Casey Justice - Academia.edu (original) (raw)

Papers by Casey Justice

Ecosphere, Jul 1, 2022

Many salmonid‐bearing rivers exhibit thermal and hydrologic heterogeneity at multiple spatial and... more Many salmonid‐bearing rivers exhibit thermal and hydrologic heterogeneity at multiple spatial and temporal scales, but how this translates into spatiotemporal patterns of fry emergence is poorly understood. Understanding this variability is important because emergence timing determines the biophysical conditions fish first experience (e.g., temperature, flow, and food supply), thereby influencing growth opportunities and survival during this critical life stage. We predicted spring Chinook Salmon (Oncorhynchus tshawytscha) emergence phenology across four northeastern Oregon subbasins over 5–9 years using empirical spawning and temperature data. We then related interannual emergence timing estimates to juvenile salmon size and growth rates at consistent sampling locations. There were clear longitudinal patterns of predicted emergence timing in each subbasin: The shape of these patterns was consistent among years, but not among subbasins. In two subbasins, emergence occurred progressively later with distance upstream, whereas in the other two subbasins emergence was earliest at upstream sites. Within each year, median emergence dates among sites within each subbasin ranged between 44 and 58 days. This spatial variation was comparable to interannual variation, with median emergence dates for a given location in each subbasin ranging between 47 and 74 days among years. Contrary to our expectations, juvenile salmon were not larger in years with earlier emergence, owing to slower estimated spring and summer growth rates compared to years with later emergence. Despite large interannual variation in estimated emergence dates, these results suggest that other factors (e.g., stream flow, temperature, and density‐dependence) were more important than growth duration in determining juvenile salmon growth rates and size among years. We demonstrated considerable spatial and interannual variation in emergence phenology within these subbasins. Understanding how this variation translates to spatiotemporal patterns of juvenile salmon habitat use, growth, and survival has important implications for guiding restoration efforts and understanding how climate change may impact these populations.

Fisheries Research, May 1, 2022

Elementa: Science of the Anthropocene, 2017

Land use legacies can have a discernible influence in present-day watersheds and should be accoun... more Land use legacies can have a discernible influence in present-day watersheds and should be accounted for when designing conservation strategies for riverine aquatic life. We describe the environmental history of three watersheds within the Grande Ronde subbasin of the Columbia River using General Land Office survey field notes from the 19th century. In the two watersheds severely impacted by Euro-American land use, stream channel widths—a metric representing habitat simplification—increased from an average historical width of 16.8 m to an average present width of 20.8 m in large streams; 4.3 m to 5.5 m in small, confined or partly confined streams; and 3.5 m to 6.5 m in small, laterally unconfined steams. Conversely, we did not detect significant change in stream widths in an adjacent, wilderness stream with minimal human impact. Using a mechanistic water temperature model and restoration scenarios based on the historical condition, we predicted that stream restoration in the impact...

Journal of environmental management, 2017

Understanding how stream temperature responds to restoration of riparian vegetation and channel m... more Understanding how stream temperature responds to restoration of riparian vegetation and channel morphology in context of future climate change is critical for prioritizing restoration actions and recovering imperiled salmon populations. We used a deterministic water temperature model to investigate potential thermal benefits of riparian reforestation and channel narrowing to Chinook Salmon populations in the Upper Grande Ronde River and Catherine Creek basins in Northeast Oregon, USA. A legacy of intensive land use practices in these basins has significantly reduced streamside vegetation and increased channel width across most of the stream network, resulting in water temperatures that far exceed the optimal range for salmon growth and survival. By combining restoration scenarios with climate change projections, we were able to evaluate whether future climate impacts could be offset by restoration actions. A combination of riparian restoration and channel narrowing was predicted to ...

