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• 11. [Article] Oral immunization for possible control of furunculosis in fish

  This project was initiated in an attempt to control furunculosis (Aeromonas salmonicida) in a production hatchery rearing coho salmon. An oral vaccine was prepared and administered to 520,000 juvenile ...

  Citation × Citation Citation Abstract Copy Title: Oral immunization for possible control of furunculosis in fish Author: Frost, Gary Douglas This project was initiated in an attempt to control furunculosis (Aeromonas salmonicida) in a production hatchery rearing coho salmon. An oral vaccine was prepared and administered to 520,000 juvenile coho salmon (Oncorhynchus kisutch) at the Siletz River Salmon Hatchery prior to the onset of a predictable naturally occurring epizootic of furunculosis. A group of 65,000 salmon served as a nonimmunized control. The Fermacell Fermentor was used to grow the Aeromonas salmonicida cells. The cell yield was more than doubled with the addition of 175 grams of dextrose to the culture media accompanied by automatic control of the pH. The cells were subjected to ultrasonic disruption and the supernatant fluid was precipitated with alum. The resulting material was lyophilized and incorporated into the Oregon Moist Pellet diet at a concentration of 201.73 milligrams ± 3 milligrams per kilogram of pellets. Immunization with vaccine-containing food was begun on March 26, 1967 with 14 consecutive days of initial vaccination followed by eight weekly boosters. It was calculated that each fish could receive approximately 360.7 micrograms of vaccine during the immunization period. During the period of May 1 through July 12, 1967, all hatchery mortalities were collected and examined for the presence of Aeromonas salmonicida. Although the nonimmunized control group showed a higher total loss and a higher furunculosis loss than the immunized groups, the results fail to indicate any distinctive difference between these two lots. The lower mortalities observed in the immunized group may indicate that slight immunity had been induced by the vaccine. However, any low-level immunity which may have been produced was not sufficient to provide protection against infection by Aeromonas salmonicida. The number of mortalities appeared to be closely associated with the hatchery water temperature. An increase in water temperature was accompanied by a corresponding increase in losses. A decline in losses appeared to be associated with a decrease in water temperature. Of the fish examined, 146 animals showed the presence of an acid-fast organism tentatively identified as Mycobacterium fortuitum (Cruz). Agglutinating antibody titers on serum samples from the immunized and nonimmunized groups of fish failed to indicate any meaningful difference between these groups. Title: Oral immunization for possible control of furunculosis in fish Author: Frost, Gary Douglas This project was initiated in an attempt to control furunculosis (Aeromonas salmonicida) in a production hatchery rearing coho salmon. An oral vaccine was prepared and administered to 520,000 juvenile coho salmon (Oncorhynchus kisutch) at the Siletz River Salmon Hatchery prior to the onset of a predictable naturally occurring epizootic of furunculosis. A group of 65,000 salmon served as a nonimmunized control. The Fermacell Fermentor was used to grow the Aeromonas salmonicida cells. The cell yield was more than doubled with the addition of 175 grams of dextrose to the culture media accompanied by automatic control of the pH. The cells were subjected to ultrasonic disruption and the supernatant fluid was precipitated with alum. The resulting material was lyophilized and incorporated into the Oregon Moist Pellet diet at a concentration of 201.73 milligrams ± 3 milligrams per kilogram of pellets. Immunization with vaccine-containing food was begun on March 26, 1967 with 14 consecutive days of initial vaccination followed by eight weekly boosters. It was calculated that each fish could receive approximately 360.7 micrograms of vaccine during the immunization period. During the period of May 1 through July 12, 1967, all hatchery mortalities were collected and examined for the presence of Aeromonas salmonicida. Although the nonimmunized control group showed a higher total loss and a higher furunculosis loss than the immunized groups, the results fail to indicate any distinctive difference between these two lots. The lower mortalities observed in the immunized group may indicate that slight immunity had been induced by the vaccine. However, any low-level immunity which may have been produced was not sufficient to provide protection against infection by Aeromonas salmonicida. The number of mortalities appeared to be closely associated with the hatchery water temperature. An increase in water temperature was accompanied by a corresponding increase in losses. A decline in losses appeared to be associated with a decrease in water temperature. Of the fish examined, 146 animals showed the presence of an acid-fast organism tentatively identified as Mycobacterium fortuitum (Cruz). Agglutinating antibody titers on serum samples from the immunized and nonimmunized groups of fish failed to indicate any meaningful difference between these groups. Close

• 12. [Article] Growth of juvenile Pacific oysters, Crassostrea gigas (Thunberg) and Manila clams, Tapes japonica (Deshayes) in effluent from salmon-macroalga polyculture system

  Experiments were carried out in fall and winter, 1990 and spring and summer, 1991 , to determine growth and mortality of juvenile Pacific oysters {Crassostrea gigas) in effluent from cultured coho salmon ...

