ML020370392

Annual Lake Norman Maintenance Monitoring Program: 2000 Summary.

ML020370392
Person / Time
Site:	McGuire, Mcguire
Issue date:	01/08/2002
From:	Barron H Duke Energy Corp
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NPDES NC0024392
Download: ML020370392 (131)

Text

Duke Energy Corporation h Duke McGuire Nuclear Station 12700 Hagers Ferry Road E Energy. Huntersville, NC 28078-9340 (704) 875-4800 OFFCE H. B. Barron (704) 875-4809 FAX Vice President January 8, 2002 U. S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555

Subject:

McGuire Nuclear Station Docket Nos. 50-369, 50-370 Please find attached a copy of the annual "Lake Norman Maintenance Monitoring Program: 2000 Summary," as required by the National Pollutant Discharge Elimination and data System (NPDES) permit NC0024392. The report includes detailed results Carolina comparable to that of previous years. The report was submitted to the North Department of Environment and Natural Resources on December 18, 2001.

Any questions regarding this submittal should be directed to Kay Crane, McGuire Regulatory Compliance at (704) 875-4306.

H. B. Barron C,0

U. S. Nuclear Regulatory Commission Document Control Desk January 8, 2002 Page 2 cc: Mr. R. E. Martin, Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. Luis Reyes, Regional Administrator U.S. Nuclear Regulatory Commission Region II Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, Georgia 30303 Mr. Scott Shaeffer Senior Resident Inspector McGuire Nuclear Station

LAKE NORMAN MAINTENANCE MONITORING PROGRAM:

2000

SUMMARY

McGuire Nuclear Station: NPDES No. NC0024392 Duke Power A Duke Energy Company December 2001

TABLE OF CONTENTS Page EXECUTIVE

SUMMARY

i LIST OF TABLES iv V

LIST OF FIGURES CHAPTER 1: McGUIRE NUCLEAR STATION OPERATION 1-1 Introduction 1-1 1-1 Operational data for 2000 CHAPTER 2: WATER CHEMISTRY 2-1 2-1 Introduction 2-1 Methods and Materials Results and Discussion-, 2-2 Future Water Chemistry Studies 2-8 Summary 2-8 Literature Cited 2-9 CHAPTER 3: PHYTOPLANKTON 3-1 Introduction 3-1 Methods and Materials 3-1 Results and Discussion 3-2 Future Phytoplankton Studies 3-9 Summary 3-9 Literature Cited 3-11 CHAPTER 4: ZOOPLANKTON 4-1 Introduction 4-1 Methods and Materials 4-1 Results and Discussion 4-2 Future Zooplankton Studies 4-6 Summary 4-6 Literature Cited 4-8 CHAPTER 5: FISHERIES 5-1 Introduction 5-1 Methods and Materials 5-1 Results and Discussion 5-3 Future Fisheries Studies 5-4 Summary 5-5 Attachment 1: Hydroacoustic and Purse Seine Data A-I

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 2000.

McGUIRE NUCLEAR STATION OPERATION The monthly average capacity factor for MNS was 100.8 %, 92.1 %, and 52.0 % during July, August, and September of 2000, respectively. These are the months when conservation of cool water and discharge temperatures are most critical and the thermal limit for MNS 0

increases from a monthly average of 95.0°F (35.0°C) to 99.0°F (37.2 C). The average "monthly discharge temperature was 97.9 0 F (36.6 0 C) for July, 96.3 0 F (35.7 0 C) for August, and 91.3 0 F (32.9 0 C) for September 2000. The low-level intake pumps of MNS were not operated to provide additional cooling in 2000. 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 DO data collected in 2000 were similar to those observed historically. Temperature and DO data collected in 2000 were within the range of previously measured values.

Reservoir-wide isotherm and isopleth information for 2000, 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 2000 was generally similar to historical conditions. All chemical parameters measured in 2000 were within the concentration ranges previously reported for the lake during both MNS preoperational and operational years. As has been observed historically, manganese concentrations in the bottom waters in the summer and fall of 2000 often exceeded the NC i

water quality standard. This is characteristic of waterbodies that experience hypolimnetic deoxygenation during the summer.

PHYTOPLANKTON Lake Norman continues to support highly viable and diverse phytoplankton communities.

No obvious short term or long term impacts of station operations were observed.

In 2000 lake-wide mean chlorophyll a concentrations were all within ranges of those observed during previous years of the program. Lake Norman continues to be classified as oligo-mesotrophic based on long term, annual, mean chlorophyll concentrations. In most cases, total phytoplankton densities and biovolumes observed in 2000 were higher than those observed during 1999, and standing crops were generally within ranges established over previous years.

The proportions of ash-free dry weights to dry weights in 2000 were slightly higher than those of 1999, indicating little change in organic/inorganic inputs into Lake Norman.

Diversity, or numbers of taxa, of phytoplankton had increased since 1999, and the total number of individual taxa was the highest yet recorded. The phytoplankton index (Myxophycean) tended to confirm the characterization of Lake Norman as oligo mesotrophic. The annual index for 2000 was higher than that of 1999, and was at the lower end of the intermediate range.

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 2000, were likely due to environmental factors and appears not to be related to plant operations.

Epilimnetic zooplankton densities during all but May of 2000 were within ranges of those observed in previous years. The epilimnetic densities at Locations 2.0 and 5.0 in May 2000 were the highest recorded from these locations for this month, and may have represented a response to comparatively high phytoplankton standing crops in the Mixing Zone at that time.

ii

One hundred and eight zooplankton taxa have been recorded from Lake Norman since the Program began in 1987 (fifty-one were identified during 2000). No previously unreported taxa were identified during 2000.

FISHERIES In accordance with the Lake Norman Maintenance Monitoring Program for the NPDES permit for MNS, specific fish monitoring programs were coordinated with the North Carolina Wildlife Resources Commission (NCWRC) and continued during 2000. General monitoring of Lake Norman and specific monitoring of the MNS mixing zone for striped bass mortalities during the summer of 2000, yielded one mortality within the mixing zone and six mortalities in the main channel outside the mixing zone.

-Spring shoreline electrofishing of Lake Norman yielded variable catches for the three areas sampled; the MNS mixing zone area, a mid-lake reference area, and the MSS mixing zone area. The total number of taxa collected was similar for all three areas.

During July 2000, forage fish densities in the six zones of Lake Norman ranged from 6,036 to 18,622 fish/ha. The estimated population was approximately 116 million fish. Purse seine sampling indicated that these fish were 96.24% threadfin shad, 3.26% alewives, and 0.50%

gizzard shad.

September 2000 forage fish densities ranged from a low of 2,112 (Zone 6) to a high of 6,482 (Zone 2) and did not demonstrate the same fish distribution trend seen in July. The estimated forage population was approximately 63 million fish. Purse seine sampling indicated that these fish were 87.40% threadfin shad, 12.37% alewives, and 0.22% gizzard shad.

During November 2000, forage fish densities in the six zones of Lake Norman ranged from 579 to 2,294 fish/ha. The estimated forage population was approximately 24 million fish. No purse seine data were available for length frequency distributions or speciation of this population estimate.

Gillnetting for shad and alewives (forage species), collected jointly by NCWRC and Duke in November 2000 yielded a total of 330 fish from 14 net nights of sampling in three zones of Lake Norman. All three forage species (gizzard shad, threadfin shad, and alewives) were i11

collected from Zones 3 and 5, while only threadfin shad and alewives were collected from Zone 4.

Fisheries data to date indicate that the Lake Norman fishery is consistent with the trophic status and productivity of the reservoir. However, one aspect of the Lake Norman fishery that warrants close monitoring in the future is the composition of forage populations. The introduction of alewives by fishermen over the past several years could have a dramatic impact on lake-wide forage populations and game species.

iv

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 2-12 Table 2-2 Water chemistry methods and analyte detection limits 2-13 Table 2-3 Heat content calculations for Lake Norman in 1998 and 1999 2-14 Table 2-4 Comparison of Lake Norman with TVA reservoirs 2-15 Table 2-5 Lake Norman water chemistry data in 1998 and 1999 2-16 Table 3-1 Mean chlorophyll a concentrations in Lake Norman 3-14 Table 3-2 Duncan's multiple rnge test for Chlorophyll a 3-15 Table 3-3 Total phytoplankton densities from Lake Norman 3-16

-Table 3-4 Duncan's multiple range test for phytoplankton densities 3-17 Table 3-5 Duncan's multiple range test for dry and ash free dry weights 3-18 Table 3-6 Phytoplankton taxa identified in Lake Norman from 1987-1999 3-19 Table 3-7 Dominate classes and species of Phytoplankton 3-29 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 1988-1999 4-13 Table 4-4 Dominant taxa and percent composition of selected zooplankton 4-17 Table 5-1 Electrofishing catches in the mixing zone of McGuire 5-7 Table 5-2 Electrofishing catches in the mid-lake reference zone 5-8 Table 5-3 Electrofishing catches in the mixing zone of Marshall 5-9 Table 5-4 Gillnetting catches from Lake Norman in 1999 5-10 V

LIST OF FIGURES Page Map of sampling locations on Lake Norman 2-19 Figure 2-1 Figure 2-2 Monthly precipitation near McGuire Nuclear Station 2-20 Figure 2-3 Monthly mean temperature profiles in background zone 2-21 Monthly mean temperature profiles in mixing zone 2-23 Figure 2-4 Figure 2-5 Monthly temperature and dissolved oxygen data 2-25 Figure 2-6 Monthly mean dissolved oxygen profiles in background zone 2-26 Figure 2-7 Monthly mean dissolved oxygen profiles in mixing zone 2-28 Figure 2-8 Monthly isotherms for Lake Norman 2-30 Figure 2-9 Monthly dissolved oxygen isopleths for Lake Norman 2-33 Figure 2-10a Heat content of Lake Norman 2-36 Figure 2-1Ob Dissolved oxygen content of Lake Norman 2-36 Striped bass habitat in Lake Norman 2-37 Figure 2-11 Chlorophyll a measurements of Lake Norman 3-30 Figure 3-1 Mean chlorophyll a concentrations by year 3-31 Figure 3-2 Chlorophyll a concentrations by location 3-32 Figure 3-3 Figure 3-4 Class composition of phytoplankton at Locations 2.0 3-34 Figure 3-4 Class composition of phytoplankton at Locations 5.0 3-35 Figure 3-5 Class composition of phytoplankton at Location 9.5 3-36 Figure 3-6 Class composition of phytoplankton at Location 11.0 3-37 Class composition of phytoplankton at Location 15.9 3-38 Figure 3-7 Figure 3-9 Annual lake-wide Myxophycean index from 1988-2000 3-39 Zooplankton density by sample location in Lake Norman 4-19 Figure 4-1 Zooplankton densities among years during February and May 4-20 Figure 4-2 Figure 4-3 Zooplankton densities among years during August and November 4-21 Figure 4-4 Lake Norman zooplankton composition in 1999 4-22 Figure 4-5 Quarterly zooplankton composition from 1990 through 1999 4-23 4-24 Figure 4-6 Annual lake-wide zooplankton composition (1998 through 1999)

Lake Norman zooplankton composition (mixing zone locations) 4-25 Figure 4-7 4-26 Figure 4-8 Lake Norman zooplankton composition (background locations)

Figure 5-1 Lake Norman creel zones 5-11 vi

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 2000.

OPERATIONAL DATA FOR 200Q "Themonthly average capacity factor for MNS was 100.8 %, 92.1 %, and 52.0 % during July, August, and September of 2000, respectively (Table 1-1). These are the months when conservation of cool water and discharge temperatures are most critical and the thermal limit 0

for MNS increases from a monthly average of 95.0°F (35.0°C) to 99.0°F (37.2 C). The 0 0 0 0 average monthly discharge temperature was 97.9 F (36.6 C) for July, 96.3 F (35.7 C) for August, and 91.3 0 F (32.9 0 C) for September 2000. The low-level intake pumps of MNS were not operated to provide additional cooling in 2000. 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 2000.

NPDES DISCHARGE CAPACITY FACTOR (%) TEMPERATURE Month Unit 1 Unit 2 Station Monthly Average Average Average Average OF °C January 105.6 99.0 102.3 69.2 20.7 February 106.0 87.8 - 96.9 65.6 18.7 March 105.7 - 105.3 105.5 73.9 23.3 April 105.4 105.0 105.2 77.3 25.2 May 96.6 104.2 100.4 83.2 28.4 June 102.6 102.8 102.7 92.4 33.6 July 101.5 100.1 100.8 97.9 36.6 August 101.3 82.9 92.1 96.3 35.7 September 102.7 1.3 52.0 91.3 32.9 October 103.6 57.2 80.4 84.0 28.9 November 104.7 97.7 101.2 79.1 26.2 December 105.5 105.1 105.3 70.6 21.4 1-2

CHAPTER 2 WATER CHEMISTRY INTRODUCTION The objectives of the water chemistry portion of the Lake Norman Maintenance Monitoring Program are to:

1. Maintain continuity in Lake Norman's chemical data base to allow detection of significant station-induced and/or natural change in the physicochemical structure of the lake; and

2. compare, where appropriatg these physicochemical data to similar data from other hydropower reservoirs and cooling impoundments in the Southeast.

This year's report focuses primarily on 1999 and 2000. Where appropriate, reference to pre-1999 data will be made by citing reports previously submitted to the North Carolina Department of Environment, Health, and Natural Resources (NC DEHNR).

METHODS AND MATERIALS The water chemistry monitoring program, including sample variables, locations, depths, and frequencies is outlined in Table 2-1. Sampling locations are identified in Figure 2-1, whereas specific chemical methodologies, along with the appropriate references are presented in Table 2-2. Data were analyzed using two approaches, both of which were consistent with earlier studies (DPC 1985, 1987, 1988a, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000). The first method involved partitioning the reservoir into mixing, background, and discharge zones, and making comparisons among zones and years. In this report, the discharge includes only Location 4; the mixing zone encompasses Locations 1 and 5; the background zone includes Locations 8, 11, and 15.

The second approach emphasized a much 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; 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.

2-1

Heat (Kcal/cm ) and oxygen (mg/cm 2 or mg/L) content of the reservoir were calculated according to Hutchinson (1957), using the following equation:

zo Lt = Ao-1.f TO*Azedz zm Where; 22 Lt = reservoir heat (Kcal/cm ) or oxygen (mg/cm2) content 2

Ao = surface area of reservoir (cm )

TO = mean temperature (0 C) or-oxygen content of layer z Az area (cm 2 ) at depth z dz = depth interval (cm) zo = surface zm = maximum depth RESULTS AND DISCUSSION Precipitation Amount Total annual precipitation in the vicinity of MNS in 2000 totaled 33.68 inches (Figure 2 2); this was similar to that observed in 1999 (35.21 inches), but appreciably less than measured in the 1997 (48.0 inches). The highest total monthly rainfall in 2000 occurred in September with a value of 7.60 inches.

Temperature and Dissolved Oxygen Water temperatures measured in 2000 illustrated similar temporal and spatial trends in the background and mixing zones (Figures 2-3, 2-4). 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 2000 were generally similar to corresponding measurements in 1999, except in early February when year 2000 temperatures averaged about 3 C cooler throughout the entire water column than observed in 1999 (Figure 2-3, 2-4). Interannual variability in water 2-2

temperatures during the spring, summer, and fall months was observed in both the mixing and background zones, but these conditions were well within the observed historical variability and were not considered of biological significance (DPC 1985, 1989, 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000).

Temperature data at the discharge location in 2000 were generally similar to 1999 (Figure 2-5) and historically (DPC 1985, 1987, 1988a, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000). The warmest discharge temperature of 2000 occurred in August and measured 34.7 'C, or 3.7 'C cooler than measured in August 1999 (DPC 2000).

Seasonal and spatial patterns of DO in 2000 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). Winter and early-spring DO values in 2000 were generally equal to or higher in the mixing zone, and lower in the background zone, than measured in 1999. These trends appear to be related to the cooler temperatures in the mixing zone, and warmer temperatures in the background zone measured in 2000 versus 1999. The cooler water temperatures would be expected to exhibit a higher oxygen content because of the direct effect of temperature on oxygen solubility, and indirectly via an enhanced convective mixing regime, which would promote reaeration.

Spring and summer DO values in 2000 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 1999 and earlier years (DPC 1985, 1987, 1988a, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000). DO values during the spring and summer of 2000 generally averaged 1-2 mg/L less throughout the water column than measured in 1999; the lone exception to this was observed in June when DO values were slightly higher than measured in 1999. All dissolved oxygen values recorded in 2000 were well within the historical range (DPC 1985, 1987, 1988a, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000).

Considerable differences were observed between 1999 and 2000 fall and early-winter DO values in both the mixing and background zones, especially in the metalimnion and hypolimnion during November (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 2-3

effects of variable weather patterns on water column 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.

Interannual differences in DO are common in Southeastern reservoirs, particularly during the stratified period, and can reflect yearly differences in hydrological, meteorological, and limnological forcing variables (Cole and Hannon 1985; Petts 1984).

The seasonal pattern of DO in 2000 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 2000 (5.4 mg/L) occurred in August, concurrent 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 2000 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 2000 are presented in Figure 2-10a; additional information on the thermal regime in the reservoir for the years 1999 and 2000 are found in Table 2-3. Annual 2

minimum heat content for the entire water column in 2000 (8.07 Kcal/cm ; 7.9 'C) 2 occurred in early February, whereas the maximum heat content (27.44 Kcal/cm ; 27.19

'C) occurred in mid-August. Heat content of the hypolimnion exhibited a somewhat different temporal trend as that observed for the entire water column. Annual minimum 2

hypolimnetic heat content occurred in early February and measured 4.3 Kcal/cm (6.6 15.46 Kcal/cm2

'C), whereas the maximum occurred in early September and measured (23.8'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 2-4

2 rate of the entire water column equalled 0.099 Kcal/cm 2/day versus 0.053 Kcal/cm /day for the hypolimnion. The 2000 heat content and heating rate data were slightly lower than measured in 1999, but similar to earlier years (DPC 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000).

The seasonal oxygen content and percent saturation of the whole water column, and the hypolimnion, are depicted for 2000 in Figure 2-10b. Additional oxygen data can be found in Table 2-4 which presents the 2000 AHOD for Lake Norman and similar estimates for 18 TVA reservoirs. Reservoir oxygen content was greatest in mid-winter when DO content measured 10.5 mg/L for the whole water column and 10.6 mg/L for the hypolimnion. Percent saturation values at this time approached 89% for the entire water column and 87% 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 4.73 mg/L (62% saturation), whereas the minimum for the hypolimnion was 0.66 mg/L (7.7% saturation). The mean rate of DO decline in the hypolimnion over the stratified period, i.e., the AHOD, was 0.033 mg/cmZ/day (0.059 mg/Liday) (Figure 2-10b), and is similar to that measured in 1999 (DPC 2000).

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 2

AHOD associated with various trophic states; oligotrophic - < 0.025 mg/cm /day, mesotrophic - 0.026 mg/cm 2 /day to 0.054 mg/cm 2 /day, and eutrophic - > 0.055 mg/cm2 /day. Employing these limits, Lake Norman should be classified as mesotrophic 2

based on the calculated AHOD value of 0.033 mg/cm /day for 2000. The oxygen based mesotrophic classification agrees well with the mesotrophic classification based on chlorophyll a levels (Chapter 3). The 2000 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 'C and DO levels > 2.0 mg/L, was found lake-wide from October 1999 2-5

through mid-June 2000. Beginning in July 2000, habitat reduction proceeded rapidly throughout the reservoir both as a result of deepening of the 26 'C 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 thin layer located in the metalimnion and a small zone of refuge in the upper, riverine portion of the reservoir, near the confluence of Lyles Creek with Lake Norman. Habitat measured in the upper reaches of the reservoir at this time 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 2000 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).

