ML12073A367

Enclosure 3, Biological Monitoring of the Tennessee River Near Watts Bar Nuclear Plant Discharge Autumn 2010

ML12073A367
Person / Time
Site:	Watts Bar
Issue date:	06/30/2011
From:	Simmons J Tennessee Valley Authority
To:	Office of Nuclear Reactor Regulation
References
Download: ML12073A367 (76)

Text

Enclosure 3 Biological Monitoring of the Tennessee River Near Watts Bar Nuclear Plant Discharge Autumn 2010 E3-1

Biological Monitoring of the Tennessee River Near Watts Bar Nuclear Plant Discharge Autumn 2010 Jeffrey W. Simmons June 2011 Tennessee Valley Authority Biological and Water Resources Chattanooga, Tennessee

Table of Contents LIST OF FIGURES...........................................................................................................................

11 LIST OF TABLES...........................................................................................................................

iii Acronyms and Abbreviations......................................................................................................

v Introduction...................................................................................................................................

1 P lant D escription.........................................................................................................................

2 Methods..........................................................................................................................................

3 Fish and Benthic Macroinvertebrate Sample Locations Upstream and Downstream of WBN.. 3 Aquatic Habitat in the Vicinity of WBN................................................................................

3 Fish Community Sampling Methods and Data Analysis for Sites Upstream and Downstream of W B N............................................................................................................................................

4 Benthic Macroinvertebrate Community Sampling Methods and Data Analysis for Sites Upstream and Downstream of WBN.....................................................................................

9 Chickamauga Reservoir Flow and WBN Temperature.........................................................

10 Water Quality Parameters at Fish Sampling Sites During RFAI Samples............................

11 Results and Discussion...........................................................................................................

11 Aquatic Habitat in the Vicinity of WBN..............................................................................

11 Fish C om m unity........................................................................................................................

12 Fish Community Summary....................................................................................................

18 Benthic Macroinvertebrate Community................................................................................

20 Benthic Macroinvertebrate Community Summary................................................................

22 Chickamauga Reservoir Flow and Temperature Near WBN...............................................

23 Water Quality Parameters at Fish Sampling Sites During RFAI Samples............................

23 Literature Cited..........................................................................................................................

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LIST OF FIGURES Figure 1. Map of WBN showing location of SCCW intake and discharge.............................

25 Figure 2. RFAI electrofishing locations, represented by black squares, downstream or within the thermal discharge of Watts'Bar Nuclear Plant, Chickamauga Reservoir inflow......... 26 Figure 3. RFAI electrofishing and gill net locations upstream of Watts Bar Nuclear Plant, Watts B ar R eservoir forebay...............................................................................................

27 Figure 4. Benthic habitat transects within the fish community sampling area upstream and downstream of W BN..............................................................................................

28 Figure 5. Locations of Watts Bar Nuclear Plant water temperature monitoring stations.....

29 Figure 6. Substrate composition at ten equally spaced points per transect across the Tennessee River downstream of W BN......................................................................................

30 Figure 7. Substrate composition at ten equally spaced points per transect across the Tennessee River downstream of W BN......................................................................................

31 Figure 8. Substrate composition at ten equally spaced points per transect across the Tennessee River downstream of W BN.....................................................................................

32 Figure 9. Substrate composition at ten equally spaced points per transect across the Tennessee River in the vicinity of the W BN discharge.............................................................

33 Figure 10. Substrate composition at ten equally spaced points per transect across the Tennessee River upstream of WBN (Watts Bar Reservoir forebay).........................................

34 Figure 11. Substrate composition at ten equally spaced points per transect across the Tennessee River upstream of WBN (Watts Bar Reservoir forebay).........................................

35 Figure 12. Substrate composition at ten equally spaced points per transect across the Tennessee River upstream of WBN (Watts Bar Reservoir forebay).........................................

36 Figure 13. Substrate composition at ten equally spaced points per transect across the Tennessee River upstream of WBN (Watts Bar Reservoir forebay).........................................

37 Figure 14. Number of indigenous species collected during every RFAI sample downstream of W BN (TRM 529), 1993 to 2010..............................................................................

38 Figure 15. Number of indigenous species collected during every RFAI sample upstream of W BN (TRM 531), 1993 to 2010..........................................

................................... 38 Figure 16. Daily average flows (cubic feet per second) from Watts Bar Dam, October 2009 through November 2010 and historic daily flows averaged for the same period 1976 through 2009................................................................................................................

39 Figure 17. Average daily water temperatures immediately below Watts Bar Dam compared to average daily water temperatures downstream of the WBN SCCW discharge mixing zone, October 2009 to November 2010..................................................................

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LIST OF TABLES Table 1. Shoreline Aquatic Habitat Index (SAHI) metrics and scoring criteria......................

41 Table 2. Expected values for upper mainstem Tennessee River reservoir inflow and forebay zones calculated from data collected from 600 electrofishing runs in upper mainstem Tennessee River reservoir inflow areas and from 900 electrofishing runs and 600 overnight experimental gill net sets in forebay areas of upper mainstem Tennessee R iver reservoirs......................................................................................................

.. 42 Table 3. Average trophic guild proportions and average number of species, bound by confidence intervals (95 %), expected in upper mainstem Tennessee River reservoir inflow and forebay zones..........................................................................................................

43 Table 4. RFAI Scoring criteria (2002) for forebay, transition, and inflow sections of Upper M ainstream Tennessee River reservoirs..................................................................

44 Table 5. Scoring criteria for benthic macroinvertebrate community samples (field-processed) for forebay, transition, and inflow sections of mainstream Tennessee River reservoirs... 45 Table 6. SAHI scores for 8 shoreline transects located within the RFAI sample reach downstream of WBN in Chickamauga Reservoir inflow, Autumn 2009............... 46 Table 7. SAHI scores for 8 shoreline transects located within the RFAI sample reach upstream of WBN in Watts Bar Reservoir forebay, Autumn 2009.......................................

47 Table 8. Substrate percentages and average water depth (ft) per transect upstream (8 transects) and downstream (8 transects) of W BN....................................................................

48 Table 9. Individual Metric Scores and the Overall RFAI Scores Downstream (TRM 529.0) of Watts Bar Nuclear Plant Discharge, Autumn 2009 and 2010.................................

49 Table 10. Individual Metric Scores and the Overall RFAI Scores Upstream (TRM 531.0) of Watts Bar Nuclear Plant Discharge, Autumn 2009 and 2010..................................

52 Table 11. Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing at Areas Downstream (TRM 529) of Watts Bar Nuclear Plant D ischarge, Autum n 2009................................................................................

55 Table 12. Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing at Areas Downstream (TRM 529) of Watts Bar Nuclear Plant D ischarge, Autumn 2010................................................................................

56 Table 13. Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing and Gill Netting at Areas Upstream (TRM 531) of Watts Bar Nuclear Plant Discharge, Autumn 2009.................................................

57 Table 14. Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing and Gill Netting at Areas Upstream (TRM 531) of Watts Bar Nuclear Plant Discharge, Autumn 2010...........................................................

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Table 15. Summary of RFAI Scores from Sites Located Directly Upstream and Downstream of Watts Bar Nuclear Plant as Well as Scores from Sampling Conducted During 1993-2010 as Part of the Vital Signs Monitoring Program in Chickamauga Reservoir....... 60 Table 16. Fish species collected including provisions for the identification of the resident important species at areas downstream (TRM 529) of WBN Discharge, Autumn 2010.

6 1 Table 17. Fish species collected including provisions for the identification of the resident important species at areas upstream (TRM 531) of WBN Discharge, Autumn 2010.. 63 Table 18. Individual Metric Ratings and the Overall RBI Field Scores for Downstream and Upstream Sampling Sites Near Watts Bar Nuclear Plant, Chickamauga and Watts Bar Reservoirs, Autumn 2001-2010...................................

65 Table 19. Comparison of Average Mean Density Per Square Meter of Benthic Taxa Collected at Upstream and Downstream Sites Near WBN, Chickamauga and Watts Bar Reservoirs, Autumn 2009 and Autumn 2010..............................................................................

66 Table 20. Summary of RBI Scores from Sites Located Directly Upstream and Downstream of Watts Bar Nuclear Plant as Well as Scores from Sampling Conducted During 1993-2010 as Part of the Vital Signs Monitoring Program in Chickamauga Reservoir....... 67 Table 21. Water quality parameters taken at the most downstream sampling point and at the most upstream sampling point of the RFAI sample upstream of WBN..................

68 Table 22. Water quality parameters taken at the most downstream sampling point and at the most upstream sampling point of the RFAI sample downstream of WBN.............. 69 iv

Acronyms and Abbreviations ATL Alternative Thermal limit BIP Balanced Indigenous Population CWA Clean Water Act EPA Environmental Protection Agency NPDES National Pollutant Discharge Elimination System QA Quality Assurance RBI Reservoir Benthic Macroinvertebrate Index RFAI Reservoir Fish Assemblage Index SAHI Shoreline Assessment Habitat Index SCCW Supplemental Condenser Cooling Water TRM Tennessee River Mile TVA Tennessee Valley Authority VS Vital Signs WBF Watts Bar Fossil Plant WBN Watts Bar Nuclear Plant v

Introduction Section 316(a) of the Clean Water Act (CWA) authorizes alternative thermal limits (ATL) for the control of the thermal component of a discharge from a point source so long as the limits will assure the protection of Balanced Indigenous Populations (BIP) of aquatic life. The term "balanced indigenous population," as defined in EPA's regulations implementing Section 316(a),

means a biotic community that is typically characterized by:

(1) diversity appropriate to ecoregion; (2) the capacity to sustain itself through cyclic seasonal changes; (3) the presence of necessary food chain species; (4) lack of domination by pollution-tolerant species; and (5) indigenous.

Prior to 1999, the Tennessee Valley Authority's (TVA) Watts Bar Nuclear Plant (WBN) was operating under a 316(a) ATL that had been continued with each permit renewal based on studies conducted in the mid-1970s. In 1999, EPA Region IV began requesting additional data in conjunction with NPDES permit renewal applications to verify that BIP was being maintained at TVA's thermal plants with ATLs. In July 1999, a Supplemental Condenser Cooling Water (SCCW) system went on line at WBN. As required by WBN's National Pollutant Discharge Elimination System (NPDES) permit TN0020168, impacts to aquatic communities in the vicinity of WBN were evaluated. TVA proposed that its existing Vital Signs (VS) monitoring program, supplemented with additional fish and benthic macroinvertebrate community monitoring upstream and downstream of thermal plants with ATLs, was appropriate for that purpose. The VS monitoring program began in 1990 in the Tennessee River System. This program was implemented to evaluate ecological health conditions in major reservoirs as part of TVA's stewardship role. One of the 5 indicators used in the VS program to evaluate reservoir health is the Reservoir Fish Assemblage Index (RFAI) methodology. RFAI has been thoroughly tested on TVA and other reservoirs and published in peer-reviewed literature (Jennings et al. 1995; Hickman and McDonough 1996; McDonough and Hickman 1999). Fish communities are used to evaluate ecological conditions because of their importance in the aquatic food web and because fish life cycles are long enough to integrate conditions over time. Benthic macroinvertebrate populations are assessed using the Reservoir Benthic Macroinvertebrate Index (RBI) methodology. Because benthic macroinvertebrates are relatively immobile, negative impacts to aquatic ecosystems can be detected earlier in benthic macroinvertebrate communities than in fish communities. These data are used to supplement RFAI results to provide a more thorough examination of differences in aquatic communities upstream and downstream of thermal discharges.

TVA initiated a study to evaluate fish and benthic macroinvertebrate communities in areas immediately upstream and downstream of WBN during 1999-2010 using RFAI and RBI multi-metric evaluation techniques. This report presents the results of autumn 2010 RFAI and RBI data collected upstream and downstream of WBN with comparisons to RFAI and RBI data collected at these sites during autumn 1999-2009. Since the WBN discharge is located within Chickamauga Reservoir inflow zone, no upstream control site data are available for comparison.

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Watts Bar Reservoir RFAI forebay site (Tennessee River Mile [TRM] 531) is used to document any notable changes in Tennessee River ecological conditions above the WBN discharge but will not be used for upstream/downstream comparisons of RFAI and RBI scores.

Plant Description Watts Bar Nuclear Plant is located on the right descending (west) bank of upper Chickamauga Reservoir near TRM 528. This one-unit nuclear generating plant went into commercial operation on May 27, 1996 and is designed for an electrical output of about 1,270 megawatts.

WBN is located approximately two miles downstream of Watts Bar Dam (TRM 529.9) and one mile downstream of the decommissioned Watts Bar Fossil Plant (WBF) (Figure 1).

In the original design, nearly all the waste heat created by the plant was dissipated in the atmosphere by the cooling towers. A small fraction of the waste heat was dissipated in the Tennessee River by the cooling tower blowdown. Blowdown from the cooling tower is discharged through multi-port diffusers located in the main river channel at TRM 527.9 (Figure 1). Makeup water and other water supply requirements are obtained from an intake channel and pumping station at TRM 528. Intake pumping flow rate is 80 cfs, and maximum diffuser discharge is about 135 cfs.

The WBN Supplemental Condenser Cooling Water System (SCCW) system became operational in July 1999. The SCCW system withdraws water from the intake structure located immediately upstream of Watts Bar Dam at TRM 529.9, which formerly served WBF. The temperature of the water in the SCCW system is usually less than that of Unit 1 cooling tower. The SCCW flow reduces the temperature of the Unit 1 condenser flow and enhances the performance of the steam cycle. The SCCW is designed to provide a maximum of 365 cfs. Water from the SCCW system is discharged through the old WBF discharge structure located on the Tennessee River approximately 1.1 miles upstream of the nuclear plant intake (Figure 1).

The SCCW system was designed and constructed as a discretionary system and has no significant impact on the original blowdown system, allowing the plant to operate with or without the SCCW system in service.

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Methods Fish and Benthic Macroinvertebrate Sample Locations Upstream and Downstream of WBN Reservoirs are typically divided into three zones for VS monitoring - inflow, transition, and forebay. The inflow zone is generally in the upper reaches of the reservoir and is riverine in nature; the transition zone or mid-reservoir is the area where water velocity decreases due to increased cross-sectional area; and the forebay is the lacustrine area near the dam. The Chickamauga Reservoir inflow RFAI sample site is located at TRM 529.0 below Watts Bar Dam and extends downstream to TRM 527 (Figure 2). This station is used to provide downstream data for the WBN thermal discharge. Since the WBN discharge is located within Chickamauga Reservoir inflow zone, no upstream site (control) data are available for comparison. Watts Bar Reservoir RFAI forebay site (TRM's 530 to 531) is used to document any notable changes in Tennessee River ecological conditions above the WBN discharge and can not be used for upstream/downstream comparisons of RFAI scores since the mixing zone for WBN is located in Chickamauga Reservoir (Figure 3).

For the benthic macroinvertebrate community, transects across the full width of the reservoir were established at TRM 527.4 (Figure 4, downstream transect 1) and TRM 533.3 (Figure 4, upstream transect 8). The Watts Bar Reservoir RBI forebay site (TRM 533.3) is used to document any notable changes in Tennessee River ecological conditions above the WBN discharge and can not be used for upstream/downstream comparisons of RBI scores since the mixing zone for WBN is located in Chickamauga Reservoir.

Aquatic Habitat in the Vicinity of WBN Shoreline Habitat An integrative multi-metric index (Shoreline Aquatic Habitat Index or SAHI) was used to measure existing fish habitat quality in the vicinity of WBN during autumn 2009. Using the general format developed by Plalkin et al. (1989), seven metrics were established to characterize selected physical habitat attributes important to reservoir resident fish populations which rely heavily on the littoral or shoreline zone for reproductive success, juvenile development, and/or adult feeding (Table 1). Habitat Suitability Indices (U.S. Fish and Wildlife Service), along with other sources of information on biology and habitat requirements (e.g. Etnier and Starnes 1993),

were consulted to develop "reference" criteria or "expected" conditions from a high quality environment for each parameter. Some generalizations were necessary in setting up scoring criteria to cover the various requirements of all species into one index.

