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• 21. [Article] Early Ocean Dispersal Patterns of Columbia River Chinook and Coho Salmon

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Taylor ...

  Citation × Citation Citation Abstract Copy Title: Early Ocean Dispersal Patterns of Columbia River Chinook and Coho Salmon Author: Orsi, J. A., Morris, J. F. T., Teel, D. J., Farley, E. V., Jr., Weitkamp, L. A., Trudel, M., Fisher, J. P., Sweeting, R. M., Hinton, S. A., Thiess, M. E. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Taylor & Francis and can be found at: http://www.tandfonline.com/toc/utaf20/current#.Uz8B2_Pn-Hs. Title: Early Ocean Dispersal Patterns of Columbia River Chinook and Coho Salmon Author: Orsi, J. A., Morris, J. F. T., Teel, D. J., Farley, E. V., Jr., Weitkamp, L. A., Trudel, M., Fisher, J. P., Sweeting, R. M., Hinton, S. A., Thiess, M. E. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Taylor & Francis and can be found at: http://www.tandfonline.com/toc/utaf20/current#.Uz8B2_Pn-Hs. Close

• 22. [Article] Innate and adaptive immune responses in migrating spring-run adult chinook salmon, Oncorhynchus tshawytscha

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier ...

  Citation × Citation Citation Abstract Copy Title: Innate and adaptive immune responses in migrating spring-run adult chinook salmon, Oncorhynchus tshawytscha Author: Schreck, Carl B., Kent, Michael L., Dolan, Brian P., Colvin, Michael E., Fisher, Kathleen M., Benda, Susan E., Peterson, James T. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/fish-and-shellfish-immunology/ Title: Innate and adaptive immune responses in migrating spring-run adult chinook salmon, Oncorhynchus tshawytscha Author: Schreck, Carl B., Kent, Michael L., Dolan, Brian P., Colvin, Michael E., Fisher, Kathleen M., Benda, Susan E., Peterson, James T. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/fish-and-shellfish-immunology/ Close

• 23. [Article] Relationships among juvenile anadromous salmonids, their freshwater habitat, and landscape characteristics over multiple years and spatial scales in the Elk River, Oregon

  Research on the distribution of juvenile salmonids in streams has been dominated by studies examining small areas over short periods. However, information relevant to freshwater influences on population ...

