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• 1471. [Image] Volume 2 : Water Resources

  	Citation × Citation Citation Abstract Copy Title: Volume 2 : Water Resources Author: Howard Humphreys & Sons Year: 1978 Title: Volume 2 : Water Resources Author: Howard Humphreys & Sons Year: 1978 Close

• 1472. [Image] Water: Not as Cheap as You Think

  	Citation × Citation Citation Abstract Copy Title: Water: Not as Cheap as You Think Year: 1986 Title: Water: Not as Cheap as You Think Year: 1986 Close

• 1473. [Image] Water of the World

  	Citation × Citation Citation Abstract Copy Title: Water of the World Year: 1980 Title: Water of the World Year: 1980 Close

• 1474. [Image] Iran--Sandy Soils: Distribution, Research and Development

  	Citation × Citation Citation Abstract Copy Title: Iran--Sandy Soils: Distribution, Research and Development Year: 1975 Title: Iran--Sandy Soils: Distribution, Research and Development Year: 1975 Close

• 1475. [Image] Studies on Dry land Farming at the College of Agriculture and Forestry , University of Mogul

  	Citation × Citation Citation Abstract Copy Title: Studies on Dry land Farming at the College of Agriculture and Forestry , University of Mogul Year: 1979 Title: Studies on Dry land Farming at the College of Agriculture and Forestry , University of Mogul Year: 1979 Close

• 1476. [Image] Is the Nile Drying Up?

  	Citation × Citation Citation Abstract Copy Title: Is the Nile Drying Up? Author: Derrick, Jonathan Year: 1987 Title: Is the Nile Drying Up? Author: Derrick, Jonathan Year: 1987 Close

• 1477. [Image] Ground Water in the eastern Mediterranean and Western Asia

  	Citation × Citation Citation Abstract Copy Title: Ground Water in the eastern Mediterranean and Western Asia Year: 1982 Title: Ground Water in the eastern Mediterranean and Western Asia Year: 1982 Close

• 1478. [Article] Aquatic Habitat in Oregon Coastal Streams: Winter, 1999-2001

  Abstract -- We compared summer and winter aquatic habitat conditions to determine patterns of seasonal habitat dynamics for coho salmon (Oncorhynchus kisutch). Winter sites corresponded to summer sites, ...

