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• 21. [Article] Review of Willamette Restoration Initiative. Restoring the Willamette River Basin: Strategical Issues and Challenges

  1 p. Review produced for HC 441: Science Colloquium: Willamette River Environmental Health, Robert D. Clark Honors College, University of Oregon, Spring term, 2004.

  Citation × Citation Citation Abstract Copy Title: Review of Willamette Restoration Initiative. Restoring the Willamette River Basin: Strategical Issues and Challenges Author: DalMolin, Aria, United States. Army. Corps of Engineers Year: 2006, 2004 1 p. Review produced for HC 441: Science Colloquium: Willamette River Environmental Health, Robert D. Clark Honors College, University of Oregon, Spring term, 2004. Title: Review of Willamette Restoration Initiative. Restoring the Willamette River Basin: Strategical Issues and Challenges Author: DalMolin, Aria, United States. Army. Corps of Engineers Year: 2006, 2004 1 p. Review produced for HC 441: Science Colloquium: Willamette River Environmental Health, Robert D. Clark Honors College, University of Oregon, Spring term, 2004. Close

• 22. [Article] Review of Seasonal and Spatial Variability of Nutrients and Pesticides in Streams of the Willamette Basin, Oregon, 1993-5

  1 p. Review produced for HC 441: Science Colloquium: Willamette River Environmental Health, Robert D. Clark Honors College, University of Oregon , Spring term, 2004.

  Citation × Citation Citation Abstract Copy Title: Review of Seasonal and Spatial Variability of Nutrients and Pesticides in Streams of the Willamette Basin, Oregon, 1993-5 Author: Koehler, Kate, Rinella, Frank, Janet, Mary Year: 2005, 2004 1 p. Review produced for HC 441: Science Colloquium: Willamette River Environmental Health, Robert D. Clark Honors College, University of Oregon , Spring term, 2004. Title: Review of Seasonal and Spatial Variability of Nutrients and Pesticides in Streams of the Willamette Basin, Oregon, 1993-5 Author: Koehler, Kate, Rinella, Frank, Janet, Mary Year: 2005, 2004 1 p. Review produced for HC 441: Science Colloquium: Willamette River Environmental Health, Robert D. Clark Honors College, University of Oregon , Spring term, 2004. Close

• 23. [Article] Habrate: A Limiting Factors Model for Accessing Stream Habitat Quality for Salmon and Steelhead in the Deschutes River Basin, 2010. Information Reports Number 2010-03

  Abstract -- Fishery managers are commonly tasked with the basic question "Will the contemporary habitat above a barrier support the fish populations that historically resided in the watershed?" Managers ...

