RARE AND SENSITIVE SPECIES: STATUS SUMMARIES Narratives summarizing the status for 39 rare and sensitive species were prepared. These narratives are arranged in phylogenetic order and are divided as follows: Distribution and Status, Habitat Relationships, and Key Factors Influencing Status. Accompanying each narrative is a map that typically illustrates the probable historic and current distribution plus any major introduction sites mapped at the watershed level. The actual distributions of these species may include small portions of the watersheds and therefore, are overestimated on the figures. General categories of research and information needs are listed for each species in table 4.53 (see following section "Information and Research Needs." These status narratives include a variety of narrowly distributed endemics, largely unknown species, and other native species that may be important and wide ranging but for which the assessment area represents a small portion of their range. The Sunapee char, an introduced species of special note, also is included. All these species are worthy of special management attention and several already receive protection under the Endangered Species Act. Resident freshwater threatened or endangered species are listed under the Endangered Species Act by the U.S. Fish and Wildlife Service, whereas the National Marine Fisheries Service has responsibility for listing anadro- mous fishes. Some rare and sensitive species are recognized as requiring special protection by the States of Oregon, Washington, Idaho, or Montana. Many are managed as sensitive species by the USDA Forest Service and/or USDI Bureau of Land Management. Several were considered by the U.S. Fish and Wildlife Service to be Category 2 Candidates for listing until a February 27, 1996 nationwide decision to delete all Category 2 taxa from Candidate species status. Although we know less about the rare and sensitive species than the seven key salmonids, analyses of existing distribution and reviews of available literature provide important insights about common threats and appropriate management needs. Many of these taxa occur in isolated areas of the Columbia River Basin, in isolated subbasins of the Great Basin, or are restricted to the upper Klamath Basin. They typically occur in relatively depauperate subbasins, perhaps with only one or two native fish species present and therefore, may not be recognized in management strategies that focus on areas of high native species diversity. Many of these taxa occur in very restricted areas, often occupying one or two small habitat patches within subwatersheds. Consequently, broad or mid-scale assessments may not adequately describe their distributions.
White Sturgeon (Acipenser transmontanus) White sturgeon were once widely distributed in the Columbia River basin. The species has been an important sport, commercial, and tribal resource. The Kootenai River (Idaho, Montana and British Columbia) white sturgeon population is listed as endangered by the U.S. Fish and Wildlife Service and the State of Idaho and as sensitive by the BLM. The Snake River white sturgeon is listed as a species of concern by the State of Idaho and as a sensitive species by Region 1 of the Forest Service. Distribution and Status Along the Pacific Coast, white sturgeon were found in accessible freshwater from the Aleutian Islands south to central California. The Columbia River represents one of three large river basins in the Pacific Northwest where white sturgeon reproduce. Historically, prior to dam construction, white sturgeon were anadromous and migrated within the Columbia River Basin up to impassable falls (map 4.35). The Kootenai River white sturgeon has been isolated from other white sturgeon populations since the last glacial age (Apperson and Anders 1991). The white sturgeon is restricted to 695 river kilometers in the Kootenai River Basin between Kootenai Falls, Montana downstream to Cora Linn Dam at Kootenay Lake, British Columbia, Canada. The Kootenai River white sturgeon have not successfully spawned in recent years. The current population, which has a no harvest restriction, has decreased to about 880 individuals (Apperson and Anders 1991). Snake River white sturgeon are found in the Snake River in Idaho up to Shoshone Falls, and in the Salmon River in Idaho likely upstream to the confluence of the East Fork Salmon River. The present distribution of Snake River white sturgeon has been fragmented into discrete subpopulations confined between mainstem dams (Hanson and others 1992). The Hells Canyon reach along the Oregon- Idaho border