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The anadromous fish that inhabit Battle Creek include chinook salmon (Oncorhynchus tshawytscha), steelhead (Oncorhynchus mykiss), and Pacific lamprey (Lampetra tridentatus). There are four distinct races, or runs, of chinook salmon that occur in the upper Sacramento River--more runs than any other river system--and historically all four runs, including winter-run, spring-run, fall-run, and late-fall-run, occurred in Battle Creek (Yoshiama et al. 1996). At present, two of the four runs, including winter-run and spring-run, are at remnant status. Other species of salmon occasionally stray into Battle Creek. During a ten year period (1949 to 1959), 45 individual salmon from salmon species including pink, chum, sockeye and coho salmon, were recovered with chinook salmon at the CNFH (Hallock and Fry 1967).
Sacramento River chinook salmon runs are designated by the seasons during which adults enter San Francisco Bay to begin their upstream spawning migrations. While the fall-run and late-fall-run both spawn shortly after arriving on the spawning grounds the spring-run and winter-run are especially adapted to stay in the vicinity of the spawning area for several months before they spawn. This ability to migrate upstream in the spring and winter months long before their spawning time allows these special runs to access the mountain reaches of the stream that are colder and out of reach of the other runs that migrate when the water is low in the fall. The placement of dams in the Sacramento River system has blocked many of the historic spawning areas in the mountains (CDFG 1993c).
Battle Creek has been regarded as a uniquely important salmon-producing watershed because of the large numbers of chinook salmon that used to be produced there and because of the diversity of the four races of chinook that inhabit Battle Creek. Early fisheries investigators claimed that Battle Creek was the most important salmon-producing tributary to the Sacramento River when its ecosystem had its original forma and function (Rutter 1904; CDFG 1993c). Others have noted the uniqueness of having four phenotypically and genetically distinct races of chinook salmon within the watershed (Yoshiama et al. 1996; NMFS 1997a; CDFG 1998b), something that occurs nowhere else with the exception of populations in the Sacramento River artificially confined downstream of Shasta Dam.
Battle Creek is still recognized as the watershed with the best potential for restoring salmon and steelhead. CDFG (1993c) suggested that restoration of Battle Creek would provide a unique opportunity to restore a drought-resistant population of winter-run chinook salmon as a safe-guard against possible extinction of the primary population of this race located in the upper Sacramento River. CDFG (1996c) regarded Battle Creek as one of four upper Sacramento River tributaries that offer the best opportunities for restoration of native and wild steelhead populations. Furthermore, the location and excellent water quality and quantity in Battle Creek fostered recognition that Battle Creek was the best site for location of a hatchery intended to mitigate for the negative impacts of Shasta Dam (Hedgpeth 1944).
Chinook salmon and steelhead
trout production was essentially the sole focus of restoration efforts in the
past. Current efforts are focused on developing an ecological approach to salmon
and steelhead restoration (the principle of such an approach are described in
Spence et al. (1996)). The Central Valley Project Improvement Act specifies
that the fisheries resources lost by operation or maintenance of the project
shall be mitigated based on the replacement of ecologically equivalent habitat.
The stated goal of the CalFed Ecosystem Restoration Program is to improve and
increase aquatic and terrestrial habitats and improve ecological functions in
the Sacramento River Bay- Delta System to support sustainable populations of
diverse and valuable plant and animal species. The foundation of the Ecological
Restoration Program Plan is restoration of ecological processes that are associated
with streamflow, stream channels, watersheds and floodplains. In addition, the
program aims to reduce the effects of stressors that inhibit ecological processes,
habitats, and species (CalFed 1998).
References
Moyle, P. B., R.M. Yoshiyama, and R.A. Knapp, 1996. Status of fish and fisheries. Chapter 33 of Sierra Nevada Ecosystem Project: Final report to Congress. Vol. II, Assessments and scientific basis for management options. University of California, Centers for Water and Wildland Resources. Davis, CA. 21 pp. [450kb].
Ward, M. B. and W.M. Kier, 1999. Battle Creek salmon and steelhead restoration plan. Prepared for the Battle Creek Working Group by Kier Associates. Sausalito, CA . 157 pp. [1.4 Mb]
Yoshiyama, R. M., E.R. Gerstung, and F.W. Fisher, 1996. Historical and present distribution of chinook salmon in the Central Valley drainage of California. Chapter 43 of Sierra Nevada Ecosystem Project: Final report to Congress. Vol. III, Assessments, Commissioned Reports and Background Information. University of California, Centers for Water and Wildland Resources. Davis, CA. 50 pp. [550kb]