... The daily movement patterns of adult smallmouth bass (Micropterus dolomieu) were monitored in... more ... The daily movement patterns of adult smallmouth bass (Micropterus dolomieu) were monitored in Melton Hill Reservoir, Tennessee. Country of Publication, United States. Language, English. Format, Medium: X; Size: 176 p. Availability, OSTI; NTIS; GPO Dep. ...
ABSTRACT Stakeholders are applying increasing pressure on many hydropower owners to change plant ... more ABSTRACT Stakeholders are applying increasing pressure on many hydropower owners to change plant operations such that downstream river flows are more conducive to healthy aquatic biological communities. These changes often result in a move away from daily-peaking operations to lower-energy run-of-river operations based on the assumption that downstream biological communities will improve under more natural flow regimes. Previous studies on natural flow regimes have focused primarily on characterizing pre- and post-dam effects by using metrics of flow variability based on daily-averaged flows, which do not accurately represent flow variability resulting from daily-peaking hydropower operations or natural flow pulses. We evaluated flow variability at four hydropower projects located in Michigan and Vermont, where the Federal Energy Regulatory Commission relicensing process resulted in a change in operations from daily-peaking to run-of-river. These hydropower projects were chosen because the relicensing occurred in the 1990s, thereby allowing for a sufficient post-operation flow record. In addition, the hydropower projects evaluated are located on rivers for which subdaily flow data were available for locations downstream of the facilities and at representative unregulated reaches. The flow data collected for the four sites were processed using three analytical tools: Indicators of Hydrological Alteration, GeoTools, and a subdaily flow worksheet developed for this study. Flow metrics were calculated using the three analytical tools, which depict flow variability at subdaily to seasonal timescales. Comparisons in flow metrics were made between unregulated and regulated reaches, as well as between daily-peaking and run-of-river operations. Results indicate that flow variability metrics calculated for run-of-river operations closely resemble unregulated reaches across temporal scales. Small to large variations in flow variability metrics were observed between daily-peaking and run-of-river operations, where the size of a facility's reservoir correlated to the amount of flow variability between operational regimes. Understanding flow variability at the subdaily scale is critical to assessing hydropower operations and their effects on downstream flow regimes. Results from this project will be used to demonstrate the utility of subdaily flow metrics for assessing changes in hydropower operations, as well as to provide comparisons between run-of-river operations and natural flow regimes of unregulated rivers.
Environmental Toxicology and Chemistry, Apr 1, 1999
Spatial distribution of contaminants in the sediments and biota of a large reservoir ecosystem we... more Spatial distribution of contaminants in the sediments and biota of a large reservoir ecosystem were related to a variety of biological responses in fish populations and communities to determine possible relationships between contaminant loading in the environment and fish health. Much of the contaminant inventory in the Clinch River/Watts Bar Reservoir (CR/WBR) system has originated from three U.S. Department of Energy facilities on the Oak Ridge Reservation, which borders this system in its upper reaches. Fish sampled from areas of the CR/WBR system with the highest levels of contaminants in the sediments and biota, primarily mercury and PCBs, had the most dramatic bioindicator responses. The major changes observed were induction of detoxification enzymes, organ dysfunction, increased frequency of histopathological lesions, impaired reproduction, and reduced fish community integrity. Mercury, the dominant contaminant, displayed a decreasing concentration gradient from the upper reaches of Poplar Creek to the lower Clinch River, which was consistent with a downstream gradient in several of the biological responses. A multivariate analysis using all of the individual fish health responses at each site in a discriminant analysis procedure also revealed a downstream gradient in integrated fish health. In Poplar Creek where contaminant concentrations were the highest, statistical correlations were observed between individual bioindicator responses such as contaminant exposure indicators, organ dysfunction, histopathological damage, and reproductive impairment. Relationships between contaminant loading and fish community indices such as species richness and relative abundance, however, were more difficult to establish in Poplar Creek because of the possible dominating influence of food and habitat availability on fish community dynamics. Using a suite of bioindicators that encompass a range of levels of biological organization and response‐sensitivity scales improves the probability of identifying cause (contaminant) and effect (biological response) and helps in distinguishing between natural and anthropogenic sources of stress in aquatic ecosystems.
