ML20199D003
| ML20199D003 | |
| Person / Time | |
|---|---|
| Site: | Mcguire, McGuire  |
| Issue date: | 12/31/1997 |
| From: | DUKE POWER CO. |
| To: | |
| Shared Package | |
| ML20199C991 | List: |
| References | |
| NUDOCS 9901190258 | |
| Download: ML20199D003 (106) | |
Text
LAKE NORMAN: 1997
SUMMARY
MAINTENANCE MONITORING PROGRAM McGUIRE NUCLEAR STATION: NPDES No. NC0024392 DUKE POWER 13339 HAGERS FERRY ROAD IIUNTERSVILLE, NORTH CAROLINA 28078 l DECEMBER 1998 9
g a napj
1 TAHLE OF CONTENTS
- Page EXECUTIVE
SUMMARY
i LIST OF TABLES v 5
LIST OF FIGURES vi CIIAPTER 1: McGUIRE NUCLEAR STATION OPERATIONAL DATA 1-1 Introduction 1-1 l Operational data for 1997 1-1 CliAPTER 2: LAKE NORMAN WATER CliEMISTRY 2-1 Introduction 2-1 I
Methods and Materials 2-1 Results and Discussion 2-2 Future Water Chemistry Studies 2-8 Summary 2-8 Literature Cited 2-10 CHAPTER 3: PHYTOPLANKTON 3-1 Introduction 3-1 Methods and Materials 3-1 Results and Discussion 3-2 Future Phytoplankton Studies 3-7 Summary 3-8 Literature Cited 3-10 CHAPTER 4: ZOOPLANKTON 4-1 Introduction 4-1 Methods and Materials 4-1 Results and Discussion 4-2 Future Zooplankton Studies 4-6 Summary 4-6 Literature Cited 4-8 CHAPTER 5: FISHERIES 5-1 Introduction 5-1 Methods and Materials 5-1 Results and Discussion 5-2 Future Fisheries Studies 5-4 Summary 5-4 (O ,/
j EXECUTIVE
SUMMARY
As required per the National Pollutant Discharge Elimination System (NPDES) pennit ,
number NC0024392 for McGuire Nuclear Station (MNS), the following annual report has been prepared. This repon summarizes environmental monitoring of Lake Norman l conducted during 1997.
OPERATIONAL DATA FOR 1997 The monthly average capacity factor of MNS averaged over 75% during July, August, and September of 1997. These are the months when conservation of cool water and discharge l temperatures are most critical and the thermal limit for MNS increases from a monthly average of 95 F to 99 F. The average monthly discharge temperature was 92.6 F (33.7 C) }
for July,97.4 F (36.3 C) for August, and 90.7 F (32.6 C) for September 1997. Low level ;
intake water was pumped by Unit I for additional cooling from September 2 to 30,1997. i 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 l Technical Specification requirements and the NPDES monthly discharge water temperature l limit. l WATER CHEMISTRY DATA l
Temporal and spatial trends in water temperature and dissolved oxygen concentration data collected in 1997 were similar to those observed historically. Reservoir-wide isotherm and
.isopleth data for 1997, coupled with heat content and hypolimnetic oxygen data, illustrated that Lake Norman exhibited thermal and oxygen dynamics characteristic of historic conditions and similar to other Southeastern reservoirs of comparable size, depth, flow conditions, and trophic status.
I i'
Availability of suitable pelagic habitat for adult striped bass in Lake Norman in 1997 was generally similar to historic conditions. In 1997 Duke Power personnel reported no i mortalities of striped bass during weekly habitat assessments in the summer within the MNS mixing zone and three mortalities in the main channel outside the mixing zone (see Chapter 5 O
y i
Fisheries). These conditions were similar to that in 1994 and 1996, when no mortalities of
\
striped bass were reported by local fishermen or observed by Duke Power personnel.
All chemical parameters measured in 1997 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 1997 often exceeded the North Carolina water quality standard. This is characteristic of waterbodies that experience hypolimnetic deoxygenation during the summer.
PIIYTOPLANKTON DATA Overall phytoplankton community composition in 1997 was similar to that in 1996. Diatoms were dominant in most samples, and were the principal contributors to standing crops in May and November. Cryptophytes were dominant in February; while green algae continued to dominate August samples, as has been the case in previous years.
The most abundant alga, on an annual basis, was the pennate diatom Tabellariafenestrata.
O U
The most common and abundant green alga and cryptophyte were Cosmarium i asphearosporum v. strigosum, and Rhodomonas minuta, respectively. All of these taxa have been common and abundant throughout the Maintenance Monitoring Program.
Chlorophyll a concentrations at locations during 1997 were generally within ranges reported during previous years, except in May, when the mean concentration was the highest ever recorded for that month. Lake Norman continues to be classified as oligo-mesotrophic based on long term annual mean chlorophyll concentrations. Lakewide chlorophyll means ,
1 increased from February to May, declined in August, then increased in November. i Chlorophyll concentrations from Locations 1 L0 through 15.9, uplake, were the highest yet I
recorded in that area of the Lake. The maximum chlorophyll value of 27.77 mg/m3 (48/L) was below the NC State Water Quality standard of 40 mg/m3 (pg/L). Considerable spatial and seasonal variability was observed during 1997, as has been the case in previous years.
In most cases, total phytoplankton densities and biovolumes observed in 1997 were within ranges of those observed during previous years. However, densities and biovolumes at Locations 11.0 and 15.9 in May exceeded NC State standing crop guidelines. This was the first time since the Program began that such an excursion was documented. Very high ii
1 standing crops of diatoms, prmarily the pennate Talv//ariafenestrata, were responsible for these high values. Since high standing crops occurred at two locations well uplake from MNS, and one location was above the MSS discharge, plant operations were not responsible for these excursions. Natural conditions such as low flow, increased retention time, earlier inputs of nutrients uptake, seasonal increases in temperature and light penetration, and longer photoperiod were most likely causes contributing to the higher than normal standing crops.
Minimum standing crops were observed in February, and values in the mixing zone were generally lower than those uplake.
Seston dry weights were higher in 1997 than in 1990, w ,nlake to uplake differences l were still quite apparent. Maximum dry and ash free dry weights were most often observed at the riverine location (69.0); while minima were most often noted in the mixing zone (2.0 I and 5.0) and at Location 9.5. The proportions of ash free dry weights to dry weights were lower in 1997 than in 1996, indicating proportionally less organic input to inorganic input in Lake Nomian. This is a continuation of a trend first observed in 1995.
ZOOPLANKTON DATA (V Lake Norman supports a highly diverse and viable zooplankton community. Thirteen taxa, previously unreported during the Program, were identified during 1997. Rotifers dominated zooplankton standing crops through most of 1997, as has been the case in previous years.
The relative abundance of copepods and cladocerans was higher in 1997 than in 1996, representing a continuing trend of increased microcmstation abundance since 1995.
l l Copepods occasionally dominated zooplankton densities in all sampling periods; while cladocerans were dominant only in the Mixing Zone in August.
Maximum zooplankton standing crops in 1997 occurred in May, with minimum values in August. This represented a shift from 1996 when peak abundance occurred in February. In 1997, densities were higher in epilimnetic samples than in whole column samples.
Zooplankton densities tended to increase from Mixing Zone to Background Locations, except during August when no consistent spatial patterns were observed.
iii
l Long term trends showed much higher year-to-year variability at Uplake or Background
() locations than at Mixing Zone locations. Epilimnetic zooplankton densities during 1997 were within ranges of those observed in previous years.
FISHERIES DATA In accordance with the Lake Norman environmental maintenance monitoring program for the NPDES permit for McGuire Nuclear Station (MNS), specific fish monitoring programs were coordinated with the NCWRC and continued during 1997. General monitoring of Lake Nonnan and specific monitoring of the MNS mixing zone for striped bass mortalities during the summer of 1997, yielded no mortalities within the mixing zone and three mortalities in the main channel outside the mixing zone.
Gill-netting for striped bass during 1997 yielded a total of 258 striped bass, ranging in length from 290 mm to 1,080 mm. Age determinations of post-stress striped bass indicated fish ranging in age from 1 to 14 years. Age 4 fish comprised the largest age group (24%). All striped bass data were submitted to the NCWRC for detailed analyses of striped bass growth s and condition.
(
The 2-ye?r IAke Norman crappie study was ; . .ted in 1997. Trap-net sampling resulted in the collection of 234 crappie, ranging in zi.e fr.cm 106 mm to 318 mm. Black crappie comprised 97% of the total catch. Age determi# ans of black crappie indicated fish ranging in age from 1 to 6 years. All crappie data were submitted to the NCWRC for detailed analyses of crappie condition and age / size composition.
Fall hydroacoustic/ purse seine sampling for estimation of Lake Norman forage fish populations continued m 1997. Analyses and interpretation of his orical data are in progress and a separate report summarizing forage populations from 1993 through 1997 will be submitted in early 1999.
Through consuhation with the NCWRC, the Lake Norman fisheries program continues to be leviewed 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.
\p v) iV
)
Og LIST OF TAIllES Page Table 1-1 Average monthly capactiy 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 1 Table 2-3 Heat centent calculations for Lake Norman in 1996 and 1997 2-15 Table 2-4 Comparison of Lake Norman with TVA reservoirs 2-16 Table 2-5 Lake Norman water chemistry cata for 1996 and 1997 2-17 Table 3-1 Mean chlorophyll a concentrations in Lake Norman 3-12 Table 3-2 Duncan's multiple range test for Chlorophyll a 3-13 Table 3-3 Total phytoplankton densities from Lake Norman 3-14 !
Table 3-4 Duncan's multiple range test for phytoplankton densities 3-15 Table 3-5 Duncan's multiple range test for dry and ash free dry weights 3-16 Table 3-6 Phytoplankton taxa identified in Lake Norman from 1987-1997 3-17 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 1987-1997 4-13 b
(
1 i
i e
b e
FG 4
, e =
( LIST OF FIGURES Page Figure 2-1 Map of sampling locations on Lake Norman 2-20 Figure 2-2 Monthly precipitation near McGuire Nuclear Station 2-21 Figure 2-3 Monthly mean temperature profiles in background zone 2-22 Figure 2-4 Monthly mean temperature proGles in mixing zone 2-24 Figure 2-5 Monthly temperature and dissolved oxygen data 2-26 Figure 2-6 Monthly mean dissolved oxygen profiles in background zone 2-27 Figure 2-7 Monthly mean dissolved oxygen profiles in mixing zone 2 l Figure 2-8 Monthly isotherms for Lake Norman 2-31 Figure 2-9 Monthly dissolved oxygen isopicths for Lake Norman 2-34 Figure 2-10a Heat content of Lake Norman 2-37 l Figure 2-10b Dissolved oxygen content of Lake Norman 2-37 Figure 2-11 Striped bass habitat in Lake Norman 2-38 l
Figure 3-1 Chlorophyll a measurements of Lake Norman 3-26 l Figure 3-2 Mean chlorophyll a concentrations by year 3-27 l Figure 3-3 Chlorophyll a concentrations by location 3-28 Figure 3-4 Class composition of phytoplankton at Locations 2.0 and 5.0 3-30 :
Figure 3-5 Class composition of phytoplankton at location 9.5 3-31 i
! Figure 3-6 Class composition of phytoplankton at Location 11.0 3-32 Figure 3-7 Class composition of phytoplankton at Location 15.9 3-33
! Figure 3-8 Annual lakewide Myxophycean index from 1988-1997 3-34 Figure 4-1 Zooplankton density by sample location in Lake Norman 4-14 Figure 4-2 Lake Norman zooplankton densities among years 4-15 Figure 4-3 Lake Norman zooplankton composition by month and location 4-17 Figure 4-4 Lake Norman zooplankton composition among years 4-18 l
l
. G t
Vi
_ ~ _ -
1 i
i CilAPTER I McGUIRE NUCLEAR STATION ,
OPERATIONAL DATA INTRODUCTION As required per the National Pollutant Discharge Elimination System (NPDES) pennit nutnber NC0024392 for McGuire Nuclear Station (MNS) issued by the North Carolina Depanment of Environment and Natural Resources (NCDENR), the following annual report has been prepared.
This report summarizes environmental monitoring of Lake Norman conducted during 1997.
OPERATIONAL DATA FOR 1997 The monthly average capacity factor of MNS averaged over 75% during July, August, and September of 1997 (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 F to 99 F. The average monthly discharge temperature was 92.6 F (33.7 C) for I July,97.4 F(36.3 C) for August, and 90.7 F (32.6 C) for September 1997. Low level intake O
t water was pumped by Unit i for additional cooling from September 2 to 30,1997. The volume l 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 monthly discharge water temperature limit. I l
I l
i 1-1
- _ . . - = _ . - .- . . - . - - - - . - . - - _ - - . . _ - - - .
!p Table 1-1. Average monthly capacity factors (%) calculated from daily unit capacity
,I 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 1997.
NPDES DISCHARGE CAPACITY FACTOR (%) TEMPERATURE Month Unit 1 Unit 2 Station Monthly Average Average Average Average OF OC January 96.6 101.3 98.9 68.4 20.2 February 46.2 101.7 74.0 67.0 19.4 March 0.0 80.8 40.2 68.5 20.3 April 0.0 97.4 48.4 72.6 22.6 May 17.7 101.2 59.4 74.4 23.6 June 0.0 103.2 51.2 82.6 28.1 July 97.4 60.2 78.8 92.6 33.7 August 98.5 97.5 98.0 97,4 36.3 September 90.5 86.5 88.5 90.7 32.6 October 100.8 5.7 53.2 85.4 29.7 November 102.3 0.0 50.9 75.7 24.3 December 102.5 30.8 66.7 67.0 19.4
.O I
l l
i i
1-2
CIIAPTER 2 i
V LAKE NORMAN WATER CIIEMISTRY 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 l
- 2) compare, where appropriate, these physicochemical data to similar data in other l hydropower reservoirs and cooling impoundments in the Southeast. j l
This year's report focuses primarily on 1996 and 1997. Where appropriate, reference to )
pre-1996 data will be made by citing reports previously submitted to the North Carolina
~
l Department of Environment and Natural Resources (NCDENR).
METHODS AND MATERIALS
/-w\
- v) i \
The complete water chemistry monitoring program, including specific variables, l
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, l
l 1989,1990,1991,1992, 1993,1994, 1995,1996,1997). The first method involved parti-l tioning the reservoir into mixing, background, and discharge zones, and making comparisons among zones and years. In this report, the discharge includes only Location l 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 (A110D),
maxi. mum whole-water column and hypolimnion oxygen content, maximum whole-water column and hypolimnion heat content, mean epilimnion and hypolimnion heating rates p over the stratified period, and the Birgean heat budget.
4 i
M 2-1
i l
f'~ licat (Kcal/cm ) and oxygen (mg/cm or 2 mg/L) content of the reservoir were calculated b according to Hutchinson (1957), using the following equation:
Lt = Ao- l e ' TO + Az e dz l
where; i Lt = reservoir heat (Kcal/cm ) or oxygen (mg/cm 2) content Ao = surface area of reservoir (cm2)
TO = mean temperature ( C) or oxygen content of layer z Az = area (cm2) at depth z dz = depth interval (cm) zo = surface j zm = maximum depth I I
l RESULTS AND DISCUSSION
!p h Precipitation Amount i
l Total annual precipitation in the vicinity of MNS in 1997 (48.0 inches) was slightly more l
than measured in the 1996 (39.6 inches) (Figure 2-2). The highest total monthly rainfall l in 1997 occurred in December with a value of 7.7 inches.
1 l
l Temperature and Dissolved Oxygen I
Water temperatures measured in 1997 illustrated similar temporal and spatial trends in the background and mixing zones (Figures 2-3, 2-4). This similarity in temperature l cattems between zones has been a conspicuous feature of the thermal regime in Lake l harman since MNS began operations in 1983. Water temperatures in the winter (January l
l and February) of 1997 were consistently warmer throughout the water column, as compared to 1996, in both zones (Figure 2-3, 2-4). Minimum metalimnion and hypolimnion winter temperatures in 1997 measured 8 to 9 C, or slightly warmer than the 5 to 6 C corresponding temperatures in 1996. No major differences between 1996 and 1997 water temperatures were observed in either the mixing or background zones for the
\ )
v 2-2
_ _~ _ - - -.
I 1
)
remainder of the lake's heating period. Some interannual variability in water temperatures during certain months were observed, 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).
The fall temperature differences observed between 1996 and 1997 can be pattially explained by variability in sampling. The October,1996 data were collected on day 23, whereas in 1997 sampling was performed on day 1, or almost three weeks earlier, and as
{
a consequence would be expected to exhibit warmer temperatures than in 1996. (Note l that no temperature data are available for the month of November 1996 due to equipment ,
malfunction.) Despite some seasonal and spatial variability in temperature data between l 1996 and 1997, the 1997 temperatures were well within the historic range (DPC 1985, l
1989,1991, 1993. 1994, 1995,1996,1997).
l Temperature data at the discharge location in 1997 were generally similar to that l measured in 1996 (Figure 2-5) and historically (DPC 1985,1987,1988a,1989,1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997). The warmest discharge temperature of 1997 l
l occurred in August and measured 37.4 C, or 0.4 C more than the previous historic )
maximum of 37.0 C measured in August,1995 (DPC 1996).
Seasonal and spatial patterns of DO in 1997 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 spring DO values in 1997 were generally lower than measured in 1996, and appeared to be related predominantly to the wamier water column temperatures measured in 1997 versus 1996. The warmer water temperatures measured in 1997 would be expected to exhibit a lower oxygen content because of the direct effect of temperature on oxygen solubility, and indirectly via a reduced convective mix;ng regime which would inhibit reacration. Summer DO values in 1997 were highly variable throughout the water column in both the mixing and background zones ranging from highs of 6 to Smg/L in the surface waters to lows o'f 0 to 2mg/L in the bottom waters; this pattern is similar to that measured in 1996 and earlier years (DPC 1985,1987,1988a, 1989, 1990, 1991, 1992, 1993,1994, 1995, 1996, 1997). All dissolved oxygen values recorded in 1997 were well within the historic range (DPC 1985,1987,1988a,1989, 1990,1991,1992,1993,1994,1995,1996,1997).
2-3
l l
O]
\
i t --
Fall and early-winter DO values were generally similar between the two years in both zones. Some interannual differences were observed in the October data; these differences 1
appear to simply reflect variability in sampling schedule, as discussed earlier. (Note that no dissolved oxygen data are available for the month of November,1996 due to equipment malfunction). Interannual differences in DO are common in Sutheastern reservoirs, particularly during the stratified period, and can reflect yearly differences in hydrological, meteorological, and limnological forcing variables (Cole and 11annon 1985; Petts1984).
l The seasonal pattern of DO in 1997 at the discharge location was similar to that measured historically, with the highest values observed during the winter and lowest observed in !
l the summer and early-fall (Figure 2-5). The lowest DO concentration measured at the '
discharge location in 1997 (4.8 mg/L) occurred in September, concurrent with low-level water usage at MNS. !
l Reservoir-wide Temperature and Dissolved Oxygen 1
l
,m
\
The monthly reservoir-wide temperature and dissolved oxygen data for 1997 are l l
j presented in Figures 2-8 and 2-9. These data are similar to that observed in previous years and are characteristic of cooling impoundments and hydropower reservoirs in the 1
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 1992,1993,1994,1995,1996,1997).
The seasonal heat content of both the entire water column and the hypolimnion for Lake Norman in 1997 are presented in Figure 2-10a; additional information on the thermal regime in the reservoir for the years 1996 and 1997 are found in Table 2-3. Annual 2
minimum heat content for the entire water column in 1997 (8.55 Kcal/cm ; 8.6 C) occurred in early-January, whereas the maximum heat content (28.02 Kcal/cm2 ; 27.4 C) occurred in August. Heat content of the hypolimnion exhibited somewhat the same temporal trend as that observed for the entire water column. Annual minimum 2
- hypolimnetic heat content occurred in February and measured 4.79 Kcal/cm (7.6 C ),
2 j whereas the maximum occurred in September and measured 15.77 Kcal/cm (24.2 C ).
i !p)
V 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 2-4
(
s 2
water column equalled 0.091 Kcal/cm / day versus 0.049 Kcal/cm2 / day for the
( hypolimnion. The 1997 heat content data were generally similar to that observed in 1996 and earlier years ( DPC 1992,1993,1994, 1995,1996,1997).
The seasonal oxygen content and percent saturation of the whole water column and the hypolimnion for 1997 are depicted in hgure 2-10b. Additional oxygen data can be found in Table 2-4 which presents the 1997 A110D for Lake Norman and contrasts it with similar estimates for 18 TVA reservoirs. Reservoir oxygen content was greatest in mid-winter when DO content measured 10.4 mg/L for both the whole water and just the hypolimnion. Percent saturation values at this time approached 93% for the entire water column and 88% for the hypolimnion. Beginning in early-spring, oxygen content began I to decline precipitiously 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 DO values for the entire water column measured 4.2 mg/L (54.1%
saturation), whereas the minimum for the hypolimnion was 0.4 mg/L (4.7% saturation).
