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• 61. [Article] Relationships between relative abundance of resident bull trout (Salvelinus confluentus) and habitat characteristics in Central Idaho mountain streams

  Resident bull trout (Salvelinus confluentus) may be particularly vulnerable to human related disturbance, however very few studies have focused on resident bull trout populations. The abundance of bull ...

  Citation × Citation Citation Abstract Copy Title: Relationships between relative abundance of resident bull trout (Salvelinus confluentus) and habitat characteristics in Central Idaho mountain streams Author: Zurstadt, Caleb Frederick Resident bull trout (Salvelinus confluentus) may be particularly vulnerable to human related disturbance, however very few studies have focused on resident bull trout populations. The abundance of bull trout is one measure of the strength and potential for persistence of a population. Habitat characteristics may influence resident bull trout abundance to differing degrees and by varying means at multiple spatial scales. We used day and night snorkel counts to assess relative bull trout abundance. A modification of the Forest Service R1/R4 Fish and Fish Habitat Inventory was used to assess habitat characteristics associated with resident bull trout. Logistic and multiple linear regression were used to assess the relationships between resident bull trout abundance and habitat characteristics at the patch (1 to 5 km), reach (0.5 to 1 km) and habitat unit (1 to 100 m) scales. Site categorical variables were used along with quantitative habitat variables to explain among-site and across-site variation in the data. The significance of both quantitative habitat variables and categorical site variables at various spatial scales suggest that relationships between bull trout abundance and habitat characteristics are complex and in part dependent on scale. The characteristics of individual habitat units explained little of the variation in bull trout presence/absence (logistic regression; Somers' D=0.44) and density (multiple linear regression; adjusted R²=0.08) in habitat units, however there were habitat characteristics that were significantly (P≤0.05) correlated to bull trout presence/absence and density in habitat units. The relationships between habitat characteristics and bull trout presence/absence and density varied between habitat unit types. There was a strong quadratic relationship between bull trout abundance and mean summer water temperature at the reach (P=0.004) and patch scales (P=0.001). The mean temperature of patches appears to explain some of the variation in bull trout density at smaller spatial scales, such as reaches and habitat units. An appreciation of the complex nature of scale dependent interactions between bull trout abundance and habitat characteristics may help resource managers make wiser decisions regarding conservation of resident bull trout populations. Title: Relationships between relative abundance of resident bull trout (Salvelinus confluentus) and habitat characteristics in Central Idaho mountain streams Author: Zurstadt, Caleb Frederick Resident bull trout (Salvelinus confluentus) may be particularly vulnerable to human related disturbance, however very few studies have focused on resident bull trout populations. The abundance of bull trout is one measure of the strength and potential for persistence of a population. Habitat characteristics may influence resident bull trout abundance to differing degrees and by varying means at multiple spatial scales. We used day and night snorkel counts to assess relative bull trout abundance. A modification of the Forest Service R1/R4 Fish and Fish Habitat Inventory was used to assess habitat characteristics associated with resident bull trout. Logistic and multiple linear regression were used to assess the relationships between resident bull trout abundance and habitat characteristics at the patch (1 to 5 km), reach (0.5 to 1 km) and habitat unit (1 to 100 m) scales. Site categorical variables were used along with quantitative habitat variables to explain among-site and across-site variation in the data. The significance of both quantitative habitat variables and categorical site variables at various spatial scales suggest that relationships between bull trout abundance and habitat characteristics are complex and in part dependent on scale. The characteristics of individual habitat units explained little of the variation in bull trout presence/absence (logistic regression; Somers' D=0.44) and density (multiple linear regression; adjusted R²=0.08) in habitat units, however there were habitat characteristics that were significantly (P≤0.05) correlated to bull trout presence/absence and density in habitat units. The relationships between habitat characteristics and bull trout presence/absence and density varied between habitat unit types. There was a strong quadratic relationship between bull trout abundance and mean summer water temperature at the reach (P=0.004) and patch scales (P=0.001). The mean temperature of patches appears to explain some of the variation in bull trout density at smaller spatial scales, such as reaches and habitat units. An appreciation of the complex nature of scale dependent interactions between bull trout abundance and habitat characteristics may help resource managers make wiser decisions regarding conservation of resident bull trout populations. Close

• 62. [Article] Bull Trout (Salvelinus confluentus) population and habitat surveys in the McKenzie and Middle Fork Willamette Basins, 2000

  DOE/BP-00004093-1

  Citation × Citation Citation Abstract Copy Title: Bull Trout (Salvelinus confluentus) population and habitat surveys in the McKenzie and Middle Fork Willamette Basins, 2000 Author: Taylor, Greg DOE/BP-00004093-1 Title: Bull Trout (Salvelinus confluentus) population and habitat surveys in the McKenzie and Middle Fork Willamette Basins, 2000 Author: Taylor, Greg DOE/BP-00004093-1 Close

• 63. [Article] Population characteristics and movement patterns of redband trout (Oncorhynchus mykiss) and mountain whitefish (Prosopium williamsoni) in the Crooked River, Oregon

  Over the last decade, the Oregon Department of Fish and Wildlife (ODFW) has documented a precipitous decline in the Crooked River redband trout (Oncorhynchus mykiss) population, prompting this study to ...

