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• 1. [Article] Age Determination of Modern and Archaeological Chinook Salmon (Oncorhynchus tshawytcha) Using Vertebrae

  Incremental growth rings in X-rays of salmon vertebrae have been used since the 1980s to age Pacific salmon (Oncorhynchus spp.) remains from archaeological sites in the Pacific Northwest. These age estimates, ...

  Citation × Citation Citation Abstract Copy Title: Age Determination of Modern and Archaeological Chinook Salmon (Oncorhynchus tshawytcha) Using Vertebrae Author: Hofkamp, Anthony Raymond Year: 2015 Incremental growth rings in X-rays of salmon vertebrae have been used since the 1980s to age Pacific salmon (Oncorhynchus spp.) remains from archaeological sites in the Pacific Northwest. These age estimates, paired with generalized life history patterns, have been used to determine salmon species, season of capture and in turn season of site occupation. This approach relies on a variety of assumptions, the most fundamental of which is that rings represent true years. Archaeologists using vertebral age determination techniques have failed to adequately test this assumption and present their methodologies. This thesis assesses the validity of using incremental growth structures in Chinook salmon (Oncorhynchus tshawytscha) vertebrae to determine the age at death of fish represented in archaeological sites. This project develops criteria and a protocol for the identification of true annuli and tests these identifications on a collection of modern Chinook salmon of known age. Finally, this protocol is applied to archaeological remains of Chinook from Cathlapotle (45CL1). Three collections of modern known age fish (N=121) were used to evaluate and test approaches to aging Chinook salmon with vertebrae. These collections contained juvenile and adult Chinook from throughout Washington and Oregon. I evaluated a variety of methods for viewing rings including magnified surface images, X-ray images and thin sections to determine which is the most accurate, reliable and efficient, also considering the extent of specimen destruction. Rings visible in X-rays were found to reflect the internal structure of vertebrae rather than annular growth. The number of these internal walls did not correspond to the known ages of fish and are therefore not true annuli. Criteria previously described by salmon fisheries biologist were used to isolate annuli (on the centrum surface) on the Hanford reach collection (N=46). In a test for accuracy 39 (85%) were aged correctly. In a test of reliability utilizing five additional readers all but 14 cases showed discrepancies among readers. Results of the test of reliability were not as successful as other researchers in fisheries biology but given the high accuracy rate the method remains valid. The final goal of this project was to determine the feasibility of applying the surface ring method of age determination to archaeological collections. Archaeological salmon vertebrae from Cathlapotle (45CL1) on the lower Columbia River, Washington state were utilized. One hundred salmon vertebrae were selected and classified to species according to Huber et al. (2011); 89 were identified as Chinook. Of these, 39 had sufficient preservation of the surface to view and interpret incremental rings. Three ages were identified 3, 4 and 5 year olds. This ageing protocol can be applied to archaeological Chinook salmon vertebrae to estimate age of ancient Chinook salmon. Additional work is needed on other salmon species to demonstrate the methods validity across all salmonid species. This analysis has great potential for modeling salmon paleo-life history by contributing data from salmon populations prior to the major impacts of the 19th and 20th century. This is particularly valuable for salmon conservation because information on size, the timing and duration of freshwater emigration as well as the age of spawning and death is critical to the management of hatchery and wild salmon populations. Title: Age Determination of Modern and Archaeological Chinook Salmon (Oncorhynchus tshawytcha) Using Vertebrae Author: Hofkamp, Anthony Raymond Year: 2015 Incremental growth rings in X-rays of salmon vertebrae have been used since the 1980s to age Pacific salmon (Oncorhynchus spp.) remains from archaeological sites in the Pacific Northwest. These age estimates, paired with generalized life history patterns, have been used to determine salmon species, season of capture and in turn season of site occupation. This approach relies on a variety of assumptions, the most fundamental of which is that rings represent true years. Archaeologists using vertebral age determination techniques have failed to adequately test this assumption and present their methodologies. This thesis assesses the validity of using incremental growth structures in Chinook salmon (Oncorhynchus tshawytscha) vertebrae to determine the age at death of fish represented in archaeological sites. This project develops criteria and a protocol for the identification of true annuli and tests these identifications on a collection of modern Chinook salmon of known age. Finally, this protocol is applied to archaeological remains of Chinook from Cathlapotle (45CL1). Three collections of modern known age fish (N=121) were used to evaluate and test approaches to aging Chinook salmon with vertebrae. These collections contained juvenile and adult Chinook from throughout Washington and Oregon. I evaluated a variety of methods for viewing rings including magnified surface images, X-ray images and thin sections to determine which is the most accurate, reliable and efficient, also considering the extent of specimen destruction. Rings visible in X-rays were found to reflect the internal structure of vertebrae rather than annular growth. The number of these internal walls did not correspond to the known ages of fish and are therefore not true annuli. Criteria previously described by salmon fisheries biologist were used to isolate annuli (on the centrum surface) on the Hanford reach collection (N=46). In a test for accuracy 39 (85%) were aged correctly. In a test of reliability utilizing five additional readers all but 14 cases showed discrepancies among readers. Results of the test of reliability were not as successful as other researchers in fisheries biology but given the high accuracy rate the method remains valid. The final goal of this project was to determine the feasibility of applying the surface ring method of age determination to archaeological collections. Archaeological salmon vertebrae from Cathlapotle (45CL1) on the lower Columbia River, Washington state were utilized. One hundred salmon vertebrae were selected and classified to species according to Huber et al. (2011); 89 were identified as Chinook. Of these, 39 had sufficient preservation of the surface to view and interpret incremental rings. Three ages were identified 3, 4 and 5 year olds. This ageing protocol can be applied to archaeological Chinook salmon vertebrae to estimate age of ancient Chinook salmon. Additional work is needed on other salmon species to demonstrate the methods validity across all salmonid species. This analysis has great potential for modeling salmon paleo-life history by contributing data from salmon populations prior to the major impacts of the 19th and 20th century. This is particularly valuable for salmon conservation because information on size, the timing and duration of freshwater emigration as well as the age of spawning and death is critical to the management of hatchery and wild salmon populations. Close

