in which fish do not return to their natal streams to spawn but spawn elsewhere (Bams 1976). Even though some straying occurs among wild populations (usually less than 5%; Lindsey et al. 1959, Vernon 1957, Rich and Holmes 1928), the amount of straying between natural and hatchery stocks is of concern because it can reduce the fitness of natural populations (Fleming and Gross 1993, Meffe 1992, Leider et al. 1990, Waples 1991). Evidence shows that some transplanted stocks are less productive than locally adapted populations, and that hatchery populations are generally less productive in nature than native locally adapted populations (Leider et al. 1990, Reisenbichler 1996, Chilcote et al. 1986). Introductions of hatchery fish into a river system can also displace wild fish or reduce their abundance (Nickelson et al. 1986). The effects of hatchery fish on wild populations are well documented (see Can. J. Fish. Aquat. Sci. 1981, 38(12), Aquaculture 1991, 98(1-3)). 

Much of my effort has been to get salmon management and Indian tribal agencies to pay attention to the results of these studies in their efforts to develop and manage salmonid fisheries. Given the documented effects that hatchery strays can have on wild populations, hatchery policies and funding should be subject to a scientific review process, and that is what this workshop is about. Hatcheries, however, are often treated as 'sacred cows' by fishery agencies, and attempts to correct problems with straying are sometimes met with accusations of 'hatchery bashing.' The problem is that a formal process of hatchery evaluation is lacking in formulating budgets. For example, in fiscal 1992, the NMFS budget for its hatchery program was $13.4 million, whereas the combined funding for fishery resource management, protected species management, and habitat restoration and conservation was only $1.8 million (R. Schmitten, NMFS Headquarters, 1315 East West Highway, Silver Spring, MD 20910. Pers. commun., March 1992). The states of Oregon and Washington have similar policies for funding hatcheries, as does the U.S. Fish and Wildlife Service. Since hatchery programs constitute a large proportion of the agencies' budgets, it is reasonable for these agencies to avoid questions about hatchery programs and their influences on wild stocks. 

Discussions of hatchery straying are often seen as attacks on hatchery programs, rather than as constructive criticisms intended to make things work better. Present policies inadequately regulate fish hatchery practices. Even the recent effort on the part of fish agencies to develop an integrated hatchery policy in the Columbia River Basin does not evaluate the effects of hatchery fish on the ecosystem once they are released. It deals chiefly with the coordination of protocols among hatcheries. An institutional mechanism to identify hatchery-related ecosystem problems is entirely lacking. Consequently, even though there are ample scientific studies on the problems hatchery strays cause, an institutional means of addressing and resolving these problems is not in place because funds for a review and evaluation are not available. 

Additional funds are required to acclimate juvenile hatchery fish so they imprint adequately during their down-river migration, to mark them, and to inventory spawning streams for them as adults. To reduce the rate of straying of hatchery fish, the trucking of juveniles will also have to be discontinued. Truck-transported juveniles are not imprinted well enough to find their way back up a river to their point of capture, so they tend to stray to other areas (Slatick et al. 1982) and can introduce such diseases as IHN to previously uninfected rivers. But we continue to truck juveniles because it is more economical than barging them. To deal with hatchery straying, a policy must be developed and implemented to determine if any rates of straying are acceptable, especially for small populations because they are at the greatest risk. Traps will have to be placed in streams so that marked hatchery fish can be removed.

Two primary kinds of hatchery strays include 1) hatchery fish that do not return to their release site, but stray into other streams, and 2) non-native hatchery fish used for fishery enhancement or mitigation that are transplanted from non-local populations. Both kinds of hatchery strays place native fish at risk through interbreeding and ecological interactions, and any policy on straying of non-native fish must be designed to protect the fitness and evolutionary potential of wild populations. This may mean closing a hatchery facility when it becomes too expensive or impractical to control the straying of non-native fish. Straying may also be induced when juveniles are transported for release to rivers where the hatchery fish are non-native. Examples, among many others, include the non-local release of Alsea Hatchery winter steelhead, Skamania Hatchery summer-run steelhead, Lower Columbia River hatchery coho salmon, and Rogue River chinook salmon (reared in net-pens in the Lower Columbia River). Adults returning to a release site may stray uncontrollably when they encounter unfavorable conditions. This occurred in the Umatilla River.

Converting hatcheries to raise only native brood stock may greatly reduce the effects of hatchery straying, but this hypothesis must be evaluated before it can be applied broadly to a river system. Captive brood stock may also diverge genetically from local wild stocks in traits that are important in local adaptation. Even with the use of only native brood stocks, hatchery strays may still adversely affect natural populations. Any policy on strays should also consider ecological interactions of juvenile hatchery fish with wild fish, especially in the large-scale use of non-native fish for mitigating run losses or for run enhancement.

Conserving genetic variability within and among native wild salmonid populatons is key to the success of fishery management. At this time, it is impossible to prevent selection for traits that favor survival in a hatchery environment, so hatchery fish will diverge from wild forms and become less fit for survival in nature. Thus, hatchery fish can be a form of biological pollution that must be controlled to maintain not only native salmon, but ultimately the consumptive fisheries.

