ML030570291
| ML030570291 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 02/03/2003 |
| From: | Jamil D Duke Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NC0024392 | |
| Download: ML030570291 (135) | |
Text
I Duke atPower.
A W,~ E-0j C-Duke Power McGuire Nuclear Station 12700 Hagers Ferry Road Huntersville, NC 28078-9340 (704) 875-4000 (704) 875-5333 OFFICE (704) 875-4809 FAX D.M. Jamil Vice President, McGuire February 3, 2003 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: 2001 Summary," as required by the National Pollutant Discharge Elimination System (NPDES) permit NC0024392. The report includes detailed results and data comparable to that of previous years. The report was submitted to the North Carolina Department of Environment and Natural Resources on January 31, 2003.
Any questions regarding this submittal should be directed to Kay Crane, McGuire Regulatory Compliance at (704) 875-4306.
Dhiaa M. Jamil
U. S. Nuclear Regulatory Commission Document Control Desk February 3, 2003 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:
2001
SUMMARY
McGuire Nuclear Station: NPDES No. NC0024392 Duke Power A Duke Energy Company January 2003
TABLE OF CONTENTS EXECUTIVE
SUMMARY
LIST OF TABLES LIST OF FIGURES CHAPTER 1: McGUIRE NUCLEAR STATION OPERATION Introduction Operational data for 2001 CHAPTER 2:
CHAPTER 3:
CHAPTER 4:
WATER CHEMISTRY Introduction Methods and Materials Results and Discussion Future Studies Summary Literature Cited PHYTOPLANKTON Introduction Methods and Materials Results and Discussion Future Phytoplankton Studies Summary Literature Cited ZOOPLANKTON Introduction Methods and Materials Results and Discussion Future Zooplankton Studies Summary Literature Cited CHAPTER 5: FISHERIES Introduction Methods and Materials Results and Discussion Future Fisheries Studies Summary : Hydroacoustic and Purse Seine Data Page i
V vi 1-1 1-1 1-1 2-1 2-1 2-1 2-2 2-8 2-8 2-9 3-1 3-1 3-1 3-2 3-9 3-9 3-11 4-1 4-1 4-1 4-2 4-6 4-6 4-7 5-1 5-1 5-1 5-2 5-5 5-6 A-1
EXECUTIVE
SUMMARY
As required by the National Pollutant Discharge Elimination System (NPDES) permit number NC0024392 for McGuire Nuclear Station (MNS), the following annual report has been prepared.
This report summarizes environmental monitoring of Lake Norman conducted during 2001.
McGUIRE NUCLEAR STATION OPERATION The monthly average capacity factor for MNS was 96.8 %, 101.3 %, and 102.0 % during July, August, and September of 2001, respectively (Table 1-1). These are the months when conservation of cool water and discharge temperatures are most critical and the thermal limit for MNS increases from a monthly average of 95.0°F (35.0°C) to 99.0°F (37.2°C). The average monthly discharge temperature was 96.2°F (35.7°C) for July, 98.0°F (36.7°C) for August, and 94.7°F (34.8°C) for September 2001.
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 2001 were similar to those observed historically. Temperature and DO data collected in 2001 were within the range of previously measured values.
Reservoir-wide isotherm and isopleth information for'2001, 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 2001 was generally similar to historical conditions. All chemical parameters measured in 2001 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 2001 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 variable and diverse phytoplankton communities.
No obvious short term or long term impacts of station operations were observed.
In 2001 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 2001 were lower than those observed during 2000, and standing crops were within ranges established over previous years.
The proportions of ash-free dry weights to dry weights in 2001 were slightly lower than those of 2000, indicating little change in organic/inorganic inputs into Lake Norman. Diversity, or numbers of taxa, of phytoplankton had decreased since 2000, and the total number of individual taxa was within ranges of previous years.
The phytopkankton index (Myxophycean) tended to confirm the characterization of Lake Norman as oligo-mesotrophic.
The annual index for 2001 was lower than that of 2000, and was at the very low end of the intermediate range.
One indication of "balanced indigenous populations" in a reservoir is the diversity, or number of taxa observed over time. Nine classes comprising 64 genera and 118 species, varieties, and forms of phytoplankton were identified in samples collected during 2001, as compared to 81 genera and 172 lower taxa identified in 2000. Two taxa previously flyre'corded dudring the Maintenance Monitoring Program were identified during 2001.
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 2001, were likely due to environmental factors and appear not to be related to plant operations.
ii
Epilimnetic zooplankton densities during all but May of 2001 were within ranges of those observed in previous years. The epilimnetic density at Location 15.9 in May 2001 was the highest recorded during the Program, and may have represented an ongoing lag response to comparatively high phytoplankton standing crops uplake at that time.
One hundred and eight zooplankton taxa have been recorded from Lake Norman since the Program began in 1987 (forty-six were identified during 2001). No previously unreported taxa were identified during 2001.
FISHERIES In accordance with the Lake Norman Maintenance Monitoring Program for the NPDES permit for MNS, specific fish monitoring programs were coordinated with the NCWRC and continued during 2001. General monitoring of Lake Norman and specific monitoring of the MNS mixing zone for striped bass mortalities during the summer of 2001, yielded -nine mortalities within the mixing zone and nine 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 the same for the MSS and MNS mixing zone areas and slightly lower for the mid-lake reference area.
September 2001 forage fish densities ranged from a low of 3,173 fish/ha (Zone 6) to a high of 11,513 fish/ha (Zone 2). The estimated forage population was approximately-78 million fish.,
Purse seine sampling indicated that these fish were 76.47% threadfin shad, 23.52% alewives, and 0.01% gizzard shad.
During December 2001, forage fish densities in the six zones of Lake Norman ranged from 1,451 to 8,647 fish/ha.
There appeared to be fewer fish in the downlake zones.
The estimated forage population was approximately 47 million fish.
Purse seine sampling indicated that these fish were 82.66% threadfin shad, 16.46% alewives and 0.88% gizzard shad.
iii
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 2-13 Table 2-2 Water chemistry methods and analyte detection limits 2-14 Table 2-3 Heat content calculations for Lake Norman in 2000 and 2001 2-15 Table 2-4 Comparison of Lake Norman with TVA reservoirs 2-16 Table 2-5 Lake Norman water chemistry data in 1998 and 1999 2-17 Table 3-1 Mean chlorophyll a concentrations in Lake Norman 3-13 Table 3-2 Duncan's multiple range test for Chlorophyll a 3-14 Table 3-3 Total phytoplankton densities from Lake Norman 3-15 Table 3-4 Duncan's multiple range test for phytoplankton densities 3-16 Table 3-5 Duncan's multiple range test for dry and ash free dry weights 3-17 Table 3-6 Phytoplankton taxa identified in Lake Norman from 1988-2001 3-18 Table 3-7 Dominate classes and species of Phytoplankton 3-28 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 1988-2001 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 5-8 Table 5-2 Electrofishing catches in the mid-lake reference zone 5-9 Table 5-3 Electrofishing catches in the mixing zone of Marshall 5-10 V
LIST OF FIGURES Figure 2-1 Figure 2-2 Figure 2-3 Figure 2-4 Figure 2-5 Figure 2-6 Figure 2-7 Figure 2-8 Figure 2-9 Figure 2-10a Figure 2-10b Figure 2-11 Figure 3-1 Figure 3-2 Figure 3-3 Figure 3-4 Figure 3-5 Figure 3-6 Figure 3-7 Figure 3-8 Figure 3-9 Figure 4-1 Figure 4-2 Figure 4-3 Figure 4-4 Figure 4-5 Figure 4-6 Figure 4-7 Figure 4-8 Figure 5-1 Figure 5-2 Figure 5-3 Map of sampling locations on Lake Norman Monthly precipitation near McGuire Nuclear Station Monthly mean temperature profiles in background zone Monthly mean temperature profiles in mixing zone Monthly temperature and dissolved oxygen data Monthly mean dissolved oxygen profiles in background zone Monthly mean dissolved oxygen profiles in mixing zone Monthly isotherms for Lake Norman Monthly dissolved oxygen isopleths for Lake Norman Heat content of Lake Norman Dissolved oxygen content of Lake Norman Striped bass habitat in Lake Norman Chlorophyll a measurements of Lake Norman Mean chlorophyll a concentrations by year Chlorophyll a concentrations by location Class composition of phytoplankton at Locations 2.0 Class composition of phytoplankton at Locations 5.0 Class composition of phytoplankton at Location 9.5 Class composition of phytoplankton at Location 11.0 Class composition of phytoplankton at Location 15.9 Annual lake-wide Myxophycean index from 1988-2001 Zooplankton density by sample location in Lake Norman Zooplankton densities among years during February and May
-Zooplankton densities among years during August and November Lake Norman zooplankton composition in 2001 Quarterly zooplankton composition from 1990 through 2001 Annual lake-wide zooplankton composition, 1988 through 2001 Lake Norman zooplankton composition (mixing zone locations)
Lake Norman zooplankton composition (background locations)
Lake Norman creel zones Striped bass weight vs length for Winter 2001 samples Striped bass weight vs length for Fall 2001 samples Page 2-20 2-21 2-22 2-24 2-26 2-27 2-29 2-31 2-34 2-37 2-37 2-38 3-29 3-30 3-31 3-33 3-34 3-35 3-36 3-37 3-38 4-19 4-20 4-21 4-22 4-23 4-24 4-25 4-26 5-11 5-12 5-13 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 2001.
OPERATIONAL DATA FOR 2001 The monthly average capacity factor for MNS was 96.8 %, 101.3 %, and 102.0 % during July, August, and September of 2001, respectively (Table 1-1). These are the months when conservation of cool water and discharge temperatures are most critical and the thermal limit for MNS increases from a monthly average of 95.0°F (35.0°C) to 99.0°F (37.2°C). The average monthly discharge temperature was 96.2°F (35.7°C) for July, 98.0°F (36.7°C) for August, and 94.7'F (34.8°C) for September 2001.
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 2001.
NPDES DISCHARGE CAPACITY FACTOR (%)
TEMPERATURE Month Unit 1 Unit 2 Station Monthly Average Average Average Average OF
°C January 83.9 104.5 94.2 63.7 17.6 February 103.7 105.1 104.4 67.9 19.9 March 26.7 104.7 65.7 70.8 21.6 April 41.8 104.5 73.2 72.3 22.4 May 104.3 104.0 104.2 83.7 28.7 June 102.8 102.7 102.8 91.9 33.3 July 101.7 92.0 96.8 96.2 35.7 August 101.4 101.1 101.3 98.0 36.7 September 102.4 101.6 102.0 94.7 34.8 October 104.0 103.4 103.7 85.3 29.6 November 104.6 104.0 104.3 79.5 26.4 December 105.0 102.7 103.8 76.3 24.6 1-2
CHAPTER 2 WATER CHEMISTRY INTRODUCTION The objectives of the water chemistry portion of the McGuire Nuclear Station (MNS)
NPDES Maintenance Monitoring Program are to:
- 1. maintain continuity in Lake Norman's chemical data base so as to allow detection of any significant station-induced and/or natural change in the physicochemical structure of the lake; and
- 2. compare, where appropriate, these physicochemical data to similar data in other hydropower reservoirs and cooling impoundments in the Southeast.
This year's report focuses primarily on 2000 and 2001. Where appropriate, reference to pre-2000 data will be made by citing reports previously submitted to the North Carolina Department of Environment, Health, and Natural Resources (NCDEHNR).
METHODS AND MATERIALS The complete water chemistry monitoring program for 2001, including specific variables, locations, depths, and frequencies is outlined in Table 2-1.
Sampling locations are identified in Figure 2-1, whereas specific chemical methodologies, along with the appropriate references are presented in Table 2-2. Data were analyzed using two ap
-proaches,-both of which were consistent with earlier studies (DPC. 1985, 1987, 1988a,:
1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001). 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, 2-1
maximum whole-water column and hypolimnion heat content, mean epilimnion and hypolimnion heating rates over the stratified period, and the Birgean heat budget.
Heat (Kcal/cm2) and oxygen content (mg/cm2) and mean concentration (mg/L) of the reservoir were calculated according to Hutchinson (1957), using the following equation:
Lt = Ao-l"f TO*Azodz where; Lt = reservoir heat (Kcal/cm 2) or oxygen (mg/cm2) content Ao = surface area of reservoir (cm 2)
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 2001 totaled 32.71 inches (Figure 2
....2); this was similar-to that observed in 2000 (33.68 inches), but appreciably less than the long-term precipitation average for this area (46.3 inches). The highest total monthly rainfall in 2001 occurred in March with a value of 6.14 inches.
Temperature and Dissolved Oxygen Water temperatures measured in 2001 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 2001 were generally similar to corresponding measurements in 2000, except in early January 2-2
when year 2001 temperatures ranged from 2 to 6 C cooler throughout the entire water column in both zones than observed in 2000 (Figure 2-3, 2-4). Interannual variability in water 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).
The major temperature differences between year 2000 and 2001 were observed in early winter (December) when year 2001 temperatures ranged from 2.5 to 6.2 C warmer than measured in 2000. These differences can be traced to the cooler than average meteorological conditions observed during the winter of 2000/2001.
Temperature data at the discharge location in 2001 were generally similar to 2000 (Figure 2-5) and historically (DPC 1985, 1987, 1988a, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001). The warmest discharge temperature of 2001 occurred in September and measured 35.8°C, or 2.58 'C cooler than measured in August, 1999 (DPC 2000).
Seasonal and spatial patterns of DO in 2001 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 2001 were generally equal to or higher than measured in 2000, and appeared to be related predominantly to the cooler water column temperatures measured in 2001 versus 2000.
The cooler water would be expected to exhibit a higher oxygen content because of the direct effect of temperature on oxygen solubility, which is an inverse relationship, and indirectly via an enhanced convective mixing regime which would promote reaeration.
Spring and summer DO values in 2001 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 2000 and earlier years (DPC 1985, 1987, 1988a, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001). Hypolimnetic DO values during the spring and summer of 2001 generally ranged from 0.1mg/L - 2.0 mg/L greater than measured in 2000; the lone exception to this was observed in September when DO values were considerably lower (by as much as 6.0 mg/L) than measured in 2000. All dissolved oxygen values recorded in 2001 were well within the historical range (DPC 1985, 1987, 1988a, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001).
2-3
Considerable differences were observed between 2001 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 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 2001 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 2001 (5.5 mg/L) occurred in August, and was similar to DO levels measured in August 2000 (5.4 mg/L). Low DO values measured at the discharge location during the summer and early fall occurred concurrently with hypolimnetic water usage at MNS for condenser cooling water needs.
Reservoir-wide Temperature and Dissolved Oxygen The monthly reservoir-wide temperature and dissolved oxygen data for 2001 are pr'esented 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 2001 are presented in Figure 2-10a; additional information on the thermal regime in the reservoir for the years 2000 and 2001 are found in Table 2-3. Annual minimum heat *content for the entire water column in 2001 (7.45 Kcal/cm2 ; 7.5 'C) 2-4
occurred in early January, whereas the maximum heat content (27.96 KcalI/cm 2; 27.57 °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 hypolimnetic heat content occurred in early January and measured 4.4 Kcal/cm 2 (6.98
°C), whereas the maximum occurred in early September ana measured 15.17 Kcal/cm2 (23.48 °C).
Heating of both the entire water column and the hypolimnion occurred at approximately a linear rate from minimum to maximum heat content. The mean heating rate of the entire water column equalled 0.090 Kcal/cm 2/day versus 0.043 Kcal/cm 2/day for the hypolimnion.
The 2001 heat content and heating rate data were slightly lower than measured in 1999 and 2000, 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 2001 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 10.6 mg/L for both the whole water and the hypolimnion.
Percent saturation values at this time approached 94.5 % for the entire water column and 90% 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 4.33 mg/L (57 %
saturation), whereas the minimum for the hypolimnion was 0.33 mg/L (3.9 % saturation).
The mean rate of DO decline in the hypolimnion over the stratified period, i.e., the AHOD, was 0.030 mglcm2/day (0.047 mg/b/day) (Figure 2-10b), and is similar to that f-ie*sfired in 2000 (DPC 2001).
Hutchinson (1938, 1957) proposed that the decrease of dissolved oxygen in the hypolimnion of a waterbody should be related to the productivity of the trophogenic zone.
Mortimer (1941) adopted a
similar perspective and proposed the following criteria for AHOD associated with various trophic states; oligotrophic - < 0.025 mg/cm 2 /day, mesotrophic - 0.026 mg/cm 2/day to 0.054 mg/cm2/day, and eutrophic - >
0.055 mg/cm2/day.
Employing these limits, Lake Norman should be classified as mesotrophic based on the calculated AHOD value of 0.030 mg/cm 2/day for 2001. The oxygen based mesotrophic classification agrees well with the mesotrophic classification based on-chlorophyll a levels (Chapter 3). The 2001 AHOD value is also similar to that 2-5
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 >Ž2.0 mg/L, was found lake-wide from October 2000 through mid-June 2001. Beginning in late-June 2001, 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 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 2001 was similar to that previously reported in Lake Norman and many other Southeastern reservoirs (Coutant 1985, Matthews 1985, DPC 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001).
Turbidity and Specific Conductance Surface turbidity values were generally low at the MNS discharge, mixing zone, and mid lake background locations during 2001, ranging from 1.04 to 2.3 NTUs (Table 2-5).
Bottom turbidity values were also relatively low over the study period, ranging from 1.22 to 12.5 NTUs (Table 2-5). These values were similar to those measured in 2000 (Table 2-5), and well within the historic range (DPC 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001).
2-6
Specific conductance in Lake Norman in 2000 ranged from 48.9 to 108 umho/cm, and was similar to that observed in 2000 (Table 2-5), and historically (DPC 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001).
Specific conductance values in surface and bottom waters were generally similar throughout the year except during the period of intense thermal stratification. These 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).
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 2000 (Table 2-5) and historically (DPC 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001). Individual pH values in 2001 ranged from 6.3 to 8.1, whereas alkalinity ranged from 14.0 to 35.0 mg/L of CaCO3.
Major Cations and Anions The concentrations (mg/L) of major ionic species in the MNS discharge, mixing, and mid-lake background zones are provided in Table 2-5. The overall ionic composition of Lake Norman during 2001 was similar to that reported for 1999 (Table 2-5) and previously (DPC 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001).
Lake-wide, the major cations were sodium, calcium, magnesium, and potassium, whereas the majoranirns were bicarbonate, sulfate, and chloride.
Nutrients Nutrient concentrations in the discharge, mixing, and mid-lake background zones of Lake Norman for 2000 and 2001 are provided in Table 2-5. Overall, nitrogen and phosphorus levels in 2001 were similar to those measured in 2000 and historically (DPC 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001). Total phosphorus concentrations in 2001, however, averaged about one-third to one-half of the values measured in 2000 for each of the zones investigated, but were well within the historical 2-7
range (DPC 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001) (Table 2-5).
Metals Metal concentrations in the discharge, mixing, and mid-lake background zones of Lake Norman for 2001 were similar to that measured in 2000 (Table 2-5) and historically (DPC 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001). Iron concentrations near the surface were generally low (< 0.1 mg/L) during 2001, whereas iron levels near the bottom were slightly higher during the stratified period. Similarly, manganese concentrations in the surface and bottom waters were generally low (< 0.1 mg/L) in both 2000 and 2001, except during the summer and fall when bottom waters were anoxic (Table 2-5). This phenomenon, i.e., the release of iron and manganese from bottom sediments because of increased solubility induced by low redox conditions (low oxygen levels), is common in stratified waterbodies (Wetzel 1975).
Manganese concentrations near the bottom rose above the NC water quality standard (0.5 mg/L) at various locations throughout the lake in summer and fall of both years, and is characteristic of historical conditions (DPC 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001). Heavy metal concentrations in Lake Norman never approached NC water quality standards, and there were no appreciable differences between 2000 and 2001.
FUTURE STUDIES No charijgs are planned for-the Water Chemistry portion of the Lake Norman maintenance monitoring program during 2002.
SUMMARY
Temporal and spatial trends in water temperature and DO data collected in 2001 were similar to those observed historically. Temperature and DO data collected in 2001 were within the range of previously measured values.
2-8
Reservoir-wide isotherm and isopleth information for 2001, 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 2001 was generally similar to historical conditions. All chemical parameters measured in 2001 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 2001 often exceeded the NC water quality standard. This is characteristic of waterbodies that experience hypolimnetic deoxygenation during the summer.
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.
....DukePower Company.1987::Lake-Norman maintenance monitoring program:
1986 summary.
Duke Power Company. 1988a. Lake Norman maintenance monitoring program: 1987 summary.
Duke Power Company. 1988b. Mathematical modeling of McGuire Nuclear Station thermal discharges. Duke Power Company, Charlotte, NC.
