RARE AND SENSITIVE SPECIES: STATUS SUMMARIES Narratives summarizing the status for 39 rare and mous fishes. Some rare and sensitive species are sensitive species were prepared. These narratives recognized as requiring special protection by are arranged in phylogenetic order and are divided the States of Oregon, Washington, Idaho, or as follows: Distribution and Status, Habitat Rela- Montana. Many are managed as sensitive spe- tionships, and Key Factors Influencing Status. cies by the USDA Forest Service and/or Accompanying each narrative is a map that typi- USDI Bureau of Land Management. Several cally illustrates the probable historic and current were considered by the U.S. Fish and Wildlife distribution plus any major introduction sites Service to be Category 2 Candidates for listing mapped at the watershed level. The actual distri- until a February 27, 1996 nationwide decision butions of these species may include small por- to delete all Category 2 taxa from Candidate tions of the watersheds and therefore, are species status. overestimated on the figures. General categories of Although we know less about the rare and sensi- research and information needs are listed for each tive species than the seven key salmonids, analyses species in table 4.53 (see following section "Infor- of existing distribution and reviews of available mation and Research Needs." literature provide important insights about com- These status narratives include a variety of mon threats and appropriate management needs. narrowly distributed endemics, largely un- Many of these taxa occur in isolated areas of the known species, and other native species that Columbia River Basin, in isolated subbasins of the may be important and wide ranging but for Great Basin, or are restricted to the upper Klamath which the assessment area represents a small Basin. They typically occur in relatively depauper- portion of their range. The Sunapee char, an ate subbasins, perhaps with only one or two native introduced species of special note, also is in- fish species present and therefore, may not be cluded. All these species are worthy of special recognized in management strategies that focus on management attention and several already areas of high native species diversity. Many of receive protection under the Endangered Spe- these taxa occur in very restricted areas, often cies Act. Resident freshwater threatened or occupying one or two small habitat patches within endangered species are listed under the Endan- subwatersheds. Consequently, broad or mid-scale gered Species Act by the U.S. Fish and Wildlife assessments may not adequately describe their Service, whereas the National Marine Fisheries distributions. Service has responsibility for listing anadro- Aquatics White Sturgeon Washington-Oregon border, the annual abun- (Acipenser transmontanus) dance of white sturgeon greater than 53 centime- ters was 893,800 fish from 1986 to 1992. In White sturgeon were once widely distributed in contrast to the Snake and Kootenai rivers where all the Columbia River basin. The species has been an captured sturgeon must be released, a consumptive important sport, commercial, and tribal resource. sturgeon fishery continues in the lower Columbia The Kootenai River (Idaho, Montana and British River. Columbia) white sturgeon population is listed as endangered by the U.S. Fish and Wildlife Service Habitat Relationships and the State of Idaho and as sensitive by the BLM. The Snake River white sturgeon is listed as a Substrate size and water velocity influence selec- species of concern by the State of Idaho and as a tion of spawning areas by white sturgeon. Spawn- sensitive species by Region 1 of the Forest Service. ing generally occurs in water over three meters deep and over cobble substrate. In the Columbia Distribution and Status River system, reproduction has been greater dur- ing years of high flows compared with years of low Along the Pacific Coast, white sturgeon were flow (Hanson and others 1992). Spawning also found in accessible freshwater from the Aleutian occurs earlier and at lower temperatures during Islands south to central California. The Columbia high flow years (Hanson and others 1992). Adults River represents one of three large river basins in and juveniles prefer deep-pool habitat with a fine the Pacific Northwest where white sturgeon repro- bottom substrate. Adults tend to move down- duce. Historically, prior to dam construction, stream in the summer and rail months and up- white sturgeon were anadromous and migrated stream in the winter and spring months. Fish tend within the Columbia River Basin up to impassable to stay in shallower water during the spring and falls (map 4.35). The Kootenai River white stur- summer and move to deeper waters during the geon has been isolated from other white sturgeon winter. populations since the last glacial age (Apperson and Anders 1991). The white sturgeon is restricted Key Factors Influencing Status to 695 river kilometers in the Kootenai River Basin between Kootenai Falls, Montana