• 2. [Article] On the Validity of the Radiographic Method for Determining Age of Ancient Salmon

  White rings visible on the centrum face of salmon vertebrae with X-rays have been used since the 1980s to age Pacific salmon (Oncorhynchus spp.), which in turn have been used to determine salmon species, ...

  Citation × Citation Citation Abstract Copy Title: On the Validity of the Radiographic Method for Determining Age of Ancient Salmon Author: Hofkamp, Anthony R., Butler, Virginia L. Year: 2017 White rings visible on the centrum face of salmon vertebrae with X-rays have been used since the 1980s to age Pacific salmon (Oncorhynchus spp.), which in turn have been used to determine salmon species, season of capture and season of site occupation. This approach relies on a variety of assumptions, the most fundamental of which is that rings represent true years. Recent aDNA analysis has shown that the X-ray approach has flaws but the source of the error has been unknown. Given the value of reconstructing salmon population demographics and life history from ancient remains, establishing a valid and reliable method of ageing salmon vertebrae is extremely worthwhile. The main goal of our study was to evaluate if X-ray images of ring patterns on vertebrae provide a valid method of estimating fish age. Vertebrae from 66 adult Chinook salmon (O. tshawytscha) of known age were studied with X-rays, thin sections or low-powered (10–30 ×) magnification. We found that the white bands observed in X-rays are structural walls that do not grow annually. While X-rays are not a valid method for ageing salmonids, incremental growth seen on the surface of fish centra shows great promise for reconstructing ancient fish life history. Title: On the Validity of the Radiographic Method for Determining Age of Ancient Salmon Author: Hofkamp, Anthony R., Butler, Virginia L. Year: 2017 White rings visible on the centrum face of salmon vertebrae with X-rays have been used since the 1980s to age Pacific salmon (Oncorhynchus spp.), which in turn have been used to determine salmon species, season of capture and season of site occupation. This approach relies on a variety of assumptions, the most fundamental of which is that rings represent true years. Recent aDNA analysis has shown that the X-ray approach has flaws but the source of the error has been unknown. Given the value of reconstructing salmon population demographics and life history from ancient remains, establishing a valid and reliable method of ageing salmon vertebrae is extremely worthwhile. The main goal of our study was to evaluate if X-ray images of ring patterns on vertebrae provide a valid method of estimating fish age. Vertebrae from 66 adult Chinook salmon (O. tshawytscha) of known age were studied with X-rays, thin sections or low-powered (10–30 ×) magnification. We found that the white bands observed in X-rays are structural walls that do not grow annually. While X-rays are not a valid method for ageing salmonids, incremental growth seen on the surface of fish centra shows great promise for reconstructing ancient fish life history. Close

• 3. [Article] Since Time Immemorial: The Decline of Columbia River Basin Salmon

  Since Time Immemorial: The Decline of Columbia River Basin Salmon studies the near extinction of what has been historically the world’s largest salmon population. By examining the issue systemically, my ...

