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• 1. [Article] AI - Reference Site Selection and Survey Results 2000

  Abstract -- The Oregon Department of Fish and Wildlife (ODFW) Aquatic Inventories Project conducts stream habitat surveys as part of the Oregon Plan for Salmon and Watersheds. The goal of these surveys ...

  Citation × Citation Citation Abstract Copy Title: AI - Reference Site Selection and Survey Results 2000 Abstract -- The Oregon Department of Fish and Wildlife (ODFW) Aquatic Inventories Project conducts stream habitat surveys as part of the Oregon Plan for Salmon and Watersheds. The goal of these surveys is to document the status and trends of stream conditions that exist in coastal drainages of western Oregon. To better interpret landscape patterns in aquatic habitat character, the Aquatic Inventories Project has sought to improve the definition of a set of reference conditions from which to compare habitat survey sites. Over the past three years, the set of reference conditions used in analyses was selected from basin-wide habitat surveys conducted between 1992 and 1997. These conditions did not adequately represent the variety of stream sizes, geologic types, or ecoregions present in all coastal streams. The Aquatic Inventories Project selected a set of new reference survey locations that better represent reference conditions in coastal streams for a variety of ecoregions, geologic types, and basins. The reference sites selected for the year 2000 represented watershed areas with low impact from human activities such as roads, development, and forest management. Ideally, areas would have been selected that were completely free from human disturbance, but we concluded it was more important to represent a larger geographic range of conditions across the landscape. Title: AI - Reference Site Selection and Survey Results 2000 Abstract -- The Oregon Department of Fish and Wildlife (ODFW) Aquatic Inventories Project conducts stream habitat surveys as part of the Oregon Plan for Salmon and Watersheds. The goal of these surveys is to document the status and trends of stream conditions that exist in coastal drainages of western Oregon. To better interpret landscape patterns in aquatic habitat character, the Aquatic Inventories Project has sought to improve the definition of a set of reference conditions from which to compare habitat survey sites. Over the past three years, the set of reference conditions used in analyses was selected from basin-wide habitat surveys conducted between 1992 and 1997. These conditions did not adequately represent the variety of stream sizes, geologic types, or ecoregions present in all coastal streams. The Aquatic Inventories Project selected a set of new reference survey locations that better represent reference conditions in coastal streams for a variety of ecoregions, geologic types, and basins. The reference sites selected for the year 2000 represented watershed areas with low impact from human activities such as roads, development, and forest management. Ideally, areas would have been selected that were completely free from human disturbance, but we concluded it was more important to represent a larger geographic range of conditions across the landscape. Close

• 2. [Article] AI - Stream Habitat Conditions in Western Oregon, 1999

  Abstract -- The physical habitat of a stream forms the template from which the biological community can develop. The structure and complexity of the stream habitat influences the species composition, distribution, ...

  Citation × Citation Citation Abstract Copy Title: AI - Stream Habitat Conditions in Western Oregon, 1999 Abstract -- The physical habitat of a stream forms the template from which the biological community can develop. The structure and complexity of the stream habitat influences the species composition, distribution, and production of the fish community. Assessing the status of stream habitat conditions in coastal Oregon streams is important for monitoring the effects of landscape and aquatic management practices on the character of riparian stream habitat. Comprehensive habitat assessments are also important for watershed assessments, restoration planning, and for studying the relationship between stream habitat, fish abundance, and fish distribution. The goals of the Oregon Plan for Salmon and Watersheds (OPSW) Habitat Monitoring Program are to 1) provide an annual update on the status of stream habitat in Western Oregon, and 2) track trends in habitat over time. This report on stream habitat conditions covers sampling that occurred between June and October of 1999. The report is grouped into six different areas: • Current habitat status by Gene Conservation Area (GCA) • The status of habitat in relation to landscape variables • An assessment of the high quality habitat existing on the landscape • A comparison of 1998 and 1999 stream conditions • An analysis of habitat variable precision • An assessment of fish distribution outside of known coho salmon distribution Title: AI - Stream Habitat Conditions in Western Oregon, 1999 Abstract -- The physical habitat of a stream forms the template from which the biological community can develop. The structure and complexity of the stream habitat influences the species composition, distribution, and production of the fish community. Assessing the status of stream habitat conditions in coastal Oregon streams is important for monitoring the effects of landscape and aquatic management practices on the character of riparian stream habitat. Comprehensive habitat assessments are also important for watershed assessments, restoration planning, and for studying the relationship between stream habitat, fish abundance, and fish distribution. The goals of the Oregon Plan for Salmon and Watersheds (OPSW) Habitat Monitoring Program are to 1) provide an annual update on the status of stream habitat in Western Oregon, and 2) track trends in habitat over time. This report on stream habitat conditions covers sampling that occurred between June and October of 1999. The report is grouped into six different areas: • Current habitat status by Gene Conservation Area (GCA) • The status of habitat in relation to landscape variables • An assessment of the high quality habitat existing on the landscape • A comparison of 1998 and 1999 stream conditions • An analysis of habitat variable precision • An assessment of fish distribution outside of known coho salmon distribution Close