  Citation × Citation Citation Abstract Copy Title: Aquatic Habitat in Oregon Coastal Streams: Winter, 1999-2001 Abstract -- We compared summer and winter aquatic habitat conditions to determine patterns of seasonal habitat dynamics for coho salmon (Oncorhynchus kisutch). Winter sites corresponded to summer sites, facilitating a direct comparison between seasons on a site specific and regional scale. The data sets included 128 sites selected from the Oregon Plan habitat sites (OPHS) surveyed in the summers of 1999 and 2000 and surveyed again in the winters of 2000 and 2001. We found significant differences among geomorphic, hydrologic, and physical habitat variables measured along identical reaches in streams between winter and summer. Increases in water volume corresponded with increased deep pool density, secondary channel habitats, and wood density. These differences highlight the importance of high winter flows in terms of their contribution towards essential habitat for coho survival and reproduction. Differences among habitat variables from consecutive winters were minimal, indicating that any differences in habitat variables may be a result of variation in annual precipitation. Moreover, minimal differences in habitat variables were observed between Basin and OPHS surveys, also leading to the suggestion that OPHS surveys, conducted during the summer may provide important baseline information on habitat variables within and among watersheds. Habitat quality, as measured by benchmarks, was shown to be independent of land ownership but not independent of monitoring area. This investigation allowed us to quantify seasonal changes in summer-to-winter habitat dynamics in coastal Oregon streams. Future research could involve the addition of juvenile salmon surveys with habitat surveys to determine any significant associations between fish density and habitat quality. Furthermore, habitat variables measured during the summer might be used to determine winter habitat conditions (i.e. and thus quality), after accounting for variation in annual precipitation. Attribute means and estimates of variation, measured at identical sites in summer and winter over the long-term, may be beneficial when linking summer to winter habitat variables and ultimately to fish density estimates, thereby increasing sample size and predictability. Title: Aquatic Habitat in Oregon Coastal Streams: Winter, 1999-2001 Abstract -- We compared summer and winter aquatic habitat conditions to determine patterns of seasonal habitat dynamics for coho salmon (Oncorhynchus kisutch). Winter sites corresponded to summer sites, facilitating a direct comparison between seasons on a site specific and regional scale. The data sets included 128 sites selected from the Oregon Plan habitat sites (OPHS) surveyed in the summers of 1999 and 2000 and surveyed again in the winters of 2000 and 2001. We found significant differences among geomorphic, hydrologic, and physical habitat variables measured along identical reaches in streams between winter and summer. Increases in water volume corresponded with increased deep pool density, secondary channel habitats, and wood density. These differences highlight the importance of high winter flows in terms of their contribution towards essential habitat for coho survival and reproduction. Differences among habitat variables from consecutive winters were minimal, indicating that any differences in habitat variables may be a result of variation in annual precipitation. Moreover, minimal differences in habitat variables were observed between Basin and OPHS surveys, also leading to the suggestion that OPHS surveys, conducted during the summer may provide important baseline information on habitat variables within and among watersheds. Habitat quality, as measured by benchmarks, was shown to be independent of land ownership but not independent of monitoring area. This investigation allowed us to quantify seasonal changes in summer-to-winter habitat dynamics in coastal Oregon streams. Future research could involve the addition of juvenile salmon surveys with habitat surveys to determine any significant associations between fish density and habitat quality. Furthermore, habitat variables measured during the summer might be used to determine winter habitat conditions (i.e. and thus quality), after accounting for variation in annual precipitation. Attribute means and estimates of variation, measured at identical sites in summer and winter over the long-term, may be beneficial when linking summer to winter habitat variables and ultimately to fish density estimates, thereby increasing sample size and predictability. Close

• 1479. [Article] Status and Distribution of Native Fishes in the Goose Lake Basin Information Reports number 2008-02

  Abstract -- This study describes the current distribution of the nine native fish species in the Oregon portion of the Goose Lake basin (Lake County): Goose Lake redband trout Oncorhynchus mykiss ssp., ...