  Citation × Citation Citation Abstract Copy Title: Since Time Immemorial: The Decline of Columbia River Basin Salmon Author: Levin, Samuel J Year: 2016 Since Time Immemorial: The Decline of Columbia River Basin Salmon studies the near extinction of what has been historically the world’s largest salmon population. By examining the issue systemically, my paper reveals that the environmental misjudgments that have brought the salmon so near extinction are not isolated, but rather are the product of cultural trends. A study of these misjudgments reveals a culture within the Columbia Basin that has, since the mid-19th century, sought expansion for expansion’s sake and valued short-term wealth over long-term sustainability. My paper illustrates how his philosophy has guided and continues to guide Columbia Basin fisheries management to neglect not just environmental and Native American considerations, but pragmatic ones as well. Title: Since Time Immemorial: The Decline of Columbia River Basin Salmon Author: Levin, Samuel J Year: 2016 Since Time Immemorial: The Decline of Columbia River Basin Salmon studies the near extinction of what has been historically the world’s largest salmon population. By examining the issue systemically, my paper reveals that the environmental misjudgments that have brought the salmon so near extinction are not isolated, but rather are the product of cultural trends. A study of these misjudgments reveals a culture within the Columbia Basin that has, since the mid-19th century, sought expansion for expansion’s sake and valued short-term wealth over long-term sustainability. My paper illustrates how his philosophy has guided and continues to guide Columbia Basin fisheries management to neglect not just environmental and Native American considerations, but pragmatic ones as well. Close

• 4. [Article] A Landscape Approach to Determining and Predicting Juvenile Coho Salmon (<i>Oncorhynchus kisutch</i>) Movement Timing and Growth Patterns Prior to Ocean Entry

  Coho salmon (Oncorhynchus kisutch) rely on unique habitats during the winter season, which may dictate how much individuals may grow and when migration from freshwater rearing habitat to the ocean occurs. ...

  Citation × Citation Citation Abstract Copy Title: A Landscape Approach to Determining and Predicting Juvenile Coho Salmon (<i>Oncorhynchus kisutch</i>) Movement Timing and Growth Patterns Prior to Ocean Entry Author: Johnson, Amelia Lee Year: 2016 Coho salmon (Oncorhynchus kisutch) rely on unique habitats during the winter season, which may dictate how much individuals may grow and when migration from freshwater rearing habitat to the ocean occurs. Here I analyze movement timing and growth patterns for coho salmon through a field-based study and a literature review. For the field portion, I examined hatchery-stocked juvenile coho salmon across four stream basins in the Russian River watershed, California to determine the relative importance of climate, landscape, and fish size metrics in predicting movement and growth patterns over a winter rearing and spring smolt outmigration time period (December 2014-June 2015). I observed three unique movement strategies: winter parr movement, spring smolt movement, and inter-tributary movement. Movement was predicted in relation to daily temperature and precipitation, followed by in-stream and upslope basin conditions in random forest modeling. Specifically, fish that moved later were associated with basins that contained higher productivity and low-gradient floodplain habitats, while fish that moved earlier came from streams that lacked invertebrate prey and had limited low-gradient rearing habitat. Fish size and timing of movement were the primary predictors of growth, with relatively larger fish in the spring growing faster than fish that were relatively smaller prior to winter. These relationships suggest that hatchery-release fish are still highly influenced by environmental conditions once released, especially in terms of initial seasonal movement, and that watershed conditions should be considered when utilizing hatchery-rearing programs to supplement wild fish populations. In North America, coho salmon populations are distributed from Alaska through California, and may exhibit unique movement and growth patterns in relationship to population-scale vulnerability (Endangered Species Act listing), basin area, and availability and types of rearing habitat. For the second part of my thesis, I conducted a literature review to assess what factors are commonly considered in predicting movement and growth patterns for these fish, as well as the types (season and life stage) and number of movement strategies reported. Eighteen studies were summarized, of which sixteen identified unique movement strategies, ranging from one to four. Despite a wide range of basin areas and latitudes, winter parr and spring smolt movements were commonly observed, with authors primarily relating these behaviors to in-stream habitat and fish size metrics. Additionally, growth was linked positively and primarily with off-channel winter rearing, which may outweigh the importance of fish size in predicting growth when high quality rearing habitats are available during the winter season. Recognizing movement timing diversity and its drivers can help recover threatened coho salmon populations. More widely distributed populations may have unique phenotypic expressions based on localized genetic and environmental interactions, increasing diversity and overall stability across the population, a concept known as the portfolio effect. Understanding fish-habitat relationships can aid recovery efforts by providing a framework of climatic and watershed conditions that support unique behaviors, even in already severely limited populations. Title: A Landscape Approach to Determining and Predicting Juvenile Coho Salmon (<i>Oncorhynchus kisutch</i>) Movement Timing and Growth Patterns Prior to Ocean Entry Author: Johnson, Amelia Lee Year: 2016 Coho salmon (Oncorhynchus kisutch) rely on unique habitats during the winter season, which may dictate how much individuals may grow and when migration from freshwater rearing habitat to the ocean occurs. Here I analyze movement timing and growth patterns for coho salmon through a field-based study and a literature review. For the field portion, I examined hatchery-stocked juvenile coho salmon across four stream basins in the Russian River watershed, California to determine the relative importance of climate, landscape, and fish size metrics in predicting movement and growth patterns over a winter rearing and spring smolt outmigration time period (December 2014-June 2015). I observed three unique movement strategies: winter parr movement, spring smolt movement, and inter-tributary movement. Movement was predicted in relation to daily temperature and precipitation, followed by in-stream and upslope basin conditions in random forest modeling. Specifically, fish that moved later were associated with basins that contained higher productivity and low-gradient floodplain habitats, while fish that moved earlier came from streams that lacked invertebrate prey and had limited low-gradient rearing habitat. Fish size and timing of movement were the primary predictors of growth, with relatively larger fish in the spring growing faster than fish that were relatively smaller prior to winter. These relationships suggest that hatchery-release fish are still highly influenced by environmental conditions once released, especially in terms of initial seasonal movement, and that watershed conditions should be considered when utilizing hatchery-rearing programs to supplement wild fish populations. In North America, coho salmon populations are distributed from Alaska through California, and may exhibit unique movement and growth patterns in relationship to population-scale vulnerability (Endangered Species Act listing), basin area, and availability and types of rearing habitat. For the second part of my thesis, I conducted a literature review to assess what factors are commonly considered in predicting movement and growth patterns for these fish, as well as the types (season and life stage) and number of movement strategies reported. Eighteen studies were summarized, of which sixteen identified unique movement strategies, ranging from one to four. Despite a wide range of basin areas and latitudes, winter parr and spring smolt movements were commonly observed, with authors primarily relating these behaviors to in-stream habitat and fish size metrics. Additionally, growth was linked positively and primarily with off-channel winter rearing, which may outweigh the importance of fish size in predicting growth when high quality rearing habitats are available during the winter season. Recognizing movement timing diversity and its drivers can help recover threatened coho salmon populations. More widely distributed populations may have unique phenotypic expressions based on localized genetic and environmental interactions, increasing diversity and overall stability across the population, a concept known as the portfolio effect. Understanding fish-habitat relationships can aid recovery efforts by providing a framework of climatic and watershed conditions that support unique behaviors, even in already severely limited populations. Close

