shortnose, and Klamath largescale suckers are all at (Simpson and Wallace 1978). In general, bridgelip risk because of lack of recruitment and adult suckers differ from most other suckers by inhabit- susceptibility to hybridization and introgression ing streams with colder, swifter water and rocky among the species. As populations become smaller substrate (Scott and Grossman 1973). Fish likely and spawning areas become increasingly modified mature after age-2 and spawn in late spring. Maxi- and restricted in area, the likelihood of hybridiza- mum size is about 25 centimeters. tion increases. Key Factors Influencing Status Wood River Bridgelip Sucker The status of Wood River bridgelip suckers will (Catostomus columbianus hubbsf) likely be influenced by the same factors that affect The native range of the bridgelip sucker the status of other native fish species in the Wood (Catostomus columbianus) in the assessment area is River drainage. Alteration of habitat by residential the Snake River drainage downstream from and agricultural development, including irrigation Shoshone Falls, Idaho and the Columbia River withdrawal, overgrazing by livestock, and intro- drainage to British Columbia. The Wood River in ductions of non-native species are likely to be Idaho supports an isolated population that is detrimental to the viability of this subspecies. "nearly 100 percent distinct" from other bridgelip sucker populations and has been described as a Torrent Sculpin (Cottus rhotheus) discrete subspecies (Smith 1966). Smith reported The torrent sculpin inhabits rivers and streams in the that the distinctness of the Wood River population Puget Sound and Columbia River drainages in the suggests that it may warrant full species status states of Oregon, Washington, Idaho, Montana, and upon further evaluation. The subspecies will be in British Columbia (Maughan 1976). The torrent reviewed for listing by the Idaho Department of sculpin is listed as a sensitive species by die Forest Fish and Game. Service in Region 1 and as a species of special concern by the Montana Department of Fish, Distribution and Status Wildlife, and Parks. The holotype of the Wood River bridgelip sucker was collected from Fish Creek, tributary to the Distribution and Status Little Wood River, in 1934 by Carl Hubbs (Smith Historically, the torrent sculpin was found 1966). Other specimens were collected from the throughout tributaries of the mid- and upper mainstem Big Wood and Litde Wood rivers. Columbia River Basin, overlapping range with the Electrofishing surveys of the Big Wood River since shorthead sculpin. In Oregon and Washington, 1986 have captured bridgelip suckers that are the torrent sculpin has been found in the Yakima, presumed to represent this subspecies (Thurow 19 Entiat, and Palouse rivers and tributaries of the 1990). No comprehensive surveys have been upper Deschutes River (map 4.65) (Wydoski completed. Therefore, the subspecies distribution and Whitney 1979). In Idaho, the torrent sculpin and abundance are uncertain. Presumed distribu- has been found in the Kootenai, Pend Oreille, tion is shown in map 4.64. Spokane, Clearwater, Salmon, St. Maries, upper Clark Fork, and Palouse river drainages and in the Habitat Relationships Snake River below Shoshone Falls (Simpson and Little is known about the biology of the bridgelip Wallace 1978). MacPhee (1966) also found the sucker in the Wood River but it is believed to torrent sculpin in Rochat Creek, a tributary to resemble that of other members of the species the St. Joe River. Aldiough the current status is unknown, the present range probably remains "Also personal communication. 1995. F. Partridge, Idaho Department of Fish and Game, Jerome, Idaho.

Aquatics Map 4.64-- Current distribution of Wood River bridgelip sucker.

Aquatics Map 4.65-- Current distribution of torrent sculpin.

