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11. [Article] Scappoose Bay Watershed Assessment
Abstract -- The Scappoose Bay Watershed Assessment focuses on habitat conditions for salmonids (salmon, steelhead and trout) in the watershed. The report follows the guidelines of the Oregon Watershed ...Citation Citation
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- Scappoose Bay Watershed Assessment
Abstract -- The Scappoose Bay Watershed Assessment focuses on habitat conditions for salmonids (salmon, steelhead and trout) in the watershed. The report follows the guidelines of the Oregon Watershed Enhancement Manual (WPN 1999). The Scappoose Bay Watershed Assessment presents the existing baseline information on watershed conditions (based on available reports and data) and oral history interviews. A Geographic Information System (GIS) was built to display, analyze and store much of the data. Habitat factors for the decline of salmonids are compared, and major protection and restoration opportunities are identified and prioritized. This Phase I assessment does not generally provide the detailed field reconnaissance and comprehensive field studies that are necessary for proceeding with specific protection and restoration projects. Rather, this assessment lays out the groundwork for a second phase of assessment that bridges the gap between identifying major areas for action and conducting specific projects. Topics included are preliminary analysis of existing data, GIS base map and baseline information, historical habitat conditions, channel habitat typing, fisheries resource and habitat assessment, channel modifications, sediment sources, riparian and wetland conditions, water quality, water use and hydrology, refugia, watershed condition, data gaps, significant legal and public issues, prioritized preservation and restoration, opportunities, and GIS metadata.
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12. [Article] OWEB Project Number 216-5042-12451 Phase IV - Wallowa Mountains Bull Trout Monitoring, Final Report
Abstract -- Bull trout were listed as threatened under the Endangered Species Act in 1998 due to declining populations. Spawning survey data is important for determining relative abundance and distribution ...Citation Citation
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- OWEB Project Number 216-5042-12451 Phase IV - Wallowa Mountains Bull Trout Monitoring, Final Report
Abstract -- Bull trout were listed as threatened under the Endangered Species Act in 1998 due to declining populations. Spawning survey data is important for determining relative abundance and distribution trends in bull trout populations. Without adequate funding, it has been difficult to find sufficient numbers of experienced bull trout surveyors and packers for surveys in the back-country, and to obtain adequate supplies to get the work accomplished. OWEB funding supported the continued survey of bull trout spawning areas in years 2016 through 2018 in the Grande Ronde and Imnaha drainages of northeast Oregon. Surveys were conducted by fisheries consultants, the Service, Nez Perce Tribe, the Oregon Department of Fish and Wildlife, U.S. Forest Service, Freshwater Trust, Wallowa Resources, Anderson Perry, Inc., Grande Ronde Model Watershed, and volunteers. Timing of spawning, total redds, redd sizes, and redd locations are documented in the attached report. In 2016-2018, surveys were located on the Lostine and Imnaha Rivers, and Big Sheep and Bear Creeks. In addition, the Upper Minam and Wenaha were surveyed in 2018. OWEB funding helped to accomplish a total of 43.3, 41.1, and 71.7 stream miles surveyed in 2016, 2017, and 2018, respectively.
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Abstract -- Coastal Oregon populations of Pacific lamprey Lampetra tridentata and western brook lamprey L. richardsoni are considered depressed due to habitat loss and passage problems (Close et al. 2002, ...
