ML20078A178
| ML20078A178 | |
| Person / Time | |
|---|---|
| Site: | Mcguire, McGuire  |
| Issue date: | 12/31/1993 |
| From: | DUKE POWER CO. |
| To: | |
| Shared Package | |
| ML20078A161 | List: |
| References | |
| NUDOCS 9501240307 | |
| Download: ML20078A178 (93) | |
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., m LAKE NORMAN: 1993
SUMMARY
1 l MAINTENANCE MONITORING PROGRAM l McGUIRE NUCLEAR STATION: NPDES No. NC0024392 n - I m"** Ju::r , l O , I DUKE POWER COMPANY 13339 IIAGERS FERRY ROAD l HUNTERSVILLE, NORTII CAROLINA 28078 l l l l
. DECEMBER 1994
'O 9501240307 950110 9 DR ADOCK 0500 t _ _ _ _ _ . ~ . . _ _ _ _ _ _ _ . _ . _ _ _ _ _ _ . _ _
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t V) TABLE OF CONTEN'/S Page EXECUTIVE
SUMMARY
i LIST OF TABLES v LIST OF FIGURES vi CHAPTER 1: McGUIRE OPERATIONAL DATA 1-1 Introduction 1-1 Operational data for 1993 1-1 Thermal Modeling 1-1 Results and Discussion 1-2 Summary 1-4 Literature Cited 1-5 CHAPTER 2: WATER CHEMISTRY '2-1 Introduction 2-1 Methods and Materials 2-1 Results and Discussion 2-2 Future Water Chemistry Studies 2-8 Summary 2-9 Literature Cited 2-9 m CHAPTER 3: PHYTOPLANKTON 31 ' Introduction 3-1 Methods and Materials 3-1 Results and Discussi~on 3-2 Future Phytoplankton Studies 3-6 Summary 3-6 Literature Cited 3-7 CHAPTER 4: ZOOPLANKTON 4-1 Introduction 4-1 Methods and Materials 4-1 Results and Discussion 4-2 Future Zooplankton Studies 4-5 Summary 4-5 Literature Cited 4-6 CHAPTER 5: FISHERIES s. Introduction 5-1 Methods and Materials 5-2 Results and Discussion 5-2 Future Fisheries Studies 5-3 Literature Cited 5-3 APPENDIX. Progress report on summer habitat selection of striped bass in Lake Norman (Federal Aid in Fish Restoration Project F23-17) A-1 l i
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i i I EXECUTIVE
SUMMARY
i OPERATIONAL DATA-Both units were operational during July, August, and September, when conservation of cool j water and discharge temperatures are most critical. The average monthly discharge ; temperature was below the permit limit for all months and use oflow level intake water was l not necessary for compliance with the thermal limit for McGuire Nuclear Station (MNS). j This helped to conserve habitat for cool water fish in Lake Norman. i THERMAL MODELING ; As in the previously submitted 316(a) demonstration report for MNS in 1985, the meteorology for 1953 still provides a worst case scenario for MNS and Marshall Steam j Station (MSS) discharge temperatures. Th predicted take surface area affected by the thermal plumes from both MNS and MSS (at 100% load June-August,90% load the rest of ! p the year) are less than the limit established by these stations' NPDES permits (i.e.,3500 V acres). This is true for both the 90*F (32.2*C) isotherm and the 5*F (2.8*C) above ! background temperature isotherm. j ) l Use of the Low Level Intake (LLI) pumps has not been necessary to maintain compliance ! with the permitted thermal limits. In the event that LLI pumps have to be used, the predicted j thermal profiles indicate that the primary temperature change would occur in the hypolimnion only during August, when these waters are usually anoxic and consequently l have very low fish densities. l WATER CHEMISTRY DATA 1 Temporal and spatial trends in water temperature and DO data collected monthly in 1993 l were similar to those observed historically. Reservoir-wide isotherm and isopleth j information for 1993, coupled with heat content and hypolimnetic oxygen data, illustrated ! that Lake Norman exhibited thermal and oxygen dynamics efharacteristic of historic j I 1 ; k
4 t 1 Q conditions and similar to other Southeastem reservoirs of comparable size, depth, flow conditions, and trophic status. Availability of suitable pelagic habitat for adult striped bass in Lake Norman in 1993 was generally similar to historic conditions. Reservoir-wide habitat climination was observed to persist for approximately 2 months in the 1993 summer. This is somewhat longer than the duration of complete habitat elimination observed in the summer of 1992, but similar to earlier summers. All chemical parameters measured in 1993 were within the concentration ranges previously reported for the lake during both MNS preoperational and operational years. PHYTOPLANKTON DATA Chlorophyll a concentrations at all locations during 1993 were within historical ranges and in the mesotrophic range. They were generally higher than those observed during 1987 through 1990 but were similar to those observed in 1991 and 1992. v Total phytoplankton densities and biovolumes remained similar to those oNrved in previous I years. Phytoplankton taxonomic composition during 1993 was similer to that observed dur...g the same months of 1992. Diatoms, green algae and cryptophytes were the most numerically abundant classes of algae observed. Diatoms and cryptophytes generally dominated the phytoplankton biovolumes in all months except August when the phytoplankton conununity consisted of a diverse assemblage dominated by small green algae. Dinoflagellates were sporadically dominant in terms of biovolume at some locations during all months except November. Blue-green algae were never a dominant at any location or time in 1993. ZOOPLANKTON DATA Total zooplankton standing crops were generally highest in May and lowest in November during 1993. Zooplankton densitics, in general, were slightly higher in eplimnetic samples than in whole column samples. Total zooplankton densities at Mixing Zone locations were not significantly ditTerent from background locations during any quder in 1993. The typical t ii
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trend of increasing zooplankton densities from downlake to uplake was observed only in November in 1993. The range of total zooplankton densities observed during 1993 was l similar to the ranges observed since 1987. Overall, rotifers dominated zooplankton standing crops in 1993, as they did in 1992, followed closely in importance by copepods. Cladocerans were dominant numerically on only one occasion in 1993. Major rotifer taxa observed in 1993 were Keratella, Polyarthra an; Synchaeta. Copepod populations were dominated by immature forms (nauplii and ! cyclopoid copepodids). As in previous years, Bosmina was the most abundant cladoceran l taxa observed at all locations. Overall, zooplankton taxonomic composition in 1993 was similar to that observed in previous years. FISHERIES DATA Hydroacoustic density estimates of limnetic fish in lower Lake Norman were similar to ranges observed in other areas of the reservoir. Densities were lower in the heated water
,O plume on August 4,1993, than in the surrounding areas,. A clumped distribution pattern is evident, with densities ranging from less than 10,000 to greater than 90,000/ha in the MNS mixing zone and in areas of the reservoir with ambient water temperatures. Surface water
) temperatures in the discharge area during August were 35 C. This is higher than the preferred temperatures of threaGn shad, the predominant species in the limnetic area of the reservoir (Duke Power Company 1993). Nearly all (99.6%) of the fish collected in the purse seine in August were threadfin shad. The only other species sampled with the purse seine in lower Lake Norman was black crappie. Dead and dying striped bass were observed during the last 2 weeks in July 1993 in the MNS mixing zone. On July 23, fourteen dead striped bass were counted in the main channel from the dam to Marker 7, approximately 6 miles above the dam and 2 miles above the confluence of Davidson Creek and the main channel. On July 30, eleven dead striped bass were counted from the dam to Marker I A, approximately 1.5 miles above the dam. Only two of the 25 dead striped bass observed were larger than 5 pounds. Anglers fishing the area for striped bass were catching large numbers of fish less than the 20 inch size limit and returning them iii
l T to the lake. This likely contributed to the large number of dead small fish observed. Striped . bass less than 5 pounds have not been reported in the literature as stressed by high summer , water temperatures; however, recent research in Tennessee has shown angling mortalities of l greater than 60% for striped bass caught in the summer (Phil Bettoli, personal l communication). L t 9 [
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i' V LIST OF TABLES Page ... Table 1-1 McGuire Nuclear Station (MNS) 1991'capaci / factors 1-6 . I Table 1-2 Predicted MNS discharge temperatures 1-7 ! Table 1-3 MNS and Marshall Steam Station (MSS) operating conditions 1-8 Table 1-4 Hydrological and Meteorological parameters for 1953 1-8 ! > Table 1-5 90 F(32.2*C) isotherms for MNS and MSS 1-9 ! Table 1-6 5'F(2.8'C) above background isotherms for MNS and MSS 1-9 ; Table 2-1 Water chemistry monitoring program schedule 2-12 Table 2-2 Water chemistry methods and detection limits 2-13 Table 2-3 Heat content calculations for Lake Norman in 1993 2-14 : Table 2-4 Comparison of Lake Norman with TVA reservoirs 2-15 j Table 2-5 Water chemistry data for 1991 for Lake Norman 2-16 ( Table 3-1 Mean chlorophyll a concentrations in Lake Norman 3-9 Table 3-2 Duncan's multiple range test for Chlorophyll a 3-10 j Table 3-3 Total phy%1ankton densities from Lake Norman 3-11 j Table 3-4 Duncan's multiple range test for phytoplankton densities 3-12 Table 3-5 Duncan's multiple range test for seston in Lake Norman 3-13 f Table 4-1 Total zooplankton densities and composition 4-7 I 4-9 Table 4-2 Duncan's multiple range test for zooplankton densities Table 4-3 Zooplankton taxa identified in Lake Norman 1993 4-10 f L 9 h V i i
r b LIST OF FIGURES
-Page Figure 1-1 Predicted average temperature profiles for Lake Norman 1-10 Figure 2-1 Map of sampling locations on Lake Nonnan 2-19 !
Figure 2-2 Monthly precipitation near McGuire Nuclear Station 2-20 + Figure 2-3 Monthly mean temperatum profiles in background zone 2-21 ; Figure 2-4 Monthly mean temperature profiles in mixing zone 2-23 . Figure 2-5 Monthly temperature and dissolved oxygen data 2-25 ; Figure 2-6 Monthly mean dissolved oxygen profiles mixing zone 2-26 Figure 2-7 Monthly mean dissolved oxygen in background zone 2-28 l Figure 2-8 Monthly isotherms for Lake Norman 2-30
- Figure 2-9 Monthly dissolved oxygen isopleths for Lake Norman 2-33 Figure 2-10 Striped bass habitat in Lake Norman 2-36 Figure 3-1 Chlorophyll a measurements of Lake Norman 3-14 ;
Figure 3-2 Phytoplankton chlorophyll a euphotic zone 3-15 ( Figure 3-3 Total phytoplankton densities and biovolumes 3-16 l Figure 3-4 Class composition in euphotic zone 3-17 l Figure 4-1 Zooplankton density by sample location in Lake Nonnan 4-11 j Figure 4-2 Lake Norman zooplankton densities among years 4-12 : I Lake Norman zooplankton composition in 1993 4-13 Figure 4-3 : Figure 4-4 - Lake Norman zooplankton density by group 4-14 : Figure 5-1 Fish densities in lower Lake Norman August 4,1993 '5-4 [ I 4 vi
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' 'U CHAPTER 1 : McGUIRE NUCLEAR STATION i OPERATIONAL DATA : INTRODUCTION }> In addition to operational data for 1993, results of thermal modeling runs as requested per the [ NPDES permit are included in this years annual environmental summary report. This mobling was done to assess the impact of 100% load factor during the months of June, July, anu August and 90% the remainder of the year. OPERATIONAL DATA FOR 1993 Both units were operational during July, August, and Sep' ember, when conservation of cool water and discharge temperatures are most critical (Table !-1). During these months the thermal limit f'- MNS increases from a monthly average of 95 F to 990F. The average l O- monthly discharge temperature was 94.1 F (34.5 C) for July,91.9 F (33.3 C) for August, and 83.8 F (28.80C) for September 1993. Use oflow level intake water was not necessary . j for compliance with the themial limit for MNS. This helped to conserve habitat for cool i water fish in Lake Norman. The volume of cool water in Lake Norman is tracked throughout the year to ensure that an adequate volume is'available to comply with both the Nuclear j Regulatory Commission Technical Specification requirements and the NPDES monthly i discharge water temperature limit. ; e ! THERMAL MODELING RESULTS Based on a request made by the North Carolina Department of Environmental Management -l (NCDEM), Duke Power has completed additional moc.eling analyses of the thermal regime { in Lake Norman resulting from operations at McGuire Nuclear Station (MNS) and Marshall i Steam Station (MSS). Specifically, NCDEM r& u#t ested that Duke "remodel and assess the l 1 impact of 100% load factor during the months of June-August and 90% for the remainder of l the year." l-1 ,
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O ! The model set up for this additional analysis is basically the same as it was for the June 1985 . 316(a) demonstration report (Duke Power Company 1985). Please refer to that repon for a j i description of the model, the assumptions made, validation of the model, and predictiu results assuming a year-round 90% load factor for both MNS and MSS. Meteorology
. In order to demonstrate worst case conditions, it was necessary to determine which year produced meteorological conditions such that maximum discharge temperatures at MNS and i MSS would result. Meteorological records from the Charlotte Airport (approximately 17 l miles from MNS and 25 miles from MSS) were obtained for years 1951 through 1993. By ;
running this entire period of meteorological data through the thermal model (set in predictive mode),1953 produced the highest June-August discharge temperatures, as shown in Table 1- ,
- 2. (Note that this was also the case for the 316(a) demonstration report submitted in 1985.)
) Therefore,1953 meteorological data was used to obtain the model results discussed in the ;
i following section. ! Results and Disen=eion i For the 1953 predictive model run, the uad (or capacity) factor was 100% for June-August i and 90% the remainder of the year. Tables 1-3 through 1-6 provide the model results for both MNS and MSS for the June-August period when both stations were operating at 100%. Note that results for the months having a capacity factor of 90% are given in the 316(a) i demonstration report (Duke Power Company 1985). , Table 1-3 provides Condenser Cooling Water'(CCW) data for both MNS and MSS. b Although this data is fairly self-explanatary, the discharge temperature and CCW usage at , 1-2
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i MNS warrant further discussion. The thermal model (when run in a predictive mode) will ~
.l not let monthly average discharge temperatures at MNS ' exceed 37.2*C (99.0*F). To. l accomplish this, the Low Level Intake pumps (LLI) at MNS are judiciously used to bring cool water from the bot *am of Lake Norman to the surface so it can be mixed with the ; . warmer water brought in by the Upper Level Intake pumps (ULI) located near the surface of l Lake Norman. In doing this, the overall temperature of the intake water at MNS is reduced ;
enough to keep the station's discharge temperature in compliance with its 37.2*C (99.0*F) ., rnonthly average discharge limit during the summer months. Refer to the MNS 316(a) { demonstration report (Duke Power Company 1985) for a description and drawings of the LLI and UL1 pumping structures. I t For the June-August period, LLI water requirements for the 1953 predictive run were 0 cfs, f
. 108 cfs, and 173 cfs, respectively (Table 1-3). This amount of flow is very small when ;
compared to the ovesdl station CCW requirements of 4580 cfs. Thus, the majority of CCW . water used for the 1953 worst case scenario comes from the surface waters of Lake Norman !
)' and only a small amount from the cooler bottom layers. This is reflected in the predicted thermal profiles for June, July, and August (Figure 1-1). For the vast majority of years, the j model predicts that the LLI pumps will not have to operate to comply with the stations !
- NPDES discharge temperature limit, even with capacity factors of 100% during the s uner months. This has also been the experience of station personnel since the 37.2*C.(99.0*F) monthly average discharge limit was granted. Use of the LLI pumps has not been necessary to maintain compliance with tlic permitted thermal limits. In the event that LLI pumps have l to be used, the predicted thermal profiles indicate that the primary temperature change would l
occur in the hypolimnion dur'ing only August, when these waters are usually anoxic and j consequently have very low fish densities (See Chapters 2 and 5) { l l t I D l-3 . i
( b) Table 1-4 provides the hydrological and meteorological parameters used for the 1953 predictive model run. Note that the river flow values are simulated Cowans Ford Hydro discharge flow rates. Also, the meteorological data was obtained from the Charlotte Airport. The lake surface area and shore-line affected by the 90FF (32.2*C) isotherm resulting from predicted thermal discharges from MNS and MSS me given in Table 1-5. The largest 90 F (32.2*C) isotherm from MNS occurred during July (1897 acres, or approximately 7% of Lake Norman's total surface area). For MSS, the largest 90*F (32.2*C) isotherm occurred during August (336 acres, or approximately 1% of Lake Norman's total surface area). Note that neither of these isotherm acreages are greater than the limits established in these stations' NPDES permits (i.e., 3500 acres). Maximum shore-line affected by the 90*F (32.2 C) isotherm is 25 km (16 mi), or 3% of the total shore-line for MNS and 3 km (2 mi), or approximately 0.05% of the total shore-line for MSS. The lake surface area and shore-line affected by the 5*F (2.8 C) above background h temperature' isotherm resulting from predicted thermal discharges from MNS and MSS are given in Table 1-6. The largest area affected by MNS occurred during August (2100 acres, or approximately 7% of Lake Norman's total surface area). For MSS, the largest area also occurred during August (579 acres, or approximately 2% of Lake Norman's total surface area). Note that neither of these isotherm acreages are greater than the limits estabikhed in these stations' NPDES permits (i.e.,3500 acres). Maximum shore-line affected by the 5*F (2.8 C) above background isotherm is 27 km (17 mi),or 3% of tile total shore-line for MNS and 9 km (6 mi), or approximately 1% of the total shore-line for MSS. m l-4
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SUMMARY
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- 1. The meteorology for 1953 still provides a worst case scenario for MNS and MSS discharge temperatures. Note that 1953 meteorological data was also used to. predict worst case conditions in the 1985 MNS 316(a) demonstration report.
