Juvenile landlocked Chinook salmon (Oncorhynchus tshawytscha) (mean ± SD initial weight 2.6 ± 0.7 g, fork length 6.3 ± 0.5) were reared in three different water velocities [0.5, 1.5 and 3.0 body length/...Juvenile landlocked Chinook salmon (Oncorhynchus tshawytscha) (mean ± SD initial weight 2.6 ± 0.7 g, fork length 6.3 ± 0.5) were reared in three different water velocities [0.5, 1.5 and 3.0 body length/s (BL/s)] for four weeks to determine possible effects of water velocity on growth, condition, and survival. Fish were sampled for weight, fork length, condition factor, hepatosomatic index (HSI), viscerosomatic index (VSI), and fin erosion after four weeks of feeding to satiation. At the end of the feeding trial, the fish were handled and transported to simulate stocking, with survival observed over the following 10 d. Following four weeks of feeding, fish reared in 0.5 and 1.5 BL/s had the same growth and food conversion ratio, but fish reared at 3.0 BL/s had a significant reduction in both metrics. Furthermore, fish reared at 1.5 BL/s had a significantly higher condition factor than fish reared in other treatments. No significant differences were found for HSI, VSI, fin erosion, or survival. The results from this study indicate that a moderate velocity (1.5 BL/s), which is necessary for circular tanks to be self-cleaning, is not detrimental to fish growth or condition, but a faster water velocity (3.0 BL/s) negatively affects fish growth and food utilization.展开更多
Several treatment options have been developed to minimize the spread of zebra mussel Dreissena polymorphaveligers (larvae) during fish transportation. However, the effect of these treatments on the survival of newly-f...Several treatment options have been developed to minimize the spread of zebra mussel Dreissena polymorphaveligers (larvae) during fish transportation. However, the effect of these treatments on the survival of newly-fertilized salmonid eggs has not been evaluated. This study examined the survival of water-hardened landlocked fall Chinook salmon Oncorhynchus tshawytscha eggs after one of four different treatments: 1) Control (no chemicals), 2) 100 mg/L formalin for two hours, 3) 750 mg/L of potassium chloride for one hour followed by 20 mg/L formalin for two hours, and 4) 750 mg/L of potassium chloride for one hour followed by 20 mg/L formalin for three hours. The 100 mg/L formalin treatment produced complete egg mortality. Survival to hatch was not significantly different among the other three treatments. Based on these results, the use of 750 mg/L potassium chloride for one hour followed by 20 mg/L formalin for three hours is recommended when moving Chinook salmon eggs from waters potentially infested with zebra mussels to hatcheries for incubation.展开更多
Delayed fertilization of salmonid eggs can be a useful option to enhance the efficiency of artificial spawning operations. This experiment examined the fertility of landlocked fall Chinook salmon (Oncorhynchus tshawyt...Delayed fertilization of salmonid eggs can be a useful option to enhance the efficiency of artificial spawning operations. This experiment examined the fertility of landlocked fall Chinook salmon (Oncorhynchus tshawytscha) eggs stored for various times after removal from female broodstock. Fertilization occurred either immediately after spawning or the eggs were stored with oxygen at 11°C and fertilized at 4, 6, 8, 12, or 20 hours post-spawn. Survival to the eyed stage of egg development was significantly greater in the eggs fertilized immediately or after four, six, or eight hours of storage compared to those eggs stored for 12 or 20 hours prior to fertilization (P = 0.024). Survival to hatch was also significantly different (P = 0.018) and followed the same pattern. This study is the first to document the successful fertilization of landlocked fall Chinook salmon eggs after eight hours of storage.展开更多
During artificial spawning of salmonids, activated sperm is allowed to remain in contact with eggs for variable durations. This study examined multiple residence times (20, 40, 60, 90, or 120 seconds) for activated sp...During artificial spawning of salmonids, activated sperm is allowed to remain in contact with eggs for variable durations. This study examined multiple residence times (20, 40, 60, 90, or 120 seconds) for activated sperm on landlocked fall Chinook salmon (Oncorhynchus tshawytscha) eggs during spawning. There was no significant difference in egg survival to the eyed-stage of development or to hatch among any of the treatments, with a mean (SE) percent survival to the eyed stage of 63.9 (5.8). These results indicate that only relatively short residence times of activated milt on eggs during landlocked fall Chinook salmon spawning are needed to ensure egg survival, resulting in potentially substantial reductions in production-level spawning times and associated labor costs.展开更多