Turbidity and Specific Conductance Surface turbidity values were generally low at the MNS discharge, mixing zone, and mid lake background locations during 2000, ranging from 0.75 to 3.47 NTUs (Table 2-5).

Bottom turbidity values were also relatively low over the study period, ranging from 0.93 to 33.4 NTUs (Table 2-5). These values were similar to those measured in 1999 (Table 2-5), and well within the historic range (DPC 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000).

Specific conductance in Lake Norman in 2000 ranged from 56.7 to 107.5 umho/cm, and was similar to that observed in 1999 (Table 2-5), and historically (DPC 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000). Specific conductance values in surface and bottom waters were generally similar throughout the year except during the period of thermal stratification. Increases in bottom conductance values appeared 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).

2-6

pH and Alkalinity During 2000, pH and alkalinity values were similar among MNS discharge, mixing and background zones (Table 2-5); they were also similar to values measured in 1999 (Table 2-5) and historically (DPC 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000).

Individual pH values in 2000 ranged from 6.1 to 7.4, whereas alkalinity ranged from 15.0 to 32.0 mg/L of CaCO 3.

Major Cations and Anions The concentrations (mg/L) of najpor 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 2000 was similar to that reported for 1999 (Table 2-5) and previously (DPC 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000). 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 are provided in Table 2-5. Overall, nitrogen and phosphorus levels in 2000 were similar to those measured in 1999 and historically (DPC 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000). The lone exception to this pattern was total phosphorus. Total phosphorus concentrations in 2000 averaged about double that measured in 1999 for each of the zones investigated, but were well within the historical range (DPC 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000)

(Table 2-5).

Metals Metal concentrations in the discharge, mixing, and mid-lake background zones of Lake Norman for 2000 were similar to that measured in 1999 (Table 2-5) and historically (DPC 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000). Iron concentrations near the surface were generally low (< 0.1 mg/L) during 2000, whereas iron levels near the bottom were slightly higher during the stratified period. Similarly, 2-7

manganese concentrations in the surface and bottom waters were generally low (*< 0.1 mg/L) in both 1999 and 2000, 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). Heavy metal concentrations in Lake Norman never approached NC water quality standards, and there were no appreciable differences between 1999 and 2000.

FUTURE WATER CHEMISTRY STUDIES No changes are planned for the Water Chemistry portion of the Lake Norman maintenance monitoring program during 2001 or 2002.

SUMMARY

Temporal and spatial trends in water temperature and DO data collected in 2000 were similar to those observed historically. Temperature and DO data collected in 2000 were within the range of previously measured values.

Reservoir-wide isotherm and isopleth information for 2000, 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 2000 was generally similar to historical conditions. All chemical parameters measured in 2000 were within the concentration ranges previously reported for the lake during both MNS preoperational and operational years. As has been observed historically, manganese concentrations in the bottom waters in the summer and fall of 2000 often exceeded the NC water quality standard. This is characteristic of waterbodies that experience hypolimnetic deoxygenation during the summer.

2-8

LITERATURE CITED 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.

Duke Power Company. 1987. -Lake Norman Maintenance Monitoring Program: 1986 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1988a. Lake Norman Maintenance Monitoring Program: 1987 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1988b. Mathematical modeling of McGuire Nuclear Station thermal discharges. Duke Power Company, Charlotte, NC.

Duke Power Company. 1989. Lake 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.

Duke Power Company. 1992. Lake Norman Maintenance Monitoring Program: 1991 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1993. Lake Norman Maintenance Monitoring Program: 1992 Summary. Duke Power Company, Charlotte, NC.

2-9

Duke Power Company. 1994. Lake Norman Maintenance Monitoring Program: 1993 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1995. Lake Norman Maintenance Monitoring Program: 1994 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1996. Lake Norman Maintenance Monitoring Program: 1995 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1997. Lake Norman Maintenance Monitoring Program: 1996 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1998. -Lake Norman Maintenance Monitoring Program: 1997 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1999. Lake Norman Maintenance Monitoring Program: 1998 Summary. Duke Power Company, Charlotte, NC.

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);209-22 1.

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.

2-10

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.

Stumm, w. and J. J. Morgan. 1970. Aquatic chemistry: an introduction emphasizing chemical equilibria in natural waters. Wiley and Sons, Inc. New York, NY 583p.

Wetzel, R. G. 1975. Limnology. W. B. Saunders Company, Philadelphia, Pennsylvania, 7 4 3 pp.

2-11

CFCtC 0,0,0,0,0,0,0,0, (C [C[C 0,0,0,

'C;0 FcC In m,03o3km 03033034030 0303030303030303 EE99999o' CCIFCCC 00000000

_I m03o3ca0ca30303 0303030303030303 030303 0 03 egg0t Caaa Y Yao 0

03 0, 03 FCFcC cCF 00 o' aco' ar lzt::tE E

a a a a a a a a a 0, 0, 0,

.2 0aM3 03030303a 0303030303030303 80 03 03 C'

geeEC COaa00'Y C CCCCC C C a a a a a a a a aY a 0

C, 030303030303 c 0303030303030303 0

eC eCe ae a a aYaYa C CCgCCC a a a a a a a a OlCV 00

-3 z 0, 03 z z 0303030303030303 C CCC C CCC

.2 0' 03 crCC CCC( C, a a aa a a a a 00 ca a aoana a 0 z 0303030303030303 m nk 00 0' 03 rCV CCY CY CCtBzCtz Cca LUi a a a a a a a a E

00 CC CC ca z Co 0, 03 03E a, a a af a a aaa a a aa a 0

C, cca 0

aYaYa a a aO 0,aaayaaa 0,, 00g a nc E 0'

('4

.E ! 0303 m0303030 vo aV a a a, aY a CC aYa a aa Y aa Ol 0 Z: 03 0

0 0 0 C-,

S000 0 04 0~ aZ 0 2+. EE 00 0

< rC z

<E ~ ~ S 10 u

2-12

(

Table 2-2. Water chemistry methods and analyte detection limits for the McGuiie Nuclear Station NPDES long term maintenance program for Lake Norman.

Variables Method Preseration Detect~ion Limit Alkalinity, total Electrometric titration to a pH of 5.12 40C 1mg-CaCO3T1 ,

Aluminum Atomic emission/ICP-direct injecition 2 0.5% HNO0 0.3 mg 'I" Ammonium Automated phenate' 40C 0.050 m'1 Cadmium Atomic absorption/graphite furnace-direct injection 2 0.5% HNO0 0.1 ;1 g. l "

Calcium Atomic emission/ICP-dIrect injecition 2 0.5% HNO0 0.04 mg "1 Chloride Automated ferricyanide' 40C 1.0 mg .I"'

Conductance, specific Temperature compensated nickel electrodel In-situ Ipmho.cm"

• Copper Atomic absorption/graphite fumace-direct injection2 0.5% HNO 3 0.5 ligl1*1 Fluoride Potentiometric 2 40C 0.10 mg .I"1 Iron Atomic emission/ICP-direct injection 2 0.5% HNO0 '0.1 mg .I"1 Lead Atomic absorption/graphite furnace-direct injection2 0.5% HNO0 p2.0 jigl"'

Magnesium Atomic emission/ICP-direct injection 2 0.5% HNO, 0.001 mg '1"1 Manganese Atomic emission/lCP-direct injection 2 0.5% HNO0 0,003 mg 'T1 Nitrite-Nitrate Automated cadmium reduction' 40C 0.050 mg 'I' Onhophosphate Automated ascorbic acid reduction' 40C 0.005 mg T1" Oxygen, dissolved Temperature compensated polarographic cell' In-situ 0.1 mg "1*F pH Temperature compensated glass electrode' In-situ 0.1 std. units*

Phosphorus, total Persulfate ýlgestion followed by automated ascorbic acid 40C 0.005 mg '1I **

reduction 0.015 mg 1 **

Potassium Atomic absorption/graphite furnace-direct injection 2 0.5% HNO0 0.1 mg .1" Silica Automated molydosillcatei -, 40C 0.5 mg "1'F Sodium Atomic emission/ICP-direct injection 2 0.5% HNO0 0.3 mg "1'F Sulfate Turbidimetric, using a spectrophotometer ' 40C 1.0 mg 1"'

Temperature Thermistor/thermometer' In-situ 0.10C*

Turbidity Nephelometric turbidity' 40C I NTU*

Zinc Atomic emission/ICP-direct injection2 0.5% HNO, 4 pg'l"1

'United States Environmental Protection Agency 1979. Methods for chemical analysis of water and wastes.

Environmental Monitoring and Support Laboratory. Cincinnati, OH.

2 USEPA. 1982

'USEPA. 1984

• Instrument sensitivity used instead of detection limit.

• • Detection limit changed during 1989.

Table 2-3. Heat content calculations for the thermal regime in Lake Norman for 1999 and 2000.

1999 2000 Maximum areal heat content (g cal/cm 2) 28,371 27,434 Minimum areal heat content (g cal/cm 2) 10,293 8066 Maximum hypolimnetic (below 11.5 m) 15,649 15,459 areal heat content (g cal/cm)

"Birgean heat budget (g cal/cm2) 18,079 19,368 Epilimnion (above 11.5 m) heating 0.094 0.106 rate (°C /day)

Hypolimnion (below 11.5 m) heating 0.085 0.082 rate ('C /day) 2-14

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/cm 2 /day) (ug/L) (m) (m)

Lake Norman (2000) 0.033 5.2 2.45 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) 2-15

( f (

Table 2.5. Quarterly surface (0.3 m) and bottom (bottom minus I m) water chemistry lot tIheMNS discharge, mixing zone, and background locations on Lake Norman during 1999 and 2000. Values less than detection were assumed to be the detection limit fo0calculating a mean.

Mixing Zone Mixing Zone MNS Discharge Mixing Zone Background Background LOCATION: 1.0 2.0 4.0 5.0 8.0 11.0 DEPTH: Surface Bottom Surface Bottom Surface Surface Bottom Surlace Bottom Surface Bottom sO Turbidity (ntu)

Feb 3,27 1.87 4.53 6.24 3.13 1.57 3.00 8.17 3.47 1.76 1.68 1.78 3.96 4.29 3.62 1.83 33.4 7.69 3.1S 1.74 4.08 12.20 May 1.22 1.77 1.22 12.50 0.98 2.04 0.93 2.88 0.95 2.81 0.88 2.32 1.16 3.28 0.75 2.18 1.82 3.22 0.97 2.88 2.49 3.33 Aug 1.04 1.71 3.47 6,24 1.33 2.14 2.24 2.83 0.88 1.50 1.57 1.47 9.23 2.73 1.SS 1.83 4.92 2.79 1.81 1.99 5.9 2.62 Nov 0.97 1.85 8.9 3.78 1.04 2.01 7.36 5.75 1.53 2.685 1.04 2.23 3.77 4.25 1.07 2.13 8.32 4.25 1.60 2.19 2.87 12.00 Annual Mean 16 - -1 1 T 4.9 1.71 2,1 1.29 . 0 ""4.33. 3.6 7'W 7T ,92 4.6 "'1.83 - 3.84 7.5 Specific Conductance (umho/Cm)

Feb 57.1 52 67.0 88 57.1 51 58.9 61 58.1 53 67,8 52 57.0 53 57.2 51 58.7 67 60.4 53 59.5 66 May 58.5 80 68.7 95 60.2 60 59.3 59 60.6 60 60.3 60 59.8 59 81.7 80 81.3 69 60.7 60 82.9 86 Aug 84.0 80 74.0 86 64.0 80 77.0 64 65.0 60 64.0 60 75.0 63 84.0 80 70.0 83 63.0 61 74.0 61 Nov 84.0 64 107.6 105 64.2 64 105.1 79 68.7 64 66.6 84 67.4 83 85.8 83 92.3 63 68.8 64 73.3 65 Annual Mean 0T "- 4... .6 681.4 5 a * ,' M9,. 62.2 =50 64.8 M. , 8 7W.

X2.7 3. 9,5' .

pH (units)

Feb 6.5 8.3 8,8 8.3 7.0 8.8 6.7 6.3 7.2 6.6 7.0 6.7 11.6 8.4 7.0 8.7 6.8 8.8 7.0 6.7 8.8 686 May 8.9 8.3 8.1 8.2 8.8 8.5 8,1 8.5 8.0 6.5 7.1 6.6 0.3 8.7 8.9 8.7 8.2 8.5 7.1 6.7 6.2 8.4 Aug 7.2 7.1 8.2 8.3 7.4 7.2 8.3 8.2 8,8 68, 7.0 7.0 8.4 8.1 7.1 7.9 8.2 6.2 8.6 8.0 6.2 6.2 Nov 7.0 6.8 6.8 8.8 7.1 8.8 6.8 8.5 7.1 8.8 7.1 6.9 8.8 8.7 7.2 7.0 8.7 8.8 7.0 7.0 6.8 8.5 Annual Moan 69 0 -=4T 6 .38 6.99 '6.68 -7564- 8.79 6.46 6.47 =70r4 ... 77 .. 6.46 ,.48 6.92 7.11 -C4-7 Alkalinity (mg CaCO3A)

Feb 16.6 13.0 18.0 13.0 18.5 13.0 15.5 13.5 16.0 13.0 16.0 0 1i.s 13.6 18.0 12.6 15.6 13.5 15.5 13.5 15.6 12.5 May 15.5 14.6 15.8 14.0 16.0 14.0 16.5 14.0 15.0 14.0 15.5 13.5 15.6 14.0 15.0 13.5 15.0 14.0 15.0 13.5 15.5 14.0 Aug 18.5 1650 17.0 17.6 16.5 14.5 17.5 14.5 18.0 14.5 17.0 14.6 23.5 15.5 16.6 14.5 20,0 17.0 18.5 14.0 22.0 18.0 Nov 17.0 16.0 32.0 18.5 17.0 18.0 34.6 16.0 17.0 16.0 17.0 16.0 17.0 18.0 17.0. 15.5 30.0 15.5 16.5 15.5 18.5 15.5 Annual Mean J 48 ' I . W i. 14.51 18.01 14.39 9 14.26 17.89 14.7 6,T 20.1'4',1 15.89 14.14 17.8U- 4,61 Cnlonde (mOA)

Feb 5.5 4.9 6.8 5.2 5.6 5,1 5.5 6.5 8.7 4.9 5.6 4.8 5.5 5.0 6.8 4.8 6.7 5.8 8.1 4.9 "6.8 6.3 May 5.8 5.1 6.7 5.2 5.6 5.0 5.8 5.1 5.8 5.1 5.8 6.1 5.8 5.1 6.7 5.1 6.7 5,2 5.6 5.2 6.7 6.0 Aug 6.7 .50 5.9 4.8 5.6 4.9 5.8 4.9 5.7 4.9 6.6 4.9 5.8 4.9 5.7 4.9 5.7 4.7 6.7 4.9 8.0 4.8 Nov 5.6 6.0 5.9 5.0 5,7 6.0 6.0 5.0 5.7 5.0 5.8 4.9 6.7 4.9 5.8 6.0 5.8 5.0 5.8 5.0 5.6 5.4 Annual Mean .6 .8 6.0 * -7 6.13 5.73 4.98 70 , 4,a3 .5 .8 6".70 4, T.7 .=8 6.75 5 =8" Suilate (mg/4)

Feb 5.45 NS 5.78 NS 5.46 4.5 5.46 5.0 .548 4.4 5.48 NS 5.44 NS 5.53 4.3 5.46 5.3 5.97 NS 5.88 NS May 5.94 NS 5.98 NS 6.03 8.7 5.96 8.2 8.21 8.2 6.04 NS 6.95 NS 6.80 9.1 6.92 8.0 8.13 NS 5.98 NS Aug 6.22 NS 5.95 NS 8.24 8.5 5.75 NS 8.22 8.8 6.22 NS 5.31 NS 7.80 9.6 6569 NS 8.23 NS 5.47 NS Nov 6.15 NS 3.78 NS 8.14 7.7 18.6 8.2 6.13 8.8 6.06 NS 6.01 NS 7.00 7.6 3.98 7.2 6.23 NS 6.13 NS Annual Mean 5.94 -- -- =--- 8.4 7._3 -, 0 595 - 5.68 -1 3 =. 6.14 Calcium (mg/l)

Feb 2.83 2.71 2.79 2.67 2.95 2.75 3.01 2.72 2.86 2.72 2.88 2.73 2,95 2.89 2.79 2.76 2.89 2.70 2.89 2.76 2.91 2.84 May 3.05 2.88 3.09 2.95 2.91 2.87 2.89 2.92 2.93 2.88 2.99 2.87 3.03 2.88 2.82 2.89 3.05 2.97 3.06 3.10 3.20 3.04 Aug 3.15 3.01 3.37 3.33 3.14 3.02 3.46 3.21 3.18 2.99 3.12 3.00 3.57 3.15 3.11 2.99 3.40 3.29 3.21 3.05 3.85 3.26 Nov 3.29 3.11 4.03 3.17 3.21 3.13 4.11 3.15 3.22 3.12 3.22 3.17 3.25 3.14 3.22 3.14 4.02 3.18 3.19 2.97 3.07 2.68 Annual Mean .08 3. . -707 ' =3 3.00 3.04 2.93 3.05 2.94 2 2. . 4 4. 3.=

3.0 2.97 Magnesium (mg/I)

Feb 1.43 1.33 1.42 1.32 1.48 1.35 1.51 1.38 1.44 1.33 1.45 1.33 1.48 1.33 1.41 1.35 1.44 1.33 1.38 1.34 1.48 1.35 May 1.52 1.38 1.53 1.42 1.45 1,38 1.45 139 4 1.38 1.46 1.38 1.51 1.38 1.33 1.38 1.49 1.41 1.43 1.40 1.51 1.41 Aug 1.54 1.45 1.57 1.55 1.53 1.44 1.62 1.50 1.53 1.42 1.52 1.44 1,86 1.48 1.52 1.44 1.54 1.62 1.61 1.46 1.62 1.50 Nov 1.62 1.53 1.78 1.5 1.59 1.52 1.78 1.52 1.59 1.53 1.60 1.55 1.60 1.53 1.89 1.53 1.78 1.56 1.59 1.52 1.57 1.49 Annual Mean .1.63.. .Z ' 7* 1.51 1.4 1.44 1.41

- 1.43 .1.58

-,3' .4 1. 1.42 1.6 1.45 1.48 1.43 -

NS - Not Sampled

( (

Table 2-5. (Continued)

Mixing Zone Mixing Zone MNS Discharge Mixing Zone Background Background LOCATION: 1.0 2.0 4.0 5.0 8.0 11.0 DEPTH: Surface Bottom Surface Bottom Surface Surface Bottom Surface Bottom Surface Bottom PA RAM"I.4*TR YFAR* 2 Do 2000 2000 99 2000 99 2000 99 2000 99 2000 99 2000 99 2000 2000 99 2000 Potassium (mg)

Feb 1.67 1.82 1.67 1.83 1.75 1.88 1.82 1.74 1.72 1.84 1.72 1.82 1.78 1.82 1.88 1.89 1.8S 1.70 1.83 1.89 1.82 1.70 May 1.91 1.50 1.85 1.67 1.78 1.56 1.74 1.60 1.77 1.59 1.95 1.68 1.82 1.88 1.59 1.65 1.88 1.58 1.73 1.45 1.88 1.49 Aug 1.71 1.81 1.79 1.87 1.82 1.69 1.74 1.80 1,76 1.58 1.73 1.57 1.86 1.69 1.83 1.88 1.U5 1.69 1.73 1.58 1.80 1.57 Nov 1.85 1.73 1.92 1.85 1.82 1.83 1.99 1.85 1.84 1.81 1.85 1.88 1.82 1.80 1.80 1.82 1.91 1.88 1,85 1.85 1.84 1.90 Annual Mean 1.79 1 1.81 ,6 1.7T 1-66 1.82 -1.7 1.77 1.66 =81 1.66 . 1. -- 1.6 '1.77 I.68 1.74 -1.V 1.83 1.67 SooTum (mg/i)

Feb 8.43 8.84 8.27 5.98 7.33 6.80 8.99 68.52 6.57 5.63 6.34 5.51 8.52 5.77 8.40 8.87 8.55 8.74 7.18 8.18 7.41 7.02 May 8.72 8.18 8.79 8.27 6.37 6.02 6.31 6.47 6.58 8.18 6.45 5.89 8.36 8.18 5.82 8.24 6.69 8.35 8.08 6.33 6,57 6.40 Aug 7.12 8.12 8.43 8.19 6.84 5.84 7.30 56,84 8.93 8.35 7.12 6.54 8.76 5.83 7.19 8.02 8.78 .886 7.06 6.04 8.72 5.87 Nov 8.48 5.63 8.19 8.43 8.61 6.21 6.28 8.07 8.40 6.41 8.40 6.37 8.37 8.18 6.48 6.48 6.06 8.07 8.50 6.28 8.67 7.08 Annual Mean *TU 5.89 =4 =.67 .