Duke Power Company. 1989. Lake Norman maintenance monitoring program:
1988 summary.
2-9
Duke Power Company.
summary.
Duke Power Company.
summary.
Duke Power Company.
summary.
Duke Power Company.
summary.
Duke Power Company.
summary.
Duke Power Company.
summary.
Duke Power Company.
summary.
Duke Power Company.
Summary.
Duke Power Company.
Summary.
Duke Power Company.
Summary.
Duke Power Company.
Summary.
Duke Power Company.
Summary.
1990. Lake Norman maintenance monitoring program:
1991. Lake Norman maintenance monitoring program:
1992. Lake Norman maintenance monitoring program:
1993. Lake Norman maintenance monitoring program:
1994. Lake Norman maintenance monitoring program:
1995. Lake Norman maintenance monitoring program:
1989 1990 1991 1992 1993 1994 1996. Lake Norman maintenance monitoring program: 1995 1997. Lake Norman maintenance monitoring program: 1996 1998. Lake Norman maintenance monitoring program:
1997 1999. Lake Norman maintenance monitoring program:
1998 2000. Lake Norman maintenance monitoring program:
1999 2001. Lake Norman maintenance monitoring program: 2000 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.
2-10
Hannan, H. H., I. R. Fuchs and D. C. Whittenburg. 1979 Spatial and temporal patterns of temperature, alkalinity, dissolved oxygen and conductivity in an oligo mesotrophic, deep-storage reservoir in Central Texas. Hydrobilologia 51 (30);
209-221.
Higgins, J. M. and B. R. Kim. 1981. Phosphorus retention models for Tennessee Valley Authority reservoirs. Water Resour. Res., 17:571-576.
Higgins, J. M., W. L. Poppe, and M. L. Iwanski. 1981. Eutrophication analysis of TVA reservoirs. In:
Surface Water Impoundments. H. G. Stefan, Ed. Am. Soc. Civ.
Eng., NY, pp.40 4-4 12.
Hutchinson, G. E. 1938. Chemical stratification and lake morphometry. Proc. Nat. Acad.
Sci., 24:63-69.
Hutchinson, G. E. 1957. A Treatise on Limnology, Volume I. Geography, Physics and Chemistry. John Wiley & Sons, NY.
Hydrolab Corporation. 1986. Instructions for operating the Hydrolab Surveyor Datasonde.
Austin, TX. 105p.
Matthews, W. J., L. G. Hill, D. R. Edds, and F. P. Gelwick. 1980. Influence of water quality and season on habitat use by striped bass in a large southwestern reservoir.
Transactions of the American Fisheries Society 118: 243-250.
Mortimer, C. H. 1941. The exchange of dissolved substances between mud and water in lakes (Parts I and ID). J. Ecol., 29:280-329.
Petts G. E.-1984_4:nIfip6inded-RiversrPerspectives 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.
2-11
Wetzel, R. G. 1975. Limnology. W. B. Saunders Company, Philadelphia, Pennsylvania, 743pp.
2-12
WV'd9OHd DNI'IdWVS S:IlacIN 3UM93W ZOOZ
.UUUUON ole-I uo 2UUOIIUOtu 1111ý1-21,101 SU(IdN U011uls jual3nN ojinD:)W oqlioj migoid Ailsituop iomM -I-Z o1q3I (WOJ104 DAoqu w 1) womg - 9 (wC 0) dol. = I (Onyclaq) Allnuuu-nuaS - S (AON'SnV'ACIN qazl) Apolinno - 0 4,)uanb;)jj
'S3G0:)
SSSI-S piloS papwdsnS Icio.L 3sj:s spilos IC101 tos-An oicjlnS Glifli:.tf Avpiqin.L ITIVII Allutirliv
.US Wils JIs U'lls Jis J./s El,.Us Jjs Vils jis njo u'JJO DO ENJO njo 0,1A) 0'.UO 8,110 1JO Ijo wijo uijo njo 13,1JO G'1.10 UO G'IjO flujo G'.1.1s U'lis GIVS U'vo 8,1JO lis
.us lis lis Jjs Irijo G'.Ub S3SA'IVNV IVNOLLIGGV PCOI jadduz) tunurwPCO 3urz Luntpos wnissulOd Os*ut:3ucN WnIsDuac" uOil ulnolvo tunununIV ad-VDII fIz)-VDH GO-VDH rz-dol VZ-d0l X-90C vZdDI VZ-dDl K-dDl pz-dDl PZ-dDl I's
.US ils 8'.us 8,11s 9,11s G'J./s GIus 0,11s W.Us GIDS U'JJs Ls ils ils Ils lis jis lis lis lis
.us lis
.US lis JU0 6,ijo alijo frijo 11,M)
U'IJO ijb aujo (1,116 Jib Wjjo ENJO G*.UO GUJO Eivo ub UIJJO ElJib Jib G'jjO G'jjO laujo Wilo 11%U0 JJO U'110 ouit)
Jib Ei'lio 8,1JO W.U0 El'JJO GIVO UO GIuO ENJO Jib uujo Ervo Guib G'jjo 8'.UO Jib vio GUA)
Jib ulijo ti'vo U'vo U'vo B'ijo vo GIVO 1:11.1jo 1JO fIjjO U11JO ulijo GIDO G*Jjo Jib vi?)
U,.Uo Jib Wijo EIIJJO GjjO U'vo njo Jis Q'jjs G'jjO Erijo ENJO Enjo Wijo Elijo 8,1JO uujo Jjs S3Sk'IVNV 'IY.LN3W3-13 NXI'VV NNJ.
inN-VV D
InN-vv otils d-Dudl:vv snjoqdsoqd Ivio.L InN-VY
- juqdsoqdoqvo lnm-vv OjIjjIN+OInAIN InN-vv cluounuv 8,110
,uo GIVO Glijo U'vo U'vo U'vo JJ0 U'vo H'ijo Jib Wjjo Q'Ijo li'vo 8,1JO njo jib Q'jjO Enjo DO 13,JJO U'vo ti'vo uUJO U'lio Jib GIjo Eljib Jib alijo ulijo G1110 GjjO G'jjO Jib wijo (1,1A)
Jib U'Ijo G,.Uo Uvo Ulio EIUJO jib Elijo Elijb ijo G'jjO U'vo 611JO UU10 UUJO Jib 6,1JO G'jjO u'.UO uijo El,.Uo Cub El*jjo U,110 U'lio u'JJO Ils J./s Vs Jis
.us
.US SaSA-IVNV INHISInN qLIOJPAH
,jujquq sscq podlils ýoj isnanv-Alnr tuujj ARJýA% u*491 DIU fluDwOM9011; wunoq oAoqu w 1 ot wE o wojj slumam w I JU SUOIJUDOI '3Aoqv 04110 A[41UOw P01301103 On sluawonsrow nils-ul qui-pAH
, I qul-pAH AIIAWnPUOD lid UOJAXO PDAIOSSI(I ainjujadLuO.L Sao:) wvs SISAIYNV njjs-N, cz EZ 01 lz LZ Oz 9
CE E I c (W) H1A3G Oil 56 09 05 0 1, 0 z 0 i SNOLLVD01 SIMISNY11W 091 008 0 ZL 069 0 Z9 6ý1 051 0171 Ocl
C C
Water chemistry methods and analyte detection limits for the McGuire Nuclear Station NPDES long term maintenance program for Lake Norman.
Variables Alkalinity, total Aluminum Ammonium Cadmium Calcium Chloride Conductance, specific Copper Fluoride Iron Lead Magnesium Manganese Nitrite-Nitrate Orihophosphate Oxygen, dissolved pH Phosphorus, total Potassium Silica Sodium Sulfate Temperature Turbidity Zinc Method I
Preservation Electrometric titration to a pH of 5.12 40C Atomic emission/ICP-direct injecition 2 0.5% HNO3 Automated phenate' 4*C Atomic absorption/graphite fumace-direct injection2 0.5% HNO3 Atomic emission/ICP-direct injecition 2 0.5% HNO0 Automated ferricyanideI 40C Temperature comperiiated nickel electrode' In-situ Atomic absorption/graphite fumace-dircct injection 0.5% HNO0 Potentiometric 40C Atomic emission/ICP-direct injection 0.5% HN03 Atomic absorption/graphite furnace-direct injection2 0.5% HNO 3 Atomic emission/ICP-direct injection2 0.5% HNO0 Atomic emission/ICP-direct injection' 0.5% HNO0 Automated cadmium' reduction' 40C Automated ascorbic acid reduction' 41C Temperature compensiated polarographic cell' In-situ Temperature comperisated glass electrode' In-situ Persulfate digestion followed by automated ascorbic acid 41C reduction' I
Atomic absorption/graphite furnace-direct injection2 0,5% HINO 3 Automated molydosilicate'
, 40C Atomic emissionilCP-direct injection2 0.5% HNO0 Turbidimetric, using a spectrophotometer) 40C Thermistor/thermometer' In-situ Nephelometric turbidity' 40C Atomic emission/ICP-direct injection2 0.5% HN03 Detection Limit img-CaCO3.1
- 0.3 mg '1"t 0.050 mg '1"1 0.1 lpg'll 0.04 mg.rt 1.0 mg.I*1 I pmho'cm"'
- 0.5.g'l"{
0.10 mg '1"l 0.1 mg '1"1 2.0 pg-l"l 0.001 mg "1" 0.003 mg '11 0.050 mg "1 0.005 mg '1"1 0.1 mg-P1 0.1 std. units' 0.005 mg l; 0.015 mg.1 0.1 mg,I*
0.5 mg '1"1 0.3 mg.1" 1.0 mg '1"1 0.100*
I NTU*
4 pg{l1l
'United States Environmental Protection Agency 1979, Methods for chemical analysis of water and wastes.
Environmental Monitoring and Support Laboratory. Cincinnati, OH.
2USEPA.
1982
'USEPA.
1984
'Instrument sensitivity used instead of detection limit.
I *Detection limit changed during 1989.
Table 2-2.
Table 2-3. Heat content calculations for the thermal regime in Lake Norman for 2000 and 2001.
2001 2000 Maximum areal heat content (g cal/cm2) 27,964 27,434 Minimum areal heat content (g cal/cm2) 7451 8066 Maximum hypolimnetic (below 11.5 m) 15,173 15,459 areal heat content (g cal/cm2)
Birgean heat budget (g cal/cm2) 20,513 19,368 Epilimnion (above 11.5 m) heating 0.094 0.106 rate ('C /day)
Hypolimnion (below 11.5 m) heating 0.062 0.082 rate (°C /day) 2-15
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 Clii a Secchi Depth Mean Depth Reservoir (mg/cm2 /day)
(ug/L)
(m)
(m)
Lake Norman (2001)
TVA a Mainstem Kentucky Pickwick Wilson Wheelee Guntersville Nickajack Chickamauga Watts Bar Fort London Tributary Chatuge Cherokee Douglas Fontana Hiwassee Norris South Holston Tims Ford Watauga 0.030 0.012 0.010 0.028 0.012 0.007 0.016 0.008 0.012 0.023 0.041 0.078 0.046 0.113 0.061 0.058 0.070 0.059 0.066 5.9 9.1 3.9 5.9 4.4 4.8 2.8 3.0 6.2 5.9 5.5 10.9 6.3 4.1 5.0 2.1 6.5 6.1 2.9 2.03 1.0 0.9 1.4 1.1 1.1 1.1 1.0 0.9 2.7 1.7 1.6 2.6 2.4 3.9 2.6 2.4 2.7 10.3 5.0 6.5 12.3 5.3 5.3 6.8 5.0 7.3 7.3 9.5 13.9 10.7 37.8 20.2 16.3 23.4 14.9 24.5 a Data from Higgins et al. (1980), and Higgins and Kim (1981) 2-16
C C
Table 2-5 Quarterly surface (0.3 m) and bottom (bottom minus I m) water chemistry for the MNS discharge, mixing zone, and background locations on Lake Norman during 2000 and 2001.
Values less than detection were assumed to be the detection limit for calculating a mean.
LOCATION Rurlane MIxing Zone 10 Bottom Surface Mixing Zone 2
Bottom MNS Discharge Mixing Zone 40 50 surface Surface Bottom
Background
80 Surface
Background
110 Bottom Surface 000 2001 2000 2001 Bottom 2000 2001 PAAEER ER 2000 2001 2000 20011 2000 2001 2000 20011 2000 20012000 2001 200 327 201 1 22 1 55 1.04 1 65 A*O?
1 02 4 53 3.7f 1.22 1 31 347 2 5, 69 27.=
313 161 098 124 1.33 1.75 104 193 300 265 093 1.22 2.24 246 736 4 6 3 47 1 58 095 1.52 088 1.74 1 63 143 1 68 1 30 068 127 1 57 169 1.04 230 3 96 1.60 1.16 1 82 923 408 377 462 3 62 1,14 075 136 1 55 1.52 107 104 33 4 1 41 1 82 2.57 4.92 230 832 898 315 1 40 408 217 0 97 1.48 249 2 53 1.61 1 58 59 401 1 60 199 287 1250 168 16 384 53 NO 42 2
1-62
-6 33 17 161 41 29_1_6_453_301_1.75
~~ ~~~~~~~
18_
7 2
6_____________
Annual Mean 1 63 1.78 40 21 16i63816 Specific Conductance (umnio/cm)
Feb 57.1 S7 May 585 49 Aug 640 67.1 Nov 640 731 Annual Mean 609 743 pH (units)
Feb 65 7.1 May 69 72 Aug 72 75
- ..711 76 570 56 587 489 740 765 1076 108 57.1 56 602 493 640 674 642 73 569 56 593 49 770 731 105.1 98 58.1 68 606 50 650 676 667 747 578 57 603 50 640 NS 666 738 570 56 S98 492 750 NS 674 74 57 2 56 56.7 56 61.7 493 61 3 49 5 640 672 700 72 656 728 923 73 60.4 58 59 5 59 607 496 629 508 630 671 740 725 655 722 733 719 6*2-7" 6-1-7 67-4 63-6
-74~3 7231 614-613 746 6891 626 6261 622 bui
'{-'-*
-1 64-0 2
6.6 7.1 61 69 62 64 68 69 70 72 68 75 7.4 76 7.1 74 67 7.1 6.1 60 63 63 68 88 72 7.3 69 72 68 74 71 75 70 72 71 73 70 NS 71 7.6 66 70 63 68 64 NS 66 71 7.0 7.2 69 73 7.1 79 7.2 76 68 7 C 62 6S 62 64 67 7C 70 72 7.1 72 66 81 70 76 66 70 62 67 62 64 66 69 V47 675 Annual Mean 691 643 643 684 707 742 648 679 699 732 704 737 64tj0 oVW u
Aiahnity (mg CaCO3/)
15 185 160 165 165 160 155 16.5 160 165 160 165 155 165 160 170 155 165 155 185 155 165 May 155 155 15.5 180 10 160 155 160 150 160 155 160 155 160 150 160 150 160 150 155 155 180 Aug 165 17.0 170 175 185 170 17.5 170 16.0 170 17.0 175 235 210 165 165 200 140 165 16,5 220 180 Nov 170 180 320 350 170 185 345 195 170 185 170 190 170 185 17.0 185 300 185 16 5 166 185 186 Annual Mean 1614 1676 2014 2126 1626 1688 207-7 172" 1601 1701 6639 1726 1789 1801 1814 17014 1626 1569 1678 1789 1726 Chloride (mg/I) 57 6.1 61 62 58 63 Feb 55 6.1 56 62 56 61 55 82 5.7 8.1 56 60 55 8.1 58 6.1 1
58 63 May 58 55 57 5
58 55 58 5,3 58 554 58 55 58 55 5.7 57 5.7 54 56 54 57 5.1 Aug 57 88 59 87 5.8 87 58 87 5 7
67 56 7.1 56 7.4 57 88 57 7.1 57 66 60 67 Nov 58 68 59 67 57 61 60 63 57 2
568 NS 57 60 56 62 58 62 56 83 56 62 Annual Mean 565 823 578 600 563 610 578 6,13 573 610 570 620 565 62" 570 620 5.73 820 575 613 578 606 Sulfate (mg/I) 553 62 546 61 597 NS sea NS Feb 545 NS 5.76 NS 546 62 546 86 548 83 548 NS 544 N
5 6
NO May 594 NS 598 NS 603 67 5.96 85 621 66 604 NS 595 NS 680 67 592 67 613 NS 598 NO Aug 622 NO 595 NS 824 67 575 86 622 70 622 69 531 85 7.50 69 559 66 623 NS 547 NS Nov 615 NO 378 NS 614 60 165 65 613 67 606 NS 601 NS 700 67 396 62 623 NS 613 NS AnnualMean 594 NS 537 NS 597 638 643 6"53 601 666 595 691 568 651 671 664-523 640 614 588 Calcium (mg/I) 289 2.98 269 2.90 201 303 Feb 283 320 279 334 295 371 301 321 2.86 331 268 296 295 322 279 314 May 305 317 309 339 291 325 289 3.09 293 311 299 321 303 341 262 346 305 330 308 354 320 313 Aug 315 333 337 344 314 335 346 340 3.16 337 312 338 357 337 311 3.34 340 358 321 336 365 360 Nov 329 347 403 437 321 43 411 396 322 378 322 379 325 364 322 388 402 352 319 335 307 328 Annual Mean 308 332 332 364 305=
367 337 344 304 339 305 334 320 341 294 345 334 335 304 328 321 326 Magnesium (mg/I) 1 44 1.52 1 38 1 so 148 1 56 Feb 1.43 153 1 42 1.62 1 46 1.72 1.51 1.59 1 44 1 62 1.45 1 52 1.48 157 1,41 155 May 1 52 1.51 1 53 1 64 145 161 145 1 55 146 161 1 46 160 1 51 167 133 168 149 1 58 1.43 1.70 1.51 1 50 Aug 154 1 60 1 57 1.65 1 53 1.63 162 166 153 161 1.52 162 1.65 1.72 1.52 162 1 54 1.70 1 51 161 1 62 169 Nov 162 166 1.76 168 159 200 1,78 1 87 1 59 186 160 187 160 181 159 1 89 176 175 1.59 1 69 1.57 1 67 Annual Mean 153 157 157 1.70 1t51 1-74 159 1.67 150 167 151 165 156 169 46 168 156 164 148 163 1
NS - Not Sampled Turoidity (ntu)
Feb May Aug C
C C
Table 2-5 (Continued)
Mixing Zone LOCATION 1 0 DEPTH Surface BottOm PARAMETERS YEAR 2000 2001 2000 2001 Potassium (mg/I)
Feb 1 67 183 1 67 1.84 May 1 91 184 185 1 82 Aug 1.71 1 83 1 79 1.85 Nov 185 196 1_92 2 02 Annual Mean 1 79 1 81 1 81 1t Sod'um (mg/I)
Feb 643 678 627 7 25 May 672 689 679 6 98 Aug 7.12 709 643 63!
Nov 646 738 619 74A Annual Mean 868 642 642 701 Aluminum (mg/I)
Feb May Aug 0118 0050 0,125 0061 0083 0050 0068 0050 0062 0050 0113 0050 0050 0050 0079 0050 Surface Mixing Zone 2
MNS Discharge 4.0 Bottom Surface Surface Mixing Zone 50 Bottom Surface Backgroun 80 d
Bottom
Background
110 Surface 0n0011 7411 Bottom 9001 2M001
-4
ýA 20011 20001 2001 2000 2001 200 xUlJ.