Canadian Journal of Fisheries and Aquatic Sciences, 2009

We evaluated effects of stocking level and size-at-release on survival rates of hatchery-reared j... more We evaluated effects of stocking level and size-at-release on survival rates of hatchery-reared juvenile white sturgeon ( Acipenser transmontanus ) in the Kootenai River using Cormack–Jolly–Seber and related models implemented in Program MARK. A total of 119 768 marked and unmarked hatchery juveniles were released from 1992 to 2006, of which 2938 passive integrated transponder (PIT)-tagged fish were subsequently recaptured. Annual survival rates of marked groups ranged from 0.01 to 0.84 (mean = 0.45) during the first year at large, from 0.48 to 1.0 (mean = 0.84) in the second year, and averaged 1.0 during all subsequent years. First year survival rates declined substantially in recent years, particularly for small fish (<25 cm fork length). Approximately 59% of the variation in first year survival was explained by a negative relationship with estimated juvenile abundance (linear regression, P < 0.01). Length-at-release of individuals explained a substantial proportion of the w...

Journal of Animal Ecology

Changes in biophysical conditions through time generate spatial and temporal variability in habit... more Changes in biophysical conditions through time generate spatial and temporal variability in habitat quality across landscapes. For river ecosystems, researchers are increasingly able to characterize spatial and temporal patterns in habitat conditions, referred to as shifting habitat mosaics, yet rarely demonstrate how this translates into corresponding biological processes such as organism growth and production. We assessed spatial patterns and processes determining seasonal changes in juvenile Chinook Salmon (Oncorhynchus tshawytscha) size, growth, and production over 30-40 km in two NE Oregon subbasins. We quantified seasonal patterns of growth by combining estimated emergence dates and body size distributions in July and September. We then used analysis of bioenergetics, empirical fish diets, and spatial models incorporating temperature, habitat, and population density to evaluate mechanisms driving spatio-temporal patterns of growth. Lastly, we quantified seasonal contributions to individual fish growth and to total production as a function of position within the stream network. Spatial heterogeneity in incubation temperatures corresponded to later estimated emergence timing with distance upstream in both subbasins. During spring, estimated growth rates decreased with distance upstream, and coupled with emergence patterns, resulted in a pronounced longitudinal gradients in body size by July. During summer, spatial patterns of growth reversed, with greater diet ration sizes and growth efficiencies upstream than downstream. These opposing spatio-temporal patterns of emergence timing and seasonal growth rates produced longitudinal gradients in the proportion of fish growth achieved in spring versus summer, with up to 80% of an individual's growth occurring in spring at downstream sites but as low as 10% at upstream sites. Coupling longitudinal patterns of fish density and growth revealed that in one subbasin the majority (65%) of total production occurred in spring, while in the other, in which fish were concentrated in headwaters, the majority (60%) of production occurred in summer. While recent work has emphasized inter-annual shifts in fish production across large spatial scales, this study demonstrates that longitudinal gradients of fish growth and production can reverse across seasons, and reveals important contributions of warmer, downstream habitats to overall production that occurred during cooler times of the year.

Land use legacies can have a discernible influence in present-day watersheds and should be accoun... more Land use legacies can have a discernible influence in present-day watersheds and should be accounted for when designing conservation strategies for riverine aquatic life. We describe the environmental history of three watersheds within the Grande Ronde subbasin of the Columbia River using General Land Office survey field notes from the 19th century. In the two watersheds severely impacted by Euro-American land use, stream channel widths—a metric representing habitat simplification—increased from an average historical width of 16.8 m to an average present width of 20.8 m in large streams; 4.3 m to 5.5 m in small, confined or partly confined streams; and 3.5 m to 6.5 m in small, laterally unconfined steams. Conversely, we did not detect significant change in stream widths in an adjacent, wilderness stream with minimal human impact. Using a mechanistic water temperature model and restoration scenarios based on the historical condition, we predicted that stream restoration in the impact...

Understanding how stream temperature responds to restoration of riparian vegetation and channel m... more Understanding how stream temperature responds to restoration of riparian vegetation and channel morphology in context of future climate change is critical for prioritizing restoration actions and recovering imperiled salmon populations. We used a deterministic water temperature model to investigate potential thermal benefits of riparian reforestation and channel narrowing to Chinook Salmon populations in the Upper Grande Ronde River and Catherine Creek basins in Northeast Oregon, USA. A legacy of intensive land use practices in these basins has significantly reduced streamside vegetation and increased channel width across most of the stream network, resulting in water temperatures that far exceed the optimal range for salmon growth and survival. By combining restoration scenarios with climate change projections, we were able to evaluate whether future climate impacts could be offset by restoration actions. A combination of riparian restoration and channel narrowing was predicted to ...