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- Spawning distribution and habitat use of adult Pacific and western brook lamprey in Smith River, Oregon Information Reports 2006-1
Abstract -- Coastal Oregon populations of Pacific lamprey Lampetra tridentata and western brook lamprey L. richardsoni are considered depressed due to habitat loss and passage problems (Close et al. 2002, Nawa 2003, ODFW 2006). Pacific lamprey was listed as an Oregon state sensitive species in 1993 and in 1996 was protected through restriction of harvest (ODFW 2006). Western brook lamprey is not protected and has no special state status. Abundance of Pacific lamprey throughout the coast and Columbia River has declined dramatically since the1960s. Dam counts at Winchester, Bonneville, and Leaburg dams show a dramatic decrease from historical levels (Kostow 2002, Nawa 2003, ODFW 2006). In 2003, eleven environmental groups petitioned the U.S. Fish and Wildlife Service to list Pacific, western brook, and two other lamprey species as endangered in the Pacific Northwest and California (Nawa 2003). Even though the petition cited habitat losses due to reduced in-stream flows, water diversions, dredging, scour and channnelization issues, pollution and degradation of riparian communities, the U.S. Fish and Wildlife Service determined the petition did not contain adequate information to warrant a listing (Federal Register, 69 (27 December 2004) 77158-77167). The Oregon Department of Fish and Wildlife recently reviewed the status of western brook and Pacific lamprey and found populations to be ‘at risk’ of extinction (ODFW 2006) due to habitat loss, passage barriers and pollution. However data necessary to conduct a thorough and detailed assessment are lacking. Much of the data lacking are critical to the effective management and conservation of Oregon’s coastal lamprey species. The Columbia River Basin Lamprey Technical Workgroup (CRBLTW 2005) and members of Columbia River Inter-Tribal Fish Commission (CRITFC 2004) have identified and prioritized critical data gaps for Pacific lamprey, many of which also apply to western brook lamprey. Among these are 1) methods to assess distribution and abundance of all life stages and appropriate techniques for monitoring population status; 2) population structure and delineation; 3) population dynamics; 4) basic biology including interspecific and community level relationships; 5) limiting factors and threats including passage issues, and 6) habitat needs and requirements. This study addresses information needs pertaining to distribution and habitat use in addition to providing basic descriptive ecology. Our goal was to identify habitat variables associated with spawning Pacific and western brook lamprey in order to infer distribution throughout coastal Oregon. The objectives of this study were to 1) determine distribution of spawning Pacific and western brook lamprey in the Smith River basin; 2) describe redds of both species; and 3) describe associations of spawning Pacific and western brook lamprey in relation to habitat unit and reach scale habitat characteristics.
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Abstract -- Bull trout have been adversely affected by many land, water, and fisheries management activities throughout the range of the species. Degraded and fragmented habitat and negative interactions with ...
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- Abundance, Life History, and Distribution of Bull Trout in the Hood River Basin: A Summary of Findings from 2006 to 2009 Information Reports number 2010-01
Abstract -- Bull trout have been adversely affected by many land, water, and fisheries management activities throughout the range of the species. Degraded and fragmented habitat and negative interactions with nonnative fishes have led to a decline in bull trout distribution and abundance, several local extirpations, and a federal listing in 1998 as a threatened species under the Endangered Species Act (USFWS 2002). Distribution and abundance of bull trout also have declined in Oregon, and most management units in the state are considered to be threatened by conservation risks (ODFW 2005). One of these at-risk management units exists in the Hood River basin (ODFW 2005). Bull trout in Hood River basin currently are thought to exist as two independent reproductive units (USFWS 2002), known as local populations (Rieman and McIntyre 1995). The Clear Branch local population was isolated from the rest of the basin by the construction of Clear Branch Dam in 1968. This dam provides limited downstream fish passage during periods of spill and no voluntary upstream passage. Bull trout in this population inhabit Laurance Lake reservoir and the tributaries Pinnacle Creek and upper Clear Branch, which flow into the reservoir. The Hood River local population is distributed in the mainstem Hood River, Middle Fork Hood River (Middle Fork), and a few Middle Fork tributaries. Fluvial migrants from Hood River basin also forage and winter in the Columbia River (Pribyl et al. 1996, Buchanan et al. 1997). Bull trout have been observed in the East and West Fork basins of the Hood River, but these sightings have been rare. Presently, there is little evidence to suggest local populations exist in these tributary basins (USFWS 2002, Reagan and Olsen 2008). The status of both local populations is extremely precarious. Threats that put the Clear Branch population at risk of extirpation