ML081680050
| ML081680050 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 06/11/2008 |
| From: | Howard S Tennessee Valley Authority |
| To: | Cromer P Office of Nuclear Reactor Regulation, State of TN, Dept of Environment & Conservation, Div of Water Pollution Control |
| References | |
| Download: ML081680050 (27) | |
Text
Tennessee Valley Authority, Post Office Box 2000, Soddy-Daisy, Tennessee. 37384-2000 June 11, 2008 State of Tennessee Department of Environment and Conservation Division of Water Pollution Control Enforcement & Compliance Section 6th Floor, L & C Annex 401 Church Street Nashville, Tennessee 37243-1534
Dear Mr. Patrick Cromer:
SEQUOYAH NUCLEAR PLANT - 2007 BIOLOGICAL MONITORING REPORT Enclosed is the "Biological Monitoring of the Tennessee River Near Sequcyah Nuclear Plant Discharge 2007" Report. This report is submitted in accordance with Part III, Section F of the TVA - Sequoyah Nuclear Plant NPDES Permit No. TN0026450. Please contact me at (423) 843-6700 if you have any questions or comments.
Sincerely, Stephanie A. Howard Principal Environmental Engineer Signatory Authority for Timothy P. Cleary Site Vice President Sequoyah Nuclear Plant Enclosure cc (Enclosure):
Chattanooga Environmental Assistance Center Division of Water Pollution Control State Office Building, Suite 550 540 McCallie Avenue Chattanooga, Tennessee 37402-2013 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 P,inted on
,cded paper
Biological Monitoring of the Tennessee River Near Sequoyah Nuclear Plant Discharge 2007 by Dennis S. Baxter Jeffrey W. Simmons May 2008 Tennessee Valley Authority Aquatic Monitoring and Management Knoxville, Tennessee
Table of Contents List of T ab les................................................................................................................................
i List of Fig ures.............................................................................................................................
ii A cro nym s..................................................................................................................................
i ii Intro d uctio n.................................................................................................................................
1 M etho ds.......................................................................................................................................
2 Fish C o m m unity.......................................................................................................................
2 Benthic Macroinvertebrate Community............................................................................
3 Spring Sport Fish Survey....................................................................................................
4 Results and Discussion.......................................................................................................
4 Fish C om m unity.......................................................................................................................
4 Benthic Macroinvertebrate Community............................................................................
5 Spring Sport Fish Survey....................................................................................................
5 Chickamauga Reservoir Flow.............................................................................................
6 Literature C ited...........................................................................................................................
7 List of Tables Table 1.
Scoring Results for the Twelve Metrics and Overall Scores for all RFAI Sites Sampled in Chickamauga Reservoir, 2007.......................................................
8 Table 2.
RFAI Scores Developed Using the RFAI Metrics from Samples Collected During 1993 to 2007, Upstream and Downstream of Sequoyah Nuclear P la n t..........................................................................................................................
9 Table 3.
Scoring Criteria for Forebay, Transition, and Inflow Sections of Upper Mainstem Reservoirs in the Tennessee River System. Upper Mainstem Reservoirs include Chickamauga, Fort Loudoun, Melton Hill, Nickajack, Tellico, and Watts Bar....................................................................................
.. 10 Table 4.
Species Listing and Catch Per Unit Effort for Forebay Transects on Chickamauga Reservoir During Fall Electrofishing and Gill Netting, 2007.
(Electrofishing Effort = 300 Meters of Shoreline, Gill Netting Effort = 10 Net-N ig hts )....................................................................................................................
11 Table 5.
Species Listing and Catch Per Unit Effort for the Transition and Inflow Transects on Chickamauga Reservoir During Fall Electrofishing and Gill Netting, 2007. (Electrofishing Effort = 300 Meters of Shoreline, Gill Netting Effort =10 Net-Nights)....................................................................................
12 Table 6.
Individual Metric Ratings and the Overall RBI Field Scores for Upstream (TRM 490.5) and Downstream (TRM 482) Sampling Sites Near Sequoyah Nuclear Plant, Chickamauga Reservoir, 2007..............................................................
14 i
List of Tables (continued)
Table 7.
Average Mean Density Per Square Meter of Benthic Taxa Collected at Upstream (TRM 490.5) and Downstream (TRM 482) Sampling Sites Near Sequoyah Nuclear Plant, Chickamauga Reservoir, 2007.............................
15 Table 8.
RBI Field Scores from Data Collected During 1994-2007 at Chickamauga Reservoir Transition (TRM 490.5) and Forebay (TRM 482.0 and TRM 472.3)
S ites........................................................................................................................
17 Table 9.
Electrofishing Catch Rates and Population Characteristics of Black Bass Collected During Spring Sport Fish Surveys on Chickamauga Reservoir, 1995-2007...............................................................................................................
17 Table 10.
Black Bass Catch Per Hour Compared to Habitat Types by Location During Spring Sport Fish Surveys on Chickamauga Reservoir, 2007.....................
18 List of Figures Figure 1. Annual Chickamauga Reservoir RFAI scores for sample years between 1993 and 2007......................................................................................................
19 Figure 2. Length frequency distribution for largemouth bass collected from Chickamauga Reservoir (all sites) during the Spring Sport Fish Survey, 2007..........................................................................................................................