18S8 175 1.79 1.82 1 83 1.76 1.77 1 74 1.75 1.82 1 87 1.74 1 92 1 82 201 1 99 1.97 1.79 86 182 187 7.33 680 699 692 837 7.13 631 695 684 6.70 730 674 "661 817 626 766 1.72 1 82 1.77 1 81 1.76 1 88 1 84 194 657 7 22 858 735 693 64C 640 786 1 72 187 178 1.78 1 95 1 78 1.82 1.75 1.73 1 6e 1 86 187 1 81 198 182 189 1 8-1 1-87 1 02
-1 85 T
634 706 652 687 645 688 636 694 7.12 668 6.76 7.11 640 823 637 8 0, 1 66 1.79 1 65 1.76 159 182 1 88 1.72 183 1 85 1.65 185 180 195 191 1 93 1.72 185 1 77 1 82 640 687 655 7.14 582 694 669 709 7.19 689 676 695 646 782 606 750 1.3I8 1.63 1 58 1 73 1.82 1.73 1 82 185 195 S4 1 86 7.6 78 71 72 7.16 748 608 721 706 657 650 750 1170 710 1 82 1 83 1 86 182 180 184 184 1 87 183 184 7 41 7.29 6.57 696 672 6.76 667 755 684 7.14
-79 72 T7 70 71 62 7221 8 58 7 21 650 725 647 1I Ui 0127 0050 0134 0057 0061 0050 0.061 0 05C 0094 0050 0131 0 05C 0050 0050 0077 0051 0129 0051 0081 0050 0087 0050 0050 0050 0148 0050 0121 0060 0077 0050 0076 0050 0100 0050 0150 0050 0050 0050 0050 0050 0,14 0 050 0 236 0 064 0058 0050 0086 0050 0109 0050 0118 0050 005 0050 008 0074 0124 0050 0086 0052 0098 0050 005 0050 000 005 0 159 0 080 0112 0084 0147 0094 005 0054 0117 008 Annual Mean 008 005 0096 005 0083 7 05 0.101 005 0087 005 0094 005 09 u
0 u U
00 005 Iron (mg/I) 0032 0024 0026 006g 0050 Feb 0019 0028 0026 0033 0021 0029 0037 0032 0021 0027 0020 0020 0027 0034 0020 0023 0211 May 0027 0015 0040 0.010 0019 0013 0020 0010 0017 0014 0022 0013 0051 0010 0010 0019 0027 0017 0024 0027 0063 0047 Aug 0030 0029 00 0000 0000 0004034 00 0000 000030 0028 0023 0028 0756 0.010 0033 0024 0265 0068 0029 0034 0450 0155 Nov 0033 0018 1 281 0537 0039 0024 3218 0044 0052 0015 0041 0013 0129 0030 0029 0011 1960 0070 0053 0010 0161 0067 AnnualMean 0027 0023 035*
0159 0027 02 0833 0033 0030 0 021 0027 0019
-0241 0021 0 023 0019 0616 0 047 06033 0024 0186 0080 Manganese (mg/I) 002 002 003 Feb 001 001 002 002 001 001 001 002 001 001 001 001 002 002 001 001 008 001 001 002 002 003 May 001 001 002 002 -"001 000 001 001 001 001 001 001 002 003 001 000 001 001 001 000 004 004 Aug 002 002 031 072 002 002 1.18 054 002 002 002 002 247 022 002 002 087 094 001 001 220 1.14 Nov 004 NS 518 NO 005 NS 515 NS 007 NO 007 NS 042 NS 003 NS 372 NS 007 NS 1.19 NO AnnuaMean 0 02 0,01 138 026 002 001 159 019 003 001 003 001 073 0 09 001 0701 1.17 032 020 001 086 040 Cacdmium (ug/I) 05 05 05 NS 05 NS Feb 05 NS 05 NS 05 05 05 05 08 05 0.5 NS 0.5 NO 05 5
05 0
N NS May NO NS N
S NO NS NS NS NS NO NS NS NO NS NO NS NS NO NS NS NS NO NO Aug 05 NS 05 NO 05 05 05 05 05 05 05 NS 05 NS 05 0S 05 05 05 NO 05 NS Nov 05 NS 05 NO 05 NO Os N
O O0 NS 05 NS 05 NS 05 NS 05 NO 05 NO Annual Mean 05 05 05 05 05 05 05 05 05 05 05 05 05 05 05 Copper (Ugh) 2 0
41 20 283 NS 258 NS Feb 200 NS 2
NS 2
20 2
20 2
20 2
NS 2
NO May NO NO NS NS NS NO NS NS NS NS NO NS NS NS NO NS NS NS NS NS NS NS Aug 20 NO 50 NO 23 20 2.1 20 20 20 2.0 NS 2.0 NS 20 20 20 20 20 NO 2.0 NS Nov 21 NO 22 NO 20 NS 20 NS 20 NO 20 NS 23 NS 20 NS 20 NS 31 NS 21 NO Annual Mean 20 31 2.1 20 20 2
20 20 21 20 20 30 20 27 22 Lead (ug/1)
NSS 2
2 2
2 NS 2
NS Feb 2
NS 2
NS2 2
2 2
2 2
2 NS 2
NO 2
2 2
2 2
NO 2
NO May NS NS NS NS IS NS NO NS NS NS NO O
NO NO NO NO N
NO NO NO NO Aug 2
NS 2
NS 2 2
2 2
2 2
2 NS 2
NS 2
2 2
2 2
NO 2
NS Nov 2
NS 2
NS 2 NS 2
NO 2
NS 2
NS 2
NS 2
NS 2
NS 2
NS 2
NS Annual Mean 2
2 2
2 2
2 2
2 2
2 NS. Not sampled 00 21 0 2001R'l
- M
- w=
&vv
&v 1
... 77 "1 -"
I I
1 77 1 *6 I
C C
Table 2-5. (Continued)
Mixing Zone LOCATION 13 0 DEPTH Surface Bottom PARAMuTgRS YEAR 20 001 2000 2001 ZAn i (a(ug)
Feb 20 5
8 May 5
5 5
0 Aug 5
2 12 7
Nov 2
6 9
0 Annual Mean 50 53 85 65 Nitrate (u91i)
Feb 100 110 100 120 May 160 130 240 150 Aug 20 30 290 210 Nov 70 610 4
710 Annual Mean 875 2400 12 T
A;mmonta (u ug)
Feb 20 20 20 40 May 20 20 20 20 Aug 20 20 20 70 Nov 20 30 560 600 "Annual Mean 20 32Y5 155.0 1925 Tfotai PhiosphorOus (ug/l)
Feb 7
4 7
,5 May 9
6 11 5
Aug 23 10 16 10 Nov 13 10 14 10 Annual Mean 130 75 120 75 Ornnopnospnate (ug/1)
Feb 5
2 5
2 May
,5 2
5 2
Aug 5
5 5
8 Nov
,5 5
,5 Annuanl Mean so 35 50 43 Mixing Zone 2
Surface Bottom 2000 2001 2000 2001 5
'5 5
8 5
5 5
5 5
5 5
65 5
5 5
5 50 5
50 53 100 120 100 120 160 130 240 150 20 30 240 270 70 820 20 0_
87"-'--*5 2 1500 147.5 20 20 20 30 20 20 20 50 20 20 50 50 20 20 730 g0 "200 200 205 0 550 6
4 8
5 7
16 6
8 18 10 9
10 8
10 14 10
-g-e 100 93 683 5
2 5
2 5
2 5
2 5
5 5
5 s
5 6
5 3
s50 35 53 4
Silica (mg/I)
Feb 33 29 32 30 32 30 33 30 May 34 29 40 32 35 29 4.0 31 Aug 20 24 45 40 20 27 46 4.1 Nov 27 34 53 47 27 32 56 34 AnnualMean 29 29 43 37 29 30 44 34 MNS Discharge Mixing Zone 40 50 Surfce Surface Bottom 2000 2001 2000 2001 2000 2001 5 5 5
5 S 26 4
6 5
26 10 9
10 168 73 5
2
,5 2
5 6
5
_5 50 4~
32 3C 36 26 22 2.1 27 32, 29 30 I 5
5 5
,5 g
5 5
S
,5 5
5
,5 S
5 5
5 60 50 50 so 100 110 100 120 160 130 220 150 40 30 30 170 20 50 180 60 5-7---0" Soo 132-5 1225*"
20 20 20 30 20 20 20 50 20 10 1ISO 60 2._0 2._0 2_.0 7.._
0
--T -0 1-75 600 52 5 31 4
225 31 4
6 4
8 7
8 6
10 10 20 10 159 10 11 10 520 78 113 75 5
2 5
2 6
2 6
2 5
7 5
7 5
5 5
5 53 4
53 4
32 29 32 30 35 29 39 32 2.1 27 42 41 27 33 32 34 29 30 36
34 Background
80 Surface Bottom 2000 2001 2000 2001 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
50 50 so 5
100 110 90 110 160 130 220 170 30 30 180 1460 60 40 20 100 875 77.5 127.5 460-0 20 20 20 20 20 20 20 60 20 20 60 20 20 30 610 80 200 225 1775 45C 17 63 7
4 17 63 7
A 7
7 7
10 10 11 Ic 10 10 24 16 110 225 123 5I 5
2
,5 2
14 2
5 2
5 5
5 7
5 5
5 5
73 4
so0 33 29 31 28 35 30 39 33 20 26 42 40 26 31 51 43 29 29 41 3-6
Background
11 0 Surface Bottom 2000 2001 2000 2001 5
,5 6
5 5
$ 5 5
5 5
5
,5 5
5 5
5 50 50 53 50 180 150 150 160 190 840 260 140 20 20 140 280 120 90 210 100 1225 2250 1900 1650 40 30 40 40 20 20 20 90 20 20 100 20 70 120 80 210 375 475 600 900 9
7 7
85 10 8
10 6
18 10 29 17 17 11 26 11 135 90 180 10 5 5
2 5
2 5
2 5
2 5
2 6
2 5
7 5
7 5
5 5
5 50 40 53 4
4.1 36 40 37 34 2.9 4.3 35 2.1 27 45 42 33 35 44 45 32 32 43 40 NS - Not Sampled i'.
5
_5 100 110 1,50 140
`50 30 70 20 77-5--
50 20 20I 20 30 20 20 20 20 I
D i
J q
80 2-20 7r LC N
S 22 9.5 Figure 2-1. Water quality sampling locations for Lake Norman.
McGuire Rainfall 8
6 (D -*4 2
0 Figure 2-2. Monthly pfecipitation in-the iricinity of-McGuire Nuclear Station.
2-21 MAY JUN JUL AUG Month 10 200o M 2o01
C JAN Temperature (C) 0 5
10 15 20 25 30 35 5
10 20 25 30 35 APR Temperature (C) 0 5
10 15 20 25 30 35 E15
-20 in FEB Temperature (C) 0 5
10 15 20 25 30 35 0.
- 5.
10*
-20 25 30 35 MAY Temperature (C) 0 5
10 15 20 25 30 35 MAR Temperature (C) 0 5
10 15 20 25 30 35 JUNE Temperature (C) 0 5
10 15 20 25 30 35 Figure 2-3. Monthly mean temperature profiles for the McGuire Nuclear Station background zone in 2000 (xx) and 2001 (*+ ).
C a
I I
I I
I I
I I
(*
I I
A V
t*
t*
(7 JULY Temperature (C) 0 5
10 15 20 25 30 35 5
10 EF15
- 20 25 30 35 AUGUST Temperature (C) 0 5
10 15 20 25 30 35 SEPT Temperature (C) 0 5
10 15 20 25 30 35 5
10 20 25 30 35 2
OCT Temperature (C) 0 5
10 15 20 25 30 35 SI I
1 21 I
0 5
- 10.
E 15*
-20 25' 30 35 NOV Temperature (C) 0 5
10 15 20 25 30 35 DEC Temperature (C) 0 5
10 15 20 25 30 35 Figure 2-3. (con't).
C v
5 10 251 30 35 t,,)
(
JAN Temperature (C) 0 5
10 15 20 25 30 35 APR Temperature (C) 5 10 15 20 25 30 FEB Temperature (C) 0 5
10 15 20 25 30 35 MAY Temperature (C) 0 5
10 15 20 25 30 35 0
5 10 0.
w20 25 30 35 MAR Temperature (C) 0 5
10 15 20 25 30 35 JUNE Temperature (C) 0 5
10 15 20 25 30 35 Figure 2-4. Monthly mean temperature profiles for the McGuire Nuclear Station mixing zone in 2000 (xx) and 2001 (*+ ).
C 0
5 10 S20 25 30 35 0
5 10
- 0.
20 25 30 35 It'
(
JULY Temperature (C) 0 5
10 15 20 25 30 35 AUGUST Temperature (C) 0 5
10 15 20 25 30 35 OCT NOV Temperature (C)
Temper; 0
5 10 15 20 25 30 35 0
5 10 15 ature (C) 20 25 30 35
(
SEPT Temperature (C) 0 5
10 15 20 25 30 35 DEC Temperature (C) 0 5
10 15 20 25 30 35 Figure 2-4. (con't).
10 w20 25 30 35 t'j
40.00 35.00 30.00 S25.00 ca 20.00 a)
CL E 15.00 I-10.00-5.00 0.00 12.00 10.00 8.00 6.00 4.00 2.00 0.00 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Figure 2-5. Monthly surface (0.3m) temperature and dissolved oxygen data at the discharge location (loc. 4.0) in 2000 (0) and 2001 (0).
2-26
'0 E
w (D
X 0
0
- 0 cn
(7 JAN Dissolved Oxygen (mg/L) 0 2
4 6
8 10 12 0
- 5.
- 10.
-20 25 30 35 0
5 10 C.
-20 25 30 35 APRIL Dissolved Oxygen (mg/L) 0 2
4 6
8 10 FEB Dissolved Oxygen (mg/L) 0 2
4 6
8 10 12 MAY Dissolved Oxygen (rng/L.)
0 2
4 6
8 10 12 MAR Dissolved Oxygen (mg/L.)
0 2
4 6
8 10 12 JUNE Dissolved Oxygen (mg/L.)
0 2
4 6
8 10 12 Figure 2-6. Monthly mean dissolved oxygen profiles for the McGuire Nuclear Station background zone in 2000 (xx) and 2001 (* +).
C C
t'-)
C JULY Dissolved Oxygen (mg/L) 0 2
4 6
8 10 12 0
5 10 E?15
-20 25 30 OCT Dissolved Oxygen (mrg/L) 0 2
4 6
8 10 12 0
- 5.
10
-20 25 30 C
AUGUST Dissolved Oxygen (mag/L) 0 2
4 6
8 10 12 NOV Dissolved Oxygen (mg/L.)
0 2
4 6
8 10 12 SEPT Dissolved Oxygen (mg/L.)
0 2
4 6
8 10 12 0
5 10
-20 25 30 35 DEC Dissolved Oxygen (mg/L) 0 2
4 6
8 10 12 Figure 2-6. (con't).
c t,)
tt3 00
JAN Dissolved Oxygen (mg/L.)
0 2
4 6
8 10 12 0
- 5.
10*
w20 C3 25 30 35 0'
5 10
-20 25 30 APR Dissolved Oxygen (mg/I.)
0 2
4 6
8 10 12 C
FEB Dissolved Oxygen (mg/IL) 0 2
4 6
8 10 12 MAY Dissolved Oxygen (mg/L) 0 2
4 6
8 10 12 MAR Dissolved Oxygen (mg/L) 0 2
4 6
8 10 12 JUNE Dissolved Oxygen (mg/L.)
0 2
4 6
8 10 12 Figure 2-7. Monthly mean dissolved oxygen profiles for the McGuire Nuclear Station mixing zone in 2000 (xx) and 2001 (,,).
C IN)
C JULY Dissolved Oxygen (mg/L) 0 2
4 6
8 10 12 0
10 415~
R.
-20 25 30 35 OCT Dissolved Oxygen (mg/L) 0 2
4 6
8 10 12 AUGUST Dissolved Oxygen (mg/IL) 0 2
4 6
8 10 12 NOV Dissolved Oxygen (mg/IL) 0 2
4 6
8 10 12 SEPT Dissolved Oxygen (mag/L) 0 2
4 6
8 10 12 DEC Dissolved Oxygen (mg/l.)
0 2
4 6
8 10 12 Figure 2-7. (con't).
C C
10 20 25 0
,225 I
1 o220ý 220 oE~
21,
CO C215 21 21210 uJ 20 20-"
20 Temperature (deg C) 20 "Jan 3, 2001 19190 0-5 10 15 20 25 30 35 40 45 50 55 0
5 10 Distance from Cowans Ford Dam (km) 240 240 Sampling Locations 235 0
8o 110 130 150 1S9 620 690 720 8o0 23 10 80 230 230-, =o--,,
rV*, -<.'*
-i Jf 2 2.
2 2 5 225-"
22 22C
.& 1 215 w2 1 21 20!
210 20Temperature (deg C) 20 200'...
\\2 Mar 8, 2001 o
I...
195....
.19 1
100 5
1,0, 15 20 25' 3
35 4
5 5
50 5
i Distance from Cowans Ford Dam (kin)
Figure 2-8. Monthly reservoir-wide temperature isotherms for Lake Norman in 2001.
Distance from Cowans Ford Dam (kin)
Distance from Cowans Ford Dam (km)
235-230:
225 220 2195:
2055 200 195-(.
Sampling Locations 10 80 11.0 130 1SO 1S9 820 890 720 800 Temperature (deg C)
Apr 30, 2001 t
10 15 20 25 30 35 40 45 50 55 Distance from Cowans Ford Dam (k1m) 240 Sampiing Locations 235 10 80 110 130 taO IS9 620 690 720 800 230~4'
(
225 22022 r
212 21521 210 205 200 Temperature (deg C)
"Jul 9, 2001 195 0
5 10 15 20 25 30 35 40 45 50
,55 Distance from Cowans Ford Dam (knm)
Figure 2-8. Continued.
235-i E
w 0
Samping Loation 10 80 1
1 K
11.0 130 IS0 IS9 620 690 720 800 L
L 1
4 1
1 1
1
-'4-Distance from Cowans Ford Dam (km)
Distance from Cowans Ford Dam (kim)
E 0
9U t.3 I
Sampling Locations
(240 r
Sampling Locations 235" 10 80 11.0 130 15.0 IS0 620 690 72.0 800 2
232 220E 0'
Sw m 21 20*
t Temperature (deg C) 200 Sep 5, 2001 195 o
5 0
5 10 15 20 25 30 35 40 45 5
Distance from Cowans Ford Dam (kin) 240° Sampling Locations 235-1 0 80 110 130 160 ISa 620 690 720 800 230-~i..(
225 0)0 200 Temperature (deg C) 20 20 Nov 5, 2001 195 5.)
10 15 20 25A 30 35 40 45 50 55 Dsltanece from Cowans Ford Dam (ki)
Distance from Cowans Ford Dam (kin)
Distance from Cowans Ford Dam (km)
Figure 2-8. Continued.
240 N
Sampling LocationsSamplng Locations 23 10 80 110 130 150 19 620 690 720 800 235 10 80 110 130 150 15.9 620 690 720 800 235 1 4
40 11 13 IS S
2 2
0 230 j
- .230 230 220 E 22 E
uJ 221 202
" Jan 3, 2001 Feb 6, 2001 19 0
5.1 0 '
- 15.
. 2'0..
.25..
.30..
.35s.. 40o 45 50o 55 0
0 1
0 5
3 5
40o 0
Distance from Cowans Ford Dam (kmn)
Distance from Cowans Ford Dam (kin) 20 240 Sampling Locations Smln oain 23 10 80 11.0 130 150 159 620 690 720 800 235 10 80 110 130 150 15.9 620 690 720 800 225 C
22 E
222C 22 S21 215" S215-:
M 21 C" 210 20 205 2oo Dossolved Oxygen (mg/I) 20
-'N
~~~Dissolved Oxygen (mg/I) 200DsovdOxgn(gI M220Apr 2, 2001 195-lgI "
,,0,
'i'
- 1.
..' 2
`
3 '
- 40....
.. 5 0
5 10 115....
15
'20 5....
3`0....
40 45 50 55 0
5 10s15 n20 25om 30 35 40r 45 m0 55
,~.
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 2001.
Sampling Locations 235 1.0 80 110 130 I50 15.9 820 690 720 800 230 A24 225 70 E
8 uJ 210" 2015 20 Dissolved Oxygen (mg/I)
Apr 30, 2001 19 ".
....1'.. t.
.'0... '2 5....3 '0....3' 5
'..4
['o
.,'45...5 1'O 7 5.
0 5
10 15 20 2
30 5
40 5
50 5
Distance from Cowans Ford Dam (kin) 240 Sampling Locations 2355 so 11.0 130 IS0 159 820 690 720 800 230 bN4
~2250 0 2252 cc2150
"' 21 (>
20; 20 Dissolved Oxygen (mg/I)
"Jul 9, 2001 0
5 10 15 20 25
,V30 35 40 45 50 55 UJ*I Distance from Cowans Ford Dam (kin)
Figure 2-9. Continued.
Distance from Cowans Ford Dam (kin)
Distance from Cowans Ford Dam (kin)
0 w
40 Sampling Locations 2355 so 110 130 ISO 1S9 620 coo 720 800 4 t 4
I t
t4 230 225 220 215 1w3 2110 205 200.
Dissolved Oxygen (mg/I)
Sep 5, 2001 19 Trr-0 5
0 5
10 15 20 25 30 35 40 45 50 55 Distance from CowanS Ford Dam (kin) 240 Sampling Locations 235 10 80 11.0 130 150 159 620 690 720 800 230 00 220
-4 215 210 205-200 Dissolved Oxygen (mg/I)
Nov 5, 2001 195" 7,
0
.1
,5....
2,0"r T, 1 T
l I
.i I
5 015 20 25 30 35 40 45 50 5s Distance from Cowbrns Ford Dam (kin)
Figure 2-9. Continued.