contains the highest densities of Snake River white sturgeon. In the Columbia River downstream from McNary Dam, on the Washington-Oregon border, the annual abundance of white sturgeon greater than 53 centimeters was 893,800 fish from 1986 to 1992. In contrast to the Snake and Kootenai rivers where all captured sturgeon must be released, a consumptive sturgeon fishery continues in the lower Columbia River. Habitat Relationships Substrate size and water velocity influence selection of spawning areas by white sturgeon. Spawning generally occurs in water over three meters deep and over cobble substrate. In the Columbia River system, reproduction has been greater during years of high flows compared with years of low flow (Hanson and others 1992). Spawning also occurs earlier and at lower temperatures during high flow years (Hanson and others 1992). Adults and juveniles prefer deep-pool habitat with a fine bottom substrate. Adults tend to move downstream in the summer and rail months and upstream in the winter and spring months. Fish tend to stay in shallower water during the spring and summer and move to deeper waters during the winter. Key Factors Influencing Status Hydropower dams on the Columbia and Snake rivers have prevented migration, fragmented riverine populations, and reduced the effectiveness of natural propagation (Hanson and others 1992). Dams have also reduced spawning success, by decreasing the amount of suitable spawning areas or creating poor incubation environments. In general, the length of time required to reach sexual maturity, typically 10 to 15 years, results in low rates of natural recruitment. Most reproductively capable fish are protected by harvest regulations based on fish length. The decrease in spring river flows below Libby Dam, Montana appears to have contributed to spawning failures of the Kootenai River population in recent years (Apperson and Anders 1991). Land management activities are considered a secondary impact to white sturgeon.
Map 4.35--Historical and current distribution plus introduced sites of white sturgeon. A q u at i c s 1269
Klamath Lamprey (Lampetra similis) The Klamath lamprey (L. similis) is a parasitic form from the Klamath River of Oregon and California (Vladykov and Kott 1979). The Klamadi lamprey is poorly understood, restricted in its distribution, and may be threatened with extinction. Distribution and Status The Klamath lamprey is one of five species of lampreys described from the Klamath Basin of northern California and south-central Oregon. The other forms include the Miller Lake lamprey (L. minima), a dwarf parasitic form that was endemic to Miller Lake, Oregon, and is now extinct (Bond and Kan 1973); the Modoc brook lamprey (LfoUetti), a nonparasitic form known only from Willow Creek and the Lost River portions of the Klamath River drainage in Modoc County, California (Vladykov and Kott 1979); the Pit-Klamath brook lamprey (L lethophaga), a more widely distributed nonparasitic form known from the upper Klamath drainage and the Goose Lake drainage in Oregon and California and the upper Pit River system in California (Hubbs 1971); and the widespread Pacific lamprey (L. tridentata). The Klamath lamprey is known from the Klamath River and upper Klamath Lake in Oregon (map 4.36) (Vladykov and Kott 1979). The Pacific lamprey reported from Copco Reservoir on the Klamath River in California may instead represent L similis (Moyle and others 1989). Information about the status of the Klamath lamprey is lacking. Habitat Relationships Little is known about the specific habitat requirements of the Klamath lamprey. The species is parasitic, presumably on the larger trouts and suckers in the Klamath Basin. Key Factors Influencing Status The many dams, water diversions, and other modifications common to the upper Klamath River drainage are presumed to have disrupted the distribution and life history of this species. Many native fishes in the Klamath Basin, which would serve as hosts for the lamprey, have declined. Based on the restricted range and threatened status of many host species, the Klamath lamprey may be at high risk of extinction. Specific information is lacking. River Lamprey (Lampetra ayresi) River lamprey are anadromous and parasitic. They are rare and, according to the limited available literature, apparently migrate short distances inland compared with the Pacific lamprey. Distribution and Status The river lamprey is distributed along the Pacific Coast of North America from the Sacramento River, California north to Tee Harbor near Juneau, Alaska (map 4.37) (Kan 1975). In the Columbia River, the river