The mean rate of DO decline in the hypolimnion over the stratified period, i.e., the 2
AllOD, was 0.040 mg/cm / day (0.063 mg/Uday) (Figure 2-10b ), and is similar to that i
measured in 1996 (DPC 1997).
b IIutchinson (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 AllOD associated with various trophic states; oligotrophic - 5 0.025 2 2 mg/cm / day, mesotrophic - 0.026 mg/cm / day to 0.054 mg/cm 2/ day, and cutrophic - 2 2
0.055 mg/cm / day. Employing these limits, Lake Norman should be classified as 2
l mesotrophic based on the calculated AliOD value of 0.040 mg/cm / day. The oxygen l based mesotrophic classification agrees well with the mesotrophic classification based on chlorophyll a levels (Chapter 3). The 1997 AllOD value is also similar to that found in other Southeastern reservoirs of comparable depth, chlorophyll a status, and secchi depth (Table 2-4).
Striped Bass liabitat Suitable pelagic habitat for adult striped bass, defined as that layer of water with temperatures s 26 C and DO levels 2 2.0 mg/L, was found lake-wide from late-(v) September 1996 through July 1997, Beginning in July 1997, habitat reduction proceeded 2-5
rapidly throughout the reservoir both as a result of deepening of the 26 C isotherm and d metalimnetic and hypolimnetic deoxygenation (Figure 2-11). liabitat reduction was most severe from early August to early September with essentially no suitable habitat observed in the majority of the reservoir. A small refuge was observed during this period in the upper, riverine portion of the reservoir, near the confluence of Lyles Creek with Lake Norman. liabitat measured in the upper reaches of the reservoir at this time appeared to be influenced by both innow from Lyles Creek and discharges from Lookout Shoals flydroelectric 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.
l Physicochemical habitat was observed to have expanded appreciably by early October primarily as a result of epilimnion cooling and deepening, and in response to changing i meteorological conditions. The temporal and spatial pattern of striped bass habitat ;
expansion and reduction observed in 1997 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). The duration of habitat elimination in 1997
,. (except for the small refuge near the confluence of Lyles Creek) extended from about ,
early August to early September, or about one month, and was well within the historic l range. In 1997 Duke Power personnel reported no mortalities of striped bass during weekly habitat assessments in the summer within the MNS mixing zone and three mortalities in the main channel outside the mixing zone (see Chapter 5). These
,mditions were similar to that in 1994 and 1996 when no mortalities of striped bass were I reported by local fishermen or observed by Duke Power personnel.
Turbidity and Specific Conductance l l
Surface turbidity values were generally low at the MNS discharge, mixing zone, and mid-lake background locations during 1997, ranging from 1.88 to 14.5 NTUs (Table 2-5). l l
Bottom turbidity values were also relatively low over the study period, ranging from 1.8 l to 16.1 NTUs (Table 2-5). These values were similar to those measured in 1996 (Table i 2-5), and well within the historic range (DPC 1989,1990,1991,1992,1993,1994,1995, 1
1996,1997).
s Specific conductance in Lake Norman in 1997 ranged from 47 to 59 umho/cm and was similar to that observed in 1996 (Table 2-5) and historically (DPC 1989,1992, 1993, 2-6
,s
[~ 1994, 1995, 1996, 1997). Specific conductance values in surface and bottom waters c
l were generally similar throughout the year except during the period of intense thermal
! stratification when bottom waters averaged about 10 umhos/cm higher than surface values. These increases in conductance appeared to be related primarily to the release of i 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 l hypolimnetic oxygen depletion (Hutchinson 1957, Wetzel 1975).
pIIand Alkalinity During 1997, pH and alkalinity values were similar among MNS discharge, mixing and background zones (Table 2-5); they were also similar to values measured in 1996 (Table 2-5) and historically (DPC 1989,1992, 1993, 1994, 1995, 1996, 1997). Individual pH values in 1997 ranged from 5.9 to 7.6, whereas alkalinity ranged from 9.5 to 16.5 mg/L of CACO3. J Major Cations and Anions l i
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' 1997 was similar to that reported for 1996 (Table 2-5) and previously (DPC 1989,1992, 1993, 1994, 1995, 1996, 1997). Lake-wide, the major cations were sodium, calcium, magnesium, and potassium, whereas the major anions were bicarbonate, sulfate, and chloride.
Nutrients Nutrient concentrations in the discharge, mixing, and mid-lake background zones of Lake Norman are provided in Table 2-5. Overall, nitrogen and phosphorus levels in 1997 were similar to those measured in 1996 and historically (DPC 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997); they were also characteristic of the lake's oligo-mesotrophic status. Ammonia nitrogen concentrations increased in bottom waters in each of the two zones and at the discharge location during the summer and fall, concurrent with the development of anoxic conditions. Total and soluble phosphorus concentrations in 1997 l- were similar to values recorded in 1996 and historically (DPC 1989,1990,1991,1992, f' 1993,1994,1995,1996,1997).
2-7
I C l i j Metals Metal concentrations in the discharge, mixing, and mid-lake background zones of Lake Norman for 1997 were similar to that measured in 1996 (Table 2-5) and historically (DPC 1989,1990,1991,1992,1993,1994,1995,1996,1997). Iron concentrations near the surface were generally low (s 0.1 mg/L) during 1996 and 1997, whereas iron levels l
near the bottom were slightly higher during the stratified period. Similarly, manganese concentrations in the surface and bottom waters were generally low (5 0.1 mg/L) in both )
1996 and 1997, 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 the bottom sediments due to solubility changes 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 ne'L) at various locations throughout the lake in summer and fall of both years, and is characteristic of historic conditions (DPC 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997). Heavy metal concentrations in Lake Norman never approached NC water quality standards, and there
,( )
.I 1 lg were no consistent appreciable differences between 1996 and 1997.
w/
FUTURE STUDIES l No changes are planned for the Water Chemistry portion of the Lake Norman maintenance monitoring program during 1998 or 1999.
SUMMARY
Temporal and spatial trends in water temperature and DO data collected in 1997 were l
l similar to those observed historically. Temperature and DO data collected in 1997 were within the range of previously measured values.
Reservoir-wide isotherm and isopleth information for 1997, coupled with heat content and hypolimnetic oxygen data, illustrated that Lake Norman exhibited thermal and
, oxygen dynamics characteristic of historic conditions and similar to other Southeastern t
v) reservoirs of comparable size, depth, flow conditions, and trophic status.
2-8
a I \
(_/ Availability of suitable pelagic habitat for adult striped bass in Lake Norman in 1997 was generally similar to historic conditions. In 1997 Duke Power personnel reported no mortalities of striped bass during weekly habitat assessments in the summer within the MNS mixing zone and three mortalities in the main channel outside the mixing zone (see Chapter 5). These conditions were similar to that in 1994 and 1996 when no mortalities of striped bass were reported by local fishermen or observed by Duke Power personnel.
All chemical parameters measured in 1997 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 1997 often exceeded the NC water quality standard. This is characteristic of waterbodies that experience hypolimnetic deoxygenation during the summer.
? \
'u i
i f\
(- )
2-9
(3 LITER ATIJRF. CITED s \
Coutant, C. C.1985. Striped bass, temperature, and dissolved oxygen: a speculative hypothesis for environmental risk. Trans. Amer. Fisher. Soc. I14:31-61.
Cole, T. M. and II. H. Hannon.1985. Dissolved oxygen dynamics. In: Reservoir Limnology: Ecological Perspectives. K. W. Thornton, B. L. Kimmel and F. E. Payne editors. John Wiley & Sons. NY.
Duke Power Company.1985. McGuire Nuclear Station,316(a) Demonstration. Duke Power Company, Charlotte, NC.
Duke Power Company.1987. Lake Norman maintenance monitoring program: 1986 summary.
Duke Power Company.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 Nonnan maintenance monitoring program: 1988
!p summary.
Duke Power Company.1990. Lake Nonnan maintenance monitoring program: 1989 summary.
Duke Power Company.1991. Lake Norman maintenance monitoring program: 1990 summary.
Duke Power Company.1992. Lake Norman maintenance mo 6toring program: 1991 summary.
Duke Power Company.1993. Lake Norman maintenance monitoring program: 1992 summary.
l l Duke Power Company.1994. Lake Norman maintenance monitoring program: 1993 summary.
Duke Power Company.1995. Lake Norman maintenance monitoring program: 1994 summary.
Duke Power Company.1996. Lake Norman maintenance monitoring program: 1995 summary.
' )
\ /
w-2-10
.O Duke Power Company 1997. Lake Norman maintenance monitoring program: 1996 h summary.
Ford, D. E.1985. Reservoir transport processes. In: Reservoir Limnology: Ecological Perspectives. K. W. Thornton, B. L. Kimmel and F. E. Payne editors. John Wiley &
Sons. NY.
Ilannan, II. II., I. R. Fuchs and D. C. Whittenburg. 1979 Spatial and temporal patterms of temperature, alkalinity, dissolved oxygen and conductivity in an oligo-mesotrophic, deep-storage reservoir in Central Texas. Hydrobilologia 51 (30);209-221.
Higgins, J. M. and B. R. Kim.1981. Phosphorus retention models for Tennessee Valley Authority reservoirs. Water Resour. Res., 17:571-576.
Higgins, J. M., W. L. Poppe, and M. L. Iwanski.1981. Eutrophication analysis of TVA reservoirs. In: Surface Water Impoundments. H. G. Stefan, Ed.
Am. Soc. Civ. Eng., NY, pp.404-412.
i 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.
l l Matthews, W. J., L. G. Hill, D. R. Edds, and F. P. Gelwick. 1980. Influence of water l quality and season on habitat use by striped bass in a large southwestem reservoir.
Transactions of the American Fisheries Society 118: 243-250.
Mortimer, C. H.1941. The exchange of dissolved substances between mud and water in lakes (Parts I and II). J. Ecol.,29:280-329.
, Petts G. E.,1984. Impounded Rivers: Perspectives For Ecological Management. John
! Wiley and Sons. New York. 326pp.
l i 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.
8 >
v 2-11
e i
i 1
I Wetzel, R. G. 1975. Limnology. W.13. Saunders Company. Philadelaphis, Pennsylvania,743pp. ,
i i
i 2-12
(^s Ni
( {m d
Table 2-1. Water chemistry program for McGuire Nuclear Station NPDES long-term maintenance monitoring on Lake Norman.
1997McGlilRENPDES SAMPLING PROGRAM Sampse Cenessee sen.duas ter toes PARAMETERS IDCATIONS l.0 2.0 4.0 5.0 8.0 9.$ t t.0 13.0 14.0 13.0 13.9 62.0 69.0 72 0 30.0 16.0 DEPTN (m) 33 33 S 20 32 23 27 25 to 23 23 15 7 5 4 3 SAM CODE IN-S!TU ANALYSIS Temperature Hydrolab Dissolved Oxygen Hydrolab In-situ -- 1 are collemed monthly at the above locations at im Intervals hem 0.3m to Im above bottom.
pH Hydrolab Measurements are taken woukly Gom July August for striped base habitat.
Conductivery Hydrolab NtfrRIENT ANAt,YSES Ammonia AA-Nut QrTA QtTA QT OTA OrTA QT.B OTA QrrA 07 OTA OTA S/T Nitrue+Nitdte AA Nut OTA OTA QT QrrA QrTA OrTA OrTA OTA QT QtTA orTA S/T l
Onhophosphate AA-Nut QrTA QrTA Qrr Orf.B QTA QrTA OrTA QrrA QrT WTA QrrA S/T t
Total Phosphorus AA-TP.DO-P OrTA QrTA OT WTA OrTA QTA Sitia QrrA QTA OT QrrA OTA ST AA-Nut QTA QrTA QT QTA QrTA ort.B Qrrs OTA Cl QT QTA QTA SrT AA Nut OTA QFTA Qrf QTA QrrA QTA QTA QTA TKN OT OTA QrTA S/T AA-TKN SfrA S/TA Y ;
G asMsNT4 ANuYSs3 Aluminum ICP-24 OTA S/rA ' S/T QTA OrrA OrTA QTA OTA Orr OTA OTA S,T Calcium ICP-24 QrrA QrTA ort QrTA QrrA OrrA QrTA QTA QT QrTA OrrA S/T tmn ICP-24 OrrA QTA GT WrA OrTA OTA OTA QrrA QT OrTA OTA S/r Magnesium ICP 24 OTA OrTA Wr QrrA QrTA OrTA QTA OrTA OT QTA QrTA S/r Manganese ICP-24 ort.B OfTA QT OrTA QTA QrT.B OTA QrTA WT QrTA QrTA S,7 Petassium 306-K OTA WTA QrT QTA QTA QTA WTA QTA WT QrTA OTA S/T Sodium ICP-24 QrT.B Qrr.B Qrf OrrA Orr.B Zine OrTA OrrA QTA OT OTA OrTA S/r j !CP-24 OrTA QrTA OT OT.B OTA QrTA OrTA QrrA Qrr OTA orTA S/r Cadminum HOA4D SfrA Sfr S/rA S/TA S/T S/TA Copper HOA4U SfrA Sfr Sfr StrA S.TA S/T S/TA Sfr Lead HOA-PB SfrA S/T S/TA S/TA S/T S/TA $<T ADDmONAL ANALYSs3 i
Alkalinity T-ALKT yrA QrTA Qrr OTA QT.B OTA Wrs OTA Qrr orTA orr.B S/T Turbidity F-TURB WTA QrTA Orr QTA QrTA OTA QrTA WTA QT QtTA OTA S.T Sutrete UV_SO4 S/TA S/r StrA Sfr S.TA Total Solids S-TSE STA $/T ST StrA S/T S/TA S.T Tota! Susmded So S-TSSE SfrA $/T StrA S/T S/TA S/r i CODES: Frequency Q = Quarterty(Feb. Mey. Aug Now) S = Semi-ennually (FebAus)
T = Top (0.3m) B = Bottom (1m above bottom) 1
/- ,
( ,
v Table 2-2. Water chemistry methods and analyte detection limits for the McGuire Nuclear Station NPDES long-term maintenance program for Lake Norman.
Variables Method Preservation Detection I imir 2
Alkalinity, total Electrometric titration to a pH of 5.1 4'O Img-CACO 3 r
Aluminum Atomic emission /ICP-direct injecition* 0.5% HNO3 0.3 mg T' l Ammonium Automated phenate' 4*C 0.050 mg T' 2
Cadmium Atomic absorption / graphite furnace-direct injection 0.5% HNO 3 0.1 pg r' 3
Calcium Atomic emission /ICP-direct injecition* O.5% HNO3 0.04 mg r' Chloride Automated ferricyanide' 4*C 1.0 mg r' '
Conductance, specific Temperature compensated nickel electrode' In-situ 1 mho cm
- 2 ,
Copper ' Atomic absorp* tion / graphite fumace-direct injection HNO3 0.5% 0.5 pg r' Fluoride Potentiemetric 4*C 0.10 mg r' ;
Iron Atomic emission /ICP-direct injection
- 0.5% HNO3 0.1 mg r' Lead Atomic absorption / graphite fumace-direct injection
- 0.5% HNO 3 2.0 pg r' i 2
Magnesium Atomic emission /ICP-direct injection 0.5% HNO3 0.001 mg T' !
Manganese Atomic emission /ICP-direct injection
- 0.5% HNO 0.003 mg r' Nitrite-Nitrate Automated cadmium teduction' 4*C 0.050 mg T'-
Orthophosphate Automated ascorbic acid reduction' 4'C 0.005 mg r' Y Oxygen, dissolved Temperature compensated polarographic cell' In-situ 0.1 mg r' E pH Temperature compensated glass electrode' In-situ 0.1 std. units *
- Phosphorus, total Persulfate qigestion followed by automated ascorbic acid 4*C 0.005 mg -r' " .
reduction 0.015 mg' T'" !
Potassium Atomic absorption / graphite fumace-direct injection
- 0.5% HNO3 0.1 mg r Silica Automated molydosilicate' 4*C 0.5 mg T' I Sodium Atomic emission /ICP-direct injection
- 0.5% HNO 3 0.3 mg r' ;
Sulfate Turbidimetric, using a spectrophotometer' 4'C 1.0 mg r' i Temperature Thermistor / thermometer' In-situ 0. I'C' l Turbidity Nephelometric turbidity' 4*C 1NTU* i Zine Atomic emission /ICP-direct injection: 0.5% HNO3 4 pg r'
' United States Environmental Protection Agency 1979. Methods for chemical analysis of water and wastes.
Environmental Monitoring and Support Laboratory. Cincinnati, OH.
2 USEPA. 1982
'USEPA. 1984
- Instrument sensitivity used instead of detection limit.
" Detection limit changed during 1989. ;
i L
I l
1 Table 2-3.11 eat content calculations for the thermal regime in Lake Norman in 1996 and 1997.
l I
1 l
l !
1997 1996 l
~
l Maximum areal heat content ( g cal /cm') 28,019 27,959 l l
l 2
l Minimum areal heat content (g cal /cm ) 8,547 5,470 Maximum hypolimnetic (below 11.5 m) 15,766 15,243 :
areal heat content (g cal /cm')
l Birgean heat budget (g cal /cm') 19,472 22,489 i
Epilimnion (above 11.5 m) heating 0.094 0.114 D
i rate ( C / day) l 1
Hypolimnion (below 11.5 m) heating 0.074 0.089 rate ( C / day) l l
l l
l iO
!V 2-15
Table 2-4. A comparison of areal hypolimnetic oxygen deficits (AllOD), summer GN chlorophyll a (chi a), secchi depth (SD), and mean depth of Lake Norman and 18 TVA reservoirs.
AHOD Summer Chl a Secchi Depth Mean Depth Reservoir (mg/cm2/ day) (ug/L) (m) (m)
Lake Nomian 0.040 9.9 1.7 10.3 TVAa Mainstem Kentucky 0.012 9.1 1.0 5.0 Pickwick 0.010 3.9 0.9 6.5 Wilson 0.028 5.9 1.4 12.3 Wheelee 0.012 4.4 5.3 ,
Guntersville 0.007 4.8 1.1 5.3 Nickajack 0.016 2.8 1.1 6.8 Chickamauga 0.008 3.0 1.1 5.0 Watts Bar 0.012 6.2 1.0 7.3 Fort London 0.023 5.9 0.9
'G 7.3 Tributary Chatuge 0.041 5.5 2.7 9.5 Cherokee 0.078 10.9 1.7 13.9 Douglas 0.046 6.3 1.6 10.7 Fontana 0.113 4.I 2.6 37.8 Hiwassee 0.061 5.0 2.4 20.2 Norris 0.058 2.1 3.9 16.3 South Holston 0.070 6.5 2.6 23.4 Tims Ford 0.059 6.1 2.4 14.9 l Watauga 0.066 2.9 2.7 24.5 a Data from Higgins et al. (1980), and Higgins and Kim (1981) 1
.i i
2-16
_ m m s i
b Nd Tabte 2-5.
Quarte ty surface (0 3 m) and bottom (bottom minus 1 m) water chemistry for the MNS discharge, mbdng zone, and background locations on Lake Norman during 1996 and 1997. Values less than detection were assumed to be the detection limit for ca:culating a mean.
