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• 1901. [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State a proposed rule to list anadromous cutthroat as threatened under the federal Endangered Species Act (ESA) was withdrawn after the US Fish and Wildlife Service (USFWS) decided during its review process to include resident and anadromous forms in the same Distinct Population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

• 1902. [Article] Amphibian Distribution in Wadeable Streams and Ponds in Western and Southeast Oregon, 2009-2010 Progress Reports 2011

  Abstract -- The ODFW Oregon Conservation Strategy identified monitoring needs for 17 amphibian species native to the state of Oregon that are designated as “Strategy Species”, or “Species of Greatest Conservation ...

  Citation × Citation Citation Abstract Copy Title: Amphibian Distribution in Wadeable Streams and Ponds in Western and Southeast Oregon, 2009-2010 Progress Reports 2011 Abstract -- The ODFW Oregon Conservation Strategy identified monitoring needs for 17 amphibian species native to the state of Oregon that are designated as “Strategy Species”, or “Species of Greatest Conservation Need” (per USFWS requirements for State Wildlife Action Plans). The distribution of many species of amphibians in western Oregon is sparsely documented (Oregon Conservation Strategy, page 27). Although a broad-scale survey for amphibian presence would provide important baseline information about amphibian species composition and distribution, most studies have focused on limited areas. The majority of Oregon’s amphibians rely on aquatic habitats at some point of their life, either for breeding and juvenile development or to inhabit as adults. Most aquatic amphibians breed from late winter to early summer, and adults frequently remain in or near their breeding sites into the summer. Most tadpoles and juvenile amphibians are also active in and occupy aquatic habitats during the summer. Ongoing aquatic habitat and fish surveys are opportunities to observe species and life stages (breeding adults, tadpoles and juveniles) that occupy aquatic or riparian habitats during the summer. One cost-effective approach is to combine amphibian surveys with existing aquatic habitat and fish surveys such as those conducted as part of the Oregon Plan for Salmon and Watersheds (OCSRI 1997). The Oregon Plan has been in place since 1997 and the monitoring component provides a survey framework for streams in the lower Columbia River and Oregon coast drainages. The sampling framework is also compatible with implementation of the aquatic components of the Conservation Strategy, as demonstrated by this study. This study describes the presence of amphibians in and along wadeable streams in coast and lower Columbia River drainages of Oregon, ponds and sloughs in the Willamette Valley, and selected streams in the Great Basin of southeast and central Oregon. As a component of monitoring under the Oregon Plan, the Aquatic Inventories Project (AIP) conducts aquatic habitat surveys at randomly selected and spatially balanced sites across all 1st through 4th order streams in coastal and lower Columbia River drainages. The purpose of the habitat surveys is to describe stream morphology, instream physical habitat, and riparian vegetation. Because the surveyors were already observing features within and alongside the stream channel, they were able to record observations of amphibians. The advantage of coupling an amphibian component with the OR Plan aquatic surveys was that it not only was an efficient use of resources, but more importantly, provided information using a statistically rigorous survey design across a broad geographic area. The Native Fish Investigations Project began a six year study in 2007 to document the distribution and abundance of redband trout in the Great Basin region of Eastern Oregon. The site selection procedure is comparable to the statistical standards as the Oregon Plan survey design. Amphibian data are also collected during three other survey projects, and although the site selection procedure does not conform to the same statistical standards as the Oregon Plan survey design, the projects offer a number of opportunities to collect amphibian occurrence information over a wide variety of habitats. The amphibian observations from these three projects are also included in this report. The three projects are as follows: AIP conducts aquatic habitat surveys on selected streams throughout the state. AIP conducts aquatic habitat surveys at stream habitat restoration projects in Western Oregon. Native Fish Project conducts surveys of pond and slough sites for Oregon chub in the Willamette Valley. Due to the success of the 2007 and 2008 field studies, we continued our research during the summer of 2009 and 2010 to improve our knowledge of distribution and community structure of amphibians. The summer 2009 and 2010 surveys took place in 9 of Oregon’s 10 ecoregions (Figure 1) (Thorson et al. 2003). Ecoregions provide a framework for discussing amphibian distribution across the state because they are relatively large areas defined by distinctive geographic and ecological (flora and fauna) characteristics. The goals of our 2009-2010 work were to: Increase the consistency, efficiency and ability of habitat crews in