- 2. Use of the LLI pumps have not been necessary to maintain compliance with u.e ~.irrent j permitted thennal limits. In the event that LLI pumps has to be used, the predicted l thermal profiles indicate that the primary temperature change would occur in the- i hypolimnion only during August, when these waters are usually anoxic and consequently i have very low fish densities.
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- 3. The predicted lake surface area affected by the thermal plumes from both MNS and MSS
. (at 100% load June-August, 90% load the rest of the year) are less than the limit ,
established by these stations' NPDES permits (i.e.,3500 acres). This is true for both the l 90*F (32.2*C) isotherm and the 5'F (2.8*C) above background temperature isothenn. l f LITERATURE CITED Duke: Power Company.1985. McGuire Nuclear Station,316(a) Demonstration. Duke Power ! Company, Charlotte, NC. 5
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LJ Average monthly capacity factors (%) calculated from daily unit capacity Table 1-1. factors [ Net Generation (Mwe per unit day) x 100 / 24 h per day x 1129 mw per unit] and monthly average discharge water temperatures for McGuire Nuclear Station during 1993 CAPACITY FACTOR (%) TEMPERATURE Month ' Unit 1 Unit 2 Station Monthly Average Average Average Average OF OC January 101.0 101.9 101.4 67.0 19.4 February 101.90 89.0 95.4 65.1 18.4 March 35.2 94.9 65.1 61.3 16.3 April 0 101.8 50.7 69.3 20.7 May 0 98.1 48.7 75.0 23.9 June 38.2 78.0 58.1 84.0 28.9 July 96.6 0 47.9 94.1 34.5 August 65.2 0 32.0 91.9 33.3 September 0 34.2 16.5 83.8 28.8 O i October 40.3 49.2 44.8 76.8 24.9 U November December 95.3 100.6 100.1 82.8 97.7 91.7 75.5 69.6 24.2 20.9 I s l-6
1 1 1 [m (j} Table 1-2: Predicted MNS discharge temperatures (MNS and MSS capacity factors = 100% June, July, and August; 90% the remainder of the year). ]
- l JUN-AUG YR JAN l'EB MAR APR MAY NN JUL AUG SEP OCT NOV DEC AVO 1951 72.5 71 S 74.8 77.4 84.1 9/.2 98.0 99.0 94.1 86.9 77.3 73.7 96.1 1932 73.9 74.5 74S 77.7 83.7 %0 99.0 98.7 92.1 84.2 76.7 74.4 97.9 1953 73.7 74.2 74.9 78.7 86.7 97.0 98.9 98.6 93.4 86.1 78.1 73.3 98.2 1954 71.1 73.9 75.7 793 82.7 90.9 98.1 99.0 94.1 86.5 75.9 71.4 96.0 1955 71.2 71.2 73.1 80.1 85.8 913 983 97.8 92.0 84.4 76.4 71.7 95.8 1956 683 74.4 74.9 77.1 84.0 91.7 98.0 983 91.1 82.2 77.4 74.8 %0 1957 73.2 74.4 74.8 773 85.1 92.9 983 %5 92.3 80.9 73.6 74.7 95.9 1958 683 69.2 74.1 77.1 83.2 92.6 97.8 98.5 91.6 83.5 77.2 713 963 1959 69.7 73 3 743 783 86.0 92.4 963 98.5 91.5 85.9 76.8 73.6 95.7 1960 72.2 71.6 68.6 77.9 82.6 93.0 97.3 %8 91.8 85.5 75.7 71.9 95.7 1961 70.2 70.6 75.1 75.2 81.8 90.8 %I %S 92.2 84J 79.2 743 94.5 1962 70.2 72.6 743 77.5 86.7 93.4 95.7 95.3 91.2 84.8 74.8 69.7 94.8 1963 68.6 67S 74.1 30.4 83.7 91.2 95.0 97.1 90.6 83.7 76.7 70.8 94.4 1964 69.0 70,0 73 3 77.8 84.1 92.7 95.3 95.4 90.5 81.5 78.0 74.8 94.5 1965 72.2 72.6 73.7 78.7 87.7 92.8 MO 96.8 92.5 83.2 76.4 74.2 95.2 1966 70.1 69.8 74.0 77.1 84.0 91.4 97.1 %0 91.6 83.1 77.0 72.7 94.8 1967 70.7 71.0 743 80.4 81.5 89.5 953 %0 c8.8 83.1 76.2 74.8 93.6 1968 683 70.0 73.5 79.4 83.5 90.9 97.2 98.5 90.8 84.8 76.8 71.9 95.5 1969 68.7 713 72.1 79.0 84.6 92.7 98.5 E4 90 3 83.6 76.0 70.4 95.9
%_- 1970 67.0 71.3 75.2 78.2 85.5 91.8 95.8 95.6 93.1 84.9 77.4 74.4 94.4 1971 69.8 68.9 74.5 77.4 82.7 91.4 95.9 95.1 92.4 86.1 78.8 74.7 94.1 1972 74.5 70.1 75.5 77.6 32.1 88.3 94.8 95.1 90.5 31.5 77.0 73.6 92.7
) 1973 70.7 69.4 74.6 76.4 81.3 92.0 M6 963 *23 84.9 75.9 72.8 95.0 1974 74.8 74.6 75.5 77.8 83.7 90.9 94.5 94.5 R9.0 81.0 76.9 71.2 933 1975 73.2 74.7 74.5 77.1 85.9 92.1 94.6 98.1 92.2 84.9 79.0 73.6 94.9
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1976 68.9 74.0 75.4 78.7 82.3 89.1 94.7 94.7 88.9 82.6 74.7 70.8 92.8 1977 65.0 683 75.5 79.5 83.8 91.8 98.5 97.4 93.9 82.6 77.3 73.2 95.9 i 1978 68.1 66.8 72.2 79.6 82.1 94.0 98.2 98.9 95.0 83.1 79.0 74.2 97.0 1979 68.2 67.0 75.0 79.9 843 90.6 94.4 %9 91.2 82.1 77.5 73.8 94.0 1980 70.7 69.4 73.1 78.9 82.9 92.1 97.9 98.5 95.5 83.4 76.4 72.5 96.2 1981 66.6 70.6 74.7 79.2 32.1 94.2 97.0 943 90.9 81.4 75.7 703 95.4 1982 67.2 72.4 74.7 77.4 84.9 93.6 98.8 98.2 90.9 8).9 76.7 74.9 96.9 1983 69.9 72.0 75.2 76.5 82J 89.4 %8 98.1 93.6 83.0 76.0 723 94.8 1984 67.4 72.4 73.6 76.1 81.7 90.6 95.4 95.9 90.5 84.9 783 74.8 94.0 1985 69.6 69.0 75.2 78.8 85.6 933 96.6 96.3 92.0 83.7 79.8 7J.7 95.4 1986 683 71.8 74.2 79.8 84.9 94.6 99.0 98.0 91.7 87.0 78.4 74.6 97.2 1987 70.4 70.9 74.0 77.2 83.0 92.6 98.9 98.9 93.8 81.8 76.0 74.1 %8 1988 67.7 71.5 75.2 79.4 83.9 913 %3 98.7 90.9 81.8 75.2 73 3 95.4 1989 73.7 74.2 74S 78.0 823 92.8 %7 M1 91.6 83.5 78.1 69.6 95.2 1990 71.9 75.9 73.2 77.8 843 92.7 97.7 98.0 94.2 86.2 77.7 75.0 %1 1991 73.5 73.8 76.4 80.1 85.6 92.8 98.3 97.1 93.6 843 76.6 74.7 96.1 O 1992 72.1 74.1 76.1 78.7 80.4 86.9 97.0 95.4 92.8 81.9 77.6 73.4 93.1 1993 73.0 71.9 73.1 77.0 82.5 93.0 99.0 98.2 94.7 83 3 763 73.1 %7 1-7
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Table 1-3: MNS and MSS Operating Conditions for 1953 Predictive Run. McGUIRE NUCLEAR STATION MARSHALL STEAM STATION Total Lil CCW Capacit Intake Discharge CCW CCW Capacity Intake Discharge MO/YR CCW CCW AT y Factor Temp Temp Flow AT Factor Temp Temp cfs efs *C PF) (%) 'C cF) 'C cF) cms (cfs) 'C PF) (%) 'C PF) 'C cF) Jun /1953 4580 0 9.0 (16.2) 100 27.0 (80.6) 36.0 (96.8) 51 (1784) 11.2 (20.1) 100 17.7 (63.9) 28.9 (84.0) Jul /1953 4580 108 9.1 (16.3) 100 28.2 (82.7) 37.2 (99.0) 59 (2068) 9.6 (17.3) 100 22.9 G3.3) 32.6 (90.6) Aug/1953 4580 173 9.1 (16.4) 100 27.8 (82.1) 36.9 (98.5) 64 (2264) 8.8 (15.8) 100 26.4 G9.6) 35.2 (95.4) Table 1-4: Hydrological and Meteorobgical Parameters for 1953 Predictive Run. HYDROLOGICAL METEOROLOGICAL Background Water Surface River Dry Dew Cloud Solar Wind Speed at MO/YR Temp Elevation Flow Bulb Poinc Cover Radiation height = 26 m fo m/s (mph)
'C PF) m (ft) ems (cfs) 'C PF) 'C PF) (%) LY/ Day Jun I1953 28.2 (82.8) 230.1 G55.0) 42 (1472) 24.6 G6.3) 18.6 (65.5) 60 511.0 2.19 (4.9)
Jul/1953 29.6 (85.2) 229.4 G52.5) 36 (1256) 26.3 G9.4) 19.1 (66.4) 60 513.2 2.15 (4.8) Aug/1953 29.2 (84.5) 230.1 (755.0) 36 (1274) 25.2 G7.3) 18.1 (64.5) 40 486.1 1.83 (4.1) l l
O - C O . Table 1-5: 90 F (32.2 C) Isotherms for MNS and MSS for 1953 Predictive Run. l 90*F (32.2*C) ISOTHERM McGUIRE NUCLEAR STATION MARSHALL STEAM STATION TOTAL OF BOTH PLANTS Surface Laket Shore. Lake 2 Surface Laket Shore- Lake 2 Surface Laket Shore- Lake2 . MO/YR Area Surface line Shore Area Surface line Shore Area Surface line Shore Ha (ac) % km (mi) % Ha (ac) % km (mi) % Ha (ac) % km (mi) % , Jun/ 400 (990) 3 17 (11) 2 0 (0) 0 0 (0) 0 400 (990) 3 17 (11) 2 1953 Jul/1953 768 (1897) 7 25 (16) 3 6 (14) 0 0 (0) 0 774 (1911) 7 25 (16) 3 Au/1953 625 (1545) 5 22 (14) 3 136 (336) 1 3 (2) 0 761 (1881) 6 25 (16) 3 Table 1-6: 5*F (2.8 C) Above Background Temperature Isotherm for MNS and MSS 1953 Predictive Run. 5'F (2.8'C) ABOVE BACKGROUND TEMPERATURE ISOTHERM McGUIRE NUCLEAR STATION MARSHALL STEAM STATION TOTAL OF BOTH PLANTS
- Surface Laket Shore- Lake
- Surface Laken Shore- Lake 2 Surface Laket Shore. Lake 2 b MO/YR Area Surface line Shore Area Surface line Shore Area Surface line Shore Ha (ac) % km (mi) % Ha (ac) % km (mi) % Ha (ac) % km (mi) %
Jun/ 797 (1969) 7 25 (16) 3 0 (0) 0 0 (0) 0 797 (1969) 7 25 (16) 3 1953 Jul/1953 768 (1897) 7 25 (16) 3 6 (14) 0 0 (0) 0 774 (1911) 7 25 (16) 3 Au/1953 850 (2100) 7 27 (17) 3 234 (579) 2 9 (6) 1 1084 (2679) 9 36 (22) 4
- 1. Lake surface areas (based on monthly water surface elevations): June 11780 Ha (29100 ac); July 11030 Ha (27250 ac); August 11780 Ha (29100 ac).
- 2. Based on total shoreline mileage of 840 km (522 mi).
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-0 5 10 15 20 25 30 35 40 0 5 10 15 20 25 30 35 40 0 5 10 15 20 25 30 35 40 TEMPERATURE (deg C) TEMPERATURE (deg C) TEMPERATURE (deg C)
Figure 1-1. Predicted average temprature profile comparisons for capacity factors of 90% and 100% at both MNS and MSS.
t i j l I ! CHAPTER 2 .I WATER CHEMISTRY INTRODUCTION l The objectives of the water chemistry portion of the McGuire Nuclear Station'(MNS) ; NPDES Maintenance Monitoring Program are to:
- 1) maintain continuity in Lake Norman's chemical data base so as to allow I detection of any significant station-induced and/or natural change in the physicochemical structure of the lake; and
- 2) compare, where appropriate, these physicochemical data to similar data in ;
other hydropower reservoirs and cooling impoundments in the Southeast. [ This year's mport focuses primarily on 1992 and 1993. Where appropriate, reference to pre- [ 1992 data will be made by citing reports previously submitted to the North Carolina Department of Environment, Health, and Natural Resources (NCDEHNR). j METHODS AND MATERIAI S ? l The complete water chemistry monitoring program, including specific variables, locations, depths, and frequencies is outlined in Table 2-1. Sampling locations are identified in Figum ; 2-1, whereas specific chemical methodologies, along with the appropriate references are presented in Table 2-2. Data were analyzed using two approaches, both of which were ; consistent with earlier studies (Duke Power Company 1985,1987,1988a,1989,1990,1991, i 1992, 1993). The first method involved partitioning the reservoir into mixing, background, and discharge zones, and making comparisons among zones and years. In this report, the discharge includes only Location 4; the mixing zone encompasses Locations 1 and 5; the background zone includes Locations 8,11, and 15. The second approach emphasized a much l broader lake-wide investigation and encompassed the plotting of monthly isotherms and l isopleths, and summer-time striped bass habitat. Several quantitative calculations.were also performed. These included the calculation of the areal hypolimnetic oxygen deficit (AHOD), ; maximum whole-water column and hypolimnion heat content, mean epilimnion and i hypolimnion heating rates over the stratified period, and the Birgean heat budget. ) l
\ !
2-1 l u
- _ , - - - _ _ _ _ _ - _ , - _ _ _ _ _l
. ~ - . . .- . . .- . . .