  Citation × Citation Citation Abstract Copy Title: Status and Distribution of Native Fishes in the Goose Lake Basin Information Reports number 2008-02 Abstract -- This study describes the current distribution of the nine native fish species in the Oregon portion of the Goose Lake basin (Lake County): Goose Lake redband trout Oncorhynchus mykiss ssp., Goose Lake lamprey Entosphenus sp., Goose Lake tui chub Siphateles bicolor thalassinus, Goose Lake sucker Catostomus occidentalis lacusanserinus, Modoc sucker Catostomus microps, Pit-Klamath brook lamprey Entosphenus lethophagus, speckled dace Rhinichthys osculus, Pit roach Lavinia symmetricus mitrulus, and Pit sculpin Cottus pitensis. The Goose Lake basin is an endorheic, or topographically closed basin located in south central Oregon and northeastern California. The basin is within the usually closed northeastern extremity of the adjoining Sacramento River basin, astride the Oregon-California boundary. Although most of the lake lies in California, most of its valley and nearly two-thirds of the total drainage area (~722 sq. mi.) are in Oregon. The largest streams in the basin are Drews, Cottonwood, and Thomas Creeks. Annual precipitation averages about 36 cm per year (Phillips and van Denburgh 1971). Goose Lake overflowed briefly into the North Fork Pit River in 1868 and 1881, but storage and diversion of irrigation water has substantially reduced the inflow and future overflow is unlikely (USGS 1971). The lakebed was dry in the summers of 1926, 1929- 1934, and 1992. About half the basin is forestland, 20% is hay fields and pastureland, and 16% is shrub and rangeland. Currently, almost 35% of the inflow is diverted for irrigation (OWRD 1989). The Goose Lake basin is home to four endemic fish taxa: the Goose Lake redband trout, lamprey, sucker, and tui chub. Endemic fishes of the Goose Lake basin split their life histories between Goose Lake and its tributaries, as opposed to the five native but non-endemic species that primarily occupy stream habitats. Pit roach and all endemic fishes except Goose Lake tui chub are listed as a “species of concern” by the USFWS, a designation that implies there is concern about species viability, but not enough information is known to initiate a listing review for threatened or endangered status. The Modoc sucker was listed as a federally endangered species in 1985 (USFWS 1985). No formal recovery plan was required due to an existing “Action Plan for the Recovery of the Modoc Sucker” (USFWS 1984). Most of the recovery actions outlined in the action plan were either completed or are no longer relevant (Stewart Reid, Western Fishes, personal communication). However, actions 26 and 27 pertaining to range expansion remain incomplete. Action 26 suggests reclassification to threatened upon establishment of safe populations (for 3-5 years) throughout the Rush and Turner Creek watersheds in the Pit River basin. Action 27 suggests delisting upon establishing safe populations in two other historic streams. At the time of listing, the historic range of Modoc sucker was thought to have included only two small tributaries of the Pit River in Modoc and Lassen Counties, Ash and Turner Creeks (USFWS 1985). Therefore, a major recovery goal was to expand the species’ range with additional populations (USFWS 1984). In 2001, reexamination of historical documents and museum specimens established that Modoc suckers had also historically occupied Thomas Creek in the Goose Lake basin. Field collections in 2001, with subsequent morphological and genetic analysis, confirmed that the population was still present in Thomas Creek (Stewart Reid, Western Fishes, personal communication); however, the broader range of Modoc sucker in the Goose Lake watershed was not known. In 1995, the Goose Lake Fishes Working Group drafted a conservation plan for “prelisting” recovery of all native fish in response to severe drought and habitat degradation (GLFWG 1995). The Aquatic Inventories Project of the Oregon Department of Fish and Wildlife (ODFW) conducted habitat and fish distribution surveys (1991-1995) to obtain baseline information to help inform recovery efforts (ODFW, unpublished data). Since then, field work