Large woody debris is frequently placed into streams of the Pacific Northwest in an effort to imp... more Large woody debris is frequently placed into streams of the Pacific Northwest in an effort to improve habitat conditions for rearing juvenile salmonids. Unfortunately, many restoration projects do not incorporate monitoring of biotic response to these activities. This project compared stream reaches and pool habitats with differing quantities of large woody debris to determine the effects of large woody debris restoration structures on biomass, size, growth, and survival of juvenile coho salmon, age-1+ steelhead, and age-0 trout in two coastal streams in Northern California from July 2004 through June 2005. No significant differences in fish response variables were detected between treatment and control reaches. However, some significant relationships between physical habitat features and fish response variables were detected. Biomass and length of age-1+ steelhead were positively related to the proportion of pool habitat, while growth was positively related to mean reach depth. Length of age-0 trout was positively related to large woody debris density during the fall, and growth was positively related to pool depth. Fish responses at the habitat unit scale were more variable, but generally indicated preferences for pools and, in some cases, cover. Overall, the proportion of pool habitat and stream depth appeared to be the most important physical habitat features influencing salmonid productivity in these two coastal streams. Although direct effects of habitat restoration were not detected in this study, these results indicated that stream iv restoration structures that substantially increase the amount of pool habitat and create deeper pools can positively benefit coho salmon and steelhead populations. v ACKNOWLEDGEMENTS This thesis would not have been possible without the help and support of many people. First and foremost, I would like to thank my advisor, Dr. Walt Duffy, for contributing valuable biological insight, as well as financial, logistical, and moral support throughout this project. His door was always open for advice and help with the numerous questions and obstacles that I encountered during this study. I would also like to extend thanks to the entire crew and staff at the California Cooperative Fish Research Unit at HSU for your tireless efforts preparing for and carrying out the often grueling field activities required for this project, your insightful comments about field methods and salmonid biology, and for your excellent friendship. The following people helped

Fisheries

Despite immense resources directed towards habitat restoration, recovering fish populations remai... more Despite immense resources directed towards habitat restoration, recovering fish populations remains a daunting and perplexing issue. In 2015, recommendations for a comprehensive approach to habitat restoration in the Columbia River basin were published in Fisheries, which included elements of landscape ecology and resilience, broad public support, governance for collaboration and integration, and capacity for learning and adaptation. Using the Grande Ronde River basin as a case study, we convened a working group consisting of local restoration practitioners, managers, and researchers involved in habitat restoration research, monitoring, and evaluation to assess progress towards meeting these recommendations. We concluded that partnerships and collaborations in governance have been formed and research using a landscape perspective has been integrated into decision making, but efforts would benefit from gaining broader public support, formalizing an adaptive management strategy, and defining objectives and indicators for biological and ecological diversity. Continued progress will require consistent policy and funding support from the broader region. We envision this self-assessment at the 5-year milestone would be helpful to other groups facing similar challenges.

Canadian Journal of Fisheries and Aquatic Sciences, 2009

We evaluated effects of stocking level and size-at-release on survival rates of hatchery-reared j... more We evaluated effects of stocking level and size-at-release on survival rates of hatchery-reared juvenile white sturgeon (Acipenser transmontanus) in the Kootenai River using Cormack-Jolly-Seber and related models implemented in Program MARK. A total of 119 768 marked and unmarked hatchery juveniles were released from 1992 to 2006, of which 2938 passive integrated transponder (PIT)-tagged fish were subsequently recaptured. Annual survival rates of marked groups ranged from 0.01 to 0.84 (mean = 0.45) during the first year at large, from 0.48 to 1.0 (mean = 0.84) in the second year, and averaged 1.0 during all subsequent years. First year survival rates declined substantially in recent years, particularly for small fish (<25 cm fork length). Approximately 59% of the variation in first year survival was explained by a negative relationship with estimated juvenile abundance (linear regression, P < 0.01). Length-at-release of individuals explained a substantial proportion of the within-year variation in survival during the first year at large. Our results provide strong evidence of density-and size-dependent mortality in hatchery-reared juvenile white sturgeon in the Kootenai River. Management actions that prioritize the release of fewer, larger-sized fish will likely improve first year survival rates and subsequent recruitment to the spawning-age population.