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RESULTS AND DISCUSSION Precipitation Amount Precipitation in the vicinity of MNS measured about 46 inches in 1993, compared to 49 l inches in 1992 (Figure 2-2.). The wettest month of 1993 was March in which 8.65 inches of l precipitation fell. t Temperature and Dissolved Oxygen Water temperatures measured in 1993 illustrated similar temporal and spatial trends in the j background and mixing zones (Figures 2-3,2-4). Water temperatures in the winter and spring of 1993 were generally equal to or cooler throughout the water column as compared to 1992 in both zones (Figure 2-3,2-4). The only exception to this occurred in February when epilimnibn temperatures in the mixing zone were 2 to 5 C (3.6 to 9.0*F) warmer than the O V background zone. Both zones exhibited slightly warmer epilimnion and metalimnion temperatures in the summer of 1993 than in 1992 with the greatest between year differences j I (3 to 5 C or 5.4 to 9.0*F) measured in July and September. Fall temperatures were similar I throughout the reservoir in 1992 and 1993. Despite some seasonal and spatial variability in temperature data between 1992 and 1993, the 1993 te, iperatures were well within the historic j range (Duke Power Company 1985, 1989, 1991, 1993). Temperature data at the discharge location in 1993 were generally similar to or slightly cooler than measured in 1992 (Figure 2-e 5) and historically (Duke Power Company 1985,1987,~ 1988a,1989,1990,1991,1992, 1993). The warmest temperature at the discharge location in 1993 occurred in August and measured 35.3 C (95.5 F), slightly less than the historic maximum of 36.3"C (97.3*F) ; measured in August,1991 (Duke Power Company 1992). kr i i t 2-2
- - - - - . _ __ _.__ _ )
O ! Seasonal and spatial pattems of DO in 1993 were reflective of the patterns temperature, i exhibited for e., generally similar in both the mixing and background zo nes (Figures ~ 2-6 and 2-7). Winter and spring DO values generally ranged from abo . er throughout the water column in both zones in 1993 than in 1992 , and were historic range (Duke Power Company well within the 1985,1987,1988a,1989,1990 1991 1992 1993) , Summer DO values in 1993 were generally lower throughout the wate e mixing Power Company and background zones than observed in 1992,e but within the 1985, 1987, 1988a, 1989, 1990, 1991, 1992, 1993). g-These lower values in 1993 may be related, at least partially, to t'e warmer water which temperatures in would decrease oxygen solubility and increase microbial respiration (We . values were generally similar between the two years. Some differences were observed in November but these data are probably a reflection of meteorological diffe ng the rate of water column cooling and reoxygenation. Interannual differences in DO are common in Southeastern reservoirs, part;cularly during thec stratified period , yearly differences in hydrological, meteorological, and limnological forc and Hannon 1985; Petts1984). [ The seasonal pattern of DO in 1993 at the discharge location was simil historically, with the highest values observed during the winter and low j summer and early-fall (Figure 2-5). Generally, DO values in 1993 were eith l i slightly less than in 1992, but within the historic range (Duke Power Com , , l 1988a, 1989, 1990, 1991, 1992, 1993). The lowest DO concentration discharge location in 1993 (4.1 e me August,1992, low of 5.0 mg/l (Figure 2-5).mg/l) occurred an the in August and \ Reservoir-wide Temperature and Dissolved Oxygen The monthly reservoir-wide temperature and dissolved noxygen data for 1 Figures 2-8 and 2-9. For the most part, the temporal sand of spatial distribu both temperature and dissolved oxygen are similar to other and cooling impou hydropower reservoirs in the Southeast (Cole and. During Hannon the 1985; Petts 1984 winter cooling predominated, with theand mixing period, vertical rather than re horizontal homog shallower uplake ' riverine' zone exhibiting slightly cooler temperatures than the deeper downlake ' lacustrine' zone (Figure 2 8). Th - 2-3
, _ _ . _ _ _ - - - - ~ " "
J n f i QJ Seasonal and spatial patterns of DO in 1993 were reflective of the patterns exhibited for ternperature, i. e., generally similar in both the mixing and background zones (Figures ~ 2-6 and 2-7). Winter and spring DO values generally ranged from about 0.2 to 2.0 mg/l higher throughout the water column in both zones in 1993 than in 1992, and were well within the historic range (Duke Power Company 1985, 1987, 1988a, 1989, 1990, 1991, 1992, 1993). Summer DO values in 1993 were generally lower throughout the water column in both the mixing and background zones than observed in 1992, but within the historic range (Duke Power Company 1985,1987,1988a,1989,1990,1991,1992,1993). These lower values in 1993 may be related, at least partially, to the warmer water temperatures in 1993 which would decrease oxygen solubility and increase microbial respiration (Wetzel 1975). Fall DO values were generally similar between the two years. Some dille nces were observed in November but these data are probably a reflection of meteorological differences influencing the rate of water column cooling and reoxygenation. Interannual differences in DO are common in Southeastern reservoirs, particularly during the stratified period, and can reflect yearly differences in hydrological, meteorological, and limnological forcing variables (Cole and Hannon 1985; Petts1984). p/ G The seasonal pattem of DO in 1993 at the discharge location was similar to that measured ) historically, with the highest values observed during the winter and lowest observed in the summer and early-fall (Figure 2-5). Generally, DO values in 1993 were either equal to or slightly less than in 1992, but within the historic range (Duke Power Company 1985,1987, 1988a, 1989, 1990, 1991, 1992, 1993). The lowest DO concentration measured at the discharge location in 1993 (4.1 mg/l) occurred in August and was slightly lower than the August,1992, low of 5.0 mg/l (Figure 2-5). I Reservoir-wide Temperature and Dissolved Oxygen The monthly reservoir-wide temperature and dissolved oxygen data for 1993 are presented in ,
- Figures 2-8 and 2-9. For the most part, the temporal and spatial distributional patterns of
' both temperature and dissolved oxygen are similar to other cooling impoundments and hydropower reservoirs in the Southeast (Cole and Hannon 1985; Petts 1984). During the winter cooling and mixing period, vertical rather than horizontal homogeneity in temperature .
I s predominated, with the shallower uplake ' riverine' zone exhibiting slightly cooler ( temperatures than the deeper downlake ' lacustrine' zone (Figure 2-8). These longitudinal 2-3
differences in temperatures were clearly illustrated in 'anuary and February. The principal factors influencing this gradient in Lake Norman are thermal discharges from MSS and MNS, morphometric (depth) differences within the reservoir, and surface water inputs from j the upper reaches of the reservoir. i l
. The heating period in Lake Norman generally begins in March, as more heat is gained at the !
\
water's surface than is lost at night. During the initial stages of the heating period, buoyancy i forces " smooth out" the horizontal differences in temperature, thereby reducing temperature ! differences between up-reservoir and down-reservoir locations. Due to the vertical instability q of the water column during this period, temperature increases are observed at all depths. These points are illustrated by contrasting the January and February temperature data with ) I the March and April data (Figure 2-8). As solar radiation and air temperatures increase, heating occurs at a greater rate in the upper waters than in the mid or bottom waters due to f differential thermal absorption and vertical density differences (Wetzel 1975, Ford 1985 ). ; Eventually, differential heating at the surface leads to the formation of the classical. ! O epilimnion, metalimnion, and hypolimnion zones. These zones are clearly depicted in the ; July,1993 data (Figure 2-8). j In contrast to most natural lakes, but not unlike many reservoirs in the Southeast, a distinct - thermocline within the metalimnion was not observed in Lake Norman in 1993 and is consistent with that observed in previous years (Duke Power Company 1992,1993). Rather, l the metalimnion was more or less continuous with respect to vertical density differences ; within the lower water column, and even showed signs of merging with the hypohmmon, as j illustrated in the August data (Figure 2-8). , Cooling of the water column began in early September as illustrated by decreases in surface temperatures compared to August data. Concurrent with decreases in surface temperatures was an increase in the depth of the epilimnion (caused by convective mixing) and a disruption of the horizontal homogeneity in epilimnion temperatures (caused by reservoir-wide differential heating and cooling, and advective inputs from upstream). Continuation of . these differential vertical and horizontal processes led to even more pronounced thermal f differences within the reservoir. For example, by October the uplake riverine zone had already ' turned over', while the downlake lacustrine zone was still strongly stratified. Not until early November was Lake Norman completely mixed vertically throughout the j 2-4 i
< - , f; y ;
reservoir. Morphometric, and in particular, depth differences throughout the longitudinal - reaches of the reservoir, coupled with seasonal variability in the volume and density of : upstream inputs are major contributors to these horizontal gradients of heating and cooling in . reservoirs (Ford 1986;Imberger 1987 ; Petts 1984). l l Distributional patterns of dissolved oxygen in 1993 were similar to but not identical to temperature (Figure 2-9). Generally, dissolved oxygen concentrations were greatest during j the winter cooling and mixing period when biological respiration was at a minimum and-atmospheric reaeration was at a maximum. The highest reservoir-wide mean concentration of dissolved oxygen (11.6 mg/l) occurred in March when the reservoir exhibited a mean j temperature of 8.7*C or 47.7'F (Figure 2-8). Unlike the thermal regime, no major ! longitudinal differences existed in dissolved oxygen within the reservoir during the winter. - Not until the lake became stratified, thereby isolating the metalimnion and hypolimnion from atmospheric reaeration and vertical water mass exchanges, were uplake-to-downlake gradients in dissolved oxygen observed. Longitudinal gradients in metalimnetic and O hypolimnetic dissolved oxygen in 1993 were first observed in May. Differential dissolved oxygen depletion and eventual anoxia were first observed in the transitional zone (Locations 15 through 62) where hypolimnetic volume is small, water column and sediment organic matter high, and advective mixing minimal. This longitudinal and progressive display of f oxygen depletion has been reported for many southern U.S. impoundments (Hannon et. al., 1979; Cole and' Hannon 1985; Petts 1984). By August, the complete hypolimnion throughout the reservoir below elevation 219 m was anoxic. This represents appmximately 22% of the entire volume of the lake at full pond. Complete hypolimnetic deoxygenation l (below the thermocline) in natural lakes is indicative of the net effect of cultural eutrophication (Wetzel 1975). Alternatively, the occurrence of hypoxia in reservoirs is j influenced by a combination of hydrologic, hydraulic, morphometric and limnological factors (Cole and Hannon 1985; Petts 1984; Ruane 1989). u i Reaeration of the water column started in September concomitantly with the cooling and l mixing of the reservoir. Decreasing air temperatures cooled the surface waters resulting in a l convective deepening, aided by wind-induced mixing, of the epilimnion. As the oxygenated epilimnion eroded progressively deeper into the ' uter column, the width of the anoxic zone , decreased. Longitudinal differences in reacration were also observed and apparently were related to differential mixing caused by MNS and MSS, and upstream advective inputs from 2-5 l
l g) L) Lookout Shoals Hydroelectric Facility. Reaeration of the reservoir was essentially complete by early November, except for the bottom waters in the downlake " lacustrine" zone. Table 2-3 presents some common quantitative limnological calculations for the thermal environment in Lake Norman. Few comparable calculations exist in the literature for reservoirs, but these data are generally within the "ballpark" of those presented by Hutchinson (1957) for natural lakes at similar latitudes throughout the world. Table 2-4 presents the 1993 AHOD for Lake Norman compared to similar estimates for 18 TVA reservoirs. The data illustrate that Lake Norman exhibits an AHOD that is similar to other Southeastern reservoirs of comparable depth, chlorophyll a status, and secchi depth. Striped Bass Habitat Suitable pelagic habitat for adult striped bass, defined as that layer of water with temperatures s 26 C and DO levels 2: 2.0 mg/1, was found lake-wide from October 1992 [] () through June 1993. Beginning in late June, habitat reduction proceeded rapidly throughout the reservoir both as a result of deepening of the 26 C isotherm and metalimnetic and 0 hypolimnetic deoxygenation (Figure 2-10). Complete habitat elimination occurred sometime . in mid-July and persisted until mid-September, or about 2 months. Refugia for adult striped bass were recorded during this period but these areas were oflimited size and restricted to the uplake, riverine sections of the reservoir just below the Lookout Shoals Hydroelectric facility. Physicochemical habitat was observed to expand appreciably in late September, primarily as a result of epilimnion cooling, and in response to changing meteorological conditions The temporal and spatial pattern of striped bass habitat expansion and reduction observed in 1993 was similar to that previously reported in Lake Norman and many other Southeastern reservoirs (Coutant 1985, Matthews 1985; DPC 1992, DPC 1993). The duration of complete habitat elimination in 1993 was greater than observed in 1992 but well within the historic range. 1
1 l l l
, . l 8 )
w./ Turbidity and Specific Conductance Surface turbidity values were low at the MNS discharge, mixing zone, and mid-lake background locations during 1992 and 1993, ranging from 2-6 NTUs (Table 2-5). Bottom turbidity values were also low over the twc yeaa period, ranging fomi 1-10 NYUs (Table 2-5). These values were well within the range (Duke Power Company 1989, 1990, 1991, 1992). Specific conductance in Lake Norman in 1993 ranged from 51 to 88 umho/cm and was similar to that observed in 1992 (Table 2-5) and historically (Duke Power Company 1989,1992). Specific conductance in surface and bottom waters was generally similar throughout the year except in late fall at several of the deeper locations when bottom waters averaged about 20-40 umhos/cm higher than surface values. These increases in conductance were undoubtedly related to the release of soluble iron and manganese from the lake bottom under anoxic conditions (Table 2-5).
/^'N ? /
Lf pH and Alkalinity e During 1993, pH and alkalinity values were similar among MNS discharge, mixing, and mid-lake-lake background zones (Table 2-5); they were also similar to values measured in 1992 (Table 2-5) and historically (DPC 1989,1992). Individual pH values in 1993 ranged from 6.1 to 6.9, whereas alkalinity ranged from 10.6 to 23.8 mg-CACO3/1. Major Cations and Anions The concentrations (mg/l) of major ionic species in the MNS discharge, mixing, and mid-lake background zones are provided in Table 2-5. The overall ionic composition of Lake Norman w during 1993 was similar to that reported for 1992 (Table 2-5) and previously (Duke Power Company 1989,1992). Lake-wide, the major cations were sodium, calcium, magnesium, and potassium; major anions were bicarbonate, sulfate, and chloride. 2-7
- p. 1~
r v' Nutrients !
-Nutrient concentrations in the discharge, mixing, and m:d-lake background zones of Lake Norman are provided in Table 2-5. Overall, nitrogen and phosphorus levels in 1993 were similar to those measured in 1992 and historically (Duke Power Company 1989,1990,1991, ,
1992); they are also characteristic of the lake's oligo-mesotrophic status (Rodriguez 1982). Ammonia nitrogen concentrations increased in bottom waters in each of the three zones during the summer and fall, r oncurrent with the development of anoxic conditions. Total and soluble phosphorus concenistions in 1993 were similar to values recorded in 1992 and ! historically (Duke Power Company 1989,1990,1991,1992 ,1993). Metals Metal concentrations in the discharge, mixing, and mid-lake background zones of Lake Norman for 1993 were similar to that measured in 1992 (Table 2-5) and historically (DPC f 1989, 1990, 1991, 1992, 1993). Iron concentrations near the surface were generally low (s 0.1 mg/l) during 1992 and 1993, whereas iron levels near the bottom were slightly higher ( during the stratified period, particularly in early fall. Similarly, manganese concentrations in
) ' the surface and bottom waters were generally low (s 0.1 mg/1) in both 1992 and 1993, except ,
during the summer and fall when bottom waters approached or became anoxic (Table 2-5). i Manganese concentrations near the bottom rose above the NC water quality standard (0.5 mg/l) at various locations throughout the lake in summer and fall of both years, and is . characteristic of historic conditions (Duke Power Company 1989,1990,1991, 1992, 1993). i Heavy metal concentrations in Lake Norman never approached NC water quality standards, and there were no consistent appreciable differences between 1992 and 1993. FUTURE STUDIES No changes are planned for the Water Chemistry portion of the Lake Norman maintenance f monitoring program during 1994. i s ~
\ .
2-8 l l
i O SbMMARY , Temporal and spatial trends in water temperature and DO data collected monthly in 1993 ' ! were similar to those observed historically. Temperature and DO data collected in 1993 were i within the range of previously measured values. i Reservoir-wide isotherm and isopleth information for 1993, coupled with heat content and hypolimnetic oxygen data, illustrated that Lake Norman exhibited thermal and oxygen dynamics characteristic of historic conditions and similar to other Southeastern reservoirs of comparable size, depth, flow conditions, and trophic status. 1 Availability of suitable pelagic habitat for adult striped bass in Lake Norman in 1993 was j generally similar to historic conditions. Reservoir-wide habitat elimination was observed to i persist for approximately 2 months in 1993. This is somewhat longer than the duration of complete habitat elimination observed in 1992, but similar to that in earlier years. j/ . All chemical parameters measured in 1993 were within the concentration ranges previously reported for the lake during both MNS preoperational and operational years. As has been observed historically, manganese concentrations in the bottom waters in the summer and fall -
- of 1993 often exceeded the NC water quality standard.
LITERATURE CITED j i Coutant, C. C.1985. Striped bass, temperature, and dissolved oxygen: a speculative hypothesis for environmental risk. Trans. Amer. Fisher. Soc. I14:31-61. l Duke Power Company.1985. McGuire Nuclear Station,316(a) Demonstration. Duke Power j Company, Charlotte, NC. !
. Duke Power Company.1987. Lake Norman maintenance monitoring program: 1986 summary. {
Duke Power Company, Charlotte, NC. , 1 E 2-9
+
Y
l
\
l r ( i Duke Power Company.1988a. Lake Norman maintenance monitoring program: 1987 sununary. Duke Power Company, Charlotte, NC.