include low abundance, negative interactions with illegally introduced smallmouth bass, isolation from upstream migration and immigration, and diminished spawning and rearing habitat (USFW 1998). The Hood River population also appears to be small and is affected by passage barriers, unscreened irrigation diversions, impaired water quality, and periodic debris flows during glacial outbursts (USFWS 1998). As mandated by their federally designated threatened status, recovery plans were drafted by the US Fish and Wildlife Service (USFWS) for each distinct population segment, including for Hood River bull trout in 2002. This draft plan listed four goals for recovery in this basin: 1) establish at least one more local population in addition to the two existing populations, 2) increase the estimated adult population in the basin to at least 500 individuals, 3) achieve a stable or increasing trend at the population recovery level for at least two generations (=10 years), and 4) improve habitat connectivity by addressing problems with passage and screening at diversions and seasonal water quality barriers (USFWS 2002). The recovery plan also sets out research and monitoring needs critical to the recovery of these populations. Needed are accurate adult abundance estimates; a standardized monitoring program; more life history information for each local population, including how Hood River bull trout use of the Columbia River and the effects of potential passage obstructions on movement; and more information on the threat posed to the Clear Branch population by the illegal introduction of smallmouth bass in Lake Laurance reservoir. The Oregon Department of Fish and Wildlife (ODFW), with the help of the USDA Forest Service (USFS), initiated a four-year study in 2006 seeking to address these needs by synthesizing available data and conducting further studies to improve our understanding of the abundance, life history, and potential limiting factors of bull trout in the Hood River recovery unit. This report describes our findings, summarizes previous studies in the context of new information, and recommends a standardized monitoring protocol and future research. Our specific study objectives were as follows: 1. Assess adult abundance of the Clear Branch local population and develop a monitoring protocol to track abundance trends that is statistically reliable, cost-effective, and that minimizes potential adverse effects on this small isolated population. 2. Describe the juvenile and adult life history patterns of the Clear Branch local population. 3. Assess the potential impact of smallmouth bass on bull trout in Laurance Lake reservoir. 4. Determine current distribution of bull trout reproduction and early rearing in potential bull trout streams in the Hood River basin. 5. Describe the migratory life history of Hood River bull trout and assess the potential impacts of Coe Diversion and two new falls on the Middle Fork Hood River (scoured by the November 2006 glacial outburst) on bull trout migrations.
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Abstract -- The Warner sucker (Catostomus warnerensis) is endemic to the Warner Valley, an endorheic subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. Historically, this species ...
Citation Citation
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- 2011 Warner Sucker Investigations (Honey Creek) Progress Reports 2011
Abstract -- The Warner sucker (Catostomus warnerensis) is endemic to the Warner Valley, an endorheic subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. Historically, this species was abundant and its range included 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) (U.S. Fish and Wildlife Service 1985). 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 sucker inhabits the lakes and low gradient stream reaches of the Warner Valley. The Warner sucker metapopulation is comprised of both lake and stream life history morphs. The lake suckers are lacustrine adfluvial or potamodromous fish that normally spawn in the streams. However, upstream migration may be blocked by low stream flows during low water years or by irrigation diversion dams. When this happens, spawning may occur in nearshore areas of the lakes (White et al. 1990). Large lake-dwelling populations of introduced fishes likely reduce recruitment by preying on young suckers (U.S. Fish and Wildlife Service 1998). The stream suckers inhabit and spawn in Honey, Deep, and Twentymile Creeks. 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 recovery criteria for delisting the species. These criteria require that: 1) a self-sustaining metapopulation is distributed throughout the Twentymile, Honey, and Deep Creek (below the falls) drainages, and in Pelican, Crump, and Hart Lakes, 2) passage is restored within and among the Twentymile, Honey, and Deep Creek (below the falls) drainages so that the 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. To inform progress towards the first criteria, our objectives in 2011 were: 1) obtain a population estimate for suckers in the Honey Creek drainage and describe their current distribution and 2) describe the association between the distribution of suckers and habitat variables in Honey Creek. In addition, we obtained a population estimate of suckers at the Summer Lake Wildlife Management Area (WMA), where a self-sustaining population became established after a fish salvage from Hart Lake in 1991 when the lakes desiccated.