Ecosphere, Jul 1, 2022

Many salmonid‐bearing rivers exhibit thermal and hydrologic heterogeneity at multiple spatial and... more Many salmonid‐bearing rivers exhibit thermal and hydrologic heterogeneity at multiple spatial and temporal scales, but how this translates into spatiotemporal patterns of fry emergence is poorly understood. Understanding this variability is important because emergence timing determines the biophysical conditions fish first experience (e.g., temperature, flow, and food supply), thereby influencing growth opportunities and survival during this critical life stage. We predicted spring Chinook Salmon (Oncorhynchus tshawytscha) emergence phenology across four northeastern Oregon subbasins over 5–9 years using empirical spawning and temperature data. We then related interannual emergence timing estimates to juvenile salmon size and growth rates at consistent sampling locations. There were clear longitudinal patterns of predicted emergence timing in each subbasin: The shape of these patterns was consistent among years, but not among subbasins. In two subbasins, emergence occurred progressively later with distance upstream, whereas in the other two subbasins emergence was earliest at upstream sites. Within each year, median emergence dates among sites within each subbasin ranged between 44 and 58 days. This spatial variation was comparable to interannual variation, with median emergence dates for a given location in each subbasin ranging between 47 and 74 days among years. Contrary to our expectations, juvenile salmon were not larger in years with earlier emergence, owing to slower estimated spring and summer growth rates compared to years with later emergence. Despite large interannual variation in estimated emergence dates, these results suggest that other factors (e.g., stream flow, temperature, and density‐dependence) were more important than growth duration in determining juvenile salmon growth rates and size among years. We demonstrated considerable spatial and interannual variation in emergence phenology within these subbasins. Understanding how this variation translates to spatiotemporal patterns of juvenile salmon habitat use, growth, and survival has important implications for guiding restoration efforts and understanding how climate change may impact these populations.

Fisheries Research, May 1, 2022

Elementa: Science of the Anthropocene, 2017

Land use legacies can have a discernible influence in present-day watersheds and should be accoun... more Land use legacies can have a discernible influence in present-day watersheds and should be accounted for when designing conservation strategies for riverine aquatic life. We describe the environmental history of three watersheds within the Grande Ronde subbasin of the Columbia River using General Land Office survey field notes from the 19th century. In the two watersheds severely impacted by Euro-American land use, stream channel widths—a metric representing habitat simplification—increased from an average historical width of 16.8 m to an average present width of 20.8 m in large streams; 4.3 m to 5.5 m in small, confined or partly confined streams; and 3.5 m to 6.5 m in small, laterally unconfined steams. Conversely, we did not detect significant change in stream widths in an adjacent, wilderness stream with minimal human impact. Using a mechanistic water temperature model and restoration scenarios based on the historical condition, we predicted that stream restoration in the impact...

Journal of environmental management, 2017

Understanding how stream temperature responds to restoration of riparian vegetation and channel m... more Understanding how stream temperature responds to restoration of riparian vegetation and channel morphology in context of future climate change is critical for prioritizing restoration actions and recovering imperiled salmon populations. We used a deterministic water temperature model to investigate potential thermal benefits of riparian reforestation and channel narrowing to Chinook Salmon populations in the Upper Grande Ronde River and Catherine Creek basins in Northeast Oregon, USA. A legacy of intensive land use practices in these basins has significantly reduced streamside vegetation and increased channel width across most of the stream network, resulting in water temperatures that far exceed the optimal range for salmon growth and survival. By combining restoration scenarios with climate change projections, we were able to evaluate whether future climate impacts could be offset by restoration actions. A combination of riparian restoration and channel narrowing was predicted to ...

Canadian Journal of Fisheries and Aquatic Sciences, 2009

We evaluated effects of stocking level and size-at-release on survival rates of hatchery-reared j... more We evaluated effects of stocking level and size-at-release on survival rates of hatchery-reared juvenile white sturgeon ( Acipenser transmontanus ) in the Kootenai River using Cormack–Jolly–Seber and related models implemented in Program MARK. A total of 119 768 marked and unmarked hatchery juveniles were released from 1992 to 2006, of which 2938 passive integrated transponder (PIT)-tagged fish were subsequently recaptured. Annual survival rates of marked groups ranged from 0.01 to 0.84 (mean = 0.45) during the first year at large, from 0.48 to 1.0 (mean = 0.84) in the second year, and averaged 1.0 during all subsequent years. First year survival rates declined substantially in recent years, particularly for small fish (<25 cm fork length). Approximately 59% of the variation in first year survival was explained by a negative relationship with estimated juvenile abundance (linear regression, P < 0.01). Length-at-release of individuals explained a substantial proportion of the w...