  Citation × Citation Citation Abstract Copy Title: Relationships among juvenile anadromous salmonids, their freshwater habitat, and landscape characteristics over multiple years and spatial scales in the Elk River, Oregon Author: Burnett, Kelly M. Research on the distribution of juvenile salmonids in streams has been dominated by studies examining small areas over short periods. However, information relevant to freshwater influences on population persistence is likely to derive from longer-term, multi-scale studies. Relationships were examined among juvenile anadromous salmonids, their freshwater habitat, and landscape characteristics throughout the Elk River, Oregon over 7 years at multiple spatial scales. Ocean-type chinook salmon (Oncorhynchus tshawytscha), coho salmon (0. kisutch), coastal cutthroat trout (0. clarki) and winter-run steelhead (0. mykiss) comprised the salmonid assemblage. Habitat selection was quantified at stream system, valley segment, and channel unit scales by selection ratios estimated with bootstrapping methods. Unconstrained valleys in tributaries and pools in the mainstem were typically selected by each species except steelhead, which often avoided these. Valley segment types generally did not differ for characteristics routinely assessed in stream surveys. Thus, fish probably perceived other biotic or abiotic differences among valley segment types. Evidence suggested competition may have influenced selection by coho and chinook salmon. Discriminant analysis indicated that level of use by juvenile chinook salmon appeared related to valley segment type and spatial position. Unconstrained valleys, nearby valley segments, and valley segments with larger, deeper pools, containing more wood were most highly used by chinook salmon. Mean volume and maximum depth of pools were each directly related to catchment area, which explained more variation than landscape characteristics summarized at any of five spatial scales. At each scale except the most spatially extensive, wood density in valley segments was negatively related to the percent area in resistant rock types and positively related to the percent area in mature to old forests. The most variation was explained with these landscape variables summarized at an intermediate spatial scale (i.e., sub-catchment). Although spatial scales appeared similar in processes affecting wood density, finer scales omitted key source areas for wood delivery, and coarser scales included source areas less tightly coupled to wood dynamics in surveyed channels. If only 1 or 2 years of data or one spatial scale had been examined, as commonly occurs, conclusions may have differed substantially from those in this study. Title: Relationships among juvenile anadromous salmonids, their freshwater habitat, and landscape characteristics over multiple years and spatial scales in the Elk River, Oregon Author: Burnett, Kelly M. Research on the distribution of juvenile salmonids in streams has been dominated by studies examining small areas over short periods. However, information relevant to freshwater influences on population persistence is likely to derive from longer-term, multi-scale studies. Relationships were examined among juvenile anadromous salmonids, their freshwater habitat, and landscape characteristics throughout the Elk River, Oregon over 7 years at multiple spatial scales. Ocean-type chinook salmon (Oncorhynchus tshawytscha), coho salmon (0. kisutch), coastal cutthroat trout (0. clarki) and winter-run steelhead (0. mykiss) comprised the salmonid assemblage. Habitat selection was quantified at stream system, valley segment, and channel unit scales by selection ratios estimated with bootstrapping methods. Unconstrained valleys in tributaries and pools in the mainstem were typically selected by each species except steelhead, which often avoided these. Valley segment types generally did not differ for characteristics routinely assessed in stream surveys. Thus, fish probably perceived other biotic or abiotic differences among valley segment types. Evidence suggested competition may have influenced selection by coho and chinook salmon. Discriminant analysis indicated that level of use by juvenile chinook salmon appeared related to valley segment type and spatial position. Unconstrained valleys, nearby valley segments, and valley segments with larger, deeper pools, containing more wood were most highly used by chinook salmon. Mean volume and maximum depth of pools were each directly related to catchment area, which explained more variation than landscape characteristics summarized at any of five spatial scales. At each scale except the most spatially extensive, wood density in valley segments was negatively related to the percent area in resistant rock types and positively related to the percent area in mature to old forests. The most variation was explained with these landscape variables summarized at an intermediate spatial scale (i.e., sub-catchment). Although spatial scales appeared similar in processes affecting wood density, finer scales omitted key source areas for wood delivery, and coarser scales included source areas less tightly coupled to wood dynamics in surveyed channels. If only 1 or 2 years of data or one spatial scale had been examined, as commonly occurs, conclusions may have differed substantially from those in this study. Close

• 24. [Article] Regions to streams : spatial and temporal variation in stream occupancy patterns of coho salmon (Oncorhynchus kisutch) on the Oregon coast

  Aquatic ecological investigation is expanding to encompass considerations of multiple scales across large landscapes. Much of the analysis included in this work focuses specifically on coho salmon (Oncorhynchus ...