lamprey has been reported from Bonneville Dam and locations downstream (Kan 1975). Very little is known on the status of this species. Habitat Relationships River lampreys require small, clear water streams for spawning, with ammocoetes (the larval form) living in silty backwaters of such streams (Moyle and others 1989). Known hosts for adults include smelt, herring, kokanee salmon, and coho salmon (Kan 1975). In Canada, the adults begin their spawning migration in freshwater between September and late winter after they have spent two years in the ocean (Beamish 1980). They spawn the following April to June, and subsequently die. At the appropriate age, the young begin to metamorphose in July but do not emigrate to the ocean until the following May to July (Beamish 1980). Key Factors Influencing Status Relative to Pacific lamprey, the river lamprey's tendency to use areas close to the coast may protect it to some degree from mortality associated with mainstem dam passage. The limited distribution of river lamprey relative to Pacific lamprey may increase their vulnerability. Information to assess that or other risks is not available.,v
Pacific Lamprey (Lampetra tridentata) The Pacific lamprey is an anadromous and parasitic lamprey widely distributed along the Pacific Coast of North America and Asia. Traditionally, Pacific lamprey were an important ceremonial and subsistence resource for native peoples. In the assessment area, they occur in all waters that remain accessible to salmon and steelhead (Simpson and Wallace 1978). The Idaho Department of Fish and Game lists Pacific lamprey as a state endangered species. Distribution and Status Within the Columbia River Basin, Pacific lamprey are believed to have migrated to all waters accessible to anadromous salmonids (Simpson and Wallace 1978). Kan (1975) suggested that the primary consideration for presence of lamprey was access rather than distance from the ocean. Historic runs were large; in some years up to 400,000 lampreys were counted as they migrated past Bonneville Dam (Harrison 1995). Counts of lamprey passing Ice Harbor Dam totaled 40 in 1993 and 399 in 1994, compared with the 1960s when nearly 50,000 were counted annually (Harrison 1995). Similar to other anadromous fishes, the distribution and abundance of Pacific lamprey has been reduced by construction of dams and water diversions as well as degradation of spawning and rearing habitat. Using the distribution of steelhead as an indicator, Pacific lamprey currently are blocked from entering more than 50 percent of their historic range (map 4.38). Consequently they are precluded from large areas, including upstream from Hell's Canyon Dam on the Snake River and Chief Joseph Dam on the Columbia River. Landlocked populations have been found in areas from which the anadromous form has been precluded (Wallace and Ball 1978), but they have not persisted and Beamish and Northcote (1988) concluded that metamorphosed lamprey were unable, in such areas, to survive to maturity. Habitat Relationships Pacific lamprey adults enter freshwater between July and September, and may migrate several hundred kilometers inland (for details of life history, see Scott and Grossman 1973). They do not mature until the following March. They spawn in sandy gravel immediately upstream from riffles between April and July and die soon after. Eggs hatch in two to three weeks and the ammocoetes spend up to the next six years in soft substrate as filter-feeders before they emigrate to the ocean. They remain in the ocean for 12 to 20 months before returning to freshwater to spawn. Diatoms appear to be a primary food supply for the ammocoetes. Key Factors Influencing Status The Idaho Chapter of the American Fisheries Society (IDAFS 1995) concluded that dams on the Snake and Columbia rivers, alteration of streams, and harvest of ammocoetes by bait fisheries are the most serious threats to the Pacific lamprey in Idaho. Pacific lamprey, similar to salmonids, are likely to be vulnerable to land disturbances that cause sedimentation in nursery streams. The ammocoetes depend on quality habitat in freshwater for up to six or seven years before they emigrate to the ocean. Such an extended period in freshwater makes them especially vulnerable to degraded stream conditions. Their anadromous life-history necessitates maintenance of access to spawning and rearing areas. Water quality consistent with robust diatom production may be a key factor for their continued success.
Map 4.36--Historical and current distribution of Klamath lamprey. 1272
Map 4.37 Historical and current distribution of river lamprey.