  Citation × Citation Citation Abstract Copy Title: Population characteristics and movement patterns of redband trout (Oncorhynchus mykiss) and mountain whitefish (Prosopium williamsoni) in the Crooked River, Oregon Author: Nesbit, Shivonne M. Over the last decade, the Oregon Department of Fish and Wildlife (ODFW) has documented a precipitous decline in the Crooked River redband trout (Oncorhynchus mykiss) population, prompting this study to address potential factors contributing to the decline. There are two main goals to this project: (1) identify potential factors contributing to the reduction of the redband trout population in the Crooked River fishery and (2) provide management recommendations to all of the agencies responsible for managing the Crooked River that might effect a change in the redband trout population trend. This thesis had three objectives: (1) evaluate the movement patterns of redband trout and mountain whitefish in the Crooked River below Bowman Dam, (2) monitor total dissolved gas levels (TDG) in the Crooked River to evaluate the incidence of supersaturated water and gas bubble disease in redband trout and mountain whitefish and (3) implement a more comprehensive population estimate survey to document both redband trout and mountain whitefish population densities. Prior to this study, limited data existed on the distribution and movement patterns of redband trout and mountain whitefish in the Crooked River below Bowman Dam. Based on the results from the 2-year telemetry study, redband trout and mountain whitefish population exhibit a resident life history strategy and stay in the Wild and Scenic Section of the Crooked River below Bowman Dam. Two potential explanations for the observed population decline were plausible: the decline was actually a decline, or the fish moved to other sections of the Crooked River downstream of Bowman Dam. The telemetery study showed that redband trout and mountain whitefish stay within this section of river, thereby providing evidence against the explanation that the observed population decline was a result of movement of fish to other sections of river. The total dissolved gas study demonstrated that gas saturation levels become elevated enough to cause gas bubble disease in the Crooked River below Bowman Dam. The gas saturation in the Crooked River is equivalent or higher than levels shown to produce gas bubble disease (GBD) in fishes. When flows exceed 600 cfs, the total dissolved gas saturation exceeds the maximum Oregon Department of Environmental Quality mandated level of 110% gas saturation in the Crooked River. Flows in excess of 600cfs are common during spring runoff events below Bowman Dam. From 1989-2009, flows exceeded 600 cfs in 13 of the 21 years and 1000 cfs in 10 of the 21 years. The past population effects of high flows and supersaturated waters on redband trout and mountain whitefish are difficult to quantify, but based on the hydrograph and the saturation curve, the years when gas bubble disease might have been present in fish can be predicted. Given the strong linear relationship between TDG and stream average daily discharge (r2 = 0.93), discharge itself can be used as a predictive tool for assessing TDG levels in the river. Based on the flow data from the USBOR gauging station and the gas saturation curve for the wild and scenic section of the Crooked River generated here, gas bubble disease was probably present in fish in 1993, 1996, 1997, 1998, 1999, and 2004. The redband trout population density has varied considerably from year to year, with a peak observed in 1994 and the lowest point observed in 2006. A large increase in the number of redband trout per km occurred between 1993 and 1994, indicating that the density of fish can increase substantially in one year. The decline in redband trout density from 1994 to 2006 appears to be more gradual than the increase in density observed from 1993 to 1994. Since 2006, the redband trout population density appears to be increasing based on qualitative patterns. One interesting finding was that in 2007, the mountain whitefish density was estimated to be 7 times greater than the redband trout population, in 2008 it was estimated to be 4 times greater, but in 2009, the mountain whitefish density was only marginally higher than the redband trout population. In the three years of this study, there appears to be a shift in the relative abundance of redband trout and mountain whitefish directly below Bowman Dam. The reduction in the mountain whitefish population density from 2007 to 2008 was not expected based on angler accounts of the increase in mountain whitefish population densities. Title: Population characteristics and movement patterns of redband trout (Oncorhynchus mykiss) and mountain whitefish (Prosopium williamsoni) in the Crooked River, Oregon Author: Nesbit, Shivonne M. Over the last decade, the Oregon Department of Fish and Wildlife (ODFW) has documented a precipitous decline in the Crooked River redband trout (Oncorhynchus mykiss) population, prompting this study to address potential factors contributing to the decline. There are two main goals to this project: (1) identify potential factors contributing to the reduction of the redband trout population in the Crooked River fishery and (2) provide management recommendations to all of the agencies responsible for managing the Crooked River that might effect a change in the redband trout population trend. This thesis had three objectives: (1) evaluate the movement patterns of redband trout and mountain whitefish in the Crooked River below Bowman Dam, (2) monitor total dissolved gas levels (TDG) in the Crooked River to evaluate the incidence of supersaturated water and gas bubble disease in redband trout and mountain whitefish and (3) implement a more comprehensive population estimate survey to document both redband trout and mountain whitefish population densities. Prior to this study, limited data existed on the distribution and movement patterns of redband trout and mountain whitefish in the Crooked River below Bowman Dam. Based on the results from the 2-year telemetry study, redband trout and mountain whitefish population exhibit a resident life history strategy and stay in the Wild and Scenic Section of the Crooked River below Bowman Dam. Two potential explanations for the observed population decline were plausible: the decline was actually a decline, or the fish moved to other sections of the Crooked River downstream of Bowman Dam. The telemetery study showed that redband trout and mountain whitefish stay within this section of river, thereby providing evidence against the explanation that the observed population decline was a result of movement of fish to other sections of river. The total dissolved gas study demonstrated that gas saturation levels become elevated enough to cause gas bubble disease in the Crooked River below Bowman Dam. The gas saturation in the Crooked River is equivalent or higher than levels shown to produce gas bubble disease (GBD) in fishes. When flows exceed 600 cfs, the total dissolved gas saturation exceeds the maximum Oregon Department of Environmental Quality mandated level of 110% gas saturation in the Crooked River. Flows in excess of 600cfs are common during spring runoff events below Bowman Dam. From 1989-2009, flows exceeded 600 cfs in 13 of the 21 years and 1000 cfs in 10 of the 21 years. The past population effects of high flows and supersaturated waters on redband trout and mountain whitefish are difficult to quantify, but based on the hydrograph and the saturation curve, the years when gas bubble disease might have been present in fish can be predicted. Given the strong linear relationship between TDG and stream average daily discharge (r2 = 0.93), discharge itself can be used as a predictive tool for assessing TDG levels in the river. Based on the flow data from the USBOR gauging station and the gas saturation curve for the wild and scenic section of the Crooked River generated here, gas bubble disease was probably present in fish in 1993, 1996, 1997, 1998, 1999, and 2004. The redband trout population density has varied considerably from year to year, with a peak observed in 1994 and the lowest point observed in 2006. A large increase in the number of redband trout per km occurred between 1993 and 1994, indicating that the density of fish can increase substantially in one year. The decline in redband trout density from 1994 to 2006 appears to be more gradual than the increase in density observed from 1993 to 1994. Since 2006, the redband trout population density appears to be increasing based on qualitative patterns. One interesting finding was that in 2007, the mountain whitefish density was estimated to be 7 times greater than the redband trout population, in 2008 it was estimated to be 4 times greater, but in 2009, the mountain whitefish density was only marginally higher than the redband trout population. In the three years of this study, there appears to be a shift in the relative abundance of redband trout and mountain whitefish directly below Bowman Dam. The reduction in the mountain whitefish population density from 2007 to 2008 was not expected based on angler accounts of the increase in mountain whitefish population densities. Close

