Text

Lake Norman Maintenance Monitoring Program: 2012 Summary
	ML14050A126
Person / Time
Site:	McGuire, Mcguire
Issue date:	01/21/2014
From:	Abney M, Derwort J, Foris W; Duke Energy Carolinas
To:	; Office of Nuclear Reactor Regulation
References
	MNS-14-018
	Download: ML14050A126 (134)
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LAKE NORMAN C

MAINTENANCE MONITORING PROGRAM:

2012

SUMMARY

McGuire Nuclear Station: NPDES No. NC0024392 Principal Investigators:

Michael A. Abney John E. Derwort William J. Foris Prepared By:

Michael A. Abnjy Date:

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Prepared By:

Reviewed By:

Approved By:

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John E. Derwort f-aZ-70/Y Willi J. Foris John C. Williamson Linda D. Hickok 1 z2/9/

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DUKE ENERGY Environmental Services Water Resources McGuire Environmental Center 13339 Hagers Ferry Road Huntersville, NC 28078 December 2012

LAKE NORMAN MAINTENANCE MONITORING PROGRAM:

2012

SUMMARY

McGuire Nuclear Station: NPDES No. NC0024392 Principal Investigators:

Michael A. Abney John E. Derwort William J. Foris Prepared By:

Prepared By:

Reviewed By:

Michael A. Abqny John E. Derwort WfllmJ. Foris John C. Williamson Date:

Date:

/-~2 h-~o//

( 761~f Approved By:

Date:

Linda D. Hickok DUKE ENERGY Environmental Services Water Resources McGuire Environmental Center 13339 Hagers Ferry Road Huntersville, NC 28078 December 2012

LAKE NORMAN MAINTENANCE MONITORING PROGRAM:

2012

SUMMARY

McGuire Nuclear Station: NPDES No. NC0024392 Principal Investigators:

Michael A. Abney John E. Derwort William J. Foris DUKE ENERGY Environmental Services McGuire Environmental Center 13339 Hagers Ferry Road Huntersville, NC 28078 January 2014

ACKNOWLEDGMENTS The authors wish to express their gratitude to a number of individuals who made significant contributions to this report. First, we are much indebted to the Environmental Services field staff in carrying out a complex, multiple-discipline sampling effort that provides the foundation of this report. Mark Auten, Kim Baker, Dave Coughlan, Bob Doby, and Tyler Dubose conducted fisheries collections and sample processing. Chuck Campbell, Courtney Flowe, Bill Foris, David Home, Glenn Long, and Josh Quinn performed water quality field collections and data analyses. John Williamson assembled the plant operating data. John Derwort, Glenn Long, and Jan Williams conducted plankton sampling, sorting, and taxonomic processing.

We would also like to acknowledge the valuable contributions of Sherry Reid and Molly Doby. The benefit of their diligent efforts and patience in assembling and editing several drafts of the report can hardly be overstated. Finally, we are indebted to multiple reviewers; including Penny Franklin, Linda Hickok, and Tom Thompson. The insightful commentary and suggestions from these individuals and also between co-authors have benefited the report in myriad ways.

ii

TABLE OF CONTENTS EXECUTIVE SUM M ARY..............................................................................................

v LIST OF TA BLES.............................................................................................................

viii LIST O F FIG URES......................................................................................................

x CHAPTER 1-MCGUIRE NUCLEAR STATION.......................................................

1-1 INTROD UCTION...........................................................................................................

1-1 OPERATION AL DATA FO R 2012..........................................................................

1-1 CH A PTER 2-W ATER Q UALITY.....................................................................................

2-1 INTRO D UCTION...........................................................................................................

2-1 M ETHODS AN D M ATERIA LS....................................................................................

2-1 RESULTS AN D D ISCUSSION.....................................................................................

2-4 Precipitation and A ir Tem perature...............................................................................

2-4 Dissolved Oxygen........................................................................................................

2-7 Reservoir-W ide Tem perature and D issolved O xygen.................................................

2-9 Striped Bass Habitat and Fish M ortalities.................................................................

2-11 Turbidity and Specific Conductance..........................................................................

2-13 A lkalinity and pH.......................................................................................................

2-13 M ajor Cations and Anions.........................................................................................

2-13 Nutrients.....................................................................................................................

2-14 M etals.........................................................................................................................

2-14 SUM M ARY..................................................................................................................

2-15 CH A PTER 3-PHY TO PLAN K TO N...............................................................................

3-1 INTROD UCTION...........................................................................................................

3-1 M ETHO DS AND M ATERIA LS....................................................................................

3-1 RESULTS AND DISCU SSION..............................................

.................................. 3-2 Standing Crop..............................................................................................................

3-2 Chlorophyll...............................................................................................................

3-2 Total Abundance.......................................................................................................

3-4 Seston...........................................................................................................................

3-5 Secchi Depths...............................................................................................................

3-5 Comm unity Com position............................................................................................

3-5 Species Com position and Seasonal Succession...........................................................

3-6 SU M M AR Y....................................................................................................................

3-7 CH A PTER 4-ZO O PLANK TO N....................................................................................

4-1 IN TRODUCTION...........................................................................................................

4-1 M ETHODS AN D M ATERIA LS....................................................................................

4-1 RESULTS AN D D ISCUSSION.....................................................................................

4-2 Total A bundance..........................................................................................................

4-2 Comm unity Com position.............................................................................................

4-3 Copepoda..................................................................................................................

4-4 iii

Cladocera..................................................................................................................

4-4 Rotifera.......................................

..... 4-4 SUM M ARY....................................................................................................................

4-5 CH APTER 5-FISH ERIES..................................................................................................

5-1 INTRODUCTION...........................................................................................................

5-1 M ETHODS AND M ATERIA LS....................................................................................

5-1 Spring Electrofishing Survey.......................................................................................

5-1 Sum m er Striped Bass M ortality Surveys.....................................................................

5-2 Striped Bass Netting Survey........................................................................................

5-2 Fall Hydroacoustics and Purse Seine Surveys.............................................................

5-2 RESULTS AND DISCUSSION.....................................................................................

5-3 Spring Electrofishing Survey.......................................................................................

5-3 Sum m er Striped Bass M ortality Surveys.....................................................................

5-5 W inter Striped Bass Netting Survey............................................................................

5-6 Fall Hydroacoustics and Purse Seine Surveys.........................

5-7 SUM M ARY....................................................................................................................

5-7 LITERATURE CITED...................................................................................................

L-1 iv

EXECUTIVE

SUMMARY

In accordance with National Pollutant Discharge Elimination System (NPDES) permit number NC0024392 for McGuire Nuclear Station (MNS), the Lake Norman Maintenance Monitoring Program continued during 2012. The 2012 station operation data is summarized and continues to demonstrate compliance with thermal limits and cool water requirements.

Annual precipitation in the vicinity of MNS in 2012 totaled 87.6 cm or less than the long-term average (117.6 cm), but greater than the minimum annual total of 64.4 cm measured in 1981.

The 2012 total was also the 8th lowest over the 1975 - 2012 period. Monthly air temperatures in 2012 were mostly equal to or wanner than the long-term average with the winter and spring air temperatures approaching close to 35% higher than the long-term mean.

Seasonal and spatial patterns of water temperatures and DO concentrations throughout Lake Norman in 2012 were similar to that measured historically, although winter and spring lake temperatures were among the warmest measured since MNS began operations. Regulatory thermal discharge limits were met for all months in 2012 at MNS.

All chemical parameters measured in 2012 were within concentration ranges previously reported. Specific conductance values and all cation and anion concentrations were low, as were nutrient concentrations, with many values reported equal to or below the analytical reporting limit (ARL). Concentrations of metals in 2012 were also low, often below the respective ARLs, and consistently below the North Carolina water quality standard or action level for each respective metal. The lone exception was manganese concentrations which were consistently low in 2012 except during the summer when bottom waters exceeded the state water quality action level (200 ýtg/L), which is characrtersic of historical conditions.

Suitable pelagic habitat for adult striped bass in 2012 was totally eliminated from the reservoir from mid-July through early September, or approximately for seven weeks, which is within the MNS operational historical range. Striped bass mortalities in 2012 totaled 835 fish and represented the fourth consecutive year that summertime mortalities of adult striped bass exceeded 300 fish in the reservoir. Mortalities were observed concurrent with habitat elimination and were similar in timing and location as previous die-offs.

During 2012, Lake Norman was oligo-mesotrophic based on long-term annual mean chlorophyll concentrations.

All chlorophyll concentrations during 2012 were within historical ranges but were most often in the low range. Annual maxima typically occurred in v

the summer with minima most often occurred in February. Chlorophyll concentrations were all well below the NC State standard of 40 jig/L.

Phytoplankton diversity, or the number of phytoplankton taxa, was lower than 2011, but was in the high historical range. The taxonomic compositions of phytoplankton communities during 2012 were similar to those of most previous years. Diatoms were dominant during May and November, while cryptophytes were dominant during February.

Green algae dominated summer assemblages. Blue-green algae typically comprised less than 4% of total densities.

The most abundant algae during 2012 were: the cryptophyte, Rhodomonas minuta in February, the diatom Tabellaria fenestrate in May and November, and the green alga, Cosmarium asphearosporum v. strigosum during August.

All of these taxa have been common and abundant throughout the Lake Norman Maintenance Monitoring Program.

Seston dry and ash-free weights were most often higher in 2012 than in 2011. Maximum dry and ash-free weights were generally observed uplake while minimum values were observed most often downlake.

Secchi depths often reflected suspended solids, with shallow depths loosely related to high dry weights. Secchi depths decreased from downlake to uplake locations. The lakewide mean Secchi depth in 2012 was the highest recorded since 1992.

Zooplankton monitoring also continued in 2012. In most cases, zooplankton densities varied considerably and no consistent seasonal trends were observed. Zooplankton densities in 2012 were most often within historical ranges. As in past years, epilimnetic densities were higher than whole-column densities and within the ranges of those observed in previous years.

Spatial trends of zooplankton populations were generally similar to those of the phytoplankton, with increasing densities from downlake to uplake.

Mean zooplankton densities tended to be higher among background locations than among mixing zone locations during 2012. Long-term trends showed much higher year-to-year variability at background locations than at mixing zone locations.

Zooplankton samples from Lake Norman in 2012 were dominated by rotifers and their relative abundances increased since 2011. The most abundant rotifers observed in 2012, as in many previous

years, were Kellicotia, Polyarthra, Ptygura, and Keratella.

vi

Microcrustaceans (copepods and cladocerans) decreased in relative abundances in 2012 and their percent compositions were within historical ranges.

Copepods were dominated by immature forms. Adults rarely accounted for more than 7% of zooplankton densities. As in previous years, the most important adult copepods were Tropocyclop and Epishura. Bosmina was the predominant cladoceran as often the case in previous years of the Program.

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

Spring electrofishing indicated that numbers and biomass of fish in 2012 were generally similar to those noted since 1993. The littoral fish populations in the three sampling areas were comprised of 14 to 15 species of fish and two hybrid complexes. The fish surveys were numerically and gravimetrically dominated by centrarchids.

The pelagic forage fish population, dominated by threadfin shad, continued to demonstrate considerable variability within and among zones evident since 1997. Largemouth bass number of individuals and biomass were the lowest recorded since surveys began in 1993.

Spotted bass number of individuals and biomass decreased from 2011 levels, but remain high, likely displacing largemouth bass.

Summer striped bass mortalities were the third highest number ever recorded. Catfish mortalities also occurred in lower Lake Norman during late summer, likely due to coinciding anoxic to severely hypoxic conditions. It is not known why catfish died in appreciable numbers in 2012 and not prior years.

Monitoring results from 2012 are consistent with results from previous years. No obvious short-term or long-term impacts were observed in the water quality, phytoplankton, zooplankton, and fish communities of Lake Norman. McGuire Nuclear Station continues to demonstrate compliance with thermal limits and cool water requirements.

vii

LIST OF TABLES Table Title Page 1-1 Average monthly capacity factors (%) and monthly average discharge water tem peratures for M N S during 2012............................................................................

1-2 2-1 Water quality 2012 program for the MNS NPDES Maintenance Monitoring Program on Lake N orm an.........................................................................................

2-17 2-2 Analytical methods and reporting limits employed in the 2012 MNS NPDES Maintenance Monitoring Program for Lake Norman..................................

2-18 2-3 Heat content calculations for the thermal regime in Lake Norman for 2011 an d 2 0 12....................................................................................................................

2 -19 2-4 A comparison of areal hypolimnetic oxygen deficits (AHOD), summer chlorophyll a (Chl a), Secchi depth, and mean depth of Lake Norman and 18 T V A reservoirs.....................................................................................................

2-20 2-5 Quarterly surface (0.3 m) and bottom (bottom minus I m) water chemistry for the MNS discharge, mixing zone, and background locations on Lake Norman during 2011 and 2012. Values less than detection were assumed to be equal to the detection limit for calculating a mean..............................................

2-21 3-1 Mean chlorophyll a concentrations (*tg/L) in composite samples and Secchi depths (m) observed in Lake Norm an in 2012............................................................

3-9 3-2 Mean phytoplankton densities (units/mL) and biovolumes (mm 3/m3) by location and sample month from samples collected in Lake Norman during 2 0 12...........................................................................................................................

3 -10 3-3 Total mean seston dry and ash free-dry weights (mg/L) from samples collected in Lake Norm an during 2012.....................................................................

3-10 3-4 Dominant classes, their most abundant species, and their percent composition (in parentheses) at Lake Norman locations during each sam pling period of 20 12............................................................................................

3-11 4-1 Total zooplankton densities (No. X 1000/mi3), densities of major zooplankton taxonomic groups, and percent composition (in parentheses) of major taxa in the epilimnion and whole-column net tow samples collected from Lake Norman in winter (February), spring (May), summer (August),

and fall (N ovem ber) 2012...........................................................................................

4-7 4-2 Zooplankton taxa identified from samples collected quarterly on Lake N orm an from 1987 - 2012..........................................................................................

4-9 4-3 Dominant copepod (adults), cladoceran, and rotifer taxa and their percent composition (in parentheses) of the copepod, cladoceran and rotifer densities by location and sample period in Lake Norman in 2012...........................

