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• 7431. [Article] Klamath Mountains Province Steelhead Project, 2001-02 Annual Report Report Number: OPSW-ODFW-2004-08

  Abstract -- The steelhead supplement to the Oregon Plan for Salmon and Watersheds (OSPW) is intended to maintain wild steelhead populations in Oregon at sustainable and productive levels that provide substantial ...

  Citation × Citation Citation Abstract Copy Title: Klamath Mountains Province Steelhead Project, 2001-02 Annual Report Report Number: OPSW-ODFW-2004-08 Abstract -- The steelhead supplement to the Oregon Plan for Salmon and Watersheds (OSPW) is intended to maintain wild steelhead populations in Oregon at sustainable and productive levels that provide substantial environmental, cultural, and economic benefits. The OSPW attempts to better define "sustainable and productive" by committing the Oregon Department of Fish and Wildlife (ODFW) to establish "Population Health Goals" for each Evolutionary Significant Unit (ESU) of wild steelhead within the state. In addition, section ODFW IB1S of the plan calls for ODFW to assess adult escapement and juvenile production of wild steelhead in each ESU. The National Marine Fisheries Service identified seven ESUs for steelhead in Oregon and concluded that steelhead produced in coastal basins between Cape Blanco in southern Oregon and the Klamath River Basin in northern California constitutes one ESU. This area closely corresponds to the geologic boundaries of the Klamath Mountains Province (KMP). Steelhead in the KMP differ from those in adjoining areas because of distinctive life history and genetic characteristics (Busby et al. 1994). Primary differences in life history parameters have been identified for wild KMP steelhead. Summer steelhead and winter steelhead differ in time of return as adults, tendency to return to fresh water on a false spawning migration (the "half-pounder" run), age at ocean entry, growth rate and migration patterns of juveniles in fresh water (ODFW 1990; ODFW 1994). As a result of these differences, separate health goals seem warranted for summer and winter steelhead populations. Winter steelhead inhabit streams throughout the KMP, while summer steelhead are found only in a portion of the Rogue River Basin. However, the distribution of summer and winter steelhead overlap in major areas of the Rogue River Basin (Everest 1973) and, as juveniles of the respective races cannot be differentiated, some population health goals have to apply to both races. The status of wild steelhead in the Klamath Mountains Province ESU is not readily apparent from historic sources of information. Uncertainty about resource status, coupled with a comprehensive conservation plan developed by Oregon and the termination of wild fish harvest in almost all KMP streams, lead the National Marine Fisheries Service (NMFS), in 1998, to defer a listing of KMP steelhead under the Endangered Species Act. On 30 March, 2001, NMFS announced that, after a review of new information, that an Endangered Species Act listing was not warranted for KMP steelhead. In 2002, ODFW adopted new methods to monitor steelhead populations on the Oregon coast. Allied with the decision, ODFW decided to terminate the KMP steelhead project. Consequently, this report presents findings from the third, and final, year of the project. The goal of the project was to develop and implement assessment methods to determine the status of wild steelhead in the Oregon portion of the KMP. Project objectives included (1) develop population health goals and allied monitoring methods and (2) determine resource status in relation to health goals Satterthwaite (2002a). Directed sampling began in 1999 and findings from the first two years of the project were reported by Satterthwaite (2002b) and Satterthwaite (2003). Title: Klamath Mountains Province Steelhead Project, 2001-02 Annual Report Report Number: OPSW-ODFW-2004-08 Abstract -- The steelhead supplement to the Oregon Plan for Salmon and Watersheds (OSPW) is intended to maintain wild steelhead populations in Oregon at sustainable and productive levels that provide substantial environmental, cultural, and economic benefits. The OSPW attempts to better define "sustainable and productive" by committing the Oregon Department of Fish and Wildlife (ODFW) to establish "Population Health Goals" for each Evolutionary Significant Unit (ESU) of wild steelhead within the state. In addition, section ODFW IB1S of the plan calls for ODFW to assess adult escapement and juvenile production of wild steelhead in each ESU. The National Marine Fisheries Service identified seven ESUs for steelhead in Oregon and concluded that steelhead produced in coastal basins between Cape Blanco in southern Oregon and the Klamath River Basin in northern California constitutes one ESU. This area closely corresponds to the geologic boundaries of the Klamath Mountains Province (KMP). Steelhead in the KMP differ from those in adjoining areas because of distinctive life history and genetic characteristics (Busby et al. 1994). Primary differences in life history parameters have been identified for wild KMP steelhead. Summer steelhead and winter steelhead differ in time of return as adults, tendency to return to fresh water on a false spawning migration (the "half-pounder" run), age at ocean entry, growth rate and migration patterns of juveniles in fresh water (ODFW 1990; ODFW 1994). As a result of these differences, separate health goals seem warranted for summer and winter steelhead populations. Winter steelhead inhabit streams throughout the KMP, while summer steelhead are found only in a portion of the Rogue River Basin. However, the distribution of summer and winter steelhead overlap in major areas of the Rogue River Basin (Everest 1973) and, as juveniles of the respective races cannot be differentiated, some population health goals have to apply to both races. The status of wild steelhead in the Klamath Mountains Province ESU is not readily apparent from historic sources of information. Uncertainty about resource status, coupled with a comprehensive conservation plan developed by Oregon and the termination of wild fish harvest in almost all KMP streams, lead the National Marine Fisheries Service (NMFS), in 1998, to defer a listing of KMP steelhead under the Endangered Species Act. On 30 March, 2001, NMFS announced that, after a review of new information, that an Endangered Species Act listing was not warranted for KMP steelhead. In 2002, ODFW adopted new methods to monitor steelhead populations on the Oregon coast. Allied with the decision, ODFW decided to terminate the KMP steelhead project. Consequently, this report presents findings from the third, and final, year of the project. The goal of the project was to develop and implement assessment methods to determine the status of wild steelhead in the Oregon portion of the KMP. Project objectives included (1) develop population health goals and allied monitoring methods and (2) determine resource status in relation to health goals Satterthwaite (2002a). Directed sampling began in 1999 and findings from the first two years of the project were reported by Satterthwaite (2002b) and Satterthwaite (2003). Close

• 7432. [Article] Life History Variability, Habitat Use, and Migratory Behavior of Coastal Cutthroat Trout in the Salmon River, Oregon Report Number: OPSW-ODFW-2012-10

  Abstract -- Coast basins in Oregon support resident and anadromous cutthroat trout (Oncorhynchus clarki clarki). Cutthroat trout isolated above barriers are stream resident, but those with access to river, ...

