There are seven anadromous species of Salmonidae present in Washington, Oregon, and California: chinook salmon (Oncorhynchus tshawytscha), chum salmon (O. keta), coho salmon (O. kisutch), pink salmon (O. gorbuscha), sockeye salmon (O. nerka), steelhead (O. mykiss), and sea-run cutthroat trout (O. clarki). Each of these species begins its life in fresh water, migrates to salt water to mature, and returns to fresh water to spawn. The exact details of this cycle vary between and within the seven species, but the environmental conditions necessary to complete these cycles are generally similar. These conditions include adequate stream flow, unimpeded access to ocean habitats and upriver spawning habitat, appropriate composition of the river or stream bottom, and complexity of habitat where spawning and fry development take place.
Anadromous salmonids are comprised of populations that originate from specific watersheds as juveniles and generally return to their natal streams to spawn. While the environmental requirements of all salmonids on the Pacific coast are generally quite similar, individual stocks have developed complex adaptations to the specific local conditions of the particular river systems that they inhabit. Ricker (1972) defined a salmonid "stock" as salmon that spawn in a particular river system (or portion of it) at a particular season and that do not interbreed to any substantial degree with any group spawning in a different place, or in the same place at a different season. Because local populations of salmonid stocks possess adaptive genetic differences, salmonids are more appropriately managed and conserved by stock, rather than by species (MacLean and Evans 1981). Populations of salmonids are loosely distinguished based on the season of the year during which they return to their native streams to spawn. Thus, spring-run fish enter the rivers in the spring, summer-run fish in the summer, fall-run fish in the fall, and winter-run fish in the winter (Nickelson et al. 1992).
In recent years, native, naturally spawning salmonid populations have declined as a result of habitat loss and degradation; inadequate riverine passage and flows due to hydropower, agriculture, logging, and other developments; overfishing; negative interactions with other species and hatchery fish; and environmental fluctuations and declines in fresh water (drought) and marine (El Niño) productivity. Nehlsen et al. (1991) evaluated the status of all salmonid stocks for Washington, Oregon, California, and Idaho, and identified 214 native, naturally spawning Pacific salmonid stocks that they classified as facing a high or moderate risk of extinction, or as of special concern. Nehlsen et al. (1991) suggested that 18 of these stocks may already be extinct. Of the 214 stocks they identified, 101 were at high risk of extinction, 58 were at moderate risk of extinction, 54 were of special concern, and one was classified as threatened under the ESA. Thirty-nine of these stocks occur in California, 58 on the Oregon coast, 76 in the Columbia River Basin, and 41 in the Washington coast/Puget Sound area (Nehlsen et al. 1991). Some of these stocks consist of small wild populations for which spawning has not been observed for some time. In other cases, hatchery programs were established to supplement native stocks, and the continued existence of some native stocks is in doubt. Because escapement is estimated as the aggregate of all fish returning to a basin, a decline in a native stock may be masked by returns of hatchery fish. Nehlsen et al. (1991) also reported that 104 of the 214 stocks identified were believed to have a high probability of introgression, or genetic "mingling" of hatchery stock with wild stocks. When native stocks reproduce with non-native stocks, the characteristics of the native population may be altered or lost (Nehlsen et al. 1991, Hindar et al. 1991, Waples 1991a, Hard et al. 1992). This can result in a reduction in fitness of the native stocks and an increased susceptibility to disease.
Recent efforts to preserve salmonids have focused on federal protection under the ESA. Since 1990, the NMFS has received a number of petitions to list populations of Pacific salmonids as threatened or endangered under the ESA; the first to be listed as endangered was the Sacramento River winter chinook salmon. If listed, the ESA requires that recovery plans be developed and implemented.