4-13 viii

LIST OF TABLES, Continued Table Title Page 5-1 Number of individuals (No.) and biomass (Kg) of fish collected from electrofishing ten 300-m transects each, at three areas (MSS, REF, MNS) in Lake N orm an, spring 20 12..........................................................................................

5-9 5-2 Mean TL (mm) at age (years) for spotted bass and largemouth bass collected from electrofishing ten 300-m transects each, at three areas (MSS, REF, M NS) in Lake Norm an, spring 2012.................................................................

5-9 5-3 Number of individuals (No.), percent composition of forage fish, and threadfin shad modal TL class collected from purse seine surveys in Lake Norman during late summer/early fall, 1993 - 2012................................................

5-10 ix

LIST OF FIGURES Figure Title Page 2-1 Water quality sampling locations (numbered) for Lake Norman.............................

2-24 2-2a Annual precipitation totals in the vicinity of MNS...................................................

2-25 2-2b Monthly precipitation totals in the vicinity of MNS in 2011 and 2012.................... 2-25 2-2c Mean monthly air temperatures recorded at MNS beginning in 1989...................... 2-26 2-3 Monthly mean temperature profiles for the MNS background zone in 2011 and 2 0 12....................................................................................................................

2 -2 7 2-4 Monthly mean temperature profiles for the MNS mixing zone in 2011 and 2 0 12...........................................................................................................................

2 -2 9 2-5 Monthly surface (0.3 m) temperature and dissolved oxygen data at the discharge location (Location 4.0) in 2011 and 2012.................................................

2-31 2-6 Monthly mean dissolved oxygen profiles for the MNS background zone in 20 11 and 20 12...........................................................................................................

2-32 2-7 Monthly mean dissolved oxygen profiles for the MNS mixing zone in 2011 and 20 12....................................................................................................................

2-34 2-8 Monthly reservoir-wide temperature isotherms for Lake Norman in 2012.............. 2-36 2-9 Monthly reservoir-wide dissolved oxygen isopleths for Lake Norman in 2 0 12...........................................................................................................................

2 -3 9 2-10a Heat content of the entire water column and the hypolimnion in Lake N orm an in 20 12........................................................................................................

2-42 2-1 Ob Dissolved oxygen content and percent saturation of the entire water column and the hypolimnion of Lake Norman in 2012.........................................................

2-42 2-11 Striped bass habitat in Lake Norman in June, July, August, and September 2 0 12...........................................................................................................................

2 -4 3 2-12 Lake Norman lake levels, expressed in meters above mean sea level (mmsl) from 2002 -

2012.

Lake level data correspond to the water quality sam pling dates over this tim e period.........................................................................

2-45 3-1 Lake Norman phytoplankton chlorophyll a seasonal maximum and minimum lake-wide means since August 1987 compared with the long-term seasonal lake-wide means and lake-wide means for 2012........................................

3-12 3-2 Phytoplankton chlorophyll a, densities, biovolumes, and seston dry weights at locations in Lake Norman in February, May, August, and November 2 0 12...........................................................................................................................

3 -13 3-3 Phytoplankton mean chlorophyll concentrations by location for samples collected in Lake Norman from February 1988 through 201.2 (Note: change in axis for 15.9 and 69.0, and that clear data points represent long-term m ax im a).....................................................................................................................

3 -14 3-4 Phytoplankton mean chlorophyll concentrations by location for samples collected in Lake Norman from May 1988 through 2012.........................................

3-15 3-5 Phytoplankton mean chlorophyll concentrations by location for samples collected in Lake Norman during August 1987 through 2012..................................

3-16 x

LIST OF FIGURES, Continued Figure Title Page 3-6 Phytoplankton mean chlorophyll concentrations by location for samples collected in Lake Norman during November 1987 through 2012............................

3-17 3-7 Class composition of phytoplankton standing crop parameters (mean density and biovolume) from euphotic zone samples collected at Location 2.0 in Lake N orm an during 2012..............................................................................

3-18 3-8 Class composition of phytoplankton standing crop parameters (mean density and biovolume) from euphotic zone samples collected at Location 5.0 in Lake N orm an during 2012..............................................................................

3-19 3-9 Class composition of phytoplankton standing crop parameters (mean density and biovolume) from euphotic zone samples collected at Location 9.5 in Lake N orm an during 2012..............................................................................

3-20 3-10 Class composition of phytoplankton standing crop parameters (mean density and biovolume) from euphotic zone samples collected at Location 11.0 in Lake N orm an during 2012............................................................................

3-21 3-11 Class composition of phytoplankton standing crop parameters (mean density and biovolume) from euphotic zone samples collected at Location 15.9 in Lake N orm an during 2012............................................................................

3-22 4-1 Total zooplankton density by location for samples collected in Lake N orm an in 20 12........................................................................................................

4-15 4-2 Zooplankton community composition by sample period and location for epilimnetic samples collected in Lake Norman in 2012...........................................

4-16 4-3 Total zooplankton densities by location and year for epilimnetic samples collected in Lake Norman in the winter periods of 1988 - 2012..............................

4-17 4-4 Total zooplankton densities by location and year for epilimnetic samples collected in Lake Norman in the spring periods of 1988 - 2012 (clear data points represent long-term m axim a).........................................................................

4-18 4-5 Total zooplankton densities by location and year for epilimnetic samples collected in Lake Norman in the summer periods of 1987 - 2012...........................

4-19 4-6 Total zooplankton densities by location and year for epilimnetic samples collected in Lake Norman in the fall periods of 1987 - 2012...................................

4-20 4-7 Annual percent composition of major zooplankton taxonomic groups from mixing zone locations (Locations 2.0 and 5.0 combined) during 1988 -

2 0 12...........................................................................................................................

4 -2 1 4-8 Annual percent composition of major zooplankton taxonomic groups from background Locations (Locations 9.5, 11.0, and 15.9 combined) during 1988 - 20 12...............................................................................................................

4-22 4-9 Copepod densities during each season of each year among epilimnetic samples collected in Lake Norman from 1990- 2012.............................................

4-23 4-10 Cladoceran densities during each season of each year among epilimnetic samples collected in Lake Norman from 1990 - 2012.............................................

4-24 xi

LIST OF FIGURES, Continued Figure Title Page 4-11 Rotifer densities during each season of each year among epilimnetic samples collected in Lake Norman from 1994-2012.............................................

4-25 5-1 Sampling locations and zones associated with fishery assessments in Lake N orm an......................................................................................................................

5-11 5-2 Total number of individuals (a) and biomass (b) of fish collected from electrofishing ten 300-m transects each, at three areas (MSS, REF, MNS) in Lake Norman, spring 1993 - 1997 and 1999 - 2012................................................

5-12 5-3 Total number of individuals (a) and biomass (b) of spotted bass collected from electrofishing ten 300-m transects each, at three areas (MSS, REF, M NS) in Lake Norm an, spring 2001 - 2012.............................................................

5-13 5-4 Size distributions of spotted bass (a) and largemouth bass (b) collected from electrofishing ten 300-m transects each, at three areas (MSS, REF, MNS) in Lake N orm an, spring 2012........................................................................................

5-14 5-5 Condition (Wr) for spotted bass (a) and largemouth bass (b) collected from electrofishing ten 300-m transects each, at three areas (MSS, REF, MNS) in Lake N orm an, spring 2012........................................................................................

5-15 5-6 Number of individuals (a) and biomass (b) of largemouth bass collected from electrofishing ten 300-m transects each, at three areas (MSS, REF, MNS) in Lake Norman, spring 1993 - 1997 and 1999 - 2012.................................

5-16 5-7 Number of striped bass mortalities by date in summer 2004, 2009 - 2012.............. 5-17 5-8 Mean TL and condition (Wr) by age of striped bass collected in Lake Norman, winter 2012. Numbers of fish by age are inside bars................................

5-17 5-9 Zonal density estimates of pelagic forage fish in Lake Norman, late sum m er/early fall 1997 - 2012.................................................................................

5-18 5-10 Number of individuals and size distribution of threadfin shad and alewife collected from purse seine surveys in Lake Norman, September 2012....................

5-19 xii

CHAPTER 1 MCGUIRE NUCLEAR STATION INTRODUCTION The following annual report was prepared for the McGuire Nuclear Station (MNS) National Pollutant Discharge Elimination System (NPDES) permit (# NC0024392) issued by North Carolina Department of Environment and Natural Resources (NCDENR).

This report summarizes environmental monitoring of Lake Norman conducted during 2012.

OPERATIONAL DATA FOR 2012 Station operational data for 2012 are listed in Table 1-1.

The monthly average station capacity factors exceeded 100% for eight months, January - August, when both Units I and 2 were fully operational.

Scheduled maintenance of Unit 2 in September, October, and November resulted in capacity factors for that unit being reduced to less than 50% and less than 80% for the station monthly average.

The thermal compliance discharge limit for MNS is 95 'F (35.0 'C) for the period October -

June and increases to 99 'F (37.2 'C) for July - September. Thermal discharge limits were met for each month in 2012 and reached a maximum of 98.8 'F (37.1 'C) for July. The volume of cool water in Lake Norman was also tracked throughout the year to ensure that an adequate volume was available to comply with both the Nuclear Regulatory Commission Technical Specification requirements and the NPDES discharge water temperature limits.

1-1

Table 1-1.

Average monthly capacity factors (%) and monthly average discharge water temperatures for MNS during 2012.

Monthly average Monthly average NPDES capacity factors (%)

discharge temperatures Month Unit 1 Unit 2 Station F

C Jan 105.82 105.55 105.68 70.3 21.3 Feb 105.81 105.57 105.69 70.2 21.2 Mar 105.41 105.35 105.38 74.1 23.4 Apr 105.42 105.22 105.32 80.6 27.0 May 105.02 104.85 104.94 86.2 30.1 Jun 104.10 104.30 104.20 92.1 33.4 Jul 103.02 103.02 103.02 98.2 36.8 Aug 103.27 102.74 103.01 98.1 36.7 Sep 103.32 47.05 75.18 95.0 35.0 Oct 104.75 0.00 52.37 84.6 29.2 Nov 104.96 0.00 52.48 70.0 21.1 Dec 105.24 94.27 99.75 73.4 23.0 Average 104.68 81.49 93.09 82.7

[

28.2 1-2

CHAPTER 2 WATER QUALITY INTRODUCTION The objectives of the water quality portion of the McGuire Nuclear Station (MNS) NPDES Maintenance Monitoring Program (MMP) are to:

1. maintain continuity in the water quality data base of Lake Norman to allow detection of any significant station-induced and/or natural change in the physicochemical structure of the lake; and

2. compare, where applicable, these physicochemical data to similar data in other hydropower reservoirs and cooling impoundments in the South.

This report focuses primarily on 2011 and 2012 data. Where appropriate, reference to pre-2011 data will be made by citing reports previously submitted to the NCDENR.

METHODS AND MATERIALS The complete water quality monitoring program for 2012, including specific variables, locations, depths, and frequencies is outlined in Table 2-1. Sampling locations are identified in Figure 2-1. Sampling locations were selected at the initiation of the Lake Norman MMP in 1986 to provide a thorough assessment of water quality throughout the spatial expanse of the reservoir and include sites within the projected impact of the thermal discharge from MNS, and in background zones. Physicochemical data collected at these locations also serve to track the temporal and spatial variability in striped bass habitat in the reservoir during the stratified period.

Measurements of temperature, dissolved oxygen (DO), DO percent saturation, pH, and specific conductance were taken, in situ, at each location with a Hydrolab Data Sonde (Hydrolab 2006) starting at the lake surface (0.3 m) and continuing at one-meter intervals to lake bottom. Pre-and post-calibration procedures associated with operation of the Hydrolab 2-1

were strictly followed, and documented in hard-copy format. Hydrolab data were captured and stored electronically and converted to spreadsheet format following data validation.

Water samples for laboratory analysis were collected with a Kemmerer or Van Dom water bottle at the surface (0.3 m), and from one meter above bottom, where specified (Table 2-1).

Samples not requiring filtration were placed directly in pre-acidified high density polyethylene (HDPE) bottles. Samples requiring filtration were first processed in the field by filtering through a 0.45-jIm filter (Gelman AquaPrep 600 Series Capsule) which was pre-rinsed with 500 mL of sample water, and then placed in pre-acidified HDPE bottles (Table 2-1). Upon collection, all water samples were immediately stored in the dark, and on ice, to minimize the possibility of physical, chemical, or microbial transformation.

Analytical methods, reporting limits, and sample preservation techniques employed were identical to those used in 2011, except where noted, and are summarized in Table 2-2. All laboratory water quality analyses were performed by the Duke Energy analytical laboratory located in Huntersville, NC. This laboratory is certified to perform analytical assessments for inorganic and organic parameters in North Carolina (North Carolina Division of Water Quality, certificate number 248).

A Quality Assurance/Quality Control Program (QA/QCP) is fundamental to the collection, reporting, and interpretation of water quality data, and most investigators implement some type of QA/QCP to identify, quantify, and document bias and variability in data resulting from the collection, processing, shipping, handling and analysis of samples by field and laboratory personnel.

Both the United States Environmental Protection Agency (USEPA 1998a and 1998b) and the United States Geological Survey (USGS 1998 and 2002) require that any agency-funded project have an approved quality assurance program, and that this program incorporate both a field and laboratory component. USGS also requires that any agency funded study that includes laboratory assessments must also participate in their Standard Reference Program (SRP). This program was originally developed by USGS in the 1960s and currently involves analysis by participating laboratories of standards (blind unknowns) created by the agency on a biannual schedule (USGS 2002).

The QA/QCP employed for this study followed the recommendation of the USEPA and USGS, and included both a field and laboratory component.

Field blanks, i.e. deionized water placed in sample bottles, were subjected to the same sample collection and handling procedures, including filtration, applied to actual samples. Periodically, samples were also 2-2

split prior to submittal to the laboratory for analysis with the goal of quantifying intra-sample analytical variability. The laboratory QA/QCP involved a variety of techniques commonly used in analytical chemistry and included reagent blanks, spikes, replicates, and performance samples.

To supplement this program, additional performance samples were run on the major ions and nutrients. Beginning in 2005, standards were purchased from the USGS, through the agency's SRP, and submitted at least annually to Duke Energy's laboratory to serve as a "double blind" assessment of analytical performance. These standards allowed quantification of the uncertainty of the analytical results against known values that were within the same concentration matrix as actual samples. The goal of this effort is to assemble additional data on analytical uncertainty which can be incorporated into statistical analyses assessing trends in time or space.