identifying amphibians through improved training. Increase knowledge of distribution, community structure, and habitat associations of amphibians in streams in: Western Oregon coastal and lower Columbia drainages. Ponds, sloughs and other off-channel aquatic habitats in the Willamette Valley. Great Basin of eastern Oregon and selected streams in central Oregon. Combine the 2009-2010 observations with the 2007-2008 results. Title: Amphibian Distribution in Wadeable Streams and Ponds in Western and Southeast Oregon, 2009-2010 Progress Reports 2011 Abstract -- The ODFW Oregon Conservation Strategy identified monitoring needs for 17 amphibian species native to the state of Oregon that are designated as “Strategy Species”, or “Species of Greatest Conservation Need” (per USFWS requirements for State Wildlife Action Plans). The distribution of many species of amphibians in western Oregon is sparsely documented (Oregon Conservation Strategy, page 27). Although a broad-scale survey for amphibian presence would provide important baseline information about amphibian species composition and distribution, most studies have focused on limited areas. The majority of Oregon’s amphibians rely on aquatic habitats at some point of their life, either for breeding and juvenile development or to inhabit as adults. Most aquatic amphibians breed from late winter to early summer, and adults frequently remain in or near their breeding sites into the summer. Most tadpoles and juvenile amphibians are also active in and occupy aquatic habitats during the summer. Ongoing aquatic habitat and fish surveys are opportunities to observe species and life stages (breeding adults, tadpoles and juveniles) that occupy aquatic or riparian habitats during the summer. One cost-effective approach is to combine amphibian surveys with existing aquatic habitat and fish surveys such as those conducted as part of the Oregon Plan for Salmon and Watersheds (OCSRI 1997). The Oregon Plan has been in place since 1997 and the monitoring component provides a survey framework for streams in the lower Columbia River and Oregon coast drainages. The sampling framework is also compatible with implementation of the aquatic components of the Conservation Strategy, as demonstrated by this study. This study describes the presence of amphibians in and along wadeable streams in coast and lower Columbia River drainages of Oregon, ponds and sloughs in the Willamette Valley, and selected streams in the Great Basin of southeast and central Oregon. As a component of monitoring under the Oregon Plan, the Aquatic Inventories Project (AIP) conducts aquatic habitat surveys at randomly selected and spatially balanced sites across all 1st through 4th order streams in coastal and lower Columbia River drainages. The purpose of the habitat surveys is to describe stream morphology, instream physical habitat, and riparian vegetation. Because the surveyors were already observing features within and alongside the stream channel, they were able to record observations of amphibians. The advantage of coupling an amphibian component with the OR Plan aquatic surveys was that it not only was an efficient use of resources, but more importantly, provided information using a statistically rigorous survey design across a broad geographic area. The Native Fish Investigations Project began a six year study in 2007 to document the distribution and abundance of redband trout in the Great Basin region of Eastern Oregon. The site selection procedure is comparable to the statistical standards as the Oregon Plan survey design. Amphibian data are also collected during three other survey projects, and although the site selection procedure does not conform to the same statistical standards as the Oregon Plan survey design, the projects offer a number of opportunities to collect amphibian occurrence information over a wide variety of habitats. The amphibian observations from these three projects are also included in this report. The three projects are as follows: AIP conducts aquatic habitat surveys on selected streams throughout the state. AIP conducts aquatic habitat surveys at stream habitat restoration projects in Western Oregon. Native Fish Project conducts surveys of pond and slough sites for Oregon chub in the Willamette Valley. Due to the success of the 2007 and 2008 field studies, we continued our research during the summer of 2009 and 2010 to improve our knowledge of distribution and community structure of amphibians. The summer 2009 and 2010 surveys took place in 9 of Oregon’s 10 ecoregions (Figure 1) (Thorson et al. 2003). Ecoregions provide a framework for discussing amphibian distribution across the state because they are relatively large areas defined by distinctive geographic and ecological (flora and fauna) characteristics. The goals of our 2009-2010 work were to: Increase the consistency, efficiency and ability of habitat crews in identifying amphibians through improved training. Increase knowledge of distribution, community structure, and habitat associations of amphibians in streams in: Western Oregon coastal and lower Columbia drainages. Ponds, sloughs and other off-channel aquatic habitats in the Willamette Valley. Great Basin of eastern Oregon and selected streams in central Oregon. Combine the 2009-2010 observations with the 2007-2008 results. Close