  Citation × Citation Citation Abstract Copy Title: Regions to streams : spatial and temporal variation in stream occupancy patterns of coho salmon (Oncorhynchus kisutch) on the Oregon coast Author: Flitcroft, Rebecca L. Aquatic ecological investigation is expanding to encompass considerations of multiple scales across large landscapes. Much of the analysis included in this work focuses specifically on coho salmon (Oncorhynchus kisutch) in multiple subbasins on the Oregon coast. Coho salmon were chosen for an investigation of spatial scales, network connections, and life history stages due to their broad distribution on the Oregon coast, and abundant data describing their distribution, habitat needs, behavior, and survival. Chapter 2 introduces dynamic network topology (DNT) as a framework for analysis and interpretation of aquatic obligate species. DNT is based on the premise that in-stream habitats change in form and organization over time, and native aquatic species are adapted to those changes through movement and life history diversity. Chapter 3 analyzes juvenile coho salmon density and stream network occupancy at three spatial scales (site, patch, and subbasin). The site scale analysis indicated that combining network and traditional in-stream habitat metrics (i.e., substrate and habitat juxtaposition variables) are most effective at describing juvenile coho salmon density. Patch sizes of juvenile coho salmon were defined using variograms. Variogram shape indicated that a nested spatial structure may be present in larger subbasins, indicating overlapping patterns of juvenile stream use. At the subbasin scale, stream network occupancy by juvenile coho salmon was shown to vary over time within subbasins, and appeared to increase or decrease similarly to the size of the adult spawning run. In chapter 3, two-tier Bayesian hierarchical models were applied to adult (subbasin and basin scales) and juvenile (site and subbasin scales) coho salmon in an attempt to combine spatial scales that might be influential at each life history stage. The best fitting adult model included the percent of large trees in the riparian zone at the subbasin scale with mean annual precipitation at the basin scale. The best fitting juvenile model included three variables, percent sand, stream order, and network distance to spawning habitat which mirrors the result of modeling efforts in Chapter 3. Multiple spatial scales and the framework of a stream network were informative at detecting patterns and interactions among scales and life history stages of coho salmon. Title: Regions to streams : spatial and temporal variation in stream occupancy patterns of coho salmon (Oncorhynchus kisutch) on the Oregon coast Author: Flitcroft, Rebecca L. Aquatic ecological investigation is expanding to encompass considerations of multiple scales across large landscapes. Much of the analysis included in this work focuses specifically on coho salmon (Oncorhynchus kisutch) in multiple subbasins on the Oregon coast. Coho salmon were chosen for an investigation of spatial scales, network connections, and life history stages due to their broad distribution on the Oregon coast, and abundant data describing their distribution, habitat needs, behavior, and survival. Chapter 2 introduces dynamic network topology (DNT) as a framework for analysis and interpretation of aquatic obligate species. DNT is based on the premise that in-stream habitats change in form and organization over time, and native aquatic species are adapted to those changes through movement and life history diversity. Chapter 3 analyzes juvenile coho salmon density and stream network occupancy at three spatial scales (site, patch, and subbasin). The site scale analysis indicated that combining network and traditional in-stream habitat metrics (i.e., substrate and habitat juxtaposition variables) are most effective at describing juvenile coho salmon density. Patch sizes of juvenile coho salmon were defined using variograms. Variogram shape indicated that a nested spatial structure may be present in larger subbasins, indicating overlapping patterns of juvenile stream use. At the subbasin scale, stream network occupancy by juvenile coho salmon was shown to vary over time within subbasins, and appeared to increase or decrease similarly to the size of the adult spawning run. In chapter 3, two-tier Bayesian hierarchical models were applied to adult (subbasin and basin scales) and juvenile (site and subbasin scales) coho salmon in an attempt to combine spatial scales that might be influential at each life history stage. The best fitting adult model included the percent of large trees in the riparian zone at the subbasin scale with mean annual precipitation at the basin scale. The best fitting juvenile model included three variables, percent sand, stream order, and network distance to spawning habitat which mirrors the result of modeling efforts in Chapter 3. Multiple spatial scales and the framework of a stream network were informative at detecting patterns and interactions among scales and life history stages of coho salmon. Close

• 25. [Article] Distribution, Stock Composition and Timing, and Tagging Response of Wild Chinook Salmon Returning to a Large, Free-Flowing River Basin

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the American Fisheries ...

  Citation × Citation Citation Abstract Copy Title: Distribution, Stock Composition and Timing, and Tagging Response of Wild Chinook Salmon Returning to a Large, Free-Flowing River Basin Author: Schreck, Carl B., Spencer, Ted R., Eiler, John H., Driscoll, Richard J., Masuda, Michele M. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the American Fisheries Society and published by Taylor & Francis. It can be found at: http://www.tandfonline.com/loi/utaf20#.VLRgimN_t8E. Title: Distribution, Stock Composition and Timing, and Tagging Response of Wild Chinook Salmon Returning to a Large, Free-Flowing River Basin Author: Schreck, Carl B., Spencer, Ted R., Eiler, John H., Driscoll, Richard J., Masuda, Michele M. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the American Fisheries Society and published by Taylor & Francis. It can be found at: http://www.tandfonline.com/loi/utaf20#.VLRgimN_t8E. Close

• 26. [Article] An economic analysis of alternative water allocations and habitat investments for anadromous fish production, John Day Basin, Oregon

  This thesis focuses on the economic efficiency of alternative habitat, streamfiow, and land use allocations within a major drainage of the Pacific Northwest. Specifically, productivity of present habitat and ...