• 64. [Image] Crater Lake National Park bull trout restoration program: status review and study plan

  	ill.; Report title; "Prepared for: U.S. Fish and Wildlife Service, Klamath Falls, Oregon." - T.p.; Includes bibliographic references
  	Citation × Citation Citation Abstract Copy Title: Crater Lake National Park bull trout restoration program: status review and study plan Author: Buktenica, Mark Year: 2000, 2010 ill.; Report title; "Prepared for: U.S. Fish and Wildlife Service, Klamath Falls, Oregon." - T.p.; Includes bibliographic references Title: Crater Lake National Park bull trout restoration program: status review and study plan Author: Buktenica, Mark Year: 2000, 2010 ill.; Report title; "Prepared for: U.S. Fish and Wildlife Service, Klamath Falls, Oregon." - T.p.; Includes bibliographic references Close

• 65. [Article] Distribution and juvenile ecology of bull trout (Salvelinus confluentus) in the Cascade Mountains

  Distribution and juvenile habitat use of bull trout (Salvelinus confluentus) were surveyed in selected areas of the Upper Willamette, Deschutes, upper Yakima, and upper Cedar River basins in Oregon and Washington ...

  Citation × Citation Citation Abstract Copy Title: Distribution and juvenile ecology of bull trout (Salvelinus confluentus) in the Cascade Mountains Author: Goetz, Frederick Allen Distribution and juvenile habitat use of bull trout (Salvelinus confluentus) were surveyed in selected areas of the Upper Willamette, Deschutes, upper Yakima, and upper Cedar River basins in Oregon and Washington from 1989 to 1991, using day snorkeling, night snorkeling, and electrofishing. These methods were selected after a preliminary diel streamside study of juvenile bull trout showed fry (age 0) counts were significantly higher (P<0.00l) during the day, while counts of juvenile fish (age 1 and 2) were significantly higher (P<0.00l) at night. The highest counts of juveniles occurred during a "quiet period" immediately after dusk, during which time fish were inactive, out of cover, and easily counted with underwater flashlights. In a comparison of four sampling methods on Jack Creek, electrofishing was significantly correlated (P<0.05) with day (r=0.8l) and night (r=0.89) snorkeling counts, but not with streambank counts. In a comparison of day and night snorkeling in 10 streams, total density estimates were significantly greater (P<0.0l) for night snorkeling than day. The diel study and sampling methods comparison suggested surveys of distribution and habitat use of bull trout should include night surveys as well as day. Distribution surveys found that, except for one stream, juvenile bull trout were found only in, or near, spring-fed areas created by recent lava flows. Presence of bull trout in a stream was related to cold groundwater temperatures, as they were not found in streams with temperatures above 14°C. Distribution of bull trout in Oregon and Washington followed a pattern of decreasing elevation with increasing latitude and longitude(Ra=-0.9l6) Presence at lower than expected elevations were explained when groundwater temperatures were predicted from mean annual air temperatures. Actual water temperatures for these spring-fed streams were significantly lower (p<0.00l) than predicted based on elevation, latitude, and longitude. Comparison of historical distribution of bull trout showed extant bull trout were found in the Willamette and Deschutes River Basins of Oregon, respectively, in only 26.2 and 56.2% of their former ranges. Factors associated with bull trout demise in Oregon Cascade streams were (1) isolation and inundation of spring-fed stream habitat by water control structures, (2) introduction of brook trout and brown trout, and (3) large flood events and habitat degradation. Juvenile habitat use was analyzed at the macrohabitat (habitat unit) level in five river basins. Diel and seasonal microhabitat use was also documented for one spring-fed stream, Jack Creek. There was a clear difference in habitat use day and night, associated with the low water temperature of the spring-fed streams (mean=8.0°C). All habitat unit types (pool, riffle, glide, side channel) were used day and night, but bull trout only elected to use side channels in both time periods. Bull trout were found at night in (1) a higher percentage of habitat units, (2) in higher densities by unit, and (3) in increasing numbers with increasing habitat unit area. In Jack Creek, bull trout elected to use shallow water depths, low mean velocities, instream woody debris, and small substrates. Title: Distribution and juvenile ecology of bull trout (Salvelinus confluentus) in the Cascade Mountains Author: Goetz, Frederick Allen Distribution and juvenile habitat use of bull trout (Salvelinus confluentus) were surveyed in selected areas of the Upper Willamette, Deschutes, upper Yakima, and upper Cedar River basins in Oregon and Washington from 1989 to 1991, using day snorkeling, night snorkeling, and electrofishing. These methods were selected after a preliminary diel streamside study of juvenile bull trout showed fry (age 0) counts were significantly higher (P<0.00l) during the day, while counts of juvenile fish (age 1 and 2) were significantly higher (P<0.00l) at night. The highest counts of juveniles occurred during a "quiet period" immediately after dusk, during which time fish were inactive, out of cover, and easily counted with underwater flashlights. In a comparison of four sampling methods on Jack Creek, electrofishing was significantly correlated (P<0.05) with day (r=0.8l) and night (r=0.89) snorkeling counts, but not with streambank counts. In a comparison of day and night snorkeling in 10 streams, total density estimates were significantly greater (P<0.0l) for night snorkeling than day. The diel study and sampling methods comparison suggested surveys of distribution and habitat use of bull trout should include night surveys as well as day. Distribution surveys found that, except for one stream, juvenile bull trout were found only in, or near, spring-fed areas created by recent lava flows. Presence of bull trout in a stream was related to cold groundwater temperatures, as they were not found in streams with temperatures above 14°C. Distribution of bull trout in Oregon and Washington followed a pattern of decreasing elevation with increasing latitude and longitude(Ra=-0.9l6) Presence at lower than expected elevations were explained when groundwater temperatures were predicted from mean annual air temperatures. Actual water temperatures for these spring-fed streams were significantly lower (p<0.00l) than predicted based on elevation, latitude, and longitude. Comparison of historical distribution of bull trout showed extant bull trout were found in the Willamette and Deschutes River Basins of Oregon, respectively, in only 26.2 and 56.2% of their former ranges. Factors associated with bull trout demise in Oregon Cascade streams were (1) isolation and inundation of spring-fed stream habitat by water control structures, (2) introduction of brook trout and brown trout, and (3) large flood events and habitat degradation. Juvenile habitat use was analyzed at the macrohabitat (habitat unit) level in five river basins. Diel and seasonal microhabitat use was also documented for one spring-fed stream, Jack Creek. There was a clear difference in habitat use day and night, associated with the low water temperature of the spring-fed streams (mean=8.0°C). All habitat unit types (pool, riffle, glide, side channel) were used day and night, but bull trout only elected to use side channels in both time periods. Bull trout were found at night in (1) a higher percentage of habitat units, (2) in higher densities by unit, and (3) in increasing numbers with increasing habitat unit area. In Jack Creek, bull trout elected to use shallow water depths, low mean velocities, instream woody debris, and small substrates. Close