20 Figure 3. Relative stock density values for Tennessee River reservoirs calculated from 2007 Spring Sport Fish Survey samples.........................................................
20 Figure 4. Proportional stock density values for Tennessee River reservoirs calculated from 2007 Spring Sport Fish Survey samples................................................
21 Figure 5. Chickamauga Reservoir mean relative weights (Wr) for largemouth bass by RSD category and number of fish during 2007.......................
21 Figure 6. Weekly average flows in cubic feet per second from Watts Bar Dam during October 2006 through September 2007 with long term trend line from 1976 through 2006........................................................................................................
22 ii
Acronyms BIP Balanced Indigenous Population NPDES National Pollutant Discharge Elimination System PSD Proportional Stock Density QA Quality Assurance RBI Reservoir Benthic Macroinvertebrate Index RFAI Reservoir Fish Assemblage Index RSD Relative Stock Density RSDM Relative Stock Density of Memorable-sized RSDP Relative Stock Density of Preferred-sized RSDT Relative Stock Density of Trophy-sized SAHI Shoreline Assessment Habitat Index SQN Sequoyah Nuclear Plant SSS Spring Sport Fish Survey TRM Tennessee River Mile TVA Tennessee Valley Authority VS Vital Signs Wr Relative Weight iii
Introduction Section 316(a) of the Clean Water Act specifies that industrial, municipal, and other facilities must obtain permits if their thermal discharges go directly to surface waters. Industries responsible for point-source discharges of heated water can obtain a variance from state water quality standards if the industry can demonstrate compliance with thermal criteria by documenting the maintenance of Balanced Indigenous Populations (BIP) of aquatic life in the vicinity of its discharge.
Sequoyah Nuclear Plant's (SQN) current National Pollutant Discharge Elimination System (NPDES) permit number TN0026450 states, "For Section 316(a), the permittee shall analyze previous and new data to determine whether significant changes have occurred in the plant operation, reservoir operation, or in stream biology that would necessitate the need for changes in the thermal variance." The permittee shall use the Reservoir Fish Assemblage Index (RFAI) to assess Chickamauga Reservoir fish community health. Any apparent decline in the fish community health will be further investigated to discover whether it is a valid conclusion and if it is real to identify possible sources for the fish community decline. As part of the identification of potential sources for the decline, the instream effects of the discharges made under this permit will be investigated (TDEC 2000). In response to this requirement, Tennessee Valley Authority's (TVA's) Vital Signs (VS) monitoring program (Dycus and Meinert 1993) will be used to evaluate areas of Chickamauga Reservoir upstream and downstream of SQN discharge.
The purpose of this document is to briefly summarize and provide results of the Calendar Year 2007 monitoring and analyses to the Tennessee Department of Environment and Conservation and compare these results with historical monitoring data.
Prior to 1990, TVA conducted reservoir ecological assessments to meet specific needs as they arose. In 1990, TVA instituted a Valley-wide VS monitoring program which is a broad-based evaluation of the overall ecological conditions in major reservoirs. Data are evaluated with a multi-metric monitoring approach utilizing five environmental indicators: dissolved oxygen, chlorophyll, sediment quality, the benthic macroinvertebrate community, and the fish community. When this program was initiated, specific evaluation techniques were developed for each indicator, and these techniques were fine-tuned in order to better represent ecological conditions. The outcome of this effort was the development of a multi-metric evaluation to assess the fish assemblage and benthic community. The two indices, the RFAI and the Reservoir Benthic Macroinvertebrate Index (RBI), have proven successful in TVA's monitoring efforts as well as for other federal and state monitoring programs. Therefore, they will form the basis of evaluating these monitoring results. For consistency, only RFAI analyses between 1993 and 2007 will be utilized. The RBI is used primarily to support the RFAI analysis.
The TVA Spring Sport Fish Survey (SSS) is conducted to evaluate sport fish populations in TVA Reservoirs. The results of the survey are used by state agencies to protect, improve, and assess the quality of sport fisheries. Predominant habitat types in the reservoir are surveyed to determine sport fish abundance. In addition to accommodating TVA and state databases, this surveying method aligns with TVA Watershed Team and TVA's Reservoir Operations Study objectives. Sample sites are selected using the shoreline habitat characteristics employed by the Watershed Teams. The survey targets three species of black bass (largemouth, smallmouth, and spotted bass) and black and white crappie. These species are the predominant sport fish sought after by fisherman.
I
Methods Fish Community 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 zone sample site is located at Tennessee River Mile (TRM) 529.0, the transition zone sampling site is located at TRM 490.5, and the forebay zone sampling sites are located at TRM 482.0 and 472.3. The transition zone sampling site, which is located approximately 7.2 river miles upstream of the SQN discharge, is used as a control site to provide upstream data for 316(a) thermal variance studies conducted during sample years from 1993 to 2007. The downstream station is located at TRM 482.0 and has been sampled each year from 1999 to 2007 to monitor Chickamauga Reservoir aquatic communities in close proximity to the SQN thermal effluent. Previously, the downstream station was located at TRM 472.3 during sample years from 1993 to 1997.