Map 4.38--Historical and current distribution of Pacific lamprey. 1274 A q u ati c s
Goose Lake Lamprey (Lampetra tridentata ssp.) The Goose Lake lamprey is considered a subspecies of parasitic Pacific lamprey that were isolated in the Goose Lake basin during the early Pleistocene (Moyle and others 1989). Although it is a State of Oregon sensitive species, and a State of California species of special concern, it currently receives no special management attention. Distribution and Status The species is unique to the Goose Lake Basin of Oregon and Washington (map 4.39). In California, they are reported from Lassen and Willow creeks. In Oregon, they were found in Drews Creek, Drews Reservoir, Thomas Creek, Cottonwood Creek, and Cottonwood Reservoir (ODFW 1992). They also occur in Goose Lake. Beyond this, the extent of their distribution and abundance is unknown. Habitat Relationships Specific habitat requirements of the Goose Lake lamprey are unknown. The parasitic adults live for a time in Goose Lake, a shallow (less than 7 meters), turbid lake. Lake temperatures range from 1 to 24 C (Johnson and others 1985). They migrate to lake tributaries to spawn. The young remain in the tributaries for an unknown amount of time before they metamorphose and move to the lake. Requirements in nursery streams are thought to include gravel spawning areas and soft substrate for the filter-feeding ammocoetes. Pit-Klamath Brook Lamprey (Lampetra. lethophaga) This brook lamprey completes its life-cycle in freshwater and is nonparasitic. It occurs in the Klamath and upper Pit river systems of northern California and south-central Oregon. Distribution and Status The Pit-Klamath brook lamprey is reported from the North Fork Pit, Pit, and Fall rivers, and Hat Creek, in California; the Sprague, North Fork Sprague, Sycan, and Williamson rivers, and Crooked and Meryl creeks in Oregon (map 4.40) (Hubbs 1971; Kan 1975). Habitat Relationships Metamorphosis may occur anytime between May and late October (Kan 1975) and neotenic ammocoetes are common. Spawners have only been found from March to May. The larval period extends for five or six years. Key Factors Influencing Status Factors influencing the habitat of the species have not been described. Stream alterations that reduce productivity for diatoms and other food items, and that increase water temperature would be likely to be deleterious for the species. The species is narrowly distributed and is therefore vulnerable to the effects of small population size and fragmentation. Key Factors Influencing Status Goose Lake dried in 1992 because of drought. Extended drought could lead to extinction of the species. Water diversions during the period that ammocoetes emigrate to the lake would likewise contribute to the demise of the species. The subspecies does not have a wide distribution and is therefore vulnerable to the effects of small population size and fragmentation. Declines of native hosts, particularly chub, sucker, and redband trout, would likely be detrimental to the lamprey. 1275
Map 4.39--Historical and current distribution of Goose Lake lamprey.
Map 4.40--Historical and current distribution of Pit-Klamath brook lamprey. A quat ic s 1277
Sockeye Salmon (Oncorhynchus nerka) Sockeye salmon were once an abundant and widely distributed species in the Columbia River Basin and apparently also occurred in the Klamath Basin (Wydoski and Whitney 1979). Sockeye salmon were an important sport, commercial, and tribal resource. Native stocks have declined and a remnant population of sockeye salmon in the upper Snake River Basin in Idaho is federally listed as endangered. Sockeye salmon exhibit two dominant life history forms, the anadromous form and a resident form called kokanee. Introduced and native kokanee salmon populations that now exist in lakes and reservoirs throughout the assessment area are viewed as one of the Basin's most important sport fishery resources (Rieman and Maiolie 1995; Rieman and Myers 1992). Kokanee salmon are a highly valued food fish and are also a key forage fish (Wydoski and Bennett 1981). Distribution and Status The historic range of sockeye salmon extended across the northern rim of the Pacific Ocean down the west coast of North America as far south as the Sacramento River in California (Burgner 1991). Anadromous sockeye salmon are now believed to be extinct south of the Columbia River Basin and the remaining runs represent the most southerly and longest migrating populations of the species in the world (Waples and others 199la). The historic range included large segments of the Columbia River Basin where natural lakes and surrounding watersheds are connected by river systems to the Pacific Ocean (maps 4.4la and 4.4Ib). Eleven major watersheds and at least 24 lakes are believed to have supported native populations of sockeye salmon within the Columbia River Basin (Fulton 1970; Waples and others 199la; Wydoski and Whitney 1979). Historic runs of anadromous adults at the mouth of the Columbia River may have numbered more than two million before the turn of the century. Numbers are now consistently less than 100,000 fish. Today, only lakes Wenatchee and Osoyoos in the upper Columbia River produce significant numbers of anadromous sockeye (Mullan 