• 3. [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

• 4. [Article] Neacoxie Watershed

  Abstract -- Previously, little information was known about the ecology or the condition of native habitats in the Neacoxie sub-watershed that drains from the city of Warrenton into the north section of ...

  Citation × Citation Citation Abstract Copy Title: Neacoxie Watershed Abstract -- Previously, little information was known about the ecology or the condition of native habitats in the Neacoxie sub-watershed that drains from the city of Warrenton into the north section of the Necanicum Estuary in the city of Seaside. In 2002, the Necanicum Watershed Council completed an assessment for the Necanicum River watershed, but with major knowledge gaps for the Neacoxie watershed, which includes the Neacoxie Creek corridor and the Clatsop Plains. In order for the North Coast Land Conservancy (NCLC) and other land managers to develop stewardship priorities and to make informed decisions about land management actions in this region, additional information was required. Together with the Necanicum Watershed Council and the North Coast Watershed Association, NCLC secured funding to conduct habitat inventories of the Neacoxie watershed. The Neacoxie Watershed Assessment summarizes the results of terrestrial plant transects and aquatic plant surveys completed in the summer of 2011 on ten properties owned by the North Coast Land Conservancy (NCLC) in the Neacoxie Creek watershed (please refer to Appendices A & B). Habitat types include stabilized sand dunes dominated by coastal prairie habitat, interdunal wetland swales and lakes, upland Sitka spruce forest, and forested wetlands. Percent composition of each plant community type observed was calculated. Invasive non-native plant species were recorded. Surveys were also conducted for both native and non-native plants in four water bodies owned by NCLC or adjacent to land trust properties. The plant community data that were collected will be used to evaluate baseline ecological conditions in the Neacoxie watershed. Plant communities can be used as indicators of long-term tidal and hydrologic conditions as well as the ecological health of the landscape. Repeated measurements can be used to assess community changes over time and to assess how plant community composition compares to that described for natural conditions. This information will assist the land trust in making science-based stewardship decisions on its properties, and can be used by other landowners to better understand changes occurring in plant communities in similar habitats on their properties as a result of human disturbance (e.g., land development, farming, grazing) and invasion by non-native plants. Title: Neacoxie Watershed Abstract -- Previously, little information was known about the ecology or the condition of native habitats in the Neacoxie sub-watershed that drains from the city of Warrenton into the north section of the Necanicum Estuary in the city of Seaside. In 2002, the Necanicum Watershed Council completed an assessment for the Necanicum River watershed, but with major knowledge gaps for the Neacoxie watershed, which includes the Neacoxie Creek corridor and the Clatsop Plains. In order for the North Coast Land Conservancy (NCLC) and other land managers to develop stewardship priorities and to make informed decisions about land management actions in this region, additional information was required. Together with the Necanicum Watershed Council and the North Coast Watershed Association, NCLC secured funding to conduct habitat inventories of the Neacoxie watershed. The Neacoxie Watershed Assessment summarizes the results of terrestrial plant transects and aquatic plant surveys completed in the summer of 2011 on ten properties owned by the North Coast Land Conservancy (NCLC) in the Neacoxie Creek watershed (please refer to Appendices A & B). Habitat types include stabilized sand dunes dominated by coastal prairie habitat, interdunal wetland swales and lakes, upland Sitka spruce forest, and forested wetlands. Percent composition of each plant community type observed was calculated. Invasive non-native plant species were recorded. Surveys were also conducted for both native and non-native plants in four water bodies owned by NCLC or adjacent to land trust properties. The plant community data that were collected will be used to evaluate baseline ecological conditions in the Neacoxie watershed. Plant communities can be used as indicators of long-term tidal and hydrologic conditions as well as the ecological health of the landscape. Repeated measurements can be used to assess community changes over time and to assess how plant community composition compares to that described for natural conditions. This information will assist the land trust in making science-based stewardship decisions on its properties, and can be used by other landowners to better understand changes occurring in plant communities in similar habitats on their properties as a result of human disturbance (e.g., land development, farming, grazing) and invasion by non-native plants. Close