to monitor the distribution and abundance of Goose Lake fishes has been limited and sporadic, targeting only Goose Lake redband trout and Modoc sucker (Dambacher 2001; Reid 2007). No comprehensive follow up work has been conducted to evaluate fish response to climatic conditions, habitat restoration projects, and continued irrigation activities. ODFW recently drafted a status review of native fish of Oregon (ODFW 2005). Except for redband trout, Goose Lake fishes were not included in the status review due to a lack of new information since the previous status review in 1995 (Kostow et al. 1995). Further, the review of Goose Lake redband trout was limited by a lack of long-term data series. The first objective of this study was to document the current distribution of native fishes in Oregon’s portion of the Goose Lake basin and assess changes in distribution that may have occurred since the last surveys were conducted 12 years ago. The second objective was to provide new information about the distribution of Modoc suckers within the basin. The third objective was to determine relative abundance and age-class diversity of native fishes at randomly selected sample sites. All objectives were addressed throughout the potential riverine distribution of fish in the Oregon portion of the Goose Lake basin. Information gathered in this study is critical to effective conservation and management of each species and its habitat. In addition, this report describes the distribution and relative abundance of nonnative fishes (fathead minnow (Pimephales promelas), brown bullhead (Ameiurus nebulosus), white crappie (Pomoxis annularis), yellow perch (Perca flavescens), pumpkinseed (Lepomis gibbosus), and brook trout (Salvelinus fontinalis)) in the basin. Unlike prior efforts, this study used a statisticallybased design to select sample points with the aim of achieving a representative sample across the Oregon portion of the Goose Lake watershed. Additionally, a wide array of fish sampling gear was employed to maximize our ability to capture all fish species present across the diversity of habitat types encountered. Title: Status and Distribution of Native Fishes in the Goose Lake Basin Information Reports number 2008-02 Abstract -- This study describes the current distribution of the nine native fish species in the Oregon portion of the Goose Lake basin (Lake County): Goose Lake redband trout Oncorhynchus mykiss ssp., Goose Lake lamprey Entosphenus sp., Goose Lake tui chub Siphateles bicolor thalassinus, Goose Lake sucker Catostomus occidentalis lacusanserinus, Modoc sucker Catostomus microps, Pit-Klamath brook lamprey Entosphenus lethophagus, speckled dace Rhinichthys osculus, Pit roach Lavinia symmetricus mitrulus, and Pit sculpin Cottus pitensis. The Goose Lake basin is an endorheic, or topographically closed basin located in south central Oregon and northeastern California. The basin is within the usually closed northeastern extremity of the adjoining Sacramento River basin, astride the Oregon-California boundary. Although most of the lake lies in California, most of its valley and nearly two-thirds of the total drainage area (~722 sq. mi.) are in Oregon. The largest streams in the basin are Drews, Cottonwood, and Thomas Creeks. Annual precipitation averages about 36 cm per year (Phillips and van Denburgh 1971). Goose Lake overflowed briefly into the North Fork Pit River in 1868 and 1881, but storage and diversion of irrigation water has substantially reduced the inflow and future overflow is unlikely (USGS 1971). The lakebed was dry in the summers of 1926, 1929- 1934, and 1992. About half the basin is forestland, 20% is hay fields and pastureland, and 16% is shrub and rangeland. Currently, almost 35% of the inflow is diverted for irrigation (OWRD 1989). The Goose Lake basin is home to four endemic fish taxa: the Goose Lake redband trout, lamprey, sucker, and tui chub. Endemic fishes of the Goose Lake basin split their life histories between Goose Lake and its tributaries, as opposed to the five native but non-endemic species that primarily occupy stream habitats. Pit roach and all endemic fishes except Goose Lake tui chub are listed as a “species of concern” by the