62,83 6,14 6.58 -K 5.7 , 6.47 6.1V 6.M 6. 2 T7-0 ... 6.21 . 7-59 Aluminum (tg/I)

Feb 0.12 0.05 0.125 0.10 0.127 0.10 0.134 0.16 0,129 0.09 0.148 0.08 L0.121 0.12 0.14 0.11 0.236 0.14 0.124 0.11 0.159 0.23 May 0.08 0.06 0.068 0.26 0.061 0.13 0.081 0.13 0.081 0.13 0.077 0.11 0.078 0.12 0.088 0.13 0.088 0.18 0.088 0.11 0.112 0.12 Aug 0.062 0.05 0.113 0.19 0.094 0.07 0,131 0.16 0.087 0.09 0.1 0.08 0.185 0.12 0.109 0.10 0.118 0.15 0.098 0.11 0.147 0.16 Nov 0.05 0.05 0.08 0.20 0.05 0.14 0.08 0.21 0.05 0.15 0.05 0.18 0.05 0.18 0.05 0.18 0.08 0.19 0.05 0.16 0.05 0.33 Annual Mean = .1 *i 0.0-77 7 = .i -U 0,0. 0.14 '0 1 = .17 0.089 " 0,7712 =i -It?

Iron (rag/l)

Feb 0.019 0.029 0.028 0,098 0,021 0.031 0,037 0.145 0.021 0.030 0.020 0.032 0.027 , 0.084 0.020 0.024 0.211 0.121 0.024 0.038 0.069 0.368 May 0.027 0.041 0.040 0.369 0,019 0.037 0.020 0.039 0.017 0.032 0.022 0.027 0.051 0.041 0.010 0,028 0.027 0.068 0,024 0.054 0.063 0,082 Aug 0.030 0.048 0.068 0.309 0.028 0.038 0.055 0.142 0,030 0.041 0.023 0.035 0.756 0.105 0.033 0.037 0.265 0.153 0.029 0,035 0.450 0.108 Nov 0.033 0.035 1.281 0,147 0,039 0.043 3.218 0.127 0.052 0,048 0.041 0.044 0.129 0.113 0.029 0.038 1.960 0.071 0.053 0.057 0.161 0.388 AnnualMean * * , U7 7 0.1 0 0.038 ,0.0272 0. 0 0 01 0.10 0 ,

Manganese (mg7,)

Feb 0.01 0.02 0.02 0.08 0.01 0.01 0.01 0.08 0.01 0.01 0.01 0.01 0.02 0.04 0.01 0.01 0.08 0.07 0,01 0.01 0.02 0.09 May 0.01 0.01 0.02 0.07 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.01 0.01 0.01 0.03 0.01 0.01 0.04 0.05 Aug 0.02 0.02 0.31 1.30 0.02 0.02 1.18 0.75 0.02 0.02 0.02 0.02 2.47 0.45 0.02 0.01 0.87 0.32 0.01 0.03 2.20 0.89 Nov 0,04 0.04 6.18 0.29 0,0S 0.04 5.15 0.13 0.07 0.04 0.07 0,04 0.42 0.09 0.03 0.03 3.72 0.03 0.07 0.02 1.19 0.35 Annual Mean .*3 -"n " 4 , 0t , 0 -U -' 073 - - 0.1 0 , 't 7T 0.1 - =,0 =2 = - .9 Cadmium (aug/)-S Feb 0.6 NS 0.5 NS 0.5 0.5 0.5 0.5 0.5 0.5 0.5 NS 0.6 NS 0,1 0.5 0.8 0.6 0.5 NS 0.5 NS May NS NS NS NS NS NS NS NS NS NS NS NS NS NS INS IN NS NS NS NS NS NS Aug 0.6 NS 0.6 NS 0.5 NS 0.5 NS 0.6 NS 0.5 NS 0.5 NS 0.6 NS 0.6 NS 0.5 NS 0.5 NS Nov 0.6 NS 0.6 NS 0.5 NS 0.5 NS 0.5 NS 0.5 NS 0.5 NS 0.6 NS 0.5 NS 0.6 NS 0.6 NS Annual Mean - 15.6 - .5 0.5 .0.5 0,5 0,66 -

0.5 = 0-T '06.T ' ,, 0.6 Copper (ug/i)

Feb 2.00 NS 2 NS 2 2.0 2 4.8 2 2.0 2 NS 2 NS 2 2.0 4.89 2.0 2.83 NS 2.58 NS May 'NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS Aug 2,0 NS 5.0 NS 2.3 NS 2.1 NS 2.0 NS 2.0 NS 2.0 NS 2.0 NS 2.0 NS 2.0 NS 2.0 NS Nov 2.1 NS 2,2 NS 2.0 NS 2.0 NS 2.0 NS 2.0 NS 2.3 NS 2.0 NS 2.0 NS 3.1 NS 2.1 NS Annual Mean 2, 20 2 4,8 2.0 2. 2.0 2.0 3.0 ., -

Lead (ug/I)

Feb 2 NS 2 NS 2 2 2 2 2 2 2 NS 2 NS 2 2 2 2 2 NS 2 NB May NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS, NB NS NS NS NS NS Aug 2 NS 2 NS 2 NS 2 NS 2 NS 2 NS 2 NS 2 NS 2 NS 2 NS 2 NS Nov 2 NB_ 2 N 2 NB 2 NS 2 NS 2 NS 2 NS 2 NS 2 NS 2 NB 2 N, Annual Mean 2 " " - 2 * .-2 2 -

NS - Not sampled

00 oolo 0. 010 01IS' 4 OtatataL 8 t t tO 1 .

000010 888 000010 00 0o[ 0,S tat0, t t 04 tr tr 040.

0 000010 O 00 ta[ 000 S4]0 0-004 tIc 00 S' 00001.4, 04 04 04 000404 L-d 0 0 04 '4 ooOOIta 000 88 w 0404 04[

Oj.O 000 -

0 4 000010. 000 000 '0f C ONj F 82IN N N - tI 000 000 8 tar 04 00 N Oj 000 000 8 0q4tR04 04 000 888 8I "-

0 10 04 04tv 00zý40404 F 0!.C, 008 000 tar C 04 S0 000 0jo 000010 00 000010

- 0 00 c0c 8

-04.- V ,-o ooI Co coo do 08 0000 0000 0g O~ 0 00 0 000 O~r17!.

0-W 5-000.

~

OooOIO 00 ~ 0 ~ 000001 ~ 00 ~ 004C o 8a -- 1 0r4444 0 '- 0000

.... Il 04 0100 t 4 04 t oj 0004 04 04 04 1 04 F

0) z 04 toolo I d s,,oJ In z

<z c 000.

. NO 1.3 >- 004 88 0 SS! <Z c

cc 100 C <Z 'C C4 Cc 2-18

80 -N

.,*7269w "

LC

"*. '* -5.9 MS

• *~13

,'* o* '*"  :* 9.5 i ' 4 Figure 2-1 Map of sampling locations on Lake Norman 2-19

McGuire Rainfall 8

6 2

0 Month W2000 E 199 Figure 2-2. Monthly precipitation in the vicinity of McGuire Nuclear Station.

2-20

IT-I11 Depth (m) Depth (m) 8888 N U~ E 0 0>

88 8 c5, 00m 0 0

0 0

rn.-x-, -4 b0

-8 *1

-8

-8 CD bi Depth (m) Depth (m) bý88N8U8oo8 S888 *

• oD o 0

o8 0 C.)

0 0

0 .........

0

-4 0

)

0* 01 8 -I 8

z -8 8

\0 o

0

\0 bi AO.

co C Depth (m)

C>

8* 888* I *

• oo 0 0

- 01 00 01 C*)

0 0

C

0. -4 0

I -8

-8 8*

8 8

ZZ-Z Depth (m)

'TI o 0 0*

CD 0

CY)

It.

0 8*

8l Depth (m) 88 8 ),

0 8*

.0

-8 Depth (m) "- bepth (m) 0 I I I I I I 0

- (1) 0

-I

-o 8

8

( C .

JAN FEB M12 T0'5 e(2 0 5 10 15 20 25 30 35 0 5 10 15 20 25 3) 35 0 5 10 15 20 25 30 35 AOR NAY T015 10 (00 0 5 10 15 20 25 30 35 0 5 10 15 23 25 33 35 0 5 10 15 23 25 30 35 Z 15.

20 Figure 2-4. Monthly mean temperature profiles for the McGuire Nuclear Station mixing zone in 1999 (4*) and 2000 (xx).

Depth (m) 88 8 8 n o

"-11 0 0 0

0 x

'4.

'CC 8

8

.0 8 0i Depth (m) Depth (m) 8L8 8 IC) 0 8888* 5* *o cn 8 :11 8*

'C-CC-CC-n Depth (m) -r* Depth (m) a 8 'N B G1 01 8 c" 8 8 i5 01m 0 0

• 0 01 0

................ CSCC-CC-CC,,(

1*

'C 8

'C 8

45 40 35 S30

_ 25 1.

a 20 E

(D j- 15 10 5-I I I i Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month 1) 10

".0 8

X 6-0

=0

_> 4-2-

0 i Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan M,onth Figure 2-5. Monthly surface (0.3m) temperature and dissolved oxygen data at the discharge location (loc. 4.0) in 2000 (0) and 1999 (0).

2-25

( ( (

JAN FEB 48R MsdwOvje(n~t) 0 2 4 6 8 10 12 0 2 4 6 8 10 '12 0 2 4 6 8 10 12 03, 5.

10,

~15 020 X 25 I 30 AmRL MAY J08 0 _2d 6c (n 1L 0

0 2 4 6 8 10 12 0 2 4 6 8 10 12 0 2 4 6 8 10 12 5

10 25 3:)

35 to Figure 2-6. Monthly mean dissolved oxygen profiles for the McGuire Nuclear Station background zone in 1999 (, +) and 2000 (xx).

Depth (m) Depth (m)

S 8 8* *8 i 8 8 G c o>

0 C

ý11 0\

• N) N)

C) 0 0)

I co is a N)

Depth (m) 888]b E* *

• o o C)

Al~

'C,'

co OD 0

F5 Depth (m) i l I i i i 0 0

• N)

[H I

• 0)

I co 0

N)

( ( (

FE08 WAR 2 4O9A 6 (n 1 1 O~ssd'd OW*e (rnVI 2 4 6 8 0 2 4 6 8 10 ,12 10 12 0 2 4 6 8 10 12 20 V

APR 0AY JLW D~ssdvwd ON (nigit)

CsdVed OW (np*)

0 2 4 6 8 10 12 0 2 4 6 8 10 12 0 2 4 6 8 10 12 00 00 Figure 2-7. Monthly mean dissolved oxygen profiles for the McGuire Nuclear Station mixing zone in 1999 (+ +) and 2000 (xx).

( ( (

tLY 024 610 1 SE08 Uwdvso'*cycm- (nvl 1,mo',Ado Ogm (n-gn 2 4 6 8 10 12 0 2 4 6 8 10 ,12 0 2 4 6 8 10 12 5.

10' 25 30.

l NIOV wdQ On(rn1 0 2 O4 8(nV¶.)

0 2 4 6 8 10 12 0 2 4 6 8 10 12 0 2 4 6 8 10 12 0

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

( H Sampling Locations 235: 1.0 8.0 11.0 13.0 15.0 15.9 62.0 69.0 72.0 80.0

. & I & I I I, I I.

225 220 215

- 210 2o0 200 Temperature (deg C)

Jan 6, 2000 20 1 5 .. 3 3. 40 45 5'0 55 Distance from Cowans Ford Dam (kin) 240 Sampling Locations 23 1.0 8.0 11.0 13.0 15.0 15.9 62.0 80.0 72.0 80.0 230- I I,-- I6 I" 225:

112 220 o 0, 215

210"- ,m 205 2o0( Temperature (deg C)

Mar 7, 2000 956 .. . . 1. 150 2'S 10 25 30 73'5 40 ' '4 '50 .... 55 0 fl.*tnn*e~ frtom Ctownr* Fored fl:o, flcm'l Distance from Cowans Ford Dam fkm' Distance from Cowans Ford Dam (km)

Figure 2-8. Monthly reservoir-wide temperature isotherms for Lake Norman in 2000.

( zLu 4 Sampling Locations Sampling Locations 235 1.0 8.0 11.0 13.0 15.0 15.9 62.0 69.0 72.0 80.0 235 1.0 8.0 11.0 13.0 15.0 15.9 62.0 69.0 72.0 80.0

& t 1 1 1 & I 1 4 230, 230

, 225 225 "42 E

S220' S220" E

215 . 215" W 210-, w 210 14,5 205 205-..

200-

"Temperature (deg C) 200 Temperature (deg C)

May 1, 2000 Jun 6,2000 4o3*

"6 1 ..... .... 210 ' 2'5 '*31

'15 . .... S5 .... '..

.4'0 4'5 .... 5'0 .... '5'5 6 .... .. 1. .. .2'0 ,

.5 2,5 3 '0 ' .... 4'0 . 45 .... 5 55 Distance from Cowans Ford Dam (kin) Distance from Cowans Ford Dam (kin) 2407 Sampling Locations

-10 23 8.0 11.0 13.0 15.0 15.9 82.0 89.0 72.0 80.0 230 E 220:

5 m 210.:

205 200- Temperature, (deg Aug 7, 2000 lvý . -

. 1 7 120 .A 37 47 45 50 5.5 Distance from Cowans Ford Dam (km) Distance from Cowans Ford Dam (kin)

Figure 2-8. Continued.

(

Distance from Cowans Ford Dam (kin) Distance from Cowans Ford Dam (kin)

E

>E k,,

Distance from Cowan& Ford Dam (kin) Distance from Cowans Ford Dam (km)

Figure 2-8. Continued.

( Sampling Locations z4 v Sampling Locations I.

235 1.0 8.0 11.0 13.0 15.0 15.9 62.0 69.0 72.0 80.0 235.:

1.0 8.0 11.0 13.0 15.0 15,9 62.0 69.0 72.0 80.0 I

L I 1 1 1 1 1I 230. 230 22$

E 225 0 222. 220.

21 215.

W 21 w 210-'

205 205 200-Dissolved Oxygen (mg/I) 200- Dissolved Oxygen (mg/I)

Jan 6,2000 Feb 7, 2000

. 1. . I *2.

..o . 5.A 3'0" ' '35 . ' 40 .... 50 55 ".' 15 . .2 2 ...300 . 3. 40 .... 45 '50 ' 55 Distance from Cowans Ford Dam (kin) Distance from Cowans Ford Dam (km) 240 240 Sampling Locations Sampling Locations 235- 1,o 8.0 11.0 13.0 15.0 15.9 62.0 890 72.0 80.0 235 1.0 8.0 11.0 13.0 15.0 15.9 62.0 69,0 72.0 800.

I 2300 230 22&: 225 E

41 220, S220 M

S 215 215.

210 W 210 205 205 200- Dissolved Oxygen (mg/I) 200- Dissolved Oxygen (rag/l)

Mar 7,2000 S~Anr* *nmn uJ 195 ' . ." . .. 1'0 1'5 210 '

An 6" 20ry)v 25 ' 3'0 5... ' .00 .... 4' .... 5'0 ....

I;2J 6

4 . . 1117 11 15 " 2b 25 310. 5 .... 4'0. 4'5 .... 5'0 . 5 Distance from Cowans Ford Dam (kin) Distance from Cowans Ford Dam (kin)

Figure 2-9. Monthly reservoir-wide dissolved oxygen isopleths for Lake Norman in 2000.

(

s22C 21 21 (6 205 2~1 0 -5 20 Dissolved Oxygen (mg/I)

"May1, 2000 170 5 20 2S .... 3'0 .... 35 .... 4'0 .... 4'5 .... ....5' S5 Distance from Cowans Ford Dam (kin) Distance from Cowans Ford Dam (kin) 240 Sampling Locations 23 1.0 8.0 11.0 13.0 15.0 15.9 82.0 690 72.0 80.0

. 1. , 1 1* ,1 1 1 230 \9 A.

20220 5215-:

210 205 20 Dissolved Oxygen (mg/I)

Jul 3, 2000 195 Distance from Cowans Ford Dam (km) Distance from Cowans Ford Dam (kin)

Figure 2-9. Continued.

( 240 Sampling Locations Sampling Locations 23.1.0 8.0 11.0 13.0 15.0 15.9 82.0 69.0 72.0 80.0 235 1,0 8.0 11.0 13.0 15,0 15.9 62.0 89.0 72.0 80.0

, I, I, I I 1 1. 1 1 1 1, 1, I £ t I I t 23b,- 230 225: 225-220- 220 ,~201 E

215: 215 7

- 210o S210 205 205`

200Dissolved Oxygen (mg/) 200 Dissolved Oxygen (mg/I)

Sep 5,2000 Oct 2, 2000 195I'l 195 .. 1

, t i' 2 31o 4 1 . . .4 20 25 1 3 1 1 '0 35 40. .... 5'0 .. 5.

Distance from Cowans Ford Dam (kin) Distance from Cowans Ford Dam (ki) 240. 240 Sampling Locations Sampling Locations 235- 1.0 8.0 11.0 13.0 15.0 15.9 62.0 69.0 72.0 80.0 235" 1,0 8.0 110 13.0 15.0 15.9 82.0 69.0 72.0 80.0 L I .

• 230- 230:

(*22001 0 S225 22 210 22-c215. 612 215.