Sampling effort consisted of fifteen 300-meter electrofishing runs (approximately 10 minute duration) and ten experimental gill net sets (five 6.1 meter panels with mesh sizes of 2.5, 5.1, 7.6, 10.2, and 12.7 cm) per site. Attained values for each of the 12 metrics were compared to reference conditions for transition zones of lower mainstream Tennessee River reservoirs and assigned scores based upon three categories hypothesized to represent relative degrees of degradation: least degraded - 5; intermediate - 3; and most degraded - 1. These categories are based on "expected" fish community characteristics in the absence of human-induced impacts other than impoundment. Individual metric scores for a site are summed to obtain the RFAI score.
Comparison of the attained RFAI score from the potential impact zone to a predetermined criterion has been suggested as a method useful in identifying presence of normal community structure and function and hence existence of a BIP. For multi-metric indices, two criteria have been suggested to ensure a conservative screening for a BIP. First, if an RFAI score reaches 70% of the highest attainable score (adjusted upward to include sample variability), and second, if fewer than half of RFAI metrics potentially influenced by thermal discharge receive a low (1) or moderate (3) score, then normal community structure and function would be present indicating that a BIP existed. Under these conditions, the heated discharge would meet screening criteria and no further evaluation would be needed.
Potential 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 variance for RFAI scores in TVA reservoirs is 6 (+ 3).
Therefore, any location that attains an RFAI score of 45 (42 + our sample variance of 3) or higher would be considered to demonstrate a BIP. It must be stressed that scores below this endpoint do not necessarily reflect an adversely impacted fish community. The endpoint is used to serve as a conservative screening level; for example, 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 a BIP exists. If a score below this criterion is obtained, an inspection of individual RFAI metric results would be an initial step to help identify if SQN operation is a contributing factor. This approach is appropriate if a validated multi-metric index is being used and scoring criteria applicable to the zone of study are available. Additionally, upstream/downstream site comparisons can be used to identify if SQN operation is adversely 2
affecting the downstream fish community. A similar or higher RFAI score at the downstream station compared to the upstream (control) station is used as one basis for determining presence/absence of SQN operational impacts on the resident fish community. Definition of "similar" is integral to accepting the validity of these interpretations.
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 stations each year. Experience to date with the QA component of VS shows that the comparison of RFAI index scores from 54 paired sample sets collected over a seven year period ranged from 0 to 18 points, the 7 5 th percentile was 6, the 9 0 th percentile was 12. The mean difference between these 54 paired scores is 4.6 points with 95% confidence limits of 3.4 and 5.8. Based on these results, a difference of 6 points or less is the value selected for defining "similar" scores between upstream and downstream fish communities. That is, if the downstream RFAI score is within 6 points of the upstream score, the 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 Ten benthic grab samples were collected at equally spaced points along a transect extending from the right descending bank to the left descending bank at each site. A Ponar sampler was used for most samples but a Peterson sampler was used when larger substrate was encountered. Collection and processing techniques followed standard VS procedures. Bottom sediments were washed on a 533ýt screen; organisms were then picked from the screen and remaining substrate and identified to Order or Family level in the field using no 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 compared to reference conditions developed for VS sample sites. The ratings for the seven metrics were summed to produce a total benthic score for each sample site. Each reservoir section (inflow, transition, or forebay) differs in their maximum potential for benthic diversity; thus, the criteria for assigning metric ratings were adjusted accordingly such that the total benthic scores from sites at different reservoir sections are comparable. 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. A similar or higher benthic index score at the downstream site compared to the upstream site is used as basis for determining absence of impact on the Chickamauga Reservoir benthic macroinvertebrate community related to SQN's thermal discharge.
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 7 5 th percentile was 4 and the 9 0 th percentile was 6. The mean difference between these 49 paired scores is 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 upstream and downstream benthic communities. That is, if the downstream benthic score is within 4 points of the upstream score, the communities will be considered similar and it will be concluded that SQN has had no effect. 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 3
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.
Spring Sport Fish Survey A Spring Sport Fish Survey was conducted on Chickamauga Reservoir March 20-22, 2007.
During the sampling period, water levels on Chickamauga Reservoir were 676.7 to 677.2 msl (summer pool level is 682.5 msl). Sampling was conducted using a boat mounted electrofishing unit at a total of twelve sites at Harrison Bay, Ware Branch, and Sale Creek. Sampling effort at each site consisted of thirty minutes of continuous electrofishing in the littoral zones of prominent habitat types present. After being stunned, fish were collected with dip nets, counted, weighed, measured, and then released unharmed.
Results of the SSS monitoring were calculated using Shoreline Assessment Habitat Index (SAHI), Relative Stock Density (RSD), Proportional Stock Density (PSD), and Relative Weight (Wr). Habitat type is evaluated using the SAHI metric and is a critical component incorporated into the SSS. The resultant habitat designations ("Good", "Fair", and "Poor") are correlated to black bass abundance (numbers/hour). RSD is the number of fish greater than a minimum preferred length in a stock divided by the number of fish greater than or equal to a minimum stock size. PSD is the number of fish greater than or equal to a minimum quality length in a sample divided by the number of fish greater than or equal to a minimum stock length. Wr is an index that quantifies fish condition and the preferred range value is 90%-105% for moderate density bass populations such as those found in the Tennessee Valley latitudes.