0 LU :
d En tO)
Distance from Cowans Ford Dam (kin)
Distance from Cowans Ford Dam (kin)
30 25 200 5
0 I
I I
I I
I I
I I
I 0
50 100 150 200 250 300 350 Julian Date Figure 2-10a. Heat content of the entire water column (91) and the hypolimnion (0) in Lake Norman in 2001.
12 10 8
6
- 4.
2 0
0 50 100 150 200 Julian Date 100 OU
- 0 602
,40
":1.
?-
25 30 250 300 350 Figure 2-10b. Dissolved oxygen content (-) and percent saturation (---) of the entire water column (M) and the hypolimnion (0) of Lake Norman in 2001.
2-37
- 03)
E X
0
-- C-Q
?
/_.'%j
24 C
240o 240}
LAKE NORMAN STRIPED BASS HABITAT LAKE NORMAN STRIPED BASS HABITAT 23-, 1.0 8.0 11.0 13.0 15.015.9 62.0 69.0 72.0 80.0 235z.0 8.0 11.0 13.0 15.015.9 62.0 69.0 72.080.0 236:
230 2
2
.~.............
.225-25 0E S22( ý:~i 220; 215 215 cia 210 t21 205 205.
200 Jun 11,2001 20 Jun 27, 2001 19
-T -
- 19.
0 5
10 15 20 25 30 35 40 45 50 55 0
5 10 15 20 25 30 35 40 45 50 55 Distance from Cowans Ford Dam (kin)
Distance from Cowans Ford Dam (kin) 240 240 LAKE NORMAN STRIPED BASS HABITAT LAKE NORMAN STRIPED BASS HABITAT 23 1.0 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 80.0 230:
2304 220-2 22 2
C 0
12o 221 200 Jul 9, 2001 2-Jul 24, 2001 0
5 10 15 20 25 30 35 40 45 50 55 0
510 15 2025 30 36 40455055 daDistance from Cowans Ford Dam (kin)
Distance from Cowans Ford Dam (kin) 00i Figure 2-11. Striped bass hatitat (temperatures < 26 0 C and dissolved oxygen _> 2.0 mg/L) in Lake Norman in June, July, August, Jld September 2001.
19 5 19 r
C EC U)
.2 Ca 0U 230 S225 E
220 0 °.; 215 ai 210 205:
200-Distance from Cowans Ford Dam (km)
E C
0 cc Distance from Cowans Ford Dam (km)
Figure 2-11. Continued.
Aug 20, 2001 0
5 10 15 20 25 30 35 40 45 55 Distance from Cowans Ford Dam (km) 240 SLAKE NORMAN STRIPED BASS HABITAT 235 1.0 8.0 11.0 13.0 15.015.9 62.0 69.0 72.080.0 230 20 Sep 25, 2001 1
- 9......
5 10 15 20 Cowans For Da (ki u
Distance from Cowans Ford Dam (km) 24o:i LAKE NORMAN STRIPED BASS HABITAT 235 1.0 8.0 11.0 13.0 15.015.9 62.0 69.0 72.080.0 E
E 0
ca Ei t) 00 0
CHAPTER 3 PHYTOPLANKTON INTRODUCTION Phytoplankton standing crop parameters were monitored in 2001 in accordance with the NPDES permit for McGuire Nuclear Station (MNS). The objectives of the phytoplankton section for the Lake Norman Maintenance Monitoring Program are to:
- 1. Describe quarterly patterns of phytoplankton standing crop and species composition throughout Lake Norman; and
- 2. Compare phytoplankton data collected during this study (February, May, August, November 2001) 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 9 February, 1 May, 6 August, and 5 November 2001. Phytoplankton density, biovolume and taxonomic composition were determined for samples collected at Locations 2.0, 5.0, 9.5, 11.0, and 15.9; chlorophyll a concentrations and seston dry and ash-free dry weights were determined for samples from all locations.
Chlorophyll a and total phytoplankton densities and biovolumes were used in determining phytoplankton standing crop. Field sampling and laboratory methods used for chlorophyll a, seston dry weights and population identification and enumeration were identical to those 3-1
used by Rodriguez (1982). Data collected in 2001 were compared with corresponding data from quarterly monitoring beginning in August 1987.
A one way ANOVA was performed on chlorophyll a concentrations, phytoplankton densities and seston dry and ash free dry weights by quarter. This was followed by a Duncan's Multiple Range Test to determine which location means were significantly different.
RESULTS AND DISCUSSION Standing Crop Chlorophyll a Chlorophyll a concentrations (mean of two replicate composites) ranged from a low of 1.42 ug/1 at Location 2.0 in February, to a high of 32.57 ug/l at Location 69.0 in August (Table 3 1, Figure 3-1). All values were below the North Carolina water quality standard of 40 ug/l (NCDEHNR 1991). Lake-wide mean chlorophyll concentrations were within ranges of those recorded in previous years (Figure 3-2). The seasonal trend in 2001 of minimum values in February, increasing slightly in May, achieving maximum values in August, then declining to the second highest levels in November, has never been observed during the course of the Lake Norman Maintenance Monitoring Study.
Based on quarterly mean chlorophyll concentrations, Lake Norman was in the mesotrophic range during 2001, although a number of individual values were less than 4 ug/l (oligotrophic) and greater than 12 ug/l (eutrophic).
Lake-wide quarterly mean concentrations of below 4 ug/1 have been recorded on eight previous occasions, while concentrations of greater than 12 ug/l were only recorded during May 1997, and May 2000.
During 2001 chlorophyll a concentrations showed somewhat less spatial variability than in 2000. Maximum concentrations were observed at Location 69.0 during all quarters, while minimum concentrations occurred at Location 2.0 in all but August (Table 3-2). The trend of increasing chlorophyll concentrations from down-lake to up-lake, which had been observed during most quarters of 2000, was apparent in varying degrees during all quarters of 2001 (Table 3-1, Figure 3-1).
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 (Table 3-2). Flow in the riverine zone of a reservoir is subject to wide fluctuations depending, ultimately, on meteorological conditions (Thornton, 3-2
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 2001) have varied considerably. During February 2001, Locations 2.0 through 13.0 had chlorophyll concentrations in the low range, and the value at Location 5.0 was the lowest yet recorded for February (Figure 3-3). The chlorophyll concentration at Location 15.9 was in the intermediate range, while the value at Location 69.0 was the highest February chlorophyll yet observed. 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.
As stated above, the highest February value at location 69.0 occurred in 2001. Locations 2.0 through 9.5 had lower chlorophyll concentrations in February 2001 than in February 2000, while concentrations at Locations 11.0 through 69.0 were higher than in February 2000.
During May 2001 chlorophyll concentrations at Locations 2.0 through 11.0 were in the low range, in fact the concentrations at Locations 5.0 through 11.0 were the lowest recorded for May. Location 13.0 was in the intermediate range for May, while the value at 15.9 was in the high range. Once again, Location 69.0 demonstrated a record high value 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 2001.
All but Locations 69.0 had lower chlorophyll concentrations in May 2001 than'during this period in 2000.
August 2001 chlorophyll concentrations at most locations were in the intermediate range.
The concentration at Location 69.0 was the highest August concentration yet observed at this location (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 2001. Locations 2.0 through 13.0, and 69.0 3-3
had higher August concentrations in 2001 than in 2000, while concentrations at all other locations were lower than the previous year.
In November 2001, chlorophyll concentrations were in the low range at Locations 2.0 through 9.5. At Locations 11.0 through 69.0, November 2001 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 15.9 had higher November values in 2001 than in 2000.
Total Abundance Density and biovolume are measurements of phytoplankton abundance. The lowest density during 2001 occurred at Location 2.0 in February (669 units/ml), and the lowest biovolume (208 mm3/m3) occurred at Location 5.0 during May (Table 3-3, Figure 3-1). The maximum density (6,430 units/ml) and biovolume (4,468 mm3/m3) were observed at Location 15.9 in May. Phytoplankton standing crops during February and November 2001 were generally higher than those of February and November 2000, while May 2001 standing crops were lower than in May 2000 (Duke Power Company 2001).
August 2001 densities were generally higher than those of August 2000, while biovolumes during August 2001 were most often lower than those of August 2000. Phytoplankton densities and biovolumes during 2001 never exceeded the NC guidelines 10,000 units/ml density, and 5,000 mm3/m3 biovolume (NCDEHNR 1991). Densities and biovolumes in excess of NC guidelines were recorded in 1987, 1989, 1997, 1998, and 2000 (Duke Power Company 1988, 1990, 1998, 1999, 2001).
Total densities at locations in the Mixing Zone during 2001 were within the same statistical ranges during all sampling periods but February (Table 3-4). In all sampling periods except August, Location 15.9 had significantly higher densities than both Mixing Zone locations.
During August, Location 9.5 had the maximum density, and was in the same statistical range as Location 15.9 and Mixing Zone locations. During all but August, phytoplankton densities showed a spatial trend similar to that of chlorophyll, that is lower values at down-lake locations versus up-lake locations.
3-4
Seston Seston dry weights represent a combination of algal matter, and other organic and inorganic material. Dry weights during 2001 were most often lower than those of 2000. Location 69.0, the uppermost riverine location, had the highest seston dry weights during all sample periods (Table 3-5). A pattern of increasing values from down-lake to up-lake was observed in all quarters to some extent (Figure 3-1). Statistically, Location 69.0 had significantly higher values than other locations during all quarters of 2001. From 1995 through 1997 seston dry weights had been increasing (Duke Power Company 1998). Values since 1998 represented a reversal of this trend, and were in the low range at most locations during 1999 through 2001 (Duke Power Company 2001). Low dry weights over the past four years were likely a result of prolonged drought conditions.
Seston ash-free dry weights represent organic material and may reflect trends of algal standing crops. In some cases, this relationship held true in 2001; most notably at Location 69.0, which had the highest ash-free dry weights, as well as maximum chlorophyll values during all quarters of 2001 (Tables 3-1, 3-2, and 3-5).
Location 15.9, which -had comparatively high ash-free dry weights in February, May, and November, also had seasonal maximum density values during these periods (Tables 3-4 and 3-5). During all sampling periods, the only significant statistical difference was that Location 69.0 was in a higher range than other locations. The proportions of ash free dry weights to dry weights during 2001 were slightly lower than in 2000, and similar to those of 1999, indicating very little change in inorganic inputs during those three years. Between 1994 and 1997 a trend of declining organic/inorganic ratios was observed (Duke Power Company 1995, 1996, 1997, 1998, 2001).
Secchi Depths Secchi depth is a measure of light penetration.
Secchi depths were often the inverse of suspended sediment (seston dry weight), with the shallowest depths at Locations 13.0 through 69.0 and deepest from Locations 9.5 through 2.0 down-lake. Depths ranged from 1.10 m at Location 69.0 in May, to 3.50 m at Location 11.0, also in May (Table 3-1). The lake-wide mean secchi depth during 2001 was the second highest recorded since measurements were first reported in 1992. The highest lake-wide mean secchi depth was recorded for 1999 (Duke Power Company 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001). Again, high secchi depths were likely due to low rainfall over the past few years.
3-5
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 2001. Nine classes comprising 64 genera and 118 species, varieties, and forms of phytoplankton were identified in samples collected during 2001, as compared to 81 genera and 172 lower taxa identified in 2000 (Table 3-6).
The 2001 total represented an average number of individual taxa based on monitoring since 1987. Two taxa previously unrecorded during the Maintenance Monitoring Program were identified during 2001.
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 all locations in February 2001 (Table 3 7, Figures 3-4 through 3-8). In May, cryptophytes (Cryptophyceae) were dominant at all but Location 15.9, where diatoms were predominant. 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, 2000-2001). The most'abundant diatoms during February were Tabellaria fenestrata (Locations 2.0 through 11.0), and Melosira distans (Location 15.9).
During May, the most abundant cryptophyte was the small flagellate, Rhodonionas mninuta, which was dominant at all but Location 15.9, where the diatom Fragillaria crotonensis was most abundant (Table 3-7). All of these species have been common and abundant at various times throughout the course of the Program. Rhodonmonas minuta has been one of the most common and abundant forms observed in Lake Norman samples since monitoring began in 1987. Cryptophytes are characterized as light limited, often found deeper in the water column, or near surface under low light conditions, which are common during winter (Lee 1989). In addition, R. minuta's small size and high surface to 3-6
volume ratio would allow for more efficient nutrient uptake during periods of limited nutrient availability (Harris 1978).
During August 2001 diatoms dominated densities at all but Location 15.9, where green algae, primarily the small desmid Cosmarium asphearosporurn var. strigosum, were dominant (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 and August 2000. During August periods of the Lake Norman study prior to 1999, green algae (Chlorophyceaea), with blue-green algae (Myxophyceae) as occasional dominants or co dominants, were the primary constituents of summer phytoplankton assemblages.
This pattern of diatom dominance in August periods of 1999 through 2001 was generally lake wide. 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 three deepest lake-wide secchi depths were recorded from 1999 through 2001), extended periods of low water due to draw-down, shifts in nutrient inputs and concentrations, and macrophyte control procedures upstream (Duke Power Company 2000).
Whatever the cause, the phenomenon was lake-wide, and not localized near MNS or Marshall Steam Station (MSS); therefore, it was most likely due to a combination of environmental factors, and not station operations.
During November 2001, densities at all but Location 2.0 were dominated by diatoms, while cryptophytes were most abundant at Location 2.0 (Figures 3-4 through 3-8). The dominant species at Locations 5.0, 11.0, and 15.9 was T.fenestrate. The dominant taxa at Locations 2.0 and 9.5 were the cryptophyte R. minuta, and the centrate diatom Cyclotella comta (Table 3 7). During previous yearg 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 2001 samples. Their overall contribution to phytoplankton densities was lower in 2001 than in 2000 and 1999. Densities of blue-greens seldom exceeded 2% of totals. The highest percent composition of Myxophyceae (2.5%) during all sampling periods in 2001 occurred at Location 15.9 in August. Prior to 1991, blue-green algae were often dominant at up-lake locations during the summer (Duke Power Company 1988, 1989, 1990, 1991, 1992).
3-7
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 opposed to chlorophyll, which gives an "instantaneous" view of phytoplankton concentrations. The index was calculated on an annual basis for the entire lake, for each sampling period, and for each location during 2001 (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, 1998, and 2000; and in the low, or oligotrophic, range in 1988, 1995, 1997, and 1999. The index for 2001 was lower than that of 2000, and fell in the very low mesotrophic range.
The highest index value among sample periods of 2001 was observed in November, and the lowest index value occurred in February (Figure 3-9). The highest lake-wide chlorophyll was in August, with the minimum in February, therefore, the index did not completely reflect chlorophyll concentrations observed throughout the lake during 2001. The index values for locations during 2001 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-obsrrved during,'most-quarters of 2001.
During 2000, this pattern of increasing trophic state from down-lake to up-lake locations was also observed during most sampling periods (Duke Power Company 2001).
3-8
FUTURE STUDIES No changes are planned for the phytoplankton portion of the Lake Norman Maintenance Monitoring program during 2002.
SUMMARY
In 2001 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 mean chlorophyll in February represented the annual minimum. The lake-wide mean increased slightly during May, then increased to the annual maximum in August. The lake wide mean declined to the second highest value in November. This seasonal pattern had never been recorded during the Maintenance Monitoring Study. Some spatial variability was observed in 2001; however, maximum chlorophyll concentrations were most often observed up-lake, while comparatively low chlorophyll concentrations were recorded from Mixing Zone locations.
Location 69.0, the furthest upstream location, demonstrated long term maximum chlorophyll concentrations in February, May, and August of 2001. The highest chlorophyll value recorded in 2001, 32.57 ug/l, was below the NC State Water Quality standard of 40 ug/l.
In most cases, total phytoplankton densities and biovolumes observed in 2001 were lower than those observed during 2000, and standing crops were within ranges established over previous years. Phytoplankton densities and biovolumes during 2001 never exceeded the NC guidelines for algae blooms. Standing crop values in excess of bloom guidelines have been recorded during five previous years of the progfam:'" 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 lower in 2001 than in 2000, 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 Location 69.0, while low values were most often noted at Locations 2.0 through 11.0. The proportions of ash-free dry weights to dry weights in 2001 were slightly lower than those of 2000, indicating little change in organic/inorganic inputs into Lake Norman.
3-9
Secchi depths reflected suspended solids, with shallow depths related to high dry weights.
The lake-wide mean secchi depth in 2001 was the second deepest recorded since measurements were first reported in 1992. The greatest annual mean lake-wide secchi depth was recorded for 1999. High secchi depths over the last few years were likely due to low rainfall.
Diversity, or numbers of taxa, of phytoplankton had decreased since 2000, and the total number of individual taxa was within ranges of previous years. The taxononic composition of phytoplankton communities during February, May, and November were similar to those of certain previous years. Diatoms were dominant at most locations during all sampling periods except May, when cryptophytes were most often dominant.
A shift in community composition was first observed in August 1999 when diatoms, primarily the periphytic form Anomoeonies vitrea, dominated phytoplankton assemblages at Lake Norman locations. This pattern was again observed during August periods of 2000 and 2001. During most previous August periods, green algae (and occasionally blue-green algae) dominated the phytoplankton. This shift was likely the result of a variety of environmental factors, and not related to station operations. Blue-green algae were less abundant during 2001 than during 2000, and their contribution to total densities seldom exceeded 2%.
The most abundant alga, on an annual basis, was the cryptophyte Rhodomonas minuta.
Common and abundant diatoms were Tabellaria fenestrata in February and November; and Anomoeneis vitrea during August. Other diatoms, Melosira ditans, Fragillaria crotonensis, and Cyclotella conita; as well as small desmids, were occasionally dominant.
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 2001 was lower than that of 2000, and was at the very low end of the intermediate range. Quarterly index values increased from February to May, declined in August, then increased in November. Quarterly values did not completely 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 variable 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. 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:199 4 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.
3-11
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.
Duke Power Company. 2001. Lake Norman maintenance monitoring program:
2000 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 limonplankton. John Wiley and Sons, New York, NY.
Lee, R. E. 1989. Phycology (2nd. Ed.). Cambridge University Press. 40 West 20th. St., New York, NY.
Menhinick, E. F. and L. D. Jensen. 1974. Plankton populations, p. 120-138 In L. D. Jensen (ed.). Environmental responses to thermal discharges from Marshall Steam Station, Lake Norman, NC. Electric Power Research Institute, Cooling Water Discharge Project (RP-49) Report No. 11. Johns Hopkins Univ., Baltimore MD.
North Carolina Department of Environment, Health and Natural Resources, Division of Environmental Management (DEM), Water Quality Section. 1991. 1990 Algal Bloom Report.
Nygaard, G. 1949. Hydrological studies of some Danish pond and lakes II. K. danske Vilensk. Selsk. Biol. Skr.
Rodriguez, M. S. 1982. Phytoplankton, p. 154-260 In J. E. Hogan and W. D. Adair (eds.).
Lake Norman summary. Technical Report DUKEPWR/82-02 Duke Power Company, Charlotte, NC.
Thornton, K. W., B. L. Kimmel, F. E. Payne. 1990. Reservoir Limnology. John Wiley and Sons, Inc. N. Y.
3-12
Table 3-1. Mean chlorophyll a concentrations (ug/1) in composite samples and secchi depths (m) observed in Lake Norman, NC, in 2001.
Chlorophyll a T.ncntinn 2.0 5.0 8.0 9.5 11.0 13.0 15.9 69.0 FEB 1.85 2.27 2.29 2.62 3.78 5.42 7.08 12.47 MAY 1.42 1.53 1.70 1.44 1.98 6.80 12.82 14.15 AUG 6.40 6.73 7.37 7.66 6.00 5.69 8.30 32.57 NOV 3.34 3.46 4.71 4.47 8.21 5.72 8.10 9.54 Secchi depths FEB MAY AUG nrfn MAY-2.56 2.45 2.66 2.40 2.60 1.79 1.78 1.20 3.15 2.98 3.44 2.97 3.50 1.84 1.76 1.10 2.4/
1.58 3.00 2.06 2.28 1.50 1.30 1.25 T netlnn 2.0 5.0 8.0 9.5 11.0 13.0 15.9 69.0 NOV 1.52 2.10 2.30 2.01 2.00 1.59 1.35 3-13 T ni-tion FEB
Table 3-2. Duncan's multiple Range Test on chlorophyll a concentrations in Lake Norman, NC, during 2001.
February Location 2.0 5.0 8.0 9.5 11.0 13.0 15.9 69.0 Mean 1.85 2.27 2.29 2.62 3.78 5.42 7.08 12.47 2.0 1.42 9.5 5.0 8.0 11.0 13.0 15.9 69.0 1.44 1.53 1.70 1.98 6.80 12.82 14.15 13.0 11.0 2.0 5.0 8.0 9.5 15.9 69.0 5.69 6.00 6.40 6.73 7.37 7.66 8.30 32.57 2.0 5.0 9.5 8.0 13.0 15.9 11.0 69.0 3.34 3.46 4.47 4.71 5.72 8.10 8.21 9.54 3-14 May Location Mean August November Location Mean Location Mean
Table 3-3. Total mean phytoplankton densities and biovolumes from samples collected in Lake Norman, NC, during 2001.