  Citation × Citation Citation Abstract Copy Title: An economic analysis of alternative water allocations and habitat investments for anadromous fish production, John Day Basin, Oregon Author: Cerda, Arcadio Alberto This thesis focuses on the economic efficiency of alternative habitat, streamfiow, and land use allocations within a major drainage of the Pacific Northwest. Specifically, productivity of present habitat and streamfiow conditions is evaluated with respect to anadromous fish species (chinook salmon and steelhead trout) in the John Day River Basin, a high-desert system in the Pacific Northwest. Alternative water allocations and fish habitat enhancements to improve anadromous fish productivity are also examined. This biophysical information is combined with economics concepts to evaluate comparative benefits and economic efficiency of selected technically feasible habitat/streamflow alternatives. The John Day River Basin is used as a case study because it provides one of the most significant runs of wild summer steelhead trout and spring chinook salmon in the Columbia River Basin. Specific categories of alternative enhancements included water transfers to instream flow, habitat vegetation improvements, and habitat structural measures. The benefits of changes in fish numbers are valued through the travel cost method. Costs of habitat investments are derived from a synthesis of cost data for similar investments for the region. For most lower-reach stream sections, benefits of habitat investments/streamflow alternatives do not equal costs. However, changes in water allocations and habitat do appear economically efficient to some upper reaches. The main results suggest that economic efficiency varies greatly within the system, indicating the need for site-specific proposals for streamfiow or habitat alterations within this or similar high desert streams. In addition to providing preliminary estimates of the economic efficency of streamfiow and habitat investments, this thesis serves as a methodological template for future integrated bioeconomic evaluations of water and fishery management issues. Title: An economic analysis of alternative water allocations and habitat investments for anadromous fish production, John Day Basin, Oregon Author: Cerda, Arcadio Alberto This thesis focuses on the economic efficiency of alternative habitat, streamfiow, and land use allocations within a major drainage of the Pacific Northwest. Specifically, productivity of present habitat and streamfiow conditions is evaluated with respect to anadromous fish species (chinook salmon and steelhead trout) in the John Day River Basin, a high-desert system in the Pacific Northwest. Alternative water allocations and fish habitat enhancements to improve anadromous fish productivity are also examined. This biophysical information is combined with economics concepts to evaluate comparative benefits and economic efficiency of selected technically feasible habitat/streamflow alternatives. The John Day River Basin is used as a case study because it provides one of the most significant runs of wild summer steelhead trout and spring chinook salmon in the Columbia River Basin. Specific categories of alternative enhancements included water transfers to instream flow, habitat vegetation improvements, and habitat structural measures. The benefits of changes in fish numbers are valued through the travel cost method. Costs of habitat investments are derived from a synthesis of cost data for similar investments for the region. For most lower-reach stream sections, benefits of habitat investments/streamflow alternatives do not equal costs. However, changes in water allocations and habitat do appear economically efficient to some upper reaches. The main results suggest that economic efficiency varies greatly within the system, indicating the need for site-specific proposals for streamfiow or habitat alterations within this or similar high desert streams. In addition to providing preliminary estimates of the economic efficency of streamfiow and habitat investments, this thesis serves as a methodological template for future integrated bioeconomic evaluations of water and fishery management issues. Close

• 27. [Article] The size of the Oregon coastal salmon runs in the mid-1800s

  Abstract.- Increasing the abundance of salmon in coastal Oregon rivers and streams is a high priority public policy objective. Salmon runs have been reduced from pre-development conditions (typically defined ...