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16. [Article] Warner Sucker Investigations (2009)
Abstract -- The Warner sucker (Catostomus warnerensis) is endemic to the Warner Valley, an endorheic subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. Historically, this species ...Citation Citation
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- Warner Sucker Investigations (2009)
Abstract -- The Warner sucker (Catostomus warnerensis) is endemic to the Warner Valley, an endorheic subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. Historically, this species was abundant and its range included 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) (U.S. Fish and Wildlife Service 1985). 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 sucker inhabits the lakes and low gradient stream reaches of the Warner Valley. The Warner sucker metapopulation is comprised of both lake and stream life history morphs. The lake suckers are lacustrine adfluvial or potamodromous fish that normally spawn in the streams. However, upstream migration may be blocked by low stream flows during low water years or by irrigation diversion dams. When this happens, spawning may occur in nearshore areas of the lakes (White et al. 1990). Large lake-dwelling populations of introduced fishes likely reduce recruitment by preying on young suckers (U.S. Fish and Wildlife Service 1998). The stream suckers inhabit and spawn in Honey, Deep, and Twentymile Creeks. 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 recovery criteria for delisting the species. These criteria require that: 1) a self-sustaining metapopulation is distributed throughout the Twentymile, Honey, and Deep Creek (below the falls) drainages, and in Pelican, Crump, and Hart Lakes, 2) passage is restored within and among the Twentymile, Honey, and Deep Creek (below the falls) drainages so that the 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. Objectives of our 2009 investigations included: 1) obtain a mark-recapture population estimate for suckers in the Twentymile Creek drainage and describe their current distribution, 2) describe associations between the distribution of suckers and habitat variables in Twentymile Creek, 3) evaluate a non-lethal ageing technique, 4) track radiotagged lake suckers (tagged in 2008) in Hart and Crump Lakes to assess spring movement patterns, 5) track spring spawning movements of lake suckers across a PIT-tag antenna installed at the mouth of Honey Creek, 6) test the feasibility of trapping larval suckers near the mouth of Honey Creek using larval drift nets and light traps to describe the relative abundance and timing of larval sucker movements, and 7) obtain a mark-recapture population estimate of suckers at the Summer Lake Wildlife Management Area (WMA), where a self-sustaining population became established after a fish salvage from Hart Lake during the 1991 drought.
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Abstract -- The Warner sucker (Catostomus warnerensis) is endemic to the Warner Valley, an endorheic subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. This species was historically ...
Citation Citation
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- Warner Valley Fish Investigations- Warner Suckers Progress Reports 2008
Abstract -- The Warner sucker (Catostomus warnerensis) is endemic to the Warner Valley, an endorheic subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. This species was historically abundant 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 which 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 1976). 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). In 2008, precipitation and snow pack were near average and Hart and Crump Lakes never filled completely. In 2007, Crump Lake water levels were very low with less than a quarter of the surface area wetted during the winter. Both lakes have been watered continuously since 1993. The Warner sucker inhabits the lakes and low gradient stream reaches of the Warner Valley. Two life history forms are present that comprise the metapopulation of Warner suckers: lake and stream morphs. The lake suckers are lacustrine adfluvial or potamodromous fish which normally spawn in the streams. However, upstream migration may be blocked by low stream flows during dry water years or by irrigation diversion dams and spawning may occur in nearshore areas of the lakes (White et al. 1990). The stream suckers inhabit and spawn in the three major tributary drainages (Honey, Deep, and Twentymile Creeks). 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). 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 recovery criteria for delisting the species. These criteria require that (1) a self-sustaining metapopulation is distributed throughout the Twentymile, Honey, and Deep Creek (below the falls) drainages, and in Pelican, Crump, and Hart Lakes, (2) passage is restored within and among the Twentymile, Honey, and Deep Creek (below the falls) drainages so that the 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. In 2008, we conducted investigations in Hart and Crump Lakes to quantify the abundance and distribution of Warner suckers, to search for evidence of recent recruitment, and to estimate sucker abundance relative to nonnative fish abundance. In addition we investigated growth and movement patterns. We used Passive Integrated Transponder (PIT) tagged suckers to determine growth rates and movements, tracked radio-tagged suckers to document seasonal spawning migrations, fished a screw trap in Twelvemile Creek to monitor downstream movements, and operated a trap at the Dyke diversion dam on Twentymile Creek to monitor upstream movements.
