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Restoration of Pacific Salmon in Columbia River Basin. Abstract
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Restoration of Pacific Salmon in Columbia River Basin Abstract The number of Pacific salmon returning to spawn in the Columbia River has declineddrastically over the last 150 years. Annual spawning runs prior to European settlement in the 19th century are estimated to have been in the range of 10-16 million salmon; in contrast, only approximately 1 million returned per year during the late 1990s. Many native stocks have gone extinct and a number of others are presently listed as threatened or endangered by extinction under the Endangered Species Act. The initial declines were largely due to the overharvest of adult salmon returning to spawn in the river. During the same period, logging, mining, agriculture, and urbanization resulted in the degradation of aquatic habitats in many parts of the Columbia River Basin. The most significant habitat alteration was the construction of numerous dams in the river system for the purposes of hydroelectric power generation, flood control, and irrigation. These dams made significant portions of the river inaccessible to migrating adult salmon and have turned mainstem river habitats into reservoirs with very little flow. These changes have negatively impacted the ability of smolts to migrate to the sea. Lastly, hatcheries constructed by federal, state, and tribal authorities have resulted in millions of fingerling salmon being deposited into the river each year. These fish compete with naturally spawned smolts for resources in the river, leading to the loss of local adaptations when hatchery-reared fish return to the river as adults and spawn with native stocks. Habitat loss, hydropower dams, and hatcheries all continue to challenge the persistence of natural salmon populations in the Columbia River system.
Pacific salmon populations have declined dramatically in the Columbia River and its tributaries over the past century and a half. This crisis is the direct result of human development of the river. Extensive recovery efforts have been unsuccessful. Today, thirteen evolutionarily significant units (ESUs) are listed as endangered or threatened by extinction under the Endangered Species Act. Hundreds of populations have already gone extinct.
The Columbia River Basin (green area in map) is the dominant water system in the Pacific Northwest, draining an area of 258,500 square miles (an area approximately the size of France). The river provides power, food (through irrigation), transportation (through navigation), recreation, fisheries, and, to a lesser extent, municipal and industrial water supply to human populations. These anthropogenic uses have ultimately led to the depletion of native salmon populations.
Eggs are laid in freshwater stream gravel Larvae develop in freshwater stream gravel Fry emerge from gravel, develop into smolts, and migrate to ocean Adults spawn in home streams Migration back to freshwater spawning grounds Fish grow and mature in ocean Pacific salmon are anadromous (adults migrate from the ocean to freshwater streams to spawn, then offspring migrate to the ocean from the streams to grow). This complicated life history makes them especially vulnerable to changes in the river environment. Species and populations differ in the time of the year and part of the Basin in which they return to spawn.
Coho salmon (Oncorhynchus kisutch) Chinook salmon (Oncorhynchus tshawytscha ) Chum salmon (Oncorhynchus keta) Sockeye salmon (Oncorhynchus nerka) Steelhead (Oncorhynchus mykiss) Salmon of the Columbia Basin(steelhead are anadromous trout, not technically salmon, but all five species will be referred to as salmon in this presentation for the sake of simplicity)
Human development has drastically changed river environments in the Columbia River Basin. The major threats to salmon are: Habitat degradation Harvest Hatcheries Hydropower
Prior to European settlement, the Columbia River produced some of the largest salmon runs in the world: 10-16 million adult salmon from 200 distinct stocks returned to the river annually. Native American tribes value salmon as food and spiritual symbols. Stocks persisted with traditional harvest methods.
1805 Lewis and Clark reach Columbia River Basin Commercial logging begins in the Pacific Northwest 1827 1850 There are 37 sawmills operating in the Pacific Northwest First railroad constructed in proximity to the Columbia River 1851 1859 First large-scale irrigation project in the Columbia Basin 1861 Commercial fishing industry begins with packing of salted salmon on the Columbia River 1866 First salmon cannery is begun 50 miles upstream of the mouth of the Columbia European settlement of the Columbia River Basin
This graph indicates how many pounds of salmon were harvested in the Columbia River Basin. through time.
19th century cannery at Astoria, Washington 1866: First cannery begins operation with two boats harvesting salmon in the Columbia Basin.
1872: One hundred boats harvesting salmon in the Columbia Basin.
1874: Two hundred and fifty boats harvesting salmon in the Columbia Basin.
1878: Five hundred boats harvesting salmon in the Columbia Basin.