  Citation × Citation Citation Abstract Copy Title: Life History Variability, Habitat Use, and Migratory Behavior of Coastal Cutthroat Trout in the Salmon River, Oregon Report Number: OPSW-ODFW-2012-10 Abstract -- Coast basins in Oregon support resident and anadromous cutthroat trout (Oncorhynchus clarki clarki). Cutthroat trout isolated above barriers are stream resident, but those with access to river, estuary, and marine environments may express a variety of life history and migratory patterns. Past studies (e.g. Giger 1972, Sumner 1972, Tipping 1981) indicated that estuaries serve primarily as a migratory corridor or short-term rearing environment. However, recent advances in marking and tracking technology have permitted researchers to gain a better understanding of the complex migratory and habitat use patterns of cutthroat. Krentz (2007) conducted studies in Salmon River on the central Oregon coast to explore migratory patterns of cutthroat and examine the role of the estuary as a rearing environment. Coastal cutthroat trout reared for extended periods of time throughout the available channel habitats in Salmon River estuary (Krentz 2007) during spring, summer, and fall. The estuarine resident population appeared to represent a significant portion of the migratory individuals, and included all older age classes. Estuary growth was similar to that of their ocean migrant counterparts, and survival in the estuary was high. Because cutthroat were collected and marked primarily within the estuary (Krentz 2007), it is unclear what portion of the migrant population reared in the estuary relative to the watershed or ocean, or whether the tagged group was representative of the migratory populations. The current study was designed to track a representative sample of the downstream migrant population, and assess the relative success (survival) of the estuary and ocean migrants. Similar studies in the Columbia River documented directed and rapid migration through the estuary (Zydlewski et al. 2008, Hering et al. 2009). With rare exception, cutthroat trout were not observed to rear in the estuary. In addition, many fish disappeared before reaching the ocean and few of the ocean migrants returned to the natal tributary. In this study we replicated the study design used in the Columbia River studies to further comparisons of estuary migration and rearing strategies between the two estuaries. The primary objective of our work in the Salmon River was to increase understanding of coastal cutthroat trout biology and the relationship between stream-resident and migratory, or “sea-run” cutthroat. Here we use the term “sea-run” to indicate migration into the tidally-inundated, or estuarine portions of the Salmon River watershed or to the ocean. Study objectives were to: 1.Estimate the distribution and abundance of coastal cutthroat trout in the Salmon River watershed 2.Quantify the proportions of the cutthroat populations that are migratory, identify which individuals migrate and describe the timing of migration 3.Describe estuary habitats used by sea-run migrants and characterize behavior within the Salmon River estuary 4.Estimate growth rate of stream and estuary resident cutthroat 5.Estimate estuary and ocean survival of sea-run individuals and document return to estuary and lower river. 6.Compare migratory behavior in Salmon River to that observed in the lower Columbia River Title: Life History Variability, Habitat Use, and Migratory Behavior of Coastal Cutthroat Trout in the Salmon River, Oregon Report Number: OPSW-ODFW-2012-10 Abstract -- Coast basins in Oregon support resident and anadromous cutthroat trout (Oncorhynchus clarki clarki). Cutthroat trout isolated above barriers are stream resident, but those with access to river, estuary, and marine environments may express a variety of life history and migratory patterns. Past studies (e.g. Giger 1972, Sumner 1972, Tipping 1981) indicated that estuaries serve primarily as a migratory corridor or short-term rearing environment. However, recent advances in marking and tracking technology have permitted researchers to gain a better understanding of the complex migratory and habitat use patterns of cutthroat. Krentz (2007) conducted studies in Salmon River on the central Oregon coast to explore migratory patterns of cutthroat and examine the role of the estuary as a rearing environment. Coastal cutthroat trout reared for extended periods of time throughout the available channel habitats in Salmon River estuary (Krentz 2007) during spring, summer, and fall. The estuarine resident population appeared to represent a significant portion of the migratory individuals, and included all older age classes. Estuary growth was similar to that of their ocean migrant counterparts, and survival in the estuary was high. Because cutthroat were collected and marked primarily within the estuary (Krentz 2007), it is unclear what portion of the migrant population reared in the estuary relative to the watershed or ocean, or whether the tagged group was representative of the migratory populations. The current study was designed to track a representative sample of the downstream migrant population, and assess the relative success (survival) of the estuary and ocean migrants. Similar studies in the Columbia River documented directed and rapid migration through the estuary (Zydlewski et al. 2008, Hering et al. 2009). With rare exception, cutthroat trout were not observed to rear in the estuary. In addition, many fish disappeared before reaching the ocean and few of the ocean migrants returned to the natal tributary. In this study we replicated the study design used in the Columbia River studies to further comparisons of estuary migration and rearing strategies between the two estuaries. The primary objective of our work in the Salmon River was to increase understanding of coastal cutthroat trout biology and the relationship between stream-resident and migratory, or “sea-run” cutthroat. Here we use the term “sea-run” to indicate migration into the tidally-inundated, or estuarine portions of the Salmon River watershed or to the ocean. Study objectives were to: 1.Estimate the distribution and abundance of coastal cutthroat trout in the Salmon River watershed 2.Quantify the proportions of the cutthroat populations that are migratory, identify which individuals migrate and describe the timing of migration 3.Describe estuary habitats used by sea-run migrants and characterize behavior within the Salmon River estuary 4.Estimate growth rate of stream and estuary resident cutthroat 5.Estimate estuary and ocean survival of sea-run individuals and document return to estuary and lower river. 6.Compare migratory behavior in Salmon River to that observed in the lower Columbia River Close

• 7433. [Article] Abundance, distribution, and migratory behavior of coastal cutthroat trout in two lower Columbia River tributaries

  Abstract -- Coastal cutthroat trout (Oncorhynchus clarki clarki) exhibit multiple life history types characterized by diverse migratory strategies, including anadromous, potomodromous, and freshwater resident ...