• 5. [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

• 6. [Article] Recovery of Wild Coho Salmon in Salmon River Basin, 2008 Report Number: OPSW-ODFW-2009-10

  Abstract -- Recovery and conservation of naturally self-sustaining salmon populations is a central goal of the Oregon Plan for Salmon and Watersheds. In 1998, the Oregon Department of Fish and Wildlife ...

  Citation × Citation Citation Abstract Copy Title: Recovery of Wild Coho Salmon in Salmon River Basin, 2008 Report Number: OPSW-ODFW-2009-10 Abstract -- Recovery and conservation of naturally self-sustaining salmon populations is a central goal of the Oregon Plan for Salmon and Watersheds. In 1998, the Oregon Department of Fish and Wildlife (ODFW) initiated a comprehensive program to monitor the status of coho salmon (Oncorhynchus kisutch) populations and aquatic habitat in coastal drainages of Oregon (OWEB 2003). A 2005 assessment by ODFW concluded that Oregon coastal coho were viable at the scale of the Evolutionary Significant Unit (ESU) and demonstrated resilience in response to improving ocean conditions. Yet 7 of 21 (33%) individual populations within the ESU failed one or more of five criteria used to assess viability (Chilcote et al. 2005), and it is uncertain whether productivity levels across the ESU will recover sufficiently to withstand future periods of poor ocean conditions. The coho population in Salmon River was the only population in the ESU to fail all five viability criteria. Uncertainty remains about the response of Oregon coastal coho salmon to different combinations of freshwater and marine limiting factors, complicating recovery efforts (Lawson 1993; Lawson et al. 2004; IMST 2006). Such uncertainty cannot be resolved entirely by existing Oregon Plan monitoring programs, which target only a portion of the habitats and coho salmon life stages in large river basins, and with few exceptions (e.g., Johnson et al. 2005), were not designed to test population responses to individual management manipulations. In 2007, in response to the failure of viability criteria, ODFW managers discontinued releases of hatchery coho salmon into Salmon River as one of the primary management actions under the Oregon Conservation Plan for the Oregon Coast Coho Evolutionarily Significant Unit (hereafter “coho plan,” Nicholas 2006). This change affords the first opportunity in Oregon to monitor the results of a large scale experiment in removing hatchery coho salmon from a basin for at least four generations (twelve years). Hatchery production has been a centerpiece of salmon management for decades, but rarely has full recovery from hatchery influence been given a chance to succeed. Salmon River offers a test basin to explore whether an independent population of coho salmon can recover from a prolonged period of very low abundance following removal of the primary factor limiting productivity. Here we describe the first year of a study to monitor the dynamics of the coho salmon population in the Salmon River basin on the central Oregon coast and to determine whether management changes targeting both hatchery influence and stream habitat complexity improve population viability. This research will validate assumptions about factors limiting coho recovery and determine whether recovery measures proposed by the Coho Plan have been effective. Our research is designed to document changes in population abundance, distribution, and life history structure of coho salmon following the removal of hatchery coho salmon from the watershed. It integrates adult, juvenile, and habitat components to establish links and describe variability between juvenile performance and adult recovery. It also monitors the coho salmon population across habitat types and life history stages to identify population responses at a landscape scale. We will establish the link between productivity and survival at each salmon life stage and recovery of the adult population. From these indicators, we will determine the potential resiliency of coho salmon, detail the biological benefits/tradeoffs of returning the ecosystem to natural salmon production, and assess whether supplementation should remain an option in Salmon River. As a conceptual framework, our research design and analyses are guided by the “viable salmonid population” criteria identified by McElhany (2000) and modified by Chilcote et al. (2005) and Nicholas (2006), including abundance, productivity, distribution, diversity, and habitat quality. The results of our new research will be integrated with habitat survey and adult population data collected under the existing Oregon Plan monitoring program and coho salmon population and life history data available from previous Salmon River surveys (Mullen 1978, 1979; Cornwell et al. 2001; Bottom et al 2005; Volk et al. in review). Together these data will address four principal objectives: 1. Quantify viability of the coho salmon population before and after hatchery coho salmon are removed from Salmon River. 2. Assess whether viability of the Salmon River coho population is limited by quantity and complexity of stream habitat. 3. Describe the diversity of juvenile and adult life histories of coho salmon in the Salmon River basin and estimate the relative contributions of alternate juvenile life history to adult returns. 