Targeted metabolomic analysis was conducted on juvenile Chinook salmon exposed for 10 days to wastewater effluent(WWE)from a large urban treatment plant.Exposures included five dilutions of WWE(20%,5.3%,1.4%,0.4%,and ...Targeted metabolomic analysis was conducted on juvenile Chinook salmon exposed for 10 days to wastewater effluent(WWE)from a large urban treatment plant.Exposures included five dilutions of WWE(20%,5.3%,1.4%,0.4%,and 0.1%)and a control with 7 replicates per treatment.Liver was extracted from fish and analyzed via liquid chromatography–mass spectrometry(LC-MS)for 361 endogenous metabolites,of which 185 were detected.Control-versus-treatment comparisons identified several metabolites that were associated with altered biochemical pathways observed for all treatments,including several that are important for energy generation and utilization.These altered pathways are crucial for fish health and may be an early indicator of potential adverse effects on growth,reproduction,behavior,and immune function.Juvenile ocean-type Chinook salmon spend several days to weeks in the nearshore estuary where they may encounter high concentrations of WWE contaminants.They are exposed to a wide range of potent pharmaceuticals,personal care products,and industrial compounds from WWE that have the potential to affect physiological homeostasis and disrupt their normal life cycle.展开更多
Wastewater treatment plants release complex mixtures of chemicals into the aquatic environment as wastewater effluent(WWE);however,the effects of these mixtures are still poorly understood.Chinook salmon(Oncorhynchus ...Wastewater treatment plants release complex mixtures of chemicals into the aquatic environment as wastewater effluent(WWE);however,the effects of these mixtures are still poorly understood.Chinook salmon(Oncorhynchus tshawytscha)are a culturally important species in the Pacific Northwest and are a vital food resource for southern resident killer whales(Orcinus orca)that are listed as‘critically endangered’under the U.S.Endangered Species Act(ESA).Chinook populations have declined drastically in this region and have failed to show significant recovery despite regional-to-federal efforts,resulting in many populations being listed as threatened under the ESA.One source of stress to juvenile Chinook is chemical pollution from WWE during their outmigration along river corridors and residency in estuaries.In this study,we investigated effects of WWE on juvenile Chinook health in a ten-day exposure to dilutions of WWE from 0.1%to 20%.At the end of the exposure,we measured endpoints associated with endocrine disruption,brain function,osmoregulation,stress,and metabolism.Exposure to WWE significantly(α=0.1 for all analyses)induced vitellogenesis,indicating endocrine system disruption.We saw significant reductions in plasma glucose,an indication of stress,and brain Na+/K+-ATPase(NKA)activity,an enzyme essential for neuronal signaling.Lastly,metabolism was affected as evidenced by altered total protein,cholesterol,and albumin in plasma,a drastic decrease in whole body lipid content,and a significant increase in visible liver anomalies.We compared contaminant concentrations in exposure water with effects concentrations from the literature for chemicals known to induce vitellogenin or inhibit brain NKA.For most contaminants,concentrations in exposure waters were several orders of magnitude below effects concentrations in the literature.The exception was estrogenic hormones,which were detected at similar concentrations in this study compared to concentrations in other studies that induced vitellogenin.Based on comparisons to the literature,contaminants measured in this study could not explain the inhibition of brain NKA;however,WWE mixtures contain many quantified and undetected compounds that are likely acting together to cause harmful effects in Chinook.This research highlights the need for improved wastewater treatment to improve aquatic health and mitigate effects to threatened species like Puget Sound Chinook salmon.展开更多