down- Hydropower dams on the Columbia and Snake stream to Cora Linn Dam at Kootenay Lake, rivers have prevented migration, fragmented British Columbia, Canada. The Kootenai River riverine populations, and reduced the effectiveness white sturgeon have not successfully spawned in of natural propagation (Hanson and others 1992). recent years. The current population, which has a Dams have also reduced spawning success, by no harvest restriction, has decreased to about 880 decreasing the amount of suitable spawning areas individuals (Apperson and Anders 1991). Snake or creating poor incubation environments. In River white sturgeon are found in the Snake River general, the length of time required to reach sexual in Idaho up to Shoshone Falls, and in the Salmon maturity, typically 10 to 15 years, results in low River in Idaho likely upstream to the confluence rates of natural recruitment. Most reproductively of the East Fork Salmon River. The present distri- capable fish are protected by harvest regulations bution of Snake River white sturgeon has been based on fish length. The decrease in spring river fragmented into discrete subpopulations confined flows below Libby Dam, Montana appears to have between mainstem dams (Hanson and others contributed to spawning failures of the Kootenai 1992). The Hells Canyon reach along the Oregon- River population in recent years (Apperson and Idaho border contains the highest densities of Anders 1991). Land management activities are Snake River white sturgeon. In the Columbia considered a secondary impact to white sturgeon. River downstream from McNary Dam, on the Aquatics 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 lamprey, have declined. Based on the restricted range and threatened status of many host species, the The Klamath lamprey (L. similis) is a parasitic form Klamath lamprey may be at high risk of extinction. from the Klamath River of Oregon and California Specific information is lacking. (Vladykov and Kott 1979). The Klamadi lamprey is poorly understood, restricted in its distribution, and River Lamprey (Lampetra ayresi) may be threatened with extinction. River lamprey are anadromous and parasitic. They Distribution and Status are rare and, according to the limited available literature, apparently migrate short distances The Klamath lamprey is one of five species of lam- inland compared with the Pacific lamprey. preys described from the Klamath Basin of northern California and south-central Oregon. The other Distribution and Status forms include the Miller Lake lamprey (L. minima), a dwarf parasitic form that was endemic to Miller The river lamprey is distributed along the Pacific Lake, Oregon, and is now extinct (Bond and Kan Coast of North America from the Sacramento 1973); the Modoc brook lamprey (LfoUetti), a River, California north to Tee Harbor near Juneau, nonparasitic form known only from Willow Creek Alaska (map 4.37) (Kan 1975). In the Columbia and the Lost River portions of the Klamath River River, the river lamprey has been reported from drainage in Modoc County, California (Vladykov Bonneville Dam and locations downstream (Kan and Kott 1979); the Pit-Klamath brook lamprey (L 1975). Very little is known on the status of this lethophaga), a more widely distributed nonparasitic species. form known from the upper Klamath drainage and the Goose Lake drainage in Oregon and California Habitat Relationships and the upper Pit River system in California (Hubbs 1971); and the widespread Pacific lamprey (L. River lampreys require small, clear water streams tridentata). The Klamath lamprey is known from the for spawning, with ammocoetes (the larval form) Klamath River and upper Klamath Lake in Oregon living in silty backwaters of such streams (Moyle (map 4.36) (Vladykov and Kott 1979). The Pacific and others 1989). Known hosts for adults include lamprey reported from Copco Reservoir on the smelt, herring, kokanee salmon, and coho salmon Klamath River in California may instead represent L (Kan 1975). In Canada, the adults begin their similis (Moyle and others 1989). Information about spawning migration in freshwater between the status of the Klamath lamprey is lacking. September and late winter after they have spent two years in the ocean (Beamish 1980). They Habitat Relationships spawn the following April to June, and subse- quently die. At the appropriate age, the young Little is known about the specific habitat require- begin to metamorphose in July but do not ments of the Klamath lamprey. The species is para- emigrate to the ocean until the following May sitic, presumably on the larger trouts and suckers in to July (Beamish 1980). the Klamath Basin. Key Factors Influencing Status Key Factors Influencing Status Relative to Pacific lamprey, the river lamprey's The many dams, water diversions, and other modifi- tendency to use areas close to the coast may pro- cations common to the upper Klamath River drain- tect it to some degree from mortality associated age are presumed to have disrupted the distribution with mainstem dam passage.