Individual metrics are scored through comparison of observed conditions with these "reference" conditions and assigned a corresponding value: good-5; fair-3; or poor-I (Table 1). The scores for each metric are summed to obtain the Shoreline Aquatic Habitat Index (SAHI) value. The range of potential SAHI values (7-35) is trisected to provide some descriptor of habitat quality (poor 7-16, fair 17-26, and good 27-35).

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The quality of shoreline aquatic habitat was assessed while traveling parallel to the shoreline in a boat and evaluating the habitat within 10 vertical feet of full pool. This was much easier to accomplish when the reservoir was at least 10 feet below full pool during the assessment, which allowed for accurate determination of near-shore aquatic habitat quality. Eight line-of-sight transects were established across the width of Chickamauga Reservoir inflow within the WBN downstream fish community sampling areas (TRM's 527 to 529.7) and across the width of Watts Bar Reservoir forebay fish community sampling areas upstream of WBN (TRM's 530 to 533.3).

Near-shore aquatic habitat was assessed along sections of shoreline corresponding to the left descending (LD) and right descending (RD) bank locations for each of the eight line-of-sight transects. These individual sections (8 on the LD bank and 8 on the RD bank for a total of 16 shoreline assessments) were then scored using SAHI criteria. Percentages of aquatic macrophytes in the littoral areas of the 8 LD and 8 RD shoreline sections were also estimated.

River Bottom Habitat Along each of the 8 line-of-sight transects described above, 10 benthic grab samples were collected with a Ponar sampler at equally spaced points from the left descending bank to the right descending bank. Substrate material collected with the Ponar was dumped into a screen and substrate percentages were estimated'to determine existing benthic habitat across the width of the river. Water depths at each sample location were recorded (feet). If no substrate was collected after multiple Ponar drops, it was assumed that the substrate was bedrock. For example, when the ponar was pulled shut, collectors could feel substrate consistency; if it shut easily and was not embedded in the substrate on numerous drops within the same location, substrate was recorded as bedrock.

Fish Community Sampling Methods and Data Analysis for Sites Upstream and Downstream of WBN Fish sampling downstream of WBN was conducted by boat electrofishing (Reynolds 1996). Fish sampling upstream of WBN was conducted by boat electrofishing and gill netting (Hubert 1996; Reynolds 1996). Electrofishing methodology consisted of fifteen boat electrofishing runs near the shoreline, each 300 meters long, with a duration of approximately 10 minutes each. The total near-shore area sampled is approximately 4,500 meters (15,000 feet).

Experimental gill nets (so called because of their use for research as opposed to commercial fishing) are used as an additional gear type to collect fish from deeper habitats not effectively sampled by electrofishing. Each experimental gill net consists of five 6.1-meter panels for a total length of 30.5 meters (100.1 feet). The distinguishing characteristic of experimental gill nets is mesh size that varies between panels. For this application, each net has panels with mesh sizes of 2.5, 5.1, 7.6, 10.2, and 12.7 cm. Experimental gill nets are typically set perpendicular to river flow extending from near-shore to the main channel of the reservoir. Ten overnight experimental gill net sets were used upstream of WBN. Gill nets were not used downstream of WBN; inflow areas are not suitable to set gill nets due to higher water velocities which renders the nets ineffective.

Fish collected were identified by species, counted, and examined for anomalies (such as disease, deformities, or hybridization). The resulting data were analyzed using RFAI methodology.

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The RFAI uses 12 fish community metrics from four general categories: Species Richness and Composition; Trophic Composition; Abundance; and Fish Health. Individual species can be utilized for more than one metric. Together, these 12 metrics provide a balanced evaluation of fish community integrity. The individual metrics are shown below, grouped by category:

Species Richness and Composition (1) Total number of indigenous species -- Greater numbers of indigenous species are considered representative of healthier aquatic ecosystems. As conditions degrade, numbers of species at an area decline.

(2) Number of centrarchid species -- Sunfish species (excluding black basses) are invertivores and a high diversity of this group is indicative of reduced siltation and suitable sediment quality in littoral areas.

(3) Number of benthic invertivore species -- Due to the special dietary requirements of this species group and the limitations of their food source in degraded environments, numbers of benthic invertivore species increase with better environmental quality.

(4) Number of intolerant species -- This group is made up of species that are particularly intolerant of physical, chemical, and thermal habitat degradation.

Higher numbers of intolerant species suggest the presence of fewer environmental stressors.

(5) Percentage of tolerant individuals (excluding Young-of-Year) -- This metric signifies poorer water quality with increasing proportions of individuals tolerant of degraded conditions.

(6) Percent dominance by one species -- Ecological quality is considered reduced if one species inordinately dominates the resident fish community.

(7) Percentage of non-indigenous species -- Based on the assumption that non-indigenous species reduce the quality of resident fish communities.

(8) Number of top carnivore species -- Higher diversity of piscivores is indicative of the availability of diverse and plentiful forage species and the presence of suitable habitat.

Trophic Composition (9) Percent of individuals as top carnivores -- A measure of the functional aspect of top carnivores which feed on major planktivore populations.

(10) Percentage of individuals as omnivores -- Omnivores are less sensitive to 5

environmental stressors due to their ability to vary their diets. As trophic links are disrupted due to degraded conditions, specialist species such as insectivores decline while opportunistic omnivorous species increase in relative abundance.

Abundance (11) Average number per run -- (number of individuals) -- This metric is based upon the assumption that high quality fish assemblages support large numbers of individuals.

Fish Health (12) Percentage of individuals with anomalies -- Incidence of diseases, lesions, tumors, external parasites, deformities, blindness, and natural hybridization are noted for all fish measured, with higher incidence indicating less favorable environmental conditions.

RFAI methodology addresses all five attributes or characteristics of a "balanced indigenous population" defined by the CWA, as described below:

(1) A biotic community characterized by diversity appropriate to the ecoregion:

Diversity is addressed by the metrics in the Species Richness and Composition category, especially metric 1 - "Number of indigenous species." Determination of reference conditions based on the inflow zones of upper mainstem Tennessee River reservoirs (as described below) ensures appropriate species expectations for the ecoregion.

(2) The capacity for the community to sustain itself through cyclic seasonal change:

TVA uses an autumn data collection period for biological indicators, both VS and upstream/downstream monitoring. Autumn monitoring is used to document condition or health after being subjected to the wide variety of stressors throughout the year.

One of the main benefits of using biological indicators is their ability to integrate stressors through time. Examining the condition or health of a community at the end of the "biological year' (i.e., autumn) provides insights into how well the community has dealt with the stresses through an annual seasonal cycle. Likewise, evaluation of the condition of individuals in the community (in this case, individual fish as reflected in Metric 12) provides insights into how well the community can be expected to withstand stressors through winter. Further, multiple sampling years during the permit renewal cycle adds to the evidence of whether or not the autumn monitoring approach has correctly demonstrated the ability of the community to sustain itself through repeated seasonal changes.

(3) The presence of necessary food chain species:

Three dominant fish trophic levels exist within Tennessee River reservoirs; insectivores, omnivores, and top carnivores. To determine the presence of necessary food chain species, these three groups should be well represented within the overall fish community.

Other fish trophic levels include benthic invertivores, planktivores, herbivores, and 6

parasitic species. Insectivores include most sunfish, minnows, and silversides.

Omnivores include gizzard shad, common carp, carpsuckers, buffalo, and channel and blue catfish. Top carnivores include bass, gar, skipjack herring, crappie, flathead catfish, sauger, and walleye. Benthic invertivores include drum, suckers, and darters.

Planktivores include alewife, threadfin shad, and paddlefish. Herbivores include largescale stonerollers. Lampreys in the genus Ichthyomyzon are the only parasitic species occurring in Tennessee River reservoirs.

To establish expected proportions of each trophic guild and the expected number of species included in each guild occurring in upper mainstem Tennessee River reservoirs (Nickajack, Chickamauga, Watts Bar, and Fort Loudon reservoirs), data collected from 1993 to 2010 was analyzed for each reservoir zone (forebay, transition, inflow). Samples collected in the downstream vicinity of thermal discharges were not included in this analysis so that accurate expectations could be calculated with the assumption that these data represent what should occur in upper mainstem Tennessee River reservoirs absent from point source effects (i.e. power plant discharges). Therefore, data from Chickamauga Reservoir inflow, collected in the vicinity of WBN discharge, was not included in this analysis. Data from 600 electrofishing runs (a total of 180,000 meters of shoreline sampled) were included in this analysis for inflow areas in upper mainstem Tennessee River reservoirs. Data from 900 electrofishing runs (a total of 270,000 meters of shoreline sampled) and from 600 overnight experimental gill net sets were included in this analysis for forebay areas in upper mainstem Tennessee River reservoirs. From these data, the range of proportional values for each trophic level and the range of the number of species included in each trophic level were trisected. This trisection is intended to show less than expected, expected and above expected values for trophic level proportions and species occurring within each reservoir zone in upper mainstem Tennessee River reservoirs (Table 2). These data were also averaged and bound by confidence intervals (95%) to further evaluate expected values for proportions of each trophic level and the number of species expected for each trophic level by reservoir zone (Table 3).

(4) A lack of domination by pollution-tolerant species: Domination by pollution-tolerant species is measured by metrics 3 ("Number of benthic invertivore species"), 4 ("Number of intolerant species"), 5 ("Percentage of tolerant individuals"), 6 ("Percent dominance by one species"), and 10 ("Percentage of individuals as omnivores").

(5) Indigenous: Non-indigenous species reduce the quality of indigenous fish communities through increased competition for resources, predation on indigenous species, and degradation of the water quality. Metrics measuring the indigenousness of the fish communities are 1 ("Number of indigenous species") and 7 ("Percentage of non-indigenous species").

Scoring categories are based on "expected" fish community characteristics in the absence of human-induced impacts other than impoundment of the reservoir. These categories were developed from historical fish assemblage data representative of transition zones from upper mainstem Tennessee River reservoirs (Hickman and McDonough 1996). Attained values for 7

each of the 12 metrics were compared to the scoring criteria and assigned scores to represent relative degrees of degradation: least degraded (5); intermediate degraded (3); and most degraded (1). Scoring criteria for upper mainstem Tennessee River reservoirs is shown in Table 4.

If a metric was calculated as a percentage (e.g., "Percentage of tolerant individuals"), the data from electrofishing and gill netting were scored separately and allotted half the total score for that individual metric. Individual metric scores for a sampling area (i.e., upstream or downstream) are summed to obtain the RFAI score for the area.

TVA uses RFAI results to determine maintenance of BIP using two approaches. One is "absolute" in that it compares the RFAI scores and individual metrics to predetermined values.

The other is "relative" in that it compares RFAI scores attained downstream to the upstream control site. The "relative" approach does not apply to WBN since the upstream site is located upstream of Watts Bar Dam in the Watts Bar Reservoir forbay which contains different fish and benthic communities which are not comparable to the downstream site. The "absolute" approach is based on Jennings et al. (1995) who suggested that favorable comparisons of the attained RFAI score from the potential impact zone to a predetermined criterion can be used to identify the presence of normal community structure and function and hence existence of BIP. For multi-metric indices, TVA uses two criteria to ensure a conservative screening of BIP. First, if an RFAI score reaches 70% of the highest attainable score of 60 (adjusted upward to include sample variability as described below), and second, if fewer than half of RFAI metrics receive a low (1) or moderate (3) score, then normal community structure and function would be present indicating that BIP had been maintained, thus no further evaluation would be needed.

RFAI scores range from 12 to 60. Ecological health ratings (12-21 ["Very Poor"], 22-31

["Poor"], 32-40 ["Fair"], 41-50 ["Good"], or 51-60 ["Excellent"]) are then applied to scores. As discussed in detail below, the average variation for RFAI scores in TVA reservoirs is 6 (+/- 3).

Therefore, any location that attains an RFAI score of 45 (42 plus the upward sample variation of

3) or higher would be considered to have BIP. It must be stressed that scores below this threshold do not necessarily reflect an adversely impacted fish community. The threshold is used to serve as a conservative screening level; i.e., any fish community that meets these criteria is obviously not adversely impacted. RFAI scores below this level would require a more in-depth look to determine if BIP exists. An inspection of individual RFAI metric results and species of fish used in each metric would be an initial step to help identify if operation of WBN is a contributing factor. This approach is appropriate because a validated multi-metric index is being used and scoring criteria applicable to the zone of study are available.

The Quality Assurance (QA) component of VS monitoring deals with how well the RFAI scores can be repeated and is accomplished by collecting a second set of samples at 15%-20% of the sites each year. Previous statistical analyses with the QA component of VS has shown that the comparison of RFAI index scores from 54 paired sample sets collected over a seven year period ranged from 0 to 18 points. Based on these findings, the 75th percentile is 6 and the 9 0th percentile is 12. The mean difference between these 54 paired scores is 4.6 points with 95 percent confidence limits of 3.4 and 5.8. Therefore, a difference of 6 points or less was the value selected for defining "similar" scores between years sampled at the downstream site. That is, if the downstream RFAI score is within 6 points compared to prior year's score then the fish 8

communities will be considered similar. It is important to bear in mind that differences greater than 6 points can be expected simply due to method variation (25% of the QA paired sample sets exceeded that value). When this occurs, a metric-by-metric examination will be conducted to determine what caused the difference in scores and the potential for the difference to be thermally related.

Benthic Macroinvertebrate Community Sampling Methods and Data Analysis for Sites Upstream and Downstream of WBN Benthic grab samplers were used to collect samples at ten equally-spaced points along the upstream and downstream transects. A Ponar sampler (area per sample 0.06 M2) was used for most samples. When heavier substrate was encountered, a Peterson sampler (area per sample 0.11 mi2) was used. Collection and processing techniques followed standard VS procedures (OER-ESP-RRES-AMM-21.11; Quantitative Sample Collection - Benthic Macroinvertebrate Sampling with a Ponar Dredge). Bottom sediments were washed on a 533[t screen; organisms were then picked from the screen and any remaining substrate. Organisms were identified in the field to Order or Family level without magnification.

Benthic community results were evaluated using seven community characteristics or metrics.

Results for each metric were assigned a rating of 1, 3, or 5 depending upon how they scored based on reference conditions developed for VS reservoir inflow (downstream of WBN) and forebay (upstream of WBN) sample sites. Scoring criteria for mainstem Tennessee River reservoirs are shown in Table 5. The ratings for the seven metrics were summed to produce a benthic score for each sample site. Potential scores ranged from 7 to 35. Ecological health ratings (7-12 "Very Poor", 13-18 "Poor", 19-23 "Fair", 24-29 "Good", or 30-35 "Excellent") are then applied to scores. The individual metrics are shown below:

(1) Taxa richness-This metric is calculated by averaging the total number of taxa present in each sample at a site. Taxa generally mean Family or Order level because samples are processed in the field. For chironomids, taxa refers to obviously different organisms (i.e., separated by body size, head capsule size and shape, color, etc.). Greater taxa richness indicates better conditions than lower taxa richness.

(2) EPT-This metric is calculated by averaging the number of Ephemeroptera, Plecoptera, and Trichoptera taxa present in each sample at a site. Higher diversity of these taxa indicates good water quality and better habitat conditions.

(3) Long-lived organisms-This is a presence/absence metric which is evaluated based on the proportion of samples with at least one long-lived organism (Corbicula, Hexagenia, mussels, and snails) present. The presence of long-lived taxa is indicative of conditions which allow long-term survival.

(4) Percentage as Oligochaetes-This metric is calculated by averaging the percentage of oligochaetes in each sample at a site. Oligochaetes are considered tolerant organisms so a higher proportion indicates poor water quality.

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(5) Percentage as dominant taxa-This metric is calculated by selecting the two most abundant taxa in a sample, summing the number of individuals in those two taxa, dividing that sum by the total number of animals in the sample, and converting to a percentage for that sample. The percentage is then averaged for the 10 samples at each site. Often, the most abundant taxa differed among the 10 samples at a site.

This allows more discretion to identify imbalances at a site than developing an average for a single dominant taxon for all samples combined at a site. This metric is used as an evenness indicator. Dominance of one or two taxa indicates poor conditions.