  Citation × Citation Citation Abstract Copy Title: Abundance, distribution, and migratory behavior of coastal cutthroat trout in two lower Columbia River tributaries Abstract -- Coastal cutthroat trout (Oncorhynchus clarki clarki) exhibit multiple life history types characterized by diverse migratory strategies, including anadromous, potomodromous, and freshwater resident forms. The factors contributing to life history variation within populations are not well understood, but probably are not strictly genetic (e.g. Johnson et al, in review). Variation in migration tendency within cutthroat populations may result from phenotype plasticity, influenced by density, frequency, or condition dependent processes (Hendry et al. 2004). For example, an individual cutthroat’s choice to migrate at a given time or age may be a response to environmental conditions mediated by a genetically determined reaction norm (Hutchings 2004). This report summarizes a study undertaken to describe the expression of migratory behavior within coastal cutthroat trout populations, the relationship among migratory and non-migratory individuals, and the implications of life history diversity for management of cutthroat trout in tributaries of the lower Columbia River. The relationship between resident and migratory populations (or resident and migratory individuals within populations) is of central importance for management of coastal cutthroat trout. In the lower Columbia River and southwest Washington State a proposed rule to list anadromous cutthroat as threatened under the federal Endangered Species Act (ESA) was withdrawn after the US Fish and Wildlife Service (USFWS) decided during its review process to include resident and anadromous forms in the same Distinct Population Segment (DPS). Debate over proposed ESA listing highlighted a general lack of knowledge about coastal cutthroat trout life history, relationships between resident and migratory forms, and estuarine habitat use in the lower Columbia River. In 2009, the decision not to list the DPS as threatened was remanded to the USFWS on the grounds that the Service had not adequately considered whether marine and estuarine habitats formed a significant portion of the range of the DPS (USFWS 2009). We evaluated the distribution and abundance of coastal cutthroat trout in Big Creek and Bear Creek, two tributaries that join the Columbia River estuary from the south (Oregon) side roughly 30 kilometers from the ocean, and monitored the migratory behavior of cutthroat that emigrated from these streams and entered the Columbia River estuary. Big Creek is an interesting system because a fish weir and diversion dam at an ODFW hatchery, established in 1941 and refurbished in 1957, prevent cutthroat trout from passing upstream, isolating the cutthroat spawning population above the hatchery. Despite this barrier to upstream migration, offspring of resident cutthroat in the upper watershed continue to “smolt” and migrate downstream past the barrier. We were interested in the fate of these fish and their contribution to the adult population. Bear Creek, on the other hand, has always had full access for anadromous cutthroat through much of its drainage. These two systems permit a comparison of life history characteristics, migration, and survival of coastal cutthroat rearing in streams above and below migration barriers, and provide study sites in Oregon to compliment research by USFWS of coastal cutthroat migration behavior in tributaries entering the estuary from the north side of the Columbia River (USFWS 2008; and see Hudson et al. 2008; Johnson 2008; Zydlewski et al. 2008). A major objective of our work in Big Creek and Bear Creek was to increase understanding of coastal cutthroat trout biology and the relationship between resident and migratory cutthroat in lower Columbia tributaries. Additionally, we sought to document habitat use in the Columbia River estuary by migrant cutthroat. Our specific objectives were to: • Estimate abundance of coastal cutthroat trout in Big Creek (above hatchery barrier) and Bear Creek (above and below a large dam) • Quantify the proportions of the cutthroat populations that are migratory, identify which individuals migrate and describe the timing of migration • Describe habitats used by anadromous migrants and characterize migration behavior within the Columbia River estuary • Measure estuarine/marine survival of anadromous individuals and document return to natal streams Title: Abundance, distribution, and migratory behavior of coastal cutthroat trout in two lower Columbia River tributaries Abstract -- Coastal cutthroat trout (Oncorhynchus clarki clarki) exhibit multiple life history types characterized by diverse migratory strategies, including anadromous, potomodromous, and freshwater resident forms. The factors contributing to life history variation within populations are not well understood, but probably are not strictly genetic (e.g. Johnson et al, in review). Variation in migration tendency within cutthroat populations may result from phenotype plasticity, influenced by density, frequency, or condition dependent processes (Hendry et al. 2004). For example, an individual cutthroat’s choice to migrate at a given time or age may be a response to environmental conditions mediated by a genetically determined reaction norm (Hutchings 2004). This report summarizes a study undertaken to describe the expression of migratory behavior within coastal cutthroat trout populations, the relationship among migratory and non-migratory individuals, and the implications of life history diversity for management of cutthroat trout in tributaries of the lower Columbia River. The relationship between resident and migratory populations (or resident and migratory individuals within populations) is of central importance for management of coastal cutthroat trout. In the lower Columbia River and southwest Washington State a proposed rule to list anadromous cutthroat as threatened under the federal Endangered Species Act (ESA) was withdrawn after the US Fish and Wildlife Service (USFWS) decided during its review process to include resident and anadromous forms in the same Distinct Population Segment (DPS). Debate over proposed ESA listing highlighted a general lack of knowledge about coastal cutthroat trout life history, relationships between resident and migratory forms, and estuarine habitat use in the lower Columbia River. In 2009, the decision not to list the DPS as threatened was remanded to the USFWS on the grounds that the Service had not adequately considered whether marine and estuarine habitats formed a significant portion of the range of the DPS (USFWS 2009). We evaluated the distribution and abundance of coastal cutthroat trout in Big Creek and Bear Creek, two tributaries that join the Columbia River estuary from the south (Oregon) side roughly 30 kilometers from the ocean, and monitored the migratory behavior of cutthroat that emigrated from these streams and entered the Columbia River estuary. Big Creek is an interesting system because a fish weir and diversion dam at an ODFW hatchery, established in 1941 and refurbished in 1957, prevent cutthroat trout from passing upstream, isolating the cutthroat spawning population above the hatchery. Despite this barrier to upstream migration, offspring of resident cutthroat in the upper watershed continue to “smolt” and migrate downstream past the barrier. We were interested in the fate of these fish and their contribution to the adult population. Bear Creek, on the other hand, has always had full access for anadromous cutthroat through much of its drainage. These two systems permit a comparison of life history characteristics, migration, and survival of coastal cutthroat rearing in streams above and below migration barriers, and provide study sites in Oregon to compliment research by USFWS of coastal cutthroat migration behavior in tributaries entering the estuary from the north side of the Columbia River (USFWS 2008; and see Hudson et al. 2008; Johnson 2008; Zydlewski et al. 2008). A major objective of our work in Big Creek and Bear Creek was to increase understanding of coastal cutthroat trout biology and the relationship between resident and migratory cutthroat in lower Columbia tributaries. Additionally, we sought to document habitat use in the Columbia River estuary by migrant cutthroat. Our specific objectives were to: • Estimate abundance of coastal cutthroat trout in Big Creek (above hatchery barrier) and Bear Creek (above and below a large dam) • Quantify the proportions of the cutthroat populations that are migratory, identify which individuals migrate and describe the timing of migration • Describe habitats used by anadromous migrants and characterize migration behavior within the Columbia River estuary • Measure estuarine/marine survival of anadromous individuals and document return to natal streams Close

