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• 281. [Article] Reducing Bycatch in Oregon's Recreational Groundfish Fishery: Experimental Results with Angling Gear Configured to Increase Bait Height Above Bottom Information Reports number 2008-03

  Abstract -- Several long-lived, late-maturing rockfish (Sebastes) species found off the U.S. west coast have been seriously depleted by overfishing and are managed under long-term rebuilding plans that ...

  Citation × Citation Citation Abstract Copy Title: Reducing Bycatch in Oregon's Recreational Groundfish Fishery: Experimental Results with Angling Gear Configured to Increase Bait Height Above Bottom Information Reports number 2008-03 Abstract -- Several long-lived, late-maturing rockfish (Sebastes) species found off the U.S. west coast have been seriously depleted by overfishing and are managed under long-term rebuilding plans that greatly restrict fishery impacts (PFMC 2006). Two of these species, canary rockfish (Sebastes pinniger) and yelloweye rockfish (S. ruberrimus), are caught in waters off Oregon and Washington as bycatch in recreational fisheries directed at black rockfish (S. melanops), yellowtail rockfish (S. flavidus), lingcod (Ophiodon elongatus) and Pacific halibut (Hippoglossus stenolepis). Recreational fishery impacts on the depleted species are constrained primarily via seasonal restrictions on the maximum depth of fishing, area closures and a ban on retention (PFMC 2006). However, needed future reductions in allowable impacts on either species could lead to more severe fishery restrictions, including bag limit reductions and seasonal or area closures (PFMC 2006). If angling gears can be developed that capture the target species effectively but are inefficient for these two bycatch species, then bag limit reductions or closures of the recreational groundfish fishery could be avoided. The nearshore recreational fishery targeting black and blue rockfish (Sebastes mystinus) also captures several rockfish species which have not been the subject of formal stock assessments. A few of these rockfish species are long-lived and considered to be more vulnerable to overfishing than black rockfish. For example, china rockfish (Sebastes nebulosus) live to at least age 78 and tiger rockfish (S. nigrocinctus) to at least age 116 (Munk 2001). Harvest strategies that are acceptable for black and blue rockfish may result in overfishing of these sympatric rockfish species. Many of these unassessed, but vulnerable, rockfish species are also species that are most closely associated with the seafloor (Love et al. 2002). Conversely, many of the target species of the recreational fishery are more semi-pelagic in their vertical distribution, in that they are frequently found at some distance above the seafloor (Love et al. 2002). Gear-based methods that maintain catch rates for semi-pelagic rockfishes but reduce rates for more demersally oriented rockfish could therefore also be helpful in successful mixed-stock management of nearshore fisheries. In this study, we tested the hypothesis that angling gear that keeps baits farther above the bottom would reduce the relative catch rates of yelloweye, canary and several demersal rockfishes, while maintaining acceptable catch rates for the semipelagic rockfish species most commonly caught off Oregon. In this report, we use the term “semi-pelagic” to specifically refer to black, blue, yellowtail, widow and redstripe rockfish (S. proriger). We use the term “demersal” to refer to rockfishes that are believed to live in close association with rocky substrate, specifically yelloweye, china (S. nebulosus), quillback (S. maliger), greenstriped (S. elongatus) and rosethorn (S. helvomaculatus) rockfishes. Title: Reducing Bycatch in Oregon's Recreational Groundfish Fishery: Experimental Results with Angling Gear Configured to Increase Bait Height Above Bottom Information Reports number 2008-03 Abstract -- Several long-lived, late-maturing rockfish (Sebastes) species found off the U.S. west coast have been seriously depleted by overfishing and are managed under long-term rebuilding plans that greatly restrict fishery impacts (PFMC 2006). Two of these species, canary rockfish (Sebastes pinniger) and yelloweye rockfish (S. ruberrimus), are caught in waters off Oregon and Washington as bycatch in recreational fisheries directed at black rockfish (S. melanops), yellowtail rockfish (S. flavidus), lingcod (Ophiodon elongatus) and Pacific halibut (Hippoglossus stenolepis). Recreational fishery impacts on the depleted species are constrained primarily via seasonal restrictions on the maximum depth of fishing, area closures and a ban on retention (PFMC 2006). However, needed future reductions in allowable impacts on either species could lead to more severe fishery restrictions, including bag limit reductions and seasonal or area closures (PFMC 2006). If angling gears can be developed that capture the target species effectively but are inefficient for these two bycatch species, then bag limit reductions or closures of the recreational groundfish fishery could be avoided. The nearshore recreational fishery targeting black and blue rockfish (Sebastes mystinus) also captures several rockfish species which have not been the subject of formal stock assessments. A few of these rockfish species are long-lived and considered to be more vulnerable to overfishing than black rockfish. For example, china rockfish (Sebastes nebulosus) live to at least age 78 and tiger rockfish (S. nigrocinctus) to at least age 116 (Munk 2001). Harvest strategies that are acceptable for black and blue rockfish may result in overfishing of these sympatric rockfish species. Many of these unassessed, but vulnerable, rockfish species are also species that are most closely associated with the seafloor (Love et al. 2002). Conversely, many of the target species of the recreational fishery are more semi-pelagic in their vertical distribution, in that they are frequently found at some distance above the seafloor (Love et al. 2002). Gear-based methods that maintain catch rates for semi-pelagic rockfishes but reduce rates for more demersally oriented rockfish could therefore also be helpful in successful mixed-stock management of nearshore fisheries. In this study, we tested the hypothesis that angling gear that keeps baits farther above the bottom would reduce the relative catch rates of yelloweye, canary and several demersal rockfishes, while maintaining acceptable catch rates for the semipelagic rockfish species most commonly caught off Oregon. In this report, we use the term “semi-pelagic” to specifically refer to black, blue, yellowtail, widow and redstripe rockfish (S. proriger). We use the term “demersal” to refer to rockfishes that are believed to live in close association with rocky substrate, specifically yelloweye, china (S. nebulosus), quillback (S. maliger), greenstriped (S. elongatus) and rosethorn (S. helvomaculatus) rockfishes. Close

• 282. [Article] Stream Habitat Conditions in Western Oregon 2005 Monitoring Report Report Number: OPSW-ODFW-2007-5

  Abstract -- Monitoring programs under the Oregon Plan for Salmon and Watersheds were designed to assess the status and trend in fish populations and aquatic habitat in Oregon’s coastal basins. Although ...