Water quality data were subjected to various numerical, graphical, and statistical techniques in an attempt to describe spatial and temporal trends within the lake and interrelationships among constituents. Whenever analytical results were reported to be equal to or less than the method reporting limit, these values were set equal to the reporting limit for numerical and statistical assessments.

Data were analyzed using two approaches, both of which were consistent with earlier studies on the lake (Duke Power Company 1985, 1987, 1988; Duke Power 2005; Duke Energy 2011, 2012). The first method involved partitioning the reservoir into mixing, background, and discharge zones, consolidating the data into these sub-sets, and making comparisons among zones and years.

In this report, the discharge includes only Location 4.0; the mixing zone, Locations 1.0 and 5.0; the background zone includes Locations 8.0, 11.0, and 15.0 (Figure 2-1). The second approach, applied primarily to the in situ data, emphasized a much broader lake-wide investigation and encompassed the plotting of monthly isotherms and isopleths, and summer striped bass (Morone saxatili) habitat.

Several quantitative calculations were also performed on the in situ data; these included calculation of the areal hypolimnetic oxygen deficit (AHOD), maximum whole-water column and hypolimnion oxygen content, maximum whole-water column and hypolimnion heat content, mean epilimnion and hypolimnion heating rates over the stratified period, and the Birgean heat budget (maximum - minimum heat content).

Heat and oxygen content were expressed on an area and volume basis for the entire water column, the epilimnion, and the hypolimnion. Heat and dissolved oxygen mass calculations provide a convenient approach of integrating the influence of various physical, chemical, and biological processes on the thermal and DO structure of a waterbody. Heat and oxygen mass were calculated at one meter intervals within the water column employing the in-situ profile 2-3

data, bathymetric (area and volume) data for Lake Norman and the following equation, modified after Hutchinson (1957):

Lt = Ao-I TO 9 Az e dz where; Lt = reservoir heat (Kcal/cm 2) or oxygen (mg/cm 2) content A0 = surface area of reservoir (cm 2)

TO = mean temperature (°C) or oxygen content (mg/L) of layer z Az = area (cm 2) at depth z dz = depth interval (cm) zo = surface Zm = maximum depth (in)

Precipitation and air temperature data were obtained from a meteorological monitoring site established near MNS in 1975.

These data are employed principally by Duke Energy as input variables into meteorological modeling studies to address safety issues associated with potential radiological releases into the atmosphere by MNS (Duke Power 2004b), as required by the Nuclear Regulatory Commission. The data also serve to document localized temporal trends in air temperatures and rainfall patterns. Lake level and hydroelectric flow data were obtained from within Duke Energy.

RESULTS AND DISCUSSION Precipitation and Air Temperature Annual precipitation in the vicinity of MNS in 2012 totaled 87.6 cm (Figures 2-2a and 2-2b) which is considerably less than observed in 2011 (118.0 cm), and the long-term average (117.6 cm), based on Charlotte, NC airport data, but greater than the minimum annual total of 64.4 cm measured in 1981. Monthly rainfall totals in 2012 was greatest in May with 18.0 cm and the least in November with 1.7 cm.

Monthly average air temperatures measured near MNS in 2012 were either equal to or warmer than the long-term average except for November which was cooler than both the long-term average and 2011 (Figure 2-2c).

Further, year 2012 monthly average air 2-4

temperatures were either equal to or warmer than observed in 2011 with the greatest difference, approximately 5 'C, observed in March.

Degree day calculations, a convenient method to quantify the influence of air temperatures on water temperatures, were calculated for the lake's winter cooling and summer heating periods, defined as January - March and May - September, respectively, from 1975 - 2012, The degree-days total for the 2012 cooling period was approximately 40% warmer than 2011 and 35% warmer than the long-term mean. Based on these meteorological conditions, one would expect less heat loss from the lake to the atmosphere, resulting in warmer winter water temperatures in 2012, compared to both 2011 and the long-term mean. In contrast, the degree-days total for the 2012 heating period was only 2% warmer than the long-term average and cooler by 2% than 2011.

Water temperatures measured in 2012 illustrated similar temporal and spatial trends in the background and mixing zones (Figures 2-3 and 2-4) as they did in 2011. This similarity in temperature patterns between zones has been a dominant feature of the thermal regime in Lake Norman since MNS began full operations in 1983. When between-zone differences in temperatures are observed, they occur predominately during the cooling period, and can be traced to the influence of the thermal discharge at MINS on mixing zone temperatures.

Additionally, interannual differences in water temperatures in Lake Norman typically parallel differences in air temperatures but with a one-month lag time (Duke Power 2002; Duke Energy 2011, 2012).

Water temperatures in winter and early spring 2012 were typically either equal to or warmer than measured in 2011, with only minor differences observed between zones (Figures 2-3 and 2-4). Minimum winter water temperatures in 2012 were among the warmest measured in Lake Norman over the last two decades, reaching a water column average of 11.5 'C, contrasted with a water column average of 8.0 'C in 2011.

Historical data illustrates that interannual differences in water temperatures generally parallel differences in air temperatures, but because lake sampling is routinely performed in the first week of each month, the observed data often reflects the cumulative influences of meteorology and hydrology prior to that date.

Differences in winter and early spring water temperatures between 2012 and 2011 tracked air temperatures (Figure 2-2c) and were consistent with historical observations.

Minimum winter 2012 water temperatures recorded in early January and February ranged from 9.7 'C 2-5

to 11.2 'C in the background zone and were as much as 3.9 'C warmer than measure in 2011 (Figures 2-3 and 2-4). In the mixing zone, 2012 winter minimum temperatures were slightly warmer than observed in the background zone due to the thermal discharge from MNS, and ranged from 10.1 'C to 16.9 'C, or up to 5.3 'C warmer than measured in 2011. Part of this interannual difference in mixing zones temperatures was also likely attributed to lower capcity factors at MNS in spring 2011 (Duke Energy 2012). Minimum water temperatures measured in 2012 were among the warmest observed over the historical operational range for MNS (Duke Power Company 1985, 1987, 1994, 1995; Duke Power 2004a, 2005; Duke Energy 2011, 2012).

The influence of the unusually warm air temperatures in 2012 was also noted in both zones during spring, especially in April in the upper water layers when temperatures were up to 7.5

'C warmer than measured in 2011 (Figures 2-3 and 2-4).

By June and continuing into August, 2012 air temperature moderated resulting in water temperatures that were either cooler than or about equal to 2011 measurements, and for the most part, generally followed the between-year differences in air temperatures over this period. As discussed previously (Duke Energy 2012), epilimnion (0-15 m depth) water temperatures in summer 2011 were the warmest measured in both the background and mixing zones zones since MNS became fully operational in 1983, due primarily to unusually warm air temperatures.

Late-summer, fall, and early winter (September - December) water temperatures in both zones indicate that the process known as "lake turnover", which involves cooling, convectively mixing and reaeration of the water column, was somewhat slower in 2012 than observed in 2011 (Figures 2-3 and 2-4) eventhough Unit 2 was at reduced capacity or completely off-line over most of this period (Table 1-1). Declining air temperatures in the fall results in the concurrent cooling of the surface waters, combined with a vertically progressive but short-term heating (increase in temperatures) of the deeper waters until isothermal conditions are created, normally by early November.

Temperatures at the discharge location in 2012 were generally similar to 2011, particularly during the summer (Figure 2-5). The maximum discharge temperature at Location 4.0 in 2012 (37.1 "C) was measured in August and was 2.0 "C less than the historical maxima of 39.1 measured in 2011. Temperatures for all months in 2012 were within historical ranges (Duke Power Company 1985, 1987, 1988; Duke Power 2004a, 2005; Duke Energy 2011, 2012).

2-6

Dissolved Oxygen Seasonal and spatial patterns of DO in 2012 were reflective of the patterns exhibited for temperature, i.e., generally similar in both the mixing and background zones (Figures 2-6 and 2-7). As observed with water column temperatures, this similarity in DO patterns between zones has been a dominant feature of the oxygen regime in Lake Norman since MNS began operations in 1983.

Winter and spring DO values in 2012 were generally equal to or slightly less (maximum difference of about 0.7 mg/L) throughout the water column in both zones than measured in 2011, a year that exhibited cooler than average January air temperatures (Figures 2-6 and 2-7). The interannual differences in DO values between these two years were likely related predominantly to the differences in water column temperatures in 2012 versus 2011, and were consistent with observations made during previous years (Duke Energy 2011, and 2012). Cooler temperatures would be expected to exhibit higher oxygen values because of increased oxygen solubility and an enhanced convective mixing regime associated with increased water column instability. Conversely, warmer water would be expected to exhibit a lesser oxygen content because of the direct effect of temperature on oxygen solubility, which is an inverse relationship, and indirectly via a restricted convective mixing regime, which would limit water column reaeration.

One consistent feature of the vertical DO pattern in Lake Norman observed during the stratified period is the presence of a negative heterograde oxygen curve (NHOC), also commonly called a "metalimnetic oxygen minimum". The NHOCs are characterized by a vertical oxygen profile with a pronounced middle water layer (metalimnion) of low DO positioned between upper (epilimnion) and lower (hypolimnion) zones of higher oxygen content (Home and Goldman 1994). The NHOCs are common in Southeastern reservoirs and often caused by vertical differences in animal and microbial respiratory activities associated with the consumption and degradation of both autochthonous and allochthonous derived organic materials (Cole and Hannan 1985). The NHOCs are typcially formed via a combination of two processes; differential oxygen consumption within the middle section of the water column by aerobic degradation of organic matter, and oxygen consuming microbial decomposition of organic matter in the bottom sediments, often coined "sediment oxygen demand" (SOD). Rates of SOD within a reservoir are generally higher in the upper, shallow reaches of the waterbody where allochthonous inputs of labile (readily decomposable) organic matter tend to accumulate in the bottom sediments compared to the deeper, downlake 2-7

segments of the reservoir. These higher up-reservoir rates of SOD result in oxygen being depleted sooner and faster in the hypolimnion of these areas than downreservoir. And as these deeper waters are pulled down-reservoir by power generation withdrawals, a mid-water zone of low DO layered between zones of higher oxygen is observed. In rarer instances, the presence of NHOCs have been traced to interflows of low DO waters entering the waterbody, most frequently from an upstream, hypolimnetic withdrawal reservoir (Cole and Hannan 1985). Seasonal progression of these two important oxygen consuming processes within the waterbody eventually create a reservoir-wide zone of water below the thermocline that is totally devoid of oxygen (Figures 2-6, 2-7, 2-9, and 2-11).

The development and progression of the NHOC in summer 2012 was similar to that observed in 2011 (Figures 2-6, 2-7, and 2-9).

By early July, water column and sediment oxygen demands had reduced DO concentrations in the middle and lower portions of the water column in both the backgropund and mixing zones. Metalimnetic and hypolimnetic DO levels at this time were depleted more severely in the background zone with concentrations ranging from a low of 0.40 mg/L at 13 m to a high of 2.2 mg/L at 27 m. In the mixing zone, DO levels were slightly higher ranging from a minimum of 1.6 mg/L at 14 m to 3.4 mg/L at 26 m.

Normally, by early August DO values in Lake Norman are < 1.0 mg/L below the thermocline (10-12 m) and often approach anoxic conditions, with the background zone exhibiting slightly more severe conditions than the mixing zone. August 2012 DO profiles exhibited slightly more severe oxygen depletion within the epilimnion than in 2011, especially in the mixing zone, but these patterns were consistent with historical trends (Figures 2-6, 2-7, and 2-9). It was previously postulated (Duke Energy 2010) that elevated levels of allochthonous organic loading associated with higher than normal spring rains might explain the yearly variability in the timing and severity of summertime metalimntic and hypoliminetic oxgen regimes in Lake Norman. This hypothesis was formulated based on study results presented by Ford (1987) who found that nutrient and organic loading to DeGray Resevoir in Arkansas was dominated by rainfall and associated terrestrial runoff events during the spring. Spring rainfall totals in 2012 were similar to 2011 but about 20% less than observed in 2010, a year which exhibited summer NHOC's more severe than measured in 2012 and 2011.

In many other years, however, this relationship was less evident.

Clearly, a multitude of factors influence the development of the NHOCs in Lake Norman.

2-8

Historically, interannual differences in the late summer and fall DO values in both the mixing and background zones, especially in the metalimnion and hypolimnion, are frequently observed in Lake Norman. These interannual differences in DO levels during the cooling season are common in Catawba River reservoirs and are explained by the effects of variable weather patterns on water column cooling rates and mixing. Cooler air temperatures increase the rate and magnitude of water column heat loss, thereby promoting convective mixing of oxygenated surface waters resulting in reaeration of subsurface waters earlier in the year.

Conversely, warmer air temperatures delay water column cooling which in turn, delays the onset of convective mixing of the water column and the resultant reaeration of the metalimnion and hypolimnion.

The 2012 late summer and autumn DO data indicate that convective reaeration of the water column proceeded slower than in corresponding months in 2011 (Figures 2-6 and 2-7).

These between-year differences in DO corresponded strongly with the degree of thermal stratification which, as discussed earlier, correlated with interannual differences in air temperatures (Figures 2-2c, 2-3, and 2-4).

Interannual differences in DO patterns are common not only within the Catawba River Basin, but throughout Southeastern reservoirs and can reflect yearly differences in hydrologic, meteorologic, and limnologic forcing variables (Cole and Hannan 1985, Petts 1984).

The seasonal pattern of DO in 2012 at the discharge location was similar to that measured historically, with the highest values observed during the winter and lowest observed in the summer and early fall (Figure 2-5). The lowest DO concentration measured at the discharge location in 2012 (3.8 mg/L) occurred in August and was similar to previously measured values (Duke Power Company 1985, 1987, 1988; Duke Power 2004a, 2005; Duke Energy 2011, 2012).