Density (units/mi)
Locations Month 2.0 5.0 9.5 11.0 15.9 Mean FEB 669 962 1106 1262 3275 1455 MAY 877 929 1202 1450 6430 2178 AUG 2957 3059 3221 2764 3155 3031 NOV 1286 1422 1611 2494 2873 1937 Biovolume (mm 3/m3)
Locations Month 2.0 5.0 9.5 11.0 15.9 Mean FEB 484 868 1258 1104 2786 1300 MAY 310 208 270 277 4468 1107 AUG 1474 1649 1706 1278 2975 1816 NOV 964 1180 1514 2680 2730 1814 3-15
Table 3-4. Duncan's multiple Range Test on phytoplankton densities in Lake Norman, NC, during 2001.
2.0 5.0 669 962 2.0 5.0 877 929 11.0 2764 2.0 2957 9.5 11.0 1106 1262 9.5 11.0 1202 1450 5.0 3059 15.9 3155 2.0 5.0 1286 1422 9.5 1611 11.0 15.9 2494 2873 February Location Mean May Location Mean August Location Mean 15.9 3275 15.9 6430 9.5 3221 November Location Mean 3-16
Table 3-5. Duncan's multiple Range Test on dry and ash free dry weights (mg/1) in Lake Norman, NC during 2001.
DRY WEIGHT February Location 5.0 11.0 2.0 8.0 9.5 13.0 15.9 69.0 Mean 0.50 0.92 0.98 1.12 1.18 1.56 2.75 7.61 Location Mean Location Mean Location Mean 8.0 9.5 11.0 5.0 2.0 13.0 15.9 69.0 0.58 0.78 0.78 0.87 0.90 1.96 2.52 5.53 11.0 13.0 2.0 9.5 8.0 5.0 15.9 69.0 1.45 1.67 2.04 2.07 2.18 2.32 2.39 7.43 8.0 9.5 2.0 15.9 11.0 5.0 13.0 69.0 1.39 1.58 1.60 1.93 2.36 2.87 2.96 7.20 ASH FREE DRY WEIGHT February Location Mean May August November Location Mean Location Mean Location Mean 5.0 8.0 9.5 11.0 13.0 2.0 15.9 69.0 0.48 0.59 0.63 0.70 0.85 0.93 1.09 1.98 9.5 2.0 8.0 11.0 5.0 13.0 15.9 69.0 0.49 0.53 0.55 0.78 0.82 0.96 1.11 2.10 13.0 11.0 15.9 8.0 2.0 0.88 1.06 1.31 1.56 1.58 5.0 9.5 69.0 1.67 1.80 3.11 8.0 9.5 13.0 2.0 11.0 15.9 5.0 69.0 0.82 0.86 0.87 0.88 0.91 1.00 1.17 1.74 3-17 May August November
Table 3-6. Phytoplankton taxa identified in quarterly samples collected in Lake Norman from February 1988 to November 2001.
TAXON 88 89190 9192 9394 9596 97 198 99 00 01 CLASS: CHLOROPHYCEAE
-Acanthosphaera zachanasi Lernrn.
XX
-X Actide-smium hookeri Reinsch X
Actinastrum hantzchii Lagerhein x
X X
X X X---------
Anldstrodesmus braunii (Naeg) Brunn XIX x
x~~
X x A.
convolutus Gorda II IIx A.
falcatus (Corda)
Ralfs X
X x
X X
X X~x x
X XX X
X X,
A.
fusiformis Corda sensu Korsch.
XI X
X I
X X
I A.
nannoselene Skuja I
Ix A.
spiralis (Turner)
Lenunfl X
x x
xIx--
-X A.
spp.
Corda X
IX Arthrodesmus convergens EhrenbergI A.
incus (Breb.)
Hassall X
X
__Xx A.
subulatus Kutzing
-X---
A.
spp.
Ehrenberg x
I Asterococcus limneticus G.
M.
Smnith X
X X
X X
x Botryococcus brazunii Kutzing X
X II Carteriafrtzschii Takeda x
I I
I C.
spp.
Diesing x
I I
x I-xxxI Characium spp.
Braun XII Chiarnydomonas spp.
Ehrenberg xX X
xX xxx xx xXx x
Chiorella vulgaris Beycrink X
Chiorogoniurn euchlorwn Ehrenberg X
X X
C.
spirale Scherffel
&Pascher-X I
I_
Closteriopsis longissirna West West x
I X
X X I X
X X
X x
x XI x
x Closterium cornu Ehrenberg I
I C.
gncucule Brebisson IX x
Coccomonas orbicularis Stein x
Coelastrurn cambricun Archer X
X X
X x
X X
X X
X X
X X
x C.
microporurn Nageli X
I_
I__
"C reticulaturn (Dang.)
Sinn
-x "C sphaericum Nageli x
x I_
x_
I__
X X
C.
proboscideurn Boblin II C
spp.
Nageli-Cosinanurn angulosuni
- v.
concinnum (Rab)
W&W C.
asphaerosporum
- v. strigosunt Nord.
x X
X X
X X
X T
X X
X X
X 3-18
_88 89 90 9192 9394 959697 98 99 00 01 C. contractum Kirchner x-X x
X-X x
X X
X x
C. monii~forme (Turp.) Ralfs X
C. phaseolus f minor Boldt.-------------------------X X x X
C. pokornyanum (Grun.) W. & G.S. West Ix C. polygonum (Nag.) Archer x
x x
xx xYx C regnellii Wille-----------------------------x x
x x x x C. regnesi Schmidle X
X X C. tenue Archer x
x X
X X
X X
XX C.tinctum Ralfs x
-X XXX x
X I
X x
x C. tin etum v. subretusum Messik.
x C tinctum v. lumidum Borge.
X X
XX C. spp. Corda x
X XX X
X Crucigenia crucifiera (\\Volle) Collins X
X X X
X X
X X
x C.fenestrata Schmidle IX C. irregularis Wille I-I_
I x_
C. rectangularis (A. Braun) Gay I
IIX C. tetrapedia (Kirch.) West & West X
x x
x x
X x
x X
x X
X X
x Dictyospaerium ehrenbergianum Nageli x--------------------
D. pulchellum Wood X
X x
x x
x x
X x
X X
X X
x Dimorphococcus spp. Braun x
I Elakatothrix gelatinosa Wille x
x x
x x
x x
x x
X x
X x
X Euastrum denticulatunz (Kirch.) Gay x x i3 x x x x
E. spp. Ehrenberg x
x x
xI Eudorina elegans Ehrenberg XI Franceia droescheri (Lemm.) G. M. Smith x
I-----
x x
X X
X x
F. ovalis (France) Lemm.
X X I x
x x
x X
Giceocystis botrycides (Kutz.) Nageli X
G. gigas Kutzing x
x-----------x x
xxIx X
G. major Gerneck ex. Lermnermann x
G.'jjlanktonica (W~t & West) Lemm.
x x
X NX X
X x
X X
X X
X G. vesciculosa Naegeli Ix G. spp. Nageli Yjxx x xxX Golenkinia paucispina West & West x
I G radiata Chodat X
X X
X X
XXX XX X
X IX Gonium pectorale Mueller I
G. sociale (Duj.) Warming x------------
X I
Kirchneriella contorta (Schmidle) Boblin x
X X
X X
X X
I K. elongata G.M. Smith I-x_
K. lunaris (Kirch.) Mobius X
X X
K. luinaris v. dianae Bohim X
xX K. luinaris v. irregularis G.M SmithX K obesa W. West x
X X
X x
xx 3-19 page 2 of 10
88 89 90 91 92 93 94 95 96 97 98 99 00 01 K subsolitaria G. S. West x
x x
x x
x x
K spp. Scbn-tidlc x
x x
x Lagerheimia ciliala (Lag.) Chodat L. citriformis (Snow) G. M. Smith x
L. longiseta (Lemmermann) Printz L. quadriseta (LemnL) G. M. Smith x
x x
x L. subsala Lemmerman.
x x
x x
x x
x x
x x
Mesostigma viride Lauterborne x
x x
x x
x x
Micractiniumpusillum Frcsen.
XIX x
x x
x x
x x
x x
x x
x Monoraphidium contortum Thurct x I x x
x x
x I
M. pusillum Printz x
x XIX x
x Mougeitia elegantula Whittrock x
I M. spp. Agardh x
x x
x Nephrocytium agardhianum Nageh x
x N. limneticum (G.M. Smith) G.M. Smith x
Oocystis borgii Snow x
x xi
- 0. ellyptica W. West x
x
- 0. lacustris Chodat x
I
- 0. parva West & West x
x x
I x I x I x x
x x
x
- 0. pusilla Hansgirg x
x x
x x
x x
x XIX x
- 0. pyriformis Prescott x
I I
- 0. spp. Nageli x
I I
Pandorina charkowiensis Kprshikov P. morum Bory x
x I x x
Pediastrum biradiatum Meyen I
P. duplex Meyen x
x x I x
x x
x x
x x
P. duplex v. gracillimum West and West x
x P. tetras v. tetroadon (Corda) Rabenhorst x
x x
x x
x x
x x
x x
x x
x dx P. spp. Meyen x
x Planktosphaeria gelatinosa G. M. Smith
_x X-I Quadrigula closterioides (Bohlin) Printz x
x x
x Q lacustris (Chodat) G. M. Smith x
Scenedesnius abundans (Kirchner) Chodat x
x x
S abundans v. asymetrica (Schr.) G. Sm.
x x
x x
x x
XI x
x I I x S abundans v. brevicauda G. M. Smith I
x I
I S. acuminatus (Lagerheim) Chodat x
x x
x x
I x x
x I x S. armatus v. bicaudatus (Gug.-Prin.)Chod x
I x x I x x
x x
x x I x x
x I x S. býuga (Turp.) Lagerheim x
x I x x
x x
x x
x x
x x
S. btjuga v. alterans (Reinsch) Hansg.
S. brasiliensis Bohlin x
x x
x x
x -X S denticulatus Lagerheim x
x I x x
xjx x
X: X, x
x, x ý_x Talkli-q-A (t-nnt;n"i-rl)
Daae 3 of 10
ýx 3-20
T2hle. -6 (continued
page 4 oflO
-1r
z1U I I
I i.5
'+
I I
U' S. dimorphus (Turp.) Kutzing X -
X IX X I X
X X
X S. incrassulatus G. M. SmithI II S. quadricauda (Turp.) Brebisson X
X X
X IX X
X X
X X
X X
X -X S smithii Teiling I
X_
I_ -
S. spp. Meyen XXXXXX Schizochiamys compacta Prescott X
IX XI S.
gelatinosa A.
Braun X
Schoederia setigera (Scbroed.)
Lenim.
X
-I X--
Selenastrum gracile Reinsch IXII I
S.
minutum (Nageli)
Collins X
X IX IX X
XIX X
x xIX S.
westii G.
M.
Smith X
X X
X XX Sorastrum americanum (Bohlin)
Scbmidle x
Sphaerocystis schoeteri Chodat X
-X
__X X
X IX Sphaerozosrna granulatunz Roy Bliss X
I Stauastrum americanum (W&W)
G.
Smn.
X_
xX~
X X
5X S.
apiculatum Brebisson 5X X
X XX S brachiatum Ralfs X
IX X
S brevispinum Brebisson x__
S.
chaetocerus (Schoed.)
G.
M.
Smith--
-X X
X
-I S
curvatum W.
West X
X XX XXX XX XX X
S.
cuspidatum Brebisson I
X X
X X
x S.
dejectum Brebisson X
X X
X X
X I_
X S
dickeii
- v.
maximum West West X
I
-I S
gladiosum Turner I
X--
S leptocladurn
- v.
sin ualum Wolle X
II S.
manfeldtii v.fluminense Schumacher X
X X
I XX IXXIX Smegacanthurn Lundell X
I XI S
ophiura
- v.
cambricum (Lund)
W.
W.
I IIX S.
orbiculare Ralfs II S. paradoxum Meyen X
-X-X-IX
-X X-I I
X XI S
paradoxuni
- v.
cingulum West WestII S
prdoxy
- v.
parvum W.
WestI S.
subcruciatum Cook Wille I__
___XI Stletracerum Ralfs X
X X
X X
X XIXXX X
X X
X S
turgescens de Not.
XII S.
spp.
Meyen x
xN I_
Stigeoclonium spp.
KutzingI Tetraedron b/ifurcatum
- v.
minor PrescottII X
T'.
caudatuni (Corda)
Hansgirg X
X X
X X
-X X
X X
xx T.
limneticuin Borge X
T' lobulatuin (Naeg.)
Hansgirg T'
lobulatuin
- v.
crassum PrescottX 3-21 page 4 of 10 YO 7
89 yo y
88 90 91 1 92-1 93 94 1 95
cq
)
0 0
9 9
K>
3-23 88 89 90 91 92 93 94 95 96 97 98 99 00 01 Eunotia flexuosa v. eurycephala Grun.
X E. zasuminensis (Cab.) Koerner X
x X
X X X
X X X
X X
X X
Fragilaria crotonensis Kitton X
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
X x 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 X x M. granulata (Ehr.) Ralfs X
X X I X
M. granulata v. angustissima 0. Muller X
X X
X X
X X X X
X X
X X
X M. italica (Ehr.) Kutzing x
I I
I I
M. varians Agardh I
I x
M. spp. Agardh X
X XX X
XX X XX Navicula cryptocephala Kutzing X
X X
N. exigua (Gregory) 0. Muller X
N. exigua v. capitata Patrick X
N. subtilissima Cleve X
X X
N. spp. Bory X
X X X X X Nitzschia acicularis W. Smith X
X X
X X
X X
X X
X X
N. agnita Hustedt X
X X
X X
X X X X
X X
X X
X N. holsatica Hustedt X
X X
XX IX X
X X
X N. linearis W. Smith X
N. palea (Kutzing) W. Smith X I X X X
X X
N. sublinearis Hustedt X
I X
I___2X N. spp. Hassall X
X XX X
X X X Pinnularia spp. Ehrenberg X
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
X X
Stephanodiscus spp. Ehrenberg X
X X
X X
X X
X X X X
Surirella linearis v. constricta (Ehr.) Grun.
X I
Synedra actinastroides Lemmerman X
S acusKutzing X
X X
X X
X S. delicatissima Lewis X
X X
S filifonnis v. exilis Cleve-Euler X
X X
S. planktonica Ehrenberg X
X X
X X
X X X X
X X
X X
X X S rumpens Kutzing x-X X
X X X
X X X S rumpens v.fragilarioides Grunow X
S rurnpens v. scotica Grunow X
S. ulna (Nitzsch) Ehrenberg X
X X
X X
X X
X S spp. Ehrenberg X
X XX X
X X x Tabellariafenestrata (Lyngb) Kutzing X
X X
X X
X X
X X
X X
X X
X T. flocculosa (Roth.) Kutzing X
X I X
X pae6 ofl10
K>
3-24 88_8_90._1_9 %
93
%94 597 798 99 10O0 GLASS: CHRYSOPHYCEAEI A4ulomonas purdyii Lackey x
X X X X X X X Rico eca petiolatum (Stien) Pringsheimn XX Calycomonas pascheri (Van Goor) Lund------------------x x
Chromulina spp. Chien.
x x
Chrysosphaerella solitaria Lauterb.
xx x xX xX X
x x x Codomonas annulata Lackey x
x x x x
Dinobryon bavaricum Imnhof X x X X X X X X X X X X X X D. cylindricum Imthof x
X X X
x iiXI D. divergens Imihof I x
-x x x X X XX D. sertularia Ehrenberg X
I_
IX x
D. spp. Ehrenberg X XX XXX x
X X x Domatomococcus cylindricum Lackey X X Erkinia subaequicilliata Skuja X X X X X I
X X X XX Kephyrion littorale Lund X
K.rubi-claustri Conrad x----------------------
K.skujae Ettl x
K. spp. Pascher IX X XX X
X X X X X Mallomonas acaroides Perty IX M. akrokomos (Naumann) Krieger X
XX M. alpina Pascher X
x M.caudata Conrad x x X x x x I
xX M. globosa Schiller xX x
M. producta Iwanoff IIx M pseudocoronata Prescott X X X X X x X X x x X X X X M. tonsurata Teilmg x X X X x x x X x x X X X X M.spp. Perty Ochromonas granularis Doflein X XX X
0.mutabilis Kiebs X
- 0. spp. Wyss X x 7x Yx ___
x Pseudokephyrion schilleri Conrad X
P. tintinabulum Conrad X
Rhizochrisis polyrnorpha Naumann X
R. spp. Pascher x
X Salpingoecafrequentissima (Zachary) Lemm.----------------------
X X Stelexornonas dichotoma Lackey X
X X
X X
X x x X X X X
Stokesiella epipyxis Pascher I
X XX Synura spinosa Korschikov x
X
___xx S. uvella Ehrenberg x
X X
X X X
-x S spp. Ehrenberg X
X X xx x
Uro glen opsis americana (Caulk.) Lemm.
x
__-XXX
-X page 7 of 10
Table 3-6 (continued)
CLASS: HAPTOPHYCEAE I
I I
I Chrysochromulina parva Lackey x
x Ix x
x x
x x
x x
x x
x x
I CLASS: XANTHOPHYCEAE I
Characiopsis dubia Pascber I
Ix x
x x
x x
Dichotomococcus curvata Korschikov I
Ophiocytium caoitatum v. longisp. (M) Lem x
x CLASS: CRYPTOPHYCEAE Cryptomonas erosa Ehrenberg x
x x
x x
x XIX x
x x
x x
x C. erosa v. reflexa Marsson x
x x
x x
C. gracilia Skuja I
x C. marsonii Skuja x
x x I x x
x C ovata Ehrenberg x
I x x
x x
x x
x x
x x
x x
x C. phaseolus Skuja x
x x
x I x x
C. refle-xa Skuj a x
x x
x x
x xlx.
x x
x x
x x
C. spp. Ehrenberg x
x x
x x
x I I
I Rhodomonas minula Skuja x
x x
x x
x XIX x
XIX x
x x
I CLASS: MYXOPHYCEAE I
I Agmenellum quadriduplicatum Brebisson I
x x
x x
x x
XI x x
Anabaena catenula (Kutzing) Born.
x x
x A. inaequalis (Kutz.) Born.
x A. scheremetievi Elenkin x
I x x
x A. ivisconsinense PrescoU x
x x
x I x x
x x
.4. spp. Bory x
xlx_
x x
x XI x
I x
Ix Anacystis incerta (Lemm.) Druet & Daily x
x x
x x
x x
x x
A spp. Meneghini Chroococcus dispersus (Keissl ) Lemm.
x x
C limneticus Lemmermann XI x
I -
x Xj x X-X C minor Kutzing I
C turgidus (Kutz.) Lernmermann x
x C. spp. Nageli x
x x
I x x
XIX x
XIX x
x x
Coelosphaerium kuetzingtana Nageh x
I I
dx Dactylococcopsis irregularis Hansgirg x
x I
x I
D. rupestris Hansgirg I
I x
I D. smithii Chodat and Chodat x
x x
D. spp. Hansgirg x
Gomphospaeria lacustris Chodat x
x x
x x
x x
Lyngbya contorta Lemmermann x
I x I
L hinnetica Lemmermann x
x XIX x
x I
page 8 of 10 V4 YD YO y /
yo yy uv VI 88 1 89 1 90 91 92 93 3-25
3-26 Talkle-'A-6 (continued)
I I
i
- ý I I
I An nI L. ochracea (Kutz.) Thuret 11 1
1 1
x L. subtifis W. West x
x XIX X1 I
L. spp. Agardh x
x x
XIx-x x I X. x x
x x
x x
Merismopedia tenuissima Lernrnerniann.