  Citation × Citation Citation Abstract Copy Title: Stream Habitat Conditions in Western Oregon 2005 Monitoring Report Report Number: OPSW-ODFW-2007-5 Abstract -- Monitoring programs under the Oregon Plan for Salmon and Watersheds were designed to assess the status and trend in fish populations and aquatic habitat in Oregon’s coastal basins. Although the Oregon Plan for Salmon and Watersheds was initiated in response to the petition to list Oregon coastal coho salmon (Oncorhynchus kisutch) as threatened under the Endangered Species Act (ESA), monitoring was subsequently expanded to include other salmonids. Through coordinated surveys we are able to evaluate freshwater habitat, fish distribution, and abundance of juvenile and adult coho salmon and steelhead trout. The habitat survey project has the broadest geographic scope of inference and ties to other program components as well – basin surveys, surveys at habitat restoration sites, adult and juvenile coho surveys, and life cycle watersheds (Flitcroft et al. 2002). The Oregon Plan facilitated cooperation and partnerships to study the contemporary life history dynamics of coho salmon in the Oregon coastal ESU (Evolutionary Significant Unit). A viability and status assessment of Oregon coastal Coho (Chilcote 2005) and the Conservation Plan for the Oregon Coast Coho Evolutionary Significant Unit (Nicholas 2006) evaluated the relationship of aquatic habitat to the productivity of coho salmon populations and recommended actions to promote recovery. The habitat portion of the viability assessment was based on a review of aquatic and riparian habitat collected by the Aquatic Inventories Project (ODFW) from 1990 to 2004 (Rodgers et al. 2005). The authors of the habitat assessment (Rodgers et al 2005) and viability assessment (Chilcote 2005) concluded that coho productivity in 22 coastal coho populations was limited by the complexity of stream habitat used by juvenile coho during their first winter of freshwater residence. The term “stream complexity” integrates geomorphic and structural characteristics of streams and associated aquatic habitat. Complex geomorphic features may be observed in low gradient streams flowing through wide valley floors with multiple channels and off-channel habitats. Structural complexity refers to the size and configuration of pools, large wood pieces and jams, substrate, and undercut banks. The combination of geomorphic and structural features provides cover and refugia during high winter flows for juvenile coho. Stream reaches that can or have the potential to create these conditions are commonly located in lower reaches of moderate size streams in areas with wide valley floors and are considered to contain high quality habitat for juvenile coho. Burnett et al. (2007) developed spatial models to estimate high-quality habitat rearing potential, termed intrinsic potential, in coastal streams. A stream’s intrinsic potential was modeled using valley width, gradient, and stream flow. Historically, streams identified as having high intrinsic potential may have been the most productive for juvenile coho salmon; restoration of these reaches may be the key to recovery of coho salmon. The viability assessment and Coho Plan recommend that we monitor the trends in total amount and spatial distribution of these habitats in coastal drainages. This report discusses the findings from aquatic habitat surveys conducted in summer 2005 in coastal drainages. Our objectives are to describe and compare channel morphology, instream habitat and complexity, and riparian conditions in all wadeable streams in five monitoring areas. The sample design permitted us to post stratify the sample sites into three additional frames: sites within coho and steelhead distribution, sites outside coho distribution, and sites within high intrinsic potential for coho. We also used two habitat models to integrate habitat attributes to describe the habitat quality and capacity for different life stages of juvenile coho and steelhead. Title: Stream Habitat Conditions in Western Oregon 2005 Monitoring Report Report Number: OPSW-ODFW-2007-5 Abstract -- Monitoring programs under the Oregon Plan for Salmon and Watersheds were designed to assess the status and trend in fish populations and aquatic habitat in Oregon’s coastal basins. Although the Oregon Plan for Salmon and Watersheds was initiated in response to the petition to list Oregon coastal coho salmon (Oncorhynchus kisutch) as threatened under the Endangered Species Act (ESA), monitoring was subsequently expanded to include other salmonids. Through coordinated surveys we are able to evaluate freshwater habitat, fish distribution, and abundance of juvenile and adult coho salmon and steelhead trout. The habitat survey project has the broadest geographic scope of inference and ties to other program components as well – basin surveys, surveys at habitat restoration sites, adult and juvenile coho surveys, and life cycle watersheds (Flitcroft et al. 2002). The Oregon Plan facilitated cooperation and partnerships to study the contemporary life history dynamics of coho salmon in the Oregon coastal ESU (Evolutionary Significant Unit). A viability and status assessment of Oregon coastal Coho (Chilcote 2005) and the Conservation Plan for the Oregon Coast Coho Evolutionary Significant Unit (Nicholas 2006) evaluated the relationship of aquatic habitat to the productivity of coho salmon populations and recommended actions to promote recovery. The habitat portion of the viability assessment was based on a review of aquatic and riparian habitat collected by the Aquatic Inventories Project (ODFW) from 1990 to 2004 (Rodgers et al. 2005). The authors of the habitat assessment (Rodgers et al 2005) and viability assessment (Chilcote 2005) concluded that coho productivity in 22 coastal coho populations was limited by the complexity of stream habitat used by juvenile coho during their first winter of freshwater residence. The term “stream complexity” integrates geomorphic and structural characteristics of streams and associated aquatic habitat. Complex geomorphic features may be observed in low gradient streams flowing through wide valley floors with multiple channels and off-channel habitats. Structural complexity refers to the size and configuration of pools, large wood pieces and jams, substrate, and undercut banks. The combination of geomorphic and structural features provides cover and refugia during high winter flows for juvenile coho. Stream reaches that can or have the potential to create these conditions are commonly located in lower reaches of moderate size streams in areas with wide valley floors and are considered to contain high quality habitat for juvenile coho. Burnett et al. (2007) developed spatial models to estimate high-quality habitat rearing potential, termed intrinsic potential, in coastal streams. A stream’s intrinsic potential was modeled using valley width, gradient, and stream flow. Historically, streams identified as having high intrinsic potential may have been the most productive for juvenile coho salmon; restoration of these reaches may be the key to recovery of coho salmon. The viability assessment and Coho Plan recommend that we monitor the trends in total amount and spatial distribution of these habitats in coastal drainages. This report discusses the findings from aquatic habitat surveys conducted in summer 2005 in coastal drainages. Our objectives are to describe and compare channel morphology, instream habitat and complexity, and riparian conditions in all wadeable streams in five monitoring areas. The sample design permitted us to post stratify the sample sites into three additional frames: sites within coho and steelhead distribution, sites outside coho distribution, and sites within high intrinsic potential for coho. We also used two habitat models to integrate habitat attributes to describe the habitat quality and capacity for different life stages of juvenile coho and steelhead. Close