1881: Twelve hundred boats harvesting salmon in the Columbia Basin.
1889: Canneries begin processing sockeye salmon and steelhead for the first time. Coho and chum salmon are accepted a few years later.
1911: Peak year for salmon landings (all species combined), 49.5 million pounds.
1912: Ocean trolling for salmon begins off the mouth of the Columbia River.
1941: Grand Coulee Dam is completed; salmon lose access to 500 miles of the upper Columbia River.
1967: Hells Canyon Dam is completed; salmon cannot access the upper Snake River.
1991: First Columbia salmon stocks listed under the Endangered Species Act.
1993: U.S. District Judge orders government to alter dam operations to lessen hazards to salmon.
1994: Salmon fishing banned off Oregon and Washington coasts for first-time.
1995: Federal government dictates more water must be used for fish rather than power production and irrigation.
Cannery dock workers. Photo of the collection baskets of a fish wheel. Harvest and Columbia River Salmon Harvest was the first activity to depress salmon populations in the Columbia River Basin. The commercial fishing industry captured so many fish that there were not enough adult salmon reaching the spawning grounds to produce the next generation to be harvested. The predictable timing and location of the salmon runs made them easy to capture in large numbers using a variety of methods (nets, traps, and an invention called a fish wheel that scooped up migrating salmon in baskets and deposited them in a holding compartment). During the first few decades of the Columbia River fishery, fisherman often captured more salmon than the canneries could process and the corpses of the unprocessed fish were returned to the river as waste. Concerns about the declining salmon fishery led the United States Senate to commission a report in 1887 that concluded it was “ . . . a sort of a miracle that any fish escape to go up the river.” (Jones 1888)
Harvest and Columbia River Salmon Early warnings did not prevent the current crisis because the short-term economic benefits of harvest were given precedence over long-term conservation, the harvest restrictions were weak and poorly enforced, and, at the time, knowledge of salmon biology was limited. Today, harvest restrictions cannot solve the Columbia River salmon crisis (because of the effects of habitat degradation, hydropower, and hatcheries). In addition, ineffective harvest regulations will lead to the extinction of endangered and threatened stocks. The effectiveness of current management actions is limited by: • The erroneous interpretation of the number of salmon passing certain key hydroelectric dams as estimates of spawning stock abundance. To set effective harvest regulations, managers need to have accurate estimates of the productive capacities of individuals stocks; these estimates can only be achieved through measuring the number of adult salmon returning to individual tributaries in the Columbia River. (2) The failure to account for fishing mortality – particularly in the ocean. Many fish are caught but not kept (they could be the wrong size, wrong species, etc.). A significant number of fish returned to the ocean do not survive. These losses are not considered in management plans.
Habitat Degradation and Columbia River Salmon Human land-use activities have dramatically degraded the freshwater habitats required for salmon survival and reproduction. Many salmon stocks travel hundreds of miles (over several weeks or months) to migrate between freshwater reproductive habitats and the ocean. These stocks are unlikely to persist when human development alters river environments to the extent that they no longer resemble the historic habitats in which the fish are adapted to survive and reproduce. Managers recognized that half of the best spawning and rearing habitat had been lost or severely degraded by 1932. (Oregon Fish Commission 1933)
Habitat Degradation and Columbia River Salmon Human land-use activities have reduced the amount of spawning (and rearing) habitat for salmon and have made migration between reproductive habitats and the ocean much more difficult. Logging Agriculture Livestock grazing Mining
Habitat Degradation and Columbia River Salmon First and foremost, salmon require cold, clean water to survive. Salmon physiology is controlled by environmental temperature, therefore seasonal water temperatures have influenced when salmon migrate between the ocean and freshwater spawning habitats. Human land-use has reduced the amount of riparian vegetation and cover, resulting in water temperatures being more than 2°C higher than historical levels in 855 managed watersheds (National Academy of Sciences 1996). These elevated temperatures affect fish directly through influences on metabolism and indirectly through food web changes. Salmon require deep pools, riparian cover, undercut banks, and in-stream woody debris to avoid predation during river migration. These habitat features have been reduced by human development of the river. In particular, large accumulations of wood provide refuge from predators, create low velocity resting areas, lead to the scouring of deep pools, trap sediments and organic material that contribute to food webs, and create a diverse and stable habitat. There is much less woody debris present in steams today due to logging, grazing, and other developments of riparian areas.