(6) Density excluding Chironomids and Oligochaetes-This metric is calculated by first summing the number of organisms, excluding chironomids and oligochaetes, present in each sample and then averaging these densities for the 10 samples at a site. This metric examines the community, excluding taxa which often dominate under adverse conditions. A higher abundance of non-chironomids and non-oligochaetes indicates good water quality conditions.

(7) Zero-samples (Proportion of samples with no organisms present)-This metric is the proportion of samples at a site which have no organisms present. "Zero-samples" indicate living conditions unsuitable to support aquatic life (i.e. toxicity, unsuitable substrate, etc.). Any site having one empty sample was assigned a score of three, and any site with two or more empty samples received a score of one. Sites with no empty samples were assigned a score of five.

The QA component of VS monitoring shows that the comparison of benthic index scores from 49 paired sample sets collected over a seven year period ranged from 0 to 14 points; the 75th percentile was 4 and the 90th percentile was 6. The mean difference between these 49 paired scores was 3.1 points with 95 percent confidence limits of 2.2 and 4.1. Based on these results, a difference of 4 points or less is the value selected for defining "similar" scores between years sampled at the downstream site. That is, if the downstream benthic score is within 4 points of the prior year's score, the communities will be considered similar and it will be concluded that WBN has had no effect. The Watts Bar Reservoir RBI forebay site (TRM 533.3) is used to document any notable changes in Tennessee River ecological conditions above the WBN discharge but will not be used for upstream/downstream comparisons of RBI scores. Once again, it is important to bear in mind that differences greater than 4 points can be expected simply due to method variation (25% of the QA paired sample sets exceeded that value). When this occurs, a metric-by-metric examination will be conducted to determine what caused the difference in scores and the potential for the difference to be thermally related.

Chickamauga Reservoir Flow and WBN Temperature Daily average flow from Chickamauga Dam was used to describe the amount of water flowing past WBN and was obtained from TVA's River Operations database.

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Water temperature data was also obtained from TVA's River Operations database. Locations of water temperature monitoring stations used to measure water temperatures upstream and downstream of the WBN discharge are depicted in Figure 5. Station 30 was used for ambient water temperatures upstream of the WBN discharge and was located at the base of Watts Bar Dam. Downstream temperatures were calculated by first averaging temperatures at depths of three, five, and seven feet at each station. The resultant values from these stations were averaged again to obtain an overall average water temperature.

Water Quality Parameters at Fish Sampling Sites During RFAI Samples Water quality conditions were measured using a hydrolab which provided readings for dissolved oxygen (ppm), water temperature, conductivity (ps/cm), and pH. Readings were taken along a vertical gradient from just above the bottom of the river to approximately 0.3 meters from the surface at one meter intervals. Readings were conducted in the mid-channel at the most downstream and upstream boundaries of the electrofishing sample area at both stations upstream and downstream of WBN.

Results and Discussion Aquatic Habitat in the Vicinity of WBN Shoreline Habitat The SAHI methodology was used to evaluate the quality of the aquatic habitat along the shoreline of Chickamauga and Watts Bar reservoirs within the WBN downstream and upstream fish community sampling areas. Eight shoreline sections on the left descending and right descending banks were assessed at both the downstream and upstream locations.

Within the RFAI sample area downstream from WBN (Chickamauga Reservoir inflow),

shoreline aquatic habitat quality averaged a SAHI rating of 22 "Fair" on the left descending shoreline and a rating of 19 "Fair" on the right descending shoreline (Table 6). Of the eight shoreline sections evaluated on each river bank, 75% scored "Fair" while 25% scored "Poor."

Within the RFAI sample area upstream from WBN (Watts Bar Reservoir forebay), shoreline aquatic habitat quality averaged a SAHI rating of 21 "Fair" on both the left and right descending shorelines (Table 7). Of the eight shoreline sections evaluated on the left descending river bank, 12.5% scored "Good." 62.5% scored "Fair," and 25% scored "Poor." Of the eight shoreline sections evaluated on the right descending river bank, 87.5% scored "Fair" and 12.5% scored "Poor."

River Bottom Habitat A characterization of river bottom habitat was conducted along 8 transects within both the WBN downstream and upstream fish sampling areas during autumn 2009. Substrate percentages were estimated at 10 equally spaced drops along each transect. Figures 6-9 display substrate proportions as well as water depth at each sample point along each of the 8 transects downstream of WBN. Figures 10-13 display substrate proportions as well as water depth at each sample point along each of the 8 transects upstream of WBN.

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The three most dominant substrate types encountered along the 8 transects downstream of WBN were bedrock (36.0%), mollusk shell (25.9%), and gravel (25.6%), while the 3 most dominant substrate types encountered along the 8 transects upstream of WBN were silt (49.1%), gravel (17.1%), and bedrock (10.6%) (Table 8). Substrates encountered at the downstream areas near WBN are typical of inflow areas whereas finer substrates such as silt are more commonly associated with impounded areas such as Watts Bar Reservoir forebay upstream of WBN.

Overall average water depth was deeper upstream of WBN (37.4 ft) compared to downstream (23.2 ft) (Table 8).

Fish Community In 2010, a fish community RFAI score of 44 ("Good") was observed at the site downstream of WBN (Table 9). This site met BIP screening criteria and received the same RFAI score as in 2009. When compared to the 2009 sample, the 2010 sample contained two additional benthic invertivore species, two additional intolerant species, a higher percentage of tolerant individuals, a mudh lower percentage of non-native species, a higher percentage of top carnivore and omnivore species, a lower average of fish collected per electrofishing run, and a slightly higher percentage of observed fish anomalies (Table 9).

RFAI data collected at TRM 531, Watts Bar Reservoir forebay, is used to indicate the health of the fish community upstream from WBN, but is not used as an upstream comparison between the sites since the mixing zone for WBN is located in Chickamauga Reservoir. In 2010, a fish community RFAI score of 41 ("Good") was observed at this site (Table 10). This was a four point decrease from the previous year. When compared to the 2009 sample, the 2010 sample contained one additional indigenous species, one additional centrarchid species, one additional intolerant species, a higher percentage of tolerant individuals, a higher percentage of dominance by one species, a much lower percentage of non-native species, one additional top carnivore species, a lower overall percentage of top carnivores, a higher percentage of omnivores, and a slightly lower average number of fish per run (Table 10).

The downstream site is compared with the previous sample at this site to determine BIP using the five characteristics listed below. Because the upstream site is separated from the downstream site by Watts Bar dam and is within a forebay zone rather than an inflow zone, it will be compared to the previous sample at this site for explanation of upstream conditions that could affect the downstream site in the Chickamauga Reservoir inflow.

(1) A biotic community characterized by diversity appropriate to the ecoregion Site downstream of WBN (Inflow scoring criteria)

Total number of indigenous species (> 27 required for highest score)

During 2009 and 2010, 31 indigenous species were collected, which resulted in the highest score for this metric (Tables 11 and 12). Seven indigenous species were encountered in 2010 that were not collected during 2009 (skipjack herring, river redhorse, rock bass, largescale stoneroller, bullhead minnow, blue catfish, and logperch). During 2009, seven indigenous species were collected that were not encountered during 2010 (golden shiner, brook silverside, spotted gar, threadfin shad, emerald shiner, steelcolor shiner, and sauger).

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Total number of centrarchid species (> 4 required for highest score)

During 2009 and 2010, the same eight centrarchid species were collected, resulting in the highest score for this metric (Table 9).

Total number of benthic invertivore species (> 6 required for highest score)

This site received the mid-range score for this metric during 2009 and the highest score for this metric during 2010. Four benthic invertivore species were collected during 2009, while six were collected during 2010. In addition to the same four species that were collected during 2009, river redhorse and logperch were collected during 2010 (Table 9).

Total number of intolerant species (> 4 required for highest score)

During 2009 and 2010, this site received the highest score for this metric. Five intolerant species were collected during 2009, while seven intolerant species were collected during 2010. River redhorse, rock bass, and skipjack herring were collected during 2010 but not during 2009, while brook silverside was collected during 2009 but not during 2010 (Table 9).

Total number of top carnivore species (> 6 required for highest score)

During 2009 and 2010, this site received the highest score for this metric. Eleven top carnivore species were collected each year. Sauger and spotted gar were collected during 2009. but not during 2010, while rock bass and skipjack herring were collected during 2010 but not during 2009 (Table 9).

This site received the highest score for these 5 diversity metrics during 2010 and for four of the five diversity metrics during 2009, indicating that fish community diversity in the vicinity of WBN has been maintained.

Site upstream of WBN (Forebay scoring criteria)

Total number of indigenous species (> 27 required for highest score)

During 2009 and 2010, 28 indigenous species were collected, which resulted in the highest score for this metric (Tables 13 and 14). Two indigenous species were encountered in 2009 that were not collected during 2010 (river redhorse and threadfin shad). Conversely, two indigenous species were encountered during 2010 that were not collected during 2009 (black redhorse and longear sunfish).

Total number of centrarchid species (> 4 required for highest score)

During 2009, seven centrarchid species were collected, resulting in the highest score for this metric (Table 10). During 2010, eight centrarchid species were collected, which also resulted in the highest score for this metric. Longear sunfish was collected during 2010, but not during the 2009 sample.

Total number of benthic invertivore species (> 7 required for highest score)

During 2009 and 2010, five benthic invertivore species were collected, resulting in the mid-range score for this metric (Table 10). River redhorse were collected during 2009 but not during 2010, while black redhorse were collected during 2010 but not during 2009.

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Total number of intolerant species (> 4 required for highest score)

During 2009, five intolerant species were collected, resulting in the highest score for this metric (Table 10). During 2010, six intolerant species were collected, also resulting in the highest score for this metric. River redhorse were collected during 2009 but not during 2010, while black redhorse and longear sunfish were collected during 2010 but not during 2009.

Total number of top carnivore species (> 7 required for highest score)

During 2009 and 2010, this site received the highest score for this metric (Table 10). Nine top carnivore species were collected during 2009, while ten were collected during 2010 (spotted bass was collected during 2010 but not during 2009).

During 2009 and 2010, four of the five diversity metrics received the highest score, indicating that fish community diversity in Watts Bar Reservoir forebay is good.

(2) The capacity for the community to sustain itself through cyclic seasonal change Site downstream of WBN (Inflow scoring criteria)

With the exception of 1998, autumn RFAI sampling was conducted downstream of WBN from 1993 to 2010. RFAI scores during this period have averaged a score of 45 "Good" and are shown in Table 15.

The composition of the autumn sample should be indicative of the ability of the fish community to withstand the stressors of an annual seasonal cycle. The numbers of indigenous species collected during autumn RFAI samples downstream of WBN during 1993 to 2010 are shown in Figure 14. During this time period, the number of indigenous species ranged from 24 to 34 and the average number of indigenous species was 29. During 2009 and 2010, 31 indigenous species were collected which indicates that a diverse fish community has continued to persist and has exhibited the ability to sustain itself through cyclic seasonal change.

Percentage of anomalies (< 2% required for highest score)

The percentage of anomalies (i.e. visible lesions, bacterial and fungal infections, parasites, muscular and skeletal deformities, and hybridization) in the autumn sample should also be indicative of the ability of the fish community to withstand the stressors of an annual seasonal cycle. During 2009 and 2010, the percentage of anomalies was low (Table 9)

Site upstream of WBN (Forebay scoring criteria)

With the exception of 1995 and 1997, autumn RFAI sampling was conducted upstream of WBN from 1993 to 2010. RFAI scores during this period are shown in Table 15. During this time period, RFAI scores have averaged a score of 42 "Good."

The numbers of indigenous species collected during autumn RFAI samples downstream of WBN during 1993 to 2010 are shown in Figure 15. During this time period, the number of indigenous species ranged from 26 to 31 and the average number of indigenous species was 28. During 2009 and 2010, 28 indigenous species were collected which indicates that a diverse fish community has continued to persist and has exhibited the ability to sustain itself through cyclic seasonal change.

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Percentage of anomalies (< 2% in gill net and electrofishing samples required for highest score)

During 2009 and 2010, the percentage of anomalies was very low (2009 electrofishing 0.4%;

2009 gill net 0.9%; 2010 electrofishing 1.5%; 2010 gill net 0%;), resulting in the highest score for this metric (Table 10).

(3) The presence of necessary food chain species Site downstream of WBN During autumn 2009, insectivores comprised 82.3%, omnivores comprised 8.5%, top carnivores comprised 7.2%, planktivores comprised 1.4%, and benthic invertivores comprised 0.7% of the overall fish sample downstream of WBN. Proportions of insectivores greatly exceeded the average proportion observed in historical upper mainstem Tennessee River reservoir inflow areas, which consequently lowered proportions of all other trophic guilds (Tables 2 and 3). This was primarily due to collection of a high number of bluegill which consisted of 53.4% of the overall number of fish collected (Tables 9 and 11). The proportions of omnivores and planktivores were lower than average, which exceeded the expectations calculated from historical data. The proportions of benthic invertivores and top carnivores were low and did not meet the average proportional expectations.

The composition of the fish community during autumn 2010 was somewhat different than in 2009. The proportion of insectivores (69.7%) and planktivores (0.1%) decreased; proportions of omnivores (14.7%), top carnivores (11.5%), and benthic invertivores (3.9%) increased; and a very low proportion of herbivores (0.1%) was present. The proportions of insectivores, omnivores, planktivores, and herbivores exceeded expectations, while the proportions of benthic invertivores and top carnivores were below the average expectations for upper mainstem inflow areas (Tables 2 and 3). Once again, the proportion of insectivores was high, primarily due to collection of a high number of inland silversides which consisted of 52.7% of all fish collected (Tables 9 and 12).

Overall fish diversity was high at this site during 2009 and 2010. During 2009, trophic levels were represented with 11 insectivorous species, 11 top carnivore species, 6 omnivorous species, 4 benthic invertivore species, and 1 planktivorous species (Table 11). The number of species for each observed trophic guild met or exceeded expectations with the exception of omnivores which were below the average expectations. During 2010, trophic levels were represented with 10 insectivorous species, II top carnivore species, 6 omnivorous species, 6 benthic invertivore species, 1 planktivorous species, 1 herbivorous species (Table 12). During 2009, the number of species for each observed trophic guild met or exceeded expectations with the exception of omnivores which were below the average expectations.

Site upstream of WBN During autumn 2009, insectivores comprised 71.8%, omnivores comprised 8.8%, top carnivores comprised 13.3%, planktivores comprised 4.2%, and benthic invertivores comprised 1.9% of the overall fish sample upstream of WBN. The proportions of insectivores, omnivores, and planktivores exceeded expectations, while the proportions of benthic invertivores and top carnivores were below the average expectations for upper mainstem forebay areas (Tables 2 and 15

3). The proportion of insectivores was high, primarily due to collection of a high number of inland silversides and bluegill which consisted of 58.6% of all fish collected (Tables 10 and 13).

The composition of the fish community during autumn 2010 was similar to 2009. The proportion of insectivores (71.2%), top carnivores (11.3%), and benthic invertivores (2.6%)

changed very little, while omnivores increased (14.9%) and planktivores were not encountered.

The proportions of insectivores and omnivores exceeded expectations, the proportion of benthic invertivores met expectations, and the proportion of top carnivores was below the average expectation for upper mainstem forebay areas (Tables 2 and 3). The proportion of insectivores was high, primarily due to collection of a high number of bluegill which consisted of 46.5% of all fish collected (Tables 10 and 14).

Overall fish diversity was high at this site during 2009 and 2010. During 2009, trophic levels were represented with 9 insectivorous species, 10 top carnivore species, 6 omnivorous species, 5 benthic invertivore species, and 1 planktivorous species (Table 13). During 2010, trophic levels were represented with 11 insectivorous species, 10 top carnivore species, 6 omnivorous species, and 5 benthic invertivore species (Table 14). During both years, the number of species for each observed trophic guild met or exceeded expectations.

(4) A lack of domination by pollution-tolerant species Site downstream of WBN Five pollution intolerant species were collected during 2009, while seven were collected during 2010. Brook silverside was collected during 2009 but not during 2010, while river redhorse, rock bass, and skipjack herring were collected during 2010 but not during 2009. This RFAI metric received the highest score during both years (Table 9).