The ESA allows listing of "distinct population segments" of salmonids, but provides no explicit guidance on how to determine when a population is distinct enough to qualify as an ESA "species." NMFS developed a policy to determine what constitutes a species of wild Pacific salmonid under the ESA. To be considered distinct, a salmonid population must be substantially reproductively isolated and make a substantial contribution to the evolutionary legacy of the biological species (Waples 1991b). A distinct population that meets these criteria is defined as an "Evolutionarily Significant Unit" (ESU). Within an ESU that is listed or proposed for listing, some individual wild populations or stocks may be considered healthy. Conversely, a "not warranted" determination with respect to ESA listing does not necessarily mean that all wild populations within the ESU are healthy. When evaluating the two criteria to determine an ESU, a variety of factors are considered, including genetic and life-history traits of the wild salmonid populations, ecological characteristics of their habitats, and the effects of human factors (e.g., stock transfers) that may have altered native gene pools. After the ESUs are identified, NMFS evaluates the level of risk to determine whether a listing as threatened or endangered under the ESA is warranted. The following is a summary of the ESA listing actions and status reviews on Pacific salmonids.
In addition to the federal classification system, each state has a somewhat different system for classifying stock status and uses separate definitions for the categories. The definitions used by the states and the federal government for the various categories of salmonid stocks are listed in Appendix B. Terms used to describe salmonids such as "wild stock," "cultured stock," and "escapement" are described in Appendix C.
The Working Group summarized the status of salmonids in Washington, Oregon, and California, using the most recent data available from the states. Appendix D lists the overall status of wild, naturally producing salmonid populations by region, along with numbers of pinnipeds present during salmonid migration. Appendix E shows the status of salmonid populations in greater detail, by river and state. The summary for Washington State relies on the "1992 Washington State Salmon and Steelhead Stock Inventory" (SASSI) report (WDF et al. 1992) and on more recent information provided by the Washington Department of Fish and Wildlife (WDFW). The data on Oregon salmonids is derived from the Oregon Department of Fish and Wildlife's (ODFW) "Status of Anadromous Salmonids in Oregon Coastal Basins," (Nickelson et al. 1992) and from more recent evaluations provided by ODFW. The status of California salmonid stocks relies on a paper, "Petition for a Rule to List Steelhead as Threatened or Endangered under the Endangered Species Act and to Designate Critical Habitat," by the Oregon Natural Resources Council et al. 1995, as well as Moyle and Yoshiyama 1992, Nehlsen et al. 1991, and updated information from the California Department of Fish and Game (CDFG). Classifications by the states and NMFS are different for some stocks. For ease of reference in this report, each state is divided into regions (Figs. 1-4) based on pinniped distribution, natural geographic partitions, and major salmonid river systems.
Washington
Washington is divided into eight regions for analysis of the status of salmonid and pinniped populations: 1) Eastern Bays, 2) Puget Sound, 3) Hood Canal, 4) Strait of Juan de Fuca/San Juan Islands, 5) Washington Coast, 6) Grays Harbor, 7) Willapa Bay, and 8) Columbia River Basin. Figures 1 and 2 show these regions as well as the major rivers and areas referenced in this report. The following paragraphs describe the status of salmonids in each region using Washington's three categories to describe salmonid status: healthy, depressed, and critical (definitions of these terms are in Appendix B). More details on the status and run-timing of these salmonid populations are in Appendices D and E.
Pink salmon--Pink salmon occur in four of the Washington regions (Appendix D). Populations are generally rated as healthy, with four exceptions. In the Strait of Juan de Fuca, the Upper Dungeness River run is classified as depressed, and the Lower Dungeness and Elwha River runs are classified as critical. In Hood Canal, the Dosewallips River run is classified as depressed.
Sockeye salmon--Sockeye salmon occur in four of the Washington regions (Appendix D). The status of Washington Coast sockeye salmon stocks is mixed. The sockeye salmon run is healthy in the Quinault River and depressed in the Ozette River. The Eastern Bays stocks are classified as critical. In Puget Sound, sockeye salmon stocks are depressed. Sockeye salmon runs are healthy in two Washington tributaries of the Upper Columbia River (the Wenatchee and Okanogan Rivers). Sockeye salmon in the Snake River are listed as endangered under the ESA.
