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• 31. [Article] An evaluation in rainbow trout of biliary excretion of sulfobromophthalein and effects of biliary excretion on the toxicity of rotenone

  Biliary excretion has been of considerable interest in mammals but has not been extensively studied in fish. To understand the significance of biliary excretion in rainbow trout (Salmo gairdneri), two ...

  Citation × Citation Citation Abstract Copy Title: An evaluation in rainbow trout of biliary excretion of sulfobromophthalein and effects of biliary excretion on the toxicity of rotenone Author: Schmidt, Dana C. Biliary excretion has been of considerable interest in mammals but has not been extensively studied in fish. To understand the significance of biliary excretion in rainbow trout (Salmo gairdneri), two studies were conducted. The objective of the initial study was to evaluate the ability of rainbow trout to excrete a foreign compound typically excreted by the vertebrate liver. This problem was approached by evaluating biliary excretion and metabolism of sulfobromophthalein (BSP) in trout and comparing the results with literature values for mammals. Results indicated this dye is metabolized and excreted similarily in trout, dogfish (Squalus acanthias) and mammals. Large differences between trout and other species in transport maxima (Tm) of BSP based on body weights, were explained when the Tm values were based on liver blood clearance of BSP, a physiological rate reflecting blood flow. The objective of the second study was to determine if biliary excretion affects the toxicity of a foreign compound toxic to trout. This problem was approached by evaluating the effect of bile and cystic duct ligation on the mean lethal dose (LD 50) of rotenone to trout. To determine if biliary excretion affected the selective toxicity of this compound to trout, the effect of bile duct ligation on the rotenone LD 50 to rats was estimated and the results were compared with those obtained from the trout. The toxicant was administered intraperitoneally and intravenously in trout and intraperitoneally in rats. No increase in toxicity of rotenone occurred upon surgical impairment of bile flow in either the trout or the rats, Similarities in the toxicity of rotenone to trout and rats were observed when the toxicant was administered intraperitoneally, The data suggest the selective toxicity of rotenone to fish may be primarily caused by different routes of entry. The results of these experiments indicate the excretory functions of the liver of fish and mammals are similar. Title: An evaluation in rainbow trout of biliary excretion of sulfobromophthalein and effects of biliary excretion on the toxicity of rotenone Author: Schmidt, Dana C. Biliary excretion has been of considerable interest in mammals but has not been extensively studied in fish. To understand the significance of biliary excretion in rainbow trout (Salmo gairdneri), two studies were conducted. The objective of the initial study was to evaluate the ability of rainbow trout to excrete a foreign compound typically excreted by the vertebrate liver. This problem was approached by evaluating biliary excretion and metabolism of sulfobromophthalein (BSP) in trout and comparing the results with literature values for mammals. Results indicated this dye is metabolized and excreted similarily in trout, dogfish (Squalus acanthias) and mammals. Large differences between trout and other species in transport maxima (Tm) of BSP based on body weights, were explained when the Tm values were based on liver blood clearance of BSP, a physiological rate reflecting blood flow. The objective of the second study was to determine if biliary excretion affects the toxicity of a foreign compound toxic to trout. This problem was approached by evaluating the effect of bile and cystic duct ligation on the mean lethal dose (LD 50) of rotenone to trout. To determine if biliary excretion affected the selective toxicity of this compound to trout, the effect of bile duct ligation on the rotenone LD 50 to rats was estimated and the results were compared with those obtained from the trout. The toxicant was administered intraperitoneally and intravenously in trout and intraperitoneally in rats. No increase in toxicity of rotenone occurred upon surgical impairment of bile flow in either the trout or the rats, Similarities in the toxicity of rotenone to trout and rats were observed when the toxicant was administered intraperitoneally, The data suggest the selective toxicity of rotenone to fish may be primarily caused by different routes of entry. The results of these experiments indicate the excretory functions of the liver of fish and mammals are similar. Close

• 32. [Article] Food relations and production of cutthroat trout, Salmo clarki clarki Richardson, in an experimental stream

  Production, food consumption and food habits by groups of small, mixed and large sizes of cutthroat trout were studied in enriched and unenriched sections of the Berry Creek Experimental Stream, Oregon ...

