1950 From 1950 to 1987 is notable for having no multiyear droughts in the bottom 15 percentile. (Gedalof et al 2004)
1953 McNary Dam is completed just downstream from the mouth of the Snake River. This dam removed mainstem spawning areas for fall chinook and created passage problems.
1953 Federal dam construction in the Willamette River Basin begins. Seven large dams are built between 1953 and 1968. These dams block wild spring chinook and winter steelhead form most of the high quality spawning grounds in the basin.
1953 Lookout Point and Dexter dams are completed on the Middle Fork of the Willamette R eliminating 345 km of salmon habitat (Cramer et al. 1996). Only Fall Cr basin remains accessible to spring chinook and winter steelhead. See 1965 and 1995.
. 1955 Chief Joseph Dam is completed and eliminates mainstem spawning on the upper Columbia.
. 1956 The Dalles Dam is completed just downstream from the mouth of the Deschutes River. The reservoir behind this dam flooded historic Native American fishing grounds at Celilo Falls. This dam was supported by the states because they believed the Indian harvest of salmon would be eliminated and the salmon would be saved.
. 1957 Pelton Dam is completed on the Deschutes River in Oregon, blocking spawning areas for spring chinook, steelhead and sockeye salmon. The national fight to save the Deschutes was lost.
. 1958 Brownlee Dam is completed on the Snake River, blocking all salmon migration into the Snake above that point, eliminating salmon spawning in the Boise, Weiser, Payette, Malheur, Powder, Salmon Creek, and many other watersheds.
1958 The original and long standing objective of hatcheries is to maintain the supply of salmon, i.e., replace natural production lost to habitat destruction and over-harvest. But the evaluation of hatchery programs focused on whether hatcheries contribute to the fisheries. This divergence between the goal and evaluation lead to an outcome where salmon could continue to decline but hatchery program were considered a success as long as the cost of artificial propagation was less than their economic contribution to the fishery. The cost of hatchery production did not include the loss of natural production resulting from watershed development or from hatchery operations.
1958 From 1921 through 1958 the harvest of chinook in the Columbia averaged 15 million pounds, down from the average catch of 25 million pounds in the period 1889 to 1920. Form 1954 to 1958 the average harvest was only 6.9 million pounds. Some of this decline is attributed to an expanding ocean troll fishery, but a chinook decline in the river is still evident for this period.
. 1958 A OFC survey observed 3,198 spring chinook redds in the McKenzie River (Willis et al. 1960) See 1963.
. 1959 Priest Rapids Dam is completed on the Columbia above the mouth of the Snake River. This dam removes mainstem spawning for fall chinook and presents a passage problem for all species.
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. 1959 Two new fishways are completed on Columbia River tributaries for a total of 20 major fishways constructed since the Columbia River Fishery Development Program began in 1948.
. 1960 Hatchery production increased rapidly due to improved diets and disease control. The release of chinook in the Columbia increased from 61million fish in 1960 to 144 million in 1989 and a peak of 160 million in 1988. But as releases of hatchery fish increased, the return of adult chinook decreased.
1960 Doubling the hatchery program for chinook salmon did not result in a sustained reversal of the decline from earlier years. Hatchery fish now make up 80% of the returning salmon and steelhead in the Columbia. By limiting the focus of hatchery evaluations on cost-benefit analysis fish managers declare the hatchery programs a success even though the program failed to achieve its mitigation objectives and total abundance in the Columbia continues to decline.
1960s Spring and summer chinook smolt to adult return rates of these populations fell from greater than 4% in the mid to late 1960s when only four dams were in place, to generally less than 2% during the 1970s after seven or eight dams were in operation on the Columbia and Snake rivers. (Raymond 1988, Williams et al. 2001).
From 1966 to 1968, with only four or five dams in place on the Columbia and Snake rivers, the per dam survival estimates for chinook and steelhead was 45%. Survival estimates decreased to 20% as dams were added in the 1970s. During low flow conditions of 1973 and 1977 survival for chinook was 1-3% and for steelhead less than 1%. For the years 1993-1999 per project survival estimates ranged from 31% to 59%. In some years system survival rates exceeded that of the 1960s when only four dams and reservoirs existed. (Williams et al. 2001).
. 1960 Introduced shad have increased greatly from 1960 to 1990 with 2-4 million adults per year migrating up the Columbia past Bonneville Dam. They migrate 600 km up the Columbia and Snake. Interactions with salmonids is unknown, but they share the same food resources in the river and may be competitive in the ocean. The transformation of the Columbia by dams has created the spawning and rearing environment that favors shad.
. 1961 Rocky Reach Dam on the Columbia and Ice Harbor and Oxbow dams on the Snake are completed. Oxbow is a block to upstream migration. When the Oxbow reservoir was filled, the Snake River downstream was dewatered, killing thousands of salmon.
1961 The first comprehensive program to study juvenile salmonid migrants in the Columbia and Snake Rivers is initiated.
1961 Hills Dam (Willamette River) put in service
1963 Mayfield Dam on the upper Cowlitz River, a large tributary to the lower Columbia River is completed, blocking wild spring chinook, coho, fall chinook, winter steelhead and summer steelhead from most of the high quality rearing grounds in the basin. In 1968 Mossyrock Dam is built.
1963 Wanapum Dam is completed on the upper Columbia. Native Fish Society
1963 Cougar Dam on McKenzie River put in service, eliminating 56 km of spawning habitat on the South Fork McKenzie R. The SF McKenzie was considered the best salmon producing stream in the drainage (USFWS 1948). (Willamette, L Col R TRT 2005)
1965 Summer chinook fishing is closed on the Columbia to protect the stock. A total of 63,500 adults passed Bonneville Dam in that year.
. 1965 Fall Cr Dam included fish passage, but they worked only during high flow years.