  Citation × Citation Citation Abstract Copy Title: Growth of juvenile Pacific oysters, Crassostrea gigas (Thunberg) and Manila clams, Tapes japonica (Deshayes) in effluent from salmon-macroalga polyculture system Author: Diaz, Maria Elena, 1958- Experiments were carried out in fall and winter, 1990 and spring and summer, 1991 , to determine growth and mortality of juvenile Pacific oysters {Crassostrea gigas) in effluent from cultured coho salmon {Oncorhynchus kisutch) , and effluent from salmon in which the red macroalga Palmaria mollis was cultured. Ambient sea water from Yaquina Bay was used as a control. Juvenile Manila clams {Tapes japonica) were also tested in summer, to compare the growth response of clams with that of Pacific oysters. Measured growth parameters included: increase in mean individual live weight, specific growth rate (% increase of mean live weight per day) and mean individual organic (ash-free) weight. Temperature, chlorophyll a, phaeopigment, carbon and nitrogen concentrations and C/N ratio for all treatments were also recorded during spring and summer, 1991. The oysters grew significantly faster in effluent from salmon and salmon conditioned by macroalgae than in the control during the Fall Experiment (September 7- 0ctober 31, 1990). Mean water temperature was 13-16°C. Growth rates were significantly greater in oysters cultured in salmon effluent than in the control during the Winter Experiment (December 7, 1990-February 15, 1991). However, growth was very poor due to low water temperatures (7-10°C). Growth of oysters was significantly greater in the control than in effluent from salmon and salmon conditioned by macrolagae in the Spring Experiment (March 7-May 24, 1991). Mean water temperature was 12°C. In the Summer Experiments, (June 3-July 4 and July 19-August 17, 1991) growth of oysters was more rapid in treatments with macroalgae as compared to treatments without macroalgae Comparative experiments with juvenile Manila clams gave similar results. Percentage mortality for both oysters and clams ranged from 0 to 5% and was highest during winter and lowest during summer. Mean chlorophyll values ranged from 1 μg/1 in spring, 1991 to 11 μg/1 summer, 1991. Title: Growth of juvenile Pacific oysters, Crassostrea gigas (Thunberg) and Manila clams, Tapes japonica (Deshayes) in effluent from salmon-macroalga polyculture system Author: Diaz, Maria Elena, 1958- Experiments were carried out in fall and winter, 1990 and spring and summer, 1991 , to determine growth and mortality of juvenile Pacific oysters {Crassostrea gigas) in effluent from cultured coho salmon {Oncorhynchus kisutch) , and effluent from salmon in which the red macroalga Palmaria mollis was cultured. Ambient sea water from Yaquina Bay was used as a control. Juvenile Manila clams {Tapes japonica) were also tested in summer, to compare the growth response of clams with that of Pacific oysters. Measured growth parameters included: increase in mean individual live weight, specific growth rate (% increase of mean live weight per day) and mean individual organic (ash-free) weight. Temperature, chlorophyll a, phaeopigment, carbon and nitrogen concentrations and C/N ratio for all treatments were also recorded during spring and summer, 1991. The oysters grew significantly faster in effluent from salmon and salmon conditioned by macroalgae than in the control during the Fall Experiment (September 7- 0ctober 31, 1990). Mean water temperature was 13-16°C. Growth rates were significantly greater in oysters cultured in salmon effluent than in the control during the Winter Experiment (December 7, 1990-February 15, 1991). However, growth was very poor due to low water temperatures (7-10°C). Growth of oysters was significantly greater in the control than in effluent from salmon and salmon conditioned by macrolagae in the Spring Experiment (March 7-May 24, 1991). Mean water temperature was 12°C. In the Summer Experiments, (June 3-July 4 and July 19-August 17, 1991) growth of oysters was more rapid in treatments with macroalgae as compared to treatments without macroalgae Comparative experiments with juvenile Manila clams gave similar results. Percentage mortality for both oysters and clams ranged from 0 to 5% and was highest during winter and lowest during summer. Mean chlorophyll values ranged from 1 μg/1 in spring, 1991 to 11 μg/1 summer, 1991. Close

• 13. [Article] Trophically transmitted parasites as ecosystem indicators : relationships among parasite community structure, juvenile salmon diet composition, and ocean conditions

  Recent research conducted throughout the Northern California Current (NCC) on the ecology of Pacific salmon (Oncorhynchus spp.) indicates that variable ocean conditions affect the community composition ...