Aquatics similar to the historic range. When found, the Bond 1963). In the mid-Columbia River Basin, the torrent sculpin was in low numbers compared species has been collected in the Coeur d'Alene and with the shorthead sculpin (MacPhee 1966). St. Joe river systems in Idaho (Maughan 1976), and in the upper Columbia in the Flathead, Little Habitat Relationships Blackfoot, and Blackfoot river systems in Montana and the Flathead River in British Columbia The torrent sculpin is primarily a benthic stream (Bailey and Bond 1963). In the Snake River drain- species but also occurs in lakes (Wydoski and age, the species occurs in the mainstem and tribu- Whitney 1979). In streams, they inhabit swift, taries of the Grande Ronde and Imnaha river cool, clear riffles with a stable bottom of scattered systems in Oregon and the Clearwater, Salmon, rubble, gravel, and boulder substrate (Simpson Boise, Owyhee, Big Lost, and Little Lost rivers and Wallace 1978). Torrent sculpin were found and Birch, Medicine, and Beaver creeks in Idaho only where rock substrate was present. Spawning, (Maughan 1976). In 1994, surveys found which occurs in riflfle areas with rubble or boulder shorthead sculpin in the upper Deschutes drainage substrate, starts in early spring and lasts to late in Oregon, the upper and lower Kootenai, Yaak, April. and Fisher rivers in Montana, the upper Yakima in Washington, and the upper and South Fork Coeur Key Factors Influencing Status d'Alene, and Little Lost rivers, and Birch Creek in 20 The torrent sculpin is probably susceptible to land Idaho. use practices (for example, livestock grazing, road construction, and mining) and climatic events that Habitat Relationships degrade water quality and diminish its natural The shorthead sculpin prefers riflfle areas and small habitat. Pollution, increased water temperatures, coldwater rivers and streams (Bowler 1974). It has and sedimentation are the major potential negative been collected in emergent grasses and slow- impacts to sculpin populations. moving waters along shorelines and in backwaters. Spawning, which occurs in riffle areas with a Shorthead Sculpin (Cottus confusus) rubble/boulder substrate, starts in early spring and The shorthead sculpin inhabits rivers and streams lasts to late April. in the Puget Sound and Columbia River drainages in the states of Oregon, Washington, Idaho, Mon- Key Factors Influencing Status tana, and in British Columbia (Bailey and Bond The shorthead sculpin is probably susceptible to 1963). The shorthead sculpin is listed by the land use practices (for example, timber harvest Forest Service as sensitive and by the Montana activities, road construction, and mining) and/or Department of Fish, Wildlife, and Parks as a climatic events that degrade water quality. Pollu- species of special concern. tion, increased water temperatures, and sedimenta- tion are the major potential negative impacts to Distribution and Status sculpin populations. Once stream populations are In the assessment area, the shorthead sculpin is eliminated, sculpin are poor recolonizers from found in the upper reaches and tributaries of the adjacent areas as compared with trout. Deschutes, Yakima, Wenatchee, and John Day river systems in the lower Columbia River Basin 20Personal communication. 1995. Lori Leatherbury, Forest and the Snake, Spokane, Pend Oreille, and Service, Boise, Idaho. Kootenai River drainages in the mid and upper Columbia River Basin (map 4.66) (Bailey and

Aquatics Map 4.66-- Current distribution of shorthead sculpin.