1986). A single remnant population of anadromous fish remains in Redfish Lake in the upper Salmon River Basin, Idaho. The number of adults returning to Redfish Lake has ranged from zero to eight fish since 1990, and that population is now federally listed as endangered (Bevan and others 1994). An intensive, captive brood-stock program has been initiated to conserve the remaining population. The resident form, kokanee salmon, still appears to be widely distributed throughout the Columbia River Basin. All of the historic rearing lakes still support some kokanee salmon although eradication programs and subsequent reintroduction of other stocks may have eliminated most if not all of the native fish from several lakes within the Stanley Basin (Chapman and others 1990). Nonnative kokanee salmon have been widely introduced to lakes and reservoirs throughout the Columbia River Basin. These introduced populations are now far more widely distributed than native populations were historically (map 4.41 a and b). Introgressive hybridization may have compromised the genetic integrity of many populations but no study of such effects has been conducted. Habitat Relationships Sockeye salmon exhibit some of the more complex life history patterns among Pacific salmon in that they often rely on both stream and lake environments for early rearing (Burgner 1991). Adults often spawn in lake inlet streams but lake shoal and outlet spawning also occurs. Sockeye salmon in the Columbia River Basin are typically late summer/fall spawners. Juveniles emerge from the gravel the following spring and move into the lake for one to two years where they feed on zooplankton before migration. Kokanee salmon will continue to rear for a total of three to five years before maturing.
Within the two primary life histories, there is wide variation in spawning, rearing, and maturation timing, site selection and duration. The indigenous distribution of kokanee salmon coincides with that of the anadromous form; natural kokanee populations have probably developed repeatedly from anadromous populations and not through dispersal of kokanee from other systems (Foote and others 1989). Non-migratory progenies of anadromous fish are known as residuals (Burgner 1991) and are believed to represent the transitional link between the two dominant forms. Native kokanee salmon still persist throughout much if not most of the historic range and thus represent an important component of the original biological diversity within the assessment area. Residual sockeye and kokanee salmon may also have the potential to support or even refound anadromous forms should change in the available habitat and migratory corridors allow (Rieman and others 1994). Conservation of all remaining native stocks, therefore, should be considered important regardless of whether they currently support anadromous returns. Key Factors Influencing Status Much of the decline in anadromous sockeye salmon can be attributed to dams blocking access to spawning and rearing streams in the early 1900s and to increased mortality of migrants caused by dams in the migratory corridors of the Snake and Columbia rivers constructed in later years (Fulton 1970; Mullan 1986; Nehlsen 1995). Available lake rearing habitat has been reduced from approximately 86,880 surface hectares to 4,400 surface hectares (Mullan 1986). Numbers of spawning sockeye were also seriously reduced by commercial fisheries around the turn of the century. Although fishing was important historically, there is no longer any legal harvest in the Columbia Basin for anadromous sockeye except a small American Indian fishery in the Priest Rapids, Washington pool and a recreational harvest in Lake Wenatchee, Washington when escapement goals are met. Ocean conditions probably account for some of the variation in annual returns and may influence productivity of stocks over long periods. Forest management may influence the quality of spawning habitats and the productivity of lake environments. Sockeye salmon are likely susceptible to factors that may increase sediment in spawning gravel and scour of redds. Factors influencing rearing lake environments, such as accelerated eutrophication, could also be important. Ultimately, however, it is unlikely that any substantial recovery of historic anadromous populations will occur without major improvements in conditions in the migratory corridors. Overall, kokanee and sockeye salmon appear to be in little danger of extinction throughout their range. However, individual stocks are susceptible to loss. The anadromous component of sockeye is near extinction in Idaho's Stanley Basin. The introduction of exotic fishes, fishing, and habitat condition may be important influences on the relative productivity and survival of those populations but, in general, most populations appear to be relatively abundant. The loss of genetic integrity in native stocks, however, may represent an important loss of biological integrity and could compromise the potential for long-term persistence of wild populations or the refounding of anadromous runs. A basic inventory of the integrity and status of native stocks would be useful. 1279
Map 4.41 a--historical and current distribution plus introduced sites of sockeye salmon.