• 1903. [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

• 1904. [Article] Hood River Bull Trout Abundance, Life History, and Habitat Connectivity, 2007 Progress Reports 2007

  Abstract -- Hood River bull trout are thought to exist as two independent reproductive units (USFWS 2004), known as local populations (Rieman and McIntyre 1995). The Clear Branch local population is isolated ...

  Citation × Citation Citation Abstract Copy Title: Hood River Bull Trout Abundance, Life History, and Habitat Connectivity, 2007 Progress Reports 2007 Abstract -- Hood River bull trout are thought to exist as two independent reproductive units (USFWS 2004), known as local populations (Rieman and McIntyre 1995). The Clear Branch local population is isolated above Clear Branch Dam, which provides limited downstream fish passage during infrequent and sporadic periods of spill and no upstream passage. Bull trout in this population inhabit Laurance Lake Reservoir and tributaries upstream of Clear Branch Dam. The Hood River local population occurs in the mainstem Hood River and Middle Fork Hood River downstream of the Clear Branch Dam and a small number of adult bull trout migrate each year into the Hood River from the Columbia River (Figure 1). The status of both populations is extremely precarious. The Clear Branch population is at risk of a random extinction event due to low numbers, negative interactions with non-native smallmouth bass, isolation and limited spawning habitat (USFWS, 1998). The Hood River population also appears to be small and is threatened by passage barriers, unscreened irrigation systems, impaired water quality and periodic siltation of spawning substrate by glacial outbursts. Clear Branch bull trout spawn in Clear Branch and Pinnacle Creek. After rearing in these two natal streams for an unknown time period, most are believed to migrate downstream to Laurance Lake Reservoir. Clear Branch bull trout have been documented passing over the dam spillway during high water events (Pribyl et al. 1996) and may provide a recruitment source for the Hood River local population. Adult bull trout tagged at Powerdale Dam have been observed at Coe Branch irrigation diversion and in a trap at the base of Clear Branch dam. These fish may have been attempting to reach spawning areas located upstream of the dam. However, the success of bull trout migrating downstream via the spillway or the possibility of successfully navigating through the diversion network has never been determined. Depending on the water year, the Middle Fork Irrigation District (MFID) may not spill at all, or the timing of the spill may not coincide with the timing of downstream migration, which is currently unknown (East Fork Hood River and Middle Fork Hood River Watershed analysis). Smallmouth bass were discovered in Lake Laurance Reservoir in the 1990s. Creel surveys have shown that large adult bass are caught occasionally in the reservoir and schools of bass fry have been seen by district fish biologist (Rod French, ODFW, personal communication), suggesting that they are spawning successfully. This illegal introduction poses a potential threat to the Clear Branch bull trout population, but its magnitude is unknown because the bass population size and degree of interaction between the two species are unknown. Bull trout and smallmouth bass have significantly different temperature preferences and tolerances, with bull trout being one of the most sensitive coldwater species and bass being a warm water species. Lake Laurance, a relatively high-altitude reservoir at 890 m (2,920 feet), does not provide ideal bass habitat so these two species may have largely non-overlapping distributions or differing activity periods (Terry Shrader, ODFW warmwater fish biologist, personal communication). However, based on past reservoir temperature data (Berger et al. 2005), there are periods in the reservoir when there is potential for bull trout and bass interaction: periods when bull trout are susceptible to bass predation and when juvenile fish might compete for resources. Spawning activity of the Hood River local population has been observed in a few locations within the Middle Fork of Hood River (Figure 1). Although consistent and extensive spawning areas for this population are not known, some of the locations where juvenile rearing or potential bull trout redds have been observed include the Middle Fork Hood River and some of its tributaries: Bear Creek, Compass Creek and Coe Branch (USFWS 2004). However, Coe Branch, Compass Creek, and the Middle Fork are glacial streams with a high volume of sand and silt which may compromise spawning success. No bull trout spawning or rearing has been observed on the East and West Forks of Hood River. The Middle Fork and mainstem Hood River provide foraging, migration and overwintering habitat. Hood River bull trout are also known to migrate into the Columbia River. Two bull trout tagged at Powerdale Dam (RK 7.2 of mainstem Hood River) were recovered near Drano Lake in Washington State; and one was captured 11 kilometers downstream of the confluence of the Hood and Columbia Rivers (USFWS 2004). Every year (usually between May and July), adult bull trout, presumably migrating upstream from the Columbia River, are captured and anchor tagged at Powerdale Dam. Although some of these tagged fish have been