• 283. [Article] Abundance Monitoring of Juvenile Salmonids In Coastal Oregon and Lower Columbia Streams, 2008 Report Number: OPSW-ODFW-2009-1

  Abstract -- As part of the Oregon Plan for Salmon and Watersheds, the Oregon Department of Fish and Wildlife (ODFW) initiated this project in 1998 to monitor the status and trend in abundance and distribution ...

  Citation × Citation Citation Abstract Copy Title: Abundance Monitoring of Juvenile Salmonids In Coastal Oregon and Lower Columbia Streams, 2008 Report Number: OPSW-ODFW-2009-1 Abstract -- As part of the Oregon Plan for Salmon and Watersheds, the Oregon Department of Fish and Wildlife (ODFW) initiated this project in 1998 to monitor the status and trend in abundance and distribution of juvenile coho salmon (Oncorhynchus kisutch) in coastal Oregon streams. This report summarizes the data collected during the summer of 2008 and, for coho salmon, compares it to data previously collected. The project originally surveyed only 1st-3rd order (tributary) streams but was expanded in 2002 to include juvenile steelhead (Oncorhynchus mykiss) and 4th-6th order (mainstem) rearing areas and in 2006 to the Oregon portion of the Lower Columbia River coho evolutionarily significant unit (ESU) (Figure 1). The sampling frame is intended to encompass all non-tidal coho and steelhead rearing habitat. The original 100k stream layer frame was replaced by a 24k frame in 2007. A Generalized Random Tessellation Stratified design (GRTS) (Stevens 2002) was used to create a spatially balanced, random point distribution. Sites were stratified by Monitoring Area (MA) and stream order (Table 1). A detailed description of the sampling frames and survey designs are found in Jepsen and Rodgers (2004) and Jepsen and Leader (2007). Field crews snorkeled all pools meeting the size criteria (6 m2 in surface area and 40 cm in maximum depth) in one kilometer of stream encompassing the GRTS point. Snorkeling was conducted during the minimum flow period from July to September using a single pass of one to four snorkelers, depending on stream width. In each pool counts were made of juvenile coho, Chinook, steelhead 90 mm, and cutthroat 90 mm. Presence was noted for dace, shiners, and trout < 90 mm. Sites with poor water clarity or quality were electrofished using a single pass without block nets to determine presence for coho, steelhead and cutthroat in each pool. To assess repeatability and quality control supervisory staff resurveyed 10% of tributary sites in each MA. Data were summarized by MA and stream order for analyses. Average pool density and percent pool occupancy for each site was averaged by MA. The percent of sites with at least one fish and with >0.7 coho/m2 are reported for each MA. 0.7 coho/m2 is regarded as full seeding after Nickelson et al. (1992) who reported full seeding based on electrofishing as 1.0 coho/m2 and Rodgers et al. (1992) who found that snorkelers observed 70% of the coho counted by electrofishing. CDFs, variances, and confidence intervals were created using tools developed by the EMAP Design and Analysis Team (EPA 2009). Title: Abundance Monitoring of Juvenile Salmonids In Coastal Oregon and Lower Columbia Streams, 2008 Report Number: OPSW-ODFW-2009-1 Abstract -- As part of the Oregon Plan for Salmon and Watersheds, the Oregon Department of Fish and Wildlife (ODFW) initiated this project in 1998 to monitor the status and trend in abundance and distribution of juvenile coho salmon (Oncorhynchus kisutch) in coastal Oregon streams. This report summarizes the data collected during the summer of 2008 and, for coho salmon, compares it to data previously collected. The project originally surveyed only 1st-3rd order (tributary) streams but was expanded in 2002 to include juvenile steelhead (Oncorhynchus mykiss) and 4th-6th order (mainstem) rearing areas and in 2006 to the Oregon portion of the Lower Columbia River coho evolutionarily significant unit (ESU) (Figure 1). The sampling frame is intended to encompass all non-tidal coho and steelhead rearing habitat. The original 100k stream layer frame was replaced by a 24k frame in 2007. A Generalized Random Tessellation Stratified design (GRTS) (Stevens 2002) was used to create a spatially balanced, random point distribution. Sites were stratified by Monitoring Area (MA) and stream order (Table 1). A detailed description of the sampling frames and survey designs are found in Jepsen and Rodgers (2004) and Jepsen and Leader (2007). Field crews snorkeled all pools meeting the size criteria (6 m2 in surface area and 40 cm in maximum depth) in one kilometer of stream encompassing the GRTS point. Snorkeling was conducted during the minimum flow period from July to September using a single pass of one to four snorkelers, depending on stream width. In each pool counts were made of juvenile coho, Chinook, steelhead 90 mm, and cutthroat 90 mm. Presence was noted for dace, shiners, and trout < 90 mm. Sites with poor water clarity or quality were electrofished using a single pass without block nets to determine presence for coho, steelhead and cutthroat in each pool. To assess repeatability and quality control supervisory staff resurveyed 10% of tributary sites in each MA. Data were summarized by MA and stream order for analyses. Average pool density and percent pool occupancy for each site was averaged by MA. The percent of sites with at least one fish and with >0.7 coho/m2 are reported for each MA. 0.7 coho/m2 is regarded as full seeding after Nickelson et al. (1992) who reported full seeding based on electrofishing as 1.0 coho/m2 and Rodgers et al. (1992) who found that snorkelers observed 70% of the coho counted by electrofishing. CDFs, variances, and confidence intervals were created using tools developed by the EMAP Design and Analysis Team (EPA 2009). Close