Juvenile salmon in a habitat with woody debris. Habitat Degradation and Columbia River Salmon Salmon eggs and fry incubate in the small spaces between gravel on the bottom of streams. Human activities that lead to erosion and sedimentation destroy reproductive areas by covering them with silt. When juvenile salmon rise out of the gravel, they need low-velocity habitats that have cover, small food particles, and refuge from predators — habitats that typically include woody debris, overhanging banks, and riparian vegetation. Sedimentation can deplete populations of invertebrate prey and impair the ability of young salmon to capture the prey that are available. Summer temperatures in most Columbia River tributaries (particularly those reaches that have been altered by human activities) far exceed the thermal optimum for larval salmon development (15°C) and often the lethal thermal maximum (24°C; Rhodes et al. 1994). Loss of habitat anywhere along the migratory path from the spawning grounds to the ocean can imperil a breeding population of salmon.
Hydropower and Columbia River Salmon Harvest and habitat degradation had already depressed Columbia River Basin salmon populations by the time the hydropower system was developed in tributaries in the late 19th century. The Rock Island Dam was the first dam completed on the mainstem of the Columbia River in 1933. Today there are 14 mainstem dams on the Columbia and Snake Rivers. Basin-wide, there are 400 dams used for hydropower and/or irrigation. Although the salmon of the Columbia Basin were challenged by human development prior to the construction of the hydropower system, dams have had devastating impacts on salmon. • The construction and operation of dams has: • Drastically reduced the amount of spawning habitat in the Basin. • Changed flow conditions encountered by migrating salmon. • Altered habitats in many reaches. • Created physical barriers to salmon migration.
Hydropower and Columbia River Salmon The Grand Coulee Dam (completed in 1941) was the first dam to block salmon passage on the Columbia River mainstem. The Hells Canyon Dam (completed 1967) blocked upstream passage to a large portion of the Snake River. Today, 55% of historic spawning and rearing habitats are blocked or inundated by dams (Northwest Power Planning Council 1992). Grand Coulee Dam Hells Canyon Dam MAP OF AREA BLOCKED BY DAMS MAP OF MAJOR DAMS IN THE BASIN
Salmon smolt (juvenile) Hydropower and Columbia River Salmon Natural river flows have been altered by dam operations which hold large volumes of water in upstream reservoirs in order to provide water for irrigation and power generation at times of the year when natural flows would not be sufficient. As a result, current flow patterns differ from the historic flow regimes to which salmon are adapted. The altered flow regimes may have the greatest effect on juvenile salmon migrating to the ocean. Historical records show that wet years (and therefore years with more flow) are correlated with better salmon production (Anderson et al. 1996), and that impoundment of the Columbia and Snake Rivers has decreased the migration speed of yearling chinook and steelhead (Giorgi et al. 2002). In addition to extending the amount of time it takes juvenile salmon to migrate to the ocean, dams have created markedly different habitats through much of the river. Rather than a flowing riverine system, today most of the mainstem river consists of reservoirs with little or no flow. These reservoirs are inhabited by different invertebrate communities (the main source of food for juvenile salmon) than flowing river segments. In addition, reservoirs are the ideal habitat for many invasive species, such as walleye and bass, that have been introduced to the river and now feed on juvenile salmon migrating to the ocean.
Hydropower and Columbia River Salmon Most mainstem dams on the Columbia River (generally 100 feet tall) pose a challenge to the migration of adult and juvenile salmon. Adults migrating upstream may pass the dams by using fish ladders or navigation channels. Juvenile salmon migrating downstream may pass dams by four routes: • Passing through the powerhouse (the interior portion of the dam where the water turns the turbines that generate energy) • Passing over the spillway (the exterior of the dam used to pass water that is not used for power generation) • Through navigation channels (locks and other channels used for ship passage, not used often and not shown in figure) • Through fish ladders (adult fish are much more likely to use fish ladders than juvenile fish)
Fish ladder Hydropower and Columbia River Salmon Fish ladders have proven to be an effective technological solution for adult salmon passage. Recent studies suggest 98% adult salmon survival at each dam on the lower Columbia and Snake Rivers (U.S. Army Corps of Engineers, the Bureau of Reclamation, and Bonneville Power Administration 2006). Improving juvenile passage has been more challenging. Research conducted shortly after the construction of mainstem dams indicated that juveniles passing through powerhouses were injured or kill by contact with turbines. Dams have been fitted with screen systems that direct juveniles away from turbines and into bypass systems, which have made significant improvements in survival. The recognition that juveniles are vulnerable to predation after passing through dams has led managers to capture a portion of juveniles in bypass systems, load them onto barges, and transport them through the mainstem of the river. Predator removal programs have also been created to help improve juvenile survival.