observed upstream (one in Coe Branch and three below Clear Branch dam), the spawning destination of fluvial adults within the Hood River basin is largely unknown. Dispersing juvenile bull trout and migrating adults in this local population are threatened by flow diversions with inadequate screening and passage facilities. Several structures are suspected to impede upstream migration or entrain juvenile and adult bull trout into irrigation works (Pribyl et al. 1996, HRWG 1999). These structures include: the diversion at Clear Branch Dam (passage and screening), Coe Branch (passage and screening), and the Farmers Irrigation District diversion (screening) on the mainstem Hood River (HRWG 1999). However, little research has been conducted to assess the impacts of these structures on migrating bull trout. Beyond a general knowledge of the distribution of Hood River bull trout and the nature of anthropogenic factors that potentially restrict their life history and habitat connectivity, little is known about this recovery unit. Baseline information about adult abundance is lacking for both local populations, the potential of a source (Clear Branch) and sink (Hood River) relationship between the two local populations has not been explored, and the migratory life history of adult fish caught at Powerdale Dam is unknown. The degree to which irrigation and hydropower diversions hamper connectivity within the Hood River basin is also poorly understood. Migratory life histories have been viewed as key to species persistence (Rieman and McIntyre 1995; Dunham and Rieman 1999), and understanding movement patterns and associated habitat requirements are critical to maintaining those migratory forms (Muhlfeld and Morotz 2005; Hostettler 2005). Gaining this information is also critical to evaluating bull trout recovery in the Hood River Subbasin (Coccoli 2004). The Oregon Department of Fish and Wildlife (ODFW) initiated a study in 2006 to improve our understanding of the abundance, life history, and potential limiting factors of the bull trout in this recovery unit. This report describes findings for the first two years of the study (2006-2007). Specific study objectives for the first two years were: 1. Determine the migratory life history of Hood River bull trout and assess the potential impacts of flow diversions and two new falls on the Middle Fork Hood River (scoured by the November 2006 glacial outburst) on bull trout migrations. 2. Determine current distribution of bull trout reproduction and early rearing in historical and potential bull trout streams in the Hood River Subbasin. 3. Determine the juvenile and adult life history the Clear Branch local population and develop a statistically reliable and cost-effective protocol for monitoring the abundance of adult Clear Branch bull trout. 4. Assess the potential impact of smallmouth bass on bull trout in Laurance Lake Reservoir. Title: Hood River Bull Trout Abundance, Life History, and Habitat Connectivity, 2007 Progress Reports 2007 Abstract -- Hood River bull trout are thought to exist as two independent reproductive units (USFWS 2004), known as local populations (Rieman and McIntyre 1995). The Clear Branch local population is isolated above Clear Branch Dam, which provides limited downstream fish passage during infrequent and sporadic periods of spill and no upstream passage. Bull trout in this population inhabit Laurance Lake Reservoir and tributaries upstream of Clear Branch Dam. The Hood River local population occurs in the mainstem Hood River and Middle Fork Hood River downstream of the Clear Branch Dam and a small number of adult bull trout migrate each year into the Hood River from the Columbia River (Figure 1). The status of both populations is extremely precarious. The Clear Branch population is at risk of a random extinction event due to low numbers, negative interactions with non-native smallmouth bass, isolation and limited spawning habitat (USFWS, 1998). The Hood River population also appears to be small and is threatened by passage barriers, unscreened irrigation systems, impaired water quality and periodic siltation of spawning substrate by glacial outbursts. Clear Branch bull trout spawn in Clear Branch and Pinnacle Creek. After rearing in these two natal streams for an unknown time period, most are believed to migrate downstream to Laurance Lake Reservoir. Clear Branch bull trout have been documented passing over the dam spillway during high water events (Pribyl et al. 1996) and may provide a recruitment source for the Hood River local population. Adult bull trout tagged at Powerdale Dam have been observed at Coe Branch irrigation diversion and in a trap at the base of Clear Branch dam. These fish may have been attempting to reach spawning areas located upstream of the dam. However, the success of bull trout migrating downstream via the spillway or the possibility of successfully navigating through the diversion network has never been determined. Depending on the water year, the Middle Fork Irrigation District (MFID) may not spill at all, or the timing of the spill may not coincide with the timing of downstream migration, which is currently unknown (East Fork Hood River and Middle Fork Hood River Watershed analysis). Smallmouth bass were discovered in Lake Laurance Reservoir in the 1990s. Creel surveys have shown that large adult bass are