• 284. [Article] Spring Chinook in the Willamette and Sandy Basins, Progress Reports 2006-2007

  Abstract -- The Willamette and Sandy rivers support intense recreational fisheries for spring Chinook salmon (Oncorhynchus tshawytscha). Fisheries in these basins rely primarily on annual hatchery releases ...

  Citation × Citation Citation Abstract Copy Title: Spring Chinook in the Willamette and Sandy Basins, Progress Reports 2006-2007 Abstract -- The Willamette and Sandy rivers support intense recreational fisheries for spring Chinook salmon (Oncorhynchus tshawytscha). Fisheries in these basins rely primarily on annual hatchery releases of 5–8 million juveniles. Hatchery programs exist in the McKenzie, Middle Fork Willamette, North and South Santiam, Clackamas, and Sandy rivers mainly as mitigation for dams that blocked natural production areas. Some natural spawning occurs in most of the major basins and a few smaller tributaries upstream of Willamette Falls. The Oregon Fish and Wildlife Commission adopted the Native Fish Conservation Policy (ODFW 2003a) and the Hatchery Management Policy (ODFW 2003b) in part to reduce adverse impacts of hatchery programs on wild native stocks. The Native Fish Conservation Policy recognizes that naturally produced native fish are the foundation for long-term sustainability of native species and hatchery programs, and the fisheries they support. Possible risks of artificial propagation programs have been well documented. Hazards include disease transfer, competition for food and spawning sites, increased predation, increased incidental mortality from harvest, loss of genetic variability, genetic drift, and domestication (Steward and Bjornn 1990; Hard et al. 1992; Cuenco et al. 1993; Busack and Currens 1995; NRC 1996; and Waples 1999). Hatcheries can also play a positive role for wild salmonids by bolstering populations, especially those on the verge of extirpation, by providing a genetic reserve as well as providing opportunities for nutrient enrichment of streams (Steward and Bjornn 1990; Cuenco et al. 1993). In the past, hatchery programs and fish passage issues were the focus of spring Chinook salmon management in the Willamette and Sandy basins. Limited information was collected on the genetic structure among basin populations, on abundance and distribution of natural spawning, on rearing and migrating of juvenile salmon, or on strategies for reducing risks that large hatchery programs pose for wild salmon populations. This study is being implemented to gather this information. A schematic of the study plan is shown in APPENDIX A. We conducted work in the main-stem Willamette River above Willamette Falls, and in the Middle Fork Willamette, McKenzie, North Santiam, South Santiam, Clackamas, and Sandy rivers in 2006 and 2007. Basin descriptions and background information on management and fish runs can be found in subbasin plans developed by the Oregon Department of Fish and Wildlife (ODFW 1988, ODFW 1992a, ODFW 1992b, and ODFW 1996). Task headings below cross reference the study plan outlined in APPENDIX A. This report covers tasks that were worked on in late 2005 through early fall 2007. Title: Spring Chinook in the Willamette and Sandy Basins, Progress Reports 2006-2007 Abstract -- The Willamette and Sandy rivers support intense recreational fisheries for spring Chinook salmon (Oncorhynchus tshawytscha). Fisheries in these basins rely primarily on annual hatchery releases of 5–8 million juveniles. Hatchery programs exist in the McKenzie, Middle Fork Willamette, North and South Santiam, Clackamas, and Sandy rivers mainly as mitigation for dams that blocked natural production areas. Some natural spawning occurs in most of the major basins and a few smaller tributaries upstream of Willamette Falls. The Oregon Fish and Wildlife Commission adopted the Native Fish Conservation Policy (ODFW 2003a) and the Hatchery Management Policy (ODFW 2003b) in part to reduce adverse impacts of hatchery programs on wild native stocks. The Native Fish Conservation Policy recognizes that naturally produced native fish are the foundation for long-term sustainability of native species and hatchery programs, and the fisheries they support. Possible risks of artificial propagation programs have been well documented. Hazards include disease transfer, competition for food and spawning sites, increased predation, increased incidental mortality from harvest, loss of genetic variability, genetic drift, and domestication (Steward and Bjornn 1990; Hard et al. 1992; Cuenco et al. 1993; Busack and Currens 1995; NRC 1996; and Waples 1999). Hatcheries can also play a positive role for wild salmonids by bolstering populations, especially those on the verge of extirpation, by providing a genetic reserve as well as providing opportunities for nutrient enrichment of streams (Steward and Bjornn 1990; Cuenco et al. 1993). In the past, hatchery programs and fish passage issues were the focus of spring Chinook salmon management in the Willamette and Sandy basins. Limited information was collected on the genetic structure among basin populations, on abundance and distribution of natural spawning, on rearing and migrating of juvenile salmon, or on strategies for reducing risks that large hatchery programs pose for wild salmon populations. This study is being implemented to gather this information. A schematic of the study plan is shown in APPENDIX A. We conducted work in the main-stem Willamette River above Willamette Falls, and in the Middle Fork Willamette, McKenzie, North Santiam, South Santiam, Clackamas, and Sandy rivers in 2006 and 2007. Basin descriptions and background information on management and fish runs can be found in subbasin plans developed by the Oregon Department of Fish and Wildlife (ODFW 1988, ODFW 1992a, ODFW 1992b, and ODFW 1996). Task headings below cross reference the study plan outlined in APPENDIX A. This report covers tasks that were worked on in late 2005 through early fall 2007. Close

• 285. [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

• 286. [Article] Preseason Report I, Stock Abundance Analysis for 1998, Ocean Salmon Fisheries

  Abstract -- This is the second report in an annual series of four reports prepared by the Salmon Technical Team (STT) of the Pacific Fishery Management Council (Council) to document and help guide salmon ...