Hatcheries and Columbia River Salmon Producing fish in hatcheries has been considered a primary means of mitigating the reduction in salmon spawning naturally due to human developments in the river (and an alternative to other means of conservation, such as harvest restrictions and habitat restoration). Although hatcheries are capable of releasing large numbers of juvenile salmon into rivers (approximately 200 million salmon are released into the Columbia Basin each year), recent evidence suggests that hatchery fish do not perform as well in the natural environment as wild fish. In recent decades, 80% of adult salmon returning to the river were hatched and reared in hatcheries (Northwest Power Planning Council 1992, National Research Council 1996). Even so, the hatchery program has failed to achieve the goals of mitigating habitat loss and degradation. The National Fish Hatchery Review Panel (1994)and National Research Council (1996)both concluded that the objectives and role of artificial propagation needed reconsideration.
Hatcheries and Columbia River Salmon • Hatchery produced fish have negatively affected salmon recovery in three ways: • Artificial production has taken resources away from other recovery efforts. Prior to 1980, 43% of recovery expenditures went to hatcheries, 1% of funds were spent on habitat (General Accounting Office 1992). In recent years 40% of funds went to hatcheries and 6% went to habitat (General Accounting Office 1993, 2002). • Artificial production leads to competition between wild and hatchery fish. Fish produced in hatcheries compete with wild fish for food and habitat resources once they are released into natural environments. There is potential for wild fish to be swamped by the release of large numbers of hatchery-reared juveniles into environments (each environment can only support a certain number of fish). This concern is especially relevant to the populations that are threatened or endangered by extinction ( and therefore already have very low natural reproduction). This competition is particularly damaging if the hatchery fish are unlikely to survive to return and contribute to reproduction as adults. There are now a number of studies showing reduced performance for hatchery-origin fish relative to wild fish in most comparisons (Fleming and Peterssen 2001, Berejikian et al. 1996, 1997, 1999, 2001a, 2001b; Kostow et al. 2003).
Hatcheries and Columbia River Salmon • Direct genetic effects can occur when hatchery fish breed with wild fish. Studies have shown that the offspring produced by these matings usually have greater mortality and lower reproductive success relative to the offspring produced by matings between wild fish (Leary et al. 1995; Fleming and Peterssen 2001). • In addition to producing inferior offspring, numerous studies have shown that these matings results in a loss of genetic variation within and among populations (Allendorf and Ryman 1987; Currens et al. 1990; Williams et al. 1996; Einum and Fleming 2001; Utter 2002). Genetic variation is the raw material for adaptation and evolution, so losing variation may limit a population’s abilities to adapt to future (or current) environmental change. Local adaptations are likely to be lost when the hatchery-produced fish are genetically dissimilar from the wild fish they mate with, or were produced by very few parents (Hindar et al. 1991; Waples 1991).
Conflict regarding Columbia River salmon restoration revolves around how much human activities in the Basin should be restricted in attempts to restore salmon. Stakeholders can generally be split into those who support salmon conservation at the expense of economic and recreational activities and those who want to minimize the impacts of salmon restoration on human activity within the Basin. However, the reality is that people exist along a continuum, with those supporting the removal of mainstem dams from the river and the prohibition of nearly all activities that impact salmon on one end, and those who do not want to allow salmon conservation to impact economic activity on the other. Commercial Fishermen Power Companies SALMON ARE THE PRIORITY IN BASIN SALMON SUBORDINATE TO OTHER ACTIVITIES Recreational Fishermen Logging Industry Agriculture/ Livestock Industry Native American Tribes
Columbia River Interstate Compact Created in 1915, a compact was developed between Washington and Oregon to coordinate commercial fishing seasons and regulations in the Columbia River. The fish and wildlife departments of the two states set seasons and regulations for five fishing zones between the river mouth and Bonneville Dam. A sixth zone is exclusive for Native American fisheries. The decisions made for zones 1-5 must leave enough fish to fulfill the legal requirement that Native fishers have rights to half the fish in the river. A U.S. District Court presently oversees harvest regulations through U.S. vs. Oregon proceedings. Magnuson-Stevens Act Regulation of ocean harvest is set by the Magnuson-Stevens Fisheries Conservation Act and the Pacific Salmon Treaty (1985 treaty designed to foster cooperation between U.S. and Canadian governments and stakeholders regarding salmon harvests).