4. Determine salmonid use and benefits of restored tidal wetlands before and after hatchery coho salmon are removed from Salmon River. By synthesizing historic data with new information for the Salmon River basin, we will compare population structure during three distinct periods – pre-hatchery (1974-77), hatchery (1990-2008), and post-hatchery (2009-2013). This annual report discusses the activities and findings from 2008, the first year of the multi-year project, including coho salmon distribution and abundance on the Salmon River spawning grounds, juvenile abundance and distribution in the watershed and estuary, migration timing, and life history diversity. Title: Recovery of Wild Coho Salmon in Salmon River Basin, 2008 Report Number: OPSW-ODFW-2009-10 Abstract -- Recovery and conservation of naturally self-sustaining salmon populations is a central goal of the Oregon Plan for Salmon and Watersheds. In 1998, the Oregon Department of Fish and Wildlife (ODFW) initiated a comprehensive program to monitor the status of coho salmon (Oncorhynchus kisutch) populations and aquatic habitat in coastal drainages of Oregon (OWEB 2003). A 2005 assessment by ODFW concluded that Oregon coastal coho were viable at the scale of the Evolutionary Significant Unit (ESU) and demonstrated resilience in response to improving ocean conditions. Yet 7 of 21 (33%) individual populations within the ESU failed one or more of five criteria used to assess viability (Chilcote et al. 2005), and it is uncertain whether productivity levels across the ESU will recover sufficiently to withstand future periods of poor ocean conditions. The coho population in Salmon River was the only population in the ESU to fail all five viability criteria. Uncertainty remains about the response of Oregon coastal coho salmon to different combinations of freshwater and marine limiting factors, complicating recovery efforts (Lawson 1993; Lawson et al. 2004; IMST 2006). Such uncertainty cannot be resolved entirely by existing Oregon Plan monitoring programs, which target only a portion of the habitats and coho salmon life stages in large river basins, and with few exceptions (e.g., Johnson et al. 2005), were not designed to test population responses to individual management manipulations. In 2007, in response to the failure of viability criteria, ODFW managers discontinued releases of hatchery coho salmon into Salmon River as one of the primary management actions under the Oregon Conservation Plan for the Oregon Coast Coho Evolutionarily Significant Unit (hereafter “coho plan,” Nicholas 2006). This change affords the first opportunity in Oregon to monitor the results of a large scale experiment in removing hatchery coho salmon from a basin for at least four generations (twelve years). Hatchery production has been a centerpiece of salmon management for decades, but rarely has full recovery from hatchery influence been given a chance to succeed. Salmon River offers a test basin to explore whether an independent population of coho salmon can recover from a prolonged period of very low abundance following removal of the primary factor limiting productivity. Here we describe the first year of a study to monitor the dynamics of the coho salmon population in the Salmon River basin on the central Oregon coast and to determine whether management changes targeting both hatchery influence and stream habitat complexity improve population viability. This research will validate assumptions about factors limiting coho recovery and determine whether recovery measures proposed by the Coho Plan have been effective. Our research is designed to document changes in population abundance, distribution, and life history structure of coho salmon following the removal of hatchery coho salmon from the watershed. It integrates adult, juvenile, and habitat components to establish links and describe variability between juvenile performance and adult recovery. It also monitors the coho salmon population across habitat types and life history stages to identify population responses at a landscape scale. We will establish the link between productivity and survival at each salmon life stage and recovery of the adult population. From these indicators, we will determine the potential resiliency of coho salmon, detail the biological benefits/tradeoffs of returning the ecosystem to natural salmon production, and assess whether supplementation should remain an option in Salmon River. As a conceptual framework, our research design and analyses are guided by the “viable salmonid population” criteria identified by McElhany (2000) and modified by Chilcote et al. (2005) and Nicholas (2006), including abundance, productivity, distribution, diversity, and habitat quality. The results of our new research will be integrated with habitat survey and adult population data collected under the existing Oregon Plan monitoring program and coho salmon population and life history data available from previous Salmon River surveys (Mullen 1978, 1979; Cornwell et al. 2001; Bottom et al 2005; Volk et al. in review). Together these data will address four principal objectives: 1. Quantify viability of the coho salmon population before and after hatchery coho salmon are removed from Salmon River. 2. Assess whether viability of the Salmon River coho population is limited by quantity and complexity of stream habitat. 3. Describe the diversity of juvenile and adult life histories of coho salmon in the Salmon River basin and estimate the relative contributions of alternate juvenile life history to adult returns. 4. Determine salmonid use and benefits of restored tidal wetlands before and after hatchery coho salmon are removed from Salmon River. By synthesizing historic data with new information for the Salmon River basin, we will compare population structure during three distinct periods – pre-hatchery (1974-77), hatchery (1990-2008), and post-hatchery (2009-2013). This annual report discusses the activities and findings from 2008, the first year of the multi-year project, including coho salmon distribution and abundance on the Salmon River spawning grounds, juvenile abundance and distribution in the watershed and estuary, migration timing, and life history diversity. Close