  Citation × Citation Citation Abstract Copy Title: Food relations and production of cutthroat trout, Salmo clarki clarki Richardson, in an experimental stream Author: McIntyre, John D. Production, food consumption and food habits by groups of small, mixed and large sizes of cutthroat trout were studied in enriched and unenriched sections of the Berry Creek Experimental Stream, Oregon State University. Continuous introduction of sucrose and urea to portions of the stream resulted in heavy growth of Sphaerotilus natans which supported large biomasses of benthic insects. Production was estimated from monthly changes of biomass. Measurements of growth rates of experimental fish and the relationship between rates of growth and rates of food consumption of fish held in aquaria made estimates of food consumption by the stream fish possible. Analyses were made of the stomach contents of trout removed monthly from the experimental sections. The seasonal contribution to trout food consumption by the important food groups was estimated. Measurements of benthic biomass showed that insects especially midge larvae, benefited greatly from the Sphaerotilus in the enriched sections but organic drift did not increase markedly as a result of enrichment. In both enriched and unenriched sections trout production and food consumption values were highest for small trout, intermediate for mixed sizes and lowest for large trout. Production and food consumption by all size groups of trout increased greatly as a result of enrichment. Title: Food relations and production of cutthroat trout, Salmo clarki clarki Richardson, in an experimental stream Author: McIntyre, John D. Production, food consumption and food habits by groups of small, mixed and large sizes of cutthroat trout were studied in enriched and unenriched sections of the Berry Creek Experimental Stream, Oregon State University. Continuous introduction of sucrose and urea to portions of the stream resulted in heavy growth of Sphaerotilus natans which supported large biomasses of benthic insects. Production was estimated from monthly changes of biomass. Measurements of growth rates of experimental fish and the relationship between rates of growth and rates of food consumption of fish held in aquaria made estimates of food consumption by the stream fish possible. Analyses were made of the stomach contents of trout removed monthly from the experimental sections. The seasonal contribution to trout food consumption by the important food groups was estimated. Measurements of benthic biomass showed that insects especially midge larvae, benefited greatly from the Sphaerotilus in the enriched sections but organic drift did not increase markedly as a result of enrichment. In both enriched and unenriched sections trout production and food consumption values were highest for small trout, intermediate for mixed sizes and lowest for large trout. Production and food consumption by all size groups of trout increased greatly as a result of enrichment. Close

• 33. [Article] Landscape-scale evaluation of genetic structure among barrier-isolated populations of coastal cutthroat trout, Oncorhynchus clarki clarki

  Citation × Citation Citation Abstract Copy Title: Landscape-scale evaluation of genetic structure among barrier-isolated populations of coastal cutthroat trout, Oncorhynchus clarki clarki Author: Guy, Troy J. Title: Landscape-scale evaluation of genetic structure among barrier-isolated populations of coastal cutthroat trout, Oncorhynchus clarki clarki Author: Guy, Troy J. Close

• 34. [Article] Geographic variation in genetic and meristic characters of coastal cutthroat trout (Oncorhynchus clarki clarki)

  Citation × Citation Citation Abstract Copy Title: Geographic variation in genetic and meristic characters of coastal cutthroat trout (Oncorhynchus clarki clarki) Author: Williams, Thomas Herbert Title: Geographic variation in genetic and meristic characters of coastal cutthroat trout (Oncorhynchus clarki clarki) Author: Williams, Thomas Herbert Close

• 35. [Article] Native Trout Studies, 2001

  Abstract -- Summary: We radio-tagged 34 adult westslope cutthroat trout in Rail Creek and Roberts Creek in the mainstem John Day River subbasin. These fish were located weekly by telemetry, as were those ...