iiii:i:iiiiii:iiiiiiiiiiiiiiiiiiiii: 1326 Aquatics Pit Sculpin (Cottuspitensis) Factors Influencing Status Pit sculpin were historically widespread in the Pit The main reasons for the Pit sculpin's current River system, from the Goose Lake Basin to the status are its rarity and limited amount of available Sacramento River (Moyle 1976). In Oregon, the habitat. Pit sculpin are limited in their ability to Pit sculpin is currently listed as sensitive by the recolonize a. stream once extirpated, this is espe- Forest Service and BLM, and as a peripheral/rare cially true in the Goose Lake Basin because of the species by the Oregon Department of Fish and apparent lack of use of the lake. Because of their Wildlife. inability to recolonize, catastrophic events, loss of habitat, extreme droughts, and introductions of Distribution and Status exotics could all lead to extirpation of individual stream populations. Extreme drought events and In Oregon, the extent of the historical distribution loss of stream habitat may have been factors limit- of Pit sculpin in the Goose Lake Basin is un- ing the current distribution of Pit sculpin in the known. However, the sculpin was recorded both Goose Lake Basin. Past management, such as historically and recently (1979), and can still be livestock grazing, timber activities, and road build- found, in a few tributaries of Goose Lake, specifi- ing, has negatively affected sculpin habitat by cally Cottonwood and Drews creeks (map 4.67) increasing siltation (ODFW 1992). Loss of peren- (Long and Bond 1979; ODFW 1992). Pit sculpin nial, cool, spring-fed stream reaches, which act as also were recorded historically in Thomas Creek, refuge sites during extreme droughts, also has Oregon, but surveys in 1983 and 1988 yielded no affected status. sculpin.21 The Pit sculpin has never been found in Goose Lake. In California, the Pit sculpin is still Slender Sculpin (Cottus tennis) widespread throughout the Pit River system and has recently been found in Lassen, Gold, and The distribution of the slender sculpin is restricted Willow creeks, all tributaries of Goose Lake. The to the Upper Klamath Basin in Oregon, upstream Pit sculpin, where found, tends to be rare. of Klamath Falls. The slender sculpin is listed as a sensitive species by Region 6 of the Forest Service Habitat Relationships and as a species of special concern by the Ameri- can Fisheries Society (Williams and others 1989). Pit sculpin are not known to migrate. They are a benthic species found mainly in small, cold water Distribution and Status tributaries (Moyle 1976). They show a strong preference for riffle habitat with small gravel The sculpin was historically distributed in the substrate (Moyle 1976).22 In the winter, they use Upper Klamath and Agency lakes and their tribu- the interstices among large gravels and cobbles taries. Recorded distributions, between 1934 and during near-freezing and ice formation periods. 1976, are the lower Williamson and Sycan rivers, They occupy water that ranges in temperature South Fork and mainstem Sprague and Wood from 6.5° C in March to 18.8° C in June.23 rivers and Odessa, Denny, Crystal Camporee Spring, Crooked, Fort, and Sevenmile creeks (map 21Personal communication. 1995. J. Williams, Bureau of Land 4.68) (Ford and Thomas 1993). The current status Management, Boise, Idaho. Personal communication of of slender sculpin is not well known, but sampling unpublished data. by Oregon State University and the Forest Service "Personal communication. 1995. J. Williams, Bureau of Land in 1992 found slender sculpins in sections of the Management, Boise, Idaho. Personal sommunication of unpublished data. Wood River and Larkin, Crystal, Crooked, and Fort creeks, and Fourmile Springs (Ford and 23Personal communication. 1995. J. Williams, Bureau of Land Management, Boise, Idaho. Personal communication of Thomas 1993). unpublished data.

Aquatics 432?' Map 4.67-- Historical and current distribution of pit sculpin.

1328 Aq uatic s

Map 4.68-- Historical and current distribution of slender sculpin.