• 66. [Article] The significance of glutathione conjugation for aflatoxin B₁ metabolism in rainbow trout and coho salmon

  In rodent models as well as in fish models there are significant species differences in the susceptibility toward aflatoxin B₁ (AFB₁) carcinogenesis. Mouse is less susceptible toward AFB₁ carcinogenesis than ...

  Citation × Citation Citation Abstract Copy Title: The significance of glutathione conjugation for aflatoxin B₁ metabolism in rainbow trout and coho salmon Author: Valsta, Liisa M. In rodent models as well as in fish models there are significant species differences in the susceptibility toward aflatoxin B₁ (AFB₁) carcinogenesis. Mouse is less susceptible toward AFB₁ carcinogenesis than rat. Researchers have come to the conclusion that the lower susceptibility of mice is not a result of less effective activation of AFB₁, but rather of more effective inactivation of the toxic intermediate AFB₁-2,3-epoxide, and especially inactivation through the glutathione (GSH) conjugation of the epoxide. Rainbow trout fed Oregon Test Diet are more sensitive toward AFB₁ hepatocarcinogenesis than coho salmon, or, than trout fed the inhibitors β-naphthoflavone (BNF), 1ndole-3-carbinol (I3C), or Aroclor 1254 (PCB). This study examined the role of AFB1-glutathione (AFB₁-SG) conjugation In these differences. A tritiated AFB₁-glutathione conjugate standard (³H-AFB₁-S6) was produced in vitro using mouse liver S-9 fraction as a source of GSH transferase. It was purified by reverse phase HPLC, and its structure verified by amino acid analysis and mass spectrometry. Coho salmon and rainbow trout fed the various diets were injected i.p. with ³H-AFB₁ (49μCi, 50 μg/ kg fish); bile, liver and kidney were collected at 24 h. Recovery of total aflatoxin radioactivity was determined for all three tissues, and the hepatic AFB₁-DNA binding was also determined. Bile metabolites were quantitated by reverse phase HPLC using the mouse ³H-AFB₁-SG as a standard. The resistance of coho salmon toward AFB₁ carcinogenicity was supported by a 20-fold lower hepatic AFB₁-DNA binding compared to control trout. AFB₁-SG was detected in bile only in control, BNF, and I3C fed trout, at < 1% of total recovered metabolites, and at < 0.2% of the original dose, being highest in control trout. The major conjugates were glucuronides of aflatoxicol (AFL) and aflatoxicol-M₁ (AFL-M₁) (80-902 of the total recovered metabolites). In vitro metabolism studies using isolated liver cell fractions supported the in vivo metabolism results. Less than 0.531 of the original AFB₁ dose was converted to AFB₁-SG conjugate in salmon and trout samples. In contrast, with isolated mouse liver cell fractions approximately 25% of the original AFB₁ dose was conjugated with GSH. The GSH concentration of control trout liver was 2.9 mmol/ kg. Coho salmon had GSH concentration 70% of that found in control trout. In BNF pre-fed trout liver GSH concentration was enhanced by 25% compared to controls. Liver GSH transferase activity using l-chloro-2,4- dlnitrobenzene as substrate was 1.15 μmol/min/mg protein in control trout. This enzyme activity In salmon was only 26% of that found in control trout. A 62% elevation In GSH transferase activity compared to controls was detected in trout fed BNF diet. There is no apparent correlation between liver GSH or GSH transferase activities among the various groups, and their relative sensitivities to AFB₁ carcinogenesis. This study indicates that AFB₁-SG conjugation is not a significant pathway in salmon and trout fed control diets, or trout fed various inhibitors, and cannot account for the variation In AFB₁ sensitivity. Title: The significance of glutathione conjugation for aflatoxin B₁ metabolism in rainbow trout and coho salmon Author: Valsta, Liisa M. In rodent models as well as in fish models there are significant species differences in the susceptibility toward aflatoxin B₁ (AFB₁) carcinogenesis. Mouse is less susceptible toward AFB₁ carcinogenesis than rat. Researchers have come to the conclusion that the lower susceptibility of mice is not a result of less effective activation of AFB₁, but rather of more effective inactivation of the toxic intermediate AFB₁-2,3-epoxide, and especially inactivation through the glutathione (GSH) conjugation of the epoxide. Rainbow trout fed Oregon Test Diet are more sensitive toward AFB₁ hepatocarcinogenesis than coho salmon, or, than trout fed the inhibitors β-naphthoflavone (BNF), 1ndole-3-carbinol (I3C), or Aroclor 1254 (PCB). This study examined the role of AFB1-glutathione (AFB₁-SG) conjugation In these differences. A tritiated AFB₁-glutathione conjugate standard (³H-AFB₁-S6) was produced in vitro using mouse liver S-9 fraction as