21Wý 210 ID 20* 2 205:

20 Dissolved Oxygen (mg/I) 20o Dissolved Oxygen (Mg/I)

Nov 6, 2000 Dec 4, 2000 10 15 20 25. ... 0 35 .. 4'0 445. 0 55 l 5 51A '7 -5....50 7 Distance from Cowans Ford Dam (kin) Distance from Cowans Ford Dam (kin)

Figure 2-9. Continued.,

( ( (

I-T I--h Kcal/sq cm Oxygen (mg/L) 0 01 0 01 0 m0 Ul C0 0

o Cb C0 4o C. 0) C I 1/6/00 0 1/20/00 2/3/00 2/17/00 0 3/2/00 0

3/16/00 :Z 3/30/00 4/13/00 4/27/00 5/11/00 c.* 5/25/00 5/25/00

= 6/8/00 S6/8/00

- © S6/22/00 S6/22/00 o S7/6/00 z-* 0 7/20/00 0 7/6/00 0

8/3/00 7/20/00 8/17/00 8/3/00 8/31/00 8/17/00 9/14/00 8/31/00 0  ; 9/28/00 PO 0D pa 9/14/00 10/12/00 9/28/00 CD 10/26/00 10/12/00 0 11/9/00 10/26/00 11/23/00 11/9/00 OD CD 11/23/00 0 0 0 0 0 0 0 S0 03 Percent Saturation C\

(/ (

LAKE NORMAN STRIPED BASS HABITAT 234 .0 8.0 11.0 13.0 15.015.9 62.0 69.0 72.0 80.0 I. I. I 1, . 1, 1* 1 1 1 2325 225 E

Ei 220 Cz 03 2 mg/Il 0 215 w1a1 210 aL 205 Jun 26, 2000 200 1954

• __I 0 Dsac 1 15 f02V 2 3F r5 D 40 45 50 55 Distance from Cowans Ford Dam (km)

'Distance from Cowans Ford Dam (kin) 240 2.410-LAKE NORMAN STRIPED BASS HABITAT 240 LAKE NORMAN STRIPED BASS HABITAT 1

235. .0 8.0 11.0 13.0 15.016.9 62.0 69.0 72.0 80.0 235- 1.0 8.0 11.0 13.0 15.015.9 62.0 69.0 72.0 80.0

4. 4, , t. I. 1 I. I, I, I I 230 23' -U- I.

7- 225. 225-:

E E 22&: 26 deg C 220 0

S21 M

a) 211 2 rrg/I 0

a LuI 215 210

.Jl 14'N

_/ 26 de20C 2 mg/I 205:

Jul17, 2000 205: /~Jul 31, 2000 200- 200o 0 S 10. 15 20 25 30 35 40 45 50 55 i V I I . I I

'-4 U 1d 5 V 20 5 30 .3 4 '45 50 55 Distance from Cowans Ford Dam (km) Distance from Cowans Ford Dam (km)

Figure 2-11. Striped bass habitat (temperatures < 26 C and dissolved oxygen >_2.0 mg/L in Lake Norman in June, July, August, and September 2000.

240 LAKE NORMAN STRIPED BASS HABITAT LAKE NORMAN STRIPED BASS HABITAT 235 .0 8.0 11.0 13.0 15.015.9 62.0 69.0 72.0 80.0 235 1.0 8.0 11.0 13.0 15.015.9 62.0 69.0 72.0 80.0 I, , ,I. J. 1. ,4. 4. 4, I. 1. 4. J. 1 4. 1. . 4.

230. 230 U5 225 U,

225 ** SS*::`~

..2 e*.... ~~

E E 220 220 26 deg C 0

1=C: 21 0 215 2rrMI 210. 0) 2106 20&:

Aug 7, 2000 205 Aug 21, 2000 200 200 195 . . .. . . I. .... .... .... .... .. 1 4

0 5 10 15 20 25 30 35 40 45 50 55 0. 5 10 15 20 2i 30 35 40 4550 55 Distance from Cowans Ford Dam (kin) bDistance from Cowans Ford Dam (km) 2240 ,. . ._ .. . . .

LAKE NORMAN STRIPED BASS HABITAT 2351'.0 8.0 11.0 13.0 15.015.9 62.0 69.0 72.0 80.0

'I 4. J. . 1. .1. J, 4.

230ý 22E E E E* 2:

E 22C 2:

0 0) 21e

'---S22 '

LLj 21C>.

205" Sep 11,2000 200o Y

IV, v vw i I I - .

0 5 10 15 20 25 30 .35 40 45 50 55 00 Distance from Cowans Ford Dam (km) Distance from Cowans Ford Dam (kin)

Figure 2-11. Continued.

CHAPTER 3 PHYTOPLANKTON INTRODUCTION Phytoplankton standing crop parameters were monitored in 2000 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 daJ4 collected during this study (February, May, August, and November 2000) 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 Company 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 3 February, 24 May, 29 August, and 10 November 2000. 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 methods, and laboratory methods used for chlorophyll a, seston dry weights and population identification and enumeration were identical to those used by Rodriguez 3-1

(1982). Data collected in 2000 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 2.04 ug/1 at Location 13.0 in February, to a high of 26.43 ug/I at Location 15.9 in May (Table 3-1, Figure 3-1). All values were well below the North Carolina water quality standard of 40 ug/l (NCDEHNR 1991). Lake-wide mean chlorophyll concentrations were within ranges of those recorded in previous years (Figure 3-2). The seasonal trend in 2000 of minimum values in February, increasing to maximum values in May, then declining values from August to November has never been observed during the course of the Lake Norman Maintenance Monitoring Study. Although Lake Norman continues to be primarily in the mesotrophic range, the lake-wide mean in February was in the oligotrophic range (<4 ug/l), while the lake-wide mean in May was in the eutrophic range

(>12 ug/1). Lake-wide quarterly mean concentrations below 4 ug/h have been recorded on eight previous occasions, while a concentration of greater than 12 ug/I was only recorded once before, in May 1997.

During 2000 chlorophyll a concentrations showed considerable spatial variability.

Maximum concentrations were observed at Location 15.9 during May and November, at Location 9.5 in February, and at Location 69.0 in August (Table 3-2). Minimum concentrations occurred at Location 13.0 in February, at Location 9.5 in May and August, and at Location 2.0 in November. The trend of increasing chlorophyll concentrations from down-lake to up-lake, which had been observed in 1994 and some previous years (Duke Power Company 1995), was apparent during all but February (Table 3-1, Figure 3-1). A consistent pattern of increasing values from down-lake to up-lake has not been observed 3-2

since 1994. Locations 15.9 (uplake, above Plant Marshall) and 69.0 (the uppermost riverine locations) had significantly higher chlorophyll values than mixing zone locations during all sample periods except February (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 2000) have varied considerably. During February 2000, all locations had chlorophyll concentrations in the low range (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 1997. All but Locations 13.0 and 69.0 had higher chlorophyll concentrations in February 2000 than in February 1999.

During May 2000, chlorophyll concentrations at Locations 2.0 through 9.5 were in the intermediate to high range. Chlorophyll concentrations at Locations 11.0 through 69.0 were in the high range for May. In fact, the chlorophyll concentration at Location 15.9 was the highest ever observed for May (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 1996. All locations had higher chlorophyll concentrations in May 2000 than during this period last year.

August 2000 chlorophyll concentrations at all but Locations 8.0 and 9.5 were in the high range, while concentrations at 8.0 and 9.5 were in the low to intermediate range (Figure 3 3). 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 Location 15.9 was observed in 1998, while Location 69.0 experienced its long term August peak in 1993. Locations 11.0, 13.0, and 3-3

69.0 had higher August concentrations in 2000 than in 1999, while concentrations at all other locations were lower than last year.

In November 2000, chlorophyll concentrations were in the low range at Locations 2.0 through 11.0. At Locations 13.0 through 69.0 November 2000 chlorophyll concentrations were in the intermediate range (Figure 3-3). 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. All but Location 69.0 had lower November values in 2000 than in 1999.

Total Abundance

"-Density and biovolume are measurements of phytoplankton abundance. The lowest density during 2000 occurred at Location 2.0 in November (867 units/ml), and the lowest biovolume (267 mm 3/m 3 ) occurred at Location 11.0 during February (Table 3-3, Figure 3 3 3 1). The maximum density (15,924 units/ml) and biovolume (14,358 mm /m ) were observed at Location 15.9 in May. Phytoplankton standing crops during February and May 2000 were generally higher than those of February and May 1999, while August and November standing crops were most often lower than in those periods of 1999 (Duke Power Company 2000). The phytoplankton density at Location 15.9 in May 2000 exceeded the NC state guideline for algae blooms of 10,000 units/ml. The biovolumes at Locations 11.0 and 15.9 during May 2000 also exceeded the NC guideline of 5,000 mm 3/m 3 biovolume (NCDEHNR 1991). Densities and biovolumes in excess of NC guidelines were recorded in 1987, 1989, 1997 and 1998 (Duke Power Company 1988, 1990, 1998, 1999).

Total densities at locations in the mixing zone during 2000 were within the same statistical ranges during all sampling periods but February (Table 3-4). In May and November, Location 15.9 had significantly higher densities than both mixing zone locations. During February, Location 9.5 had the maximum density, and was in the same statistical range as Location 15.9. In August, Location 15.9 had the highest density, but its statistical range overlapped that of the mixing zone locations. During May, and to a lesser extent in August, and November, phytoplankton densities showed a spatial trend, similar to that of chlorophyll, that is lower values at down-lake locations versus up-lake locations. During February, no such pattern was observed.

3-4

Seston Seston dry weights represent a combination of algal matter, and other organic and inorganic material. Dry weights during 2000 were most often higher than those of 1999.

Location 69.0, the uppermost riverine location, had the highest seston dry weights during all sample periods except February, when the maximum dry weight was observed at Location 13.0 (Table 3-5). A pattern of increasing values from down-lake to up-lake was observed in all but February, when no spatial trend was observed (Figure 3-1).

Statistically, Location 69.0 had significantly higher values than other locations in May and August. During February and November, - statistical differences were nonexistent or minimal. From 1995 through I9 91Lj seston dry weights had been increasing (Duke Power Company 1998). Values since 1998 represented a reversal of this trend, and were in the "lowrange at most locations during 1999 and 2000 (Duke Power Company 2000).

Seston ash-free dry weights represent organic material and may reflect trends of algal standing crops. In most cases, relationships between ash-free dry weights and chlorophyll concentrations/standing crops were not very apparent. In some cases, this relationship held true in 2000; most notably at Locations 9.5 and 69.0, which had the highest ash-free dry weights, as well as maximum chlorophyll values during May and August 2000 (Tables 3-1, 3-2, and 3-5). Locations 9.5 and 15.9, which had comparatively high ash-free dry weights in February, May, and August, also had seasonal maximum density values during these periods (Tables 3-4 and 3-5). During all sampling periods, little or no statistical differences were observed. The proportions of ash free dry weights to dry weights during 2000 were slightly higher than in 1999, indicating a very small increase in inorganic inputs during 2000. Between 1994 and 1997 a trend of declining organic/inorganic ratios was observed (Duke Power Company 1995, 1996, 1997, 1998).

Secchi Depths Secchi depth is a measure of light penetration. Secchi depths were often inversely related to 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 1.12 m at Location 69.0 in November, to 2.88 m at Location 2.0 in May (Table 3-1). The lake-wide mean secchi depth during 2000 was the second highest recorded since 3-5

measurements were first reported in 1992. The highest lake-wide mean secchi depth was recorded for 1999 (Duke Power Company 1993, 1994, 1995, 1996, 1997, 1998, 1999).

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 also true in 2000. Nine classes comprising 81 genera and 172 species, varieties, and forms of phytoplankton were identified in samples collected during 2000, as compared to 76 genera and 135 lower taxa identified in 1999 (Table 3-6).

The 2000 total was the highest number of individual taxa recorded since monitoring began in 1987. Twenty-four taxa previqusly unrecorded during the Maintenance Monitoring Program were identified during 2000.

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.

Diatoms (Bacillariophyceae) dominated densities at Locations 2.0, 5.0, and 9.5 in February 2000, and were the most abundant forms at all locations in May 2000 (Table 3-7, Figures 3-4 through 3-8). Cryptophytes (Cryptophyceae) were dominant at Locations 11.0 and 15.9 in February. 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 Company 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999). The most abundant diatoms during February were Cyclotella comta (Location 2.0), Melosira ambigua (Location 5.0), and Tabellaria fenestrata (Location 9.5). During May, the most abundant diatom was Fragillaria crotonensis. All of these species have been common and abundant at various times throughout the course of the program. The most abundant cryptophyte was the small flagellate, Rhodomonas minuta (Table 3-7). This species has been one of the most common and abundant forms observed in February samples since monitoring began in 1987. Cryptophytes are characterized as light limited, often found deeper in the water 3-6

column, or near surface under low light conditions, which are common during winter (Lee 1989). In addition, this taxon'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 2000 diatoms dominated densities at all locations (Figures 3-4 through 3 8). The most abundant diatom in August was the small pennate, Anomoeoneis vitrea (Table 3-7). This same pattern was observed in August 1999, which was the first time diatoms had ever dominated summer samples. 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 assenmb ages. This pattern of diatom dominance in August of both 1999 and 2000 was lake-wide, and not associated specifically with locations in the "vicinity of MNS or Marshall Steam Station (MSS). A. vitrea was described as a major contributor to periphyton communities on natural substrates 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 deepest and next deepest secchi depths were recorded for 1999 and 2000, respectively), extended periods of low water due to draw-down, shifts in nutrient inputs and concentrations, and macrophyte control procedures upstream (Duke Power Company 2000). Whatever the cause, the phenomenon was lake-wide, and not localized near MNS or MSS; therefore, it was most likely due to a combination of unusual environmental factors, and not station operations.

During November 2000, densities at Locations 2.0, 9.5, and 11.0 were dominated by diatoms, while cryptophytes were most abundant at Locations 5.0 and 15.9 (Figures 3-4 through 3-8). The dominant species at all locations was the small cryptophyte Rhodomonas minuta (Table 3-7). During 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 2000 samples. Although their overall contribution to phytoplankton densities was higher than in 1999, densities of blue-greens seldom exceeded 6% of totals.

The highest percent composition of Myxophyceae (6.7%) during all sampling periods in 2000 occurred at Location 5.0 in August. Prior to 1991, blue-green algae were often 3-7

dominant at up-lake locations during the summer (Duke Power Company 1988, 1989, 1990, 1991, 1992).

Phytoplankton index Phytoplankton indexes have been used with varying degrees of success ever since the concept was formalized by Kolkwitz 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 opposd 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 of 2000, and for each location during 2000 (Figure 3 9).

For the most part, the long term annual Myxophycean index values confirmed that Lake Norman has been 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, and 1998; and in the low, or oligotrophic, range in 1988, 1995, 1997, and 1999. The index for 2000 was higher than that of 1999, and fell in the lower mesotrophic range.

The highest index value among sample periods of 2000 was observed in February, and the lowest index value occurred in August (Figure 3-9). This did not reflect chlorophyll concentrations observed throughout the lake during 2000. The index values for locations during 2000 showed low values at Locations 2.0 through 9.5, with values in the high range at Locations 11.0 and 15.9. This tended to reflect the pattern of increasing algae concentrations from down-lake to up-lake locations observed during May, August, and November 2000. Last year, this pattern of increasing trophic state from down-lake to up lake locations was not as obvious (Duke Power Company 2000).

FUTURE STUDIES No changes are planned for the phytoplankton portion of the Lake Norman Maintenance Monitoring Program during 2000.

3-8

SUMMARY

In 2000 lake-wide mean chlorophyll a concentrations were all within ranges of those observed during previous years of the program. Lake Norman continues to be classified as oligo-mesotrophic based on long term, annual mean chlorophyll concentrations. The lake-wide chlorophyll mean chlorophyll in February increased from the annual minimum to the annual maximum in May, and then declined through November. This seasonal pattern had never been recorded during the Maintenance Monitoring Program.

Considerable spatial variability was observed in 2000, however, maximum chlorophyll concentrations were most often observed- up-lake; while comparatively low chlorophyll concentrations were recorded ..frm mixing zone locations. The 2000 maximum chlorophyll value of 26.43 ug/l ,gas well below the NC State Water Quality standard of 40 ug/1l.

In most cases, total phytoplankton densities and biovolumes observed in 2000 were higher than those observed during 1999, and standing crops were generally within ranges established over previous years. The maximum density at Location 15.9 in May, and the biovolumes at Locations 11.0 and 15.9 that same month exceeded NC guidelines for algae blooms. Standing crop values in excess of bloom guidelines have been recorded during four 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 and ash free dry weights were generally higher in 2000 than in 1999, and down-lake to up-lake differences were apparent most of the time. Maximum dry and ash free dry weights were most often observed at Locations 13 through 69.0, while minima were most often noted at Locations 2.0 through 11.0. The proportions of ash-free dry weights to dry weights in 2000 were slightly higher than those of 1999, indicating little change in organic/inorganic inputs into Lake Norman.

Secchi depths reflected suspended solids values, with shallow depths related to high dry weights. The lake-wide mean secchi depth in 2000 was the second deepest recorded since measurements were first reported in 1992. The greatest annual mean lake-wide secchi depth was recorded for 1999.

3-9

Diversity, or numbers of taxa, of phytoplankton had increased since 1999, and the total number of individual taxa was the highest yet recorded. The taxonomic composition of phytoplankton communities during February, May, and November was similar to those of previous years. Diatoms were dominant at most locations during all sampling periods. 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 2000. During most previous August periods, green algae (and occasionally blue-green algae) dominated the phytoplankton. This shift was likely the result of a variety of unusual environmental factors, and not related to station operations. Blue-green algae were somewhat more abundant during 2000 than 1999; however- their contribution to total densities seldom exceeded 6%.

The most abundant alga, on an annual basis, was the cryptophyte Rhodomonas minuta.

Common and abundant diatoms were Cyclotella comta, Melosira ambigua, and Tabellaria fenestrata in February; Fragillariacrotonensis in May; Anomoeneis vitrea during August, and T.fenestrata in November. All of these taxa, except A. vitrea, have been common and abundant throughout the Maintenance Monitoring Program. A. vitrea was found to be a major contributor to periphyton communities on natural substrates during studies conducted from 1974 through 1977.

The phytoplankton index (Myxophycean) tended to confirm the characterization of Lake Norman as oligo-mesotrophic. The annual index for 2000 was higher than that of 1999, and was at the lower end of the intermediate range. Quarterly index values declined from February to August, and then increased in November. Quarterly values did not reflect seasonal changes in phytoplankton standing crops. Location values tended to reflect increases in phytoplankton standing crops from down-lake to up-lake.

Lake Norman continues to support highly viable and diverse phytoplankton communities.

No obvious short term or long term impacts of station operations were observed.

3-10

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. 1IqcGuire 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.

Duke Power Company. 1992. Lake Norman Maintenance Monitoring Program: 1991 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1993. Lake Norman Maintenance Monitoring Program: 1992 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1994. Lake Norman Maintenance Monitoring Program: 1993 Summary. Duke Power Company, Charlotte, NC.

3-11

Duke Power Company. 1995. Lake Norman Maintenance Monitoring Program: 1994 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1996. Lake Norman Maintenance Monitoring Program: 1995 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1997. Lake Norman Maintenance Monitoring Program: 1996 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1998. Lake Norman Maintenance Monitoring Program: 1997 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1999. 'Lake Norman Maintenance Monitoring Program: 1998 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 2000. Lake Norman Maintenance Monitoring Program: 1999 Summary. Duke Power Company, Charlotte, NC.

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 20'b. 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, 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.

3-12

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. 990. Reservoir Limnology. John Wiley and Sons, Inc. N. Y.