)
Duke Power Company.1988b. Mathematical modeling of McGuire Nuclear Station thermal discharges. Duke Power Company, Charlotte, NC. . Duke Power Company.1989. Lake Nonnan maintenance monitoring program: 1988 summary. Duke Power Company, Charlotte, NC. j Duke Power Company.1990. Lake Norman maintenance monitoring program: 1989 summary. f Duke Power Company, Charlotte, NC. ; Duke Power Company.1991. Lake Norman maintenance monitoring prograrr 1990 summary. Duke Power Company, Charlotte, NC. Duke Power Company.1992. Lake Norman maintenance monitoring program: 1991 summary. ; Duke Power Company, Charlotte, NC. 1 Duke Power Company. 1993. Lake Norman maintenance monitoring program: 1992 summary. i Duke Power Company, Charlotte, NC. Hannan, H. H., I. R. Fuchs and D. C. Whittenburg. 1979 Spatial and temporal patterns of ' temperature, alkalinity, dissolved oxygen and conductivity in an oligc-mesotrophic, deep-storage reservoir in Central Texas. Hydrobilologia 51 (30);209-221. ; i Higgins, J. M. aiid B. R. Kim.1981. Phosphorus retention models for Tennessee Valley Authority reservoirs. Water Resour. Res.,17:571-576. Higgins, J. M., W. L. Poppe, and M. L. Iwanski.1981. Eutrophication analysis of TVA reservoirs. In: Surface Water Impoundments. H. G. Stefan, Ed. Am. Soc. Civ. Eng., i NY, pp.404-412. l l Hutchinson, G. E.1957. A Treatise on Limnology, Volume I. Geography, Physics and l Chemistry. John Wiley & Sons, NY. ,i r ! Hydrolah Corporation.1986. Instructions for operating the Hydrolab Surveyor Datasonde. Austin, TX. 105p. L Matthews, W. J., L. G. Hill, D. R. Edds, and F. P. Gelwick. 1980. Influence of water quality and season on habitat use by striped bass in a large southwestern reservoir. Transactions of the American Fisheries Society 118: 243-250. 2-10 >
l 7-t Petts G. E.,1984. Impounded Rivers: Perspectives For Ecological Management. John Wiley and Sons. New York. 326pp. Rodriquez, M. S.1982. Relationships between phytoplankton growth rates and nutrient dynamics in Lake Norman, NC DPC DUKEPWR/82-01. Iluntersville, NC 39p. l Ryan, P. J. and D. F. R. Harleman.1973. Analytical and experimental study of transient cooling pond behavior. Report No.161. Ralph M. Parsons Lab for Water Resources and ; Hydrodynamics, Massachusetts Institute of Technology, Cambridge, MA. l Stumm, w. and J. J. Morgan.1970. Aquatic chemistry: an introduction emphasizing chemical equilibria in natural waters. Wiley and Sons, Inc. New York, NY 583p. , Wetzel, R. G.1975. Limnology. W. B. Saunders Company, Philadelaphis, Pennsylvania, 743pp. i O 2-11
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l Table 2-2. Water chemistry metilods and analyte detection limits for the McGuire Nuclear Station NPDES long-l l term maintenance program for Lake Norman.
' ~'
Preservation Detection limit Variables d Method f 4*C 1mg-CaCD, 1- $
- Alkaltnity, total E Electrometric titration to a pH of 5.18 l Atomic emission /ICP-direct injection
- 0.5% HNO, 0.3 mg.1-8 Aluminus 4*C 0.050 a g1 8 A:nnonium Automated phenate 8 O.5% HNO, 0.1 9g 1-8 Atomic absorption / graphite furnace-direct injection'
~
Cadmium 0.5% HNO, 0.04 mg 1-8 Calcium Atomic' emission /ICP-direct injection
- 4*C r ; 1- 8 Chloride Autornated ferricyanide' Temperature compensated nic'Let electrode 8 In-sttu .ce-
j Conductance. specific Atomic absorption / graphite furnace-direct injection' O.5% H 0, # 1-8 Copper 4'C 0.10mg.1-' Fluoride Potenticmetric a Atomte emission /ICP-direct injection' O.5% HNO, 0.1 mg 1-' tron Atomic absorption graphite furnace-direct injection' 0.5% HNO, 2.0 99 1-8 Lead 0.5% HNO, 0.001 mg 1-8 Magnesium Atomic emission /1CP-direct injection
- O.5% HNO, 0.003 mg 1-8
,Y_, Manganese Atomic emission /ICP-direct injection' 4'C 0.050 mg.1-'
" Nitrite + Nitrate Automated Cadmium reduction' 4'C 0.005 mg.1-8 Orthophosphate Automated ascorbic acid reduction, Temperature compensated polarographic cell' In-situ 0.1 mg 1-
0xygen. dissolved Temperature compensated glass electrode 8 In-situ 0.1 std. units
- pH 4*C 0.005 ag 1- 8" Phosphorus, total Persulfate digestion followed by automated ascorbic acid O.015 ag 1* *"
reouction' Atomic absorption graphite furnace-direct injection
- 0.5% HNO, 0.1 mg.1 '
Potassium Automated molydostlicate' 4*C 0.5 og 1 Silica Atomic emission /ICP-direct injection' O.5% HNO, 0.3 m-g1*' Sodium Turbidimetric, using a spectrophotcmeter* 4'C 1.0 mg 1-' Sulfate In-situ 0.1*C' Temperature Thermistor / thermometer
- Nephelometric turbidity' 4'C 1 HTU*
Turbidity ~' Z1ne Atomic emission /ICP-direct injection
- 0.5% HNO, 4991
' United States Environmental Protection Agency 1979. Methods for chemical analysts of water and wastes.
Environmental Monitoring and Support Laboratory. Cincinnatt, OH.
'USEPA. 1982. . *
'USEPA. 1984
- Instrument sensitivity used Instead of detection limit.
" Detection ilmtt changed during 1989.
~ - -. .. . . . . _ . . . - .- . . . - . _ - - - - . - _-
l i l l Table 2-3. Heat content calculations for the thermal regime in Lake Norman in 1993. 1 Maximum areal heat content 28,141 g cal em 2 ] i i Maximum hypolimnetic (below 11.5 m) 15,106 g cal em 2 areal heat content l i Birgean heat budget 19,251 g cal em 2 Epilimnion (above 11.5 m) heating 0.114 C/ day l rate j Hypolimnion (below 11.5 m) heating 0.087 C/ day l rate r i i p I l h l t
- 2-14 l
r. r js b Table 2-4. A comparison of areal hypolimnetic oxygen defin s (AHOD), summer chlorophyll a (chi a), secchi depth (SD), and mean depth of Lake Norman and 18 TVA reservoirs. AHOD Summer Chi a Secchi Depth Mean Depth Reservoir (mg/cm2/ day) (ug/L) (m) (m) I Lake Norman 0.057 5.0 3.0 10.3 TVA a Mainstem Kentucky 0.012 9.1 1.0 5.0 Pickwick 0.010 3.9 0.9 6.5 Wilson 0.028 5.9 1.4 12.3 Wheelee 0.012 4.4 5.3 Guntersville 0.007 4.8 1.1 5.3 Nickajack 0.016 2.8 1.1 6.8 Chickamauga 0.008 3.0 1.1 5.0 ( Watts Bar 0.012 6.2 1.0 7.3 . Fort London 0.023 5.9 0.9 7.3
) '
Tributary Chatuge 0.041 5.5 2.7 9.5 Cherokee 0.078 10.9 1.7 13.9 Douglas 0.046 6.3 1.6 10.7 Fontana 0.113 4.1 2.6 37.8 ,. Hiwassee 0.061 5.0 2.4 20.2 Norris 0.058 2.1 3.9 16.3 South Holston 0.070 6.5 2.6 23.4 Tims Ford 0.059 6.1 2.4 14.9 Watauga 0.066 2.9 2.7 24.5 / a Data from liiggins et al. (1980), and liiggins and Kim (1981) I O 2-15
n s i Table 2-5. Quarterly surface (o.3 m) and bottom (bottom minus 1 m) water chemistry for the MNS discharge, mixing zone, and background locations on Lake Norman during 1993. Values less than detection were assumed to be the ! detection limit for calculating a mean. aseg Zane Meeg Zane knee (Deseres semNe Zone seedymsus someysee LOCA?cN to 2.s 4.s se to tte DEPTN- ! Ween somem Suisee Benem Sutsee Sutese Geesm Swtes Desem Swease Deseos PARAMETEMS YEAR M e3 'e2 e3 12 e3 12 e3 W e3 W e3 W e3 M e3 M e3 M es M e3 Tis'asy (rmo Feb 2 4 3 e 3 4 3 s 3 3 2 4 4 4 2 4 3 7 4 to to 11 May NS e e to 4 s e e NS ? NS s e o NS s e 12 NS 12 to e Aug 2 2 1 e 2 2 2 7 2 2 2 3 4 11 2 2 4 0 3 3 4 e
% J 3 4 e 2 3 3 J 2 Amal Mean 2 33 3 FS 3$ 2.75 4S F F 1e?
2 a 4 d 2 2 is JF2s 2 4 JJ e F 3s F 15 2 33 S F 125 ele 3 FJ5 FS Specmc Cerecerce breame Fee 50 Se to se Se Se et M Se sF sf N s7 Se e4 Ss s7 s2 e7 M M Se l usy se - si se Si et es es si et Se se s3 es se se et et s1 et es et to Aug so s1 Fe B eo 51 FF Se et 32 es st F3 e1 as et 74 Se et $2 F4 e1
- ge_ ss es m JL _ m. ,,, gt. _.at so B _R. JL _._at _t1 _ tL it _.EL _ m 3L tL t1. _.1L
! amm u.en se S s33 r:3 es se s Su Fi e es e som ss Se s3 822 sea ses s2 ats eu eu Su se ss e pH (wes) Foo Se se es as se se se se as (7 as em F se 7 s.e F to F es se se u.y se es es es et se es es se se e.e se se e2 es es RF em se 7.1 e7 es A. F eS e3 et F e4 e.3 e se e F e4 to et 72 es to e u as es Et
- _e2 ee e4 ea e7 eF 31 ,,, g a _gi _g.t _it eF e4 __g.g _gi ,,13. _ g1 ,_13 _,gg. 13. _gi _.it Am.i ueen e Se er e 4e tS es e.4 e.s3 em ese E43 See See e.e as sie e.e eis tas F tes es3 es meereye gl CACO 3A) y Fen 12 e its is su tie its 13 su 12.s su 11e su t17 ste til tu 117 too s12 tem 13e 1e e -
. may NS te e 12 e fe e 12 e is ele to e NS Sto NS 11 4 12 e ste No itF sie ios MS tee tra is.
- Aug 11 3 11.7 15 4 15 0 122 11 3 117 1s e 12 it s 12 itA te3 tt2 12 11e its to 12.s 113 its 184 O m _11Z. _121 _211 2Lt 121 E E 218 E 111 Ammi heen 12.3 11 5 113 EE E 23 11F EE E 111 11e E _.111 ._111 ui 1S F 15 4 ile 11 s 14.4 1S F 11 3 12 4 11A tie ils 11A 12.s 117 11A 117 11F creanos emos Fee s as s.4 is sf 1/ e 22 te le se le s4 is F 1e s.3 13 e.e 12 u 2 Mey NS 41 Fe 4 s.2 3s - se 42 NS 17 NS 3.7 s.1 3e MS 43 17 42 NS 32 se 12 Aus s2 4s e 4.7 s2 4 ss 3s e 4 s.2 s es 41 se s at s2 se F se 4
- 47 41 _ 1 11 il 44 _l1 42 _10. _C _iZ. 44 ._.11 _i2 1E. _il 11_$J4 E4 ._1L 41 a.-n m Amm ucen s er 3 e3 s ee 3.es $2 3 es (F3 las S FF m _ _st 4 tes 3.se se 4.os sie d it un aos us Feb NS NS NS MS e 13 e se 4.1 se 3.7 NIL NS MS NS F 4.1 s3 Se NS NS No NS AWI Amal aneen J N,1 NS NS NS s NS J NS _,13 so NS _R L Jeg, ,, J e J ,,,,,13 L NS L MS e F.S2 SA 4 3e 4 21 F U2 s2 4.4 Castman (m04)
Fee to is 2e to 17 2s le 2e 2.s .is 17 2.s 2e le is 2.s 17 1s 17 17 1F 17 May NS 2.s MS le MS 2.s NS 28 NS is No 2.e NS 17 No 2.s MS le MS 2A NS 2.s Aug 2s 27 2.s 13 2.s IF 3 13 1s le 2.s 2.8 3 at is le 11 14 18 le 11 14
- _21 2 31 31 21 21 J _3.f J.L _2.E 19. 1I. 13. J 1L 21 13. J JJ JJ Amaf Mean 2.s3 2e 2 e7 3 2e 2.Sd 1F3 1 03 2e 2.s le les 17 1FS is le 17 le 2.83 17 2.F 2e wepwsnan tag %
Foo 12 1.2 13 u L3 L2 12 u L3 u 13 u 13 12 U 12 13 u 13 12 13 u Wey NS L1 12 11 11 1.1 1.1 Lt NS 1.1 NS 11 12 12 NS 1.1 1.1 1.1 NS 11 u 11 Aug 12 12 12 1.3 12 12 t4 13 12 13 12 12 L3 1.3 u 13 1.4 1.3 L2 13 14 14
% 11. 13 1* 14 U 12,. d 14 dJ 11 _LI. J 1.2e 13 13. 312 J _12 11 ._ 11 ._.13. 11 Amal aaeon 1 23 1.2 13 1 25 1 23 1.ie 12e 1 25 1R 1.2 1R 12 1.25 1R 1Je 123 1R 12 13 123 N$ e Nel Sangend
1 1 l l \ ,
\ / i %.J 1 l
- d: *:-d 22:d: ;;;dn si: ::: :P 888d8 a s:1* E rll; g **
g s l l l (* l y
- 8 ::::8.
unas: ::2d: .s.s e .nt. 2r : : 82828 i 3 :::*$ ;: '& 2220: ;2;;j 83] 3 ;E; *E
- IE 88R80 y
*t::= ZI" at E " ;f;;; 85838
. ... IE *R: *EAE8
== "E 5:-*: 222" ; ::: ;;; 308 88480 88888 g,
- 2:2 8. 2 tax: ;;2*'A 988H.8 : 8E8E8 y ]. ..
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;;; ::8. "*" 88888
. d od d . E E p . . . ...
g
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I N
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, :n :e ::::: as: : :n;;; gigag sq ::: ---
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;g;;; ;z. ""a
- q.
*I*:G :I :: E S. g E. t.s. 8g8p?
- 3. ,
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- 2:5:5 ;;; ;:= ~~~ 88888 j, ::::: ::::: 88.:=: .. _
, ::::s 2:2 3 : ::: ;;::: es=e ::t q: --- 8,8,8 i
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}
I
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t
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Table 2-5. Continued.