Pacific Salmon Recovery Areas COLUMBIA BASIN DOMAINS Endangered Species Act In 1991, the National Oceanic and Atmospheric Administration (NOAA) received a petition to protect Northwest Salmon under the Endangered Species Act (ESA). As a first step, the Northwest and Southwest Fisheries Science Centers conducted a systematic review of all anadromous west coast salmon species between 1994 to 1999. This review identified 52 Pacific salmon Evolutionarily Significant Units (ESUs), five of which were listed as endangered, and 21 were listed as threatened with extinction under the ESA. (weblink to most recent ESU info) Thirteen ESUs inhabit the Columbia River Basin. NOAA split the Basin into two separate regions for developing recovery plans: a Willamette/Lower Columbia recovery domain and an Interior Columbia recovery domain.
Columbia Basin ESUs listed under ESA Endangered Species Act Technical Recovery Teams (assembled by NOAA to identify the scientific basis for salmon recovery) have designated critical habitat for all but the most recently listed Coho salmon ESU. Final recovery plans have been accepted for only two ESUs. The other ESUs are at different stages in the recovery plan’s development process.
Endangered Species Act The development of salmon recovery plans has been fraught with legal challenges under the Endangered Species Act (ESA). For example, the first draft recovery plan for Snake River salmon was issued by the technical recovery team in 1995, however, environmental interests thought the plan did not go far enough in ensuring that acceptable proportions of smolts survived downriver migration, and economic interests thought the recommended plans went too far. As a result of these differing opinions, Snake River recovery plans have not progressed beyond the draft stage over the past 13 years. Federal judges have rejected each of the four sets of biological opinions (BiOps) that NOAA has released since 1993 (most recently in 2004). Under the ESA, NOAA is required to develop BiOps that direct federal agencies to take specific actions in order to avoid jeopardizing listed species. BiOps direct recovery efforts while recovery plans are being developed. The groups that have filed legal challenges to BiOps have included environmental organizations, fishing organizations, state fish and wildlife agencies, Indian tribes, electric utilities, and industries that rely on water or electricity from the Columbia River Basin. Judges have ruled that the actions set forth by NOAA in BiOps were illegal in that they did not offer the level of protection required by listing under the ESA. The greatest obstacle has been the failure of the BiOps to include changes in hydropower operations that could be expected to improve the survival of migrating salmon. NOAA released the fifth biological opinion in May 2008. The National Wildlife Federation challenged the opinion in July 2008.
The most recent status review of the Pacific salmon ESUs (completed by NOAA in 2005) changed the status of one ESU from endangered to threatened and listed the thirteenth ESU for protection under the ESA. No ESUs were delisted (i.e., had recovered). The PacificOoean salmon fishery was declared a failure and closed in May 2008 due to historically low salmon returns. Disaster funds have been disbursed to fisherman. The scope of the Columbia River salmon crisis is enormous: each of the four major factors challenging salmon recovery would present a substantial conservation challenge by themselves, the impacted area is as large and developed as many countries, and the conservation actions with the best chance of success would all present serious economic impacts. The hydropower system presents the primary obstacle to salmon recovery at this point; even if the effects of habitat, harvest, and hatcheries were minimized, salmon populations would be likely to remain depressed as long as hydropower operations were not significantly altered. It is difficult to conceive of any legislation that would be able to resolve a situation as large and complication as the Columbia River Salmon Recovery.
Additional Resources Books: RETURN TO THE RIVER: RESTORING SALMON TO THE COLUMBIA RIVER. 2006. Richard N. Williams, eds. El Sevier Academic Press, Burlington, MA. (weblink) Internet: Columbia River History Project (http://www.nwcouncil.org/history/Default.asp): Website operated by the Northwest Power and Conservation Council that has extensive information on biological, historical, and conservation/management topics regarding the Columbia River. Northwest Regional Office (NOAA, http://www.nwr.noaa.gov/): Website operated by the government office responsible for directing Pacific salmon recovery efforts. Includes information on general conservation/management topics as well as actions related to the Endangered Species Act. Salmon Recovery.gov (http://www.salmonrecovery.gov/): Website operated by the Federal Caucus, which consists of eight agencies that play a role in natural resource conservation in the Columbia Basin. Includes both news and historical information on recovery efforts. Pacific Fishery Management Council (http://www.pcouncil.org/): Website for the agency responsible for the management of the ocean salmon fisheries. The site provides basic information regarding their role in managing salmon.