caught occasionally in the reservoir and schools of bass fry have been seen by district fish biologist (Rod French, ODFW, personal communication), suggesting that they are spawning successfully. This illegal introduction poses a potential threat to the Clear Branch bull trout population, but its magnitude is unknown because the bass population size and degree of interaction between the two species are unknown. Bull trout and smallmouth bass have significantly different temperature preferences and tolerances, with bull trout being one of the most sensitive coldwater species and bass being a warm water species. Lake Laurance, a relatively high-altitude reservoir at 890 m (2,920 feet), does not provide ideal bass habitat so these two species may have largely non-overlapping distributions or differing activity periods (Terry Shrader, ODFW warmwater fish biologist, personal communication). However, based on past reservoir temperature data (Berger et al. 2005), there are periods in the reservoir when there is potential for bull trout and bass interaction: periods when bull trout are susceptible to bass predation and when juvenile fish might compete for resources. Spawning activity of the Hood River local population has been observed in a few locations within the Middle Fork of Hood River (Figure 1). Although consistent and extensive spawning areas for this population are not known, some of the locations where juvenile rearing or potential bull trout redds have been observed include the Middle Fork Hood River and some of its tributaries: Bear Creek, Compass Creek and Coe Branch (USFWS 2004). However, Coe Branch, Compass Creek, and the Middle Fork are glacial streams with a high volume of sand and silt which may compromise spawning success. No bull trout spawning or rearing has been observed on the East and West Forks of Hood River. The Middle Fork and mainstem Hood River provide foraging, migration and overwintering habitat. Hood River bull trout are also known to migrate into the Columbia River. Two bull trout tagged at Powerdale Dam (RK 7.2 of mainstem Hood River) were recovered near Drano Lake in Washington State; and one was captured 11 kilometers downstream of the confluence of the Hood and Columbia Rivers (USFWS 2004). Every year (usually between May and July), adult bull trout, presumably migrating upstream from the Columbia River, are captured and anchor tagged at Powerdale Dam. Although some of these tagged fish have been observed upstream (one in Coe Branch and three below Clear Branch dam), the spawning destination of fluvial adults within the Hood River basin is largely unknown. Dispersing juvenile bull trout and migrating adults in this local population are threatened by flow diversions with inadequate screening and passage facilities. Several structures are suspected to impede upstream migration or entrain juvenile and adult bull trout into irrigation works (Pribyl et al. 1996, HRWG 1999). These structures include: the diversion at Clear Branch Dam (passage and screening), Coe Branch (passage and screening), and the Farmers Irrigation District diversion (screening) on the mainstem Hood River (HRWG 1999). However, little research has been conducted to assess the impacts of these structures on migrating bull trout. Beyond a general knowledge of the distribution of Hood River bull trout and the nature of anthropogenic factors that potentially restrict their life history and habitat connectivity, little is known about this recovery unit. Baseline information about adult abundance is lacking for both local populations, the potential of a source (Clear Branch) and sink (Hood River) relationship between the two local populations has not been explored, and the migratory life history of adult fish caught at Powerdale Dam is unknown. The degree to which irrigation and hydropower diversions hamper connectivity within the Hood River basin is also poorly understood. Migratory life histories have been viewed as key to species persistence (Rieman and McIntyre 1995; Dunham and Rieman 1999), and understanding movement patterns and associated habitat requirements are critical to maintaining those migratory forms (Muhlfeld and Morotz 2005; Hostettler 2005). Gaining this information is also critical to evaluating bull trout recovery in the Hood River Subbasin (Coccoli 2004). The Oregon Department of Fish and Wildlife (ODFW) initiated a study in 2006 to improve our understanding of the abundance, life history, and potential limiting factors of the bull trout in this recovery unit. This report describes findings for the first two years of the study (2006-2007). Specific study objectives for the first two years were: 1. Determine the migratory life history of Hood River bull trout and assess the potential impacts of flow diversions and two new falls on the Middle Fork Hood River (scoured by the November 2006 glacial outburst) on bull trout migrations. 2. Determine current distribution of bull trout reproduction and early rearing in historical and potential bull trout streams in the Hood River Subbasin. 3. Determine the juvenile and adult life history the Clear Branch local population and develop a statistically reliable and cost-effective protocol for monitoring the abundance of adult Clear Branch bull trout. 4. Assess the potential impact of smallmouth bass on bull trout in Laurance Lake Reservoir. Close