a source of GSH transferase. It was purified by reverse phase HPLC, and its structure verified by amino acid analysis and mass spectrometry. Coho salmon and rainbow trout fed the various diets were injected i.p. with ³H-AFB₁ (49μCi, 50 μg/ kg fish); bile, liver and kidney were collected at 24 h. Recovery of total aflatoxin radioactivity was determined for all three tissues, and the hepatic AFB₁-DNA binding was also determined. Bile metabolites were quantitated by reverse phase HPLC using the mouse ³H-AFB₁-SG as a standard. The resistance of coho salmon toward AFB₁ carcinogenicity was supported by a 20-fold lower hepatic AFB₁-DNA binding compared to control trout. AFB₁-SG was detected in bile only in control, BNF, and I3C fed trout, at < 1% of total recovered metabolites, and at < 0.2% of the original dose, being highest in control trout. The major conjugates were glucuronides of aflatoxicol (AFL) and aflatoxicol-M₁ (AFL-M₁) (80-902 of the total recovered metabolites). In vitro metabolism studies using isolated liver cell fractions supported the in vivo metabolism results. Less than 0.531 of the original AFB₁ dose was converted to AFB₁-SG conjugate in salmon and trout samples. In contrast, with isolated mouse liver cell fractions approximately 25% of the original AFB₁ dose was conjugated with GSH. The GSH concentration of control trout liver was 2.9 mmol/ kg. Coho salmon had GSH concentration 70% of that found in control trout. In BNF pre-fed trout liver GSH concentration was enhanced by 25% compared to controls. Liver GSH transferase activity using l-chloro-2,4- dlnitrobenzene as substrate was 1.15 μmol/min/mg protein in control trout. This enzyme activity In salmon was only 26% of that found in control trout. A 62% elevation In GSH transferase activity compared to controls was detected in trout fed BNF diet. There is no apparent correlation between liver GSH or GSH transferase activities among the various groups, and their relative sensitivities to AFB₁ carcinogenesis. This study indicates that AFB₁-SG conjugation is not a significant pathway in salmon and trout fed control diets, or trout fed various inhibitors, and cannot account for the variation In AFB₁ sensitivity. Close

• 67. [Image] Trout

  	Manuscript depicting the importance of trout, especially for farming communities. Goes on to protest the implementation of non-native fish, especially the Loch Leven trout.
  	Citation × Citation Citation Abstract Copy Title: Trout Author: Finley, William L. (William Lovell), 1876-1953 Year: 1910 Manuscript depicting the importance of trout, especially for farming communities. Goes on to protest the implementation of non-native fish, especially the Loch Leven trout. Title: Trout Author: Finley, William L. (William Lovell), 1876-1953 Year: 1910 Manuscript depicting the importance of trout, especially for farming communities. Goes on to protest the implementation of non-native fish, especially the Loch Leven trout. Close

• 68. [Image] Rainbow trout

  	Head of a rainbow trout with an open mouth. Image note: side view, large.
  	Citation × Citation Citation Abstract Copy Title: Rainbow trout Author: Finley, William L. (William Lovell), 1876-1953 Year: 1905 Head of a rainbow trout with an open mouth. Image note: side view, large. Title: Rainbow trout Author: Finley, William L. (William Lovell), 1876-1953 Year: 1905 Head of a rainbow trout with an open mouth. Image note: side view, large. Close

• 69. [Image] Rainbow trout

  	Head of a rainbow trout with an open mouth. Image note: front view.
  	Citation × Citation Citation Abstract Copy Title: Rainbow trout Author: Finley, William L. (William Lovell), 1876-1953 Year: 1905 Head of a rainbow trout with an open mouth. Image note: front view. Title: Rainbow trout Author: Finley, William L. (William Lovell), 1876-1953 Year: 1905 Head of a rainbow trout with an open mouth. Image note: front view. Close

• 70. [Image] Rainbow trout

  	Head of a rainbow trout. Image note: side view, large.
  	Citation × Citation Citation Abstract Copy Title: Rainbow trout Author: Finley, William L. (William Lovell), 1876-1953 Year: 1905 Head of a rainbow trout. Image note: side view, large. Title: Rainbow trout Author: Finley, William L. (William Lovell), 1876-1953 Year: 1905 Head of a rainbow trout. Image note: side view, large. Close

• 71. [Image] Rainbow trout

  	Side view of a dead rainbow trout in the grass.
  	Citation × Citation Citation Abstract Copy Title: Rainbow trout Author: Finley, William L. (William Lovell), 1876-1953 Year: 1905 Side view of a dead rainbow trout in the grass. Title: Rainbow trout Author: Finley, William L. (William Lovell), 1876-1953 Year: 1905 Side view of a dead rainbow trout in the grass. Close