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18. [Article] Status of Oregon Stocks of Coho Salmon, 2004 through 2008 Report Number: OPSW-ODFW-2009-3
Abstract -- This report summarizes five years of monitoring status and trend in Oregon’s naturally spawning coho salmon (Oncorhynchus kisutch) populations. The five coho run years reported are 2004 through ...Citation Citation
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- Status of Oregon Stocks of Coho Salmon, 2004 through 2008 Report Number: OPSW-ODFW-2009-3
Abstract -- This report summarizes five years of monitoring status and trend in Oregon’s naturally spawning coho salmon (Oncorhynchus kisutch) populations. The five coho run years reported are 2004 through 2008. Monitoring results include: abundance of naturally spawning coho; density of spawning coho; coho spawn timing; and proportion of hatchery (marked) coho in naturally spawning populations. These results are based on data from randomly selected spawning surveys, as well as other methods in areas without adequate random surveys. Results for coho standard spawning surveys, as well as spawning surveys for other species are covered in data summaries and reports posted on an Oregon Department of Fish and Wildlife (ODFW) web page (see: http://oregonstate.edu/dept/ODFW/spawn/index.htm). Monitoring occurs at three hierarchical spatial scales, as defined by the National Marine Fisheries Service (NMFS): Evolutionarily Significant Unit (ESU); Stratum; and coho Population. There are three coho ESU’s located entirely or partially within the State of Oregon: the Lower Columbia River (LCR) Coho ESU; the Oregon Coast (OC) Coho ESU; and the Southern Oregon/Northern California Coasts (SONCC) Coho ESU. This report summarizes results for coho populations in the portion of each ESU that is within the State of Oregon. In the Oregon portion of the LCR Coho ESU sufficient surveys were conducted to meet precision goals at the ESU level three out of the five sampling years. At the population complex scale, yearly precision goals were rarely met. Wild spawner abundance remained fairly stable over the five sampling years; hatchery abundance was more variable. Regional patterns in fish distribution, spawn timing, and hatchery proportion are apparent at both the stratum and population scale. In the Oregon Coast ESU sufficient surveys were conducted to meet precision goals at the ESU level in all five sampling years, however at the population scale, precision goals were rarely met. Wild spawner abundance declined over the first four sampling years, but showed a significant increase in the fifth sampling year. The proportion of hatchery fish was generally low, but variable over the five sampling years. Only two populations, Salmon River and North Umpqua River, consistently had over 10% hatchery fish on the spawning grounds. Regional patterns in fish distribution, spawn timing, and hatchery proportion are apparent. Inadequate funding and the need to update the GRTS sampling frame continue to hamper monitoring of the Oregon portion of the Southern Oregon/Northern California Coasts Coho ESU. In the Oregon portion of the ESU insufficient surveys were conducted to meet precision goals at the ESU level in any of the four years when GRTS surveys were done. However, estimates of wild coho spawners were obtained in all five years based on Huntley Park seining. Wild coho spawner abundance declined substantially over the five run years; but the proportion of hatchery coho spawning naturally was fairly low and stable. Regional patterns in fish distribution, spawn timing, and hatchery proportion are apparent.