  Citation × Citation Citation Abstract Copy Title: Trophically transmitted parasites as ecosystem indicators : relationships among parasite community structure, juvenile salmon diet composition, and ocean conditions Author: Losee, James P. Recent research conducted throughout the Northern California Current (NCC) on the ecology of Pacific salmon (Oncorhynchus spp.) indicates that variable ocean conditions affect the community composition of zooplankton in the nearshore environment which, in turn, can affect the quality of prey for fish, sea birds and mammals. Interannual variability in the quality and composition of the copepod community in the NCC during early marine residency of some Pacific salmon populations is related to survival to adulthood. However, copepods make up a small portion of the diet of coho and Chinook salmon, and the mechanistic linkages between ocean climate, zooplankton composition and salmon prey remain unclear. Parasite analysis provides a supplement to traditional diet analysis that can describe the foraging history of a host species. Coho salmon (O. kisutch) and Chinook salmon (O. tshawytscha) serve as hosts to an array of marine parasites acquired through consumption of infected intermediate hosts such as copepods, euphausiids, and planktivorous fishes. Causing little or no harm to their salmon host, the presence of trophically transmitted parasites provides information on the dietary history of their salmonid host beyond the 24 hours associated with traditional diet analysis. This study (1) examined differences in feeding behavior of coho and Chinook salmon during their early marine residency using both stomach and parasite community analyses and (2) tested the hypothesis that variability in ocean circulation patterns (measured through the Pacific Decadal Oscillation, sea surface temperature (SST) and Bakun's upwelling index) and copepod species composition are related to variability in the community structure of trophically transmitted marine parasites found in juvenile salmon. I compared the abundance and species composition of parasites recovered from juvenile Columbia River coho and upper Columbia River summer and fall Chinook salmon captured off the coast of Washington from 2002 to 2009. I also compared interannual variability in parasite assemblages to physical and biological indices of ocean conditions. Coho and Chinook salmon consumed similar prey taxa; however, the species richness and abundance of trophically transmitted parasites indicated that Chinook salmon consumed a greater diversity and abundance of infected prey. In addition, differences in the abundance of fish in the diet and Anisakis simplex, a parasitic nematode known to infect salmon through fish consumption, suggest that Chinook salmon consistently consumed more fish prey than coho. In contrast, coho appeared to consume more euphausiids as indicated by stomach content analysis and increased abundance of the euphausiid parasite, Rhadinorhynchus trachuri. Shifts in the parasite community composition of both coho and Chinook salmon were related to interannual variability in SST and the biomass of southern-origin copepods (r > 0.7, P < 0.05). The acanthocephalan R. trachuri and a tetraphyllid cestode were associated with "warm" SSTs and greater biomass of lipid-poor, subtropical copepods while the nematode A. simplex was more abundant in years of "cold" SST and a relatively low biomass of subtropical copepods. These results provide novel insight into differences in the diet of Columbia River coho and Chinook salmon and illustrate linkages between ocean climate, zooplankton community composition and salmon diet during early marine residency. Title: Trophically transmitted parasites as ecosystem indicators : relationships among parasite community structure, juvenile salmon diet composition, and ocean conditions Author: Losee, James P. Recent research conducted throughout the Northern California Current (NCC) on the ecology of Pacific salmon (Oncorhynchus spp.) indicates that variable ocean conditions affect the community composition of zooplankton in the nearshore environment which, in turn, can affect the quality of prey for fish, sea birds and mammals. Interannual variability in the quality and composition of the copepod community in the NCC during early marine residency of some Pacific salmon populations is related to survival to adulthood. However, copepods make up a small portion of the diet of coho and Chinook salmon, and the mechanistic linkages between ocean climate, zooplankton composition and salmon prey remain unclear. Parasite analysis provides a supplement to traditional diet analysis that can describe the foraging history of a host species. Coho salmon (O. kisutch) and Chinook salmon (O. tshawytscha) serve as hosts to an array of marine parasites acquired through consumption of infected intermediate hosts such as copepods, euphausiids, and planktivorous fishes. Causing little or no harm to their salmon host, the presence of trophically transmitted parasites provides information on the dietary history of their salmonid host beyond the 24 hours associated with traditional diet analysis. This study (1) examined differences in feeding behavior of coho and Chinook salmon during their early marine residency using both stomach and parasite community analyses and (2) tested the hypothesis that variability in ocean circulation patterns (measured through the Pacific Decadal Oscillation, sea surface temperature (SST) and Bakun's upwelling index) and copepod species composition are related to variability in the community structure of trophically transmitted marine parasites found in juvenile salmon. I compared the abundance and species composition of parasites recovered from juvenile Columbia River coho and upper Columbia River summer and fall Chinook salmon captured off the coast of Washington from 2002 to 2009. I also compared interannual variability in parasite assemblages to physical and biological indices of ocean conditions. Coho and Chinook salmon consumed similar prey taxa; however, the species richness and abundance of trophically transmitted parasites indicated that Chinook salmon consumed a greater diversity and abundance of infected prey. In addition, differences in the abundance of fish in the diet and Anisakis simplex, a parasitic nematode known to infect salmon through fish consumption, suggest that Chinook salmon consistently consumed more fish prey than coho. In contrast, coho appeared to consume more euphausiids as indicated by stomach content analysis and increased abundance of the euphausiid parasite, Rhadinorhynchus trachuri. Shifts in the parasite community composition of both coho and Chinook salmon were related to interannual variability in SST and the biomass of southern-origin copepods (r > 0.7, P < 0.05). The acanthocephalan R. trachuri and a tetraphyllid cestode were associated with "warm" SSTs and greater biomass of lipid-poor, subtropical copepods while the nematode A. simplex was more abundant in years of "cold" SST and a relatively low biomass of subtropical copepods. These results provide novel insight into differences in the diet of Columbia River coho and Chinook salmon and illustrate linkages between ocean climate, zooplankton community composition and salmon diet during early marine residency. Close