  Citation × Citation Citation Abstract Copy Title: Preseason Report I, Stock Abundance Analysis for 1998, Ocean Salmon Fisheries Abstract -- This is the second report in an annual series of four reports prepared by the Salmon Technical Team (STT) of the Pacific Fishery Management Council (Council) to document and help guide salmon fishery management off the coasts of Washington, Oregon, and California. This report will be formally reviewed at the Council's March meeting. The third and fourth reports in this series will be developed at the close of the March and April Council meetings, respectively. They will analyze the impacts of the Council's proposed and final ocean salmon fishery management recommendations for 1998. This report provides 1998 salmon stock abundance projections and an analysis of the impacts of 1997 regulations, or regulatory procedures. The report focuses on chinook and coho stocks that have been important in determining Council fisheries in recent years. However, decisions on whether or not to propose Endangered Species Act listings for several chinook stocks ranging from central California to Puget Sound are anticipated in the near future. In the event that the National Marine Fisheries Service proposes new listings, information concerning the status of these stocks may significantly affect Council deliberations on the final salmon fishing seasons. Chapter I provides a summary of the 1998 stock abundance projections. Chapters II and Ill provide detailed stock-by-stock analyses of abundance and a description of prediction methodology and accuracy of past abundance predictions for chinook and coho salmon, respectively. Chapter IV summarizes abundance information for pink salmon. Four appendices provide supplementary information as follows: Appendix A provides a summary of Council stock management goals; Appendix 8 contains pertinent data for Oregon production index (OPI) area coho; Appendix C provides historical salmon catch data for the Cape Flattery and Strait of Juan de Fuca areas; and Appendix D contains the Council's current harvest allocation schedules. Summaries of preseason and postseason abundance estimates are included in: • Table 11-2 for Central Valley Index fall chinqok since 1985; • Table 11-4 for Klamath River fall chinook since 1985; • Table 11-8 for selected Columbia River fall chinook stocks since 1984; • Table 11-9 for Puget Sound summer/fall chinook stocks since 1993; • Table 111-1 for OPI area produced coho stocks since 1992 and • Table 111-3 for selected naturally spawning Puget Sound and Washington coastal coho stocks since 1984. Differences between preseason and postseason estimates are caused by a number of factors, including: (1) inaccuracies in abundance forecasts for these and other stocks which are exploited by mixed stock fisheries, (2) deviations of actual catches and fishery patterns from preseason expectations, (3) anomalies in stock distribution and migration patterns, and (4) for the Puget Sound coho stocks, differences in assessment methodologies (postseason estimates are based on run reconstruction assumptions which differ substantially from those represented in the Fishery Regulatory Assessment Model). The STT has not been able to complete a proper evaluation of abundance estimates which would take all these factors into account. Title: Preseason Report I, Stock Abundance Analysis for 1998, Ocean Salmon Fisheries Abstract -- This is the second report in an annual series of four reports prepared by the Salmon Technical Team (STT) of the Pacific Fishery Management Council (Council) to document and help guide salmon fishery management off the coasts of Washington, Oregon, and California. This report will be formally reviewed at the Council's March meeting. The third and fourth reports in this series will be developed at the close of the March and April Council meetings, respectively. They will analyze the impacts of the Council's proposed and final ocean salmon fishery management recommendations for 1998. This report provides 1998 salmon stock abundance projections and an analysis of the impacts of 1997 regulations, or regulatory procedures. The report focuses on chinook and coho stocks that have been important in determining Council fisheries in recent years. However, decisions on whether or not to propose Endangered Species Act listings for several chinook stocks ranging from central California to Puget Sound are anticipated in the near future. In the event that the National Marine Fisheries Service proposes new listings, information concerning the status of these stocks may significantly affect Council deliberations on the final salmon fishing seasons. Chapter I provides a summary of the 1998 stock abundance projections. Chapters II and Ill provide detailed stock-by-stock analyses of abundance and a description of prediction methodology and accuracy of past abundance predictions for chinook and coho salmon, respectively. Chapter IV summarizes abundance information for pink salmon. Four appendices provide supplementary information as follows: Appendix A provides a summary of Council stock management goals; Appendix 8 contains pertinent data for Oregon production index (OPI) area coho; Appendix C provides historical salmon catch data for the Cape Flattery and Strait of Juan de Fuca areas; and Appendix D contains the Council's current harvest allocation schedules. Summaries of preseason and postseason abundance estimates are included in: • Table 11-2 for Central Valley Index fall chinqok since 1985; • Table 11-4 for Klamath River fall chinook since 1985; • Table 11-8 for selected Columbia River fall chinook stocks since 1984; • Table 11-9 for Puget Sound summer/fall chinook stocks since 1993; • Table 111-1 for OPI area produced coho stocks since 1992 and • Table 111-3 for selected naturally spawning Puget Sound and Washington coastal coho stocks since 1984. Differences between preseason and postseason estimates are caused by a number of factors, including: (1) inaccuracies in abundance forecasts for these and other stocks which are exploited by mixed stock fisheries, (2) deviations of actual catches and fishery patterns from preseason expectations, (3) anomalies in stock distribution and migration patterns, and (4) for the Puget Sound coho stocks, differences in assessment methodologies (postseason estimates are based on run reconstruction assumptions which differ substantially from those represented in the Fishery Regulatory Assessment Model). The STT has not been able to complete a proper evaluation of abundance estimates which would take all these factors into account. Close

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

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

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

• 288. [Article] Willamette Biological Opinion Hatchery Research 2010 Annual Report

  Abstract -- Task 1.1: Distribution, Abundance, and Proportion of Hatchery and Natural-Origin Chinook Salmon: Counts of spring Chinook redds were similar in 2010 compared to the 2002–2009 averages for the ...