Results and Discussion Fish Community RFAI fish data collected during autumn 2007 from TRM 490.5 upstream from SQN resulted in a RFAI score of 44 ("Good"), while the downstream site at TRM 482 scored 38 ("Fair") (Table 1).
Although the downstream site scored "Fair", this site has averaged "Good" over all sample years with a average score of 42 (70% of the maximum score) (Table 2). Even though the downstream site scored six points and is considered similar, individual RFAI metrics were examined to evaluate this difference and to determine if this score was indicative of thermal effects (Table 3).
Species richness and composition metrics constituted four points of the six-point score difference (Table 1). The total number of species at the upstream site was 31, compared to 26 at the downstream site, which resulted in a two point scoring difference for the metric "Number of species". During 2007, seven species were collected at the upstream site that were not found at the downstream site (smallmouth buffalo, white bass, warmouth, white crappie, logperch, brook silverside, and chestnut lamprey) and one species was collected at the downstream site that was not encountered at the upstream site (golden redhorse) (Tables 4 and 5). Although more species were collected at the upstream site, all seven species mentioned above were collected in low numbers.
The downstream site (TRM 482) scored one point lower than the upstream site (TRM 490.5) for each of the metrics "Percent tolerant individuals", "Percent top carnivores", and "Average number per run" because of a lower catch rate in gill net samples at the downstream site (Table 1).
4
It is important to note that the upstream site is scored with transition criteria and the downstream site is scored using forebay criteria (Table 3). More accurate comparisons can be made between sites that are located in the same reservoir zone (i.e., transition to transition).
Due to the location of SQN, it is not possible to have an upstream and downstream site within the same reservoir zone. SQN is located at the downstream end of the transition zone on Chickamauga Reservoir; therefore the downstream site is located in the upstream section of the forebay. The physical and chemical composition of a forebay is different than that of a transition; consequently, inherent differences exist among the aquatic communities (e.g.
species diversity is often higher in a transition than a forebay zone).
RFAI scores (Table 1, Figure 2) and electrofishing and gill netting catch rates (Tables 4 and 5) are presented for Chickamauga Reservoir inflow and forebay sites (TRM 529 and 472.3) to provide an overview of ecological health throughout the reservoir; however, aquatic communities at these sites are not affected by SQN temperature effects and are not used to determine BIP in relation to SQN. Both of these sites scored "Good" during 2007.
Benthic Macroinvertebrate Community Benthic macroinvertebrate data collected during autumn 2007 from TRM 490.5 upstream from SQN resulted in a RBI score of 21 ("Fair"), while the downstream site at TRM 482 scored 25
("Good") (Table 6). Table 7 provides density by taxon from the 2007 samples at these sites.
With the exception of the 2000 and 2007 sample, the RBI scores have remained in the "Good" to "Excellent" ecological health range for all sampling seasons at both sites (Table 8). These data indicate that a healthy benthic macroinvertebrate community exists in both the upstream and downstream vicinity of SQN and that the plant is not adversely impacting this fauna.
Data collected in Chickamauga Reservoir forebay (TRM 472.3) resulted in a RBI score of 19 "Fair". This site is located 11 river miles downstream of SQN and sampling results should not reflect temperature effects from the plant. This site is included to provide additional data on the downstream health of the benthic macroinvertebrate community (Table 8).
Spring Sport Fish Survey A total of 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br /> of electrofishing resulted in collection of 940 largemouth bass, 123 spotted bass, and 38 smallmouth bass; of these, 63.2% were harvestable size (>10 inches). Overall catch rate (61.1 fish/hour) was substantially more than the 2006 survey (39.4 fish/hour), but was similar to the average catch rate from all thirteen sample years (Table 9). The largest black bass collected was a 6.7 pound largemouth bass taken from Harrison Bay. Large bass were well represented with 50 bass greater than three pounds, 20 greater than four pounds, and 8 over five pounds. The three and four-pound categories showed an increase of 78% and 70%
over 2006 results, while the five-pound category remained constant. Length frequency histograms illustrated a bimodal distribution of black bass with the dominant size classes being the 6-7 inch and 11-13 inch groups (Figure 3). Fish >14 inches comprised 18% of the overall sample. All size classes up to 21 inches were represented in the population and one was in the 27 inch class.
Habitat type is derived from the SAHI which was developed by TVA's Resource Stewardship Program. The resultant habitat designations ("Good", "Fair", and "Poor") are correlated to black bass abundance (numbers/hour). Among the three areas sampled during 2007, the 5
correlations of habitat type to black bass abundance at Harrison Bay were positive while bass collected at Sale Creek and Skull Island showed some variability among habitat types, i.e., the catch rates (abundance) did not align with the habitat designation types (Table 10).
The following results describe the quality and condition of black bass collected in Chickamauga Reservoir during spring 2007: The RSD value (21) fell within the desirable range (10-25)
(Figure 4). The PSD value (65) was also within the preferred range (40-70) (Figure 5). Wr values shown in Figure 6 are designated by inch groups which reflect the classical categories, i.e., 0-7 = substock, 8-11 = stock, 12-14 = quality, 15-19 = preferred, 20-24 =
memorable and 25+ = trophy. All categories except the trophy group fell within the desired range, which reflects excellent condition of black bass in all size groups of the population. In addition, field observations of large numbers of prey fish indicate an abundance of forage for all size classes of black bass.
