Upstream Salmon and Society in the Pacific Northwest (1996) / Chapter Skim
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4 Status of Salmon
4 Status of Salmon
Pages 75-114
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From page 75... ...
Using a geographic information system based on state agencies' status reports from the American Fisheries Society and other sources, the Wilderness Society (1993) estimated current extinction risks of Pacific Northwest salmon throughout their historical ranges (Table 4-1J.
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From page 76... ...
spring/summer chinook, summer steelhead, and sockeyeare extinct over a greater percentage of their range than species limited primarily to coastal rivers. Salmon whose populations are stable over the greatest percentage of their range (fall chinook, chum, pink, and winter steelhead)
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From page 77... ...
The remainder of this chapter discusses some of the difficulties in evaluating the status of wild populations and how these problems have been addressed in recently published status reports. It then summarizes regional trends in salmon populations in the Fraser River Basin, Puget Sound, the Columbia River Basin, and coastal river basins of Washington, Oregon, and California.
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From page 78... ...
Puget Sound fisheries on Fraser River sockeye masked trends of Puget Sound sockeye populations unless more refined catch data were examined. THE STOCK CONCEPT In the jargon of Pacific salmon fisheries, managers refer to stocks of salmon, i.e., populations or groups of salmon populations that are recognizable for management.
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From page 79... ...
In theory, the stock concept makes no allowance for deme size or metapopulation structure, in which populations consist of locally reproducing groups connected by some gene flow within a larger area. The management of stocks by state fisheries agencies has generally not recognized the geographical structure of salmon populations at such fine scales.
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From page 80... ...
In contrast, The Wilderness Society (1993) stated that "chum salmon are depleted or extinct in the rivers of southern Puget Sound .
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From page 81... ...
(1992) , The Wilderness Society (1993)
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From page 82... ...
FRASER RIVER BASIN The Fraser River produces more salmon than any other river in the world (Northcote and Larkin 1989:172-204) , including the seven species of anadromous salmon on which this report focuses.
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From page 83... ...
1914~. The Hell's Gate rockslide accounts for the major loss of sockeye catch that started in 1916, and the loss of pink salmon populations in the Thompson River (Ricker 1989~.
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From page 84... ...
in the Fraser River area (Statistical areas 28 and 29) between 1876 and 1985.
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From page 85... ...
250 -Spring/summer esc ClTerminal Catch g 200 ldlOnNl 111 nil a_ nn ° 1 00 z 50 o 1 952 1 962 1 972 1 982 1 992 Return Year FIGURE 4-2a to 4-2e Long-term changes in catch and escapement from Fraser River, B.C. Source: (a)
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From page 86... ...
However, other species had about half or more of their stocks classified as depressed or critical (Table 4-31. Puget Sound was considered to have fewer depressed stocks than the Columbia River basin but more than the Washington 1Data on the total runs of Fraser sockeye and pink salmon were provided by the Pacific Salmon Commission.
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From page 87... ...
Some river systems have productive habitat and large, relatively stable salmon populations; other rivers have been heavily altered and have few or no healthy populations. For example, the river basins of northern Puget Sound had the fewest depressed salmon runs of any region in Washington, Oregon, Idaho, and California, according to The Wilderness Society (1993~.
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From page 88... ...
coho stocks in the Puget Sound region Skagit River and Deer Creek, a tributary of the Stillaguamish River were purely wild; all other stocks have been supplemented with hatchery fish of nonnative origin at some time. About half the total number of coho stocks were being supported by hatchery production, although most of the coho in southern Puget Sound were of hatchery origin and most of the coho from Hood Canal and the Strait of Juan de Fuca were wild.
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From page 89... ...
Surprisingly, most of the steelhead stocks from heavily urbanized portions of Puget Sound were classified as healthy or unknown by WDF et al. (1993~; there were a few notable exceptions, including Lake Washington winter steelhead, a depressed population that is subject to heavy predation by sea lions at the Ballard Locks (Box 2-1)
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From page 90... ...
At least three separate sea-run cutthroat stocks in Puget Sound have been identified on the basis of electrophoretic comparisons of specimens from different areas: a northern Puget Sound stock, a northern Hood Canal stock, and a southern Hood Canal stock (Compton and Utter 1987~. The species was considered at moderate risk of extinction by Nehlsen et al.
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From page 91... ...
Sockeye passage at Ice Harbor Dam has varied widely but declined sharply after 1976 (Figure 4-31. The only production area now used by Snake River sockeye is Redfish Lake in the headwaters of the Stanley basin.
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From page 92... ...
The number of fall chinook returning to the Snake River, as counted at Ice Harbor Dam, declined from 1968 to 1976, remained low but stable through 1985, and then increased slightly (Figure 4-4) , probably in response to production from Lyons Ferry Hatchery and straying from the Umatilla and Columbia rivers (Chapman et al.
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From page 93... ...
(by Index area read counts for wild summer chinook salmon in Idaho. foreshadowing a greatly diminished adult run in 19959.
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From page 94... ...
Numbers of B-group steelhead escaping the Zone 6 fishery have trended upward very slightly since 1986 (Figure 4-61. Beginning in 1991, efforts to protect wild fall chinook that originate in the Snake River have increased the B-group steelhead.