Reservoir-Wide Temperature and Dissolved Oxygen The monthly reservoir-wide temperature and DO data for 2012 are presented in Figures 2-8 and 2-9. The data are generally similar to the temporal and spatial patterns observed in these parameters in previous years and are characteristic of cooling impoundments and hydropower reservoirs in the Southeast (Cole and Hannan 1985; Hannan et al. 1979; Petts 1984). Detailed discussions on the seasonal and spatial dynamics of temperature and DO during both the cooling and heating periods in Lake Norman have been presented previously (Duke Power Company 1993, 1995, 1996).

2-9

The seasonal heat content of both the entire water column and the hypolimnion for Lake Norman in 2012 are presented in Figure 2-10a; additional information on the thermal regime in the reservoir for the years 2011 and 2012 are presented in Table 2-3. Annual minimum heat content for the entire water column in 2012 (11.52 Kcal/cm2, 11.5 °C) occurred in early February, whereas the maximum heat content (28.78 Kcal/cm2, 28.2 °C) occurred in August.

Heat content of the hypolimnion exhibited a somewhat different temporal trend compared to that observed for the entire water column. Annual minimum hypolimnetic heat content also occurred in early February and measured 6.36 Kcal/cm 2 (9.9 °C), but the maximum occurred in early September and measured 16.00 Kcal/cm 2 (24.51 °C). Annual maximum heat content of both the entire water column and hypolimnion in 2012 were less than observed in 2011 which were the highest recorded for Lake Norman. 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 rates of the eplimnion equaled 0.11 °C/day and 0.09 °C/day for the hypolimnion and were slightly less than observed in 2011 (Table 2-3).

The seasonal oxygen content and percent saturation of the whole water column, and the hypolimnion, are depicted for 2012 in Figure 2-1 Ob. Additional oxygen data can be found in Table 2-4 which presents the 2012 AHOD for Lake Norman and similar earlier estimates for 18 Tennessee Valley Authority (TVA) reservoirs. Reservoir oxygen content, expressed as a volume-weighted average, was greatest in mid-winter when DO content measured 10.3 mg/L for the whole water column and 10.4 mg/L for the hypolimnion, which was slightly less than observed in 2011. Percent oxygen saturation values at this time approached 95% for the entire water column and 89% for the hypolimnion, indicating that reaeration of the reservoir did not achieve 100% saturation in 2012, which is typical. Beginning in early spring, oxygen content began to decline rapidly in both the whole water column and the hypolimnion, and continued to decline linearly until reaching a minimum in late summer.

The minimum summer volume-weighted DO value for the entire water column measured 3.6 mg/L (48%

saturation), whereas the minimum for the hypolimnion was 0.11 mg/L (1.3% saturation).

The mean rate of DO decline in the hypolimnion over the stratified period, i.e., the AHOD, was 0.038 mg/cm 2/day (0.060 mg/L/day) (Figure 2-1Ob), which was almost exactly to that measured in 2011 and similar to values measured for MNS operational years (Duke Energy 2012).

Hutchinson (1938 and 1957) proposed that the decrease of DO 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 AHODs associated with 2-10

various trophic states; oligotrophic < 0.025 mg/cm 2/day, mesotrophic 0.026 mg/cm 2/day to 0.054 mg/cm 2/day, and eutrophic > 0.055 mg/cm 2/day.

Employing these limits, Lake Norman should be classified as mesotrophic based on the calculated AHOD value of 0.038 mg/cm 2/day for 2012, which is similar to 2011. The oxygen-based mesotrophic classification agrees well with the mesotrophic classification based on chlorophyll a levels (Chapter 3).

The 2012 AHOD value is also similar to that found in other Southeastern reservoirs of comparable depth, chlorophyll a status, and Secchi depth (Table 2-4).

Striped Bass Habitat and Fish Mortalities Striped bass, a coolwater predator often introduced in Southeastern reservoirs to enhance and diversify the sport fishery, have been stocked in Lake Norman by the North Carolina Wildlife Resources Commission (NCWRC) since the late 1960s. In many instances these introductions have been successful; however, periodic summertime mortalties have been observed. Coutant (1985) hypothesized that summertime mortalities of adult striped bass could be explained by a temperature-dissolved oxygen "squeeze" within the water column.

Seasonal warming of the oxygenated epilimnion would force fish downward to seek deeper, cooler waters offering their preferred temperatures, whereas microbial deoxygenation of the middle and bottom waters would force fish upward to seek oxygenated but warmer water.

As stratification intensified, continued epilimnion warming and deepening, coupled with mid and bottom water deoxygenation, would ultimately force fish to occupy water layers that lack the appropriate physicochemical conditions critical for survival, and eventually would lead to mortalities.

Coutant (1985) proposed that suitable physicochemical habitat critical for survival of adult striped bass included water temperatures of about 18-25 'C and DO concentrations above about 2-3 mg/L.

Preferred habitat for adult striped bass in this report is defined as pelagic waters with temperatures < 26 'C and DO levels > 2.0 mg/L. These individual criteria were originally selected to define critical habitat based on analyses of physicochemical conditions observed during the summer of 1983 when the first reported die-off (163 fish) of adult striped bass occurred in lower Lake Norman near Cowans Ford Dam Preferred habitat for striped bass existed in Lake Norman from mid-September 2011 through mid-July 2012 (Figure 2-11).

Beginning in late June 2012, as thermal stratification intensified, habitat reduction proceeded rapidly throughout the reservoir both as a result of deepening of the 26 'C isotherm and metalimnetic and hypolimnetic deoxygenation (Figure 2-11

2-11). Wind and power generation induced mixing were primarily responsible for deepening of the 26 'C isotherm and reduction of habitat in the upper layers of the water column during the summer. Spatial differences in the magnitude and rates of metalimnetic and hypolimnetic deoxygenation throughout the reservoir contributed to habitat depletion in the middle and lowers layers of the water column. Habitat conditions in 2012 were most severe from late July through mid-September when no preferred habitat was observed in the reservoir except in the deeper waters between Locations 69 and 80 (Figure 2-11). Preferred habitat for adult striped bass was totally eliminated from the reservoir for approximately 7 weeks in 2012, which is similar to that observed in 2011 and within the historical range.

Physicochemical habitat expanded appreciably by approximately the third week of September, primarily as a result of epilimnion cooling and deepening, and in response to changing meteorological conditions (Figure 2-2c). By early October, preferred habitat was present both vertically and horizontally throughout most of the reservoir. The temporal and spatial patterns of habitat reduction observed in Lake Norman during the stratified period in 2012 were similar to historical observations and generally similar to other Southeastern reservoirs (Coutant 1985; Matthews et al. 1985; Duke Power Company 1985, 1987, 1988, 1996; Duke Power 2005; Duke Energy 2009, 2010, 2011, 2012).

Striped bass mortalities in 2012 totaled 835 fish and represented the fourth consecutive year that summertime mortalties of adult striped bass exceeded 300 fish. Mortalities occured concurrent with habitat elimination and were similar in timing and locations as previous die-offs.

It was hypothesized (Duke Energy 2011) that these mortalities are linked to the introduction of alewife (Alosa pseudoharengus) into Lake Norman in the late 1990s which resulted in a shift in the seasonal and spatial distribution of striped bass within the reservoir, in response to seasonal migration patterns of adult alewifes seeking coolwater habitat.

Mortalities of catfish in appreciable numbers were also observed for the first time in lower Lake Norman over a 10 day period in mid-August, and coincided with coolwater habitat elimination and development of anoxic to severely hypoxic (< 0.35 mg/L) water on 13 August below elevation 219 msl.

The total catfish count equaled 1,204 fish and was comprised mostly of blue catfish (926 fish), followed by channel catfish (276 fish) and a few flathead catfish (2). Additional discussion of striped bass and catfish mortalities in 2012 is presented in Chapter 5.

2-12

Turbidity and Specific Conductance Surface turbidity values were generally low at the MNS discharge, mixing zone, and background locations during 2012 ranging from 0.9 to 2.4 NTUs (Table 2-5).

Bottom turbidity values were also low but slightly higher than surface readings and ranged from 0.9 to 3.5 NTUs. Turbidity values observed in 2012 were within the historical range (Duke Power Company 1985, 1987, 1988, 1996; Duke Power 2004a, 2005; Duke Energy 2009, 2010, 2011,2012).

Specific conductance in Lake Norman in 2012 ranged from 64 to 188 lImhos/cm and was generally similar to that observed in 2011 (Table 2-5) and historically (Duke Power Company 1985, 1987, 1988, 1996; Duke Power 2004a, 2005; Duke Energy 2009, 2010, 2011, 2012).

Conductance values in surface and bottom waters in 2011 were similar throughout the year except during the period of intense thermal stratification (i.e., August and November) when an increase in bottom conductance values was observed at locations within both the mixing and background zones.

These increases in bottom conductance values appeared related primarily to the release of soluble iron and manganese from the lake bottom under anoxic conditions (Table 2-5). This phenomenon is common in both natural lakes and reservoirs that exhibit extensive hypolimnetic oxygen depletion (Hutchinson 1957 and Wetzel 1975) and recurs annually in Lake Norman.

Alkalinity and pH Alkalinity and pH values in 2012 were similar among MNS discharge, mixing, and background zones (Table 2-5). Alkalinity values, expressed as CaCO 3, in 2012 ranged from 14.0 to 17.0 mg/L in surface waters and from 14.0 to 20.0 mg/L in bottom waters. Values of pH in 2012 ranged from 6.8 to 7.7 in surface waters and from 6.4 to 7.5 in bottom waters and were also generally similar to values measured in 2011 (Table 2-5) and historically (Duke Power Company 1985, 1987, 1988, 1996; Duke Power 2004a, 2005; Duke Energy 2009, 2010, 2011, 2012).

Major Cations and Anions The concentrations of major ionic species in the MNS discharge, mixing and background zones are provided in Table 2-5.

Lake-wide, the major cations were sodium, calcium, magnesium and potassium, whereas the major anions were bicarbonate, sulfate, and chloride.

2-13

The overall ionic composition of Lake Norman during 2012 was generally similar to that reported for 2011 (Table 2-5) and previously (Duke Power Company 1985, 1987, 1988, 1996; Duke Power 2004a, 2005; Duke Energy 2009, 2010, 2011, 2012).

Nutrients Nutrient concentrations in the discharge, mixing, and background zones of Lake Norman in 2012 (Table 2-5) were low and generally similar to those measured in 2011 and historically (Duke Power Company 1985, 1987, 1988, 1996; Duke Power 2004a, 2005; Duke Energy 2009, 2010, 2011, 2012). For total phosphorus (TP), 32 of 44 samples analyzed in 2012 exceeded 5 lag/L, the analytical reporting limit (ARL) and values were consistently slightly lower than observed in 2011, but within the historical range.

All but one of the measurements of orthophosphorus (N = 43; value = 7 gag/L) in 2012 were < 5 lag/L, the ARL.

Nitrite-nitrate and ammonia nitrogen concentrations were low at all locations in 2012 and consistently averaged less than observed in 2011.

Metals Metal concentrations in the discharge, mixing, and background zones of Lake Norman for 2012 were similar to those measured in 2011 (Table 2-5) and historically (Duke Power Company 1985, 1987, 1988, 1996; Duke Power 2004a, 2005; Duke Energy 2009, 2010, 2011, 2012). Iron concentrations in surface and bottom waters were generally low (< 0.2 mg/L) during 2012 with only 3 of 44 samples exceeding 0.20 mg/L. The maximum iron concentration measured in 2012 was 0.226 mg/L, and no samples exceeded the North Carolina water quality action level for iron (1.0 mg/L; NCDENR 2004).

Manganese concentrations in the surface and bottom waters in 2012 were also generally low

(< 100 ttg/L), except during the summer stratified period when bottom waters were anoxic (Table 2-5). Manganese concentrations in the bottom waters rose above the North Carolina water quality action (200 jtg/L; NCDENR 2004) at all locations in August 2012, and were characteristic of historical conditions (Duke Power Company 1985, 1987, 1988, 1996; Duke Power 2004a, 2005; Duke Energy 2009, 2010, 2011, 2012). The highest concentration of manganese reported in 2012 (2,480 ttg/L) was measured in the bottom waters at Location 5.0 in August.

This phenomenon, i.e., the release of manganese (and iron) from bottom sediments in response to low redox conditions (low oxygen levels), is common in stratified waterbodies (Stumm and Morgan 1970, Wetzel 1975).

2-14

Concentrations of other metals in 2012 were low and often below the ARL for the specific constituent (Table 2-5). These findings are consistent with those reported for earlier years (Duke Power Company 1985, 1987, 1988, 1996; Duke Power 2004a, 2005; Duke Energy 2009, 2010, 2011, 2012). All values for cadmium and lead were reported as either equal to or below the ARL for those parameters.

Approximately 93% of zinc values (41 of 44 samples) in 2012 were below the ARL with the maximum concentration (1.4,tg/L) measured in the bottom waters at Location 11.0 in November. All copper concentrations, measured as total recoverable copper, were < 1.3 gtg/L and 24 of 44 values (55%) were less than the ARL of 1.0 jig/L. All values reported for cadmium, lead, zinc, and copper in 2012 were below the State action level for each of these metals (NCDENR 2004).

SUMMARY

Annual precipitation in the vicinity of MNS in 2012 totaled 87.6 cm which is appreciably less than the long-term average (117.6 cm), but greater than the minimum annual total of 64.4 cm measured in 1981. The 2012 total was also the eighth lowest over the 1975 - 2012 period. Monthly air temperaratures in 2012 were mostly equal to or warmer than the long-term average with the winter and spring air temperatures approaching close to 35% higher than the long-term mean.

Temporal and spatial trends in water temperature and DO in 2012 were similar to those observed historically, and all data were within the ranges of previously measured values.

Water temperatures in winter and spring 2012 were either equal to or wanner than measured in 2011, and were among the warmest measured historically. Summer and early fall 2012 temperatures were either equal to or cooler than 2011 and generally paralleled differences exhibited in monthly air temperature data, but with about a one month lag time.

Temperatures at the discharge location in 2012 were generally similar to 2011, particularly during the summer stratified period. The maximum discharge temperature at Location 4.0 in 2012 (37.1 °C) was measured in August and was 2.0 'C less than the historical maxima of 39.1 measured in 2011.

Temperatures for all months in 2012 were within thermal compliance limts and historical ranges.

