ML040200834

Lake Norman Environmental Monitoring Program: 2002 Summary Report

ML040200834
Person / Time
Site:	McGuire, Mcguire
Issue date:	01/07/2004
From:	Gordon Peterson Duke Power Co
To:	Sullins C Office of Nuclear Reactor Regulation, State of NC, Dept of Environment & Natural Resources
References
NC0024392
Download: ML040200834 (136)

Text

{{#Wiki_filter:* Duke 'Power. A Duke Energy Company Duke Power McGuire Nuclear Station 12700 Hagers Ferry Road Huntersville, NC 28078 January 7, 2004 Ms. Coleen Sullins Deputy Director Division of Water Quality North Carolina Department of Environment and Natural Resources 1617 Mail Service Center Raleigh, NC 27699-1617

Subject:

McGuire Nuclear Station Lake Norman Environmental Monitoring Program: 2002 Summary Report Certified: 7002 2030 0000 0802 5496

Dear Ms. Sullins:

Enclosed are three copies of the annual Lake Norman Environmental Monitoring Program: 2002 Summary Report, as required by NPDES permit NC0024392 for McGuire Nuclear Station. Fishery studies continue to be coordinated with the Division of Inland Fisheries of the North Carolina Wildlife Resource Commission to address Lake Norman fishery management concerns. Results of the 2002 data were comparable with that of previous years. If you have any questions concerning this report, please contact either, John Williamson (704) 875-5894, or Robert W. Caccia (704) 382-3696. Sincerely, Gary P erson McGuire Site Vice President xc: Mr. Scott Van Hom North Carolina Wildlife Resource Commission

LAKE NORMAN MAINTENANCE MONITORING PROGRAM: 2002

SUMMARY

McGuire Nuclear Station: NPDES No. NC0024392 Duke Power A Duke Energy Company January 2004

TABLE OF CONTENTS Page i EXECUTIVE

SUMMARY

LIST OF TABLES LIST OF FIGURES vi vii CHAPTER 1: McGUIRE NUCLEAR STATION OPERATION Introduction Operational data for 2002 CHAPTER 2: WATER CHEMISTRY Introduction Methods and Materials Results and Discussion Future Studies Summary Literature Cited CHAPTER 3: PHYTOPLANKTON Introduction Methods and Materials Results and Discussion Future Phytoplankton Studies Summary Literature Cited CHAPTER 4: ZOOPLANKTON Introduction Methods and Materials Results and Discussion Future Zooplankton Studies Summary Literature Cited CHAPTER 5: FISHERIES Introduction Methods and Materials Results and Discussion Future Fisheries Studies Summary Literature Cited : Hydroacoustic and Purse Seine Data 1-1 1-1 1-1 2-1 2-1 2-1 2-3 2-9 2-9 2-10 3-1 3-1 3-1 3-2 3-8 3-8 3-10 4-1 4-1 4-1 4-2 4-6 4-6 4-7 5-1 5-1 5-1 5-2 5-3 5-4 5-5 A5-1

EXECUTIVE

SUMMARY

As required by the National Pollutant Discharge Elimination System (NPDES) permit number NC0024392 for McGuire Nuclear Station (MNS), the following annual report has been prepared. This report summarizes environmental monitoring of Lake Norman conducted during 2002. McGUIRE NUCLEAR STATION OPERATION The monthly average capacity factor for MNS was 101.0 %, 97.3 %, and 72.0 % during July, August, and September of 2002, respectively (Table 1-1). These are the months when conservation of cool water and discharge temperatures are most critical and the thermal limit for MNS increases from a monthly average of 95.00F (35.00C) to 99.00F (37.20C). The average monthly discharge temperature was 97.80F (36.60C) for July, 98.40F (36.90C) for August, and 94.20F (34.60C) for September 2002. The volume of cool water in Lake Norman was tracked throughout the year to ensure that an adequate volume was available to comply with both the Nuclear Regulatory Commission Technical Specification requirements and the NPDES discharge water temperature limits. WATER CHEMISTRY Temporal and spatial trends in water temperature and dissolved oxygen (DO) data collected in 2002 were similar to those observed historically, and all data were within the range of previously measured values. Water temperatures in the winter of 2002 were 1-5 'C warmer throughout the water column in both the mixing and background zones, and appeared to be reflective of the unusually mild winter meteorology. Reservoir-wide isotherm and isopleth information for 2002, coupled with heat content and hypolimnetic oxygen data, illustrated that Lake Norman exhibited thermal and oxygen dynamics characteristic of historical conditions and similar to other Southeastern reservoirs of comparable size, depth, flow conditions, and trophic status. Availability of suitable pelagic habitat for adult striped bass in Lake Norman in 2002 was generally similar to historical conditions, and no significant mortalities of large striped bass were observed during the summer. All chemical parameters measured in 2002 were within the concentration ranges previously reported for the lake during both MNS's preoperational i

and operational years. Conductance values were slightly higher in 2002 than in 2001, as were chloride, magnesium, and sodium concentrations. These differences apparently were related to record low precipitation totals, and low reservoir inflow and outflow rates. Manganese concentrations in the bottom waters in the summer and fall of 2002 often exceeded the NC water quality standard, as has been observed historically. This is characteristic of waterbodies that experience hypolimnetic deoxygenation during the summer. PHYTOPLANKTON Lake Norman continues to support highly variable and diverse phytoplankton communities. No obvious short term or long term impacts of station operations were observed. In 2002 lake-wide mean chlorophyll a concentrations were generally in the low range, and the November mean was the lowest recorded for that period. Lake Norman continues to be classified as oligo-mesotrophic based on long term, annual mean chlorophyll concentrations. Lake-wide mean chlorophyll declined from February to May, increased to the maximum in August, then declined to the annual minimum in November. This seasonal pattern had never been recorded during the Maintenance Monitoring Program. The highest chlorophyll value recorded in 2002, 16.29 ug/l, was below the NC State Water Quality standard of 40 ug/l. In most cases, total phytoplankton densities and biovolumes observed in 2002 were lower than those observed during 2001, and standing crops were within ranges established over previous years. Phytoplankton densities and biovolumes during 2002 never exceeded the NC guidelines for algae blooms. As in past years, high standing crops were usually observed at up-lake locations; while comparatively low values were noted down-lake. Seston dry weights were generally higher in 2002 than in 2001, and down-lake to up-lake differences were apparent most of the time. Conversely, ash-free dry weights were usually lower in 2002 than in 2001. The proportions of ash-free dry weights to dry weights in 2002 were considerably lower than those of 2001, indicating an increase in organic composition among 2002 samples. The lake-wide mean secchi depth in 2002 was the second deepest recorded since measurements were first reported in 1992. High secchi depths over the last few years were likely due to low rainfall. Diversity, or numbers of taxa, of phytoplankton had increased substantially since 2001, and the total number of individual taxa was the highest yet recorded. The taxononic composition ii

of phytoplankton communities during 2002 was similar to those of many previous years. Diatoms were dominant at most locations during all sampling periods except August, when green algae were dominant. Blue-green algae were slightly more abundant during 2002 than during 2001, however, their contribution to total densities seldom exceeded 2%. The phytoplankton index (Myxophycean) characterized Lake Norman as oligotrophic during 2002, and was the lowest annual index value recorded. ZOOPLANKTON Lake Norman continues to support a highly diverse and viable zooplankton community. Long term and seasonal changes observed over the course of the study, as well seasonal and spatial variability observed during 2002, were likely due to environmental factors and appears not to be related to plant operations. Maximum epilimnetic and whole column zooplankton densities occurred in May, while minimum epilimnetic densities were recorded in February (Locations 5.0, 9.5, and 11.0), and November (Locations 2.0 and 15.9). Minimum whole column densities were observed in February (Locations 2.0 through 9.5), and August (11.0 and 15.9). Mean zooplankton densities tended to be higher among Background Locations than among Mixing Zone locations during 2002, and a general pattern of increasing values from downlake to uplake was observed. In addition, long term trends showed much higher year-to-year variability at Background Locations than at Mixing Zone Locations. Epilimnetic zooplankton densities in August were within ranges of those observed in August of previous years. The epilimnetic densities at Locations 5.0, 11.0, and 15.9 in May 2002 were the highest recorded from these locations during the Program, and may have represented an ongoing lag response to changing phytoplankton standing crops at that time. Record low densities for February were observed at Locations 2.0 and 5.0, while a record low density for November occurred at Locations 15.9. Record low densities may have been in response to long term drought conditions through much of 2002.

One hundred and nine zooplankton taxa have been recorded from Lake Norman since the Program began in 1987 (Fifty-one were identified during 2002). One previously unreported rotifer was identified during 2002. Overall relative abundance of copepods in 2002 had decreased substantially since 2001, and they were only dominant during August. Cladocerans were occasionally dominant at only one location in August, while rotifers were dominant in all samples collected during the other three quarters. Overall, the relative abundance of rotifers had increased considerably since 2001, and their relative abundances were often similar to years prior to 1995. Historically, copepods and rotifers have shown annual peaks in May; while cladocerans continued to demonstrate year-to-year variability. Copepods were dominated by immature forms with adults rarely accounting for more than 8% of zooplankton densities. The most important adult copepods were Tropocyclops, Epischura, and Mesocyclops as was the case in previous years. Bosmina was the predominant cladoceran, as has also been the case in most previous years of the Program. Bosminopsis dominated most cladoceran populations in August. The most abundant rotifers observed in 2002, as in many previous years, were Polyarthra, Conochilus, and Kellicottia, while Karetella and Syncheata were occasionally important among rotifer populations. FISHERIES In accordance with the Lake Norman Maintenance Monitoring Program for the NPDES permit for MNS, specific fish monitoring programs were coordinated with the NCWRC and continued during 2002. Spring electrofishing indicated that 14 to 20 species of fish and 1 hybrid complex composed fish populations in the 3 sampling locations, and that numbers and biomass of fish in 2002 were generally similar to those previously noted at these locations since 1993. Lake Norman continues to support fish populations that are consistent with the trophic status and productivity of this reservoir. Few dead striped bass were noted during the summer survey period indicating no major die-offs occurred. Relative weight (Wr) of Lake Norman striped bass in November and December may have improved somewhat in 2002 over that noted in 2001, but large striped bass continued to exhibit low Wr's at this time of the year. iv

Forage fish densities in the five zones of Lake Norman ranged from 5,068 to 12,580 fish/ha in July 2002. Forage fish densities were highest uplake (Zone 5) and lowest downiake. The estimated lakewide population was approximately 103 million fish. Purse seine sampling indicated that these fish were 74.75% threadfin shad and 25.25% alewives. September 2002 forage fish densities ranged from a low of 3,228 (Zone 4) to a high of 9,363 (Zone 5). The estimated lakewide forage population was approximately 74 million fish. Purse seine sampling indicated that these fish were 70.27% threadfin shad and 29.73% alewives. Forage fish densities in the five zones of Lake Norman ranged from 1,413 to 2,172 fish/ha in December 2002. There were considerably fewer fish in the uplake zones compared to July and September estimates; densities were fairly homogeneous throughout the lake. The estimated forage population was approximately 25 million fish. Purse seine sampling indicated that these fish were 75.26% threadfin shad, 24.55% alewives, and 0.19% hybrid shad. Open water purse seine samples have undergone a dramatic shift in recent years. From 1993 through 1999, when the first alewife was collected, purse seine samples were totally composed of small threadfin shad (typically *55 mm). From 2000 through 2002 the open water forage fish community has shown increasing contributions from alewives (now -25% of the community) and a concurrent wider size range of individuals. v

LIST OF TABLES Page Table 1-1 Average monthly capacity factors for McGuire Nuclear Station 1-2 Table 2-1 Water chemistry program for McGuire Nuclear Station 2-14 Table 2-2 Water chemistry methods and reporting limits 2-15 Table 2-3 Heat content calculations for Lake Norman in 2001 and 2002 2-16 Table 2-4 Comparison of Lake Norman with TVA reservoirs 2-17 Table 2-5 Lake Norman water chemistry data in 2001 and 2002 2-18 Table 3-1 Mean chlorophyll a concentrations in Lake Norman. 3-13 Table 3-2 Duncan's multiple range test for chlorophyll a. 3-14 Table 3-3 Total phytoplankton densities and biovolumes from Lake Norman. 3-15 Table 3-4 Duncan's multiple range test for phytoplankton densities. 3-16 Table 3-5 Duncan's multiple range test for dry and ash free dry weights. 3-17 Table 3-6 Phytoplankton taxa identified in Lake Norman from 1988-2002. 3-18 Table 3-7 Dominate classes and species of Phytoplankton 3-27 Table 4-1 Total zooplankton densities and composition. 4-10 Table 4-2 Duncan's multiple range test for zooplankton densities. 4-12 Table 4-3 Zooplankton taxa identified in Lake Norman from 1988-2002. 4-13 Table 4-4 Dominant taxa and percent composition of selected zooplankton. 4-17 Table 5-1 Common and scientific names of fish collected from Lake 5-6 Norman. Table 5-2 Numbers and biomass of fish collected near MNS April, 2002. 5-7 Table 5-3 Numbers and biomass of fish collected between MNS and Marshall Steam Station April, 2002. 5-8 Table 54 Numbers and biomass of fish collected near Marshall Steam 5-9 Station April, 2002. Table 5-5 Dead or dying striped bass in Lake Norman July-September 2002. 5-10 Appendix Tables: Table A5-1 Lake Norman forage fish densities and population estimates A5-4 for 2002. vi

LIST OF FIGURES Page Figure 2-1 Figure 2-2 Figure 2-3 Figure 2-4 Figure 2-5 Figure 2-6 Figure 2-7 Figure 2-8 Figure 2-9 Figure 2-lOa Figure 2-lOb Figure 2-11 Map of sampling locations on Lake Norman Monthly precipitation near McGuire Nuclear Station Monthly mean temperature profiles in background zone Monthly mean temperature profiles in mixing zone Monthly temperature and dissolved oxygen data in discharge location Monthly mean dissolved oxygen profiles in background zone Monthly mean dissolved oxygen profiles in mixing zone Monthly temperature isotherms for Lake Norman Monthly dissolved oxygen isopleths for Lake Norman Heat content of Lake Norman Dissolved oxygen content of Lake Norman Striped bass habitat in Lake Norman 2-21 2-22 2-23 2-25 2-27 2-28 2-30 2-32 2-35 2-38 2-38 2-39 Figure 3-1 Chlorophyll a measurements, densities and biovolumes of Lake Norman. Figure 3-2 Mean chlorophyll a concentrations for 1987-2002. Figure 3-3 Chlorophyll a concentrations by location for 1987-2002. Figure 3-4 Class composition of phytoplankton at Locations 2.0. Figure 3-5 Class composition of phytoplankton at Locations 5.0. Figure 3-6 Class composition of phytoplankton at Location 9.5. Figure 3-7 Class composition of phytoplankton at Location 11.0. Figure 3-8 Class composition of phytoplankton at Location 15.9. Figure 3-9 Annual lake-wide Myxophycean index from 1988-2002. 3-28 3-29 3-30 3-32 3-33 3-34 3-35 3-36 3-37 Figure 4-1 Figure 4-2 Figure 4-3 Figure 4-4 Figure 4-5 Figure 4-6 Figure 4-7 Figure 4-8 Figure 5-1 Figure 5-2 Figure 5-3 Zooplankton density by sample location in Lake Norman. Zooplankton densities among years during February and May. Zooplankton densities among years during August and November. Lake Norman zooplankton composition in 2002. Quarterly zooplankton composition from 1990 through 2002. Annual lake-wide zooplankton composition, 1988 through 2002. Lake Norman zooplankton composition (mixing zone locations). Lake Norman zooplankton composition (background locations). Lake Norman sampling zones Numbers and biomass of fish in Lake Norman 1993-2002. Striped bass weight vs length for winter 2002. 4-19 4-20 4-21 4-22 4-23 4-24 4-25 4-26 5-11 5-12 5-13 vii

Appendix Figures: Figure A5-1 Lake Norman forage fish for June, 2002. A5-5 Figure A5-2 Lake Norman forage fish for September, 2002. A5-6 Figure A5-3 Lake Norman forage fish for December 2002. A5-7 viii

CHAPTER 1 McGUIRE NUCLEAR STATION OPERATION INTRODUCTION As required by the National Pollutant Discharge Elimination System (NPDES) permit number NC0024392 for McGuire Nuclear Station (MNS) issued by the North Carolina Department of Environment and Natural Resources (NC DENR), the following annual report has been prepared. This report summarizes environmental monitoring of Lake Norman conducted during 2002. OPERATIONAL DATA FOR 2002 The monthly average capacity factor for MNS was 101.0 %, 97.3 %, and 72.0 % during July, August, and September of 2002, respectively (Table 1-1). These are the months when conservation of cool water and discharge temperatures are most critical and the thermal limit for MNS increases from a monthly average of 95.00F (35.00C) to 99.00F (37.20C). The average monthly discharge temperature was 97.80F (36.60C) for July, 98.40F (36.90 C) for August, and 94.20F (34.60C) for September 2002. The volume of cool water in Lake Norman was tracked throughout the year to ensure that an adequate volume was available to comply with both the Nuclear Regulatory Commission Technical Specification requirements and the NPDES discharge water temperature limits. 1-1

Table 1-1. Average monthly capacity factors (%) calculated from daily unit capacity 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 2002. MONTHLY AVERAGE MONTHLY AVERAGE CAPACITY FACTORS (%) NPDES DISCHARGE TEMPERATURES Month Unit 1 Unit 2 Station OF °C January 105.4 104.8 105.1 69.2 20.7 February 105.2 80.6 92.9 69.0 20.6 March 93.2 8.2 50.7 66.0 18.9 April 104.7 104.7 104.7 78.4 25.8 May 103.9 104.0 104.0 83.9 28.8 June 102.4 102.8 102.6 91.8 33.2 July 100.9 101.2 101.0 97.8 36.6 August 101.0 93.5 97.3 98.4 36.9 September 42.3 101.6 72.0 94.2 34.6 October 64.5 102.6 83.6 85.8 29.9 November 104.7 104.1 104.4 77.4 25.2 December 105.2 102.0 103.6 70.5 21.4 Averages 94.4 92.5 93.5! 1-2

CHAPTER 2 WATER CHEMISTRY INTRODUCTION 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 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 report focuses primarily on 2001 and 2002. Where appropriate, reference to pre-2001 data will be made by citing reports previously submitted to the North Carolina Department of Environment, Health, and Natural Resources (NCDENR). METHODS AND MATERIALS The complete water chemistry monitoring program for 2002, including specific variables, locations, depths, and frequencies is outlined in Table 2-1. Sampling locations are identified in Figure 2-1, whereas specific chemical methodologies and associated analytical reporting limits, along with the appropriate references are presented in Table 2-2. Measurements of temperature, dissolved oxygen (DO), DO saturation, pH, and specific conductance were taken, in situ, throughout the water column at each of the stations sampled with a Hydrolab Data-Sonde (Hydrolab 1986) starting at the lake's surface (0.3 m) and continuing at I m intervals to one meter above lake bottom. Pre-and post-calibration procedures associated with operation of the Hydrolab were strictly followed, and appropriately documented in hard-copy format. Hydrolab data were captured and stored electronically. Water samples for laboratory analysis were collected with a Kemmerer water bottle at the surface (0.3 in), and from one meter above bottom, where specified, and placed in non-reusable PET bottles. Samples for the analysis of soluble nutrients (orthophosphate, nitrite-nitrate, and ammonia) were obtained in the field by filtering a known volume of water through a 0.45 micron glass-fiber filter. Upon collection, all water samples were immediately preserved, and stored in the 2-1

dark, and on ice, to minimize the possibility of physical, chemical or microbial transformation. Water quality data were subjected to various graphical and statistical techniques in an attempt to describe spatial and temporal trends within the lake, and interrelationships among constituents. Whenever analytical values were encountered that were equal to or less than the method reporting limit, these were set equal to the reporting limit for statistical purposes. Data were analyzed using two approaches, both of which were consistent with earlier studies (DPC 1985, 1987, 1988a, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002). The first method involved partitioning the reservoir into mixing, background, and discharge zones, consolidating the data into these sub-sets, 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, applied primarily to the in-situ data, emphasized a much broader lake-wide investigation and encompassed the plotting of monthly isotherms and isopleths, and summer-time striped bass habitat. Several quantitative calculations were also performed on the in-situ Hydrolab data; these included the calculation of the areal hypolimnetic oxygen deficit (AHOD), maximum whole-water column and hypolimnion oxygen content, maximum whole-water column and hypolimnion heat content, mean epilimnion and hypolimnion heating rates over the stratified period, and the Birgean heat budget. Heat (Kcallcm ) and oxygen content (mg/cm2) and mean concentration (mg/L) of the reservoir were calculated according to Hutchinson (1957), using the following equation: Zm Lt = Ao-1l TO

• A,. d, where; Lt = reservoir heat (Kcal/cm ) or oxygen (mg/cm2) content A, = surface area of reservoir (cm2)

TO = mean temperature (0C) or oxygen content of layer z Az= area (cm 2) at depth z d= depth interval (cm) z= surface z= maximum depth 2-2

RESULTS AND DISCUSSION Precipitation Amount Total annual precipitation in the vicinity of MNS in 2002 totaled 39.81 inches (Figure 2-2); this was slightly higher than observed in 2000 (33.68 inches) and 2001 (33.68 inches), but appreciably less than the long-term precipitation average for this area (46.3 inches). Precipitation through the period January to September 2002 (24.02 inches) was one of the driest nine-month periods on record, and about 5 inches less than observed in 2001. The highest total monthly rainfall in 2002 occurred in December with a value of 6.13 inches. Temperature and Dissolved Oxygen Water temperatures measured in 2002 illustrated similar temporal and spatial trends in the background and mixing zones (Figures 2-3, 2-4), as occurred in 2001. This similarity in temperature patterns between zones has been a dominant feature of the thermal regime in Lake Norman since MNS began operations in 1983. Water temperatures in the winter of 2002 (January and February) were consistently warmer throughout the entire water column in both zones than observed in 2001 (Figure 2-3, 2-4). Water temperatures at this time ranged from about 1-5 'C warmer than measured in 2001, and was partially reflective of the unusually mild January and preceding December meteorology. Interannual variability in water temperatures during the spring, summer, and fall months was observed in both the mixing and background zones, but temperature differences between years were typically minimal and therefore were not considered of biological significance. The observed differences were also well within the observed historical variability (DPC 1985, 1989, 1991, 1993. 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002). The major temperature differences between year 2001 and 2002 were observed in early winter (December) when 2002 temperatures ranged from 4 to 6 'C cooler than measured in 2001. These differences can be traced to the cooler than average meteorological conditions observed during December 2002 versus 2001. Temperature data at the discharge location in 2002 were generally similar to 2001 (Figure 2-

5) and historically (DPC 1985, 1987, 1988a, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002).

