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• 1. [Article] A mathematical model for adsorptive bubble-separation processes

  Adsorptive bubble-separation processes are used to remove adsorptive contaminants from wastewater. A mathematical model was developed for the adsorptive bubble separation processes in a countercurrent ...

  Citation × Citation Citation Abstract Copy Title: A mathematical model for adsorptive bubble-separation processes Author: Tʻang, Li Adsorptive bubble-separation processes are used to remove adsorptive contaminants from wastewater. A mathematical model was developed for the adsorptive bubble separation processes in a countercurrent column. The model included an assumption that linear adsorption of the solute occurred on the gas bubbles. Predictions indicated that aqueous column height has less effect on the solute removal efficiency than water flow rates, gas flow rates or bubble size. Increased water flow rates reduce removal efficiency; greater gas flow rates increase removal efficiency. The maximum removal efficiency is determined by adsorption characteristics of the solute; the removal rate is controlled by mass-transfer rate. However, influent concentrations of the solute in the water phase do not affect removal efficiency. These predictions were tested by means of solvent sublation experiments conducted in a laboratory setting. The data were collected from the sublation of Triton-X100 in a water-ethyl acetate-nitrogen system. Linear regression was used to compare predictions and experimental data with respect to column height. Five column heights ranged from 30 to 100 cm were compared at three water flow rates, 3.0, 5.5 and 13.0 ml/min. The calculated column heights agreed the observed column heights well. As the model predicted, the effect of influent concentraion on the removal efficiency was not significant. The surface excess of Triton-X100 (0.75 E-10 to 7.5 E-10 g mole/cm²) estimated from the adsorption constant in the model agrees with other published values (2.6 E-10 to 2.8 E-10 g mole/cm²). The mass-transfer coefficients of Triton-X100 in water (kL, which ranged from 0.50 to 0.60 cm/min) determined from the model and experimental data at 3.0, 5.5, 8.0 and 13.0 ml/min water flows (Qw) are proportional to the 0.124 power of the water flow rates. kL = 0.0441 Qw⁰.¹²⁴ This empirical exponent correlation between mass-transfer coefficients and water flow rates for the adsorption processes is similar to the correlation determined from previous absorption models. Title: A mathematical model for adsorptive bubble-separation processes Author: Tʻang, Li Adsorptive bubble-separation processes are used to remove adsorptive contaminants from wastewater. A mathematical model was developed for the adsorptive bubble separation processes in a countercurrent column. The model included an assumption that linear adsorption of the solute occurred on the gas bubbles. Predictions indicated that aqueous column height has less effect on the solute removal efficiency than water flow rates, gas flow rates or bubble size. Increased water flow rates reduce removal efficiency; greater gas flow rates increase removal efficiency. The maximum removal efficiency is determined by adsorption characteristics of the solute; the removal rate is controlled by mass-transfer rate. However, influent concentrations of the solute in the water phase do not affect removal efficiency. These predictions were tested by means of solvent sublation experiments conducted in a laboratory setting. The data were collected from the sublation of Triton-X100 in a water-ethyl acetate-nitrogen system. Linear regression was used to compare predictions and experimental data with respect to column height. Five column heights ranged from 30 to 100 cm were compared at three water flow rates, 3.0, 5.5 and 13.0 ml/min. The calculated column heights agreed the observed column heights well. As the model predicted, the effect of influent concentraion on the removal efficiency was not significant. The surface excess of Triton-X100 (0.75 E-10 to 7.5 E-10 g mole/cm²) estimated from the adsorption constant in the model agrees with other published values (2.6 E-10 to 2.8 E-10 g mole/cm²). The mass-transfer coefficients of Triton-X100 in water (kL, which ranged from 0.50 to 0.60 cm/min) determined from the model and experimental data at 3.0, 5.5, 8.0 and 13.0 ml/min water flows (Qw) are proportional to the 0.124 power of the water flow rates. kL = 0.0441 Qw⁰.¹²⁴ This empirical exponent correlation between mass-transfer coefficients and water flow rates for the adsorption processes is similar to the correlation determined from previous absorption models. Close

• 2. [Article] Cardiac output and respiratory measurements in the rainbow trout and their application to the study of blood and water flow limitations on chemical flux at the gill

  A method has been developed for the continuous automated monitoring of cardiac output in adult rainbow trout. Average cardiac output measured under control conditions and varied environmental conditions ...