Mixing Zone Mang Zooe MNS Dschage Muung Zone Background Bangv3 LOCA7 ION 1.0 20 40 50 80 11 0 ctmt Sudace Bonom Suvace Bonom Suence Sudace PAR AVETERS VEng Bonom Sudace Boeom Sw* ace Boco-90 g7 90 97 96 97 9e 97 96 97 Turtnedy (ntu) 96 97 96 97 96 97 96 97 9e 97 Ga 97 Fet 7.7 39 90 de 47 28 34 10 5 64 33 53 57 58 45 11 29 12 7 53 21 36 May 90 91 12 4 85 8.3 10.3 12.7 33 91 11.3 77 33 14 3 23 11.1 Aug 30 1 88 7.0 4 16 1 7.7 40 13.3 3.3 81 14 5 16 2 10 5 49 19 73 45 39 38 42 20 53 18 38 48 48 20 4 71 No 30 31 33 20 37 29 51 43 61 41 20 28 31 22 39 44 31 26 55 25 32 22 12 0 46 Aoaval Mea 9 5 e6 4 495 7 93 50 S ie 45 8 90 39 5 35 53 5 08 33 7 33 67 6 40 36 9 08 33 9 06 e9 Specec Comeuctance (umewom) *4 33 76 Feb 53 51 54 50 54 51 54 50 56 52 54 51 53 50 54 49 54 49 May 54 54 53 55 55 48 55 47 54 54 54 55 55 55 54 55 54 55 54 Aug 59 40 54 53 55 54 51 52 $4 68 58 59 49 67 58 60 50 SO 49 74 Nov 57 59 48 65 57 59 48 67 59 57 53 57 53 57 53 57 53 Aaevat Veea 55 8 Si e 58 0 54 0 56 0 51 8 58 0 54 0 J 54 58 53 $7 53 57 53 56 53 $7 54 e3 54 57 3 52 8 56 5 52 0 $9 5 53 8 56 0 51 0 57 2 pH (umts) 53 5 56 3 5: 3 Se 5 53 5 Feb 65 66 67 66 66 6.7 08 66 65 66 67 68 69 66 68 69 69 65 May 62 6.7 63 59 68 67 67 68 67 64 64 59 65 66 66 68 63 0.0 68 68 63 0.0 70 76 Au9 61 68 6.3 60 66 67 62 63 59 Nov 60 64 85 6.5 67 0.1 60 67 70 6.2 60 69 68 62 61 69 66 68 J _ 69 66 67 65 g Aaaval Mesa 66 66 68 66 66 66 66 07 67 66 _ 68 e6 63 64 6 43 6 68 6 53 6 25 6 73 6 68 6 53 6 25 6 50 6 58 6 65 6 73 6 48 6 30 6 78 6 85 6 53 6 28 6 85 Amahady (mg CACO 3n) 6 95 6 38 6 20
] Feb May 90 12 5 13 0 11 5 11.5 13 0 85 12 5 13 0 10.0 80 95 70 12 5 95 11.0 80 11 0 10 0 13 0 75 11 0 de 12 5 t 12.0 11.5 12.5 11 5 12.0 11.5 11.0 11 5 11.5 12 0 Aug 11.0 12.0 12.0 11.5 12.5 12.5 12 5 11 5 12 5 12 0 12.5 11.5 14 0 to 0 13 0 10.5 13 0 14 0 12 5 12.0 12.5 10 5 14 0 16.5 12.5 11.0 13 5 15 5 13 0 12 0 Nov 12 0 13 0 11 0 11 5 12 5 13 5 12 5 16 5 11 5 12 0 11 0 13 5 11 5 _ 12 5 13 0 12 0 12 0 Aaavai vena 11 50 12 25 12 0 12 0 13 0 12 0 12 0 '30 13 0 12 13 13 00 11 63 12 00 12 38 11 89 to 63 11 63 1063 11 86 Cmence (mgn} 11 88 12 88 11 13 11 38 12 00 13 50 11 25 1 63 *3 t5 '3 50 Feb 51 55 52 55 57 5.7 5.1 55 5.2 55 51 56 54 54 54 54 56 53 $5 May 48 52 50 5.2 50 54 48 54 50 Se 49 40 49 50 54 46 52 51 50 47 5.2 47 Au9 53 54 55 5.7 56 47 51 49 62 49 46 53 hev 5.1 55 59 50 88 54 52 52 5.2 55 46 50 50
$1 48 . 52 - 48 54 47 53 46 Anava' Mesa 53 48 53 48 52 49 53 48 52 48 55 51 58 51 5 06 5 23 5 23 5 30 5 43 5 13 5 C8 5 15 5 18 5 08 5 23 5 43 5 05 6 0e 5 30 5 10 5 18 5 13 5 30 Suvate (mgn) 4 90 5 25 5 C8 Feb NS NS NS NS NS 37 NS 58 NS 40 NS NS NS NS NS 36 NS 45 NS May NS NS NS NS 7 55 NS NS NS NS 713 NS 6 26 NS NS NS NS NS 6 11 NS 6 99 NS Aug NS NS NS NS 36 NS NS NS NS
- 55 93 39 63 34 NS NS NS NS 55 41 61 35 NS Aaau siVesa 6 53 3 65 8 22 4 85 NS NS NS 6 20 3 70 5 61 3 85 6 55 4 00 Cacum (mon)
Feb 2.70 2 66 2 74 2 66 2.64 2 64 2 76 2 64 2 68 2 64 2 65 2 63 2 70 2 60 2 79 2.70 '
var 2 84 2 61 2.99 2 82 2 67 2 87 2 85 2 88 2 89 2 86 2 89 2 60 2.94 2 88 2 88 2 81 2 88 2 78 2 93 Aug 2 94 2 86 2 67 2 62 3 01 2 90 2 97 2 81 3 07 2 97 2 60 3 18 3 17 2 94 2 68 3.15 3,14 2 93 2.68 Nov 2 90 2.69 3.13 3 18 3 05 2 62 3.24 3.17 3 03 i 2 73 2 77 2 72 2 76 2 66 2 74 2 65 3 21 3 17 2 79 2 74 2 76 2 75 2 77 2 74 2 77 2 64 2 75 2 73 Aaavat Mesa 2 80 2 71 2 77 2 79 2 59 2 53 2 e2 2 51 2 91 2 86 2 78 2 71 2 91 2 85 2 81 2 72 2 80 2 71 2 88 Msgaetum (mg't) 2 82 2 e6 2 72 2 96 2 88 2 86 27, 2 95 2 88 Feb 1.24 1.29 1 26 1.29 1.24 1.28 1.26 1.28 1.25 1 29 1 25 1 28 1.27 1 26 1.25 1.28 May 1 23 1.23 1 28 1.25 1.26 1 24 1 26 1 23 1 26 1 26 1.25 1.22 1.25 1.26 1 25 1.23 1.25 1.35 1.27 Aug 1.29 1.30 1.25 1.23 1.28 1.27 1 24 1 20 1 28 1 27 1.26 1.33 1.37 1.29 1.30 1 32 1.37 1.29 Nov 1.30 1.28 1.23 1.33 1.26 1.33 1 27 1.34 1.37 1.32 i 33 1 36 J4, 1 37 1 29 1 34 1 36 _ 1 34 1 33 1 36 1 28 1 33 1 38
_ 1 34 1 31 1 34 1 39 _ 1 34 1 36 1 34 1 38 1 31 Aaavat Mesa 1 27 1 29 1 30 1 32 1 27 12S 1 30 1 33 4 33 9 33 1 31 1 28 1 29 1 26 1 29 1 30 1 30 1 29 1 28 1 30 1 32 1 29 1 27
- 29 ' 31 NS e Not Sampled
_ _ _ _ _ _ _ _ - _ _ _ _ --_________m_m-. - _ _ , ._ - __ _
m ]
z b G/ %./
TWe 2-3. (Continued)
Men 0 Zone Meng Zoae MNS O,scha ge Meng Zone LOCA710N 1.0 Backgroved Bacag w ac 20 40 50 00 CEPm S # ace Boeom S# ace 11 0 Bettom S# ace Sudace Boeom Sudace PAR AVE'ERS VEAR 96 07 96 97 96 Boeom S # ace Beom 97 96 97 96 97 96 07 96 97 Potassnam (mgn) 96 97 96 97 9e 97 96 9' Feb 1 60 1.76 1 63 1.77 1.62 1.75 1 63 1.74 1 67 1 75 t SS 1 73 1.71 1 72 May 1 48 1 58 1 61 1 64 1 72 1 57 1 69 1 61 1 65 1 61 1 67 1.56 1 64 1 60 1 67 1 60 1 62 1 55 1 63 Aug 1 50 1 $5 1.70 1 56 1 64 1 57 1 55 1 61 1 51 1 45 1 42 1 56 1 56 1 44 1 52 1 51 1 51 1 51 1 52 1 46 1 51 1 51 1 50 1 49 1 58 1 53 1 55 Nov i 60 1 56 1 e3 1 57 1 73 1 47 1 57 1 42 1 55 1 45 1 58 1 56 1 62 1 55 1 60 1 59 i 60 1 55 1 56 1 de Aaavel Vese 1 55 1 58 1 61 1 62 1 54 1 61 1 59 1 e5 1 56
- e2 1 62 1 61 1 61 1 61 1 60 1 59 1 60 1 61 i e' Sooeum tmgn) 5 58 1 62 1 59 1 61 1 60 1 55 1 e2 1 55 t 56 1 56 1 59 Feb 4 91 6 24 4 85 5 70 4 73 6 03 5 38 5 60 4 90 5 59 5 26 6 06 5 00 May 3 81 4 69 4 39 4 54 5 91 5 13 5 77 4 83 5 94 4 98 5 22 5 09 4 58 4 73 4 62 4 67 4 55 4 38 4 75 4 56 4 74 Aug 4 27 4 75 4 43 4 51 4 55 4 37 4 75 44' 4 '6 3 71 3 92 3 90 4.19 4 00 3 89 3 68 3 94 4 25 4 38 Nov 3 81 4 08 3 84 3 78 3 96 4 29 4 23 3 73 3 96 4 46 _ 4 95 4 67 4 56 5 65 4 SS 5 13 3 99 4 26 3 92 3 99 4 60 .5 15 4 64 5 05 4 73 5 12 4 54 4 97 4 50 Anasat Mess a 36 4 90 4 46 4 6e 4 63 4 88 5 15 4 74 5 39 45? 5 92 5 17 '
4 77 4 6e 4 59 4 75 4 74 4 64 4 66 4 71 Atumreum (mgn) 4 73 4 76 4 52 4 e5 4 e9 4 53 4C 4 e$
Feb NS 0 11 NS 0 12 0 15 0.10 0 24 0.11 0 18 0 09 NS 0 11 May NS NS 0 11 0 21 013 0 18 0 11 0 26 0 18 0 09 NS 0 09 0.14 0.10 019 0 09 0 to 0 12 NS 0 27 0 t9 Aug 0132 0.12 NS 0 16 0 13 0 10 0.18 0 09 0 15 0 10 0 03 0 14 0 09 0 12 0 06 0 18 0 08 0.14 0 21 0 13 Nov 0 08 0 12 0 06 0.13 0 08 0 06 0.18 010 = 0 09 011 < 0 09 011 = 0 09 0 it 0 09 01 0 C5 0 *6 0 09 Aaave' Mene 0 12 0 08 011 = 0 09 017 = 0 09 012 < _ 0 09 0 14
- _ 0 09 017 < 0 09 C 15 0 18 0 '6 = C C9 0 2*
- 0 09 0 13 0 10 0 13 0 09 0 16 0 09 0 16 0 09 0 12 0 10 0 14 0 11 017 0 09 tro" (mEM)
Feb 017 E O 17 C" 21 0 12 0100 0 041 0.121 0 082 0 068 0 054 0122 0 056 Vay 0 075 0 046 0 062 0 048 0 090 0 053 0.115 0 056 0.117 0 081 0124 0 057 0 218 0 090 0 095 0 049 0 035 0.103 0 072 0 066 0 041 0 050 0 036 0 177 0 20C 0231 Aug 0 054 0 016 0 260 0.262 0 040 0 066 0.189 0.114 0075 0 053 0 028 0 110 0 095 0 056 0 040 0150 0 106 Nov 00*2 0 077 0 221 0 052 0 043 0 038 0 036 0 077 0 293 0 042 0 031 0 105 0394 0C36 0C26 0 501 0 073 0 114 0 069 0 059 0 079 0 093 0 067 0 059 0 257 Aaava?Vesa 0 055 0 075 0 062 0 000 0 058 0 053 0 109 0325 0 068 0 088 0141 0136 0 057 0 054 0123 0 111 0 066 0 046 0 052 0 080 til 02 4 0 C75 u segenese (mgn) 0 049 0 0e6 0 120 0 067 0 042 0 110 0 224 0 C8' O O'=
'9 0 t6' Feb 0 02 0 01 0 02 0 03 0 02 0 01 0 02 0 02 0 01 0 01 0 01 0 01 May 0 01 0 01 0 02 0 03 0 02 0 01 0 02 0.04 0 03 0 03 0 07 0 04 0 01 0 01 0 05 0 03 0 01 0 01 0 01 0 03 0 09 Aug 0 02 0 01 0 05 0 04 < 0 01 0 01 0 03 0 04
{ 0 02 0 88 1 50 0 02 0 02 0 62 1 31 0 03 0 04 0 02 0 03 0 01 0 01 0 04 0 06 Nov 0 05 0 04 0 60 1.63 0 01 0 01 0 66 1 44 0 03 0 03 0 45 0 05 0 0e 0 05 0 04 0 06 0 05 0 05 0 04 1 56 Amavat Mean 0 05 0 06 0 04 0 05 0 03 0 03 0 04 0 02 0 02 0 26 0 41 0 02 0 02 0 19 0 10 0 04 0 06 00' 0 05 Cadm.vm (vgq 0 35 0 02 0 02 0 02 0 03 018 0 44 0 02 0 01 0 19 0 40 0 C3 0 03 0 '5 0 44 Feb NS NS NS NS NS
- O1 NS < 01 NS
- 01 NS NS NS NS May NS NS NS NS
- NS
- 01 NS = 01 NS NS NS NS 0.1 NS < 01 NS < 01 NS NS NS NS NS = 0.1 Aug NS NS NS NS < 01 = 01 NS = 0.1 NS NS NS NS NS
= 01 < 01 < 01 = 0i NS yL NS N9 < 01 = 01 <
AaaverMeam < 01 < 01 01 < 01 <
01 < of NS NS NS NS Cooper (ugn) 01 < 01
- 61
- 01 < 01 = 01 Feb NS NS NS NS NS 24 NS 20 NS 22 NS NS NS NS May NS NS NS NS 1.5 NS 14 NS 19 NS 18 NS NS NS NS Aq NS 16 NS NS NS NS NS 15 NS NS NS NS NS 21 15 17 09 1.3 NS NS NS NS NS Aaavar Mesa 19 09 NS NS NS NS 17 09 24 13 NS NS 18 20 1 55 15 1 75 NS NS LteG (vg'!) 16 16 14 1 85 16 Fee NS NS NS NS NS < 2 NS < 2 NS
- 2 NS NS May NS NS NS NS NS NS < 2 NS < 2 NS NS NS NS
- 2 NS
- 2 NS < 2 NS NS NS NS Aug NS NS NS NS NS NS
- 2 NS < 2 NS NS NS NS
< 2< 2 e 2e 2< NS Anava!vesa
- 2< 2 < 2< 2
- 2e 2=
] NS NS NS NS e 2< 2 e 2< 2 NS N$ NS NS Ziec (vgM) 2 < 2= =
2 2< 2 Feb 8 = 5 7 < $= 5= 5 S< 5 5 5< 5* 5 6< 5 e May a 5 * $ = $= 5< 5= 5* 5 < Sa 5 5* 5 < 5
- 5 5 = 5= 5
- 5< $< 5= 5 = 5* 5 = 5< f Aug 8
- 5 5= 5 < 5= 5
- 5 = 5 <
- 5 5= 5
- 5< $= 5= 5< $< $ = 5=
5 5 Nov < 5 = 5 * $< 5= 5= 5
- 5 < 5= 5 = 5< $< 5 6
- 5 < 5 5< 5
- 5= 5* 5* 5 < 5= 5 < 5*
Amaunivenn 65 * $0 55
- 50 50< 5 < 5< $< $< 5
- 5 = 5 50 50
- 50 50= 50 < 50 e 50 53 < 50 < 50= 50 < 50= 50 50 50 = t2 < $0 NS
- Not Sampted I
Tab?e 2-5. (Contnued)
/ ,~\ [
/ N i
/ \
/ \ I [
(b e
( ,} \ v <j Mn869Zow Metag Zone MNS Dschage MmmgZone Background LOCA7CN 1.0 Ba:x;*ow 20 40 5.0 80 11 0 etPM Sudace Bottom Sufface Bottom Surface Sudace Boeom Sudace Boeom Sudece Boeom PAR AMUER S YEAR 96 97 96 97 96 97 96 07 96 97 96 97 96 97 96 07 96 97 9< 97 9< 97 Nea'e (ug/I)
Feb 200 250 200 200 230 210 270 210 250 230 220 250 250 210 310 230 320 250 350 300 May 250 280 370 380 360 320 270 300 360 380 200 280 270 330 320 360 Aug 260 280 400 380 260 230 400 400 170 130 370 310 150 130 390 320 180 140 160 150 310 260 120 100 390 280 90 120 410 290 Nov 120 90 120 90 130 90 130 90 120 00 130 90 130 90 130 _ 100 120 90 Aneual Mese 2000 '87 5 280 0 2a5 0 195 0 182 5 2S75 160 150 150 '50 250 0 1875 165 0 1950 205 0 252 5 230 0 205 0 1775 307 5 250 0 255 0 Ammonis (vgn) .5 0 332 5 2900 Feb < 50 50 < 50 = 50 < 50 < 50 < 50 60 < 50 < 50 < 50 < 50 < 50 00 * $0 < 50 <
May < SO 4 S0 < 50 < 50 < 50 60 <
$0 60 90
- 50 90 60 50 < 50 < 50 80 < 50 < 50 < 50 < 50 < 50 < 50 < 50 < SC <
Aug < 50 < SO 80 90 < 50 < 50 a 50 < 50 a 50 50 60 70 100< $0 e 50 * $0 60 130 < 50 = 50 <
Nov 70 60 50 80 50 < 50 80 80 100 60 70 60 70 50 80 50 . 80 60 60 Anny3I Mese 55 0 60 60 < 50 60 <50 e 50 < 50 < 50 * $0
$2 5 70 0 62 5 55 0 55 0 57 5 67 5 70 0 57 5 57 5 52 5 Total P%sphorous (uon) 55 0 75 0 52 5 = 50 0 52 5 60 0 60 0 < sc 0 e' 5 60 0 Fen 15 10 18 12 8 13 1a 15 12 9 11 8 13 8 20 8 May 11 9 15 28 23 36 14 36 25 26 12 10 14 7 9 6 10 11 -
11 9 12
- 5 9 6 13 11 12 17 '5 25 Av9 18 18 11 10 11 19 12 11 22 7 Nov 15 16 14 8 15 8 12 17 13 8 10 12 < . 5 10 7 10 10 9 8 7 8 0 8 9 8 9 8 Aamu elMese 11 5 11 13 5 17 95 24 11 *0 99 7 11 13 3 13 10 3 6 13 0 8 12 0 11 12 8 6 15 5 17 Cc,.@osp5ete (ugn) 17 8 15 20 e 19 Feb = 5< 5 = 54 5 5
- 5
- 5 6 < 5 5
- 5 5 5* 5 7< 5 10 < 5 May = 5= 5 8< 5= 10 < 5 10 8 5 5 = 5< $ = 7 5= 5 5= 5 10 < 5 7* 5 7=
Aug = 5= 5 9 5
- 5< 5 = 5 5 5< $
7
- 5 6 7 8 < 5 12 6 8 = 5 e Now 5< $ < 5< $ e 5< $ < 5* 5 6 ,0
$< 5 g 5* 5 < $ 2 < $< $ < 5= 5
- 5= 5 6< 9<
Aaeu stMesa 50 50 10 0 50 50 50 50 6 50 5 5 0 55 5 50 7 7.0 6 68 5 70< 75 Saca (mgi) 5 7 Feb 38 29 38 30 35 2.9 38 30 36 29 34 May 2.7 35 30 3.7 30 40 31 41 34 42 38 43 41 3.3 4.3 2.8 35 33 4.3 20 3.5 32 36 3.2 4.2 25 36 38 4.4 32 31 39 48 g Aue 25 1.9 43 5.0 2.4 2.0 40 49 20 Nor 2.8 25 2.1 37 43 2.3 1.7 42 4.6 23 22 41 48 e 32 29 32 28 33 28 33 28 33 28 32 29 32 29 32 28 31 27 g Aaav alvea9 30 28 37 36 30 28 36 38 29 28 31 29 35 36 31 26 38 36 34 33 35 32 35 40 35 43 NS e Not Sampled
4 80
' N N~
-# 72 l
8 LC l j
\
s i
s A 5.9 i MS
\
.rA l l 13 9.5
- g. ;
11
- l q, s
- s 8
l i
0
- . l A 5 l
27 1 i
\
'4 \
Figure 2-1. Water quality sampling locations for Lake Norman.
I 2-20
i i
McGuire Rainfall i 8 l
! 6-l l' $
- 54- -
i i
s l 2-
!O 0 : : : :1:::'::
{ JAN FEB MAR APR MAY JUN JUL AUG SEP OCT'NOV'DEC
- Month l i
) C 1996 E 1997 l i
j Figure 2-2. Monthly precipitation in the vicinity of McGuire Nuclear Station.
l 1
j O
2-21
/- . r ,.,,.,
> 4 , 4
\%s/
\
%. / \
%y/
JAN FEB MAR Temperature (C) Temperature (C) Temperature (C) 0 5 to 15 20'- 25 30 35 0 5 10 15' -20 25 30 35 0 '--- ' ' *- '
0 ' - ' '- ' '
0 5 10 15 20'- 25 '
30' 35 0 ~ 0 ' ' '
l Si
[
5 Si ici ici 10f g15i g15i g15i G G S
$ 20i h20i $20i 25i 25i '
25i 30i l 30i 30i 35 ' 35 ' 35 '
APR MAY JUN b)
Temperature (C) Temperature (C) Temperature (C) 0 5 to 15 20 '25 30'- 35 0 5 to 15 20 25 30 35 0 $ to' 15 20 25 30' 35 0 ' '
'. 0 '- ' "'- '- *- '
0 ' '
t -
55 Si Si 10i 10f ici 1 155 K Si 1 15i k h . 5
$ 20-.
- '0;
$ 20i 25i ';i; 25i I 30i 30i ) 30i ;I 35 ' 35' 35 '
Figure 2-3. Monthly mean temperature profiles for McGuire Nuclear Station background zone in 1996 (-) and 1997 (-).
% s s \
f i
JUL AUG SEP [
Temperature (C) Temperature (C) Temperature (C) 0 5 10 15'- *20 25 30 35 0 5'- 10 15 20 25 30 35 0 0 ' ' ' - - - ' -
0 '^ *- '- '- ' 5'- 10 15'- 20 25 30 35
'- '- ' i O
) ;
5, 5,2 5,2 t
102 102
< 102 -
j, ,.
K15i E15i 1 155 (
E E [
E 8 23i 8 20i 8 20i 25- { 25- 25-L
)
30- 30- l 30i I
35 35 ' 35 '
y OCT NOV DEC Temperature (e) Temperature (C) Temperature (C) 0 5 '- '
10 15 20 25 30 35 0 $ to'- '15 20'- 25 30 35 0 5 to 15 20 25 30 35 0, ' ' ' '
O, O,
[
Si 55 Si i
toi toi 10i 1 15i 1 15i 1 15i :
R E E !