I conclude with a quote by Yu. P. Altukhov and Salmenkova (1991, p. 28, 35-36): ". . . many anadromous fish are now reproduced artificially in hatcheries and reared and released into the rivers--but the method is insufficiently effective. This is because the species' population genetic structure has not been taken into account . . . . These data testify to the negative genetic effects of existing salmonid exploitation and management practices. Artificial reproduction, commercial fisheries, and transfers result in the impairment of gene diversity in salmon populations, and so cause their biological degradation."

Altukhov, Y. P, and E. A. Salmenkova. 1991. The genetic structure of salmon populations. Aquaculture 98:11-40.

Bams, R. A. 1976. Survival and propensity for homing as affected by presence or absence of locally adapted paternal genes in two transplanted populations of pink salmon. J. Fish. Res. Board Can. 33:2716-2725.

Chilcote, M. W., S. A. Leider, and J. J. Loch. 1986. Differential reproductive success of hatchery and wild summer-run steelhead under natural conditions. Trans. Am. Fish. Soc. 115:726-735. 

Fleming, I. A., and M. R. Gross. 1993. Breeding success of hatchery and wild coho salmon in competition. Ecol. Appls. 3:230-245. 

Leider, S. A., P. L. Hulett, J. J. Loch, and M. W. Chilcote. 1990. Electrophoretic comparison of reproductive success of naturally spawning transplanted and wild steelhead trout through the returning adult stage. Aquaculture 88:239-252.

Lindsey, C. C., T. G. Northcote, and G. F. Hartmann. 1959. Homing of rainbow trout into inlet and outlet spawning streams at Loon Lake, British Columbia. J. Fish. Res. Board Can. 16:695-719. 

Meffe, G. K. 1992. Techno-arrogance and halfway technologies: salmon hatcheries on the Pacific coast of North America. Conserv. Biol. 6:350-354.

Nickelson, T. E., M. F. Solazzi, and S. L. Johnson. 1986. Use of hatchery coho salmon presmolts to rebuild wild populations in Oregon coastal streams. Can. J. Fish. Aquat. Sci. 43:2443-2449. 

Reisenbichler, R. R. 1996. Genetic factors contributing to declines of anadromous salmonids in the Pacific Northwest. In D. J. Stouder, P. A. Bisson and R. J. Naiman (editors), Pacific Salmon and their Ecosystems, p. 223-244. Chapman Hall, New York.

Rich, W. H., and H. B. Holmes. 1928. Experiments in marking young chinook salmon on the Columbia River, 1916-1927. Bull. Bur. Fish. 44:215-264.

Rich, W. H., and H. B. Holmes. 1939. Local populations and migration in relation to conservation of Pacific salmon in the western states and Alaska. Amer. Assoc. Adv. Sci. Publ. 8:45-50.

Ricker, W. E. 1972. Hereditary and environmental factors affecting certain salmonid populations. In: R. C. Simon and P. A. Larkin (editors), The Stock Concept in Pacific Salmon, p. 19-160. MacMillan Lectures on Fisheries. Univ. British Columbia, Vancouver, B.C.

Slatick, E., L. G. Gilbreath, J. R. Harmon, and K. A. Walch. 1982. Imprinting salmon and steelhead trout for homing. Report to the U.S. Bonneville Power Administration, Division of Fish and Wildlife, Contract DE-A179-81-BP27891, 52 p. with appendices. (Available from Northwest Fisheries Science Center, 2725 Montlake Blvd. E., Seattle, WA 98112.)

Vernon, E. H. 1957. Morphometric comparison of three races of kokanee within a large British Columbia lake. J. Fish. Res. Board Can. 14:573-598.

Waples, R. S. 1991. Genetic interactions between hatchery and wild salmonids: lessons from the Pacific Northwest. Can. J. Fish. Aquat. Sci. 48(suppl. 1):124-133.

Question: Dave Johnson (Nez Pierce Tribal Fisheries): The peoples in the Pacific Northwest have eaten salmon for thousands of years, and the United States government made promises when the land was taken from Indian peoples. Among these promises was the ability to live off salmon. If, as you suggest, we manage for a particular population of salmon, we in effect lose our treaty rights and our means of subsistence is taken away. For thousands of years we have lived on salmon, and now within 100-150 years salmon have practically disappeared. We are not so concerned with the genetics of these fish, we just want the fish to eat and we support whatever hatchery programs are needed to give us those fish. 

Answer: Bill Bakke: I understand your point of view, but are artificially propagated salmon as good as natural fish "from the creator" for your spiritual and cultural well-being? The Snake River has been pressed into many different uses that adversely affect salmon populations, and I hope that the tribes and others can begin to correct the problems causing the decline of salmon populations. Sustainable artificial propagation of salmon in the long term has its own problems. For example, we have a shrinking supply of eggs for the lower Snake River hatcheries and are forced to import non-native eggs. It does not appear that hatchery technology is solving the problem.

Comment: Robin Waples: I think it is good to get these ideas out, because they show the complexity of the issue and the strong feelings on all sides. The panel, however, has not been asked to deal with these social and cultural issues, but will deal only with scientific issues.

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