• 72. [Image] Rainbow trout

  	A rainbow trout under the water.
  	Citation × Citation Citation Abstract Copy Title: Rainbow trout Author: Finley, William L. (William Lovell), 1876-1953 Year: 1905 A rainbow trout under the water. Title: Rainbow trout Author: Finley, William L. (William Lovell), 1876-1953 Year: 1905 A rainbow trout under the water. Close

• 73. [Image] Rainbow trout

  	A rainbow trout under the water.
  	Citation × Citation Citation Abstract Copy Title: Rainbow trout Author: Finley, William L. (William Lovell), 1876-1953 Year: 1905 A rainbow trout under the water. Title: Rainbow trout Author: Finley, William L. (William Lovell), 1876-1953 Year: 1905 A rainbow trout under the water. Close

• 74. [Article] A Trout Management Program for the Main Stem Lower Deschutes River 1978

  Abstract -- The Deschutes River is a north flowing tributary of the Columbia River in Central Oregon and is a designated scenic waterway. Summer run steelhead and resident trout are the most important ...

  Citation × Citation Citation Abstract Copy Title: A Trout Management Program for the Main Stem Lower Deschutes River 1978 Abstract -- The Deschutes River is a north flowing tributary of the Columbia River in Central Oregon and is a designated scenic waterway. Summer run steelhead and resident trout are the most important species to the local recreational fishery, although significant numbers of spring, summer, and fall chinook are also taken from the river. The salmon contribute significantly to fisheries in the Pacific Ocean and Columbia River and steelhead enter fisheries in the Columbia. The Deschutes also supports a good population of whitefish, lesser numbers of other trout species, small runs of coho and sockeye salmon, and several species of nongame fish. Title: A Trout Management Program for the Main Stem Lower Deschutes River 1978 Abstract -- The Deschutes River is a north flowing tributary of the Columbia River in Central Oregon and is a designated scenic waterway. Summer run steelhead and resident trout are the most important species to the local recreational fishery, although significant numbers of spring, summer, and fall chinook are also taken from the river. The salmon contribute significantly to fisheries in the Pacific Ocean and Columbia River and steelhead enter fisheries in the Columbia. The Deschutes also supports a good population of whitefish, lesser numbers of other trout species, small runs of coho and sockeye salmon, and several species of nongame fish. Close

• 75. [Article] Fish Management Plan North Fork of Middle Fork Willamette River 1979

  Abstract -- The North Fork is a moderate-sized tributary originating at Waldo Lake and entering the Middle Fork Willamette near the town of Oakridge. The river and its tributaries contain approximately ...

  Citation × Citation Citation Abstract Copy Title: Fish Management Plan North Fork of Middle Fork Willamette River 1979 Abstract -- The North Fork is a moderate-sized tributary originating at Waldo Lake and entering the Middle Fork Willamette near the town of Oakridge. The river and its tributaries contain approximately 160 miles of trout producing water. The habitat is generally capable of producing a good trout population. Native cutthroat and rainbow are present throughout the system and brook trout, having moved out of Waldo Lake, are found a short distance downstream. In July 1979, the Oregon Fish and Wildlife Commission accepted the Department's recommendation to continue to manage the North Fork, Middle Fork Willamette River for wild trout. The Commission concurrently imposed a fly angling only restriction to fishing in this stream. Title: Fish Management Plan North Fork of Middle Fork Willamette River 1979 Abstract -- The North Fork is a moderate-sized tributary originating at Waldo Lake and entering the Middle Fork Willamette near the town of Oakridge. The river and its tributaries contain approximately 160 miles of trout producing water. The habitat is generally capable of producing a good trout population. Native cutthroat and rainbow are present throughout the system and brook trout, having moved out of Waldo Lake, are found a short distance downstream. In July 1979, the Oregon Fish and Wildlife Commission accepted the Department's recommendation to continue to manage the North Fork, Middle Fork Willamette River for wild trout. The Commission concurrently imposed a fly angling only restriction to fishing in this stream. Close

• 76. [Article] A Report upon the Production and Management of Trout in the State of Oregon, with Recommendations for Increased Efficiency

  Abstract -- This report of the production of trout and the management of the game fisheries resources within the State of Oregon summarizes the observations made during a 5.5-month survey of these conditions ...

  Citation × Citation Citation Abstract Copy Title: A Report upon the Production and Management of Trout in the State of Oregon, with Recommendations for Increased Efficiency Abstract -- This report of the production of trout and the management of the game fisheries resources within the State of Oregon summarizes the observations made during a 5.5-month survey of these conditions extending through the spring and summer of 1934. This survey was financed jointly by the Oregon Game Commission and the Division of Scientific Inquiry, United States Bureau of Fisheries. Inasmuch as this survey was purposely confined to a study of the trout of Oregon, unless specifically stated to the contrary, all statements, criticisms, and recommendations included within this report are applicable only to trout, as it was neither the purpose nor the scope of this survey to include any other game animals. Title: A Report upon the Production and Management of Trout in the State of Oregon, with Recommendations for Increased Efficiency Abstract -- This report of the production of trout and the management of the game fisheries resources within the State of Oregon summarizes the observations made during a 5.5-month survey of these conditions extending through the spring and summer of 1934. This survey was financed jointly by the Oregon Game Commission and the Division of Scientific Inquiry, United States Bureau of Fisheries. Inasmuch as this survey was purposely confined to a study of the trout of Oregon, unless specifically stated to the contrary, all statements, criticisms, and recommendations included within this report are applicable only to trout, as it was neither the purpose nor the scope of this survey to include any other game animals. Close

• 77. [Image] Status of Oregon's bull trout : distribution, life history, limiting factors, management considerations, and status