=== zer. ame,z asne pensee imagz enswawes easy e tocAror 10 to 40 So se 11,o OEptM &a%m senere &stece essem esteen Safase estum hs9es. esame omrees eenem pavutTras vva w es w e3 m e3 w e3 w e3 m e3 m e3 m e3 m a w e3 m e3
==e tuo9 Foo irr 143 tes 19e 174 140 201 14e 1e0 140 180 140 1Ss 140 21e 142 19e ice ate 23 25 20$
wey as 270 22e See 21e 2os 2se 3Se Ns ser we see 220 32e Me 2s3 Nr 388 2sr 2r3 See me 127 e3 135 327 tSO 305 es 2t1 tas 1s3 114 227 se 12r es see see se er 2et 223 Nov knalwee 100 13r tes es Sr 210 22S 30 f37 170 es 20e 30s te3 235 _J te3 es Jte3 J te3 134 10r 1SF J, J 1re 157 et J141 147 1re 23 232 os J 108 JJE3 1$3 193 233 Am N eetup4 Fee SO SO 50 SO SO SG 50 50 30 $s SO SO Se 30 Se 90 SO So SO 90 74 90 wer m3 90 SO SO SO SO SO SO Ns 90 no 50 SO So Na 50 SO So 90 90 90 Aus 50 SO 90 82 50 es et 90 es 90 SO Se e3 100 m So 111 117 SO re 73 101 New So tot J esi 82 11e tre J SO J JJ 74 Je23 JSs3 os JJ J 145 en 14e W ween 50 95 3 101 211 Se re S 84 3 220 Se 3 79 3 53.3 Se e4 3 e15 se e eC S S0 e03 71 3 er $ Tem Peepronus tuyg peo as se as e ns te ne ne no les no ne 13 12 e 11 15 te ne se ne is wey NS 11 Ns 14 ns 12 ns 14 ns 13 No 1 fee 1 no 13 No 1r ne te no 20 Au0 e S e. s r r r r r r si e to r a 7 e e S 7 e a "a _t __i l. J e e e 11. 11 7 _g a e 11 _, g i e _2L _g e _J 2L e Arnar ween o e5 eS 4 10 3 12.5 11 3 r e 25 e5 $$ 11 4JS 73 14 3 15 ti .e SJ 14 13 5 13.3, we ruu4 roe as S na e as S ns S no S ns S ne $ no S ne r no e no a wey as S as 10 ns S ns 7 ns 1 ns r no e no S no e ne 12 me 13
== 11 S e r S S e S e S S S 7 S S S S 4 e S 'r S Now J r e e e J 13 J 10 J 10 S 11 J 11 S JJ J r 11 J1 w wee eS SS e t r$ e$ S rS eS e.2s SS 4 rs SS s S r5 0 S es eJS es e e e rS S*ce M Fee $3 42 St 43 31 42 $2 42 S.t 4.2 5 4.1 5 42 S4 42 to- 43 53 4.S SS 4e way as 42 S 45 4e 41 5 43 no 4.3 fee 42 S 4.4 no 4.1 S 43 No 4.1 S.1 43 y Aue 3r SS 4e 45 3r 47 $ 19 Se 38 3A 15 4e 4.4 is 14 S.1 4A SA 3e 4e 4e s New J 44 4e J 42 43 4r J JJ J 4.4 J4 r5 JJ 4J 44 4.1 42 JS 13 S Arnaf waan 4 33 4 00 4 se 4 73 4 4e 4 33 4Ae 44S 4 27 4 11 423 45 4.2r 4 428 43 433 438 40s No e Nat eengsee er 6
l l
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I l Figure 2-1. Sampling locations on Lake Norman, North Carolina during maintenance j monitoring program for McGuire Nuclear Station. ; x 2-19
McGuire Rainfall ! 10 l i 8-1 U 4_ 0 ' ' l JAN ' FEB ' MAR APR MAY JUN ' JUL 'AUG' SEP 'OCT NOV DEC Month l O 1992 E 1993 i , Figure 2-2. Monthly precipitation in tne vicinity of McGuire Nuclear Station. 1 0 2-20
FEBI= [ MARCH N-JANUARY s 0- , 0- 0- I, s e
, . p
- C 10 - 10 - , 10 - ,'
ft i
.I i
{ i E - i - E - { 20- , E { 20 - 1 { 20 - i 8 d 8 ' i , . 6 . i . 30 - i 30 - 30-40 40 40
,,,,j,,,,g,,,,g.,,,g,,,, ,,,,g ,,,g ,,,, ,,,, ,,,, ,,,, ,,,, ,,,, ,,,, ,,,, ,,,, ,,,, ,,,, ,,,, ,,,, ,,,,
0 5 10 15 20 25 30 35 0 5 10 15 20 25 30 35 0 5 to 15 20 25 30 35 Temperature 'C , , , Temperaturo 'C Temperature *C t4 MAY JUNE h APRIL 0- 0- 0_ , 9 r [
- s
- . o
- . p 10 - 10 - , 10 ,
n n n n a 1 , 1 ~ E - { 20 - , { 20 -- { 20-8 i 8 - 8 :
- i 30 - i 30 -- l 30
- . g
. . s.
40 40 g .. g .. g...,g.,,, ,,,,y 40
,,,,gi,,ig3,,,gi.. g ..,g ,,,g....; sisijainigissiginingeieijiosigiisig ,,,,g.
0 5 10 15 20 25 30 35 0 5 10 15 20 25 30 35 0 5 10 15 20 25 30 35. Temperature 'O Temperature 'O Temperature 'C i Figure 2-3. Monthly mean temperature profiles for the McGuire Nuclear Station background zone in 1992 ( ... ) and 1993 (-).
- . - w r r- .r- -s y e-w e s. .-+r,..--w._ . i.w ---
3 -- - -er-.----we - - ~ , - - - = = *w wn m a w e-.c -= w =www-w
N s
) '
AO w i SEPTEMBER 0- , 0- 0- . r . o 10 - ' 10 - r 10 -
. . s n
o 5 1 ' E : ,' { 20-i I' { 20- 20 - o o - o .
~
30 - 30- 30
~
40 ,g.. 4gie. gi ig .. g 40 40 ii.,j,6 ,g6. .. .g...ig,;.igi. .g.. .g.. g g ,,.,g ..,g....g... g....g...,g... g o 5 10 15 20 25 30 35 0 5- 10 15 20 25 30 35 0 5 10 15 20 25 30 35 Temperature 'C Temperature 'O Temperature *C Y w OCTOBER NOVEMBER DECEMBER N 0- , 0 -- . 0- , 3 I e
- 8 10 - i 10-8 10 -
~
_ e
~
i n n g n 1 ' ' { 20 - ' { 20 - { 20 - s , e : 3 : 30 -- 8 30 - d 30 - i 3 40 40
,,,,gi. .g..,,g... g....g..uge...g . ..g.. .gi . g....g....g.. ig....;
40
,,,,g...g....g*...g...gu,g63,g i
0 5 to 15 20 25 30 35 0 5 10 15 20 25 30 35 0 5 to 1d 20 25 30 35 Temperature *C Temperature 'O Temperature 'C Figure 2-3. Continued. - t
< - ~-%,, . ... .. ....-:. ----.-..-...--2. .ez. .- . - -- . - - - - - . - - -_ - - - - - - - - - - - - - . -
u I p- , ( --
- / ) [ )
d JANUARY F Y MARCH w/ 0 -- o_ o_
. i .
I f 10 - 10 , jo ,' I - e - e - e i E 5 ~ ll 5 - I l { 20 - , [ k 20 ' { 20 t l o ' 8 : 8 : ' l s . . t 30 - ' ' l 30 30 , E - - lI 40' ,,,,,,,,,g.. ,g,,,,g 4o ' ,,,, ,,,, ,,,, ,,,, ,,,, ,,,, ,,,, 4ol 7,,, ,,,, ,,,, ,,,, ,,,, ,,,, ,,,,
,gi. iig,i,,g 0 5 10 15 20 25 30 35 0 5 10 15 20 25 30 35 0 5 10 15 20 25 30 35 Temperature *C Temperature *C Temperature *C APAll MAY JUNE y 0- , 0- ,
0-U i
, I 10 -
~
[ , 10-10 - E {, b T
. g E
{o 20 - -
,I {o 20 - -
,e
{ 20 - o Q - O . Q - e . t - 30 - 30 5 30 s . \s . 40 40 40
.i..j..i.jiii4l6444g66 6liiiigiiiij ,,,,g,,,,g ..,g...,g,,,,g ,,,g ..,g ,,,,g ,,,g,,,fg,,,, ,,,,g,,,,g,,,,g 0 5 10 15 20 25 30 35 0 5 10 15 20 25 30 35 0 5 10 i15 20 25 30 35 Temperature 'C Temperature *C Temperature 'C Figure 2-4. Monthly mean temperature pro 61es for the McGuire Nuclear Station mixing zone in 1997. (... )
and 1993 (-).
JULY A's
' SEPTEMBER
- )
0- 0- 0-a . l 10 - ,' 10 - , 10 7 ,
, . o
- - ' ~ -
n n E l E
# 1 .
o E 5 20 - % 20-g 20 - n , 1 S . e - O a o . 30 - 30 30 l 40
,,,ig,,,, i,,,g ..,g,,,,g,,,,g ,,,g 40
,,,,g... g.,,,g... g...,g ,,,g ...
40 ',,,,g...,g...,g ..,g ,,,g.. ,
,,,,g 0 5 10 15 20 25 30 35 0 5 to 15 20 25 30 35 0 5 to 15 20 25 30 35 Temperature *C Temperature 'O Temperature *C l
i OCTOBER NOVEMBER DECEMBER N , L b 0-
. 0-
. o- -
p i
- 8 . : ,
10 - , 10 - , jo- 8 n . e - 1 ' & : j & : , { 20 - i { 20- { 20-8 ,' 8 : 8 : g .- \ 30 - 8 30 - 30 - ' p - E y
~
40 40 go ' ,,,,,,,,,,,,,!,,,,,,,,,,,,,,,
,,,,g ..,jii ,g.,,,g ,,,g .. g ,,,g ,,,, ,,,, ,,,, ,,,,g ,,,g ..,g .. g 0 5 10 15 20 25 30 35 0 5 10 15 20 25 30 35 0 5 10 19'.20 25 30 35 Temperature *C Temperature *C Temperature *C l
Figure 2-4. Continued. l l .
l 40 35 - u 1 O t "30 - 8 W c u x a . D 25 -- o F o g 20 - a. . . . m , , . O. m 2 15 -- W I-10 --
=
5 : : : : : : : : : : : : JAN FEBMAR APRMAYJUN JUL AUGSEP OCTNOVDEC MONTH l .= tm o iml m 12
- 8 11 -- o '
O 5 m g 10 -~o " g.. , Z " '- W 8- " O O 7 o a Q h 8 ~.. - e O . o a 5- a = W 4- a
>J 3--
O u) 2-
@ 1-Q 0 : : : : : : : : : : : :
JAN FEB MAR APR MAYJUN JUL AUG SEP OCTNOVDEC MONTH
' '~ '
l = im o iml Figure 2-5. Monthly temperature and dissolved oxygen data at the discharge location ( in 1992 and 1993. 2-25
FEBRU- MARCH
\
j JANUARY 0- 0- 0-I . g
. s t8 . gh t 10 - , 10 10 _ s
. e T
- .i E
g
- 8
. i j 20- ,, ,
y 20- ; y 20-} s, o . O - o _ 8
- 8
- . t l ,
i j . ! 30 - 30- [ J, - 30 _ e1 l 40 ,, ;,. .
. ,,,,,,, ,,. ,, 40 ... ... . ,,... . ...,,,,, ao', ,,,,,,,,,,,,,,,,, , , ,,,
l 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 14 0 2 4 6 8 to 12 14 Dissolved Oxygen (mg/l) Dissolved Oxygen (mg/l) Dissolved Oxygen (mg/l) l MAY JUNE APRIL 0 -- 0- . o_ , 8
- t s 3 ,
t s , 10 - 10 - 10 - I , _ s .
,e
~
m 8 e ! E , E .' E : 20 - $ -5 20 - ,' 20 7 I O , o a e l - t
- a . g ,
' ' 30 - e 30 ~ e ;( 3G
_ ij - I . l 40 ,
,,. . ...,,,,,,,,,...,,,,, 40 40 ..................,',,.......,
0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 14 0 2 4 6 8 ,,10 12 14 l Dissolved Oxygen (mg/l) Disso!ved Oxygen (m'p/1) Dissoked Oxygen (mgn) I i Figure 2-6. Monthly mean dissolved oxygen profiles for the McGuire Nuclear Station mixing zone in 1992 ( ... ) [ and 1993 (-). I l r i
\ fh JULY jST SEPTEMBER Ll 0- 0- 0-
- t .
t s ~ f . p
*
- a 10 -
' 10 - ," 10 - ,
{ ,' i $ f
- E
{. 20 - i j' i. 20 -- i r[o. 20-8 . 5 30 - 30 U 30 5
/ _
_= l - 40 40 ........... ......... . ...I 40 ........'........ ........ ., 0 2 4 6 8 10 12 14 0 2 4 6- 8 to 12 14 0 2 4 6 8 to 12 14 Dissolved Oxygen (mgM) Dissolved Oxygen (mgM) Dissolved Oxygen (mgn) l l DECEMBER OCTOBER NOVEMBER 0- 0- ,p 0- i
~
. J 4 e _
{ l - g lr' 10 - 10 - 10 - g i r l * - \ t
-
- n
- a n E -
E ! E e - . i e o r ,. e 20 -- g 40 -- g g 40 - ,- Q : o - o . I I, _ 8 i 8 30 - ,e 30 - l 30- ' g t _ i
~
l l 40 ........... ... .. . .. ,,. l 40 ..
..... .. ....... ..., 40 ....... ........... ...,,..,
0 2 4 6 8 10 12 14 0 2 4e 6 8 10 12 14 0 2 4 6 8 10 12 14 Dissolved Oxygen (mgM) Dissolved Oxygen (mgM) Dissolved Oxygen (mgM) ( Figure 2-6. Continuei l l ,
, . - . . - . ~ . .- - - _ - - . . -. . - - - - -
s JANUARY FEB MARCH (S n 'l
% %l 0- ,
0-b o. g
)
. I
\
t . 10 - i 10 - i 10 - 8 s 8 - 8 1 _ 8 8 1 - 8 E - {o 20 - j' o {e 20- - s 8{ {a 20 - , o i o o . <
',. - 8
, f 30 - / 30 - 30 $ -
40 .,- i... ... >i 40 .. ... ... . . i- .. ...i... ... 40 , ,,, ,,, ,,,,,,, ,, ,,, , 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 14 0 2 4 6 8 to 12 14 Dissolved Oxygen (mgn) Dissolved Oxygen (mg/l) Dissolved Oxygen (mga) JUNE w APRIL MAY h 0- 0 . oo 0- 7 s
~ . i g
I
} .
- 10 - '
10 - to . s \ - E g n
- l E -
1 - ! 5 -
,'. 20
{ 20 - 8 l { 20 - O S . 3 a [ , 8'
. i 30 i
30 : I 30 - ' s 7 l - I
. - I 40 ...g...g... ... ...i... ...
40 ... ....... ..">i... . .i....
.0 .
6 .i.. i...i.. i. ii. 0 2 4 6 8 10 12 14 0 2 4 6 ** 8 to 12 14 0 2 4 6 8 10 12 14 U 88 '" I* I Dissolved Oxygen (mgn) Figure 2-7. Monthly mean dissolved oxygen profiles for the McGuire Nuclear Station background zone in 1992 (...) and 1993 (-). l
w - 1 JUI.Y DST SEPTEMBER i 0- . 0- 0-
- s
,e .
a . , 10 - ," 10 T e" to .
~
~
E i l E 5
' 5 '
{o 20- ,8 1 j' {O 20-- I 6Q t O % O -
$ s s s 30 - 8 30 [ 30f 40 ,,, ,,. ... ............., 40 ... ...........,... ... ...I 40 ... ... ... ...,. . ..... ,,
0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 .14 0 2 4 6 8 10 12 14 Dissolved Oxygen (mga) Dissolved Oxygen (mg/l) Dissolved Oxygen (mg/l) DECEMBER to OCTOBER NOVEMBER 0-h
- o_ 0-i : : i f .
I - g 3g _ to_ [ 10 i i ( ) l m 1
' # {
~
_ g E i da po _ e 6a 20 - s 8 {* 20 - - 8 Q - s [ 1 ! 30 30 30 - 40 40 ... ... .......g... . ... ,, 40 ......... ..........., ... ... ....... ... ... ...,
.... 0 2 4 6 10 12 14 0 2 4 6 8 .10 12 14 8,
- O 2 4 6 8 10 12 14 I
Dissolved Oxygen (mgn) Dissolved Oxygen (mgn) Dissolved Oxygen (mgn) i . Figure 2-7. Continued. ! s-
- _.- .- ~ .--- - ,,- ~m e.- - -
- - . - . - . - - . ~ - . - _ . . .
- (
24 2n _ ' Sorna l (n o La c e t to n e E Samp i to o Loca t ton e E
? 18 18 '? ? ? ? 5 15,' '? 8.' 7/ ?
f T 8.' .I t h I e 1,1 3/ h j to e ce :
'1 *1
- _ 23e _
J e - o - Em Em : ; l
- ! k e : E : e
- 22e - w 22e a
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Figure 2-10. Striped bass habitat (temperatures s 26 C ai.d dissolved oxygen 2 2.0 mg/L in Lake Norman in June, July, August and September 1993.
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Figure 2-10. Continued. I
- ~ . . . _ . ._ ~.- -
?
CHAPTER 3 - PHYTOPLANKTON INTRODUCTION Phytoplankton population parameters were monitored in 1993 in accordance with the NPDES permit for McGuire Nuclear Station. The objectives of the phytoplankton section for the Lake ! Norman Maintenance Monitoring Program are to: i
- 1. Describe quarterly patterns of phytoplankton standing crop and species . !
composition throughout Lake Norman; and j
- 2. Compare phytoplankton data collected during this study (February, May, !