  Citation × Citation Citation Abstract Copy Title: Willamette Biological Opinion Hatchery Research 2010 Annual Report Abstract -- Task 1.1: Distribution, Abundance, and Proportion of Hatchery and Natural-Origin Chinook Salmon: Counts of spring Chinook redds were similar in 2010 compared to the 2002–2009 averages for the Middle Fork Willamette, McKenzie and the North Santiam rivers and significantly higher in the South Santiam River Preliminary analyses indicate that the proportions of hatchery fish recovered as carcasses from the spawning grounds varied significantly among all four surveyed sub-basins (South Santiam > M. Fork Willamette > North Santiam > McKenzie) Task 1.2: Monitor fin-clipped & unclipped fish passing Leaburg and Upper Bennett dams. Adult fish passage at Leaburg and Upper Bennett dams was continuously monitored in 2010. We estimated that 2,696 spring Chinook (52% unclipped) passed above Leaburg Dam and 5,956 passed above upper Bennett Dam (14% unclipped). Passage at Leaburg Dam of fin-clipped fish was strongly bimodal with peaks in June (coincident with passage of the majority of unclipped fish) and September (coincident with a smaller proportion of unclipped fish). This bimodal peak suggests that hatchery fish might be removed in September to reduce the proportion of hatchery origin spawners while simultaneously reducing the impacts of handling wild fish. Task 2.1: Collection, spawn timing, and Hatchery/Wild (H/W ) composition for broodstock management. Collection, spawn timing, and H/W composition for broodstock management were successfully monitored at all facilities in 2010. Task 2.2: Determine Survival of Outplanted Fish and Abundance of Spawners. Patterns of pre-spawning mortality were similar to results in 2009 with mortality below project dams significantly higher than that above project dams. We did not detect significant differences in mortality between clipped and unclipped spring Chinook. In comparisons of pre-spawning mortality among sub-basins above project dams, pre-spawning mortality was uniformly low in the Breitenbush and N. Santiam above Detroit, S. Santiam above Foster, and in the S. Fork McKenzie. Pre-spawning mortality was uniformly higher above project dams in the N. Fork Mid. Fork Willamette, Fall Creek and the Little N. Fork Santiam. No comprehensive surveys were conducted in the Middle Fork Willamette. Task 3.1: Determine the extent of summer steelhead reproduction in the wild: We developed a formal study plan to analyze and interpret genetic results from a collection of 299 tissue samples from unclipped juvenile steelhead at Willamette Falls, five from the mainstem Willamette River, and two from the South Santiam River in 2010 in addition to a single sample from an unclipped adult steelhead at the Minto fish collection facility. Samples were preserved 7 and cataloged and then shipped to the NOAA Fisheries Manchester, Washington (WA) laboratory for analysis. Task 3.2: Evaluate release strategies for summer steelhead to increase migration and reduce impacts on wild fish. Study plans to evaluate advantages and disadvantages of volitional release strategies were completed and presented in the 2009 annual report to USACE (Cannon et al. 2010). Funding to process the tissue samples was not available in 2010, and no progress was made in executing the proposed work. Title: Willamette Biological Opinion Hatchery Research 2010 Annual Report Abstract -- Task 1.1: Distribution, Abundance, and Proportion of Hatchery and Natural-Origin Chinook Salmon: Counts of spring Chinook redds were similar in 2010 compared to the 2002–2009 averages for the Middle Fork Willamette, McKenzie and the North Santiam rivers and significantly higher in the South Santiam River Preliminary analyses indicate that the proportions of hatchery fish recovered as carcasses from the spawning grounds varied significantly among all four surveyed sub-basins (South Santiam > M. Fork Willamette > North Santiam > McKenzie) Task 1.2: Monitor fin-clipped & unclipped fish passing Leaburg and Upper Bennett dams. Adult fish passage at Leaburg and Upper Bennett dams was continuously monitored in 2010. We estimated that 2,696 spring Chinook (52% unclipped) passed above Leaburg Dam and 5,956 passed above upper Bennett Dam (14% unclipped). Passage at Leaburg Dam of fin-clipped fish was strongly bimodal with peaks in June (coincident with passage of the majority of unclipped fish) and September (coincident with a smaller proportion of unclipped fish). This bimodal peak suggests that hatchery fish might be removed in September to reduce the proportion of hatchery origin spawners while simultaneously reducing the impacts of handling wild fish. Task 2.1: Collection, spawn timing, and Hatchery/Wild (H/W ) composition for broodstock management. Collection, spawn timing, and H/W composition for broodstock management were successfully monitored at all facilities in 2010. Task 2.2: Determine Survival of Outplanted Fish and Abundance of Spawners. Patterns of pre-spawning mortality were similar to results in 2009 with mortality below project dams significantly higher than that above project dams. We did not detect significant differences in mortality between clipped and unclipped spring Chinook. In comparisons of pre-spawning mortality among sub-basins above project dams, pre-spawning mortality was uniformly low in the Breitenbush and N. Santiam above Detroit, S. Santiam above Foster, and in the S. Fork McKenzie. Pre-spawning mortality was uniformly higher above project dams in the N. Fork Mid. Fork Willamette, Fall Creek and the Little N. Fork Santiam. No comprehensive surveys were conducted in the Middle Fork Willamette. Task 3.1: Determine the extent of summer steelhead reproduction in the wild: We developed a formal study plan to analyze and interpret genetic results from a collection of 299 tissue samples from unclipped juvenile steelhead at Willamette Falls, five from the mainstem Willamette River, and two from the South Santiam River in 2010 in addition to a single sample from an unclipped adult steelhead at the Minto fish collection facility. Samples were preserved 7 and cataloged and then shipped to the NOAA Fisheries Manchester, Washington (WA) laboratory for analysis. Task 3.2: Evaluate release strategies for summer steelhead to increase migration and reduce impacts on wild fish. Study plans to evaluate advantages and disadvantages of volitional release strategies were completed and presented in the 2009 annual report to USACE (Cannon et al. 2010). Funding to process the tissue samples was not available in 2010, and no progress was made in executing the proposed work. Close

• 289. [Article] Willamette BiOp - Genetic Stock Identification and Relative Natural Production of Willamette River Steelhead

  Abstract -- We used genotypic data from 15 microsatellite loci to characterize the stock structure of Oncorhynchus mykiss in the upper Willamette River basin. We then used two analytical approaches, implemented ...

