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• 31. [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

• 32. [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

• 33. [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

• 34. [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

• 35. [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

• 36. [Article] Life history of rainbow trout and considerations for introducing steelhead into southern Chile

  Citation × Citation Citation Abstract Copy Title: Life history of rainbow trout and considerations for introducing steelhead into southern Chile Author: Poblete Arellano, Tirso S. Title: Life history of rainbow trout and considerations for introducing steelhead into southern Chile Author: Poblete Arellano, Tirso S. Close

• 37. [Article] The acute effects of stress on plasma proteins of rainbow trout, Oncorhynchus mykiss

  Citation × Citation Citation Abstract Copy Title: The acute effects of stress on plasma proteins of rainbow trout, Oncorhynchus mykiss Author: Demers, Nora Egan Title: The acute effects of stress on plasma proteins of rainbow trout, Oncorhynchus mykiss Author: Demers, Nora Egan Close

• 38. [Article] Lake Billy Chinook - 1998 Length Frequency Estimates

  Abstract -- Reports length and frequency of bull trout, Kokanee, small mouth bass, Rainbow trout, and brown trout, that were caught in Lake Billy Chinook in 1998.

  Citation × Citation Citation Abstract Copy Title: Lake Billy Chinook - 1998 Length Frequency Estimates Abstract -- Reports length and frequency of bull trout, Kokanee, small mouth bass, Rainbow trout, and brown trout, that were caught in Lake Billy Chinook in 1998. Title: Lake Billy Chinook - 1998 Length Frequency Estimates Abstract -- Reports length and frequency of bull trout, Kokanee, small mouth bass, Rainbow trout, and brown trout, that were caught in Lake Billy Chinook in 1998. Close

• 39. [Article] 2017 Bull Trout Redd Monitoring in the Wallowa Mountains

  Abstract -- Bull trout were listed as threatened under the Endangered Species Act in 1998 due to declining populations. The U. S. Fish and Wildlife Service (Service) recommends monitoring bull trout in subbasins ...

  Citation × Citation Citation Abstract Copy Title: 2017 Bull Trout Redd Monitoring in the Wallowa Mountains Abstract -- Bull trout were listed as threatened under the Endangered Species Act in 1998 due to declining populations. The U. S. Fish and Wildlife Service (Service) recommends monitoring bull trout in subbasins where little is known about the populations, including the Grande Ronde and Imnaha subbasins. Spawning survey data is important for determining relative abundance and distribution trends in bull trout populations. This report summarizes the 2017 bull trout spawning data collected in the Wallowa Mountains of northeast Oregon and compares this with past years’ data. Bull trout spawning surveys have been conducted on similar index areas for selected Grande Ronde and Imnaha River streams from 1999 to 2017. These surveyed streams are located within the Wallowa River/Minam River and Imnaha River bull trout core areas. Surveys in 2017 were conducted by the Nez Perce Tribe (NPT), the Oregon Department of Fish and Wildlife (ODFW), the Service, U.S. Forest Service (USFS), Freshwater Trust, and fisheries consultants. Objectives of the survey included: (1) locate bull trout spawning areas; (2) determine redd characteristics; (3) determine bull trout timing of spawning; (4) collect spawning density data; (5) determine and compare the spatial distribution of redds along the Lostine River in 2006 through 2017; and (6) over time use all of the data to assess local bull trout population trends and the long-term recovery of bull trout. Timing of spawning, total redds, redd sizes, and redd locations are documented in the report. Title: 2017 Bull Trout Redd Monitoring in the Wallowa Mountains Abstract -- Bull trout were listed as threatened under the Endangered Species Act in 1998 due to declining populations. The U. S. Fish and Wildlife Service (Service) recommends monitoring bull trout in subbasins where little is known about the populations, including the Grande Ronde and Imnaha subbasins. Spawning survey data is important for determining relative abundance and distribution trends in bull trout populations. This report summarizes the 2017 bull trout spawning data collected in the Wallowa Mountains of northeast Oregon and compares this with past years’ data. Bull trout spawning surveys have been conducted on similar index areas for selected Grande Ronde and Imnaha River streams from 1999 to 2017. These surveyed streams are located within the Wallowa River/Minam River and Imnaha River bull trout core areas. Surveys in 2017 were conducted by the Nez Perce Tribe (NPT), the Oregon Department of Fish and Wildlife (ODFW), the Service, U.S. Forest Service (USFS), Freshwater Trust, and fisheries consultants. Objectives of the survey included: (1) locate bull trout spawning areas; (2) determine redd characteristics; (3) determine bull trout timing of spawning; (4) collect spawning density data; (5) determine and compare the spatial distribution of redds along the Lostine River in 2006 through 2017; and (6) over time use all of the data to assess local bull trout population trends and the long-term recovery of bull trout. Timing of spawning, total redds, redd sizes, and redd locations are documented in the report. Close

• 40. [Article] Carcinogenicity and acute toxicity of dimethylnitrosamine in rainbow trout (Salmo gairdneri)

  A dose related carcinogenic response was established for dimethylnitrosamine administered in the diet of rainbow trout (Salmo gairdneri). An equation was derived for the relationship between dose and hepatocellular carcinoma ...

  Citation × Citation Citation Abstract Copy Title: Carcinogenicity and acute toxicity of dimethylnitrosamine in rainbow trout (Salmo gairdneri) Author: Grieco, Mary Porter A dose related carcinogenic response was established for dimethylnitrosamine administered in the diet of rainbow trout (Salmo gairdneri). An equation was derived for the relationship between dose and hepatocellular carcinoma incidence. From a published dose response study using Porton rats as a test animal, a second equation was derived for comparison. The rat and the trout were approximately equivalent in their sensitivity to dimethylnitrosamine carcinogenesis. The histological nature of the carcinogenic response in trout was similar to to that of mammalian species. Apart from carcinogenesis, no indications of chronic toxicity were observed after a one year feeding experiment. The median lethal dose after intraperitoneal injection of dimethylnitrosamine was 1,770 mg/kg body weight in rainbow trout. Relative to the range of 15 to 50 mg/kg body weight reported for several mammalian species, trout were resistant to the acutely toxic effects of dimethylnitrosamine. Title: Carcinogenicity and acute toxicity of dimethylnitrosamine in rainbow trout (Salmo gairdneri) Author: Grieco, Mary Porter A dose related carcinogenic response was established for dimethylnitrosamine administered in the diet of rainbow trout (Salmo gairdneri). An equation was derived for the relationship between dose and hepatocellular carcinoma incidence. From a published dose response study using Porton rats as a test animal, a second equation was derived for comparison. The rat and the trout were approximately equivalent in their sensitivity to dimethylnitrosamine carcinogenesis. The histological nature of the carcinogenic response in trout was similar to to that of mammalian species. Apart from carcinogenesis, no indications of chronic toxicity were observed after a one year feeding experiment. The median lethal dose after intraperitoneal injection of dimethylnitrosamine was 1,770 mg/kg body weight in rainbow trout. Relative to the range of 15 to 50 mg/kg body weight reported for several mammalian species, trout were resistant to the acutely toxic effects of dimethylnitrosamine. Close