August, November 1993) with historical data collected during these same { months. 3 i Previous studies on Lake Norman have reported considerable spatial and temporal variability j in phytoplankton standing crops and taxonomic composition (Duke Power Company 1976, j 1985; Menhinick and Jensen 1974; Rodriguez 1982). Rodriguez (1982) classified the lake as l oligo-mesotrophic based on phytoplankton abundance, distribution, and taxonomic j composition. ; ). l l METHODS AND MATERIALS I Quarterly phytoplankton sampling was conducted at Locations 2.0,5.0,8.0,9.5,11.0,13.0, , 1 15.9, and 69.0 in Lake Norman (see map oflocations in Chapter 1, Figure 1-1). Duplicate composite grabs from 0.3,4.0, and 8.0 m (i.e., the euphotic zone) were taken at all locations. Sampling was conducted on 23 February, 25 May,12 August, and 30 November 1993. Phytoplankton density, biovolume and taxonomic composition were determined for samples collected at Locations 2.0,5.0,9.5,11.0, and 15.9; chlorophyll a concentrations and seston dry and ash-free dry weights were determined for samples from all locations. Chlorophyll a and total phytoplankton densities and biovolumes are used in determining phytoplankton standing crop. Field sampling methods and laboratory methods used for chlorophyll a, seston dry weights, secchi depth, and population identification and enumeration were identical to those used by Rodriguez (1982). Data collected in 1993 were compared with corresponding data from quarterly monitoring beginning in August 1987. 3-1
g _j A one way ANOVA was performed on chlorophyll a concentrations, phytoplankton densities and seston dry and ash free dry weights by quarter. This was followed by a Duncan's Multiple Range Test to determine which location means were significantly different. The significance level of comparison among means was 0.05. RESULTS AND DISCUSSION e Chlorophyll a Chloreghyll a concentrations from all locations except Location 69.0 ranged from about 5 mg/m3 o t 14 mg/m3 ni 1993 (Table 3-1; Figure 3-1). Chlorophyll a concentrations observed at the uplake riverine Location 69.0 were more variable; ranging from 1.9 mg/m3i n May to 23.5 mg/m3 in August, the highest value recorded since the Maintenance Monitoring Program was begun in 1987. However, even this value is well below the N. C. Water Quality Standard of 40 mg/m3 for chlorophyll. Overall, the range of chlorophyll a values observed in Lake Norman in 1993 was simil. r to that observed in 1991 and 1992 and continue to place this reservoir in the mesotrophic r'. age. O] G Chlorophyll a values at the riverine Location 69.0 were significantly lower than all other l locations in February and May and significantly higher than all other locations in August based on the results of Duncan's Multiple Range Test (Table 3-2). The riverine zone of a reservoir is subject to fluctuations in inflow depending on meteorological conditions (Thornton 1992). Typically, algal production would be supprmsed during periods of high flow, due in part to washout; pmduction would increase during periods of low flow when retention time is greater and wi. shout is decreased. Apparently, the former conditions prevailed in February and May and the latter conditions prevailed in August. Chlorophyll a concentrations at the transitional zone Location 15.9 were significantly higher than other locations in November of 1993. The transitional zone is typically the area of a reservoir with highest algal production (Thomton 1992). Few other consistent patterns in chlorophyll a concentrations were observed in 1993. In general, chlorophyll a concentrations observed at Mixing Zone Locations (2.0 and 5.0) were similar to those observed at other main body locations in Lake Norman. (] Lakewide, chlorophyll a values for 1993 were similar to 1992 and 1991 but were higher than U/ those observed in 1987 through 1990 (Figure 3-2). Lake means of chlorophyll in 1991 and 3-2
i l I Q Q 1*)2 by quarter were in the 8 to 10 mg/m3 range compared with the 2 to 7 mg/m3 range observed in 1987 through 1989. This increase in the lake wide average by quarter appears to l be due to increased chlorophyll concentrations from Location 13.0 downlake to I ocation 2.0 l (Figure 3-3). The greatest increase occurred in February, May, and August. i Total Abundance. l Total phytoplankton densities ranged from a low of 793 units /ml at Location 15.9 in February j to a high of 4373 units /ml at Location 11.0 in May (Table 3-3, Figure 3-1). Total ; phytoplankton biovolumes ranged from a low of 280 mm3 /m3 at Location 15.9 in February to a high of 1589 mm3 /m3 at Location 9.5 in May. Total phytoplankton densities in the , Mixing Zone (Locations 2.0 and 5.0) were signifiently lower than other lake locations : during May and November (Table 3-4). Total densities at Location 15.9 was always
- significantly different from the Mixing Zone. During February and May the separation between the Mixing Zone locations was similar to that of the chlorophylls (Table 3-2). In general, trends in phytoplankton densities parallel trends in chlorophyll a concentrations. ,
Seston f b Seston dry weights in 1993 ranged from a low of 2.26 mg/l at Location 2.0 in August to a high of 10.65 mg/l at Location 69.0 in November (Figure 3-1). Seston ash free dry weights .! ranged from a low of 0.75 mg/l at Location 8.0 and 11.0 in November to a high of 3.05 mg/l ! at Location 69.0 in August. Seston dry weights were significantly higher at uplake Location j 69.0 than other locations in May, August and November (Table 3-5), possibly due to I allocthonous inputs of sediment and high algal abundance. Ash free dry weights were significantly higher at Location 69.0 than other locations in August (Table 3-6). These ! weights did not correspond well with chlorophyll and densities indicating varying inputs of I allochthonous and autochthonous materials. No consistent pattem of seston weights was : observed at the downlake locations. ; I Secchi Depths ; Secchi depths were generally lowest at uplake Location 69.0 due to the previously mentioned l higher amounts of suspended materials (Table 3-1). Secchi depths ranged from a low of 0.5 i m at Location 69.0 in November to a high of 2.38 m at Location 2.0 in August. l 3-3 f
-- -an..-.. , - - - - - .--. , . -
l Community Composition Eleven classes comprising 104 genera and 262 taxa of phytoplankton were identified from ! samples collected in Lake Norman in 1993. The distribution of taxa within classes was as ! I follows: Chlorophyceae (Green algae), 132; Bacillariophyceae (Diatoms), 49- ! Chrysophyceae, 21; Haptophyceae,1; Xanthophyceae, 2; Cryptophyceae, 7; Myxophyceae [ (Blue-green algae), 23; Euglenophyceae, 9; Dinophyceae,14; Chloromonadophyceae, 3; and j 1 Unidentified taxon (see DPC 1992 for species list). Two new taxa, green algae in the ; desmid order, (Tetraedron lobulatum v. crassum Prescott and Staurastrum gladiosum ; Prescott), were identified in 1993 which had not previously been recorded in the Maintenance ; Monitoring Program. l Species Composition and Seasonal Succession j l Species composition in February differed slightly from past years. Cryptophytes numerically ! O dominated phytoplankton assemblages in February due to the abundance of Rhodomonas minuta which comprised over 28.0% of the total density at all locations. Rhodomonas minuta is the most frequent numerical dominant observed in Lake Norman although typically t I I not in February when diatoms generally dominate (Duke Power Company 1992). Diatoms : were second in abundance in February due primarily to Melosira ambigua which comprised l more than 15.0% of the total biovolume at all locations except 9.5. Melosira ambigua, ! formerly called Melostra italica, typically exhibits a large peak .in' abundance in late ! i winter /early spring (February) followed by a rapid decline prior to the onset of stratification. ; In February, the Chrysophyceae density (Kephyrion spp.) at Loc.15.9 and Dinophyceae ! biovolume (Peridinium umbonatum) at Loc. 2.0 were important. l i Phytoplankton species composition in May was dominated by cryptophytes and diatoms much like in February. Fragilaria crotonensis was an important compone.it of the ; biovolume (at all locations except 5.0) and Achnanthes spp. was important in terms of density at Locations 9.5 and 11.0. Diatoms and cryptophytes were numerically codominant in the mixing zone, diatoms were numerically dominant at Loc. 9.5 and I1.0 and j chrysophytes were numerically dominant at Loc.15.9. Rhodomonas minuta was the l numerical dominant at all locations except Location 9.5. 3-4 i
i- s s I As in past years, the phytoplankton community in August consisted of a diverse assemblage dominated by chlorophyceae (green algae) species. Green algae were numerically dominant at all locations except Location 15.9 where diatoms were dominant. A small desmid, Cosmarium asphaerophorum.v. strigosum, was the numerical dominant compnsmg more ! than 20% of the total density at down lake lacustrine locations (2.0, 5.0 and 9.5). Small ! coccoid greens were also important downlake and they were numerically dominant at ! midlake Location 11.0. In terms of biovolume, dinoflagellates (Peridinium spp.) were dominant at Locations 5.0,9.5 and 11.0 in August with diatoms dominant at Locations 2.0 and 15.9. The phytoplankton assemblage at the transition zone Location 15.9 in August was , quite different than other locations. It was dominated in numbers and biovolume by a diatom, Synedra spp., and also had higher numbers of blue green algae. Blue-green algae I comprised about 15% of the density at Location 15.9 in August compared with about- 5% of i the total density at all other locations. Typically, the highest numbers of blue green algae are observed at Location 15.9 in August (DPC 1989,1990,1991,1992). In November, except for Location 15.9, diatoms were the dominant class due primarily to the
]
'I abundance of the large filamentous diatom Melosira ambigua. Also, Melostra ambigua comprised more than 50% of the biovolume at Locations 2.0,5.0 and 9.5 and more than 35%
of the biovolume at Location 11.0. Melostra ambigua is typically most abundant during the ; ) unstratified periods in Lake Norman (Duke Power Company 1989,1990,1991,1992. The . ) phytoplankton community at the uplake transition zone location 15.9 was different from the other locations. It was dominated by cryptophytes, numerically by Rhodomonas minuta and in biovolume by Cryptomonas ovata. In 1993, other species comprising more than 10% of the total density or biovolume were coccoid greens, unidentified flagellates, Nitzschia agerita and in terms of density and
~
Cryptomonas erosa, Cryptomonasovata, and Melosira varians in terms of biovolume. All major taxa observed in 1993 have been common in previous years. ! l i I a O, 3-5 I i
L l O I Q FUTURE STUDIES No changes.are planned for the phytoplankton portion of the Lake Norman maintenance j monitoring program.
SUMMARY
l i
- Chlorophyll a, seston weights and dry weights were most often significantly ;
different at Location 69.0 than other locations in 1993. This location is more :iverine ! in nature and is subject to flucuations in flow. Few .;ignificant differences were ; observed between parameters sampled in the mixing zone and other locations in 1993.
, i
- Chlorophyll a conwntrations at all locations during 1993 were within historical !
- ranges and in the mesotrophic range. They were generally higher than those observed ( during 1987 through 1990 but were similar to those observed in 1991 and 1992. !
- Total phytoplankton densities and b Knu'umes remained similar to those observed m f previous years. !
r 1
~
I
- Phytoplankton taxonomic composition during 1993 was similar to that observed during the same months of 1992. Diatoms, green algae and cryptophytes were the :i most numerically abundant classes of algae observed. Diatoms and cryptophytes [
generally dominated the phytoplankton biovolumes in all months except August when j the phytoplankton community consisted of a diverse assemblage dominated by small ; green algae. Dinoflagellates were sporadically dominant in terms of biovolume at l some locations during all months except November. Blue-green algae were never j
~
dominant part at any location or time in 1993.
- Major taxa observed in 1993 were similar to these observed in 1992. Rhodomonas !
minuta was the most frequent numerical dominant during 1993 as in previous years. ! Mclosira ambigua dominated the algal biovolume at most locations during the f unstratified periods (February and November). i 3-6
m LITERATURE CITED Duke Power Company.1976. McGuire Nuclear Station, Units 1 and 2, Environmental Report,-Operating License Stage. '6th rev. Volume 2. Duke Power Company, Charlotte, NC. Duke Power Company.1985. McGuire Nuclear Station,316(a) Demonstration. Duke Power Company, Charlotte, NC. Duke Power Company.1988. Lake Norman maintenance monitoring program: 1987
- summary.
Duke Power Company.1989. Lake Norman maintenance monitoring program: 1988 summary. Duke Power Company.1990. Lake Norman maintenance monitoring program: 1989 summary. Duke Power Company.1991. Lake Norman maintenance monitoring program: 1990 summary. Duke Power Company,1992. Lake Norman maintenance monitoring program: 1991 summary. Menhinick, E. F and L. D. Jensen.1974. Plankton populations, p. 120-138 In L. D.
.Jensen (ed.). Environmental responses to thermal discharges from Marshall Steam
. Station, Lake Norman, NC. Electric Power Research Institute, Cooling Water Discharge Project (RP-49) Report No. I1. Johns Hopkins Univ., Baltimore MD. 235 P-North Carolina Department of Environment, Health and Natural Resources, Division of Environmental Management (DEM), Water Quality Section. 1991.1990 Algal Bloom-Report Rodriguez, M. S.1982. Phytoplankton, p. 154-260 In J. E. Hogan and W. D. Adair (eds.). Lake Norman summary, Technical Report DUKEPWR/82-02 Duke Power Company, Charlotte, NC. 460 p.
3-7
Thornton, K. W., B. L. Kimmel, F. E. Payne.1990. Reservoir Limnology. John Wiley and Sons, Inc. N. Y. 246 pp. O 1 l i 3-8 I I
O 3 Table 3-1. Mean chlorophyll a concentrations (mg/m ) and secchi depths recorded during 1993 from locations in Lake Norman, NC. Lake Norman Chlorophyll a - 1993 i 1 FEB MAY AUG NOV ! Location Mean Mean Mean Mean l 2.0 6.83 5.80 5.88 5.55 , 5.0 6.67 6.02 7.11 4.86 l 8.0 7.18 8.54 11.61 4.91 9.5 6.44 10.05 13.39 7.52 11.0 7.06 9.84 8.67 6.01 13.0 6.39 12.42 7.00 5.01 15.9 4.60 11.09 13.73 9.15 69.0 2.85 1.92 23.50 3.84 ' Secchi Depths - 1993 Location FEB MAY AUG NOV 2.0 1.74 1.95 2.38 1.25 5.0 1.46 1.95 1,81 1.05 ! 8.0 1.53 2.25 2.16 1.28 9.5 2.01 1.Pr) 1.80 1.17 . 11.0 0.95 1.80 2.23 1.36 13.0 0.79 1.70 1.22 1.06 15.9 0.67 1.60 1.78 1.52 69.0 0.85 0.90 1.34 0.50 h F 3-9 ,
l
/3 Table 3-2. Duncan's Multiple Range Test on Chlorophyll a concentrations in Lake Norman, NC during 1993. (Means connected by lines are not significantly different.) ,
i February Location 69.0 15.9 13.0 9.5 5.0 2.0 11.0 8.0 Mean 2.85 4.60 6.39 6.44 6.67 6.83 7.06 7.18 i i May Location 69.0 2.0 5.0 8.0 11.0 9.5 15.9 13.0 Mean 1.92 5.80 6.02 8.54 9.84 10.04 11.09 12.42 August Location 2.0 13.0 5.0 11.0 8.0 9.5 15.9 69.0 Mean 5.88 7.00 7.11 8.67 11.61 13.40 13.73 23.50 0 : I November Location 69.0 5.0 8.0 13.0 2.0 11.0 9.5 15.9 : Mean 3.84 4.86 4.91 5.01 5.55 6.01 7.52 9.15 , j 1 i f 1 6 O 3-10
i r Table 3-3. Total phytoplankton densities and biovolumes from samples coll' ected in Lake Norman, NC in February, May, August and November 1993. Total Phytoplankton - Lake Norman - 1993 Density Locations Class 2.0 5.0 9.5 11.0 15.9 Mean ' FEB 1507 1673 1765 1702 793 1488 MAY 2045 1824 3766 4372 3612 3124 AUG 1638 2230 2881 1445 3742 2387 NOV 937 1138 1431 1451 1614 1314 Biovolume . 2.0 5.0 9.5 11.0 15.9 Mean FE8 671 465 490 577 280 497 MAY 797 652 1589 1391 1411 1168 O AUG NOV 423 773 789 536 1387 955 1050 722 1236 489 976 695 3 p 3-11
Table 3-4. Duncan's Multiple Range Test on Phytoplankton Densities in Lake Norman, NC
-( during 1993. (Means connected by lines are not significantly different.)
February Location 15.9 2.0 5.0 11.0 9.5 j Mean 793 1507 1673 1703 1765 ; 4 3 May Location 5.0 2.0 15.9 9.5 11.0 Mean 1824 2045 3612 3766 4373 1 i August Location 11.0 2.0 5.0 9.5 15.9 : Mean 1445 1639 2230 2882 3742 > November Location 2.0 5.0 9.5 11.0 15.9 , Mean 938 1138 1431 1451 1615 , ) i 4
?