Seasonal and spatial patterns of DO in 2012 were reflective of the patterns exhibited for temperature (i.e., generally similar in both the mixing and background zones). Winter and spring DO values in 2012 were typically equal to or slightly less than measured in 2011 and 2-15

were related to differences in water temperatures and the influence on oxygen solubility.

Summer DO values in 2012 were also slightly less than measured in 2011, especially in the metalimnion and hypolimnion in August, but well within historical ranges. The seasonal pattern of DO in 2012 at the discharge location was similar to that measured historically, with the highest values observed during the winter and lowest observed in the summer and early fall. The lowest DO concentration measured at the discharge location in 2012 (3.8 mg/L) occurred in August and was similar to previously measured values.

Reservoir-wide isotherm and isopleth information for 2012, coupled with heat content and hypolimnetic oxygen data, illustrated that Lake Norman exhibited thermal and oxygen dynamics characteristic of historical conditions and similar to other Southeastern reservoirs of comparable size, depth, flow conditions, and trophic status. Suitable pelagic habitat for adult striped bass was found lake-wide from mid-September 2011 through mid-July 2012.

Beginning in late June 2012, habitat reduction proceeded rapidly throughout the reservoir both as a result of deepening of the 26 'C isotherm and metalimnetic and hypolimnetic deoxygenation. Habitat reduction was most severe from mid-July through mid-September with total elimination observed for about seven weeks, which was consistent with earlier years. Observed striped bass mortalities in 2012 totaled 835 fish.

All chemical parameters measured in 2012 were similar to 2011 and within the concentration ranges previously reported during both preoperational and operational years of MNS.

Turbidity and specific conductance values, and all cation and anion concentrations were low, as were nutrient concentrations, with many values reported equal to or below the analytical reporting limit (ARL). Concentrations of metals in 2012 were also low, often below the respective ARLs, and consistently below the North Carolina water quality standard or action level for each respective metal. The lone exception was manganese concentrations which were consistently low in 2012, except during the summer when bottom waters exceeded the state water quality action level (200 ttg/L), which is representative of historical conditions.

2-16

Table 2-1.

Water quality 2012 program for the MNS NPDES Maintenance Monitoring Program on Lake Norman.

2012 McGUIRE NPDES SAMPLING PROGRAM LOCATIONS I

2 4

5 8

9.5 1i 13 14 15 15.9 62 69 72 80 PARAMETERS

.DEPTH(m) 33 33 5

20 32 23 27 21 10 23 23 15 7

5 4

IN-SITU ANALYSIS Method Temperature Hydrolab Dissolved Oxygen Hydrolab In-situ measurements are collected monthly at the above locations at I m intervals from 0.3m to I m above bottom.

pH Hydrolab Measurements are taken weekly from July-Augzst for striped bass habitat at all locations except 5 & 9.5.

Condsctivity Hydrolab NUTRIENT ANALYSES Ammonia C-NH3 Q/T,B Q/T,B Q/T Q/T,B Q/TB Q/T,B QiT,B Q/T,B Q/T Q/T,B Q)T,B Q/T,B

.Nitrate+Nitrite C_NO2NO3 Q/T,B Q/T,B Q/T Q/T,B Q/TB QJT,B Q/T,B. Q/T,B Q/T QFT,B Q/T,B Q/T,B Orthophosphate COPO4 Q[I,B Q/TB Q/T Qfr,B Q[1,B Q/TB Q/TB Qt,B QOT QfT,B Q/T,B QT.,B Total Phosphorus CTP QJTB Q/T,B QfT Q/T,B QfT,B Q/T,B Q/TB Q/f,B Q/T QrT,B Q/T,B QtT,B Silica CS102 Q/TB Q/T,B Q/T Q([,B Q!T,B QFI,B Q/T,B QfT,B Q/l Q/TB QTr,B Q/r,B

Cl CCL QIT,B Q/T,B Q/T Q/T.B QTI.B Q/T,B Qf/,B QiT,B Q/T Q/T,B Q/T.B Q/T,B ELEMENTAL ANALYSES Aluminum ICP Undigested Q[F,B S/T,B Q/T Q/T,B QIT,B Q/T,B Q/TB Q/T,B QfT Q/T, B Q/TB QfT,B Calcium ICP Undigested Q/T,B Q/T,B Q/T Q/T,B Q/T,B Q/T,B. Q/T,B Q/r,B Q/T Q/T,B Q/T,B Q/T,B Iron IMSTRM Qfl,B Q/TB Q/T Q/rB. Q/T,B QfT,B Q/T,B Q/IB Q/T Q/T,B Q/T,B QTf,B Magnesiumn ICP Undigested QtT,B Q/T.B Q/T Q/T,B QIT,B Q/T,B Q/TB QfT.B QfT Q/T.B Q/T,B Qf.,B Manganese IMSTRM Qfr,B Q/T,B Q/T QrI,B, QIT,B. Q/r,B Q/T,B, QFr,B QtT Q/T,B Q/T,B QTF,B Potassitim ICP Undigested QITB QiT,B Q/T Q/T,B" Qr-,B Q/T,B Q/T,B Qfr,B Q/T Q/T,B QiT,B Q/r,B Sodiun ICP Undigested Q/i,B Q/IT,B Q/I Q/TB QT,B Q/T,B Q/T,B-Q/T,B Qrl Q1T,B Q/T,B QfF,B

,Zinc..

IMSTRM Qf1T,B Qf"'B QiT,B Q/T,B Q/T,B Q/T,B Q/T,B Q/T Q/T,B Q/T,B Q/r,B Cadminum IMSTRM Qf/,B Q/T,B Q/T Q'T,B Q/TB Q/T,B Q/T.B QfrB Q/T QJT,B Q/T,B QrT,B

.Copper (Total Recoverable)

IMSTRM QfrB Q/T,B' Q/T-QTB Q/T,B QITB QfT,B Qfr,B, Q/T Q/T,B Q/T,B Q/r,B Copper (Dissolved)

IMS Dissolved QfTB Q/T,B Q/T QTB Q/TB Qfr,B Q/T,B QfI,B Q/T Q/T,B Q/TB Qfr,B Lead IMSTRM QiT.B Q/T,B Q/T QfI,B QfIB. Q/T,B Q/T,B QfT,B Q/T Q/TB Q/T,B QT,B ADDITIONAL ANALYSES Alkalinity ALKFIX5.1 Q/T,B Q/TB Q/T QfTB QfF,B Q/T,B Q/T,B Qi',B Q/T Q/T,B Q/T,B QiT,B Turbidity TURB QfT,B Q/T,B Q/T Q/T,B Q/T,B Q/T,B Q/T,B Q/T,B Q/T Q/T,B Q/T,B Qf/,B Sulfate DIONEX Q/T,B Q/T.B Q/T Q/TB Q/T,B QfT,B Q/T,B Q/T,B QfT Q/T.B Q/T,B QfT,B CODES:-

Frequency Q = Quarterly (Feb, May, Aug, Nov)

T =Top (0.3m)

B = Bottom (I m above bottom)

Table 2-2. Analytical methods and reporting limits employed in the 2012 MNS NPDES Maintenance Monitoring Program for Lake Norman.

Parameter Method (EPA/APHA)

Preservation Reporting Limit Alkalinity, Total Total Inflection Point, EPA 310.1 4 °C 0.01 meq/L Aluminum ICP, EPA 200.7 0.5% HNO 3 0.05 mg/L Cadmium, Total Recoverable ICP Mass Spectroscopy, EPA 200.8 0.5% HNO 3 1.0 pg/L Calcium ICP, EPA 200.7 0.5% HNO 3 30 pg/L Chloride Colorimetric, EPA 325.2 4 'C 1.0 mg/L Copper, Total Recoverable ICP Mass Spectroscopy, EPA 200.8 0.5% HNO 3 1.0 pg/L Copper, Dissolved ICP Mass Spectroscopy, EPA 200.8 0.5% HNO 3 1.0 pg/L Iron, Total Recoverable ICP, EPA 200.7 0.5% HNO 3 10 pg/L Lead, Total Recoverable ICP Mass Spectroscopy, EPA 200.8 0.5% HNO 3 1.0 pg/L Magnesium Atomic Emission/ICP, EPA 200.7 0.5% HNO 3 30 pg/L Manganese, Total Recoverable ICP Mass Spectroscopy, EPA 200.8 0.5% HNO 3 1.0 pg/L Nitrogen, Ammonia Colorimetric, EPA 350.1 0.5% H2SO4 20 pg/L Nitrogen, Nitrite + Nitrate Colorimetric, EPA 353.2 0.5% H2SO4 10 pg/L Nitrogen, Total Kjeldahl Colorimetric, EPA 351.2 0.5% H2SO4 100 pg/L Phosphorus, Orthophosphorus Colorimetric, EPA 365.1 4 "C 5 pg/L Phosphorus, Total Colorimetric, EPA 365.1 0.5% H2SO4 5 pg/L Potassium ICP, EPA 200.7 0.5% HNO 3 250 pg/L Silica APHA 4500Si-F 0.5% HNO 3 500 pg/L Sodium Atomic Emission/ICP, EPA 200.7 0.5% HNO 3 1.5 mg/L Sulfate Ion Chromatography 4 °C 0.1 mg/L Turbidity Turbidimetric, EPA 180.1 0.5% H2SO4 0.05 NTU Zinc, Total Recoverable ICP Mass Spectroscopy, EPA 200.8 0.5% HNO 3 2.0 pg/La

References:

USEPA 1983, and APHA 1995 a - Reporting limit changed to 1.0 ug/L in April 2012.

00

Table 2-3. Heat content calculations for the thermal regime in Lake Norman for 2011 and 2012.

2011 2012 Maximum Areal Heat Content (Kcal/cm 2 )

29.678 28.785 Minimum Areal Heat Content (Kcal/cm 2) 8.018 11.521 Birgean Heat Budget (Kcal/cm 2) 21.660 17.264 Epilimnion (above 11.5 m) Heating Rate (°C/day) 0.13 0.11 Hypolimnion (below 11.5 m) Heating Rate (°C/day) 0.10 0.09 2-19

Table 2-4. A comparison of areal hypolimnetic oxygen deficits (AHOD), summer chlorophyll a (Chl a), Secchi depth, and mean depth of Lake Norman and 18 TVA reservoirs.

AHOD Summer Chl a Secchi Depth Mean Depth Reservoir (mg/cm2/day)

(ýtg/L)

(m)

Lake Norman (2012) 0.038 5.5 2.4 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 7.3 Tributary Chatuge 0.041 5.5 2.7 9.5 Cherokee 0.078 10.9 1.7 13.9 Douglas 0.046 6.3 1.6 10.7 Fontana 0.113 4.1 2.6 37.8 Hiwassee 0.061 5.0 2.4 20.2 Norris 0.058 2.1 3.9 16.3 South Holston 0.070 6.5 2.6 23.4 Tims Ford 0.059 6.1 2.4 14.9 Watauga 0.066 2.9 2.7 24.5 Data from Higgins et al. (1980), and Higgins and Kim (1981).

2-20

Table 2-5. Quarterly surface (0.3 m) and bottom (bottom minus 1 m) water chemistry for the MNS discharge, mixing zone, and background locations on Lake Norman during 2011 and 2012. Values less than detection were assumed to be equal to the detection limit for calculating a mean.

Mixing Zone 1.0 Mixing Zone

2.0 LOCATION

AM S E:

PARAMETERS YEAR:

MNS Discharge 4.0 Surface 2011 201; Mixing Zone 5.0 Surface 2011 2012 Bottom Surface 2011 2012 2011 2012 Bottom 2011 2012

Background

E.0 Surface Bottom 2011 2012 2011 2012

Background

11.0 Surface Botton 2011 2012 2011 2012 Surface 2011 2012 Bottom 2011 2012 Turbidiy (NTU)

Fab 1.2 1.2 2.0 1.6 1.2 1.1 2.5 2.4 1.3 1.3 1.3 1.5 1.9 3.1 1.0 1.0 Z2 3.3 2.1 0.9 2.0 3.5 May 1.8 1.2

" 1.

0.59 0.9 1.4 2.7 1.1 1.3 1.2 1.1 1.3 2.1 1.5 1.1 1.0 2.9 1.1 1.2 1.4 2.6 1.5 Aug 1.2 1.5 2.7 1.3 1.9 1.5 2.1 0.9 1.1 1.3 1.0 1.4 1.5 1.1 1.2 1.3 1.0 1.3 2.3 2.1 0.9 1.6 Nov 1.1 2.4 1.9 2.1 1.6 1.7 2.9 2.3 1.5 1.6 1.7 1.9 1.8 22 1.4 2.0 9.1 3.3 2.2 1.7 4.1 2.1 Annual Mean 1.3 1.6 2.1 1.5 1.4 1.4 2.6 1.7 1.3

14.

1.3 1.5 1.8 20 1.2 1.3 3.8 2.3 2.0 1.5 2.4 2.2 Specfic Conductance (uMhr/cm)

Feb 66.0 69.0 66.0 67.0 66.0 69.0 66.0 67.0 67.0 70.0 67.0 69.0 66.0 6&.0 E5.0 68.0 6.0 E5.0 70.0 66.0 69.0 64.0 May 69.0 60.0 68.0 67.0 69.0 66.0 68.0 67.5 70.0 69.0 69.0 69.0 69.0 68.0 69.0 68.0 6110 67.0 70.0 68.0 68.0 67.0 Aug 69.0 68.0 81.0 77.0 69.0 68.0 79.0 75.0 69.0 68.0 69.0 60.0 79.0 68.0 68.0 60.0 00.0 75.0 77.0 69.0 77.0 76.0 Nov 69.0 68.0 69.0 91.0 69.0 69.0 69.0 188.0 70.0 69.0 69.0 69.0 68.0 68.0 68.0 68.0 69.0 60.0 76.0 70.0 75.0 70.0 Annual Mean 66.3 68.3 71.0 75.5 68.3 68.5 70.5 99.3 69.0 69.0 60.5 68.5 70.5 68.0 67.5 68.0 70.8 68.8 73.3 66.5 72.3 69.3 pH (units)

Feb 7.1 7.3 7.0 7.3 7.3 7.4 7.0 7.1 7.3 7.4 7.3 7.4 7.1 7.2 7.4 7.4 7.1 7.1 7.2 6.9 7.3 7.0 May 7.6 7.3 6.6 6.5 7.5 7.5 6.7 6.5 7.4 7.4 7.5 7.6 6.8 6.6 7.6 7.7 68 6.7 7.7 7.7 7.9 6.7 Aug 7.4 6.9 6.5 6.4 7.3 7.1 6.4 6.5 7.0

60.