Because a healthy benthic macroinvertebrate community is required to support a diverse benthic invertivore fish community, the prescence of several species of benthic invertivores can indicate good water quality conditions. Four benthic invertivore species were collected during 2009, while six benthic invertivores were collected during 2010 (Table 9). Both years received the mid-range score for this metric (> 6 benthic invertivore species required for the highest score).

Percentage of tolerant individuals (< 29% required for highest score)

During 2009, 33.8% of the fish collected were tolerant individuals, resulting in the mid-range score for this metric (Table 9). A majority of these individuals consisted of bluegill (21.1%),

followed by gizzard shad (5.9%). During 2010, 73.0% of individuals were tolerant, predominantly due to large numbers of bluegill (53.4%), resulting in the lowest score for this metric (Table 9).

Percentage of omnivores (< 27% required for highest score)

Omnivores consisted of 8.5% of the overall sample during 2009 and 14.7% during 2010, resulting in the highest score for this metric both years (Table 9). Expected proportions of omnivores in upper mainstem Tennessee River reservoir inflows are 32.3 to 57.5% (Table 2).

Proportions of omnivores during 2009 and 2010 exceeded expectations, indicating good water quality conditions.

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Percent dominance by one species (< 23% required for highest score)

This metric received the lowest score during 2009 and 2010. The 2009 sample was dominated by inland silversides (non-indigenous) and the 2010 sample was dominated by bluegill (Table 9).

Site upstream of WBN Five pollution intolerant species were collected during 2009, while six were collected during 2010. River redhorse was collected during 2009 but not during 2010, while black redhorse and longear sunfish were collected during 2010 but not during 2009. This RFAI metric received the highest score during both years (Table 10).

Percentage of tolerant individuals (< 31% in electrofishing samples; < 14% in gill net samples required for highest score)

During 2009, 54.8% of the fish collected during electrofishing were tolerant individuals, resulting in the mid-range score for this metric (Table 10). A majority of these individuals consisted of bluegill (34.5%), followed by spotfin shiner (7.5%). During 2010, 78.1% of individuals collected during electrofishing were tolerant, predominantly due to large numbers of bluegill (34.5%), resulting in the lowest score for this metric. During 2009, 23.7% of the fish collected during gill netting were tolerant individuals, resulting in the mid-range score for this metric (Table 10). A majority of these individuals consisted of gizzard shad (15.9%), followed by largemouth bass (6.4%). During 2010, 44.3% of individuals collected during gill netting were tolerant, predominantly due to large numbers of gizzard shad (35.7%), resulting in the lowest score for this metric.

Percentage of omnivores (< 24% in electrofishing samples and <17% in gill net samples required for highest score)

Omnivores consisted of 6.2% of the overall electrofishing sample during 2009 and 9.9% during 2010, resulting in the highest score for this metric both years (Table 10). In gill net samples, omnivores consisted of 25.4% during 2009 and 47.9% during 2010, resulting in the mid-range score and the lowest score, respectively, for this metric.

Percent dominance by one species (< 25% in electrofishing samples and <15% in gill net samples required for highest score)

This metric received the lowest score during 2009 and 2010 for the gill net portion and during 2010 for the electrofishing portion. The 2009 and 2010 electrofishing samples were dominated by bluegill, the 2009 gill net samples were dominated by yellow bass, and the 2010 gill net samples were dominated by gizzard shad (Table 10).

(5) Indigenous Site downstream of WBN (Inflow scoring criteria)

Percentage of non-indigenous species (< 2% required for highest score)

During 2009, 31 indigenous and two non-indigenous species (common carp, 0.1% and inland silverside, 52.6%) were collected compared to 31 indigenous and four non-indigenous species (inland silverside, 1.0%; alewife, 0.1%; common carp, 0.5%; and yellow perch, 0.1%) during 2010 (Table 9). During 2009, this site received the lowest score due to collection of large numbers of inland silversides. Although more non-indigenous species were collected during 2010, this metric received the highest score due to a low overall percentage.

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Inland silversides have successfully invaded the entire mainstem Tennessee River. They were first collected in Chickamauga Reservoir during 2004, and have been observed at much lower densities until 2009. All of the aforementioned non-indigenous species are considered aquatic nuisance species (Table 16).

Site upstream of WBN (Forebay scoring criteria)

Percentage of non-indigenous species (< 2% in electrofishing samples; < 8% in gill net samples required for highest score)

During 2009, 28 indigenous and three non-indigenous species (common carp, 0.04%, inland silverside, 33.5%, and striped bass, 2.7%) were collected compared to 28 indigenous and three non-indigenous species (common carp, 0.3%; inland silverside, 4.6%; and yellow perch, 0.3%)

during 2010 (Table 10). During 2009, this site received the highest score for the gill net portion and the lowest score for the electrofishing portion due to collection of large numbers of inland silversides. This species was first collected in Watts Bar Reservoir during 2002, and have been observed at much lower densities until 2009. During 2010, this site received the lowest score for the electrofishing portion but the percentage of non-indigenous species was much lower than observed during 2009. This site received the highest score for the gill net portion due to a low percentage of non-indigenous species.

All of the aforementioned non-indigenous species, with the exception of striped bass, are considered aquatic nuisance species (Tables 16 and 17).

Fish Community Summary Site downstream of WBN (TRM 529-Chickamauga inflow)

Analysis of the five characteristics of BIP and their respective metrics indicated the site downstream of WBN was similar to the previous year and that this portion of Chickamauga Reservoir supported a diverse fish community during 2010. When compared to 2009, the 2010 sample contained two additional benthic invertivore and intolerant species, a much higher percentage of tolerant individuals (primarily due to high numbers of bluegill), a much lower percentage of non-indigenous species, a higher percentage of top carnivores, a lower catch rate, and a slightly higher percentage of anomalies.

During 2009, 31 indigenous species and 33 representative important species were collected at this site. During 2010, 31 indigenous species and 35 representative important species were collected at this site (Table 16). Representative important species are defined in EPA guidance as those species which are representative in terms of their biological requirements of a balanced, indigenous community of fish, shellfish, and wildlife in the body of water into which the discharge is made (EPA and NRC 1977).

Three species were collected at the downstream site (spotted sucker, logperch, and alewife) which are considered thermally sensitive (Table 16). Water temperatures greater than 32.2 0C (90'F) are known to be lethal to the aforementioned species (Yoder et al. 2006). Two 18

commercially valuable species and 21 recreationally valuable species were also collected at this site during 2010 (Table 16).

RFAI scores have an intrinsic variability of +3 points. This variability comes from various sources, including annual variations in air temperature and stream flow; variations in pollutant loadings from nonpoint sources; changes in habitat, such as extent and density of aquatic vegetation; natural population cycles and movements of the species being measured (TWRC 2006). Another source of variability arises from the fact that nearly any practical measurement, lethal or non-lethal, of a biological community is a sample rather than a measurement of the entire population. As long as the score is within the 6-point range, there is no certainty that any real change has taken place beyond method variability.

RFAI scores for the inflow site downstream from the WBN thermal discharge have averaged a score of 45 during the 17 sample years from 1993 to 2010 (Table 15). Scores from every sample year 'were > 70% of the highest attainable score of 60 indicating that BIP had been maintained.

The greatest score difference between consecutive sample years at this site was six points, which has been observed twice throughout the duration of RFAI sampling at this site (Table 15).

Site upstream of WBN (TRM 531-Watts Bar forebay)

Analysis of the five characteristics of BIP and their respective metrics indicated the site upstream of WBN was similar to the previous year and that this portion of Watts Bar Reservoir supported a diverse fish community during 2010. When compared to the 2009 sample, the 2010 sample contained a higher percentage of tolerant individuals in both electrofishing and gill net samples, due to collection of higher proportions of bluegill and gizzard shad. The percentage of omnivores in the gill net sample increased considerably from the previous year. Aside from these two differences, the 2009 and 2010 samples were fairly similar.

Twenty-eight indigenous species and 32 representative important species were collected at this site during 2010 (Table 17). Two species were collected at this site (spotted sucker and logperch) which are considered thermally-sensitive (Table 17). Two commercially valuable species and 20 recreationally valuable species were also collected at this site during 2010 (Table 17).

RFAI scores for Watts Bar Reservoir forebay site have averaged a score of 42 during the 17 sample years from 1993 to 2010 (Table 15). Scores from 9 of the 17 sample years were > 70%

of the highest attainable score of 60.

Other sites within Chickamauga Reservoir Other RFAI samples in Chickamauga Reservoir (transition TRM 490.5, forebay TRM 472.3, and embayment Hiwassee River Mile 8.5), with the exception of TRM 482, have averaged scores >

42 from 1993 to 2010 which are > 70% of the highest attainable score of 60 indicating that BIP had been maintained throughout Chickamauga Reservoir (Table 15). The forebay site located at TRM 482 has averaged a score of 41, which is 68% of the highest attainable score. Long term trends in RFAI scores do not indicate that overall fish community health, diversity, and structure has declined in the vicinity of WBN or throughout Chickamauga Reservoir.

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Benthic Macroinvertebrate Community Benthic macroinvertebrate data collected during autumn 2010 from TRM 527.4 downstream from WBN resulted in a RBI score of 21 ("Fair"), which was two points lower than 2009 (Table 18). A difference of four points or less between the previous sample year is used to define "similar" conditions between the two samples; therefore, similar conditions have existed downstream of WBN during the past four sample years (Table 18).

Benthic macroinvertebrate data collected during autumn 2010 from TRM 533.3 upstream from WBN above Watts Bar Dam resulted in a RBI score of 13 ("Poor"), which was 2 points higher than the 2009 score (Table 18). Similar conditions have existed at this site during the past six sample years (Table 18). Because the upstream site is separated from the downstream site by Watts Bar dam and is within a forebay zone rather than an inflow zone, it will be compared to the previous sample at this site for explanation of upstream conditions that could affect the downstream site in the Chickamauga inflow.

The following provide an explanation of 2010 results for each metric for the downstream and upstream sites with a comparison to 2009 results:

Site downstream of WBN (Inflow scoring criteria)

Average number of taxa (> 5.8 required for highest score)

An average of 3.9 taxa was collected during 2010, compared to 4.2 during 2009, resulting in the mid-range score for this metric during both years (Table 18).

Proportion of samples with long-lived organisms (which includes Corbicula, Hexagenia mayflies, mussels, and snails; > 0.8 required for highest score)

The metric received the highest score during 2009 and the mid-range score during 2010. All samples collected at this site during 2009 contained at least one long-lived organism, while 60%

of 2010 samples contained a long-lived organism (Table 18).

Average number ofEPT taxa (mayflies, stoneflies, and caddisflies; > 0.8 required for highest score)

An average of 0.4 EPT taxa were present in 2010 samples, resulting in the mid-range score for this metric (Table 18). EPT taxa represented 6.4 % of the average density of organisms per meter2 (Table 19). No EPT taxa were collected during 2009, resulting in the lowest score for this metric (Table 18).

Average proportion of oligochaete individuals (_ 20 required for highest score)

The average proportion of oligochaete individuals in each sample was low during both 2009 (0.6%) and 2010 (0.8%), resulting in the highest score for this metric during both years (Table 18). Oligochaetes are considered tolerant of poor water quality conditions; a low proportion of Oligochaetes in the samples are an indication of good water quality conditions.

Proportion of total abundance comprised by two dominant taxa (< 78.7 required for highest score) 20

During 2010, the proportion of total abundance comprised by the two most dominant taxa was 78%, resulting in the highest score for this metric (Table 18). The two most dominant taxa were Corbicula and chironomids (Table 19). During 2009, the proportion of total abundance comprised by the two most dominant taxa was 92%, resulting in the lowest score for this metric (Table 18). The two most dominant taxa were Corbicula and amphipods (Table 19). Corbicula are long-lived and large numbers can indicate good water quality conditions. Amphipods are not typically tolerant of polluted waters, and are sometimes used as bio-indicators in water quality assessments.

Average density excluding chironomids and oligochaetes (> 1,153 required for highest score)

Many taxa of chironomids and oligochaetes are very tolerant of poor water quality conditions; a dominance of these taxa could indicate water quality degradation. During 2009, densities excluding chironomids and oligochaetes were average, resulting in the mid-range score for this metric (Table 18). Densities of non-chironomid and oligochaete taxa were lower during 2010, resulting in the lowest score for this metric. Densities of oligochaetes were the same between years, but chironomids were present in higher densities during 2010; no chironomids were collected during 2009 (Table 19).

Proportion of samples containing no organisms (no samples lacking organisms required for highest score)

Two of the 10 samples were void of organisms during 2010, resulting in the lowest score for this metric. There were no samples which were void of organisms during 2009 (Table 18).

Site upstream of WBN (Forebay scoring criteria)

Average number of taxa (> 4.8 required for highest score)

An average of 2.2 taxa was collected during 2009 compared to 2.4 during 2010, which resulted in the lowest score for this metric during both years (Table 18).

Proportion of samples with long-lived organisms (which includes Corbicula, Hexagenia mayflies, mussels, and snails; > 0.8 required for highest score)

This metric received the lowest score during 2009 and 2010 (Table 18). No 2010 samples, contained long-lived organisms, while 20% of 2009 samples contained long-lived organisms (snails and Corbicula) (Tables 18 and 19).

Average number ofEPT taxa (mayflies, stoneflies, and caddisflies; > 0.8 required for highest score)

An average of 0.2 EPT taxa were present in 2010 samples and no EPT taxa were present in 2009 samples, resulting in the lowest score for this metric during both years (Table 18).

Average proportion of oligochaete individuals (_ 14.8 required for highest score)

The average proportion of oligochaete individuals in each sample was average during 2009 (28.5%) and during 2010 (16.7%), resulting in the mid-range score for this metric during both years (Table 18).

21

Proportion of total abundance comprised by two dominant taxa (< 81.3 required for highest score)

During 2009 and 2010, the proportion of total abundance comprised by the two most dominant taxa was 96.8% and 95.5%, respectively, resulting in the lowest score for this metric (Table 18).

Taxa were dominated by chironomids and leeches during 2009 and by oligochaetes and chironomids during 2010 (Table 19).

Average density excluding chironomids and oligochaetes (> 236 required for highest score)

This metric received the lowest score during 2009 and 2010 (Table 18). Relatively low densities of additional taxa were collected during 2009 and 2010 (Table 19).

Proportion of samples containing no organisms (no samples lacking organisms required for highest score)

During 2009, 1 of the 10 samples contained no organisms, which resulted in the mid-range score for this metric (Table 18). There were no samples which were void of organisms during 2010 (Table 18).

Benthic Macroinvertebrate Community Summary Site downstream of WBN (TRM 527.4-Chickamauga inflow)

The 2010 sample contained EPT taxa and was less dominanted by two particular taxa. This sample received lower scores than the previous year for three of the seven metrics due to a lower percentage of long-lived organisms, higher densities of chironomids, and contained two samples void of organisms. This site received its lowest RBI score since this site was first sampled in 2001, but was similar to the previous three years (Tables 18 and 20).

Site upstream of WBN (TRM 533.3-Watts Bar forebay)

Although this site scored 2 points higher during 2010, taxa density was lower. Five of the 7 metrics received the lowest score during both 2009 and 2010. During 2009, 2 of the 7 metrics received a mid-range score, while 1 received the highest score and 1 received the mid-range score during 2010. Watts Bar Reservoir forebay RBI data collected between 1994 and 2010 reflect little change in the overall ecological health of the benthic macroinvertebrate community at this site; 12 of the 14 sample seasons scored in the "Poor" range, while the 1996 and 2009 samples scored "Very Poor" (Table 20).

Other sites within Chickamauga Reservoir The Chickamauga Reservoir VS inflow zone (TRM 518), transition zone (TRM 490.5), and forebay (TRM 482.0 and 472.3) sampling sites are included to provide additional information on the downstream integrity of the benthic macroinvertebrate community (Table 20). These sites are located > 37 river miles downstream of WBN and sampling results should not reflect temperature effects from the plant. All of these sites have a long-term average score of "Good" (Table 20).

22

Chickamauga Reservoir Flow and Temperature Near WBN Average daily flows from Watts Bar Dam from October 2009 to November 2010 are shown in Figure 16. Daily average flows were higher during winter months and lower during spring, summer, and autumn months compared to historical daily average flows from 1976 through 2009.