As a component of the Clinch River Remedial Investigation Project, multi-response bioindicators h... more As a component of the Clinch River Remedial Investigation Project, multi-response bioindicators have been used as integrative and holistic measures of fish population and community health. The integrated bioindicator approach involves measuring a suite of selected indicators at several levels of biological organization from the biomolecular to the community levels. Multi-response indicators of stress at several levels of biological organization provides insights into causal mechanisms between contaminant exposure and population-level effects and provides a basis for which the effectiveness of future remedial actions on fish population health can be evaluated. Bioindicator responses were grouped into six functional categories representing indicators of (1) contaminant exposure (detoxification enzymes), (2) organ dysfunction, (3) histopathology, (4) overall fish health (condition indices), (5) feeding and nutritional status, and (6) fish community integrity. Detoxification enzyme induction, histopathological effects, reproductive dysfunction, bioenergetic impairment, and reduced fish community diversity was observed at several sample sites in the Clinch River System. When all the bioindicators were evaluated together in a canonical variate analysis procedure, the integrated site responses segregated clearly into contaminant affected sites and reference areas. Most of these effects appear to be related to the downstream gradient in contaminant loading from the Oak Ridge Reservation and tomore » the pattern of specific PCB congeners occurring at these sites.« less
... The daily movement patterns of adult smallmouth bass (Micropterus dolomieu) were monitored in... more ... The daily movement patterns of adult smallmouth bass (Micropterus dolomieu) were monitored in Melton Hill Reservoir, Tennessee. Country of Publication, United States. Language, English. Format, Medium: X; Size: 176 p. Availability, OSTI; NTIS; GPO Dep. ...
ABSTRACT Stakeholders are applying increasing pressure on many hydropower owners to change plant ... more ABSTRACT Stakeholders are applying increasing pressure on many hydropower owners to change plant operations such that downstream river flows are more conducive to healthy aquatic biological communities. These changes often result in a move away from daily-peaking operations to lower-energy run-of-river operations based on the assumption that downstream biological communities will improve under more natural flow regimes. Previous studies on natural flow regimes have focused primarily on characterizing pre- and post-dam effects by using metrics of flow variability based on daily-averaged flows, which do not accurately represent flow variability resulting from daily-peaking hydropower operations or natural flow pulses. We evaluated flow variability at four hydropower projects located in Michigan and Vermont, where the Federal Energy Regulatory Commission relicensing process resulted in a change in operations from daily-peaking to run-of-river. These hydropower projects were chosen because the relicensing occurred in the 1990s, thereby allowing for a sufficient post-operation flow record. In addition, the hydropower projects evaluated are located on rivers for which subdaily flow data were available for locations downstream of the facilities and at representative unregulated reaches. The flow data collected for the four sites were processed using three analytical tools: Indicators of Hydrological Alteration, GeoTools, and a subdaily flow worksheet developed for this study. Flow metrics were calculated using the three analytical tools, which depict flow variability at subdaily to seasonal timescales. Comparisons in flow metrics were made between unregulated and regulated reaches, as well as between daily-peaking and run-of-river operations. Results indicate that flow variability metrics calculated for run-of-river operations closely resemble unregulated reaches across temporal scales. Small to large variations in flow variability metrics were observed between daily-peaking and run-of-river operations, where the size of a facility's reservoir correlated to the amount of flow variability between operational regimes. Understanding flow variability at the subdaily scale is critical to assessing hydropower operations and their effects on downstream flow regimes. Results from this project will be used to demonstrate the utility of subdaily flow metrics for assessing changes in hydropower operations, as well as to provide comparisons between run-of-river operations and natural flow regimes of unregulated rivers.
