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• 1. [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

• 2. [Article] Life histories of juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Columbia River estuary as inferred from scale and otolith microchemistry

  Despite evidence that juvenile Chinook salmon (Oncorhynchus tshawytscha) utilize North Pacific estuaries for growth and salinity acclimation, research in the Columbia River estuary has lead to opposing ...

  Citation × Citation Citation Abstract Copy Title: Life histories of juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Columbia River estuary as inferred from scale and otolith microchemistry Author: Campbell, Lance A. Despite evidence that juvenile Chinook salmon (Oncorhynchus tshawytscha) utilize North Pacific estuaries for growth and salinity acclimation, research in the Columbia River estuary has lead to opposing hypotheses about the estuary’s importance as a salmon rearing environment. Many contemporary tagging studies indicate that salmon residency within the estuary is short (< 1 week) and that mortality of estuarine migrants is a significant impediment to recovery of depressed salmon stocks. On the other hand, life history interpretations from fish scales collected early in the twentieth century suggest that juvenile Chinook salmon reared extensively in the estuary, leading some to hypothesize that life history variation has been constrained by anthropogenic changes in the Columbia River basin. To test these hypotheses we first validated previous methods of life history interpretation by comparing the results of otolith chemistry, scale chemistry, and scale morphology from juvenile salmon collected during monthly beach seine surveys in 2003. Although scale and otolith chemistry were strongly correlated, and scale chemistry was an accurate indicator of salt-water entry, scale morphometric characteristics did not coincide consistently with the time of salmon entry into brackish water. We measured Strontium 86 and Calcium 43 in salmon otoliths collected in the lower Columbia River estuary in 2003-05 to quantify the period of salt-water residency of juvenile salmon and to back-calculate their size at salt-water entry. The estimated salt-water residency of juvenile Chinook ranged from 0-176 days with a mean residence time of 54, 67 and 30 days in 2003, 2004 and 2005, respectively. Chinook salmon that resided in salt water for more than 30 days comprised 55, 51 and 30% of the total estuary beach seine collections during each of these years. Forty to fifty percent of Chinook salmon had entered the saline portion of the estuary at a fork length < 60 mm. Furthermore we found a negative relationship between the size and time of entry with residency, where smaller earlier migrants on average resided for longer periods then larger late migrants. Peak migration times occurred in May, and 90% of the outmigration was completed by August 30 in all years. This pattern is substantially truncated relative to the results of a 1914-1916 salmon life-history survey, which showed that the historical outmigration period lasted well into the fall and was characterized by late pulses of new recruits into the lower estuary. Nonetheless, recent otolith results indicate that subyearling Chinook salmon use the saline portion of the estuary in a high proportion and for extended periods of time in contrast to short residency times reported by contemporary tagging and marking studies. Title: Life histories of juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Columbia River estuary as inferred from scale and otolith microchemistry Author: Campbell, Lance A. Despite evidence that juvenile Chinook salmon (Oncorhynchus tshawytscha) utilize North Pacific estuaries for growth and salinity acclimation, research in the Columbia River estuary has lead to opposing hypotheses about the estuary’s importance as a salmon rearing environment. Many contemporary tagging studies indicate that salmon residency within the estuary is short (< 1 week) and that mortality of estuarine migrants is a significant impediment to recovery of depressed salmon stocks. On the other hand, life history interpretations from fish scales collected early in the twentieth century suggest that juvenile Chinook salmon reared extensively in the estuary, leading some to hypothesize that life history variation has been constrained by anthropogenic changes in the Columbia River basin. To test these hypotheses we first validated previous methods of life history interpretation by comparing the results of otolith chemistry, scale chemistry, and scale morphology from juvenile salmon collected during monthly beach seine surveys in 2003. Although scale and otolith chemistry were strongly correlated, and scale chemistry was an accurate indicator of salt-water entry, scale morphometric characteristics did not coincide consistently with the time of salmon entry into brackish water. We measured Strontium 86 and Calcium 43 in salmon otoliths collected in the lower Columbia River estuary in 2003-05 to quantify the period of salt-water residency of juvenile salmon and to back-calculate their size at salt-water entry. The estimated salt-water residency of juvenile Chinook ranged from 0-176 days with a mean residence time of 54, 67 and 30 days in 2003, 2004 and 2005, respectively. Chinook salmon that resided in salt water for more than 30 days comprised 55, 51 and 30% of the total estuary beach seine collections during each of these years. Forty to fifty percent of Chinook salmon had entered the saline portion of the estuary at a fork length < 60 mm. Furthermore we found a negative relationship between the size and time of entry with residency, where smaller earlier migrants on average resided for longer periods then larger late migrants. Peak migration times occurred in May, and 90% of the outmigration was completed by August 30 in all years. This pattern is substantially truncated relative to the results of a 1914-1916 salmon life-history survey, which showed that the historical outmigration period lasted well into the fall and was characterized by late pulses of new recruits into the lower estuary. Nonetheless, recent otolith results indicate that subyearling Chinook salmon use the saline portion of the estuary in a high proportion and for extended periods of time in contrast to short residency times reported by contemporary tagging and marking studies. Close