Average daily water temperatures immediately below Watts Bar Dam and average daily water temperatures downstream of the WBN SCCW discharge mixing zone, recorded during October 2009 to November 2010 are shown in Figure 17. There was very little difference in water temperature above and below the discharge throughout the year.

Water Quality Parameters at Fish Sampling Sites During RFAI Samples Observed values of water temperature, dissolved oxygen, conductivity, and pH are listed for each profile with corresponding water depth in Tables 21 and 22. Water temperatures at the sampling site upstream of WBN ranged from 74 'F at 22 meters deep to 76 'F at 0.3 meters deep (Table 21). Downstream of WBN, water temperatures were between 75 and 76 'F at all depths (maximum depth was 6 meters, compared to 22 meters upstream of WBN) (Table 22).

Dissolved oxygen concentrations ranged from 5.6 to 6.2 ppm at the sampling site downstream of WBN (Table 22). Dissolved oxygen readings taken at the sampling site upstream of WBN ranged from 0.65 to 6.89 ppm (Table 21). Conductivity was slightly higer downstream of WBN and pH readings were similar upstream and downstream of WBN (Tables 21 and 22).

23

Literature Cited EPA (U.S. Environmental Protection Agency) and NRC (U.S. Nuclear Regulatory Commission). 1977 (draft). Interagency 316(a) technical guidance manual and guide for thermal effects sections of nuclear facilities Environmental Impact Statements. U.S.

Environmental Protection Agency, Office of Water Enforcement, Permits Division, Industrial Permits Branch, Washington, DC.

Etnier, D.A. and W.C. Starnes. 1993. The Fishes of Tennessee. University of Tennessee Press, Knoxville, Tennessee, 681 p.

Hickman, G. D. and T. A. McDonough. 1996. Assessing the Reservoir Fish Assemblage Index-A potential measure of reservoir quality. In: D. DeVries (Ed.) Reservoir symposium-Multidimensional approaches to reservoir fisheries management. Reservoir Committee, Southern Division, American Fisheries Society, Bethesda, MD. Pp 85-97.

Hubert, W. A., 1996. Passive capture techniques, entanglement gears. Pages 160-165 in B. R.

Murphy and D. W. Willis, editors. Fisheries techniques, 2nd edition. American Fisheries Society Bethesda, Maryland, USA.

Jennings, M. J., L. S. Fore, and J. R. Karr. 1995. Biological monitoring of fish assemblages in the Tennessee Valley reservoirs. Regulated Rivers 11:263-274.

McDonough, T.A. and G.D. Hickman. 1999. Reservoir Fish Assemblage Index development: A tool for assessing ecological health in Tennessee Valley Authority impoundments. In:

Assessing the sustainability and biological integrity of water resources using fish communities. Simon, T. (Ed.) CRC Press, Boca Raton, pp 523-540.

Plafkin, J.L., Barbour, M.T., Porter, K.D., Gross, S.K., and Hughes, R.M. (1989). Rapid assessment protocols for use in streams and rivers: benthic macroinvertebrates and fish.

EPA/444/4-89-001, Washington DC, USA.

Reynolds, J. B., 1996. Electrofishing. Pages 221-251 in B. R. Murphy and D. W. Willis, editors. Fisheries techniques, 2nd edition. American Fisheries Society Bethesda, Maryland, USA.

TWRC 2006. Strategic Plan, 2006-2012. Tennessee Wildlife Resources Commission, Nashville, TN. March 2006. pp 124-125. http://tennessee.gov/twra/pdfs/StratPlan06-1 2.pdf Yoder, C.O., B.J. Armitage, and E.T. Rankin. 2006. Re-evaluation of the technical justification for existing Ohio River mainstem temperature criteria. Midwest Biodiversity Institute, Columbus, Ohio.

24

SCCW Intake SCCW Discharac 770 Intake Pumping Station Submerged Mulstiport Diffusers 30 Feet Figure 1. Map of WBN showing location of SCCW intake and discharge.

25

Figure 2. RFAI electrofishing locations, represented by black squares, downstream or within the thermal discharge of Watts Bar Nuclear Plant, Chickamauga Reservoir inflow.

26

Figure 3. RFAI electrofishing and gill net locations upstream of Watts Bar Nuclear Plant, Watts Bar Reservoir forebay. Black squares represent electrofishing locations; red circles represent gill net locations.

27

TRANSECT 2 TRANSECT 3 TRANSECT 8-IT RANSECT 7 4

TRANSECT6 KJTRANSECT 5

• yTRANSECT 4 PRANSECT 3 MILE MARKE:!--R A

SC I

05 2

10

[Kilometers Figure 4. Benthic habitat transects within the fish community sampling area upstream and downstream of WBN. SAHI data was collected on the left and right descending banks at endpoints of each transect. Benthic macroinvertebrate samples were collected along transect 1 downstream of WBN and along transect 8 upstream of WBN.

28

Figure 5. Locations of Watts Bar Nuclear Plant water temperature monitoring stations. Station 30 records water temperature upstream of the thermal discharge; stations 33 and 34 measure water temperature below the SCCW mixing zone. Outfall 113 is the SCCW discharge.

29

I ---

M

]iSubstrate

• NDpth~ft) of water wbere sampla was taken 4?0 e

g

ý z

TNA -E&T -ES&R le 0

[

GEOGRAPHIC I*NF*MTION & ENGINEERING SEP* BER 2010 Figure 6. Substrate composition at ten equally spaced points per transect across the Tennessee River downstream of WBN. *Water depth (ft) at each point is denoted. Transects 1 and 2 are the most downstream transects of the eight transects in the vicinity of WBN discharge.

30

Substrate Type

-0

\\'

04__e___

• Depth(ft) of water where sample was takeni TWA-E&T - ES&R GEOGRAPHIC INFORMATION & ENGINEERING Figure 7. Substrate composition at ten equally spaced points per transect across the Tennessee River downstream of WBN. *Water depth (ft) at each point is denoted.

31

Substrate jZye

-4b

• Dpth(ft) of water where sample was taken TVA - E&T - ES&R GEOGRAPHIC INFORMATION & ENGINEERING SEPTEMBER 2010 Figure 8. Substrate composition at ten equally spaced points per transect across the Tennessee River downstream of WBN. *Water depth (ft) at each point is denoted.

32

Substrate Type N

• Depth(ft) of water where sample was taken g,

\\0TVA-E&T-ES&R GEOGRAPHIC INFORMATION & ENGINEERING

'IV COv x*SEPTEMBER 2010 Figure 9. Substrate composition at ten equally spaced points per transect across the Tennessee River in the vicinity of the WBN discharge. *Water depth (ft) at each point is denoted.

33

lIII Substrate Type N

• Depth(ft) of water where sample was taken

-A co Cj CPO teý TVA - E&T - ES&R GEOGRAPHIC INFORMATION & ENGINEERING SEPTEMBER 2010 Figure 10. Substrate composition at ten equally spaced points per transect across the Tennessee River upstream of WBN (Watts Bar Reservoir forebay). *Water depth (ft) at each point is denoted. Transects 1 and 2 are the most downstream transects of the eight transects upstream of Watts Bar Dam.

34

Substrate e

• Depth(fl) of water where sample C-10-1 -,ýp 4ý1 6

e\\

\\OTVA

-E&T -ES&R C10ý1 GEOGRAPHIC INFORMATION & ENGINEERIN SEPTEMBER 2010 Figure 11. Substrate composition at ten equally spaced points per transect across the Tennessee River upstream of WBN (Watts Bar Reservoir forebay). *Water depth (fi) at each point is denoted.

35

ISubstrate Type

• Depth(ft) of water where sample was taken OA?

TVA - E&T-ES&R GEOGRAPHIC INFORMATION & ENGINEERING SEPTEMBER 2010 Figure 12. Substrate composition at ten equally spaced points per transect across the Tennessee River upstream of WBN (Watts Bar Reservoir forebay). *Water depth (ft) at each point is denoted.

36

U.:)

I 01 I... o l1 i 3 Kilometers Substrate Type e

O e,

Cp

• Depth(ft) of water where sample was taken TVA-E&T-ES&R GEOGRAPHIC INFORMATION & ENGINEERING SEPTEMBER 2010 Figure 13. Substrate composition at ten equally spaced points per transect across the Tennessee River upstream of WBN (Watts Bar Reservoir forebay). *Water depth (ft) at each point is denoted.

37

35 30 In 26 2

26 27 20 S25 20 M 2 15 0

" 10 5

0 7

i 1-1 1

1 1

mn n

ID r-Ch 0

1-4 rN mn It In~ ID 00 IM(

0 0'1 0

0) 0')

CA

0) 0 0

0 0

0 0

0 0

0 0

r-(")

0")

0)

)

0)

0) 0 0

0 0

0 0

0 0

0 0

0

-4 r

-I r

-i

-4 (N

C4 (N

(N (N4 rN IN C(4 (N

(N IN Year Figure 14. Number of indigenous species collected during every RFAI sample downstream of WBN (TRM 529), 1993 to 2010.

35 30 S25 20

0. 15.

O" 20 a

0 I'D 3"

10

-31 31 31 29 29 27 27 20 27 20 28 26 26 5

! ! 1 i i I I I I I I i I I 0 -I M

1 00 Ml 0

v-1 -N M

T In W

t-00 C)i 0

C71 C71 C

0 C7 0

0 0

0 0

0 0

0 0

0 r-4

0)

0)

M~

0)

Ms 0

0 0

0 0

0 0

0 0

0

-4 V-4 r-4

.- 1 (N4 N

(N IN (N

IN (N

(N4 (N

(j IN Year Figure 15. Number of indigenous species collected during every RFAI sample upstream of WBN (TRM 531), 1993 to 2010.

38

120000 100000 1l0000 Historical Daily Average 1976-20 80000 60000 0

20000 2000 Figure 16. Daily average flows (cubic feet per second) from Watts Bar Dam, October 2009 through November 2010 and historic daily flows averaged for the same period 1976 through 2009.

39

90 80 70 60o 4

50 CL E

40 i-40 S30

-,Upstream of WBN Discharge 20

-Downstream of WBN 10 Discharge 0

I I

I Date Figure 17. Average daily water temperatures immediately below Watts Bar Dam compared to average daily water temperatures downstream of the WBN SCCW discharge mixing zone, October 2009 to November 2010.

40

Table 1. Shoreline Aquatic Habitat Index (SAHI) metrics and scoring criteria.

Metric Scoring Criteria Score Cover Stable cover (boulders, rootwads, brush, logs, aquatic vegetation, artificial structures) in 25 5

to 75 % of the drawdown zone Stable cover in 10 to 25 % or > 75 % of the drawdown zone 3

Stable Cover in < 10 % of the drawdown zone 1

Substrate Percent of drawdown zone with gravel substrate > 40 5

Percent of drawdown zone with gravel substrate between 10 and 40 3

Percent substrate gravel < 10 1

Erosion Little or no evidence of erosion or bank failure. Most bank surfaces stabilized by woody 5

vegetation.

Areas of erosion small and infrequent. Potential for increased erosion due to less desirable 3

vegetation cover (grasses) on > 25 % of bank surfaces.

Areas of erosion extensive, exposed or collapsing banks occur along > 30% of shoreline.

1 Canopy Cover Tree or shrub canopy > 60 % along adjacent bank 5

Tree or shrub canopy 30 to 60 % along adjacent bank 3

Tree or shrub canopy < 30 % along adjacent bank 1

Riparian Zone Width buffered > 18 meters 5

Width buffered between 6 and 18 meters 3

Width buffered < 6 meters I

Habitat Habitat diversity optimum. All major habitats (logs, brush, native vegetation, boulders, 5

gravel) present in proportions characteristic of high quality, sufficient to support all life history aspects of target species. Ready access to deeper sanctuary areas present.

Habitat diversity less than optimum. Most major habitats present, but proportion of one is 3

less than desirable, reducing species diversity. No ready access to deeper sanctuary areas.

Habitat diversity is nearly lacking. One habitat dominates, leading to lower species diversity. No ready access to deeper sanctuary areas.

Gradient Drawdown zone gradient abrupt (> 1 meter per 10 meters). Less than 10 percent of 5

shoreline with abrupt gradient due to dredging.

Drawdown zone gradient abrupt. (> 1 meter per 10 meters) in 10 to 40 % of the shoreline 3

resulting from dredging. Rip-rap used to stabilize bank along > 10 % of the shoreline.

Drawdown zone gradient abrupt in > 40 % of the shoreline resulting from dredging.

1 Seawalls used to stabilize bank along > 10 % of the shoreline.

41

Table 2. Expected values for upper mainstem Tennessee River reservoir inflow and forebay zones calculated from data collected from 600 electrofishing runs in upper mainstem Tennessee River reservoir inflow areas and from 900 electrofishing runs and 600 overnight experimental gill net sets in forebay areas of upper mainstem Tennessee River reservoirs. This trisection is intended to show less than expected (-), expected or average (Avg), and above expected or average (+) values for trophic level proportions and species occurring within each reservoir zone in upper mainstem Tennessee River reservoirs.

Upper Mainstem Tennessee River Inflow Upper Mainstem Tennessee River Forebay Proportion Number of species Proportion Number of species Trophic Guild Avg

+

Avg

+

Avg

+

Avg

+

Benthic Invertivore

< 6.4 6.4 to 12.3

> 12.3

< 3 3 to 6

> 6

< 2.2 2.2 to 4.2

> 4.2

< 2 2 to 4

> 4 Insectivore

<26.9 26.9 to 49.2

>49.2

<3 3 to 7

> 7

<34.2 34.2 to 62.6

> 62.6

<4 4 to 8

> 8 TopCarnivore

<14.6 14.6to25.7

>25.7

<4 4to8

>8

<18.8 18.8to33.4

>33.4

<4 4to8

>8 Omnivore

>57.5 32.3 to 57.5

<32.3

>5 3to5

<3

>40.1 21.4 to 40.1

<21.4

>6 3to6

<3 Planktivore

> 11.6 5.8 to 11.6

< 5.8 0

1

> 1

> 10.4 5.2 to 10.4

< 5.2 0

1

>1 Parasitic

< 0.1 0.1 to 0.2

> 0.2 0

1

> 1

< 0.4 0.4 to 0.8

> 0.8 0

1

> 1 Herbivore

> 0.3 0.2 to 0.3

< 0.2 0

1

> 1 42

Table 3. Average trophic guild proportions and average number of species, bound by confidence intervals (95 %), expected in upper mainstem Tennessee River reservoir inflow and forebay zones. These values were calculated from data collected from 600 electrofishing runs in upper mainstem Tennessee River reservoir inflow areas and from 900 electrofishing runs and 600 overnight experimental gill net sets in forebay areas of upper mainstem Tennessee River reservoirs.

Inflow Forebay Trophic Guild Average Average Number Average Average Number TrophicGuild Proportion of Species Proportion of Species Benthic Invertivore 8.0+ 1.5 6.2+0.4 2.3+0.4 3.3 +0.3 Insectivore 33.1 +5.9 8.2+0.6 50.4+5.7 8.7+0.5 Top Carnivore 15.5 + 2.9 8.7 + 0.7 19.0 + 2.7 9.9 + 0.3 Omnivore 37.4 + 6.9 5.6 + 0.3 22.4 + 3.5 6.1 + 0.3 Planktivore 1.9+1.4 0.7+0.2 1.8+0.9 1.0+0.1 Parasitic 0.05 + 0.03 0.3 + 0.1 0.05 + 0.05 0.1 + 0.08 Herbivore 0.03 + 0.03 0.1 + 0.1 43

Table 4. RFAI Scoring criteria (2002) for forebay, transition, and inflow sections of Upper Mainstream Tennessee River reservoirs.

Upper Mainstream reservoirs include Chickamauga, Fort Loudoun, Melton Hill, Nickajack, Tellico, and Watts Bar. Inflow scoring criteria were used for the site downstream of WBN. Forebay scoring criteria were used for the Watts Bar Reservoir site upstream of WBN.