USFWS, a designation that implies there is concern about species viability, but not enough information is known to initiate a listing review for threatened or endangered status. The Modoc sucker was listed as a federally endangered species in 1985 (USFWS 1985). No formal recovery plan was required due to an existing “Action Plan for the Recovery of the Modoc Sucker” (USFWS 1984). Most of the recovery actions outlined in the action plan were either completed or are no longer relevant (Stewart Reid, Western Fishes, personal communication). However, actions 26 and 27 pertaining to range expansion remain incomplete. Action 26 suggests reclassification to threatened upon establishment of safe populations (for 3-5 years) throughout the Rush and Turner Creek watersheds in the Pit River basin. Action 27 suggests delisting upon establishing safe populations in two other historic streams. At the time of listing, the historic range of Modoc sucker was thought to have included only two small tributaries of the Pit River in Modoc and Lassen Counties, Ash and Turner Creeks (USFWS 1985). Therefore, a major recovery goal was to expand the species’ range with additional populations (USFWS 1984). In 2001, reexamination of historical documents and museum specimens established that Modoc suckers had also historically occupied Thomas Creek in the Goose Lake basin. Field collections in 2001, with subsequent morphological and genetic analysis, confirmed that the population was still present in Thomas Creek (Stewart Reid, Western Fishes, personal communication); however, the broader range of Modoc sucker in the Goose Lake watershed was not known. In 1995, the Goose Lake Fishes Working Group drafted a conservation plan for “prelisting” recovery of all native fish in response to severe drought and habitat degradation (GLFWG 1995). The Aquatic Inventories Project of the Oregon Department of Fish and Wildlife (ODFW) conducted habitat and fish distribution surveys (1991-1995) to obtain baseline information to help inform recovery efforts (ODFW, unpublished data). Since then, field work to monitor the distribution and abundance of Goose Lake fishes has been limited and sporadic, targeting only Goose Lake redband trout and Modoc sucker (Dambacher 2001; Reid 2007). No comprehensive follow up work has been conducted to evaluate fish response to climatic conditions, habitat restoration projects, and continued irrigation activities. ODFW recently drafted a status review of native fish of Oregon (ODFW 2005). Except for redband trout, Goose Lake fishes were not included in the status review due to a lack of new information since the previous status review in 1995 (Kostow et al. 1995). Further, the review of Goose Lake redband trout was limited by a lack of long-term data series. The first objective of this study was to document the current distribution of native fishes in Oregon’s portion of the Goose Lake basin and assess changes in distribution that may have occurred since the last surveys were conducted 12 years ago. The second objective was to provide new information about the distribution of Modoc suckers within the basin. The third objective was to determine relative abundance and age-class diversity of native fishes at randomly selected sample sites. All objectives were addressed throughout the potential riverine distribution of fish in the Oregon portion of the Goose Lake basin. Information gathered in this study is critical to effective conservation and management of each species and its habitat. In addition, this report describes the distribution and relative abundance of nonnative fishes (fathead minnow (Pimephales promelas), brown bullhead (Ameiurus nebulosus), white crappie (Pomoxis annularis), yellow perch (Perca flavescens), pumpkinseed (Lepomis gibbosus), and brook trout (Salvelinus fontinalis)) in the basin. Unlike prior efforts, this study used a statisticallybased design to select sample points with the aim of achieving a representative sample across the Oregon portion of the Goose Lake watershed. Additionally, a wide array of fish sampling gear was employed to maximize our ability to capture all fish species present across the diversity of habitat types encountered. Close