Temperature data for March 2002 was significantly cooler than observed in March 2001 due to station load reduction on the day of sampling; however, station discharge temperatures for March 2002 were typical for this time 2-3

of year. The warmest discharge temperature of 2002 at location 4 occurred in August and measured 38.5 0C, or 2.8 0C warmer than measured in August, 2001 (DPC 2002). Seasonal and spatial patterns of DO in 2002 were reflective of the patterns exhibited for temperature, i. e., generally similar in both the mixing and background zones (Figures 2-6 and 2-7). As observed with water column temperatures, this similarity in dissolved oxygen patterns between zones has been a dominant feature of the oxygen regime in Lake Norman since MNS began operations in 1983. Winter (January and February) DO values in 2002 were consistently lower than measured in 2001, and appeared to be related predominantly to the warmer water column temperatures measured in 2002 versus 2001. The warmer water would be expected to exhibit a lower oxygen content because of the direct effect of temperature on oxygen solubility, which is an inverse relationship, and indirectly via a reduced convective mixing regime which would suppress reaeration of the water column. Spring and summer DO values in 2002 were highly variable throughout the water column in both the mixing and background zones ranging from highs of 6 to 8 mg/L in the surface waters to lows of 0 to 2 mg/L in the bottom waters. This pattern is similar to that measured in 2001 and earlier years (DPC 1985, 1987, 1988a, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002). Metalimnetic and hypolimnetic DO values during the spring and summer of 2002 generally ranged from 0.1 mg/L to 2.5 mg/L lower than measured in 2001; exceptions to this were observed in June and September when DO values were slightly higher than measured in 2001. All dissolved oxygen values recorded in 2002 were well within the historical range (DPC 1985, 1987, 1988a, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002). Considerable differences were observed between 2001 and 2002 fall and early winter DO values in both the mixing and background zones, especially in the metalimnion and hypolimnion during November and December (Figures 2-6 and 2-7). These interannual differences in fall DO levels are common in Catawba River reservoirs and can be explained by the effects of variable weather patterns on water colurnn cooling and mixing. Warmer air temperatures would delay water column cooling (Figure 2-3, 2-4) which, in turn, would delay the onset of convective mixing of the water column and the resultant reaeration of the metalimnion and hypolimnion. Conversely, cooler air temperatures would promote the rate and magnitude of this process resulting in higher DO values sooner in the year. The 2002 November and December DO data indicate that fall reaeration was more complete than observed in the corresponding months in year 2001. Interannual differences in DO patterns 2-4

are common in Southeastern reservoirs, and can reflect yearly differences in hydrological, meteorological, and limnological forcing variables (Cole and Hannon 1985; Petts, 1984). The seasonal pattern of DO in 2002 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). The lowest DO concentration measured at the discharge location in 2002 (5.4 mg[L) occurred in August, and was similar to DO levels measured in August 2000 (5.4 mg/L), and August 2001 (5.5). Low DO values measured at the discharge location during the summer and early fall occurred concurrently with hypolimnetic water usage at MNS for condenser cooling water needs. Reservoir-wide Temperature and Dissolved Oxygen The monthly reservoir-wide temperature and dissolved oxygen data for 2002 are presented in Figures 2-8 and 2-9. These data are similar to that observed in previous years and are characteristic of cooling impoundments and hydropower reservoirs in the Southeast (Cole and Hannon, 1985; Hannon et al., 1979; Petts, 1984). For a detailed discussion on the seasonal and spatial dynamics of temperature and dissolved oxygen during both the cooling and heating periods in Lake Norman, the reader is referred to earlier reports (DPC 1992, 1993, 1994, 1995, 1996). The seasonal heat content of both the entire water column and the hypolimnion for Lake Norman in 2002 are presented in Figure 2-lOa; additional information on the thermal regime in the reservoir for the years 2001 and 2002 are found in Table 2-3. Annual minimum heat content for the entire water column in 2002 (10.04 KcalIcm 2; 10.2 'C) occurred in early January, whereas the maximum heat content (28.25 Kcal/cm2; 28.2 'C) occurred in early August. Heat content of the hypolimnion exhibited a somewhat different temporal trend as that observed for the entire water column. Annual minimum hypolimnetic heat content occurred in early January and measured 5.6 Kcal/cm2 (9.0 'C), whereas the maximum occurred in early September and measured 15.35 Kcal/cm2 (24.3 'C). Heating of both the entire water column and the hypolimnion occurred at approximately a linear rate from minimum to maximum heat content. The mean heating rate of the entire water column equalled 0.088 Kcal/cm2/day versus 0.042 Kcal/cm2/day for the hypolimnion. The 2002 heat content and heating rate data were slightly higher than measured in 2001, but similar to earlier years (DPC 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2002). 2-5

The seasonal oxygen content and percent saturation of the whole water column, and the hypolimnion, are depicted for 2002 in Figure 2-lOb. Additional oxygen data can be found in Table 2-4 which presents the 2002 AHOD for Lake Norman and similar estimates for 18 Tennessee Valley Authority (TVA) reservoirs. Reservoir oxygen content was greatest in mid-winter when DO content measured 10.1 mgfL for both the whole water and the hypolimnion. Percent saturation valuls at this time approached 90.1 % for the entire water column and 87.8% for the hypolimnion. Beginning in early spring, oxygen content began to decline precipitously in both the whole water column and the hypolimnion, and continued to do so in a linear fashion until reaching a minimum in mid-summer. Minimum summer volume-weighted DO values for the entire water column measured 4.21 mg/L (54.8 % saturation), whereas the minimum for the hypolimnion was 0.12 mg/L (1.4 % saturation). The mean rate of DO decline in the hypolimnion over the stratified period, i.e., the AHOD, was 0.030 mg/cm2/day (0.047 mgftLday) (Figure 2-lOb), and is similar to that measured in 2001 (DPC 2002). Hutchinson (1938, 1957) proposed that the decrease of dissolved oxygen in the hypolimnion of a waterbody should be related to the productivity of the trophogenic zone. Mortimer (1941) adopted a similar perspective and proposed the following criteria for AHOD associated with various trophic states; oligotrophic - < 0.025 mg/cm2 /day, mesotrophic - 0.026 mg/cm2/day to 0.054 mg/cm2/day, and eutrophic - 2 0.055 mg/cm2/day. Employing these limits, Lake Norman should be classified as mesotrophic based on the calculated AHOD value of 0.030 mg/cm2/day for 2002. The oxygen based mesotrophic classification agrees well with the mesotrophic classification based on chlorophyll a levels (Chapter 3). The 2002 AHOD value is also similar to that found in other Southeastern reservoirs of comparable depth, chlorophyll a status, and secchi depth (Table 2-4). Striped Bass Habitat Suitable pelagic habitat for adult striped bass, defined as that layer of water with temperatures < 26 IC and DO levels 2 2.0 mg/L, was found lake-wide from October 2001 through mid-June 2002. Beginning in mid-June 2002, habitat reduction proceeded rapidly throughout the reservoir both as a result of deepening of the 26 0C isotherm and metalimnetic and hypolimnetic deoxygenation (Figure 2-11). Habitat reduction was most severe from mid-July through early September when no suitable habitat was observed in the reservoir except for a small zone of refuge in the upper, riverine portion of the reservoir, near the confluence of 2-6

Lyles Creek with Lake Norman, and the lower portion of the lake near the dam. The reservoir was completely devoid of habitat for adult striped bass from the period 29 July to 3 September, or about 30-35 days. Habitat measured in the upper reaches of the reservoir appeared to be influenced by both inflow from Lyles Creek and discharges from Lookout Shoals Hydroelectric facility, which were somewhat cooler than ambient conditions in Lake Norman. Upon entering Lake Norman, this water apparently mixes and then proceeds as a subsurface underflow (Ford 1985) as it migrates downriver. Physicochemical habitat was observed to have expanded appreciably by mid-September, primarily as a result of epilimnion cooling and deepening, and in response to changing meteorological conditions. The temporal and spatial pattern of striped bass habitat expansion and reduction observed in 2002 was similar to that previously reported in Lake Norman and many other Southeastern reservoirs (Coutant 1985, Matthews 1985, DPC 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002). No significant mortalities of large striped bass were observed in 2002; a few (< 10 ) dead fish were found over the summer period, but these appeared to be the result of other causes, e.g., hooking mortalities, which are common throughout the Southeast. Turbidity and Specific Conductance Surface turbidity values were generally low at the MNS discharge, mixing zone, and mid-lake background locations during 2002, ranging from 1.02 to 5.06 NTUs (Table 2-5). Bottom turbidity values were also relatively low over the study period, ranging from 2.09 to 7.86 NTUs (Table 2-5). These values were slightly higher than measured in 2001 (Table 2-5), but well within the historical range (DPC 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,2002). Specific conductance in Lake Norman in 2002 ranged from 69 to 110 umho/cm, and was similar to that observed in 2001 (Table 2-5), and historically (DPC 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002). Conductance values in 2002 were, on the average, about 10 umhos/cm higher than observed in 2001; this difference may have been related to below average precipitation totals, and the correspondingly below average reservoir inflow and outflow rates in 2002 which would tend to concentrate dissolved constituents within the water column. Specific conductance values in surface and bottom waters were generally similar throughout the year except during the period of intense thermal stratification, i.e., August and November. Increases in bottom conductance values appeared 2-7

to be related primarily to the release of soluble iron and manganese from the lake bottom under anoxic conditions (Table 2-5). This phenomenon is common in both natural lakes and reservoirs that exhibit hypolimnetic oxygen depletion (Hutchinson 1957, Wetzel 1975). pH and Alkalinity During 2002, pH and alkalinity values were similar among MNS discharge, mixing and background zones (Table 2-5); they were also similar to values measured in 2001 (Table 2-5) and historically (DPC 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002). Individual pH values in 2002 ranged from 6.2 to 7.4, whereas alkalinity ranged from 16 to 22 mg/L of CaCO3. 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 during 2002 was similar to that reported for 2001 (Table 2-5) and previously (DPC 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002). Interestingly, the concentration of several constituents (chloride, magnesium, and sodium) in 2002 were slightly higher than measured in 2001, and this may have been related to low reservoir inflow/outflow rates, as discussed for conductance. It's also likely that these increased constituent levels were responsible for the higher conductance values observed in 2002 versus 2001. Lake-wide, the major cations were sodium, calcium, magnesium, and potassium, whereas the major anions were bicarbonate, sulfate, and chloride. Nutrients Nutrient concentrations in the discharge, mixing, and mid-lake background zones of Lake Norman for 2001 and 2002 are provided in Table 2-5. Overall, nitrogen and phosphorus levels in 2002 were low and similar to those measured in 2001 and historically (DPC 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002). Total phosphorus and ortho-phosphorus concentrations appeared to be slightly higher in 2002 than 2001, but these differences can be attributed to higher analytical reporting limits for these tests applied in 2002, versus 2001, i.e., 10 ug/L and 5 ug/L, respectively. 2-8

Metals Metal concentrations in the discharge, mixing, and mid-lake background zones of Lake Norman for 2002 were similar to that measured in 2001 (Table 2-5) and historically (DPC 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002). Iron concentrations near the surface were generally low (< 0.1 mg/L) during 2002, whereas iron levels near the bottom of some sites were slightly higher during the stratified period. Similarly, manganese concentrations in the surface and bottom waters were generally low (< 0.1 mg/L) in both 2001 and 2002, except during the summer and fall when bottom waters were anoxic (Table 2-5). This phenomenon, i.e., the release of iron and manganese from bottom sediments because of increased solubility induced by low redox conditions (low oxygen levels), is common in stratified waterbodies (Wetzel 1975). 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 historical conditions (DPC 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002). Heavy metal concentrations in Lake Norman never exceeded NC water quality standards, and there were no appreciable differences between 2001 and 2002. Most values were also typically below the analytical reporting limit for the specific constituent. Zinc values appeared to be higher in 2002 than 2001, but these differences can be attributed to the analytical reporting limit for the later year. In year 2001 the reporting limit for zinc was 5 ug/L, whereas in 2002 the reporting limit was increased to 20 ug/L due to a change in methodology. FUTURE STUDIES No changes are planned for the Water Chemistry portion of the Lake Norman maintenance monitoring program during 2003.

SUMMARY

Temporal and spatial trends in water temperature and DO data collected in 2002 were similar to those observed historically, and all data were within the range of previously measured values. Water temperatures in the winter of 2002 were 1-5 'C warmer throughout the water column in both the mixing and background zones, and appeared to be reflective of the 2-9

unusually mild winter meteorology. Interannual variability in water temperatures during the spring, summer and fall months was observed in both zones, but differences between years were within observed historical variability. Winter dissolved oxygen values in 2002 were lower than measured in 2001, and appeared to be related to the warmer water column temperatures which would limit oxygen solubility and suppress convective reaeration of the water column. Spring and summer oxygen values were highly variable throughout the water column but similar to historical trends. Reservoir-wide isotherm and isopleth information for 2002, coupled with heat content and hypolimnetic oxygen data, illustrated that Lake Norman exhibited thermal and oxygen dynamics characteristic of historical conditions and similar to other Southeastern reservoirs of comparable size, depth, flow conditions, and trophic status. Availability of suitable pelagic habitat for adult striped bass in Lake Norman in 2002 was generally similar to historical conditions, and no significant mortalities of large striped bass were observed during the summer. All chemical parameters measured in 2002 were within the concentration ranges previously reported for the lake during both MNS's preoperational and operational years. Conductance values were slightly higher in 2002 than in 2001, as were chloride, magnesium, and sodium concentrations. These differences apparently were related to record low precipitation totals, and low reservoir inflow and outflow rates. Manganese concentrations in the bottom waters in the summer and fall of 2002 often exceeded the NC water quality standard, as has been observed historically. This is characteristic of waterbodies that experience hypolimnetic deoxygenation during the summer. LITERATURE CITED American Public Health Association (APHA). 1995. Standard Methods for the Examination of Water and Wastewater. 19th Edition. APHA, Washington, DC Coutant, C. C. 1985. Striped bass, temperature, and dissolved oxygen: a speculative hypothesis for environmental risk. Trans. Amer. Fisher. Soc. 114:31-61. Cole, T. M. and H. H. Hannon. 1985. Dissolved oxygen dynamics. In: Reservoir Limnology: Ecological Perspectives. K. W. Thornton, B. L. Kimmel and F. E. Payne editors. John Wiley & Sons. NY. Duke Power Company. 1985. McGuire Nuclear Station, 316(a) Demonstration. Duke Power Company, Charlotte, NC. 2-10

Duke Power Company. 1987. Lake Norman maintenance monitoring program: 1986 summary. Duke Power Company. 1988a. Lake Norman maintenance monitoring program: 1987 summary. Duke Power Company. 1988b. Mathematical modeling of McGuire Nuclear Station thermal discharges. Duke Power Company, Charlotte, NC. 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. Duke Power Company. 1993. Lake Norman maintenance monitoring program: 1992 summary. Duke Power Company. 1994. Lake Norman maintenance monitoring program: 1993 summary. Duke Power Company. 1995. Lake Norman maintenance monitoring program: 1994 summary. Duke Power Company. 1996. Lake Norman maintenance monitoring program: 1995 summary. Duke Power Company. 1997. Lake Norman maintenance monitoring program: 1996 Summary. Duke Power Company. 1998. Lake Norman maintenance monitoring program: 1997 Summary. Duke Power Company. 1999. Lake Norman maintenance monitoring program: 1998 Summary. Duke Power Company. 2000. Lake Norman maintenance monitoring program: 1999 Summary. 2-11

Duke Power Company. 2001. Lake Norman maintenance monitoring program: 2000 Summary. Duke Power Company. 2002. Lake Norman maintenance monitoring program: 2001 Summary. Ford, D. E. 1985. Reservoir transport processes. In: Reservoir Limnology: Ecological Perspectives. K. W. Thornton, B. L. Kimmel and F. E. Payne editors. John Wiley & Sons. NY. Hannan, H. H., I. R. Fuchs and D. C. Whittenburg. 1979 Spatial and temporal patterns of temperature, alkalinity, dissolved oxygen and conductivity in an oligo-mesotrophic, deep-storage reservoir in Central Texas. Hydrobilologia 51 (30); 209-221. Higgins, J. M. and 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., NY, pp.404-412. Hutchinson, G. E. 1938. Chemical stratification and lake morphometry. Proc. Nat. Acad. Sci., 24:63-69. Hutchinson, G. E. 1957. A Treatise on Limnology, Volume I. Geography, Physics and Chemistry. John Wiley & Sons, NY. Hydrolab Corporation. 1986. Instructions for operating the Hydrolab Surveyor Datasonde. Austin, TX. 105p. 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. Mortimer, C. H. 1941. The exchange of dissolved substances between mud and water in lakes (Parts I and II). J. Ecol., 29:280-329. Petts G. E., 1984. Impounded Rivers: Perspectives For Ecological Management. John Wiley and Sons. New York. 326pp. 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. 2-12

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. U.S. Environmental Protection Agency (USEPA). 1983. Methods for the Chemical Analysis of Water and Wastes. Environmental Monitoring and Support Lab. Office of Research and Development, Cincinnati, Wetzel, R. G. 1975. Limnology. W. B. Saunders Company, Philadelphia, Pennsylvania, 7 4 3p. 2-13

(. ( Table 2-1. Water chemistry program for the McGuire Nuclear station NPDES long-term monitoring on Lake Norman. 2002 McGUIRE NPDES SAMPLING PROGRAM LOCATIONS 1 2 4 5 8 9.5 11 PARAMETERS 13 14 15 15.9 62 69 72 80 16 DEPTII(m) 33 33 5 20 32 23 27 21 10 23 23 15 7 5 4 3 iN-SrrU ANALYSIS Temperature Ilydrolab Dissolved Oxygen Hydrolab In-situ measurements are collected monthly at the above locations at Im intervals from 0.3m to Im above bottom. P11 Hydrolab Measurements are taken weekly from July-August for striped bass habitat. Conductivity Hydrolab NUTRIENT ANALYSES Ammonia AA-Nut QfT,B Q/TB Q/T Q/TB Q/TB QfT,B Q/rB QfT,B Q/T Q/T,B QfT,B SfT Nitmte+Nitrite AA-Nut Q/T,B Q/T,B Q/T Q/T,B Q/T,B Q/T,B Q/TB Q/TB Q/T QfT,B Q/T,B S/T Orthophosphate AA-Nut Q/T,B Q/T.B Q/T Q/TB Q/T.B Q/TB QfT,B Q/T,B Q/T QfT,B QIT,B S/T Total Phosphorus AA.TPDG-P Q/T,B Q/T,B Q/T QfT,B Q/T,B Q/T,B Q/T,B Q/T,B Q/T Q/T,B Q/T,B SIT Silica AA-Nut QfT,B Q/T.B Q/T Q/T,B Q/TB Q/TB Q/T,B Q/T,B Q/T Q/T,B QfrB S/T Cl AA-Nut QfT,B Q/T,B QfT QfT,B Q/TB Q/T,B Q/T,B Q/T,B QfT Q/T,B Q/TB SIT TKN AA-TKN QfT,B Q/TB QfT,B ELEMENTAL ANALYSES Aluminum ICP-24 QfTB SfT,B SfT Q/T,B Q/TB Q/T,B QfT,B Q/T,B QfT Q/TB QfT,B SfT Calcium ICP-24 QITB Q/T,B QfT QfT,B QfT,B QfT,B Q/T,B QfT,B Q/T Q/T,13 Q/T,B S/T Iron ICP-24 QfT,B Q/T,B Q/T Q/T,B QfT,B QfT,B Q/T,B Q/TB Q/T QfT,B QfT,B S/T Magnesium ICP-24 Q/T,B Q/T,B Q/T Q/T,B Q/T,B Q/T,B QfT,B QfT,B QfT QfT,B QfT,B SfT Manganese ICP-24 Q/TB QfT,B QfT QfT,B QfT,B Q/T,B Q/T.B QfT,B QfT Q/T,B Q/T,B SfT Potassium 306-K Q/TB Q/T,B QfT Q/TB Q/T,B Q/T,B QfTB Q/T,B QfT Q/T,B Q/T,B SIT Sodium ICP-24 QfT,B QfT,B QfT QfT,B Q/T,B QfT,B QfT,B Q/T,B QfT QfT,B Q/T,B SIT Zinc ICP-24 Q/T,B Q/T,B Q/T QfT,B QfT,B QfT,B Q/T,B QfT,B QfT QfT,B QfT,B SIT Cadminum ICP-MS SfT,B S/T SfT,B SfTB SfT S/T,B SIT Copper ICP-MS S/TB SIT S/T,B SfT,B SIT S/T,B S/T Lead ICP-MS SIrB S/T S/T,B S/TB S/T SfT,B SfT ADDITIONAL ANALYSES Alkalinity T-ALKT QfT,B QfT,B QfT QfT,B QfT,B Q/T,B QfT,B QfT,B Q/T Q/T,B Q/T,B SfT Turbidity F-TURB QfT,B QfT,B QfT QfT,B QfT,B Q/TB Q/TB QfT,B QfT Q/T,B QfT,B SfT Sulfate W`V_S04 SfT.B S/T S/T,B S/T SfT,B SIT Total Solids S-TSE SfT,B SfT SfT,B S/T SfT,B S/T Total Suspended Solids S-TSSE S/T,B SIT S/T,B SIT SfT,B1 SIT CODES: Frequency Q - Quarterly (Feb. May, Aug. Nov) S = Semi-annually (Feb,Aug) T = Top (0.3m) B = Bottom (Im above bottom) It'3

( ( c Table 2-2. Analytical methods and reporting limits employed in the McGuire Nuclear Station NPDES long-term maintenance monitoring program for Lake Norman. Parameter Method (EPA/APHA) Preservation Reporting Limit Alkalinity, Total Total inflection point, EPA 310.1 4 0C 0.01 me /L Aluminum Atomic emission/ICP, EPA 200.7 0.5% HNO3 0.05 mg/L Cadmium, Total Recoverable ICP Mass Spectroscopy, EPA 200.8 0.5% HNO3 0.5 ug/L Calcium Atomic emission'ICP, EPA 200.7 0.5% HNO3 30 ug/L Chloride Colorimetric, EPA 325.2 4 0C 1.0 mg/L Copper, Total Recoverable ICP Mass Spectroscopy, EPA 200.8 0.5% HNO3 2.0 ug/L Iron Atomic emission/ICP, EPA 200.7 0.5% HNO3 10 ug/L Lead, total Recoverable ICP Mass Spectroscopy, EPA 200.8 0.5% HNO3 2.0 ug/L Magnesium Atomic emission/ICP, EPA 200.7 0.5% HNO3 30 ug/L Manganese, Total Recoverable ICP Mass Spectroscopy, EPA 200.8 0.5% HN03 1.0 Ug1L Nitrogen, Ammonia Colorimetric, EPA 350.1 4 0C 20 ug/L Nitrogen, Nitrite + Nitrate Colorimetric, EPA 353.2 4 °C 20 ugtL Nitrogen, Total Kjeldahl Colorimetric, EPA 351.2 4 °C 100 uglL Phosphorus, Orthophosphorus Colorimetric, EPA 365.1 4 °C 5 ug/L Phosphorus, Total Colorimetric, EPA 365.1 4 °C 10 ug/L Potassium Atomic emission/ICP, EPA 200.7 0.5% HNO3 250 ug/L Silica APHA 4500Si-F 0.5% HNO3 500 ugtL Sodium Atomic emission/ICP, EPA 200.7 0.5% HNO3 1.5 mg/L Solids, Total Gravimetric, EPA 160.2 4 °C 0.1 mg/L Solids, Total Suspended Gravimetric, EPA 160.2 4 °C 0.1 mg/L Sulfate Ion Chromatography 4 °C 0.1 mg/L Turbidity Turbidimetric, EPA 180.1 4 °C 0.05 NTU Zinc, Total Recoverable ICP Mass Spectroscopy, EPA 200.8 0.5% HN03 1.0 ug/L t-j

References:

USEPA 1983, and APHA et. al., 1995 U,

Table 2-3. Heat content calculations for the thermal regime in Lake Norman for 2001 and 2002. 2001 2002 Maximum areal heat content (g cal/cm,) 27,964 28,252 Minimum areal heat content (g cal/cm2) 7,451 10,042 Maximum hypolimnetic (below 11.5 m) 15,173 15,347 areal heat content (g cal/cm2) Birgean heat budget (g cal/cm ) 20,513 18, 210 Epilimnion (above 11.5 m) heating 0.094 0.113 rate (0C /day) Hypolimnion (below 11.5 m) heating 0.062 0.066 rate (0C /day) 2-16

Table 2-4. A comparison of areal hypolimnetic oxygen deficits (AHOD), summer chlorophyll a (chl a), secchi depth (SD), and mean depth of Lake Norman and 18 TVA reservoirs. AHOD Summer Chl a Secchi Depth Mean Depth Reservoir (mg/cm2/day) (ugfL) (m) (m) Lake Norman (2002) 0.030 2.6 2.2 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 Higgins et al. (1980), and Higgins and Kim (1981) 2-17

N., ( Table 2-5. Quarterly surface (0.3 m) and bottom (bottom minus I m) water chemistry for the MNS discharge, mixing zone, and background locations on Lake Norman during 2001 and 2002. Values less than detection were assumed to be the detection limit for calculating a mean. Mixing Zone

1.0 LOCATION

DEPTn+ Mixing Zone 2 eo Bottom -. MNS Disctarge 40 Surface Moixng Zone

5.0 Background

8.0

Background

11.0 Surface Bottom B Surfa Surface tom. ur e Btom Surface Bottom A-A-HAAG 1 ~z zWi1 IUUL _U1 zuUw dMIJ zuu.' 2001 Z02 2001 2002 2001 2002 2001 2002 2001 20012 2001 Turbidity (ntu) Feb 3.75 2.01 6.30 3.76 3.83 1.61 3.39 2.85 3.29 1.58 4 1.30 5653 1.50 5.06 1.14 6.77 1.41 4.08 1.40 7.86 2.17 may 1.59 1.53 3.50 1.37 1.02 1.24 2.41 1.22 1.48 1.52 1.43 1.27' 2.53 1.82 1.83 1.38 2.8 2.57 2.19 1.48 NS 2.53 Aug 1.45 1.85 2.57 2.52 1.5 1.75 2.09 2.46 1.4 1.74 1.46 1.69 3.63 4.08 1.32 1.52 2.99 2.30 2.11 1.58 2.49 4.01 Noy 2 80 1.92 2.68 .7 3.13 1.93 369 4.62 3 05 1.43 2.98 2.30 7.53 4 62 2.72 1.04 5.77 898e 332 1 99 6 46 12.50 Annua4Mean 2.40 1.78 3~~~~--79 2 6 2.32 1 6 2 90 2 7 2.31 1.6 247 i6 4 81 3 0 2.8 3 4.58 3 8 2 93 168 560 5.3 Specilic Conductance (umholcm) Feb 72.0 57 71.0 58 72 56 71 56 74 58 73 57 71.0 58 70 56 70 58 70 58 89 59 May 75.0 49 73 48.9 74 49.3 73 49 75 50 75 50 73 49.2 74 49.3 73 49.5 72 4968 72 50.8 Aug 77.0 67.1 75.0 76.5 75.0 67.4 79.0 73.1 74.0 67.8 75.0 NS 81.0 NS 75.0 87.2 77.0 72 74.0 67.1 79.0 72.5 Nov 74 0 73.1 1100 108 74.0 73 77.0 98 74 0 74.7 74.0 736 74 0 74 74 0 72.6 720 73 73 0 72.2 73 0 71 9 Annual~ean 74 5 6186 830 72.3 7380 01.3 750 68 9 74.3 62 6 74.3 63 74 8 69.7 73 3 61.3 73 0 62.7 72.3 61.7

73.