• 7434. [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 Citation Abstract Copy Title: 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. Title: 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. Close

• 7435. [Article] 2006 Borax Lake Chub Investigations Progress Reports 2006

  Abstract -- Borax Lake chub (Gila boraxobius) is represented by a single population that inhabits a 4.1 hectare geothermally-heated alkaline lake in Harney County, Oregon. The Borax Lake chub is a small ...

  Citation × Citation Citation Abstract Copy Title: 2006 Borax Lake Chub Investigations Progress Reports 2006 Abstract -- Borax Lake chub (Gila boraxobius) is represented by a single population that inhabits a 4.1 hectare geothermally-heated alkaline lake in Harney County, Oregon. The Borax Lake chub is a small minnow endemic to Borax Lake and adjacent wetlands in Oregon’s Alvord Basin (Williams and Bond 1980). Borax Lake is a natural lake, perched 10 meters above the desert floor on sinter deposits, which is fed almost exclusively by thermal groundwater. The Borax Lake chub was listed as endangered under the federal Endangered Species Act in 1982 (U.S. Fish and Wildlife Service 1982). Population abundance estimates obtained in 1991-1996 indicated a fluctuating population ranging from a low of 8,144 fish to a high of 34,634 fish (Salzer 1997). The basis for the Borax Lake chub’s listed status was not population size, but the security of a very limited, unique, isolated, and vulnerable habitat. Because Borax Lake is situated above salt deposits on the desert floor, alteration of the salt crust shoreline could reduce lake levels and the habitat quantity and quality available to Borax Lake chub. At the time of the listing, Borax Lake was threatened by habitat alteration caused by geothermal energy development and alteration of the lake shore crust to provide irrigation to surrounding pasture lands. The Borax Lake chub federal recovery plan, completed in 1987, advocated protection of the lake ecosystem through the acquisition of key private lands, protection of groundwater and surface waters, controls on access, and the removal of livestock grazing (U.S. Fish and Wildlife Service 1987). Numerous recovery measures implemented since listing have improved the conservation status of Borax Lake chub and protection of its habitat (Williams and Macdonald 2003). When the species was listed, critical habitat was designated on 259 hectares of land surrounding the lake, including 129 hectares of public lands and two 65- hectare parcels of private land. In 1983, the U.S. Bureau of Land Management designated the public land as an Area of Critical Environmental Concern. The Nature Conservancy began leasing the private lands in 1983 and purchased them in 1993, bringing the entire critical habitat into public or conservation ownership. The Nature Conservancy ended water diversion from the lake for irrigation and livestock grazing within the critical habitat. Passage of the Steens Mountain Cooperative Management and Protection Act of 2000 removed the public BLM lands from mineral and geothermal development within a majority of the basin. These actions, combined with detailed studies of the chub and their habitat have added substantially to our knowledge of the Borax Lake ecosystem (Scoppettone et al. 1995, Salzer 1992, Perkins et al. 1996). However, three primary threats remain. These include the threat to the fragile lake shoreline, wetlands, and soils from a recent increase in recreational use around the lake (particularly off-road vehicle usage), the threat of introduction of nonnative species, and potential negative impacts to the aquifer from geothermal groundwater withdrawal if groundwater pumping were to occur on private lands outside the protected areas (Williams and Macdonald 2003). Although an increase in abundance is not a goal in the successful recovery of this species, monitoring trends in abundance over time is an important management tool to assess species status. From 1998-2004, data describing the abundance of the Borax Lake chub population are not available. Abundance estimates were obtained from 1986- 1997 by The Nature Conservancy (Salzer 1997) (Figure 1). Abundance estimates for 1986-1990 are not comparable with those obtained in 1991-1997. Prior to 1991, estimates were obtained only from traps set around the perimeter of the lake. In 1991, estimates were obtained from traps set on a regularly spaced grid throughout the lake. A study comparing the methods suggests that prior to 1991 abundance was under estimated, perhaps by as much as 50 percent (Salzer 1992). A recent review of the conservation status of the Borax Lake chub by Williams and Macdonald (2003) cited the lack of recent and ongoing population and ecosystem monitoring as one argument against downlisting or delisting the species at this time. The chub population has experienced substantial fluctuations in abundance over the time period (1986-1997) when abundance data are available (Figure 1). At the time of the review, the most recent abundance estimates that were obtained in 1996 and 1997 were some of the lowest estimates since 1991. Borax Lake chub population abundance estimates from 1986 to 1997 and 2005 to 2006. Horizontal bars represent 95% confidence limits. In 1986-1990 (solid symbols), only the perimeter of the lake was trapped. After 1990 (open symbols) the entire lake was trapped. Estimates are not directly comparable across these time periods. There are limited data on population age structure that offer valuable insight into the productivity of Borax Lake chub. Williams and Bond (1983) examined lengthfrequency data and concluded that the population consisted primarily of age 1 fish, with few age 2 and age 3 fish present. Limited opercle bone aging of chub collected in 1992- 1993 also indicated that most Borax Lake were less than one year of age (67-79%), yet a few individuals were aged at 10+ years (Scoppettone 1995). Because Borax Lake chub are only found in one location and the population is apparently dominated by a single year-class of adults, the species has a high inherent risk of extinction. 