7.3 7.2 6.5 6.6 8.3 7.5 6.5 6.5 7.5 7.1 7.6 6.6 Nan 7.2 6.9 7.2 0.9 7.3 7.2 7.2 7.5 7.4 7.3 7.5 7.3 7.2 7.2 7.4 7.3 7.4 7.2 7.5 7.2 7.2 7.2 Annual Mean 7.3 7.1 6.8 6.8 73 7.3 6.8 6.9 71 72 74 7.4 6.9 6.9 7.7 7.5 6.9 6.9 7.5 7.2 7.5 609 Alkalinity (mg CaCO31L)

Feb 15 14 15 14 14 14 15 14 15 14 15 14 15 14 15 14 15 14 16 14 15 14 May 14 16 15 14 15 15 15 14 15 15 15 15 16 Is 15 15 15 15 14 15 15 15 Aug 14 15 19 15 14 15 17 14 15 15 14 15 21 20 10 15 21 19 16 15 17 16 Nov 14 17 14 17 15 17 13 17 14 17 14 17 15 17 15 17 15 17 16 16 16 17 Annual Mean 14.3 15.5 15.8 15.0 14.5 15.3 15.0 14.8 1468 153.

14.5 15.3 16.8 16.5 13.8 15.3 16.5 16.3 15.5 15.0 15.6 15.5 Ctdodde (mg/L)

Feb 7.1 0.2 7.1 7.8 7.1 8.1 7.2 7.5 7.2 7.7 7.2 7.7 7.1 7.7 7.2 7.5 7.2 6.5 8.1 7.6 7.6 6.4 May 7.9 7.1 7.6 6.9 7.6 7

6.0 6.9 7.4 7

7.9 7

7.9 7.0 7.7 7.1 7.7 6.8 7.9 6.9 7.7 6.6 Aug 7.1 6.8 6.8 7.0 7.0 6.0 6.9 7.0 7.1 6.6 7.3 6.7 6.7 6.8 7.3 6.8 6.7 7.0 6.3 7

6.9 6.9 NOw 7.7 6.8 7.7 6.8 7.6 6.8 7.7 6.8 7.7 6.6 7.6 6.8 7.6 6.8 7.6 6.6 7.7 6.6 5.6 6.9 8.4 6.9 Annual Mean 7.5 7.2 7.3 7.1 7.3 7.2 7.5 7.1 7.4 7.0 7.5 7.1 7.3 7.1 7.5 7.1 7.3 6.0 0.2 7.1 7.7 6.7 Sulfate (mg/L)

Feb 4.2 4.6 4.2 4.5 4.2 4.5 4.2 4.4 4.2 4.4 4.2 4.3 4.2 4.3 4.2 4.2 4.2 4.0 4.3 4.3 4.3 4.0 May 4.1 4.2 4.1 4.1 4.2 4.2 4.1 4.1 4.1 4.2 4.1 4.2 4.1 4.1 4.0 4.2 4.0 4.1 4.2 4.2 4.0 4.0 Aug 4.3 4.1 4.1 4.2 4.0 4.1 4.1 4.3 4.1 4

4.3 4.1 3.9 4.1 4.2 4.1 369 4.2 4.5 4.2 4.1 4.2 Nov 4.1 3.8 4.2 3.8 4.1 3.8 5.7 3.9 4.2 3.8 4.1 3.8 4.1 3.8 4.1 3.8 4.2 3.9 4.4 3.9 4.3 a9 Annual Mean 4.2 4.2 4.2 4.1 4.2 4.5 4.2 4.2 4.1 4.2 4.1 4.1 4.1 4.1 4.1 4.1 4.1 4.4 4.2 4.2 4.0 Calcium (mgIL)

Feb 4.44 4.06 4.42 4.20 4,35 4.09 4.44 4.18 4.34 4.06 4.41 4.69 4.37 4.14 4.42 4.09 4.49 4.19 4.70 4.11 4.64 4.11 May 4.69 4.01 4.57 4.23 4,47 4.09 4.66 4.29 4.57 4.05 4.52 4.03 4.66 4.26 4.58 4.04 4.64 4.29 4.73 4.16 4.58 4.34 Aug 4.27 4.08 5.17 4.46 4.13 4.06 5.11 4.40 4.31 4.06 4.24 4.08 5.19 4.47 4.16 4.08 5.18 4.52 5-28 4.14 5.66 4.41 NoV 4.00 4.15 4.07 4.15 4,06 4.11 4.08 4.26 4.05 4.1 4.08 4.07 3.98 4.13 4.07 4.11 4.20 4.18 5.07 4.34 4.86 4.32 Annual Mean 4.33 4.08 4.56 4.26 4.25 4.69 4.57 4.29 4.32 4.06 4.31 4.07 4.55 4.25 4.31 4.08 4.63 4.30 4.95 4.19 4.79 4.30 Magnesiun (mg0L)

Feb 1.88 1.66 1.86 1.90 1.85 1.97 1.86 1.09 1.85 1.96 1.85 1.97 1.85 1.95 1.86 1.96 1.86 1.75 1.86 1.94 1.87 1.66 May 1.90 1.95 1.89 1.92 1.87 1.98 1.91 1.95 1.90 1.95 1.91 1.95 1.94 1.97 1.90 1.97 1.90 1.92 1.93 1.95 1.66 1.90 Aug 2.07 1.92 2.06 1.98 2.01 1.92 2.05 1.94 2.01 1.89 2.03 1.9 2.12 2.00 2.00 1.91 2.07 1.98 2.27 1.94 2.04 1.94 Nor 2.00 1.94 2.02 1.92 2.04 1.91 2.03 1.96 2.03 1.9 2.04 1.91 2.04 1.90 2.03 1.91 2.05 1.94 2.21 1.94 2.15 1.93 Annual Mean 1.96 1.94 1.96 1.93 1.94 1.95 1.96 1.93 1.95 1.92 1.96 1,93 1.69 1.96 1.95 1.94 1.97 1901 2.07 1.94 1.99 1.86 li'.

NS = Not Sampled: NA= Not Applcable; FQC = Failed Quality Control

Table 2-5. (Continued)

Mixing Zone

1.0 LOCATION

PARAMETERS YEAR:

Mixir Surface 2011 2012 ri Zone 2.0 Bottom 2011 2012 MNS Discharge 4.0 Surface 2011 2012 Mixing Zone 5.o

Background

8.0 Bottom 2012 2011 2012

Background

11.0 Surface Bottom 2011 2012 2011 2012 Surface 2011 2012 Bottom 2011 2012 Surface 2011 2012 Bottom Surface 2011 2012 2011 Potassium (rng/L)

Feb 1.68 1.80 1.66 1.78 1.65 1.79 1.67 1.76 1,64 1.79 1.67 1.80 1.65 1.80 1.68 1.80 1.68 1.72 1.71 1.79 1.72 1.66 Mwy 1.74 1.76 1.72 1.71 1.72 1.76 1.75 1.74 1.74 1.75 1.74 1.74 1.75 1.76 1.74 1.77 1.71 1.73 1.72 1.73 1.70 1.72 Aug 1.91 1.75 1.88 1.75 1.87 1.75 1.87 1.72 1.85 1.73 1.88 1.74 1.90 1.76 1.86 1.75 1.88 1.76 1.87 1.77 1.86 1.73 NOV 1.81 1.81 1.82 1.7 1.81 1.78 1.82 1.84 1.83 1.78 1.83 1.78 1.84 1.78 1.83 1.78 1.83 1.83 1.85 1.78 1.83 1.78 Annual Mean 1.79 1.78 1 77 1.76 1.76 1.77 1.78 1.77 1.77 1.76 1.78 1.77 1.79 1.78 1.78 1.78 1.78 1.76 1.79 1.77 1.78 1.72 Sodium (rug/L)

Feb 4.09 4.65 4.10 4.62 4.01 4.64 4.15 4.59 4.03 4.6 4.08 4.66 4.08 4.66 4.09 4.64 4.21 4.50 4.44 4.63 4.41 4.41 May 4.50 4.61 4.44 4.50 4.40 4.64 4.50 4.95 4.46 4.55 4.46 4.57 4.45 4.57 4.47 4.59 4.49 4.51 4.50 4.57 4.47 4.49 Aug 4.97 4.45 4.85 4.51 4.84 4.44 4.84 4.45 4.84 4.37 4.87 4.42 4.83 4.48 4.87 4.48 4.88 4.49 4.82 4.49 4.88 4.47 Nov 4.54 4.48 4.59 4.42 4.58 4.45 4.61 4.54 4.60 4.43 4.62 4.44 4.60 4.39 4.59 4.4 4.55 4.50 4.72 4.41 4.63 4.38 Anmual Mean 4.63 4.59 4.50 4.51 4.48 4.54 4.53 4.53 4.48 4.49 4.51 4.52 4.49 4.53 4.51 4.53 4.53 4.50 4.62 4.53 4.60 4.44 Aluminum (ragOL)

Feb 0.039 0.033 0.048 0.032 0.040 0.037 0.064 0.047 0.042 0.03 0.045 0.041 0.049 0.050 0.039 0.038 0.056 0.073 0.061 0.038 0.061 0.069 May 0.046 0.037 0.062 0.038 0.027 0.015 0.056 0.029 0.035 0.018 0.032 0.019 0.050 0.025 0.030 0.02 0.058 0.046 0.031 0.029 0.073 0.033 Aug 0.021 0.007 0.009 0.009 0.019 0.008 0.010 0.006 0.031 0.005 0.020 0.009 0.044 0.014 0.017 0.007 0.012 0.007 0.019 0.01 0.009 0.007 NOv 0.044 0.044 0.078 0.048 0.055 0.044 0.079 0.053 0.051 0.043 0.099 0.042 0.077 0.044 0.039 0.037 0.105 0.068 0.069 0.044 0.097 0.059 Annual Mean 0.038 0.030 0.049 0.033 0.035 0.020 0.05 0.034 0.040 0.024 0.039 0.028 0.055 0.033 0.031 0.026 0.059 0.049 0.645 0.030 0.060 0.041 In (mgOL)

Feb 0.045 0.107 0.093 0.107 0.053 0.113 0.121 0.122 0.062 0.124 0.058 0.024 0.092 0.200 0.047 0.172 0.095 0.226 0.092 0.117 0.111 0.205 May 0.050 0.094 0.116 0.075 0.046 0.107 0.115 0.070 0.049 0.134 0.041 0.110 0.071 0.081 0.040 0.064 0.150 0.064 0.054 0.053 0.162 0.075 Aug 0.022 0.027 0.046 0.080 0.020 0.029 0.039 0.035 0.107 0.029 0.023 0.035 0.124 0.219 0.020 0.033 0.066 0.095 0.063 0.044 0.029 0.056 NOv 0.062 0.079 0.150 0.106 0.076 0.090 0.200 0.110 0.098 0.1`15 0.082 0.079 0.106 0.111 0.061 0.093 0.446 0.200 0.103 0.099 0.245 0.153 Annual Mean 0.045 0.077 0.101 0.092 0.049 0.085 0.119 0.084 0.078 0.100 0.051 0.062 0.098 0.153 0.042 0.090 0.189 0.146 0.078 0.078 0.137 0.122 Manganese (ug/L)

Feb 10 9

21 22 11 9

26 24 12 11 12 9

20 43 9

7 17 38 24 8

23 47 Mut 7

8 48 21 7

8 52 18 7

8 7

9 30 31 6

7 42 16 8

9 42 30 Aug 32 33 1340 1470 31 52 1110 818 223 109 35 73 1800 2480 15 39 2040 1750 179 29 489 1440 NoV 28 8D 48 72 36 83 46 51 42 84 37 72 47 107 26 58 61 58 45 60 114 74 Annual Mean 19 32 364 396 21 38 309 228 71 53 23 41 474 665 14 28 540 465 64 26 167 398 Cadmium (ugIL)

Feb 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 May 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Aug 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Nov 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Annual Mean 10 1.0 1.0 1.0 1.0 10 10 1.0 1.0 10 10 1.0 1.0 1.0 1.0 1.0 1.0 10 1.0 1.0 1.0 1.0 Copper (0g)

Feb 1.6 1.1 1.8 1.2 1,6 1.1 1.7 1.2 1.6 1.1 1.4 1.2 1.5 1.2 2.0 1.0 1.6 1.3 2.2 1.0 2.3 1.2 May 1.6 1.2 2.8 1.1 1.6 1.2 1.5 1.0 1.6 1."

1.5 1.2 1.3 1.1 1.4 1.1 1.6 1.1 1.8 1.3 1.7 1.2 Aug 1.6 1.0 1.4 1.0 1.4 1.0 1.5 1.0 2.4 1.0 1.4 1.0 1.3 1.0 1.4 1.0 1.3 1.0 1.9 1.0 1.3 1.0 Nov 1.0 1.0 1.0 1.0 1.0 1.0 1.1 1.0 1.1 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.7 1.0 1.6 1.0 1.5 1.2 Annual Mean 1.5 1.1 1.8 1.1 1.4 1.1 1.4 1.1 1.7 1.1 1.3 1.1 1.3 1.1 1.4 1.0 1.5 1.1 1.9 1.1 1.7 1.2 Lead (ugIL)

Feb 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 May 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Aug 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 NOV 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Annual Mean 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 NS = Not Sampled: NA= Not Applicable; FQC = Failed Quality Control tsj t'j

Table 2-5. (Continued)

LOCATION:

PARAMETERS YEAR:

Mixing Zone 1.0 Surface Bottom 2011 2012 2011 2012 Mixing Zone 2.0 Surface Bottom 2011 2012 2011 2012 MNS Discharge 4.0 Surface 2011 2012 Mixing Zone 5.0 Surface Bottom 2011 2012 2011 201L

Background

8.0 Surface Bottom 2011 2012 2011 2012

Background

11.0 Surface Bottom 2011 2012 2011 2012 Zinc WUI)

Feb May Aug Nov Annual Mean 2.0 2.0 2.5 2.0 2.8 1.0 2.9 1.0 2.0 1.0 2.2 1.0 2.0 1.0 2.0 1.3 2.2 1.3 2.4 1.3 2.0 2.0 2.0 2.C 2.0 1.0 2.0 1.(

2.0 1.0 2.0 1.0 2.0 1.0 2.0 1.V 2.0 1.3 2.0 1.2 2.0 2.C 2.0 1.C 2.6 1.1 2.0 1.14 2.2 1.'