• 14. [Article] Reproductive rates of copepods in experimental ponds in Oregon

  Rates of birth, death and population change were calculated for Cyclops sp. and Diaptornus forbesi in Soap Creek Ponds V-VIII near Corvallis, Oregon during the interval April, 1968 to April, 1969. An egg ...

  Citation × Citation Citation Abstract Copy Title: Reproductive rates of copepods in experimental ponds in Oregon Author: Lindland, Ronald L. Rates of birth, death and population change were calculated for Cyclops sp. and Diaptornus forbesi in Soap Creek Ponds V-VIII near Corvallis, Oregon during the interval April, 1968 to April, 1969. An egg ratio method was used in calculating these rates. Duration of development of the eggs of both species was determined in the laboratory and found to be highly correlated with water temperature. Even though the ponds are adjacently located and morphometrically very similar, significant differences in birth rates and population densities between ponds were noted. Eggs were collected most frequently in pond VI for Cyclops sp. and in ponds VII and VIII for D. forbesi. Consequently, populations of each species were most stable in these respective ponds. Predation by small fishes was probably the main cause of zooplankton mortality in all four ponds. Title: Reproductive rates of copepods in experimental ponds in Oregon Author: Lindland, Ronald L. Rates of birth, death and population change were calculated for Cyclops sp. and Diaptornus forbesi in Soap Creek Ponds V-VIII near Corvallis, Oregon during the interval April, 1968 to April, 1969. An egg ratio method was used in calculating these rates. Duration of development of the eggs of both species was determined in the laboratory and found to be highly correlated with water temperature. Even though the ponds are adjacently located and morphometrically very similar, significant differences in birth rates and population densities between ponds were noted. Eggs were collected most frequently in pond VI for Cyclops sp. and in ponds VII and VIII for D. forbesi. Consequently, populations of each species were most stable in these respective ponds. Predation by small fishes was probably the main cause of zooplankton mortality in all four ponds. Close

• 15. [Article] Factors affecting the smolt yield of Coho salmon (Oncorhynchus kisutch) in three Oregon streams

  Data from the coho salmon migration were examined from three streams of the Alsea Watershed Study, conducted on tributaries to Drift Creek, Oregon, from 1959 through 1973. With the migration season defined ...