  Citation × Citation Citation Abstract Copy Title: Cardiac output and respiratory measurements in the rainbow trout and their application to the study of blood and water flow limitations on chemical flux at the gill Author: Schmieder, Patricia K. (Patricia Kathleen) A method has been developed for the continuous automated monitoring of cardiac output in adult rainbow trout. Average cardiac output measured under control conditions and varied environmental conditions of hypoxia and post-hypoxia was significantly higher (P≤ 0.05) in male than female trout. The cardiac output of trout in spawning condition was significantly higher (P≤ 0.05) than that of trout not in spawning condition. Measurements of pulsatile cardiac output were made simultaneously with trout ventilation, and revealed ventilatory interactions with blood flow that varied depending on environmental oxygen condition. The method for monitoring gill blood flow was used with methods for automated measurement of gill water flow, oxygen uptake, and chemical flux in vivo. An experimental protocol was developed in which environmental oxygen was varied to obtain maximum increases in water flow over the gills without blood flow changes, and subsequent attainment of maximum increases in blood flow through the gills with decreasing water flow. The protocol was used as a probe to study variations in chemical flux with varied blood or water flow. The changes in gill flux of butanol (Log octanol/water partition coefficient (P) = 0.88) measured during control, hypoxia, and post-hypoxia correlated with observed changes in blood flow. A 70% increase in butanol flux was noted with a 50% increase in cardiac output, but there was no increase in butanol flux with a 100% increase in ventilation volume. Changes observed in the gill flux of decanol (Log P = 4.57) measured under varied environmental oxygen conditions correlated with observed changes in ventilation volume. A 100% increase in decanol flux was noted with a 160% increase in ventilation volume. The observed blood flow limitations to uptake of the low Log P butanol, and the water flow limitations to uptake of the high Log P decanol helped to verify assumptions made in recently proposed flow-limited models for prediction of chemical flux across fish gills. Title: Cardiac output and respiratory measurements in the rainbow trout and their application to the study of blood and water flow limitations on chemical flux at the gill Author: Schmieder, Patricia K. (Patricia Kathleen) A method has been developed for the continuous automated monitoring of cardiac output in adult rainbow trout. Average cardiac output measured under control conditions and varied environmental conditions of hypoxia and post-hypoxia was significantly higher (P≤ 0.05) in male than female trout. The cardiac output of trout in spawning condition was significantly higher (P≤ 0.05) than that of trout not in spawning condition. Measurements of pulsatile cardiac output were made simultaneously with trout ventilation, and revealed ventilatory interactions with blood flow that varied depending on environmental oxygen condition. The method for monitoring gill blood flow was used with methods for automated measurement of gill water flow, oxygen uptake, and chemical flux in vivo. An experimental protocol was developed in which environmental oxygen was varied to obtain maximum increases in water flow over the gills without blood flow changes, and subsequent attainment of maximum increases in blood flow through the gills with decreasing water flow. The protocol was used as a probe to study variations in chemical flux with varied blood or water flow. The changes in gill flux of butanol (Log octanol/water partition coefficient (P) = 0.88) measured during control, hypoxia, and post-hypoxia correlated with observed changes in blood flow. A 70% increase in butanol flux was noted with a 50% increase in cardiac output, but there was no increase in butanol flux with a 100% increase in ventilation volume. Changes observed in the gill flux of decanol (Log P = 4.57) measured under varied environmental oxygen conditions correlated with observed changes in ventilation volume. A 100% increase in decanol flux was noted with a 160% increase in ventilation volume. The observed blood flow limitations to uptake of the low Log P butanol, and the water flow limitations to uptake of the high Log P decanol helped to verify assumptions made in recently proposed flow-limited models for prediction of chemical flux across fish gills. Close

• 3. [Article] Thesis Appendices.zip

  Citation × Citation Citation Abstract Copy Title: Thesis Appendices.zip Author: Scherberg, Jacob N. Title: Thesis Appendices.zip Author: Scherberg, Jacob N. Close

• 4. [Article] Evaporator analysis for application to water-source and ice-maker heat pumps

  Water-source and ice-maker heat pumps share many characteristics. However, each presents different technical difficulties that have prevented them from being used more widely. In a water-source heat pump ...