Only 149 crappie (11 black and 138 white crappie) were collected during the survey. Crappies were collected predominantly from tree tops, stumps, and other physical structures in shallow water. Optimum water temperatures for crappie spawning occurred earlier in the spring of 2007.
Chickamauga Reservoir Flow Average weekly flows from Watts Bar Dam from October 2006 to September 2007 are shown in Figure 6. Weekly average flows were 83% less than the 30-year long-term weekly average flows from 1976 through 2006. The Tennessee Valley has experienced an exceptional drought and it was the worst on record in the last 118 years. Even with the low flow conditions resulting from the drought, annual aquatic monitoring has not reflected negative trends in the aquatic communities in Chickamauga Reservoir. Spawning success of fish or year-class strength would be apparent in subsequent years to come.
6
Literature Cited Dycus, D. L. and D. L. Meinert. 1993. Reservoir Monitoring, Monitoring and Evaluation of Aquatic Resource Health and Use Suitability in Tennessee Valley Authority Reservoirs.
Tennessee Valley Authority, Water Resources, Chattanooga, Tennessee, TVAIWM-93/15.
Tennessee Department of Environment and Conservation. 2000. Draft NPDES Permit Number TN0026450.
7
m m-m-m-m-m-n m-m-m-
m m-m--m Table 1. Scoring Results for the Twelve Metrics and Overall Scores for all RFAI Sites Sampled in Chickamauga Reservoir, 2007.
Forebay. (
Forebay I Transition Inflow TRM 472.3 TRM 482. 0 TRM 490.5 TRM 529.0
,Downstream Site Upstream Site Metric Obs Score Obs Score lObs Score Obs Score A. Species richness and composition
- 1. Number of species
- 2. Number of centrarchid species
- 3. Number of benthic invertivores
- 4. Number of intolerant species
- 5. Percent tolerant individuals
- 6. Percent dominance by one species
- 7. Number non-native species
- 8. Number of top carnivore species B. Trophic composition
- 9. Percent top carnivores
- 10. Percent omnivores electrofishing gill netting electrofishing gill netting electrofishing gill netting electrofishing gill netting electrofishing gill netting 22 7
1
- 86:6 27.1 55.3 26.1 3.2 0.4 8
6
- 66.:8 1,0.9, 27.5 3
0.5 1.5 0.5 1.5 1.5 2.5 5
26 6
j 3
175.7 S37.7 36.3 31.6 0.7 0.4 9
3 5
1 3
0.5 0.5 1.5 0.5 2.5 2.5 5
1.5 1.5 2.5 0.5 31 5
27 8
5 7
3 1
6 4
3 6
76.5 0.5 75.6 29 1.5 29.7 1'.55 51.9 27.7 J.5:
2 251 0.3 1
5, 8
10.7 1.5 12 62 2.5 33.9 1.5 16.1 27.7 1.5 1.5 6.4 2.5 40.4 1.5:: 1 51.3 8
m M
1m M
M M
M 1
1 M M
M M
M m
Table 1. (continued)
Forebay '
Forebay Transition`-ý Inflow TRM 472.3 TRM 482.0 TRM 490.5 TRM 529.0 Downstream Site: Upstream Site Metric Obs 'Scorel Obs Score Obs' Scoreb", Obs Score C. Fish abundance and health
- 11. Average number per run electrofishing },.45.3 0.5 37.3 0.5 54'9 0.5 51.6 3
gill netting 28 2.5 1 22.8 1.5 32.1 2.5
- 12. Percent anomalies electrofishing 0.6 2.5 1.4 2.5 1.6 2.5 3.2 3
gill netting
-0.4, 2.5 1.3 2.5 0.6,
,2.5 RFAI 41' 38
-44 42 I
Good Fair Good Good
- TRM 472.3 and 482 scored with forebay criteria, TRM 490.5 scored with transition criteria, and TRM 529 scored with inflow criteria (Refer to Table 3). RFAI Scores: 12-21 ("Very Poor"), 22-31 ("Poor"), 32-40 ("Fair"), 41-50 ("Good"), or 51-60 ("Excellent")
Table 2. RFAI Scores Developed Using the RFAI Metrics from Samples Collected During 1993 to 2007, Upstream and Downstream of Sequoyah Nuclear Plant.
Station Reservoir Location 1993 1994 1995 1997 1999 2000* 2001 2002* 2003 2004* 2005 2006 2007 1993-2007 Average TRM Upstream Chickamauga 490.5 49 40 46 39 45 46 45 51 42 49 48 47 44 45 TRM 41 48 46 43 45 41 39 37 38 42 Downstream Chickamauga 482.0 TRM Downstream Chickamauga 472.3 44 44 47 39 45 45 48 46 43 43 46 44 41 44
- The 2000, 2002, 2004, and 2006 sample years were not part of the VS monitoring program, however the same methodology was applied.
9
M 1=1 M-M M
M M
M M
M Table 3. Scoring Criteria for Forebay, Transition, and Inflow Sections of Upper Mainstem Reservoirs in the Tennessee River System. Upper Mainstem Reservoirs include Chickamauga, Fort Loudoun, Melton Hill, Nickajack, Tellico, and Watts Bar.