Journal of Animal Ecology

Changes in biophysical conditions through time generate spatial and temporal variability in habit... more Changes in biophysical conditions through time generate spatial and temporal variability in habitat quality across landscapes. For river ecosystems, researchers are increasingly able to characterize spatial and temporal patterns in habitat conditions, referred to as shifting habitat mosaics, yet rarely demonstrate how this translates into corresponding biological processes such as organism growth and production. We assessed spatial patterns and processes determining seasonal changes in juvenile Chinook Salmon (Oncorhynchus tshawytscha) size, growth, and production over 30-40 km in two NE Oregon subbasins. We quantified seasonal patterns of growth by combining estimated emergence dates and body size distributions in July and September. We then used analysis of bioenergetics, empirical fish diets, and spatial models incorporating temperature, habitat, and population density to evaluate mechanisms driving spatio-temporal patterns of growth. Lastly, we quantified seasonal contributions to individual fish growth and to total production as a function of position within the stream network. Spatial heterogeneity in incubation temperatures corresponded to later estimated emergence timing with distance upstream in both subbasins. During spring, estimated growth rates decreased with distance upstream, and coupled with emergence patterns, resulted in a pronounced longitudinal gradients in body size by July. During summer, spatial patterns of growth reversed, with greater diet ration sizes and growth efficiencies upstream than downstream. These opposing spatio-temporal patterns of emergence timing and seasonal growth rates produced longitudinal gradients in the proportion of fish growth achieved in spring versus summer, with up to 80% of an individual's growth occurring in spring at downstream sites but as low as 10% at upstream sites. Coupling longitudinal patterns of fish density and growth revealed that in one subbasin the majority (65%) of total production occurred in spring, while in the other, in which fish were concentrated in headwaters, the majority (60%) of production occurred in summer. While recent work has emphasized inter-annual shifts in fish production across large spatial scales, this study demonstrates that longitudinal gradients of fish growth and production can reverse across seasons, and reveals important contributions of warmer, downstream habitats to overall production that occurred during cooler times of the year.

Land use legacies can have a discernible influence in present-day watersheds and should be accoun... more Land use legacies can have a discernible influence in present-day watersheds and should be accounted for when designing conservation strategies for riverine aquatic life. We describe the environmental history of three watersheds within the Grande Ronde subbasin of the Columbia River using General Land Office survey field notes from the 19th century. In the two watersheds severely impacted by Euro-American land use, stream channel widths—a metric representing habitat simplification—increased from an average historical width of 16.8 m to an average present width of 20.8 m in large streams; 4.3 m to 5.5 m in small, confined or partly confined streams; and 3.5 m to 6.5 m in small, laterally unconfined steams. Conversely, we did not detect significant change in stream widths in an adjacent, wilderness stream with minimal human impact. Using a mechanistic water temperature model and restoration scenarios based on the historical condition, we predicted that stream restoration in the impact...

Understanding how stream temperature responds to restoration of riparian vegetation and channel m... more Understanding how stream temperature responds to restoration of riparian vegetation and channel morphology in context of future climate change is critical for prioritizing restoration actions and recovering imperiled salmon populations. We used a deterministic water temperature model to investigate potential thermal benefits of riparian reforestation and channel narrowing to Chinook Salmon populations in the Upper Grande Ronde River and Catherine Creek basins in Northeast Oregon, USA. A legacy of intensive land use practices in these basins has significantly reduced streamside vegetation and increased channel width across most of the stream network, resulting in water temperatures that far exceed the optimal range for salmon growth and survival. By combining restoration scenarios with climate change projections, we were able to evaluate whether future climate impacts could be offset by restoration actions. A combination of riparian restoration and channel narrowing was predicted to ...