  Citation × Citation Citation Abstract Copy Title: Evaporator analysis for application to water-source and ice-maker heat pumps Author: Aceves, Salvador M. Water-source and ice-maker heat pumps share many characteristics. However, each presents different technical difficulties that have prevented them from being used more widely. In a water-source heat pump a very important consideration is to reduce water consumption, while in an ice-maker heat pump a major concern is to reduce the number of deicing cycles while keeping a high performance. Previous research by this author has indicated that the use of the flow reversal method (reversing periodically the water flow direction in the evaporator) has the effect of partly deicing the evaporator, reducing pressure drop and enhancing heat transfer. This thesis shows the development and application of analytical and numerical models to study the effect of different evaporator parameters on heat pump efficiency, as well as the possible advantages of using the flow reversal method in a water-source or ice-maker heat pump. The conclusion reached from these studies is that periodic water flow reversals inside an evaporator with freezing help improve the performance of a heat pump system in two different ways. First, periodic water flow direction reversals serve to enhance heat transfer in the evaporator. Second, reversing the water flow direction also delays ice blockage in the evaporator, or totally prevents blockage from happening. Delaying ice blockage represents a substantial improvement for ice-maker heat pumps, since these may then operate for a longer time without deicing. Preventing ice blockage represents a substantial improvement for water-source heat pumps, since these may then operate at lower water flow rates. Suggestions for future work include further testing of the flow reversal method for different evaporator geometries, as well as an experimental evaluation of the flow reversal method. Title: Evaporator analysis for application to water-source and ice-maker heat pumps Author: Aceves, Salvador M. Water-source and ice-maker heat pumps share many characteristics. However, each presents different technical difficulties that have prevented them from being used more widely. In a water-source heat pump a very important consideration is to reduce water consumption, while in an ice-maker heat pump a major concern is to reduce the number of deicing cycles while keeping a high performance. Previous research by this author has indicated that the use of the flow reversal method (reversing periodically the water flow direction in the evaporator) has the effect of partly deicing the evaporator, reducing pressure drop and enhancing heat transfer. This thesis shows the development and application of analytical and numerical models to study the effect of different evaporator parameters on heat pump efficiency, as well as the possible advantages of using the flow reversal method in a water-source or ice-maker heat pump. The conclusion reached from these studies is that periodic water flow reversals inside an evaporator with freezing help improve the performance of a heat pump system in two different ways. First, periodic water flow direction reversals serve to enhance heat transfer in the evaporator. Second, reversing the water flow direction also delays ice blockage in the evaporator, or totally prevents blockage from happening. Delaying ice blockage represents a substantial improvement for ice-maker heat pumps, since these may then operate for a longer time without deicing. Preventing ice blockage represents a substantial improvement for water-source heat pumps, since these may then operate at lower water flow rates. Suggestions for future work include further testing of the flow reversal method for different evaporator geometries, as well as an experimental evaluation of the flow reversal method. Close

• 5. [Article] Numerical computation of free surface water flow

  The present thesis is a report of investigations on a model for computing the water flow in the wave tank of the OSU Wave Laboratory. A wave board, established at one end of the 100 m long, 4 m wide and ...

  Citation × Citation Citation Abstract Copy Title: Numerical computation of free surface water flow Author: Kuhnert, Jorg The present thesis is a report of investigations on a model for computing the water flow in the wave tank of the OSU Wave Laboratory. A wave board, established at one end of the 100 m long, 4 m wide and 6 m deep wave tank, produces water waves by periodically moving back and forth. The resulting free surface water flow will be modeled physically. This physical model will be transformed into a mathematical model which is implemented on a computer. The goal is to approximately compute the velocity distribution of the fluid modeled as a linear combination of basis functions. Certain well known mathematical tools such as the Galerkin method or the idea of finite elements are employed. The theoretical developments are done for the three-dimensional case. However, numerical experiments are performed in two dimensions only. Two different types of basis functions will be introduced and investigated. Their advantages, disadvantages and capability to compute realistic results will clearly be shown and demonstrated in practice. Several problems occured during the development of the computation algorithms. These problems are outlined in this thesis, and several solutions are suggested. For example, a method how to deal with rising and falling water surface at a vertical boundary will be presented. The results of five numerical test runs will be exhibited, underlining what the theory predicts. Title: Numerical computation of free surface water flow Author: Kuhnert, Jorg The present thesis is a report of investigations on a model for computing the water flow in the wave tank of the OSU Wave Laboratory. A wave board, established at one end of the 100 m long, 4 m wide and 6 m deep wave tank, produces water waves by periodically moving back and forth. The resulting free surface water flow will be modeled physically. This physical model will be transformed into a mathematical model which is implemented on a computer. The goal is to approximately compute the velocity distribution of the fluid modeled as a linear combination of basis functions. Certain well known mathematical tools such as the Galerkin method or the idea of finite elements are employed. The theoretical developments are done for the three-dimensional case. However, numerical experiments are performed in two dimensions only. Two different types of basis functions will be introduced and investigated. Their advantages, disadvantages and capability to compute realistic results will clearly be shown and demonstrated in practice. Several problems occured during the development of the computation algorithms. These problems are outlined in this thesis, and several solutions are suggested. For example, a method how to deal with rising and falling water surface at a vertical boundary will be presented. The results of five numerical test runs will be exhibited, underlining what the theory predicts. Close