  Citation × Citation Citation Abstract Copy Title: The size of the Oregon coastal salmon runs in the mid-1800s Author: Meengs, Chad C. Abstract.- Increasing the abundance of salmon in coastal Oregon rivers and streams is a high priority public policy objective. Salmon runs have been reduced from pre-development conditions (typically defined as the 1 850s), but it is unclear by how much. Considerable resources have been allocated to restoring salmon runs, but it is uncertain what the current recovery potential is because much of the freshwater and estuarine habitat for salmon has been altered. The goals of all recovery efforts are based on assumptions, often unstated, for what the size if the runs were prior to significant habitat alteration, coupled with an estimate of the amount and quality of freshwater and estuarine habitat currently available. At one extreme, it may be that current run sizes reflect the recovery potential of the existing salmon habitat. At the other extreme, the recovery potential may be as high as the mid 1800 levels. Historical salmon runs sizes on the Oregon coast were estimated using two methods: (1) Converting aboriginal population levels and their salmon consumption rate into numbers of salmon; (2) Extrapolating cannery pack into numbers of salmon. Annual aboriginal harvest of all salmon species is estimated to have been approximately 10 million pounds/year or between 1.75 million and 5.36 million salmonids, a harvest level similar to that occurring during the height of commercial fishing on Oregon's coastal rivers in the late 1 800s and early 1 900s. Extrapolating cannery pack data, the estimated size of the late 1 800s aggregate runs of coho (Oncorhynchus kisutch) was 1.5-2.5 million. The estimated size of aggregate runs of chinook (Oncorhynchus tshawytscha) runs was 290,000-517,000. Compared to mid 1 800s coho estimates, current runs (during favorable ocean conditions), are 11-19%. During poor ocean conditions, current coho runs are 3-6% of the historical size. Title: The size of the Oregon coastal salmon runs in the mid-1800s Author: Meengs, Chad C. Abstract.- Increasing the abundance of salmon in coastal Oregon rivers and streams is a high priority public policy objective. Salmon runs have been reduced from pre-development conditions (typically defined as the 1 850s), but it is unclear by how much. Considerable resources have been allocated to restoring salmon runs, but it is uncertain what the current recovery potential is because much of the freshwater and estuarine habitat for salmon has been altered. The goals of all recovery efforts are based on assumptions, often unstated, for what the size if the runs were prior to significant habitat alteration, coupled with an estimate of the amount and quality of freshwater and estuarine habitat currently available. At one extreme, it may be that current run sizes reflect the recovery potential of the existing salmon habitat. At the other extreme, the recovery potential may be as high as the mid 1800 levels. Historical salmon runs sizes on the Oregon coast were estimated using two methods: (1) Converting aboriginal population levels and their salmon consumption rate into numbers of salmon; (2) Extrapolating cannery pack into numbers of salmon. Annual aboriginal harvest of all salmon species is estimated to have been approximately 10 million pounds/year or between 1.75 million and 5.36 million salmonids, a harvest level similar to that occurring during the height of commercial fishing on Oregon's coastal rivers in the late 1 800s and early 1 900s. Extrapolating cannery pack data, the estimated size of the late 1 800s aggregate runs of coho (Oncorhynchus kisutch) was 1.5-2.5 million. The estimated size of aggregate runs of chinook (Oncorhynchus tshawytscha) runs was 290,000-517,000. Compared to mid 1 800s coho estimates, current runs (during favorable ocean conditions), are 11-19%. During poor ocean conditions, current coho runs are 3-6% of the historical size. Close

• 28. [Article] The intrusion of logging debris into artificial gravel streambeds

  The objective of this study was to quantitatively describe the intrusion of logging debris into artificial gravel streambeds during conditions of low stream flow with a stable streambed, and begin an analysis ...

  Citation × Citation Citation Abstract Copy Title: The intrusion of logging debris into artificial gravel streambeds Author: Garvin, William Fredrick The objective of this study was to quantitatively describe the intrusion of logging debris into artificial gravel streambeds during conditions of low stream flow with a stable streambed, and begin an analysis of the effect of high flow and unstable streambeds. This study was initiated because prior studies indicated that logging debris was responsible for dissolved oxygen reduction within the gravel bed of spawning streams. Low flow -- stable streambed studies were run for eighteen to twenty days in a flume. Two control samples of the gravel were taken. Logging slash was then placed on the gravel in volumes approximating those of logged streams. A sample was taken every other day for eighteen to twenty days using a device which froze a core of the streambed gravel. Since there were many problems with vandalism and weather, only two low flow replications were completed. shows the large random error which occurs even in the deeper sections. The range of debris concentrations of the two deeper sections for low flow studies one and two were .07 gm/l and .15 gm/l respectively. The average concentration values for low flow studies one and two were .03 gm/l and .02 gm/l respectively. No variables in the high flow study were found to be good predictors of intrusion. Natural random error and the extreme variability of this dynamic system were too great to draw even general conclusions. The range of concentrations of high flow studies one and two were .14 gm/l and .04 gm/l respectively. The average concentration values for high flow studies one and two were .01 gm/l and .02 gm/l respectively. Beneath the armour layer, the streambed exhibits less variability, but the large random error is sufficient to make prediction of intrusion difficult. During high flow periods where the streambed is moving, no predictive equation could be developed to estimate organic material release or incorporation owing to the large variability existing in the system. Title: The intrusion of logging debris into artificial gravel streambeds Author: Garvin, William Fredrick The objective of this study was to quantitatively describe the intrusion of logging debris into artificial gravel streambeds during conditions of low stream flow with a stable streambed, and begin an analysis of the effect of high flow and unstable streambeds. This study was initiated because prior studies indicated that logging debris was responsible for dissolved oxygen reduction within the gravel bed of spawning streams. Low flow -- stable streambed studies were run for eighteen to twenty days in a flume. Two control samples of the gravel were taken. Logging slash was then placed on the gravel in volumes approximating those of logged streams. A sample was taken every other day for eighteen to twenty days using a device which froze a core of the streambed gravel. Since there were many problems with vandalism and weather, only two low flow replications were completed. shows the large random error which occurs even in the deeper sections. The range of debris concentrations of the two deeper sections for low flow studies one and two were .07 gm/l and .15 gm/l respectively. The average concentration values for low flow studies one and two were .03 gm/l and .02 gm/l respectively. No variables in the high flow study were found to be good predictors of intrusion. Natural random error and the extreme variability of this dynamic system were too great to draw even general conclusions. The range of concentrations of high flow studies one and two were .14 gm/l and .04 gm/l respectively. The average concentration values for high flow studies one and two were .01 gm/l and .02 gm/l respectively. Beneath the armour layer, the streambed exhibits less variability, but the large random error is sufficient to make prediction of intrusion difficult. During high flow periods where the streambed is moving, no predictive equation could be developed to estimate organic material release or incorporation owing to the large variability existing in the system. Close