• 1905. [Article] Information Report 2018-03: Genetic influence from hatchery stocks on upper Willamette River steelhead Oncorhynchus mykiss

  Abstract -- In this study we used microsatellite markers to genetically characterize 1,012 unmarked (presumed to be naturally produced), juvenile Oncorhynchus mykiss, collected at Willamette Falls in 2009, ...

  Citation × Citation Citation Abstract Copy Title: Information Report 2018-03: Genetic influence from hatchery stocks on upper Willamette River steelhead Oncorhynchus mykiss Abstract -- In this study we used microsatellite markers to genetically characterize 1,012 unmarked (presumed to be naturally produced), juvenile Oncorhynchus mykiss, collected at Willamette Falls in 2009, 2010 and 2011, and from multiple locations throughout the upper Willamette River basin in 2014. From the genetic data, we estimated the proportion of each year’s sample that could be assigned as native resident rainbow trout, native winter steelhead, hatchery summer steelhead, the likely descendants of a discontinued hatchery winter steelhead program, or hybrids of these groups. We also attempted to assign individuals to pure or hybrid classes (e.g. F1, F2, backcrosses) and evaluated the predicted accuracy of these class assignments. Although the majority of fish analyzed in each year were assigned as native winter steelhead, we found evidence of natural production by introduced stocks of steelhead. Genetic influence from a discontinued winter steelhead hatchery program was most evident in the Tualatin, Yamhill, Molalla, and below-dam reaches of the North and South Santiam rivers. Pure and hybrid signals from introduced summer steelhead were almost entirely restricted to below-dam reaches of major eastern tributaries and the Molalla River. Evidence of non-native steelhead was nearly absent from above-dam reaches of major tributaries and the Calapooia River. Despite continued hatchery releases of summer steelhead in the Willamette River, we found no compelling evidence for the presence of first-generation hybrid offspring (F1s) that might result from hatchery summer and native winter steelhead matings. However, simulation analyses revealed low statistical power to confidently identify such individuals from our data. We recommend that areas containing native steelhead populations with high genetic integrity receive protection through directed conservation efforts, and continued genetic monitoring should be conducted to inform these efforts and future status reviews. Title: Information Report 2018-03: Genetic influence from hatchery stocks on upper Willamette River steelhead Oncorhynchus mykiss Abstract -- In this study we used microsatellite markers to genetically characterize 1,012 unmarked (presumed to be naturally produced), juvenile Oncorhynchus mykiss, collected at Willamette Falls in 2009, 2010 and 2011, and from multiple locations throughout the upper Willamette River basin in 2014. From the genetic data, we estimated the proportion of each year’s sample that could be assigned as native resident rainbow trout, native winter steelhead, hatchery summer steelhead, the likely descendants of a discontinued hatchery winter steelhead program, or hybrids of these groups. We also attempted to assign individuals to pure or hybrid classes (e.g. F1, F2, backcrosses) and evaluated the predicted accuracy of these class assignments. Although the majority of fish analyzed in each year were assigned as native winter steelhead, we found evidence of natural production by introduced stocks of steelhead. Genetic influence from a discontinued winter steelhead hatchery program was most evident in the Tualatin, Yamhill, Molalla, and below-dam reaches of the North and South Santiam rivers. Pure and hybrid signals from introduced summer steelhead were almost entirely restricted to below-dam reaches of major eastern tributaries and the Molalla River. Evidence of non-native steelhead was nearly absent from above-dam reaches of major tributaries and the Calapooia River. Despite continued hatchery releases of summer steelhead in the Willamette River, we found no compelling evidence for the presence of first-generation hybrid offspring (F1s) that might result from hatchery summer and native winter steelhead matings. However, simulation analyses revealed low statistical power to confidently identify such individuals from our data. We recommend that areas containing native steelhead populations with high genetic integrity receive protection through directed conservation efforts, and continued genetic monitoring should be conducted to inform these efforts and future status reviews. Close

• 1906. [Article] Comprehensive Plan for Production and Management of Oregon's Anadromous Salmon and Trout: Coastal Chinook Salmon Plan

  Abstract -- This is the fourth in a series of individual species plans concerning management of anadromous salmonid populations in the state of Oregon. This plan focuses on the actions the agency will ...

  Citation × Citation Citation Abstract Copy Title: Comprehensive Plan for Production and Management of Oregon's Anadromous Salmon and Trout: Coastal Chinook Salmon Plan Abstract -- This is the fourth in a series of individual species plans concerning management of anadromous salmonid populations in the state of Oregon. This plan focuses on the actions the agency will take regarding chinook salmon Oncorhynchus tshawytscha populations produced in Oregon Coastal watersheds from the Necanicum River in the north to the Winchuck River at the Oregon-California border. Management of chinook salmon in the Columbia River basin is shaped by a cooperative agreement with the state of Washington, the Columbia River Treaty Indian Tribes, and the Federal Government. This management plan for wild and hatchery coastal chinook salmon in coastal river basins is the product of an ongoing planning process. The process began with the preparation of a report that contains descriptions of the life histories and assessments of recent trends in the run strengths of chinook salmon stocks in Oregon coastal river basins (Nicholas and Hankin 1988). ODFW staff and public representatives developed a comprehensive list of issues of concern and actions needed to improve management of coastal chinook salmon. These actions were based in part on a review of historic and contemporary habitat, harvest, and enhancement management practices in Oregon and on a review of the fisheries scientific literature. Title: Comprehensive Plan for Production and Management of Oregon's Anadromous Salmon and Trout: Coastal Chinook Salmon Plan Abstract -- This is the fourth in a series of individual species plans concerning management of anadromous salmonid populations in the state of Oregon. This plan focuses on the actions the agency will take regarding chinook salmon Oncorhynchus tshawytscha populations produced in Oregon Coastal watersheds from the Necanicum River in the north to the Winchuck River at the Oregon-California border. Management of chinook salmon in the Columbia River basin is shaped by a cooperative agreement with the state of Washington, the Columbia River Treaty Indian Tribes, and the Federal Government. This management plan for wild and hatchery coastal chinook salmon in coastal river basins is the product of an ongoing planning process. The process began with the preparation of a report that contains descriptions of the life histories and assessments of recent trends in the run strengths of chinook salmon stocks in Oregon coastal river basins (Nicholas and Hankin 1988). ODFW staff and public representatives developed a comprehensive list of issues of concern and actions needed to improve management of coastal chinook salmon. These actions were based in part on a review of historic and contemporary habitat, harvest, and enhancement management practices in Oregon and on a review of the fisheries scientific literature. Close