  Citation × Citation Citation Abstract Copy Title: Factors affecting the smolt yield of Coho salmon (Oncorhynchus kisutch) in three Oregon streams Author: Knight, Ned J. Data from the coho salmon migration were examined from three streams of the Alsea Watershed Study, conducted on tributaries to Drift Creek, Oregon, from 1959 through 1973. With the migration season defined as November 1 through May 31, the mean seasonal smolt count was 2022 fish in Deer Creek, 665 in Flynn Creek, and 277 in Needle Branch. A general decline in numbers in the later years of the study was countered by a significant increase in mean length. The peak migration time was in late March and early April in each stream. A general approach to correlate physical and biological factors to the total seasonal smolt count in each stream through single regression analyses was mostly unsuccessful. A hypothesized positive relationship between summer discharge and smolt yield could not be supported, either by using mean monthly or mean maximum flows. A negative relationship between winter discharge and smolt count was hypothesized, due to increased mortality from higher flows. This hypothesis was supported by significant regressions that included mean January flows and mean highest flows. Summer temperatures (mean monthly and mean maximum for 7, 15, and 30 days) showed little correlation with the smolt output. Suspended sediment concentrations were negatively correlated with the number of smolts, as expected from the close relationship between sediment and streamflow. September biomass of juveniles in Flynn Creek was significantly related to the smolt output, though the relationships were weaker in the other two streams. The number of spawning females was positively related to the resulting smolt count but the correlations were not significant. Cutthroat trout biomass showed very little correlation with the coho smolt output. Combinations of variables in multiple regression analyses proved generally more successful than the single correlations with smolt count, but interpretation of the variables that proved significant was not always clear. For Deer Creek, 63.9% of the variability in smolt yield could be explained by the regression with September biomass and mean May maximum temperatures. September biomass, January discharge, and mean sediment concentration accounted for 80.7% of the variability in Flynn Creek smolt output. Only 53.8% of the variability in Needle Branch smolt count could be adequately explained (from January discharge and timing of the mean lowest discharge for 15 days), perhaps due to changes in stream variables following logging. When total smolt weight (biomass) was used as the dependent variable instead of count, only the Flynn Creek regression was significant (R²=0.888, with September biomass, mean lowest discharge for 15 days, and spawning female count). It is evident from these analyses that the juvenile populations in each stream have different relationships with various physical and biological factors. Other studies have shown strong positive relationships between commercial catch of coho salmon off Oregon and Washington and streamflow two years previously, corresponding to the freshwater residence period of the juveniles. In this study, however, negative relationships between winter discharge and smolt output were found. It seems that this negative correlation is masked by downstream, estuary, or ocean factors that are inherent in the relationships between catch and flow. Title: Factors affecting the smolt yield of Coho salmon (Oncorhynchus kisutch) in three Oregon streams Author: Knight, Ned J. Data from the coho salmon migration were examined from three streams of the Alsea Watershed Study, conducted on tributaries to Drift Creek, Oregon, from 1959 through 1973. With the migration season defined as November 1 through May 31, the mean seasonal smolt count was 2022 fish in Deer Creek, 665 in Flynn Creek, and 277 in Needle Branch. A general decline in numbers in the later years of the study was countered by a significant increase in mean length. The peak migration time was in late March and early April in each stream. A general approach to correlate physical and biological factors to the total seasonal smolt count in each stream through single regression analyses was mostly unsuccessful. A hypothesized positive relationship between summer discharge and smolt yield could not be supported, either by using mean monthly or mean maximum flows. A negative relationship between winter discharge and smolt count was hypothesized, due to increased mortality from higher flows. This hypothesis was supported by significant regressions that included mean January flows and mean highest flows. Summer temperatures (mean monthly and mean maximum for 7, 15, and 30 days) showed little correlation with the smolt output. Suspended sediment concentrations were negatively correlated with the number of smolts, as expected from the close relationship between sediment and streamflow. September biomass of juveniles in Flynn Creek was significantly related to the smolt output, though the relationships were weaker in the other two streams. The number of spawning females was positively related to the resulting smolt count but the correlations were not significant. Cutthroat trout biomass showed very little correlation with the coho smolt output. Combinations of variables in multiple regression analyses proved generally more successful than the single correlations with smolt count, but interpretation of the variables that proved significant was not always clear. For Deer Creek, 63.9% of the variability in smolt yield could be explained by the regression with September biomass and mean May maximum temperatures. September biomass, January discharge, and mean sediment concentration accounted for 80.7% of the variability in Flynn Creek smolt output. Only 53.8% of the variability in Needle Branch smolt count could be adequately explained (from January discharge and timing of the mean lowest discharge for 15 days), perhaps due to changes in stream variables following logging. When total smolt weight (biomass) was used as the dependent variable instead of count, only the Flynn Creek regression was significant (R²=0.888, with September biomass, mean lowest discharge for 15 days, and spawning female count). It is evident from these analyses that the juvenile populations in each stream have different relationships with various physical and biological factors. Other studies have shown strong positive relationships between commercial catch of coho salmon off Oregon and Washington and streamflow two years previously, corresponding to the freshwater residence period of the juveniles. In this study, however, negative relationships between winter discharge and smolt output were found. It seems that this negative correlation is masked by downstream, estuary, or ocean factors that are inherent in the relationships between catch and flow. Close

• 16. [Article] Social interaction between juvenile coho and fall chinook salmon in Sixes River, Oregon

  The nature of the interaction between juvenile coho salmon, Oncorhynchus kisutch (Walbaum), and fall chinook salmon, 0. tshawytscha (Walbaum), was studied in Sixes River, Oregon. Seining, snorkeling, and ...