8 20i 8 20i 8 20i i 25i 25i 25i ,
30i f. 30i 302
~
35 ~ 35
~
35 I
[
Figure 2-3. Monthly mean temperature profiles for McGuire Nuclear Station background zone in 1996 (-) and 1997 (H.
)
i
- - . . _ . . . - . . . _ ~ - _ - -._ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ - _ - - _ _ _ _ _ - . . - - - _ _ - _ _ -
s d
~
JAN FEB MAR Temperature (C) Temperature (C) 0 5 to 15 20 25 30 35 Temperature (C) 0 5'- to 15 20 25 30 35
'O, ' ' - '- -'- * '-
0, ' - ' ' *- '-
0 5 10' 15 20 25 30 35 0, '
5 Si Si 10i toi 10i g15i { 15i f g15i N-t . t t 8 20-f $ 205 f 5 20i 25i 25i 25i 30i - 30i 30i 35' 35' ~
35 N APR N MAY JUN
.A Tempemture (C) Temperature (C) Temperature (C) 0 5 to 15' - 20 25' -
30 35 0
' ' ' 5'- '
10 15' -'20 25 30 35 0 5 10 15 20 25' 30' 35 0~ 0 '
O ' ' ' '
f I Si Si Si toi 10i ici g15i g15i g15i t 2
$ 20i i 8 205 $ 20i 25- 25-
~
255
}
30- 30-
~
30-k I l j 35 ' 35 ' 35 '
i Figure 2-4. Monthly mean temperature profiles for the McGuire Nuclear Station mixing zone in 1996 (-) and 1997 (-).
m- . . . . . . . . . . . . - . . . - - . - - - .-
k '
b i
JUL AUG SEP Temperature (C) Temperature (C) Temperature (C) 0 5 10 15 20*- *- 25 30 35 0 5 to 15 20'- 25 30 35
'- ' 0 5'- '10 15*- '20 25 30 35 0 0 '- * ' '- '- '- -
0
(!
52 52 52 i
102 102 '
10-i !
{ 15i g15i { 15i ,
f R f '
8 20i 8 20i 8 20i /
25i 25i 25i 30i i 30i j 30' j ) '
35 35 " 35 '
bJ Temperature (C) Temperature (C) Temperature (C) 0 5 10 15' 20 25 30 35 0 5'- '10 15 20 25 30 35 0 5 to 15 20 25 30' 35 0, ' ' ' '
0, ' ' ' ' ' '- ' '
0- p' ;
Si Si Si 10i 10f 10f l E15i E15i E15i 5 5 6
$ 20i $ 20i 2 20i ; i i
25i 25i 25i 30i 30i 30i !
35' 35 ' 35
~
Figure 2-4. Monthly mean temperature profiles for the McGuire Nuclear Station mixing zone in 1996 (-) and 1997 (A :
l l
/~'
\ '
40 35 - ,p-
- n ,
m 30 - ',
O '
w .e o g 25 -- j c ,o-
$O 20 --/
1 I
o' Q.15 -- ,,-
E p* 10 - I i
5--
0 : : : : : : : : : : : :
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month I
1 l
l L']
lQ 12 a*, ,
t 10 -- 'o.,
i o m ~
c:d 8 -- '* - #
cn ',
i v
E o,
- ,. l l c- 6-- .. - -e 1 tn N
4 !
O i 1
l l 2-l 0 : : : : : : : : : : : :
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month
- Figure 2-5. Monthly temperature and dissolved oxygen data at the discharge location (loc 4.0 @ 0.3m) in 1996 (O) and 1997 (5).
a 2-26
~
[
'd t JAN FEB MAR i
Distofwed Owygen (mg4 Ofssotved Owygen (mg4 Dissotved Owygen (mg4 4
0 2 4 6 8 10 12 0 2 4 6 8 10 12
- * - 0 2 4 6 8 10 12 0 ' ' '
0 ' '- ' '
0 ' ' '
i
( -
'r ^ -
'\ -
. t 5- . .
5: 5-ici h toi 10i i
gisi gisi gisi ,
t i f R 8 20-. 8 20 . .
8 20:. ;
t
^
2si 2si 2s-.
{
20- 1 20i 30i (
3s' 3s ' 3s' .
M APR w MAY JUN N Dissolved Oxygen (mg4 Dissotved Oxygen (mgM D!ssolved Oxygen (mg4 0 2 4 8 8 10 12 0 2 4 6 8 10 12
^'^ ' 0 2 4 6 8 10 12 0, ' '-
r, 0, ^'^ * ' ' '-
0, '- ' ' ' '
si si si 102 ~
10i toi i
E15i E15i Etsi s s s 20i b
$20i k20i
(
d 2s i- i 2s 2si ( I 30i I 30i 30i 1
as as ' -
as f i
Figure 2-6. Monthly mean dissolved oxygen profiles for the McGuire Nuclear Station background zone in 1996 (-) and 1997 (-). !
i l
I i
- - - . - - . . . ..,n
JUL AUG SEP Dissowed owygen (mg4 Dissotved Owygen (mg4 Dissolved oxygen (malt.)
0 2 4 8 8 10 12 0 2 4 8 9 10 12
'- 0 2 4 8 8 10 12 0, ' ' '- ^*^
0, *- * ' ' -
0 ' ' ' -
i Si Si Si 10i 10-~
ici g155 { 15 2 ,
g15i R R R
$20i 8 20-' $ 20-' i 25i : 25- 25-
\ ,
30f 30- 30-35 35 ~
~
35 OCT NOV DEC Dlssotved Owygen (mgG Dissolved Owygen (mg4 DIssotved Owygen (mg4 0 2 4 8 9 10 12 0 2 4 8 10 12 0 ' ' *- '
9 0 2 4 6 8 10 12
- O ' ' '
0 ' ' '
5- [
ff' Si 5-.
f 1
10i i 10i 102 g15i g15i g15i s e s 20i 20i k20i ('
25i 25i 255 i 30-30-[ 30-[
35' 35 ~ 35
~
l Figure 2-6. Monthly mean dissolved oxygen profiles for the McGuire Nuclear Station background zone in 1996 (-) and 1997.(-). [
C O O JAN FEB MAR Ots sot.-ad Owygen (mg4 Dissotved owygen (mg4 Diesotved Oxygen (mg4 0 2 4 8 8 10 12 0 2 4 6 8 10 12
- 0 2 4 6 8 10 12 0 ' ' ' - -
0 * ' ' ' ' ' ^'- ^'^
0 '
Il l l1 Si l si l Si I 10i ici 10i l
g15i g15i g15-'
5 5 5 k 20i , k20i k20i d l
!)
25; 1 25;. 25-30 , 30
( 30z 1 4 35' 35' 35 '
9 APR MAY JUN Dissolved Owygen (mg4 Dissolved Oxygen ( ng4 Dissolved Oxygen (mg4 0 2 4 8 9 to 12 0 2 4 6 8 10 12
'- ^'- 0 2 4 8 9 10 12 0, ' '
0,
' ' ' * '^
0, ' ' ' '
Si Si l Si 10f 1ci 10f g15i g15i g15i g g g 8 20f L 8 20i 8 20i 25-f j\
25- 25-30,2 j i 302 30.
ff p 35 ' 35 ' 35 '
Figure 2-7. Monthly mean dissolved oxygen profiles for the McGuire Nuclear Station mixing zone in 1996 (-) and 1997 (-).
m r% -
\ \4- %
\
i JUL AUG SEP DIseotved Owygen (mg4 Otssotved Owygen (mo4 0 2 Otssotved owygen (mgo 4 6 9 10 12 0 2 4 6 8 10 12 j 0 ^'- ^*- '- '- '
0 2 4 6 9 10 12 0< 0 '
( l 5 5 5 l 10-10-
/ 10-
[
g15i g15i ,
g15i R R R 8 20f 8 20i .,
8 20-
- )
2Si 255 25-30i 30i 30-b 35 35 ~ 35 '
I4
. uo OCT NOV DEC Disserved owygen (mgo Dissolved owy=en (mg4 Dissolved oxygen (mgo O 2 4 6 9 10 12 0 2 4 6 8 to 12 0 2 4
- - 6 0 10 12 0, '
-/ '
0, ' '- -- '
O, 5 .' 5 . 5 ?
10i 10i 10f j ;
i g15i g15i g15i :
E R E '
820i 3 20i (
) 8 20i ( ;
~
25-r 25i 25i ;
i 30-30i 30i ,
35 ' 35 ' ~
35 Figure 2-7. Monthly mean dissolved oxygen profiles for the McGuire Nuclear Station mixing zone in 1996 (-) and 1997 (-).
t h
I I
Sampung Locations S:rnpeng Locations 235: , o eo si o uo $s.o ise s2.o es o no ear 235' i.e $ ,.o
- . . . , t . . i . .
e.o 52.e sto ss.. e2.o ato no no
- j =
y y%= p *'$ _./ m ) Sw* y
)
g "S / I T 9 O L g* (/
j 220 s 2 22 e r
5 2tol
/ , cy 5 21o2 2o5' 205' e
2coi Temperature (deg C) 2eg Temperature (deg C)
Jan 20,1997 Feb 6,1997 195 -
.g. .g. .g. ;
.g. .g. .
.g. . ..
.g 19f' . . ... . . . . . . . . . . . .
Distance from Cowans Ford Dam (km)
Distance from Cowans Ford Dam (km)
Y d 240
, 240, Sampung Locadons
- Sampling Locations 235' 1o eo 1s 0 1s 9 235' t10 13 o 62.0 es o 72 o 80 0 1.0 eo 11 o 13 0 15 o 15.s e2.0 $9 0 i a a a a a a a a a
'2 o 80 o
- a a a a a a a a 23o-
} ,Q gy 23o' ) \
6 %9 W Vo
_ 225' 22 E -- ~ tt s 9 E -
S ,
to j 220 j 22d , /
215' 215 I 21 e 21o' m
=
205- V' O= 205-i if 2cg o Temperature (deg C) 2od Temperature (deg C)
)
Mar 4,1997 :
195 - l Apr 10,1997
.g. g .g . . .
- j. .g 19f' . . . . . . . . . .;. . . . . . . - .
Dist nce from Cowans Ford Dam (km)
Distance from Cowans Ford Dam (km)
Figure 2-8. Monthly reservoir-wide temperature isotherms for Lake Norman in 1997.
/
_ Sampang Locasone Scynpane Locations 23s' 1o eo 11.0 13 0 15 a 15 9 82 0 es 0 72.0 00 0 23s' 1.0 80 11.0 13 0 15.0 15 e 62 0 es c '2 c 50 o 1 1 1 1 1 1 1 1 1 1 1 1 t i t t t t . .
3G
- [ 6 230: ) n % 1 "' =o , , - -
225' _ ,o w 22s' '
- C 7
v w / j us 1 ns 1,,,. -
j N, L s 5 21L ~
W ^~"% '^/ ,, ,
f 20 .
E
- 210' m 4 20s' 205' O'
20g Temperature (deg C) 20 s Temperature (deg C)
May 8,1997 7 Jun 10,199<
195 '
u' s~ 'th' ~1 h' ~2 b' '2s ab' 's's ' 'to' 'sh ' u - 'g' w w w W
'4h ' 'sb ' -2's ' W 'ic' ~45' u ss Distance from Cowans Ford Dam (km)
Distance from Cowans Ford Dam (km)
Ig d 240 Sampling Lccasons 240 Sampnng Locations 235' t0 e0 11.0 13 0 15.0 15 e e2.0 59 0 72.0 80 0 23 0 1.0 80 11 0 13.0 15o 15e e2.0 690 ao e:: 0 t 1 i t i i i i i i i a 1 i 1 1 A . .
U l -l
*'# U #
,225- L 2e- I
,22s' f ,m/
- D !
g220-1 w
D j-v O 20 3
-q' f220-g _ m*
5 215, 1
_g 21s-y _- r eM ~- wg j
w
% ]s j
~ '
g9 2io" _
w
= 210' o] $
2052 5 205- - seb 2d )
i Q Temperature (deg C)
Jul 9,1997 2cg Temperature (deg C) l Aug 6,1997 19e. ' 19'_
g-g -
g g 3 jg- is' 'u' 's'
'sb ' 's's 'E' '6 'i6 '6 '6 's' ~i0' 'is' s' 's's Distance from Cowans Fod Dam (km)
Distance from Cowans Ford Dam (km)
Figure 2-8. Continued.
240 Sompting Locations
Samp!ing Location 3 335' 1.0 00 11.0 13.0 ta0 129 G20 G9 0 F2.0 80.0 235' 1.0 e0 11.0 13 0 150 159
. . . . . . . . . 62.0 69 0 *20 80 0 23q j ,( qv e ~ 29 ,o_
22 w 23 s _,j z we j j j ,, s 225 4
j 220 j 22s )
E -
f27 E
g 215'
= _
~ __ -
~
fs 215' Q
210- _
210
'% 0 2eg Temperature (deg C) 20g Temperature (deg C)
- ~
Sep 3,1997 195~
Oct 1,1997 195' 4
.,.. .,3 .
Distance from Cowans Ford Dam (km)
Distance from Cowans Ford Dam (km) bJ b
W 240 240 Sampling Locations Samphng Locations 23 10 90 11.0 13 0 15.0 15 9 235-* 1.0 62 0 89 0 72.0 00 0 80 11 0
. 13 0 15 0 15.9 62 0 69 0 '20 00 0 23d g (,,j g gg 2ss v, ,,, , ,
22
~
I
? s: 7 22s f'
j 22s j220- V E
E f215' f 21s [ 13 9 9 b 210' 3 2 210' 20$- I 205-
~
2cs Temperature (deg C) 2cs Temperature (deg C)
.__ Nov 6,1997 : Dec 2,1997 195" . - . . . . . .. . . . . . . . . . . . .
195' .
Distance from Cowans Ford Dam (km)
Distance from Cowans Ford Dam (km)
Figure 2-8. Continued.
340, Sampfing Locanons -
SampNng Locations 83b 1.0 Q.0 11.0 13 0 1G 0 19.9 82.0 69 0 23 72 0 . 80.0 1.0 a0 11.0 .13.0 150 15e s20 69 0 72 o ec o a a a a a a a a a a -
a a a a a a a a i .
j 23 6 , 230' f 225' ,
225' >
1 1 -
9 !
I 2205 4 -
/ m =l220' E : :
A
( 0 t I 215- -
J, 215: 3 !
s 210' O 210'
=
205" 205' 3
/
2cg Dissolved Oxygen (mgA) 2o0 Dissolved Oxygen (mgM)
' j
. Jan 20,1997 -
Feb 6,1997 195 . . . . . . . . . . . . . . . . . .
. . 19f . . . . . . . . . . . . . . . .
. . . . I Distrw from Cowans Ford Dam (km)
Distance from Cowans Ford Dam (km)
Y W 240 A 240 Sampling Locations !
} Sampilng Locations
[
23k 1.0 00 11.0 13.0 15.0 159 62.0 69 0 72 0 80 0 23k 1.0 80 11.0 13.0 15.0 15.9 62,0 a a a a a a a a a a 69 0 72 0 80 3 a a a a a a a a . t 23y 23o' V 9 -
, 2~ .
, d .- ;
220' 22 g 215' '
4-i
"' 210 ' t) \ 9 j 21%
210-205-205, ,
ros Dissolved Oxygen (mgA) 2od Dissolved Oxygen (mgM) j Mar 4,1997 : Apr 10,199e 19t ' . .
.g . . . . . - .
.g. . .
.g. .g 19
(
Distance from Cowans Ford Dam (km)
Distance frordi Cowans Ford Dam (km) !
Figure 2-9. Monthly reservoir-wide dissolved oxygen isopleths for Lake Norman in 1997.
f 1
240 Sempfing Loca"Jons SOrrpling Locations 23c10 00 11.0 13 0 15.C 15 0 F2 0 69 0 72.0 80 0 235' t.0 80 11.0 13 0 15 0 15 0 e2.0 es o 72 : 80 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 . .
23 S d *d S$ F 230~ \ O
- A' * ' #
, nc I
, nc 0 H W
j~ 210 s% 8
!":7m
.i
- 210' 1
l 2:s-
- 20s Q fh 2eg Dissolved Oxygen (mgM)
May 8,1997 20 s y Dissolved Oxygen (mga)
Jun 10,1997 195~
19E Distance from Cowans Ford Dam (km)
Distance from Cowans Ford Dam (km) 9 24C 240 Sampling Locations Sampling Locations 235~ 10 80 11.0 13 0 15 0 15 e e2.0 00 0 72 0 00 0 2 1 235' 1.0 50 11.0 13 0 15.0 15 9 (20 690 '2 C 60 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 .
22 6 9
22 "
22 21 %
215-
'f b 5 -
w 210~
- j Jul 9,1997 Aug 6,1997
.g- .g. g.
19
.g . '56 E5' 5'S U' '$' '1'0 ' '1E '2'O ' '2'5 ' 30' 'i5' '40 '4 5 ' 50 '55 Dis *ance from Cowans Ford Dam (km)
Distance from Cowar* Ford Dam (km)
Figure 2-9. Continued.
240
_. Sampling Locations
[ Sampline Locations 235J t0 80 11.0 13 0 15.0 159 82 C 69 0 72 0 80.0 23$ 10 80 11.0 13 0 15.0 15.9 s a a a 6 a a a a s 62.0 69 0 72 0 80 0 4 a a a a 6 4 . . .
230 -
e e US 6 % 230' i /
/
225 -
_ 225- O ~'
h -
km $
~
~
1 N #
)
215
.) 215-.
9
- 210- 210' s O
205 205' ""
200 Dissolved Oxygen (mgM) 20g Dissolved Oxygen (mgM)
Sep 3,1997 i Oct 1,1997 195 .
.g- - - - . - - - - -
g- g j- g. g 19-C -
.g. . . . - - - - - - - - - - - - - - -
Distance from Cowans Ford Dam (km)
Distance from Cowans Ford Dem (km)
M 240 240 Sampting Locations Sampling Locations 235' to 80 11 0 15 0 15.9 23N 13 0 62 0 690 72 0 80 0 1.0 00 11 0 13 0 150 159 62.0 69 0 72 0 00 0
- . . . . . . t i . . . . . . . . . .
230' s m 6 -
23
~ - -
~
225' ! -
22N T
I 220a i s -
i .
j T 4
X 220' C'
1 { :
- e- g g 215- 3 j 215-,
I C 210-
~
I W
21CL' #
205' h-f 205' l 203] j Dissolved Oxygen (mgM) 20g Dissolved Oxygen (mgn) i i Nov 6,1997 Dec 2,1997 195-
- g. g- 195 g- -2'O ' 25' '3b' '65' '4b' '45' '5b' '5'S 0' '$' '1b' 'th' '2b ' '2'5 ' '3b ' 'i5' 'do' 'd5' 50 '55 Distance from Cowans Ford Dam (km)
Dista9ee fmm Cowans Ford Dam (km)
Figure 2-9. Continued.
}
(D
- N.J 30
/r' N 25 1
E 20 1 O
su$15 ,-
u== * ' a .
l
@ .o..e a# ,
l x in '
~.,
l 5 a-e "'...
l 0 l : : : : :
97000 97050 97100 97150 97200 97250 97300 97350 Julian Date I i
Figure 2-10a. Heat content of the entire water column (E) and the hypolimnion (O) l(- in Lake Norman in 1997.
4 12 -100 n
a 10 ',-
.-e" " .--, -80 e = ', '
=
c O
D 8 -
'.', E I E - "*e. .==.
r="'"l7 i
-60 2m l C '
- ! U) eCD 6 - - i p '.
- -40 C
g O 4 %,
[ g a-2
- 20
\ ..
0 . : : . . : 0 97000 97050 97100 97150 97200 97250 97300 97350 i-Julian Date l
i
- Figure 2-10b. Dissolved oxygen content (-) and percent saturation (--) of the entire water column (E) and the hypolimnion (O) of Lake Norman in 1997.
i 2-37
c 24C LAKE NORMAN STRIPED BASS HABITAT LAKE NORMAN STRIPED BASS HABITAT 235-1.0 8.0 11.0 13.0 15.015.9 62.0 69.0 72.0 80.0 23 1.0 8.0 11.0 13.0 15.015.9 62.0 69.0 72.0 80.0 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4
? hh [ '
a> w e ngsagge, a >>t%gr a%q;ep g 22
' 3 up g 22 e g et a g g g g ' g y#
8 id; r T 26deg C '/49p3% 74d77' w 21s-g g e .Wyg p#H)p p a ~#g
- M edS M W n ggewe % a
- rp< -
- 2rrgi j g&d A g N+QAggp"E@W.
8
= 215 3 N@gr seg -
26 deg C 2 mg1 Q gg{
21
' 03: $ 21
,03w"
{~""~'
- }kswg4)g*4W
.1z1g
'~
+' Jun 10,1997 '
; Jul 2,1997 200" lg fhy " 7 200'
. ~
19"' - 19 0 5 10 15 2G 25 30 35 40 45 50 55 0 5 10 15 20 25 30 35 40 45 50 55 Distance from Cowans Ford Dam (km) Distance from Cowans Ford Dam (km) Y t.a " 24C 24C~ LAKE NORMAN STRIPED BASS HABITAT LAKE NORMAN STRIPED BASS HABITAT 23 .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
~
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
~
1 1 1 230' * #'W40~ y 44 s s A 230'* #3
.,g "
W 225 ~ E ac f~"# n W 225' $" E I 220' g [ M [M WI.'