• 1480. [Article] Status, Distribution, and Life History Investigations of Warner Suckers, 2006-2010 Information Reports number 2011-02

  Abstract -- The Warner sucker Catostomus warnerensis is endemic to the Warner Valley, a subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. This species was historically abundant ...

  Citation × Citation Citation Abstract Copy Title: Status, Distribution, and Life History Investigations of Warner Suckers, 2006-2010 Information Reports number 2011-02 Abstract -- The Warner sucker Catostomus warnerensis is endemic to the Warner Valley, a subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. This species was historically abundant (Snyder 1908) and its historical range includes three permanent lakes (Hart, Crump, and Pelican), several ephemeral lakes, a network of sloughs and diversion canals, and three major tributary drainages (Honey, Deep, and Twentymile creeks). Warner sucker abundance and distribution has declined over the past century and it was federally listed as threatened in 1985 due to habitat fragmentation and threats posed by the proliferation of piscivorous non-native game fishes (U.S. Fish and Wildlife Service 1985). The Warner Valley is a northeast-southwest trending endorheic basin that extends approximately 90 km (Figure 1). The elevation of the valley floor is approximately 1,370 m and the basin is bound by fault block escarpments, the Warner Rim on the west and Hart Mountain and Poker Jim Ridge on the east. The Warner basin was formed during the middle Tertiary and late Quaternary geologic periods as a result of volcanic and tectonic activity (Baldwin 1974). Abundant precipitation during the Pleistocene Epoch resulted in the formation of Pluvial Lake Warner (Hubbs and Miller 1948). At its maximum extent approximately 11,000 years ago, the lake reached approximately 100 m in depth and 1,300 km2 in area (Snyder et al. 1964; Weide 1975). The Warner sucker inhabits the lakes and low gradient stream reaches of the Warner Valley. The metapopulation of Warner suckers is comprised of two life history forms: lake and stream morphs. The lake suckers display a lacustrine-adfluvial pattern in which they spend most of the year in the lake and spawn in the streams. However, when upstream migration is hindered by low stream flows during drought years or by irrigation diversion dams, lake suckers may spawn in nearshore areas of the lakes (White et al. 1990). Large lake-dwelling populations of introduced fishes in the lakes likely reduce sucker recruitment by predation on young suckers (U.S. Fish and Wildlife Service 1998). Periodic lake desiccation also threatens the lake suckers. The stream suckers display a fluvial life-history pattern and spawn in the three major tributary drainages (Honey, Deep, and Twentymile Creeks). Threats specific to the stream form include water withdrawals for irrigation and impacts from grazing. Stream suckers recolonized the lakes after past drying events (mid-1930’s and early-1990’s). The Recovery Plan for the Threatened and Rare Native Fishes of the Warner Basin and Alkali Subbasin (U.S. Fish and Wildlife Service 1998) sets three recovery criteria for delisting the species. These criteria require that: (1) a self-sustaining metapopulation is distributed throughout the drainages of Twentymile Creek, Honey Creek, and below the falls on Deep Creek, and in Pelican, Crump, and Hart Lakes; (2) passage is restored within and among these drainages so that individual populations of Warner suckers can function as a metapopulation; and (3) no threats exist that would likely threaten the survival of the species over a significant portion of its range. The Oregon Department of Fish and Wildlife’s (ODFW’s) Native Fish Investigations Project conducted investigations from 2006 through 2010 to describe the conservation (recovery) status of Warner suckers. The objectives of our investigations were to: 1) describe the current distribution of suckers in the Warner subbasin, 2) estimate their abundance in the lakes and streams, 3) collect life history information, and 4) describe the primary factors that currently limit the sucker’s ability to maintain a functioning metapopulation, including connectivity/fragmentation of habitats and factors affecting successful recruitment in the lake and stream environments. Previous similar studies were conducted in 1990, 1991, 1994, 1995, 1996, 1997, and 2001 (White et al. 1990; White et al. 1991; Allen et al. 1994; Allen et al. 1995; Allen et al. 1996; Bosse et al. 1997; Hartzell et al. 2001). We addressed these objectives by implementing the following tasks: 1) conducting surveys in Hart and Crump Lakes to describe the distribution and quantify the abundance of Warner suckers, search for evidence of recent recruitment, estimate sucker abundance relative to nonnative fish abundance, and describe certain life history characteristics, 2) tagging suckers with Passive Integrated Transponder (PIT) tags in the lakes and tributaries to estimate growth rates and describe seasonal movements, 3) radio tracking suckers in the lakes and tributaries to describe seasonal movements, 4) fishing screw traps in Warner basin tributaries to monitor downstream movements, 5) operating a trap at a fish ladder on a Warner tributary to assess upstream passage success, 6) conducting surveys in Warner basin tributaries to describe the current distribution of stream resident populations of Warner suckers and to quantify their abundance, 7) describing associations between the distribution of suckers and habitat variables in Twentymile Creek, 8) trapping larval suckers in the tributaries to describe the relative abundance and timing of larval movements, 9) describing life history parameters including growth rates, length frequency distributions, length at maturity, and weight-length relationships, 10) evaluating a nonlethal ageing technique, 11) describing the distribution and abundance of the Warner suckers at Summer Lake Wildlife Management area, where a self-sustaining population became established after fish salvage from Hart Lake during the 1992 drought, and 12) collecting tissue samples for future