63 pH (units) Feb 7.0 7.1 6.7 7.1 7.2 7.2 6.8 7.1 7.2 7.3 7.2 7.2 6.9 7.0 6.4 7.2 6.7 7.0 6.6 7.2 6.6 7.0 May 6.9 7.2 6.6 690 7.11 7.5 6 6 6.9 7.0 7.2 7.1 7.3 6.8 6.8 7.3 7.3 6.6 6.9 7.2 7.2 668 6.7 Aug 7.1 7.5 6.3 6.4 7.4 7.6 6.4 6.3 7.1 7.4 7.2 NS 6.6 NS 6 9 7.9 6.2 6.4 7.7 6.1 6.3 6.4 Nov 66a 76 68a 69a 7.1 7 4 69 88 7.0 7.5 7.0 76a 6 9 7.1 7.1 7.6 7.1 7.0 7.1 76a 7.0 6 9 Annual Mean 690 6 60 860 6 84 7.20 7.42 668 69 7.07 7.10 7.13 7.37 680 6 99 8 93 7.9 666 6 82 7,15 7.52 63 67 Alkalminty (mg CaCO3A) Feb 20.0 16.5 19 5 165 19.5 16,0 19.5 16 5 19.5 16.5 19.5 16.5 19.5 16.5 19 5 17.0 19.0 18.5 19.0 16.5 18.5 16.5 May 16.5 15.5 17.0 16.0 17.0 16.0 16.5 18.0 17.0 16.0 17.0 16.0 17.0 16.0 17.0 16.0 17.0 16.0 16.0 155 NA 16.0 Aug 17.5 17.0 18.0 17.5 18.0 17.0 16.0 17.0 17.5 17.0 17.5 17.5 22.0 21.0 `17.5 16.5 18.0 '14.0 17.5 16.5 19.5 18.0 Nov 190 180 19 0 35 8 8 200 195 18 85 18.5 190 190 185 180 185 180 18 5 186 185 18 0 16 5 Annual Mean 18 25 1676 18 38 21 26 1825 18 180 17.26 1.3 701 18.13 17.28 19 38 1801 1800 17.01 18 00 16 26 177 166 187 72 Chloride (mngf) Feb 7.3 6.1 6.9 6.2 6 6 6.1 668 6.2 6.9 6.1 6.6 6.0 6.7 6.1 6.6 6.1 6.4 6.1 690 6.2 6.9 6.3 May 6.7 5.5 6 6 5.2 6 6 5 5 6.4 5.3 6.5 5.4 6.6 5 5 6 4 5.5 6 5 5.7 6.4 5.4 6 6 5.4 NS 8.1 Aug 7.0 6.6 6.7 6.7 7.1 6.7 6.7 6.7 7.0 6.7 7.0 7.1 68a 7.4 7.1 6.8 6.8 7.1 7.0 66 6.9 6.7 NOV 7.2 6.5 NS 5.9 7.5 6 1 7.3 63 7.4 6.2 7.4 NB 7.4 6 0 7.3 6.2 7.5 8 2 7.2 83 7.3 6 2 Annual Mean 7.05 6.23 673 600 695 6.10 680 6.3 95 6.10 690 6 20 6683 62 68 6.0.7 6 0613.3 6 8 Suftate (mg/I) Feb 6.05 NS 6.72 NS NB 6.2 NS 68 6a67 6.3 6.8 NS 6.74 NB NS 6.2 6 6.1 a669 NS 6 68 NS May 5.32 NS 5.86 NS 5.59 6.7 5.78 6.5 7.3 6.6 6.03 NS 5.37 NS 4.78 6.7 5.6 6.7 5.32 NB NB NB Aug 6.40 NS NS NS NS 6 7 NS a68 6.24 7.0 6.09 6.9 6.30 6.5 6.24 6.9 14.44 6.6 5.93 NS 6.24 NS Nov 680o NS 68 so MS 6.77 6 0 6 6 8.5 6909 6.7 6.75 NS 6.74 NS 6.82 6.7 6 92 6 2 6 59 NS 6 62 NS Annual Mean 6.~~14 NrS

6. 6 N

. 6 6 8 61 6 6 6 42 691 629 6.61 595 664 8 2 4 145 8 Calcium (mgAi) Feb 3.25 3.20 3.05 3.34 2.92 3.71 3682 321 3.26 3.31 3.3.4 2.96 3.15 3 22 3.05 3.14 3.07 2.98 3.20 2.90 2.89 3.03 may 328 3.17 3.31 3.39 3.26 3.25 3.29 309 3.26 3.1 329 3.21 3.31 3.41 3.24 3.46 3.29 3.30 3.38 3 54 NS 3.13 Aug 3.53 3.33 3.75 3.44 3.52 3.35 3.82 3.49 3.52 3.37 3.52 3 38 3.96 3.37 3.49 3.34 3.62 3.58 359 3.38 3.95 3860 Nov 3 41 347 341 47 346 4.38 3.51 398 3 43 3 78 344 379 343 3 64 3 45 3688 3 40 3 52 3.51 335 3 52 3 28 AnnualMean 3-37 329 338 36.4 329 _367 3 58 3.44t 3 37 339 340 334 348 3.41 3 31 345 3 40 35 34 3235 36 Magnesium (mg/i) Feb 1.57 1.53 1.58 1.62 1.54 1.72 1.77 1.59 1.67 1.62 1.57 1.52 1.60 1.57 1.55 1.55 1.55 1.52 1.50 1.50 1.47 1.58 may 1.55 1.51 1.57 1.84 1.55 1651 1.56 1.55 1.57 1.81 1.56 1860 1.58 1.67 1.55 1.58 1.55 1.58 1.51 1.70 NB 1.50 Aug 1.67 1860 1.70 1.65 1568 1.63 1.71 1.88 1.85 1.61 1.65 1.62 1.78 1.72 1885 1.62 1.74 1.70 1.65 1.61 1.79 1.69 Nov 1.72 1 66 1.72 1.88 1.72 200 1.74 1 87 1.72 188 1-74 1.57 1.72 1.81 1.73 1.89 1.70 1.75 1.70 1.69 1.70 1 67 Annual Mean 1 63 1567 1.64 1.701 162 1 74 1 70 1.67 1.65 1-67 1863 1 65 1 67 1891 162 1 68 1 64 1 64 1 62 1.63 165 1 61 NS - Not Sampled 00

Table 2-5. (Continued) C C LOCATION: OEP-h PARAMETERS YEAR-MixIng Zone 1.0 Mixing Zone 2 IMNS Disharg 4.0 Botnom Surface 2002 2001 2002 2001 Ma Surface 2002 2001 cing Zone

5.0 Background

8.0

Background

11.0 Surface Bottom 2002 2001 2002 2001 Surface 2002 2001 Bottom Surface 2002 20011 2002 2001 Bottom Surface 2002 20011 2002 2001 Boltom 2002 2001 Potassium (mgit) Feb 1.80 1.83 1.77 1.84 11.85 1.70 11.88 1.83 1.80 1.82 1.80 1.87 1.83 1.78 1.87 1.79 1.84 1.78 1.80 1.88 1,75 1.83 May 1.91 1.84 1.98 1.82 1.94 1.77 1.91 1.75 11.89 11.81 1.93 1.78 1.80 1175 1.88 1.82 1.91 1.72 1.83 1.82 NS 1.82 Aug 2.11 1.83 2.111 1.85 2.11 1.87 2.07 1.92 2.03 1.88 2.05 1.88 2.11 1.87 2.00 1.85 2.08 1.85 2.04 1.82 2.07 1.84 Nov 2.12 1 98 2.12 2 02 2.18 201 2.23 1.97 2.17 1 94 2.22 1.98 2.17 1909 2.14 1905 2.18 1.93 2.12 1.95 2 10 1.87 Annual ean 1 99 1.8? 1.99 1.54 2.02 1 88 2.02 1087

1. 97 1.86 2.00 1.87 2 00 1.85 1.97 1 85 2 00 1.82 1 95 1 88 1 97 1.84 Sodium (mg/I)

Feb 7.08 8.78 7.82 7.25 8.03 8.80 7.54 8.92 8.08 7.22 7.29 7.08 8.05 8.87 7.83 6.87 7.82 7.14 7.75 7.48 7.91 7.29 may 7.81 6.89 8.11 6.98 7.90 7.13 7.93 8.95 7.80 7.39 7.71 8 88 7.57 6.94 8.03 8.94 7.71 7.09 7.95 7.21 NS 8986 Aug 8.28 7.09 7.94 8.35 8.31 8.70 8.05 8.74 7.85 8.40 8.18 688 7.83 7.17 8.05 8.89 7.90 8.95 8.41 8.57 8 8.78 Nov 7.18 7.38 7.18 7 48 7.72 8`17 785 786 7.15 7.85 7.77 8 23 7.58 802 7 55 7 82 7.27 750S 8 03 7 50 7.78 7 55 Annual Moan 7.58 7 04 7.78 7 0 7 99 720 7.79 77 7.72 7.? 7.74 7.21 7.78 7 25 7 87 7.13 7863 7.17 8 04 7.19 789 7.14 Aluminum (mg/I) Feb 0.092 0.050 0.142 0 081 0.080 0.050 0.151 0.057 0.087 0.051 0.101 0.050 0.163 0.060 0.085 0.050 0.172 0.084 0.13-5 0.050 0.3111 0 080 may 0.050 0.050 0.065 0 050 0 050 0.050 0.051 0.050 0.05 0.050 0.050 0.050 0.083 0050 0.050 0.050 0 083 0.050 0.050 0,052 NS 0.084 Aug 0.050 0.050 0.080 0 050 0.050 0.050 0.050 0050 0.05 0.050 0.050 0,050 0.107 0.050 0.050 0.050 0.070 0.050 0.050 0 050 0.066 0.094 Nov 0 078 0 050 0.078 00(50 0 089 0 050 0 082 0083 0 095 0 050 0 087 0050 0240 0 050 0 087 0 050 0 188 0 074 0 108 0 050 0 237 0 054 Annual Mean 0 07 0.05 0 088 0 05 0 067 0~05 0 084 0 053 0 071 05 0 072 0 05 0.143 005 0 063 0 05 0123 008 0 085 0 05 0205 008 Iro (mg/1) Feb 0.108 0.028 0.198 0 033 0.113 0.029 0.205 0032 0.103 0.027 0.1137 0,020 0.245 0.034 0.121 0.023 0.270 0.032 0.185 0 028 0.452 0050 May 0.052 0.015 0.117 0 010 0.04.4 0.013 0.098 0.010 0.041 0.014 0.034 0.013 0.115 0.010 0.058 0.019 0.122 0.017 0.103 0.027 NS 0.047 Aug 0.088 0.029 0.119 0.057 0.062 0.034 0 086 0.047 0.081 0.028 0.084 0.028 0.239 0.010 0.049 0 024 0.143 0.088 0.083 0.034 0.142 0.155 Nov 0'107 00`18 0.107 0 537 0.125 0 024 0211 0044 0.138 0 015 0.133 0 013 0.385 0.030 0.101 0.01 1 0.255 0 070 0.141 0 010 0 309 0 087 Anniual Mean 008 . 2 01 5 0 5 00 8 0 25 01 0033 00 8 0 2 .0 2 00 9 0 48 0021 0 082 0 01 9 0.198 0047 0.12 3 0 024 0301 0 080 Manganese (mg/I) Feb 001 0.01 0.05 0.02 0.01 0.01 0.05 002 0.01 0.01 NS 0.01 0.05 0.02 0.02 0.01 NS 0.01 0.02 0.02 0.05 0.03 Ma3y 001 0.01 0.03 0.92 0 01 0.00 0.03 0 01 0.01 0.01 0.011 0.01 0.94 0.03 0.01 0.00 0.03 0.01 0.01 0.00 MS 0.04 Aug 0.02 0.02 NS 0.72 0.02 0.02 0.52 0.54 0.02 0.0 0.02 0.02 1.78 0.22 0.01 0.02 0863 0.04 0.03 0.01 1.22 1.14 Nov 0.11 NS 0.11 NS 0 09 NS 0864 MS 0.13 NS 0.12 MS 0.33 MS 0 08 NS 0.03 NS 005 NS 0 08 MS Annual Mean 0 04 0 01 008 0.25 003 001 0.31 0.1 9 004 00 005 =001 0.54 -009 0.03 0.01 023 0.37 003 0.01 0745 0.40 Cadmium (ugA) Feb NS MS MS MS 0.5 0 5 0.5 0.5 0.5 0.5 MS NS NS MS 0.5 0.5 0.5 0.5 MS NS NS NS may 0.5 NS 0.5 MS 0,5 MS 0.5 NS 0.5 NS 0.5 NS 0.5 MS 0.5 MS 0 5 NS 0.5 NS NS NS Aug MS NS MS NS 0.5 0.5 0.5 0.5 0 5 0.5 NS NS MS MS 0.5 0.5 0.5 0.5 NS NS NS NS Nov 0.5 NS 0 5 NS 0 5 MS 0 5 NS 0 5 NS 0.5 NS 0.5 NS 0 5 MS 0 5 MS 0 5 NS 0 5 NS AnnualMean 0.5 -05 0 5 -05 -0.5 -05 _05 -05 05 05 0.5 05 0.5 05 05 copper (ugh) Feb NS NS NS MS 2.0 2.0 2.1 2.0 2.0 2.0 MS MS NS NS 2.0 2.0 2.5 2.0 2.4 MS NS NS May 8.8 NS 3.0 MS 2.4 NS 2.3 MS 2.2 MS 2.3 NS 4.5 MS 2.2 MS 2.3 MS 3.3 MS MS NS Aug NS NS MS MS 2.8 2.0 2.3 2.0 2.3 2.0 NS NS MS NS 2.5 2.0 2.2 2.0 NS MS MS MS Nov 2 0 MS 2.0 NS 2 2 MS 2.3 NS 2.3 NS 2 0 NS 2 4 MS 2.3 NS 2 4 MS 3.1 NS 3.1 MS Annual M ean 4__4_2___2_3_ _2___2_2_2__ __2_2_2___2_ __I_2_2_2 2_3_2___2_a -3.1 Lead (ugA) Feb MS MS MS MS 2 2 2 2 2 2 MS MS MS MS 2 2 2 2 2 MS MS MS May 2 MS 2 MS 2 MS 2 MS 2 MS 2 MS 2 MS 2 MS 2 MS 2 MS MS MS Aug MS MS MS MS 2 2 2 2 2 2 MS MS MS MS 2 2 2 2 MS MS MS MS Nov 2 MS 2 MS 2 MS 2 MS 2 MS 2 MS 2 MS 2 MS 2 MS 2 MS 2 MS Annual Mean 2 - 2 221 2 2 22 _2 NS = Not sampled N- "10

Table 2.5. (Continued) ( ( LOCATION: DEPTH' PARAMETES YWAR-Mixing Zone 1.0 Surface Bottom 2002 200t 2002 200 I Mixing Zone 2 MNS I DiSure Mixing Zone 4 0 5.0 Surface I Surface Bottom

13ivv,

~Ii oNV" ,nni -AI, OInel Baoo Surface WV02 200 grfound 80 Bottom WM0 9001 Backgmund 11.0 Surface

9nni, 900I Surface I0M1

-001 Bottom' -"l2 2001 Bottom 2002 20141 Zinc (ugh) Feb 5 5 5 5 5 5 5 5 5 5 a 5 5 5 7 5 5 5 5 5 10 5 May 5 5 5 5 5 5 5 5 5 5 9 5 5 5 5 5 5 5 5 5 NS 5 Aug 5 5 8 9 5 5 5 6 5 5 5 5 5 5 5 5 6 5 6 5 5 5 Nov 20 6 20 7 20 5 20 5 20 5 20 5 20 5 20 5 20 20 5 20 5 AnnualMean 88 53 95 86 88 50 88 53 68 50 100 50 88 50 93 50 88 50 90 50 117 50 Ntrate (ugh) Feb 110 110 120 120 110 120 130 120 120 110 110 110 120 120 120 110 130 110 150 150 220 160 May 120 130 170 1SO 130 130 170 150 130 140 130 130 160 150 120 130 190 170 150 640 NS 140 Aug 20 30 170 260 20 30 160 270 20 30 20 30 90 170 20 30 1SO 1400 20 20 160 260 Nov 50 690 50 710 so 620 050 60 20 60 so 50 st 60 40 70 100 140 ao 140 1w0 AnnualMean 750 2400 1275 310 0 2750 1275 1475 825 750 800 800 1050 1225 800 775 1350 460 0 1150 2250 1733 1850 Ammomia (ug/) Feb 20 20 40 40 20 20 so 30 30 20 20 40 30 20 20 190 20 40 30 50 40 May 20 20 20 60 20 20 20 So 20 l 20 20 20 so 20 20 20 6o 20 20 NS 90 Aug 20 20 20 70 20 20 40 SO 20 20 10 8o 60 20 20 60 20 20 20 50 20 Nov 60 30 60 600 60 20 110 90 60 20 60 20 8o 70 60 30 50 80 60 120 60 210 Annual Mean 30.0 225 350 1925 300 200 550 6-55 325 22.5 300 17.5 550 525 300 225 800 450 325 41.5 53.3 900 Total Ptospttoiis (ugJ) Feb 10 4 10 5 10 4 10 5 10 10 4 10 4 10 63 10 4 10 7 16 8 May 10 6 10 5 10 1e 10 8 10 10 7 26 6 1s 7 10 s 10 8 NS 6 Aug 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 17 Nov 10 10 10 10 10 10 22 10 10 10 10 10 10 10 10 10 10 16 10 11 10 11 AnnualMean 100 7.5 100 7t.6 100 100 130 83 100 73 10o 78 140 7.5 120 225 100 93 100 90 120 105 Onhopnospnate (UgA) Feb 5 2 5 2 6 2 5 2 5 2 5 2 5 2 5 2 5 2 5 2 5 2 May 5 2 5 2 5 2 5 2 5 2 5 2 14 2 5 2 5 2 5 2 NS 2 Aug 5 5 5 8 5 5 5 5 5 5 5 7 5 7 5 5 5 7 5 7 5 7 Nov 6 5 5 5 5 5 13 5 a 5 5 5 5 5 5 5 5 5 5 5 5 5 AnnualMean 50 35 50 4.3 53 35 70 4 50 4 50 4 73 4 50 4 50 4 50 40 50 4 Silica (mg/1) Feb 3.2 2.9 34 30 3.3 30 3.5 3.0 3.3 3.0 3.3 2.9 3.4 30 3.3 2.9 3.5 2.8 36 3 6 3.8 3.7 May 34 2.9 38 3.2 3.4 2.9 3.8 3.1 3.4 2.9 34 2.9 4.0 3.2 3.3 30 3.9 3.3 3.8 29 NS 3.5 Aug 3 0 2.4 4.3 40 3.0 2.7 4.4 4.1 3.0 2.7 3.0 2.7 4.4 4.1 3.0 2.6 4.3 4.0 3.2 2.7 4.4 4.2 Nov 43 34 4.3 4.7 4.5 32 45 34 44 32 45 33 4.5 34 44 31 43 4.3 48 35 48 45 AnnualMean 35 2.9 4.0 37 36 30 4.1 34 35 30 36 30 4.1 34 35 29 40 36 3.9 32 43 40 NS

• Not Sampled 0

80 72 69 62 15.9 0 1 IG~oneters 0 2 4 1 1.0 MNS Figure 2-1. Water quality sampling locations for Lake Norman. 2-21

( c McGuire Rainfall (' 7 6 5 U) G) 4 3 2 0 JAN FEB MAR APR MAY JUN JI j02001 F2i t'- Figure 2-2. Monthly precipitation in the vicinity of McGuire Nuclear Station. JL AUG SEP OCT NOV DEC 102

(7 ( ( JAN Temperature (C) 0 5 10 15 20 25 30 35 FEB Temperature (C) 0 5 10 15 20 25 30 35 MAR Temperature (C) 0 5 10 15 20 25 30 35 0 5 10 i.5 . 20 25 30 35 APR Temperature (C) 0 5 10 15 20 25 30 35 MAY Temperature (C) 0 5 10 15 20 25 30 35 JUNE Temperature (C) 0 5 10 15 20 25 30 35 0 5 10 25 20 25 30 tw3 Figure 2-3. Monthly mean temperature profiles for the McGuire Nuclear Station background zone in 2002 (xx) and 2001 (* *).

( ( ( JULY Temperature (C) 0 5 10 15 20 25 30 35 AUGUST Temperature IC) 0 5 10 15 20 25 30 35 SEPT Temperature (C) 0 5 10 15 20 25 30 35 15~ 'L20 - OCT Temperature (C) 0 5 10 15 20 25 30 35 NOV DEC Temperature (C) 0 5 10 15 20 25 30 35 \\ .I I I Temperature (C) 0 5 10 15 20 25 30 35 nU 5 10 E15 o 20 25 30 35 t I IIIIIII II ti3 Figure 2-3. (con't).

C ( ( JAN Temperature (C) 0 5 10 15 20 25 30 35 FEB Temperature (C) 0 5 10 15 20 25 30 35 MAR Temperature (C) 0 5 10 15 20 25 30 35 10 _ 15 o20 0; U 5 10 E915 e 20 25 30 I It I I1 I It 10 g15 a 20 35 - APR Temperature (C) 0 5 10 15 20 25 30 35 MAY Temperature (C) 0 5 10 15 20 25 30 35 JUNE Temperature (C) 0 5 10 15 20 25 30 35 5 10 E15 . 20 25 t'j Figure 2-4. Monthly mean temperature profiles for the McGuire Nuclear Station mixing zone in 2002 (xx) and 2001 (* *).

(I ( C JULY Temperature (C) 0 5 10 15 20 25 30 35 AUGUST Temperature (C) 0 5 10 15 20 25 30 35 SEPT Temperature IC) 0 5 10 15 20 25 30 35 0 5 10 o20 25 30 35 OCT Temperature (C) 0 5 10 15 20 25 30 35 NOV Temperature (C) 0 5 10 15 20 25 30 35 DEC Temperature (C) 0 5 10 15 20 25 30 35 215 .20 .a Cal Figure 2-4. (con't).

45.00 40.00 35.00 U 30.00 = 25.00 cV 20.00-E .0. 0 0 I I I (5 w 15.00-10.00-5.00 - 0.00 12.00 10.00 - 8.00-6.00 - 4.00-2.00-Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month -j 03 0 la 0.00 I I I I I I Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Figure 2-5. Monthly surface (0.3m) temperature and dissolved oxygen data at the discharge location (loc. 4.0) in 2002 (0) and 2001 (M). 2-27

(- C C JAN Dissolved Oxygen (mgIl) 0 2 4 6 8 10 12 FEB Dissolved Oxygen (mg/L) 0 2 4 6 8 10 12 MAR Dissolved Oxygen (mg/l.) 0 2 4 6 8 10 12 .E15. . 20 a; APRIL Dissolved Oxygen (mg/L) 0 2 4 6 8 10 12 MAY Dissolved Oxygen (mg/L) 0 2 4 6 8 10 12 JUNE Dissolved Oxygen (m/I) 0 2 4 6 8 10 12 t'.) 00 Figure 2-6. Monthly mean dissolved oxygen profiles for the McGuire Nuclear Station background zone in 2002 (xx) and 2001 (+ *).