• 6. [Article] Estimating water flow rates

  Declared out of print December 2009. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonst...

  Citation × Citation Citation Abstract Copy Title: Estimating water flow rates Author: Oregon State University. Extension Service, Trimmer, Walter L. Declared out of print December 2009. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Title: Estimating water flow rates Author: Oregon State University. Extension Service, Trimmer, Walter L. Declared out of print December 2009. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Close

• 7. [Article] Investigations into the Regional and Local Timescale Variations of Subglacial Drainage Networks

  Subglacial water plays an important role in the regulation of an ice sheet's mass balance. It may be the dominant control on the velocities of ice streams and outlet glaciers on scales of months to millennia. ...

  Citation × Citation Citation Abstract Copy Title: Investigations into the Regional and Local Timescale Variations of Subglacial Drainage Networks Author: Hiester, Justin Year: 2013 Subglacial water plays an important role in the regulation of an ice sheet's mass balance. It may be the dominant control on the velocities of ice streams and outlet glaciers on scales of months to millennia. Recent satellite observations of ice surface elevation changes have given researchers new insights into how subglacial water is stored and transported. Localized uplift and settling of the ice surface implies that lakes exist beneath the ice sheet that are being filled and drained on relatively short time scales. %At the base of an ice sheet water can be transported through a variety of drainage networks or stored in subglacial lakes. Here, a numerical investigation of the mechanisms of transport and storage of subglacial water and the associated time scales is presented. Experiments are carried out using a finite element model of coupled ice and water flow. The first experiment seeks to understand the relationship between the depth of a basal depression and the area over which the feature affects basal water flow. It is found that as the perturbation to a topographic depression's depth is increased, water is rerouted in response to the perturbation. Additionally it is found that the relationship between perturbation depth and the extent upstream to which its effects reach is nonlinear. The second experiment examines how the aspect ratio of bed features (prolate, oblate, or equidimensional) influences basal water flow. It is found that the systems that develop and their interactions are mediated by both the topography and the feedbacks taken into account by the coupling of the systems in the model. Features oriented parallel to ice and water flow are associated with distributed fan systems that develop branches which migrate laterally across the domain and interact with one another on monthly and yearly timescales. Laterally oriented features develop laterally extensive ponds. As the ratio of longitudinal to lateral dimension of the topography is increased, a combination of these two water distributions is seen. Title: Investigations into the Regional and Local Timescale Variations of Subglacial Drainage Networks Author: Hiester, Justin Year: 2013 Subglacial water plays an important role in the regulation of an ice sheet's mass balance. It may be the dominant control on the velocities of ice streams and outlet glaciers on scales of months to millennia. Recent satellite observations of ice surface elevation changes have given researchers new insights into how subglacial water is stored and transported. Localized uplift and settling of the ice surface implies that lakes exist beneath the ice sheet that are being filled and drained on relatively short time scales. %At the base of an ice sheet water can be transported through a variety of drainage networks or stored in subglacial lakes. Here, a numerical investigation of the mechanisms of transport and storage of subglacial water and the associated time scales is presented. Experiments are carried out using a finite element model of coupled ice and water flow. The first experiment seeks to understand the relationship between the depth of a basal depression and the area over which the feature affects basal water flow. It is found that as the perturbation to a topographic depression's depth is increased, water is rerouted in response to the perturbation. Additionally it is found that the relationship between perturbation depth and the extent upstream to which its effects reach is nonlinear. The second experiment examines how the aspect ratio of bed features (prolate, oblate, or equidimensional) influences basal water flow. It is found that the systems that develop and their interactions are mediated by both the topography and the feedbacks taken into account by the coupling of the systems in the model. Features oriented parallel to ice and water flow are associated with distributed fan systems that develop branches which migrate laterally across the domain and interact with one another on monthly and yearly timescales. Laterally oriented features develop laterally extensive ponds. As the ratio of longitudinal to lateral dimension of the topography is increased, a combination of these two water distributions is seen. Close