Scoring Criteria Forebay Transition Inflow Metric Gear 1
3 5
1 3
5 1
3 5
A. Species richness and composition
- 1. Total species Combined
<14 14-27
>27
<15 15-29
>29
<14 14-27
>27
- 2. Total Centrarchid species Combined
<2 2-4
>4
<2 2-4
>4
<3 3-4
>4
- 3. Total benthic invertivores Combined
<4 4-7
>7
<4 4-7
>7
<3 3-6
>6
- 4. Total intolerant species Combined
<2 2-4
>4
<2 2-4
>4
<2 2-4
>4
- 5. Percent tolerant individuals Electrofishing
>62%
31-62%
<31%
>62%
31-62%
<31%
>58% 29-58%
<29%
Gill netting
>28%
14-28% <14%
>32%
16-32%
<16%
- 6. Percent dominance by 1 species Electrofishing
>50% 25-50% <25%
>40% 20-40%
<20%
>46% 23-46%
<23%
Gill netting
>29%
15-29% <15%
>28%
14-28%
<14%
- 7. Percent non-native species Electrofishing
>4%
2-4%
<2%
>6%
3-6%
<3%
>17%
8-17%
<8%
Gill netting
>16%
8-16%
<8%
>9%
5-9%
<5%
- 8. Total top carnivore species Combined
<4 4-7
>7
<4 4-7
>7
<3 3-6
>6 B. Trophic composition
- 9. Percent top carnivores Electrofishing
<5%
5-10%
>10%
<6%
6-11%
>11%
<11% 11-22%
>22%
Gill netting
<25%
25-50% >50%
<26%
26-52% >52%
- 10. Percent omnivores Electrofishing
>49%
24-49%
<24%
>44%
22-44% <22%
>55% 27-55%
<27%
Gill netting
>34%
17-34%
<17%
>46%
23-46% <23%
C. Fish abundance and health
- 11. Average number per run Electrofishing
<121 121-241
>241
<105 105-210
>210
<51 51-102
>102 Gill netting
<12 12-24
>24
<12 12-24
>24
- 12. Percent anomalies Electrofishing
>5%
2-5%
<2%
>5%
2-5%
<2%
>5%
2-5%
<2%
Gill netting
>5%
2-5%
<2%
>5%
2-5%
<2%
10
Table 4. Species Listing and Catch Per Unit Effort for Forebay Transects on Chickamauga Reservoir During Fall Electrofishing and Gill Netting, 2007. (Electrofishing Effort =
300 Meters of Shoreline, Gill Netting Effort = 10 Net-Nights)
Forebay TRM 472.3 Forebay TRM 482.0 Electrofishing Electrofishing Gill Netting Electrofishing Electrofishing Gill Netting Catch Rate Catch Rate Catch Rate Catch Rate Catch Rate Catch Rate Common Name Per Per Per Per Per Per Run Hour Net Night Run Hour Net Night Spotted gar 0.07 0.30
-0.10 0.27 1.27 0.10 Longnose gar 0.10 Skipjack herring 2.40 1.80 Gizzard shad 4.60 20.54 5.90 7.27 34.49 7.20 Threadfin shad 0.13 0.60 0.13 0.63 0.10 Hybrid shad 0.30 Common carp 0.10 0.10 Golden shiner 0.13 0.60 0.10 Emerald shiner 2.67 12.66 Spotfin shiner 0.27 1.19 1.33 6.33 Bluntnose minnow 0.07 0.32 Bullhead minnow 0.20 0.95 Spotted sucker 0.53 2.53 Golden redhorse 0.07 0.32 Blue catfish 1.10 0.07 0.32 3.20 Channel catfish 0.20 0.89 0.60 0.80 3.80 0.80 Flathead catfish 0.47 2.08 0.30 0.07 0.32 0.40 Yellow bass 7.30 3.20 Warmouth 0.20 0.89 Redbreast sunfish 7.67 34.23 4.53 21.52 0.10 Green sunfish 0.47 2.08 0.20 0.95 Bluegill 25.07 111.90 0.70 13.53 64.24 0.80 Longear sunfish 0.40 1.79 0.60 2.85 Redear sunfish 1.47 6.55 0.30 2.67 12.66 0.30 Smallmouth bass 0.20 0.89 0.10 0.07 0.32 0.10 Spotted bass 0.87 3.87 1.90 0.60 2.85 1.20 Largemouth bass 1.07 4.76 0.90 1.33 6.33 0.20 Black crappie 0.07 0.30 5.70 0.07 0.32 2.10 Yellow perch 0.40 1.79 0.60 0.13 0.63 Freshwater drum 0.60 Brook silverside 0.13 0.60 Inland silverside 1.47 6.55 0.13 0.63 Total 54.95 240.93 32.10 37.34 177.24 22.80 Number Samples 15 10 15 10 Number Collected 680 280 560 228 Species Collected 20 15 23 20 11
Table 5. Species Listing and Catch Per Unit Effort for the Transition and Inflow Transects on Chickamauga Reservoir During Fall Electrofishing and Gill Netting, 2007.