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From page 95... ...
Fishery agencies release ten times more steelhead from Snake River hatcheries than from middle Columbia River hatcheries upstream from Priest Rapids Dam. Total releases of chinook salmon and steelhead from Snake River hatcheries average near 20 million fish.
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From page 96... ...
1990~. Sockeye of the upper Snake River might have originated as residual sockeye in Stanley basin lakes after the partial removal of Sunbeam Dam in the 1920s, whereas Columbia River sockeye have had continuous access to the sea and to their natal areas.
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From page 97... ...
main Okanogan River. Summer-fall chinook populations in the middle Columbia River are more abundant now than they were in the 1930s, when counts became available at Rock Island Dam.
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From page 98... ...
The high returns in the 1980s apparently benefited from reduction in ocean fishenes, a result of the U.S.-Canada treaty, and perhaps from relatively high ocean survival. In-river fishing was also cut back to protect the summer component of the summer-fall chinook run and to reduce the catch of steelhead and fall chinook destined for the upper Snake River.
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From page 99... ...
Some of the stocks remained stable through the middle 1980s but have experienced severe short-term declines. No naturally spawning coho populations remain in the Columbia River basin upstream of The Dalles Dam, although they once inhabited many subbasins in the middle Columbia and Snake River systems (The Wilderness Society 1993~.
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From page 100... ...
. Adult summer steelhead for hatchery broodstock are trapped at Wells Dam, and progeny are distributed to the Wenatchee, Methow, and Okanogan rivers.
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From page 101... ...
(1991) listed 11 extinct stocks of summer steelhead from the middle and upper Columbia basin and from the Snake River system, and 13 of 15 wild stocks identified by WDF et al.
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From page 102... ...
Chum salmon populations are seriously depressed in the lower Columbia. Nehlsen et al.
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From page 103... ...
Only a single fall chinook stock was listed as depressed, whereas 40% of the spring-summer chinook stocks were depressed. According to WDF et al.
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From page 104... ...
, all remaining spring and summer chinook populations in northern California are at high risk of extinction. Fall chinook, although not as imperiled in most areas, nevertheless are seriously depressed.
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From page 105... ...
Overall, although historical coho runs in California once totaled in the hundreds of thousands, estimated numbers of naturally spawning adults are now fewer than 5,000 (The Wilderness Society 19933.
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From page 106... ...
Chum salmon have been recorded along the West Coast south to the San Lorenzo River in Monterey Bay (Moyle 1976) , but the current southernmost population of chum salmon is in the lower Smith River of northern California (Higgins et al.
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From page 107... ...
As late as the 1970s, a few stray pink salmon were observed in some northern California rivers, but the only reproducing population occurred in the Sacramento River system (Moyle 1976~. The Sacramento River population was surely a zoogeographic enigma, being over 1,000 km south of the southern limit of pink salmon distribution in Puget Sound.
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From page 108... ...
Winter steelhead populations in northern California are generally in much better condition than summer steelhead. Most are thought to have been fairly stable in recent decades, but nearly all populations have declined somewhat over the last 5 years (Wilderness Society 1993~.
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From page 109... ...
RIVER COAST ORE. CALIFORNIA 109 FIGURE 4-14 Percentages of wild steelhead in Alaska, British Columbia, coastal Washington and Puget Sound, Columbia River Basin, coastal Oregon, and California.
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From page 110... ...
The primary fisheries-management objective in the Willapa Bay Basin is the production and capture of hatchery fish, and hatcheries have been present there for almost a century. Of the six salmon hatcheries constructed since 1895, three are still operational.
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From page 111... ...
Willapa Bay Basin hatcheries recently produced 11% of the fall chinook and 7% of the coho released by all stateoperated hatcheries in Washington (Suzumoto 1992~. Many of the hatchery fish are released directly from rearing facilities, but chinook, coho, and chum fry have all been planted in the basin's streams to increase returns to hatchery trapping locations and to bolster declining wild runs.
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From page 112... ...
From 1968 to 1991, chum spawning counts for the Willapa Bay Basin averaged about 28,000 which agrees reasonably well with the escapement goal of 35,000 (Table 4-61. However, average annual chinook spawning counts from 1987 to 1991 averaged about 15,000 (Suzumoto 1992)
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From page 113... ...
It is likely that this absence of nutrient capital has further reduced the capacity of the Willapa basin to produce fish, shellfish, and other important aquatic resources and has led to a long-term decline in ecosystem productivity. The current condition of wild salmon in the Willapa Bay Basin illustrates a systemic problem along the Pacific Northwest coast: habitat, hatchery, and fishery management decisions have failed to protect the natural capacity of these areas to produce salmon.
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From page 114... ...
4 UPSTREAM: SALMON AND SOCIETY IN THE PACIFIC NORTHWEST TABLE 4-8 Histoncal and Recent Annual Loading of Salmon-Carcass Phosphorus, Nitrogen, and Total Biomass to Willapa Bay and Its Tnbutanesa Delivery to Streams (kg/km of stream length) Delivery to Willapa Bay (kg/ha of surface area)
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