  Citation × Citation Citation Abstract Copy Title: Habrate: A Limiting Factors Model for Accessing Stream Habitat Quality for Salmon and Steelhead in the Deschutes River Basin, 2010. Information Reports Number 2010-03 Abstract -- Fishery managers are commonly tasked with the basic question "Will the contemporary habitat above a barrier support the fish populations that historically resided in the watershed?" Managers in central Oregon were confronted with that question in an effort to reestablish fish populations in 375 kilometers of stream above the Round Butte-Pelton Dam complex (Rkm 161) on the Deschutes River. Stream surveys had been conducted in most of the available stream habitat, but had not been synthesized in a form that allowed managers to view the quality and complexity of stream habitat in an easily-understandable fashion. In response, we developed a limiting factors model (HabRate) that assessed the potential quality of stream habitat using stream survey data for each juvenile life stage of salmon and steelhead. The model was developed for a specific application to the middle Deschutes River basin in Oregon, but was intended for general application to Pacific Northwest basins. To paramatize the model, we summarized available literature on salmonid habitat requirements. Habitat criteria were developed for discrete life history stages (i.e. spawning, egg survival, emergence, summer rearing, and winter rearing) and used to rate the quality of stream reaches as poor, fair, or good, based on attributes relating to stream substrate, habitat unit type, cover, gradient, temperature, and flow. Reach level summaries of stream habitat data were entered into MS Excel, and interpreted by a series of algorithms to provide a limiting factor assessment of potential egg-to-fry and fry-to-parr survival for each reach. Model output lists habitat quality by species and life stage for each reach of stream. The model is a decision making tool that is intended to provide a qualitative assessment of the habitat potential of stream reaches within a basin context. Design criteria for the model were simplicity, flexibility, and transparency. While HabRate was based on our interpretations of the published literature, specific criteria for habitat quality were structured to be easily adjusted where interpretations differ from ours. Information not common to standard stream survey designs, such as seasonal flow or temperature extremes can be included as input from professional judgment. The results were integrated into a GIS coverage coupled with the stream network and habitat data to provide a comprehensive map-based perspective of habitat quality in a watershed. Title: Habrate: A Limiting Factors Model for Accessing Stream Habitat Quality for Salmon and Steelhead in the Deschutes River Basin, 2010. Information Reports Number 2010-03 Abstract -- Fishery managers are commonly tasked with the basic question "Will the contemporary habitat above a barrier support the fish populations that historically resided in the watershed?" Managers in central Oregon were confronted with that question in an effort to reestablish fish populations in 375 kilometers of stream above the Round Butte-Pelton Dam complex (Rkm 161) on the Deschutes River. Stream surveys had been conducted in most of the available stream habitat, but had not been synthesized in a form that allowed managers to view the quality and complexity of stream habitat in an easily-understandable fashion. In response, we developed a limiting factors model (HabRate) that assessed the potential quality of stream habitat using stream survey data for each juvenile life stage of salmon and steelhead. The model was developed for a specific application to the middle Deschutes River basin in Oregon, but was intended for general application to Pacific Northwest basins. To paramatize the model, we summarized available literature on salmonid habitat requirements. Habitat criteria were developed for discrete life history stages (i.e. spawning, egg survival, emergence, summer rearing, and winter rearing) and used to rate the quality of stream reaches as poor, fair, or good, based on attributes relating to stream substrate, habitat unit type, cover, gradient, temperature, and flow. Reach level summaries of stream habitat data were entered into MS Excel, and interpreted by a series of algorithms to provide a limiting factor assessment of potential egg-to-fry and fry-to-parr survival for each reach. Model output lists habitat quality by species and life stage for each reach of stream. The model is a decision making tool that is intended to provide a qualitative assessment of the habitat potential of stream reaches within a basin context. Design criteria for the model were simplicity, flexibility, and transparency. While HabRate was based on our interpretations of the published literature, specific criteria for habitat quality were structured to be easily adjusted where interpretations differ from ours. Information not common to standard stream survey designs, such as seasonal flow or temperature extremes can be included as input from professional judgment. The results were integrated into a GIS coverage coupled with the stream network and habitat data to provide a comprehensive map-based perspective of habitat quality in a watershed. Close

• 24. [Article] Arsenic in ground water of the Willamette Basin, Oregon

  Arsenic concentrations exceeding the U.S. Environmental Protection Agency (USEPA) current Maximum Contaminant Level (MCL) of 50 micrograms per liter are widespread in ground water in the Willamette Basin. ...

  Citation × Citation Citation Abstract Copy Title: Arsenic in ground water of the Willamette Basin, Oregon Author: Hinkle, Stephen R., Oregon. Water Resources Dept., Geological Survey (U.S.), Polette, Danial J. Arsenic concentrations exceeding the U.S. Environmental Protection Agency (USEPA) current Maximum Contaminant Level (MCL) of 50 micrograms per liter are widespread in ground water in the Willamette Basin. The Oregon Water Resources Department and the U.S. Geological Survey began a cooperative study in the Willamette Basin in 1996. One goal of this study is to characterize the regional distribution of naturally occurring poor-quality ground water, such as ground water with high concentrations of arsenic. Characterization of the regional distribution of arsenic concentrations in the Willamette Basin will be useful to public health officials, water-resource managers, the medical community, and those using ground water for drinking and cooking. Title: Arsenic in ground water of the Willamette Basin, Oregon Author: Hinkle, Stephen R., Oregon. Water Resources Dept., Geological Survey (U.S.), Polette, Danial J. Arsenic concentrations exceeding the U.S. Environmental Protection Agency (USEPA) current Maximum Contaminant Level (MCL) of 50 micrograms per liter are widespread in ground water in the Willamette Basin. The Oregon Water Resources Department and the U.S. Geological Survey began a cooperative study in the Willamette Basin in 1996. One goal of this study is to characterize the regional distribution of naturally occurring poor-quality ground water, such as ground water with high concentrations of arsenic. Characterization of the regional distribution of arsenic concentrations in the Willamette Basin will be useful to public health officials, water-resource managers, the medical community, and those using ground water for drinking and cooking. Close