Aquatics 1329 Habitat Relationships mainstem of the Tucannon and mainstem and tributaries of the Walla Walla (Washington) and Slender sculpins reside in both lake and stream Umatilla (Oregon) rivers (map 4.69). In the Walla environments and use a variety of habitat types. Walla River Basin, they are found in the North and They are found in detritus, mud, sand, gravel, and South forks, the Touchet River including the North, rubble substrate and occupy pools, riffles, and South and Wolf forks, and Pine, Dry, Mill, Couse, glides (Bond 1963). Similar to other sculpins, they and Cottonwood creeks. In the Umatilla Basin, prefer low water temperatures and high dissolved they are found in the McKay River and East Birch, oxygen levels. The upper lethal temperature is Pearson, Johnson, Rail, and Buder creeks. Although 31° C and dissolved oxygen concentrations less confined to streams in the Blue Mountains, the than four parts per million are generally avoided species is abundant within this range. (Bond 1963). Habitat Relationships Key Factors Influencing Status Lonzarich (1993) found that the margined sculpin The very restricted distribution of this species prefers pools and glides with low velocity water suggests very specific habitat needs or preferences. flowing over cobble and gravel substrate. While it Changes in habitat features and water quality appears tolerant of variable habitat conditions, would likely result in population declines. The relatively little is known about this species. Most effects of introduced predators and potential sculpin species prefer relatively low water tempera- competitors, now prevalent in the Upper Klamath tures. In Oregon, the margined sculpin is often Basin, are not known. So little is known of the found in association with rainbow trout, speckled distribution, life history, and habitat needs of dace, longnose dace, and Paiute sculpin (Wydoski slender sculpins that assessing their status or un- and Whitney 1979). derstanding the precise effects of human activities is difficult. Key Factors Influencing Status Margined Sculpin The restricted distribution of the margined sculpin (Cottus marginatus) makes it especially vulnerable to environmental changes. Land management activities could lead to The margined sculpin is the only freshwater fish the rapid decline in margined sculpin population confined entirely to the middle Columbia River numbers and status. Major potential effects from drainage in the northern portion of the Blue these activities include reduced amounts of Mountains of eastern Washington and Oregon. preferred pool habitat, habitat fragmentation, Due to its limited range, the species is currently increased water temperatures, loss of streamside listed as a BLM tracking species, a State of Oregon vegetation, increased water velocities, and vulnerable species; and a State of Washington increased sedimentation. Lonzarich (1993) monitor species. noted the degraded condition from grazing and logging in the Touchet River, particularly the Distribution and Status South and Wolf forks. Also, Oregon Department of Fish and Wildlife (1992) cited potential The historic distribution of margined sculpin has impacts from agricultural chemicals, heavy not been studied in detail, mainly because it over- sedimentation, and toxic material spills as laps the distribution of Paiute sculpin and is diffi- reasons for listing the species. cult to identify in the field. The most comprehensive study on die distribution of margined sculpins (Lonzarich 1993) revealed that they occur in the

Aquatics Map 4.69-- Historical and current distribution of margined sculpin.

A q u at ic s 1331 Wood River Sculpin Key Factors Influencing Status (Cottus leiopomus) The most significant threat to Wood River sculpin The Wood River sculpin is endemic to the Wood is the loss of habitat caused by development of River drainage in south-central Idaho. The Wood irrigation projects in the Wood River drainage and River sculpin is currently listed as a State of Idaho by floodplain encroachment. Habitat destruction species of special concern and as a sensitive species from irrigation projects includes stream dewater- by the BLM and Region 4 of the Forest Service. ing, flooding of stream channels by reservoir construction, and formation of migration barriers. Distribution and Status Non-native fish introductions have also occurred. These introductions have created adverse effects The Wood River sculpin was first collected from on the population, including predation, competi- the Little Wood River near Shoshone, Idaho in tion, potential hybridization with Paiute sculpin, 1893 (map 4.70) (Gilbert and Evermann 1895). and potential introduction of disease. Most habitat Historically, the range of Wood River sculpin loss occurred on private lands prior to the 1930s, consisted of all permanent, interconnected waters with additional habitat loss resulting from over- from the falls on the Malad River at Interstate 84 grazing in the upper Big Wood River. More re- in Idaho upstream into the Little Wood and Big cently, sculpin habitat has been degraded by Wood rivers and their tributaries (Simpson and agriculture and residential development within the Wallace 1978). It is likely that the Wood River floodplain. sculpin was the only sculpin present in the drain- age. The Wood River sculpin was more widely Shoshone Sculpin (Cottus greenet) distributed in the drainage historically than at present.24 However, no basin-wide inventories The Shoshone sculpin is endemic to springs along have been conducted to determine its present the Snake River in the Hagerman Valley of south- range accurately. Inventories conducted on 26 central Idaho. Because of its restricted range and streams in the drainage from the 1970s to 1990s the development pressures on spring systems, the found sculpins at 40 locations but not at 8 loca- Shoshone sculpin is classified as threatened by the tions.25 Where found, sculpin were common to American Fisheries Society (Williams and others abundant. 1989), as a State of Idaho species of special con- cern, and as a sensitive species by the BLM. Habitat Relationships Distribution and Status The Wood River sculpin has similar habitat requirements as other sculpins found in Idaho Shoshone sculpins are restricted to portions of the (Merkley and Griffth 1993). The Wood River Snake River in south-central Idaho that contain sculpin seems to select fast water riffles with boul- spring systems (map 4.71). Wallace and Griffith der, cobble, and gravel substrate. In some streams, (1982) reported the species from 49 locations sculpins make limited use of overhanging banks within 25 spring systems in the Hagerman Valley. and beaver ponds. In the Big Wood River, sculpins Most locations are along the north bank of the were found seasonally in ephemeral side channels river in the Thousand Springs formation of with suitable cobble and boulder substrates. Gooding County. Two localities along the south side of the river in Twin Falls County contained "Wallace, R.L. University of Idaho. 1995. Letter dated Shoshone sculpin. Shoshone sculpin also were September to B. Reininger, Idaho Department of Fish and collected from Billingsley Creek, a tributary of the Game, Jerome, Idaho. Snake River near Hagerman. Many spring and "Personal communication. 1995. F. Partridge, Idaho Depart- stream systems in the region contain the more ment of Fish and Game, Jerome, Idaho. Personal communica- tion of unpublished data.