3 The objectives of this study were to: 1) obtain a mark-recapture population estimate of Borax Lake chub, and 2) to evaluate ways to reduce handling of Borax Lake chub when monitoring population abundance both by modifying previous mark-recapture protocols and by developing snorkeling survey protocols to use as an alternative to mark-recapture estimates. In addition, we collected data regarding lake temperatures, chub size (age) structure, and the condition of the fragile lake shoreline and outflows. Title: 2006 Borax Lake Chub Investigations Progress Reports 2006 Abstract -- Borax Lake chub (Gila boraxobius) is represented by a single population that inhabits a 4.1 hectare geothermally-heated alkaline lake in Harney County, Oregon. The Borax Lake chub is a small minnow endemic to Borax Lake and adjacent wetlands in Oregon’s Alvord Basin (Williams and Bond 1980). Borax Lake is a natural lake, perched 10 meters above the desert floor on sinter deposits, which is fed almost exclusively by thermal groundwater. The Borax Lake chub was listed as endangered under the federal Endangered Species Act in 1982 (U.S. Fish and Wildlife Service 1982). Population abundance estimates obtained in 1991-1996 indicated a fluctuating population ranging from a low of 8,144 fish to a high of 34,634 fish (Salzer 1997). The basis for the Borax Lake chub’s listed status was not population size, but the security of a very limited, unique, isolated, and vulnerable habitat. Because Borax Lake is situated above salt deposits on the desert floor, alteration of the salt crust shoreline could reduce lake levels and the habitat quantity and quality available to Borax Lake chub. At the time of the listing, Borax Lake was threatened by habitat alteration caused by geothermal energy development and alteration of the lake shore crust to provide irrigation to surrounding pasture lands. The Borax Lake chub federal recovery plan, completed in 1987, advocated protection of the lake ecosystem through the acquisition of key private lands, protection of groundwater and surface waters, controls on access, and the removal of livestock grazing (U.S. Fish and Wildlife Service 1987). Numerous recovery measures implemented since listing have improved the conservation status of Borax Lake chub and protection of its habitat (Williams and Macdonald 2003). When the species was listed, critical habitat was designated on 259 hectares of land surrounding the lake, including 129 hectares of public lands and two 65- hectare parcels of private land. In 1983, the U.S. Bureau of Land Management designated the public land as an Area of Critical Environmental Concern. The Nature Conservancy began leasing the private lands in 1983 and purchased them in 1993, bringing the entire critical habitat into public or conservation ownership. The Nature Conservancy ended water diversion from the lake for irrigation and livestock grazing within the critical habitat. Passage of the Steens Mountain Cooperative Management and Protection Act of 2000 removed the public BLM lands from mineral and geothermal development within a majority of the basin. These actions, combined with detailed studies of the chub and their habitat have added substantially to our knowledge of the Borax Lake ecosystem (Scoppettone et al. 1995, Salzer 1992, Perkins et al. 1996). However, three primary threats remain. These include the threat to the fragile lake shoreline, wetlands, and soils from a recent increase in recreational use around the lake (particularly off-road vehicle usage), the threat of introduction of nonnative species, and potential negative impacts to the aquifer from geothermal groundwater withdrawal if groundwater pumping were to occur on private lands outside the protected areas (Williams and Macdonald 2003). Although an increase in abundance is not a goal in the successful recovery of this species, monitoring trends in abundance over time is an important management tool to assess species status. From 1998-2004, data describing the abundance of the Borax Lake chub population are not available. Abundance estimates were obtained from 1986- 1997 by The Nature Conservancy (Salzer 1997) (Figure 1). Abundance estimates for 1986-1990 are not comparable with those obtained in 1991-1997. Prior to 1991, estimates were obtained only from traps set around the perimeter of the lake. In 1991, estimates were obtained from traps set on a regularly spaced grid throughout the lake. A study comparing the methods suggests that prior to 1991 abundance was under estimated, perhaps by as much as 50 percent (Salzer 1992). A recent review of the conservation status of the Borax Lake chub by Williams and Macdonald (2003) cited the lack of recent and ongoing population and ecosystem monitoring as one argument against downlisting or delisting the species at this time. The chub population has experienced substantial fluctuations in abundance over the time period (1986-1997) when abundance data are available (Figure 1). At the time of the review, the most recent abundance estimates that were obtained in 1996 and 1997 were some of the lowest estimates since 1991. Borax Lake chub population abundance estimates from 1986 to 1997 and 2005 to 2006. Horizontal bars represent 95% confidence limits. In 1986-1990 (solid symbols), only the perimeter of the lake was trapped. After 1990 (open symbols) the entire lake was trapped. Estimates are not directly comparable across these time periods. There are limited data on population age structure that offer valuable insight into the productivity of Borax Lake chub. Williams and Bond (1983) examined lengthfrequency data and concluded that the population consisted primarily of age 1 fish, with few age 2 and age 3 fish present. Limited opercle bone aging of chub collected in 1992- 1993 also indicated that most Borax Lake were less than one year of age (67-79%), yet a few individuals were aged at 10+ years (Scoppettone 1995). Because Borax Lake chub are only found in one location and the population is apparently dominated by a single year-class of adults, the species has a high inherent risk of extinction. 3 The objectives of this study were to: 1) obtain a mark-recapture population estimate of Borax Lake chub, and 2) to evaluate ways to reduce handling of Borax Lake chub when monitoring population abundance both by modifying previous mark-recapture protocols and by developing snorkeling survey protocols to use as an alternative to mark-recapture estimates. In addition, we collected data regarding lake temperatures, chub size (age) structure, and the condition of the fragile lake shoreline and outflows. Close

• 7436. [Article] Life history variability, habitat use, and migratory behavior of coastal cutthroat trout in the Salmon River, Oregon Annual Progress Report

  Abstract -- A previous study characterized a diversity of life history strategies of coastal cutthroat trout (Oncorhynchus clarki clarki) in Salmon River (Krentz 2007). In contrast to life history patterns ...