• 8. [Article] The development of a hydrological model for the Walla Walla Basin using IWFM.pdf

  Citation × Citation Citation Abstract Copy Title: The development of a hydrological model for the Walla Walla Basin using IWFM.pdf Author: Scherberg, Jacob N. Title: The development of a hydrological model for the Walla Walla Basin using IWFM.pdf Author: Scherberg, Jacob N. Close

• 9. [Article] Statistical Analysis for Groundwater / Surface Water Interaction at a Drinking Water Well

  Drinking water at a certain groundwater well is located at the confluence of a north fork and south fork of a major river. Data was collected to determine if the well is under direct influence by surface ...

  Citation × Citation Citation Abstract Copy Title: Statistical Analysis for Groundwater / Surface Water Interaction at a Drinking Water Well Author: Garlitz, John Year: 2008 Drinking water at a certain groundwater well is located at the confluence of a north fork and south fork of a major river. Data was collected to determine if the well is under direct influence by surface water. Direct influence and the extent of the correlation was determined by statistically analyzing the well turbidity with surface water flow and temperature variability. The surface water flow and was lagged per period and with a weighted average to determine the highest correlation. Logistic regression models were developed to determine if a predictive model can predict permit conditions based on the data collected. Title: Statistical Analysis for Groundwater / Surface Water Interaction at a Drinking Water Well Author: Garlitz, John Year: 2008 Drinking water at a certain groundwater well is located at the confluence of a north fork and south fork of a major river. Data was collected to determine if the well is under direct influence by surface water. Direct influence and the extent of the correlation was determined by statistically analyzing the well turbidity with surface water flow and temperature variability. The surface water flow and was lagged per period and with a weighted average to determine the highest correlation. Logistic regression models were developed to determine if a predictive model can predict permit conditions based on the data collected. Close

• 10. [Article] Effects of estuarine circulation patterns and stress on the migratory behavior of juvenile salmonids (Oncorhynchus sp.)

  For the first objective of this thesis, we attempt to understand the role of water flow and directionality in determining steelhead (Oncorhynchus mykiss) and spring/summer and fall Chinook (O. tschawytscha) ...