• 25. [Article] USDA report on water and related land resources : Lower Willamette River Basin, Oregon ; based on a cooperative survey by the State Water Resources Board of Oregon and the United States Department of Agriculture : report

  Citation × Citation Citation Abstract Copy Title: USDA report on water and related land resources : Lower Willamette River Basin, Oregon ; based on a cooperative survey by the State Water Resources Board of Oregon and the United States Department of Agriculture : report Author: USDA Field Advisory Committee, USDA Oregon River Basin Survey Party, United States. Forest Service, United States. Dept. of Agriculture. Economic Research Service, United States. Soil Conservation Service, Oregon. State Water Resources Board Title: USDA report on water and related land resources : Lower Willamette River Basin, Oregon ; based on a cooperative survey by the State Water Resources Board of Oregon and the United States Department of Agriculture : report Author: USDA Field Advisory Committee, USDA Oregon River Basin Survey Party, United States. Forest Service, United States. Dept. of Agriculture. Economic Research Service, United States. Soil Conservation Service, Oregon. State Water Resources Board Close

• 26. [Article] Fish and amphibian use of intermittent streams within the upper Willamette Basin, Oregon

  In the fall through spring of 2002/03 and 2003/04, the composition of fish and amphibian communities were examined in intermittent streams in the upper Willamette river basin in western Oregon. I recorded ...