  Citation × Citation Citation Abstract Copy Title: Willamette BiOp - Genetic Stock Identification and Relative Natural Production of Willamette River Steelhead Abstract -- We used genotypic data from 15 microsatellite loci to characterize the stock structure of Oncorhynchus mykiss in the upper Willamette River basin. We then used two analytical approaches, implemented in the programs ONCOR and STRUCTURE, to assign (presumably) natural-origin, unmarked fish to their most likely reporting group or hybrid class. We investigated sibling relationships among unknown samples with the program ML RELATE. In the upper Willamette River, O. mykiss genetic structure can be characterized by four principal groups: summer steelhead of Skamania stock ancestry, eastern tributaries winter steelhead, western tributaries winter steelhead and resident rainbow trout. We found that about 10% of unmarked juvenile O. mykiss sampled at Willamette Falls in 2009-2011 were summer steelhead and that an additional 10% of samples were summer x winter steelhead hybrids. Most O. mykiss sampled from the McKenzie River were either summer steelhead or summer x winter steelhead hybrids. Natural production of pure summer steelhead appeared to be very low in the North and South Santiam rivers, though summer steelhead hybrids represented 11.1% and 14.8% of samples. Results from ML RELATE analyses appeared unreliable and inconclusive, and may have been limited by low genetic diversity among summer steelhead samples. We provide several recommendations to better understand and reduce potentially negative interactions between hatchery summer steelhead and native upper Willamette River O. mykiss populations. These include reductions in adult steelhead on natural spawning grounds, improved reproductive isolation between hatchery and native populations and additional research to evaluate genetic integrity within and among O. mykiss populations. Title: Willamette BiOp - Genetic Stock Identification and Relative Natural Production of Willamette River Steelhead Abstract -- We used genotypic data from 15 microsatellite loci to characterize the stock structure of Oncorhynchus mykiss in the upper Willamette River basin. We then used two analytical approaches, implemented in the programs ONCOR and STRUCTURE, to assign (presumably) natural-origin, unmarked fish to their most likely reporting group or hybrid class. We investigated sibling relationships among unknown samples with the program ML RELATE. In the upper Willamette River, O. mykiss genetic structure can be characterized by four principal groups: summer steelhead of Skamania stock ancestry, eastern tributaries winter steelhead, western tributaries winter steelhead and resident rainbow trout. We found that about 10% of unmarked juvenile O. mykiss sampled at Willamette Falls in 2009-2011 were summer steelhead and that an additional 10% of samples were summer x winter steelhead hybrids. Most O. mykiss sampled from the McKenzie River were either summer steelhead or summer x winter steelhead hybrids. Natural production of pure summer steelhead appeared to be very low in the North and South Santiam rivers, though summer steelhead hybrids represented 11.1% and 14.8% of samples. Results from ML RELATE analyses appeared unreliable and inconclusive, and may have been limited by low genetic diversity among summer steelhead samples. We provide several recommendations to better understand and reduce potentially negative interactions between hatchery summer steelhead and native upper Willamette River O. mykiss populations. These include reductions in adult steelhead on natural spawning grounds, improved reproductive isolation between hatchery and native populations and additional research to evaluate genetic integrity within and among O. mykiss populations. Close

• 290. [Article] Oregon North Coast Spring Chinook Stock Assessment – 2005-06 Information Reports 2008-01

  Abstract -- Chinook salmon populations of the Oregon coast exhibit two general life history types, classified as either spring-run or fall-run depending on adult life-history traits. Fall chinook are present ...