3-13

Table 3-1. Mean chlorophyll a concentrations (ug/l) in composite samples (0.3, 4 and 8m depths) and secchi depths (m) observed in Lake Norman, NC, in 2000.

Chlorophyll a Location FEB MAY AUG NOV 2.0 3.36 8.25 6.07 2.26 5.0 3.05 7.20 6.20 3.06 8.0 3.71 7.48 5.68 3.23 9.5 4.92 7.02 5.31 3.50 11.0 2.62 14.95 10.26 3.99 13.0 2.04 16.02 6.53 5.51 15.9 3.76 26:43 10.08 8.92 69.0 2.52 10.41 15.48 5.05 Secchi depths Location FEB MAY AUG NOV 2.0 2.30 2.88 2.35 2.00 5.0 2.20 2.28 2.40 1.80 8.0 2.50 2.49 2.85 2.15 9.5 2.00 2.04 2.81 2.30 11.0 2.40 1.72 2.34 2.40 13.0 2.10 1.68 1.79 1.55 15.9 2.30 1.76 2.45 1.90 69.0 2.30 1.53 1.50 1.12 3-14

Table 3-2. Duncan's multiple Range Test on chlorophyll a concentrations in Lake Norman, NC, during 2000.

February Location 13.0 69.0 11.0 5.0 2.0 8.0 15.9 9.5 Mean 2.04 2.52 2.62 3.05 3.36 3.71 3.76 4.92 May Location 9.5 5.0 8.0 2.0 69.0 11.0 13.0 15.9 Mean 7.02 7.20 7.48 8.25 10.41 14.95 16.02 26.43 August Location 9.5 8.0 2.0 5.0 13.0 15.9 11.0 69.0 Mean 5.31-,. 5.68 6.07 6.20 6.53 10.07 10.26 15.49 November Location 2.0 5.0 8.0 9.5 11.0 69.0 13.0 15.9 Mean 2.58 2.71 2.87 3.42 3.74 3.92 6.02 6.93 3-15

Table 3-3. Total mean phytoplankton densities and biovolumes from samples collected in Lake Norman, NC, during 2000.

Density (units/mi)

Locations Month 2.0 5.0 9.5 11.0 15.9 Mean FEB 1090 1060 1488 1039 1450 1225 MAY 3426 3030 4230 7616 15924 6845 AUG 2632 2694 2246 3149 3463 2836 NOV 867 981 1106 1245 2493 1338 3 3 Biovolume (mm /m )

Locations Month 2.0 5.0 9.5 11.0 15.9 Mean FEB 974 833 1778 267 947 960 MAY 3343 3121 4208 7056 14358 6417 AUG 1807 2096 1795 2731 2533 2192 NOV 566 658 741 878 2065 982 3-16

Table 3-4. Duncan's multiple Range Test on phytoplankton densities in Lake Norman, NC, during 2000.

February Location 11.0 5.0 2.0 15.9 9.5 Mean 1040 1060 1090 1450 1487 May Location 5.0 2.0 9.5 11.0 15.9 Mean 3030 3426 4230 7616 15924 August Location 9.5 2.0 5.0 11.0 15.9 Mean 2246 2632 2694 3149 3463 November Location 2.0 5.0 9.5 11.0 15.9 Mean 867 980 1106 1244 2493 3-17

Table 3-5. Duncan's multiple Range Test on dry and ash free dry weights (mg/1) in Lake Norman, NC during 2000.

DRY WEIGHT February Location 11.0 2.0 9.5 5.0 69.0 15.9 8.0 13.0 Mean 0.86 1.39 1.41 1.44 1.51 1.55 1.57 1.58 May Location 5.0 8.0 9.5 2.0 11.0 13.0 15.9 69.0 Mean 1.99 2.24 2.32 2.35 3.09 3.86 4.48 9.40 August Location 8.0' 2.0 5.0 9.5 11.0 15.9 13.0 69.0 Mean 1.28 1.33 1.52 1.90 1.97 2.07 2.18 3.05 November Location 11.0 8.0 5.0 2.0 15.9 9.5 13.0 69.0 Mean 1.33 1.47 1.84 1.93 2.01 2.52 3.04 5.06 ASH FREE DRY WEIGHT February Location 13.0 11.0 8.0 69.0 5.0 15.9 2.0 9.5 Mean 0.84 0.84 0.93 1.07 1.09 1.21 1.24 1.30 May Location 5.0 9.5 2.0 8.0 13.0 11.0 15.9 69.0 Mean 1.57 1.77 1.91 1.96 2.34 2.49 2.67 3.05 August Location 2.0 13.0 8.0 9.5 5.0 11.0 15.9 69.0 Mean 1.01 1.22 1.27 1.32 1.39 1.61 1.96 2.47 November Location 11.0 15.9 9.5 5.0 2.0 8.0 69.0 13.0 Mean 1.30 0.68 0.79 0.92 1.23 1.48 1.51 1.53 3-18

Table 3-6. Phytoplankton taxa identified in quarterly samples collected in Lake Norman from August 1987 to November 2000.

TAXON 87 88 89 90 91 92 93 94 -95 -96 -97 98 99 00 CLASS: CHLOROPHYCEAE Acanthospaera zachariasiLemm. X X X Actidesmium hookeri Reinsch -- x -- - -

Actinastrum hantzchii Lagerheim X - xXI XXX II II Ankistrodesmus braunii (Naeg) Brunn -- - -- xX A. convolutus Corda x A.falcatus (Corda) Ralfs X x X- X X X x X X X X X X X A. fusiformis Corda sensu Korsch. I X X XX X X A. nannoselene Skuja I- I I x A. spiralis(Turner) Lemm. xI X- X x X x I - I I - _ _

A. spp. Corda X X Arthrodesmus convergens Ehrenberg x A. incus (Breb.) Hassall - X - - x _

A. subulatus Kutzing XX x x A. spp. Ehrenberg-----------------------X X - _

Asterococcus limneticus G. M. Smith X X X X X X Botryococcus braunii Kutzing x x CarteriafrtzschiiTakeda X X __ _ __ - - __ - - - - X C. spp. Diesing X X X xX Characiumspp. Braun X -I __ -___

Chiamydomonas spp. Ehrenberg X X X X X X X X X x X x X x Chiorella vulgaris Beyerink------------------------- X Chiorogonium euchiorum Ehrenberg x - - - ---- XX-x C. spiraleScherffel & Pascher __ __ XX Closteriopsis Iongissima West & West x X X X X X X X X X X X I XI Closterium cornu Ehrenberg X C. gracile Brebisson - -

C. incurvum Brebisson x x -- -- X X X X xX C. tumidum Johnson -- _ ____

C. spp. Nitzsch __ X XX x Coccomonas orbicularis Stein - I _ I

__ - - - X -

Coelastrum cambricum Archer XIX x X X X x x X X X- x x x C. microporum Nageli------------------------- X - x -x C. reticulatum (Dang.) Sinn. - -- - __ _

C. sphaericum Nageli - - X - X -XxX x C. proboscideum Bohlin X C. spp. Nageli XXx _

Cosinariutn agulosuin v. concinnurn (Rab) W&W X - __ __ - - - - __ - - X I____

C. asphaerosporum v. strigosurn Nord. X IX X XX X X X X X X X X X 3-19

Table 3-6 (continued) page 2 of 10 87 88 89 90 91 92 93 94 95 96 97 98 99 00 "C.contractum Kirchner X X X X X X X X X "C.moniliforme (Turp.) Ralfs X "C.phaseolus f. minor Boldt. X X X "C.pokornyanum (Grun.) W. & G.S. West X "C.polygonum (Nag.) Archer X X X X X X X "C.regnellii Wille X X X X X X X "G.regnesi Schmidle X X X

". tenueArcher X x X X X X X X C. tinctumRalfs X X X X XX X X X X C. tinctum v. subretusum Messik. X C. tinctum v. tumidum Borge. X X X C. spp. Corda X X "X X X X X X Crucigeniacrucifera (Wolle) Collins _ X X X X X X X X X X C.fenestrata Schmidle X C. irr.egularisWille 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 DictyospaeriumehrenbergianumNageli X X X D. pulchellum Wood X X X X X X X X X X X X X X Dimorphococcusspp. Braun X Elakatothrixgelatinosa Wille X X X X X X X X X X X X X X Euastrumdenticulatum (Kirch.) Gay X X X X X X E. spp. Ehrenberg X X X X Eudorina elegansEhrenberg X X Franceiadroescheri (Lemm.) G. M. Smith X X X X X X X X F. ovalis (France) Lemm. X X X X X X X X Gloeocystis botryoides (Kutz.) Nageli X X G. gigas Kutzing X X X X X X X X G. major Gerneck ex. Lemmermann X G. planktonica (West & West) Lemm. X X X X X X X X X X X X G. vesciculosa Naegeli X G. spp. Nageli X X X X X X X X Golenkinia paucispinaWest & West X X G. radiataChodat X X X X X X X X X X X X X X Gonium pectorale Mueller IX G. sociale (Duj.) Warming X XX X _

Kirchneriellacontorta (Schmidle) Bohlin X X X X X X X X K. elongata G.M. Smith I I x K. lunaris (Kirch.) Mobius X X X K. lunaris v. dianae Bohlin X X X K. lunaris v. irregularisG.M. Smith X K. obesa W. West X X XX X X X_

3-20

Table 3-6 (continued) page 4 of 10 87 88 89 90 91 92 93 94 95 96 97 98 99 00 S. dimorphus (Turp.) Kutzing X X X X X X X X X S. incrassulatusG. M. Smith X S. quadricauda(Turp.) Brebisson X X X X X X X X X X X X X X S. smithii Teiling X S. spp. Meyen X X X X X X Schizochlamys compacta Prescott X X X S. gelatinosaA. Braun X Schoederia setigera (Schroed.) Lemm. X X Selenastrum gracile Reinsch X X S. minutum (Nageli) Collins X X X X X X X X X X X X X X S. westiiG. M. Smith X X X X X X X _

Sorastrum americanum (Bohlin) Schmidle I X Sphaerocystis schoeteri Chodat _X X X I -X X X X Sphaerozosma granulatum Roy & Bliss . X X I Stauastrum americanum (W&W) G. Sm. X X I X X X X X X S. apiculatum Brebisson X X X X X S. brachiatum Ralfs X X S. brevispinum Brebisson X X S. chaetocerus (Schoed.) G. M. Smith X X X S. curvatum W. West X - X X X X X X X XXX X S. cuspidatum Brebisson X X X X X S. dejectum Brebisson XX X X X X X X S. dickeii v. maximum West & West X S. gladiosum Turner X S. leptocladum v. sinuatum Wolle X X S. manzfeldtii v.fluminense Schumacher X X X - X X X X X S. megacanthum Lundell X X X X S. ophiura v. cambricum (Lund) W. & W. X S. orbiculareRalfs X S. paradoxum Meyen I X X X X X X X X S. paradoxum v. cingulum West & West X I S. paradoxum v. parvum W. West X X S. subcruciatumCook & Wille X X XX Xx S. tetracerum Ralfs X X X X X X X X X X X X X X S. turgescens de Not. X X S. spp. Meyen I X X X X Tetraedron bifurcatum v. minor Prescott X T. caudatum (Corda) Hansgirg 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 I 3-22

Table 3-6 (continued) -- - page 5of 10 87 88 8990191 92 93 94 95 96 97 98 99 00 T. minmum (Braun) Hansgirg x X x X1 - - X XX X X X T. muticum (Braun) Hansgirg x - X X X X XX I T. obesum (W & W) Wille ex Brunnthaler X T. planktonicum G. M. Smith --

T. pentaedricum West & West X X T. regulare Kutzing -- - x T. regulare v. bifurcatum WilleI T. regulare v. incus Teiling X X I__ ___

T. trigonum(Nageli) Hansgirg X X X I - I - X X X -x T. trigonum v. gracile (Reinsch) DeToni - - -- XX-X T. spp. Kutzing------------------------- - - -

Tetraspora lamellosa Prescott x T.spp. Link z.x x Tetrastrum heteracanthum (Nordst.) Chod. x I Treubariasetigerum (Archer) G. M. Smith x x x X X X x I X xX X X X -x Westella botryoides (West & West) Wilde. X X W. linearis G. M. Smith -x - - - - - - - - - x x Xanthidium spp. Ehrenberg X _ I_

CLASS: BACILLARIOPHYCEAB Achnanthes microcephala Kutzing x X X X XX XX X A. spp. Bory X X X X X xX XX x Anomoeoneis vitrea (Grunow) Ross X X X X X X X X A. spp. Pfitzer I -_ _ - x AsterionellaformosaHassall X X X IX x X X XI X I X - X Attheya zachariasiJ.Brun X X- X X X X X X x X x x X Cocconets placentula Ehrenberg X X __ XX C. spp. Ehrenberg I Cyclotella comta (Ehrenberg)_Kutzing ___ ___ x C. glomerata Bachmann --- -- -- -- -x "5x x C. meneghiniana Kutzing X X __X X X ____ __ __

C. pseudostelligera Hustedt xI C. stelligera Cleve & Grunow X X x XX X xxXx x xx C- spp. Kutzing XX x _ ___

Cymbella affinis Kutzing X C. minuta (Bliesch & Rabn.) Reim. X - XX X X - xX C. tumida (Breb.) van Huerck - __ _ - X C. turgida(Gregory) Cleve -x --- ___

C. spp. Agardh x ____x__

Denticula the rrnalis Kuetzing - x Diploneis spp. Ehrenberg X __ ________

3-23

Table 3-6 (continued) page 6 of 10 87 88 89 90 91 92 93 94 95 96 97 98 99 00 Eunotia flexuosa v. eurycephalaGrun. x E. zasuminensis (Cab.) Koerner x x x x x x x x x x x x Fragilariacrotonensis Kitton x x x x x x x x x x x x x Frustulia rhomboides (Ehr.) de Toni x x Gomphonema spp. Agardh x x Melosira ambigua (Grun.) 0. Muller x x x x x LX x x x x x x x x M. distans (Ehr.) Kutzing x x x x x x x x x x x x x M. granulata(Ehr.) Ralfs x x x x I M. granulatav. angustissima 0. Muller x x X- x x x x x x x x x x x M. italica (Ehr.) Kutzing x x M. varians Agardh x x x M. spp. Agardh x X- x x x x x x x x Navicula cryptocephala Kutzing x x x N. exigua (Gregory) 0. Muller x N. exigua v. capitata Patrick x N. subtilissimaCleve x x N. spp. Bory x x x x XIX Nitzschia acicularisW. Smith x x x x XI I x x x x x N. agnita Hustedt x x x x x x XI X- x x x x x N. holsaticaHustedt x x x x x x Ix x x x N. linearisW. Smith I x N. palea (Kutzing) W. Smith x x x x x x x N. sublinearisHustedt x I x x N. spp. Hassall x x x x x x x x Pinnulariaspp. Ehrenberg x I Rhizosolenia spp. Ehrenberg x x x x x x x x x x x x x x Skeletonema potemos (Weber) Hilse, x x x x x I x x XI Stephanodiscus spp. Ehrenberg x x x XI x x x x x x Ix x Surirella linearisv. constricta (Ehr.) Grun. Ix Synedra actinastroidesLernmerman x I S. acus Kutzing x x x x x Ix x S. delicatissimaLewis x x x I S. filiformis v. exilis Cleve-Euler Ix x S. planktonica Ehrenberg x XIX x x x x x x x x x x x S. rumpens Kutzing x x I x x x x x x S. rumpens v. fragilarioidesGrunow x S. rumpens v. scotica Grunow x S. ulna (Nitzsch) Ehrenberg x x x x x I X- x x -x S. spp. Ehrenberg x x x x x x x x I Tabellariafenestrata(Lyngb) Kutzing x x x x x x x x x x x x T.flocculosa (Roth.) Kutzing x x x x 3-24

Table 3-6 (continued) page 7 of 10 87 88 89 90 91 92 93 94 95 96 97 98 99 00 CLASS: CHRYSOPHYCEAE Aulomonas purdyii Lackey 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 ChrysosphaerellasolitariaLauterb. X X X X X X X X X X Codomonas annulataLackey X X X DinobryonbavaricumImhof X X X X X X X X X X X X X X D. cylindricum Imhof X X X X 1 X X D. divergens Imhof X X X X X X X X D. sertulariaEhrenberg X X x D. spp. Ehrenberg X- X X X X X XX X X Domatomococcus cylindricum Lackey X X Erkinia subaequicilliataSkuja X X X X X X X X X X X Kephyrion littorale Lund X K. rubi-claustriConrad X X K. skujae Ettl X K. spp. Pascher X X X XX X X XX x X X Mallomonas acaroidesPerty X M. akrokomos (Naumann) Krieger X X X X M. alpina Pascher X X M. caudata Conrad X X XX X X X XX M. globosa Schiller x x x M. producta Iwanoff X M. pseudocoronataPrescott X X X X X X X X X X X X X M. tonsurataTeiling X X x X XX X X X X X X X X M. spp. Perty X X XX X XX X X OchromonasgranularisDoflein X X X

0. mutabilis Klebs X 0.spp. Wyss XX X X XXX XX X X Pseudokephyrion schilleri Conrad X X P. tintinabulum Conrad X Rhizochrisis polymorphaNaumann X X R. spp. Pascher - X X Salpingoecafrequentissima(Zachary) Lemm. X X X Stelexomonas dichotoma Lackey 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 S. uvella Ehrenberg X X X X X X S.spp. Ehrenberg X X X X X X Uroglenopsis americana(Caulk.) Lemm. X X X X X 3-25

xxxxxx 170

r cq A

Table 3-6 (continued) page 10 of 10 87 88 89 90 91 92 93 94 95 96 97 98 99 00 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 Peridinium aciculiferum Lemmermann X P. inconspicuum Lemmermann XX X X X X X X X X X X X X P. intermedium Playfair X X X P. pusillum (Lenard) Lemmermann 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 P. spp. Ehrenberg X I X X X X X CLASS: CHLOROMONADOPHYCEAE Gonyostomum depresseum Lauterborne X x x X G. semen (Ehrenberg) Diesing X G. spp. Diesing X X X X 3-28

Table 3-7. Dominant classes and species of Phytoplankton, and their percent composition (in parenthesis) at Lake Norman locations during each sampling period of 2000.

LOC FEBRUARY MAY 2.0 BACILLARIOPHYCEAE (61.9) BACILLARIOPHYCEAE (76.7)

Cyclotella comta (25.4) T.fenestrata (25.3) 5.0 BACILLARIOPHYCEAE (48.7) BACILLARIOPHYCEAE (85.1)

Melosira ambigua (19.0) Fragillariacrotonensis (25.1) 9.5 BACILLARIOPHYCEAE (75.2) BACILLARIOPHYCEAE (78.2)

Tabellariafenestrata (31.0) F. crotonensis(27.9) 11.0 CRYPTOPHYCEAEA (72.6) BACILLARIOPHYCEAE (87.1)

Rhodomonas minuta (67.7) F. crotonensis(48.3) 15.9 CRYPTOPHYCEAE (40.2) BACILLARIOPHYCEAE (93.0)

R. minuta (34.7) -* F. crotonensis (63.2)

AUGUST NOVEMBER 2.0 BACILLARIOPHYCEAE (42.2) BACILLARIOPHYCEAE (40.1)

Anomoeoneis vitrea (34.1) R. minuta (30.4) 5.0 BACILLARIOPHYCEAE (44.0) CRYPTOPHYCEAE (39.7)

A. vitrea (34.2) R. minuta (34.2) 9.5 BACILLARIOPHYCEAE (47.0) BACILLARIOPHYCEAE (41.3)

A. vitrea (31.0) R. minuta (29.9) 11.0 BACILLARIOPHYCEAE (42.7) BACILLARIOPHYCEAE (36.0)

A. vitrea (21.0) R. minuta (30.8) 15.9 BACILLARIOPHYCEAE (34.1) CRYPTOPHYCEAE (37.5)

A. vitrea (9.8) R. minuta (28.2) 3-29

CHLOROPHYLL a (ug/I) DENSITY (units/ml) 30 18000 16000 25 14000 12000 20 10000 15 8000 6000 10 4000 2000 0 50 2.0 5.0 9.5 11.0 15.9 2.0 5.0 8.0 9.5 11.0 13.0 15.9 69.0 BIOVOLUME (mm3Im3)

SESTON DRY WEIGHT (mg/I) BIOVOLUME (mm3/m3) 16000 10 9 14000 8

12000 7

10000 6

8000 6000 4000 2000 0 0

9.5 11.0 13.0 15.9 69.0 2.0 5.0 9.5 11.0 15.9 LOCATIONS 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 2000.