  Citation × Citation Citation Abstract Copy Title: Fish and amphibian use of intermittent streams within the upper Willamette Basin, Oregon Author: Colvin, Randall William In the fall through spring of 2002/03 and 2003/04, the composition of fish and amphibian communities were examined in intermittent streams in the upper Willamette river basin in western Oregon. I recorded standard aquatic habitat variables and water nutrient concentrations (nitrate and phosphate) and correlated them with fish and amphibian communities present. Fish and amphibian communities were also compared between seasons (winter and spring), capture method (minnowtrap and backpack electrofishing) and channel morphology (incised and gently sloping channels). Fish were tagged with visual implant elastomer to assess movement and distribution. Fourteen species of fish and five species of amphibians were present in these habitats over two field seasons. Fish and amphibian species composition and abundance was correlated with characteristics of the upper Willamette basin. The regional characteristics associated with the differences were a) the amount of the watershed covered in forest and b) upstream slope; whereas mean maximum water velocity separated fish dominated communities from amphibian dominated communities. Approximately 99% of fish and amphibian species caught were native to the Willamette river basin and the number of fish species decreased as the sampling distance from perennial water increased. Significant differences were found in fish and amphibian community composition between winter and spring and between capture methods. Surface/mid-water feeding fish were more abundant in gently sloping channels than benthic feeding fishes. Only 2.6% of the 498 tagged fish were recaptured between December and April. In the fall through spring 2003/04, the composition of fish communities and their invertebrate diets were compared between 12 sites on four intermittent streams. The distance between consecutive sites was approximately 900 to 1500-m. Two intermittent streams had incised channels, confining high flows to a narrow channel. The remaining two streams had gently sloping channels, where flood waters had access to the floodplain. Two hundred and thirty individual diets were sampled from cutthroat trout, northern pikeminnow, redside shiner, sculpin, speckled dace, threespine stickleback in both winter and spring. About 60% of the stomach samples contained invertebrates and approximately 90% of them were aquatic species. There was a significant difference in the numbers of invertebrates consumed by redside shiners, sculpins and speckled dace. These three fish species fed most often on benthic invertebrates compared to surf ace/midwater invertebrates, but only sculpins and redside shiners were significantly different. However, the proportions of benthic and surface/midwater invertebrates in the diet of these fish species were not significantly different between seasons or channel types. This thesis inventories fish and amphibian species found in intermittent stream habitats of the upper Willamette basin, and identifies the main habitat features that influence the distribution of those species. It also examines the diet composition of a subset of widely distributed fish species. The findings of this study can be used to understand how land uses, such as grass seed agriculture, affect intermittent streams, and to design future studies on the effectiveness of habitat enhancement conservation practices (such as grassed waterways, residue management, filter strips, streambank protection, etc.) to improve and/or protect these important seasonal habitats in the upper Willamette basin. Title: Fish and amphibian use of intermittent streams within the upper Willamette Basin, Oregon Author: Colvin, Randall William In the fall through spring of 2002/03 and 2003/04, the composition of fish and amphibian communities were examined in intermittent streams in the upper Willamette river basin in western Oregon. I recorded standard aquatic habitat variables and water nutrient concentrations (nitrate and phosphate) and correlated them with fish and amphibian communities present. Fish and amphibian communities were also compared between seasons (winter and spring), capture method (minnowtrap and backpack electrofishing) and channel morphology (incised and gently sloping channels). Fish were tagged with visual implant elastomer to assess movement and distribution. Fourteen species of fish and five species of amphibians were present in these habitats over two field seasons. Fish and amphibian species composition and abundance was correlated with characteristics of the upper Willamette basin. The regional characteristics associated with the differences were a) the amount of the watershed covered in forest and b) upstream slope; whereas mean maximum water velocity separated fish dominated communities from amphibian dominated communities. Approximately 99% of fish and amphibian species caught were native to the Willamette river basin and the number of fish species decreased as the sampling distance from perennial water increased. Significant differences were found in fish and amphibian community composition between winter and spring and between capture methods. Surface/mid-water feeding fish were more abundant in gently sloping channels than benthic feeding fishes. Only 2.6% of the 498 tagged fish were recaptured between December and April. In the fall through spring 2003/04, the composition of fish communities and their invertebrate diets were compared between 12 sites on four intermittent streams. The distance between consecutive sites was approximately 900 to 1500-m. Two intermittent streams had incised channels, confining high flows to a narrow channel. The remaining two streams had gently sloping channels, where flood waters had access to the floodplain. Two hundred and thirty individual diets were sampled from cutthroat trout, northern pikeminnow, redside shiner, sculpin, speckled dace, threespine stickleback in both winter and spring. About 60% of the stomach samples contained invertebrates and approximately 90% of them were aquatic species. There was a significant difference in the numbers of invertebrates consumed by redside shiners, sculpins and speckled dace. These three fish species fed most often on benthic invertebrates compared to surf ace/midwater invertebrates, but only sculpins and redside shiners were significantly different. However, the proportions of benthic and surface/midwater invertebrates in the diet of these fish species were not significantly different between seasons or channel types. This thesis inventories fish and amphibian species found in intermittent stream habitats of the upper Willamette basin, and identifies the main habitat features that influence the distribution of those species. It also examines the diet composition of a subset of widely distributed fish species. The findings of this study can be used to understand how land uses, such as grass seed agriculture, affect intermittent streams, and to design future studies on the effectiveness of habitat enhancement conservation practices (such as grassed waterways, residue management, filter strips, streambank protection, etc.) to improve and/or protect these important seasonal habitats in the upper Willamette basin. Close

• 27. [Article] The fish and wildlife resources of the Lower Willamette Basin, Oregon, and their water use requirements.

  Federal Aid to Fish Restoration Progress Report

  Citation × Citation Citation Abstract Copy Title: The fish and wildlife resources of the Lower Willamette Basin, Oregon, and their water use requirements. Author: Hutchison, James M., Aney, Warren W. Federal Aid to Fish Restoration Progress Report Title: The fish and wildlife resources of the Lower Willamette Basin, Oregon, and their water use requirements. Author: Hutchison, James M., Aney, Warren W. Federal Aid to Fish Restoration Progress Report Close

• 28. [Article] Upper Nehelam Habitat Assessments - Winter 2006 & 2007

  Abstract -- Project staff utilized the ODFW Aquatic Inventory protocol to assess habitat in selected small, medium, and large sized streams in the Upper Nehalem basin. In addition, the project personnel ...