"h 26 deg C A 22ou- ^ ^
%$[T!f' w 215-. ,
8 m 215-
. # 26 deg C g -
2 rrgi g - 2 ng1 e e G 210', m 210-205'- Jul 17,1997 205' Aug 1,1997 200' 200' 190' - ., -:- -.-- ,-- --- ,- .--.... .---- ..- - . 190' - 0 5 10 15 20 25 30 35 40 45 50 55 0 5 10 15 20 25 30 35 40 45 50 55 1 Distance from Cowans Ford Dam (km) Distance from Cowans Ford Dam (km) Figure 2-11. Striped bass habitat (temperatures s 26 C and dissolved oxygen 2 2.0 mg/L in Lake Norman in June, July, August, September and October 1997.
s b
]
U' c LAKE NORMAN STRIPED BASS HABITAT 24C " ./ i LAKE NORMAN STRIPED BASS HABITAT 235't.O 8.0 11.0 13.0 15.015.9 62.0 69.0 72.0 80.0 8.0 11.0 13.0 15.015.9 62.0 69.0 1 1 235.j1.0 72.0 80.0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 230 230' ' T 2252 54'59 T 225' E : E g 22r g 22( g ' 4' 2s deg c g % 2s degc r 2152 c 215-w 26 g ' 2ng1 g 2 ng1 3 210' $ 210' 20p 20y Aug 13,1997 Sep 3,1997 200' 200' 19f .
, --- , ,- ,- . . -- , .- ,- - .. -, 195' -
0 5 10 20 25 30 35 40 15 45 50 55 0 5 10 15 20 25 30 35 40 45 50 55 Distance from Cowans Ford Dam (km) Distance from Cowans Ford Dam (km) ! i I w l LAKE NORMAN STRIPED BASS HABITAT ~ LAKE NORMAN STRIPED BASS HABITAT 235$.0 8.0 11.0 13.0 15.015.9 62.0 69.0 72.0 80.0 8.0 1 1 1 1 1 1 1 1 235't.0 11.0 13.0 15.015.9 62.0 69.0 72.0 80.0 1 1 1
- 1 1 1 1 1 1 1
~
2302 230'{' ..
.?
E J7 E g 220
- l$3558 kF J E 220- '
l t 8 . 26 deg C 8 : 4
! l 26 deg C 215-.hp !
r[ j 3x 2 ngi j 215- 7 ,
~-
2ng1 o . e Q 210-G 210-. . 1 205' 20p *
~ '
Sep 17,1997 -- Oct 1,1997 200' 200' 195' . . - - - .- - ,-- .-- 195' jg jg gig - g - g g- >- - , .
- - j .
Distance from Cowans Ford Dam (km) Distance from Cowans Ford Dam (km) i Figure 2-11. Continued. f
/3 ) \
CII APTER 3 L/ PIIYTOPLANKTON INTRODUCTION Phytoplankton population parameters were monitored in 1997 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 l
1
- 2. Compare phytoplankton data collected during this study (February, May, August, November 1997) with historical data collected in other years during these same months.
1
/ \
In previous studies on Lake Norman considerable spatial and temporal variability in I I ( ) phytoplankton standing crops and taxonomic composition have been reported (Duke l
\') Power Company 1976, 1985; Menhinick and .lensen 1974; Rodriguez 1982). Rodriguez (1982) classified the lake as oligo-mesotrophic based on phytoplankton abundance, distribution, and taxonomic composition.
METHODS AND MATERIALS i Quarterly sampling was conducted at Locations 2.0, 5.0, 8.0, 9.5,11.0,13.0,15.9, and l 69.0 in Lake Norman (see map of locations in Chapter 2, Figure 2-1). Duplicate l composite grabs from 0.3,4.0, and 8.0 m (i.e., the estimated cuphotic zone) were taken at all locations. Sampling was conducted on 27 February, 31 May, 21 August, and 24 November 1997. Phytoplankton density, biovolume and taxonomic composition were j determined for samples collected at Locations 2.0,5.0,9.5,11.0, and 15.9; chlorophyll a concentrations and seston dry and ash-free dry weights were determined for samples from all locations. Chlorophyll a and total phytoplankton densities and biovolumes were used in determining phytoplankton standing crop. Field sampling methods, and laboratory 7 methods used for chlorophyll a, seston dry weights and population identification and ( ) enumeration were identical to those used by Rodriguez (1982). Data collected in 1997 v 3-1
- - - _ . - - = . --.- -. .- --. - - -- - . - .-.. - - - _-
were compared with corresponding data from quarterly monitoring beginning in August 1987. Seston dry and ash free dry weights were not available for November 1997 due to analytical error. A one way ANOVA was performed on chlorophyll a concentrations, phytoplankton densities and seston dry and ash free dry weights by quaner. 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 ranged from a low of 1.44 mg/m3 at Location 69.0 in November to a high of 27.77 mg/m3 at Location 11.0 during May (Table 3-1, Figure 3-1). All values were below the North Carolina water quality standard of 40 mg/m3 (pg) (NCDEHNR 1991). The range of chlorophyll observed in 1997 was similar to that observed during previons years since 1987 with the exception of May. The lakewide annual mean for May 1997 was the highest ever reponed for this month (Figure 3-2). Lake Norman continues to be primarily in the mesotrophic range (with the exception of Locations 11.0 thmugh 15.9 in May). The annual trend of minimum to maximum values from February to May, lower values in August, followed by an increase in November was only observed in 1992 (Figure 3-2). During 1997, chlorophyll a concentrations showed considerable spatial variability with maximum and minimum values observed at different locations each season. The trend of l increasing chlorophyll concentrations from downlake to uplake, which had been observed j ! in 1994 (Duke Power Company 1995), was only noted in February of 1997 (Table 3-1, i Figure 3-1).- Location 15.9 (uplake, above Plant Marshall) had significantly higher l l chlorophyll values than Mixing Zone locations (2.0 and 5.0) in May, and Location 69.0 (the uppermost, riverine location) had significantly higher values in February (Table 3-2). p Locations 2.0 and 5.0 had significantly higher concentrations than 15.9 and 69.0 in p August. During May, Location i1.0 had the highest chlorophyll values, while Location
,( 5.0 had the lowest. In August, maximum concentrations were noted at Location 5.0, with 3-2
O minimum values noted at location 15.9. The November maximum was observed at Location 9.5, with the minimum Location 69.0. This type of overall variability was similar to that observed during 1996 (Duke Power Company 1997). The riverine zone of a reservoir is subject to wide fluctuations in flow depending, ultimately, on meteorological conditions (Thornton 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. In contrast to high variability observed uplake, chlorophyll a concentrations at Locations 2.0 and 5.0, the most downlake locations, were very similar and did not fluctuate greatly throughout the year. Average quarterly chlorophyll concentrations during the period of record (August 1987 - November 1997) have varied considerably. During February 1997, Locations 2.0 through 9.5 had concentrations in the low range, with long term peaks occurring in 1996 (Figure 3-3). Chlorophyll concentrations at Locations 11.0 through 15.9 during February were in the low to mid range, with long term peaks occurring in 1991. The February 1997 concentration at Location 69.0 was the highest yet observed for this month. During May n 1997, Locations 8.0,11.0,13.0, and 15.9 had the highest concentrations ever observed for I ( this month; while the concentration at Location 69.0 was the lowest ever recorded for \ (w ! 1 May. Locations 2.0,5.0, and 9.5 had concentrations in the low to mid range, with May peaks occurring in 1991 and 1992. August 1997 values at all locations were in the mid range. Long term August maxima at locations 2.0 and 5.0 occurred in 1992; while August peaks at Locations 8.0,9.5,13.0, and 69.0 occurred in 1993. The highest August value at Location 11.0 occurred in 1991. During November 1997, Locations 2.0 and 9.5 l had the highest chlorophyll concentrations observed for this month. Locations 5.0,8.0, 1 l 11.0, and 15.9 had values in the upper mid range; while at Location 69.0, the chlorophyll concentration in November 1997 was in the low range. Long term November peaks at Locations 5.0,8.0,11.0, and 15.9 occurred in 1996; while November peaks at Locations 13.0 and 69.0 occurred in 1992 and 1991, respectively. l Total Abundance Total density and biovolume are measurements of phytoplankton abundance. The lowest density and biovolume for 1997 occurred at Location 9.5 in February (1126 units /ml,306 mm3/m3). The maximum annual density and biovolume occurred at Location 15.9 in May Q (14,083 units /ml,13,965 mm3/m3) (Table 3-3, Figure 3-1). The May 1997 density and 3-3
O biovolume values from Locations 15.9 and 11.0 were above the NC State guidelines for phytoplankton blooms of 10,000 units /ml density, and 5,000 mm3/m3 biovolume (NCDEllNR 1991). Standing crop values at Location 15.9 in May were the highest - recorded from Lake Norman since the Maintenance Monitoring Program began. Locations 11.0 and 15.9, where the high standing crops occurred, are well uplake and out of the influence of the MNS mixing zone. Location 15.9, where maximum density and biovolume occurred, is also well above the discharge of the Marshall Steam Station (MSS). Therefore, it is unlikely that operations of these plants were responsible for the high phytoplankton standing crops. Duke Power monthly precipitation totals for 1997 showed that May had much lower than normal rainfall; while April had a higher than normal total. High rainfall in April, with upstream runoff and subsequent nutrient inputs; followed by dry conditions, low flow and increased retention time, seasonal increase in temperatures, greater light penetration, and longer photoperiod were most likely responsible for the unusually high phytoplankton standing crops observed in May. Although densities and biovolumes exceeded state guidelines for algal blooms, l chlorophyll concentrations were still below the state water quality standard of 40 mg/m3 O (j (pg/L). Diatoms, primarily the pennate Tabellaria fenestrata, were the principal components of uplake phytoplankton assemblages in May. Diatoms typically have much lower chlorophyll to volume ratios than other forms (Patrick and Reimer 1966, Strathman
'1967). This would explain why the chlorophyll concentrations remained below the state standard.
Total densities at locations in the Mixing Zone (2.0 and 5.0) were not significantly different in Febraury, May, and August (Table 3-4). In November, Location 2.0 had a significantly higher density than Location 5.0. In February and May, l_ocation 15.9 had significantly higher densities than Mixing Zone locations; while in August there was no statistically significant difference between these locations. In November, Location 5.0 had a significantly lower density than all other locations. In February and May, phytoplankton densities showed a general spatial trend of lower values at downlake locations versus uplake locations. During August and November, no consistent distribution patterns were observed. 3-4
,im ( ( Seston Seston dry weights represent a combination of algal matter, and other organic and inorganic material. Location 69.0, the uppermost riverine location, had the highest seston dry weights during all sample periods analyzed (November data were not available), and these values were significantly higher than all other locations (Table 3-5). A general trend of increasing values from downlake to uplake was evident in 1997, as was the case in previous years (Figure 3-1). Maximum seston dry weight values during 1997 were greater than those of 1996. Mean values during 1997 ranged from a low of 1.65 mg/l at Location 9.5 in Febmary, to a high of 25.3 mg/l at Location 69.0, also in February; compared to a range of 0.8 to 15.15 mg/l in 1996 (Duke Power Company 1997). The maximum values reported in 1996 were greater than those of 1995 (Duke Power Company 1996), indicating an increase in seston over the last three years. Seston ash free dry weights represent organic material and may reflect trends of algal standing crops. For w most part, this was not the case during 1997; most notably at Location 69.0 which had the highest ash free dry weights, and comparatively low ( ) chlorophyll concentrations during February, May, and August. In terms of statistical i significance, Location 69.0 had significantly higher values than other locations in February and August (Table 3-5). In May, three distinct statistical groups were indentified: Locations 2.0,5.0, and 9.5 in the low range; Locations 8.0, and 69.0 in the intermediate range; and, Locations 15.9,13.0, and 11.0 in the high range. Lakewide, ash free dry weights this year were somewhat higher than those of 1996, and the proportions of ash free dry weights to seston dry weights were lower than last year, indicating lower inputs of organic material into Lake Norman, and/or higher rates of inorganic input from runoff. This trend of declining organic / inorganic ratio has been ongoing since 1994 (Duke Power Company 1995,1996,1997). Secchi Depths Secchi depth is a measure of light penetration. Secchi depths were often the inverse of suspended sediment (seston dry weight), with the lowest depths at Locations 13.0 through 69.0 and highest from Locations 9.5 through 2.0 downlake. Depths ranged from 0.8 m at
. Location 69.0 in May to 2.60 m at Location 9.5 in February (Table 3-1). \ l O
3-5
t (3 Community Composition _Y Seven classes comprising 70 genera and 122 species, varieties, and forms of phytoplankton were identified in samples collected during 1997, as compared to 71 genera and 128 lower taxa identified in 1996 (Table 3-6). The distribution of taxa within classes was as follows: Chlorophyceae (green algae), 61; Bacillariophyceae (diatoms), 24; Chrysophyceae,15; Haptophyceae, one; Cryptophyceae (cryptophytes),4; Myxophyceae (blue-green algae),11; and Dinophyceae (dinoflagellates),6. Since the Program began in 1987, 117 genera and 312 lower taxa have been recorded. Eleven taxa previously unrecorded during the Maintenance Monitoring Program were observed in 1997. Species Compositon and Seasonal Succession Lake Norman supports a rich community of phytoplankton species. This community varies both seasonally and spatially within the reservoir. In addition, considerable variation may also be observed between years for the same months sampled. As mentioned earlier, bloom guidelines (i.e.. based on densities in excess of 10,000 units /ml g and biovolumes in excess of 5,000 mm3/m3) were exceeded in May 1997 at Locations ( l1.0 and 15.9, the first time this had happened since the Program began in August 1987. Diatoms accounted for approximately 80% of the densities and 90% of the biovolumes in these samples. Diatoms dominated algal densities and biovolumes during May and November (Figures 3-4 through 3-7). During 1996, diatoms were dominant during all sample periods except j August (Duke Power Company 1997). The dominant diatom was Tabellariafenestrata. T. fenestrata has always been a common constituent of phytoplankton assemblages in Lake Norman, and was the most abundant form observed during 1996. This taxon has been described as being found in meso-eutrophic water, acidophilous, and often tycho-meroplanktonic (Patrick and Reimer 1966, Lowe 1974). Cryptophytes dominated densities during February, as has been the case in previous years. The most important cryptophyte was the small flagellate Rhodomonas minuta, another common and abundant form in Lake Norman. p 3-6
l l(~T in 1997, and most previous years, green algae dominated August samples. The most abundant green alga identified was the small desmid. Cosmarium asphearosporum v. strigosum, a common constituent of summer phytoplankton assemblages in Lake Norman. Blue green algae, whch are often implicated in nuisance blooms, did not constitute a significant proportion of phytoplankton in any 1997 samples. Densities and biovolumes of blue greens seldom exceed 2%, as was the case in 1996. Phytoplankton index Phytoplankton nadexes have been used with varying degrees of success ever since the concept was formalized by Kolkwitz and Marsson in 1902 (Hutchinson 1967). In 1949 Nygaard proposed a series of indexes based on the number of species in certain taxonomic categories (Divisions, Classes, and Orders). We have selected the Myxophycean index to help determine long term changes in the trophic status of Lake Norman. This index is a ratio of the number of blue green algal taxa to desmid taxa, and was designed to reflect the
" potential" trophic status; while chlorophyll gives an " instantaneous" view of phytoplankton concentrations. The index was calculated on an annual basis for the entire lake, for each sampling period of 1997, and for each location during 1997 (Figure 3-8).
('a) For the most part, the long term annual Myxophycean index values tended to confirm the conclusion that Lake Norman has been in the oligo-mesotrophic (low to intermediate) range since 1988 (Figure 3-8). Values were in the high, or eutrophic, range in 1989,1990, and 1992; in the intermediate, or mesotrophic, range in 1991,1993,1994, and 1996; and in the low, or oligotrophic, range in 1988,1995, and 1997. The index for 1997 was the lowest yet observed. The 1997 index was the lowest recorded, despite the high standing crops observed uplake during May. One reason for the low annual index in 1997 was the comparatively high number of desmid taxa observed in August. A breakdown by season shows that the index for May 1997 was well into the high range (Figure 3-8). Annual index values for Locations 11.0 and 15.9, while still in the low range, were higher than those of downlake j locations during 1997, consistent with the general uplake-downlake trend of decreasing l abundance. l
,q
- I }
\j 3-7
(N FUTURE STUDIES ( )
%/
No changes are planned for the phytoplankton portion of the Lake Norman Maintenance Monitoring program during 1998.
SUMMARY
Chlorophyll a concentrations at locations during 1997 were generally within ranges reported during previous years, except in May, when the mean concentration was the highest ever recorded for that month. Lake Norman continues to be classified as oligo-mesotrophic based on long term annual mean chlorophyll concentrations. Lakewide chlorophyll means increased from February to May, declined in August, then increased in November. Chlorophyll concentrations from Locations 11.0 through 15.9, uplake, were j the highest yet recorded in that area of the Lake. The maximum chlorophyll value of 27.77 mg/m3 was below the NC State Water Quality standard of 40 mg/m3 (pg/L) Considerable spatial and seasonal variability was observed during 1997, as has been the case in previous years. l!v) s In most cases, total phytoplankton densities and biovolumes observed in 1997 were within ranges of those observed during previous years. However, densities and biovolumes at i j Locations 11.0 and 15.9 in May exceeded NC State standing crop guidelines. This was j the first time since the Program began that such an excursion was documented. Very high standing crops of diatoms, prmarily the pennate Tabellaria fenestrata, were responsible for these high values. Chlorophyll concentrations remained below the standard of 40
- mg/m3 (pg/L) due to the low chlorophyll to volume ratios assosiated with diatoms. Since l high standing crops occurred at two locations well uplake from MNS, and one location l was above the MSS discharge, plant operations were not responsible for these excursions.
Natural conditions such as low flow, increased retention time, earlier inputs of nutrients uplake, seasonal increases in temperature and light penetration, and longer photoperiod were most likely causes contributing to the higher than normal standing crops. Minimum i standing crops were observed in February, and values in the mixing zone were generally lower than those uplake. A Seston dry weights were higher in 1997 than in 1996, and downlake to uplake differences p.- were still quite apparent. Maximum dry and ash free dry weights were most often observed at the riverine location (69.0); while minima were most often noted in the mixing (J 7 3-8
r . _ . . - _ . ._ ___ l l i l zone (2.0 and 5.0) and at Location 9.5. The proportions of ash free dry weights to dry l ( weights were lower in 1997 than in 1996, indicating proportionally less organic input to inorganic input in Lake Norman. This is a continuation of a trend first observed in 1995. Overall phytoplankton community composition was similar to 1996. Diatoms were dominant in most samples, and were the principal contributors to standing crops in May and November. Cryptophytes were dominant in Febraury; while green algae continued to dominate August samples, as has been the case in previous years. l l The most abundant alga, on an annual basis, was the pennate diatom Tabellariafenestrata. l The most common and abundant green alga and cryptophyte were Cosmariurn l l asphearosporum v. strigosum, and Rhodornonas ininuta, respectively. All of these taxa ( have been common and abundant throughout the Maintenance Monitoring Program. l I l l .t s l I O .V l 3-9 1
l l LITERATURE CITED i (s Duke Power Company.1976. McGuire Nuclear Station, Units I and 2, Environ-mental Report, Operating License Stage. 6th rev. Volume 2. Duke Power l Company, Charlotte, NC. j Duke Power Company.1985. McGuire Nuclear Station,316(a) Demonstration. Duke Power Company, Charlotte, NC. Duke Power Company.1995. Lake Norman maintenance monitoring program: 1994 summary. Duke Power Company.1996. Lake Norman maintenance monitoring program: 1995 summary. I Duke Power Company.1997. Lake Norman maintenance monitoring program: I 1996 summary. Hutchinson, G. E.1967. A Treatise on Limnology, Vol. II. Introduction to the i limonplankton. John Wiley and Sons, New York, NY. i 1
- Lowe, R. L.1974. Environmental requirements and pollution tolerance of freshwater 1 l n diatoms. United States Environmental Protection Agency, Cincinnati, Ohio.