Scoring Criteria Forebay Transition Inflow Metric Gear 1

3 5

1 3

5 1

3 5

1. Total species

2. Total Centrarchid species

3. Total benthic invertivores

4. Total intolerant species

5. Percent tolerant individuals

6. Percent dominance by 1 species

7. Percent non-indigenous species

8. Total top carnivore species

9. Percent top carnivores

10. Percent omnivores

11. Average number per run

12. Percent anomalies Combined Combined Combined Combined

<14 14-27

>27

<15 15-29

>29

<14 14-27

>27

<2 2-4

>4

<2 2-4

>4

<3 3-4

>4

<4 4-7

>7

<4 4-7

>7

<3 3-6

>6

<2 2-4

>4

<2 2-4

>4

<2 2-4

>4 Electrofishing Gill netting Electrofishing Gill netting Electrofishing Gill netting

>62%

31-62%

<31%

>62%

31-62%

<31%

>28%

14-28%

<14%

>32%

16-32%

<16%

>50%

25-50%

<25%

>40%

20-40%

<20%

>29%

15-29%

<15%

>28%

14-28%

<14%

>4%

2-4%

<2%

>6%

3-6%

<3%

>16%

8-16%

<8%

>9%

5-9%

<5%

>58%

29-58%

<29%

>46%

23-46%

<23%

>17%

8-17%

<8%

Combined

<4 4-7

>7

<4 4-7

>7

<3 3-6

>6 Electrofishing Gill netting Electrofishing Gill netting Electrofishing Gill netting Electrofishing Gill netting

<5%

5-10%

• >10%

<6%

6-11%

>11%

<25%

25-50%

>50%

<26%

26-52%

>52%

>49%

24-49%

<24%

>44%

22-44%

<22%

>34%

17-34%

<17%

>46%

23-46%

<23%

<121 121-241

>241

<105 105-210

>210

<12 12-24

>24

<12 12-24

>24

>5%

2-5%

<2%

>5%

2-5%

<2%

>5%

2-5%

<2%

>5%

2-5%

<2%

<11%

11-22%

>22%

>55%

27-55%

<27%

<51 51-102

>102

>5%

2-5%

<2%

44

Table 5. Scoring criteria for benthic macroinvertebrate community samples (field-processed) for forebay, transition, and inflow sections of mainstream Tennessee River reservoirs. Inflow scoring criteria were used for the site downstream of WBN.

Forebay scoring criteria were used for the Watts Bar Reservoir site upstream of WBN.

Benthic Community Forebay Transition Inflow Metrics 1

3 5

1 3

5 1

3 5

Average number of taxa

• 2.4 2.5-4.7

_>4.8

• 2.1 2.2-4.3

_4.4

• <2.8 2.9-5.7

->5.8 Proportion of samples with long-lived

• 0.3 0.4-0.7

-Ž0.8

• 0.3 0.4-0.7

-Ž0.8

• <0.3 0.4-0.7

-Ž0.8 organisms Average number of EPT

<0.4 0.5-0.7

>0.8

• 0.3 0.4-0.7

Ž0.8

• 0.3 0.4-0.7

>-0.8 (Ephemeroptera, Plecoptera, Trichoptera)

Average proportion of oligochaete

>Ž29.7 14.9-29.6

<14.8

Ž>28.0 14.0-27.9

• 13.9

Ž40.0 20.1-39.9

<20.0 individuals Average proportion of total abundance

Ž>90.7 81.4-90.6

• 81.3

Ž>87.8 78.8-87.7

• <78.7

Ž!85.0 78.8-84.9

<78.7 comprised by the two most abundant taxa Average density excluding chironomids

• 118 119-235

Ž>236

• <291 292-580

>581

• 568 569-1152

Ž>1153 and oligochaetes Zero-samples - proportion of samples

Ž0.2 0.1 0

>0.2 0.1 0

Ž0.2 0.1 0

containing no organisms 45

Table 6. SAHI scores for 8 shoreline transects located within the RFAI sample reach downstream of WBN in Chickamauga Reservoir inflow, Autumn 2009. Eight shoreline sections were located on the left descending bank (LD) and 8 were located on the right descending bank (RD).

1(LD) 2(LD) 3(LD) 4(LD) 5(LD) 6(LD) 7(LD) 8(LD)

Avg.

Latitude 35.58826 35.59048 35.5924 35.59687 35.60293 35.60751 35.61227 35.61712 Longitude

-84.79591

-84.78782

-84.78342

-84.77759

-84.77477

-84.77464

-84.7752

-84.77593 Aquatic Macrophytes 0%

0%

0%

0%

0%

0%

0%

0%

0%

SAHI Variables Cover 3

5 1

5 3

1 1

1 3

Substrate 5

1 1

1 1

1 1

1 2

Erosion 5

5 5

3 5

5 5

5 5

Canopy Cover 5

5 5

5 5

5 1

1 4

Riparian Zone 5

5 5

5 5

5 1

1 4

Habitat 1

3 1

3 3

1 1

1 2

Slope 1

1 1

1 3

3 1

1 2

Total 25 25 19 23 25 21 11 11 22 Rating Fair Fair Fair Fair Fair Fair Poor Poor Fair 1(RD) 2(RD) 3(RD) 4(RD) 5(RD) 6(RD) 7(RD) 8(RD)

Avg.

Latitude 35.59074 35.5931 35.59475 35.59838 35.60309 35.60717 35.61166 35.61521 Longitude

-84.79699

-84.78904

-84.78563

-84.78133

-84.77867

-84.77826

-84.779

-84.78058 Aquatic Macrophytes 0%

0%

0%

0%

0%

0%

0%

0%

0%

SAHI Variables Cover 5

3 3

3 5

3 5

1 4

Substrate 1

1 1

1 1

1 1

1 1

Erosion 3

5 3

3 5

5 5

5 4

Canopy Cover 5

3 5

5 5

5 1

1 4

Riparian Zone 5

1 5

3 1

1 1

1 2

Habitat 3

3 3

3 3

3 1

1 3

Slope 1

1 1

1 1

1 1

1 1

Total 23 17 21 19 21 19 15 11 19 Rating Fair Fair Fair Fair Fair Fair Poor Poor Fair Scoring criteria: Poor (7-16); Fair (17-26); and Good (27-35).

46

Table 7. SAHI scores for 8 shoreline transects located within the RFAI sample reach upstream of WBN in Watts Bar Reservoir forebay, Autumn 2009. Eight shoreline sections were located on the left descending bank (LD) and 8 were located on the right descending bank (RD).

1(LD) 2(LD) 3(LD) 4(LD) 5(LD) 6(LD) 7(LD) 8(LD)

Avg.

Latitude 35.62819 35.62909 35.62393 35.63842 35.64143 35.65411 35.66239 35.6668 Longitude

-84.77888

-84.79279

-84.79553

-84.79329

-84.80098

-84.77146

-84.79468

-84.77029 Aquatic Macrophytes 0%

0%

0%

0%

0%

0%

0%

0%

0%

SAHI Variables Cover 1

5 5

3 1

5 5

3 4

Substrate 1

1 1

1 1

3 1

1 1

Erosion 3

3 3

3 3

3 5

1 3

Canopy Cover 3

5 5

5 1

5 1

5 4

Riparian Zone 3

5 5

5 1

5 1

5 4

Habitat 1

3 3

3 1

3 3

3 3

Slope 3

5 3

1 1

1 1

1 2

Total 15 27 25 21 9

25 17 19 21 Rating Poor Good Fair Fair Poor Fair Fair Fair Fair I(RD) 2(RD) 3(RD) 4(RD) 5(RD) 6(RD) 7(RD) 8(RD)

Avg.

Latitude 35.6328 35.62579 35.6227 35.63424 35.63902 35.65653 35.65813 35.66878 Longitude

-84.78064

-84.79022

-84.79298

-84.79388

-84.80306

-84.79766

-84.79785

-84.78266 Aquatic Macrophytes 0%

0%

0%

0%

0%

0%

0%

0%

0%

SAHI Variables Cover 3

5 5

1 1

5 5

5 4

Substrate 1

1 1

1 1

1 5

1 2

Erosion 3

5 3

3 5

5 5

5 4

Canopy Cover 5

5 5

5 5

1 1

5 4

Riparian Zone 5

5 5

5 5

1 1

3 4

Habitat 3

3 3

1 1

1 1

1 2

Slope 1

1 1

1 3

1 1

1 1

Total 21 25 23 17 21 15 19 21 21 Rating Fair Fair Fair Fair Fair Poor Fair Fair Fair Scoring criteria: Poor (7-16); Fair (17-26); and Good (27-35).

47,

Table 8. Substrate percentages and average water depth (ft) per transect upstream (8 transects) and downstream (8 transects) of WBN.

% Substrate per transect downstream of WBN 1'

2 3

4 5

6 7

8 AVG Bedrock 18 56 9.5 18.5 46 38.5 47 54.5 36.0 Mollusk shell 31.5 21 51 38.5 22.5 11 24.5 7.5 25.9 Gravel 27 9

23.5 19.5 27.5 46.5 26.5 25 25.6 Cobble 2.5 4

4 7.5 1

3.5 2

9 4.2 Clay 6.5 7.5 1.5 14 0

0 0

0 3.7 Sand 9.5 0.5 7.5 2

2 0.5 0

3 3.1 Detritus 5

0 3

0 0

0 0

0 1.0 Silt 0

2 0

0 0

0 0

1 0.4 Boulder 0

0 0

0 1

0 0

0 0.1 Avg. depth (ft) 26.4 25.1 26.7 21.5 20.3 21.9 23.4 20.6 23.2 Actual depth range: 9.1 to 35.7 ft

% Substrate per transect upstream of WBN 1

2 3

4 5

6 7

8 AVG Silt 27 56 46 47.5 36.5 79.5 60.5 39.5 49.1 Gravel 25.5 12 13.5 4.5 34 11 19.5 16.5 17.1 Bedrock 18.5 0

29 19 9.5 0

9 0

10.6 Clay 10.5 22.5 0

0.5 0

0 0

27 7.6 Sand 9

0 3

17.5 1

5 4.5 10.5 6.3 Detritus 5

6.5 8

9.5 3.5 4

4 3.5 5.5 Cobble 3

0 0

0.5 15.5 0

2.5 0

2.7 Mollusk shell 1.5 3

0.5 1

0 0.5 0

3 1.2 Avg. depth (ft) 29.9 34.5 30.3 40.2 25.2 51.7 43.2 44.1 37.4 Actual depth range: 6.9 to 86.7 ft 48

Table 9. Individual Metric Scores and the Overall RFAI Scores Downstream (TRM 529.0) of Watts Bar Nuclear Plant Discharge, Autumn 2009 and 2010.

2009 TRM 529.0 2010 TRM 529.0 Metric Obs Score Obs Score A. Species richness and composition

1. Number of indigenous species (refer to Tables 11 and 12)

2. Number of centrarchid species (less Micropterus)

3. Number of benthic invertivore species 31 5

31 5

8 Black crappie Bluegill Green sunfish Longear sunfish Redbreast sunfish Redear sunfish Warmouth White crappie 4

Black redhorse Freshwater drum Golden redhorse Spotted sucker

4. Number of intolerant species

5. Percent tolerant individuals 8

Black crappie Bluegill Green sunfish Longear sunfish Redbreast sunfish Redear sunfish Warmouth White crappie 6

Black redhorse Freshwater drum Golden redhorse Logperch River redhorse Spotted sucker 7

Black redhorse Longear sunfish River redhorse 5

Rock bass Skipjack herring Smallmouth bass Spotted sucker 73.0%

Bluegill 53.39%

Bluntnose minnow 0.82%

Common carp 0.46%

Gizzard shad 9.25%

Green sunfish 2.93%

3 Largemouth bass 2.29%

Longnose gar 0.82%

Redbreast sunfish 1.65%

Spotfin shiner 1.28%

White crappie 0.09%

5 3

5 Black redhorse Brook silverside Longear sunfish Smallmouth bass Spotted sucker 33.8%

Bluegill 21.08%

Bluntnose minnow 0.27%

Common carp 0.09%

Gizzard shad 5.86%

Golden shiner 0.63%

Green sunfish 0.49%

Largemouth bass 2.73%

Longnose gar 0.3 1%

Redbreast sunfish 0.8 1%

Spotfin shiner 1.48%

White crappie 0.04%

5 1

49

Table 9. (Continued) 2009 TRM 529.0 2010 TRM 529.0 Metric Obs Score Obs Score

6. Percent dominance by one species 52.7%

53.4%

Inland silverside I

Bluegill 1

7. Percent non-indigenous species

8. Number of top carnivore species B. Trophic composition 52.8%

Common carp 0.09%

Inland silverside 52.64%

11 Black crappie Flathead catfish Largemouth bass Longnose gar Sauger Smallmouth bass Spotted bass Spotted gar White bass White crappie Yellow bass

9. Percent top carnivores

10. Percent omnivores 7.2%

Black crappie 0.40%

Flathead catfish 0.22%

Hybrid bass 0.09%

Largemouth bass 2.73%

Longnose gar 0.3 1%

Sauger 0.04%

Smallmouth bass 0.67%

Spotted bass 1.57%

Spotted gar 0.04%

White bass 0.04%

White crappie 0.04%

Yellow bass 0.99%

8.5%

Bluntnose minnow 0.27%

Channel catfish 1.57%

Common carp 0.09%

Gizzard shad 5.87%

Golden shiner 0.63%

Smallmouth buffalo 0.04%

1.6%

Alewife 0.09%

Common carp 0.46%

Inland silverside 1.01%

Yellow perch 0.09%

11 Black crappie Flathead catfish Largemouth bass Longnose gar Rock bass Skipjack herring Smalimouth bass Spotted bass White bass White crappie Yellow bass 11.5%

Black crappie 0.27%

Flathead catfish 2.11%

Hybrid bass 0.18%

Largemouth bass 2.29%

Longnose gar 0.82%

Rock bass 0.46%

Skipjack herring 0.09%

Smallmouth bass 1.56%

Spotted bass 2.75%

White bass 0.64%

White crappie 0.09%

Yellow bass 0.27%

14.7%

Blue catfish 1.37%

Bluntnose minnow 0.82%

Channel catfish 2.75%

Common carp 0.46%

Gizzard shad 9.25%

Smallmouth buffalo 0.09%

5 5

3 5

50

Table 9. (Continued) 2009 TRM 529.0 2010 TRM 529.0 Metric Obs Score Obs Score C. Fish abundance and health

11. Average number per run 148.7 5

72.8 3

12. Percent anomalies 1.7%

5 3.5%

3 Overall RFAI Score 44 44 Good Good 51

Table 10. Individual Metric Scores and the Overall RFAI Scores Upstream (TRM 531.0) of Watts Bar Nuclear Plant Discharge, Autumn 2009 and 2010.