Map 4.41 b--historical spawning and rearing areas of sockeye salmon. Aquatios
Chum Salmon (Oncorhynchus keta) Chum salmon have the widest distribution of any of the Pacific salmon in North America. In the Columbia River Basin, chum salmon were abundant in lower river tributaries and the mainstem Columbia River, where they supported tribal, sport, and commercial fisheries. Populations had dwindled to a point of minor importance by the 1950s (Fulton 1970). Because several populations are on the verge of extinction, the species is an Oregon state sensitive species (ODFW 1990). The American Fisheries Society lists the chum salmon in the lower Columbia River as at moderate risk of extinction (Nehlsen and others 1991). Distribution and Status Chum salmon have spawned and reared in streams from the Sacramento River in California to the arctic shore of Alaska and eastward to the Mackenzie River on the arctic coast of Canada (Bakkala 1970). In the assessment area, most chum salmon spawned in the lower tributaries of the Columbia River below Bonneville Dam (map 4.42). Major wild production areas include Grays Basin and Hardy and Hamilton creeks in Washington (Howell and others 1985a). Chum salmon were also distributed above Bonneville Dam in the lower portions of tributaries upstream to the Umatilla River in Oregon and the Walla Walla River in Washington (Nelhsen and others 1991). Chum salmon are essentially extinct in the Columbia River Basin above Bonneville Dam. Former spawning areas above Bonneville Dam included lower portions of the Little White Salmon River; Hamilton, Rock, and Herman creeks; and areas along the margins of river banks in the main Columbia River (Fulton 1970). Chum salmon are currently found only in the lower sections of tributaries entering the Columbia River below Bonneville Dam (Howell and others 1985a). Historical commercial harvest ranged from 450,000 to 3.9 million kilograms, peaking in 1928 at about 700,000 fish (Chancy and Perry 1976). Since 1978, commercial harvest has not exceeded 2,000 fish (ODFW and WDF 1981). Chum salmon have also experienced similar declines coast-wide. No significant hatchery production of chum salmon occurs in the Columbia River. Habitat Relationships Most chum salmon spawn within the lower reaches of streams and frequently within the tidal zone. In the Columbia River Basin, spawning usually occurred a short distance upstream from the head of tidewater, in margins of mainstem rivers, and at the mouths of lower tributary streams. Clean, abundant gravel in these areas is needed for successful spawning. Water temperatures for spawning range from 4 to 16 C (Neave 1966). Eggs hatch between about 1.5 and 4.5 months after fertilization. Survival from egg to fry stage is usually less than 10 percent (Bakkala 1970). Survival is related to flows and temperatures during incubation. The greatest cause of egg mortality is fluctuating streamflows, dislodged eggs from shifting gravels, and sediments deposited on and in gravels impeding intragravel flows. Unlike most other anadromous salmonids, chum salmon fry enter saltwater soon after emergence and form schools in estuaries. Key Factors Influencing Status Dramatic declines in run size can be attributed to siltation and stream blockages from logging activities and inundation of spawning areas following construction of Bonneville Dam (Fulton 1970). Poor condition of chum populations is attributed to their sensitivity to poor water quality primarily caused by habitat degradation and loss from forest and agricultural practices, urbanization, and pollution; incidental over-harvest in mainstem fisheries directed at coho and chinook salmon; and competition with hatchery fish in streams (Nehlsen and others 1991).
Map 4.42--Historical and current distribution of chum salmon.