  Citation × Citation Citation Abstract Copy Title: Life history variability, habitat use, and migratory behavior of coastal cutthroat trout in the Salmon River, Oregon Annual Progress Report Abstract -- A previous study characterized a diversity of life history strategies of coastal cutthroat trout (Oncorhynchus clarki clarki) in Salmon River (Krentz 2007). In contrast to life history patterns in other Oregon estuaries (Giger 1972), cutthroat trout of all sizes resided for extended periods of time throughout the available channel habitats in Salmon River estuary. The estuarine resident population appeared to represent a significant portion of the migratory individuals, and included all age classes. Estuary growth was similar to that of their ocean migrant counterparts, and survival in the estuary was high. Because cutthroat were collected and marked primarily within the estuary (Krentz 2007), it is unclear what portion of the migrant population remained in the estuary relative to the ocean migrants, or whether the tagged group was representative of the anadromous populations. The current study was designed to track a representative sample of the downstream migrant population, and assess the relative success (survival) of the estuary and ocean migrants. Similar studies in the Columbia River documented directed and rapid migration through the estuary (Zydlewski et al. 2008, Hering et al. 2009). With one exception, cutthroat trout were not observed to rear in the estuary. In addition, many fish disappeared before reaching the ocean and few of the ocean migrants returned to the site of release. In this study we replicated the study design used in the Columbia River studies to allow comparison of estuary migration and rearing strategies between the two estuaries. The primary objective of our work in the Salmon River was to increase understanding of coastal cutthroat trout biology and the relationship between resident and migratory cutthroat. Study objectives were to: 1. Estimate the distribution and abundance of coastal cutthroat trout in the Salmon River watershed 2. Quantify the proportions of the cutthroat populations that are migratory, identify which individuals migrate and describe the timing of migration 3. Describe habitats used by anadromous migrants and characterize migration behavior within the Salmon River estuary 4. Estimate growth rate of estuary resident cutthroat 5. Estimate estuarine/marine survival of anadromous individuals and document return to estuary 6. Compare migratory patterns and survival with cutthroat in the Columbia River In this report, we will discuss migration patterns, habitat use, and growth. The study will be continued in 2010 to meet objectives (1), (2), and (6), and provide more detail to objectives (3), (4), and (5). Title: Life history variability, habitat use, and migratory behavior of coastal cutthroat trout in the Salmon River, Oregon Annual Progress Report Abstract -- A previous study characterized a diversity of life history strategies of coastal cutthroat trout (Oncorhynchus clarki clarki) in Salmon River (Krentz 2007). In contrast to life history patterns in other Oregon estuaries (Giger 1972), cutthroat trout of all sizes resided for extended periods of time throughout the available channel habitats in Salmon River estuary. The estuarine resident population appeared to represent a significant portion of the migratory individuals, and included all age classes. Estuary growth was similar to that of their ocean migrant counterparts, and survival in the estuary was high. Because cutthroat were collected and marked primarily within the estuary (Krentz 2007), it is unclear what portion of the migrant population remained in the estuary relative to the ocean migrants, or whether the tagged group was representative of the anadromous populations. The current study was designed to track a representative sample of the downstream migrant population, and assess the relative success (survival) of the estuary and ocean migrants. Similar studies in the Columbia River documented directed and rapid migration through the estuary (Zydlewski et al. 2008, Hering et al. 2009). With one exception, cutthroat trout were not observed to rear in the estuary. In addition, many fish disappeared before reaching the ocean and few of the ocean migrants returned to the site of release. In this study we replicated the study design used in the Columbia River studies to allow comparison of estuary migration and rearing strategies between the two estuaries. The primary objective of our work in the Salmon River was to increase understanding of coastal cutthroat trout biology and the relationship between resident and migratory cutthroat. Study objectives were to: 1. Estimate the distribution and abundance of coastal cutthroat trout in the Salmon River watershed 2. Quantify the proportions of the cutthroat populations that are migratory, identify which individuals migrate and describe the timing of migration 3. Describe habitats used by anadromous migrants and characterize migration behavior within the Salmon River estuary 4. Estimate growth rate of estuary resident cutthroat 5. Estimate estuarine/marine survival of anadromous individuals and document return to estuary 6. Compare migratory patterns and survival with cutthroat in the Columbia River In this report, we will discuss migration patterns, habitat use, and growth. The study will be continued in 2010 to meet objectives (1), (2), and (6), and provide more detail to objectives (3), (4), and (5). Close

• 7437. [Article] Trout lakes of the Oregon Cascades; A review of fish management

  Abstract -- In 1990 the author, a former Oregon Department of Fish and Wildlife (ODFW) career fish biologist, retired and began gathering material to pen a brief description of Oregon's Cascade Mountain ...