3-30

14 12 10 8

,I 0

n 6 0

O

_,)

0F FEB MAY AUG NOV MONTH

-x1990 1991

- .-- 1987 1992 -

.--- 1988 1993 .-- -- 1989

-- 1994 a- -1995 -- o--1996

-1997 --- 1998 -- o--1999 -- 0--2000 Figure 3-2. Phytoplankton chlorophyll a annual lake means from all locations in Lake Norman, NC, for each quarter since August 1987.

3-31

CHLOROPHYLL a (ug/I)

FEBRUARY MAY 1---2.0 -5.0

-4,.2.0 -- 5.0 12 12 MIXING ZONE 10 -- - -----------------

10 8

6 8

6

-- ----------------- 4 i

4 4 --- ------------ -- ---

2 2 - ------------------

0 0 87 88 89 90 91 92 93 94 95 96 97 98 99 00 87 88 89 90 91 92 93 94 95 96 97 98 99 00 1----8.0 -"9.5 1 I--*-8.0 9.5 20 12 10 - - - - - - - - - - - - - - - - - - - - - - - -

15 8 - - - - - - - - - - - - - - - - - - - - - - - - - -

6 - - - - - - - - - - - - - - - - - - - - - -

III 10

-5 0

4 2

0 87 88 89 90 91 92 93 94 95 96 97 98 99 00 87 88 89 90 91 92 93 94 95 96 97 98 99 00 I-

• 11.0 -- 13.0 11.0 1370 16 30 14 -------- -------------------- ----------------------- ------

25 12 ------- --------------------

I

---

20 10 ------ --

8 ----- ----- ------- -------- 15 ---------------------- -------

6 ----- -------- ---- -------

10 ----------- - --- --- --

4 2

0

-- ---------------------- I 5

0 87 88 89 90 91 92 93 94 95 96 97 98 99 00 87 88 89 90 91 92 93 94 95 96 97 98 99 00

[--- 15.9 -- 069.0 -*-15.9 --- 69.0 16 30 14 25 12 20 10 8 15 6 10 4

5 2

0 0 87 88 89 90 91 92 93 94 95 96 97 98 99 00 87 88 89 90 91 92 93 94 95 96 97 98 99 00 YEARS YEARS Figure 3-3. Phytoplankton chlorophyll a concentrations by location for samples collected in Lake Norman, NC, from August 1987 through November 2000.

3-32

CHLOROPHYLL a (ug/I)

AUGUST NOVEMBER

- -2.0 - -5.01 1-- 2.0 -- 5.0]

12 12 MIXING ZONE 10- --------------------------- --- 10

---

------------ - 8 6 --------- ---- --- ----- ---- I 6 41 ---------- 4 2 ---

2 0

87 88 89 90 91 92 93 94 95 96 97 98 99 00 87 88 89 90 91 92 93 94 95 96 97 98 99 00 1---8.0 W-9.5] 1--- 8.0 -- 9.5]

16 14 14 12 ---------------------- ------

12 10 -------------------- --- ------

10 -----

8 ------------ --- -----

8 6 ---------- -- -- -------- --- -

6 4

2 0

4 21 0

87 88 89 90 91 92 93 94 95 96 97 98 99 00 37 88 89 90 91 92 93 94 95 96 97 98 99 00

--- IO110 -M-- 13.0 1 -- +-11.0 0--13:0]

14 12 10 8

6 4

2 0

87 88 89 90 91 92 93 94 95 96 97 98 99 00 87 88 89 90 91 92 93 94 95 96 97 98 99 00

""-*--15.9 -- I--69.0] ----- 15.9 W-U69.0]

25 25 20 20 15 15 10 10 5 5 0 0 87 88 89 90 91 92 93 94 95 96 97 98 99 00 87 88 89 90 91 92 93 94 95 96 97 98 99 00 YEARS YEARS Figure 3-3 (continued).

3-33

LOC. 2.0 7000 6500 DCHLOROPHYCEAE 13BACILLARIOPHYCEAE NCHRYSOPHYCEAE UCRYPTOPHYCEAE 6000 1 MYXOPHYCEAE 0 DINOPHYCEAE 5500 E OTHERS 5000 4500 4000.

C 3500.

U) z 3000 w

2500 2000 1500 1- NM 1000 500 0

FEB MAY AUG NOV LOC. 2.0 4000 3500 3000 - ..

E E

U 2000 .

0 1000 500FBMYAGN 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 2000.

3-34

LOC. 5.0 7000 6500 0 CHLOROPHYCEAE I BACILLARIOPHYCEAE

[]CHRYSOPHYCEAE U]CRYPTOPHYCEAE 6000 MMYXOPHYCEAE 0 DINOPHYCEAE 5500 m OTHERS 5000 4500 S4000 3500 S3000 z

w O 2500 2000 1500 1000 500 i

0*

FEB MAY AUG NOV LOC- 5-0 4000 3500 I-3000 S2 500 CV)

E E

W 2000 M

0 S1500 1000 500 0

-- I r-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 2000.

3-35

LOC. 9.5 8500 LOG.

8000 [] CHLOROPHYCEAE M BACILLARIOPHYCEAE 7500 iCHRYSOPHYCEAE NCRYPTOPHYCEAE 7000 [] MYXOPHYCEAE 13 DINOPHYCEAE 6500 EmOTHERS 6000 5500 E

(A 5000 S4500 S4000 S3500

'u O 3000 2500 2000 1500 1000 500 0

I I I I FEB MAY AUG NOV 5000 4500 4000 3500 E

M 3000 E

E W 2500 0 2000 0

M 1500 -

1000 4-500 --

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 2000.

3-36

LOC. 11.0 10000 I Q CHLOROPHYCEAE DBACILLARIOPHYCEAE ICHRYSOPHYCEAE ODINOPHYCEAE 0 CHLOROPHYCEAE BACILLARIOPHYCEAE U CHRYSOPHYCEAE

• 13 MYXOPHYCEAE 9000 [] CRYPTOPHYCEAE

• CRYPTOPHYCEAE M MYXOPHYCEAE El DINOPHYCEAE

• OTHERS 8000 E OTHERS 7000 6000 EL 5000 r', 4000 Z

3000 2000 1000 0-I I FEB MAY AUG NOV 8000 7000 6000 5000 E

E ul 4000

,-j 0

3000 0

2000 1000 0- I AUG I nNOV FEB MAY 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 2000.

3-37

LOC. 15.9 20000 I 0 CHLOROPHYCEAE 13 BACILLARIOPHYCEAE CHRYSOPHYCEAE C S CRYPTOPHYCEAE 18000 MMYXOPHYCEAE o DINOPHYCEAE MOTHERS 16000 14000 E 12000 C

10000 (n

z 8000 w

6000 4000 2000 1,m I I 0

FEB MAY AUG NOV 16000 14000 12000 E

LL 8000 i

0 0

4000 2000 1 0

FEB MAY AUG NOV Figure 3-8. Class composition (density and biovolume) of phytoplankton from euphotic zone samples collected at Location 15.9 in Lake Norman, NC, during 2000.

3-38

MYXOPHYCEAN INDEX: LAKE NORMAN 1.8 1.7 1.6 1.5 1.4 HIGH 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 r*

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 YEARS 3.50 3.25 3.00 2.75 2.50 2.25 X 2.00 7 Di o1.75

_ 1.50!

1.25 1.00 0.75 0.50 0.25 0.00-FEB MAY AUG NOV MONTH 1.6 1.5 1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 2 5 9.5 11 15.9 LOCATIONS Figure 3-9. Myxophycean index values by year (top), each season in 2000 (mid), and each location in Lake Norman, NC, during 2000.

3-39

CHAPTER 4 ZOOPLANKTON 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 2000) with historical data collected during the period 1987-1999.

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 Company 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 3 February, 24 May, 29 August, and 10 November 2000 (Note: due to loss of mooring buoys and high winds, 10 m to surface samples were not collected at Location 5.0 in February and Location 15.9 in August; and bottom to surface net samples were not collected at Locations 5.0 and 9.5 in February and Location 15.9 in August). 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 2000 were compared with corresponding data from quarterly monitoring begun in August 1987.

4-1

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.

RESULTS AND DISCUSSION Total Abundance During 2000, some degree of seasonal variability was observed in epilimnetic samples.

Total zooplankton densities in all epilimnetic samples were highest in May (Table 4-1, Figure 4-1). The lowest epilimnetic densities at Locations 2.0, 5.0, and 15.9 occurred in November, while annual minimum densities at Locations 9.5 and 11.0 were observed in February. Epilimnetic densities *ranged from a low of 24,000/m 3 at Location 2.0 in November, to a high of 361,400/m 3 at Location 15.9 in May. In the whole column samples, maximum densities at all but Location 11.0, which had its highest density in August, were observed in May. Minimum densities were observed in November at all but Location 9.5, which had its lowest density in August. Whole column densities ranged from 34,400/m 3 at Location 2.0 in February, to 178,300/M 3 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 2000, as has been the case in previous years (Duke Power Company 2000). 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 down-lake to up-lake was observed during 2000 (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 all but August, when Location 11.0 demonstrated the significant maximum (Table 4-2). Note that during August 4-2

Location 15.9 was not sampled. In most previous years of the Program, Background Locations had higher mean densities than Mixing Zone locations (Duke Power Company 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999).

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 2000 (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 locatiors 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).

Epilimnetic zooplankton densities during all but May of 2000 were within the seasonal ranges of those observed during previous years of the Program. The mean epilimnetic zooplankton densities at Locations 2.0 and 5.0 in May 2000 were the highest May values yet observed for these locations. These high epilimnetic zooplankton concentrations may have been a response to comparatively high phytoplankton concentrations in this part of the lake during May 2000 (Chapter 3). The highest February densities recorded during the Program at Locations 5.0 and 9.5 occurred in 1995, and in 1996 at Locations 2.0 and 11.0 (Figure 4-2). The long-term February maximum at Location 15.9 was observed in 1992.

Long-term maximum densities for May occurred at Location 11.0 in 1995, and at Locations 9.5 and 15.9 in 1988. 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 eight 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 2000, compared to fifty-two taxa recorded during 1999 (Duke Power Company 2000). No previously unreported taxa were identified in 2000.

Copepods were dominant most often during 2000 (Table 4-1, Figures 4-4 and 4-5). These microcrustaceans were dominant at Location 15.9 in February, at Locations 2.0 (whole column), 5.0, and 15.9 (epilimnion) in May, at all locations in August, and at Locations 2.0, 5.0 (whole column) and 11.0 in November. Cladocerans were dominant at Location 2.0 (whole column) in February2, and Location 9.5 in November. Rotifers dominated zooplankton at Locations 2.0 (epilimnion), 9.5, and 11.0 in February, at Locations 2.0 (epilimnion), 9.5, 11.0, and 15.9 (whole column) in May, and at Locations 5.0 (epilimnion) and 15.9 in November. Microcrustaceans remained dominant in all areas of the lake during 2000 (Figures 4-6 through 4-8). Compared with 1999, the percent composition of microcrustaceans had increased in lake-wide and Background epilimnetic samples, and in Mixing Zone whole column samples. Their relative abundance had declined slightly in Lake-wide and Background whole column samples since last year.

During most years of the Program, microcrustaceans dominated Mixing Zone samples, but were less important among Background locations.

Copepoda Copepod populations were consistently dominated by immature forms (primarily nauplii) during 2000, as has always been the case. Adult copepods seldom constituted more than 8% of the total zooplankton density at any location during 2000. Tropocyclops and Epischura were often important constituents of adult populations; while Mesocyclops were occasionally important (Table 4-4).

Copepods tended to be more abundant, if not dominant, at Background Locations than at Mixing Zone Locations during 2000, and their densities peaked in May at both Mixing Zone and Background Locations. In fact, the mean copepod density for Background Locations in May was the highest yet observed (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 2000 samples, as has been the case in most previous studies (Duke Power Company 2000, 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 at several locations in February and November. Diaphanosomaand Bosminopsis were also important among cladocerans (Table 4-4). During May, Diaphanosomadominated cladoceran populations in all but the whole column sample from Location 5.0. Bosminopsis dominated cladoceran populations at Location 5.0 (whole column) in May and in both sets of samples from this location in August. Bosminopsis expressed lower dominance during August 2000 as compared to August 1999, however, similar ppat.erns of Diaphanosoma-Bosminopsisdominance have been observed in past years of the'Program (Duke Power Company 2000).

Long-term seasonal trends of cladoceran densities were variable: From 1990 to 1993, peak densities occurred in February; while in 1994 and 1995, maxima were recorded in May (Figure 4-5). During 1996, peak cladoceran densities occurred in May in the Mixing Zone, and in August among Background Locations. During 1997, cladoceran densities again peaked in May. Maximum cladoceran densities in 1998 occurred in August. During 1999, maximum densities in the Mixing Zone were observed in May, while Background Locations showed peaks in August. During 2000, peak cladoceran densities were again observed in May. Spatially, cladocerans were more important at Mixing Zone Locations than at other locations (Table 4-1, Figure 4-4).

Rotifera Keratella was the most abundant rotifer in 2000 samples. This taxon dominated most rotifer populations in May (Table 4-4). Keratella also dominated rotifer populations at Locations 2.0, 15.9 (epilimnion), and 11.0 in November. Polyarthra was dominant in most August samples, as well as at Locations 2.0, and 11.0 (whole column) in May and whole column samples from Locations 5.0 and 15.9 in November. Conochilus dominated rotifer populations at Location 11.0 in February, and Locations 2.0 (epilimnion) and 15.9 (whole column) in November. Kellicottia dominated rotifer densities at most Locations in February. Asplanchna was the dominant rotifer in samples from Location 11.0 in August, while Trichocerca was the dominant rotifer at Location 9.5 (whole column) in August.

All of these taxa have been identified as important constituents of rotifer populations, as 4-5

well as zooplankton communities, in previous studies (Duke Power Company 2000; Hamme 1982).

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 Company 1989, 1990). During 2000, peak densities at all locations were observed in May.

FUTURE STUDIES No changes are planned for the zooplankton portion of the Lake Norman Maintenance Monitoring Program in 2001 and 2002.

SUMMARY

Maximum epilimnetic zooplankton densities occurred in May, while minimum values were recorded in February (Locations 9.5, and 11.0), and November (Locations 2.0 and 15.9). In most whole column samples, maximum densities also occurred in May, with minimum values most often observed in November. 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 2000, 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 during all but May of 2000 were within ranges of those observed in previous years. The epilimnetic densities at Locations 2.0 and 5.0 in May 2000 were the highest recorded from these locations for this month, and may have represented a response to comparatively high phytoplankton standing crops in the Mixing Zone at that time.

One hundred and eight zooplankton taxa have been recorded from Lake Norman since the Program began in 1987 (fifty-one were identified during 2000). No previously unreported taxa were identified during 2000.

4-6

Copepods dominated zooplankton standing crops most often during 2000. Overall relative abundance of copepods in 2000 had increased slightly since 1999. Cladocerans were occasionally dominant in February and November, while rotifers were dominant in most samples in February and May. Overall, the relative abundance of rotifers had decreased since 1999. 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 seldom 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. Diaphanosoma and Bosminopsis dominated cladoceran populations in May.

The most abundant rotifers observed in 2000, as in previous years, were Keratella and Polyarthra,while Conochilus and Kellicottia were occasionally important among rotifer populations in February and November.

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 2000, were likely due to environmental factors and appears not to be related to plant operations.

4-7

LITERATURE CITED Duke Power Company. 1976. McGuire Nuclear Station, Units 1 and 2, Environmental Report, Operating License Stage. 6th rev. Volume 2. Duke Power Company, Charlotte, NC.

Duke Power Company. 1985. McGuire Nuclear Station, 316(a) Demonstration. Duke Power Company, Charlotte, NC.

Duke Power Company. 1988. Lake Norman Maintenance Monitoring Program: 1987 Summary., Duke Power Company, 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.

Duke Power Company. 1992. Lake Norman Maintenance Monitoring Program: 1991 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1993. Lake Norman Maintenance Monitoring Program: 1992 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1994. Lake Norman Maintenance Monitoring Program: 1993 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1995. Lake Norman Maintenance Monitoring Program: 1994 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1996. Lake Norman Maintenance Monitoring Program: 1995 Summary. Duke Power Company, Charlotte, NC.

4-8

Duke Power Company. 1997. Lake Norman Maintenance Monitoring Program: 1996 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1998. Lake Norman Maintenance Monitoring Program: 1997 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 1999. Lake Norman Maintenance Monitoring Program: 1998 Summary. Duke Power Company, Charlotte, NC.

Duke Power Company. 2000. Lake Norman Maintenance Monitoring Program: 1999 Summary. Duke Power Company, Charlotte, NC.

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.

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

4-9

3 Table 4-1. Total zooplankton densities (no. X 1000/M ), densities of major zooplankton taxonomic groups, and percent composition (in parentheses) of major taxa in 10m to surface (10-S) and bottom to surface (B-S) net tow samples collected from Lake Norman in February, May, August, and November 2000.

Sample Locations Date Type Taxon 2.0 5.0 9.5 11.0 15.9 2/3/00 10-s COPEPODA 7.9 11.7 27.6 74.6 (17.4) (31.3) (38.8) (47.5)

CLADOCERA 15.3 11.8 12.0 31.1 (33.7) (31.6) (17.0) (19.8)

ROTIFERA 22.2 13.8 31.3 51.2 (48.9) (37.0) (44.2) (32.7)

TOTAL 45.4 NS 32.3 70.9 156.9 B-S depth (m) of tow COPEPODA 12.2 29.7 56.2 for each (22.5) (39.3) (47.2)

Location CLADOCERA 21.9 13.3 27.7 2.0=30 (40.4) (17.6) (23.3) 5.0=17 ROTIFERA 20.2 32.5 35.0 9.5=21 (37.1) (43.1) (29.5) 11.0=25 15.9=20 TOTAL 54.3 NS NS 75.5 118.9 5/24/00 10-S COPEPODA 46.0 42.0 64.7 61.6 168.7 (37.3) (37.1) (36.7) (29.9) (46.7)

CLADOCERA 24.7 30.6 22.8 37.4 45.3 (20.0) (27.1) (12.9) (18.2) (12.5)

ROTIFERA 52.6 40.5 88.6 106.9 147.4 (42.7) (35.8) (50.3) (51.9) (40.8)

TOTAL 123.3 113.1 176.1 206.0 361.4 B-S depth (m) of tow COPEPODA 29.0 26.8 50.2 17.7 78.6 for each (49.2) (46.9) (41.1) (21.7) (44.1)

Location CLADOCERA 8.1 17.4 10.8 15.8 19.6 2.0=30 (13.8) (22.2) (8.9) (19.4) (11.0) 5.0=NS ROTIFERA 21.8 24.2 61.0 48.0 80.1 9.5=21 (37.0) (30.8) (50.0) (58.9) (44.9) 11.0=25 15.9=20 TOTAL 58.8 78.4 122.0 81.6 178.3 4-10

Table 4-1 (continued).