• 7. [Article] Recovery of Wild Coho Salmon In Salmon River Basin, 2008-2010 Report Number: OPSW-ODFW-2011-10

  Abstract -- Hatcheries have been a centerpiece of salmon management in the Pacific Northwest for more than a century but recent evidence of adverse interactions between hatchery and naturally-produced ...

  Citation × Citation Citation Abstract Copy Title: Recovery of Wild Coho Salmon In Salmon River Basin, 2008-2010 Report Number: OPSW-ODFW-2011-10 Abstract -- Hatcheries have been a centerpiece of salmon management in the Pacific Northwest for more than a century but recent evidence of adverse interactions between hatchery and naturally-produced salmon have resulted in substantial changes in many hatchery programs. In 2007 the Oregon Department of Fish and Wildlife terminated a 30-year artificial propagation program for coho salmon in the Salmon River basin after a status assessment concluded that wild population viability was threatened by hatchery effects on salmon productivity (Chilcote et al. 2005). Hatchery-reared coho comprised 50-100% of the naturally spawning population in recent years. Low productivity was reflected in a low spawner to recruit ratio, and life-stage specific survival was lower than that of nearby populations. The temporal distribution of adult spawning in the basin was truncated and peaked 1.5 months earlier relative to the pre-hatchery period and adjacent coastal populations. The cessation of hatchery releases into Salmon River not only removed the primary factor believed to limit productivity of the local population, it also constituted a rare management experiment to test whether a naturally-spawning population can recover from a prolonged period of low abundance after interactions with hatchery-produced coho salmon are eliminated. This report summarizes the results of coho population studies at Salmon River for the first three years after the hatchery program was discontinued. The study in Salmon River is timely because ecological interactions between hatchery and wild fish have been implicated in the reduced survival and decreased productivity of wild coho and other salmonid populations (Nickelson 2003, Buhle et al. 2009, Chilcote et al. 2011). Recent studies involving a diversity of salmonid species and watersheds have shown a negative relationship between hatchery spawner abundance and wild population productivity regardless of the duration of hatchery influence (Chilcote et al. 2011). Yet neither the mechanisms of these productivity declines nor their potential reversibility have been investigated. Recent management changes at Salmon River provide an opportunity to experimentally evaluate coho salmon survival and productivity following the elimination of a decades-long hatchery program. The results will provide new insights into the reversibility of hatchery effects and the rate, mechanisms, and trajectory of response by a naturally spawning coho salmon population. Hatchery programs have been shown to change the timing and distribution of naturally spawning adults, but ecological and genetic influences on the spatial structure and life history diversity of juvenile populations are poorly understood. Conventional understanding of the life history of juvenile coho has presumed a relatively fixed pattern of rearing and migration. However, recent studies have found much greater variation in juvenile life history and habitat-use patterns than previously expected (Miller and Sadro 2003, Koski 2009), including evidence that estuaries may play a prominent role in the life histories of some coho salmon populations. A recent study in the Salmon River basin found considerable diversity in the life histories of juvenile Chinook salmon, including extended rearing by fry and other subyearling migrants within the complex network of natural and restored estuarine wetlands (Bottom et al. 2005). Unfortunately, interpretation of juvenile life history variations at Salmon River was confounded by the Chinook hatchery program, which has concentrated spawning activity in the lower river near the hatchery and may directly influence juvenile migration and rearing patterns. Discontinuation of the coho hatchery program at Salmon River provides an opportunity to quantify changes in juvenile life history following the elimination of all hatchery-fish interactions with the naturally spawning population. Such responses may provide important insights into the mechanisms of hatchery influence on wild salmon productivity and population