I I
x Microcystis aeruginosa Kutz. emend Elen.
x x
x I x x
x x
x x I x x
x Oscillatoria geminata Meneghini x
x x
x x
x I x x
x alimnetica Lernmerniann x
x x
x x
x XIX asplendida Greville x
x x
- 0. subtilissima Kutz.
x x
- 0. spp. Vaucher x
x x
x Phormidium angustissimum West & West x
x x
x P. spp. Kutzing x
x x
x x
Raphidiopsis curvata Fritsch & Rich x
I x x
x x
x x
x x
R. mediter-ranea Skuja x
Rhabdoderma sigmoidea Schm. & Lautrb.
x Synecococcus lineare (Sch. & Laut.) Korn.
x x
x x
x x
x x
x x
x CLASS: EUGLENOPHYCEAE Euglena acus Ehrenberg x
x E. minuta Prescott x
x E. polymorpha Dangeard x
x E. spp. Ehrenberg x1XIX XI x
x x
x Ix x
x Lepocinclus ovum (Ehr.) Lenim x
L spp. Perty x
x Phacus cuvicauda Swirenko x
P. longicauda (Ehr.) Dujardin x
P. orbicularis Hubner I
I x I
P. tortus (Lemm) Skvor-tzow x
x I x P. spp. Dujardin x
I Trachelomonas acanthostomd (Stok.) Defl.
x ixý T hispida (Perty) Stein x
x x
x T. pulcherrima Playfair x
T. volvocina Ehrenberg x
x x
x T. spp Ehrenberg I
x x
x I
CLASS: DINOPHYCEAE Ceralium hirundinella (OFM) Schrank x
x x
x x
x x
x x
x Glenodinium borgei (Lemm.) Schiller x
x G. gymnodinium Penard x
x x
x x
x G. palustre (Lenim.) Schiller G. penardiforme (linde.) Schiller x
x page 9 of 10 YO Dly I
I Y'4 1 :;F.)
YU y
88 1 89 1 90 91 1 92 91
page 10 of 10 88 89 90 91 92 93 94 95 96 97 98 99 00 01 G. quadridens (Stein) Schiller X
x G. spp. (Ehrenberg) Stein X
X Gymnodinium aeruginosum Stein X
XX G. spp. (Stein) Kofoid & Swezy x
X X
X X
X X
X X
X Peridinium aciculiferum Lemnmermann X
P. inconspicuum Lemmermann X
X X
X X
x XX XX X
X X X P. intermedium Playfair X
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 XII P. wisconsinense Eddy X
X X
X X
X X
X XX X X
X X
P. spp. Ehrenberg XXIXX X
_I CLASS: CHLOROMONADOPHYCEAE Gonyostomum depresseum Lauterbome X I IIx X
X G. semen (Ehrenberg) Diesing X
I I -
I G. spp. Diesing X
X X
3-27
Table 3-7. Dominant classes and species, and their percent composition (in parenthesis) at Lake Norman locations during each sampling period of 2001.
LOC FEBRUARY MAY 2.0 BACILLARIOPHYCEAE (70.1)
CRYPTOPHYCEAE (51.1)
Taballariafenestrata (20.4)
Rhodomonas minuta (50.2) 5.0 BACILLARIOPHYCEAE (49.6)
CRYPTOPHYCEAE (59.5)
T. fenestrata (24.2)
R. minuta (57.8) 9.5 BACILLARIOPHYCEAE (50.0)
CRYPTOPHYCEAE (59.0)
T.fenestrata (28.6)
R. minuta (56.7) 11.0 BACILLARIOPHYCEAE (53.0)
CRYPTOPHYCEAE (63.3)
T. fenestrata (27.0)
R. minuta (59.7) 15.9 BACILLARIOPHYCEAE (75.0)
BACILLARIOPHYCEAE (65.3)
Melosira distans (38.9)
Fragillaria crotonensis (54.8)
AUGUST NOVEMBER 2.0 BACILLARIOPHYCEAE (43.3)
CRYPTOPHYCEAE (43.3)
Anomoeoneis vitrea (29.3)
R. mninuta (28.0) 5.0 BACILLARIOPHYCEAE (40.3)
BACILLARIOPHYCEAE (39.4)
A. vitrea (28.9)
T. fenestrata (11.8) 9.5 BACILLARIOPHYCEAE (41.4)
BACILLARIOPHYCEAE (36.1)
A. vitrea (26.9)
Cyclotella comita (10.4) 11.0 BACILLARIOPHYCEAE (36.3)
BACILLARIOPHYCEAE (52.0)
A. vitrea (25.2)
T.fenetrata (28.2) 15.9 CHLOROPHYCEAE (36.6)
BACILLARIOPHYCEAE (43.5)
Cosmarium asphear. strig. (13.0)
T. fenestrata (25.3) 3-28
0 20 50 80 95 110 13 0 15 9 69 0 SESTON DRY WEIGHT (mg/I) 8 7-6-
4 35 24 13 20 20 50 80 95 110 130 159 690 LOCATIONS 5000 4500 4000 3500 3000 2500 2000 1500 1000 2oo 2
BIOVOLUME (mm3fm3) 0 I
50 95 LOCATIONS 110 159 FEB MAY AUG NOV Figure 3-1. Phytoplankton chlorophyll a, densities, and biovolumes; and seston weights at locations in Lake Norman, NC, in February, May, August, and November 2001.
3-29 CHLOROPHYLL a (ug/1) 35 30 25 20 15 10 5
0 DENSITY (unltslml)
- 7000, 6000 --- - -- - - - -- - - - - -- - - - --
5000 --- - - - -- - - -- - - - - -- - - - - -
4000 3000--
2000 1000 --------------------
0 I
9 1
20 50 95 11.0 159 CHLOROPHYLL a (ugll)
S...............................................
14 12 10
,-J 0~
0 0 1 FEB MAY AUG MONTH 1987
-v--1988 1-i 9 8 9
-x-1990
-*-1991 1992
-i----1993 9-1994--
09950
--o--1996
-1997
--ao-1998 1999
--a3--2000
.-o--2001 Figure 3-2. Phytoplankton chlorophyll a annual lake means from all locations in Lake Norman, NC, for each quarter since August 1987.
3-30 NOV
CHLOROPHYLL a (ug/1)
FEBRUARY 1.--*---2 0 5 01 12 10 8
6 4
2 0
12 r
- 10. MIXV'JGZOýNE 8 -.-.--
6 ------------
S 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 20 15 10 5
0 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 I----- 110 -- a-13 0I 16 14 12 10 8
6 4
2 0
87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 MAY I.-*2 0 ----a-5 0 MDONAG ZONE 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 i-80 w95 12 87 88 89-90 91 92 93 94 95-96-97 98-99 00.01 30O 25 20------ -------------------
10------0------
0 i
S0 i i I
I 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 16 14 12 10 8
6 4
2 0
30 25 20 15
- 10.
5 0I 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 YEARS 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 YEARS Figure 3-3. Phytoplankton chlorophyll a concentrations by location for samples collected in Lake Norman, NC, from August 1987 through November 2001.
3-31 1
I ------
. --I ----
I -------
CHLOROPHYLL a (ug/I)
AUGUST 1--+'--20 "-'-0-5 0]
12 MIXING ZONE 10-
1 8 ------------- ---------------- -- ----
.1.
4 2
0
.I 8788 89 90 91 92 9394-95 9697 9899 0 01 NOVEMBER 1-4-20 50 12
- 10.
_M[IANG ZONE -------------.....
8 6 --------------
24 2
0
- 11.
1 1
III 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 I--4-8 0 -R-9 5 is 14 12 10 8
6 41 2-87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 I-4--10 ---
13 0 14I 12
I 10 ----------
1 8 ----------- ---- -- --- -------- ---- ---- 1 4
0
-- - - -- - - -- - - -- - - -- - - -I I
10 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 35 20 15 10 I
87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 YEARS 14 12
- 10.
8 6
- 4.
2 0
87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 0--1 130 14 12
- 10.
8 6
4 2'
87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 1--- 15 9 ---
69 O0 25 2 0 -.
10 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 YEARS Figure 3-3 (continued).
3-32 I
I Illlll I
I iIII1[11111111 16,
o' j
bC. 20 5000 3004 2501 Zu 200' 150 100 50
- 0.
0 0o FEB MAY 4000 3500 3000 2500 w 2000
> 1500 1000 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 2001.
3-33 o CHLOROPHYCEAE 0 BACILLARIOPHYCEAE Dl CHRYSOPHYCEAE 2 CRYPTOPHYCEAE
- MYXOPHYCEAE Dl DINOPHYCEAE
- OTHERS LOC. 2 0 LOC. 2 0 NOV AUG
LOC. 5 0 r~flfo 4500 4000 3500
- 3000 2500 Z 2000 1500 1000 500-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 2001.
3-34 OCHLOROPHYCEAE I BACILLARIOPHYCEAE mCHRYSOPHYCEAE 1 CRYPTOPHYCEAE 0 MYXOPHYCEAE E DINOPHYCEAE MOTHERS H-.
LOC. 5 0 E
w 0 0, FEB MAY AUG NOV AOC-5M
LOC. 9.5 8000 7000 6000 E 5000 4000 z
S3000 FEB MAY AUG 5000 4500 4000 3500 S300 E
E W 250
,-J 0 200 0
150 100 0
0
)0 0
0 0o, 1
f) 4- -
FEB MAY AUG NOV 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 2001.
3-35 o CHLOROPHYCEAE 13 BACILLARIOPHYCEAE In CHRYSOPHYCEAE O CRYPTOPHYCEAE 13MYXOPHYCEAE 13 DINOPHYCEAE M OTHERS
LOC. 11.0 FEB MAY AUG NOV E
I' 3000 E
E W2500
>0 2000 0
1500 1000 -
500. F
_Z FEB MAY AUG NOV 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 2001 3-36 LOC. 11.0
LOC. 15 9 S5000 S4000 U 3000 2000 o
1000 FEB MAY AUG NOV 5000 4500 4000 3500 E
- i 3000 E
E
,J 2500 0 2000 S1500 1000 500 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 2001.
3-37
MYXOPHYCEAN INULA LAL NUI(MMN MYXOPHYCEAN INDEX LAKENRP..PUMANt 20" 19 18 17-HIGH 16
- 15.
14 INTERMEDIATE 1.3 1.22 10 09 08 07 06-lu 05-f 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 YEARS 1.20 x
t 100' 080 060 040 020 000 FEB MAY AUG NOV MONTH 15 14-1 1.;
0 0
0 0
0 0
0 0
0 0
3
.2
.1
- 0.
- 9.
8 7
6 5
4 215 2
5 95 LOCATIONS 11 Figure 3-9. Myxophycean index values by year (top), each season in 2000 (mid), and each location in Lake Norman, NC, during 2001.
3-38 0
159
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 2001) with historical data collected during the period 1987 2000.
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 9 February, 1 May, 6 August, and 5 November 2001. 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 2001 were compared with corresponding data from quarterly monitoring begun in August 1987.
A one way ANOVA was performed on epilimnetic total zooplankton densities by quarter.
This was followed by a Duncan's Multiple Range Test to determine which location means were significantly different.
4-1
RESULTS AND DISCUSSION Total Abundance During 2001, some degree of seasonal variability was observed in epilimnetic samples.
Maximum epilimnetic densities were highest in May at all but Location 9.5, where the maximum occurred in November (Table 4-1, Figure 4-1). The lowest epilimnetic densities at Locations 2.0, 5.0, and 15.9 occurred in February, while annual minimum densities at Locations 9.5 and 11.0 were observed in May and August, respectively. Epilimnetic densities ranged from a low of 25,860/m 3 at Location 15.9 in February, to a high of 450,300/m3 at this same location in May. This maximum was the highest zooplankton density yet observed during the Program. Maximum densities in the whole column samples were observed at Locations 2.0 and 15.9 in May, at Location 5.0 in August, and at Locations 9.5 and 11.0 in November. Minimum whole column densities were observed in February at all but Location 11.0, which had its lowest density in August.
Whole column densities ranged from 21,000/m 3 at Location 5.0 in February, to 236,300/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 2001, as has been the case in previous years (Duke Power Company 2001). This is related to the ability of zooplankton to orient vertically in the water column in response to physical and chemical gradients and the distribution of food sources, primarily phytoplankton, which are generally most abundant in the euphotic zone (Hutchinson 1967).
Although spatial distribution varied among locations from season to season, a general pattern of increasing values from Mixing Zone to Background Locations was observed during 2001 (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 February, when Location 11.0 demonstrated the significant maximum (Table 4-2).
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, 2000, 2001).
4-2
Historically, both seasonal and spatial variability among epilimnetic zooplankton densities had been much higher among Background Locations than among Mixing Zone locations. The uppermost location, 15.9, showed the greatest range of densities during 2001 (Table 4-1, Figures 4-2 and 4-3). Apparently epilimnetic zooplankton communities are more greatly influenced by environmental conditions at the up-lake locations than at the down-lake locations. Location 15.9 represents the transition zone between river and reservoir where populations would be expected to fluctuate due to the dynamic nature of this region of Lake Norman. At the locations nearest the dam (Locations 2.0 and 5.0), seasonal variations are dampened and the overall production would be lower due to the relative stability of this area (Thornton, et al. 1990). A similar trend was observed in the phytoplankton communities (Chapter 3).
Epilimnetic zooplankton densities during all but May of 2001 were within the seasonal ranges of those observed during previous years of the Program.
The mean epilimnetic zooplankton density at Location 15.9 in May 2001 was the highest value yet observed for this, or any location, during any previous quarter.
This high epilimnetic zooplankton concentration may have been a response to comparatively high phytoplankton concentrations in this part of the lake during May 2001 (Chapter 3). Although phytoplankton chlorophyll and density values were not the highest ever observed; phytoplankton have typically displayed very high densities at this location during May.
At the time of sampling, zooplankton had likely reached their peak after grazing on the algae, which could well have been in decline by that time.
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 Locations 2.0, 5.0, and 9.5 in 2000, at Location 11.0 in 1995, and at Location 15.9 in 2001. 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). Forty-six taxa were identified during 2001, as compared to fifty-one taxa recorded during 2000 (Duke Power Company 2001). No previously unreported taxa were identified in 2001.
Copepods were dominant most often during 2001 (Table 4-1, Figures 4-4 and 4-5). These microcrustaceans were dominant at Locations 9.5, and 15.9 (epilimnion) in February, at Locations 2.0, and 9.5 (whole column) in May, at all but Location 9.5 (epilimnion) in August, and at Location 11.0 (whole column) in November. Cladocerans were dominant at Locations 2.0 and 11.0 in February, Location 9.5 (epilimnion) in August, and Locations 2.0 and 5.0 in November. Rotifers dominated zooplankton at Locations 5.0 and 15.9 (whole column) in February, at Locations 5.0, 9.5 (epilimnion), 11.0, and 15.9 in May, and at Locations 5.0, 11.0 (epilimniion) and 15.9 in November. Microcrustaceans remained dominant in all areas of the lake during 2001. Compared with 2000, the percent composition of microcrustaceans had decreased in all areas of the lake in both epilimnetic and whole column samples (Figures 4-6 through 4-8). 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 2001, as has always been the case. Adult copepods seldom constituted more than 8%
of the total zooplankton density at any location. Tropocyclops and Epischura were the most important constituents of adult populations (Table 4-4).
Copepods tended to be more abundant, if not dominant, at Background Locations than at Mixing Zone Locations during 2001, and their densities peaked in May at both Mixing Zone and Background Locations. Copepods showed similar spatial and seasonal trends during 2000 (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 2001 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 in most February samples, and in all Mixing Zone samples in November. Daphnia and Bosminopsis were also important among cladocerans (Table 4-4).
During May, Daphnia dominated cladoceran populations at Locations 2.0, 5.0, and 9.5. Bosminopsis dominated cladoceran populations at Locations 9.5 (epilimnion), 11.0, and 15.9 in August. Bosminopsis expressed higher dominance during August 2001 as compared to August 2000.
Diaphanosoma, which was the dominant cladoceran in May 2000, was never dominant among cladoceran populations during 2001.
Similar patterns of Daphnia-Bosminopsis dominance have been observed in past years of the Program (Duke Power Company 2001).
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. In 2001, maximum cladoceran densities in the Mixing Zone occurred in February, while Background locations showed peaks in November. 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 2001 samples. This taxon dominated rotifer populations at Locations 2.0, 5.0 (whole column), 11.0 (whole column), and 15.9 in February. Keratella also dominated rotifer populations at Location 15.9 in August, and all but Location 2.0 in November (Table 4-4). Polyarthra was dominant in most May samples, as well as at Location 11.0 (epilimnion) in February, and Locations 2.0 and 5.0 in August.
Conochilus dominated rotifer populations at Location 9.5 in February, Location 11.0 (whole column) in May, and Location 2.0 in November. Asplanchna was the dominant rotifer in samples from Locations 9.5 and 11.0 in August, while Synchaeta was the dominant rotifer at 4-5
Location 5.0 (epilimnion) in February. All of these taxa have been identified as important constituents of rotifer populations, as well as zooplankton communities, in previous studies (Duke power Company 2001; 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, 2001). During 2001, peak densities at most locations were observed in May.
FUTURE STUDIES No changes are planned for the zooplankton portion of the Lake Norman Maintenance Monitoring Program in 2002 and 2003.
SUMMARY
Maximum epilimnetic zooplankton densities most often occurred in May, while minimum values were recorded in February (Locations 2.0, 5.0, and 15.9), and August (Locations 9.5 and 11.0). In most whole column samples, maximum densities occurred in May (Location 15.9), August (Locations 2.0 and 5.0), and November (Locations 9.5 and 11.0). Minimum values were most often observed in February. 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 2001, 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 2001 were within ranges of those observed in previous years. The epilimnetic density at Location 15.9 in May 2001 was the highest recorded during the Program, and may have represented an ongoing lag response to comparatively high phytoplankton standing crops uplake at that time.
One hundred and eight zooplankton taxa have been recorded from Lake Norman since the Program began in 1987 (forty-six were identified during 2001). No previously unreported taxa were identified during 2001.
4-6
Copepods dominated zooplankton standing crops most often during 2001. Overall relative abundance of copepods in 2001 had decreased slightly since 2000.
Cladocerans were occasionally dominant in February, August and November, while rotifers were dominant in most samples in August, and occasionally during all other quarters. Overall, the relative abundance of rotifers had increased since 2000. 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, and Epischura, 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. Daphnia and Bosminopsis dominated cladoceran populations in May and August. The most abundant rotifers observed in 2001, as in many previous years, were Keratella and Polyarthra, while Conochilus and Asplanchna were occasionally important among rotifer populations during each quarter.
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 2001, were likely due to environmental factors and appears not to be related to plant operations.
LITERATURE CITED Duke Power Company. 1976. McGuire Nuclear Station, Units 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.
4-7
Duke Power Company. 1991. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC.
Duke Power Company. 1992. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC.
Duke Power Company. 1993. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC.
Duke Power Company. 1994. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC.
Duke Power Company. 1995. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC.
Duke Power Company. 1996. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC.
Duke Power Company. 1997. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC.
Duke Power Company. 1998. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC.
Duke Power Company. 1999. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC.
Duke Power Company. 2000. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC.
Duke Power Company. 2001. Lake Norman Maintenance Summary. Duke Power Company, Charlotte, NC.
monitoring program: 1990 monitoring program: 1991 monitoring program: 1992 monitoring program: 1993 monitoring program: 1994 monitoring program: 1995 monitoring program: 1996 monitoring program: 1997 monitoring program: 1998 monitoring program:
1999 monitoring program: 2000 Hamme, R. E. 1982. Zooplankton, In J. E. Hogan and W. D. Adair (eds.). Lake Norman Summary, Technical Report DUKEPWR/82-02. p. 323-353, Duke Power Company, Charlotte, NC. 460 p.
Hutchinson, G. E. 1967. A Treatise on Limnology. Vol. II. Introduction to Lake Biology and the Limnoplankton. John Wiley and Sons, Inc. N. Y. 1115 pp.
Menhinick, E. F. and L. D. Jensen. 1974. Plankton populations. In L. D. Jensen (ed.).
Environmental responses to thermal discharges from Marshall Steam Station, Lake Norman, North Carolina. Electric Power Research Institute, Cooling Water Discharge Research Project (RP-49) Report No. 11., p. 120-138, Johns Hopkins University, Baltimore, MD 235 p.
4-8
Thornton, K. W., B. L. Kimmel, F. E. Payne. 1990. Reservoir Limnology. John Wiley and Sons, Inc. New York, NY.
4-9
Table 4-1. Total zooplankton densities (no. X 1000/m 3), densities of major zooplankton taxonomic groups, and percent composition (in parentheses) of major taxa in 1Om to surface (10-S) and bottom to surface (B-S) net tow samples collected from Lake Norman in February, May, August, and November 2001.