(7 ( ( JULY Dissolved Oxygen (mgIL) 0 2 4 6 8 10 12 AUGUST Dissolved Oxygen (mg&) 0 2 4 6 8 10 12 SEPT Dissolved Oxygen (mgIL) 0 2 4 6 8 10 12 0 5 10 -15

20 25 30 35 0

5 10 !.5 " 20 0 25 30 35 OCT Dissolved Oxygen (mgIL) 0 2 4 6 8 10 12 NOV Dissolved Oxygen (mgIL) 0 2 4 6 8 10 12 DEC Dissolved Oxygen (mgIL) 0 2 4 6 8 10 12 it~ %O Figure 2-6. (con't).

( ( ( JAN Dissolved Oxygen (mg)L) 0 2 4 6 8 10 12 FEB Dissolved Oxygen (mg/L) 0 2 4 6 8 10 12 MAR Dissolved Oxygen (mgIL) 0 2 4 6 8 10 12 0 5 10 n20 25 30 35 0 5 10 o 20 25 30 35 APR Dissolved Oxygen (mgtL) 0 2 4 6 8 10 12 MAY Dissolved Oxygen (mg)L) 0 2 4 6 8 10 12 JUNE Dissolved Oxygen (mgL) 0 2 4 6 8 10 12 5 10

15 a 20 25 30 tW

'J CD Figure 2-7. Monthly mean dissolved oxygen profiles for the McGuire Nuclear Station mixing zone in 2002 (xx) and 2001 (*,).

(7 c7 (7 JULY Dissolved Oxygen (mg)L) 0 2 4 6 8 10 12 AUGUST Dissolved Oxygen fmgs) 0 2 4 6 8 10 12 SEPT Dissolved Oxygen (mg)L) 0 2 4 6 8 10 12 5 E15 m 20 la 25 OCT Dissolved Oxygen (mg)l) 0 2 4 6 8 10 12 NOV Dissolved Oxygen (mg)l) 0 2 4 6 8 10 12 DEC Dissolved Oxygen (nigh) 0 2 4 6 8 10 12 0 5 10 .:5

• 20 25 30 35 0

5 10 " 20 25 30 35 w Figure 2-7. (con't).

I I IW (1 ( I I Distance from Cowenr Ford Dam (km) Distance from Cowana Ford Dam (kin) N') Distance from Cowans Ford Dam (km) Distance from Cowana Ford Dam (km) Figure 2-8. Monthly reservoir-wide temperature isotherms for Lake Norman in 2002.

(7 C 240. 235-1.0 6.0 11.0 L L Samping Locations 13.0 160 1.9 60 69.O 72.0 e0.0 I I I t I L iE. Fs itV DZ 6 r-230-225-220-215-210 205-200D. =2 Temperature (deg C) Jun 3, 2002 Distance trom Cowan. Ford Dam (km) 19§... I I I I , I I,,. .0 10 15 20 25 30 35 40 4S 50 55 Distance from Cowans Ford Dam (km) 240 .Sampling Locations 23 1.0 6.0 11.0 13.0 15.0 1s.S 62.0 go0 72.0 ro 4 4 .4 4 t 23 % z4L, 235S 230-T 225-1 220: 5 213-W 210-20S-Sampling Locations 8.0 11.0 13.0 16.0 1S.9 20 69.0 L t I.e 72z0 eo o Temperature (deg C) -Jul 8, 2002 -F 22t i 220-3$ 215-Gl 210-20§5 200-20 Temperature (deg C) Aug 5, 2002 200-W W t. w *.. 6 ib -IV - 2bi-t r m a 'o am

• 1c
• * ' '5' '. '

SS Dlstanee from Cowans Ford Darn (km) . -- I.... I.... I.... D i....A.... ., ' ~ I ' 0 5 10 15 20 25 20 25 40 45 50 55 Distance from Cowans Ford Dam (km) Figure 2-8. Continued.

240 24 Sampling Locations Sampling Locations 23 1io t.o liMO Mio 15.0 15.0 nto eo.o 72iO so. 235-10 so 11.0 130 15i0 15.9 M2.O 69.0 72.0 Sao I 1 &0 A4 ,~22, 21~~~~~~~~~~~~~~~~~~~~~~~~~2 Temperature (deg C) Temperature (deg C) Sep 10, 2002 Oct 10, 2002 0 5 10 5 200 25 35 45 10 25 i0 35 4'0 4'5 50 5S Dl9tance from Cowans Ford Dam (km) Distance from Cowans Ford Darn (km) 240 240 Sampling Locations Sampling Locations 23 1.0 a0 11.0 13.0 0 16.9 62.0 69.0 720 M0 23 1.0 a.0 11.0 13.0 16.0 15.0 62.0 69.0 70 80.

4.

I I I I I 4 I I I I I I I £ 4 23 E ~22 21 ~2 21 ~~~~~~~~~~~~~~~~~~~~~~~~a21 20 ~~~~~~~Temperature (deg C) 2Temperature (deg C) Nov 4, 2002 Dec 15, 2002 10 15 .1S 405 20 25 30' 35 4 45 so 5' uIJ law *rur wwans orr uniT mtJ Figure 2-8. Continued.

( C ( Distance from Cowans Ford Dam (km) DIstance from Cowans Ford Darn (km) 2413 IF S I; LU 235: 230 T 225-E 2 g -2 210-205 200 1.0 8.0 11.0 I L I Sempinq tocations 13.0 18.0 15.0 e2.0 8e.0 I 1 1 I D;ssolved Oxygen (mg/l) Apr 3, 2002 7Z.0 80. MO MO W t
, VI -6 l5 1 0 S. .20 2 30 5 40. 4S Dhtance from Cowans Ford Dam (km) 50 55 DIstanoe frm Cowans Ford Dam (km) Figure 2-9. Monthly reservoir-wide dissolved oxygen isopleths for Lake Norman in 2002.

240 SamplIng Locations Samping Locssions 2 1.0 s.0 11.0 13.0 15.0 15.9 W20 69.0 72.0 w.o 23 1lo 6.0 11.0 13.0 s.0 15.9 62.0 09.0 2 () 23 .22 M a y .6,.2002 Jun 3 202 2 S21021S 20 25 30 35 40 45 S0 55 6 tO 16 20 2S 30 35 40 45 .j21 21/ 2 20 .2f Dissolved Oxygen (mg/I) Dissolved Oxyge May 6, 2002 Jun 3, 2002 s t95* ,,,,,,,,~~~~~~~~~~~~~~~~. 2 tD 5 .,....4, , 4,,15 a.... A 10 1S 20 25 30 35 40 45 So 5 5 10 15 20 25 30 35 40 45 DIOtanco from Cowans Ford Dam (krm) DEstance from Cowans Ford Darn (kem) Figure2-90 Contin .240 Sampling Locations Sampling Locations 23

1.

.0 11.0 13.0 15.0 15.0 82.0 60.0 72.0 SOC 2 1.0 a.0 11.0 13.0 15.0 15.9 62.0 MO. 230 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~3 22 22 ~211~U 21 0 W05 215 Dissolved Oxygen (mg/1) Dissolved Oxyge Jul 8, 200220 Aug 5, 2002 0. 1015 .~~~~~~ I 31 s415. .50 55.e 0 5 10 b ~ "5 1540 45 C\\ ~~~~~~~~~~Distanoe from Cowans Ford Dam (kcm) Distance frm Cowmna Ford Dam (kmi) Figure 2-9. Continued.

(7 (7-Distance from Cowais Ford Dam (k~m) Distance from Cowens Ford Dwm (ion) Wt!jj Distanoc from Cowans Ford Dam (kn) Distance from Cowan, Ford Dam (km) Figure 2-9. Continued.

30* 25 5 20 U) (a15 I 10 5*~ 0 50 100 150 200 250 300 350 Julian Date Figure 2-lOa. Heat content of the entire water column (U) and the hypolimnion (O) in Lake Norman in 2002. 12 10 100 E 0 8 6 4 0 CD a') C-D L.. 2 0 0 50 100 150 Julian a !3! I, lo 200 250 300 350 Date Figure 2-lOb. Dissolved oxygen content (-) and percent saturation (---) of the entire water column (U) and the hypolimnion (0) of Lake Norman in 2002. 2-38

( C C Distanc. from Cowens Ford Darn (kcm) Distance from Cowans Ford Dam (krn) Distance from Cowans Ford Dam (kmn) Dbstance from Cowans Ford Darn (an) Figure 2-11. Striped bass habitat ((temperatures *20 C and dissolved oxygen >2 mgfL) in Lake Norman, summer 2002.

C ( C 240 240 LAKE NORMAN STRIPED BASS HABITAT LAKE NORMAN STRIPED BASS HABITAT 23 1.0 8.0 11.0 13.0 16.0 15.9 M20 80.0 72.0 60.0 23 1.0 8.0 11.0 15.0 1s.0 15.9 82.0 e9.0 4 4 £ 22 22 26 deg C A 28 26 di 2mg/i 215 2m 205 3 Jul 23, 2002 205 Aug 5, d 65 ~ ~ 95 0 5 10 165 20 .2S 30 35 40 45 60 SS 5 0 5 20 25 30 35 40 45 Distance from Cowans Ford Dam (krm) Distance from Cowans Ford Dam (kcm) 24 240 LAKE NORMAN STRIPED BASS HABITAT LAKE NORMAN STRIPED BASS HABITAT 23 1.0 8.0 11.0 130. 15.0 15.0 82.0 89.0 .72.0 80.0 23 1.0 8.0 11.0 ls.o 1S.0 15.9 6O 89.0 .I l~~~~~~~~a ~~~~~~26 dgCE 26di 821 21.*S do 201 ~ ~~~~~~Sep 10, 2002 20 Oct 10, 5 1O 15 20 0l 30 35 40 4S 50 55 0 5 10 15 20 25 30 35 3 35 40 45 Distance from Cowans Ford Dam (1km) Distance from Cowans Ford Dam (ion) Figure 2-11. Continued

CHAPTER 3 PHYTOPLANKTON INTRODUCTION Phytoplankton standing crop parameters were monitored in 2002 in accordance with the NPDES permit for McGuire Nuclear Station (MNS). The objectives of the phytoplankton section for the Lake Norman Maintenance Monitoring Program are to:

1. Describe quarterly patterns of phytoplankton standing crop and species composition throughout Lake Norman; and

2. Compare phytoplankton data collected during this study (February, May, August, November 2002) with historical data collected in other years during these months.

In previous studies on Lake Norman considerable spatial and temporal variability in phytoplankton standing crops and taxonomic composition have been reported (Duke Power 1976, 1985; Menhinick and Jensen 1974; Rodriguez 1982). Rodriguez (1982) classified the lake as oligo-mesotrophic based on phytoplankton abundance, distribution, and taxonomic composition. Past Maintenance Monitoring Program studies have tended to confirm this classification. METHODS AND MATERIALS Quarterly sampling was conducted at Locations 2.0, 5.0 (Mixing Zone), 8.0, 9.5, 11.0, 13.0, 15.9, and 69.0 in Lake Norman (see map of locations in Chapter 2, Figure 2-1). Duplicate grabs from 0.3, 4.0, and 8.0 m (i.e., the estimated euphotic zone) were taken and then composited at all but Location 69.0, where grabs were taken at 0.3, 3.0, and 6.0 m due to the shallow depth. Sampling was conducted on 4 February, 6 May, 5 August, and 4 November 2002. 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 were used in determining phytoplankton standing crop. Field sampling and laboratory methods used for chlorophyll a, seston dry weights and population identification and enumeration were identical to those 3-1

used by Rodriguez (1982). Data collected in 2002 were compared with corresponding data from quarterly monitoring beginning in August 1987. 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. RESULTS AND DISCUSSION Standing Crop Chlorophyll a Chlorophyll a concentrations (mean of two replicate composites) ranged from a low of 1.28 ug/l at Location 9.5 in May, to a high of 16.29 ug/L at Location 69.0 in August (Table 3-1, Figure 3-1). All values were below the North Carolina water quality standard of 40 ug/L (NCDEHNR 1991). Lake-wide mean chlorophyll concentrations in February, May, and August were within ranges of those recorded in previous years, while the lake-wide mean in November was the lowest recorded for that period (Figure 3-2). The seasonal trend in 2002 of low values in February, increasing slightly in May, achieving maximum values in August, then declining to the annual lake-wide minimum in November, has never been observed during the course of the Lake Norman Maintenance Monitoring Study. Based on quarterly mean chlorophyll concentrations, Lake Norman was in the low mesotrophic range during February and August, and in the upper oligotrophic range in May and November 2002. Over 62% of individual chlorophyll values were less than 4 ug/L (oligotrophic), while only one value was greater than 12 ug/L (eutrophic). Lake-wide quarterly mean concentrations of below 4 ugfL have been recorded on eight previous occasions, while concentrations of greater than 12 ug/L were only recorded during May of 1997 and 2000, and August of 2001 (Duke Power 2002). During 2002 chlorophyll a concentrations showed a higher degree of spatial variability than in 2001. Maximum concentrations were observed at Location 69.0 during all but November, when that location had the lowest chlorophyll concentration. Minimum concentrations occurred at Location 2.0 in February, Location 9.5 in May and August, and Location 69.0 in November (Table 3-2). The trend of increasing chlorophyll concentrations from down-lake to up-lake, which had been observed during most quarters of 2000 and 2001, was apparent in 3-2

varying degrees during most quarters of 2002 (Table 3-1, Figure 3-1). Locations 15.9 (uplake, above Plant Marshall) and 69.0 (the uppermost riverine location) had significantly higher chlorophyll values than Mixing Zone locations during all sample periods (Table 3-2). Flow in the riverine zone of a reservoir is subject to wide fluctuations depending, ultimately, on meteorological conditions (Thornton, et al. 1990), although influences may be moderated due to upstream dams. During periods of high flow, algal production and standing crop would be depressed, due in great part, to washout. Conversely, production and standing crop would increase during periods of low flow and high retention time. Over long periods of low flow, production and standing crop would gradually decline once more. These conditions result in the high variability in chlorophyll concentrations observed between Locations 15.9 and 69.0 throughout the year, as opposed to Locations 2.0 and 5.0 which were very similar during each sampling period. Average quarterly chlorophyll concentrations during the period of record (August 1987 - November 2002) have varied considerably. During February 2002, Locations 2.0 through 9.5, and 15.9 had chlorophyll concentrations in the mid range, while chlorophyll concentrations at Locations 11.0 and 13.0 were in the low range. The value at Location 69.0 was the second highest February concentration recorded for this location (Figure 3-3). Long term February peaks at locations 2.0 through 9.5 occurred in 1996; while long term February peaks at Locations 11.0 through 15.9 were observed in 1991. The highest February value at location 69.0 occurred in 2001. Locations 2.0 through 11.0 had lower chlorophyll concentrations in February 2002 than in February 2001, while concentrations at Locations 13.0 through 69.0 were higher than in February 2001. During May, August, and November, chlorophyll concentrations at most locations were lower than normal, and several record low concentrations were recorded: Locations 8.0 and 9.5 in May-, Locations 5.0, 8.0, and 9.5 in August; and all but Locations 2.0 and 13.0 in November. Location 69.0 demonstrated comparatively high chlorophyll concentrations during all but November, when this location had a record low for that period. In most cases, chlorophyll concentrations during 2002 were lower than in 2001 (Figure 3-3). Long term May peaks at Locations 2.0 and 9.5 occurred in 1992; at location 5.0 in 1991; at Locations 8.0, 11.0, and 13.0 in 1997; and at Location 69.0 in 2001. Long term August peaks in the Mixing Zone were observed in 1998; while year-to-year maxima at Locations 8.0 and 9.5 occurred in 1993. Long term August peaks at Locations 11.0 and 13.0 were observed in 1991 and 1993, respectively. The highest August chlorophyll concentration from 3-3

Location 15.9 was observed in 1998, while Location 69.0 experienced its long term August peak in 2001. Long term November peaks at Locations 5.0, 8.0, and 11.0 through 15.9 occurred in 1996; while November maxima at Locations 2.0 and 9.5 were observed in 1997. The highest November chlorophyll concentration at location 69.0 occurred in 1991. Total Abundance Density and biovolume are measurements of phytoplankton abundance. The lowest density during 2002 occurred at Location 9.5 in November (597 units/ml), and the lowest biovolume (258 mm3/m3) occurred at this location during May (Table 3-3, Figure 3-1). The maximum density (4,850 units/ml) and biovolume (3,696 mm3/m3) were observed at Location 15.9 in August. As with chlorophyll concentrations, most standing crop values during 2002 were lower than those of 2001 (Duke Power Company 2002). Phytoplankton densities and biovolumes during 2002 never exceeded the NC guidelines for algae blooms of 10,000 units/ml density, and 5,000 mm3/m3 biovolume (NCDEHNR 1991). Densities and biovolumes in excess of NC guidelines were recorded in 1987, 1989, 1997, 1998, and 2000 (Duke Power 1988, 1990, 1998, 1999, 2001). Total densities at locations in the Mixing Zone during 2002 were within the same statistical ranges during all sampling periods (Table 34). In all sampling periods Location 15.9 had significantly higher densities than all other locations. During all but August, phytoplankton densities showed a spatial trend similar to that of chlorophyll, that is lower values at down-lake locations versus up-lake locations. Seston Seston dry weights represent a combination of algal matter, and other organic and inorganic material. Dry weights during 2002 were most often higher than those of 2001. A general pattern of increasing values from down-lake to up-lake was observed in all quarters to some extent (Figure 3-1). Statistically, Location 69.0 had significantly higher values than other locations during all quarters of 2002 (Table 3-5). From 1995 through 1997 seston dry weights had been increasing (Duke Power 1998). Values since 1998 represented a reversal of this trend, and were in the low range at most locations during 1999 through 2001 (Duke Power 2002). Low dry weights over the past four to five years were likely a result of prolonged drought conditions. 34

Seston ash-free dry weights represent organic material and may reflect trends of algal standing crops. In some cases, this relationship held true in 2002; most notably at Location 69.0, which had high ash-free dry weights, as well as elevated chlorophyll values during February, May, and August of 2002 (Tables 3-1, 3-2, and 3-5). In addition, ash-free dry weights, like chlorophyll and standing crops were lower in 2002 than in 2001. During all but February, the only significant statistical difference was that Location 69.0 had higher ash-free dry weights than other locations. The proportions of ash free dry weights to dry weights during 2002 were considerably lower than in 2001 and 2000, indicating higher organic composition among samples in 2002 as compared to previous years. Between 1994 and 1997 a trend of declining organic/inorganic ratios was observed (Duke Power 1995, 1996, 1997, 1998, 2001, 2002). Secchi Depths Secchi depth is a measure of light penetration. Secchi depths were often the inverse of suspended sediment (seston dry weight), with the shallowest depths at Locations 13.0 through 69.0 and deepest from Locations 9.5 through 2.0 down-lake. Depths ranged from 0.61 m at Location 69.0 in November, to 3.95 m at Location 2.0 in May (Table 3-1). The lake-wide mean secchi depth during 2002 was slightly higher than in 2001, and was the second highest recorded since measurements were first reported in 1992. The highest lake-wide mean secchi depth was recorded for 1999 (Duke Power 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002). Again, high secchi depths were likely due to low rainfall over the past few years. Community Composition One indication of "balanced indigenous populations" in a reservoir is the diversity, or number of taxa observed over time. Lake Norman typically supports a rich community of phytoplankton species this was certainly true in 2002. Ten classes comprising 89 genera and 208 species, varieties, and forms of phytoplankton were identified in samples collected during 2002, as compared to 64 genera and 118 lower taxa identified in 2001 (Table 3-6). The 2002 total represented the highest number of individual taxa recorded in any year since monitoring began in 1987. Twenty-two taxa previously unrecorded during the Maintenance Monitoring Program were identified during 2002. 3-5

Species Composition and Seasonal Succession The phytoplankton community in Lake Norman varies both seasonally and spatially within the reservoir. In addition, considerable variation occurs between years for the same months sampled. During February 2002, diatoms (Bacillariophyceae) dominated densities at Locations 2.0 through 9.5, while cryptophytes (Cryptophyceae) were dominant at Locations 11.0 and 15.9 (Table 3-7, Figures 3-4 through 3-8). In May, diatoms were dominant at all locations. During most previous years, cryptophytes, and occasionally diatoms, dominated February phytoplankton samples in Lake Norman. Diatoms have typically been the predominant forms in May samples of previous years; however, cryptophytes dominated May samples in 1988, and were co-dominants with diatoms in May 1990, 1992, 1993, and 1994 (Duke Power 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002). The most abundant diatom during February was Tabellaria fenestrata (Locations 2.0 through 9.5), while the most abundant cryprophyte at Locations 11.0 and 15.9 was the small flagellate Rhodomonas minuta. In addition, R. minuta was found in high abundances at locations dominated by diatoms. During May, the most abundant diatoms were Cyclotella stelligera (Locations 2.0 through 9.5), and Fragillaria crotonensis (Locations 11.0 and 15.9). All of these species have been common and abundant at various times throughout the course of the Program. Rhodomonas minuta has been one of the most common and abundant forms observed in Lake Norman samples since monitoring began in 1987. Cryptophytes are characterized as light limited, often found deeper in the water column, or near surface under low light conditions, which are common during winter (Lee 1989). In addition, R. minuta's small size and high surface to volume ratio would allow for more efficient nutrient uptake during periods of limited nutrient availability (Harris 1978). During August 2002 green algae (Chlorophyceae) dominated densities at all Locations (Figures 3-4 through 3-8). The most abundant green alga was the small desmid, Cosmarium asphearosponum var. strigosum (Table 3-7). During August periods of the Lake Norman study prior to 1999, green algae (Chlorophyceaea), with blue-green algae (Myxophyceae) as occasional dominants or co-dominants, were the primary constituents of summer phytoplankton assemblages, and the predominant green alga was also C. asphearosponum var. strigosum. During August periods of 1999 through 2001, Lake Norman phytoplankton were dominated by diatoms, primarily the small pinnate Anomoeoneis vitrea (Table 3-7). A. vitrea was described as a major contributor to periphyton communities on natural substrates 3-6

during studies conducted from 1974 through 1977 (Derwort 1982). The possible causes of this significant shift in summer taxonomic composition were discussed in the 1999 report, and included deeper light penetration (the three deepest lake-wide secchi depths were recorded from 1999 through 2001), extended periods of low water due to draw-down, shifts in nutrient inputs and concentrations, and macrophyte control procedures upstream (Duke Power 2000). Whatever the cause, the phenomenon was lake-wide, and not localized near MNS or Marshall Steam Station (MSS); therefore, it was most likely due to a combination of environmental factors, and not station operations. During November 2002, densities at all locations were again dominated by diatoms (Figures 3-4 through 3-8). The dominant species at Location 2.0 was C. stelligera, while the dominant species at all other locations was T. fenestrata (Table 3-7). During the November quarters of previous years diatoms have been dominant on most occasions, with occasional dominance by cryptophytes. Blue-green algae (Myxophyceae), which are often implicated in nuisance blooms, were never abundant in 2002 samples. Their overall contribution to phytoplankton densities was slightly higher in 2002 than in 2001, and similar to that of 2000. Densities of blue-greens seldom exceeded 2% of totals. The highest percent composition of Myxophyceae (4.7%) during all sampling periods in 2002 occurred at Location 15.9 in August. Prior to 1991, blue-green algae were often dominant at up-lake locations during the summer (Duke Power 1988, 1989, 1990, 1991, 1992). Phytoplankton index Phytoplankton indexes have been used with varying degrees of success ever since the concept was formalized by Koikwitz and Marsson in 1902 (Hutchinson 1967). Nygaard (1949) proposed a series of indexes based on the number of species in certain taxonomic categories (Divisions, Classes, and Orders). The Myxophycean index was selected to help determine long term changes in the trophic status of Lake Norman. This index is a ratio of the number of blue-green algae taxa to desmid taxa, and was designed to reflect the "potential" trophic status as opposed to chlorophyll, which gives an "instantaneous" view of phytoplankton concentrations. The index was calculated on an annual basis for the entire lake, for each sampling period, and for each location during 2002 (Figure 3-9). 3-7

For the most part, the long term annual Myxophycean index values confirmed that Lake Norman has been primarily in the oligo-mesotrophic (low to intermediate) range since 1988 (Figure 3-9). Values were in the high, or eutrophic, range in 1989, 1990, and 1992; in the intermediate, or mesotrophic, range in 1991, 1993, 1994, 1996, 1998, 2000, and 2001; and in the low, or oligotrophic, range in 1988, 1995, 1997, and 1999. The index for 2002 fell into the oligotrophic range, and was the lowest annual index value recorded during the Maintenance Monitoring Program. The highest index value among sample periods of 2002 was observed in May, and the lowest index value occurred in November (Figure 3-9). The highest lake-wide chlorophyll was in August, with the minimum in November, therefore, the index did not completely reflect chlorophyll concentrations observed throughout the lake during 2002. The index values for locations during 2002 showed a gradual decline in values from Locations 2.0 through 9.5, with values increasing from Locations 9.5 through 15.9, which had the maximum index value. This tended to reflect the pattern of increasing algae concentrations from mid-lake to up-lake locations observed during most quarters of 2002. During 2001, a pattern of increasing trophic state from down-lake to up-lake locations was observed during most sampling periods (Duke Power 2002). FUTURE STUDIES No changes are planned for the phytoplankton portion of the Lake Norman Maintenance Monitoring Program during 2003.