Chum salmon--Chum salmon occur in each of the eight Washington regions. The status of Washington Coast chum salmon runs is unknown. Runs are healthy in Grays Harbor and Willapa Bay. The Strait of Juan de Fuca/San Juan Islands fall chum salmon runs are classified as unknown, the summer run as critical. The fall chum salmon runs in Hood Canal are healthy, while most summer runs are critical. Chum salmon are healthy in Puget Sound and the Eastern Bays. Fall chum salmon in the Washington tributaries of the Lower Columbia River are depressed. Chum salmon do not occur above the Lower Columbia River.
Coho salmon--Coho salmon occur in each of the eight Washington regions. Coho salmon status is mixed throughout Washington. Coho salmon in the Puget Sound, Eastern Bays, Hood Canal, Grays Harbor, and Willapa Bay regions are candidate species for listing under the ESA, and the status of runs is mixed with some unknown and others healthy or depressed. In the Strait of Juan de Fuca/San Juan Islands region, the eastern portion of the region (east of Salt Creek) is part of the ESU that is a candidate species for listing under the ESA, and the status of runs is mixed. Coho salmon were extirpated above Bonneville Dam.
Chinook salmon--Chinook salmon occur in each of the eight Washington regions. Their status varies considerably by area and by run within regions. Washington Coast spring and fall chinook salmon runs are classified as healthy, summer runs are mixed, and spring/summer runs are depressed. Other healthy runs include Grays Harbor (spring) and Willapa Bay (fall). Grays Harbor (summer) and Willapa Bay (early fall) chinook runs are depressed. The Strait of Juan de Fuca/San Juan Islands fall runs are depressed. The summer/fall chinook salmon runs in this region are healthy, while spring/summer runs are critical. The Eastern Bays summer runs are mixed, while the spring and fall runs are depressed. The Nooksack River spring chinook salmon run in this region is classified as critical. Hood Canal summer/fall runs are depressed. The Puget Sound summer/fall runs are mixed status. Spring and fall runs in Washington tributaries of the Lower Columbia River and Upper Columbia River (late fall) runs are healthy. Washington has classified the Snake River spring/summer and fall chinook runs as critical, and these are listed as threatened under the ESA.
Steelhead--Steelhead occur in each of the eight Washington regions. The status of winter runs in the Washington Coast and Grays Harbor regions is mixed. Willapa Bay winter runs are healthy. The status of summer runs in the Washington Coast region is unknown, and Grays Harbor summer runs are depressed. The Strait of Juan de Fuca/San Juan Islands summer runs are depressed, while the status of winter runs is mixed. The Eastern Bays winter runs are healthy and summer runs are mixed, except the Deer Creek summer run is critical. The Puget Sound summer and winter steelhead runs are healthy, although the Lake Washington run of winter steelhead is now classified as critical. The status of Hood Canal winter runs is mixed and unknown for summer runs. The summer and winter runs in the Washington tributaries of the Upper and Lower Columbia River are classified as depressed, as is summer steelhead in the Snake River. Lower and Upper Columbia River steelhead have been proposed for listing under the ESA as threatened and endangered respectively.
Sea-run cutthroat trout--Sea-run cutthroat occur in each of the eight Washington regions. Although classification of the runs has not been completed, most are considered depressed or critical due to severe habitat degradation and chronically low returns.
Oregon
Oregon is divided into six regions for analysis of the status of salmonid and pinniped populations: 1) Columbia River Basin, 2) North Oregon Coast, 3) Tillamook Bay, 4) Umpqua River, 5) Rogue River, and 6) South Oregon Coast. Figure 3 shows these regions and major rivers and areas referenced in the text. The following paragraphs describe the status of salmonids in each region using Oregon's three categories: healthy, special concern, and depressed (definitions of these terms are in Appendix B). More details on the status and run-timing of these salmonid populations are in Appendices D and E.
Pink salmon--Pink salmon occasionally occur in Oregon waters, but there is no evidence of permanent populations.
Sockeye salmon--Sockeye salmon are generally no longer found in Oregon, except those migrating in the Columbia River and a few of unknown origin that return each year to the Deschutes River.
Chum salmon--Chum salmon occur in three of the Oregon regions. In the North Oregon Coast and Tillamook Bay regions, most runs are classified as of special concern. Chum stocks in Nehalem River are in somewhat better condition than others. Chum salmon runs in the Oregon tributaries of the Columbia River no longer exist except as occasional strays.