• 29. [Article] In the midst of a revolution : science, fish culture, and the Oregon Game Commission, 1935-1949

  This thesis will address the transformation of biological sciences during the 1930s and 1940s and it effects on fisheries science. It will focus on Oregon State College and specifically the Department ...

  Citation × Citation Citation Abstract Copy Title: In the midst of a revolution : science, fish culture, and the Oregon Game Commission, 1935-1949 Author: Hahn, Linda This thesis will address the transformation of biological sciences during the 1930s and 1940s and it effects on fisheries science. It will focus on Oregon State College and specifically the Department of Fish and Game Management and the interaction with the Oregon Game Commission. Support for mutation theory and neo- Lamarckism lasted throughout this study's time frame. The resulting belief that the environment can directly affect species fitness could have been a factor in fisheries managers' support for fish hatcheries. Throughout this time frame the science of ecology was emerging, but the dominant science of agricultural breeding science within wildlife management took precedence over ecology. Two case studies show changing ideas about agricultural breeding science as applied to wildlife management. In the first case study, the debate concerning fishways over Bonneville Dam shows that fish hatcheries were counted on to mitigate the loss of salmon habitat due to construction, and to act as a failsafe should the fishways fail. When the 1934 Oregon Game Commission members failed to enthusiastically support the construction of the dam and the fishway plans, this thesis argues that the commission members were dismissed in 1935. The second case study addresses the actions of the Oregon Game Commission in placing some high dams on tributaries of the Willamette River, the Willamette Valley project. This thesis shows that the inclusion of ecological principles in the evaluation of fish hatcheries led the commission to oppose this project. For their opposition, this thesis argues that the 1949 Oregon Game Commission members were dismissed. In both cases, this thesis concludes that the federal funding of water development projects played an important role in the dismissals of both Oregon Game Commissions. In addition, the evolving nature of biological science during the 1 930s and 1940s shows that lingering beliefs in mutation theory and neo-Lamarckism would have supported the use of fish hatcheries as a scientifically acceptable solution to declines in fish runs within the scientific tradition of agricultural methods of breeding wildlife. Title: In the midst of a revolution : science, fish culture, and the Oregon Game Commission, 1935-1949 Author: Hahn, Linda This thesis will address the transformation of biological sciences during the 1930s and 1940s and it effects on fisheries science. It will focus on Oregon State College and specifically the Department of Fish and Game Management and the interaction with the Oregon Game Commission. Support for mutation theory and neo- Lamarckism lasted throughout this study's time frame. The resulting belief that the environment can directly affect species fitness could have been a factor in fisheries managers' support for fish hatcheries. Throughout this time frame the science of ecology was emerging, but the dominant science of agricultural breeding science within wildlife management took precedence over ecology. Two case studies show changing ideas about agricultural breeding science as applied to wildlife management. In the first case study, the debate concerning fishways over Bonneville Dam shows that fish hatcheries were counted on to mitigate the loss of salmon habitat due to construction, and to act as a failsafe should the fishways fail. When the 1934 Oregon Game Commission members failed to enthusiastically support the construction of the dam and the fishway plans, this thesis argues that the commission members were dismissed in 1935. The second case study addresses the actions of the Oregon Game Commission in placing some high dams on tributaries of the Willamette River, the Willamette Valley project. This thesis shows that the inclusion of ecological principles in the evaluation of fish hatcheries led the commission to oppose this project. For their opposition, this thesis argues that the 1949 Oregon Game Commission members were dismissed. In both cases, this thesis concludes that the federal funding of water development projects played an important role in the dismissals of both Oregon Game Commissions. In addition, the evolving nature of biological science during the 1 930s and 1940s shows that lingering beliefs in mutation theory and neo-Lamarckism would have supported the use of fish hatcheries as a scientifically acceptable solution to declines in fish runs within the scientific tradition of agricultural methods of breeding wildlife. Close