SUMMARY

In 2002 lake-wide mean chlorophyll a concentrations were generally in the low range, and the November mean was the lowest recorded for that period. Lake Norman continues to be classified as oligo-mesotrophic based on long term, annual mean chlorophyll concentrations. Lake-wide mean chlorophyll declined from February to May, increased to the maximum in August, then declined to the annual minimum in November. This seasonal pattern had never been recorded during the Maintenance Monitoring Program. Some spatial variability was observed in 2002; however, maximum chlorophyll concentrations were most often observed up-lake, while comparatively low chlorophyll concentrations were recorded from Mixing Zone and mid lake locations. Location 69.0, the furthest upstream location, demonstrated maximum chlorophyll concentrations in February, May, and August of 2002, but had the 3-8

lowest chlorophyll value in November. The highest chlorophyll value recorded in 2002, 16.29 ug/l, was below the NC State Water Quality standard of 40 ug/l. In most cases, total phytoplankton densities and biovolumes observed in 2002 were lower than those observed during 2001, and standing crops were within ranges established over previous years. Phytoplankton densities and biovolumes during 2002 never exceeded the NC guidelines for algae blooms. Standing crop values in excess of bloom guidelines have been recorded during five previous years of the Program. As in past years, high standing crops were usually observed at up-lake locations; while comparatively low values were noted down-lake. Seston dry weights were generally higher in 2002 than in 2001, and down-lake to up-lake differences were apparent most of the time. Conversely, ash-free dry weights were usually lower in 2002 than in 2001. Maximum dry and ash-free dry weights were most often observed at Location 69.0, while low values were most often noted at Locations 2.0 through 11.0. The proportions of ash-free dry weights to dry weights in 2002 were considerably lower than those of 2001, indicating an increase in organic composition among 2002 samples. Secchi depths reflected suspended solids, with shallow depths related to high dry weights. The lake-wide mean secchi depth in 2002 was the second deepest recorded since measurements were first reported in 1992. High secchi depths over the last few years were likely due to low rainfall. Diversity, or numbers of taxa, of phytoplankton had increased substantially since 2001, and the total number of individual taxa was the highest yet recorded. The taxonomic composition of phytoplankton communities during 2002 was similar to those of many previous years. Diatoms were dominant at most locations during all sampling periods except August, when green algae were dominant. A shift in community composition was first observed in August 1999 when diatoms, primarily the periphytic form Anomoeonies vitrea, dominated phytoplankton assemblages at Lake Norman locations. This pattern was again observed during August periods of 2000 and 2001. During August of 2002, green algae were dominant, as had been the case in most August periods prior to 1999. These shifts were likely the result of a variety of environmental factors, and not related to station operations. Blue-green algae were slightly more abundant during 2002 than during 2001, however, their contribution to total densities seldom exceeded 2%. 3-9

The most abundant alga, on an annual basis, was the cryptophyte Rhodomonas minuta. Common and abundant diatoms were Tabellariafenestrata in February and November; and Cyclotella stelligera and Fragilariafenestrate in May 2002. The small desmid, Cosmarium asphearosporum var. strigosum was dominant in August 2002. All of these taxa have been common and abundant throughout the Maintenance Monitoring Program. The phytoplankton index (Myxophycean) characterized Lake Norman as oligotrophic during 2002, and was the lowest annual index value recorded. Quarterly index values increased from February to May, then declined through August and November. Quarterly values did not completely reflect seasonal changes in phytoplankton standing crops. Location values tended to reflect increases in phytoplankton standing crops from mid-lake to up-lake. Lake Norman continues to support highly variable and diverse phytoplankton communities. No obvious short term or long term impacts of station operations were observed. LITERATURE CITED Derwort, J. E. 1982. Periphyton, p 279-314. In J. E. Hogan and W. D. Adair (ed.). Lake Norman Summary, vol. II. Duke power Company, Technical Report DUKE PWR/82-

02.

Duke Power

Company, Production Support Department, Production Environmental Services, Huntersville, NC.

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, Charlotte, NC. Duke Power Company. 1989. Lake Norman Maintenance monitoring program: 1988 Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1990. Lake Norman Maintenance monitoring program: 1989 Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1991. Lake Norman Maintenance monitoring program: 1990 Summary. Duke Power Company, Charlotte, NC. 3-10

Duke Power Company. 1992. Lake Norman Maintenance monitoring program: Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1993. Lake Norman Maintenance monitoring program: Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1994. Lake Norman Maintenance monitoring program: Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1995. Lake Norman maintenance monitoring program: summary. Duke Power Company, Charlotte, NC. 1991 1992 1993 1994 Duke Power Company. 1996. Lake Norman maintenance summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1997. Lake Norman maintenance summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1998. Lake Norman maintenance summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1999. Lake Norman maintenance summary. Duke Power Company, Charlotte, NC. Duke Power Company. 2000. Lake Norman maintenance summary. Duke Power Company, Charlotte, NC. Duke Power Company. 2001. Lake Norman maintenance summary. Duke Power Company, Charlotte, NC. Duke Power Company. 2002. Lake Norman maintenance summary. Duke Power Company, Charlotte, NC. monitoring program: monitoring program: monitoring program: monitoring program: monitoring program: monitoring program: monitoring program: 1995 1996 1997 1998 1999 2000 2001 Harris, G. P. 1978. Photosynthesis, productivity and growth: the physiological ecology of phytoplankton. Arch. Hydrobiol. Beih. Ergeb. Limnol. 10: 1-171. Hutchinson, G. E. 1967. A Treatise on Limnology, Vol. II. Introduction to the limnoplankton. John Wiley and Sons, New York, NY. Lee, R. E. 1989. Phycology (2nd. Ed.). Cambridge University Press. 40 West 20th. St., New York, NY. 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, 3-11

Lake Norman, NC. Electric Power Research Institute, Cooling Water Discharge Project (RP-49) Report No. 11. Johns Hopkins Univ., Baltimore MD. North Carolina Department of Environment, Health and Natural Resources, Division of Environmental Management (DEM), Water Quality Section. 1991. 1990 Algal Bloom Report. Nygaard, G. 1949. Hydrological studies of some Danish pond and lakes II. K. danske Vilensk. Selsk. Biol. Skr. 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. Thornton, K. W., B. L. Kimmel, F. E. Payne. 1990. Reservoir Limnology. John Wiley and Sons, Inc. N. Y. 3-12

Table 3-1. Mean chlorophyll a concentrations (ug/1) in composite samples and secchi depths (m) observed in Lake Norman, NC, in 2002. Chlorophyll a Location FEB MAY AUG NOV 2.0 I 5.0 8.0 9.5 11.0 13.0 15.9 69.0 3.16 3.42 3.62 3.84 4.23 3.45 6.33 8.84 1.40 1.58 1.40 1.28 3.12 4.87 5.65 11.75 3.36 3.31 3.20 2.27 5.39 4.33 7.90 16.29 2.03 2.19 2.54 2.27 3.23 4.19 5.50 1.28 Secchi depths Location FEB MAY AUG NOV 2.0 5.0 8.0 9.5 11.0 13.0 15.9 69.0 2.12 1.13 1.71 1.63 1.49 1.14 1.22 1.20 3.95 3.06 3.04 2.97 2.70 2.17 2.27 1.70 3.20 2.44 2.70 2.80 2.32 1.62 2.19 1.10 2.35 2.30 2.25 3.30 2.40 1.95 1.90 0.61 3-13

Table 3-2. Duncan's multiple Range Test on chlorophyll a concentrations in Lake Norman, NC, during 2002. February Location Mean 2.0 3.16 5.0 13.0 8.0 9.5 11.0 15.9 69.0 3.42 3.45 3.62 3.84 4.23 6.33 8.84 May Location Mean 9.5 1.28 2.0 8.0 5.0 11.0 13.0 15.9 69.0 1.40 1.40 1.58 3.12 4.87 5.65 11.75 August Location 9.5 8.0 5.0 2.0 13.0 11.0 15.9 69.0 Mean 5.69 6.00 6.40 6.73 7.37 7.66 8.30 32.57 November Location 69.0 Mean 3.34 2.0 5.0 9.5 8.0 11.0 13.0 15.9 3.46 4.47 4.71 5.72 8.10 8.21 9.54 3-14

Table 3-3. Total mean phytoplankton densities and biovolumes from samples collected in Lake Norman, NC, during 2002. Density (units/ml) Locations Month 2.0 5.0 9.5 11.0 15.9 Mean FEB 1054 1054 1194 1366 1879 1309 MAY 755 851 641 1506 2179 1186 AUG 1687 1458 1130 2688 4850 2363 NOV 621 599 597 954 1783 911 Biovolume (mm3/m3) Locations Month 2.0 5.0 9.5 11.0 15.9 Mean FEB 1026 1054 1194 1366 1879 1304 MAY 277 472 258 704 1232 589 AUG 676 1189 679 1818 3696 1612 NOV 414 584 357 654 1382 678 3-15

Table 3-4. Duncan's multiple Range Test on phytoplankton densities in Lake Norman, NC, during 2002. February Location Mean 2.0 1054 5.0 1054 9.5 1194 11.0 1366 15.9 1879 May Location Mean 9.5 641 2.0 755 5.0 851 August Location Mean 9.5 5.0 2.0 1130 1458 1687 11.0 1506 11.0 2688 15.9 2179 15.9 4850 November Location Mean 9.5 597 5.0 2.0 599 621 11.0 954 15.9 1783 3-16

Table 3-5. Duncan's multiple Range Test on dry and ash free dry weights (mg/L) in Lake Norman, NC during 2002. DRY WEIGHT February Location Mean 2.0 5.0 8.0 9.5 1.82 2.11 2.11 2.35 11.0 2.35 15.9 13.0 69.0 3.37 3.72 7.60 May Location Mean 9.5 2.0 8.0 15.9 0.53 0.82 0.86 1.17 5.0 11.0 13.0 69.0 1.26 1.30 1.67 6.75 August Location Mean 8.0 9.5 5.0 11.0 1.36 1.38 1.51 1.87 2.0 1.93 15.9 13.0 69.0 2.55 2.58 9.02 November Location Mean 8.0 9.5 2.0 15.9 1.10 1.74 1.85 2.20 5.0 2.23 11.0 13.0 69.0 2.55 2.99 13.60 February Location Mean ASH FREE DRY WEIGHT 9.5 15.9 13.0 11.0 2.0 5.0 69.0 8.0 0.10 0.10 0.10 0.10 0.10 0.40 0.58 0.64 May Location Mean 9.5 8.0 15.9 11.0 2.0 13.0 5.0 69.0 0.23 0.27 0.29 0.39 0.40 0.44 0.53 1.46 August Location 5.0 8.0 9.5 11.0 13.0 2.0 15.9 69.0 Mean 0.76 0.82 0.82 1.03 1.07 1.12 1.27 2.96 November Location Mean 5.0 2.0 8.0 9.5 15.9 11.0 13.0 69.0 0.32 0.32 0.35 0.41 0.64 0.64 0.82 2.53 3-17

Table 3-6. Phytoplankton taxa identified in quarterly samples collected in Lake Norman from February 1988 to November 2002. TAXON 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 CLASS: CHLOROPHYCEAE Acanthosphaerazachariasi Lemm. = X X X = = = = Actidesmium hookeri Reinsch X Actinastrum hantzchli Lagerheim X X X X X X X Ankistrodesmus braunii (Naeg) Brunn _X X X X X X X X A. convolutus Corda X A.falcatus (Corda) Ralfs X X X X X X X X X X X X X X X A.fusiformis Corda sensu Korsch. = X X X X X X A. nannoselene Skuja X A. spiralis (Turner) Lemm. X X X X X = X I _ I I A. spp. Corda X I X I Arthrodesmus convergens Ehrenberg X X A. incus (Breb.) Hassall X X X X X A. octocornis X A. subulatus Kutzing _X X X X X X A. spp. Ehrenberg X X I I Asterococcus limneticus G. M. Snith X X X X X X X Botryococcus braunii Kutzing = = = X X = = Carterlafrtzschii Takeda X = = = = = = = = = = X = C. globosa X C. spp. Diesing X X X X X I X Characium spp. Braun X Chlamydomonas spp. Ehrenberg X X X X X X X X X X X X X X X ChMorella vulgaris Beyerink= X Chlorogonium euchlorum Ehrenberg X I I X X X C spirale Scherffel & Pascher X X Closteriopsis longissima W. & W. X X X X X X X X X X X X X X X Closterium cornu Ehrenberg IX = = X C gracile Brebisson X C incurvum Brebisson X X X X X X X X X X C. tumidum Johnson X C spp. Nitzsch X X X X Coccomonas orbicularis Stein X X Coelastrum cambricum Archer X X X X X X X X X X X X X X X C microporum Nageli X X X X C reticulatum (Dang.) Sinn. I X = C. sphaericum Nageli I=X X X X =X=X X X X C. proboscideum Bohlin X C spp. Nageli = = X X = Cosmarium angulosum v. concin. (Rab) W&W X X C asphaerosporum v. strigosum Nord. X X X X X X X X X X X X X X X C contractum Kirchner X I X X X X X X X X X C. moniliforme (Turp.) Ralfs =X = = C phaseolus f. minor Boldt. X X X 3-18

Table 3-6 (continued). Paize 2 of 9 TAXON 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 C pokornyanum (Grun.) W. & G.S. West X C polygonum (Nag.) Archer X X X X X X X X C. raciborskii =_- X C regnellii Wille X X X X X X X X C regnesi Schmidle = X X X - = X C subreniforme x C tenue Archer X X X X X X X XX C tinctum Ralfs X X X X X X X X X X X C tinctum v. subretusum Messik.

=

X C tinctum v. tumidum Borge. X X X X X C trilobatum v. depressum

==X C tumidum

== X C spp. Corda X X X X X XX

Crucigenia apiculata X Crucigenia crucifera (Wolle) Collins X X X X X X X X X X X Cfenestrata Schmidle = = X

=

X C. irregularis Wille X = X X X X X = X = X C rectangularis (A. Braun) Gay X C*tetrapedia (Kirch.) West & West X X X X X X X X X X X X X X X Dictyospaerium ehrenbergianum Nageli X = = = X X X D. pulchellum Wood X X X X X X X X X X X X X X X Dimorphococcus spp. Braun X =- Elakatothrix gelatinosa Wille X X X X X X X X X X X X X X X Errerella bornheimiensis X Euastrum ansatum v. dideltiforme X E. binale X E. denticulatum (Kirch.) Gay X X X X X X X X E. spp. Ehrenberg X X X X Eudorina elegans Ehrenberg X -X X Franceia droescheri (Lernm.) G. M. Sm. X X X X X X X X X F. ovalis (France) Lernum. X X X X X X X X _X X Gloeocystis botryoides (Kutz.) Nageli x G. gigas Kutzing X X X X X X X X G. major Genmeck ex. Lemnermann X G. planktonica (West & West) Lernm. X X X X X X X X X X X X X X G. vesciculosa Naegeli X X G. spp. Nageli XXXXXXX = = = = = Golenkinia paucispina West & West X = = = = X G. radiata Chodat X X X X X X X X X X X X X X X Gonium pectorale Mueller X =__ X G. sociale (Duj.) Warming X = = = = = X X X X Kirchneriella contorta (Schrnidle) Bohlin X X X X X X X X X K. elongata G.M. Snith X K. lunaris (Kirch.) Mobius X X X = = K lunaris v. dianae Bohlin I X X __ X K lunaris v. irregularis G.M. Smith = I I I I X = = 3-19

Table 3-6 (continued) mpae 3 of 9 TAXON 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 K. obesa W. West X X X X X X X K. subsolitaria G. S. West X X X X X X X X K. spp. Schnidle X = -= X X X =_ X Lagerheimia ciliata (Lag.) Chodat X L. citriformis (Snow) G. M. Smith = = = X = = = = L. longiseta (Lemnnernann) Printz X L. quadriseta (Lemrm.) G. M. Smith = X X X X = = L. subsala Leirnmernan X X X X X X X X X X X Mesostigma viride Lauterbo=e X X X X X X X = X Micractinium pusillum Fresen. X X X X X X X X X X X X X X X Monoraphidium contortum Thuret X X X X X X M. pusillum Printz X X X X X X Mougeitia elegantula Whittrock X X X X X X X X X M. spp. Agardh X X X X Nephrocytium agardhianum Nageli X X _X N. limneticum (G.M. Smith) G.M. Smith X X X Oocystis borgii Snow

== X X X = X O. ellyptica W. West X X X

0. lacustris Chodat X

O. parva West & West X X X X X X X XX X X O. pusilla Hansgirg X X X X X X X X X X X X

0. pyriformis Prescott

== X =__ X

0. spp. Nageli X

Pandorina charkowiensis Kprshikov P. morum Bory X X XX Pediastrum biradiatum Meyen P. duplex Meyen X X X X X X X = X X X P. clatheatum ___X P. duplex v. gracillimum West and West=- X X = X P. tetras v. tetroadon (Corda) Rabenhorst X X X X X X X X X X X X X X X P. spp. Meyen X X Planktosphaeria gelatinosa G. M. Smith XX X X Quadrigula closterioides (Bohlin) Printz X = X X X X Q. lacustris (Chodat) G. M. Srnith X X Scenedesmus abundans (Kirchner) Chodat X X X = = = = S. abundans v. asymetrica (Schr.) G. Sm. X X X X X X X X X = = X S. abundans v. brevicauda G. M. Smith X S. acuminatus (Lagerheim) Chodat X X X X X X X X X X S. armatus v. bicaudatus (Gug.-Pr..)Chod X X X X X X X X X X X X X X S. bijuga (Turp.) Lagerheim X X X X X X X X X X X X X S. bijuga v. alterans (Reinsch) Hansg. I S. brasiliensis Bohlin X X X X X X X X S. denticulaws Lagerheim X X X X X X X X X X X X X X S. dimorphus (Turp.) Kutzing X X X X X X X = X S. incrassulatus G. M. Smith S. quadricauda (Turp.) Brebisson I X X X X X X X X X X X X X X S. smithii Teiling IX IX 3-20

Table 3-6 (continued) page 40of9 TAXON 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 S. spp. Meyen X X X X X X Scheochlamys compacta Prescott X X X X S. gelatinosa A. Braun X X Schoederia setigera (Schroed.) Lefmi X-X Selenastrum gracile Reinsch X X X S. minutum (Nageli) Collins X X X X X X X X X X X X X X X S. westi G. M. Smith X = = X = = XX XX = = X Sorastrum americanum (Bohlin) Schri. X Sphaerocystis schoeteri Chodat X X = = = X X X X X Sphaerozosma granulatum Roy & BL. X Stauastrum americanum (W&W) G.Srn X = = = = X X X X X X X X S. apiculatum Brebisson X X X X X S. brachiatum Ralfs X X X X S. brevispinum Brebisson X S. chaetocerus (Schoed.) G. M. Smith = = X S. curvatum W. West X X X X X X X X X X X X X S. cuspidatum Brebisson X X X X X X S. dejectum Brebisson X X X X X X S. dickeii v. maximum West & West X

=

S. dickeii v. rhomboidium X S. gladiosum TurnerX S. leptocladum v. sinuatum Wolle X S. manfeldtii v.fluminense Schunacher X = X X X X X X X X S. megacanthum Lundell X X X =_= S. ophiura v. cambricum (Lund) W. & W. = = = = = = = X = S. orbiculame Ralfs X X S. paradoxum Meyen X x X X X X X S. paradoxum v. cingulum West & West__ S. paradoxum v. parvum W. West = = = = = = =

= X = = = X S. pentacerum

= = = = =

X S. subcrucialum Cook & Wille X X X X X X S. tetracerum Ralfs X X X X X X X X X X X X X X _X S. turgescens de Not. X = = = = = =

= = = = = = S. vestitum X S. spp. Meyen X X X X Stichococcus scopulinus X Stigeoclonium spp. Kutzing X Tetraedron arthrodesmiforme X Tetraedron bifurcatum v. minor Prescott X T. caudatum(Corda)Hansgirg X X X = X = X X X X X X X X T. limneticum Borge X T. lobulatum (Naeg.) Hansgirg

_

X T. lobulatum v. crassum Prescott = = = = X T minmum (Braun) Hansgirg X X X XX X X X X X X T muticum (Braun) Hansgirg X = X X X X X X X T. obesum (W & W) Wille ex Brunnthaler X 3-21

_t. t_ - I __.!_ _ tw ____ r _rn I able 3-6 tcontinued) pa e of Y TAXON 88 89 90 91 92 93 94 95 96 97 98 99 °° 0 l1 02 T. pentaedricum West & West = X X T. planktonicum G. M. Srnith X X X T. regulare Kutzing X X X X T. regulare v. bifurcatum Wille = = = = -= X = = T. regulare v. incus Teiling X X X T. trigonum (Nageli) Hansgirg X I X X X X X X X X X T. trigonum v. gracile (Reinsch) DeToni X X X T. spp. Kutzing X X X Tetrallantos lagerheimi= Tetraspora lamellosa Prescott X T. spp. Link X X Tetrastrum heteracanthum (Nor.) Chod. X = = = = = = X Treubaria setigerum (Archer) G. M. Sm. X X X X X X X X X X X X X X X W~estella botryoides (W. & W.) Wilde. = X X W linearis G. M. Smith X =X Xanthidium critatatum v. uncinatum X X. spp. Ehrenberg X __X CLASS: BACILLARIOPHYCEAE Achnanthes lanceolata X A. microcephala Kutzing X X X X X X X X X A. spp. Bory X X X X XX I X Amphiphora ornata = X Anomoeoneis vitrea (Grunow) Ross X X X X X X X X X X A. spp. Pfitzer X Asterionella formosa Hassall X X X X X 7 X X X X X X X X Attheya zachariasi J. Bnrn X X X X X X X X X X X X X X Cocconeis placentula Ehrenberg X = = = X X =__ C spp. Ehrenberg = X Cyclotella comta (Ehrenberg) Kutzing X X X X X X X X X C. glomerata Bachmann X X XX X C. meneghiniana Kutzing X X X X X X X X X = X C pseudostelligera Hustedt + C stelligera Cleve & Grunow X = X X X X X X X X X X X X C. spp. Kutzing X X X Cymbella affinis Kutzing X C. minuta (Bliesch & Rabn.) Reim = 7 X x X X X = X C tumida (Breb.) van Huerck X C turgida (Gregory) Cleve X C spp. Agardh X X Denticula elegans D. thermalis Kutzing X X Diploneis spp. Ehrenberg X Eunotia flexuosa v. eurycephala Grun. X E. zasuminensis (Cab.) Koerner X X X X X X X X X X 7 X Fragilaria crotonensis Kitton X X X X X X X X X X X X X X 3-22

____ r _rn -I able ) tcontlnued) _pae of TAXON 88 89 90 91 92 93 94 95 96 97 98 99 o0 01 02 Frustulia rhomboides (Ehr.) de Toni X Gomphonema angustatum X G. parvulum

_

X G. spp. Agardh X X_ Melosira ambigua (Grnm.) 0. Muller X X X X X X X X X X X X X X X M. distans (Her.) Kutzig X X X X X X X X X X X X X X X M. granulata (Ehr.) Ralfs X X X X M. granulata v. angustissima 0. Muller X X X X X X X X X X X X X X X M. italica (Ehr.) Kutzing X = = _ = = = = = = = = = M. varians Agardh X X X M. spp. Agardh X X X X X X X X X X X Meridion circulare X Navicula cryptocephala Kutzing = = X X X X N. exigua (Gregory) 0. Muller X