  Citation × Citation Citation Abstract Copy Title: Social interaction between juvenile coho and fall chinook salmon in Sixes River, Oregon Author: Stein, Roy A. The nature of the interaction between juvenile coho salmon, Oncorhynchus kisutch (Walbaum), and fall chinook salmon, 0. tshawytscha (Walbaum), was studied in Sixes River, Oregon. Seining, snorkeling, and tagging were used to determine distribution and patterns of growth of these two species in the stream environment. Experiments conducted in flowing-water observation troughs that provided volitional residence were designed to examine the outcome of agonistic behavior between these two species. Both species were distributed throughout the entire river system in early spring. During this period, underwater surveys in the main river and selected tributaries indicated that both species preferred the same habitat. As temperatures increased during the late spring, coho disappeared from the main river, but continued to occupy cool tributaries. Fall chinook, on the other hand, were found primarily in the main river until early summer, when they moved to the estuary. Relatively few individuals remained in the tributaries. Experiments conducted in the troughs revealed that agonistic behavior, including nipping, chasing, lateral display, submission, and fleeing, occurred between juvenile coho and fall chinook. When the two species were together in the troughs and in cool tributary streams, coho grew faster than chinook. When isolated in troughs, both grew at similar rates. Coho tolerated fewer individuals per unit area than did chinook, and occupied positions of dominance near the source of incoming food at the upstream end of the troughs. Coho had brighter fin and body colors, greater fin development, deeper bodies, and were heavier than fall chinook of the same length. Coloration and morphology appeared to be important factors influencing the "apparent" size and presumably the social status of both species. Juvenile coho, with extensive development of fins and coloration and intense territorial behavior, are hypothesized to be adapted to small, cool tributary streams. Fall chinook, on the other hand, with conservative development of fins and coloration and related behavior patterns, appear to be adapted to conditions in the main river and estuary. Title: Social interaction between juvenile coho and fall chinook salmon in Sixes River, Oregon Author: Stein, Roy A. The nature of the interaction between juvenile coho salmon, Oncorhynchus kisutch (Walbaum), and fall chinook salmon, 0. tshawytscha (Walbaum), was studied in Sixes River, Oregon. Seining, snorkeling, and tagging were used to determine distribution and patterns of growth of these two species in the stream environment. Experiments conducted in flowing-water observation troughs that provided volitional residence were designed to examine the outcome of agonistic behavior between these two species. Both species were distributed throughout the entire river system in early spring. During this period, underwater surveys in the main river and selected tributaries indicated that both species preferred the same habitat. As temperatures increased during the late spring, coho disappeared from the main river, but continued to occupy cool tributaries. Fall chinook, on the other hand, were found primarily in the main river until early summer, when they moved to the estuary. Relatively few individuals remained in the tributaries. Experiments conducted in the troughs revealed that agonistic behavior, including nipping, chasing, lateral display, submission, and fleeing, occurred between juvenile coho and fall chinook. When the two species were together in the troughs and in cool tributary streams, coho grew faster than chinook. When isolated in troughs, both grew at similar rates. Coho tolerated fewer individuals per unit area than did chinook, and occupied positions of dominance near the source of incoming food at the upstream end of the troughs. Coho had brighter fin and body colors, greater fin development, deeper bodies, and were heavier than fall chinook of the same length. Coloration and morphology appeared to be important factors influencing the "apparent" size and presumably the social status of both species. Juvenile coho, with extensive development of fins and coloration and intense territorial behavior, are hypothesized to be adapted to small, cool tributary streams. Fall chinook, on the other hand, with conservative development of fins and coloration and related behavior patterns, appear to be adapted to conditions in the main river and estuary. Close

• 17. [Article] Marine environment-based forecasting of coho salmon (Oncorhynchus kisutch) adult recruitment

  This is the publisher’s final pdf. The published article is copyrighted by Wiley and can be found at: http://onlinelibrary.wiley.com/.