  Citation × Citation Citation Abstract Copy Title: Trout lakes of the Oregon Cascades; A review of fish management Abstract -- In 1990 the author, a former Oregon Department of Fish and Wildlife (ODFW) career fish biologist, retired and began gathering material to pen a brief description of Oregon's Cascade Mountain lakes and their trout. He shortly set the collected records aside, opting to travel and go fishing instead. Upon recent discovery of the stored information, he decided to prepare this summary, largely to provide a partial list of aging documents which might otherwise become lost or forgotten. Many reports have been written regarding Cascade Range lakes and their fish. Unfortunately, a large number of those were unpublished, so may now be difficult to find. Larson and Donaldson (1971) probably offer the most comprehensive bibliography of those reports. The reference list herein adds several documents not contained in Larson and Donaldson, but only limited effort was made to identify or include those written after the late 1980s. Title: Trout lakes of the Oregon Cascades; A review of fish management Abstract -- In 1990 the author, a former Oregon Department of Fish and Wildlife (ODFW) career fish biologist, retired and began gathering material to pen a brief description of Oregon's Cascade Mountain lakes and their trout. He shortly set the collected records aside, opting to travel and go fishing instead. Upon recent discovery of the stored information, he decided to prepare this summary, largely to provide a partial list of aging documents which might otherwise become lost or forgotten. Many reports have been written regarding Cascade Range lakes and their fish. Unfortunately, a large number of those were unpublished, so may now be difficult to find. Larson and Donaldson (1971) probably offer the most comprehensive bibliography of those reports. The reference list herein adds several documents not contained in Larson and Donaldson, but only limited effort was made to identify or include those written after the late 1980s. Close

• 7438. [Article] Crooked River Fish Management Plan 1979

  Abstract -- The Crooked River is a major tributary to the Deschutes River and has the habitat to produce a good rainbow trout population, especially between Prineville Dam and Rice-Baldwin Dam. However, ...

  Citation × Citation Citation Abstract Copy Title: Crooked River Fish Management Plan 1979 Abstract -- The Crooked River is a major tributary to the Deschutes River and has the habitat to produce a good rainbow trout population, especially between Prineville Dam and Rice-Baldwin Dam. However, winter streamflow is minimal and high turbidity is common. The. river is not stocked but various ages and sizes of hatchery fish emigrate from Prineville Reservoir during periods of spill; and these fish constitute a sizable portion of the trout population in the river. The Crooked River has maintained a successful fishery on the combination of wild and hatchery (from Prinevi11e Reservoir) trout under general statewide regulations. In July 1979, the Oregon Fish and Wildlife Commission accepted the Department's recommendation to continue to manage this portion of Crooked River for wild and hatchery fish. Hatchery fish will not be stocked in this section of the river, but large numbers of hatchery trout migrate from Prineville Reservoir into the river below the dam. Title: Crooked River Fish Management Plan 1979 Abstract -- The Crooked River is a major tributary to the Deschutes River and has the habitat to produce a good rainbow trout population, especially between Prineville Dam and Rice-Baldwin Dam. However, winter streamflow is minimal and high turbidity is common. The. river is not stocked but various ages and sizes of hatchery fish emigrate from Prineville Reservoir during periods of spill; and these fish constitute a sizable portion of the trout population in the river. The Crooked River has maintained a successful fishery on the combination of wild and hatchery (from Prinevi11e Reservoir) trout under general statewide regulations. In July 1979, the Oregon Fish and Wildlife Commission accepted the Department's recommendation to continue to manage this portion of Crooked River for wild and hatchery fish. Hatchery fish will not be stocked in this section of the river, but large numbers of hatchery trout migrate from Prineville Reservoir into the river below the dam. Close

• 7439. [Article] Abundance and life history characteristics of steelhead (Oncorhynchus mykiss) and Coho Salmon (Oncorhynchus kisutch) smolts in two direct ocean tributaries on the central Oregon coast, Information Report 2018-07

  Abstract -- In 1991, the Oregon Department of Fish and Wildlife (ODFW) began an intensive research study at Tenmile Creek on the central Oregon coast to evaluate the effects of a large wood addition on ...

  Citation × Citation Citation Abstract Copy Title: Abundance and life history characteristics of steelhead (Oncorhynchus mykiss) and Coho Salmon (Oncorhynchus kisutch) smolts in two direct ocean tributaries on the central Oregon coast, Information Report 2018-07 Abstract -- In 1991, the Oregon Department of Fish and Wildlife (ODFW) began an intensive research study at Tenmile Creek on the central Oregon coast to evaluate the effects of a large wood addition on juvenile salmonid populations. Nearby Cummins Creek served as a reference site. Annual monitoring of juvenile salmonid out-migrants began in 1992 at the two sites, continued through 2012 at Cummins Creek, and is ongoing at Tenmile Creek. These data offer an unusually long time-series of smolt abundance and life history characteristics for steelhead and Coho Salmon at monitoring sites located less than a kilometer from the point of ocean entry. Annual estimates of steelhead smolt abundance ranged from 740 to 3,236 smolts at Cummins Creek, and from 2,464 to 19,602 smolts at Tenmile Creek. For Coho Salmon, annual estimates ranged from 319 to 3,164 smolts at Cummins Creek, and from 1,637 to 11,553 smolts at Tenmile Creek. Steelhead smolt production at Tenmile Creek appeared to increase significantly relative to Cummins Creek following the large wood addition in 1996, but there was no evidence of a similar effect on Coho Salmon smolt production. Most steelhead smolts spent 2 years rearing in freshwater before out-migration, and we observed a higher proportion of age-1 smolts and lower proportion of age-3 smolts than several other studies in Oregon coastal streams. Coho Salmon smolt out-migrants were dominated by age-1 individuals at both sites, but there was evidence that some juvenile Coho Salmon out-migrated as age-0 smolts. Smolts of both species tended to be larger at Tenmile Creek than at Cummins Creek, and negative relationships between mean smolt size and smolt abundance suggest that rearing density may influence growth for juvenile salmonids in these streams. The median migration date of steelhead smolts was consistent over time and tracked closely between the two sites. Coho Salmon smolt out-migration timing was more variable and tended to be slightly later than for steelhead, particularly at Tenmile Creek. During peak migration, a high proportion of steelhead migrants classified as smolts based on length had body coloration consistent with smoltification. External signs of smoltification were not as prevalent among steelhead captured early in the season, particularly among smaller migrants. This long term out-migrant monitoring at the ocean entrance illustrates the variation that occurs in freshwater production and the patterns that occur in salmonid smolt life history but also shows that without spawner abundance data conclusions about freshwater production are limited. Title: Abundance and life history characteristics of steelhead (Oncorhynchus mykiss) and Coho Salmon (Oncorhynchus kisutch) smolts in two direct ocean tributaries on the central Oregon coast, Information Report 2018-07 Abstract -- In 1991, the Oregon Department of Fish and Wildlife (ODFW) began an intensive research study at Tenmile Creek on the central Oregon coast to evaluate the effects of a large wood addition on juvenile salmonid populations. Nearby Cummins Creek served as a reference site. Annual monitoring of juvenile salmonid out-migrants began in 1992 at the two sites, continued through 2012 at Cummins Creek, and is ongoing at Tenmile Creek. These data offer an unusually long time-series of smolt abundance and life history characteristics for steelhead and Coho Salmon at monitoring sites located less than a kilometer from the point of ocean entry. Annual estimates of steelhead smolt abundance ranged from 740 to 3,236 smolts at Cummins Creek, and from 2,464 to 19,602 smolts at Tenmile Creek. For Coho Salmon, annual estimates ranged from 319 to 3,164 smolts at Cummins Creek, and from 1,637 to 11,553 smolts at Tenmile Creek. Steelhead smolt production at Tenmile Creek appeared to increase significantly relative to Cummins Creek following the large wood addition in 1996, but there was no evidence of a similar effect on Coho Salmon smolt production. Most steelhead smolts spent 2 years rearing in freshwater before out-migration, and we observed a higher proportion of age-1 smolts and lower proportion of age-3 smolts than several other studies in Oregon coastal streams. Coho Salmon smolt out-migrants were dominated by age-1 individuals at both sites, but there was evidence that some juvenile Coho Salmon out-migrated as age-0 smolts. Smolts of both species tended to be larger at Tenmile Creek than at Cummins Creek, and negative relationships between mean smolt size and smolt abundance suggest that rearing density may influence growth for juvenile salmonids in these streams. The median migration date of steelhead smolts was consistent over time and tracked closely between the two sites. Coho Salmon smolt out-migration timing was more variable and tended to be slightly later than for steelhead, particularly at Tenmile Creek. During peak migration, a high proportion of steelhead migrants classified as smolts based on length had body coloration consistent with smoltification. External signs of smoltification were not as prevalent among steelhead captured early in the season, particularly among smaller migrants. This long term out-migrant monitoring at the ocean entrance illustrates the variation that occurs in freshwater production and the patterns that occur in salmonid smolt life history but also shows that without spawner abundance data conclusions about freshwater production are limited. Close