Taxon COPEPODA CLADOCERA ROTIFERA TOTAL COPEPODA CLADOCERA ROTIFERA TOTAL 2.0 10.6 (24.6) 17.6 (41.0) 14.8 (34.4) 43.0 4.4 (14.3) 13.6 (43.7) 13.1 (42.1) 31.1 5.0 5.0 (17.4) 8.4 (29.3) 15.2 (53.3) 28.6 4.2 (19.9) 8.2 (38.8) 8.7 (41.3) 21.0 Locations 9.5 28.3 (46.7) 24.8 (40.9) 7.5 (12.4) 60.5 17.4 (48.7) 10.8 (30.2) 7.5 (21.1) 35.7 11.0 24.6 (40.2) 36.0 (58.7) 0.7 (1.1) 15.9 16..3 (63.0) 9.5 (36.7) 7.6 (29.4) 61.3 33.4 22.8 (39.0) 27.6 (47.4) 8.0 (13.6) 58.3 7.8 (36.1) 4.5 (20.7) 9.3 (43.1) 21.7 10-S COPEPODA CLADOCERA ROTIFERA TOTAL COPEPODA CLADOCERA ROTIFERA TOTAL 41.9 (46.6) 7.7 (8.5) 40.4 (44.9) 90.0 21.7 (53.2) 3.6 (8.9) 15.5 (38.0) 40.8 42.2 (42.5) 9.6 (10.3) 47.4 (47.8) 99.2 24.8 (42.5) 5.3 (9.2) 28.2 (48.3) 58.4 15.9 (14.0) 9.6 (8.4) 92.2 (81.5) 66.3 (39.9) 27.0 (15.9) 76.8 (45.2) 101.7 (22.6) 10.6 (2.3) 338.0 (75.1) 117.7 170.1 450.3 26.3 (61.4) 8.3 (19.4) 8.2 (19.2) 42.9 34.5 (42.8) 8.8 (10.9) 37.4 (46.4) 53.0 (22.4) 5.8 (2.4) 183.0 (77.4) 80.7 241.7 4-10 Date 2/9/01 Sample Type 10-S B-S depth (m) of tow for each Location 2.0=30 5.0=18 9.5=20 11.0=25 15.9=21 5/1/01 B-S depth (m) of tow for each Location 2.0=30 5.0=20 9.5=20 11.0=24 15.9=20
Table 4-1 (continued).
Sample 10-S 2.0 33.1 (62.3) 13.2 (24.9) 6.8 (12.8) 53.2 22.3 (62.4) 10.2 (28.4) 3.3 (9.2) 35.8 5.0 29.0 (42.5) 10.4 (15.3) 28.8 (42.2) 68.3 33.7 (54.5) 7.7 (12.4) 20.5 (33.1) 61.9 Locations 9.5 18.3 (36.7) 19.8 (39.6) 11.8 (23.7)
Taxon COPEPODA CLADOCERA ROTIFERA TOTAL COPEPODA CLADOCERA ROTIFERA TOTAL 11.0 35.4 (64.6) 15.0 (27.4) 4.4 (8.0) 15.9 58.3 (53.7) 22.2 (20.4) 28.1 (25.9) 54.8 108.6 33.9 (70.4) 10.0 (20.8) 4.2 (8.6) 55.2 (53.1) 25.5 (24.5) 23.2 (22.4) 40.4 48.2*
103.9 10-S COPEPODA CLADOCERA ROTWFERA TOTAL 48.4 B-S depth (m) of tow COPEPODA 13.1 for each (39.6)
Location CLADOCERA 18.9 2.0=28 (57.1) 5.0=17 ROTIFERA 1.1 9.5=19 (3.2) 11.0=24 15.9=19 TOTAL 33.1
- = Chaoborus observed in sample (110/m 3, 0.2%).
42.9 132.8 14.4 (38.3) 20.1 (53.3) 3.2 (8.4) 37.6 19.6 (21.3) 13.5 (14.6) 59.2 (64.1) 92.3 87.2 127.2 42.1 (48.1) 16.2 (18.5) 29.2 (33.4) 87.6 27.2 (31.3) 13.2 (15.2) 46.5 (53.5) 86.9 Date 8/6/01 50.0 20.2 (50.0) 16.7 (41.4) 3.4 (8.6)
B-S depth (m) of tow for each Location 2.0=30 5.0=18 9.5=20 11.0=24 15.9=20 11/5/01 15.4 (31.9) 28.3 (58.6) 4.6 (9.6) 12.6 (29.3) 23.8 (55.6) 6.4 (15.0) 22.6 (17.1) 9.9 (7.4) 100.2 (75.5) 34.6 (39.6) 10.6 (12.1) 42.1 (48.2) 57.2 (45.0) 12.1 (9.5) 57.8 (45.4) 4-11
Table 4-2. Duncan's Multiple Range Test on epilimnetic zooplankton densities (no. X 1000/m 3) in Lake Norman, NC during 2001.
5.0 15.9 2.0 9.5 11.0 28.6 33.4 43.0 60.5 61.3 2.0 5.0 9.5 11.0 90.0 99.2 117.7 170.1 15.9 450.3 9.5 2.0 11.0 5.0 15.9 50.0 53.2 54.8 68.3 108.6 5.0 2.0 11.0 15.9 9.5 42.9 48.4 87.2 127.2 132.8 4-12 February Location Mean Location Mean May August Location Mean November Location Mean
Table 4-3. Zooplankton taxa identified from samples collected quarterly on Lake Norman from 1988 through 2001.
TAXON 88 89 90 91 92 93 94 95 96 97 98 99 00 01 COPEPODA Cyclops thomasi Forbes X
X X
X X
X X X X C. vernalis Fischer X
C. spp. 0. F. Muller X
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
XX X
X X
X X
D. pallidus Herick X
X X
X X X X
D. reighardi Marsh I -
x D. spp. Marsh x
_XX x
xX x x
xX_ xxx Epishurafluviatilis Herrick X X XX X X X Ergasilus spp.
X Eucyclops agilis (Koch)
X Mesocyclops edax (S. A. Forbes)
X x
X1 XX X
X X
X X X M spp. Sars X
X X
X XX I
XX X
Tropocyclops prasinus (Fischer)
X X
X X XX XX X T. spp.
X X
X X
X X
X X x X
X Calanoid copepodites X X XX X X X X X X X XX X
Cyclopoid copepodites X X X X X X X X XX X X X X Harpacticoidea X X X
Nauplii X 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 I Bosmina longirostris (0. F. M.)
X X
X X
X x I x
x B. spp. Baird X
X X
x XXXxXXxX XX Bosminopsididtersi Richard X
x XIX X XIX X
XIX X
XIX X
Ceriodaphnia lacustris Birge X
X X
X X
X C. spp. Dana X
X X
X X
X X X XIX X
X X X Chydorusspp. Leach X
X X X
X X
X X
Daphnia ambigua Scourfield X
X X
X X
X X
X D. catawba Coker X
X X
D. galeata Sars X
D. laevis Birge I
X D. longiremis Sars IXI X I XX D. lumholziSars X
X X
XX X
X X
D. mendotae (Sars) Birge X
XXX D. parvulaFordyce X
X X
x X
X X
X X
X D. pidex (de Geer)
X X
4-13
nie 2 of4 I
4U1J tJ 11LL1U%,
TAXON 88 8990 91 9293 94 95 96 97 98 99 00 01 CLADOCERA (continued)-----------------
D. pulicaria Sars D. retrocurva Forbes XX XiX x_
D. schodleri Sars
___X D. spp. Mullen x
xXXX XX XX xxxxx x
xxx Diaphanosoma brachyurum (Lievin)
X Nx x x x XXXXXXXX D.
spp. Fischer x___ ____
x_
x_
x_
x_
x_
x_
Eubosmina spp. (Baird)
X II_
Holopedium anzazonicunz Stinge.
xx X
X X
XXX X
H. gibberum Zaddach X
X X
H. spp. Stingelin XX
_ IXX XX X
X X Ilyocrypttus sordidus (Lieven)
X X
xII L spinifer Herrick Ix I. spp. Sars x
x x
x XX-x Latona setifera (0 F. Muller)
X__
Leptodora kindtii (Focke)
XX x X
XX X
xX xXX x
Leydigia spp. Freyberg I
X xX Moina spp. Baird x_
I__
Sida crystallina 0. F. Muller X
X X X Sitnocephalus expinosus I
Sitnocephalus spp. Schodler Ix ROTIFERA Anuraeopsis spp. Lauterbomne x
x x
XXX xx____
Asplanchna brightwelli Gosse X
___X A. priodonta Gosse X XX A. spp. Gosse XIX X
XX X
X x
I X X Brachionuis caudata Barr. & Daday X
X X I
I B. havanensis Rousselet X
X X
B.-patulus 0. F. Muller x
x x
x B. spp. Pallas x
X X
x x
C/iromogaster ovalis (Bergendel)-------------------X xXX-x C. spp. Lauterborne x
xxxX IX xXxxII Collotheca balatonica Harring---------------X x I X
x x
C. muttabilis (Hudson)
XX X X X C. spp. Harring x
XX XXX I xxxxxxxxxx X X Colurella spp. Bory de St. Vincent X
C~onochiloides dossuarius Hudson xxxx C spp. Hlava xX X XX X
XX x
X Conochiluis unicornis (Rousselet)
X X
X I_
Ix XXXx 4-14
nape 3 of 4 TAXON 88 89 90 91 92 93 94 95 96 97 98 99 00 01 ROTIFER (continued)
C. spp. Hlava x
xX xx x
xx x
x Filinia spp. Bory de St. Vincent XX X
Gastropus stylifer Inmhof I
x xx x
G. spp. Imhof xX XX XX X
x xxxxxxx Hexarthra mira Hudson XXX
___x H. spp. Schmada XXX XXXX X1 Kellicottia bostoniensis (Rousselet)
X X
X X
X XXXXX X
K. ion gispina Kellicott I
IIX XXX X
K spp.Rousselet.
xXX xxxx x
xxx X1 I
X Keratella cochlearis------------------------X I
_x _
K.ltarocephala Myers N
N N
N xx x
K. spp. Bory de St. Vincent
___xx x
Lecanie spp. Nitzsch xX x x I_
XI x_
XX xxx Macrochaetus sub guadratus Perty I
I I
x x
M. spp. Perty x_ x___xxx Monostyla stenroosi (Meissener)
X I
M.spp. Ehrenberg X
X X
xX x X
I Notholca spp. Gosse X
X X
I Piceosoma hudsonii Brauer I
X X X X X XX xX P. truncatum (Levander) xX x x
XXx x
xX X
P. spp. Herrick X
X XXX X
X x
X Polyarthra euryptera (Weirzeij ski)
X X X xX P. major Burckhart X
x x_
P. vulgaris Carlin-X XX X-x xx P. spp. Ehrenberg x
x x
x-_____xI x
x Pompholyx spp. Gosse---------------___
x Ptygura libra Meyers XX P. spp. Ehrenberg x
x Synchaeta spp. Ehrenberg X
X X
X X
X X X X
X X XX X Trichocerca capuicina (Weireij ski)
X X
X X
X X
XX T. cylindrica (llmho) x x x X XX XX X
T. ion giseta Schrank----------------------
T. multicriniis Kellicott)
X X X T. porcellus (Gosse)------------------____
x T. pusilla Jennings---------------------____
T. similis Lamnark T spp. Lamnark XXX X
X XXX ll X X Trichotria spp. Bory de St. Vincent
___]
I I
IX 4-15
ne4 of 4 TAXON 88 89 90 91 92 93 94 95 96 97 98 99 00 01 ROTIFERA (continued)
Unidentified Bdelloida XX X X X X
X X X Unidentified Rotifera X XX X X X X X
X X INSECTA Chaoborus spp. Lichtenstein X
X X
XXX 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 2001.
FEBRUARY MAY AUGUST NOVEMBER COPEPODA EPILIMNION 2.0 Epischura (6.0)
Epischura (4.7)
Tropocyclops (4.4)*
Tropocyclops (8.9)*
5.0 Tropocyclops (4.4)
Epischura (7.4)
Tropocyclops (6.7)*
Tropocyclops (8.5) 9.5 Epischura (19.8)
Epischura (6.6)
Tropocyclops (6.8)
Epischura (5.4) 11.0 Cyclops (1.6)*
Epishura (8.0)
Tropocyclops (4.3)
Tropocyclops (7.6) 15.9 Epischura (1.2)*
Epischura (3.3)
Tropocyclops (5.7)*
Tropocyclops (2.5)*
COPEPODA WHOLE COLUMN 2.0 Epischura (10.9)
Epischura (5.0)
Tropocyclops (4.3)
Epischura (6.8) 5.0 Mesocyclops (4.8)
Epischura (3.5)
Tropocyclops (4.9)
Tropocyclops (4.4) 9.5 Epischuria (8.6)
Epischura (4.1)
Tropocyclops (3.9)
Tropocyclops (11.3) 11.0 Epischuria (2.5)
Epischra (7.0)
Tropocyclops (5.6)
Diaptomus (9.0) 15.9 Cyclops (7.4)
Epischras (2.3)
Tropocyclops (4.0)
Tropocyclops (3.9)
CLADOCERA EPILIMNION 2.0 Bosmina (100.0)
Daphnia (53.2)
Bosmina (78.0)
Bosinina (94.2) 5.0 Bosmina (100.0)
Daphnia (36.8)
Bosmina (64.8)
Bosmina (98.4) 9.5 Bosmina (100.0)
Daphnia (58.1)
Bosminopsis (55.7)
Bosmina (100.0) 11.0 Bosmina (95.2)
Bosmina (36.9)
Bosminopsis (63.9)
Bosmina (85.9) 15.9 Bosmina (93.9)
Bosmina (70.3)
Bosminopsis (72.4)
Bosmina (94.9)
CLADOCERA WHOLE COLUMN 2.0 Bosmina (98.4)
Daphnia (48.3)
Bosmina (83.3)
Bosmina (85.2) 5.0 Bosmina (97.5)
Daphnia (43.6)
Bosmina (54.8)
Bosmina (93 2) 9.5 Bosmina (100.0)
Daphnia (61.7)
Bosimna (48.4)
Bosmina (98.5) 11.0 Bosmina (95.4)
Bosmina (41.4)
Bosminopsis (62.7)
Bosinina (63.1) 15.9 Bosmina (93.6)
Bosmina (68.3)
Bosminopsis (57.1)
Bosmina (86.0) 4-17
I auklt An
~JA~
,A~
nnn-I nmwrri 1PIP"I*I T T ARY" ROTIFERA EPILIMNION 2.0 Keratella (27.8)
Polyarthra (57.8)
Polyarthra (100.0)
Conochilus (44.1) 5.0 Synchaeta (33.6)
Plyarthra (56.2)
Polyarthra (98.5)
Keratella (63.5) 9.5 Conochilus (44.9)
Polyarthra (49.7)
Asplanchna (75.2)
Keratella (59.6) 11.0 Polyarthra (45.3)
Polyarthra (51.6)
Asplanchna (26.3)
Keratella (64.7) 15.9 Keratella (28.1)
Polyarthra (52.7)
Keratella (66.7)
Keratella (55.1)
ROTIFERA WHOLE COLUMN 2.0 Keratella (63.1)
Polyarthra (53.8)
Polyarthra (67.9)
Conochilus (44.4) 5.0 Keratella (37.5)
Polyarthra (56.5)
Polyarthra (98.5)
Keratella (33.7) 9.5 Conochilus (34.7)
Polyarthra (46.3)
Asplanchna (57.7)
Keratella (56.6) 11.0 Keratella (49.3)
Conochilus (43.8)
Asplanchna (26.6)
Keratella (65.0) 15.9 Keratella (45.7)
Polyarthra (51.1)
Keratella (52.1)
Keratella (48.9)
- = Only adults present in samples.
4-18 AUG.UST I
fU V IMIh*K MAY
Figure 4-1. Total zooplankton density by location for samples collected in Lake Norman, NC, in 2001.
4-19 1Om TO SURFACE TOWS 500 4 5 00 -.-.-
3 5 0 -5 0
3000 -.-.----------------------------------------------------------------------------------------------------.--.
C, x
2 0 00 0
z 0
50 5
20 50 95 11.0 159 BOTTOM TO SURFACE TOWS -FEB -U-MAY AUG -- X-NOV]
2401 220 ------------------------------------------------------------------------------------------------------------
180 - ----------------------------------------------------------------------------------------------------------
160 ----------------------------------------------------------------------- ------------
60 140 ---------------------------------
40 1
.40*
2 0 - --------------------
0 I i
I I
20 50 95 110 159 LOCATIONS
MIXING ZONE FFRRI IARY - 20 --
O--5 0
-A l..........................................................
l..........................................................
87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 BACKGOUND 250 225 200 175 150 125 100
- 75.
50 25 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 LOCATIONS 450 400 350
- 300 250*
200" 150" 100 50 0-87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 YEARS Figure 4-2. Total zooplankton densities by location for epilimnetic samples collected in Lake Norman, NC, in February and May of 1988 through 2001.
4-20 MAY 225 200 175 150 125 100.
75.
x z
FEBRUARY
,an -
iii!-iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
MIXING ZONE 250 225 200 175
- 150 c125 100 S75
- 50.
25, 87u 99l19 3949 69 89 00 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 225 200 175 150 125 100 75 50 25 0
87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 BACKGROUND LOCATIONS 400 350
- 300 250 200 150 z
LU 100 501 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 YEARS Figure 4-3. Total zooplankton densities by location for epilimnetic samples collected in Lake Norman, NC, in August and November of 1987 through 2001.
4-21 AUGUST S.
..1-4 2 0 - -* -- 5 01 ---------------------
S.................................................
S.................................................
S..
NOVEMBER 1-4--95 ----
110 -'-- 15 9 I
LOCATIONS I
iCOPEPODS
ýCLADOCERANS MýRROTIFERS Figure 4-4. Zooplankton community composition by month for epilimnetic samples collected in Lake Norman, NC, in 2001.
4-22
Figure 4-5. Zooplankton composition by quarter for epimlimnetic samples collected in Lake Norman, NC, from 1990 through 2001.
4-23
LAKE-WIDE: EPILIMNION Figure 4-6. Annual lake-wide percent composition of major zooplankton taxonomic groups from 1988 through 2001.
4-24 1"1COPEPODS ;CLADOCERANS EROTIFERS 100%
90%
80%
z o 70%
o 60%
o 50%
I.-
z 40%
w 30%
0 20%
10%
0%
1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 YEARS LAKE-WIDE: WHOLE COLUMN 11COPEPODS 13CLADOCERANS U ROTIFERS 100%
90%--
80%
z 0
70%
I C,)
o 60%
0 50%
o 40%
I.
Z 40%
w 30%
20%
10%
0%-
1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 YEARS
MIXING ZONE (LOCATIONS 2.0 + 5.0): EPILIMNION Figure 4-7. Annual percent composition of major zooplankton taxonomic groups from Mixing Zone Locations: 1988 through 2001.
4-25 IOCOPEPODS 13CLADOCERANS EROTIFERS 100%
90% "
80%
z o
70%
o 60%
- 0.
IL 0
40%
2 30%
0 10%
1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 YEAR MIXING ZONE (LOCATIONS 2 0 + 5 0): WHOLE COLUMN IOCOPEPODS 1CLADOCERANS EROTIFERS]
W 0
_0 I-0 LU uJ 0.
1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 YEAR
BACKGROUND (LOCATIONS 9.5 + 11.0 + 15.9): EPILIMNION Figure 4-8. Annual percent composition of major zooplankton taxonomic groups from Background Locations: 1988 through 2001.
4-26 n COPEPODS OCLADOCERANS EROTIFERS 100%
90%*
80%
z 0_
70%
o 60%
- 0.
o 50%
U I
z 40%
ul um 30%
20%.
10%
0%
1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 YEAR BACKGROUND (LOCATIONS 9.5 + 11.0 + 15.9). WHOLE COLUMN FE-C OPEPODS 13CLADOCERANS EROTIFERS 100%
90% -
80%-
z 0270%--
0 60%-
0 50% -
UJ 2 0%-
10%
10%
1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 YEAR
CHAPTER 5 FISHERIES INTRODUCTION In accordance with the NPDES permit for McGuire Nuclear Station (MNS), monitoring of specific fish population parameters was continued during 2001. The components of the 2001 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. Continue to support the bioenergetics study on Lake Norman, to include spring, summer and fall hydroacoustic and purse seine samples and fall gill net samples to enumerate and describe species composition of the lake's shad and herring populations;
- 5. Revise annual, spring shoreline electrofishing program to be conducted every 2 years, beginning spring 1999, with next sample scheduled for spring 2001;
- 6. Continue to 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 conducted on March 4 (MNS mixing zone), April 5 (Marshall Steam Station mixing zone) and April 16 (mid-lake reference area).
The locations sampled were the same locations sampled during 1999; 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 5-1
Steam Station (MSS) mixing 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 5 through September 14, 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 2001, gill net sampling for striped bass condition was conducted during the winter (January 30 - February 1) and fall (November 6 - 9). 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 2001 are presented in a separate report included as Attachment 1.
During 2001, the gill netting for-shad and alewives" was conducted by the NCWRC to evaluate the taxa composition and size distribution of Lake Norman forage species. As in previous years, netting was conducted in creel zones 3, 4, and 5 (Figure 5-1). Since the sampling was conducted by the NCWRC, the results of that sampling are not presented in this report.