'I 3-12
-- .--,-,-m,-m -- , . - - + - , ., = -,.4 v . - - e wy
l Table 3-5 . Duncan's Multiple Range Test on Seston Dry and Ash Free Dry Weight concentrations in Lake Norman, NC during 1993. Dry Weight February location 2.0 9.5 5.0 8.0 11.0 13.0 69.0 15.9 Mean 2.67 2.74 2.96 3.08 3.85 4.32 4.70 4.99 May Iocation 8.0 9.5 11.0 5.0 13.0 2.0 15.9 69.0 Mean 2.76 3.24 3.28 3.52 3.68 4.06 4.37 8.60 August location 2.0 11.0 13.0 8.0 15.9 9.5 5.0 69.0 Mean 2.26 2.27 2.27 2.34 2.50 3.02 3.09 7.98 November Iocation 15.9 11.0 2.0 8.0 5.0 13.0 9.5 69.0 Mean 3.41 3.41 3.50 4.00 4.49 4.74 4.80 10.65 ' O kl Ash Free Dry Weight February location 9.5 69.0 5.0 2.0 8.0 11.0 13.0 15.9 Mean 0.82 0.90 1.00 1.01 1.06 1.08 1.13 1.21 May location 5.0 8.0 2.0 9.5 11.0 15.9 13.0 69.G ; Mean 1.24 1.37 1.51 1.58 1.69 1.71 1.85 1.98 i August Location 13.0 2.0 11.0 15.9 8.0 5.0 9.5 69.0 { Mean 1.02 1.23 1.35 1.44 1.48 1.53 1.78 3.05 l l November Location 11.0 8.0 2.0 13.0 15.9 9.5 5.0 69.0 Mean 0.75 0.75 0.76 0.82 0.94 0.99 1.04 1.99 3-13
mg/m3 No./mi 26 6,000 O I Chlorophyll a f Total Density
,r s
20 -
,f 4,000 .
,e s l
? '.p I o l
16 - [ 3,000 - f
,A /
/
\. s, .l / '. l t
x . o ./ \. . l
,/ *-W \ l ** /*'
10 - t 2,000 A \.
/ ' 4' \ / 9 x*' d
- \ _,/
o,
%.g' :.: .s., df '
. s . . . . . .% , . . . . c S gp*e....d ..- o . , e, -
. g, g., 1,000 ,....*,..
to 6 0 ' ' ' ' ' ' ' ' ' 2 6 8 9.6 11 13 16.9 69 o'2 ' ' ' 6 9.6 11 16.9 m9 mm3/m3 12 2,000 Dry Weight p Total Biovolume 10 - l
.I 1,600 - ' *'s '
e . l, lt. '+--*
.s I: \
!*:g 'l ^\ ,/*s a l'
f*l 6 - l 1,000 -
/
t !' A * . n,
- S ?. M, , ,. I .
4 *.- y ~
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~" ' f.l s ,, / 600 -.
] ___ t .c.
g' e- .w. .s.. 4 d 2 1 0 O ' ' ' ' 2 6 8 9.6 11 13 16.9 69 2 6 9.6 11 16.9' Feb May Aug Nov a _ + _ 4 _..c. e~ (s I Figure 3-1. Chlorophyll a, dry weights, total densities and total biovolumes for locations in Lake Nomlan, North Carolina, in February, May, August, and November 1993. 3-14
l l l i I l Chlorophyll a Lake Means by Year mg/m3 12 10
- s . . ..*~. 4 . / . * ~ . ~ . .
- e ./* "'~ -e - .-...-.?_:.x y ~..-. . --- e l
8 -
. . ~g i
~
- o. ' " ' . . -A..'
p 6 ..
- s. -
,_ .....s., s ..
A. . . .
.............o. '
q - 4 m ,- ?$ _x../
.. g-2 -
l 1 1 0 i Feb May Aug Nov 1987 1988 _.g_ 1989 1990
.o.
l o 1991 1992 1993 ,
-m- -e- --A- )
l i
)
i Figure 3-2. Chlorophyll a, lake means by year samples were collected in Lake Norman, North Carolina, from August 1987 through November 1993. 1 / ' 3-15 i
, m February May August November
'5 $5
, Loc. 2.0 c-e " '
c Loc. 5.0 A-- A O to ic N .A , o ' e %, A _C I *# 3 s _A, s ,A* x ii 86 49 i0 91 N b ii 8. 8'l b S1 52 f e j , g ,, ,o g ,a ,3 0, ,, ,, ,, ,, ,-2 i3
's is Loc. 8.0 C D '5 -
'5 '
Loc. 9.5 a-- A -
^
agg to 10 4 b* 10 10 o- ,s s~ 9 4 4 8 r
,, ~s s t m s #
o - 4 8 is N 90 N i2 93 8 ii s'o 5 ia 6 'l'i ii O
.'S n is o.
.. li to A 92 h .s so si sa s o is j
is Loc.11.0 C D
- s Loc.13.0 A- - A A to 10 A te to t+>
- O. l , l'*
- A E 35 A 5 5 , ,
, A . 4, ' s -
<6 o, 0 6 h h
;, 6 h 0i h h 6 h h h 0 (i 6 6 6 h k h *
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, as 2s as as A
o O o
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o Loc. 6 9.0 a- - A e e f is - ts - ts ; is
, s to 10 g,
10 , to s , s
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/
s s s s s
/ h
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., ., so . si
,2 u
.7 .. ., n si n n er .. .. n n = n ei .. ., n si n n Figure 3-3. Chlorophyll a concentrations (mg/m') by location fcr samples collected in Lake Norman, North Carolina, fium August 1987 through November 1993.
I unito/mi DOncity mms /m3 Blovolur71e - 5.000 2,000 Mixing =,000 -- -- Zone Loo. 2 & S Feb May Aug Nov Feb May Aug Nov 5,000 2,000
%,000 3,000 -.-
Loo. 9.6 5 cao 2,000 .- . 1,000 -- -
~ ~
Feb May Aug- Nov F May Aug Nov 5,000 3,000 n,000 ~- - - 3,000 ~.. Lo c.11.0 i.000 - 3,000 - . - 0 Feb May Aug Nov Feb May Aug Nov 5.000 2,000 a e,000 -
,/ , ,
s.000 - ..c y .. ,- . Loc.1 S.9 '"' ~ t,000 - ',
-{. ]. . ,
m
+
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'. -- Y
/f 0- -
0 -
... . ... .0 - . . ... ... ~0 . . .
In Bacillarlophyc e ao 13 Chlorophyceae GChrysophyceae "i Cryp tophy c e a e o Myxophyceae a Dinophyceae O Other Figure 3-4, Class composition of phytoplankton from euphotic zone composite samples collected at locations in lake Norman, North Carolina, during 1993. 3-17
~ -- , - ._- . . - . . . _ - -
ev CHAPTER 4 l ZOOPLANKTON , 1 INTRODUCTION ! The objectives of the Lake Norman Maintenance Monitoring Program for zooplankton are to:
- 1. Describe quarterly patterns of zooplankton standing crops at selected locations on Lake Norman and i
- e. Compare zooplankton data collected during this study (February, May, l
August, and November 1993) with historical data collected for this Program during the period 1987-1991 for these same months. ; Previous studies of Lake Norman zooplankton populations have demonstrated a bimodal seasonal distribution with highest recorded values occurring in spring and a less pronounced , fall peak. Considerable spatial and year to year variability has been observed in zooplankton ; abundance in Lake Norman (Duke Power Company 1976,1985; Hamme 1982; Menhinick i*
;G ;
and Jensen 1974). } . ! METHODS AND MATERIALS i i Duplicate 10 m to surface and bottom to surface net tows were taken at Locations 2.0,5.0, f 9.5,11.0, and 15.9 in Lake Norman (Chapter 2, Figure 1-1) on February 23, May 25, August 12, and November 30, 1993. For discussion purposes the 10 m to surface tow samples will be referred to as eplimnetic samples and the bottom to surface net tow samples ; will be referred to as whole column samples. Locations 2.0 and 5.0 are defined as the Mixing ) Zone and Locations 9.5,11.0 and 15.9 are defined as Background locations. Field and i laboratory methods for zooplankton standing crop analysis were the same as those reported in Hamme (1982). Zooplankton standing crop data from 1992 were compared with corresponding data from quarterly monitoring begun in August 1987. l l 4-1 l l
h I q( A'one way ANOVA was performed on epilimnetic t.otal zooplankton densities by quarter. This was followed by a Duncan's Multiple Range Test to determine which location means i l were significantly different. The significance level of comparison among means was 0.05. RESULTS AND DISCUSSION Total Abundance Lakewide, total zooplankton densities in both epilimnetic and whole column samples in 1993 l were highest in May and lowest in November (Table 4-1). Spring is historically the time of
- maximum zooplankton standing crop in Lake Norman (Hamme 1982). The greatest observed zooplankton densities in 1993 for epliranetic samples were observed at Location 2.0 [
in February (115,300/m3) and for whole colu'nn samples were observed at Location 5.0 in j May (132,600/m3). The lowest zooplankton densities for both eplimnetic and whole column ; O samples were observed in November at Location 9.5 - (16,000/m3 and 12,600/m3, respectively). The trend of increasing zooplankton population densities from downlake to uplake observed in previous years was only evident in November of 1993 (Figure 4-1). ). Total zooplankton densities were generally greater in epilimnetic samples than in whole column samples in 1993 as in previous years (Duke Power Company 1988,1989,1990,1991 and 1992). This phenomenon is related to the ability of zooplankton to orient vertically in the water column in response to a variety of physical and chemical gradients and the distribution of food sources, primarily phytoplankton (Hutchinson 1967). 6 4-2 l
e . . . -. -- - ---,-- .. y i p . I Location Comparisons l A one way ANOVA on total zooplankton densities in eplimnetic samples showed no 1 consistent spatial pattem among locations in 1993 (Table 4-2). Zooplankton densities from j I Locations 2.0 and 9.5 were significantly higher than other locations in February, the month with the greatest differences in observed densities between locations. Total zooplankton ! density at Location 9.5 was significantly higher than other locations in. August. Both j zooplankton densities from Location 11.0 and 15.9 were significantly different from the ! lower lake locations in an increasing pattern moving uplake in November. [ t Year to Year Comparisons t Total zooplankton densities from eplimnetic samples collected during February, May, August I and November of 1993 were generally within the range of those reported for these months in f previous years (Figure 4-2). Major trends in epilimnetic zooplankton abundance included f higher total zooplankton densities at Locations 2.0 and 9.5 in February than those observed since 1987. The November 1993 densities in the Mixing Zone were the lowest recorded since 1987, while the highest densities occurred in the Mixing Zone in May during the same period. No consistent pattems were noted for the Background locations. Community Composition j i i i Fifty-seven zooplankton taxa have been identified in ramples collected since the Lake Norman Maintenance Monitoring Program was initiated in August 1987 (Table 4-3). No ; new zooplankton taxa were identified in samples collected in 1993. Rotifers most often j dominated zooplankton assemblages in Lake Norman during 1993 as in previous years, j followed by copepods (Table 4-1; Figure 4-3). Cladocerans were numerically dominant only l at Location 2.0 in November in 1993. Rotifers were most consistently abundant lakewide , during the warmer months when they comprised an average 60.7% and 76.0% of the total i g density in eplimnetic tows in May and August, respectively. Copepods were second most { V abundant during each sampling period except August when they comprised less than 10% of [ 4-3 l i I
O, ' the total density in epilimnetic samples at all locations. In November, rotifers exhibited increasing densities from downlake to uplake in both eplimnetic and whole water column samples,eg. 2,100/m3 at Location 2.0 to 47,500/m3 at Location 15.9 in eplimnetic samples. This was the only month in 1993 in which a consistent downlake uplake trend ofincreasing rotifer densities occurred as had been observed in past years. Hamme (1982) found that the highest rotifer densities generally occurred at uplake locations. During February 1993 Polyarthra and Synchaeta were the major constituents of rotifer populations. Keratella and Polyarthra were the dominant rotifers at all locations in May. Conchiloides, Conochilus and Trichocerca joined Keratella as the most important rotifer taxa in August of 1993. Conochilus was the overall dominant in August of 1993 at Location 15.9 where it comprised more than 40% of the total density in both eplimnetic and whole column samples. Keratella and Polyarthra were again the major components of the rotifers in November. Major rotifer taxa observed in 1993 were also the most abundant rotifers observed in previous years (Duke Power Company 1988,1989,1990,1991,1992; Hamme I n 1 1982). N)
- Copepod populations were dominated by immature forms (primarily nauplii and cyclopold copepodids with some calanoid copepodids) during all sampling periods of 1993 as was the l
case in 1991. Mesocyclops spp. was the only major adult copepod taxon observed in 1993, comprising more than 5% of the total densities in the whole column samples at Location 9.5 in May. No distinct spatial trend in copepod abundance was noted for samples collected in 1993 (Figure 4-3). Bosmina was the most abundant cladoceran observed in samples collected in 1993, as in 1992 (Duke Power Company 1993) and in previous years (Hamme 1982). Bosmina comprised more than 25% of the total zooplankton density in both epilimnetic and whole j column samples at Location 2.0 in February. In November of 1993 as in 1992, Bosmina comprised more than 20% of the total density in whole column samples in the Mixing Zone. f The only other major cladoceran taxa observed in 1993 was Bosminopsis aeitersi at downlake locations 2.0,5.0 and 9.5 (both epilimnetic and whole column samples) in August O (J 4-4
L - 1 l i' l where it comprised between 13% to 37% of the total zooplankton density. No consistent l h', spatial trend in cladoceran abundance was observed in 1993 (Figure 4-3). i Several patterns are evident in comparison of group composition during 1993 with the past four years (Figure 4-4). Group densities at Location 9.5 for copepods and Cladocerans in l February and Cladocerans in August ere above historical ranges. Rotifer densities in the i Mixing Zone during May and August are above the historical range while rotifer densities at i Location 15.9 in 1993 were lower overall than observed in the past four years. FUTURE STUDIES l i t No changes are planned for the zooplankton portion of the Lake Norman maintenance monitoring program.
SUMMARY
j )
- Total zooplankton standing crops were generally highest in May and lowest in ;
November. Zooplankton densities, in general, were slightly higher in eplimnetic l I samples than in whole column samples. Total zooplankton densities at Mixing Zone locations were not significantly different from background locations during any l quarter in 1993. The typical trend ofincreasing zooplankton densities fmm downlake l to uplake was observed only in November in 1993. The range of total zooplankton densities observed during 1993 was similar to the ranges observed since 1987. i 1 i
- Overall, rotifers dominated zooplankton standing crops in 1993, as they did in ;
1992, followed closely in importance by copepods. Cladocerans were dominant l numerically on only one occasion in 1993. Major rotifer taxa observed in 1993 were Keratella, Polyarthra and Synchaeta. Copepod populations were dominated by j
-immature forms (nauplii and cyclopoid copepodids). As in previous years, Bosmina was the most abundant cladoceran taxa observed at all locations. Overall, i 1
4-5 [ i
, ' x zooplankton taxonomic composition in 1993 was similar to that observed in previous ;
years. LITERATURE CITED Duke Power Company.1976. McGuire Nuclear Station, Units 1 and 2, Environmental Report, Operating License Stage. 6th rev. Volume 2. Duke Power Company, . Charlotte , NC.
. Duke Power Company.1985. McGuire Nuclear Station,316(a) Demonstration. Duke Power Company, Charlotte, NC.