  Citation × Citation Citation Abstract Copy Title: Marine environment-based forecasting of coho salmon (Oncorhynchus kisutch) adult recruitment Author: Rupp, David E., Lawson, Peter W., Wainwright, Thomas C., Peterson, William T. This is the publisher’s final pdf. The published article is copyrighted by Wiley and can be found at: http://onlinelibrary.wiley.com/. Title: Marine environment-based forecasting of coho salmon (Oncorhynchus kisutch) adult recruitment Author: Rupp, David E., Lawson, Peter W., Wainwright, Thomas C., Peterson, William T. This is the publisher’s final pdf. The published article is copyrighted by Wiley and can be found at: http://onlinelibrary.wiley.com/. Close

• 18. [Article] Density of the Waterborne Parasite Ceratomyxa shasta and Its Biological Effects on Salmon

  This is the publisher’s final pdf. The published article is copyrighted by American Society for Microbiology and can be found at: http://www.asm.org/.

  Citation × Citation Citation Abstract Copy Title: Density of the Waterborne Parasite Ceratomyxa shasta and Its Biological Effects on Salmon Author: Bartholomew, Jerri L., Holt, Richard A., Ray, R. Adam, Atkinson, Stephen D., Buckles, Gerri R., Hallett, Sascha L., Hurst, Charlene N. This is the publisher’s final pdf. The published article is copyrighted by American Society for Microbiology and can be found at: http://www.asm.org/. Title: Density of the Waterborne Parasite Ceratomyxa shasta and Its Biological Effects on Salmon Author: Bartholomew, Jerri L., Holt, Richard A., Ray, R. Adam, Atkinson, Stephen D., Buckles, Gerri R., Hallett, Sascha L., Hurst, Charlene N. This is the publisher’s final pdf. The published article is copyrighted by American Society for Microbiology and can be found at: http://www.asm.org/. Close

• 19. [Article] The antibody response of juvenile coho salmon (Oncorhynchus kisutch) to Aeromonas salmonicida, the causative agent of furunculosis

  This research was initiated to investigate the effects of various parameters on the immune response of juvenile coho salmon to Aeromonas salmonicida. The antibody response and development of protective immunity ...

  Citation × Citation Citation Abstract Copy Title: The antibody response of juvenile coho salmon (Oncorhynchus kisutch) to Aeromonas salmonicida, the causative agent of furunculosis Author: Paterson, William Douglas This research was initiated to investigate the effects of various parameters on the immune response of juvenile coho salmon to Aeromonas salmonicida. The antibody response and development of protective immunity in juvenile coho salmon were followed after a single intraperitoneal injection of formalin killed A. salmonicida cells emulsified in Freund's (complete) adjuvant. The first elevated antibody levels and protective immunity were detected four weeks after injection. High antibody titers were observed for a year after injection. Animals as small as 1.2 g were immunologically competent to administration of this antigen preparation. In a representative experiment, 96.7 percent of the animals injected with this preparation produced high levels of antibody. Selected methods of infection with A, salmonicida were investigated. Variability of culture virulence was demonstrated by injected LD₅₀ values, which ranged from a single cell to 10⁸ cells. Endotoxin was extracted from A. salmonicida cells with trichloroacetic acid. This endotoxin was found to be non lethal, but was antigenic to juvenile coho salmon at doses ranging from 1 to 5, 000 μg when administered intraperitoneally with and without an aluminum hydroxide carrier. The A. salmonicida endotoxin was lethal to white mice when administered by this same route. LD₅₀ values for several preparations ranged from 232 to 536 μg per mouse. An antibody response to A. salmonicida endotoxin was demonstrated in juvenile coho salmon held at 6.7°C, 12.2°C and 17.8°C. At these temperatures the first elevated antibody levels were observed at four, two and one week, respectively. Title: The antibody response of juvenile coho salmon (Oncorhynchus kisutch) to Aeromonas salmonicida, the causative agent of furunculosis Author: Paterson, William Douglas This research was initiated to investigate the effects of various parameters on the immune response of juvenile coho salmon to Aeromonas salmonicida. The antibody response and development of protective immunity in juvenile coho salmon were followed after a single intraperitoneal injection of formalin killed A. salmonicida cells emulsified in Freund's (complete) adjuvant. The first elevated antibody levels and protective immunity were detected four weeks after injection. High antibody titers were observed for a year after injection. Animals as small as 1.2 g were immunologically competent to administration of this antigen preparation. In a representative experiment, 96.7 percent of the animals injected with this preparation produced high levels of antibody. Selected methods of infection with A, salmonicida were investigated. Variability of culture virulence was demonstrated by injected LD₅₀ values, which ranged from a single cell to 10⁸ cells. Endotoxin was extracted from A. salmonicida cells with trichloroacetic acid. This endotoxin was found to be non lethal, but was antigenic to juvenile coho salmon at doses ranging from 1 to 5, 000 μg when administered intraperitoneally with and without an aluminum hydroxide carrier. The A. salmonicida endotoxin was lethal to white mice when administered by this same route. LD₅₀ values for several preparations ranged from 232 to 536 μg per mouse. An antibody response to A. salmonicida endotoxin was demonstrated in juvenile coho salmon held at 6.7°C, 12.2°C and 17.8°C. At these temperatures the first elevated antibody levels were observed at four, two and one week, respectively. Close