Large woody debris is frequently placed into streams of the Pacific Northwest in an effort to imp... more Large woody debris is frequently placed into streams of the Pacific Northwest in an effort to improve habitat conditions for rearing juvenile salmonids. Unfortunately, many restoration projects do not incorporate monitoring of biotic response to these activities. This project compared stream reaches and pool habitats with differing quantities of large woody debris to determine the effects of large woody debris restoration structures on biomass, size, growth, and survival of juvenile coho salmon, age-1+ steelhead, and age-0 trout in two coastal streams in Northern California from July 2004 through June 2005. No significant differences in fish response variables were detected between treatment and control reaches. However, some significant relationships between physical habitat features and fish response variables were detected. Biomass and length of age-1+ steelhead were positively related to the proportion of pool habitat, while growth was positively related to mean reach depth. Length of age-0 trout was positively related to large woody debris density during the fall, and growth was positively related to pool depth. Fish responses at the habitat unit scale were more variable, but generally indicated preferences for pools and, in some cases, cover. Overall, the proportion of pool habitat and stream depth appeared to be the most important physical habitat features influencing salmonid productivity in these two coastal streams. Although direct effects of habitat restoration were not detected in this study, these results indicated that stream iv restoration structures that substantially increase the amount of pool habitat and create deeper pools can positively benefit coho salmon and steelhead populations. v ACKNOWLEDGEMENTS This thesis would not have been possible without the help and support of many people. First and foremost, I would like to thank my advisor, Dr. Walt Duffy, for contributing valuable biological insight, as well as financial, logistical, and moral support throughout this project. His door was always open for advice and help with the numerous questions and obstacles that I encountered during this study. I would also like to extend thanks to the entire crew and staff at the California Cooperative Fish Research Unit at HSU for your tireless efforts preparing for and carrying out the often grueling field activities required for this project, your insightful comments about field methods and salmonid biology, and for your excellent friendship. The following people helped

Fisheries

Despite immense resources directed towards habitat restoration, recovering fish populations remai... more Despite immense resources directed towards habitat restoration, recovering fish populations remains a daunting and perplexing issue. In 2015, recommendations for a comprehensive approach to habitat restoration in the Columbia River basin were published in Fisheries, which included elements of landscape ecology and resilience, broad public support, governance for collaboration and integration, and capacity for learning and adaptation. Using the Grande Ronde River basin as a case study, we convened a working group consisting of local restoration practitioners, managers, and researchers involved in habitat restoration research, monitoring, and evaluation to assess progress towards meeting these recommendations. We concluded that partnerships and collaborations in governance have been formed and research using a landscape perspective has been integrated into decision making, but efforts would benefit from gaining broader public support, formalizing an adaptive management strategy, and defining objectives and indicators for biological and ecological diversity. Continued progress will require consistent policy and funding support from the broader region. We envision this self-assessment at the 5-year milestone would be helpful to other groups facing similar challenges.

Canadian Journal of Fisheries and Aquatic Sciences, 2009

We evaluated effects of stocking level and size-at-release on survival rates of hatchery-reared j... more We evaluated effects of stocking level and size-at-release on survival rates of hatchery-reared juvenile white sturgeon (Acipenser transmontanus) in the Kootenai River using Cormack-Jolly-Seber and related models implemented in Program MARK. A total of 119 768 marked and unmarked hatchery juveniles were released from 1992 to 2006, of which 2938 passive integrated transponder (PIT)-tagged fish were subsequently recaptured. Annual survival rates of marked groups ranged from 0.01 to 0.84 (mean = 0.45) during the first year at large, from 0.48 to 1.0 (mean = 0.84) in the second year, and averaged 1.0 during all subsequent years. First year survival rates declined substantially in recent years, particularly for small fish (<25 cm fork length). Approximately 59% of the variation in first year survival was explained by a negative relationship with estimated juvenile abundance (linear regression, P < 0.01). Length-at-release of individuals explained a substantial proportion of the within-year variation in survival during the first year at large. Our results provide strong evidence of density-and size-dependent mortality in hatchery-reared juvenile white sturgeon in the Kootenai River. Management actions that prioritize the release of fewer, larger-sized fish will likely improve first year survival rates and subsequent recruitment to the spawning-age population.