• 5. [Article] Factors Influencing the Survival of Outmigrating Juvenile Salmonids Through Multiple Dam Passages: An Individual-Based Approach

  Substantial declines of Pacific salmon populations have occurred over the past several decades related to large-scale anthropogenic and climatic changes in freshwater and marine environments. In the Columbia ...

  Citation × Citation Citation Abstract Copy Title: Factors Influencing the Survival of Outmigrating Juvenile Salmonids Through Multiple Dam Passages: An Individual-Based Approach Author: Elder, Timothy, Woodley, Christa M., Weiland, Mark A., Strecker, Angela L. Year: 2016 Substantial declines of Pacific salmon populations have occurred over the past several decades related to large-scale anthropogenic and climatic changes in freshwater and marine environments. In the Columbia River Basin, migrating juvenile salmonids may pass as many as eight large-scale hydropower projects before reaching the ocean; however, the cumulative effects of multiple dam passages are largely unknown. Using acoustic transmitters and an extensive system of hydrophone arrays in the Lower Columbia River, we calculated the survival of yearling Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) passing one, two, or three dams. We applied a unique index of biological characteristics and environmental exposures, experienced by each fish individually as it migrated downstream, in order to examine which factors most influence salmonid survival. High outflow volumes led to involuntary spill in 2011 and created an environment of supersaturated dissolved gas concentrations. In this environment, migrating smolt survival was strongly influenced by barometric pressure, fish velocity, and water temperature. The effect of these variables on survival was compounded by multiple dam passages compared to fish passing a single dam. Despite spatial isolation between dams in the Lower Columbia River hydrosystem, migrating smolt appear to experience cumulative effects akin to a press disturbance. In general, Chinook salmon and steelhead respond similarly in terms of survival rates and responses to altered environmental conditions. Management actions that limit dissolved gas concentrations in years of high flow will benefit migrating salmonids at this life stage. Title: Factors Influencing the Survival of Outmigrating Juvenile Salmonids Through Multiple Dam Passages: An Individual-Based Approach Author: Elder, Timothy, Woodley, Christa M., Weiland, Mark A., Strecker, Angela L. Year: 2016 Substantial declines of Pacific salmon populations have occurred over the past several decades related to large-scale anthropogenic and climatic changes in freshwater and marine environments. In the Columbia River Basin, migrating juvenile salmonids may pass as many as eight large-scale hydropower projects before reaching the ocean; however, the cumulative effects of multiple dam passages are largely unknown. Using acoustic transmitters and an extensive system of hydrophone arrays in the Lower Columbia River, we calculated the survival of yearling Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) passing one, two, or three dams. We applied a unique index of biological characteristics and environmental exposures, experienced by each fish individually as it migrated downstream, in order to examine which factors most influence salmonid survival. High outflow volumes led to involuntary spill in 2011 and created an environment of supersaturated dissolved gas concentrations. In this environment, migrating smolt survival was strongly influenced by barometric pressure, fish velocity, and water temperature. The effect of these variables on survival was compounded by multiple dam passages compared to fish passing a single dam. Despite spatial isolation between dams in the Lower Columbia River hydrosystem, migrating smolt appear to experience cumulative effects akin to a press disturbance. In general, Chinook salmon and steelhead respond similarly in terms of survival rates and responses to altered environmental conditions. Management actions that limit dissolved gas concentrations in years of high flow will benefit migrating salmonids at this life stage. Close

• 6. [Article] Historical Vegetation of Three Salmon-Bearing Watersheds in the Interior Columbia River Basin

  Land use practices can be a contributing factor to environmental degradation and have been the focus of many ecological studies. One aspect that is less addressed is land use history and the effects that ...