  Citation × Citation Citation Abstract Copy Title: Native Trout Studies, 2001 Abstract -- Summary: We radio-tagged 34 adult westslope cutthroat trout in Rail Creek and Roberts Creek in the mainstem John Day River subbasin. These fish were located weekly by telemetry, as were those with active transmitters applied in 2000, to determine seasonal movements. Habitat measurements were collected at each re-location of each radio-tagged fish to determine their seasonal habitat preferences. We collected tissue samples from westslope cutthroat trout and rainbow trout in two streams for genetic description of the populations, and to determine the extent of hybridization between the two species. We helped survey Davis Creek, tributary to the Middle Fork John Day River, to determine whether bull trout were present Title: Native Trout Studies, 2001 Abstract -- Summary: We radio-tagged 34 adult westslope cutthroat trout in Rail Creek and Roberts Creek in the mainstem John Day River subbasin. These fish were located weekly by telemetry, as were those with active transmitters applied in 2000, to determine seasonal movements. Habitat measurements were collected at each re-location of each radio-tagged fish to determine their seasonal habitat preferences. We collected tissue samples from westslope cutthroat trout and rainbow trout in two streams for genetic description of the populations, and to determine the extent of hybridization between the two species. We helped survey Davis Creek, tributary to the Middle Fork John Day River, to determine whether bull trout were present Close

• 36. [Image] The Bull trout (salvelinus confluentus) population within Crater Lake National Park: summarized information relating to its conservation and perpetuation

  	ill.,; Report title; "On October 7 and 8, 1991 an advisory panel\recovery team met at Crater Lake National Park to review the status of the park's only native fish population, and to develop recommendations ...
  	Citation × Citation Citation Abstract Copy Title: The Bull trout (salvelinus confluentus) population within Crater Lake National Park: summarized information relating to its conservation and perpetuation Author: Pister, Edwin P. Year: 1992, 2010 ill.,; Report title; "On October 7 and 8, 1991 an advisory panel\recovery team met at Crater Lake National Park to review the status of the park's only native fish population, and to develop recommendations for a recovery program to restore the Sun Creek Bull Trout population to historic range and abundance within Crater Lake National Park." - P. [ii].; Title: The Bull trout (salvelinus confluentus) population within Crater Lake National Park: summarized information relating to its conservation and perpetuation Author: Pister, Edwin P. Year: 1992, 2010 ill.,; Report title; "On October 7 and 8, 1991 an advisory panel\recovery team met at Crater Lake National Park to review the status of the park's only native fish population, and to develop recommendations for a recovery program to restore the Sun Creek Bull Trout population to historic range and abundance within Crater Lake National Park." - P. [ii].; Close

• 37. [Image] Trout studies and a stream survey of Crater Lake National Park, Oregon

  	Ill., map; Typescript; Map of Crater Lake National Park and vicinity, issued by the U.S. Geological Survey, edition of 1946; Thesis (M.S.)--Oregon State College, 1948; Includes bibliographical references ...
  	Citation × Citation Citation Abstract Copy Title: Trout studies and a stream survey of Crater Lake National Park, Oregon Author: Wallis, O. L. Year: 1948, 2008 Ill., map; Typescript; Map of Crater Lake National Park and vicinity, issued by the U.S. Geological Survey, edition of 1946; Thesis (M.S.)--Oregon State College, 1948; Includes bibliographical references (leaves 118-120) Title: Trout studies and a stream survey of Crater Lake National Park, Oregon Author: Wallis, O. L. Year: 1948, 2008 Ill., map; Typescript; Map of Crater Lake National Park and vicinity, issued by the U.S. Geological Survey, edition of 1946; Thesis (M.S.)--Oregon State College, 1948; Includes bibliographical references (leaves 118-120) Close

• 38. [Article] Migration and Passage of Redband Trout in the Donner und Blitzen River, 2007-2009, Information Reports Number 2009-05

  Abstract -- Movement of redband trout (Oncorhynchus mykiss gairdneri) was tracked between March 2007 and June 2009 in the Donner und Blitzen River (Blitzen River). We had three primary study objectives: ...