• 30. [Article] Caspian tern (Hydroprogne caspia) foraging ecology and predation on juvenile salmonids in San Francisco Bay, California

  Brooks Island, located in central San Francisco Bay, California, currently supports the largest breeding colony of Caspian terns (Hydroprogne caspia) in the Bay Area, and is one of several proposed relocation ...

  Citation × Citation Citation Abstract Copy Title: Caspian tern (Hydroprogne caspia) foraging ecology and predation on juvenile salmonids in San Francisco Bay, California Author: Adrean, Lindsay J. Brooks Island, located in central San Francisco Bay, California, currently supports the largest breeding colony of Caspian terns (Hydroprogne caspia) in the Bay Area, and is one of several proposed relocation sites for some Caspian terns from the world's largest colony in the Columbia River estuary of Oregon. Juvenile salmonids have been identified in the diet of Caspian terns nesting at Brooks Island, so I investigated whether the colony, at its current or an enhanced size, poses a threat to the recovery of several runs of salmonids (Oncorhynchus spp.) in San Francisco Bay that are listed under the U.S. Endangered Species Act (ESA). I also examined the foraging ecology of Brooks Island Caspian terns to 1) determine whether the colony is suitable for expansion based on availability of forage fish resources, a factor potentially limiting the size and productivity of the colony, and 2) investigate how Caspian terns nesting at this colony exploit forage fish resources. I used a bioenergetics modeling approach, employing estimates of tern energy requirements and proportions of energy supplied by various prey types, to estimate consumption of juvenile salmonids by Caspian terns nesting on Brooks Island during 2008 and 2009. Estimated salmonid consumption was 205,000 smolts (95% CI: 175,000 – 245,000 smolts) in 2008 and 167,000 smolts (95% CI: 144,000 – 191,000 smolts) in 2009. Predation rates on ESA-listed Central Valley spring-run Chinook salmon (O. tshawytscha; 0.08%) were lower than those on unlisted fall-run Chinook salmon (1.0%). Average per capita predation rates on juvenile salmonids by Brooks Island Caspian terns (2008: 126 fish; 2009: 123 fish) were less than half those of Caspian terns nesting in the Columbia River estuary. If the current downward trend in the number of Caspian terns nesting on Brooks Island continues until the colony is no longer extant, the resulting declines in predation on salmonids would lead to increases in annual population growth rates (Δλ) of salmonid runs of just small fractions of one percentage point. The proposed enhancement of the Brooks Island Caspian tern colony to 3,000 individuals would at most cause declines in annual population growth rates of 0.3% for fall-run Chinook salmon and 0.02% for threatened spring-run Chinook salmon, assuming that smolt mortality from tern predation is 100% additive. This level of impact to the ESA-listed spring-run Chinook salmon stock is less than the level considered acceptable by the National Marine Fisheries Service (Δλ = 0.05%). Radio-tracking of Caspian terns nesting on Brooks Island revealed that the maximum foraging distance from the colony was 80 km. The median foraging distance from the colony was greater in 2009 compared to 2008 (20.6 km vs. 14.0 km), average number of foraging trips per day was higher (4.4 vs. 3.4 foraging trips), and average adult colony attendance was lower (43% vs. 52% of daylight hours). These results indicate that the colony was more food-limited during the 2009 breeding season, concurrent with anomalous downwelling along the coast of northern California and reduced availability and size of marine forage fishes, such as herring, sardines, and anchovies. Caspian terns used a number of core foraging areas within 30 km of the Brooks Island colony, both inside and just outside the Bay. Two large core foraging areas were close to or overlapped with the release site for juvenile salmonids in eastern San Pablo Bay, where > 10 million hatchery-raised smolts were released from net pens during both the 2008 and 2009 tern nesting seasons. This finding supports the hypothesis that most juvenile salmonids consumed by terns nesting at the Brooks Island colony were captured at or near the release site. Individual Caspian terns displayed foraging site fidelity, suggesting that foraging at the release site for hatchery-raised salmonids was a learned behavior by some terns. The Brooks Island colony site is within foraging distance of adequate marine forage fish resources in most years, and Caspian terns nesting