• 7440. [Article] Abundance, Productivity, and Life History of Fifteenmile Creek Steelhead; Annual Report 2016

  Abstract -- The Fifteenmile Creek watershed in North Central Oregon hosts a native population of steelhead (Oncorhynchus mykiss) that is without influence of previous hatchery augmentation. The Fifteenmile ...

  Citation × Citation Citation Abstract Copy Title: Abundance, Productivity, and Life History of Fifteenmile Creek Steelhead; Annual Report 2016 Abstract -- The Fifteenmile Creek watershed in North Central Oregon hosts a native population of steelhead (Oncorhynchus mykiss) that is without influence of previous hatchery augmentation. The Fifteenmile Creek steelhead are a subpopulation within the Distinct Population Segment (DPS) of the Middle Columbia River steelhead and was listed as ‘threatened’ by the National Marine Fisheries Service (NMFS) first on March 25, 1999 and relisted as a DPS on January 5, 2006. Subsequently, a conservation and recovery management plan was developed for the Middle Columbia River steelhead DPS within Oregon state borders. The goal of the plan is to recover Middle Columbia River steelhead to a level that would allow the removal of threatened status, in addition to providing a long-term goal to recover the population sufficiently to provide sustainable fisheries and other ecological, cultural, social and economic benefits for future generations. The DPS-level recovery plan sets specific recovery goals for the areas within the DPS, which designates Fifteenmile Creek explicitly. The Fifteenmile Creek steelhead population is considered the most inland winter race of steelhead in the Columbia River Basin, as designated by NOAA fisheries. However review of this designation may be necessary at the next Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp) status-review because the run-timing of adult steelhead passing Bonneville Dam has been inconsistent with known winter-run steelhead in the area. The population was identified as “must have viable” status by the Interior Columbia Technical Recovery Team (ICTRT), and reaching viable status is essential for achieving DPS delisting. The ICTRT, Recovery Plan, and the Federal Columbia River Power System (FCRPS-BiOp) have all identified this population as high priority for improving precision and accuracy of abundance, productivity, diversity, and spatial structure information. Title: Abundance, Productivity, and Life History of Fifteenmile Creek Steelhead; Annual Report 2016 Abstract -- The Fifteenmile Creek watershed in North Central Oregon hosts a native population of steelhead (Oncorhynchus mykiss) that is without influence of previous hatchery augmentation. The Fifteenmile Creek steelhead are a subpopulation within the Distinct Population Segment (DPS) of the Middle Columbia River steelhead and was listed as ‘threatened’ by the National Marine Fisheries Service (NMFS) first on March 25, 1999 and relisted as a DPS on January 5, 2006. Subsequently, a conservation and recovery management plan was developed for the Middle Columbia River steelhead DPS within Oregon state borders. The goal of the plan is to recover Middle Columbia River steelhead to a level that would allow the removal of threatened status, in addition to providing a long-term goal to recover the population sufficiently to provide sustainable fisheries and other ecological, cultural, social and economic benefits for future generations. The DPS-level recovery plan sets specific recovery goals for the areas within the DPS, which designates Fifteenmile Creek explicitly. The Fifteenmile Creek steelhead population is considered the most inland winter race of steelhead in the Columbia River Basin, as designated by NOAA fisheries. However review of this designation may be necessary at the next Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp) status-review because the run-timing of adult steelhead passing Bonneville Dam has been inconsistent with known winter-run steelhead in the area. The population was identified as “must have viable” status by the Interior Columbia Technical Recovery Team (ICTRT), and reaching viable status is essential for achieving DPS delisting. The ICTRT, Recovery Plan, and the Federal Columbia River Power System (FCRPS-BiOp) have all identified this population as high priority for improving precision and accuracy of abundance, productivity, diversity, and spatial structure information. Close