2009 TRM 531.0 2010 TRM 531.0 Metric Obs Score Obs Score A. Species richness and composition

1. Number of indigenous species (refer to Tables 13 and 14)

2. Number of centrarchid species (less Micropterus)

3. Number of benthic invertivore species

4. Number of intolerant species 28 5

28 5

7 Black crappie Bluegill Green sunfish Redbreast sunfish Redear sunfish Warmouth White crappie 5

Freshwater drum Logperch Northern hog sucker River redhorse Spotted sucker 5

Brook silverside Northern hog sucker River redhorse Smallmouth bass Spotted sucker 54.8%

Bluegill 34.49%

Bluntnose minnow 1.40%

Common carp 0.44%

Gizzard shad 3.9 1%

Green sunfish 2.2 1%

Largemouth bass 3.10%

Redbreast sunfish 1.77%

Spotfin shiner 7.52%

23.7%

Gizzard shad 15.98%

Largemouth bass 6.39%

White crappie 1.37%

8 Black crappie Bluegill Green sunfish 5

Longear sunfish Redbreast sunfish Redear sunfish Warmouth White crappie 5

Black redhorse Freshwater drum 3

Logperch Northern hog sucker Spotted sucker 6

Black redhorse Brook silverside 5

Longear sunfish Northern hog sucker Smallmouth bass Spotted sucker 78.1%

Bluegill 53.3 1%

Bluntnose minnow 2.17%

Common carp 0.33%

1.5 Gizzard shad 6.51%

Green sunfish 4.45%

Largemouth bass 3.26%

Redbreast sunfish 5.2 1%

Spotfin shiner 2.82%

5 3

5

5. Percent tolerant individuals Electrofishing 0.5 Gill Netting 1.5 44.3%

Bluegill 1.43%

Common carp 1.43%

Gizzard shad 35.71%

Largemouth bass 5.0%

White crappie 0.71%

0.5 52

Table 10 (Continued) 2009 TRM 531.0 2010 TRM 531.0 Metric Obs Score Obs Score

6. Percent dominance by one species Electrofishing 34.5%

53.3%

0.5 Gill Netting Electrofishing

7. Percent non-indigenous species isluegill 33.8%

Yellow bass 34.0%

Common carp 0.44%

Inland silverside 33.53%

3.2%

Hybrid striped bass 0.46%

Striped bass 2.74%

l.;

Gill Netting

8. Number of top carnivore species l51uegill 9

Black crappie Flathead catfish Largemouth bass Sauger Smallmouth bass Spotted gar White bass White crappie Yellow bass 35.7%

0.5 Gizzard shad 5.2%

Common carp 0.33%

0.5 Inland silverside 4.56%

Yellow perch 0.33%

2.9%

Common carp 1.43%

2.5 Hybrid striped bass 0.71%

Striped bass 0.7 1%

10 Black crappie Flathead catfish Largemouth bass Sauger 5

Smallmouth bass Spotted bass Spotted gar White bass White crappie Yellow bass 6.1%

Black crappie 0.11%

Flathead catfish 1.41%

0.5 Largemouth bass 3.26%

Smallmouth bass 0.87%

Spotted gar 0.33%

White bass 0.11%

45.7%

Black crappie 3.57%

Flathead catfish 4.29%

Hybrid striped bass 0.71%

2.5 Largemouth bass 5.0%

Sauger 0.71%

Striped bass 0.71%

White bass 5.0%

White crappie 0.71%

Yellow bass 25.0%

0.5 0.5 2.5 5

B. Trophic composition

9. Percent top carnivores Electrofishing Gill Netting 4.7%

Black crappie 0.07%

Flathead catfish 0.37%

Largemouth bass 3.10%

Smallmouth bass 1.11%

Spotted gar 0.07%

66.2%

Black crappie 11.87%

Flathead catfish 4.57%

Hybrid striped bass 0.46%

Largemouth bass 6.39%

Sauger 3.20%

Striped bass 2.74%

White bass 1.83%

White crappie 1.37%

Yellow bass 33.79%

1.5 1.5 53

Table 10 (Continued) 2009 TRM 531.0 2010 TRM 531.0 Metric Obs Score Obs Score

10. Percent omnivores Electrofishing 6.2%

9.9%

Bluntnose minnow 1.40%

Bluntnose minnow 2.17%

Channel catfish 0.37%

Channel catfish 0.65%

Common carp 0.44%

2.5 Common carp 0.33%

2.5 Gizzard shad 3.91%

Gizzard shad 6.5 1%

Smallmouth buffalo 0.07%

Hybrid shad 0.11%

Smallmouth buffalo 0.11%

Gill Netting 25.1%

47.9%

Blue catfish 5.94%

Blue catfish 3.57%

Channel catfish 2.28%

Channel catfish 6.43%

0.5 Gizzard shad 15.98%

1.5 Common carp 1.43%

Hybrid shad 0.46%

Gizzard shad 35.71%

Smallmouth buffalo 0.46%

Smallmouth buffalo 0.71%

C. Fish abundance and health

11. Average number per run Electrofishing 90.5 0.5 61.4 0.5 Gill Netting 21.9 1.5 14.0 1.5

12. Percent anomalies Electrofishing 0.4%

2.5 1.5%

2.5 Gill Netting 0.9%

2.5 0%

2.5 Overall RFAI Score 45 41 Good Good 54

Table 11. Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing at Areas Downstream (TRM 529) of Watts Bar Nuclear Plant Discharge, Autumn 2009. Trophic level: benthic invertivore (BI), insectivore (IN), omnivore (OM), parasitic (PS), planktivore (PK), top carnivore (TC). Tolerance:

tolerant (TOL), intolerant (INT).

Longnose gar Gizzard shad Common carp Golden shiner Spotfin shiner Bluntnose minnow Redbreast sunfish Green sunfish Bluegill Largemouth bass White crappie Spotted sucker Black redhorse Longear sunfish Smallmouth bass Brook silverside Spotted gar Threadfm shad Emerald shiner Steelcolor shiner Smallmouth buffalo Golden redhorse Channel catfish Flathead catfish White bass Yellow bass Warmouth Redear sunfish Hybrid sunfish Spotted bass Hybrid bass Black crappie Sauger Freshwater drum Scientific name Lepisosteus osseus Dorosoma cepedianum Cyprinus carpio Notemigonus crysoleucas Cyprinella spiloptera Pimephales notatus Lepomis auritus Lepomis cyanellus Lepomis macrochirus Micropterus salmoides Pomoxis annularis Minytrema melanops Moxostoma duquesnei Lepomis megalotis Micropterus dolomieu Labidesthes sicculus Lepisosteus oculatus Dorosoma petenense Notropis atherinoides Cyprinella whipplei Ictiobus bubalus Moxostoma erythrurum Ictalurus punctatus Pylodictis olivaris Morone chrysops Morone mississippiensis Lepomis gulosus Lepomis microlophus Hybrid lepomis sp.

Micropterus punctulatus Hybrid micropterus sp.

Pomoxis nigromaculatus Sander canadense Aplodinotus grunniens Trophic level TC OM OM OM IN OM IN IN IN TC TC BI BI IN TC IN TC PK IN IN OM BI OM TC TC TC IN IN IN TC TC TC TC BI Sunfish species x

x x

x x

x x

x x

Indigenous species x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

Tolerance TOL TOL TOL TOL TOL TOL TOL TOL TOL TOL TOL INT INT INT INT INT EF Catch Rate Per Run 0.47 8.73 0.13 0.93 2.2 0.4 1.2 0.73 31.4 4.07 0.07 0.13 0.33 0.8 1

1.33 0.07 2.07 0.07 0.27 0.07 0.2 2.33 0.33 0.07 1.47 0.73 5.2 0.07 2.33 0.13 0.6 0.07 0.33 EF Catch Rate Per Hour 1.91 35.69 0.54 3.81 8.99 1.63 4.9 3

128.34 16.62 0.27 0.54 1.36 3.27 4.09 5.45 0.27 8.45 0.27 1.09 0.27 0.82 9.54 1.36 0.27 5.99 3

21.25 0.27 9.54 0.54 2.45 0.27 1.36 Total fish EF 7

131 2

14 33 6

18 11 471 61 1

2 5

12 15 20 1

31 1

4 1

3 35 5

1 22 11 78 1

35 2

9 1

5 iladlU SilversiUe ivwentata oerynina 11N 0.1+

) ZV.f-f+

11 /0 Total 148.73 607.86 2231 Number of Samples 15 Indigenous Species Collected 31 (Excluding hybrids) 55

Table 12. Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing at Areas Downstream (TRM 529) of Watts Bar Nuclear Plant Discharge, Autumn 2010. Trophic level: benthic invertivore (BI), insectivore (IN), omnivore (OM), parasitic (PS), planktivore (PK), top carnivore (TC). Tolerance:

tolerant (TOL), intolerant (INT).

Trophic Sunfish Indigenous Electrofishing Electrofishing Total fish level species species Tolerance Catch Rate Per Catch Rate Per EF Common Name Scientific name Run Hour Longnose gar Lepisosteus osseus TC X

TOL Gizzard shad Dorosoma cepedianum OM X

TOL Common carp Cyprinus carpio OM TOL Spotfin shiner Cyprinella spiloptera IN X

TOL Bluntnose minnow Pimephales notatus OM X

TOL Redbreast sunfish Lepomis auritus IN X

X TOL Green sunfish Lepomis cyanellus IN X

X TOL Bluegill Lepomis macrochirus IN X

X TOL Largemouth bass Micropterus salmoides TC X

TOL White crappie Pomoxis annularis TC X

X TOL Skipjack herring Alosa chrysochloris TC X

INT Spotted sucker Minytrema melanops BI X

[NT River redhorse Moxostoma carinatum BI X

INT Black redhorse Moxostoma duquesnei BI X

INT Rock bass Ambloplites rupestris TC X

INT Longear sunfish Lepomis megalotis IN X

X

[NT Smallmouth bass Micropterus dolomieu TC X

[NT Alewife Alosapseudoharengus PK Largescale stoneroller Campostoma oligolepis HB X

Bullhead minnow Pimephales vigilax IN X

Smallmouth buffalo Ictiobus bubalus OM X

Golden redhorse Moxostoma erythrurum BI X

Blue catfish Ictalurusfurcatus OM X

Channel catfish Ictalurus punctatus OM X

Flathead catfish Pylodictis olivaris TC X

White bass Morone chrysops TC X

Yellow bass Morone mississippiensis TC X

Warmouth Lepomis gulosus IN X

X Redear sunfish Lepomis microlophus IN X

X Hybrid sunfish Hybrid Lepomis sp.

IN X

X Spotted bass Micropteruspunctulatus TC X

Hybrid bass Hybrid Micropterus sp.

TC X

Black crappie Pomoxis nigromaculatus TC X

X Yellow perch Percaflavescens IN Logperch Percina caprodes BI X

Freshwater drum Aplodinotus grunniens BI X

0.60 6.73 0.33 0.93 0.60 1.20 2.13 38.87 1.67 0.07 0.07 0.27 0.07 1.20 0.33 1.07 1.13 0.07 0.07 0.07 0.07 0.73 1.00 2.00 1.53 0.47 0.20 0.53 5.00 0.13 2.00 0.13 0.20 0.07 0.07 0.47 2.37 26.58 1.32 3.68 2.37 4.74 8.42 153.42 6.58 0.26 0.26 1.05 0.26 4.74 1.32 4.21 4.47 0.26 0.26 0.26 0.26 2.89 3.95 7.89 6.05 1.84 0.79 2.11 19.74 0.53 7.89 0.53 0.79 0.26 0.26 1.84 9

101 5

14 9

18 32 583 25 1

1 4

1 18 5

16 17 1

1 1

1 11 15 30 23 7

3 8

75 2

30 2

3 1

1 7

Inland silverside Menidia beryllina IN 0.73 2.89 11 Total 72.81 287.34 1,092 Number of Samples 15 Indigenous Species Collected 31 (Excluding hybrids) 56

Table 13. Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing and Gill Netting at Areas Upstream (TRM 531) of Watts Bar Nuclear Plant Discharge, Autumn 2009.

Common Name Gizzard shad Common carp Spotfm shiner Bluntnose minnow Redbreast sunfish Green sunfish Bluegill Largemouth bass White crappie Northern hog sucker Spotted sucker River redhorse Smallmouth bass Brook silverside Spotted gar Threadfin shad Hybrid shad Steelcolor shiner Smallmouth buffalo Blue catfish Channel catfish Flathead catfish White bass Yellow bass Striped bass Hybrid striped x white bass Warmouth Redear sunfish Black crappie Logperch Sauger Freshwater drum Inland silverside Total Number of Samples Indigenous Species Collected (Excluding hybrids)

Scientific name Dorosoma cepedianum Cyprinus carpio Cyprinella spiloptera Pimephales notatus Lepomis auritus Lepomis cyanellus Lepomis macrochirus Micropterus salmoides Pomoxis annularis Hypentelium nigricans Minytrema melanops Moxostoma carinatum Micropterus dolomieu Labidesthes sicculus Lepisosteus oculatus Dorosoma petenense Hybrid dorosoma Cyprinella whipplei lctiobus bubalus Ictalurusfurcatus Ictalurus punctatus Pylodictis olivaris Morone chrysops Morone mississippiensis Morone saxatilis Hybrid morone Lepomis gulosus Lepomis microlophus Pomoxis nigromaculatus Percina caprodes Sander canadense Aplodinotus grunniens Menidia beryllina Trophic level OM OM IN OM IN IN IN TC TC BI BI BI TC IN TC PK OM IN OM OM OM TC TC TC TC TC IN IN TC BI TC BI IN Sunfish species x

x x

x x

x x

Indigenous species x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

Tolerance TOL TOL TOL TOL TOL TOL TOL TOL TOL INT INT INT INT JNT EF Catch Rate Per Run 3.53 0.4 6.73 1.27 1.6 2

31.2 2.8 0

0.07 0.2 0

1 0.47 0.07 4.4 0

0.07 0.07 0

0.33 0.33 0

0 0

0 0.13 2.8 0.07 0.27 0

0.33 30.33 EF Catch Rate Per Hour 15.5 1.75 29.53 5.56 7.02 8.77 136.84 12.28 0

0.29 0.88 0

4.39 2.05 0.29 19.3 0

0.29 0.29 0

1.46 1.46 0

0 0

0 0.58 12.28 0.29 1.17 0

1.46 133.04 EF 53 6

101 19 24 30 468 42 0

1 3

0 15 7

1 66 0

1 1

0 5

5 0

0 0

0 2

42 1

4 0

5 455 Total fish GN Catch Rate Per Net Night 3.5 0

0 0

0 0

0 1.4 0.3 0

1 0.1 0

0 0

0 0.1 0

0.1 1.3 0.5 1

0.4 7.4 0.6 0.1 0.1 0.1 2.6 0

0.7 0.6 0

Total Gill net fish 35 0

0 0

0 0

0 14 3

0 10 0

0 0

0 0

1 0

1 13 5

10 4

74 6

1 1

1 26 0

7 6

0 Total fish Combined 88 6

101 19 24 30 468 56 3

1 13 1

15 7

1 66 1

1 2

13 10 15 4

74 6

1 3

43 27 4

7 11 455 90.47 396.8 1357 21.9 219 1576 15 10 22 16 57

Table 14. Species Collected, Trophic level, Indigenous and Tolerance Classification, Catch Per Effort During Electrofishing and Gill Netting at Areas Upstream (TRM 531) of Watts Bar Nuclear Plant Discharge, Autumn 2010.

Common Name Scientific name Gizzard shad Common carp Spotfm shiner Bluntnose minnow Redbreast sunfish Green sunfish Bluegill Largemouth bass White crappie Northern hog sucker Spotted sucker Black redhorse Longear sunfish Smallmouth bass Brook silverside Spotted gar Hybrid shad Steelcolor shiner Smallmouth buffalo Blue catfish Channel catfish Flathead catfish White bass Yellow bass Striped bass Hybrid striped x white bass Warmouth Redear sunfish Hybrid sunfish Black crappie Yellow perch Logperch Sauger Dorosoma cepedianum Cyprinus carpio Cyprinella spiloptera Pimephales notatus Lepomis auritus Lepomis cyanellus Lepomis macrochirus Micropterus salmoides Pomoxis annularis Hypentelium nigricans Minytrema melanops Moxostoma duquesnei Lepomis megalotis Micropterus dolomieu Labidesthes sicculus Lepisosteus oculatus Hybrid Dorosoma Cyprinella whipplei Ictiobus bubalus Ictalurusfurcatus Ictalurus punctatus Pylodictis olivaris Morone chrysops Morone mississippiensis Morone saxatilis Hybrid Morone Lepomis gulosus Lepomis microlophus Hybrid Lepomis sp.

Pomoxis nigromaculatus Percaflavescens Percina caprodes Stizostedion canadense Trophic level OM OM IN OM IN IN IN TC TC BI BI BI IN TC IN TC OM IN OM OM OM TC TC TC TC TC IN IN IN TC IN BI TC Sunfish species x

x x

x x

x x

x x

Indigenous species x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

Tolerance Electrofishing Electrofishing Total fish Gill Netting Catch Catch Rate Per Run Catch Rate Per Hour EF Rate PerNet Night TOL 4.00 15.75 60 5.00 TOL 0.20 0.79 3

0.20 TOL 1.73 6.82 26 TOL 1.33 5.25 20 TOL 3.20 12.60 48 TOL 2.73 10.76 41 TOL 32.73 128.87 491 0.20 TOL 2.00 7.87 30 0.70 TOL 0.10 INT 0.07 0.26 1

INT 0.07 0.26 1

0.20 INT 0.07 0.26 1

INT 0.07 0.26.

