In 1989 the fish rescue team collected 455,762 stranded salmonids, most of them steelhead. A pilot program was initiated to rear rescued Scott River steelhead in ponds on Kidder Creek in 1990. Water quality problems caused a loss of all the fish.
It is if man had been suddenly appointed managing director of the biggest business of all, the business of evolution ... whether he is conscious of what he is doing or not, he is in point of fact, determining the course of evolution on this Earth. That is his inescapable destiny, and the sooner he realizes it and starts believing in it, the better for all concerned.Rich (1939) argues that the best path to maintaining a species was to preserve as many local populations as possible. Therefore, we should save the populations in as many creeks in the Klamath Basin as possible. The CDFG stock transfer policy (draft 1987) states that "the Department ... will maintain the genetic integrity of all identifiable stocks of salmon and steelhead in California." Local populations in the Klamath Basin do show some genetic variation (Gall et al. 1989), but the significance of genetic traits remains a mystery. Some of these changes might be a result of random drift and confer no selective advantage (Parkinson 1984). Others may be key traits for survival that govern behavior or confer resistance to disease. If these latter traits are lost as sub-populations in the basin are extirpated, re-colonization of some of the Basin's streams may be extremely difficult. Atlantic salmon restoration programs have only met with success in re-establishing self-sustaining natural spawning populations where proximate locally adapted stocks were available for broodstock (Saunders 1981).
There is no clear answer to the question as to how much diversity will insure future survival. Preserving genetic diversity was likened by McIntyre et al. (1988) to maintaining a diverse financial portfolio. Just as the economic climate is difficult to predict, so are swings in the natural environment. As one maintains a diverse portfolio, economic swings will effect only a portion of one's wealth. Maintaining stock diversity will allow similar stability in returns in the face of environmental change. As diverse stocks have different outmigration and spawning times, different ocean migration patterns, resistance to disease and other attributes, they can better collectively withstand droughts, floods, El Nino events, and long term environmental change.
A considerable amount of genetic diversity has been lost already and some of what remains is embodied in remnant runs. Scudder (1989) suggests that remnant populations, restricted to marginal habitats, are very important to the survival of the species overall. These greatly reduced populations can serve as genetic repositories due to a process termed "centripetal gene flow" (Scudder 1989), in which the fish remaining retain effective population size of the large ancestral population. Large effective population size is an important factor in artificial production programs (Simon 1988). Remnant stocks may also harbor solutions to intensive selective pressure which could significantly contribute to survival of the wider population if it meets similarly harsh environmental factors. Even if remnant populations from smaller tributaries are too small for founding broodstocks, other breeding programs from adjacent drainages could avoid inbreeding by including just one individual every few generations from these small isolated groups (Simon 1988).
Fisheries managers have argued that if any stock transfers have occurred in the past to a stream, then the salmon or steelhead there are no longer a pure genetic strain and therefore special efforts to preserve that stock are no longer warranted. When stock introductions have ceased and the population has continued to survive on its own, it has retained sufficient adaptive traits to be of value (Riesenbechler and Phelps 1989). While it may or may not have changed from its original genetic makeup, stocks founded from these remaining runs stand a much better chance of taking hold, and becoming self reproducing, than stocks introduced from another area.
Maintaining the fullest genetic diversity in both Trinity River and Iron Gate Hatchery broodstocks is critical for the long term stability of hatchery production in the basin.
The Economic Considerations of Using Locally-Adapted Stocks
Stock transfer studies in the Klamath basin were conducted by Snyder and Schofield (1924). Sacramento River chinook introduced at Fall Creek Hatchery showed a return to the ocean fishery of just 0.04 percent as opposed to 0.73 percent for native stocks. Return to the river of just 0.012 percent was exhibited by the Sacramento fish, while natives returned at a rate 10 times higher (0.12 percent). The return on investment in hatchery programs is, therefore, substantially higher if well-adapted stocks are used.