  Citation × Citation Citation Abstract Copy Title: Historical Vegetation of Three Salmon-Bearing Watersheds in the Interior Columbia River Basin Author: Smith, Tyanna Year: 2014 Land use practices can be a contributing factor to environmental degradation and have been the focus of many ecological studies. One aspect that is less addressed is land use history and the effects that past practices, such as logging and grazing, can have on the current landscape. This paper describes research and the synthesis of material on the environmental history and watershed characteristics for three watersheds located within spawning and rearing areas for Chinook salmon in the Grande Ronde River Basin in Northeast Oregon: upper Grande Ronde River, Catherine Creek, and Minam River. The Grande Ronde Basin is critical spawning and rearing habitat for salmonids listed under the Endangered Species Act. The primary historical data sources for reconstructing 19th century stream and riparian conditions are the General Land Office township survey notes from 1863 - 1901. Data about the habitat conditions of the landscape were extracted from notes of each township survey source regarding vegetation, stream crossings, and other features found on the landscape in tabular and spatial forms. Data were organized to describe common stream and riparian conditions for the historical time period using a geographic information system. Watershed basin, Chinook salmon life history, ecoregion and surveyor were analyzed using multivariate techniques to determine which parameters were strongly connected to historical vegetation. Ecoregion had the strongest correlation with plant communities. For future research, these historical data could be compared to current habitat survey data, such as the Oregon Department of Fish & Wildlife’s Aquatic Habitat Inventories, to evaluate the degree of change over time of stream and riparian conditions. Title: Historical Vegetation of Three Salmon-Bearing Watersheds in the Interior Columbia River Basin Author: Smith, Tyanna Year: 2014 Land use practices can be a contributing factor to environmental degradation and have been the focus of many ecological studies. One aspect that is less addressed is land use history and the effects that past practices, such as logging and grazing, can have on the current landscape. This paper describes research and the synthesis of material on the environmental history and watershed characteristics for three watersheds located within spawning and rearing areas for Chinook salmon in the Grande Ronde River Basin in Northeast Oregon: upper Grande Ronde River, Catherine Creek, and Minam River. The Grande Ronde Basin is critical spawning and rearing habitat for salmonids listed under the Endangered Species Act. The primary historical data sources for reconstructing 19th century stream and riparian conditions are the General Land Office township survey notes from 1863 - 1901. Data about the habitat conditions of the landscape were extracted from notes of each township survey source regarding vegetation, stream crossings, and other features found on the landscape in tabular and spatial forms. Data were organized to describe common stream and riparian conditions for the historical time period using a geographic information system. Watershed basin, Chinook salmon life history, ecoregion and surveyor were analyzed using multivariate techniques to determine which parameters were strongly connected to historical vegetation. Ecoregion had the strongest correlation with plant communities. For future research, these historical data could be compared to current habitat survey data, such as the Oregon Department of Fish & Wildlife’s Aquatic Habitat Inventories, to evaluate the degree of change over time of stream and riparian conditions. Close

• 7. [Article] A Statistical Investigation of Lower Columbia River Water Temperature, 1915-2003

  The Columbia River is home to anadromous salmon populations that migrate upriver every year to spawn. These fish require cool water temperatures (Tw) to survive. In recent years, high summer Tw in the ...