The role of geomorphic habitat type, drift cell scale, and geographic scale in defining fish use of nearshore habitats is poorly known, particularly for Pacific salmon and their prey. In this study, key areas of nears...The role of geomorphic habitat type, drift cell scale, and geographic scale in defining fish use of nearshore habitats is poorly known, particularly for Pacific salmon and their prey. In this study, key areas of nearshore habitat in central and western Strait of Juan de Fuca were categorized by geomorphic habitat type and assessed for fish use within a degraded （Elwha） and intact comparative drift cells over a one year period. Juvenile Chinook and coho salmon were also sampled for genetic analysis to define regional dispersal patterns. Key findings are： （1） Ecological function of the area＇s nearshore is complex, with very strong seasonal variation in fish use both within and across GMHT （geomorphic habitat type）; （2） GMHT link to nearshore function for fish use differs depending on the fish species and time of year. Surf smelt and sand lance were the most abundant. And they were seasonally used embayed, spit, and bluff shorelines more than lower rivers. Juvenile Chinook, coho, and chum salmon occurred in much lower density than forage fish species, and used lower rivers more than other GMHTs; （3） When GMHTs were combined and analyzed at the drift cell scale, the degraded drift cell had different ecological patterns than the intact drift cell; （4） Cross regional juvenile fish use of nearshore is an important component of habitat use： juvenile Chinook and coho from as far away as the Columbia River Oregon and Klamath River California utilize central Strait of Juan de Fuca shorelines. Forage fish species may do so as well. Drift cell and cross regional scales are therefore most important for accurately defining nearshore ecological function, management, and restoration actions.展开更多
A fish ladder, weir, and raceway at Whitlock Spawning Station are used to capture and retain feral fall Chinook salmon (<em>Oncorhynchus tshawytscha</em>) for spawning from Lake Oahe, South Dakota. Nearly ...A fish ladder, weir, and raceway at Whitlock Spawning Station are used to capture and retain feral fall Chinook salmon (<em>Oncorhynchus tshawytscha</em>) for spawning from Lake Oahe, South Dakota. Nearly 40% of the salmon ascending the fish ladder have been documented to escape from the holding raceway by descending the ladder. This manuscript describes modifications to the weir that eliminated nearly all escapements, except for an inconsequential number of small non-spawning fish. The modified design using the existing structure incorporated free-swinging, spaced steel bars with a back-stop to create a one-way gate. The modified gate does not require springs, hydraulics, or electrical power. It is relatively simple to construct and requires minimal maintenance.展开更多
In regulated rivers,shaping seasonal flows to recover species at risk depends on understanding when to expect conflicts with competing water users and when their interests are aligned.Multi-objective optimization can ...In regulated rivers,shaping seasonal flows to recover species at risk depends on understanding when to expect conflicts with competing water users and when their interests are aligned.Multi-objective optimization can be used to reveal such conflicts and commonalities.When species are involved,multi-objective optimization is challenged by the need to simulate complex species responses to flow regimes.Previously,we addressed that challenge by developing a simplified salmon model(Quantus)that defines cohorts of salmon by the river section and time in which they were spawned.Salmon in these space-time cohorts are tracked from the time redds(nests)are constructed until the cohort exits the tributary en route to the ocean.In this study,we modeled seasonal patterns in energy value and developed a Pareto-optimal frontier of seasonal flow patterns to maximize in-river salmon survival and hydropower value.Candidate flow regimes were characterized by two pulse flows varying in magnitude,timing,and duration and constrained by a total annual flow near the historical median.Our analysis revealed times when economic and salmon objectives were aligned and times when they differed.Pulse flows that favored higher energy value were timed to meet demand during extreme temperatures.Both salmon and hydropower objectives produced optimal flow regimes with pulse flows in early summer,but only solutions favoring hydropower value included high flows in mid-winter.Solutions favoring higher age-0 salmon survival provided an extended pulse flow in late winter/early spring,which suggests that access to productive floodplain habitat allowed faster growth and earlier out-migration and reduced the need for higher temperature-moderating flows later in spring.Minimum flows were also higher among solutions favoring salmon over energy.The tools used to produce these results can help to design simplified seasonal flow regimes by revealing compromise solutions that satisfy both fish and energy producers and highlighting when potential conflicts are likely.展开更多