Glossary: Anadromous: A life history that includes migration from the ocean to freshwater to breed. Anadromous fishes begin their lives in freshwater as eggs and/or developing young, migrate to the ocean for some period of their life, and then return to freshwater to reproduce. Evolutionarily significant units: A population or organisms that is considered distinct for the purposes of conservation. The term can apply to any species, subspecies, geographic race, or population. ESUs are often referred to as stocks when discussing fish or marine animals. ESUs are the basis for protection under the Endangered Species Act, where to be considered an ESU the organisms in question must be substantially reproductively isolated from other conspecific populations and represent an important component in the evolutionary legacy of the biological species. Mainstem: The principal river within a drainage basin, into which smaller tributaries are linked. Riparian: Interface between terrestrial and aquatic habitats. Semelparous: A life history in which organisms reproduce once in their lifetime, often dying shortly thereafter. Smolt: Juvenile salmon that has begun the migration from freshwater to the sea. Stock: Subpopulations of a particular species of fish, for which intrinsic parameters (growth, recruitment, mortality and fishing mortality) are the only significant factors in determining population dynamics, while extrinsic factors (immigration and emigration) are considered to be insignificant.
References Allendorf, F.W., and N. Ryman. 1987. Genetic management of hatchery stocks. Pages 141-160 in N. Ryman and F. Utter, eds. Population genetics and fishery management. University of Washington Press, Seattle. Anderson, D.A., G. Christofferson, R. Beamsdorfer, B. Woodward, M. Rowe, and J. Hansen. 1996. StreamNet: Report on the status of Salmon and Steelhead in the Columbia River Basin-1995. Bonneville Power Administration. DOE/BP-65130-1. Portland, Oregon. 76 p. Berejikian, B.A., S.B. Matthews, and T.P. Quinn. 1996. Effects of hatchery and wild ancestry and rearing environments on the development of agonistic behavior in steelhead trout (Oncorhynchus mykiss) fry. Canadian Journal of Fisheries and Aquatic Sciences 53:2004-2014. Berejikian, B.A., E.P. Tezak, S.L. Schroder, C.M. Knudsen, and J.J. Hard. 1997. Reproductive behavioral interactions between wild and captively-reared coho salmon (Oncorhynchus kisutch). ICES Journal of Marine Science 54:1040-1050. Berejikian, B.A., E.P. Tezak, S.L. Schroder, T.A. Flagg, and C.M. Knudsen. 1999. Competitive differences between newly emerged offspring of captively reared and wild coho salmon (Oncorhynchus kisutch). Transactions of the American Fisheries Society 128:832-839. Berejikian, B.A. 2001a. Release of captively-reared adult salmon for use in recovery. World Aquaculture 32:63-65. Berejikian, B.A., E.P. Tezak, and S.L. Schroder. 2001b. Reproductive behavior and breeding success of captively-reared Chinook salmon (Oncorhynchus tshawytscha). North American Journal of Fisheries Management 21:255-260. Chapman, D.W. 1986. Salmon and steelhead abundance in the Columbia River in the nineteenth century. Transactions of the American Fisheries Society 115:662-670. Countant, C.C. 1998. Turbulent attraction flows for juvenile salmonid passage at dams. Oak Ridge National Laboratory. ORNL/TM-13608. Oak Ridge, TN. 28 pp. (http://www.ornl.gov/info/reports/1998/3445604452090.pdf) Currens, K.P., C.B. Schreck, and H.W. Li. 1990. Allozyme and morphological divergence of rainbow trout (Oncorhynchus mykiss) above and below waterfalls in the Deschutes River, Oregon. Copeia 1990:730-746. Einum, S., and I.A. Fleming. 2001. Implications of stocking: ecological interactions between wild and released salmonids. Nordic Journal of Freshwater Research 75:56-70. Fleming, I.A. and E. Petersson. 2001. The ability of released hatchery salmonids to breed and contribute to the natural productivity of wild populations. Nordic Journal of Freshwater Research 75:71-98. General Accounting Office (GAO) 1992. Endangered species: Past actions taken to assist Columbia River Salmon. US General Accounting Office. Report to Congressional Requesters, GAO/RCED-91-173BR. Washington, DC. General Accounting Office (GAO) 1993. Endangered species: Potential economic costs of further protection for Columbia River salmon. US General Accounting Office. Report to Congressional Requesters, GAO/RCED-93-41. Washington, DC. General Accounting Office (GAO) 2002. Columbia River salmon and steelhead: Federal agencies’ recovery responsibilities, expenditures and actions.. US General Accounting Office. Report to Congressional Requesters, GAO/RCED-02-612. Washington, DC. Giorgi, A.E., M. Miller, and J. Stevenson. 2002. Mainstem Passage Strategies in the Columbia River System: Transportation, Spill, and Flow Augmentation. Doc. 2002-3. Northwest Power Planning Council. Portland, Oregon. 97 pp. Henjum, M.G., J.R. Karr, D.L. Bottom, J.C. Bednarz, S.G. Wright, S.A. Beckwitt, and E. Beckwitt. 1994. Interim protection for late-successional forests, fisheries, and watersheds: National forests east of the Cascade Crest, Oregon and Washington. The Wildlife Society, Bethesda, Maryland.