there are not dependent on juvenile salmonids as a food resource. Consumption of juvenile salmonids by Brooks Island terns would be largely curtailed by modification of hatchery release practices. Title: Caspian tern (Hydroprogne caspia) foraging ecology and predation on juvenile salmonids in San Francisco Bay, California Author: Adrean, Lindsay J. Brooks Island, located in central San Francisco Bay, California, currently supports the largest breeding colony of Caspian terns (Hydroprogne caspia) in the Bay Area, and is one of several proposed relocation sites for some Caspian terns from the world's largest colony in the Columbia River estuary of Oregon. Juvenile salmonids have been identified in the diet of Caspian terns nesting at Brooks Island, so I investigated whether the colony, at its current or an enhanced size, poses a threat to the recovery of several runs of salmonids (Oncorhynchus spp.) in San Francisco Bay that are listed under the U.S. Endangered Species Act (ESA). I also examined the foraging ecology of Brooks Island Caspian terns to 1) determine whether the colony is suitable for expansion based on availability of forage fish resources, a factor potentially limiting the size and productivity of the colony, and 2) investigate how Caspian terns nesting at this colony exploit forage fish resources. I used a bioenergetics modeling approach, employing estimates of tern energy requirements and proportions of energy supplied by various prey types, to estimate consumption of juvenile salmonids by Caspian terns nesting on Brooks Island during 2008 and 2009. Estimated salmonid consumption was 205,000 smolts (95% CI: 175,000 – 245,000 smolts) in 2008 and 167,000 smolts (95% CI: 144,000 – 191,000 smolts) in 2009. Predation rates on ESA-listed Central Valley spring-run Chinook salmon (O. tshawytscha; 0.08%) were lower than those on unlisted fall-run Chinook salmon (1.0%). Average per capita predation rates on juvenile salmonids by Brooks Island Caspian terns (2008: 126 fish; 2009: 123 fish) were less than half those of Caspian terns nesting in the Columbia River estuary. If the current downward trend in the number of Caspian terns nesting on Brooks Island continues until the colony is no longer extant, the resulting declines in predation on salmonids would lead to increases in annual population growth rates (Δλ) of salmonid runs of just small fractions of one percentage point. The proposed enhancement of the Brooks Island Caspian tern colony to 3,000 individuals would at most cause declines in annual population growth rates of 0.3% for fall-run Chinook salmon and 0.02% for threatened spring-run Chinook salmon, assuming that smolt mortality from tern predation is 100% additive. This level of impact to the ESA-listed spring-run Chinook salmon stock is less than the level considered acceptable by the National Marine Fisheries Service (Δλ = 0.05%). Radio-tracking of Caspian terns nesting on Brooks Island revealed that the maximum foraging distance from the colony was 80 km. The median foraging distance from the colony was greater in 2009 compared to 2008 (20.6 km vs. 14.0 km), average number of foraging trips per day was higher (4.4 vs. 3.4 foraging trips), and average adult colony attendance was lower (43% vs. 52% of daylight hours). These results indicate that the colony was more food-limited during the 2009 breeding season, concurrent with anomalous downwelling along the coast of northern California and reduced availability and size of marine forage fishes, such as herring, sardines, and anchovies. Caspian terns used a number of core foraging areas within 30 km of the Brooks Island colony, both inside and just outside the Bay. Two large core foraging areas were close to or overlapped with the release site for juvenile salmonids in eastern San Pablo Bay, where > 10 million hatchery-raised smolts were released from net pens during both the 2008 and 2009 tern nesting seasons. This finding supports the hypothesis that most juvenile salmonids consumed by terns nesting at the Brooks Island colony were captured at or near the release site. Individual Caspian terns displayed foraging site fidelity, suggesting that foraging at the release site for hatchery-raised salmonids was a learned behavior by some terns. The Brooks Island colony site is within foraging distance of adequate marine forage fish resources in most years, and Caspian terns nesting there are not dependent on juvenile salmonids as a food resource. Consumption of juvenile salmonids by Brooks Island terns would be largely curtailed by modification of hatchery release practices. Close