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19. [Article] 2017 Bull Trout Redd Monitoring in the Wallowa Mountains
Abstract -- Bull trout were listed as threatened under the Endangered Species Act in 1998 due to declining populations. The U. S. Fish and Wildlife Service (Service) recommends monitoring bull trout in subbasins ...Citation Citation
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- 2017 Bull Trout Redd Monitoring in the Wallowa Mountains
Abstract -- Bull trout were listed as threatened under the Endangered Species Act in 1998 due to declining populations. The U. S. Fish and Wildlife Service (Service) recommends monitoring bull trout in subbasins where little is known about the populations, including the Grande Ronde and Imnaha subbasins. Spawning survey data is important for determining relative abundance and distribution trends in bull trout populations. This report summarizes the 2017 bull trout spawning data collected in the Wallowa Mountains of northeast Oregon and compares this with past years’ data. Bull trout spawning surveys have been conducted on similar index areas for selected Grande Ronde and Imnaha River streams from 1999 to 2017. These surveyed streams are located within the Wallowa River/Minam River and Imnaha River bull trout core areas. Surveys in 2017 were conducted by the Nez Perce Tribe (NPT), the Oregon Department of Fish and Wildlife (ODFW), the Service, U.S. Forest Service (USFS), Freshwater Trust, and fisheries consultants. Objectives of the survey included: (1) locate bull trout spawning areas; (2) determine redd characteristics; (3) determine bull trout timing of spawning; (4) collect spawning density data; (5) determine and compare the spatial distribution of redds along the Lostine River in 2006 through 2017; and (6) over time use all of the data to assess local bull trout population trends and the long-term recovery of bull trout. Timing of spawning, total redds, redd sizes, and redd locations are documented in the report.
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20. [Article] Oregon Chub Investigations, Progress Report 2001
Abstract -- Populations of Oregon chub Oregonichthys crameri, endemic to the Willamette Valley, have been drastically reduced. Factors in the decline of this fish include changes in flow regimes and habitat ...Citation Citation
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- Oregon Chub Investigations, Progress Report 2001
Abstract -- Populations of Oregon chub Oregonichthys crameri, endemic to the Willamette Valley, have been drastically reduced. Factors in the decline of this fish include changes in flow regimes and habitat characteristics resulting from the construction of flood control dams, revetments, channelization, diking, and the drainage of wetlands. The Oregon chub is further threatened by predation and competition by non-native species such as largemouth bass Micropterus salmoides, small mouth bass M. dolomieui, crappies Pomoxis sp., sunfishes Lepomis sp., bullheads Ameiurus sp., and western mosquitofish Gambusia affinis. We surveyed in the Willamette River drainage in April-October 2000 to quantify existing Oregon chub populations, search for unknown populations, evaluate potential introduction sites, and monitor introduced populations. We sampled a total of 77 sites in 2000. We collected Oregon chub for the first time from Barnard Slough in the Middle Fork Willamette drainage. Oregon chub were last collected from this location in 1983 (Bond 1984). Thirty-one of the 77 sites were new sites that were sampled for the first time in 2000. Forty-six sites, sampled in 1991-1999, were revisited. Three sites were sampled twice. We confirmed the continued existence of Oregon chub at 20 locations. These include naturally occurring populations in the Santiam drainage (Geren Island, Santiam Conservation Easement, Gray Slough, Santiam 1-5 backwaters, Pioneer Park backwater, Santiam Public Works Pond), Mid-Willamette drainage (Finley Gray Creek Swamp) and Middle Fork Willamette drainage (Dexter Reservoir Alcoves, East Fork Minnow Creek Pond, Shady Dell Pond, Buckhead Creek, Oakridge Slough, Elijah Bristow State Park, Rattlesnake Creek, and Hospital Pond) and introduced populations in the Middle Fork Willamette (Wicopee Pond, Fall Creek Spillway Ponds), Santiam (Foster Pullout Pond), and Mid-Willamette drainages (Dunn Wetland, Finley Display Pond). Oregon