,( !\ Menhinick, E. F. and L. D. Jensen.1974. Plankton populations, p. 120-138 Ln l L. D. Jensen (ed.). Environmental responses to thermal discharges from Marshall l Steam Station, Lake Norman, NC. Electric Power Research Institute, Cooling Water Discharge Project (RP-49) Report No. I1. Johns Hopkins Univ., Baltimore l M D. 1 North Carolina Department of Environment, Health and Natural Resources, Division of Environmental Management (DEM), Water Quality Section. 1991,1990 Algal Bloom Report. I Nygaard, G.1949. Hydrological studues of same Danish pond and lakes II. K. danske I l l Vilensk. Selsk. Biol. Skr. 1 Patrick, R. and C. W. Reimer.1966. The diatoms of the United States, Vol II, Part 1. Acad. Nat. Sci. Philadelphia, Monograph 13. 213 pp. Rodriguez, M. S.1982. Phytoplankton, p. 154-260 In J. E. Hogan and W. D. Adair (eds.). Lake Norman summary. Technical Report DUKEPWR/82-G2 Duke Power i Company, Charlotte, NC. 1
- g. Strathman, R. R.1967. Estimating the organic carbon content of phytop!ankton from cell
( volume or plasma volume. Limnol. and Oceanogr. 12 (3):411-418. i
- 3-10
i i i 1 i l j- Thornton, K. W., B. L. Kimmel, F. E. Payne.1990. Reservoir Limnology. John Wiley and j Sons, Inc. N. Y. 1 l 1 i f I i 1 3 i d i a 1 f l i ! 1
- l' i
1 I i i 4 3-11
Table 3-1. Mean chlorophyll a concentrations (mg/m3) in composite samples (0.3,5 and 8m depths) and secchi depths (m) observed in Lak:: Norman, NC, in 1997. l Chlorophyll a Location FEB MAY AUG NOV 2.0 1.72 2.93 4.67 10.19 5.0 2.50 2.47 4.14 9.72 8.0 2.67 10.82 6.64 11.21 9.5 2.30 2.90 8.I2 12.28 11.0 3.79 27.77 8.02 12.02 13.0 3.64 25.10 5.59 9.16 15.9 4.70 24.30 11.75 10.68 69.0 7.91 2.98 6.41 1,44 Secchi depths Location FEB MAY AUG NOV 2.0 1.95 2.40 2.50 1.97 ,[ 5.0 2.10 2.20 2.40 1.78 l 8.0 2.40 2.10 2.50 2.10 9.5 2.60 2.50 2.10 2.00 11.0 2.10 1.10 2.20 1.55 13.0 1.30 1.10 1.35 1.30 15.9 1.50 1.30 2.05 1.70 69.0 1.30 0.80 1.25 1.15 'O 3-12
TaHe 3-2. Duncan's multiple Range Test on chlorophyll a concentrations in Lake f 9 Norman, NC, during 1997. February Location 2.0 9.5 5.0 8.0 13.0 11.0 15.9 69.0 Mean 1.72 2.30 2.50 2.67 3.64 3.79 4.70 7.91 May Location 5.0 9.5 2.0 69.0 8.0 15.9 13.0 I 1.0 Mean 2.46 2.90 2.93 2.98 10.82 24.30 25.10 27.77 August Location 5.0 2.0 13.0 69.0 8.0 11.0 9.5 15.9 Mean 4.14 4.67 5.59 6.41 6.64 8.02 8.12 11.75 November Location 69.0 13.0 5.0 2.0 15.9 8.0 11.0 9.5 Mean 1.44 9.16 9.71 10.19 10.68 11.21 12.02 12.28 9 /3 V 3-13
i lp) Table 3-3. Total mean phytoplankton densities and biovolumes from samples collected in Lake Norman, NC, during 1997. Density (units /ml) Locations Month 2.0 5.0 9.5 11.0 15.9 Mean , FEB 1131 1502 1126 1715 3120 1719 : MAY 1661 1967 1300 11534 14083 6109 AUG 2202 1735 4249 3822 2185 2839 i NOV 3152 1920 3267 3088 3278 2941 1 l i Biovolume (mm3/m3) i Locations Month 2.0 5.0 9.5 11.0 15.9 Mean j FEB 428 658 306 742 1581 743 MAY 725 1254 915 13073 13965 5986 l AUG 1483 1706 2898 2168 2996 2250 NOV 3332 2292 3784 3327 2031 2953 l O 3-14 l L f
Table 3-4. Duncan's multiple Range Test on phytoplankton densities in Lake Norman, NC, during 1997. Febmary Location 9.5 2.0 5.0 11.0 15.9 Mean 1126 1131 1502 1715 3120 May Location 9.5 2.0 5.0 11.0 15.9 Mean 1300 1661 1967 11534 14083 August Location 5.0 15.9 2.0 11.0 9.5 hiean 1735 2185 2202 3822 4249 j November Location 5.0 11.0 2.0 9.5 15.9 i Mean 1920 3088 3152 3267 3278 e 4
- j. l L
l.- 1 i e a i i 4 I' I I
- 3-15 ,
i l
.,. _ , _ . - . . - . ._ ,, . . . - .- .. .- _ . ~ . _ . . . -. . _ . -.
i l t ' ( Table 3-5. Duncan's multiple Range Test on dry and ash free dry weights (mg/l) in Lake Norman. NC during 1997. DRY WEIGliT February Location 9.5 11.0 8.0 2.0 5.0 13.0 15.9 69.0 Mean 1.65 1.70 1.85 1.90 2.15 2.65 3.60 25.30 May Location 9.5 2.0 5.0 8.0 15.9 13.0 11.0 69.0 Mean 1.79 1.81 1.89 3.60 6.31 6.86 7.32 8.20 August laation 2.0 8.0 5.0 11.0 15.9 13.0 9.5 69.0 Mean 2.15 2.48 2.49 2.51 2.64 3.24 3.58 19.12 Nuember No Samples ("] ASH FREE DRY WEIGHT ,V February L.ocation l 9.5 8.0 2.0 5.0 11.0 13.0 15.9 69.0 Mean 0.62 0.71 0.75 0.82 0.85 1.02 1.27 4.15 l May Location 2.0 9.5 5.0 8.0 69.0 15.9 13.0 11.0 Mean , 0.62 0.62 0.65 1.28 1.42 2.20 2.29 2.40 August Location 2.0 5.0 13.0 8.0 11.0 15.9 9.5 69.0 Mean 1.42 1.50 1.56 1,72 1.74 1.75 1.86 3.96 L l November No Samples
' LO]
l l 3-16
i i l
\
Table 3-6. Phytoplankton taxa identified in quarterly samples collected in Lake Norman from August 1987 to November 1997. TAXON 87 88 89 90 91 92 93 94 95 96 97 CLASS: CHLOROPHYCEAE Acanthospaera tachariasi Lemm. X X X i Actidesmium hookeri Reinsch X Actinastrum hantzchii tagerheim \ X X X X X X X i Ankistrodesmus braunii(Naeg) Brunn X X X A.falcatus (Corda) Ralfs X X X X X X X X X X X l A. fusiformis Corda sensu Korsch. X X X X X X l A. spiralis (Turner) Lemm. X X X X X X X A. spp. Corda X X Arthrodesmus convergens Ehrenberg X A. incus (Breb.) Hassall X X X j A. subulatus Kutring X X \ A. spp. Ehrenberg X X Asteococcus limneticus G. M. Smith X X X X X Botryococcus braunii Kutzing X X Carteriafrt:schii Takeda X X C spp. Diesing X X X X X g Characium spp. Braun X Chlamydomonas spp. Ehrenberg X X X X X X X X X X X Chlorella vulgaris Beyerink X Chlorogonium euchlorum Ehrenberg X X X X C spirale Scherffel & Pasc.her X X Closteriopsis longissima West & West X X X X X X X X X X X Closterium gracile Brebisson X C incurvum Brebisson X X X X X X C spp.Nitzsch X X X X Coetastrum cambricum Archer X X X X X X X X X X X C microporum Nageli X X C sphaericum Nageli X X X X C proboscideum Bohlin X C spp. Nageli X X Cosmarium anulosum v. concinnum otab) W&w X C asphaerosporum v. strigosum Nord. X X X X X X X X X X X C contractum Kirchner X X X X X X C polygonum (Nag.) Archer X X X X C phaseolus f. minor Boldt. X i C rc.gnellii Wille X X X X ( l 3-17
. . -- - - _. _~ -_ _ - _- - - _ - . - . _ . - - - _ - - . - - - . . . . . - - - - - ~
Table 3-6 (continued) page 2 of 9 87 88 89 90 91 92 93 94 95 96 97 ' C. regnesi Schmidle X X X C tenue Archer X X X X X C. tinctum Ralfs X X X X X X X C. tinctum v. tumidum Borge. X C. spp. Corda X X X X X X X X Crucigenia crucifera (Wolle) Collins X- X X X X X X C. fenestrata Schmidle X C. irregularis Wille X X X X X C. retrapedia 'Kirch.) West & West X X X X X X X X X X X Dictyospaerium ehrenbergianum Nageli X X D. pulchellum Wood X X X X X X X X X X X Dimorphococcus spp. Braun X Elakatothrix gelatinosa Wille X X X X X X X X X X X Euastrum denticulatum (Kirch.) Gay X X X E. spp. Ehrenberg X X X X Eudorina elegans Ehrenberg X X Franceia droescheri (Lemm.) G. M. Smith X X X X X F. ovalis (France) Lemm. X X. X X X X X ! Gloeocystis botryoides (Kutz.) Nageli X G. gigas Kutzing X X X X X G. planktonica (West & West) Lemm. X X X X X X X X X l G. spp. Nageli X X X X X X X X l Golenkinia paucispina West & West X X G. radiata Chodat X X X X X X X X X X X Gonium sociale (Duj.) Warming X X Kirchneriella contorta (Schmidle) Bohlin X X X X X X X K. lunaris (Kirch.) Mobius X X X K. funaris v. dianae Bohlin X X K. obesa W. West X X X X X X X K. subsulitaria G. S. West X X X X X K. spp. Schmidle X X X X X Lagerheimia ciliata (Lag.) Chodat X L citdformis (Snow) G. M. Smith ' X L longiseta (lemmermann) Printz X l L quadriseta (Lemm.) G. M. Smith X X X X L subsala Lemmerman X X X X X X X X X Mesostigma ririda Lauterborne X X X X X Micractinium pusillum Fresen. X X X X X X X X X X X l Monoraphidium contortum Thuret X X X X X X M. pusillum Printz X X X X X X Mougeiria elegantula Whittrock X X X X X 0 3-18
_ _ _ _ _ _ _ . _ _ _ _ _ _ . _ _ _ ._. _ _ . _ . _ m._.._._.._ Table 3-6 (continued) page 3 of 9 87 88 89 90 91 92 93 94 95 96 97 Af. spp Agardh X X X X
' Nephrocytium agardhianum Nageli X X N. limneticum (G.M. Smith) G.M. Smith X X Occystis ellyptica W. Wcst X 0, lacustris Chadat X
O. parva West & West X X X X X X X O. pusilla llansgirg X X X X X X X O. spp. Nageli X Pandorina charkowiensis Kprshikov X P. morum Bory X X X X l Pediastrum biradiatum Meyen X l P. duplex Meyen X X X X X X X X P. duplex v. gracillimum West and West l X P. terras v. terroadon (Corda) Rabenhorst X X X X X X X X X X X P. spp. Meyen X X Planktosphaeria gelatinosa G. M. Smkh X X X h Guadrigula closterioides (Bohlin) Printz X X X G. lacustris (Chodat) G. M. Smith X Scenedesmus abundans (Kirchner) Chodat X X X X S. abundans v. asymetrica (Schr.) G. Sm. X X X X X X X X X X ) S. abundans v. brevicauda G. M. Smith X X l [ !( S. acuminatus (Lagerheim) Chodat S. armatus v. bicaudatus (Gug.-Prin.)Chod X X X X X X l X X X -X X X X X X X l I\ . S. bijuga (Turp.) Lagerheim X X X X X X X X X S. bijuga v. alterans (Reinsch) flansg. X S. brasiliensis Bohlin X X X S. denticulatus Lagerheim X X X X X X X X X X S. dimorphus (Turp.) Kutzing X X X X X X S. incrassulatus G. M. Smith X i S. padricauda (Turp.) Brebisson X X X X X X X X X X X i S. smithiiTeiling X l S. spp. Meyen X X X X X X Schizochlamys compacta Prescott X Schoederia setigera (Schroed.) Lemm. X X Selenastrum gracile Reinsch X X S. minutum (Nageli) Collins X X X X X X X X X X X S. westii G. M. Smith .X X X X X Sorastrum americanum (Bohlin) Schmidle X
. Sphaerocystis schoeteriChodat X X. X X
- . Sphaerozosma granulatum Roy & Bliss X X i Stauastrum americanum (W&W) G. Sm. X X X X X w
7 3-19 i
n Table 3-6 (continued) page 4 of 9 87 88 89 90 91 92 93 94 (U) S. apicul:tua. liretasson X 95 96 97 X S. brachiatum Rai(s X S. brevispinum Brebisson X S. chaetoccrus (Schoed.) G. M. Smith X X X S. curvatum W. West X X X X X X X X X S. cuspidatum Brebisson X X S. dejectum Bcebisson X X X X X X X S. dicAcii v. maximum West & West X S. gladiosum Turner X S. leptocladum v. sinuatum Wolie X X S. manfeldtii v.fluminense Schumacher X X X X X X S. megacanthum Lundell X X X X S. orbiculare Ralls X S. paradoxum Meyen X X X X X X S. paradoxum v. cingulum West & West X S. paradoxum v. parvum W. West X S. subcruciatum Cook & Wille X X X S. retraccrum Ralfs X X X. X X X X X X X X S. turgescens de Not. X X S. spp. Meyen X X X X X Tetraedron bifurcatum v. minor Prescott X ps T. caudatum (Corda) Hansgirg X X X X X X X X 4
\ T. limneticum Borge X T. lobulatum v. crassum Prescott X ;
T. minmum (Braun) Hansgirg X X X X X X X T. muticum (Braun) Hansgirg X X X X X X X T. obesum (W & W) Wille ex Brunnthaler X T. pentaedricum West & West X X T. regulare Kutzing X X X X T. regulare v. incus Teiling X X X T. trigonum (Nageli) Hansgirg X X X X X X X ' T, trigonum v. gracile (Reinsch) DeToni X X T. spp. Kutzing X X X ) Terrospora spp. Link X X Tetrastrum heteracanthum (Nordst.) Chod. X Treubaria setigerum (Archer) G. M. Smith X X X X X X X X X X X Westella linearis G. M. Smith X Xanthidium spp. Ehrenberg X l CLASS: BACILLARIOPHYCEAE ' l Achnanthes microcephala Kutzing X X X X X X bh .R.] ( 3-20
Table 3-6 (continued) page 5 of 9 87 88 89 90 91 92 93 94 95 96 97 A. spp. Bory X X X X X X X X X Anomoconeis vitrea (Grunow) Ross X X X X X A. spp. Pfitzer X Asterionellaformosa flassall X X X X X X X X X X Artheya zachariasi J. Brun X X X X X X X X X X Cocconeis placentula Ehrenberg X X C spp. Ehrenberg X Cyclatella conta (Ehrenberg) Kutzing X X X X X C glomerata Bachmann X X X C meneghiniana Kutzing X X -X X X X C pseudostelligera 11ustedt X C stelligera Cleve & Grunow X X X X X X X X X X C spp. Kutzing X X X Cymbella minuta (Bliesch & Rabn.) Reim. X X X X X C tumida (Breb.) van liuerck X , C. turgida (Gregory) Cleve X l C spp. Agardh X X I Diploncis spp. Ehrenberg l X l Eunotia rasuminensis (Cab.) Koerner X X X X X X X X X-l Fragilaria crotonensis Kitton X X X X X X X X X X Frustulia rhomboides (Ehr.) de Toni X X p Gomphonema spp. Agardh X X ( Melosira ambigua (Grun.) O. Muller X X X X X X X X X X X l
~ M. distans (Ehr.) Kutzing X X X X X X X X X X M. granulata (Ehr.) Ralfs X X X X l M. granulata v. angustissima O. Moller X X X X X X X X X X X M. italica (Ehr.) Kutzing X X M. varians Agardh X X
- M. spp.'Agardh X X X X X X X X X Navicula cryptocephala Kutzing X X X N. exigua (Gregory) O. Muller X N. exigua v. capitata Patrick X N. subtilissima Clcve X l- N. spp. Bory X X X X X X l Nit:schia acicularis W. Smith X X X X X X X l N. agnita liustedt X X X X X X X X X X N. holsatica Hustedt X X X X X X X N. palca (Kutzing) W. Smith X X X X X X
! N. sublinearis liustedt X X ! N. spp. liassail X X X X X X X X Pinnularia spp. Ehrenberg X i E
- 4 i-1 3-21 '
1
1 1 Table 3-6 (continued) page 6 of 9 (m Rhitosolenia spp. Ehrenberg 87 88 89 90 91 92 93 94 95 96 97 l X X X X X X X X X X X Skeletonema potemos (Weber) Hilse X X X X X Stephanodiscus spp. Ehrenberg X X X X X X X X X X X ! Synedra actinastroides Lemmerman X S. acus Kutzing X X X X X ' S. delicatissima Lewis X X X l S. planktonica Ehrenberg X X X X X X X X X X X S. rumpens Kutzing X X X X X S. rumpens v.fragilarioides Grunow X S. rumpens v. scotica Grunow X S. ulna (Nitzsch) Ehrenberg X X X X X X S spp. Ehrenberg X X X X X X X X Tabellariafenestrata (Lyngb) Kutzing X X X X X X X X X X X T.flocculosa (Roth.) Kutzing X X X X CLASS: CHRYSOPIIYCEAE I Aulomonas purdyii Lackey X X X X X Bicocca petiolatum (Stien) Pringsheim X Calcicomonas pascheri (Van Goor) Lund X Chromulina spp. Chien. X X Chrysosphaerella solitaria Lauterb. X X X X X X X [ Codomonas annulata Lackey X X '( Dinobryon bararicum Imhof X X X X X X X X X X X D. cylindricum Imhof X X X X X X D. divergens Imhor l X X X X X X X ' D. serrularia Ehrenberg X X D. spp. Ehrenberg X X X X X X X Erkinia subarquicilliata Skuja X X X X X X X X Kephyrion rubi-claustri Conrad X X K. skujae X K. spp. P ~ her X X X X X X X X X Mallom< as acaroides Perty X M. akrokomos (Naumann) Krieger X M. caudata Conrad X X X X X X X M. globosa Schiller X M. pseudocoronata Prescott X X X X X X X X X X M. tonsurata Teiling X X X X X X X X X X X i M. spp. Perty X X X X X X X X Ochromonas spp. Wyssot. X X X X X X X l Rhi:ochrisis spp. Pascher X X l l Stelexomonas dichotoma Lackey X X X X X X X X X X l l n ( )\ u l 3-22
- .. . _ , - - . -. .- . . - _. _ - = - - . . . . . . -. . . - .
!, \ Table 3-6 (continued) page 7 of 9 87 88 89 90 91 92 93 94 95 96 97 Stokesiella epipyxis Pascher X Synura spinosa Korschikov X X X X X X , ! S. urella Ehrenberg X X X X X X S. spp. Ehrenberg X X X X X X Uroglenopsis americana (Caulk.) Lemm. X X X X l CLASS:11AirTOPliYCEAE Chrysochromulina parva Lackey X X X X X X X X X X X CLASS: XANTHOPflYCEAE Characiopsis dubia Pascher X X Dichotomococcus curvata Korschikov X Ophiocytium caoitatum v. longispinum X X
'(Moebius) Lemmerman CLASS: CRYl'TOPIIYCEAE 1
Cryptomonas crosa Ehrenberg X X X X X X X X X X X ' C crosa v. reflexa Marsson X C marsonii Skuja X' X X X X X C. ovata Ehrenberg X X X X X X X X X X X C phaseolus Skuja X X X X X X n C reflexa Skuja X X X X X X X X X X X C spp. Ehrenberg X X X X X X X Rhodomonas minuta Skuja X X X X X X X X X X X l CLASS: MYXOPHYCEAE Agmenellum quadriduplicatum Brebisson X X X X X Anabaena catenuta (Kutring) Born. X X A. scheremetieri Elenkin X A. wisconsinense Prescott X X X X X A. spp. Bory X X X X X X X X Anacystis incerta (12mm.) Druet & Daily X X X X X X A. spp. Meneghini X Chroccoccus limneticus Lemmermann X X X X C minor Kutzing X C turgidus (Kutz.) Lemmermann X X C spp. Nageli X X X X X X X X X X Coelosphaerium kueningiana Nageli X Dactylococcopsis irregularis Hansgirg X X X D. smithiiChodat and Chodat X Gomphospaeria lacustris Chodat X X X X X X X 3-23
i Table 3-6 (continued) page 8 of 9 I 87 88 89 90 91 92 93 94 95 96 97
\ Lyngbya contorta Lemmermann X X L limnetica Lemmermann X X X X X X L subtilis W. West X X X X X L spp. Agardh X X X X X X X X X X X Microcystis aeruginosa Kutz. emend Elen. X X X X X X X X X Oscillatoria geminata Meneghini X X X X X X O. limnetica Lemmermann X X X X 0, splendida Greville X X O. 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 X X X X X X l Rhabdoderma sigmoidea Schm. & Lauttb. X Synecococcus lineare (Sch. & Laut.) Kom. X X X X X X X l l
CLASS: EUGLENOPHYCEAE I Euglena acus Ehrenberg X j E. minuta Prescott X. E. polymorpha Dangeard X l E. spp. Ehrenberg X X X X X X X X l Lepocinclus spp. Perty X l ,r Phacus orbicularis Hubner X P. tortus (Lemm.) Skvortzow X X X j P. spp. Dujardin X Trachelomonas acanthostoma (Stok) De11. X T. hispida (Perty) Stein X X ! T. pulcherrima Playfair X T. votrocina Ehrenberg X X X T. spp. Ehrenberg X X X l l CLASS: DINOPHYCEAE Cerarium hirundinella (OFM) Schrank X X X X X X X X Glenodinium borgel(Lemm.) Schiller X X X G. gymnodinium Penard X X X X X X G. palustre (Lemm.) Schiller X j G. quadridens (Stein) Schiller X X l G. spp. (Ehrenberg) Stein X X l ' Gymnodinium spp. (Stein) Kofoid & Swezy X X X X X X X Peridinium acicuhferum Lemmermann X P. inconspicuum Lemrnermann X X X X X X X X X X X . P. pusillum (Lenard) Lemmermann X X X X X X X X X X X m e 3-24
.- . - . . . - - . ~
Table 3-6 (continued) page 9 of 9 8 89 9 91 92 93 94 95 96 97 P. umbonatum Stein
' X X P. wisconsinense Eddy X X X X X P. spp. Ehrenberg X X X X X X CLASS: CilLOROMONADOPHYCEAE Gonyostomum depresseum Lautcrborne X X G. semen (Ehrenberg) Diesing X G. spp. Diesing X X X X l
3-25
. . . ~ , . .. -- - . . . _ - . . . . - _ ._ -.. . . . = . . - . - _ - _ _ . - . . - . . _ .