1 INT 0.53 2.10 8

INT 2.00 7.87 30 0.20 0.79 3

0.07 0.26 1

0.67 2.62 10 0.07 0.26 1

0.10 0.50 0.40 1.57 6

0.90 0.87 3.41 13 0.60 0.07 0.26 1

0.70 3.50 0.10 Total Gill Total fish net fish Combined 50 110 2

5 26 20 48 41 2

493 7

37 1

1 1

2 3

1 1

8 30 3

1 10 1

2 5

5 9

15 6

19 7

8 35 35 1

1 1

1 3

53 5

5 6

3 5

1 1

0.20 3.53 0.33 0.07 0.20 0.33 0.79 13.91 1.31 0.26 0.79 1.31 3

53 5

1 3

5 0.10 0.50 0.10 58

Table 14. (Continued)

Scientific name Trophic Sunfish Indigenous Tolerance Electrofishing Electrofishing Total fish Gill Netting Catch Total Gill Total fish Common Name level species species Catch Rate Per Run Catch Rate Per Hour EF Rate PerNet Night net fish Combined Freshwater drum Aplodinotus grunniens BI X

0.87 3.41 13 0.50 5

18 Inland silverside Menidia beryllina IN 2.80 11.02 42 42 Total 61.41 241.69 921 14.00 140 1,061 Number of Samples 15 10 Indigenous Species Collected 24 14 (Excluding hybrids) 59

Table 15. Summary of RFAI Scores from Sites Located Directly Upstream and Downstream of Watts Bar Nuclear Plant as Well as Scores from Sampling Conducted During 1993-2010 as Part of the Vital Signs Monitoring Program in Chickamauga Reservoir.

Station Location 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 Average WBN Upstream TRM 531.0 44 48 43 41 36 44 39 39 45 43 47 42 36 36 45 41 42 Forebay WBN Downstream TRM 529.0 52 52 48 42 44 42 44 46 48 48 42 42 42 42 44 44 44 45 Inflow Transition TRM 490.5 51 40 48 44 39 45 46 45 51 42 49 46 47 44 34 41 39 44 Forebay TRM 482.0 47 41 48 46 43 45 41 39 35 38 38 37 39 41 Forebay TRM 472.3 43 44 47 40 45 45 48 46 43 43 46 43 41 41 42 40 44 Hiwassee River HiRM 8.5 46 39 39 40 43 43 47 36 42 45 41 42 42 Embayment RFAI Scores: 12-21 ("Very Poor"), 22-31 ("Poor"), 32-40 ("Fair"), 41-50 ("Good"), or 51-60 ("Excellent").

60

Table 16. Fish species collected including provisions for the identification of the resident important species at areas downstream (TRM 529) of WBN Discharge, Autumn 2010. Trophic: benthic invertivore (BI), insectivore (IN),

omnivore (OM), planktivore (PK), top carnivore (TC). Tolerance: tolerant (TOL), intolerant (INT)

Trophic Indigenous Representative Thermally Threatened/

Commercially Recreationally Trphe InImnsRporentantiv Aquatic Tolerance Sensitive Endangered Valuable Valuable Common Name Scientific name level species Important Nuisance (Pollution)

Ses Ederal Species Species (Federal Status)

Species Species Longnose gar Gizzard shad Common carp Spotfin shiner Bluntnose minnow Redbreast sunfish Green sunfish Bluegill Largemouth bass White crappie Skipjack herring Spotted sucker River redhorse Black redhorse Rock bass Longear sunfish Smallmouth bass Alewife Largescale stoneroller Bullhead minnow Smallmouth buffalo Golden redhorse Blue catfish Channel catfish Flathead catfish White bass Yellow bass Warmouth Redear sunfish Hybrid sunfish Lepisosteus osseus Dorosoma cepedianum Cyprinus carpio Cyprinella spiloptera Pimephales notatus Lepomis auritus Lepomis cyanellus Lepomis macrochirus Micropterus salmoides Pomoxis annularis Alosa chrysochloris Minytrema melanops Moxostoma carinatum Moxostoma duquesnei Ambloplites rupestris Lepomis megalotis Micropterus dolomieu Al osa pseudoharengus Campostoma oligolepis Pimephales vigilax lctiobus bubalus Moxostoma erythrurum lctalurusfurcatus Ictalurus punctatus Pylodictis olivaris Morone chrysops Morone mississippiensis Lepomis gulosus Lepomis microlophus Hybrid Lepomis sp.

TC OM OM IN OM IN IN IN TC TC TC BI BI B1 TC IN TC PK HB IN OM BI OM OM TC TC TC IN IN IN x

x TOL TOL TOL TOL TOL TOL TOL TOL TOL TOL INT INT INT INT INT INT INT x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

61

Table 16. (Continued)

Representative Thermally Threatened/

Commercially Recreationally Trophic Indigenous RersnaieAquatic Tolerance Sensitive Endangered Valuable Valuable Common Name Scientific name level species Important Nuisance (Pollution)

Species Species (Federal Status)

Species Species Spotted bass Micropterus punctulatus TC X

X X

Hybrid bass Hybrid Micropterus sp.

TC X

Black crappie Pomoxis nigromaculatus TC X

X X

Yellow perch Percaflavescens IN X

X Logperch Percina caprodes BI X

X X

Freshwater drum Aplodinotus grunniens BI X

X X

I n l a n d s i l v e r s i d e M e n i d i a b e r y l l i n a I N X

X Total 31 35 3

3 0

2 21 (Excluding Hybrids) 62

Table 17. Fish species collected including provisions for the identification of the resident important species at areas upstream (TRM 531) of WBN Discharge, Autumn 2010. Trophic: benthic invertivore (BI), insectivore (IN), omnivore (OM),

planktivore (PK), top carnivore (TC). Tolerance: tolerant (TOL), intolerant (INT)

Trophic Indigenous Representative Thermally Threatened/

Commercially Recreationally Common Name Scientific name level species Important Nuisance (Pollution Sensitive Endangered Valuable Valuable Species Species (Federal Status)

Species Species Gizzard shad Common carp Spotfm shiner Bluntnose minnow Redbreast sunfish Green sunfish Bluegill Largemouth bass White crappie Northern hog sucker Spotted sucker Black redhorse Longear sunfish Smallmouth bass Brook silverside Spotted gar Hybrid shad Steelcolor shiner Smallmouth buffalo Blue catfish Channel catfish Flathead catfish White bass Yellow bass Striped bass Hybrid striped x white bass Warmouth Redear sunfish Hybrid sunfish Black crappie Dorosoma cepedianum Cyprinus carpio Cyprinella spiloptera Pimephales notatus Lepomis auritus Lepomis cyanellus Lepomis macrochirus Micropterus salmoides Pomoxis annularis Hypentelium nigricans Minytrema melanops Moxostoma duquesnei Lepomis megalotis Micropterus dolomieu Labidesthes sicculus Lepisosteus oculatus Hybrid Dorosoma Cyprinella whipplei Ictiobus bubalus Ictalurusfurcatus Ictalurus punctatus Pylodictis olivaris Morone chrysops Morone mississippiensis Morone saxatilis Hybrid Morone Lepomis gulosus Lepomis microlophus Hybrid Lepomis sp.

Pomoxis nigromaculatus OM OM IN OM IN IN IN TC TC BI BI BI IN TC IN TC OM IN OM OM OM TC TC TC TC TC IN IN IN TC TOL TOL TOL TOL TOL TOL TOL TOL TOL INT INT INT INT INT INT x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

x x

63

Table 17. (Continued)

Representative Thermally Threatened/

Commercially Recreationally Trophic Indigenous Aquatic Tolerance Sensitive Endangered Valuable Valuable Common Name Scientific name level species Important Nuisance (Pollution)

Species Species (Federal Status)

Species Species Yellow perch Percaflavescens IN X

X X

L ogp erch P ercina cap rod es B I X

X X

Sauger Stizostedion canadense TC X

X X

Freshwater drum Aplodinotus grunniens BI X

X X

I n l a n d s i l v e r s i d e M e n i d i a b e r y l l i n a I N X

X Total 28 32 3

2 0

2 20 (Excluding Hybrids) 64

Table 18. Individual Metric Ratings and the Overall RBI Field Scores for Downstream and Upstream Sampling Sites Near Watts Bar Nuclear Plant, Chickamauga and Watts Bar Reservoirs, Autumn 2001-2010. *TRM 527.4 was not sampled during 2006; data from TRM 518 was used for the downstream site during 2006. Reservoir Benthic Index Scores: 7-12 ("Very Poor"), 13-18 ("Poor"), 19-23 ("Fair"), 24-29 ("Good"), 30-35 ("Excellent").

Downstream 2

0 (TA 2.)

2001 2002 2003 2004 2005 2006*

2007 12008 f2009 2010 Metric Obs S

Avg No. Taxa 6.1

% Long-Lived 0.9 Avg. No. EPT taxa 0.1

% Oligochaetes 1.9

% Dominant Taxa 77.3 Density excl chiron and!o618.3 oligo Zero Samples 0

Overall Score Upstream 2001 (TRM 533.3)

Metric Obs Si Avg No. Taxa 3.4

% Long-Lived 0.1 Avg. No. EPT taxa 0

% Oligochaetes 32.3

% Dominant Taxa 98.3 Density excl chiron and, oligo 2.7 Zero Samples 0

Overall Score core Obs 5

5.1 5

1 1

0.5 5

1.6 5

77 3

147.3 5

0 29 Score Obs 3

6.6 5

1 3

1 5

0.5 5

75.4 1

926.7 5

0 27 Score: Obs 5

11.6 5

0.9 5

2.7 5

1 5

63.5 3

1*538.3 5

0 33 Score Obs 5

6.8 5

1 5

0.9 5

0.8 5

72 5

480 5

0 35 Score! Obs 5

5 5

5 5

5 31 core Ob 3

4 1

0.]

1 0

1 59.

1 98.

1 23.

5 0

13 2002 2003 2004

• s Score Obs Score Obs S4 3

3.8 3

4 1

0.1 1

0 1

0 1

0 2

1 27.4 3

23.9 8

1 96 1

88.3 3

1 76.7 1

38.3 5

0 5

0 13 15 2005 core Obs S

3 2.9 1

0.2 1

0.1 3

10.2 3

95.4 1

21.7 5

0.1 17 200 Score Obs S

3.2 0.8

--- j 0.4 1.2 86.2 168.3 0

D6 2007 Score Obs S

3 3.4 1

0 1

0 3

35.6 1

100 1

0 3

0 13 core Obs 3

3.3 1

0.1 1

0 5

28.5 1

97.4 1

16.7 3

0.1 15 21 core Obs 3

2.5 1

0 1

0 1

77.7 1

100 1

0 5

0 13 core Obs 3

5.1 5

0.4 3

0.1 5

10.4 1

66.4 1

165 5

0 23 00 Score Obs 3

4.2 3

1 1

0 5

0.6 5

' 92 1

685 5

0 23 08 2(

Score Obs 3

2.2 1

0.2 1

0 1

28.5 1

96.8 1

31.7 5

0.1 13 00 Score] Obs Sc 3

3.9 5

0.6 1

0.4 5

0.8 1

78 3

228.3 5

0.2 23 09 2010 Score Obs Sc 1

2.4 1

0 1

0.2 3

16.7 1

95.5 1

5 3

0 11.

ore 3

3 3

5 5

1 11 ore 1

1 3

1 5

13 65

Table 19. Comparison of Average Mean Density Per Square Meter of Benthic Taxa Collected at Upstream and Downstream Sites Near WBN, Chickamauga and Watts Bar Reservoirs, Autumn 2009 and Autumn 2010.

Downstream Upstream TRM 527.4 TRM 533.3 Taxa 2009 2010 2009 2010 Tubellaria Tricladida Planariidae Oligocheata Oligochactes Hirudinea Crustacea Amphipoda Isopoda Insecta Ephemeroptera Trichoptera Odonata Diptera Chironomidae Chironomids Gastropoda Snails Bivalvia Unionoida Unionidae Mussels Veneroida Corbiculidae Corbicula (<10mm)

Corbicula (>10mm)

Sphaeriidae Fingernail clams Dreissenidae Dreissena polymorpha 15 15 V

5.

40 5

3 8

7 28 55 5

13 3

47 15 7

3 73 190 8

13 428 158 78 72 7

2

-- 2 8

17 7

15 Density of organisms per meter' 690 280 160 223 Number of samples 10 10 10 10 Total area sampled (meter2) 0.6 0.6 0.6 0.6 66

Table 20. Summary of RBI Scores from Sites Located Directly Upstream and Downstream of Watts Bar Nuclear Plant as Well as Scores from Sampling Conducted During 1993-2010 as Part of the Vital Signs Monitoring Program in Chickamauga Reservoir.

Station Location 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 Avg.

Forebay TRM 533.3 13 11 13 15 13 13 15 17 15 13 13 13 11 13 13 WBN Up Inflow WBN Down TRM 527.4 29 27 33 35 31 23 23 23 21 27 Inflow TRM 518.0 19 31 25 21 23 29 23 27 35 29 33 25 31 27 Transition TRM 490.5 33 29 31 31 23 25 25 31 31 31 27 21 17 27 23 27 Forebay TRM 482.0 23 31 29 29 33 31 31 25 25 23 29 28 Forebay TRM 472.3 31 27 29 25 27 27 21 27 29 27 29 19 25 23 26 Reservoir Benthic Index Scores: 7-12 ("Very Poor"), 13-18 ("Poor"), 19-23 ("Fair"), 24-29 ("Good"), 30-35 ("Excellent")

67

Table 21. Water quality parameters taken at the most downstream sampling point and at the most upstream sampling point of the RFAI sample upstream of WBN.

Most downstream RFAI sampling point upstream of WBN Water Conductivity Dissolved Depth (meters)

Temperature ('F)

(lAs/cm)

Oxygen (ppm) pH 0.3 76.3 182.3 6.89 7.96 1.5 76.2 182 6.84 7.93 3

76.1 182.3 6.7 7.89 4

76.0 182.2 6.53 7.85 6

75.8 182.7 6.38 7.8 8

75.8 182 6.18 7.77 10 75.7 182.2 6.04 7.71 12 75.7 182.3 5.86 7.65 14 75.7 182.3 5.77 7.62 16 75.6 182.4 5.78 7.58 18 75.5 183.5 4.62 7.22 20 74.8 190.6 2.31 6.94 22 74.2 195 0.65 6.8 Most upstream RFAI sampling point upstream of WBN Water Conductivity Dissolved Depth (meters)

Temperature (IF)

(As/cm)

Oxygen (ppm) pH 0.3 75.7 182.2 6.62 8.1 1.5 75.7 182.3 6.58 8

3 75.6 182.2 6.48 7.98 4

75.6 182.4 6.44 7.97 6

75.6 182.3 6.42 7.97 8

75.6 182.1 6.1 7.88 10 75.5 182.4 5.75 7.81 12 75.5 183.6 6

7.82 14 75.5 182.8 5.83 7.8 16 75.4 182.8 5.08 7.62 18 76.0 186.9 3.37 7.44 20 74.6 190.3 1.89 7.2 68

Table 22. Water quality parameters taken at the most downstream sampling point and at the most upstream sampling point of the RFAI sample downstream of WBN.

Most downstream RFAI sampling point downstream of WBN Water Conductivity Dissolved Depth (meters)

Temperature (°F)

(Ps/cm)

Oxygen (ppm) pH 0.3 76.6 202 6.2 7.75 1.5 75.8 202 5.81 7.65 3

75.5 201 5.75 7.59 4

75.4 201 5.69 7.56 5

75.4 201 5.66 7.53 6

75.5 202.3 5.66 7.46 Most upstream RFAI sampling point downstream of WBN Water Conductivity Dissolved Depth (meters)

Temperature (IF)

(jIs/cm)

Oxygen (ppm) pH 0.3 76.0 201 5.8 7.64 1.5 75.9 201 5.76 7.6 3

75.9 201 5.75 7.6 4.5 75.9 201 5.73 7.6 69