chub were not found at several locations (Jasper Park Slough, Wallace Slough, East Ferrin Pond, Dexter East Alcove, Hospital lmpoundment Pond, Logan Slough, Green's Bridge Backwater, Camas Swale) where they were collected on at least one occasion between 1991-1999 (Scheerer et. al. 1992; 1993; 1994; 1995; 1996; 1998; 1999; 2000; Scheerer and Jones 1997). Non-native fish were common in off-channel habitats that were surveyed in the Willamette River drainage. Non-native fish were collected from 23 of the 31 new sites sampled in 1999 (74%); no fish were collected at three locations (10%). Western mosquitofish and centrarchids (largemouth bass and bluegill) were the most common non-native fish collected. Oregon chub were introduced into Menear's Bend Pond in the Santiam River drainage in the October 2000. Additional Oregon chub were introduced into Foster Pullout Pond in October 2000, to supplement the 85 fish introduced in 1999. In the summer of 2000, a habitat enhancement project creating new habitat to benefit Oregon chub was completed in the Long Tom drainage (Mid-Willamette River). Seven potential Oregon chub reintroduction sites were monitored and evaluated. These included four sites in the Mid-Willamette River drainage (Finley National Wildlife Refuge Beaver and Cattail Ponds, Ankeny National Wildlife Refuge Dunlin-Woodduck Pond, Long Tom Ranch Pond), one site in the Santiam River drainage (Menear's Bend Pond), one site in the McKenzie River drainage (Russell Pond), and one site in the Coast Fork Willamette drainage (Layng Pond). Estimates of abundance were obtained for naturally occurring populations of Oregon chub in East Fork Minnow Creek Pond, Shady Dell Pond, Elijah Bristow State Park Sloughs, Hospital Pond, Dexter Reservoir Alcoves, Buckhead Creek, Oakridge Slough, Santiam Conservation Easement Sloughs, Geren Island Ponds, and Finley Gray Creek Swamp. Five of these populations showed an increase in abundance in 2000 (East Fork Minnow Creek Pond, Shady Dell Pond, Middle Buckhead Creek, Dexter Reservoir Alcoves, Finley Gray Creek Swamp). Four populations decreased in abundance (or remain depressed) in 2000 (Geren Island, Santiam Conservation Easement, Elijah Bristow Sloughs, Oakridge Slough) (Table 1 ). Abundance estimates for introduced populations of Oregon chub were also obtained. The Oregon chub population in East Ferrin Pond declined from 7,200 fish in 1997 to O fish in 2000, and is presumed extinct. The Oregon chub population in the Fall Creek Spillway Pond totaled 5,030 fish in 2000, compared to 6,300 fish in 1999. The Oregon chub population in Wicopee Pond expanded dramatically from ~50 fish in 1999 to 4,580 fish in 2000. The Oregon chub population in the Dunn Wetland Ponds increased from 4,860 fish in 1999 to 14,090 fish in 2000. The Oregon chub population in Finley Display Pond increased from 360 fish in 1999 to 1,750 fish in 2000. Three of the four largest populations in 2000 were introduced populations. The Middle Fork Willamette River drainage supported the largest number of Oregon chub populations (n=12), followed by the Santiam drainage (n=B), and the Mid-Willamette drainage (n=5). The most abundant Oregon chub populations were found in the Middle Fork Willamette and Mid-Willamette drainages. The Oregon Chub Recovery Plan (U .S. Fish and Wildlife Service 1998) set a recovery goal for downlisting the species to "threatened" and for delisting the species. The criteria for downlisting the species was to establish and manage ten populations of at least 500 adult fish. All populations must exhibit a stable or increasing trend for five years. At least three populations must be located in each of the three sub-basins (Middle Fork Willamette River, Santiam River, Mid-Willamette River tributaries). In 2000, there were 11 populations totaling 500 or more individuals and six of these populations exhibited a stable or increasing trend for the past five years (Table 1 ). Five of these six populations were located in the Middle Fork Willamette drainage. In summary, Oregon chub remain at risk due to their limited distribution compared with their historic geographic range in the Willamette Valley, the loss of suitable habitat and the continued threats posed by the proliferation of non-native fishes, illegal water withdrawals, unauthorized fill and removal operations, and potential chemical spills or careless pesticide applications.