  	EXECUTIVE SUMMARY Limited historical references indicate that bull trout Salvelinus confluentus in Oregon were once widely spread throughout at least 12 basins in the Klamath River and Columbia River ...
  	Citation × Citation Citation Abstract Copy Title: Status of Oregon's bull trout : distribution, life history, limiting factors, management considerations, and status Author: Buchanan, David V; Hanson, Mary L; Hooton, Robert M Year: 1997, 2007, 2005 EXECUTIVE SUMMARY Limited historical references indicate that bull trout Salvelinus confluentus in Oregon were once widely spread throughout at least 12 basins in the Klamath River and Columbia River systems. No bull trout have been observed in Oregon's coastal systems. A total of 69 bull trout populations in 12 basins are currently identified in Oregon. A comparison of the 1991 bull trout status (Ratliff and Ho well 1992) to the revised 1996 status found that 7 populations were newly discovered and 1 population showed a positive or upgraded status while 22 populations showed a negative or downgraded status. The general downgrading of 32% of Oregon's bull trout populations appears largely due to increased survey efforts and increased survey accuracy rather than reduced numbers or distribution. However, three populations in the upper Klamath Basin, two in the Walla Walla Basin, and one in the Willamette Basin showed decreases in estimated population abundance or distribution. Some Oregon river basins have bull trout populations at extreme risk of extinction. This statewide status review listed only 19% of the bull trout populations in Oregon with a ulow risk of extinction" or "of special concern." Therefore, 81% of Oregon's bull trout populations are considered to be at a "moderate risk of extinction," "high risk of extinction," or "probably extinct." Populations in the Hood, Klamath, and Powder basins, as well as the Odell Lake population in the Deschutes basin, which contain only a few remaining bull trout, are examples of populations having a "moderate" or "high risk" of extinction. Approximately 55% of current bull trout distribution occurs on lands managed by the U.S. Forest Service. A much smaller proportion occurs on Bureau of Land Management managed lands (2%). Only 16% of current bull trout distribution occurs within a protected area defined as Wilderness, Wild and Scenic River, or within a National Park. The Northwest Forest Plan, Inland Native Fish Strategy, and Interim Strategies for Managing Anadromous Fish-producing Watersheds in Eastern Oregon and Washington, Idaho, and Portions of California have provided increased protection for bull trout habitat depending on their scope and geographic areas affected, and the extent to which they are being effectively implemented in watersheds containing bull trout. Recent reduction in timber production on National Forests (up to 50% in western Oregon National Forests and over 30% in eastern Oregon National Forests) should help improve riparian and stream habitat conditions for bull trout. The remaining bull trout distribution occurs on private, state, or tribal owned lands. A comparison of approximately 39 locations throughout the state with protective angling regulations on bull trout (in some areas more than one bull trout population is protected by one regulation) shows that all state managed areas were upgraded in a protective angling status or at least maintained in 1996 compared to 1989. Restrictive angling regulations prohibit angler harvest of all bull trout populations in Oregon except for one in the Deschutes Basin. Restrictive bull trout angling regulation changes (including the elimination of bull Vll trout harvest in all spawning areas) may be the major reasons why the Metolius River/Lake Billy Chinook and mainstem McKenzie River populations have shown significant increases in abundance. Statewide stocking of non-native brook trout, including the high lakes stocking program, has been discontinued in locations where managers believe brook trout could migrate downstream and potentially interact with native bull trout. Hatchery stocking of legal rainbow trout to promote recreational fisheries has been discontinued in most locations near bull trout populations to avoid incidental catch of bull trout. The spatial and temporal distributions of bull trout reported for each river basin in this status report should be used as an accurate baseline for fisheries managers. Current distribution and relative change of distribution should be useful indicators of population health and status. The GIS maps in this report provide a template to add new layers of data such as critical spawning and juvenile rearing areas, or as a method to compare distribution changes through time. Length frequency data are presented for most Oregon bull trout populations. This should provide estimates for the presence of multiple age classes and the percent of fluvial size life history component. Vlll Title: Status of Oregon's bull trout : distribution, life history, limiting factors, management considerations, and status Author: Buchanan, David V; Hanson, Mary L; Hooton, Robert M Year: 1997, 2007, 2005 EXECUTIVE SUMMARY Limited historical references indicate that bull trout Salvelinus confluentus in Oregon were once widely spread throughout at least 12 basins in the Klamath River and Columbia River systems. No bull trout have been observed in Oregon's coastal systems. A total of 69 bull trout populations in 12 basins are currently identified in Oregon. A comparison of the 1991 bull trout status (Ratliff and Ho well 1992) to the revised 1996 status found that 7 populations were newly discovered and 1 population showed a positive or upgraded status while 22 populations showed a negative or downgraded status. The general downgrading of 32% of Oregon's bull trout populations appears largely due to increased survey efforts and increased survey accuracy rather than reduced numbers or distribution. However, three populations in the upper Klamath Basin, two in the Walla Walla Basin, and one in the Willamette Basin showed decreases in estimated population abundance or distribution. Some Oregon river basins have bull trout populations at extreme risk of extinction. This statewide status review listed only 19% of the bull trout populations in Oregon with a ulow risk of extinction" or "of special concern." Therefore, 81% of Oregon's bull trout populations are considered to be at a "moderate risk of extinction," "high risk of extinction," or "probably extinct." Populations in the Hood, Klamath, and Powder basins, as well as the Odell Lake population in the Deschutes basin, which contain only a few remaining bull trout, are examples of populations having a "moderate" or "high risk" of extinction. Approximately 55% of current bull trout distribution occurs on lands managed by the U.S. Forest Service. A much smaller proportion occurs on Bureau of Land Management managed lands (2%). Only 16% of current bull trout distribution occurs within a protected area defined as Wilderness, Wild and Scenic River, or within a National Park. The Northwest Forest Plan, Inland Native Fish Strategy, and Interim Strategies for Managing Anadromous Fish-producing Watersheds in Eastern Oregon and Washington, Idaho, and Portions of California have provided increased protection for bull trout habitat depending on their scope and geographic areas affected, and the extent to which they are being effectively implemented in watersheds containing bull trout. Recent reduction in timber production on National Forests (up to 50% in western Oregon National Forests and over 30% in eastern Oregon National Forests) should help improve riparian and stream habitat conditions for bull trout. The remaining bull trout distribution occurs on private, state, or tribal owned lands. A comparison of approximately 39 locations throughout the state with protective angling regulations on bull trout (in some areas more than one bull trout population is protected by one regulation) shows that all state managed areas were upgraded in a protective angling status or at least maintained in 1996 compared to 1989. Restrictive angling regulations prohibit angler harvest of all bull trout populations in Oregon except for one in the Deschutes Basin. Restrictive bull trout angling regulation changes (including the elimination of bull Vll trout harvest in all spawning areas) may be the major reasons why the Metolius River/Lake Billy Chinook and mainstem McKenzie River populations have shown significant increases in abundance. Statewide stocking of non-native brook trout, including the high lakes stocking program, has been discontinued in locations where managers believe brook trout could migrate downstream and potentially interact with native bull trout. Hatchery stocking of legal rainbow trout to promote recreational fisheries has been discontinued in most locations near bull trout populations to avoid incidental catch of bull trout. The spatial and temporal distributions of bull trout reported for each river basin in this status report should be used as an accurate baseline for fisheries managers. Current distribution and relative change of distribution should be useful indicators of population health and status. The GIS maps in this report provide a template to add new layers of data such as critical spawning and juvenile rearing areas, or as a method to compare distribution changes through time. Length frequency data are presented for most Oregon bull trout populations. This should provide estimates for the presence of multiple age classes and the percent of fluvial size life history component. Vlll Close