  Citation × Citation Citation Abstract Copy Title: Upper Nehelam Habitat Assessments - Winter 2006 & 2007 Abstract -- Project staff utilized the ODFW Aquatic Inventory protocol to assess habitat in selected small, medium, and large sized streams in the Upper Nehalem basin. In addition, the project personnel conducted a snorkeling survey to estimate juvenile salmonid distribution in these streams. The 2006 and 2007 habitat surveys completed the remaining non-surveyed Coho freshwater habitat streams found within the Upper Nehalem. During the 2006 and 2007 seasons we surveyed 218 stream reaches in 87 streams totaling 242.82 kilometers (150.54 miles) of habitat. In addition, the project staff snorkeled 445 pools within the surveyed areas. Title: Upper Nehelam Habitat Assessments - Winter 2006 & 2007 Abstract -- Project staff utilized the ODFW Aquatic Inventory protocol to assess habitat in selected small, medium, and large sized streams in the Upper Nehalem basin. In addition, the project personnel conducted a snorkeling survey to estimate juvenile salmonid distribution in these streams. The 2006 and 2007 habitat surveys completed the remaining non-surveyed Coho freshwater habitat streams found within the Upper Nehalem. During the 2006 and 2007 seasons we surveyed 218 stream reaches in 87 streams totaling 242.82 kilometers (150.54 miles) of habitat. In addition, the project staff snorkeled 445 pools within the surveyed areas. Close

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

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

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

• 30. [Article] Stream DOC, nitrate, chloride and SUVA response to land use during winter baseflow conditions in sub-basins of the Willamette River Basin, OR

  To better understand the impact of land use on stream nutrient export, a synoptic sampling of 57 sub-basins within the Willamette River basin was conducted during winter baseflow conditions (February 2009). ...

  Citation × Citation Citation Abstract Copy Title: Stream DOC, nitrate, chloride and SUVA response to land use during winter baseflow conditions in sub-basins of the Willamette River Basin, OR Author: Frentress, Jay To better understand the impact of land use on stream nutrient export, a synoptic sampling of 57 sub-basins within the Willamette River basin was conducted during winter baseflow conditions (February 2009). I assessed whether stream dissolved organic carbon (DOC), NO₃⁻ and Cl⁻ and specific ultra-violet absorbance (SUVA) values were correlated with individual watershed land use variables: percent urban, agriculture, and forest. Simple linear regression analysis indicated that stream DOC, NO₃⁻ and Cl⁻ increased significantly with increasing percent agriculture and urban area in sampled watersheds, and decreased significantly with increasing percent forest. Stream order and watershed area were not significantly related to any stream chemistry variables. Simple linear regression analysis indicated that SUVA, a measure of the aromaticity of DOC, decreased significantly with increasing percent urban area in catchments, but was not significantly related to percent agriculture or urban. Ordination of streams on the basis of their chemistry supported simple linear regression analyses, clustering of streams with low SUVA values and higher DOC, NO₃⁻, and Cl concentrations, which were also largely associated with increasing percent urban, and slightly less associated with increasing percent agriculture. Results indicate that stream nutrient concentrations are strongly influenced by associated land use within the watershed. SUVA results suggest a combination of land use and variable hydrologic flowpaths affects the composition of stream DOC under winter baseflow conditions. Title: Stream DOC, nitrate, chloride and SUVA response to land use during winter baseflow conditions in sub-basins of the Willamette River Basin, OR Author: Frentress, Jay To better understand the impact of land use on stream nutrient export, a synoptic sampling of 57 sub-basins within the Willamette River basin was conducted during winter baseflow conditions (February 2009). I assessed whether stream dissolved organic carbon (DOC), NO₃⁻ and Cl⁻ and specific ultra-violet absorbance (SUVA) values were correlated with individual watershed land use variables: percent urban, agriculture, and forest. Simple linear regression analysis indicated that stream DOC, NO₃⁻ and Cl⁻ increased significantly with increasing percent agriculture and urban area in sampled watersheds, and decreased significantly with increasing percent forest. Stream order and watershed area were not significantly related to any stream chemistry variables. Simple linear regression analysis indicated that SUVA, a measure of the aromaticity of DOC, decreased significantly with increasing percent urban area in catchments, but was not significantly related to percent agriculture or urban. Ordination of streams on the basis of their chemistry supported simple linear regression analyses, clustering of streams with low SUVA values and higher DOC, NO₃⁻, and Cl concentrations, which were also largely associated with increasing percent urban, and slightly less associated with increasing percent agriculture. Results indicate that stream nutrient concentrations are strongly influenced by associated land use within the watershed. SUVA results suggest a combination of land use and variable hydrologic flowpaths affects the composition of stream DOC under winter baseflow conditions. Close