Aquatics Map 4.70-- Historical and current distribution of Wood River sculpin.

A quatics 1333 Map 4.71-- Historical and current distribution of Shoshone sculpin.

1334 Aquatics common mottled sculpin (C. bairdi). Results of a the Steens Mountain, the Silver Creek drainage, recent Idaho Chapter American Fisheries Society the Silvies River and tributary streams, and the Workshop (IDAFS 1995) indicate some popula- isolated drainages of Poison and Rattlesnake tion loss but an overall "fairly stable" population creeks. The sculpin in the Harney Basin is consid- status during the past decade. ered by Bailey and Bond (1963) and Bond (1974) to represent an undescribed relative of the mottled Habitat Relationships sculpin in the Snake River drainage. Within the Silvies Basin, Bisson and Bond (1971) reported Shoshone sculpin are found only in association the Malheur sculpin from the mainstem Silvies with spring outflows. Highest population densities River, Scotty Creek, and Emigrant Creek. Accord- occur near the headwaters of springs and lower ing to the BLM (1992), Malheur sculpin occur on densities occur with decreasing influence of spring BLM-administered lands in the upper Silvies River water on water quality (Wallace and Griffith and Emigrant, Yellowjacket, Hay, Myrtle, and 1982). Younger sculpins prefer areas with more Sawtooth creeks in the Silvies Basin. Historic plant cover and fewer large rocks than do older collections suggest that the subspecies was broadly Shoshone sculpins. Both juvenile and adult distributed within its range. Bond (1974) reported Shoshone sculpins prefer relatively low water that the subspecies has been extirpated from the velocities (less than 20 cm per second) with tem- Rattlesnake Creek subbasin. peratures near 15°C (Wallace and Griffith 1982). Habitat Relationships Key Factors Influencing Status Very little is known about the life history of the Shoshone sculpins are dependent on maintenance Malheur sculpin, but it is assumed to be compa- of the natural integrity of spring flows. The nu- rable to that of other mottled sculpins, Cottus merous spring systems that are located along the bairdi. According to Bond (1974), the Malheur Snake River provide a valuable, but finite resource. sculpin requires cool-water streams with large Diversion of spring water has caused dewatering of gravel or rubble substrates for cover and spawning. Shoshone sculpin habitat in many areas (Wallace It requires water temperatures below 26° C, with and Griffith 1982). Spring waters are used for a high dissolved oxygen and very low turbidity. variety of purposes, including aquaculture facili- Given these characteristics, the Malheur sculpin ties, hydropower operations, and agriculture. can occupy small headwater streams and larger These practices have diverted, dried, and polluted rivers, such as the lower Blitzen River. springs. Various private and Federal fish hatcheries also serve as sources of non-native invertebrates, Key Factors Influencing Status fishes, diseases, and parasites. Malheur sculpin appear to be very sensitive to Malheur Sculpin (Cottus bairdi spp.) changes in water quality, including increases in temperature, sediments, and turbidity. Aquatic The Malheur sculpin is endemic to the Harney habitat and water quality conditions are consid- Basin of southeastern Oregon. This undescribed ered poor in the upper Silvies River because of subspecies is listed as a sensitive species by the elevated water temperature, silt loads, and live- State of Oregon. stock grazing; and poor on Hay and Yellowjacket creeks because of elevated water temperature, silt Distribution and Status loads, and timber harvesting (BLM 1992). On The Malheur sculpin is endemic to streams in the Emigrant Creek, BLM (1992) rated water quality Harney Basin, including the Silvies and Blitzen condition as fair and aquatic habitat condition as river systems (map 4.72). Historic distribution good but considers both conditions to be declin- includes the Blitzen River and tributary streams on

Aquatics Map 4.72-- Historical and current distribution of Malheur sculpin.