Coho salmon--Coho salmon occur in each of the six Oregon regions. Coho salmon are classified as depressed in all of the coastal regions, except the Coos and Coquille River populations are healthy. Oregon coastal coho salmon have been proposed for listing as threatened under the ESA. Lower Columbia River coho salmon are classified as depressed.
Chinook salmon--Chinook salmon occur in each of the six Oregon regions. Based on an internal ODFW review in October 1995, conservation concerns have been identified for all North Oregon Coast spring chinook salmon runs, except for the Nehalem River runs which are considered healthy. Fall chinook salmon are typically healthy in northern Oregon, with the exception of the Salmon and Sixes Rivers and Dry Creek, where the runs are classified as of special concern. Fall chinook salmon are depressed in the South Oregon Coast. Both spring and fall chinook salmon in Oregon tributaries of the Columbia River are considered depressed, except the Deschutes River fall run which is healthy. Umpqua River Basin fall chinook and North Umpqua spring chinook salmon are healthy; however, South Umpqua spring chinook are depressed. The Rogue River has a healthy spring chinook salmon run. The fall chinook salmon in the Rogue River Basin are classified as healthy in the middle and upper Rogue River and in the Applegate River, but classified as depressed in the lower Rogue River and the Illinois River (tributary of the Rogue River). Spring/summer and fall chinook salmon in the Snake River have been listed as threatened under the ESA.
Steelhead--Steelhead occur in each of the six Oregon regions. Most winter steelhead populations in Oregon are depressed. The only exceptions are the winter steelhead in the North Umpqua, Coquille, Rogue, and Winchuk Rivers, which are healthy. However, the steelhead in the Illinois River are depressed. Of the summer steelhead populations in Oregon, only those in the North Umpqua River are healthy. All other summer steelhead are considered depressed. Coastal steelhead populations have been proposed for listing as threatened under the ESA.
Sea-run cutthroat trout--Adequate data to determine trends in abundance for most populations of sea-run cutthroat trout are not available. All sea-run cutthroat populations in Oregon are considered depressed. Nehlsen et al. (1991) listed sea-run cutthroat trout stocks in Oregon coastal streams and in small tributaries of the lower Columbia River as being at moderate risk of extinction. They listed Hood River sea-run cutthroat trout as being at high risk of extinction (the definitions of "moderate" and "high" risk of extinction used by Nehlsen et al. (1991) are the same as the definitions used by the State of California as listed in Appendix B). Because populations of sea-run cutthroat trout in Oregon occur near the extreme southern edge of the range of the subspecies, they may be particularly vulnerable to climatic change, habitat loss, or the cumulative effects of these and other disturbances (Nickelson et al. 1992). Umpqua River sea-run cutthroat trout have been listed as endangered under the ESA.
California
California is divided into eight regions for analysis of the status of salmonid and pinniped populations: 1) Smith River, 2) Klamath River, 3) Cape Mendocino, 4) North California Coast, 5) San Francisco Bay, 6) Monterey Bay, 7) Central California Coast, and 8) Southern California Bight. Figure 4 shows these regions and major rivers and areas referenced in this report. The following paragraphs describe the status of salmonids in each region using California's four categories: healthy, special concern, moderate risk of extinction, and high risk of extinction (definitions of these terms are in Appendix B). More details on the status and run-timing of these salmonid populations are in Appendices D and E.
Pink salmon--California is the southern edge of the pink salmon range and they have never been common there (Moyle and Yoshiyama 1992). Today, pink salmon are considered extremely rare in California. Moyle and Yoshiyama (1992) report small numbers of pink salmon in the San Lorenzo River, the Sacramento River and tributaries, Klamath River, Russian River, Garcia River, and Ten Miles River. They hypothesize that these are probably "strays" from the ocean that followed other salmon runs up the river and thus are not distinct "runs." Nehlsen et al. (1991) consider pink salmon runs in the Klamath, Russian, and Sacramento Rivers to be extinct.