2.0 2.0 2.0 z2 2.0 1.0 2.6 1.0 2.0 1.0 3.0 1.A 2.0 1.0 2.9 1.0 2.0 1.3 2.6 1.1 3.7 2.0 20 2.C 2.0 1.0 20 IV 2.0 1.0 20 1.V 2.0 1.0 2.0 1.0 2.4 1.3 22 1.2 2.0 2.0 2.0 2.0 2.0 1.0 2.7 1.0 2.0 1.0 2.0 1.0 2.0 1.0 2.1 1.4 2.0 1.3 2.2 1.4 4

NintteNitrte (ug/L)

Feb May Aug Nov Annual Mean 180 160 180 190 220 140 280 260 76 14 280 240 60 45 60 45 134 90 200 184 170 160 190 201 220 140 280 25C 81 25 270 26C 61 45 63 44 133 93 201 18C 180 161 230 15C 100 47 61 4E 143 101 180 160 180 17(

220 140 250 25C 93 34 220 12C 60 45 63 4E 138 95 178 147 170 160 190 230 220 140 300 260 34 13 230 20(

60 49 71 4C 121 91 198 18' 240 170 240 240 240 120 300 280 76 10 290 220 120 91 120 92 169 98 23B 208 Ammonia (ug/L)

Feb 21 63 48 78 33 63 44 74 28 65 26 62 37 69 27 62 46 75 36 65 36 73 May 72 87 75 130 100 130 160 130 76 130 95 130 96 130 62 130 87 130 66 130 110 130 Aug 130 60 140 68 240 63 270 58 140 66 240 59 290 100 150 53 220 86 20 62 180 80 Nov 180 95 180 78 230 83 230 75 180 82 170 81 210 84 180 82 140 84 190 75 180 74 Annual Mean 101 76 111 89 151 85 176 84 106 86 133 83 158 96 105 82 123 94 34 83 127 89 Total Phosphorous (ugIL)

Feb 7

5 8

8 7

5 9

9 7

9 6

8 8

7 5

9 12 10 5

10 16 May 7

7 8

7 6

6 8

6 18 5

9 7

7 8

6 7

9 7

8 5

8 8

Aug 8

11 8

8 6

9 6

6 9

9 6

8 6

8 8

8 6

7 Nov 5

11 5

10 5

7 6

5 7

5 6

5 5

5 11 6

9 6

7 7

Annual Mean 7

9 7

8 6

7

7 6

10 6

7 7

6 6

9 8

9 6

a 10 04hopfo-phate (ugI)

Feb 5

5 5

7 5

5 May 5

5 5

5 Aug 5

5 5

5 Nov 5

5 5

5 Annual Mean 5

5 5

5 Silicon (m/gi.)

Feb 5.0 4.5 4.7 4.4 4.8 4.6 4.8 4.4 4.9 4.5 4.7 4.6 4.7 4.5 4.7 4.5 4.7 4.3 4.6 4.4 4,6 4.2 May 4.6 3.9 5.1 4.5 4.7 3.9 5.0 4.6 4.7 3.9 4.9 3.9 5.0 4.7 4.8 3.9 5.1 4.5 4.6 3.6 5.1 4.5 Aug 4.6 3.6 5.3 4.8 4.4 3.6 5.2 4.6 4.4 3.6 4.5 3.7 5.1 4.5 4.4 3.6 5.3 4.7 4.6 3.5 5.1 4.6 Nov 4.7 4.3 4.8 4.2 4.8 4.2 4.8 4.2 4.8 4.2 4.8 4.2 4.9 4.2 4.8 4.1 4.8 4.2 4.8 4.3 4.9 4.3 Annual Mean 4.7 4.1 5.0 4.5 4.7 4.1 4.9 4.5 4.7 4.1 4.7 4.1 4.9 4.5 4.7 4.0 5.0 4.4 4.6 4.0 4.9 4.4 t

Nj do NS = Not Samnpleed: NA= Not Applicable; FQC = Failed Qualit Control

II 1.0

,62. O Water Quality Sampling Locations vf'*

15.0" Mar all Steam Station 13.k 177 N

00.51 2

3 1110 _

Miles 0

1 2

4 Cowans Ford Da Kilometers McGuire Nuclear Station Ij 715.9g7r

,(

k

,(- I

-N w

Figure 2-1.

Water quality sampling locations (numbered) for Lake Norman. Approximate locations of MSS and MNS are also shown.

2-24

180 70 160 60 140 50 120 40 100 Eo-l 80 C

30 60 20 40 10 20 0

0 Figure 2-2a. Annual precipitation totals in the vicinity of MNS.

25 20 -8 7

15 -6 (D

-i 5c0 C

5 -2 0

f t0 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Figure 2-2b. Monthly precipitation totals in the vicinity of MNS in 2011 and 2012.

2-25

C',

0-E 30 28 26 24 22 20 18 16 14 12 10 8

6 4

2 0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 1 Long-term average

--U--2012

-&-2011 1

Figure 2-2c. Mean monthly air temperatures recorded at MNS beginning in 1989. Data were compiled from average daily tLj temperatures which, in turn, were created from hourly measurements.

0 JAN Temperature ('C) 0 5

10 15 20 25 30 35 FEB Temperature ('C) 0 5

10 15 20 25 30 35 MAR Temperature ('C) 0 5

10 15 20 25 30 35 15 20 25 30 35 0

5 10 15

20 25 30 35 S

0 5

10 15 25 30 35 APR Temperature (C) 0 5

10 15 20 25 30 35 MAY Temperature(C) 0 5

10 15 20 25 30 35 JUN Temperature ('C) 0 5

10 15 20 25 30 35 5

10 15

20 25 30 35 a

Figure 2-3. Monthly mean temperature profiles for the MNS background zone in 2012 (xx) and 2011 (,).

0 JUL Temperature(C) 0 5

10 15 20 25 30 35 AUG Temperature ('C) 0 5

10 15 20 25 30 35 SEP Tprature ('C) 0 5

10 15 20 25 30 35

20 a

2.

3' 3

2 2

3 5

0 5.

5.

0 5

10 15 S20 25 30 35 OCT Temperaure ('C) 0 5

10 15 20 25 30 35 NOV Temperature 'C) 0 5

10 15 20 25 30 35 DEC Temperature

('C) 0 5

10 15 20 25 30 35 0

I..

05 05 E

0 5

10 15 20 25 30 10 20 25 30 35 t

Figure 2-3.

(Continued).

00

0 5

10 15

2) 25 3D 35 F00 0

5 10 15 2D 25 3D 35 05R 0

5 10 15

2) 25 3D 35 0

5 v2 Z

2)

Z M) 30 JtN4 0 5 r0* MS TOs5F 0

1a5 0

5 ID 15 2D 25 30 35 0

5 10 i5 2)

F115 0

Figure 2-4. Monthly mean temperature profiles for the MNS mixing zone in 2012 (xx) and 2011 (* ).

JUL Tempemture ('C) 0 5

10 15 20 25 30 35 AUG Temperature ('C) 0 5

10 15 20 25 30 35 SEP Temperature('C) 0 5

10 15 20 25 30 35 5

10

,5 20 25 30 35 0

5.

10 115 20 25 30 OCT Temperature (C 0

5 10 15 20 25 30 35 0

5 10 20 25 30 35 0

5 10 E15

20 25 30 35 NOV Temperature ('C) 0 5

10 15 20 25 30 35 0

5 10

20 25 30 35 0

5 10 E15 e 20 25 30 35 DEC Temperature ('C) 0 5

10 15 20 25 30 35 tlj Figure 2-4.

(Continued).

45 40 35 S30 25 I-(D 20 0.

E 15 10 5

0

--0 ---2012

-U-2011 a

-0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month

-j E)

C a) 0

'a 12 11 10 9

8 7

6 5

4 b,

1" 0

2 1

0 " 2012 2011 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Figure 2-5. Monthly surface (0.3m) temperature (a) and dissolved oxygen (b) data at the discharge location (Location 4.0) in 2011 and 2012.

2-31

0 JAN Dissolved Oxygen (mg/L) 0 2

4 6

8 10 12 0

0 5

10 15

20 20 25 30 35 0

1 5

10 15 o 20 25 30 35 FEB Dissolved Oxygen (mgfL) 2 4

6 8

10 12 MAR Dissolved Oxygen (mrgL) 0 2

4 6

8 10 12 0

5 10 S15

~20 25 30 35 APR Dissolved Oxygen (mg/L) 0 2

4 6

8 10 12 MAY Dissolved Oxygen (mgJL) 0 2

4 6

8 JUN Dissolved Oxygen (mgIL) 0 2

4 6

8 10 12 10 12 0

5 10 15 20 25 30 35 0

5 10 S15 A20 25 30 35 tFigure 2-6. Monthly mean dissolved oxygen profiles for the MNS background zone in 2012 (xx) and 2011 (,,).

JUL Dissolved Oxygen (mgL) 0 2

4 6

8 10 12 AUG Dissolved Oxygen (mrgL) 0 2

4 6

8 10 12 SEP Dissolved Oxygen (mgIL) 0 2

4 6

8 10 12 S

10 615

20 25 30 35 0

5 10 i15 20 25 30 35 u

5" O.

5 OCT Dissolved Oxygen (mg/L) 0 2

4 6

8 10 12 S1.

2 35 3i 25 3

35 5.

5.

NOV Dissolved Oxygen (mg/L) 0 2

4 6

8 10 12 0

5 10 25 25 30 35 5.

10 E15-20 25 30-35-DEC Dissolved Oxygen (mg/L) 3 2

4 6

8 10 12 ik 0

5 25 0o 1

5 ix tIj Figure 2-6.

(Continued).

0 JAN Dissolved Oxygen (mgg/L) 4 6

8 10 12 FEB Dissolved Oxygen (mgfL) 0 2

4 6

8 10 12 MAR Dissolved Oxygen (mgfL) 0 2

4 6

8 10 12 0

2 10 15 20 25 30 35 APR Dissolved Oxygen (mWgL) 4 6

8 10 12 MAY Dissolved Oxygen (ragIL) 0 2

4 6

a 10 12 0

5 10 S15 20 25 30 35 0

5 10 S20 25 30 35 JUN Dissolved Oxygen (mglL) 0 2

4 6

8 10 12 0

2 5

10

20 25 30 35 t'.)

Monthly mean dissolved oxygen profiles for the MNS mixing zone in 2012 (xx) and 2011 (* * ).

JUL Dissolved Oxygen (mgtL) 0 2

4 6

8 10 12 AUG Dissolved Oxygen (mg(.)

4 6

8 10 12 SEP Dissolved Oxygen (mrg/L) 0 2

4 6

8 10 12 0

2 15 20 25 30 35 0

5" 10

[15 e 20 a

25 30 35 OCT Dissolved Oxygen (mg/L) 0 2

4 6

8 10 12 5

10 15 S20 25 30 35 0

5 10 e20 25 30 35

,i NOV Dissolved Oxygen (mg/[)

0 2

4 6

8 10 12 DEC Dissolved Oxygen (mg/L) 4 6

8 10 12 0

2 SFigure 2-7.

(Continued).

ZZ

- 22 S22

~22 j21

.21 21 0

21 Temperature ( C) 20 Jan 5, 2012 20 2o 20 199

.A..

19 L 0

5 10 115 2

25 40 45 5...

50 55 Distance from Cowans Ford Dam (kin) 244 Sampling Locations 23 1.0 8.0 11.0 13.0 15.0 15.9 62.0 69.0 72.0 80.0 23 1_o 8.0 23 U

cf 1_

230

,%23 22' 22

220-22 210 21 21 21 Temperature (C) 20 Mar 5, 2012 20 20 20 19-

.. 1 1'

'1

..A...A..

'O A

1 1g9 S10 15 20 2

0 35 40 45 50 5

Distance from Cowans Ford Dam (kin)

SFigure 2-8. Monthly reservoir-wide temperature isotherms for Lake Norman in 2012.

Distance from Cowans Ford Dam (kin)

24 Sampling Locations

-iSampling Locations 23 1.0 8.0 11.0 13.0 15.0 15.9 62.0 69.0 72.0 80.0 23 1.0 8.0 11.0 13.0 15.0 15.9 62.0 69.0 72.0 80.0

-~~2 23*

2

- __,/----

/

-*_..Temperaturere((°)

EJun 4, 2012 Distance from Cowans Ford Dam (kin)

Distance from Cowans Ford Dam (kin) 2420

,g g

,10 15 0

25.

1 30 3

0 4

0 5------------0 1

0 125 30 35 0

74 o 5005 D22nefomCw

-od a

kl) itnefomCwn or a

kn F1 2-21 (We ai-2 Temperatue02(c, C) 21!*

Temperature 0°C) 20*

Ma 7, 201 20Aun 4,2012 20 20 J

1 5

....10.

....15

.... 2 10 2.5.....

30....

35....

190 2

510 A1

14.

0~~~2 5

0 15 2

-A..

0..

5 40 4

50 5

107 A

2!5 30 35 4

Distance from Cowens Ford Dam (kmn)

Distance from Cowans Ford Darn(m n

Fiur 2-.

(otne)

'5

0 240 Sampling Locations 23 1.0 8.0 11.0 13.0 15.0 15.9 62.0 6

1L 1

1 L

L 23 I

IIý

-. 22 S22 2

g 215 W21 Ter 20 20 19 o..

'.... I.

.1.

.2s.. '.

.3s..

Distance from Cowans Ford Dam (kin) 24FgurSampling Locations 23 1

8-0 11.0 13.0 15-0 15.9 62.0 6

230" S22G S21p

_%1 M

1Ter 0

5 10 1

2W i5 so 35 4

Distance from Cowans Ford Dom (krn)

,* Figure 2-8. (Continued).