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 923 fish were collected, weighing a total of 62.60 kg and representing 19 taxa (Table 5-2
5-1). Although the total number of fish collected during 2001 (923 fish) was less than half the number collected during 2000 (2,175 fish), the total biomass during 2001 (62.60 kg) was more than 1.5 times higher than during 2000 (38.13 kg). The total number of taxa collected during 2001 (19 taxa) was slightly higher than during 2000 (17 taxa). In addition to the typical historical species collected from the MNS mixing zone area, one bowfin, one walleye and six spotted bass were collected during 2001.
Spotted bass were introduced into the reservoir by fishermen and were collected for the first time during 2001. The abundance and distribution of spotted bass is apparently increasing, as evidenced by the collection of this species from three of the ten sample transects.
The substantially lower total number of fish collected from the MNS mixing zone area during 2001 is primarily attributable to lower catches of redbreast sunfish and bluegill. These lower catches may be reflective of increased predation on these species due to the increasing abundance of blue and flathead catfish in lower Lake Norman. The higher biomass during 2001 is primarily attributable to higher largemouth bass biomass and to the collection of 14 common carp, a species not collected during 2000. Individual transect catches ranged from a low of 13 fish to a high of 156 fish.
The total catch from the reference area was 1,951 fish, weighing 81.07 kg and representing 17 taxa (Table 5-2). During 2001, the total number of taxa was only slightly higher than during 2000 (16 taxa). The total number of fish collected during 2001 was about 48 % higher than the number collected during 2000 (1,314 fish), however, the biomass of fish collected during 2001 was slightly lower than during 2000 (89.28 kg). Individual transect catches ranged from 84 to 339 fish.
The total catch from the MSS mixing zone area was 1,946 fish, weighing 118.85 kg and representing 19 taxa (Table 5-3). Unlike the previous two years, during 2001, the MSS mixing zone area did not yield the highest number of fish, although the catch was only slightly less than that for the highest area, the reference area (1,951 fish). The total biomass from this area was substantially higher than that for the MNS mixing zone area (62.60 kg) and the reference area (81.07 kg).
Compared to the 2000 sample, the total number of fish collected from the MSS mixing zone area during 2001 was about 28 % lower than during 2000 (2,496 fish), however, the total biomass was about 40 % higher than during 2000 (84.93 kg). The number of taxa collected during 2001 (19 taxa) was slightly higher than during 2000 (17 taxa). Individual transect 5-3
catches ranged from 79 fish to 329 fish. Similar to the 2000 sample, the 2001 sample included the collection of a single rainbow trout.
The condition of Lake Norman striped bass, as indicated by relative weight (Wr), varied by season. During the winter, 96 % of the 107 striped bass collected had Wr values of >_.80, and 42 % had Wr values >_.90 (Figure 5-2). The lowest Wr recorded during the winter was
.76. Three fish had Wr values > 1.00, with the highest Wr value being 1.03.
The Wr values for striped bass collected during the fall indicated substantially poorer body condition than was present during the winter (Figure 5-3). During the fall, only 38 % of the 82 striped bass collected had Wr values _>.80, and only 6 % had Wr values _.90. The lowest Wr value during the fall was.63, while the highest Wr was.96. The poorer body condition during the fall is consistent with striped bass condition decreases noted during previous years, however, the fall 2001 sample indicates that the degree of body condition decrease during 2001 was more dramatic than in previous years.
The poorer condition of Lake Norman striped bass during the fall 2001 is probably related to the additional summer stress resulting from the extended drought. Additionally, forage availability may also be a factor in the poorer condition, as increasing populations of blue and flathead catfish over the past several years may be resulting in increased competition for forage.
General monitoring of Lake Norman and specific monitoring of the MNS mixing zone for striped bass mortalities during the summer of 2001, yielded nine mortalities within the mixing zone and nine mortalities in the main channel outside the mixing zone. The 18 observed mortalities ranged in size from 455 mm to 670 mm. Specific observations by date were:
5-4
DATE LOCATION LENGTH (mm)
NUMBER July 5 Vicinity of MNS Intake 491 1
Vicinity of Channel Marker 21 522 1
August 3 Vicinity of MNS Intake 653 1
August 8 Vicinity of Channel Marker 6 510 1
Vicinity of Channel Marker D 5 535 1
Vicinity of Channel Marker D 8 534 1
August 17 Vicinity of MNS Intake 534 1
Vicinity of Cowans Ford Dam 485 2
521 Vicinity of Channel Marker 1 489 3
491 526 August 22 Vicinity of Channel Marker D 1 553 2
554 August 27 Vicinity of Cowans Ford Dam 670 1
Vicinity of Channel Marker D 2 476 1
Vicinity of Channel Marker D 7 455 1
Vicinity of Channel Marker 14 530 1
Results of the purse seine and hydroacoustics sampling on Lake presented in a separate report included as Attachment 1.
Norman during 2001 are 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 2003.
5-5
"* Continue the late summer purse seine sample and fall small mesh gill net sample to monitor changes in Lake Norman forage population.
"* 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 2001. General monitoring of Lake Norman and specific monitoring of the MNS mixing zone for striped bass mortalities during the summer of 2001, yielded nine mortalities within the mixing zone and nine 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 mid-lake reference area, followed by the MSS mixing zone, and MNS mixing zone areas, respectively. The highest total catch gravimetrically was from the MSS mixing zone area, followed by the mid-lake reference and MNS mixing zone areas, respectively. The total number of taxa collected was the same for the MSS and MNS mixing zone areas and slightly lower for the mid-lake reference area.
The condition of Lake Norman striped bass, as indicated by relative weight (Wr), varied by season. Striped bass condition was substantially better during the winter than during the fall.
During the winter, 96 % of the striped bass collected had Wr values _.80, while only 38 % of the fall striped bass had Wr values Ž_.80. The poorer body condition during the fall is consistent with striped bass condition decreases noted during previous years, however, the 5-6
degree of body condition decrease during 2001 was more dramatic than in previous years and is probably related to the extended drought.
During June 2001, forage fish densities in the six zones of Lake Norman ranged from 2,401 to 9,841 fish/ha. No trend in forage fish abundance was evident. The estimated population was approximately 74 million fish. Purse seine sampling indicated that these fish were 17.97% threadfin shad, 81.92% alewives, and 0.11% gizzard shad.
September 2001 forage fish densities ranged from a low of 3,173 fish/ha (Zone 6) to a high of 11,513 fish/ha (Zone 2). The estimated forage population was approximately 78 million fish.
Purse seine sampling indicated that these fish were 76.47% threadfin shad, 23.52% alewives, and 0.01% gizzard shad.
During December 2001, forage fish densities in the six zones of Lake Norman ranged from 1,451 to 8,647 fish/ha. There appeared to be fewer fish in the downlake zones.
The estimated forage population was approximately 47 million fish.
Purse seine sampling indicated that these fish were 82.66% threadfin shad, 16.46% alewives and 0.88% gizzard shad.
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 continues to warrant close monitoring in the future is the composition of forage populations. The introduction of alewives by fishermen over the past several years appears to be resulting in the establishment of a substantial alewife population and could have a dramatic impact on lake-wide forage populations and game species.
5-7
C C
Table 5-1. Numbers and biomass of fish collected from electrofishing ten 300-m transects in the MINS mixing zone of Lake Norman during March 2001.
Species Transect 1
2 3
4 5
6 7
8 9
10 ALL N
KG N
KG N
KG N
KG N
KG N
KG N
KG N
KG N
KG N
KG N
KG Longnose gar Bowfin Gizzard shad Threadfin shad Greenfin shiner Whitefin shiner Common carp Spottail shiner Channel catfish White bass Redbreast sunfish Green sunfish Warmouth Bluegill Redear sunfish Hybrid sunfish Spotted bass Largemouth bass Walleye 1
1.697 2
1.183 9
3420 2
1085 3
1065 5
0.011 2
0003 2
0005 1 0001 12 0.035 4
0005 33 0082 4 0010 42 0042 4
4.892 1
1.012 1 2250 1
0.004 2
0.012 1 0.006 1 0640 2 0.614 25 0.337 23 0281 4
0033 6
0.104 5 0090 71 0519 49 0.545 53 0395 69 0540 4 0023 18 0.662 18 0.516 33 0.565 21 0.455 6
0.337 3
0029 8
0.165 6
0.100 3 0058 1
0.171 2
0.135 16 3.920 13 5.830 6
1.466 6
1.402 1 1.330 1 0535 1
2.165 1
2.165 1
1.697 17 7.288 5
2 0.004 6
0.009 13 57 0048 4
0011 1 0004 64 0.118 48 0.123 269 1 2.180 1 2365 3
4685 3
3.780 14 1 0004 1 0006 21 0.101 27 1 0430 2
0.510 4
2 2
0015 3
0055 8
0.185 1 0033 2
0014 74 7
0.009 7
1 0.005 3
0.011 9
1 0006 3 0029 5
0.039 16 0.125 4
0017 275 1 0002 1 0016 10 0.310 2
0.016 7
1.020 117 1 0.007 5
0.125 1
0.007 27 3
1.345 6
1 1.175 5
1.057 3
0.813 4
1005 54 0.011 0.022 0478 21.164 0.133 1.580 0614 1 057 0 009 0.106 2.238 3.899 0.491 1.651 16668 1
1.330 00
(
All 156 13.452 127 11.909 146 3833 115 7.854 61 1.034 70 0517 13 3466 38 4.629 95 5811 102 10096 923 62.601
C C
C 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 April 2001.
Species Gizzard shad Greenfin shiner Whitefin shiner Common carp Spottail shiner Channel catfish Flathead catfish White bass Redbreast sunfish Warmouth Bluegill Redear sunfish Hybrid sunfish Largemouth bass Black crappie Tessellated darter Transect 1
2 3
4 5
6 7
8 9
10 ALL N
KG N
KG N
KG N
KG N
KG N
KG N
KG N
KG N
KG N
KG N
KG 1 0541 2
0.008 138 0.341 1 1.580 22 0084 12 0216 6
0.058 114 0648 27 0761 2
0016 13 4.239 1 0311 4
1 3
0.006 1
3 0.134 82 1
1.926 3
7 1
0.420 2
2 9
0.157 3
0.153 57 0.343 7
0.100 1 0.008 7
1.472 29 2
50 4
2 18 0 381 0.003 0.249 4.904 0 029 0.433 2.413 0 680 0.021 0.643 0.212 0 063 4.946 21 3
71 1
27 1
14 1
14 10 2
8 8 279 0.008 0.160 1.572 0.112 0.577 0.467 0.001 0.076 0 638 0.095 2.852 1
21 2
1 1
29 7
80 18 9
18 0.002 0052 114 0.322 5 603 0003 115 0555 0.265 2
0444 0357 7
0102 0.400 1 0006 0624 17 0.145 0298 2
0513 0238 1 0044 4.392 3
0.120 3
3 0.001 3
0.004 73 5.107 I
1 0474 0.005 7
0011 2 0003 0.200 86 0.145 41 0.129 1
1.214 0.007 39 0.156 4
0014 6
21 1
0414 1
0202 1 0202 5
0209 16 5
43 0.475 122 26 0661 13 2
0229 6
18 7.020 5
1 0.259 1 0001 0 357 0 038 0.708 0.447 0 286 0 590 13 0580 1
0011 59 0.602 4 0094 8
0220 4
0338 1 0.310 9 0240 3
0011 15 0.084 2 0028 2 0071 1 0.541 2
0.540 14
- 5.
1*
1 0001 24 9675 23 0047 70 1.736 12 21.906 16 0.960 10 2.957 2
2.413 1
0.310 43 3365 29 0699 71 4.348 13 3.752 35 1.270 95 26510 4
1.110 2
0002 Yellow perch 1
0009 1
0009 All 339 8803 132 4.719 203 14 977 173 14.837 187 12 234 263 2252 102 14.388 246 2841 222 2.359 84 3659 1,951 81.069
C 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 2001.
Species Gizzard shad Threadfin shad Greenfin shiner Whitefin shiner Common carp Spottail shiner Shorthead redhorse Channel catfish Flathead catfish Rainbow trout White perch Striped bass Redbreast sunfish Warmouth Bluegill Redear sunfish Hybnd sunfish Largemouth bass Transect 1
2 3
4 5
6 7
8 9
10 ALL N
KG N
KG N
KG N
KG N
KG N
KG N
KG N
KG N
KG N
KG N
KG 57 0.168 1
1.170 21 0097 3 0.960 1 0675 48 0.167 3
4.730 43 0201 1 0345 68 2
12 0.235 3.910 0 064 2
0.975 1 0.311 5 0015 46 0.226 5
0014 31 0.159 8 0033 1 0004 48 0183 71 0252 9 15270 1
1.850 23 0.122 49 0.177 20 0.055 7 13350 7
0036 22 0.138 1
0.268 2
0609 1
1.100 1 0860 1
0.154 1 0.036 3
0.144 11 1
26 0.260 11 0.208 53 8 0.365 18 0.780 15 1
10 2.597 8 2.920 22 0.258 27 0.377 4
0.010 0015 3
0019 1
0.001 0.570 144 1007 152 0.800 0.725 8
0.254 24 0.397 0012 8
0087 6
0068 7.661 8
1.385 11 4.925 1
0002 45 0.740 57 3
0.025 1
4 0081 96 0.730 190 6
0290 37 1.100 7
1 0.085 6
0.175 5
7 2.159 15 1.570 13 0.770 0.014 1.346 0245 0.147 2488 9
0.183 1
0.007 21 0.160 4
0149 4
0.171 18 3669 95 0.245 3
5705 57 0260 5
49 2
18 2
0830 1
1 0028 1
0965 5
0265 16 1
4 16000 70 7
0.330 13 3
13 3.151 12 1
0.311
.1 0.241 5
0.014 p5 1.674 6
45985
.6 0922 1
0345 1
4.742 2
1.535 1
0028 1
0.154 1
0.965 3
2.785 0
0081 1
21.162 4
4.635 31 0.745 5
32.525 Tessellated darter 1 0.001 1
0.001 All 128 6.328 136 9.496 187 14.425 235 3307 259 7.053 79 18833 299 8524 329 5223 106 17.882 188 27.779 1.946 118.850 L/I1 C
ZONE3 rZONE 2
ZONE 3~
Figure 5-1. Sampling zones on Lake Normnan, North Carolina.
5.11
(
Lake Norman striped bass relative weight (Wr) at total length (mm) for the Winter 2001 sample.
January/February 2001 Striped Bass Relative Weights 300 400 500 600 Total Length (mm)
C Figure 5-2.
(
110 100 90 80 70 60 200 Vi 700
Figure 5-3. Lake Norman striped bass relative weight (Wr) at total length (mm) for the Fall 2001 sample.
November 2001 Striped Bass Relative Weights 110 N=82 100 90 80:
70 60 200 300 400 500 600 700 Total Length (mm)
Lake Norman Hydroacoustic and Purse Seine Data: 2001 INTRODUCTION In accordance with the NPDES permit for McGuire Nuclear Station (MNS), monitoring of forage fish population parameters was conducted in 2001. 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 2001.
METHODS AND MATERIALS Three mobile hydroacoustic surveys of the entire lake were conducted on June 12 and 13, (Bioenergetics Study), September 10 and 11 (MNS NPDES), and December 5 and 6 (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 June 12, September 10, and December 3, 2001 from the lower (main channel near Marker 1), mid (mouth of Davidson Creek), and uplake (just downlake of Lake Norman (Duke Power) State Park) areas of the reservoir.
The purse seine measured 118 x 9 m (400 x 30 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 2,401 to 9,841 fish/ha in June 2001 (Table 1). No trend in forage fish abundance (e.g., higher densities uplake as compared to downlake) were evident. The estimated population was approximately 74 million fish. Purse seine sampling indicated that these fish were 17.97% threadfin shad, A-I
81.92% alewives, and 0.11% gizzard shad. The length frequency distribution indicated that alewives dominated a single large size class of forage fish under 80 mm (Figure 1).
September 2001 forage fish densities ranged from a low of 3,173 (Zone 6) to a high of 11,513 (Zone 5). The estimated forage population was approximately 78 million fish.
Purse seine sampling indicated that these fish were 76.47% threadfin shad, 23.52%
alewives, and 0.01% gizzard shad. The length frequency distribution indicated that threadfin shad dominated a single large size class of forage fish with a modal length of approximately 60 mm with alewives occupying the higher range of this size class (Figure 2).
Forage fish densities in the six zones of Lake Norman ranged from 1,451 to 8,647 fish/ha in December 2001.
There appeared to be fewer fish in the downlake zones. The estimated forage population was approximately 47 million fish. Purse seine sampling indicated that these fish were 82.66% threadfin shad, 16.46% alewives, and 0.88%
gizzard shad. The length frequency distribution indicated that threadfin shad dominated a single large size class of forage fish with a modal length of approximately 65 mm while alewives occupied a higher size class with a modal length of approximately 90 mm (Figure 3).
The 2001 population estimates demonstrated some interesting results with the highest estimate occurring in September. The 2000 population estimates demonstrated a steady decline from the first sample (July) through the last (December) in contrast to the trend seen in 2001. Our initial fears about conducting a June population estimate, and missing a large portion of the threadfin shad population that may have been spawning in near shore locations, appears to have been well founded. This supposition is supported by the low percentage and extremely small size'of threadfin shad in the June 2001 purse seine hauls as compared to the dominating percentages and much larger sizes on the two subsequent purse dates. Despite the bitterly cold winter of 2000 - 2001, past data has consistently shown that large numbers of threadfin shad survive in the heated waters near the Marshall Steam Station and the McGuire Nuclear Station and would have been available during June 2001. Therefore we can only surmise that a large percentage of the threadfin shad population was inaccessible to the purse seine and hydroacoustic gear by occupying near-shore areas and that the June 2001 population is an underestimate of the true forage fish population size in Lake Norman. If we assume that the June estimate should be higher, it still appears that the numbers of forage fish decline steadily throughout the year.
Undoubtedly, natural mortality from disease, starvation, and A-2
predation from Lake Norman's numerous piscivorous species and adult alewives undoubtedly contributed to this decline. Fishing mortality, from bait collectors, probably represented a small proportion of the total mortality for forage fish. Population estimates in 2001 are in line with values measured from 1997 to 2000 but are lower than the estimates from 1993 to 1996.
FUTURE FISH STUDIES 0 Continue the annual fall hydroacoustic/purse seine forage population assessment.
A-3
Table 1. Lake Norman forage fish densities and population estimates by zone, and lakewide populations estimates and 95% confidence limits from three hydroacoustic samples in 2001.
Density (no/hectare)
Population Estimate Zone June September December June September December 1
6,596 4,752 1,451 15,045,476 10,839,312 3,309,731 2
4,720 4,264 2,695 14,547,512 13,142,074 8,306,260 3
4,636 6,241 1,999 16,019,791 21,565,900 6,907,584 4
5,261 5,236 5,325 6,476,291 6,445,516 6,555,075 5
9,841 11,513 8,647 20,725,146 24,246,378 22,343,848 6*
2,401 3,173 1.147,678 1,516,694 Total 73,961,894 77,755,875 47,422,498 95%LCL 69,832,155 69,997,022 41,601,019 95%UCL 78,091,633 85,514,728 53,243,977
- Less than one report (denisty estimate) was collected in Zone 6 due to low water levels. Zones 5 and 6 were combined for one density and one population estimate.
A-4
C
(
Figure 1. Lake Norman (combined) forage fish - June 2001.
300 -
I 250 200 1m E 150 z
100 50 0-
[l T Shad 0 G Shad U Alewives r P 1-r P
I I
I 1 1
1 1
1 II I
I I
I 20 35 50 65 80 95 110 125 140 155 170 185 200 215 230 245 Length Group (mm)
A-5 ivI]
Figure 2. Lake Norman (combined) forage fish - September 2001.
nI EIT Shad G Shad Alewives nI
1 U..JJj, 1U1 [111 *IJ19 M1.
IE..... 1 I,
r, r I-I I
I I
I I
I I
I I
I I
I I
I I I i
I I
I I -T 20 35 50 65 '80 95 110 125 140 155 170 185 200 215 230 245 Length Group (mm)
A-6 Q
160 1 140 120 I._ a,,
-0 E z
100 80 60 40 20 0
I!
i i
I l
I
Figure 3. Lake Norman (combined) forage fish - December 2001.
200 180 160 140 120 100 80 60 40 20 0
I I1
- 1
EIT Shad
[G Shad UAlewives I
I i
I i
ii I
I ii I
I i I
I 1
1 1
1 35 50 65 80 95 110 125 140 155 170 185 200 215 230 245 Length Group (mm)
A-7 E
z n
I F
20 i
I