• 1907. [Article] Coastal Chinook Salmon Management Plan Summary Mailing, 1991

  Abstract -- The Coastal Chinook Salmon Management Plan is the fourth in a series of individual species plans concerning management of anadromous salmonid populations in Oregon. This plan focuses on actions ...

  Citation × Citation Citation Abstract Copy Title: Coastal Chinook Salmon Management Plan Summary Mailing, 1991 Abstract -- The Coastal Chinook Salmon Management Plan is the fourth in a series of individual species plans concerning management of anadromous salmonid populations in Oregon. This plan focuses on actions the Oregon Department of Fish and Wildlife will take regarding chinook salmon populations produced in Oregon Coastal watersheds from the Necanicum River in the north to the Winchuck River at the Oregon-California border. Management of chinook salmon in the Columbia River Basin - which is guided by a cooperative agreement with Washington, the Columbia River Treaty Indian Tribes, and the Federal Government - is not included in this document. Title: Coastal Chinook Salmon Management Plan Summary Mailing, 1991 Abstract -- The Coastal Chinook Salmon Management Plan is the fourth in a series of individual species plans concerning management of anadromous salmonid populations in Oregon. This plan focuses on actions the Oregon Department of Fish and Wildlife will take regarding chinook salmon populations produced in Oregon Coastal watersheds from the Necanicum River in the north to the Winchuck River at the Oregon-California border. Management of chinook salmon in the Columbia River Basin - which is guided by a cooperative agreement with Washington, the Columbia River Treaty Indian Tribes, and the Federal Government - is not included in this document. Close

• 1908. [Article] Fish Management Plan Middle Creek (Tributary of North Fork Coquille River) 1979

  Abstract -- Middle Creek is a large tributary of the North Fork Coquille River, entering at RM 19. The stream is about 62 miles long, but only 45 miles are available to anadromous fish. The watershed contains ...

  Citation × Citation Citation Abstract Copy Title: Fish Management Plan Middle Creek (Tributary of North Fork Coquille River) 1979 Abstract -- Middle Creek is a large tributary of the North Fork Coquille River, entering at RM 19. The stream is about 62 miles long, but only 45 miles are available to anadromous fish. The watershed contains fair to good habitat, and physical stream survey information has been collected. Middle Creek contains resident and anadromous cutthroat trout, winter steelhead, and coho salmon. Hatchery fish are not released into the system. There are no special angling regulations in effect at present. In July 1979, the Oregon Fish and Wildlife Commission accepted the Department's recommendation to continue to manage Middle Creek for wild trout and steelhead. Choosing a management option for salmon will be deferred until ODFW develops a coast-wide salmon management plan. At that time, staff biologists will decide on a final recommendation to the Commission regarding the need or desirability for releasing hatchery salmon into Middle Creek. Title: Fish Management Plan Middle Creek (Tributary of North Fork Coquille River) 1979 Abstract -- Middle Creek is a large tributary of the North Fork Coquille River, entering at RM 19. The stream is about 62 miles long, but only 45 miles are available to anadromous fish. The watershed contains fair to good habitat, and physical stream survey information has been collected. Middle Creek contains resident and anadromous cutthroat trout, winter steelhead, and coho salmon. Hatchery fish are not released into the system. There are no special angling regulations in effect at present. In July 1979, the Oregon Fish and Wildlife Commission accepted the Department's recommendation to continue to manage Middle Creek for wild trout and steelhead. Choosing a management option for salmon will be deferred until ODFW develops a coast-wide salmon management plan. At that time, staff biologists will decide on a final recommendation to the Commission regarding the need or desirability for releasing hatchery salmon into Middle Creek. Close

• 1909. [Article] Siuslaw River Basin Fish Management Plan 1997

  Abstract -- The Siuslaw River Basin is one in a series of similar watersheds in the Oregon coastal mountain range extending from the Nehalem to the Coquille. Rivers and streams in these watersheds generally ...