  Citation × Citation Citation Abstract Copy Title: Migration and Passage of Redband Trout in the Donner und Blitzen River, 2007-2009, Information Reports Number 2009-05 Abstract -- Movement of redband trout (Oncorhynchus mykiss gairdneri) was tracked between March 2007 and June 2009 in the Donner und Blitzen River (Blitzen River). We had three primary study objectives: 1) examine redband trout spawning locations and spawning migration timing, 2) evaluate redband trout passage at diversion dams, and 3) investigate seasonal migration patterns of redband trout as they relate to stream temperature dynamics. We tagged 96 redband trout with radio transmitters and 706 with PIT tags. Radio tracking included both mobile and fixed station detections. We established PIT tag readers at Cato Bridge (Rkm 1), Busse Dam (Rkm 35), Grain Camp Dam (Rkm 48), and Page Dam (Rkm 76) for additional data on large-scale movement patterns. With the PIT antennas at the three diversion dams, we placed one antenna below the dam and one at the upstream exit of the fish ladders to evaluate the passage delays at each dam. Stream temperature was recorded at 10 locations in the Blitzen River throughout the study. Scales of 257 migratory trout were interpreted for age and spawning history. Our results indicated that the majority of Blitzen redband trout migrated upstream of Page Dam to spawn and that most trout spawned in the mainstem and not the tributaries. Upstream trout migration occurred from March to July, but the peak migration occurred during late April and early May. Passage problems were recorded at two of the three dams evaluated. Trout were delayed longest at Busse Dam and 44% of radio-tagged trout that approached the dam were never able to pass. Trout experienced less delay at Grain Camp Dam and only 8% of radio-tagged trout failed to pass the dam. At Page Dam, which has a recently upgraded fish ladder, trout delays were short and only 5% of trout that approached the dam were unable to pass. Potentially stressful or lethal temperatures (>24.3°C) were recorded at all monitoring locations downstream of Fish Creek, except at the site just below Page Springs. The migratory population ranged in age from 1+ to 5+, but only age 3+ and older trout were reproductively mature. This suggests that the spring upstream migration includes both adult trout seeking suitable spawning habitats and immature trout making a seasonal habitat shift for thermal refuge. A fraction of the PIT-tagged fish were observed to make two or three migrations from below Busse Dam to above Page Dam in the spring and returning back to the lower river in the fall. We recommend prioritizing fish passage at the Busse Dam and Grain Camp Dam for conservation and enhancement efforts. Title: Migration and Passage of Redband Trout in the Donner und Blitzen River, 2007-2009, Information Reports Number 2009-05 Abstract -- Movement of redband trout (Oncorhynchus mykiss gairdneri) was tracked between March 2007 and June 2009 in the Donner und Blitzen River (Blitzen River). We had three primary study objectives: 1) examine redband trout spawning locations and spawning migration timing, 2) evaluate redband trout passage at diversion dams, and 3) investigate seasonal migration patterns of redband trout as they relate to stream temperature dynamics. We tagged 96 redband trout with radio transmitters and 706 with PIT tags. Radio tracking included both mobile and fixed station detections. We established PIT tag readers at Cato Bridge (Rkm 1), Busse Dam (Rkm 35), Grain Camp Dam (Rkm 48), and Page Dam (Rkm 76) for additional data on large-scale movement patterns. With the PIT antennas at the three diversion dams, we placed one antenna below the dam and one at the upstream exit of the fish ladders to evaluate the passage delays at each dam. Stream temperature was recorded at 10 locations in the Blitzen River throughout the study. Scales of 257 migratory trout were interpreted for age and spawning history. Our results indicated that the majority of Blitzen redband trout migrated upstream of Page Dam to spawn and that most trout spawned in the mainstem and not the tributaries. Upstream trout migration occurred from March to July, but the peak migration occurred during late April and early May. Passage problems were recorded at two of the three dams evaluated. Trout were delayed longest at Busse Dam and 44% of radio-tagged trout that approached the dam were never able to pass. Trout experienced less delay at Grain Camp Dam and only 8% of radio-tagged trout failed to pass the dam. At Page Dam, which has a recently upgraded fish ladder, trout delays were short and only 5% of trout that approached the dam were unable to pass. Potentially stressful or lethal temperatures (>24.3°C) were recorded at all monitoring locations downstream of Fish Creek, except at the site just below Page Springs. The migratory population ranged in age from 1+ to 5+, but only age 3+ and older trout were reproductively mature. This suggests that the spring upstream migration includes both adult trout seeking suitable spawning habitats and immature trout making a seasonal habitat shift for thermal refuge. A fraction of the PIT-tagged fish were observed to make two or three migrations from below Busse Dam to above Page Dam in the spring and returning back to the lower river in the fall. We recommend prioritizing fish passage at the Busse Dam and Grain Camp Dam for conservation and enhancement efforts. Close