. 1966 Lower Columbia River coho salmon have a spawner abundance of 38 fish per mile
1966 Fall chinook spawners number 12,800 in the Snake River.
. 1966 Dams on Santiam River put in service
. 1967 Hells Canyon Dam is completed on the Snake River. This dam is a complete block to fish passage and removes about 80% of the fall chinook spawning habitat in the Snake River.
. 1967 Wells Dam completed on the upper Columbia. This dam inundated important spring chinook spawning areas.
. 1968 The tribes file the U.S. v Oregon law suit to protect their treaty fishing rights and gain commercial fishing rights to the Columbia above Bonneville Dam…
1968 The governors of Oregon, Washington, and Idaho establish the Columbia River Fisheries Advisory Council composed of the fish and game directors of these states. This later becomes the Columbia Basin Fish and Wildlife Authority.
1968 John Day dam is completed on the Columbia just downstream from the John Day River. This dam remains a major problem for fish passage.
1968 Leonard A. Fulton, a biologist with the NMFS, estimated that an average of 34,000 fall chinook spawned between John Day and McNary Dams. He indicated that significant numbers spawned in the area inundated by McNary Dam.
. 1968 Blue River Dam on McKenzie River put in service, eliminating 32 km of spring chinook spawning habitat. (Willamette, L Col R TRT 2005)
. 1969 Lower Monumental Dam is completed on the Snake River creating passage problems and high concentrations of gas bubble disease.
1969 Commercial fishery rules above Bonneville Dam are established to include the area from the Bridge of the Gods to the mouth of the Umatilla River, with closures at mouths of rivers, dams, and with gear restrictions.
1960s-1970s Nitrogen supersaturation kills thousands of salmon due to spill at dams. 1970 Little Goose Dam completed on the Snake River, creating passage problems.
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. 1972 Dworshak Dam is built on the North Fork Clearwater River in Idaho, blocking this large productive tributary to B-run steelhead and spring chinook. The reservoir is 50 miles long and the dam is near the mouth of the river. A hatchery was constructed to mitigate for the dam.
. 1973 Severe drought in the Columbia River Basin caused low flow conditions and extreme mortality for salmon and steelhead passing through eight hydro dams from the Snake River to below Bonneville Dam. Spring chinook juveniles survival was 1-3% (97-99 percent mortality) and summer steelhead survival was less than 1% (>99 percent mortality) (Williams et al. 2001). See 2001.
. 1973 The Endangered Species Act passed by Congress. Fish agencies begin review of salmon and steelhead status for upper Columbia and Snake rivers under the ESA. This review was suspended in 1978 in anticipation of the N.W. Power Planning Act passed by Congress in 1980. It was believed that the Power Act would supply the money and measures to recover depleted salmon and steelhead runs.
. 1974 Dworshak Dam is completed on the North Fork Clearwater River in Idaho. This blocked the major production area for B-run summer steelhead in the Columbia Basin. Dworshak Hatchery was built to rescue this unique steelhead run.
. 1975 The Columbia River sockeye salmon fishery is closed.
1975 Chum salmon harvest in the lower river is a record low of 5,700 pounds or 500 fish. This represents a 99% reduction in chum salmon abundance since 1928.
1975 By initiative measure the citizens of Oregon prohibit the sale of steelhead by commercial fishermen. The tribes are excluded from this law and continue to sell steelhead.
1975 The Oregon Fish Commission and Wildlife Commission are merged to create the Oregon Department of Fish and Wildlife.
. 1975 Lower Granite Dam is completed on the Snake River. Salmon and steelhead in the Snake Basin have eight dams to cross twice in their life cycle.
. 1976 Spring chinook fishery is closed in the Columbia River.
1976 Scientists discover a shift in ocean productivity resulting in lower survival in northwest salmonids for the next twenty years. The combination of poor ocean survival and freshwater mortality caused by dams create a severe decline in upriver stocks.
. 1976 Foster Dam blocks nearly all historical spring chinook spawning areas in the Middle Santiam River, Quartzville Creek, and South Santiam River. (Willamette, L Col R TRT 2005).
. 1977 Since 1957 summer chinook decline is 75%, the spring chinook decline is 50%, and fall chinook decline is 90%.
1977 Low flows in the Columbia and Snake rivers are caused by a severe drought causing a 97 to 99 % smolt mortality passing the eight mainstem dams.
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1977 The federal court approved a five year management and allocation agreement between the states and tribes for salmon and steelhead.
. 1977 The four Columbia River treaty Indian tribes (Warm Springs, Nez Perce, Umatilla, and Yakima tribes) form the Inter-Tribal Fish Commission to represent their interests in the salmon fishery above Bonneville Dam.
. 1978 The Oregon Department of Fish and Wildlife establishes for the first time in its history a wild fish policy. The policy is primarily concerned about where hatchery fish will not be released rather than an ecologically based protection plan. This policy is adopted as a result of public insistence.
. 1978 Evaluation of hatchery steelhead on the Deschutes River showed that interbreeding between hatchery and wild fish reduced survival and adult production. This study showed that hatchery fish survive better in the hatchery environment than in natural streams and that wild fish survival was poor in the hatchery while performing much better than hatchery fish in streams. This was the first study to raise concerns about using hatcheries as the primary mitigation tool for habitat destruction.
. 1979 Only 30 sockeye salmon cross Ice Harbor Dam on the Snake River.
1979 Idaho closes its spring chinook fishery.
1979 Oregon approves a policy to forego spawner abundance goals for coho salmon on the lower Columbia River in order to maximize the harvest of hatchery coho. Hatchery fish would be out-planted into tributaries to supplement the lack of natural spawners.
. 1979 The wild coho spawner abundance declines to 2 spawners per mile in tributaries to the lower Columbia River.