• 78. [Article] Integration and Causality in Demand: Farmed Trout in Germany

  Research Paper

  Citation × Citation Citation Abstract Copy Title: Integration and Causality in Demand: Farmed Trout in Germany Author: Honkanen, Asmo, Nielsen, Max, Virtanen, Jarno, Setala, Jari, Laitinen, Jukka, Saarni, Kaija Research Paper Title: Integration and Causality in Demand: Farmed Trout in Germany Author: Honkanen, Asmo, Nielsen, Max, Virtanen, Jarno, Setala, Jari, Laitinen, Jukka, Saarni, Kaija Research Paper Close

• 79. [Article] Annual progress report: Salmon and Trout Enhancement Program

  This archived document is maintained by the Oregon State Library as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes.

  Citation × Citation Citation Abstract Copy Title: Annual progress report: Salmon and Trout Enhancement Program Year: 1986 This archived document is maintained by the Oregon State Library as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes. Title: Annual progress report: Salmon and Trout Enhancement Program Year: 1986 This archived document is maintained by the Oregon State Library as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes. Close

• 80. [Article] Molecular cloning and sequence analysis of cystatin from rainbow trout (Oncorhynchus mykiss)

  A partial cystatin cDNA from rainbow trout was generated by reverse transcription polymerase chain reaction with two degenerate primers. The partial cystatin PCR product was 168 bp and used to screen trout ...

  Citation × Citation Citation Abstract Copy Title: Molecular cloning and sequence analysis of cystatin from rainbow trout (Oncorhynchus mykiss) Author: Li, Fugen A partial cystatin cDNA from rainbow trout was generated by reverse transcription polymerase chain reaction with two degenerate primers. The partial cystatin PCR product was 168 bp and used to screen trout liver λgt 11 cDNA library. Four positive clones were isolated and designated as cstl, cst2, cst3 and cst4. Only cst2 contained the full-length cystatin cDNA which was 674 bp and included 5' untranslated region and the polyadenylation signal sequence AATAAA in the 3' region. Translation of the cDNA contains 132 amino acid residues. Comparison of the amino acid sequence with those of family II cystatin indicated that the 21 amino acids at N-terminal end is a signal peptide that leads to cystatin secretion, and the 111 amino acids are mature cystatin. Four cysteine residues in the cystatin may form two disulfide bonds for the secondary structure. Cst2 was subcloned into pGEM-3z for Northern and Southern blot experiments. Northern blot indicated that trout cystatin mRNA is about 750 bp. Cystatin is expressed in all tissues examined but at various levels. This difference may reflect the regulation of cysteine proteinase activities. Southern blot of trout genomic DNA showed that the copy number of the trout cystatin gene is probably one per haploid genome. Title: Molecular cloning and sequence analysis of cystatin from rainbow trout (Oncorhynchus mykiss) Author: Li, Fugen A partial cystatin cDNA from rainbow trout was generated by reverse transcription polymerase chain reaction with two degenerate primers. The partial cystatin PCR product was 168 bp and used to screen trout liver λgt 11 cDNA library. Four positive clones were isolated and designated as cstl, cst2, cst3 and cst4. Only cst2 contained the full-length cystatin cDNA which was 674 bp and included 5' untranslated region and the polyadenylation signal sequence AATAAA in the 3' region. Translation of the cDNA contains 132 amino acid residues. Comparison of the amino acid sequence with those of family II cystatin indicated that the 21 amino acids at N-terminal end is a signal peptide that leads to cystatin secretion, and the 111 amino acids are mature cystatin. Four cysteine residues in the cystatin may form two disulfide bonds for the secondary structure. Cst2 was subcloned into pGEM-3z for Northern and Southern blot experiments. Northern blot indicated that trout cystatin mRNA is about 750 bp. Cystatin is expressed in all tissues examined but at various levels. This difference may reflect the regulation of cysteine proteinase activities. Southern blot of trout genomic DNA showed that the copy number of the trout cystatin gene is probably one per haploid genome. Close