  Citation × Citation Citation Abstract Copy Title: A Statistical Investigation of Lower Columbia River Water Temperature, 1915-2003 Author: Overman, Corina Christina Mae Year: 2017 The Columbia River is home to anadromous salmon populations that migrate upriver every year to spawn. These fish require cool water temperatures (Tw) to survive. In recent years, high summer Tw in the Columbia River has caused increased mortality of salmon. Different possible explanations for increased Tw include climate change, deforestation, and decreased summertime streamflow (Q) due to dams. In this study, robust linear regression models of Tw based on air temperature (Ta) and Q were developed to examine the change in Tw over time. The data was separated into an historical period (1938-1956) and a modern period (1977-2003). Seasonal regression models were used for May through October (summer) and November through April (winter) for each period. Comparison of these models showed that Tw has become less sensitive to recent atmospheric heating and cooling. By contrast, analysis suggested that Tw has become more sensitive to variations in Q. Of the 1.5ºC increase in maximum summertime Tw, approximately 1.3ºC was due to dams and reservoir management based on changes in regression coefficients and average Q. A smaller, 0.2ºC change was estimated to be caused by increasing Ta since the mid-20th century. While average maximum Tw has increased, both the statistical model and data suggest that the variability in Tw from its climatological average has decreased, probably due to reservoir management. Title: A Statistical Investigation of Lower Columbia River Water Temperature, 1915-2003 Author: Overman, Corina Christina Mae Year: 2017 The Columbia River is home to anadromous salmon populations that migrate upriver every year to spawn. These fish require cool water temperatures (Tw) to survive. In recent years, high summer Tw in the Columbia River has caused increased mortality of salmon. Different possible explanations for increased Tw include climate change, deforestation, and decreased summertime streamflow (Q) due to dams. In this study, robust linear regression models of Tw based on air temperature (Ta) and Q were developed to examine the change in Tw over time. The data was separated into an historical period (1938-1956) and a modern period (1977-2003). Seasonal regression models were used for May through October (summer) and November through April (winter) for each period. Comparison of these models showed that Tw has become less sensitive to recent atmospheric heating and cooling. By contrast, analysis suggested that Tw has become more sensitive to variations in Q. Of the 1.5ºC increase in maximum summertime Tw, approximately 1.3ºC was due to dams and reservoir management based on changes in regression coefficients and average Q. A smaller, 0.2ºC change was estimated to be caused by increasing Ta since the mid-20th century. While average maximum Tw has increased, both the statistical model and data suggest that the variability in Tw from its climatological average has decreased, probably due to reservoir management. Close

• 8. [Article] Stranding Mortality Patterns in California Sea Lions and Steller Sea Lions in Oregon and Southern Washington, 2006 to 2014

  As changing ocean conditions lead to declining fish stocks and movement of forage fish, sea lions on the Oregon coast are subject to the pressures of declining prey availability and increasing conflicts ...

  Citation × Citation Citation Abstract Copy Title: Stranding Mortality Patterns in California Sea Lions and Steller Sea Lions in Oregon and Southern Washington, 2006 to 2014 Author: Lee, Kessina Year: 2016 As changing ocean conditions lead to declining fish stocks and movement of forage fish, sea lions on the Oregon coast are subject to the pressures of declining prey availability and increasing conflicts with commercial and recreational fisheries. An analysis of strandings of California sea lions, Zalophus californianus, and Steller sea lions, Eumetopias jubatus, from 2006 to 2014, included cause of death, changing ocean conditions, and anthropogenic activity. Causes of death included disease, injury, and human interaction, such as gunshot wounds, fisheries net entanglements and boat strikes. Oregon and Washington strandings of California sea lions are primarily adult and subadult males that migrate north from California rookeries, while Steller sea lions are year-round residents and strandings are comprised of males and females of all ages. While the California sea lion population is currently at or near carrying capacity, the Eastern Pacific population of Steller sea lions was designated as Threatened under the Endangered Species Act until October 2013. Understanding impacts to these two pinniped species is vital to implementing effective management and conservation policies. Oregon and southern Washington strandings of California sea lions and Steller sea lions from 2006 to 2014 were analyzed spatially using the geographic information system (GIS), and temporally to identify possible correlations with prey availability and human interaction. Strandings were found to follow seasonal patterns from year to year: Steller sea lion strandings were highest from May to July, California sea lions peaked in September, October, and November. There was a correlation between significantly high numbers of strandings and the three largest commercial fisheries in Oregon: Chinook salmon, Coho salmon, and Dungeness crab. This analysis provides a format for continuing to monitor primary ecological and anthropogenic drivers of pinniped mortality in Oregon and southern Washington. Title: Stranding Mortality Patterns in California Sea Lions and Steller Sea Lions in Oregon and Southern Washington, 2006 to 2014 Author: Lee, Kessina Year: 2016 As changing ocean conditions lead to declining fish stocks and movement of forage fish, sea lions on the Oregon coast are subject to the pressures of declining prey availability and increasing conflicts with commercial and recreational fisheries. An analysis of strandings of California sea lions, Zalophus californianus, and Steller sea lions, Eumetopias jubatus, from 2006 to 2014, included cause of death, changing ocean conditions, and anthropogenic activity. Causes of death included disease, injury, and human interaction, such as gunshot wounds, fisheries net entanglements and boat strikes. Oregon and Washington strandings of California sea lions are primarily adult and subadult males that migrate north from California rookeries, while Steller sea lions are year-round residents and strandings are comprised of males and females of all ages. While the California sea lion population is currently at or near carrying capacity, the Eastern Pacific population of Steller sea lions was designated as Threatened under the Endangered Species Act until October 2013. Understanding impacts to these two pinniped species is vital to implementing effective management and conservation policies. Oregon and southern Washington strandings of California sea lions and Steller sea lions from 2006 to 2014 were analyzed spatially using the geographic information system (GIS), and temporally to identify possible correlations with prey availability and human interaction. Strandings were found to follow seasonal patterns from year to year: Steller sea lion strandings were highest from May to July, California sea lions peaked in September, October, and November. There was a correlation between significantly high numbers of strandings and the three largest commercial fisheries in Oregon: Chinook salmon, Coho salmon, and Dungeness crab. This analysis provides a format for continuing to monitor primary ecological and anthropogenic drivers of pinniped mortality in Oregon and southern Washington. Close