=

X N. exigua v. capitata Patrick X N. subtilissima Cleve X X N. spp. Bory X X X X X X Nitzschia acicularis W. Srnith X X X X X X X X X X X X Nagnzita Hustedt X X X X X X X X X X X X X X X N. holsatica Hustedt X X X X X X X X X X X N. linearis W. Smith X N. palea (Kutzing) W. Smith X X X X X X X N. sublinearis Hustedt X X X X N. spp. Hassall X X X 7X X X Pinnularia spp. Ehrenberg X X Rhizosolenia spp. Ehrenberg X X X X X X X X X X X X X X X Skeletonema potemos (Weber) Hilse X X X X X X X X X Stephanodiscus spp. Ehrenberg X X X X X X X X X X X Surirella linearis v. constricta (Ehr.) GrO. X Synedra actinastroides Lemnmerman X S. acus Kutzing X X X X X = X S. delicatissima Lewis X X X S. filiforimis v. exilis Cleve-Euler

===X = X X X S. plankonicaEhrenberg X X X X X X X X X X X X X X X S. rumpens Kutzing X X X X X X X X X S. rumpens v.fragilarioides Grunow X S. rumpens v. scotica Grunow X

=

S. ulna (Nitzsch) Ehrenberg X X - X X X X X X X S. spp. Ehrenberg X X X X X X X Tabellariafenestrata (Lyngb) Kutzing X X X X X X X X X X X X X X X T flocculosa (Roth.) Kutzing X X X X CLASS: CHRYSOPHYCEAE Aulomonas purdyii Lackey X X X X X X X X X Bicoeca petiolatum (Stien) Pringsheim X X Calycomonas pascheri (Van Goor) Lund X X-Chromulina spp. Chien. X = = X X 3-23

s s t / j-1\\ ___ x _rrs Table 3-6 (continued) pa Ye 7 o Y TAXON 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 Chrysosphaerella solitaria Lauterb. = = = X X X X X X X X X X X X Codomonas annulata Lackey X X X X X X Dinobryon bavaricum Imhof X X X X X X X X X X X X X X X D. cylindricum Imhof X X X X X X X X D. divergens Imhof = X X = X X X XX X= X = X D. sertularia Ehrenberg X X X D. spp. Ehrenberg X X X X X X X X X X X X Domatomococcus cylindricum Lackey X X = Erkinia subaeguicilliata Skuja X X X X X X X X X X X X Kephyrion littorale Lund X X K. rubi-claustri Conrad X _ X K. skuJae Ettl X K spp. Pascher X X X X X X X X X X X X X X Mallomonas acaroides Perty X M. akrokomos (Naumann) Krieger X-X X X M. alpina Pascher X X M. caudata Conrad X X X X X X X X X X X M. globosa Schiller X X X X X M. producta Iwanoff X X M. pseudocoronata Prescott X X X X X X X X X X X X X X X M. tonsurata Teiling X X X X X X X X X X X X X X X M. spp. Perty X X X X X X X X Ochromonas granularis Doflein =X X X XX

0. mutabilis Klebs X

0. spp.Wyss X

X = X X X X X X-X XX Pseudokephyrion schilleri Conrad X X X X P. tintinabulum Conrad X Rhizochrisis polymorpha Naumann = = X X X X R. spp. Pascher X = X = = = = = = = = = = Salpingoecafrequentissima (Zach.) Lem. X X X Stelexomonas dichotoma Lackey X X X X X X X X X X X X X Stokesiella epipyxis Pascher X X X Synura spinosa Korschikov X X X X X X X X X X S. uvella Ehrenberg X X X X X X X = S. spp. Ehrenberg X X X X X X Uroglenopsis americana (Caulk.) Lemm. X XX__ = = = = CLASS: HAPTOPHYCEAE Chrysochromulina parva Lackey X X X X X X X X X X X X X X X CLASS: XANTHOPHYCEAE Characiopsis dubia Pascher X X X X X X X Dichotomococcus curvata Korschikov Ophiocytium caoitatum v. Iongisp. (M) L. X X CLASS: CRYPTOPHYCEAE I Cryptomonas erosa Ehrenberg X X X X X X X X X X X X X X X 3-24

'roUl,- 1-4 "~"- R ^(f4 Alp 23W tWAnJI IILILUSU) ,u o l Ul TAXON 88 89 90 91 92 93 94 95 96 97 98 99 000 1 02 C erosa v. reflexa Marsson = = X = X X X X X C. gracilia Skuja X C. marsonii Skuja X X X X X X C ovala Ehrenberg X X X X X X X X X X X X X X X

• phaseolus Skuja X

X X X X X C. reflexa Skuja X X X X X X X X X X X X X X X C. spp. Ehrenberg X X X X X X Rhodomonas minuta Skuja X X X X X X X X X X X X X X X CLASS: MYXOPHYCEAE Agmenellum quadriduplicatum Brebisson X X X X X X X X X X Anabaena catenula (Kutzing) Bom. X = = = = X X A. inaegualis (Kutz.) Born. =X = A. scheremetievi Elenkin X X X X A. wisconsinense Prescott X-X X X X X X X X A. spp. Bory X X X X X X X X X X X Anacystis incerta (Lemn.) Druet & Daily X X X X XX X= X X X A. spp. Meneghini Chroococcus dispersus (Keissl.) Lemnm. X X C limneticus Lemrnerneann X X X X X X X X C. minor Kutzing

==_ X C turgidus (Kutz.) Lernmermann X X C. spp. Nageli X X X X X X X X X X X X X X Coelosphaerium kuetzingiana Nageli X Dactylococcopsis irregularis Hansgirg X X X D. rupestris Hansgirg X D. smithii Chodat and Chodat X X X D. spp. Hansgirg

=

X Gomphospaeria lacustris Chodat X X X X X X X Lyngbya contorta Lenmmermann X X L. limnetica Leurrnemann X X X X X X L. ochracea (Kutz.) Thuret X X L. subtilis W. West = X X X X X L. spp. Agardh X X X X X X X X X X X X X X X Merismopedia tenuissima Lenrmermann X Microcystis aeruginosa Kutz. emend Elen. = X X X X X X X X X X X X Oscillatoria amphibian X ._X

0. geminata Meneghini X

= X X X X X X X X X

0. limnetica Lernrnerrnann X

= = = X X X X X X X X

0. splendida Greville X

X X X

0. subtilissima Kutz.

X

=

X X X O. spp. Vaucher X X X

== X = Phormidium anguslissimum West & West X X X X P. spp. Kutzing X X X X X X Raphidiopsis curvata Fritsch & Rich X X X X XX X X X R. mediterranea Skuja X I 3-25

Table 3-6 (continued) image 9 of 9 TAXON 88 89 90 91 92 93 94 95 96 97 98 99 o0 01 02 Rhabdoderma sigmoidea Schm. & Lautrb. X Spirulina subsala X Synecococcus lineare (Sch. & Lt.) Kom. X X X X X X X X X X X = CLASS: EUGLENOPHYCEAE Euglena acus Ehrenberg X X E. minuta Prescott X X X E. polymorpha Dangeard X = X X E. spp. Ehrenberg X X X X X X X X X X X Lepocinelus ovum (Ehr.) Lemm. = X L. spp. Perty X X

== Phacus cuvicauda Swirenko X P. longicauda (Ehr.) Dujardin x=_ X P. orbicularis Hubner X P. tortus (Lemm.) Skvortzow X X X P. spp. Dujardin = X = Trachelomonas acanthostoma (Stk.) Detl. X X T. hispida (Perty) Stein X X X X X T. pulcherrima Playfair X T. volvocina Ehrenberg X XX T. spp. Ehrenberg X X X CLASS: DINOPHYCEAE Ceratium hirundinella (OFM) Schrank X X X X X X X X X X = Glenodinium borgei (Lernrn.) Schiller X X G. gymnodinium Penard = X X X X X = X G. palustre (Lenrm.) Schiller G. penardiforme (linde.) Schiller X X G. quadridens (Stein) Schiller = X X G. spp. (Ehrenberg) Stein X X Gymnodinium aeruginosum Stein X X X G. spp. (Stein) Kofoid & Swezy X X X X X X = X X = X X X Peridinium aciculiferum Lenrmerniann X = = = = = = = = P. inconspicuum Lemmernann X X X X X X X X X X X X X X X P. cinctum x P. intermedium Playfair XX X X X P. pusillum (Lenard) Lenrnermann X X X X X X X X X X X X X X X P. umbonatum Stein X X X P. wisconsinense Eddy X X X X X X X X X X X X X X P. spp. Ehrenberg XX X X X CLASS: CHLOROMONADOPHYCEAE Gonyostomum depresseum Lauterbome X X X X X G. semen (Ehrenberg) Diesing X G. spp. DiesingX X X 3-26

Table 3-7. Dominant classes their most abundant species, and their percent composition (in parenthesis) at Lake Norman locations during each sampling period of 2002. LOC FEBRUARY MAY 2.0 BACILLARIOPHYCEAE (51.7) BACILLARIOPHYCEAE (46.2) Taballariafenestrata (27.8) Cyclotella stelligera (32.4) 5.0 BACILLARIOPHYCEAE (49.0) BACILLARIOPHYCEAE (52.9) T fenestrata (23.6) C stelligera (33.6) 9.5 BACILLARIOPHYCEAE (52.3) BACILLARIOPHYCEAE (46.9) T. fenestrata (22.8) C stelligera (33.8) 11.0 CRYPTOPHYCEAE (56.0) BACILLARIOPHYCEAE (56.4) Rhodomonas minuta (50.4) Fragilaria crotonensis (27.1) 15.9 CRYPTOPHYCEAE (71.2) BACILLARIOPHYCEAE (55.5) R. minumta (67.2) F. crotonensis (32.4) AUGUST NOVEMBER 2.0 CHLOROPHYCEAE (53.0) BACILLARIOPHYCEAE (41.0) Cosmarium asphear. strig. (29.5) C stelligera (7.4) 5.0 CHLOROPHYCEAE (65.7) BACILLARIOPHYCEAE (58.9) C asphearosporum strig. (35.4) T. fenestrata (19.4) 9.5 CHLOROPHYCEAE (69.9) BACILLARIOPHYCEAE (54.4) C. asphearosporum strig. (29.8) T. fenestrata (8.7) 11.0 CHLOROPHYCEAE (65.3) BACILLARIOPHYCEAE (47.1) C asphearosporum strig. (35.3) T.fenetrata (16.8) 15.9 CHLOROPHYCEAE (47.5) BACILLARIOPHYCEAE (42.2) C asphearosporum strig. (28.5) T. fenestrata (10.3) 3-27

SESTON DRY WEIGHT (mg/i) 16 12 -------------------- 4 ----------- /, 20-2.0 5.0 8.0 9.5 11.0 13.0 15.9 69.0 LOCATIONS BIOVOLUME (mm3lm3) 4000 3000 -- -- --- --- - -- -- - -- - -- A--- 2500.---------- 2000 -. i. 1500 -- 1000 0 2.0 5.0 9.5 11.0 15.9 LOCATIONS Figure 3-1. Phytoplankton chlorophyll a, densities, and biovolumes; and seston weights at locations in Lake Norman, NC, in February, May, August, and November 2002. 3-28

14 12 10 -j C-0 non 6 0 -j 0 4a 2.. 0-FEB MAY AUG MONTH + 1987 + 1988 -Ah 1989 -- X-1990 -*---1991 - - -1992 1 1993 1994 -e 1995 1996 1997 --0-- 1998 -&--1999 ---*-2000 --{-2001 -- e-2002 NOV Figure 3-2. Phytoplankton chlorophyll a annual lake means from all locations in Lake Norman, NC, for each quarter since August 1987. 3-29

CHLOROPHYLL a (ugh) 12-10 - a8-8 4-2- (1. FEBRUARY F+4--2.0 --W-5.0 MLLG O E........... .........1 ..... \\...