Sample Locations Date Type Taxon 2.0 5.0 9.5 11.0 15.9 8/29/00 10-S COPEPODA 45.7 41.8 32.3 53.4 (62.1) (61.8) (43.0) (43.2)

CLADOCERA 19.8 11.9 26.7 27.3 (27.0) (17.6) (35.5) (22.1)

ROTIFERA 8.0 13.9 16.2 42.9 (10.9) (20.6) (21.5) (34.7)

TOTAL 73.6- 67.7 75.2 123.6 NS B-S depth (m) of tow COPEPODA 29.6 39.9 26.3 41.8 for each (61.2) (63.8) (47.9) (50.8)

Location CLADOCFRA 15.9 11.3 18.7 17.0 2.0=30 (33.0) (18.0) (34.0) (20.7) 5.0=NS ROTIFERA 2.8 11.4 9.9 23.4 9.5=19 (5.8) (18.2) (18.0) (28.5) 11.0=25 15.9=18 TOTAL 48.3 62.6 54.9 82.2 NA 11/10/00 10-S COPEPODA 10.6 13.4 26.3 45.2 30.5 (44.2) (28.3) (25.8) (45.3) (25.0)

CLADOCERA 9.6 16.5 47.0 18.5 4.6 (39.8) (35.0) (46.1) (18.6) (3.8)

ROTIFERA 3.8 17.3 28.7 36.1 86.9 (16.0) (36.6) (28.2) (36.2) (71.2)

TOTAL 24.0 47.3 102.0 99.7 122.0 B-S depth (m) of tow COPEPODA 19.3 16.7 30.6 45.3 28.8 for each (56.1) (36.6) (29.2) (60.6) (28.4)

Location CLADOCERA 10.2 13.0 40.2 12.5 4.5 2.0=30 (29.8) (28.7) (38.3) (16.8) (4.4) 5.0=NS ROTIFERA 4.8 15.8 34.1 16.9 68.2 9.5=20 (14.0) (34.7) (32.5) (22.6) (67.2) 11.0=24 15.9=NS TOTAL 34.4 45.5 104.9 74.7 101.5 NS= Sample not collected due to high winds, or no mooring buoy.

4-11

Table 4-2. Duncan's Multiple Range Test on epilimnetic zooplankton densities (no. X 1000/m 3 ) in Lake Norman, NC during 2000.

February Location 5.0 9.5 2.0 11.0 15.9*

Mean NS 37.3 45.4 70.9 156.9 May Location 5.0 2.0 9.5 11.0 15.9 Mean 113.1 123.3 176.1 206.0 361.4 August Location 15.9 5.0 2.0 9.5 11.0 Mean NS 67.7 73.6 75.2 123.6 November Location 2.0 5.0 11.0 9.5 15.9 Mean 24.0 47.3 99.7 102.0 122.3 NS = not sampled

• = only one replicate 4-12

Table 4-3. Zooplankton taxa identified from samples collected quarterly on Lake Norman from 1988 through 2000.

TAXON 88 89 90 91 92 93 94 95 96 97 98 99 00 COPEPODA Cyclops thomasi Forbes X X X X X X X X X C. vernalis Fischer X C. spp. O.F. Muller X X X X X X X X X X X Diaptomus birgei Marsh X X X X X X D. mississippiensisMarsh X X X X X X X X X X X XX D. pallidus Herick X X x x x x X D. reighardiMarsh X D. spp. Marsh X X XX X X X X X X X X X EpishurafluviatilisHerrick X X X X XX Ergasilus spp. x Eucyclops agilis (Koch) X Mesocyclops edax (S. A. Forbes) X X X X X X X X X X M. spp. Sars X X X X X X X XX Tropocyclops prasinus (Fischer) X X X X X X X X X T. spp. X X X X X X X X X X Calanoid copepodites X X X X X X X X X X X X X Cyclopoidcopepodites X X X X X X X X X X X X X Harpacticoidea X X X Nauplii X X X X X X X X X X X X X Parasitic copepods X CLADOCERA Alona spp.Baird X X Alonella spp. (Birge) X X Bosmina longirostris(0. F. M.) X X X X X X X X B. spp. Baird X X X X X X XX X X X Bosminopsis dietersi Richard X XX X X X X X X X X X X Ceriodaphnialacustris Birge X X X X X C. spp. Dana XX X X X X X X X XXXX Chydorus spp. Leach X X X X X X X Daphniaambigua Scourfield X X X X X X X D. catawba Coker X X D. galeata Sars X D. laevis Birge X D. longiremis Sars X X X D. lumholzi Sars X X X X X X X X D. mendotae (Sars) Birge XXXX D. parvulaFordyce X X X X X X X X X D. pulex (de Geer) IX XX 4-13

( (

C-, C,,)

0 Cd,)

0

-e FS 1 0 0 C) 0 C',)

0 ci,)

0 -d 0 0

-o -o C-,

0 *0 C) 0 0 Ci2 n 1 C-, 0 C/,)

C',) cdn C)

'-4 PC) C-,) C',) 0 R-,

0 C) 1 -t CA, pT CD 0 0 0 C) N C)

• 1 0 8 0 0 0 CD -i -4 0 ri,)

CJJ CD CD CD C-,) C) 0 C)

71 C.,) C)

CD~

z0 C',)

CD It CD 0

-t C)

-t Cot z

('D C) C) C)

-t 0 CD 0

C) ~1 C) 0 0 C)

C)

I C) 00 00

>< ><00 XX~~~~~< xx x X x~~~~~~;~ Xx XX x x X~~~~~>> ý ><X x jj x I X x X x x x x x Xý xX1 X x x x x x ý xx x x x~~~~~< xX x x xx xx xX X x x Xxx

( ( (

H 1 C C C CA -4 0 CA CA C CA -4 1 CA n.j

-o C 0 CA CA C C C 0 C 0 VA C 0 C 0 -5 0

C--.

-4 C 1 C C 1

0 C C n.j -d C

..j -e -o -5

-4 0

VA

-5

-4

• 0

-4 2 C C C C 0 C 0 C co5 0 0 z C C i1 0 CA C V) -5 Cn -e C '1 1 0 0n C -5

-4 0 C

'1 n.j C 0 -4 C CA C" C 0 0 0 C -e 0 CA S n.j C 0 C 0 1 C -t C 0

-o n.j 0 C

0 C C CA

-e C-1 0 0 0

C

-4 C 0 C 0 0 0 C C 0' CD C-.

-5 C 0 pi' 0 '-4 C C 0 C' C-1 0l C' 0 -5 N C C 0 C -t C 0 C CA 0 0 CA C 0 0 CA 0 C 0 0 C 0 0 CA n.j -C C 0 CA CA C C 0 C-0 0 CA 0:

0 C C -5 C. 0 0 C-1 CA 0 0 -t 0 C C 0 C 0

-t 0 CA -4 C C-1 0 cA 0 N

-t CA 0 0 0 C 0

-o 0 CA 0

0 CA CA 0 0 0

>0<

x<> X x<~ xX xx :xxx 0 X~~~~~~ xx x xX IX x x x 0 x x xx XX xxx XX X x X x x<> x< x x X x x~ X xxX xK X~ x xx x x Xx W X ~ v Xxx XN xxxxx Xx xN xx 0

x X~ X~ x0 x< X x X x xx xx x XXXX X XXX x x xx 0

e~f TAXON 88 89 90 91 92 93 94 95 96 97 98 99 00 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 Chaoborusspp. Lichtenstein 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 2000.

FEBRUARY MAY AUGUST NOVEMBER COPEPODA EPILIMNION 2.0 Tropocyclops (1.7) Epischura (1.1) Tropocyclops (8.2) Episch. + Trop (0.4ea)*

5.0 NOT SAMPLED Epischura (1.3) Tropocyclops (10.9) Epischura(0.8) 9.5 Mesocyclops (1.0) Epischura (2.1) Tropocyclops (4.2)* Epischura(1.4) 11.0 Epischura(2.6) Mesocyclops (0.6) Tropocyclops (2.5) Tropocyclops (1.5) 15.9 Epischura(4.0) Mesocyclops (2. f) - NOT SAMPLED Tropocyclops (0.5)

COPEPODA WHOLE COLUMN 2.0 Tropocyclops (0.4) Mesocyclops (1.6) Tropocyclops (9.4) Epischura(4.7)

"5.0 NOT SAMPLED Epischura (1.5) Tropocyclops (15.3) Tropocyclops (2.2) 9.5 NOT SAMPLED Epischura (1.1) Tropocyclops (4.7) Epischura(2.6) 11.0 Mesocyclops (2.2) Mesocyclops (3.1) Tropocyclops (4.3) Tropocyclops (2.5) 15.9 Cyclops (2.1) Mesocyclops (3.3) NOT SAMPLED Tropocyclops (1.2)

CLADOCERA EPILIMNION 2.0 Bosmina (100.0) Diaphanosoma(67.7) Bosmina (57.0) Bosmina (91.0) 5.0 NOT SAMPLED Diophanosoma(52.1) Bosminopsis (50.2) Bosmina (90.3) 9.5 Bosmina (89.9) Diaphanosona(46.5) Bosmina (51.9) Bosmina (99.3) 11.0 Bosmina (70.0) Diaphanosoma(58.1) Bosmina (77.9) Bosmina (91.0) 15.9 Bosmina (55.0) Diaphanosoma(55.8) NOT SAMPLED Bosmina (93.6)

CLADOCERA WHOLE COLUMN 2.0 Bosmina (97.9) Diaphanosoma(43.2) Bosmina (52.8) Bosmina (66.7) 5.0 NOT SAMPLED Bosmina (42.7) Bosminopsis (47.0) Bosmina (78.6) 9.5 NOT SAMPLED Diaphanosoma(43.8) Bosmina (61.9) Bosmina (98.5) 11.0 Bosmina (82.4) Diaphanosoma(68.0) Bosmina (68.3) Bosmina (75.8) 15.9 Bosmina (54.5) Diaphanosoma(40.7) NOT SAMPLED Bosmina (91.0) 4-17

Table 4-4 (continued)

Table 4-4 (continued)

FEBRUARY NOVEMBER I MAY 1 AUGUST ROTIFERA EPILIMNION 2.0 Kellicottia (39.5) Polyarthra(31.3) Polyarthra(80.5) Conochilus (36.4) 5.0 NOT SAMPLED Keratella (39.4) Polyarthra(74.8) Keratella (30.3) 9.5 Kellicottia (25.1) Keratella (61.1) Polyarthra(22.9) Conochilus (56.5) 11.0 Conochilus (41.2) Keratella (35.0) Asplanchna (34.3) Keratella (48.7) 15.9 Kellicottia (31.8) Keratella (58.1) NOT SAMPLED Keratella (45.0)

ROTIFERA WHOLE COLUMN 2.0 Kellicottia (46.6) Polyarthra(39.8) Polyarthra(51.8) Kellicottia (38.9) 5.0 NOT SAMPLED Keratella (52.3) Polyarthra(71.7) Polyarthra(42.4) 9.5 NOT SAMPLED Keratella (63.3) Trichocerca(27.9) Conochilus (57.0) 11.0 Conochilus (30.4) Polyarthra(42.1) Asplanchna (37.8) Keratella (45.4) 15.9 Kellicottia (31.9) Keratella (65.4) NOT SAMPLED Polyarthra(42.0)

• = Only adults present in samples.

4-18

1Om TO SURFACE TOWS 400 350 - - - - -- - - - - -- -- - - - - -- - -- - -- -- -- - - - -- - -- - -- - - -- - - - -- - - -- - - - - -- -.

300 x '5 ------- . . .. . .

.. 2---------- ----------- - ----------

-0 20 ------------------

Z6 15 0 - - - - - - - - - - - - - .. --- -..

50 -- -- - - - - -- - - - - - - --- -- -- -- -- - -- -- --

0 20 5.0 9.5 11.0 15.9 BOTTOM TO SURFACE TOWS FEB = MAY e.-- AUG ---- NOV 180, 160 140 120

• E 100 x 0 0.

z 60 40 20 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 2000.

4-19

MIXING ZONE FEBRUARY 250 250 225 225 200 200

• 175 175 E

o 150. 150 x

5 125 125 t- 100 100 z

ILl 75 0 75-50 50 25 25

-0 0 87 88 89 90 91 92 93 94 95 96 97 98 99 00 87 88 89 90 91 92 93 94 95 96 97 98 99 00 BACKGOUND LOCATIONS 400 400 350 350 300 300 250 250 x

C 200 200 I

• j 150 150 z

100 100 50 50 0 0 87 88 89 90 91 92 93 94 95 96 97 98 99 00 87 88 89 90 91 92 93 94 95 96 97 98 99 00 YEARS YEARS Figure 4-2. Total zooplankton densities by location for epilimnetic samples collected in Lake Norman, NC, in February and May of 1988 through 2000.

4-20

MIXING ZONE 250 225 200 E 175 C. 150 0 125 0j a 100 Z

75 50 25 0

87 88 89 90 91 92 93 94 95 96 97 98 99 00 87 88 89 90 91 92 93 94 95 96 97 98 99 00 BACKGROUND LOCATIONS 400 400 350 350 R 300 300 E

8250 250

'I 200 I 200 S150 150 o100 100 50 50 0 0 87 88 89 90 91 92 93 94 95 96 97 98 99 00 87 88 89 90 91 92 93 94 95 96 97 98 99 00 YEARS YEARS Figure 4-3. Total zooplankton densities by location for epilimnetic samples collected in Lake Norman, NC, in August and November of 1987 through 2000.

4-21

LOCATIONS ICOPEPODS CLADOCERANS ROTIFERS Figure 4-4. Zooplankton community composition by month for epilimnetic samples collected in Lake Norman, NC, in 2000.

4-22

180 160 140 ..............................................-.............

12 0 --- - -- -- - - - - -- -- - -- -- - - - - -- -- - - - --. - --. . - --. -- - - -- - - -- - -- - - - -

8600 - -------------------------------

---

t -... ----

4o020 .. .. .. ,-- -;, -- ---..--- -................--- -

80 (

U- < < LL < LL < <L U LU < U < UL < L LL <

Figure 4-5. Zooplankton composition by quarter for epimlimnetic samples collected in Lake Norman, NC, from 1990 through 2000 (only Location 2.0 represents the MIXING ZONE in February 2000).

4-23

LAKE-WIDE: EPILIMNION nOCOPEPODS 13CLADOCERANS UROTIFERS I 100%

80%

z 0

F 0) 0 60%

0 z 40%

(-

Iu 20%

0%

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 YEARS LAKE-WIDE: WHOLE COLUMN JOCOPEPODS UCLADOCERANS EROTIFERS I 100%

90%

80%

z 0 70%

F:

0 60%

0 50%

z 40%

0 it 30%

(Lu 20%

10%

0%

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 YEARS Figure 4-6. Annual lake-wide percent composition of major zooplankton taxonomic groups from 1988 through 2000.

4-24

MIXING ZONE (LOCATIONS 2.0 + 5.0): WHOLE COLUMN rOCOPEPODS MCLADOCERANS UROTIFERS I 100%

90%

)

80%

z 70%

0 60%

a.

0 50%

0 I-ziJi 40%

I.

w 1.1. 30%

0.

20%

10%

0%

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 YEAR Figure 4-7. Annual percent composition of major zooplankton taxonomic groups from Mixing Zone Locations: 1988 through 2000.

4-25

BACKGROUND (LOCATIONS 9.5 + 11.0 + 15.9): EPILIMNION rn COPEPODS ECLADOCERANS UROTIFERS 100%

90%

80%

z 0 70%

0 60%

cc 0.

50%

z 40%

UJ ILl 0~ 30%

20%

10%

0%

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 YEAR BACKGROUND (LOCATIONS 9.5 + 11.0 + 15.9): WHOLE COLUMN Ir'3COPEPODS ECLADOCERANS U ROTIFERSI 100%

90%

80%

z 70%

0 a1.

60%

I 0 50%

oz 40%

w w 30%

a.

20%

10%

0%

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 YEAR Figure 4-8. Annual percent composition of major zooplankton taxonomic groups from Background Locations: 1988 through 2000.

4-26

CHAPTER 5 FISHERIES INTRODUCTION In accordance with the NPDES permit for McGuire Nuclear Station (MNS), monitoring of specific fish population parameters was continued during 2000. The components of the 2000 fish monitoring program for Lake Norman were to:

1. Continue striped bass mortality monitoring throughout the summer;

2. Continue a 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 in Lake Norman;

3. Continue annual, fall hydroacoustic/purse seine forage population assessments;

4. Assist the NCWRC in shad netting collections to evaluate the taxa composition and size distribution of Lake Norman forage species;

5. Revise annual, spring shoreline electrofishing program to be conducted every 2 years, beginning Spring 1999, with next sample scheduled for Spring 2001;

6. Cooperate with NCWRC on a shoreline plantings demonstration project on Lake Norman;

7. Continue Duke participation on the Lake Norman Advisory Committee and assist the NCWRC in accessing and interpreting relevant Duke data, relative to Committee activities.

METHODS AND MATERIALS The Spring shoreline electrofishing portion of the MNS maintenance monitoring program was not scheduled to be conducted during 2000, however, shoreline electrofishing of Lake Norman was conducted as part of a watershed program in which all Catawba River reservoirs are sampled every three years. Sampling was conducted on March 27 and April 10-12. The locations sampled were the same locations sampled under the MNS monitoring program; Ten 300-m transects were sampled in each of three areas of Lake Norman (MNS mixing zone, mid-lake reference area, and Marshall Steam Station mixing zone), for a total of 30 transects.

The MNS mixing zone transects were located within the area between Ramsey Creek and Channel Marker 1 A. The mid-lake reference transects were located in the area between Channel Marker 7 and Channel Marker 9, while the Marshall Steam Station (MSS) mixing 5-1

zone transects were located in the area between Channel Marker 14 and the NC Highway 150 Bridge. All transects were subjectively selected to include the various habitat types that exist in Lake Norman and 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 species. Individual total lengths (mm) and weights (g) were obtained for all largemouth bass collected.

The mixing zone was monitored for striped bass mortalities during all summer sampling trips on the lake. Additionally, from July 3 through September 11, weekly surveys were conducted specifically to search for dead or dying striped bass in the main channel areas of the entire lake from Cowan's Ford Dam to uplake of NC Highway 150.

During 2000, no specific sampling for striped bass condition was conducted under the MNS maintenance monitoring program, however, these data were collected as part of the cooperative bioenergetics study being conducted by the NCWRC, North Carolina State University and Duke. Due to the collection of sufficient striped bass data during sampling for the bioenergetics study, no additional data were collected from the December striped bass tournament.

The materials and methods for the purse seine and hydroacoustics sampling on Lake Norman during 2000 are presented in a separate report included as Attachment 1.