The restoration of wide spread self-reproducing salmon and steelhead populations relies on preventing further losses of genetically diverse locally adapted populations (Krueger 1981, National Council on Gene Resources 1982). The rebuilding of wild steelhead populations from remnant stocks is meeting with some success in Idaho (Thurow 1987). The long term savings of being able to discontinue small scale rearing programs after restoration is complete and having the salmon and steelhead return without human intervention or funds in perpetuity is staggering.
While artificial production in the Klamath Basin has been occurring for 100 years, it was only a fraction of natural production until quite recently. Now, returns to hatcheries are beginning to contribute major portions of the river's production for the first time. Hatcheries should be operated to mitigate for losses in production due to irretrievable loss of habitat above dams. As runs have increased to both Iron Gate and Trinity River Hatcheries since 1985, far more juvenile salmon and steelhead have been produced than are called for in hatchery guidelines. California Department of Fish and Game policies state that "it is recognized that natural production provides the great bulk of the State's salmon and steelhead resources. The Department's goals of maintaining and improving this production shall not become subservient to the goals of publicly operated rearing programs." If the level of releases at the large hatcheries in the Klamath Basin are exceeding the carrying capacity of the river and the estuary, they may be an impediment to restoring the river's wild populations.
Appropriate levels of planting at hatcheries can be determined by testing different levels of release and gauging commensurate levels of return to the fisheries and to the river. Without discovering what the optimal number of hatchery juveniles are for release, we may raise more juveniles at the hatchery than is cost effective and unintentionally move the river toward much greater hatchery dependence. Cohort analysis of returns from years of very high fingerling releases (1985-88) should help unmask density dependent factors that appear to be decreasing survival of release groups. Such a study will indicate the correct level for fingerlings releases. Important work is proceeding on the Trinity to determine the relationship between increased streamflows and the survival of fish from the hatchery releases.
Yearling releases yield much higher contributions to the fisheries and to spawning escapement than do those of fingerlings. Releases of fingerlings also pose a higher risk of impacting native juveniles through competition in the river or in the estuary than do yearlings. The Task Force should cooperate with CDFG to study what level of hatchery production for mitigation and enhancement provides the highest return to fisheries without posing problems for the recovery of native salmon and steelhead populations. The Trinity River Task Force is working to define optimal release strategies at the hatchery to minimize impacts on native fish and meet mitigation goals.
Another dimension of the Trinity River Mid-Program Review is the testing of methods to decrease the tendency of steelhead smolts to remain in the river or become residuals. Similar tests should be conducted at Iron Gate Hatchery because of negative effects residuals exert through competition on native steelhead and possible problems of predation on both hatchery and native juveniles. Pond rearing programs to increase survival of fish rescued from dry stream channels or fish screens also need some method of avoiding problems with residualism. Studies are also needed to determine the level of resistance of Iron Gate Hatchery steelhead to Ceratomyxa shasta.
Small scale rearing facilities programs can help accelerate the rebuilding of wild stocks diversity, but if operated incorrectly can actually accelerate loss of appropriately adapted stocks through inbreeding. Small scale programs need to recognize they may be handling threatened stock groups. Policies are being developed by CDFG for the operation of small scale rearing programs. Parallel policies need to be adopted by tribal governments and the BIA. A Task Force technical work group should work with CDFG to make sure that policies adequately provide for the conservation of gene resources. All small scale rearing operations sponsored by the Restoration Program should strictly adhere to such rules, especially as they pertain to brood handling to avoid irretrievable losses of genetic resources. Although facilities involved are temporary, they should be state-of-the-art, and technical assistance should be available to all project operators. The cost-effectiveness of small scale rearing programs can be improved and additional benefits for the program derived by also rearing coho salmon and steelhead.