---

~~~~~~~~~~~~~~~~~~~~~~~~~~~~

MAY -_-2.0 5.0 12 MIXNG ZONt 10-87 88 89 90 91 92 93 94 95 96 97 98 99 0o 01 02 -+-8.0 --- 9.51 I 788 09 9 9 I I. 9 1 197 88 89 90 91 92 93 94 95 96 97 ss 99 oo 01 02 8.0 s.s 20 15 10 5 0 1 11 12 - 10o - - - a j - - - - 4 4 - -- - 8788899091 9293 94 95969798990001 02 8788899091 92939495969798990001 02 16 14 12 10 8 6 4 2 0 1---11.0 -13.0 1 l 1-- Lt----.--. 1--11.o -- 13. 30. 25 -------------------------- A------------ 15 ---------------------- --- 10 5 -- 87 89 91 93 95 97 99 01 87 89 91 93 95 97 99 01 - 15.9 69.0 15.9 -- 69. 16. 14 12 10 8 6 4. 2 I 25 20 15 10~ 5 I-oI l .....T I. 87 89 91 93 95 97 99 01 YEARS 87 89 91 93 95 97 99 01 YEARS Figure 3-3. Phytoplankton chlorophyll a concentrations by location for samples collected in Lake Norman, NC, from August 1987 through November 2002. 3-30

CHLOROPHYLL a (ugfl) AUGUST +42.0 5.0 NOVEMBER 4-2.0 -65.0l 10 8 6 41 MDaNG ZONE 10-8 6 4; --- UIXINGZNE------E 2~ +---.-.------------------------------------- z,p -- - - -- - - -- - - -- - - -- - - - 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 +-8.0 9.5 16 2 - 4 1 02..---------------- 878889909192939495969798990001 02 1-4-11.0 -- 13.01 8788899091 92939495969798990001 02 1-4-8.0 -- 9.5 14 12 - 8 0 ------------------------ - 14 -~ 2 - -Y o I. I I 8788899091 9293995969798990001 02 1-_-11.0 -- 13.01 14. 1t2 10 1I 1 6 i --- 4 1 14 12-10-8- 6-42 2 I------------- 87888990919293945 969798990001 02 4-15.9 - 669.01 8788899Ot 9293 95697 99 00 0102 15.9 -_-69.01 35. 30 25 20-15-10-5. n -- :
' 25 20 15 10 5 0 8.

77.

87 88e9 90 919293 94 959697 9899 00 0102 YEARS 8788899091929349496979899000102 YEARS Figure 3-3 (continued). 3-31

LOC. 2.0 3000 2500 Z 2000 0 1500 1000 500n-- 0 FEB MAY AUG NOV LOC. 2.0 4000 3500 3000

E 2500 drn 2000 0

8* 1500 1000 500 0 FEB MAY AUG NOV Figure 3-4. Class composition (mean density and biovolume) of phytoplankton from euphotic zone samples collected at Location 2.0 in Lake Norman, NC, during 2002. 3-32

LOC. 5.0 E 30 2500 Z 2000 1500 1000 500 0 FEB MAY AUG NOV LOC. akn 4000 3500 3000-AE 2500 E W 2000 100 >15000 0-FEB MAY AUG NOV Figure 3-5. Class composition (mean density and biovolume) of phytoplankton from euphotic zone samples collected at Location 5.0 in Lake Norman, NC, during 2002. 3-33

LOC. 9.5 so0o O CHLOROPHYCEAE 19 BACILLARIOPHYCEAE 4500 O CHRYSOPHYCEAE E CRYPTOPHYCEAE 4000 O~l MYXOPHYCEAE EDINOPHYCEAE

• OTHERS 3500 E 3000 2500 2000 1500 1000 500 0

FEB MAY AUG NOV 4000 3500 3000 E 2500 E as 2000 0 >1500 £.0,In 1000 500 0 FEB MAY AUG NOV Figure 3-6. Class composition (mean density and biovolume) of phytoplankton from euphotic zone samples collected at Location 9.5 in Lake Norman, NC, during 2002. 3-34

Figure 3-7. Class composition (mean density and biovolume) of phytoplankton from euphotic zone samples collected at Location 11.0 in Lake Norman, NC, during 2002 3-35

LOC. 15.9 6000 - OCHLOROPHYCEAE tgBACILLARIOPHYCEAE s500-mCHRYSOPHYCEAE B CRYPTOPHYCEAE 0 MYXOPHYCEAE D DINOPHYCEAE 5000 = OTHERS 4500 4000 3500 C ~ ~ 3000 E 2500 'U 02X 0_L I __= 1500-1000-_ 500-FEB MAY AUG NOV 4000 3500 3000 E2500-E -E 'U 2000-0 Figure 3-8. Class composition (density and biovolume) of phytoplankton from euphotic zone samples collected at Location 15.9 in Lake Norman, NC, during 2002. 3-36

MYXOPHYCEAN INDEX: LAKE NORMAN 1.8 1.7 1.6. 1.5 HIGH 1.4 1.3 _NTLKMWLATL 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 YEARS w 5.00 4.00 3.00 2.00 1.00 nn a m67 FEB MAY AUG NOV MONTH 1.2 1.1 1.0 09 0.8 0.7 0.4 0.2 0.1 2 5 9.5 11 15.9 LOCATIONS Figure 3-9. Myxophycean index values by year (top), each quarter in 2002 (mid), and each location in Lake Norman, NC, during 2002. 3-37

CHAPTER 4 ZOOPLANKION INTRODUCTION The objectives of the Lake Norman Maintenance Monitoring Program for zooplankton are to:

1. Describe and characterize quarterly patterns of zooplankton standing crops at selected locations on Lake Norman; and

2. compare and evaluate zooplankton data collected during this study (February, May, August, and November 2002) with historical data collected during the period 1987-2001.

Previous studies of Lake Norman zooplankton populations have demonstrated a bimodal seasonal distribution with highest values generally occurring in the 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 1976, 1985; Hamme 1982; Menhinick and Jensen 1974). METHODS AND MATERIALS Duplicate 10 m to surface and bottom to surface net tows were taken at Locations 2.0, 5.0, 9.5, 11.0, and 15.9 in Lake Norman (Chapter 2, Figure 2-1) on 4 February, 6 May, 5 August, and 4 November 2002 (Note: Samples from Location 5.0 in November were not counted due to loss of preservative). For discussion purposes the 10 m to surface tow samples are called epilimnetic samples and the bottom to surface net tow samples are called 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 laboratory methods for zooplankton standing crop analysis were the same as those reported in Hamme (1982). Zooplankton standing crop data from 2002 were compared with corresponding data from quarterly monitoring begun in August 1987. A one way ANOVA was performed on epilimnetic total zooplankton densities by quarter. This was followed by a Duncan's Multiple Range Test to determine which location means were significantly different. 4-1

RESULTS AND DISCUSSION Total Abundance During 2002, typical seasonal variability was observed in epilimnetic samples. Maximum epilimnetic densities were highest in May at all locations (Table 4-1, Figure 4-1). The lowest epilimnetic densities at Locations 5.0, 9.5, and 11.0 occurred in February, while annual minimum densities at Locations 2.0 and 15.9 were observed in November. Epilimnetic densities ranged from a low of 16,585/m3 at Location 5.0 in February, to a high of 578,166/m3 at Location 15.9 in May. This maximum was the highest zooplankton density yet observed during the Program. Maximum densities in the whole column samples were also observed in May, while minimum whole column densities were observed at Locations 2.0, 5.0, and 9.5 in February, and at Locations 11.0 and 15.9 in August. Whole column densities ranged from 12,819/m3 at Location 5.0 in February, to 280,769/m3 at Location 15.9 in May. Historically, maximum epilimnetic zooplankton densities at Lake Norman locations have most often been observed in May, with annual peaks observed in February about 25% of the time. Annual maxima have only occasionally been recorded for August and November. Total zooplankton densities were most often higher in epilimnetic samples than in whole column samples during 2002, as has been the case in previous years (Duke Power 2002). This is related to the ability of zooplankton to orient vertically in the water column in response to physical and chemical gradients and the distribution of food sources, primarily phytoplankton, which are generally most abundant in the euphotic zone (Hutchinson 1967). Although spatial distribution varied among locations from season to season, a general pattern of increasing values from Mixing Zone to Background locations was observed during 2002 (Tables 4-1 and 4-2, Figures 4-1 and 4-4). Location 15.9, the uppermost location, had significantly higher densities than Mixing Zone locations in February and May, while Location 11.0 had significantly higher values than Mixing Zone locations in August and November (Table 4-2). In most previous years of the Program, Background Locations had higher mean densities than Mixing Zone locations (Duke Power 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002). 4-2

Historically, both seasonal and spatial variability among epilimnetic zooplankton densities had been much higher among Background Locations than among Mixing Zone locations. The uppermost location, 15.9, showed the greatest range of densities during 2002 (Table 4-1, Figures 4-2 and 4-3). Apparently epilimnetic zooplankton communities are more greatly influenced by environmental conditions at the up-lake locations than at the down-lake locations. Location 15.9 represents the transition zone between river and reservoir where populations would be expected to fluctuate due to the dynamic nature of this region of Lake Norman. At the locations nearest the dam (Locations 2.0 and 5.0), seasonal variations are dampened and the overall production would be lower due to the relative stability of this area (Thornton, et al. 1990). A similar trend was observed in the phytoplankton communities (Chapter 3). Several records were set among epilimnetic densities during 2002. In fact, the only quarter when densities were within seasonal ranges was August (Figure 4-3). During February 2002, the lowest long term densities ever recorded occurred at Locations 2.0 and 5.0. Locations 5.0, 11.0, and 15.9 experienced record high epilimnetic densities for May during 2002, while a record low density for November was observed at Location 15.9. These record high and low densities were likely responses to short term changes in phytoplankton concentrations and availability, as well as environmental conditions such as low inputs due to the long term drought. The highest February densities recorded during the Program at Locations 5.0 and 9.5 occurred in 1995, while Locations 2.0 and 11.0 experienced February maxima in 1996 (Figure 4-2). The long term February maximum at Location 15.9 was observed in 1992. Long term maximum densities for May occurred at Locations 2.0 and 9.5 in 2000, while the highest May values at Locations 5.0, 11.0, and 15.9 occurred in May 2002. Long term August maxima occurred in 1988 at all but Location 15.9, which had its highest August value in 1996 (Figure 4-3). November long term maxima at Locations 2.0 through 9.5 occurred in 1988, and at Locations 11.0 and 15.9 in November 1999. Since 1990, the densities at Mixing Zone Locations in May, August, and November have not fluctuated much between years, while year-to-year fluctuations in densities during February have occasionally been quite substantial, particularly between 1991 and 1997. The Background Locations continue to exhibit considerable year-to-year variability in all seasons (Figures 4-2 and 4-3). 4-3

Community Composition One hundred and nine zooplankton taxa have been identified since the Lake Norman Maintenance Monitoring Program began in August 1987 (Table 4-3). Fifty-one taxa were identified during 2002, as compared to forty-six taxa recorded during 2001 (Duke Power 2002). One previously unreported taxon, the rotifer Platyiapatulus vas identified in 2002. Copepods, which were most often dominant during 2001, showed a significant decline in relative abundance during 2002. These microcrustaceans were dominant only during August in samples collected at all but Location 9.5, where cladocerans were most abundant (Table 4-1, Figures 4-4 and 4-5). Rotifers dominated zooplankton densities at all locations during the other three sampling periods of 2002. During most years of the Program, microcrustaceans dominated Mixing Zone samples, but were considerably less important among Background Locations (Figures 4-6 through 4-8). From 1995 through 1998, a trend of increasing relative abundance among microcrustaceans was observed throughout Lake Norman. Since 2000, this trend has reversed, with a subsequent increase in relative abundances of rotifers to the extent that taxonomic composition in 2002 was similar to that found during years prior to 1995. Copepoda Copepod populations were consistently dominated by immature forms (primarily nauplii) during 2002, as has always been the case. Adult copepods rarely constituted more than 8% of the total zooplankton density at any location. Tropocyclops and Epischura were the most important constituents of adult populations in epilimnetic samples, while Tropocyclops and Mesocyclops were principal components of adult populations in whole column samples (Table 4-4). Copepods tended to be more abundant, if not dominant, at Background Locations than at Mixing Zone Locations during 2002, and their densities peaked in May at both Mixing Zone and Background Locations. Copepods showed similar spatial and seasonal trends during 2001 (Table 4-1, Figure 4-5). Historically, maximum copepod densities were most often observed in May. 4-4

Cladocera Bosmina was the most abundant cladoceran observed in 2002 samples, as has been the case in most previous studies (Duke Power 2002, Hamme 1982). Bosmina often comprised greater than 5% of the total zooplankton densities in both epilimnetic and whole column samples, and was the dominant zooplankter in several samples from February and November (Table 4-4). Bosminopsis was also important among cladocerans in August when it dominated cladoceran populations at most locations. Bosminopsis expressed lower dominance during August 2002 as compared to August 2001. During May, Daphnia dominated cladoceran populations at Location 9.5, while Diaphanosoma was the dominant cladoceran in whole column samples from Location 2.0. Similar patterns of Daphnia-Bosminopsis dominance have been observed in past years of the Program (Duke Power 2002). Long-term seasonal trends of cladoceran densities were variable: From 1990 to 1993, peak densities occurred in February; while in 1994, 1995, 1997, and 2000, maxima were recorded in May (Figure 4-5). During 1996 and 1999, peak cladoceran densities occurred in May in the Mixing Zone, and in August among Background Locations. Maximum cladoceran densities in 1998 occurred in August. In 2001, maximum cladoceran densities in the Mixing Zone occurred in February, while Background locations showed peaks in November. The pattern observed in 2002 was the same as in 1996 and 1999. Spatially, cladocerans were more important at Mixing Zone Locations than at other locations (Table 4-1, Figure 4-4). Rotifera Polyarthra was the most abundant rotifer in 2002 samples (Table 4-4). This taxon dominated rotifer populations at Locations 2.0 through 9.5, and 11.0 (whole column), in May; Location 5.0 (whole column), 11.0, and 15.9 (whole column) in August; and was dominant in all samples analyzed in November (Table 4-4). Conochilus dominated rotifer populations at Locations 2.0, 9.5 and 15.9 (epilimnion) in August. Kellicottia was the dominant rotifer in whole column samples from Locations 5.0, and 9.5 in February, and Locations 11.0 (epilimnion) and 15.9 in May. Keratella and Synchaeta were dominant rotifers in most February samples All of these taxa have been identified as important constituents of rotifer populations, as well as zooplankton communities, in previous studies (Duke Power 2002; Hamme 1982). 4-5

Long term tracking of rotifer populations indicated high year-to-year seasonal variability. Peak densities have most often occurred in February and May, with an occasional peak in August (Figure 4-5, Duke Power 1989, 2002). During 2002, peak densities were observed in May. FUTURE STUDIES No changes are planned for the zooplankton portion of the Lake Norman Maintenance Monitoring Program in 2003 and 2004.

SUMMARY

Maximum epilimnetic and whole column zooplankton densities occurred in May, while minimum epilimnetic densities were recorded in February (Locations 5.0, 9.5, and 11.0), and November (Locations 2.0 and 15.9). Minimum whole column densities were observed in February (Locations 2.0 through 9.5), and August (11.0 and 15.9). As in past years, epilimnetic densities were higher than whole column densities. Mean zooplankton densities tended to be higher among Background Locations than among Mixing Zone locations during 2002, and a general pattern of increasing values from downlake to uplake was observed. In addition, long term trends showed much higher year-to-year variability at Background Locations than at Mixing Zone Locations. Epilimnetic zooplankton densities in August were within ranges of those observed in August of previous years. The epilimnetic densities at Locations 5.0, 11.0, and 15.9 in May 2002 were the highest recorded from these locations during the Program, and may have represented an ongoing lag response to changing phytoplankton standing crops at that time. Record low densities for February were observed at Locations 2.0 and 5.0, while a record low density for November occurred at Locations 15.9. Record low densities may have been in response to long term drought conditions through much of 2002. One hundred and nine zooplankton taxa have been recorded from Lake Norman since the Program began in 1987 (Fifty-one were identified during 2002). One previously unreported rotifer was identified during 2002. Overall relative abundance of copepods in 2002 had decreased substantially since 2001, and they were only dominant during August. Cladocerans were occasionally dominant at only 4-6

one location in August, while rotifers were dominant in all samples collected during the other three quarters. Overall, the relative abundance of rotifers had increased considerably since 2001, and their relative abundances were often similar to years prior to 1995. Historically, copepods and rotifers have shown annual peaks in May; while cladocerans continued to demonstrate year-to-year variability. Copepods were dominated by immature forms with adults rarely accounting for more than 8% of zooplankton densities. The most important adult copepods were Tropocyclops, Epischura, and Mesocyclops as was the case in previous years. Bosmina was the predominant cladoceran, as has also been the case in most previous years of the Program. Bosminopsis dominated most cladoceran populations in August. The most abundant rotifers observed in 2002, as in many previous years, were Polyarthra, Conochilus, and Kellicottia, while Karetella and Syncheata were occasionally important among rotifer populations. Lake Norman continues to support a highly diverse and viable zooplankton community. Long term and seasonal changes observed over the course of the study, as well seasonal and spatial variability observed during 2002, were likely due to environmental factors and appears not to be related to plant operations. LITERATURE CITED Duke Power Company. 1976. McGuire Nuclear Station, Units I 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, Charlotte, NC. Duke Power Company. 1989. Lake Norman Maintenance monitoring program: 1988 Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1990. Lake Norman Maintenance monitoring program: 1989 Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1991. Lake Norman Maintenance monitoring program: 1990 Summary. Duke Power Company, Charlotte, NC. 4-7

Duke Power Company. 1992. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1993. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1994. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1995. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1996. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1997. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1998. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 1999. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 2000. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 2001. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC. Duke Power Company. 2001. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC. monitoring program: 1991 monitoring program: 1992 monitoring program: 1993 monitoring program: 1994 monitoring program: 1995 monitoring program: 1996 monitoring program: 1997 monitoring program: 1998 monitoring program: 1999 monitoring program: 2000 monitoring program: 2000 Hamme, R. E. 1982. Zooplankton, In J. E. Hogan and W. D. Adair (eds.). Lake Norman 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. 1115 pp. Menhinick, E. F. and L. D. Jensen. 1974. Plankton populations. In L. D. Jensen (ed.). Environmental responses to thermal discharges from Marshall Steam Station, Lake Norman, North Carolina. Electric Power Research Institute, Cooling Water Discharge Research Project (RP-49) Report No. 11., p. 120-138, Johns Hopkins University, Baltimore, MD 235 p. 4-8

Thornton, K. W., B. L. Kimmel, F. E. Payne. 1990. Reservoir Limnology. John Wiley and Sons, Inc. New York, NY. 4-9

Table 4-1. Total zooplankton densities (no. X 1000/m3), densities of major zooplankton taxonomic groups, and percent composition (in parentheses) of major taxa in 1Oim to surface (10-S) and bottom to surface (B-S) net tow samples collected from Lake Norman in February, May, August, and November 2002. Date 2/4/02 Sample TIype 10-S Taxon COPEPODA CLADOCERA ROTIFERA 2.0 4.9 (16.2) 6.9 (22.4) 18.8 (61.4) 5.0 4.6 (27.5) 4.1 (24.9) 7.9 (47.5) Locations 9.5 10.1 (23.8) 9.4 (22.2) 22.9 (54.0) 11.0 15.9 (25.7) 15.4 (24.8) 30.6 (49.5) 15.9 27.8 (22.0) 30.4 (24.0) 68.5 (54.0) B-S depth (m) of tow for each Location 2.0=29 5.0=18 9.5=20 11.0=24 15.9=20 TOTAL COPEPODA CLADOCERA ROTIFERA TOTAL 30.6 4.3 (15.3) 9.5 (33.6) 14.5 (51.1) 28.3 16.6 4.3 (33.5) 4.2 (32.5) 4.4 (34.0) 12.8 42.4 12.2 (25.1) 11.2 (23.0) 25.2 (51.8) 48.6 61.9 126.7 14.4 (27.9) 10.3 (19.9) 27.1 (52.3) 51.8 16.3 (21.6) 18.6 (24.6) 40.6 (53.8) 75.5 5/6/02 10-S COPEPODA CLADOCERA ROTIFERA 34.2 (28.6) 19.1 (16.0) 66.4 (55.4) 39.2 (28.3) 29.5 (21.3) 69.7 (50.4) 35.9 (34.0) 15.0 (14.2) 54.6 (51.8) 64.4 (13.4) 15.8 (3.2) 402.0 (83.4) 84.6 (14.6) 8.1 (1.4) 485.4 (84.0) B-S Depth (m) of tow for each Location 2.0=30 5.0=20 9.5=20 11.0=25 15.9=20 TOTAL COPEPODA CLADOCERA ROTIFERA TOTAL 119.7 138.4 105.5 482.2 578.1 15.1 (32.8) 8.7 (18.8) 22.3 (48.4) 46.1 20.4 (25.0) 13.0 (16.0) 48.0 (59.0) 81.4 27.9 (41.7) 11.1 (16.6) 27.9 (41.7) 35.1 (20.5) 7.8 (4.5) 128.7 (75.0) 47.2 (16.8) 5.6 (2.0) 228.0 (81.2) 66.9 171.6 280.8 4-10

Table 4-1 (continued). Date 8/5/02 Sample Tvpe 10-S Taxon COPEPODA CLADOCERA ROTIFERA 2.0 25.1 (40.0) 13.2 (21.1) 24.4 (38.9) 5.0 34.7 (53.5) 10.8 (16.6) 19.4 (29.9) Locations 9.5 20.0 (30.7) 24.8 (38.0) 20.4 (31.3) 11.0 40.4 (39.1) 21.3 (20.6) 41.7 (40.3) 15.9 25.6 (43.8) 13.1 (22.4) 19.7 (33.7) B-S depth (m) of tow for each Location 2.0=29 5.0=18 9.5=19 11.0=25 15.9=20 TOTAL COPEPODA CLADOCERA ROTIFERA TOTAL 62.7 26.4 (60.6) 10.6 (24.3) 6.5 (15.0) 43.5 64.9 34.2 (50.8) 19.6 (29.2) 13.5 (20.0) 67.3 65.2 20.0 (30.7) 24.8 (38.0) 20.4 (31.3) 65.2 103.4 58.4 27.2 (53.0) 8.7 (17.0) 15.4 (30.0) 33.2 (49.9) 12.8 (19.3) 20.0 (30.1) 51.3 66.4* 11/4/02 10-S COPEPODA CLADOCERA ROTIFERA 8.9 (32.8) 9.0 (33.2) 9.2 (34.0) NS 13.2 (26.3) 11.6 (23.1) 25.5 (50.6) 26.4 (23.5) 12.6 (11.2) 73.2 (65.3) 24.8 (43.7) 3.7 (6.4) 28.3 (49.8) B-S depth (m) of tow for each Location 2.0=29 5.0=18 9.5=20 11.0=18 15.9=20 TOTAL COPEPODA CLADOCERA ROTIFERA TOTAL 27.1 50.3 112.2 56.8 11.8 (34.1) 10.2 (29.5) 12.6 (36.4) NS 15.4 (26.6) 13.2 (22.9) 29.1 (50.5) 35.1 (35.0) 12.3 (12.3) 52.7 (52.7) 28.9 (41.8) 3.6 (5.2) 36.7 (53.0) 34.6 57.7 100.1 69.2

• = Chaobonis observed in sample (440/m 3, 0.66%).

NS = No sample data available 4-11

Table 4-2. Duncan's Multiple Range Test on epilimnetic zooplankton densities (no. X 1000/m3) in Lake Norman, NC during 2002. February May August Location Mean Location Mean Location Mean 5.0 2.0 9.5 11.0 15.9 16.6 30.6 42.4 61.9 126.7 9.5 2.0 5.0 11.0 15.9 105.5 119.7 138.4 482.2 578.1 15.9 2.0 5.0 9.5 11.0 58.5 62.7 64.9 65.2 103.4 November Location Mean 5.0 2.0 9.5 15.9 11.0 NS 27.1 50.4 56.8 112.2 4-12

Table 4-3. Zooplankton taxa identified from samples collected quarterly on Lake Norman from 1988 through 2002. TAXON 88 891 90 1 92 1 934 1 9596 97 98 99 000 1 02 COPEPODA Cyclops thomasi Forbes X X X = -= X X = XXXX X X C vernalis Fischer X C. spp. O. F. Muller XX X X X X X X X X X X X Diaptomus birgei Marsh X X X X i X X D. mississippiensis Marsh X X X X X X X X X X X X X X X D. pallidus Herick X X X X X X D. reighardi Marsh X D. spp. Marsh X X X X X X X X X X X X X X Epishurafluviatilis Herrick X X X XX X XX Ergasilus spp. X = Eucyclops agilis (Koch) X Mesocyclops edax (S. A. Forbes) X X X X X XX XX X X X M. spp. Sars X X X XX X X X X XX Tropocyclops prasinus (Fischer) X X X X X X X X X X X T.spp. X XX X X X X X X X = = X Calanoid copepodites X X X XX X X X XX X X X X X Cyclopoid copepodites X X X XX X X X X XX X X XX Harpacticoidea I=_ X X X = Nauplii XX X X X X X X X X X X X X X Parasitic copepods X CLADOCERA I Alona spp.Baird XX Alonella spp. (Birge) X X Bosmina longirostris (0. F. M.) X X X X = = X X X XX X B. spp. Baird XX X X X X X X X X X XX Bosminopsis dietersi Richard X X X X X X X X X X X X X X X Ceriodaphnia lacustris Birge X X X X X X C. spp. Dana X X X X X X X X X X X X X X X Chydonrs spp. Leach X = X X X X X X X X Daphnia ambigua Scourfield X X X X X X XX X D. catawba Coker X Xx D. galeata Sars X D. Iaevis Birge x D. longiremis Sars X X X X D. lumholzi Sars X X X X X X X D. mendotae (Sars) Birge X X XX D.parvulaFordyce X X X X X X X XXXX D. pulex (de Geer) XX 4-13

'rn'kl
A-'I fr
rrit;rkiir-Al ,ns crr I nfa TAXON 88 89 1 90 91 92 93 94 95 1 96 97 98 99 00 1 '1 02 CLADOCERA (continued) D. pulicaria SarsX X D. retrocurva Forbes X X X X X X D. schodleri Sars X D. spp. Mullen X XX X XX X X X X X XX X X Diaphanosoma brachlyurum (Lievin) X X X X X X D. spp. Fischer X XX X X X X X X X X _X X X Eubosmina spp. (Baird) X Holopedium amazonicum Stinge. X X X X X X X X X H. gibberum Zaddach = X== X X=== H. spp. Stingelin X X X XX X X X X X X X Ilyocryptus sordidus (Lieven) X X X-I. spiniferHerrick X I. spp. Sars X X X X X Latona setifera (O.F. Muller) X Leptodora kindtii (Focke) X X X X X X X X X X X X X X Leydigia spp. Freyberg X X X X X_ Moina spp. Baird

X========

Sida crystallina 0. F. Muller X X X X Simocephalus expinosus X Simocehalussp. Schodler X ROTIFERA Anuraeopsis spp. Lauterbome X X X X X X-X- X X Asplanchna brightwelli Gosse

=

X = X A. priodonta Gosse X X X A. spp. Gosse X X XX X X X X X X X X X X X Brachionus caudata Barr. & Daday X X X B. havanensis Rousselet X X X X B. patulus 0. F. Muller X X X = = X = = = B. spp. Pallas X X X X X Chromogaster ovalis (Bergendel) x x x x C. spp. Lauterboe X X X X X X X X Collotheca balatonica Hang X X X X X X C mutabilis (Hudson) = = = =

==XXX XX

C spp. Harning X X X X X X X X X I X X I XIx Colurella spp. Bory de St. Vincent = I Conochiloides dossuarius Hudson X X X X X X C. sp. Hava X X X X X X X X X X I _ X Conochilus unicornis (Rousselet) X -X X = I = I X-X X ~X 4-14

Table 4-3 (continued) nacze 3 of 4 Tal 4-3 (cnntinued........... 3 F*4-TAXON 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 ROTIFER (continued) C. spp. Hlava XX X X X X X X X X X X Filinia spp. Bory de St. Vincent =

== X X X = = Gastropus stylifer Imhof I X X X X G. spp. Imhof X X X X X X X X X X X Hexarthra mira Hudson X X XX X H. spp. Schmada XX X X X X X X X X X Kellicouia bostoniensis (Rousselet) X X X X X X X X X X X X K longispina Kellicott I I = X XX X X X K. spp. Rousselet X X X XX X X X X X X X Keratella cochlearis =_ XX K taurocephala Myers X X K spp. Bory de St. Vincent X X XI X X X X X X X X X X X X Lecane spp. Nitzsch X X X X X X X X I X X Macrochaetus subquadratus Perty X I M.spp.Perty X XX X X X X X X Monostyla stenroosi (Meissener) X X M. spp. Ehrenberg X X X =X X X X Notholca spp. Gosse X X X Platyias patulus Harring I X PloeosomahudsoniiBrauer = = X = X X X X X X X X X P. truncatum (Levander) X X X X X X X X X X X X P. spp. Herrick X X X X XX X X X X X Polyarthra euryptera (Weirzeijski) X X X X _I P. major Burckhart X I X X X P. vulgaris Carlin XX X X X X X X P. spp. Ehrenberg X X X X X X X X X X X X X X X Pompholyx spp. Gosse X I Ptygura libra Meyers X X X X P. spp. Ehrenberg X X X X X X X X X I X Synchaeta spp. Ehrenberg X X X X X X X X X X X X X X X Trichocerca capucina (Weireijski) X X X I X X X X X X T. cylindrica (Imhof) X X X X X X X X X T. iongiseta Schrank __ X T. multicrinis (Kellicott) X X X X T. porcellus (Gosse) X X X XX X T. pusilla Jennings

=

X T. similis Lamark X T. spp. Lamark X X XX X XXX X X XXX X X Trichotria spp. Bory de St. Vincent I I I X = X 4-15