  Citation × Citation Citation Abstract Copy Title: Siuslaw River Basin Fish Management Plan 1997 Abstract -- The Siuslaw River Basin is one in a series of similar watersheds in the Oregon coastal mountain range extending from the Nehalem to the Coquille. Rivers and streams in these watersheds generally occur in a forest dominated landscape, have moderate gradients, and medium to large estuaries. There are few dams that substantially affect anadromous fish runs. Water withdrawals impact only a small portion of the total miles of stream habitat. Water quality and temperatures are suitable for salmonids for the entire year in most areas. Rainfall throughout the area is heavy, resulting in a high density of streams relative to watershed area. The Siuslaw River system alone has over one thousand contiguous miles of stream suitable for salmonids. Some of these stream reaches are highly productive, while others are severely degraded. Title: Siuslaw River Basin Fish Management Plan 1997 Abstract -- The Siuslaw River Basin is one in a series of similar watersheds in the Oregon coastal mountain range extending from the Nehalem to the Coquille. Rivers and streams in these watersheds generally occur in a forest dominated landscape, have moderate gradients, and medium to large estuaries. There are few dams that substantially affect anadromous fish runs. Water withdrawals impact only a small portion of the total miles of stream habitat. Water quality and temperatures are suitable for salmonids for the entire year in most areas. Rainfall throughout the area is heavy, resulting in a high density of streams relative to watershed area. The Siuslaw River system alone has over one thousand contiguous miles of stream suitable for salmonids. Some of these stream reaches are highly productive, while others are severely degraded. Close

• 1910. [Article] Yachats River Basin Fish Management Plan 1997

  Abstract -- The Yachats River Basin is one in a series of similar watersheds in the Oregon coastal mountain range extending from the Nehalem to the Coquille. Rivers and streams in these watersheds generally ...

  Citation × Citation Citation Abstract Copy Title: Yachats River Basin Fish Management Plan 1997 Abstract -- The Yachats River Basin is one in a series of similar watersheds in the Oregon coastal mountain range extending from the Nehalem to the Coquille. Rivers and streams in these watersheds generally occur in a forest dominated landscape, have moderate gradients, and medium to large estuaries. There are few dams that substantially affect anadromous fish runs. Water withdrawals impact only a small portion of the total miles of stream habitat. Water quality and temperatures are suitable for salmonids for the entire year in most areas. Rainfall throughout the area is heavy, resulting in a high density of streams relative to watershed area. The Yachats River system has about 69 contiguous miles of stream suitable for salmonids. Some of these stream reaches are highly productive. The Yachats River Basin has traditionally been managed for production of wild salmonids. Few hatchery fish have been released in the Yachats River Basin historically and none has been released in the past several decades. All salmonid species in the Yachats River Basin are at depressed levels with the exception of resident cutthroat trout. The depressed status of Yachats River Basin fish stocks has resulted from human induced factors including habitat degradation, excessive harvest, and hatchery influence (from adjacent streams) in combination with natural events such as droughts, floods and El Nino ocean conditions. As human induced factors are controlled and corrected, it is expected that fish abundance will increase substantially, but it is not possible to accurately forecast the shape recovery will take. In addition to the confounding effects of natural environmental variation, the recovery of individual fish species due to reduction in human impacts can only be loosely surmised. For this reason, this management plan will treat specific management targets for individual species as secondary to recovery of the entire basin and assemblage of fish species. Title: Yachats River Basin Fish Management Plan 1997 Abstract -- The Yachats River Basin is one in a series of similar watersheds in the Oregon coastal mountain range extending from the Nehalem to the Coquille. Rivers and streams in these watersheds generally occur in a forest dominated landscape, have moderate gradients, and medium to large estuaries. There are few dams that substantially affect anadromous fish runs. Water withdrawals impact only a small portion of the total miles of stream habitat. Water quality and temperatures are suitable for salmonids for the entire year in most areas. Rainfall throughout the area is heavy, resulting in a high density of streams relative to watershed area. The Yachats River system has about 69 contiguous miles of stream suitable for salmonids. Some of these stream reaches are highly productive. The Yachats River Basin has traditionally been managed for production of wild salmonids. Few hatchery fish have been released in the Yachats River Basin historically and none has been released in the past several decades. All salmonid species in the Yachats River Basin are at depressed levels with the exception of resident cutthroat trout. The depressed status of Yachats River Basin fish stocks has resulted from human induced factors including habitat degradation, excessive harvest, and hatchery influence (from adjacent streams) in combination with natural events such as droughts, floods and El Nino ocean conditions. As human induced factors are controlled and corrected, it is expected that fish abundance will increase substantially, but it is not possible to accurately forecast the shape recovery will take. In addition to the confounding effects of natural environmental variation, the recovery of individual fish species due to reduction in human impacts can only be loosely surmised. For this reason, this management plan will treat specific management targets for individual species as secondary to recovery of the entire basin and assemblage of fish species. Close