28 research outputs found
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Effect of water velocity on passage of salmonids in a transportation channel
Passage times of fish at velocities of 1 and 2 feet per second were compared in a 4-foot wide transportation channel, with a water depth of 6 feet. The timing zone was about 100 feet long. Passage times did not differ significantly between water velocities for any one of three species: chinook salmon (Oncorhynchus tshawytscha), steelhead trout (Salmo gairdneri), and sockeye salmon (Oncorhynchus nerka). The two salmon species moved faster than steelhead trout at both water velocities
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A Mechanical Method for Separating Adult Migrant Salmonids
None supplied. Introduction: When John Day Dam is Completed, one of the last primal reaches of the Columbia River channel will be inundated. A substantial number of chinook salmon (Oncorhynchus tshawytscha) is reported to use this section of river for spawning and it is generally held that flooding from the John Day pool will take this area out of production. The responsible fishery agencies have proposed that the stock now spawning in this area be separated from other salmon populations bound for more distant upriver spawning grounds. Fish would be separated in the fishways at John Day Dam, the segregation being based on external coloration of the fish. Bright, silvery fish would be returned to the river to continue their upstream migration, whereas dark-colored fish, generally considered lower river spawners) would be collected for artificial propagation. A mechanical separator would be used to shunt the fish into appropriate channels following visual inspection for determination of the fish stock. The following is a report of laboratory study to determine the feasibility of separating salmonids in the manner described above
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Further Studies on Fishway Slope and Its Effect on Rate of Passage of Salmonids
The rates of passage of chinook (Oncorhynchus tshawytscha) and sockeye (O. nerka) salmon and steelhead trout (Salmo gairdneri) were studied in 1:16- and 1:8-slope, pool-and-overfall fishways. In general, the passage of salmonids through the 1:8-slope fishway was a 1.0-foot rise between pools was as fast as, or faster than, in the 1:16-slope fishway with a 1.0-foot rise. When the rise between pools was increased to 1.5 feet in the 1:8-slope fishway, chinook and sockeye were slower. The \u27Dallas-type\u27 weir crests in a 1:16-slope fishway appeared to accelerate chinook passage. Chinook and sockeye displayed seasonal differences in times within species
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Ability of Salmonids to Ascend High Fishways
The ability and persistence of salmonids in ascending pool-and-overfall fishways was measured in experimental \u27endless\u27 fishway structures in which fishways of any height could be simulated. Six chinook salmon (Oncorhynchus tshawytscha), four sockeye salmon (O. nerka), and four steelhead trout (Salmo gairdneri) were permitted to ascend 1,000 feet in the experimental fishways. One sockeye salmon was allowed to ascend an endless fishway for over 5 days, climbing 6,648 feet, a vertical ascent of more than a mile, before the test was discontinued. Rate of ascent of all fish tested increased following an initial period of experience in the fishway. The level of blood lactate in the exercised fish showed no evidence of fatigue. Practical significance of the data in relation to fishway design is discussed
Embedding Social and Emotional Learning in Literacy and Teacher Training in Afghanistan
This field note contributes to understanding of the challenges in and opportunities for supporting social and emotional learning (SEL) in the education in emergencies context, with a particular focus on embedding social and emotional skills into literacy learning in the early grades of primary school. In Afghanistan, the current reality is that many children and their teachers have been exposed repeatedly to adversity and highly stressful situations, such as attacks on their schools. Research shows that exposure to crises affects learning and the wellbeing of students and teachers alike. In this article, we describe how SEL was embedded in the early grade literacy curriculum and teacher training in Afghanistan, and in education support systems and practices. We further elaborate on the challenges faced and lessons learned throughout this process. The experience of integrating SEL into an early grade literacy curriculum has been positive, and initial feedback on the approach suggests that it promises to continue to be so. However, further research is needed in both Afghanistan and other contexts to more fully understand the impact of embedding different SEL practices in early grade reading materials and classrooms, and in preservice and in-service teacher training. Note: This field note was written prior to the change of government in Afghanistan in August 2021
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Effect of Fishway Slope on Performance and Biochemistry of Salmonids
The effect of fishway slope on the performance and biochemical state of salmonids was studied in two experimental \u27endless\u27 fishways with slopes of 1 on 8 and 1 on 16. A locking device in each fishway permitted recycling of fish so that pool-and-overfall fishways of any height could be simulated. Ascents were generally confined to a rise of 104 feet, but a number of fish were permitted to ascend over several hundred feet and one fish was allowed to ascend over 6,000 feet. Principal species tested were chinook salmon (Oncorhynchus tshawytscha), sockeye (Columbia River blueback) salmon (O. nerka), and steelhead trout (Salmo gairdneri). Comparisons of individual passage times, patterns of movement, and biochemical phenomena associated with muscular activity showed no evidence of fatigue of the fish in either fishway when proper hydraulic conditions existed. Data indicated that ascent of a properly designed pool-and-overfall fishway is only a moderate exercise for salmonids and that the rate of ascent will not decline in the upper end of a long fishway. Hydraulic conditions were shown to control rate of ascent and pattern of movement through fishways. Differences in rate of movement and in blood lactate levels were measured between species. The effects of size, sex, maturity, and disease on performance and biochemical state of fish were also examined. Significant relationships were found only for length of male chinook and performance (larger fish were slower), and sex and blood lactate level for chinook (female chinook had higher blood lactate levels)
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