Sockeye salmon--Sockeye salmon do not occur in California waters.
Chum salmon--Chum salmon historically occurred in streams from the San Lorenzo River (Monterey Bay) to the Oregon border (Moyle and Yoshiyama 1992). Today, small runs may persist in the South Fork of the Trinity River and the Smith River. However, Moyle and Yoshiyama (1992) report that chum salmon in California are on the "verge of extinction." Nehlsen et al. (1991) report that chum salmon in the Sacramento and Klamath Rivers are extinct.
Coho salmon--Coho salmon are widely distributed in California streams (Appendix D). Historically, there are records of coho salmon in streams as far south as the Big Sur River (Central Coast) and up to the Smith River near the Oregon border (Moyle and Yoshiyama 1992). There have been significant declines in recent years, however. Klamath River coho salmon runs are listed as of special concern by Nehlsen et al. (1991). Runs in coastal streams north of San Francisco (Trinity, Mad, Noyo, and Eel Rivers) are at moderate risk of extinction, while those in the small coastal streams south of San Francisco are at high risk of extinction (Nehlsen et al. 1991). Coho salmon in Malibu Creek are thought to be extinct (Nehlsen et al. 1991). Coho salmon from the Oregon border south to and including the San Lorenzo River have been proposed for listing as threatened under the ESA.
Chinook salmon--Chinook salmon are found in six of the eight California regions (Appendix D). In the Smith River, spring chinook salmon are listed at high risk of extinction, while the fall run is at moderate risk of extinction. The spring chinook salmon in the Klamath-Trinity drainage are depleted and were rated at high risk of extinction by Nehlsen et al. (1991) and ONRC et al. (1995). The status of fall runs in this region is mixed: the Shasta River is at high risk, Redwood Creek and the lower Klamath River tributaries are at moderate risk, and the Scott River is listed as of special concern (Nehlsen et al. 1991, ONRC et al. 1995). In the Cape Mendocino region, the runs in the minor Humboldt Bay tributaries are depleted and are listed as at high risk of extinction (Nehlsen et al. 1991, ONRC et al. 1995). North Coast fall chinook salmon are at high risk of extinction. In the San Francisco Bay region, spring chinook salmon have declined severely and most runs are at high risk of extinction. Currently, spring chinook salmon occur only in Deer and Mill Creeks in the Sacramento drainage. Fall chinook in the San Francisco Bay region are of special concern (Nehlsen et al. 1991, ONRC et al. 1995). Winter chinook salmon in the Sacramento River are listed as endangered under the ESA.
Steelhead--Historically, winter steelhead occurred in California coastal streams from the Oregon border to the United States/Mexico border. Wild populations of winter steelhead in many coastal streams from the Russian River south are either severely depleted or extirpated (Moyle and Yoshiyama 1992, McEwan and Jackson 1996). Summer steelhead in the Smith River region are at high risk of extinction (Nehlsen et al. 1991). In the Klamath River, summer steelhead are at moderate risk, and in Redwood Creek they are at high risk of extinction. In the Cape Mendocino region, summer steelhead in the Eel River are at moderate risk of extinction, while the Mad River runs are listed at high risk of extinction (Nehlsen et al. 1991). Winter steelhead in the San Francisco Bay region are at high risk of extinction. In the Monterey Bay region, winter steelhead are at high risk of extinction in the Carmel and Pajaro Rivers and at moderate risk of extinction in the Salinas River. Winter steelhead in the Central Coast are at high risk of extinction in the Santa Ynez River and of special concern in the Big and Little Sur Rivers. Winter steelhead in the Southern California Bight (Malibu Creek, Santa Clara, and Ventura Rivers) are at high risk of extinction (Nehlsen et al. 1991). In the past 30-40 years, most summer steelhead populations in California have declined considerably and most are represented by 100 fish or less (Moyle and Yoshiyama 1992). All steelhead populations in California have been proposed for listing under the ESA.
Sea-run cutthroat trout--Sea-run cutthroat trout have undergone a major decline over the last two decades. Nehlsen et al. (1991) report that sea-run cutthroat trout in California coastal streams are at a moderate risk of extinction.