]
CHLOROPHYLL a (mg/m3) l l D ENSITY (u nits /m l) I
/ ! ! i 30 l 10000
~
25 12000
~
10000 15 . 8000 - . 1 6000 < 10 3 i
> 4000 .
$ 2000 N f
0 , 0 2.0 5.0 8.0 9.5 11.0 13.0 15.9 69.0
. 1 0 15.9 SESTON DRY W ElGHT (mg/m3) BIOVOLUM E (m m 3/m 3) 30 16000 14000-12000 20 - -
10000 - 15 8000 6000 l 4000 - l 2000 C i 0 i'4= _ : 0" hr$ * ' 2.0 5.0 8.0 9.5 11.0 13.0 15.9 69.0 2.0 5.0 9.S 11.0 15.9 LOCATIONS LOCATIONS I FEB MAY AUG NOV
- 4> - -m- -e- -x-J l
l Figure 3-1. Phytoplankton chlorophyll a, densities, and biovolumes; and seston weights , at locations in Lake Norman, NC, in February, May, August, and November 1997 (seston weights were not available for November). i f 3-26 +
L .%. 14 _ l 12 l i 10 ) I 5l
~
'm 8 ^
E ~ f N) x ' ; o 6- . e - O d U , k L 4 t N q
/
)vx 2 s l 0 FEB MY AUG NOV MONTH
+
--,_.lll8 + 1989 --x- 199o
-*-thhf a 1994 0 1995 - o--1996 4lll3 Figure 3-2. Phytoplankton chlorophyll a annual lake means from alllocations in Lake Norman, NC, for each quarter since August 1987.
LJ 3-27 I
.-. - .- = . -.. .- _ _
CHLOROPHYLL a (mg/m3) FEBRUARY _ . MAY ...
. [ _. +_ -- 2.0
._ _-e. . _5.0
- 20 -e-- 5 0 l j \ 12 WRCOE- - - - - - - - - 12 wig ZONE ~ ~ ^ ' ~ ~ ~ ~ ~ '
k 10 10 8 8 6 6 4 4 2 '
, 2 0 0 87 88 89 90 91 92 93 94 95 96 97 87 88 89 90 91 92 93 94 95 96 97 l --+- 8.0 --e-- 9.5 l l -+- B 0 -e-- 9.5 l 20 12 10 - -
8 10 - 6 4 = 2 0 ' O 87 88 89 90 91 92 93 94 95 96 97 87 88 89 90 91 92 93 94 95 96 97 16 l-+-- 11.0 -e- 13.0 l (: 11.0
--e.- 13.0 l 30 gs .
{ 0 20 - C) 15 - 4 . . 10 - 2 O + 5 -f ; o 87 88 89 90 91 92 93 94 95 96 97 87 88 89 90 91 92 93 94 95 96 97 l + 15.9 -e- 69.0 l l-+- 15.9 -e-69.0 l 20 30 25
'I 20 10 15 -
5- - 5-0 0 ' 87 88 89 90 91 92 93 94 95 96 97 87 88 89 90 91 92 93 94 95 90 97 YEA RS YEA RS l Figure 3-3. Phytoplankton chlorophyll a concentrations by location for samples collected in Lake Norman, NC, from August 1987 through November 1997. [ I V 3-28
CHLOROPHYLL a (mg/m3) AUGUST NOVEMBER l -+-- 2 0 --*- 5. 0 I I
--m--- 5 0 1
.g 6 -. t
[ . -+-- 2. 0 .i
\ MLXING ZONE MIXING' Z ON'E "'~-~~~~~'l
- V 8 10 l 6 5 6
! 4 2'
21 0 0 87 88 89 90 91 92 93 94 95 96 97 87 88 89 90 91 92 93 94 95 96 97 l --+--- 8.0--e- 9.5 l l -+-- 8.0 --e- 9.5 l 16 14 - 14 12 l 10 l 10 1 8 6 > 6 4; O 4 j 2 2 ' O O 87 88 89 90 91 92 93 94 95 96 97 87 88 89 90 91 92 93 94 95 96 97 l
--s-- l l-+-- 11.0 13.0 l l--+.-.- 11.0--a- 13.0 l l gx 14 14 (N )
/
12 10 - 12 > v 10 - - 8 -
> 8-6, -
i 6 4 i 4i j 2 2 0 0 --- 87 88 89 90 91 92 93 94 95 96 97 87 88 89 90 91 92 93 94 95 96 97 l-+-- 15.9 -s-- 69.0 l l-+-- 15.9 --m- 69.0 l 25 25 20 - - 20 15 15 10 - 10 i
- 5 5 0 0 87 88 89 90 91 92 93 94 95 96 97 87 88 89 90 91 92 93 94 95 96 97 YEARS YEA RS Figure 3-3 (continued).
\p \. ,/
t 3-29 m
l LOC. 2.0 & 5.0 16000 --- - - 7 OCHLOROPHYCEAE E BACILLARIOPHYCEAE y 14000 BCHRYSOPHYCEAE OCRYPTOPHYCEAE 12000 EMYXOPHYCEAE O DINOPHYCEAE e j10000 EOTHERS 5 8000 - D . m \ g 6000 0 4000 2000 .,.
> .- . ~
O FEB MAY AUG NOV 14000 12000 - E 10000 E M E E 8000 - E 3 6000 - 8 O E 4000 - l
~~' '~'
2000 0 ; : : FEB MAY AUG NOV Figure 3-4. Class composition (mean density and biovolume) of phytoplankton from cuphotic zone samples collected at Locations 2.0 and 5.0 in Lake Norman, NC, during 1997. O 3-30
1 l 10000 --- _ . _ ' .OC. 9.5 __ _ t DCHLOROPHYCEAE EBACILLARIOPHYCEAE l l 1 GCHRYSOPHYCEAE OCRYPTOPHYCEAE 12000 EMYXOPHYCEAE ODINOPHYCEAE 10000 EOTHERS
~
c f8000 ; I
$ 6000 Q
4000-i 2000 -- l
+.
FEB MAY AUG NOV 14000 12000 g 10000 l E M i l8000-E s 3 6000 8 h 4000 - 2000 - -
.Y '
o - > FEB MAY AUG NOV Figure 3-5. Class composition (mean density and biovolume) of phytoplankton from euphotic zone samples collected at Location 9.5 in Lake Norman, NC, (3 t during 1997. 3-31
_-..._...____.._.....___...m.___ . _ _ _ . . . _ _ _ _ _ _ _ - . . _ . _ . _ _ _ . _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ i 8 L O C.11.0 i j 16000 --; 7- _-,_ ____ _ _ _- 7 --- _ _ ---_-------7-----. 4 l OCHLOROPHYCEAE E B ACILL ARIO PH YC E AE 14000 ECHRYSOPHYCEAE OCRYPTOPHYCEAE 3 EMYXOPHYCEAE ODINOPHYCEAE .i 12000 MOTHERS l i _ . c. m 1 - I E 10000 i' e ' E
> 8000
!=
<n y 6000 -
O ! 4000
;[ - .y ..
0 - > l j FEB MAY AUG NOV
- 14000 --
.7
! 12000 1 4 I E 10000 i i f n ! E l g, 8000 i w i 2 i 3 6000 t O ! 9 j 80 4000
- w. n. .,.
j 2000 i . - _ l 0 : f FEB MAY AUG NOV i i Figure 3-6. Class composition (mean density and biovolume) of phytoplankton from
; euphotic zone samples collected at Location 11.0 in Lake Norman, NC, ) during 1997.
l 3-32
$ I j l
\
{ LOC.15.9
- 16000 --- - -- - - - - - - - --- - - -- - ~
OCHLOROPHYCE E EBACILt.AkldPhYCEAEi l 14000 u GCHRYSOPHYCEAE DCRYPTOPHYCEAE I BMYXOPHYCEAE O DINOPHYCEAE 12000 aOTHERS o l j10000 x ! 5 l . > 8000 - i >= ! E j $ 6000 - i f 4000 - 0 I
- I FEB MAY AUG NOV 14000 m; .
12000 - - g 10000 - E M E E 8000 - - - m . 4 2 ~ l 3 6000- - O .- 0 E 4000 -- FM 2000 - - - 5Cky#I
$0 um#
0 : : FEB MAY AUG NOV Figure 3-7. Class composition (density and biovolume) of phytoplankton from euphotiC zone samples Collected at Location 15.9 in Lake Norman, NC, during 1997. 3-33
~. _ . _ _ _ _ _ - -_ =- _ . - . . .. .~ _ _. . . .
i i
~~
M YXOPHYCEA N INDEX: L A KE NORM AN 18 ----- .. _ ,.._._.___.... _ _ _ _ _ _ _ _ . , _ . _ _ . _ _ _ _ _ _ _ , _ _ _ _ _ _ , _ _ __ ] 1.7 - { __ . _ _ __ _ _ i eg 16 - - - - _ - - . .. _
- 1. 5 - -- _ _.. _
14 - - - - . - _ . _ _ . _ _ _ _ _ . _ _ _ _ _ _.__ . , _ . _ , _ , , _ , , _ _ _ , _. 1.3 -- ----- ---
. _ . . . _ _ _ _ _ _ . . _ _ _ . _ _ _ . . . _ _ _ _ _ . _ _ . , _ . l o 1.2 _ElG H ! l E 1.1 j NT ERMEDIA TE ]
1.0 - - - _ _ = - - - =. l lll v cow l l
!!!Y 1988 1989 1990 1991 1992 1993 1994
. E3'b1995 1996 1997 YEA RS 1.50 1.25 l
1.00 _ _ E 0.75 0 . U FEB MAY AUG NOV M ONT H 0.80 1 0.70 0.60 j O 0.50 - . 0 - E---" 0.20 ' - ' ~ - : 2 5 9.5 11 15.9 LOCATIONS i Figure 3-8. Myxophycean index values by year (top), each season in 1997 (mid), and each j location in Lake Norman, NC, during 1997. t (m 3-34
-...- _ _._._ ___._~._ _.._ _ _ _ __..___._
CII Alvl'ER 4 ZOOPLANKTON INTRODUCTION 1 The objectives of the Lake Norman Maintenance Monitoring Program for zooplankton are to: l
- l. Describe and characterize quarterly patterns of zooplankton standing crops !
at selected locations on lake Norman; and l
- 2. compare and evaluate zooplankton data collected during this study l (February, May, August, and November 1997) with historical data j l collected during the period 1987-1996,.
l l Previous studies of Lake Norman zooplankton populations have demonstrated a bimodal seasonal distribution with highest values generally occurring in the spring, and a less l 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 l Duplicate 10 m to surface and bottom to surface net tows were taken at Locations 2.0, l 5.0,9.5,11.0, and 15.9 in Lake Norman (Chapter 2, Figure 2-1) on 27 February,31 May, l 21 August, and 24 November,1997. For discussion purposes the 10 m to surface tow ' samples are called epilimnetic samples and the bottom to surface net tow samples are i 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
} Ilamme (1982). Zooplankton standing crop data from 1997 were compared with corresponding data from quarterly monitoring begun in August 1987. , 4-1
A one way ANOVA was performed on epilimnetic total zooplankton densities by quarter. This was followed by a Duncan's Multiple Range Test to determine which location means were significantly different. I i i RESULTS AND DISCUSSION i Total Abundance j During 1997, total zooplankton densities in epilimnetic samples were highest in May at l Locations 5.0,9.5, and 11.0; while maximum densities at Locations 2.0 and 15.9 occurred in August and February, respectively (Table 4-1. Figure 4-1). Epilimnetic densities ranged from a low of 35,100/m3 at Location 2.0 in November, to a high of 130,500/m3 at Location 15.9 in February. In the whole column samples, maximum densities at L Locations 2.0,5.0, and 9.5 were observed in May, and maximum densities at Locations ![) 11.0 and 15.9 occurred in February. Whole column densities ranged from 26,500/m3 at Location 5.0 in February to 73,300/m3 at Location 15.9, also in February. 1997 zooplankton data were generally similar to histo'rical trends (Duke . Power Company 1997), Hamme (1982). High values in May 1997 could have been, in part, a response to elevated phytoplankton concentrations observed during that month (Chapter 3). Total zooplankton densities were consistently higher in epilimnetic samples than in whole column samples during 1997, as was has been the case in previous years (Duke Power Company 1990,1991,1992,1993,1994,1995,1996, and 1997). 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). L Considerable spatial variability in epilimnetic zooplankton densities was observed during each sampling period. In February, mean densities at Locations 11.0 and 15.9 were f significantly higher than at other locations; and Locations 2.0 and 5.0, in the Mixing 4-2
Zone, had significantly lower densities than other locations (Table 4-2). During May, the highest density was at Location 9.5, and the minimum value occurred at Location 2.0. The density at Location 2.0 was significantly higher than at all other locations in August; while densities at Locations 9.5 and 15.9 were significantly higher than those of the Mixing Zone Locations. The trend of increasing epilimnetic zooplankton population densities from Mixing Zone to Background Locations observed during February, May, and November 1997 was similar to spatial patterns observed during 1995; few spatial patterns were noted during 1996 (Duke Power Company 1996,1997). Total epilimnetic zooplankton density variability was much higher among Background Locations (9.5,11.0,15.9) than among Mixing Zone Locations (2.0,5.0). The uppermost location, 15.9, had the greatest variability (Figure 4-2). Apparently epilimnetic zooplankton communities are more greatly influenced by environmental conditions at the uplake locations than at downlake locations. Location 15.9 represents the transition zone between river and reservoir where populations are expected to be highest due to higher productivity of this dynamic region. At the locations nearest the dam (Locations 2.0 and 5.0), seasonal variations are dampened and the overall production would be lower (Thornton, et al.1990). Epilimnetic zooplankton densities during 1997 were within ranges of those observed during previous years of the Program. The highest long term February densities occurred at Locations 2.0 and 11.0 in 1996, at Locations 5.0 and 9.5 in 1995, and at Location 15.9 in 1992 (figure 4-2). During May, Locations 2.0,5.0, and i1.0 had maximum values in 1995; while peaks occurred at Locations 9.5 and 15.9 in 1988. During August maximum densities occurred in 1988, except at Location 15.9 which had its highest August value in 1996. For November, maximum densities occurred at all locations in 1988. Since 1990, the densities at Mixing Zone Locations in May, August, and November did not fluctuate much between years; while fluctuations in densities during February are increasing. The Background locations continue to demonstrate high variability. D 4-3
Conununity Composition l l l Ninety-two zooplankton taxa have been identified since the Lake Norman Maintenance Monitoring Program began in August 1987 (Table 4-3). Thirteen previously unreported taxa were identified in 1997; however, four of these had been reported from Lake Norman in previous studies (Hamme 1982, Duke Power Company 1985). Of the nine previously unreported taxa, all were rotifers (Conochiloides dossaurius, Hexarthra mira, Kellicottia longispina, Keratella taurocephala, Macrochaetus subquadratus, Polyarthra l major, Ptygura libra, Trichocerca longiseta, and T. pusilla). ; 1 I Rotifers were the most abundant and diverse group during most of 1997, as has been the case in previous studies (Table 4-1, Figures 4-3 and 4-4). Copepods dominated ) zooplankton epilimnetic and whole column assemblages at Locations 2.0 through 11.0 in February, and Locations 2.0 and 5.0 in May. Copepods also dominated whole column { zooplankton densities at Location 9.5 in August, and at laations 2.0 and 11.0 in , November. Cladocerans were numerically dominant in epilimnetic and whole column samples at Locations 9.5 and 11.0 in May; in whole column samples at Location 9.5 in 1 August, and Locations 2.0 and 11.0 in November. Microcrustaceans have increased in importance since 1995. In 1996, copepods were dominant in six samples, and cladocerans in two samples; while in 1995, copepods were dominant in six samples, and cladocerans were never dominant (Duke Power Company 1996,1997). Rotifer abundance generally increased from downlake to uptake locations, as was the case in 1996 (Duke power company 1997). This pattern was also documented by Hamme i (1982) in earlier studies on Lake Norman. Copepods and cladocerans showed no consistent spatial trends in 1997 (Table 4-1. Figure 4-3). Polyarthra dominated rotifer populations at most Lake Norman locations in February. In May, Polyarthra most often dominated rotifer densities in the Mixing Zone; while Keratella was most abundant at Background locations. Polyarthra was the dominant rotifer at all but Location 11.0 in November. During August, Keratella was the principal l component of rotifer populations in the Mixing Zone, and Conochilus dominated samples l ~ 4-4
1 9 from Background locations. Keilicottia dominated rotifer populations at Location 15.9 in May. All of these taxa have been identified as important constituents of zooplankton conununities in previous studies (Duke power Company 1988, 1989, 1990, 1991, 1992, 1993,1994,1995,1996, and 1997; Hamme 1982). Long term tracking of rotifer populations indicated some notable seasonal patterns. Peak mean densities at Mixing Zone and Background Locations typically occurred in February and May. Mean densities were higher at Background Locations than in the Mixing Zone except for May and August 1996, and August 1997 (Figure 4-4). The highest Mixing Zone mean rotifer density since 1990 occurred in February 1996; while the highest mean rotifer density from Background Locations was observed in May 1995. Since then, the densities have decreased and appear to be fluctuating in the range for the 1990-1994 period. Copepod populations were consistently dominated by immature forms (primarily nauplii, and occasionally cyclopoid copepodites) during 1997, as has always been the case. Adult G copepods seldom constituted more than 5% of the total zooplankton density at any location during 1997. Tropocyclops, Mesocyclops, and Epischura were often important constituents of adult populations; while Cyclops and Diaptomus were occasionally important. Copepod densities peaked in February at Background Locations, and in May at Mixing Zone Locations. Historically, maximum copepod densities were most often observed in May (Figure 4-4). Bosmina was the most abundant cladoceran observed in 1997 samples, as has been the case in most previous studies (Duke Power Company 1997, Hamme 1982). Bosmina often comprised greater than 5% of the total zooplankton densities in both epilimnetic and whole column samples. Bosminopsis and Daphnia were also important among cladocerans. Bosminopsis dominated cladoceran populations at all locations in August, and was the dominant zooplankter in the epilimnion at Locations 5.0,9.5, and 11.0, and in whole column samples from locations 2.0,9.5, and i1.0. Daphnia was the dominant cladoceran at Imcations 2.0,5.0, and 9.5 in May. Diaphanosoma dominated cladoceran poplations at Location 11.0 in May. Seasonal trends of cladoceran densities were Q / variable: From 1990 to 1993, peak densities occurred in February; while in 1994 and V 4-5
l l l/^\ 1995, maxima weie recorded in May (Duke Power Company 1996). During 1996, peak - cladoceran densities occurred in May in the Mixing Zone, and in August among Background Locations (Duke Power Company 1997). In 1997, cladoceran densities , l again peaked in May (Figure 4-4). I FUTURE STUDIES l No changes are planned for the zooplankton portion of the Lake Norman Maintenance Monitoring Program in 1998-99. l
SUMMARY
l Maximum zooplankton standing crops in 1997 occurred in May, with minimum values in L August. This represented a shift from 1996 when peak abundance occurred in February. In 1997, densities were higher in epilimnetic samples than in whole column samples. Zooplankton densities tended to increase from Mixing Zone to Background Locations, except during August when no consistent spatial pattems were observed. 0 ' 4 Long term trends showed much higher year-to-year variability at uplake, or Background, Locations than at Mixing Zone Locations. Epilimnetic zooplankton densities during 1997 were within ranges of those observed in previous years. Lake Norman supports a highly diverse and viable zooplankton community. Thirteen taxa, previously unreported during the Program, were identified during 1997. I i Rotifers dominated zooplankton standing crops through most of 1997, as has been the case in previous years. The relative abundance of copepods and cladocerans was higher in 1997 than in 1996, representing a continuing trend of increased microcrustation abundnce since 1995. Copepods occasionally dominated zooplankton densities in all sampling periods; while cladocerans were dominant only in the Mixing Zone in August. 1 Major rotifer taxa observed in 1996 were: Polyarthra, Keratella, Conochlius, and Kellicotia.' Copepods were dominated by immature forms with adults seldom accounting lb ~
- (
for more than 5% of zooplankton densities. Bosmina was the predominant cladoceran. 4-6
9 Bosminopsis dominated cladoceran populations in August; while Daphnia and Diaphanosoma were occasionally dominant among cladocerans at some locations. I N b I 4-7
. LITER ATURE CITED lV l Duke Power Company.1976. McGuire Nuclear Station, Units I and 2, Environmental Report, Operating License Stage. 6th rev. Volume 2. Duke Power Company, Charlotte , NC.