• 9. [Article] Study of Prestige and Resource Control Using Fish Remains from Cathlapotle, a Plankhouse Village on the Lower Columbia River

  Social inequality is a trademark of Northwest Coast native societies, and the relationship between social prestige and resource control, particularly resource ownership, is an important research issue ...

  Citation × Citation Citation Abstract Copy Title: Study of Prestige and Resource Control Using Fish Remains from Cathlapotle, a Plankhouse Village on the Lower Columbia River Author: Rosenberg, J. Shoshana Year: 2015 Social inequality is a trademark of Northwest Coast native societies, and the relationship between social prestige and resource control, particularly resource ownership, is an important research issue on the Northwest Coast. Faunal remains are one potential but as yet underutilized path for examining this relationship. My thesis work takes on this approach through the analysis of fish remains from the Cathlapotle archaeological site (45CL1). Cathlapotle is a large Chinookan village site located on the Lower Columbia River that was extensively excavated in the 1990s. Previous work has established prestige distinctions between houses and house compartments, making it possible to examine the relationship between prestige and the spatial distribution of fish remains. In this study, I examine whether having high prestige afforded its bearers greater access to preferred fish, utilizing comparisons of fish remains at two different levels of social organization, between and within households, to determine which social mechanisms could account for potential differences in access to fish resources. Differential access to these resources within the village could have occurred through household-level ownership of harvesting sites or control over the post-harvesting distribution of food by certain individuals. Previous work in this region on the relationship between faunal remains and prestige has relied heavily on ethnohistoric sources to determine the relative value of taxa. These sources do not provide adequate data to make detailed comparisons between all of the taxa encountered at archaeological sites, so in this study I utilize optimal foraging theory as an alternative means of determining which fish taxa were preferred. Optimal foraging theory provides a universal, quantitative analytical rule for ranking fish that I was able to apply to all of the taxa encountered at Cathlapotle. Given these rankings, which are based primarily on size, I examine the degree to which relative prestige designations of two households (Houses 1 and 4) and compartments within one of those households (House 1) are reflected in the spatial distribution of fish remains. I also offer a new method for quantifying sturgeon that utilizes specimen weight to account for differential fragmentation rates while still allowing for sturgeon abundance to be compared to the abundances of other taxa that have been quantified by number of identified specimens (NISP). Based on remains recovered from 1/4" mesh screens, comparisons between compartments within House 1 indicate that the chief and possibly other elite members of House 1 likely had some control over the distribution of fish resources within their household, taking more of the preferred sturgeon and salmon, particularly more chinook salmon, for themselves. Comparisons between households provide little evidence to support household-based ownership of fishing sites. A greater abundance of chinook salmon in the higher prestige House 1 may indicate ownership of fishing platforms at major chinook fisheries such as Willamette Falls or Cascades Rapids, but other explanations for this difference between households are possible. Analyses of a limited number of bulk samples, which were included in the study in order to examine utilization of very small fishes, provided insufficient data to allow for meaningful intrasite comparisons. These data indicate that the inhabitants of Cathlapotle were exploiting a broad fish subsistence base that included large numbers of eulachon and stickleback in addition to the larger fishes. This study provides a promising approach for examining prestige on the Northwest Coast and expanding our understanding of the dynamics between social inequality and resource access and control. Title: Study of Prestige and Resource Control Using Fish Remains from Cathlapotle, a Plankhouse Village on the Lower Columbia River Author: Rosenberg, J. Shoshana Year: 2015 Social inequality is a trademark of Northwest Coast native societies, and the relationship between social prestige and resource control, particularly resource ownership, is an important research issue on the Northwest Coast. Faunal remains are one potential but as yet underutilized path for examining this relationship. My thesis work takes on this approach through the analysis of fish remains from the Cathlapotle archaeological site (45CL1). Cathlapotle is a large Chinookan village site located on the Lower Columbia River that was extensively excavated in the 1990s. Previous work has established prestige distinctions between houses and house compartments, making it possible to examine the relationship between prestige and the spatial distribution of fish remains. In this study, I examine whether having high prestige afforded its bearers greater access to preferred fish, utilizing comparisons of fish remains at two different levels of social organization, between and within households, to determine which social mechanisms could account for potential differences in access to fish resources. Differential access to these resources within the village could have occurred through household-level ownership of harvesting sites or control over the post-harvesting distribution of food by certain individuals. Previous work in this region on the relationship between faunal remains and prestige has relied heavily on ethnohistoric sources to determine the relative value of taxa. These sources do not provide adequate data to make detailed comparisons between all of the taxa encountered at archaeological sites, so in this study I utilize optimal foraging theory as an alternative means of determining which fish taxa were preferred. Optimal foraging theory provides a universal, quantitative analytical rule for ranking fish that I was able to apply to all of the taxa encountered at Cathlapotle. Given these rankings, which are based primarily on size, I examine the degree to which relative prestige designations of two households (Houses 1 and 4) and compartments within one of those households (House 1) are reflected in the spatial distribution of fish remains. I also offer a new method for quantifying sturgeon that utilizes specimen weight to account for differential fragmentation rates while still allowing for sturgeon abundance to be compared to the abundances of other taxa that have been quantified by number of identified specimens (NISP). Based on remains recovered from 1/4" mesh screens, comparisons between compartments within House 1 indicate that the chief and possibly other elite members of House 1 likely had some control over the distribution of fish resources within their household, taking more of the preferred sturgeon and salmon, particularly more chinook salmon, for themselves. Comparisons between households provide little evidence to support household-based ownership of fishing sites. A greater abundance of chinook salmon in the higher prestige House 1 may indicate ownership of fishing platforms at major chinook fisheries such as Willamette Falls or Cascades Rapids, but other explanations for this difference between households are possible. Analyses of a limited number of bulk samples, which were included in the study in order to examine utilization of very small fishes, provided insufficient data to allow for meaningful intrasite comparisons. These data indicate that the inhabitants of Cathlapotle were exploiting a broad fish subsistence base that included large numbers of eulachon and stickleback in addition to the larger fishes. This study provides a promising approach for examining prestige on the Northwest Coast and expanding our understanding of the dynamics between social inequality and resource access and control. Close