Tnhlt-. A-1 Irnntinliefil naive 4 of 4 TAXON88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 ROTIFERA (continued) Unidentified Bdelloida X X X X X X X X X Unidentified Rotifera X X X X X X X X X X INSECTA Chaoborus spp. Lichtenstein X X X X X X X x X X OSTRACODA (unidentified) X 4-16

Table 4-4. Dominant taxa among copepods (adults), cladocerans, and rotifers, and their percent composition (in parentheses) of copepod, cladoceran and rotifer densities in Lake Norman samples during 2002. FEBRUARY MAY AUGUST NOVEMBER COPEPODA EPILIMNION 2.0 Mesocyclops1Tropocyci Tropocyclops (5.2) Tropocyclops (5.3)* Epishura (1.6)* ops (1.8 ea)* 5.0 Tropocyclops (17.3) Epishura (2.6) Tropocyclops (5.6)* No sample 9.5 Tropocyclops (2.4) Mesocyclops (4.4) Tropocyclops (8.6) Tropocyclops (4.7)* 11.0 Epischura (1.7) Epishura (1.4) Tropocyclops (2.7) Tropocyclops (1.2)* 15.9 No adults present Mesocyclops (3.2) Tropocyclops (3.4)* Tropocyclops (6.6)* COPEPODA WHOLE COLUMN 2.0 Mesocyclops/Tropocycl Mesocyclops (6.7) Mesocyclops (4.8) Diaptomus (5.6) ops (8.5 ea) 5.0 Tropocyclops (14.4) Epishura (3.7) Tropocyclops (7.2) No sample 9.5 Diaptomus (1.7) Mesocyclops (8.2) Tropocyclops (8.6) Tropocyclops (10.0) 11.0 Tropocyclops (2.5)* Tropocyclops (3.8) Mesocyclops (7.4) Diaptomus (8.7) 15.9 Cyclops (5.2)* Epishura (6.4) Tropocyclops (8.0) Tropocyclops (7.0) CLADOCERA EPILIMNION 2.0 Bosmina (100.0) Bosmina (40.6) Bosminopsis (69.8) Bosmina (83.6) 5.0 Bosmina (100.0) Bosmina (83.3) Bosminopsis (62.2) No sample 9.5 Bosmina (97.4) Daphnia (40.7) Bosminopsis (55.5) Bosmina (94.6) 11.0 Bosmina (92.0) Bosmina (83.7) Bosminopsis (60.8) Bosmina (90.2) 15.9 Bosmina (99.4) Bosmina (100.0) Bosmina (49.8) Bosmina (66.5) CLADOCERA WHOLE COLUMN 2.0 Bosmina (98.7) Diaphanosoma (40.1) Bosmina (57.3) Bosmina (80.6) 5.0 Bosmina (93.4) Bosmina (67.6) Bosmina (69.0) No sample 9.5 Bosmina (92.7) Daphnia (41.2) Bosminopsis (55.5) Bosmina (96.6) 11.0 Bosmina (89.4) Bosmina (79.0) Bosminopsis (53.4) Bosmina (68.4) 15.9 Bosmina (98.9) Bosmina (78.3) Bosminopsis (48.9) Bosmina (88.3) 4-17

Table 44 (continued) FEBRUARY MAY AUGUST NOVEMBER ROTIFERA EPILIMNION 2.0 Keratella (84.8) Polyarthra (87.5) Conochilus (35.8) Polyarthra (48.3) 5.0 Keratella (66.7) Polyarthra (84.8) Ptygura (37.5) No sample 9.5 Keratella (35.3) Polyarthra (81.7) Conochilus (35.9) Polyarthra (48.0) 11.0 Synchaeta (66.4) Kellicottia (61.0) Polyarthra (35.7) Polyarthra (83.1) 15.9 Synchaeta (52.4) Kellicotfia (72.4) Conochilus (53.1) Polyarthra (66.2) ROTIFERA WHOLE COLUMN 2.0 Keratella (75.4) Polyarthra (81.6) Conochilus (35.3) Polyarthra (77.0) 5.0 Kellicottia (33.8) Polyarthra (79.8) Polyarthra (43.0) No sample 9.5 Kellicottia (27.5) Polyarthra (77.9) Conochilus (35.9) Polyarthra (51.5) 11.0 Synchaeta (55.3) Polyarthra (54.0) Polyarthra (46.3) Polyarthra (86.6) 15.9 Synchaeta (40.7) Kellicottia (76.0) Polyarthra (40.1) Polyarthra (61.3)

• = Only adults present in samples.

4-18

10m TO SURFACE TOWS 600 - 500 --- n 40 0 -. C) ° 300 - z 200 -. 100-- 0 5.0 9.5 11.0 15.9 BOTTOM TO SURFACE TOWS ---FEB -MAY ---AUG -- NOV 300 C3 o 150......... 0 2.0 5.0 9.5 11.0 15.9 LOCATIONS Figure 4-1. Total zooplankton density by location for samples collected in Lake Norman, NC, in 2002. 4-19

MIXING ZONE FEBRUARY 250 225 - 200 E 175 ° 150 o 125 75 25 - O 4-2.0 --SC. 1111----- 250 MAY 225 -. 200-* 175-125* -------------------------------------------------- 50*. 259 87 88 89 90 91 92 93 94 95 98 97 98 99 CC 01 02 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 BACKGOUND LOCATIONS 600. I soo 1--0-9.5 M II.0 A 15.9 soo tDoo 300-2CC-100-I n 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 YEARS U ! I i 0 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 YEARS Figure 4-2. Total zooplankton densities by location for epilimnetic samples collected in Lake Norman, NC, in February and May of 1988 through 2002. 4-20

MIXING ZONE AUGUST LIMCFMRF 250 225 200 X 175 Qo 150 x c 125 CS 4fn.

---

1+

2.0 -5.0 --------------------- 2 2 5-........ 175-150 125-75-50' A hZ4Ai 25-, 87 88 89 90u 91 92 93 94 95 96 9X7 98 99 00 01 02 )I U)zw - a Fs 87 88 89 90u 91 92 93 9U4 95 96 97 98 99 00 01 02 BACKGROUND LOCATIONS Figure 4-3. Total zooplankton densities by location for epilimnetic samples collected in Lake Norman, NC, in August and November of 1987 through 2002. 4-21

LOCATIONS j lCOPEPODS l_ CLADOCERANS ROTIFERS Figure 4-4. Zooplankton community composition by month for epilimnetic samples collected in Lake Norman, NC, in 2002. 4-22

60 50 _E a 40 d 30 5n20 z U, 010 0 CLADOCERANS + MIXING ZONE _BACKGROUND LOCATIONS I 1--- --------- ---------- ----- Figure 4-5. Zooplankton composition by quarter for epimlimnetic samples collected in Lake Norman, NC, from 1990 through 2002 (Note: Mixing Zone in November 2002 represents Location 2.0 only). 4-23

LAKE-WIDE: EPIUMNION I0 COPEPODS A CLADOCERANS

• ROTIFERS I z0 co 0

0~ 0 I-- zLU W., LU IL IC 9 a 7 8 8 4 I U 'Yo 0% 0% '0% ~0% -

0%

~0% 10% !0% 0% I 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 YEARS LAKE-WIDE: WHOLE COLUMN OCOPEPODS OCLADOCERANS UROTIFERS z0 I-U, 0 A 0 a~- 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 YEARS Figure 4-6. Annual lake-wide percent composition of major zooplankton taxonomic groups from 1988 through 2002 (Note: Does not include Location 5.0 in November 2002). 4-24

MIXING ZONE (LOCATIONS 2.0 + S.0): EPIUMNION IOCOPEPODS ISCLADOCERANS EROTIFERS I z 0 0. 0. I.-z 0. 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% I I I I ~~~~~. 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 YEAR MIXING ZONE (LOCATIONS 2.0 + 5.0): WHOLE COLUMN IOCOPEPODS LlCLADOCERANS U ROTIFERSI 1 z0 U-0 O00 z 0 IL 0. 100% 90% 80% 70% 60% 4 (r/o 40%h 30% 20% 10% 0% I 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 YEAR Figure 4-7. Annual percent composition of major zooplankton taxonomic groups from Mixing Zone Locations: 1988 through 2002 (Note: Does not include Location 5.0 in November 2002). 4-25

Figure 4-8. Annual percent composition of major zooplankton taxonomic groups from Background Locations: 1988 through 2002. 4-26

CHAPTER 5 FISHERIES INTRODUCTION In accordance with the NPDES permit for McGuire Nuclear Station (MNS), monitoring of specific fish population parameters continued during 2002. The components of this Lake Norman Fish Monitoring Program were to:

1. Continue spring electrofishing surveys of littoral fish populations;

2. Continue summer striped bass (scientific names of fish mentioned in this chapter are listed in Table 5-1) mortality monitoring;

3. Continue fall hydroacoustic and purse seine surveys of pelagic fish populations (Attachment 1);

4. Continue cooperative striped bass study with the North Carolina Wildlife Resources Commission (NCWRC) to evaluate striped bass growth and condition as a function of stocking rates, forage availability, and summer striped bass habitat;

5. Continue supporting the NCWRCINorth Carolina State University (NCSU) striped bass bioenergetics study.

METHODS AND MATERIALS Spring electrofishing surveys were conducted in April at three locations: (1) near MNS, (2) near Marshall Steam Station (MSS), and (3) a mid-lake reference area (REF) located between MNS and MSS. The locations sampled in 2002 were the same locations sampled since implementation of this sampling program in 1993. Ten 300-m transects were sampled in each of the three locations. The MNS transects were located between Ramsey Creek and Channel Marker IA in Zone 1 (Fig. 5-1). The REF transects were located between Channel Marker 7 and Channel Marker 9 in lower Zone 3, and the MSS transects were located between Channel Marker 14 and the NC Highway 150 Bridge in Zone 4. All transects were originally selected to include the various types of fish habitat in Lake Norman that could be effectively sampled. The only areas excluded were shallow flats where the boat could not access the area within 3-4 m of the shoreline. All sampling was conducted during daylight and when water temperatures generally ranged from 15 to 20 'C. Except for largemouth bass, all fish collected were identified to species, and total number and total weight were obtained for each 5-1

species. Individual total lengths (mm) and weights (g) were obtained for all largemouth bass collected. Mortality surveys for striped bass were conducted from July 5 through September 5. During this period, weekly surveys using a boat were conducted to specifically search for dead or dying striped bass in Zones 1-4. The location of any dead or dying fish was noted along with its total length. Striped bass for calculations of relative weight (Wr) were collected from gill-net surveys conducted in November and December by the NCWRC and NCSU personnel during their bioenergetics study. Relative weight was calculated using the formula Wr = (W/Ws) x 100 where W = weight of the individual fish (g) and Ws = length-specific mean weight (g) for a fish as predicted by a weight-length equation for striped bass (Anderson and Neumann 1996). RESULTS AND DISCUSSION Numbers and biomass of fish collected from Lake Norman in 2002 spring electrofishing surveys varied among sampling locations (Tables 5-2 through 5-4). A total of 1,361 fish (14 species and 1 hybrid complex) weighing 54.9 kg were collected near MNS while 1,776 fish (18 species and I hybrid complex) weighing 103.0 kg were collected at the REF area and 1,157 fish (20 species and I hybrid complex) weighing 80.4 kg were collected near MSS. Whitefin shiners, spottail shiners, redbreast sunfish, and bluegills dominated all samples numerically, while common carp, redbreast sunfish, bluegills, and largemouth bass dominated gravimetrically. Numbers of fish collected in 2002 were highest at the REF location, intermediate at the MNS location, and lowest at the MSS location. However, fish biomass was highest at the REF location, intermediate at the MSS location, and lowest at the MNS location. While numbers of fish have varied considerably among locations and years, fish biomass has remained relatively stable (Fig. 5-2). Fish biomass has always been highest at the MSS or REF locations and lowest at the MNS location. Historically, Lake Norman exhibited spatial heterogeneity in its fish populations with uplake areas generally supporting more fish than downlake areas (Siler et al. 1986). Siler et al. (1986) indicated that this heterogeneity was related to higher nutrient levels uplake than downlake. Our data indicates that this spatial heterogeneity may still be characteristic of fish populations in Lake Norman and that lower 5-2

nutrients downlake may explain the consistently low fish biomass estimates collected at the MNS location. Total numbers of fish collected near MNS were greater in 2002 than in 2001 (Fig. 5-2) and were primarily due to increased catches of spottail shiners, redbreast sunfish, and bluegills in 2002. However, fish biomass was similar in both years (Fig. 5-2). Total numbers of fish collected at the REF location were somewhat similar in 2001 and 2002, but biomass increased from 2001 to 2002 (Fig. 5-2) due to increased catches of redbreast sunfish and larger largemouth bass. Both total numbers and biomass of fish collected near the MSS declined from 2001 to 2002 (Fig. 5-2). Declines in fish numbers at this location were related to fewer whitefin and spottail shiners being collected in 2002, and declines in biomass were related to fewer large common carp being collected. Even with the increases and decreases noted in the total numbers and biomass of fish at all locations from 2001 to 2002, these values in 2002 continued to be within the ranges observed here since this sampling program was implemented in 1993, and no overall annual trends in abundance were evident at any sampling location. Mortality surveys for striped bass in Lake Norman resulted in few fish in 2002 (Table 5-5). Only 6 dead fish (ranging in length from 450 mm to 550 mm) were observed in 2002 compared to 18 in 2001 (Duke Power 2003). Four of these fish were found near the MNS, and the remaining two were from uplake locations. Twenty-three striped bass were collected in November and December 2002 for Wr evaluations. Mean Wr was 81 and ranged from 65 to 95 (Fig. 5-3). Fewer striped bass were collected for evaluation in 2002, and Wr values appeared to be somewhat higher in 2002 than in 2001. In 2002, 57% of the striped bass had Wr's 280 compared to only 38% in 2001 (Duke Power 2003). However, too few fish were collected in 2002 to determine if this was a significant improvement. Low Wr's in striped bass 2450 mm that were collected in 2002 indicated that these fish continued to be stressed during summer. FUTURE FISH STUDIES Continue the spring electrofishing program annually and evaluate growth rates of largemouth bass 5-3

Continue the September hydroacoustic/purse seine forage population assessment and implement a small mesh gill-net sampling program to evaluate forage fish abundance in the main tributary arms Continue striped bass mortality monitoring throughout the summer Continue the cooperative striped bass study with NCWRC to evaluate striped bass growth and condition as a function of stocking rates, forage availability, and summer striped bass habitat Implement a cooperative trapnetting program with NCWRC to evaluate black crappie abundance and age composition The future studies/activities outlined above are subject to revision, based on an annual review of the data submitted to date and a re-evaluation of the McGuire Maintenance Monitoring Program by the NCWRC.

SUMMARY

In accordance with the Lake Norman Maintenance Monitoring Program for the NPDES permit for MNS, specific fish monitoring programs were coordinated with the NCWRC and continued during 2002. Spring electrofishing indicated that 14 to 20 species of fish and 1 hybrid complex composed fish populations in the 3 sampling locations, and that numbers and biomass of fish in 2002 were generally similar to those previously noted at these locations since 1993. Few dead striped bass were noted during the summer survey period indicating no major die-offs occurred. Relative weight of Lake Norman striped bass in November and December may have improved somewhat in 2002 over that noted in 2001, but large striped bass continued to exhibit low Wr's at this time of the year. 54

LITURATURE CITED Anderson, R. A., and R. M. Neumann. 1996. Length, weight, and associated structural indices. Pages 447-482 in B. R. Murphy and D. W. Willis, editors. Fisheries Techniques. American Fisheries Society, Bethesda, Maryland. Duke Power. 2003. Lake Norman maintenance monitoring program: 2001 summary. Duke Power, Charlotte, North Carolina. Siler, J. R., W. J. Foris, and M. C. McInery. 1986. Spatial heterogeneity in fish parameters within a reservoir. Pages 122-136 in G. E. Hall and M. J. Van Den Avyle, editors. Reservoir Fisheries Management: Strategies for the 80's. Reservoir Committee, Southern Division American Fisheries Society, Bethesda, Maryland. 5-5

Table 5-1. Common and scientific names of fish collected from Lake Norman. Common name Longnose gar Alewife Gizzard shad Threadfin shad Hybrid shad Greenfin shiner Whitefin shiner Common carp Spottail shiner Quillback Shorthead redhorse Channel catfish Flathead catfish White perch Striped bass Redbreast sunfish Pumpkinseed Warmouth Bluegill Redear sunfish Hybrid sunfish Spotted bass Largemouth bass Black crappie Yellow perch Scientific name Lepisosteus osseus Alosa pseudoharengus Dorosoma cepedianum Dorosoma petenense Dorosoma hybrid Cyprinella chloristia Cyprinella nivea Cyprinus carpio Notropis hudsonius Carpiodes cyprinus Moxostoma macrolepidoturm Ictalurus punctatus Pylodictis olivaris Morone americana Morone saxatilis Lepomis auritus Lepomis gibbosus Lepomis gulosus Lepomis macrochinrs Lepomis microlophus Lepomis hybrid Micropterus punctulatus Microptenrs salmoides Pomoxis nigromaculatus Perca flavescens 5-6

(. (7. C. Table 5-2. Numbers and biomass of fish collected from 10 transects near the McGuire Nuclear Station, April 2002. Transects 1 2 3 4 5 6 7 8 9 10 All Taxa N Kg N Kg N Kg N Kg N Kg N Kg N Kg N Kg N Kg N Kg N Kg Longnose gar 1 2.021 1 2.021 Gizzard shad 1 0.465 3 1.242 4 1.707 Greenfin shiner 2 0.005 3 0.010 10 0.024 17 0.049 7 0.017 7 0.022 46 0.127 Whitefin shiner 2 0.009 2 0.010 4 0.008 41 0.107 4 0.018 67 0.202 27 0.063 24 0.109 171 0.526 Common carp 1 1.115 1 2.109 1 1.928 4 7.604 4 5.270 1 1.665 12 19.691 Spottail shiner 2 0.014 72 0.362 1 0.007 16 0.077 7 0.034 37 0.215 135 0.709 Channel catfish 1 0.458 1 0.156 2 0.614 Redbreast sunfish 42 0.379 53 0.518 22 0.240 50 0.561 3 0.047 25 0.457 11 0.246 20 0.262 3 0.023 1 0.012 230 2.745 Warrnouth 1 0.009 2 0.008 1 0.013 2 0.016 1 0.008 7 0.054 Bluegill 28 0.232 107 0.794 70 0.683 118 0.985 12 0.121 2 0.028 8 0.101 21 0.162 25 0.141 10 0.100 401 3.347 Redear sunfish 22 0.360 54 0.650 51 0.514 93 1.457 1 0.024 1 0.003 3 0.014 11 0.247 8 0.264 2 0.132 246 3.665 Hybrid sunfish 2 0.012 7 0.078 3 0.043 8 0.155 2 0.043 1 0.005 2 0.057 3 0.150 1 0.011 29 0.554 Spotted bass 3 0.870 2 0.077 1 0.027 2 0.143 1 0.038 6 0.744 1 0.495 5 1.453 21 3.847 Largennouthbass 11 3.709 17 3.293 12 3.619 5 1.474 2 0.125 1 0.405 5 1.892 2 0.739 55 15.256 Yellow perch I 0.011 1 0.011 All 111 7.600 243 7.456 165 5.209 277 4.667 25 0.253 154 1.129 33 2.534 172 13.334 90 8.226 91 4.466 1361 54.874 Lh

C C C Table 5-3. Numbers and biomass of fish collected from 10 transects in a reference area between the McGuire Nuclear Station and Marshall Steam Station, April 2002. Transects 1 2 3 4 5 6 7 8 9 10 All Taxa N Kg N Kg N Kg N Kg N Kg N Kg N Kg N Kg N Kg N Kg N Kg Longnose gar 1 1.803 1 1.803 Alewife 27 0.241 1 0.009 17 0.156 45 0.406 Gizzard shad 1 0.555 4 1.828 9 3.897 7 3.136 3 1.110 4 1.798 1 0.632 29 12.956 Greenfin shiner 21 0.068 1 0.002 5 0.013 4 0.005 3 0.010 37 0.088 71 0.186 Whitefin shiner 42 0.10 20 0.070 93 0.299 45 0.142 25 0.063 24 0.081 27 0.102 27 0.075 57 0.168 28 0.115 388 1.223 Cornrnoncarp 2 3.070 1 2.110 2 3.708 2 4.S48 1 1.202 2 3.425 10 18.063 Spottail shiner 2 0.012 4 0.018 17 0.075 29 0.148 3 0.011 1 0.006 1 0.006 55 0.258 3 0.017 115 0.551 Quillback I 1.010 1 1.010 Channel catfish 1 0.273 1 1.155 2 1.428 Flathead catfish 1 0.482 1 0.910 1 0.094 1 22.700 4 24.186 White perch 1 0.223 1 0.223 Redbreast sunfish 23 0.265 68 0.900 61 0.769 14 0.286 12 0.301 3 0.067 8 0.242 30 3.550 37 0.611 52 0.704 308 7.695 Warnouth 5 0.070 2 0.013 1 0.008 1 0.004 4 0.092 1 0.002 14 0.189 Bluegill 81 0.742 72 0.679 143 1.315 25 0.360 40 0.586 5 0.045 28 0.408 44 0.435 95 1.088 45 0.460 578 6.118 Redearsunfish 18 0.520 16 0.146 10 0.135 11 0.325 10 0.612 10 0.362 4 0.121 6 0.082 85

• 2.303 Hybrid sunfish 2 0.023 3 0.015 5 0.158 4

0.091 5 0.084 1 0.042 3 0.087 4 0.064 7 0.221 3 0.070 37 0.855 Spotted bass 2 0.169 1 0.487 3 0.656 Largernouthbass 11 3.116 10 3.137 9 2.311 10 1.655 6 1.535 12 3.790 10 2.279 4 1.956 5 1.337 77 21.116 Black crappie 1 0.008 6 2.007 7 2.015 All 188 8.963 215 5.943 349 9.278 173 10.830 118 33.790 56 1.734 99 10.849 135 9.085 298 5.668 145 6.842 1776 102.982 60

( ( C-Table 5-4. Numbers and biomass of fish collected from 10 transects near the Marshall Steam Station, April 2002. Transects 1 2 3 4 5 6 7 8 9 10 All Taxa N Kg N Kg N Kg N Kg N Kg N Kg N Kg N Kg N Kg N Kg N Kg Alewife 3 0.027 3 0.027 Gizzard shad 4 1.435 1 0.532 1 0.368 6 2.335 Threadfin shad 1 0.004 1 0.004 Greenfin shiner 3 0.009 1 0.004 5 0.018 1 0.002 10 0.033 Whitefin shiner 17 0.080 2 0.006 30 0.159 10 0.041 8 0.030 113 0.455 22 0.108 68 0.303 270 1.182 Cornnioncarp 2 3.667 1 1.413 1 1.345 3 7.168 4 6.900 11 20.493 Spottail shiner 4 0.027 7 0.036 1 0.006 1 0.006 1 0.007 2 0.011 10 0.066 26 0.159 Quillback 2 2.480 2 2.480 Shorthead redhorse 1 0.239 1 0.280 2 0.519 Channel catfish 1 0.234 1 0.234 Flathead catfish 1 0.113 1 0.113 White perch 1 0.200 1 0.200 Redbreast sunfish 1 0.090 19 0.621 9 0.094 16 0.311 2 0.187 24 0.520 36 0.627 38 0.553 17 0.312 162 3.315 Pumpkinsced 4 0.140 4 0.140 Wannouth 4 0.039 2 0.046 4 0.042 2 0.010 12 0.137 Bluegill 2 0.043 4 0.284 72 1.021 80 0.672 64 0.809 5 0.173 30 0.280 98 0.950 46 0.555 22 0.310 423 5.097 Redearsunfish 6 0.496 7 0.538 8 0.760 32 0.916 8 0.550 4 0.507 2 0.133 4 0.391 7 0.940 78 5.231 Hybrid sunfish 2 0.118 1 0.139 4 0.098 8 0.216 2 0.147 3 0.068 7 0.109 2 0.010 1 0.010 30 0.915 Largernouthbass 7 1.981 11 4.829 14 6.628 16 6.427 3 2.616 15 3.781 2 0.095 10 2.335 16 4.758 15 3.761 109 37.211 Black crappie I 0.500 1 0.500 Yellow perch I 0.011 3 0.048 4 0.059 All 23 6.445 46 6.226 125 9.520 184 11.452 113 4.599 35 4.366 183 3.294 165 14.883 136 13.296 147 6.303 1157 80.384 tA

Table 5-5. Dead or dying striped bass observed in Lake Norman, July-September 2002. Date Location Length (mm) Number July 17 Channel Marker 2 520 1 July 25 Channel Marker 6 545 1 August 02 Cowan's Ford Dam 550 1 August 09 Channel Marker 3 530 1 August 22 Channel Marker 6 465 1 August 30 Cowan's Ford Dam 450 1 5-10

N ZONE3 ta ZONEs on Figure 5-1. Sampling zones on Lake Norman, Noth Carolina. ZONE 2 I 5-11

Figure 5-2. Numbers and biomass of fish collected from three areas of Lake Norman, 1993-2002. 3000 -

• MNS O REF a MSS 2500-2000-E 1500-z 1000 500-0 1993 1994 1995 1996 1997 1999 2000 2001 2002 200
• MNS o REF 180 l

a MSS 160-140 120 E 100 60-40-20-0 I 1993 1994 1995 1996 1997 1999 2000 2001 2002 5-12

C Figure 5-3. Relative weights of striped bass collected from Lake Norman, November-December 2002. C 110 100 = 90 U ._e X4 80

• ~~~

70 60 0 100 200 300 400 Total length (mm) 500 600 700 I Lake Norman Hydroacoustic and Purse Seine Data: 2002 INTRODUCTION In accordance with the NPDES permit for McGuire Nuclear Station (MNS), monitoring of forage fish population parameters was conducted in 2002. This monitoring included a mobile hydroacoustic survey to estimate forage fish density and population size. Purse seine sampling was also employed to determine species composition and size distribution for target strength evaluation. A joint Duke Power / North Carolina Wildlife Resources Commission / North Carolina State University study to evaluate striped bass bioenergetics in Lakes Norman and Badin necessitated two additional hydroacoustic assessments and purse seine samples in 2002. METHODS AND MATERIALS Three mobile hydroacoustic surveys of the entire lake were conducted on July 1 and 2, (Bioenergetics Study), September 17 and 18 (MNS NPDES), and December 11 and 12 (Bioenergetics Study) to estimate forage fish populations. Hydroacoustic surveys employed multiplexing, side-scan and down-looking transducers to detect surface-oriented fish and deeper fish (from 2.0 m below the water surface to the bottom), respectively. Both transducers were capable of determining target strength directly by measuring fish position relative to the acoustic axis. The lake was divided into five zones (Figure 5-1) due to its large size, spatial heterogeneity, and multiple power generation facilities (drought conditions and resulting low water levels in 2002 prevented the assessment of the uppermost zone (Zone

6) in Lake Norman).

Purse seine samples were collected on June 25, September 16, and December 9, 2002 from the lower (main channel near Marker 1), mid (mouth of Davidson Creek), and uplake (just downlake of Lake Norman (Duke Power) State Park) areas of the reservoir. The purse seine measured 118 x 9 m (400 x 30 fi) with a mesh size of 4.8-mm (3/16 in). A subsample of forage fish collected from each area was used to determine taxa composition and size distribution. A5-1

RESULTS AND DISCUSSION Forage fish densities in the five zones of Lake Norman ranged from 5,068 to 12,580 fish/ha in July 2002 (Table 1). Forage fish densities were highest uplake (Zone 5) and lowest downiake. The estimated lakewide population was approximately 103 million fish. Purse seine sampling indicated that these fish were 74.75% threadfin shad and 25.25% alewives. The length frequency distribution indicated that threadfin shad comprised two peaks; a lower one with a 45-mm modal length and an upper with a modal length of 100 mm. Alewives dominated a wide size range of individuals that were most numerous between 45 and 80 mm (Figure 1). September 2002 forage fish densities ranged from a low of 3,228 (Zone 4) to a high of 9,363 (Zone 5). The estimated lakewide forage population was approximately 74 million fish. Purse seine sampling indicated that these fish were 70.27% threadfin shad and 29.73% alewives. The length frequency distribution indicated a bimodal forage fish population with the lower modal length of approximately 45 mm, representing threadfin shad, and the upper mode comprised of alewives with a 70-mm modal length (Figure 2). Forage fish densities in the five zones of Lake Norman ranged from 1,413 to 2,172 fish/ha in December 2002. There were considerably fewer fish in the uplake zones compared to July and September estimates; densities were fairly homogeneous throughout the lake. The estimated forage population was approximately 25 million fish. Purse seine sampling indicated that these fish were 75.26% threadfin shad, 24.55% alewives, and 0.19% hybrid shad. The length frequency distribution indicated that threadfin shad dominated a large skewed size class of forage fish with a modal length of approximately 60 mm and lower numbers of larger individuals. Alewives occupied a larger size class with a modal length of approximately 85 mm (Figure 3). Open water purse seine samples have undergone a dramatic shift in recent years. From 1993 through 1999, when the first alewife was collected, purse seine samples were totally composed of small threadfin shad (typically <55 mm). From 2000 through 2002 the open water forage fish community has shown increasing contributions from alewives (now -25% of the community) and a concurrent wider size range of individuals. The average size of the young-of-the-year threadfin shad and alewives does increase throughout the year. The 2002 population estimates demonstrated a steady decline from the first sample (July) through the last (December) similar to the trend seen in 2000. It appears that natural mortality resulted in the steady decline of forage fish numbers throughout the year. Fishing mortality, resulting A5-2

from bait collection, probably represents a very small proportion of the total mortality for forage fish. Lakewide population estimates in September 2002 were similar to values measured from 1997 to 2001. A5-3

Table 1. Lake Norman forage fish densities and population estimates by zone, and lakewide populations estimates and 95% confidence limits from three hydroacoustic samples in 2002. Density (no/hectare) Population Estimate Zone July September December July September December 1 5,068 3,289 1,413 11,560,108 7,502,209 3,223,053 2 5,093 3,785 2,146 15,697,135 11,665,749 6,614,187 3 8,166 7,679 2,172 28,217,776 26,534,938 7,505,389 4 12,243 3,228 1,497 15,071,133 3,973,668 1,842,807 5 12,580 9,363 2,147 32,506,720 24,193,992 5,547,848 Total 103,052,873 73,870,556 24,733,284 95% LCL 95,065,240 67,453,128 21,081,450 95% UCL 111,040,506 80,287,983 28,385,118

• Zones 5 and 6 were combined for one density and one population estimate due to low water levels in Zone 6.

A5-4

( C (7 Figure 1. Lake Norman (combined) forage fish - June 2002. Data from the Davidson Creek sample has not been processed by NCSU. 140 - 120 - 100-lOT Shad 80 - lAlewives E.. E Z 60 40 20 0n. 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 Length Group (mm) ,;A

{ C C Figure 2. Lake Norman (combined) forage fish - September 2002. Data from the Davidson Creek sample has not been processed by NCSU. 300 250 200 OT Shad l Alewives L. z 150 100 50 0 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 Length Group (mm) I;h C

C C C. Figure 3. Lake Norman (combined) forage fish - December 2002. NCSU. 140 - 120 - 100 - Data from the Davidson Creek sample has not been processed by C T Shad

• Alewives E2 Hybrid Shad z*1 80 60 40 20 0

20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 Length Group (mm) I;,,,j}}