(Electrofishing Effort = 300 Meters of Shoreline, Gill Netting Effort = 10 Net-Nights)
Transition TRM 490.5 Inflow TRM 529.0 Electrofishing Electrofishing Gill Netting Electrofishing Electrofishing Catch Rate Catch Rate Catch Rate Catch Rate Catch Rate Common Name Per Per Per Per Per Run Hour Net Night Run Hour Longnose gar 0.10 0.07 0.32 Spotted gar 1.67 7.31 0.10 Skipjack herring 3.20 Gizzard shad 16.33 71.64 7.70 7.40 35.02 Threadfin shad 0.07 0.29 0.07 0.32 Common carp 0.27 1.17 0.07 0.32 Golden shiner 1.67 7.31 0.20 0.07 0.32 Emerald shiner 2.40 10.53 0.40 1.89 Spotfin shiner 0.60 2.63 1.80 8.52 Steelcolor shiner 0.07 0.32 Bluntnose minnow 0.20 0.88 Bullhead minnow 0.07 0.29 Smallmouth buffalo 0.07 0.29 0.10 Northern hog sucker 0.07 0.32 Spotted sucker 0.13 0.58 0.30 0.33 1.58 Black redhorse 0.13 0.63 Golden redhorse 0.60 2.84 Blue catfish 1.10 Channel catfish 0.20 0.89 0.60 0.80 3.79 Flathead catfish 0.47 2.08 0.30 1.87 8.83 Yellow bass 7.30 0.47 2.21 Striped bass 0.07 0.32 Rock bass 0.07 0.32 Warmouth 0.20 0.89 0.40 1.89 Redbreast sunfish 7.67 34.23 1.47 6.94 Green sunfish 0.47 2.08 0.20 0.95 Bluegill 25.07 111.90 0.70 26.80 126.81 Longear sunfish 0.40 1.79 0.60 2.84 Redearsunfish 1.47 6.55 0.30 3.60 17.03 Smallmouth bass 0.20 0.89 0.10 0.27 1.26 Spotted bass 0.87 3.87 1.90 2.00 9.46 Largemouth bass 1.07 4.76 0.90 1.13 5.36 Black crappie 0.07 0.30 5.70 0.27 1.26 12
Table 5. (continued)
Transition TRM 490.5 Inflow TRM 529.0 Electrofishing Electrofishing Gill Netting Electrofishing Electrofishing Catch Rate Catch Rate Catch Rate Catch Rate Catch Rate Common Name Per Per Per Per Per Run Hour Net Night Run Hour Yellow perch 0.40 1.79 0.60 Logperch 0.33 1.58 Freshwater drum 0.20 0.95 Brook silverside 0.13 0.60 Inland silverside 1.47 6.55 Total 54.95 240.93 32.10 51.63 244.20 Number Samples 15 10 15 Number Collected 680 280 774 Species Collected 20 15 29 13
Table 6. Individual Metric Ratings and the Overall RBI Field Scores for Upstream (TRM 490.5) and Downstream (TRM 482) Sampling Sites Near Sequoyah Nuclear Plant, Chickamauga Reservoir, 2007.
TRM 490.5 TRM 482 Upstream Downstream Metric Obs Rating Obs Rating
- 1. Average number of taxa 4.7 5
4.1 3
- 2. Proportion of samples with long-lived organisms 0.5 3
0.6 3
- 3. Average number of EPT taxa 0.3 1
0.5 3
- 4. Average proportion of oligochaete individuals 5.2 5
6.3 5
- 5. Average proportion of total abundance comprised by 93.4 1
90.6 3
the two most abundant taxa
- 6. Average density excluding chironomids and 56.7 1
125 3
oligochaetes
- 7. Zero-samples - proportion of samples containing no 0
5 0
5 organisms Benthic Index Score 21 25 Fair Good
- TRM 490.5 scored with transition criteria, TRM 482 scored with forebay criteria.
RBI Scores: 7-12 ("Very Poor"), 13-18 ("Poor"), 19-23 ("Fair"), 24-29 ("Good"), or 30-35
("Excellent")
14
Table 7. Average Mean Density Per Square Meter of Benthic Taxa Collected at Upstream (TRM 490.5) and Downstream (TRM 482) Sampling Sites Near Sequoyah Nuclear Plant, Chickamauga Reservoir, 2007.
Chickamauga Reservoir TRM 490.5 TRM 482 Upstream Downstream Species Mean Density Mean Density Tubellaria Tricladida Planariidae 0
0 Oligocheata Oligochaetes 28 13 Hirudinea 10 3
Crustacea Amphipoda 0
0 Isopoda 0
0 Insecta Ephemeroptera Mayflies Ephemeridae Hexagenia (<10 mm) 0 12 Hexagenia (>10 mm) 10 18 Megaloptera Sialidae Sialis sp.
0 0
Odonata 0
0 Anisoptera Zygoptera Trichoptera Caddisflies 0
2 Plecotera Stoneflies 0
0 Coeleoptera 0
0 Diptera Ceratopogonidae 0
0 Chironomidae Chironomids 403 142 Gastropoda Snails 0
5 Basommatophora Ancylidae Ferrissia sp.
0 0
Bivalvia Unionidae Mussels 0
0 15
Table 7. (continued)
Chickamauga Reservoir TRM 490.5 TRM 482 Upstream Downstream Species Mean Density Mean Density Veneroida Corbiculidae Corbicula (<10mm) 3 52 Corbicula (>10mm) 8 18 Sphaeriidae Fingernail clams 25 15 Dreissenidae Dreissena polymorpha 0
0 Number of samples 10 10 Total Mean Density/SQ Meter 487 280 Total area sampled (SQ Meters) 0.6 0.6 16
Table 8. RBI Field Scores from Data Collected During 1994-2007 at Chickamauga Reservoir Transition (TRM 490.5) and Forebay (TRM 482.0 and TRM 472.3) Sites.