• 39. [Article] Bioenergetic evaluation of diel vertical migration by bull trout

  I evaluated hypotheses related to growth as a driver of depth use and diel vertical migration by bull trout (Salvelinus confluentus) in a thermally stratified reservoir. I applied a bioenergetic model ...

  Citation × Citation Citation Abstract Copy Title: Bioenergetic evaluation of diel vertical migration by bull trout Author: Eckmann, Madeleine I evaluated hypotheses related to growth as a driver of depth use and diel vertical migration by bull trout (Salvelinus confluentus) in a thermally stratified reservoir. I applied a bioenergetic model to evaluate growth of bull trout in relation to potential patterns of diel depth use by bull trout in Ross Lake, Washington. Modeled patterns of growth were derived from observed vertical distributions of temperature and prey availability. I also observed bull trout depth (and corresponding temperature) use patterns to determine if observed behaviors corresponded with those predicted to maximize growth. Results of this work suggest that bull trout migrations beyond 25 m deep in Ross Lake cannot be explained exclusively by growth and survival alone, two common explanations for diel vertical migration. These deeper excursions may be explained by a third driver that has not been previously emphasized: the importance of colder water for gametogenesis. Further evaluation of this hypothesis as a means of explaining diel vertical migration for bull trout and other fish species in similar environments is warranted. Title: Bioenergetic evaluation of diel vertical migration by bull trout Author: Eckmann, Madeleine I evaluated hypotheses related to growth as a driver of depth use and diel vertical migration by bull trout (Salvelinus confluentus) in a thermally stratified reservoir. I applied a bioenergetic model to evaluate growth of bull trout in relation to potential patterns of diel depth use by bull trout in Ross Lake, Washington. Modeled patterns of growth were derived from observed vertical distributions of temperature and prey availability. I also observed bull trout depth (and corresponding temperature) use patterns to determine if observed behaviors corresponded with those predicted to maximize growth. Results of this work suggest that bull trout migrations beyond 25 m deep in Ross Lake cannot be explained exclusively by growth and survival alone, two common explanations for diel vertical migration. These deeper excursions may be explained by a third driver that has not been previously emphasized: the importance of colder water for gametogenesis. Further evaluation of this hypothesis as a means of explaining diel vertical migration for bull trout and other fish species in similar environments is warranted. Close

• 40. [Article] The influence of natural mortality and other life history factors on the yield to the angler of planted cutthroat trout in Munsel Lake, Oregon

  Citation × Citation Citation Abstract Copy Title: The influence of natural mortality and other life history factors on the yield to the angler of planted cutthroat trout in Munsel Lake, Oregon Author: Hansen, David Title: The influence of natural mortality and other life history factors on the yield to the angler of planted cutthroat trout in Munsel Lake, Oregon Author: Hansen, David Close