  Citation × Citation Citation Abstract Copy Title: Oregon North Coast Spring Chinook Stock Assessment – 2005-06 Information Reports 2008-01 Abstract -- Chinook salmon populations of the Oregon coast exhibit two general life history types, classified as either spring-run or fall-run depending on adult life-history traits. Fall chinook are present in most Oregon coastal basins, and the Oregon Department of Fish and Wildlife (ODFW) has identified 28 fall chinook populations in this area (ODFW 2005). Spring chinook salmon are found in larger river basins on the Oregon coast, and the upper portions of the Umpqua and Rogue rivers. This is a more limited distribution than coastal fall chinook and includes only 10 populations (ODFW 2005). Oregon coastal fall chinook stocks have been monitored through a set of 56 standard spawning ground surveys, many conducted since the 1950’s. There has not been a similar, consistent, coast-wide monitoring program for Oregon coastal spring chinook spawners. Abundance of these populations has been monitoring through a variety of methods including; freshwater harvest estimates, counts at dams and weirs, summer resting hole counts, and spawning ground surveys. In 1998, the National Marine Fisheries Service (NMFS) reviewed west coast chinook salmon populations in regards to status under the Federal Endangered Species Act (ESA). The NMFS identified a total of 15 Evolutionarily Significant Units (ESUs) of chinook salmon (Myers et al. 1998). Oregon coastal chinook are predominantly in the Oregon Coast ESU (Necanicum River to Elk River). This ESU includes both spring and fall chinook, and was determined to not warrant listing (Federal Register Notice 1998). In 2005, ODFW conducted a review of Oregon native fish status, in regards to the State’s Native Fish Conservation Policy. This review grouped populations by Species Management Unit (SMU), and examined coastal spring and fall chinook populations separately. The review determined the near-term sustainability of the Coastal Fall Chinook SMU was not at risk, but the Coastal Spring Chinook SMU was at risk (ODFW 2005). The Tillamook and Nestucca spring chinook populations were of particular concern because they failed to pass the interim criteria for abundance, productivity, and reproductive independence. Hatchery supplementation of spring chinook has occurred in the Tillamook and Nestucca basins since the early 1900’s. Currently, approximately 450,000 spring chinook smolts are released annually from Trask Hatchery, Cedar Creek Hatchery (Nestucca), and from a STEP program at Whiskey Creek. These hatchery smolts have been mass marked with an adipose fin clip since the 1998 brood year. Therefore, hatchery origin adult spring chinook may now be positively identified by the lack of an adipose fin. Declining trends in wild coastal spring chinook populations have resulted in management actions to target harvest on adipose fin clipped hatchery fish, and to restrict harvest of wild origin fish. Results of status reviews, and changes in management practices have required a more thorough evaluation of stock status for the Tillamook and Nestucca spring chinook populations (Keith Braun, personal communication). Therefore, ODFW developed a monitoring plan for spring chinook in these basins. The monitoring plan identified four project objectives; 1) Determine adult spring chinook abundance in the Trask, Wilson, and Nestucca Rivers, 2) Determine hatchery vs. wild ratios for these three basins, 3) Determine age structure and sex ratios for adult spawners, and 4) Determine distribution and abundance for spring chinook recycled from local ODFW hatcheries. This project began in 2004 with an exploratory season to determine distribution, survey methodology, and feasibility of the proposed protocol. In 2005 and 2006 a more intensive sampling effort was implemented, designed to cover the entire distribution of spring chinook spawning in the Nestucca, Trask, and Wilson rivers. Since 2004, project field work has been funded with Restoration and Enhancement Program (R&E) funds, administered by Oregon Department of Fish and Wildlife. Project administration is covered through existing funding for the ODFW Oregon Adult Salmonid Inventory and Sampling Project (OASIS). Funding from R&E is scheduled to continue through the 2008 spawning season. Further monitoring will require a new funding source for project field work. This report documents results for project Objectives 1 to 4, including the abundance and distribution of spring chinook spawners during 2005 and 2006 in Oregon’s Trask, Wilson, and Nestucca river basins. Title: Oregon North Coast Spring Chinook Stock Assessment – 2005-06 Information Reports 2008-01 Abstract -- Chinook salmon populations of the Oregon coast exhibit two general life history types, classified as either spring-run or fall-run depending on adult life-history traits. Fall chinook are present in most Oregon coastal basins, and the Oregon Department of Fish and Wildlife (ODFW) has identified 28 fall chinook populations in this area (ODFW 2005). Spring chinook salmon are found in larger river basins on the Oregon coast, and the upper portions of the Umpqua and Rogue rivers. This is a more limited distribution than coastal fall chinook and includes only 10 populations (ODFW 2005). Oregon coastal fall chinook stocks have been monitored through a set of 56 standard spawning ground surveys, many conducted since the 1950’s. There has not been a similar, consistent, coast-wide monitoring program for Oregon coastal spring chinook spawners. Abundance of these populations has been monitoring through a variety of methods including; freshwater harvest estimates, counts at dams and weirs, summer resting hole counts, and spawning ground surveys. In 1998, the National Marine Fisheries Service (NMFS) reviewed west coast chinook salmon populations in regards to status under the Federal Endangered Species Act (ESA). The NMFS identified a total of 15 Evolutionarily Significant Units (ESUs) of chinook salmon (Myers et al. 1998). Oregon coastal chinook are predominantly in the Oregon Coast ESU (Necanicum River to Elk River). This ESU includes both spring and fall chinook, and was determined to not warrant listing (Federal Register Notice 1998). In 2005, ODFW conducted a review of Oregon native fish status, in regards to the State’s Native Fish Conservation Policy. This review grouped populations by Species Management Unit (SMU), and examined coastal spring and fall chinook populations separately. The review determined the near-term sustainability of the Coastal Fall Chinook SMU was not at risk, but the Coastal Spring Chinook SMU was at risk (ODFW 2005). The Tillamook and Nestucca spring chinook populations were of particular concern because they failed to pass the interim criteria for abundance, productivity, and reproductive independence. Hatchery supplementation of spring chinook has occurred in the Tillamook and Nestucca basins since the early 1900’s. Currently, approximately 450,000 spring chinook smolts are released annually from Trask Hatchery, Cedar Creek Hatchery (Nestucca), and from a STEP program at Whiskey Creek. These hatchery smolts have been mass marked with an adipose fin clip since the 1998 brood year. Therefore, hatchery origin adult spring chinook may now be positively identified by the lack of an adipose fin. Declining trends in wild coastal spring chinook populations have resulted in management actions to target harvest on adipose fin clipped hatchery fish, and to restrict harvest of wild origin fish. Results of status reviews, and changes in management practices have required a more thorough evaluation of stock status for the Tillamook and Nestucca spring chinook populations (Keith Braun, personal communication). Therefore, ODFW developed a monitoring plan for spring chinook in these basins. The monitoring plan identified four project objectives; 1) Determine adult spring chinook abundance in the Trask, Wilson, and Nestucca Rivers, 2) Determine hatchery vs. wild ratios for these three basins, 3) Determine age structure and sex ratios for adult spawners, and 4) Determine distribution and abundance for spring chinook recycled from local ODFW hatcheries. This project began in 2004 with an exploratory season to determine distribution, survey methodology, and feasibility of the proposed protocol. In 2005 and 2006 a more intensive sampling effort was implemented, designed to cover the entire distribution of spring chinook spawning in the Nestucca, Trask, and Wilson rivers. Since 2004, project field work has been funded with Restoration and Enhancement Program (R&E) funds, administered by Oregon Department of Fish and Wildlife. Project administration is covered through existing funding for the ODFW Oregon Adult Salmonid Inventory and Sampling Project (OASIS). Funding from R&E is scheduled to continue through the 2008 spawning season. Further monitoring will require a new funding source for project field work. This report documents results for project Objectives 1 to 4, including the abundance and distribution of spring chinook spawners during 2005 and 2006 in Oregon’s Trask, Wilson, and Nestucca river basins. Close