genetic analyses. This report compiles the results of this work, synthesizes and interprets findings relative to the conservation status of the species, and recommends future studies. Title: Status, Distribution, and Life History Investigations of Warner Suckers, 2006-2010 Information Reports number 2011-02 Abstract -- The Warner sucker Catostomus warnerensis is endemic to the Warner Valley, a subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. This species was historically abundant (Snyder 1908) and its historical range includes three permanent lakes (Hart, Crump, and Pelican), several ephemeral lakes, a network of sloughs and diversion canals, and three major tributary drainages (Honey, Deep, and Twentymile creeks). Warner sucker abundance and distribution has declined over the past century and it was federally listed as threatened in 1985 due to habitat fragmentation and threats posed by the proliferation of piscivorous non-native game fishes (U.S. Fish and Wildlife Service 1985). The Warner Valley is a northeast-southwest trending endorheic basin that extends approximately 90 km (Figure 1). The elevation of the valley floor is approximately 1,370 m and the basin is bound by fault block escarpments, the Warner Rim on the west and Hart Mountain and Poker Jim Ridge on the east. The Warner basin was formed during the middle Tertiary and late Quaternary geologic periods as a result of volcanic and tectonic activity (Baldwin 1974). Abundant precipitation during the Pleistocene Epoch resulted in the formation of Pluvial Lake Warner (Hubbs and Miller 1948). At its maximum extent approximately 11,000 years ago, the lake reached approximately 100 m in depth and 1,300 km2 in area (Snyder et al. 1964; Weide 1975). The Warner sucker inhabits the lakes and low gradient stream reaches of the Warner Valley. The metapopulation of Warner suckers is comprised of two life history forms: lake and stream morphs. The lake suckers display a lacustrine-adfluvial pattern in which they spend most of the year in the lake and spawn in the streams. However, when upstream migration is hindered by low stream flows during drought years or by irrigation diversion dams, lake suckers may spawn in nearshore areas of the lakes (White et al. 1990). Large lake-dwelling populations of introduced fishes in the lakes likely reduce sucker recruitment by predation on young suckers (U.S. Fish and Wildlife Service 1998). Periodic lake desiccation also threatens the lake suckers. The stream suckers display a fluvial life-history pattern and spawn in the three major tributary drainages (Honey, Deep, and Twentymile Creeks). Threats specific to the stream form include water withdrawals for irrigation and impacts from grazing. Stream suckers recolonized the lakes after past drying events (mid-1930’s and early-1990’s). The Recovery Plan for the Threatened and Rare Native Fishes of the Warner Basin and Alkali Subbasin (U.S. Fish and Wildlife Service 1998) sets three recovery criteria for delisting the species. These criteria require that: (1) a self-sustaining metapopulation is distributed throughout the drainages of Twentymile Creek, Honey Creek, and below the falls on Deep Creek, and in Pelican, Crump, and Hart Lakes; (2) passage is restored within and among these drainages so that individual populations of Warner suckers can function as a metapopulation; and (3) no threats exist that would likely threaten the survival of the species over a significant portion of its range. The Oregon Department of Fish and Wildlife’s (ODFW’s) Native Fish Investigations Project conducted investigations from 2006 through 2010 to describe the conservation (recovery) status of Warner suckers. The objectives of our investigations were to: 1) describe the current distribution of suckers in the Warner subbasin, 2) estimate their abundance in the lakes and streams, 3) collect life history information, and 4) describe the primary factors that currently limit the sucker’s ability to maintain a functioning metapopulation, including connectivity/fragmentation of habitats and factors affecting successful recruitment in the lake and stream environments. Previous similar studies were conducted in 1990, 1991, 1994, 1995, 1996, 1997, and 2001 (White et al. 1990; White et al. 1991; Allen et al. 1994; Allen et al. 1995; Allen et al. 1996; Bosse et al. 1997; Hartzell et al. 2001). We addressed these objectives by implementing the following tasks: 1) conducting surveys in Hart and Crump Lakes to describe the distribution and quantify the abundance of Warner suckers, search for evidence of recent recruitment, estimate sucker abundance relative to nonnative fish abundance, and describe certain life history characteristics, 2) tagging suckers with Passive Integrated Transponder (PIT) tags in the lakes and tributaries to estimate growth rates and describe seasonal movements, 3) radio tracking suckers in the lakes and tributaries to describe seasonal movements, 4) fishing screw traps in Warner basin tributaries to monitor downstream movements, 5) operating a trap at a fish ladder on a Warner tributary to assess upstream passage success, 6) conducting surveys in Warner basin tributaries to describe the current distribution of stream resident populations of Warner suckers and to quantify their abundance, 7) describing associations between the distribution of suckers and habitat variables in Twentymile Creek, 8) trapping larval suckers in the tributaries to describe the relative abundance and timing of larval movements, 9) describing life history parameters including growth rates, length frequency distributions, length at maturity, and weight-length relationships, 10) evaluating a nonlethal ageing technique, 11) describing the distribution and abundance of the Warner suckers at Summer Lake Wildlife Management area, where a self-sustaining population became established after fish salvage from Hart Lake during the 1992 drought, and 12) collecting tissue samples for future genetic analyses. This report compiles the results of this work, synthesizes and interprets findings relative to the conservation status of the species, and recommends future studies. Close