• 20. [Article] Some effects of dissolved oxygen concentration on feeding, growth and bioenergetics of juvenile Coho salmon

  The effects of three levels of dissolved oxygen (8, 5 and 3 mg/l) upon the feeding, growth and bioenergetics of juvenile coho salmon, Oncorhynchus kisutch (Walbaum), were determined in laboratory studies. ...

  Citation × Citation Citation Abstract Copy Title: Some effects of dissolved oxygen concentration on feeding, growth and bioenergetics of juvenile Coho salmon Author: Thatcher, T. O. The effects of three levels of dissolved oxygen (8, 5 and 3 mg/l) upon the feeding, growth and bioenergetics of juvenile coho salmon, Oncorhynchus kisutch (Walbaum), were determined in laboratory studies. Experiments with individual fish were conducted during the summer, fall and spring to measure rates of food consumption, standard metabolism, waste production, activity-specific dynamic action, and growth. House fly larvae were fed to the young salmon and the temperature was kept constant year-round at 15 C. The results indicated that differences due to the dissolved oxygen concentration were not great. Food consumption rate and the slope of growth rate curves were reduced only at 3 mg /I dissolved oxygen and only at near maximum food consumption rates which appear to be higher than juvenile coho salmon generally encounter in nature. However, normal competition for food and space in stream life (not present in these experiments) would be expected to curtail feeding in naturally occurring populations of juvenile cohos exposed to dissolved oxygen levels near 3 mg/l. Energy budgets were constructed from caloric determinations of the various uses made of the energy in the consumed food. These revealed that the reduced slope of the growth curve exhibited by 3 mg/l fish at near maximum feeding levels was due to sharp increases in energy requirements for activity-specific dynamic action. These energy budgets also offered the explanation that the greater loss of weight by the starved juvenile cohos kept at 8 mg /l dissolved oxygen (as compared to those kept at 3 and 5 mg/I) was due to their greater activity. Juvenile cohos kept at 5 mg/l dissolved oxygen in these studies grew at least as well as those at 8 mg /l. Again, however, this was considered to be an artifact of this experimental procedure. Fish reported upon here were not required to expend energy in competition for food and space as are those living in nature. Title: Some effects of dissolved oxygen concentration on feeding, growth and bioenergetics of juvenile Coho salmon Author: Thatcher, T. O. The effects of three levels of dissolved oxygen (8, 5 and 3 mg/l) upon the feeding, growth and bioenergetics of juvenile coho salmon, Oncorhynchus kisutch (Walbaum), were determined in laboratory studies. Experiments with individual fish were conducted during the summer, fall and spring to measure rates of food consumption, standard metabolism, waste production, activity-specific dynamic action, and growth. House fly larvae were fed to the young salmon and the temperature was kept constant year-round at 15 C. The results indicated that differences due to the dissolved oxygen concentration were not great. Food consumption rate and the slope of growth rate curves were reduced only at 3 mg /I dissolved oxygen and only at near maximum food consumption rates which appear to be higher than juvenile coho salmon generally encounter in nature. However, normal competition for food and space in stream life (not present in these experiments) would be expected to curtail feeding in naturally occurring populations of juvenile cohos exposed to dissolved oxygen levels near 3 mg/l. Energy budgets were constructed from caloric determinations of the various uses made of the energy in the consumed food. These revealed that the reduced slope of the growth curve exhibited by 3 mg/l fish at near maximum feeding levels was due to sharp increases in energy requirements for activity-specific dynamic action. These energy budgets also offered the explanation that the greater loss of weight by the starved juvenile cohos kept at 8 mg /l dissolved oxygen (as compared to those kept at 3 and 5 mg/I) was due to their greater activity. Juvenile cohos kept at 5 mg/l dissolved oxygen in these studies grew at least as well as those at 8 mg /l. Again, however, this was considered to be an artifact of this experimental procedure. Fish reported upon here were not required to expend energy in competition for food and space as are those living in nature. Close