文摘Juvenile landlocked Chinook salmon (Oncorhynchus tshawytscha) (mean ± SD initial weight 2.6 ± 0.7 g, fork length 6.3 ± 0.5) were reared in three different water velocities [0.5, 1.5 and 3.0 body length/s (BL/s)] for four weeks to determine possible effects of water velocity on growth, condition, and survival. Fish were sampled for weight, fork length, condition factor, hepatosomatic index (HSI), viscerosomatic index (VSI), and fin erosion after four weeks of feeding to satiation. At the end of the feeding trial, the fish were handled and transported to simulate stocking, with survival observed over the following 10 d. Following four weeks of feeding, fish reared in 0.5 and 1.5 BL/s had the same growth and food conversion ratio, but fish reared at 3.0 BL/s had a significant reduction in both metrics. Furthermore, fish reared at 1.5 BL/s had a significantly higher condition factor than fish reared in other treatments. No significant differences were found for HSI, VSI, fin erosion, or survival. The results from this study indicate that a moderate velocity (1.5 BL/s), which is necessary for circular tanks to be self-cleaning, is not detrimental to fish growth or condition, but a faster water velocity (3.0 BL/s) negatively affects fish growth and food utilization.
文摘Several treatment options have been developed to minimize the spread of zebra mussel Dreissena polymorphaveligers (larvae) during fish transportation. However, the effect of these treatments on the survival of newly-fertilized salmonid eggs has not been evaluated. This study examined the survival of water-hardened landlocked fall Chinook salmon Oncorhynchus tshawytscha eggs after one of four different treatments: 1) Control (no chemicals), 2) 100 mg/L formalin for two hours, 3) 750 mg/L of potassium chloride for one hour followed by 20 mg/L formalin for two hours, and 4) 750 mg/L of potassium chloride for one hour followed by 20 mg/L formalin for three hours. The 100 mg/L formalin treatment produced complete egg mortality. Survival to hatch was not significantly different among the other three treatments. Based on these results, the use of 750 mg/L potassium chloride for one hour followed by 20 mg/L formalin for three hours is recommended when moving Chinook salmon eggs from waters potentially infested with zebra mussels to hatcheries for incubation.
文摘Delayed fertilization of salmonid eggs can be a useful option to enhance the efficiency of artificial spawning operations. This experiment examined the fertility of landlocked fall Chinook salmon (Oncorhynchus tshawytscha) eggs stored for various times after removal from female broodstock. Fertilization occurred either immediately after spawning or the eggs were stored with oxygen at 11°C and fertilized at 4, 6, 8, 12, or 20 hours post-spawn. Survival to the eyed stage of egg development was significantly greater in the eggs fertilized immediately or after four, six, or eight hours of storage compared to those eggs stored for 12 or 20 hours prior to fertilization (P = 0.024). Survival to hatch was also significantly different (P = 0.018) and followed the same pattern. This study is the first to document the successful fertilization of landlocked fall Chinook salmon eggs after eight hours of storage.
文摘During artificial spawning of salmonids, activated sperm is allowed to remain in contact with eggs for variable durations. This study examined multiple residence times (20, 40, 60, 90, or 120 seconds) for activated sperm on landlocked fall Chinook salmon (Oncorhynchus tshawytscha) eggs during spawning. There was no significant difference in egg survival to the eyed-stage of development or to hatch among any of the treatments, with a mean (SE) percent survival to the eyed stage of 63.9 (5.8). These results indicate that only relatively short residence times of activated milt on eggs during landlocked fall Chinook salmon spawning are needed to ensure egg survival, resulting in potentially substantial reductions in production-level spawning times and associated labor costs.