While some habitat has been lost due to dams, much of the degraded habitat can be restored. Unlike Atlantic salmon restoration on the East Coast, where habitat problems were so serious and long-standing that most native stocks had been lost, the Klamath retains many of its wild strains of salmon and steelhead. As the river and its tributaries are reshaped through natural processes and accelerated by the Restoration Program, these fish will return to areas of improved habitat once inhabited by their ancestors. The last decade has seen native chinook populations on the northern Oregon coast rise to their highest levels in a century. Nicholas and Hankin (1989) attribute this to natural habitat recovery and the presence of sufficient remaining genetic diversity in local stocks for the populations to rebound. With commitment and creativity, the Klamath River Basin Fisheries Task Force can achieve similar results.
Policies for Fish Population Restoration
Objective 5.A: Iron Gate Hatchery and Trinity River Hatchery should be operated to produce salmon and steelhead to mitigate for the losses of habitat above their dams and, at the same time, strive to reduce impacts on native fish.
5.A.1 The Task Force's Technical Team will work with CDFG to insure that the Basin's large-scale hatcheries operate to mitigate for loss of habitat above dams while limiting their impacts on wild stocks and maintaining the long term viability of hatchery broodstock. In coordination with Trinity River Task Force, the Task Force will:
a. Determine the optimal levels and composition of hatchery releases that can best achieve mitigation goals while minimizing impacts on native stocks.
b. Identify opportunities for enhancement and harvest supplementation using surplus hatchery eggs where it can be assured that there would be no disease transmission, genetic harm, in-river density dependent effects, or adverse harvest impacts to native stocks.
c. Encourage the continuation of hatchery practices that will maintain the fitness of hatchery broodstock and decrease undesirable impacts of straying on native fish.
d. Conduct a study to determine the resistance of Iron Gate Hatchery steelhead broodstock to Ceratomyxa shasta.
e. Support the CDFG in its effort to secure a water supply filter for Iron Gate Hatchery.
Objective 5.B: Small-scale rearing programs should be temporary measures, primarily for the purpose of accelerating the rebuilding of locally-adapted native salmon and steelhead populations, and operated to maintain the genetic integrity of such populations. Ideally, small-scale rearing programs should be operated in conjunction with habitat restoration projects.
5.B.1 Those parties having management authority over small scale rearing and pond programs in the Klamath River Basin shall, through coordinated planning, formulate independent guidelines for activities which will avoid negative effects on the genetic characteristics of native stocks. (The relevant parties, in this instance, are the Yurok, Hoopa, and Karuk Tribes and the State of California, acting through the California Department of Fish and Game.)
5.B.2 The guidelines for small-scale facilities will, to the extent possible, be consistent in content. The guidelines will be developed in accordance with the best known biological practices and their development shall be guided by a technical advisory committee, appointed by the Task Force, having expertise in genetics and fish culture. The small-scale facilities guidelines shall consider, but need not be limited to:
a. Procedures for trapping, rearing, incubating, and transferring fish, and for the control of fish diseases.
b. Broodstock management rules that ensure the maintenance of genetic integrity and the diversity of the stocks handled.
c. Requirements that an appropriate number of fish produced by small scale rearing and enhancement programs are marked and coded wire tagged so that ocean migration may be determined and that inbreeding can be avoided.
d. Methods by which to determine release strategies for pond reared steelhead from rescue programs in order to minimize residual behavior.
e. Methods to by which to evaluate program success.
5.B.3 The Task Force shall encourage small-scale fish rearing project operators to participate in research to determine:
a. Habitat quality to assess appropriate stocking levels.
b. Early life histories of fish cultured so that appropriate time for release can be determined.
c. Those levels of spawning escapement that represent "full seeding" so the Task Force may determine when populations have recovered sufficiently to close or move a facility.
5.B.4 The Task Force will explore means of improving the cost effectiveness of those small-scale rearing programs now targeting late-run fall chinook by capturing other species, such as coho and steelhead, where such efforts would contribute to Restoration Program objectives.
5.B.5 The Task Force will explore the need for green sturgeon population restoration measures.
5.B.6 The Task Force will support the continuation of fish rescue efforts in the middle Klamath Basin and the Scott and Shasta rivers as a viable tool for providing additional salmon and steelhead production.