Duke Power Company.1988. Lake Norman Maintenance monitoring program: 1987 l Summary. Duke Power Company, Charlotte, NC. Duke Power Company.1989. Lake Norman Maintenance monitoring program:1988 Summary. Duke Power Company, Chnlotte, NC. , Duke Power Company.1990. Lake Norman Maintenance monitoring program: 1989 l m Summary. Duke Power Company, Charlotte, NC. : i Duke Power Company.1991. Lake Norman Maintenance monitoring program: 1990 l Summary. Duke Power Company, Charlotte, NC. j Duke Power Company.1992. Lake Norman Maintenance monitoring program: 1991 Summary. Duke Power Company, Charlotte, NC. i Hamme, R. E.1982. Zooplankton,in J. E. Hogan and W. D. Adair (eds.). Lake Norman i Summary, Technical Report DUKEPWR/82-02. p. 323-353, Duke Power Company, ! Charlotte, NC. 460 p. ; Hutchinson, G. E.1967. A Treatise on Limnology. Vol. II. Introduction to Lake : Biology and the Limnoplankton. John Wiley and Sons,Inc N. Y. I115 pp. j i Menhinick, E. F. and L. D. Jensen.1974. Plankton populations. In L. D. Jensen (ed.). l Environmental responses to thermal discharges from Marshall Steam Station, Lake l Norman, North Carolina. Electric Power Research Institu'.e, Cooling Water Discharge Research Project (RP-49) Report No. I1., p.120-138, Johns Hopkins University, i Baltimore, MD 235 p. t 4-6 i I
t
/ Table 4-1. Total zooplankton densities (no. x 1000/m3), densities of major 5
( zooplankton taxonomic groups, and percent composition (in parentheses) of major taxa in 10 m to surface (10-S) and bottom to surface (B-S) net tow samples collected from Lake Norman in February, May, August, and
. Nomber 1993, i Sampic Imcations
_Date Tyne Taxon 2.0 5.0 9.5 11.0 15.9 02/23/93 10-S COPEPODA 40.0 8.8 65.0 13.8 3.0 : (34.7) (22.7) (56.7) (16.3) (25.4) : CIADOCERA 31.6 3.8 34.7 7.6 1.2 2 (27.4) (9.8) (30.3) (9.0) (10.1) ROTIFERA 43.7 26.3 14.9 62.9 7.7 (37.9) (67.6) (13.0) (74.61 (64.5) TOTAL 115.3 39.0 114.6 84.3 11.9 l B-S COPEPODA 9.2 6.3 81.3 .10.4 3.9 (depth [a] (29.2) (19.7) (65.1) (33.6) (26.6) of cov ' for esca CIADOCERA 7.9 5.5 28.3 7.7 0.5 location: (25.0) (17.2) (22.7) (24.8) (3.1) 2.0-31 5.0-18 ROTIFERA 14.4 20.1 15.2 12.9 10.3 ! 9.5-20 (45.8) (63.1) 112.2) (41.7) (70.31 l 11.0-26 TOTAL 31.5 31.8 124.8 31.0 14.7 l 15.9-20) J5/25/93 10-S COPEPODA 27.4 25.6 39.0 31.2 37.7 (28.3) (42.0) .(34.8) (30.8) (39.1) I CIADOCERA 3.8 7.1 2.5 1.3 2.2 i (4.0) (11.6) (2.2) (1.3) (2.3) ROTIFERA 65.7 28.2 70.7 68.6 56.5' (67.7) (46.31 (63.01 (67.9) (58.6) + TOTAL 96.9 61.0 112.1 101.1 96.4 , B-S COPEPODA 18.6 21.6 35.8 26.0 33.2 (depth [n] (35.3) (16.3) (34.7) (45.5) (46.0) of tow . for each CIADOCERA 3.7 4.0 3.5 1.6 2.7 location: (7.0) (3.0) (3.4) (2.8) (3.7) 2.0-30 5.0-19 ROTIFERA 30.5 107.0 63.8 29.7 36.3 9.5-20 (57.7) (80.7) (61.9) (45.5) (50.3) 11.0-28 15.9-21) TOTAL 52.8 132.6 103.1 57.3 72.1 i
, 4-7 :
l [% Table 4-1. (continued
\~_- ,
Sample Locations I Date- Tyne Taxon 2.0 5.0 9.5- 11.0 15.9 ' 08/12/93 10-S COPEPODA 1.9 5.3 3.8 3.4 4.9 (3.6) (9.9) (4.2) (7.0) (7.4) CLADOCERA 10.7 9.3 30.1 2.9 7.0 (20.6) (17.3) (33.5) (6.0) *(10.5) > 39.3 ROTIFERA 39.1 56.1 42.3 54.7 (75.8) (72.8) (62.3) (87.0) (82.1) TOTAL 51.9 53.7 90.0 48.6 66.5 ' B-S COPEPODA 2.2 7.5 4.7 2.4 8.5 (depth (m] (8.2) (22.0) (9.4) (10.6) (12.5) of tow for each CLADOCERA 6.5 5.5 19.6 2.9 9.2 location: (24.6) (16.0) (39.5) (13.2) (13.6) 2.0-29 5.0-18 ROTIFERA 17.7 21.1 25.4 17.0 49.9 , 9.5-20 (67.2) (62.0) (51.1) (76.2) (73.9) 11.0-26 , 4 15.9-20) TOTAL 26.3 34.1 49.8 22.3 67.5 O 11/30/93 10-S COPEPODA 7.2 (45.0) 9.6 (43.0) 9.7 (60.9) 15.3 (33.4) 22.0 (27.3) i j l CLADOCERA 6.7 4.9 1.7 4.4 11.1 (41.8) (21.9) (10.7) (9.7) (13.7) ROTIFERA 2.1 7.8 4.5 26.1 47.5 (11.11 (21.9) (28.41 (56.9) (59.0)' TOTAL 16.0 22.3 16.0 45.8 80.6 B-S COPEPODA 9.9 10.6 6.4 14.0 16.1 (depth [m] (43.9) (44.1) (50.6) (33.3) (27.1) of tow for each CLADOCERA 10.3 8.2 1.2 4.2 7.9 location: (45.8) (34.0) (9.7) (9.9) (13.3) 2.0-30 - 5.0-18 ROTIFERA 2.3 5.3 5.0 23.9 35.4 9.5-20 (10.31 (21.9) (39.7) (56.8) (59.6) ' 11.0-26 15.9-19) TOTAL 22.5 24.0 12.6 42.1 59.4 4-8 f e , , , ,
Table 4-2. Duncan's Multiple Range Test on Zooplankton Densities in Lake Norman' O NC dudng 1993. l February Location 15.9 11.0 5.0 9.5 2.0 Mean 11.9 35.1 37.2 114.5 115.2 l l May Incation 15.9 2.0 11.0 9.5 5.0 i Mean 96.4 96.8 101.0 112.1 132.5 l August IAx:ation 11.0 2.0 5.0 15.9 9.5 i Mean 48.6 49.5 53.7 66.5 89.9 l November Location 9.5 2.0 5.0 11.0 15.9 Mean 16.0 16.0 22.3 45.8 80.5 O v 4-9
1 ! Table 4-3. Zooplankton taxa identified from samples collected in Lake Norman ! quarterly from August 1987 through November 1993. t COPEPODA , Lecane app. Nitzsch Cyclops thomasi S. A. Forbes Macrocheatus spp. Party ( C. spp. Fischer Monortyla stenroosi(Meissener) Diaptomus birgel Marsh M. app. Ehunberg D. mississippiensis Marsk Ploeosome truncatum (Invander) D. pallidus Herick P. spp. Herrick D. spp. Marsh Polyanhra euryptera (Weirzeijski) Mesocyclops edar (S. A. Forbes) P. vulgaris Carhn , M. spp. Sars ' P. spp. Ehrenberg hopocyclopsprasinus (Fischer) Ptygura spp. Ehrenberg T. spp. Kiefer Syndasta spp. Ehrenberg ; Calanoid copepodites 7Hchocerm capucina (Weireijski) Cyclopoid copepodites T. cylindrica (Imhof) ; Nauplii T. spp. Immark . j Unidentified Bdelloiden CLADOCERA I INSECTA Bosmina longirostris (O. F. Muller) ; B. spp. Baird Chaoborus spp. Lichtenstein r p) t N/ Bosminopsis dieserst Richard Ceriodaphnia spp. Dana Daphnia ambigua Scourtield l l D. parvula Fordyce D. spp. Mullen Diaphanosoma spp. Fischer j Holopedium amatonicum Stingelin i H. spp. Stingelin { Leptodora kindtil(Focke) > llyocryptus sordidus (Lieven) Sida crystallina O. F. Muller i ROTIFERA Anuracopsis spp. Lauterborne Asplanchna spp. Gosse Drachionus caudata Barrois and Daday B. havanaensis Rousselet B. patulus O. F. Muller Chromogaster spp. Iauterbome ; Collotheca spp. Harring i Conochiloides spp. Hlava Conochilus unicornis (Rousselet) , C. spp. Hlava i Gartropus spp. Imhof - Feranhra spp. Schmada , O Kellicotia bostoniensis (Rousselet) K. spp. Rouselet Keratella epp. Bory de St. Vincent 4-10 i l
Zooplankton Density .,.. .
,- No. x 10 0 0/m3 150
(]s 10rg to Surf ace Tows
~~. ~~
100 , * ,
.a.
p
/
s 50 b " " " " " *... . gy-
' " ..... o l
g6~~4 / 0 2.0 5.0 9.5 11.0 15.9 Locations No. x 10 0 0/m3 150 Bottom to Surface Tows f 100 - s ,. g
' .a e-l 50 t
............o..
a
... .. .. / -
_e ,/. .g . e-0 '
- 2.0 5.0 9.5 11.0 15.9 l
l Locations i FRb gy Agg gv, , , ~ Figure 4-1. Total zooplankton density (units x1000/m') by location for samples collected in , Lake Norman, North Carolina in 1993. i 4-11 l
Mixing Zone 200 - 200 200 - 200 l Loc. 2.0 C O 150
~ ~~* -
150 - 150 - 150 -
- 100 '
100 100 y" 100
- x e
,5
- g d 50 50 -
50 50
,,*p#j -4 _*-
O'7888990919293 8 08'7 88 89 90 91 92 93 0'7888990919293 8 0'7888990919293 8 Background locations 3go 300 300 80U g .[ Loc. 9.5 e-*
- 427,000 250 Lo c. ,i.0 . -- - - 250 -
250 250
- j\.
Loc.15.9 h-4 .
* \
7200 200 - 5 i, 200 200 4 a - I ,g
$ h I'\ \ ' ,
o 150 350 9 \ k. 160
\/ \ /, .
ISO l.,g\ /JI\ .A.
/\
300 g I\ \ ./ i? 100 - N. 100 E,g% i
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- f.A4f.?q
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\ 50 f* 'Ak W * .,
Oi78889 0 91 2 93 87 88 89 N0 d1 d2 d3 0'78889$0$1d2d3 8 87 88 89 90 91 92 93 February May August November 3 Figure 4-2. Total zooplankton density (units x1000/m ) by location for samples collected during 1993 in Lake Norman, North Carolina.
~
1 O O O fio. x 1000/m3 . x 1000/m3 l February August 100 - 100 - o E o _ _ 2.0 5.0 9.5 11.0 1 S.9 2.0 5.0 9.5 11.0 15.9 P No. x 1000/m3 No.x 1000/m3 l C 150 150 May November 100 - 100 - 50 - 50 - 0 0 2.0 5.0 9.5 11.0 15.9 2.0 5.0 9.5 11.0 15.9 E copepodsE Cladoceranstil Rotifers Figure 4-3. Zooplankton composition by month for epilimnetic samples collected during 1993 in Lake Norman, North Carolina.
, e. -
No. x 1000/m3 Copepods 80 1989 1990 O) t L/ 60 - l i l 1991 l i 1992 i 1993 i l , ,, , i i:- is 40 -
!:f.%
.A. i.:,h..,
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i
+
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. '. m.
No. x 1000/m3 80 CladOCeranS 1089 ! 1990 l 19g1 1992 5 i l 1993 60 - i i i i i ! 40 - i .
- 20 -
w l/ \\
- i
.~
. l ',
) ,#
5
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!A-i o..,.,.,,.~ .....-.,.........-.,..........,.........m.,., ,,w,.
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No. x 1000/m3 Rotifers 140 1989 1990 1 , 1gg1 ; 1992 9 1993 12o . .. , l j jq l}
. . i .l -
'*i j
100 - i i
- i ;'
. i C> i i j$.
o .' i ti 80 - - l:
- s \.
f'
.i .
7 .
. I O ;
- .4 60
. l . i h/. o:y .\'
-\ :
5
- l.\ i:. t
.: . t -
il !! \. ' ! C ll. \.s-' h " o 4 -l i " . 4.!% .j : /
./ j -
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. -+- .,j 2.Vll 4- ;4 N jJ '. N O ' ' ' ' ' ' ' ' ' ' ' ' '
[o F.h M.y A.0 N.. F.h M.y AWS No. ,.'h M., A.0 N.. ..b M.y A.g ..'.',.'h M.y A.g N.. Mixingone Loo g9.5 Loc4,,1.0 1 Lo c.,,15.9 / ( 4 Figure 4-4. Comparison of zooplankton density by group in epilimnetic samples collected from 1989 through 1993 in Lake Norman, North Carolina. 4-14
. I l
I l 1
-( CHAPTER 5 FISHERIES
-1 i
INTRODUCTION In accordance with the NPDES permit for McGuire Nuclear Station (MNS), monitoring of specific fish population parameters was continued during 1993. The objectives of the fish monitoring program for Lake Norman during 1993 were to: j
- Continue striped bass mortality monitoring throughout the sumrner.
- Collect striped bass distribution information required for the NPDES permit by radio ,
tagging striped bass and tracking the striped bass during the summer period in cooperation with North Carolina Wildlife Resources Commission (NCWRC). l
- Measure limnetic fish distribution, density, and species composition in lower Lake Norman in 1993 using hydroacoustics and purse seine.
- . w The mixing zone was monitored for striped bass mortalities through the summer dunng -
) sampling trips on the lake, while tracking striped bass with NCWRC biologists. During the j i last 2 weeks of July and the first 2 weeks of August specific trips to search for dead or dying fish were conducted. f NCWRC and Duke studied striped bass movement and habitat selection by radio tagging fish [ in 1992 and 1993. Both NCWRC and Duke believe that this sampling program will identify critical summer striped bass habitat in Lake Norman. See appendix report 5.1 (NCWRC 1993 Federal Aid in Fish Restoration Project F23-17) for the sampling methodology and l results of the program. ! Hydroacoustics and a purse seine were used to determine fish distribution and species ! composition, respectively, in Lake Norman in August 1993. ; P 5-1
.g--.-4 r---r * - , --.
i METIlODS AND MATERIALS A 400-ft x 30-ft deep x 3/16-inch mesh purse seine was set near the MNS discharge aller sunset on August 10,1993, to collect limnetic fish. Fish captured were identified to species, counted, and a subsample of 500 threadfm shad were measured (mm, TL). Fish density in the limnetic areas of the MNS mixing zone were determined with 120-Kliz hydroacoustic gear on 4 August 1993. Lake Norman was sampled using methods similar to that reported in 1988 through 1990 (Duke Power Company 1990). liydroacous'.ic samples were collected along transects in the main channel of the lake and all major tributaries, including Ramsey Creek and near the MNS discharge. Fish densities were plotted using a - geographic identification system (GIS). I RESULTS AND DISCUSSION i liydroacoustic density estimates of limnetic fish in lower Lake Norman were similar to . ranges observed in other areas of the reservoir. Densities were lower in the heated water plume on August 4,1993, than in the surrounding areas, but were nct any less than in other areas of the reservoir (Figure 5-1). A clumped distribution pattern is evident, with densities ranging from less than 10,000 to greater than 90,000/ha in the MNS mixing zone and in areas h of the reservoir with ambient water temperatures. Surface water temperatures in the j discharge area during August were 35'C. This is higher than the preferred temperatures of ; i threadfin shad, the predominant species in the limnetic area of the reservoir (Duke Power Company 1993). , Nearly all (99.6%) of the fish collected in the purse seine in August were threadfm shad. The only other species sampled with the purse seine in lower Lake Norman was black - crappie. I Dead and dying striped bass were observed during the last 2 weeks in July 1993 in the MNS mixing zone. On July 23, fourteen dead striped bass were counted in the main channel from . the dam to Marker 7, approximately 6 miles above the dam and 2 miles above the confluence of Davidson Creek and the main channel. On July 30, eleven dead striped bass were counted from the dam to Marker I A, approximately 1.5 miles above the dam. Only two of the 25 i dead striped bass observed were larger than 5 pounds. Anglers fishing the area for striped O 5-2 L_._-__-____--__ _ _ , . _. __ . _ , -
b i bass were catching large numbers of fish less than the 20 inch size limit and returning them k to the lake. This likely contributed to the large number of dead small fish observed. Striped - bass less than 5 pounds have not been reported in the literature as stressed by high summer l water temperatures; however, rec ' research in Tennessee has shown angling mortalities of greater than 60% for striped bass caught in the summer (Phil Bettoli, personal communication). FUTURE FISH STUDIES
- Continue striped bass mortality monitoring throughout the summer. ,
- Determine fish distribution and conduct angler surveys to determine angler harvest, pressure, and success on Lake Norman from March 1994 through February 1995.
LITERATURE CITED ' Duke Power Company. 1990. Lake Norman: 1989 maintenance monitoring program,
) McGuire Nuclear Etation. Duke Power Company, Charlotte, NC. ;
Duke Power Company. 1993. Lake Norman: 1992 maintenance monitoring program, McGuire Nuclear Station. Duke Power Company, Charlotte, NC. D i L f l p ! 5-3 i e
Tl h) } ,
'k c;G' - & k dh y nov 6 o @*~
~% Okg, "a 'y g -
c[gPLp r w 7 Fish densities (no/ha) 2
> m.0m r 80,000 - 90.000 g;p 70.0m - 80.0m j 60,000- 70,000 .j/'C 50.000- 60.000 l
$ p 40.000 - 50.000 30,000 40,000 (t) sa [^ 4 d rsd /
20.0m . 30.m0 McGuire Nuclear ,
$$2
- g Station ,
y Figure 5-1. Hydroacoustic estimates of fish distribution and density in lower Lake Norman on 4 August 1993. l 54
APPENDIX Progress report on summer habitat selection of striped bass in Lake Norman (Federal Aid in Fish Restoration Project F23-17). A cooperative study between the North Carolina Wildlife Resources Commission and Duke Power Company. A copy will be forwarded when completed.
,~~
- 3. J
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./5 A-1 l
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