  Citation × Citation Citation Abstract Copy Title: Effects of estuarine circulation patterns and stress on the migratory behavior of juvenile salmonids (Oncorhynchus sp.) Author: Truelove, Nathan Kobun For the first objective of this thesis, we attempt to understand the role of water flow and directionality in determining steelhead (Oncorhynchus mykiss) and spring/summer and fall Chinook (O. tschawytscha) migration patterns within the Columbia River Estuary and plume by integrating recent advances in biotelemetry and environmental observation and forecasting systems (EOFS). The underlying methodology included analysis of the spatial and temporal movements of juvenile outmigrant salmonids with hydrological data from the CORIE modeling system (http://www.ccalmr.ogi.edu/CORIE). The CORIE modeling system, an EOFS for the Columbia River and nearshore environment, integrates a real-time sensor network, data management system and advanced 3-dimensional numerical models. Numerical simulations of key physical variables (water level, velocities, and directionality) were generated for the precise time and location that individual juvenile salmonids implanted with radio transmitters were present in the Columbia River Estuary. Five general behavioral trends were evident from these simulations: i) passive movement (drifting) during ebb tides, ii) active swimming with the current during ebb tides, iii) active swimming against the current during flood tides, iv) active swimming cross current during flood tides, and v) passive drifting during flood tide. Direction of water flow had a significant effect on fish velocity. All fish types showed a positive relationship between fish velocity and simulated drifter velocity with outgoing water flow. During slack water flow (< 0.25 m/s), this relationship was only observed in barged fall Chinook. With incoming water flow, spring/summer and fall Chinook fish types showed no relationship, whereas steelhead did. Analysis over a three-year period suggested that data from the CORIE modeling system corresponded well with juvenile salmonid migratory behavior and that the model may be a useful tool for evaluating the impact of different hydrological regimes on fish movement. The secondary objective of this thesis evaluated the effects of both acute and chronic crowding stressors on the migratory behavior of hatchery reared juvenile steelhead released into Abernathy Creek, a tributary of the Columbia River Estuary, Washington. The acute stress treatment consisted of surgical implantation of a NanoTag radio transmitter (Lotek Wireless, Canada), followed by 6 hours of crowding immediately prior to release. The chronic stress treatment consisted of surgical implantation of a PIT-tag (Digital Angel Corporation), 36 days of acclimation, followed by 3 weeks of crowding in low water conditions prior to release. Short-term migratory success of steelhead that received the acute stress treatment was determined by radio telemetry. Numbers of migrating fish that received experimental stress treatments and their speed was determined by both mobile radio telemetry and stationary PIT-tag and radio-tag interrogation systems already established on Abernathy Creek. Acute and chronic stress treatments both significantly delayed migration by 2 to 10 days, respectively, compared to controls. Furthermore, the acute stress treatment significantly decreased the both the rate of migration and numbers of juvenile steelhead that successfully migrated out of Abernathy creek. Title: Effects of estuarine circulation patterns and stress on the migratory behavior of juvenile salmonids (Oncorhynchus sp.) Author: Truelove, Nathan Kobun For the first objective of this thesis, we attempt to understand the role of water flow and directionality in determining steelhead (Oncorhynchus mykiss) and spring/summer and fall Chinook (O. tschawytscha) migration patterns within the Columbia River Estuary and plume by integrating recent advances in biotelemetry and environmental observation and forecasting systems (EOFS). The underlying methodology included analysis of the spatial and temporal movements of juvenile outmigrant salmonids with hydrological data from the CORIE modeling system (http://www.ccalmr.ogi.edu/CORIE). The CORIE modeling system, an EOFS for the Columbia River and nearshore environment, integrates a real-time sensor network, data management system and advanced 3-dimensional numerical models. Numerical simulations of key physical variables (water level, velocities, and directionality) were generated for the precise time and location that individual juvenile salmonids implanted with radio transmitters were present in the Columbia River Estuary. Five general behavioral trends were evident from these simulations: i) passive movement (drifting) during ebb tides, ii) active swimming with the current during ebb tides, iii) active swimming against the current during flood tides, iv) active swimming cross current during flood tides, and v) passive drifting during flood tide. Direction of water flow had a significant effect on fish velocity. All fish types showed a positive relationship between fish velocity and simulated drifter velocity with outgoing water flow. During slack water flow (< 0.25 m/s), this relationship was only observed in barged fall Chinook. With incoming water flow, spring/summer and fall Chinook fish types showed no relationship, whereas steelhead did. Analysis over a three-year period suggested that data from the CORIE modeling system corresponded well with juvenile salmonid migratory behavior and that the model may be a useful tool for evaluating the impact of different hydrological regimes on fish movement. The secondary objective of this thesis evaluated the effects of both acute and chronic crowding stressors on the migratory behavior of hatchery reared juvenile steelhead released into Abernathy Creek, a tributary of the Columbia River Estuary, Washington. The acute stress treatment consisted of surgical implantation of a NanoTag radio transmitter (Lotek Wireless, Canada), followed by 6 hours of crowding immediately prior to release. The chronic stress treatment consisted of surgical implantation of a PIT-tag (Digital Angel Corporation), 36 days of acclimation, followed by 3 weeks of crowding in low water conditions prior to release. Short-term migratory success of steelhead that received the acute stress treatment was determined by radio telemetry. Numbers of migrating fish that received experimental stress treatments and their speed was determined by both mobile radio telemetry and stationary PIT-tag and radio-tag interrogation systems already established on Abernathy Creek. Acute and chronic stress treatments both significantly delayed migration by 2 to 10 days, respectively, compared to controls. Furthermore, the acute stress treatment significantly decreased the both the rate of migration and numbers of juvenile steelhead that successfully migrated out of Abernathy creek. Close