基金support and guidance of the Wastewater Treatment Division of the King County Department of Natural Resources and Parks in addition to the King County Council for funding support(King County Contract#6113841).
文摘Targeted metabolomic analysis was conducted on juvenile Chinook salmon exposed for 10 days to wastewater effluent(WWE)from a large urban treatment plant.Exposures included five dilutions of WWE(20%,5.3%,1.4%,0.4%,and 0.1%)and a control with 7 replicates per treatment.Liver was extracted from fish and analyzed via liquid chromatography–mass spectrometry(LC-MS)for 361 endogenous metabolites,of which 185 were detected.Control-versus-treatment comparisons identified several metabolites that were associated with altered biochemical pathways observed for all treatments,including several that are important for energy generation and utilization.These altered pathways are crucial for fish health and may be an early indicator of potential adverse effects on growth,reproduction,behavior,and immune function.Juvenile ocean-type Chinook salmon spend several days to weeks in the nearshore estuary where they may encounter high concentrations of WWE contaminants.They are exposed to a wide range of potent pharmaceuticals,personal care products,and industrial compounds from WWE that have the potential to affect physiological homeostasis and disrupt their normal life cycle.
文摘Wastewater treatment plants release complex mixtures of chemicals into the aquatic environment as wastewater effluent(WWE);however,the effects of these mixtures are still poorly understood.Chinook salmon(Oncorhynchus tshawytscha)are a culturally important species in the Pacific Northwest and are a vital food resource for southern resident killer whales(Orcinus orca)that are listed as‘critically endangered’under the U.S.Endangered Species Act(ESA).Chinook populations have declined drastically in this region and have failed to show significant recovery despite regional-to-federal efforts,resulting in many populations being listed as threatened under the ESA.One source of stress to juvenile Chinook is chemical pollution from WWE during their outmigration along river corridors and residency in estuaries.In this study,we investigated effects of WWE on juvenile Chinook health in a ten-day exposure to dilutions of WWE from 0.1%to 20%.At the end of the exposure,we measured endpoints associated with endocrine disruption,brain function,osmoregulation,stress,and metabolism.Exposure to WWE significantly(α=0.1 for all analyses)induced vitellogenesis,indicating endocrine system disruption.We saw significant reductions in plasma glucose,an indication of stress,and brain Na+/K+-ATPase(NKA)activity,an enzyme essential for neuronal signaling.Lastly,metabolism was affected as evidenced by altered total protein,cholesterol,and albumin in plasma,a drastic decrease in whole body lipid content,and a significant increase in visible liver anomalies.We compared contaminant concentrations in exposure water with effects concentrations from the literature for chemicals known to induce vitellogenin or inhibit brain NKA.For most contaminants,concentrations in exposure waters were several orders of magnitude below effects concentrations in the literature.The exception was estrogenic hormones,which were detected at similar concentrations in this study compared to concentrations in other studies that induced vitellogenin.Based on comparisons to the literature,contaminants measured in this study could not explain the inhibition of brain NKA;however,WWE mixtures contain many quantified and undetected compounds that are likely acting together to cause harmful effects in Chinook.This research highlights the need for improved wastewater treatment to improve aquatic health and mitigate effects to threatened species like Puget Sound Chinook salmon.