References (continued) Jones, William A., Salmon Fisheries of the Columbia River, 50th Cong., 1st sess., 1888, S. Exec. Doc. 123, SS 2510 Kostow, K.E., A.R. Marshall, and S.R. Phelps. 2003. Naturally spawning hatchery steelhead contribute to smolt production but experience low reproductive success. Transactions of the American Fisheries Society 132:780-790. Leary, R.F., F.W. Allendorf, and G.K. Sage. 1995. Hybridization and introgression between introduced and native fish. American Fisheries Society Symposium: Uses and effects of cultured fishes in aquatic ecosystems 15: 91-101. National Academy of Sciences (NAS). 1996. Upstream. Salmon and society in the Pacific Northwest. Committee on Protection and Management of Pacific Northwest Anadromous Salmonids. National Academy Press. National Fish Hatchery Review Panel. 1994. U.S. Fish and Wildlife Service National Fish Hatchery Review. The Conservation Fund, The National Fish and Wildlife Foundation. Report. Arlington. Virginia. National Research Council. 1996. Upstream: salmon and society in the Pacific Northwest. Report on the Committee on Protection and Management of Pacific Northwest Anadromous Salmonids for the National Research Council of the National Academy of Sciences. National Academy, Press. Washington DC. Northwest Power Planning Council. 1992. Columbia River Basin Fish and Wildlife Program. Document 92-21A. Portland, Oregon. Oregon Fish Commission. 1933. Biennial report of the Fish Commission of the State of Oregon to the Governor and the thirteenth legislative assembly. Portland, Oregon. Rhodes, J.J., D.A. McCullough, and J.F.A. Espinosa. 1994. A course screening process for evaluation of the effects of land management activities on salmon spawning and rearing habitats in ESA consultations. Technical Report 94-1, Columbia River Inter-tribal Fish Commission, Portland Oregon. U.S. Army Corps of Engineers, the Bureau of Reclamation, and Bonneville Power Administration. 2006. Protecting Salmon: Highlights, Endangered Species Act Federal Columbia River Power System 2005 Progress Report. Utter, F.M. 2002. Kissing cousins: Genetic interactions between wild and cultured salmon. Pages 119-135 in B. Harvey and M. MacDuffee, eds. Ghost runs: the future of wild salmon on the North and Central Coasts of British Columbia. Rainforest Conservation Society, Victoria, British Columbia. Waples, R. S. 1991. Genetic interactions between wild and hatchery salmonids: lessons from the Pacific Northwest. Canadian Journal of Fisheries and Aquatic Sciences, (48 (Supplement 1))124-133. Washington Department of Fish and Wildlife, and Oregon Department of Fish and Wildlife. 2002. Status report. Columbia River fish runs and fisheries, 1938-2000. 2002. Washington Department of Fish and Wildlife and Oregon Department of Fish and Wildlife. Olympia, Washington, and Clackamas, Oregon. (http://wdfw.wa.gov/fish/columbia/2000_status_report_text.pdf) Williams, R.N., D.K. Shiozawa, J.E. Carter, and R.F. Leary. 1996. Genetic detection of putative hybridization between native and introduced rainbow trout populations of the Upper Snake River. Transactions of the American Fisheries Society 125:387-401.