Environmental Toxicology and Chemistry, Apr 1, 1999
Spatial distribution of contaminants in the sediments and biota of a large reservoir ecosystem we... more Spatial distribution of contaminants in the sediments and biota of a large reservoir ecosystem were related to a variety of biological responses in fish populations and communities to determine possible relationships between contaminant loading in the environment and fish health. Much of the contaminant inventory in the Clinch River/Watts Bar Reservoir (CR/WBR) system has originated from three U.S. Department of Energy facilities on the Oak Ridge Reservation, which borders this system in its upper reaches. Fish sampled from areas of the CR/WBR system with the highest levels of contaminants in the sediments and biota, primarily mercury and PCBs, had the most dramatic bioindicator responses. The major changes observed were induction of detoxification enzymes, organ dysfunction, increased frequency of histopathological lesions, impaired reproduction, and reduced fish community integrity. Mercury, the dominant contaminant, displayed a decreasing concentration gradient from the upper reaches of Poplar Creek to the lower Clinch River, which was consistent with a downstream gradient in several of the biological responses. A multivariate analysis using all of the individual fish health responses at each site in a discriminant analysis procedure also revealed a downstream gradient in integrated fish health. In Poplar Creek where contaminant concentrations were the highest, statistical correlations were observed between individual bioindicator responses such as contaminant exposure indicators, organ dysfunction, histopathological damage, and reproductive impairment. Relationships between contaminant loading and fish community indices such as species richness and relative abundance, however, were more difficult to establish in Poplar Creek because of the possible dominating influence of food and habitat availability on fish community dynamics. Using a suite of bioindicators that encompass a range of levels of biological organization and response‐sensitivity scales improves the probability of identifying cause (contaminant) and effect (biological response) and helps in distinguishing between natural and anthropogenic sources of stress in aquatic ecosystems.
As a component of the Clinch River Remedial Investigation Project, multi-response bioindicators h... more As a component of the Clinch River Remedial Investigation Project, multi-response bioindicators have been used as integrative and holistic measures of fish population and community health. The integrated bioindicator approach involves measuring a suite of selected indicators at several levels of biological organization from the biomolecular to the community levels. Multi-response indicators of stress at several levels of biological organization provides insights into causal mechanisms between contaminant exposure and population-level effects and provides a basis for which the effectiveness of future remedial actions on fish population health can be evaluated. Bioindicator responses were grouped into six functional categories representing indicators of (1) contaminant exposure (detoxification enzymes), (2) organ dysfunction, (3) histopathology, (4) overall fish health (condition indices), (5) feeding and nutritional status, and (6) fish community integrity. Detoxification enzyme induction, histopathological effects, reproductive dysfunction, bioenergetic impairment, and reduced fish community diversity was observed at several sample sites in the Clinch River System. When all the bioindicators were evaluated together in a canonical variate analysis procedure, the integrated site responses segregated clearly into contaminant affected sites and reference areas. Most of these effects appear to be related to the downstream gradient in contaminant loading from the Oak Ridge Reservation and tomore » the pattern of specific PCB congeners occurring at these sites.« less
The Basin Scale Opportunity Assessment (BSOA) initiative, led by the Department of Energy’s (DOE)... more The Basin Scale Opportunity Assessment (BSOA) initiative, led by the Department of Energy’s (DOE) Water Power Program, was designed to establish an integrative approach to assess the potential for combined increases in hydropower energy and improvements in the environment at a basin scale. Methods were developed to isolate mutual benefits to hydropower energy production and environmental protection. To date, the majority of environmental mitigation at hydropower facilities has occurred within the vicinity or project area of hydropower facilities (i.e., direct environmental opportunities). This report summarizes a methodology to identify environmental opportunities independent of a hydropower development and operations (i.e., indirect opportunities), i.e. those that occur outside the project area or not in close proximity to hydropower facilities that may complement increases in energy production. Indirect opportunities include acquisition of conservation land, wetland mitigation, riparian improvements, stream habitat restoration, and removal of non-powered dams. Using geospatial datasets summarizing landscape and stream conditions and the occurrence of high-profile aquatic and terrestrial species of concern, we created a framework to identify indirect opportunities and applied the methodology to the Roanoke Basin (North Carolina and Virginia, USA) as a case study. A scoring system was developed to prioritize indirect opportunities based on landscape/stream condition and the presence of species of concern. In addition, literature reviews and geospatial procedures were used to identify the social emphasis (overall prevalence and spatial variation in prevalence) of various direct and indirect environmental opportunities. The inclusion of indirect opportunities may provide greater potential for environmental mitigation and improvements related to a specific project or hydropower development because indirect environmental opportunities are pervasive and do not rely on direct geographic affiliation with a hydropower facility. The full potential of mutual benefits to hydropower energy production and environmental protection may be underestimated if based solely on potential opportunities near a facility. The methodology presented also has further reaching implications, such as providing environmental stakeholders with mechanisms to prioritize restoration actions within a basin, irrespective of hydropower.
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