resilience. Our research integrates adult and juvenile life stages, examines linkages to physical habitat conditions in fresh water and the estuary, and describes variability between juvenile performance and adult returns. It also monitors the coho salmon population across habitat types and life history stages to identify population responses at a landscape scale. We will determine productivity and survival at each salmon life stage and monitor the response of the adult population following the cessation of the coho salmon hatchery program. From these indicators, we will determine the potential resiliency of the coho salmon population, and evaluate the biological benefits or tradeoffs of returning the ecosystem to natural salmon production. Our study design encompasses four population phases: (1) pre-hatchery conditions (Mullen 1979), (2) dominance by hatchery-reared spawners (2008), (3) first generation naturally produced juveniles (2009-2011), and (4) second generation naturally produced juveniles (starting in 2012). This research will validate assumptions about factors limiting coho recovery and determine whether recovery actions have been effective. Here, we report on findings from 2008-2010 to address four principal objectives: 1. Quantify life stage specific survival and recruits per spawner ratio of the coho salmon population before and after hatchery coho salmon are removed from Salmon River. 2. Assess whether the Salmon River coho population is limited by capacity and complexity of stream habitat. 3. Describe the diversity of juvenile and adult life histories of coho salmon in the Salmon River basin, and estimate the relative contributions of various juvenile life histories to adult returns. 4. Determine seasonal use of the Salmon River estuary and its tidally-inundated wetlands by juvenile coho salmon. The field sampling that supported the study on coho salmon also captured Chinook salmon and steelhead and cutthroat trout during routine sampling in the watershed and estuary. This report emphasizes coho salmon results, but also summarizes catch, distribution, and migration data for other salmonids to compare densities and abundances in freshwater and the estuary. Additional results for Chinook, steelhead, and cutthroat are presented in Appendix A. See Stein et al. (2011) for more detailed information on life history diversity, migration patterns, habitat use, and abundance of cutthroat trout. Title: Recovery of Wild Coho Salmon In Salmon River Basin, 2008-2010 Report Number: OPSW-ODFW-2011-10 Abstract -- Hatcheries have been a centerpiece of salmon management in the Pacific Northwest for more than a century but recent evidence of adverse interactions between hatchery and naturally-produced salmon have resulted in substantial changes in many hatchery programs. In 2007 the Oregon Department of Fish and Wildlife terminated a 30-year artificial propagation program for coho salmon in the Salmon River basin after a status assessment concluded that wild population viability was threatened by hatchery effects on salmon productivity (Chilcote et al. 2005). Hatchery-reared coho comprised 50-100% of the naturally spawning population in recent years. Low productivity was reflected in a low spawner to recruit ratio, and life-stage specific survival was lower than that of nearby populations. The temporal distribution of adult spawning in the basin was truncated and peaked 1.5 months earlier relative to the pre-hatchery period and adjacent coastal populations. The cessation of hatchery releases into Salmon River not only removed the primary factor believed to limit productivity of the local population, it also constituted a rare management experiment to test whether a naturally-spawning population can recover from a prolonged period of low abundance after interactions with hatchery-produced coho salmon are eliminated. This report summarizes the results of coho population studies at Salmon River for the first three years after the hatchery program was discontinued. The study in Salmon River is timely because ecological interactions between hatchery and wild fish have been implicated in the reduced survival and decreased productivity of wild coho and other salmonid populations (Nickelson 2003, Buhle et al. 2009, Chilcote et al. 2011). Recent studies involving a diversity of salmonid species and watersheds have shown a negative relationship between hatchery spawner abundance and wild population productivity regardless of the duration of hatchery influence (Chilcote et al. 2011). Yet neither the mechanisms of these productivity declines nor their potential reversibility have been investigated. Recent management changes at Salmon River provide an opportunity to experimentally evaluate coho salmon survival and productivity following the elimination of a decades-long hatchery program. The results will provide new insights into the reversibility of hatchery effects and the rate, mechanisms, and trajectory of response by a naturally spawning coho salmon population. Hatchery programs have been shown to change the timing and distribution of naturally spawning adults, but ecological and genetic influences on the spatial structure and life history diversity of juvenile populations are poorly understood. Conventional understanding of the life history of juvenile coho has presumed a relatively fixed pattern of rearing and migration. However, recent studies have found much greater variation in juvenile life history and habitat-use patterns than previously expected (Miller and Sadro 2003, Koski 2009), including evidence that estuaries may play a prominent role in the life histories of some coho salmon populations. A recent study in the Salmon River basin found considerable diversity in the life histories of juvenile Chinook salmon, including extended rearing by fry and other subyearling migrants within the complex network of natural and restored estuarine wetlands (Bottom et al. 2005). Unfortunately, interpretation of juvenile life history variations at Salmon River was confounded by the Chinook hatchery program, which has concentrated spawning activity in the lower river near the hatchery and may directly influence juvenile migration and rearing patterns. Discontinuation of the coho hatchery program at Salmon River provides an opportunity to quantify changes in juvenile life history following the elimination of all hatchery-fish interactions with the naturally spawning population. Such responses may provide important insights into the mechanisms of hatchery influence on wild salmon productivity and population resilience. Our research integrates adult and juvenile life stages, examines linkages to physical habitat conditions in fresh water and the estuary, and describes variability between juvenile performance and adult returns. It also monitors the coho salmon population across habitat types and life history stages to identify population responses at a landscape scale. We will determine productivity and survival at each salmon life stage and monitor the response of the adult population following the cessation of the coho salmon hatchery program. From these indicators, we will determine the potential resiliency of the coho salmon population, and evaluate the biological benefits or tradeoffs of returning the ecosystem to natural salmon production. Our study design encompasses four population phases: (1) pre-hatchery conditions (Mullen 1979), (2) dominance by hatchery-reared spawners (2008), (3) first generation naturally produced juveniles (2009-2011), and (4) second generation naturally produced juveniles (starting in 2012). This research will validate assumptions about factors limiting coho recovery and determine whether recovery actions have been effective. Here, we report on findings from 2008-2010 to address four principal objectives: 1. Quantify life stage specific survival and recruits per spawner ratio of the coho salmon population before and after hatchery coho salmon are removed from Salmon River. 2. Assess whether the Salmon River coho population is limited by capacity and complexity of stream habitat. 3. Describe the diversity of juvenile and adult life histories of coho salmon in the Salmon River basin, and estimate the relative contributions of various juvenile life histories to adult returns. 4. Determine seasonal use of the Salmon River estuary and its tidally-inundated wetlands by juvenile coho salmon. The field sampling that supported the study on coho salmon also captured Chinook salmon and steelhead and cutthroat trout during routine sampling in the watershed and estuary. This report emphasizes coho salmon results, but also summarizes catch, distribution, and migration data for other salmonids to compare densities and abundances in freshwater and the estuary. Additional results for Chinook, steelhead, and cutthroat are presented in Appendix A. See Stein et al. (2011) for more detailed information on life history diversity, migration patterns, habitat use, and abundance of cutthroat trout. Close