Site Reservoir Location 1994 1995 1997 1999 2000 2001 2002 2003 2004 2005 2006 2007 Averag e
Upstream Chickamauga TRM 490.5 33 29 31 31 23 25 25 31 31 31 27 21 28 Downstream Chickamauga TRM 482.0 23 31 29 29 33 31 31 25 29 Downstream Chickamauga TRM 472.3 31 27 29 25 27 27 21 27 29 27 29 19 27 RBI Scores: 7-12 ("Very Poor"), 13-18 ("Poor"), 19-23 ("Fair"), 24-29 ("Good"), or 30-35 ("Excellent")
Note: No data were collected for 1996 and 1998.
Table 9. Electrofishing Catch Rates and Population Characteristics of Black Bass Collected During Chickamauga Reservoir, 1995-2007.
Spring Sport Fish Surveys on Year 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 EF Catch Rate Mean Weight (no./hr.)
(lbs.)
61.1 1.5 39.4 1.3 72.6 1.3 40.9 1.3 62.0 1.3 57.4 1.1 34.5 0.8 34.4 1
10.6 1.3 37.2 1.1 40.2 1
51 1.2 62 1.2
% Harvestable 63.2 71.7 36.9 60.2 65.8 59.4 45.2 51.2 60.7 44.5 70.1 42.6 61.8 Bass >4 lbs.
20 14 15 13 23 9
0 3
3 9
8 13 28 Bass >5 lbs.
8 7
9 6
8 4
0 0
1 2
4 9
12 Largest bass (lbs.)
6.7 7.1 6.2 6.6 6.4 6.6 2.8 4.8 6.1 6.6 8.7 7.9 8.3 17
M M m
M M m
M M-- M M
M M
M m
M M
M Table 10. Black Bass Catch Per Hour Compared to Habitat Types by Location During Spring Sport Fish Surveys on Chickamauga Reservoir, 2007.
Habitat Designation Reservoir and Site Good Fair Poor Chickamauga Harrison Bay 74 (4) 62 (4) 54 (4)
Sale Creek 53 (4) 64 (4) 33 (4)
Skull Island 78 (2) 80 (8) 25 (2)
Catch per hour = number of fish collected per hour
( ) = number of transects sampled at each location 18
Annual RFAI Scores Upstream and Downstream of SQN 60 50 40 0u) 30 7R
---e--Wr Upstream TRM 490.5 U,.
5160 Downstream TRM 482.0 Forebay TRM 472.0 20 10 0
1993 1994 1995 1997 1999 2000 2001 2002 2003 2004 2005 2006 2007 year Figure 1. Annual Chickamauga Reservoir RFAI scores for sample years between 1993 and 2007.
19
LENGTH FREQUENCY Largemouth bass CHICKAMAUGA - 2007 I
120 100 80 60 401 20 0
107110 98_
rH-hi K] HH78 H iiiin HH 31 U UUUU h 20 5"
5-1 3,~fl 0 0 00 0
1 3
5 7
9 11 13 15 17 19 21 23 25 27 INCH GROUP Figure 2. Length frequency distribution for largemouth bass collected from Chickamauga Reservoir (all sites) during the Spring Sport Fish Survey, 2007.
RSD VALUES (Quality)
MAINSTEM RESERVOIRS SPRING 2007 I
Ii' I
I Reservoir Figure 3. Relative stock density values for Tennessee River reservoirs calculated from 2007 Spring Sport Fish Survey samples.
20
PSD VALUES MAINSTEM RESERVOIRS SPRING 2007 I
100 90 80-70-60 -
50 40-30 -
20 10 0
83
__O-rlr-_---*-42___ýýýýýý 56 Desimble PSD P-ge I I i I
I I
I I Reservoir Figure 4. Proportional stock density values for Tennessee River reservoirs calculated from 2007 Spring Sport Fish Survey samples.
Chickamauga Wr Largemouth bass 2007 SPercent -#
of Fish I
120 100 80 60 40 20 0
350 300 250 200 150 100 50 0
0-7 8-11 12-14 15-19 20-24 25-+
Relative Stock Size by Inch Group Figure 5. Chickamauga Reservoir mean relative weights (Wr) for largemouth bass by RSD category and number of fish during 2007.
21
m mmm m
m m
m
-n--m-m--
Weekly Average Flows from Watts Bar Dam, 2007 vs. Long Term (1976-2006) 50000 45000 FY 2007 Long Term 40000 35000 30000 25000 u-. 20000 15000 10000 5000 0
roCO
'0AAAA Nz Qs 0
Ot,'
Z§5 Month Figure 6. Weekly average flows in cubic feet per second from Watts Bar Dam during October 2006 through September 2007 with long term trend line from 1976 through 2006.
22