• 10. [Article] Tracking Fish and Human Response to Earthquakes on the Northwest Coast of Washington State, USA: A Preliminary Study at Tse-whit-zen

  Evidence of large earthquakes occurring along the Pacific Northwest Coast is reflected in coastal stratigraphy from Oregon to British Columbia, where there also exists an extensive archaeological record ...

  Citation × Citation Citation Abstract Copy Title: Tracking Fish and Human Response to Earthquakes on the Northwest Coast of Washington State, USA: A Preliminary Study at Tse-whit-zen Author: Mohlenhoff, Kathryn A., Butler, Virginia L. Year: 2017 Evidence of large earthquakes occurring along the Pacific Northwest Coast is reflected in coastal stratigraphy from Oregon to British Columbia, where there also exists an extensive archaeological record of Native American occupation. Tse-whit-zen, a large Native American village dating between ∼2800 yrs BP and the historic era, located on the Olympic Peninsula of Washington State, was excavated with exceptionally fine stratigraphic control allowing for precise comparison of these natural and cultural records. Here we report on the ∼10,000 fish remains from one 2 × 2 m excavation block; this assemblage spans the timing of one seismic event, allowing study of changes in relative taxonomic abundance through time that may coincide with earthquakes or other environmental changes. Results indicate a wide variety of fish taxa were used throughout the dated occupation. Comparisons of fish use before and after one earthquake event shows a decline in salmon (Oncorhynchus sp.) and an increase in herring (Clupea pallasii), shifts consistent with earthquake-related habitat loss. This serves as a pilot study for a large-scale collaborative project that is drawing on the range in animal types (invertebrates, mammals, birds, and fishes) to assess human response to gradual and abrupt environmental change at Tse-whit-zen. Title: Tracking Fish and Human Response to Earthquakes on the Northwest Coast of Washington State, USA: A Preliminary Study at Tse-whit-zen Author: Mohlenhoff, Kathryn A., Butler, Virginia L. Year: 2017 Evidence of large earthquakes occurring along the Pacific Northwest Coast is reflected in coastal stratigraphy from Oregon to British Columbia, where there also exists an extensive archaeological record of Native American occupation. Tse-whit-zen, a large Native American village dating between ∼2800 yrs BP and the historic era, located on the Olympic Peninsula of Washington State, was excavated with exceptionally fine stratigraphic control allowing for precise comparison of these natural and cultural records. Here we report on the ∼10,000 fish remains from one 2 × 2 m excavation block; this assemblage spans the timing of one seismic event, allowing study of changes in relative taxonomic abundance through time that may coincide with earthquakes or other environmental changes. Results indicate a wide variety of fish taxa were used throughout the dated occupation. Comparisons of fish use before and after one earthquake event shows a decline in salmon (Oncorhynchus sp.) and an increase in herring (Clupea pallasii), shifts consistent with earthquake-related habitat loss. This serves as a pilot study for a large-scale collaborative project that is drawing on the range in animal types (invertebrates, mammals, birds, and fishes) to assess human response to gradual and abrupt environmental change at Tse-whit-zen. Close