Gill netting for shad and alewives was jointly conducted by the NCWRC and Duke during November 6-8, to evaluate the taxa composition and size distribution of Lake Norman forage species. Netting was conducted in creel zones 3, 4, and 5 (Figure 5-1). The number of nets fished by zone were: two shallow and two deep nets in zone 3, one shallow and two deep nets in zone 4 and three shallow and four deep nets in zone 5. Sampling consisted of one overnight net set for each net, for a total sampling effort of 14 net nights. Collected fish were sorted by species and measured for individual total length (mm). Netting data were recorded separately for each net fished.

5-2

RESULTS AND DISCUSSION As in previous years, spring shoreline electrofishing of Lake Norman yielded variable catches among the three areas sampled (Tables 5-1 through 5-3). In the MNS mixing zone area, a total of 2,175 fish were collected, weighing a total of 38.13 kg and representing 17 taxa (Table 5-1). Although the total number of fish and taxa collected during 2000 were higher than 1999 catches from this area (1,379 fish and 14 taxa), the total biomass during 2000 was about half of the 1999 biomass (74.21 kg). This lower biomass is primarily attributable to the absence of carp and lower catches of largemouth bass during 2000. Individual transect catches ranged from a low of 67 fish to a high of 607 fish.

The total catch from the reference area was 1,314 fish, weighing 89.28 kg and representing 16 taxa (Table 5-2). The number of taxa collected from the reference area was the same as

-during 1999, however the total number and biomass of fish collected during 2000 were higher than those for 1999 (998 fish weighing 80.45 kg). Individual transect catches ranged from 35 to 231 fish.

As in 1999, the highest total catch by number was collected from the MSS mixing zone area (Table 5-3). The total catch was 2,496 fish, weighing 84.93 kg, and representing 17 taxa.

The total number of fish collected from this area during 2000 was substantially higher than the 1999 catch (1,421 fish), however, total biomass and number of taxa were slightly lower than during 1999 (107.86 kg and 20 taxa). The 2000 sample did include the collection of an unusual species for Lake Norman. A rainbow trout was collected near the MSS discharge.

General monitoring of Lake Norman and specific monitoring of the MNS mixing zone for striped bass mortalities during the summer of 2000, yielded one mortality within the mixing zone and six mortalities in the main channel outside the mixing zone. The seven observed mortalities ranged in size from 450 mm to 615 mm. Specific observations by date were:

5-3

DATE LOCATION LENGTH (mm) NUMBER July 18 Vicinity of Channel Marker 14 450 1 July 24 Vicinity of Channel Marker 2 519 1 Vicinity of Channel Marker 16 505 1 August 7 Vicinity of Channel Marker D 3 505 1 August 22 Vicinity of Channel Marker 4 491 1 Vicinity of Channel Marker 10 580 1 Vicinity of Channel Marker 13 615 1 Results of the purse seine and hydr-opcoustics sampling on Lake Norman during 2000 are presented in a separate report included as Attachment 1.

Gillnetting for shad and alewives during 2000 yielded a total of 330 fish from 14 net nights of sampling in three zones of Lake Norman (Table 5-4). Total net catches were highest in Zone 5 (278 fish), followed by Zones 4 (28 fish), and 3 (24 fish), respectively. Species composition in Zones 3 and 5 were similar during 1999 and 2000, with collections of all three forage species (gizzard shad, threadfin shad, and alewives) from each of the two zones.

In Zone 4, however, only threadfin shad and alewives were collected during 2000, while only gizzard shad and threadfin shad were collected during 1999. Overall, a comparison of 1999 and 2000 gill net catches suggests a trend of increasing abundance and distribution of alewives within Lake Norman, especially in the upper portion of the reservoir.

FUTURE FISH STUDIES

"* Continue striped bass mortality monitoring throughout the summer.

"* Continue a 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 in Lake Norman.

"* Continue the annual, fall hydroacoustic/purse seine forage population assessment.

"* Continue spring electrofishing program on a two-year frequency, with the next sample scheduled for the Spring 2001.

"* Repeat late summer purse seine sample and fall small mesh gill net sample to monitor changes in Lake Norman forage population.

5-4

"* Cover December Striper Swipers tournament to obtain striped bass body condition data.

"* Support cooperative NCSU bioenergetics study on Lakes Badin and Norman by assisting in the collection of striped bass, forage, and summer habitat data for Lake Norman, as requested by the NCWRC.

"* Assist and support the NCWRC in the evaluation of a shoreline plantings demonstration project begun by the NCWRC and a local fishing club during 2000 in the vicinity of Duke Power State Park.

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 2000. General monitoring of Lake Norman and specific monitoring of the MNS mixing zone for striped bass mortalities during the summer of 2000, yielded one mortality within the mixing zone and six mortalities in the main channel outside the mixing zone.

Spring shoreline electrofishing of Lake Norman yielded variable catches for the three areas sampled; the MNS mixing zone area, a mid-lake reference area, and the MSS mixing zone area. The highest total catch numerically was from the MSS mixing zone area, followed by the MNS mixing zone and mid-lake reference areas, respectively. The highest total catch gravimetrically was from the mid-lake reference area, followed by the MSS and MNS mixing zone areas, respectively. The total number of taxa collected was similar for all three areas.

During July 2000, forage fish densities in the six zones of Lake Norman ranged from 6,036 to 18,622 fish/ha. There appeared to be a trend of more forage fish in uplake regions (Zones 5

& 6) than downlake. The estimated population was approximately 116 million fish. Purse seine sampling indicated that these fish were 96.24% threadfin shad, 3.26% alewives, and 0.50% gizzard shad.

September 2000 forage fish densities ranged from a low of 2,112 (Zone 6) to a high of 6,482 (Zone 2) and did not demonstrate the same fish distribution trend seen in July. The estimated 5-5

forage population was approximately 63 million fish. Purse seine sampling indicated that these fish were 87.40% threadfin shad, 12.37% alewives, and 0.22% gizzard shad.

During November 2000, forage fish densities in the six zones of Lake Norman ranged from 579 to 2,294 fish/ha. There appeared to be fewer fish in the uplake zones as lake water temperatures declined. The estimated forage population was approximately 24 million fish.

No purse seine data were available for length frequency distributions or speciation of this population estimate.

Gillnetting for shad and alewives yielded a total of 330 fish from 14 net nights of sampling in three zones of Lake Norman. All three forage species (gizzard shad, threadfin shad, and alewives) were collected from Zones 3 and 5, while only threadfin shad and alewives were collected from Zone 4.

Through consultation with the NCWRC, the Lake Norman fisheries program continues to be reviewed and modified annually to address fishery issues. Fisheries data continue to be collected through cooperative monitoring programs with the NCWRC, to allow the Commission's assessment and management of Lake Norman fish populations. Fisheries data to date indicate that the Lake Norman fishery is consistent with the trophic status and productivity of the reservoir. However, one aspect of the Lake Norman fishery that warrants close monitoring in the future is the composition of forage populations. The introduction of alewives by fishermen over the past several years could have a dramatic impact on lake-wide forage populations and game species.

5-6

(f C Table 5-1. Numbers and biomass of fish collected from electrofishing ten 300-m transects in the MNS mixing zone of Lake Norman during April 2000.

Transect 1 2 3 4 5 6 7 8 9 10 A,LL Species N KG N KG N KG N KG N KG N KG N KG N KG N KG N KG N KG Gizzard shad 2 0.995 2 0.990 1 0.350 2 0.911 1 0.460 8 3.706 Threadfin shad 11 0.081 10 0.101 21 0.182 Greenfin shiner 2 0.004 2 0.003 4 0.007 Whitefin shiner 18 0.048 18 0.043 1 0.001 30 0.089 10 0.017 111 0.360 26 0.144 47 0.148 27 0,053 1 08 0.270 396 1.173 Golden shiner 1 0.009 1 0.009 Spottail shiner 2 0.010 11 0.043 13 0.053 Flathead catfish 1 1.530 1 0.115 1 0.008 3 1.653 White bass 1 0.180 1 0.180 Striped bass 1 0.320 1 1.170 2 1.490 Redbreast sunfish 46 0.525 50 0.650 26 0.295 98 1.070 10 0.072 59 0.740 11 0.288 13 0.n55 19 0.320 15 0.205 347 4.520 Green sunfish 8 0.021 1 0.002 9 0.023 Warmouth 10 0.064 7 0.115 4 0.018 12 0.071 2 0.005 3 0.009 1 0.001 11 0.082 1 0.009 51 0.374 Bluegill 62 0.380 167 1.166 106 0.890 339 2.410 25 0,149 29 0.168 4 0.069 9 0.109 81 0.520 116 0.730 938 6.591 Redear sunfish 12 0.240 14 0.280 27 0.295 87 1.260 7 0.460 9 0.049 2 0.085 25 0.085 5 0.125 188 2.879 Hybrid sunfish 5 0.058 19 0.295 16 0.245 26 0.334 1 0.013 3 0.024 8 0.311 1 0.055 9 0,320 7 0.087 95 1.742 Largemouth bass 23 2.803 9 0.842 15 2.150 11 0.908 4 1.070 5 2.067 15 2.172 5 0.330 5 0.597 4 0.268 96 13.207 Black crappie 2 0.340 2 0.340 All 179 6.643 287 4.496 197 4.234 607 6.816 72 1.870 231 4.627 67 3.896 88 1.643 178 1.985 269 1.919 2175 38.129 5-7

( ( .

Table 5-2. Numbers and biomass of fish collected from electrofishing ten 300-m transects in the mid-lake reference area of Lake Norman during March/April 2000.

Transect 4 5 6 7 8 9 10 ALL 1 2 3 Species N KG N KG N KG N KG N KG N KG N KG N KG N KG N KG N KG 3 1.415 10 3.615 3 1.090 1 0.377 4 1.940 24 9.762 Gizzard shad 3 1.325 1 0.003 5 0.009 1 0.001 9 0.016 Greenfin shiner 2 0.003 29 0.066 29 0.066 28 0.063 9 0.018 21 0.061 15 0.034 33 0.076 186 0.458 Whitefin shiner 21 0.070 1 0.004 1 1.600 4 6.550 2 3.390 1 1.182 2 3.394 1 1.340 11 17.456 Common carp Spottail shiner 1 0.004 7 0.028 , ý1 0.077 9 0.037 38 0.146 1 0.001 1 0.001 Swallowtail shiner Blue catfish 7 10.923 7 10.923 1 0.250 1 0.455 1 0.210 1 0.215 2 2.279 1 0.162 3 0.711 10 4.282 Channel catfish White bass 1 0.377 1 0.377 Redbreast sunfish 20 0.454 21 0.605 16 0.345 3 0.028 12 0.350 1 0.081 9 0.235 33 0.477 25 0.395 21 0.722 161 3.692 Warmouth 7 0.054 1 0.001 2 0.004 3 0.125 1 0.007 1 0.001 2 0.003 1 0.001 18 0.196 Bluegill 80 0.786 41 0.655 113 1.280 5 0.070 43 0.320 3 0.053 4 0.105 119 1.175 121 0.730 107 0.715 636 5.889 Redear sunfish 7 0.067 3 0.034 5 0.490 1 0.118 11 0.530 7 0.750 3 0.110 2 0.178 10 0.421 9 0.396 58 3.094 Hybrid sunfish 1 0.078 8 0.315 3 0.067 0.034 3 0.081 2 0.170 1 0.063 4 0.210 4 0.207 27 1.225 Largemouth bass 18 5.274 16 3.036 18 4.143 7 2.396 13 1.922 8 1.715 8 2.021 17 4.359 11 2.655 6 3.246 122 30.767 1 0.210 4 0.783 5 0.993 All 160 8.488 90 4.649 161 9.591 64 13.340 119 4.695 59 6.257 35 2.914 231 21.938 196 8.013 199 9.392 1314 89.277 5-8

( (

Table 5-3. Numbers and biomass of fish collected from electrofishing ten 300-m transects in the Marshall Steam Station mixing zone area of Lake Norman during April 2000.

Transect 1 2 3 4 5 6 7 8 9 10 ALL Species N KG N KG N KG N KG N KG N KG N KG N KG N KG N KG N KG Gizzard shad 1 0.021 1 0.280 1 0.435 3 0.736 Threadfin shad 14 0.110 14 0.110 Greenfin shiner 2 0.002 3 0.010 5 0.012 Whitefin shiner 45 0.152 8 0.043 28 0.121 6 0.019 85 0.332 1 0.004 229 0.785 402 1.456 Common carp 1 0.920 3 7.235 1 1.650 2 3.185 2 4.855 1 2.220 1 2.170 1 2.015 12 24.250 Spottail shiner 91 0.412 1 0.003 13 0.052 1 0.004 142 0.590 248 1.061 Blue catfish 3.280 1 3.280 Channel catfish 1 0.335 1 0.335 Flathead catfish 0.260 1 3.595 1 0.016 1 0.063 2 0.505 6 4.439 Rainbow trout 0.009 1 0.009 Redbreast sunfish 29 0.395 27 0.415 48 1.105 12 0.085 21 0.309 1 0.052 19 0.290 34 , 0.520 71 0.930 34 0.795 296 4.896 Warmouth 4 0.044 13 0.191 6 0.078 14 0.055 4 0.071 2 0.014 4' 0.056 3 0.008 50 0.517 Bluegill 105 0.815 99 0.485 215 2.050 128 0.590 257 2.465 6 0.139 58 0.470 125 1.355 72 0.885 78 1.280 1143 10.534 Redear sunfish 7 0.158 4 0.069 11 0.078 15 0.111 13 0.172 1 0.003 14 1.080 2 0.009 6 0.059 1 0.005 74 1.744 Hybrid sunfish 1 0.120 4 0.035 13 0.280 5 0.036 12 0.364 2 0.199 3 0.150 9 0.195 7 0,073 3 0.098 59 1.550 Largemouth bass 19 4.121 14 1.838 24 4.754 11 2.559 20 1.222 15 2.315 13 1.644 18 2.678 23 3.990 23 4.864 180 29.985 Yellow perch 1 0.018 1 0.018 All 304 7.139 156 2.885 358 16.086 203 7.232 438 6.917 28 5.897 113 8.560 193 10.334 189 9.442 514 10.440 2496 84.932 5-9

( ( (

Table 5-4. Comparison of catches from gillnet sampling in three zones of Lake Noriman during the fall of 1999 and 2000.

September 20-23, 1999 Sample Zone 3 Zone 4 Zone 5 Taxa No. Length Ran.e (mm) No. Length Range (mm) No. Length Ranqe (mm)

Gizzard shad 44 84-365 5 279-356 31 183-332 Threadfin shad 60 62-161 8 68-151 219 64-160 Alewife 3 101-118 6 110-193 Total 107 13 256 November 6-8, 2000 Sample Zone 3 Zone 4 Zone 5 Taxa No. Length Range (mm) No. Length Range (mm) No. Lengqth Range (mm)

Gizzard shad 3 230-281 11 112-357 Threadfin shad 6 72-163 26 70-178 124 65-157 Alewife 15 102-178 2 102-106 143 89-117 Total 24 28 278 5-10

ZONE 2 ZONE.

ZONE'I ............... ... L Figure 5-1. Sampling zones on Lake Norman, North Carolina.

5-11

Attachment 1:

Hydroacoustic and Purse Seine Data: 2000 INTRODUCTION In accordance with the NPDES permit for McGuire Nuclear Station (MNS), monitoring of forage fish population parameters was conducted in 2000. 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 / NCWRC / NCSU study to evaluate striped bass bioenergetics in Lakes Norman and Badin necessitated two additional hydroacoustic assessments and purse seine samples in 2000.

METHODS AND MATERIALS Three mobile hydroacoustic surveys of the entire lake were conducted on July 13 and 17, (Bioenergetics Study), September 18 and 19 (MNS NPDES), and November 28 and 29 (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 (2.0 m to 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 six zones due to its large size, spatial heterogeneity, and multiple power generation facilities.

Purse seine samples were collected on July 12 and September 18, 2000 from the lower (main channel near Marker 1), mid (mouth of Davidson Creek), and uplake (just downlake of Duke Power State Park) areas of the reservoir. No purse seine sample was collected in November as destruction of the purse seine net on Lake Badin prior to the Lake Norman sample precluded the collection of data. The purse seine measured 118 x 9 m (400 x 30 ft) 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.

RESULTS AND DISCUSSION Forage fish densities in the six zones of Lake Norman ranged from 6,036 to 18,622 fish/ha in July 2000 (Table 1). There appeared to be a trend of more forage fish in uplake A-1

regions (Zones 5 & 6) than downlake. The estimated population was approximately 116 million fish. Purse seine sampling indicated that these fish were 96.24% threadfin shad, 3.26% alewives, and 0.50% gizzard shad. The length frequency distribution indicates threadfin shad dominate the lower size classes of forage fish under 100 mm while the alewives occupy the higher size classes (Figure 1).

September 2000 forage fish densities ranged from a low of 2,112 (Zone 6) to a high of 6,482 (Zone 2) and did not demonstrate the same fish distribution trend seen in July. The estimated forage population was approximately 63.2 million fish. Purse seine sampling indicated that these fish were 87.40% threadfin shad, 12.37% alewives, and 0.22%

gizzard shad. The length frequency distribution indicates threadfin shad continue to dominate the lower size classes ofJorage fish with a modal length of approximately 50 55 mm while the alewives occupy, the higher size classes (Figure 2).

Forage fish densities in the six zones of Lake Norman ranged from 579 to 2,294 fish/ha in November 2000. There appeared to be fewer fish in the uplake zones and this was thought to be related to downlake movements of fish resulting from declining water temperatures. The estimated forage population was approximately 24.3 million fish. No purse seine data were available for length frequency distributions or speciation of this population estimate.

The 2000 population estimates demonstrated declining population sizes as the year progressed. Natural mortality and predation from Lake Norman's numerous piscivorous species and adult alewives probably contributed to this decline. Population estimates in 2000 are similar to estimates during 1997 - 1999 but are lower than the estimates during 1993-1996.

FUTURE FISH STUDIES

. Continue the annual fall hydroacoustic/purse seine forage population assessment.

A-2

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 2000.

Density (no/hectare) Population Estimate Zone July September November July September November 1 6,036 4,455 1,203 13,768,116 10,161,855 2,744,043 2 7,546 6,482 2,294 23,257,527 19,978,172 7,070,337 3 6,509 5,189 2,239 22,491,980 17,930,693 7,736,909 4 7,651 3,953 2,012 9,418,381 4,866,143 2,476,772 5 18,622 4,392 1,876 39,217,932 9,249,552 3,950,856 6 16,367 2,112 579 7,823,426 1,009,536 276,762 Total 115,977,361 63,195,951 24,255,680 95% LCL 103,926,570 59,998,381 21,962,482 95% UCL 128,028,153 66,393,522 26,548,877 A-3

( ( (

Figure 1. Lake Norman (combined) forage fish - July 2000.

140 -

120 100  !

80 E El T Shad z 60 MG Shad 40 i Alewives 20 0- i ii.

~~~~t Mu. I I I I

I I I I I f-t

!YrrrE1MFm I

C I I I I I I

=F I I I I I I I I I I I I I I I i I I 20 35 50 65 80 95 110 125 140 155 170 185 200 215 230 245 Length Group (mm)

A-4

/ (

(

Figure 2. Lake Norman (combined) forage fish - September 2000.

160 140 11 120 100 E 80 z E1T Shad 60 ZG Shad

• Alewives 40 20 0

20 35 50 65 80 95 110 125 140 155 170 185 200 215 230 245 Length Group (mm)

A-5