1336 Aquatics ing because of siltation, high water temperature, aquifers and associated substrates also may be and upstream impacts from livestock grazing and degraded from over-withdrawal of groundwater, logging. Biotic interactions are not specifically geothermal exploration, or other subsurface drill- known, but the occurrence of the Malheur sculpin ing. Many spring habitats of the Shoshone sculpin would appear to be negatively correlated with have been lost because of aquaculture facilities and presence of introduced warm-water fishes such as small hydropower operations. Such species require catfish and centrarchids, which are more tolerant protection of remaining habitat if the species are of turbid water conditions. Elevated water tem- to persist. perature, increased turbidity, and sediment trans- 2. Many of these taxa are subject to increased port caused by activities such as livestock grazing, likelihood of extinction or extirpation as road construction, and timber harvest activities are environmental variability combines with low detrimental to the sculpin and have been cited by population sizes. The native lake-dwelling suck- the BLM (1992) as causes for the decline of ers of the Klamath Basin (shortnose, Lost River, Malheur sculpin populations in the mainstem and Klamath largescale) have declined to the Silvies, Hay, Yellowjacket, and Emigrant creeks extent that hybridization among the species may within the Silvies Basin. be occurring within restricted, remaining spawn- ing areas. Water quality in Upper Klamath and Conclusions Agency lakes has severely reduced the distribution Approximately 50 percent of the native fish taxa in of native fishes and has caused fish mortality in the the assessment area has exhibited significant de- past. Drought exacerbates problems of water clines compared with historic levels. Presently, 45 quality in the lakes. In the Warner Valley, the of the 88 native fish taxa (51%) in the assessment threatened Warner sucker was nearly eliminated area are identified as threatened, endangered, during the drought of the early 1990s by a combi- sensitive, or of special concern by state or Federal nation of the desiccation of lake habitats and the agencies or by the American Fisheries Society. diversion dams that prevented access to lower Eleven fish taxa are formally listed as threatened or sections of remaining tributaries. The species endangered under the Endangered Species Act. survived largely through temporary transfer of The following important concepts have emerged individuals to the Summer Basin. Drought caused from our review of historic and current distribu- similar problems to the Goose Lake lamprey when tions of rare fish and existing literature. Goose Lake dried in the early 1990s. 1. Many of these taxa are vulnerable to an- 3. Many of these taxa are poorly understood thropogenic effects and stochastic events and in need of study and rigorous monitor- because of their restricted range and fragile ing efforts. We know very little about the lam- habitat requirements. Four cyprinid fishes are preys (with the possible exception of the Pacific restricted to one or two small spring systems: lamprey), the northern roach, the leatherside Borax Lake chub, Summer Basin tui chub, Hutton chub, most of the tui chubs, the Foskett speckled tui chub, and Foskett speckled dace. Several other dace, the Wood River bridgelip sucker, and the species appear to be extremely rare, but their Malheur sculpin. Several of these taxa, for example precise status is unclear. These species include the the Hutton tui chub and the Foskett speckled Klamath lamprey, Goose Lake lamprey, Lost River dace, have long been recognized as distinct at the sucker, and shortnose sucker. The spring-dwelling subspecific level yet lack formal scientific descrip- fishes, such as the Borax Lake chub and Hutton tions. Monitoring of habitat and populations is tui chub, occupy unique desert habitats that are essential if management is to respond to factors easily disturbed by off-road vehicles, livestock that threaten the persistence of the narrowly dis- grazing, or other surface disturbances. Spring tributed endemics.

Aquatics