1 Duke Power Company.1985. McGuire Nucl - Station,316(a) Demonstration. Duke Power Company, Charlotte, NC. l Duke Power Company.1988. Lake Norman Maintenance monitoring program: 1987 l Summary. Duke Power Company, Charlotte, NC. i l Duke Power Company.1989. Lake Nonnan 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. l Duke Power Company.1993. Lake Norman Maintenance monitoring program: 1991 Summary. Duke Power Company, Charlotte, NC. Duke Power Company.1994. Lake Norman Maintenance monito;ing program: 1993 Summary. Duke Power Company, Charlotte, NC. Duke Power Company.1995. Lake Norman Maintenance monitoring program: 1994 Summary. Duke Power Company, Charlotte, NC. Duke Power Company.1996. Lake Norman Maintenance monitoring program: 1995 Summary. Duke Power Company, Charlotte, NC. l' Duke Power Company.1997. Lake Norman Maintenance monitoring program: 1996
- Summary. Duke Power Company, Charlotte, NC
; Hamme, R. E.1982. Zooplankton, In J. E. Hogan and W. D. Adair (eds.). Lake Norman Summary, Technical Report DUKEPWIJ82-02. 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. I 115 pp.
4-8
i i 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 Normac 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. i Thornton, K. W., B. L. Kimmel, F. E. Payne.1990. Reservoir Limnology. John Wiley and Sons, Inc. New Yerk, NY. l 1 t
\
l
\
l u 4-9 1
Table 4-1. Total zooplankton densities (no. X 1000/m3), densities of major zooplankton taxonomic groups, and percent composition (in parentheses) of major taxa in l 10m to surface (10-S) and bottom to surface (B-S) net tow samples collected i from Lake Norman in February, May, August, and November 1997. Sample Locations Date Type Taxon 2J 19 M i 1.0 15.9 2/27/97 10-S COPEPODA 24.2 21.9 34.6 52.4 47.0 (54.2) (61.6) (42.0) (47.5) (36.1) CLADOCERA 4.3 2.3 29.0 29.4 6.2 (9.6) (6.5) (35.3) (26.7) (4.7) l ROTIFERA 16.2 11.3 18.8 28.5 77.3 (36.2) (31.9) (22.8) (25.8) (59.2) l TOTAL 44.7 35.5 82.4 110.4 130.5 B-S depth (m) of tow COPEPODA 15.3 14.7 24.3 29.0 24.2 for each (46.8) (55.6) (44.6) (43.4) (33.0) location CLADOCERA 3.0 1.7 20.2 15.8 7.3 2.0=31 (9.3) (6.4) (37.0) (23.7) (9.9) 5.0= 19 ROTIFERA 14.3 10.0 10.0 22.0 41.9 9.5=21 (43.9) (38.0) (183) (32.9) (57.1) i1.0=25 15.9=21 TOTAL 32.6 2(.3 54.4 66.8 73.3 5/31/97 10-S COPEPODA 38.9 43.6 42.5 46.3 29.8 (55.6) (51.5) (32.8) (38.0) (30.0) CLADOCERA 18.9 30.2 75.0 47.7 25.9 (27.0) (35.7) (57.7) (39.1) (26.0) ! ROTIFERA 12.2 10.9 12.3 27.9 43.7 (17.4) (12.9) (9.5) (22.9) (44.0) TOTAL 70.0 84.8 129.9 121.9 99.4 B-S depth (m) of tow COPEPODA 26.2 33.3 24.5 20.0 18.5 ! for each (65.2) (56.6) (37.9) (36.7) (30.4) l location CLADOCERA 6.7 18.1 33.4 21.9 12.5 l 2.0=30 (l6.8) (30.7) (51.6) (40.2) (20.5) l . 5.0= 18 ROTIFERA 7.2 7.4 6.8 12.6 29.9 9.5=20 (l 8.0) (l2.6) (l0.5) (23.1) (49.1)
; I1.0=25
- 15.9=19 TOTAL 40.1 58.8 64.6 54.5 60.9 3
4-10
t p Table 4-1 (continued).
- (
. Saniple Locations Date Lpe Taxon 2.0 5.0 9.5 11.0 15.9 8/21/97 10-S COPEPODA 8.9 8.8 14.3 8.0 11.8 1 (l2.5) (l9.2) (26.6) (l 8.6) (22.2)
- j. CLADOCERA 30.6 12.6 23.1 15.3 12.2 (43.0) (27.4) (42.9) (35.7) (23.0)
ROTIFERA 31.7 24.5 16.5 19.6 29.2 (44.5) (53.4) (30.5) (45.7) (54.8) i TOTAL 71.3 45.9 53.9 43.0 53.3 , B-S l depth (m)
- of tow COPEPODA 8.3 10.4 14.8 6.9 8.5
- for each (27.C (24.2) (40.3)
' (19.8) (22.0) location CLADOCERA 10.9 9.0 14.3 9.9 9.8 i 2.0=30 (35.7) (21.0) (38.8) (28.5) (25.4) i 5.0=18 ROTIFERA 11.4 23.6 7.7 18.0 20.2 i 9.5=20 (37.3) (54.8) (20.9) (51.7) (52.6) ] I1.0=25 l 15.9=19 TOTAL 30,7 '43.0 36.8 34.8 '38.5 11/24/97 10-S COPEPODA i 1.7 12.9 52.8 19.6 21.8 (33.3) (26.1) (45.8) (25.4) (23.7) CLADOCERA 0.8 1.7 2.7 17.2 11.3 (2.4) (3.5) (2.4) (22.3) (12.3) ROTIFERA 22.6 34.8 59.7 40.3 58.8 1 (64.3) (70.5) (51.8) (52.2) (64.0) ! TOTAL 35.1 49.4 115.3 77.1 92.0 B-S depth (m) of tow COPEPODA 12.8 14.0 20.3 17.5 17.0 for each (43.0) (26.5) (31.8) (39.7) (24.9) location CLADOCERA 5.2 2.0 4.0 10.9 7.5 2.0=30 (17.3) (3.8) (6.2) (24.9) (11.0) 5.0= 18 ROTIFERA 11.8 36.7 39.7 15.6 43.8 9.5= 19 (39.7) (69.7) (62.0) (35.4) (64.1) i1.0=25 15.9=20 TOTAL 29.8 52.7 64.0 44.0 68.4 m 4-11
_ _ _ _ . _ . _ _ . _ . _ _ _ - - ~ _ _ _ . _ _ _ _ _ _ . _ . _ . _ _ . _ . _ _ _ _ . _ _ _ _ _ . _ . _ . _ _ . _ . _ . _ _ _ . _ . . j j i Table 4-2. Dunvan's Multiple Range Test on epilimnetic zooplankton densities (no. X
- 1(XX)/m3) in Lake Norman. NC during 1997.
l t i i February location 5.0 2.0 9.5 11.0 15.9
, Mean 35.5 44.7 82.4 110.4 130.5 1
} 1 May lecation 2.0 5.0 15.9 11.0 9.5 Mean 70.0 84.7 99.4 121.9 125.7 I ! August Location 11.0 5.0 15.9 9.5 2.0 i Mean 43.0 45.9 53.3 53.9 71.3 1 J l l 1 ] November Location 2.0 5.0 11.0 15.9 9.5 Mean 35.1 49.4 77.1 92.0 115.3 4 1 4 l-l I l l 4-12
Table 4-3. Zooplankton taxa identified from samples collected quarterly on Lake Norman from August 1987 through November 1997 (* indicates new taxa observed in 1997). COPEPODA ROTIFERA Cyclops thomasi Forbcs Anuropsis spp. Lauterbome C vernalis Fischer Asplanchna spp. Gosse C spp. Brachionus caydata Barrois and Daday Dioptomus birgei Marsh B. havavaensis Rousselet D. mississippiensis Marsh B. patulus O. F. Muller D. pallidus lierick B. spp. Pallas
.D. spp. Marsh Chromogaster spp. Lauterborne Epishurafluviatisis tierrick Collotheca balatonica tlarr%g '
. Ergasilus spp. C mutabilis (iiudson)
Mesocyclops edat (S. A. Forbes) C spp. liarring M. spp. Sars Colurella spp. Bory de St. Vincent Tropocyclops prasinus (Yischer) *Conochiloides dossuarius fludson T.spp. C spp. lilava Calanoid copepodites Ccnochilus unicornis (Rousselet) Cyclopold copepodites C spp. litava , liarpacticoidea Castropus spp. Imhof l Nauplii *Rexarthra mira liudson H. spp. Schmada CLADOCERA Kellicotia hostoniensis (Rousselet) l Alona spp.Baird *K. longispina Kellicott l Bosmina longirostris (O. F. Muller) K. spp. Rousselet i B. spp. Baird *Keratella taurocephala Myers Bosminopsis dictersi Richard K. spp. Bory de St. Vincent
*Ceriadaphnia lacustris Birge Lecane spp. Nitzsch C spp. Dana *Macrochaetus subquadratus Perty i ~
Chydorus spp. Leach AL spp. Perty Daphnia ambigua Scouriield Monostyla stenroosi(Meissener) D, catawba Coker M. spp. Ehrenberg D. galeata Sars Nothloca spo. Gosse D. laevis Birge Plocosoma '.udsonii Brauer D. longiremisi Sars P. tramcatum (Levandet) D. lumhol:i Sars P. spp. lierrick
*D. mendotae (Sars) Birge Polyarthra euryptera (Weiricijski)
D.parvula Fordyce *P. major Be cbart D. pulex (de Geer) P. vulgarisOn n
- j. D. pulicaria Sars P. spp. Ehren , erg
, D. retrocurva Forbes Pompholyx spp. Gosse l D. schodleri Sars *Prygure libra Meyers r D. spp. Mullen P. spp. Ehrenberg ! *Diaphanosoma brachyuram s. str. (Lievin) Synchacia spp. Ehrenberg i D. spp. Fischer Trichocerca capucina (Weireijski) Holopediwn amazonicum Stingelin T. cylindrica (Imhof) { *H. gibberum Zaddach *T. longiseta Sch ank ! H. spp. Stingelin T.porcellus (Gosse)
- lsprodora kindtii(Focke) *T. pusilla iennings
' Leydigia spp. Freyberg T. similis Ltrnark ilyocryptus sordidus (Lieven) T. spp. Lamark
- l. spp. Sars Trichotria spp. Bory de St. Vincent Sida crystallina O. F. Muller Unidentified Rdelloidea INSECTA Chavborus spp. Lichtenstein
. . . . . - . - . _ . - . . - - - . . . , _ _ _ _ . . _ - . . . . - . ~ . - - . -- - - _ . - _ _ . . . . ~ . - - _ - ~ . ~ . ~ . . . ---
10m TO SURFACE TOWS i 140 i 120-100-80 - .. .
- l
- 60 -
40 ] l 20 . 0 2.0 5.0 g.5 11.0 t 5,9 BOTTOM TO SURFACE TOWS l-+-- FEB -G- MAY --G- AUG -M-NOV { 1n0 - I M. . , 80 ' *- . . 1 i 70 - . . . , , ,, t
" 60 - - .
*- - 1 50 - .. . , . .
)
x I 40 I . l l 20 - . . . , , ,, 10 - . . , , l 2.0 5,0 9.5 11.0 , 15.9 , LOCATIONS I b Figure 4-1. Total zooplankton density by location for samples collected in Lake Norman, NC,in 1997. IO L.) 4-14
- - - _ . - . - . . . _ _ -. . _ _ _ - - . = . . - - _ _ _ - . . . _ . _ . _ - . - . . _ -
MXING 2DNE 300 N_. 300 . _. . . . MAY. ._. F61i6if] giso iso E E E im . im. so so .__- - - 1 0 0 87 88 89 90 91 92 E3 94 95 96 97 87 88 m 90 91 92 93 94 95 96 97 BACKODUND LOCADONS
.. 300 i
l-+- 9.5 -+- 11.0 -*-- 159 l so 250 -
'\
1so -
. 1 1so -
l g. , , i 9 l 8 im 100 - - so so-0 0 l 87 88 89 90 91 92 93 94 95 96 97 87 88 89 90 01 92 93 94 95 9G 97 ( vre vre i Figure 4-2. Total zooplankton densities by location for epilimnetic samples collected in Lake Norman, NC, in 1997. 4-15
4 maxltC 2DPE y AL M ST POVEMBER g i 0 ( ? ~? E E I i 4
.., a E
m. I M g 150 - 150 i E E i E im . im. , I 4 ! i , so I, so, 0 0 or a w w m x w u w w w er m m w m w w u w w or BANGOUPOLOCADONS 300 - g l-+- 9.5 -e- 11.0 --er- 15.9 l m- u. .
^
g- _ L i 15- iso
)
$ E g - ,
g iw imo e l l so n so l 0 0 er a m w m e m u w w or er m m w m x w u w w or m m Figure 4-2 (continued). O V 4-16
FEBRUARY MAY 340 . . . _ . 120 1po 100 100 - y j 2.0 5.0 9.5 11.0 15.9 2.0 5.0 9.5 11.0 15.9 AUGUST NOVEMBER I 70 - 120-100-2.0 5.0 9.5 11.0 15.9 2.0 5.0 9.5 11.0 15.9 LOCATIONS CLADOCERANS ' ROTIFERS l l COPEPODS - Figure 4-3. Zooplankton community composition by month for epilimnetic samples collected in lake Norman, NC, in 1997. O 4-!7
COPEPODS 90-
-- - ._r r
, i 80 i l
- 70 ,
6
,l l l
50 - 40 g 30 - . . 20 - 10 " ,. p , 4 0 f 60 CLADOCERANS , l -+--$4XFK3 ZONE + DAO(GROUND LOCATOta l
' . : i i
$ 40 ' I
- ?
, x 30 - G y 20 i i O l 140 ROTIFEnS 120 100-80 - 80 - l 40 - , to - O
;;suawuuuuuazzzyy y y y yy y 4**50$$$$$$$$$$$lt$1)!$5)$$$)pl:ri
*5 - - - -
25 Figure 4-4. 7mplankton composition by month for epimlimnetic samples collected in Lake Norman, NC, in 1997. [] L/ 4-I8
l 1 A CilAPTER 5 i FISI.ERIES l l INTRODUCTION In accordance with the NPDES permit for McGuire Nuclear Station (MNS), monitoring of specific fish population parameters was continued during 1997. The components of the fish monitoring program for Lake Norman were to:
- Continue striped bass mortality monitoring throughout the summer. I
- 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 fall hydroacoustic/ purse seine forage population assessment.
l
- Implement a 2-year crappie assessment utilizing fall trap-net sampling of lower, mid, and uplake areas of Lake Norman.
l METHODS AND MATERIALS l l The mixing zone was monitored for striped bass mortalities during all summer sampling trips l on the lake. From July 8 through September 19, weekly surveys were conducted specincally to locate dead or dying striped bass. Summer pre-stress and winter post-stress gill-netting samples for scriped bass were conducted during July and December, respectively, for condition factor determination as part of the cooperative study with hCWRC. The post-stress sampling for striped bass also included the collection of striped bass data from the annual Striper Swiper tournament conducted on Lake Norman on December 13. Three suspended gill-nets (each 250 feet long) were fished for two i days during July and two days during December. The number of days that gill-nets were ) fished was dependent upon catching a sufficient number and size range of fish for analysis. A total target catch of approximately 75 fish was established, with individual targets of 20 to 30 fish each in age groups two and three and some representative collections of older, larger fish. Collected striped bass were weighed (g) and measured for total length (mm). Oto!!ths 5-1
[] L/ for aging were extracted from striped bass collected during the December tournament and the post-stress gill-rc_tung sample. Mobile hydroacoustic surveys of the entire lake were conducted on October 7-8, to estimate forage fish populations. liydroacoustic surveys employed multiplexing of side-scan and down-looking transducers to detect surface-oriented fish and deeper fish (1.5 m to bottom), respectively. Purse seine samples were collected on October 14 and 16 from the lower, mid, and uplake areas of the reservoir. A subsample of forage fish collected from each area was used to determine taxa composition and size distribution. Crappie trap-netting samples for determination of crappie size, condition, and age composition were conducted during November 3-7. Fifteen trap-nets were fished for two nights each in four areas of Lake Norman (Duke Power State Park, Marshall /McCrary Creek, Mountain Creek, and Davidson Creek). Two,2-person boat crews (one NCWRC crew and one DPC crew) were employed to conduct the sampling. Collected crappie were identified by species, weighed (g), and measured for total length (mm). Otoliths for aging were removed from at least five fish per 10-mm size group per species for each of the four areas sampled. p RESULTS AND DISCUSSION ( General monitoring of Lake Norman and specific monitoring of the MNS mixing zone for striped bass nortalities during the summer of 1997, yielded no mortalities within the mixing zone and three mortalities in the main channel outside the mixing zone. The specific observations by date were: l DATE LOCATION LENGTH NUMBER l July 29 Channel Marker 21 560 ma 1 l , July 31 Just uptake of Highway 1004 400 mm 1 l August 6 Mouth of Davidson Creek 500 mm 1 l 1 Gill-netting for striped bass condition during 1997 yielded variable catches for summer and winter sampling. Pre-stress, summer gill-netting yielded 139 striped bass ranging in length ( i from 317 mm to 714 mm. Post-stress, winter sampling (tournament and netting) yielded i19 k) . 5-2 i
striped bass ranging in length from 290 nun to 1,080 mm. Of the 119 total fish, tournament d catches accounted for 60 fish ranging in size from 509 mm to 1,080 nun, while gill-netting yielded 59 fish ranging in size from 290 mm to 616 mm. Individual fish lengths and weights l for all striped bass collected in the study were reported to the NCWRC. Additionally, l otoliths removed from post-stress, winter fish were used for age determinations. Post-stress striped bass ranged in age from 1 to 14 years. Of the age groups represented, age 4 fish comprised the largest group (24%), followed by ages 3 and 2 (18% each), age 5 (17%), and age 1 (16%). Ages 7,8, and 14 years were represented by only one fish each. i Analyses of hydroacoustics data to estimate forage populations is in progress. Software and ! calibration problems which delayed analyses of historical data have been resolved, and a separate report summarizing forage populations from 1993 through 1997 will be submitted in early 1999. Purse seine sampling collected an estimated total of 4,400 shad. With the ! exception of one large gizzard shad, the catch was comprised of threadfm shad, with a modal size class of 45-49 mm. Trap-netting for Lake Norman crappie resulted in the collection of 234 crappie over the five-day sample period. Black crappie comprised 97% of the total catch and ranged in size from 106 mm to 318 mm. White crappie ranged in size from i18 mm to 248 mm. Otoliths from V 164 black crappie and 7 white crappie were used to determine age composition. The mean l lengths at age were as follows: l AGE HLACK CRAPPIE MEAN WIIITE CRAPPIE MEAN LENGTH (mm) LENGTII(mm) Age 1 162 (69 Observations) 176 ( 6 Observations) Age 2 230 (53 Observations) 248 ( 1 Observat;on) l A7,e3 265 (24 Observations) - Age 4 279 (12 Observations) -
- Age 5 281 ( 5 Observations) -
i Age 6 . 218 (l Observation) - l* i 5-3 i
(q) ) FUTURE FISil STUDIEji 1 Continue striped bass monality monitoring throughout the summer. l 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. l Continue the annual, fall hydroacoustic/ purse seine forage population assessment. i Revise spring electrofishing program to be conducted on a 2-year basis beginning with the spring 1999 sample. Compile historical forage population data to determine any changes in population density and biomass.
SUMMARY
In accordance with the Lake Norman environmental maintenance monitoring program for the NPDES permit for McGuire Nuclear Station (MNS), specific fish monitoring programs were jv) i[ coordinated with the NCWRC and continued during 1997. General monitoring of Lake Norman and specific monitoring of the MNS mixing zone for striped bass mortalities during
~
i l l the summer of 1997, yielded no mortalities within the mixing zone and three mortalities in the main channel outside the mixing zone. l Gill-netting for striped bass during 1997 yielded a total of 258 striped bass, ranging in length I
- from 290 mm to 1,080 mm. Age determinations of post-stress striped bass indicated fish l ranging in age from 1 to 14 years. Age 4 fish comprised the largest age group (24%). All striped bass data were submitted to the NCWRC for detailed analyses of striped bass growth and condition.
The 2-year Lake Nonnan crappie study was initiated in 1997. Trap-net sampling resuhed in the collection of 234 crappie, ranging in size from 106 mm to 318 mm. Black crappie compriscJ 97% of the total catch. Age detenninations of black crappie indicated fish ranging in age from 1 to 6 years. All crappie data were submitted to the NCWRC for detailed analyses of crappie condition and age / size composition.
/ . A s-5-4
l fg l'all hydroacoustic/ purse seine sampling for estimation of Lake Nonnan forage fish !s ) l populations continued in 1997. Analyses and interpretation of historical data are in progress and a separate report summarizing forage populations from 1993 through 1997 will be submitted in early 1999. 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. l l ,~n i/ i D l l l l
)
1 )
,e"y \ Y Q/
5-5 ___. __ _ _ _ _ _ _ _ _ _ . _}}