38 research outputs found
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What is "Normative" at Cooling Water Intakes? Defining Normalcy Before Judging Adverse
Judgments of adverse environmental impact from cooling water intake structures need to be preceded by an appreciation of what is normal. In its repo~ Return to the River, the Independent Scientd5c Group (now called the Independent Scientfilc Advisory Board) --the scientific peer review arm of the Northwest Power Planning Council-- advanced the notion of a "normative river ecosystem" as a new conceptual foundation for salrnonid recovery in the Columbia River basin. With this perspective, the sum of the best scientific understanding of how organisms and aquatic ecosystems function should be the norm or standard of measure for how we judge the effects of human activities on aquatic systems. ,For the best likelihood of recovery, key aspects of altered systems should be brought back toward nonnative (although not necessarily fully back to the historical or pristine state); new alterations should be judged for adversity by how much they move key attributes away from normative or what might be considered normal. In this presentation, I ask what "normative" is for the setting of cooling water intake structures and how this concept could help resolve long-standing disputes between groups interested in avoiding darnage to all organisms that might be entrained or impinged and those who take a more population or community perspective for judging adverse environmental impact. In essence, I suggest that if a water intake does not move the aquatic ecosystem outside the "normative" range, based on expressions of norrrdcy such as those discussed, then no adverse impact has occurred. Having an explicit baseline in normal or normative would place 316(b) analyses on the same conceptual foundation as 316(a) analyses, which strive to demonstrate the continuation of a balanced, indigenous community of aquatic organisms at the power station Iocation
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Fish behavior in relation to modeling fish passage through hydropower turbines: A review
We evaluated the literature on fish behavior as it relates to passage of fish near or through hydropower turbines. The goal was to foster compatibility of engineered systems with the normal behavior patterns of fish species and life stages such that entrainment into turbines and injury in passage are minimized. We focused on aspects of fish behavior that could be used for computational fluid dynamics (CFD) modeling of fish trajectories through turbine systems. Downstream-migrating salmon smolts are generally surface oriented and follow flow. Smolts orient to the ceilings of turbine intakes but are horizontally distributed more evenly, except as affected by intake-specific turbulence and vortices. Smolts often enter intakes oriented head-upstream. Non-salmonids are entrained episodically, suggesting accidental capture of schools (often of juveniles or in cold water) and little behavioral control during turbine passage. Models of fish trajectories should not assume neutral buoyancy throughout the time a fish passes through a turbine, largely because of pressure effects on swim bladders. Fish use their lateral line system to sense obstacles and change their orientation, but this sensory-response system may not be effective in the rapid passage times of turbine systems. A Effects of pre-existing stress levels on fish performance in turbine passage are not well known but may be important. There are practical limits of observation and measurement of fish and flows in the proximity of turbine runners that may inhibit development of information germane to developing a more fish-friendly turbine. We provide recommendations for CFD modelers of fish passage and for additional research. 20 refs., 2 figs
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EXPERIMENTAL DRIFTS OF JUVENILE SALMONIDS THROUGH EFFLUENT DISCHARGES AT HANFORD. PART II. 1969 DRIFTS AND CONCLUSIONS.
What is "Normative" at Cooling Water Intakes? Defining Normalcy Before Judging Adverse
Judgments of adverse environmental impact from cooling water intake structures need to be preceded by an appreciation of what is normal. In its repo~ Return to the River, the Independent Scientd5c Group (now called the Independent Scientfilc Advisory Board) --the scientific peer review arm of the Northwest Power Planning Council-- advanced the notion of a "normative river ecosystem" as a new conceptual foundation for salrnonid recovery in the Columbia River basin. With this perspective, the sum of the best scientific understanding of how organisms and aquatic ecosystems function should be the norm or standard of measure for how we judge the effects of human activities on aquatic systems. ,For the best likelihood of recovery, key aspects of altered systems should be brought back toward nonnative (although not necessarily fully back to the historical or pristine state); new alterations should be judged for adversity by how much they move key attributes away from normative or what might be considered normal. In this presentation, I ask what "normative" is for the setting of cooling water intake structures and how this concept could help resolve long-standing disputes between groups interested in avoiding darnage to all organisms that might be entrained or impinged and those who take a more population or community perspective for judging adverse environmental impact. In essence, I suggest that if a water intake does not move the aquatic ecosystem outside the "normative" range, based on expressions of norrrdcy such as those discussed, then no adverse impact has occurred. Having an explicit baseline in normal or normative would place 316(b) analyses on the same conceptual foundation as 316(a) analyses, which strive to demonstrate the continuation of a balanced, indigenous community of aquatic organisms at the power station Iocation
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Perspectives on Temperature in the Pacific Northwest's Fresh Waters
This report provides a perspective on environmental water temperatures in the Pacific Northwest as they relate to the establishment of water temperature standards by the state and their review by the US Environmental Protection Agency. It is a companion to other detailed reviews of the literature on thermal effects on organisms important to the region. Many factors, both natural and anthropogenic, affect water temperatures in the region. Different environmental zones have characteristic temperatures and mechanisms that affect them. There are specific biotic adaptations to environmental temperatures. Life-cycle strategies of salmonids, in particular, are attuned to annual temperature patterns. Physiological and behavioral requirements on key species form the basis of present water temperature criteria, but may need to be augmented with more concern for environmental settings. There are many issues in the setting of standards, and these are discussed. There are also issues in compliance. Alternative temperature-regulating mechanisms are discussed, as are examples of actions to control water temperatures in the environment. Standards-setting is a social process for which this report should provide background and outline options, alternatives, limitations, and other points for discussion by those in the region
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EFFECT OF THERMAL SHOCK ON VULNERABILITY TO PREDATION IN JUVENILE SALMONIDS. II. A DOSE RESPONSE BY RAINBOW TROUT TO THREE SHOCK TEMPERATURES.
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Behavior of ultrasonic tagged chinook salmon and steelhead trout migrating past Hanford thermal discharges (1967)
Ultrasonic tagged, adult chinook salmon and steelhead trout were tracked in the Columbia River in 1967 during upstream migration past cooling water discharges from nuclear reactors. All fish migrated near shorelines, showing preference for the river bank opposite reactors. Clear responses to local temperaature differences were exhibited by few fish, these responses being to small shoreline seepages rather than to main centerchannel outfalls. (auth
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