文摘The role of geomorphic habitat type, drift cell scale, and geographic scale in defining fish use of nearshore habitats is poorly known, particularly for Pacific salmon and their prey. In this study, key areas of nearshore habitat in central and western Strait of Juan de Fuca were categorized by geomorphic habitat type and assessed for fish use within a degraded （Elwha） and intact comparative drift cells over a one year period. Juvenile Chinook and coho salmon were also sampled for genetic analysis to define regional dispersal patterns. Key findings are： （1） Ecological function of the area＇s nearshore is complex, with very strong seasonal variation in fish use both within and across GMHT （geomorphic habitat type）; （2） GMHT link to nearshore function for fish use differs depending on the fish species and time of year. Surf smelt and sand lance were the most abundant. And they were seasonally used embayed, spit, and bluff shorelines more than lower rivers. Juvenile Chinook, coho, and chum salmon occurred in much lower density than forage fish species, and used lower rivers more than other GMHTs; （3） When GMHTs were combined and analyzed at the drift cell scale, the degraded drift cell had different ecological patterns than the intact drift cell; （4） Cross regional juvenile fish use of nearshore is an important component of habitat use： juvenile Chinook and coho from as far away as the Columbia River Oregon and Klamath River California utilize central Strait of Juan de Fuca shorelines. Forage fish species may do so as well. Drift cell and cross regional scales are therefore most important for accurately defining nearshore ecological function, management, and restoration actions.
文摘A fish ladder, weir, and raceway at Whitlock Spawning Station are used to capture and retain feral fall Chinook salmon (<em>Oncorhynchus tshawytscha</em>) for spawning from Lake Oahe, South Dakota. Nearly 40% of the salmon ascending the fish ladder have been documented to escape from the holding raceway by descending the ladder. This manuscript describes modifications to the weir that eliminated nearly all escapements, except for an inconsequential number of small non-spawning fish. The modified design using the existing structure incorporated free-swinging, spaced steel bars with a back-stop to create a one-way gate. The modified gate does not require springs, hydraulics, or electrical power. It is relatively simple to construct and requires minimal maintenance.
基金This research,conducted by Oak Ridge National Laboratory(ORNL),was supported by the US Department of Energy's(DOE)Energy Efficiency and Renewable Energy Office,Wind and Water Power Technologies ProgramORNL is managed by UT-Battelle,LLC under Contract No.DEAC05-00OR22725 with the DOE+1 种基金The publisher,by accepting the article for publication,acknowledges that the U.S.Government retains a nonexclusive,paid-up,irrevocable,world-wide license to publish or reproduce the published form of this manuscript,or allow others to do so,for U.S.Government purposesThe DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan(http://energy.gov/downloads/doe-public-access-plan).
文摘In regulated rivers,shaping seasonal flows to recover species at risk depends on understanding when to expect conflicts with competing water users and when their interests are aligned.Multi-objective optimization can be used to reveal such conflicts and commonalities.When species are involved,multi-objective optimization is challenged by the need to simulate complex species responses to flow regimes.Previously,we addressed that challenge by developing a simplified salmon model(Quantus)that defines cohorts of salmon by the river section and time in which they were spawned.Salmon in these space-time cohorts are tracked from the time redds(nests)are constructed until the cohort exits the tributary en route to the ocean.In this study,we modeled seasonal patterns in energy value and developed a Pareto-optimal frontier of seasonal flow patterns to maximize in-river salmon survival and hydropower value.Candidate flow regimes were characterized by two pulse flows varying in magnitude,timing,and duration and constrained by a total annual flow near the historical median.Our analysis revealed times when economic and salmon objectives were aligned and times when they differed.Pulse flows that favored higher energy value were timed to meet demand during extreme temperatures.Both salmon and hydropower objectives produced optimal flow regimes with pulse flows in early summer,but only solutions favoring hydropower value included high flows in mid-winter.Solutions favoring higher age-0 salmon survival provided an extended pulse flow in late winter/early spring,which suggests that access to productive floodplain habitat allowed faster growth and earlier out-migration and reduced the need for higher temperature-moderating flows later in spring.Minimum flows were also higher among solutions favoring salmon over energy.The tools used to produce these results can help to design simplified seasonal flow regimes by revealing compromise solutions that satisfy both fish and energy producers and highlighting when potential conflicts are likely.