00 ja Distance from Cowans Ford Dam (kin)

I I

Distance from Cowans Ford Dam (kin)

S 22 21 i

21 20 20 19[--

24O 23 1.0 23 22 22 21 C3 21 20 20 195 0

t, Figure 2-9.

I Distance from Cowans Ford Dam (km)

Distance from Cowans Ford Dam (kin)

[]

Distance from Cowans Ford Dam (kin)

Monthly reservoir-wide dissolved oxygen isopleths for Lake Norman in 2012.

24 24C Sampling Locations

.Sampling Locations 23 1.0 8.0 11.0 13.0 15.0 15.9 62.0 69.0 72.0 80.0 23 1.0 8.0 11.0 13.0 15.0 15.9 62.0 69.0 72.0 80.0 23; 2 3j 22 22 22 224 215 21 Dissolved Oxygen (mg/L)

Dissolved Oxygen (mg/L) 205*

May 7, 2012 205:

Ju.4 21 20:

20 196........................................................'

.15 9

20 2'90 35 4

A 0

45 A

5`0 5

10 1,0 15 2

25 30 35 40 4

50 51 Distance from Cowans Ford Dam (km)

Distance from Cowans Ford Dam (kmn) 221 Sampling Locations Sampling Locations 23 1.0 8.0 11.0 13.0 15.0 15.9 62.0 69.0 72.0 80.0 23 1.0 8.0 11.0 13.0 15.0 15.9 62.0 69.0 72.0 80.0 23" 2

2o 220 3*Jl2 02 u

,2 21 "21 Dissolved Oxygen (mg/L)

Dissolved Oxygen (mg/L) 20 20 5

10 1

0 25 30 35 40 45 55..

,0 Distance from Cowans Ford Dam (kin)

Distance from Cowans Ford Dam (kin)

Figure 2-9.

(Continued).

0>

22 21 21 20 2

195

240, 23 1.0 23 22 22 21 21 20 20 19f 0

J Figure 2-9.

I Distance from Cowans Ford Dam (kin)

Distance from Cowans Ford Dam (kin)

I.

Distance from Cowans Ford Dam (kin)

(Continued).

Distance from Cowans Ford Dam (kin)

0 x

C>

C.)

E 35 30 25 20 15 10 5

0......

0 50 100 150 200 250 300 350 Julian Date Figure 2-1Oa. Heat content of the entire water column (') and the hypolimnion (o) in Lake Norman in 2012.

CY a) 0Y) 0

0 a) 0 12 10 8

6 4

2 100 90 80 70

.0 60

("3 CU 40 0) 30 r.-

30 (3 20 10 0

0 6

37 65 96 126 157 187 218 249 279 310 340 Julian Date Figure 2-1Ob. Dissolved oxygen content (-) and percent saturation (---) of the entire water column (') and the hypolimnion (o) of Lake Norman in 2012.

2-42

2 212 21 Jun 4, 2012 1

Jun 18, 2012 21 0

26 (C) 26 (eC) o2 (mg/L) 2 (mg/L)

I

?1 5 7 -

1 V

is A -

"O.....

11 2W 2W A

1

"---------4 Distance from Cowan* Ford Dam (Ion)

Distance fom Cowonr Ford Dam (kim) 24 24 LAKE NORMAN STRIP'ED BASS HABITAT LAKE NORMAN STRIPED BASS HABITAT 23 1.0 8.0 11.0 13.0 1o0 16.S 62.-0 eo

.M 0

.o 2

1.0

.0 11.0 13.0 18.0 18.0 62.0 60 72.0 s0o0 S21 2

222 222 21JuI

2. 2012 210 Jul 16, 2012 2 1c 26 (°C )216

)

2 o e f

2 ( ra g A L )

o j

2 ( ra g/ L )

19*

e 196

?

?157....

i Distance from Cowan. Ford Dam (km)

DItMance from Cowan. Ford Dam (Sun)

Figure 2-11. Striped bass habitat (shaded areas; temperatures <26 'C and dissolved oxygen _> 2 mg/L) in Lake Norman in June, July, August, and September 2012.

M j

21 21 24----

210 21 1

Figure 2-11.

III Distance from Cowans Ford Dam (kmn)

Distance from Cowan* Ford Dam (kin)

II Distance from Cowane Ford Dam (kmn)

Distanoe from Cowan* Ford Dam (kmn)

(Continued).

232.0 Full Pond @ 231.65 mmsl 231.5 231.0 EE Z* 230,54 230.0 229.5 229.0

",- CN' N O*

CO O

't lqr-L03*- LO LOb to to3 Q0 Lr

-- CO CO' CO-M M

3 M'- C)O Cý CD-L C N Figure 2-12. Lake Norman lake levels, expressed in meters above mean sea level (mmsl) from 2002 - 2012.

Lake level data correspond to the water quality sampling dates over this time period.

U'

CHAPTER 3 PHYTOPLANKTON INTRODUCTION Phytoplankton standing crop parameters were monitored in 2012 in accordance with the NPDES permit for McGuire Nuclear Station (MNS). The objectives of the phytoplankton study of the Lake Norman Maintenance Monitoring Program are to:

1. describe quarterly/seasonal patterns of phytoplankton standing crop and species composition throughout Lake Norman; and

2. compare phytoplankton data collected during the 2012 study with data collected in prior study years (1987 - 2011).

In studies conducted on Lake Norman from 1973 through 1985, considerable spatial and temporal variability in phytoplankton standing crops and taxonomic composition were reported (Duke Power Company 1976, 1982, 1985; Menhinick and Jensen 1974; Rodriguez 1982).

Rodriguez (1982) classified the lake as oligo-mesotrophic (low to intermediate productivity) based on phytoplankton abundance, distribution, and taxonomic composition.

Past maintenance monitoring program studies have confirmed this classification (Duke Energy 2012).

METHODS AND MATERIALS Quarterly sampling was conducted at Locations 2.0 and 5.0 in the mixing zone, and Locations 8.0, 9.5, 11.0, 13.0, 15.9, and 69.0 in Lake Norman (Figure 2-1). Duplicate Van Dom samples from 0.3, 4.0, and 8.0 m (i.e., the estimated euphotic zone) were composited at all locations except Location 69.0, where Van Dorn samples were taken at 0.3, 3.0, and 6.0 m due to the shallower depth. Sampling has typically occurred in February (winter), May (spring), August (summer), and November (fall) of most years. As in previous years and based on the original study design (Duke Power Company 1988), phytoplankton density, biovolume, and taxonomic composition were determined for samples collected at Locations 2.0, 5.0, 9.5, 11.0, and 15.9; chlorophyll concentrations and seston dry and ash-free dry 3-1

weights were determined for samples from all locations.

Chlorophyll and total phytoplankton densities and biovolumes were used to determine phytoplankton standing crops. Field sampling and laboratory methods used for chlorophyll, seston dry weights, and population identification and enumeration were identical to those used by Rodriguez (1982).

Data collected in 2012 were compared with corresponding data from quarterly monitoring that began in August 1987.

RESULTS AND DISCUSSION Standing Crop Chlorophyll Chlorophyll concentrations from all locations were averaged to calculate a lakewide mean for each quarter. Quarterly lakewide mean chlorophyll concentrations were within ranges of those reported in previous years; however, all quarterly lakewide means were below the long-term means for those periods (Figure 3-1).

Chlorophyll concentrations (mean of two replicate composites) showed temporal variability consistent with previous long-term means. Concentrations ranged from a low of 1.75 Rtg/L at Location 69.0 in February, to a high of 12.14 gg/L also at Location 69.0 in August (Table 3-1 and Figure 3-2). All values were well below the North Carolina water quality standard for chlorophyll a of 40 gtg/L (NCDEHNR 1991).

Seasonally, chlorophyll concentrations increased from the annual minimum in February through May to the annual lakewide maximum in August, and then declined from August through November (Figure 3-1). Based on quarterly mean chlorophyll concentrations, the trophic level of Lake Norman was in the mesotrophic (intermediate) range during all but February, when the mean chlorophyll concentration was in the oligotrophic (low) range. Over 34% of the mean chlorophyll values were less than 4 *tg/L (oligotrophic), while all but one of the remaining chlorophyll values were between 4 and 12 gig/L (mesotrophic). Historically, quarterly mean concentrations of less than 4 jtg/L have been recorded on 26 previous occasions, while lakewide mean concentrations of greater than 12 jig/L were only recorded during May of 1997 and 2000 (Duke Power 1998, 2001; Duke Energy 2012).

3-2

During 2012, chlorophyll concentrations showed typical spatial variability.

Maximum concentrations among sampling locations were observed at Location 69.0 (furthest uplake) during May and August, while the November maximum was recorded from Location 15.9 (Table 3-1; Figure 3-1).

During February, the highest mean concentration occurred at Location 2.0. Minimum concentrations occurred at Location 69.0 in February, Location 8.0 in May, Location 13.0 in August, and Location 2.0 November.

The trend of increasing chlorophyll concentrations from downlake to uplake, which had been observed during many previous years, was apparent to some extent during all but February of 2012 when the opposite trend was observed (Table 3-1; Figure 3-2).

Flow in the riverine zone of a reservoir is subject to wide fluctuations depending, ultimately, on meteorological conditions (Thornton et al. 1990), although influences may be moderated by upstream dams.

During periods of high flow, algal production and standing crop are depressed due in great part to washout. Conversely, production and standing crop increases during periods of low flow which results in high retention time. However, over long periods of low flow, production and standing crop gradually decline. These conditions result in the comparatively high variability in chlorophyll concentrations observed between Locations 15.9 and 69.0 throughout many previous years, as opposed to Locations 2.0 and 5.0 which have usually shown similar concentrations during sampling periods.

Quarterly chlorophyll concentrations during the period of record (August 1987 - November 2012) have varied considerably, resulting in moderate to wide historical ranges. During February periods of 1988 through 2012, chlorophyll concentrations ranged from 0.75 to 28.84 jtg/L (Duke Energy 2012). For historical purposes, February concentrations up to 3.0

[tg/L were considered in the low range, concentrations from greater than 3.0 to 6.0 jtg/L were placed in the intermediate range, and concentrations greater than 6.0,ig/L were in the high range. During February 2012, chlorophyll concentrations at Locations 2.0, 5.0, and 8.0 were in the mid range for this time of year, while concentrations from all other locations were in the low range (Figure 3-3).

During May periods, chlorophyll concentrations have ranged from 0.97 to 27.77 Vtg/L (Duke Energy 2012). May chlorophyll concentrations up to 3.0 pg/L were placed in the low range, while concentrations from greater than 3.0 to 7.0 pg/L were considered in the intermediate range.

Concentrations above 7.0 gig/L were characterized as high.

During May, mean chlorophyll a concentrations at all locations were in the mid-historical range (Figure 3-4).

3-3

August periods showed chlorophyll ranging from of 2.18 to 32.57 jig/L (Duke Energy 2012).

For historical purposes, concentrations up to 5.0 jig/L were placed in the low range, while concentrations between 5.0 and 9.0 [tg/L were considered intermediate. Values greater than 9.0 pg/L were in the high range. Most August 2012 chlorophyll concentrations were in the low historical range, while concentrations at Location 9.5 and 69.0 were in the intermediate and high range, respectively (Figure 3-5).

Long-term chlorophyll concentrations in November ranged from 1.28 to 16.29 jtg/L (Duke Energy 2012). Concentrations up to 4.0 lag/L were considered low, from greater than 4.0 to 8.0 ptg/L intermediate, and those greater than 8.0 jug/L were placed in the high range.

Chlorophyll a concentrations at Locations 2.0, 5.0, 8.0, 9.5, and 69.0 in November 2012 were in the low historical range, while concentrations at Locations 11.0 and 13.0 were in the intermediate range (Figure 3-6). The concentration at Location 15.9 was in the high range.

Total Abundance Density and biovolume represent phytoplankton numbers and biomass, respectively and give an estimate of phytoplankton standing crops.

In most cases, these parameters mirror the temporal trends of chlorophyll concentrations. During 2012, this was most often the case.

Phytoplankton densities were highest in August, while biovolumes were most often highest in November. Mean standing crop variables demonstrated lowest annual values in February, as was the case with chlorophyll.

The lowest density (487 units/mL) was recorded at Location 2.0 in November, while the lowest biovolume (148 mm 3/m3) was recorded from Location 9.5 in February (Table 3-2; Figure 3-2). The maximum density (2,288 units/mL) and biovolume (3,521 mm 3/m3) were recorded at Location 15.9 in November. The maximum biovolume at Location 15.9 was due to the high relative abundance of large diatoms with very low chlorophyll to volume ratios. Most standing crops during 2012 were lower than those observed during 2011 (Duke Energy 2012). Phytoplankton densities and biovolumes during 2012 never exceeded the NC state guidelines for algae blooms of 10,000 units/mL density and 5,000 mm3/m3 biovolume (NCDEHNR 1991). Densities or biovolumes in excess of NC state guidelines occurred in 1987, 1989, 1997, 1998, 2000, 2003, 2006, and 2008 (Duke Power Company 1988, 1990; Duke Power 1998, 1999, 2001, 2004a; Duke Energy 2007, 2009).

3-4

Phytoplankton densities and biovolumes demonstrated a spatial trend similar to that of chlorophyll a; that is, lower values at downlake locations verses uplake locations except during February (Table 3-2; Figure 3-2).

Seston Seston dry weights represent a combination of algal matter and other organic and inorganic material. Dry weights during 2012 were most often higher than those recorded during 2011 (Duke Energy 2012; Table 3-3). A general pattern of increasing values from downlake to uplake was observed during all periods (Figure 3-2). For the most part, this spatial trend was similar to that of chlorophyll concentrations and standing crops.

Seston ash-free dry weights represent organic material and may reflect spatial trends of chlorophyll a and phytoplankton standing crop values.

This relationship was generally noticeable to varying extents during all seasons, especially with respect to increasing values from downlake to uplake areas; however, on occasion, ash-free dry weights declined from Locations 2.0 through 9.5, and then increased through the uplake Location 69.0 (Tables 3-1 through 3-3).

Secchi Depths Secchi depth is a visual measure of light penetration. Secchi depths were often the inverse of suspended sediment (seston dry weight), with the shallowest depths at Locations 13.0 through 69.0 and deepest from Locations 2.0 through 9.5 downlake. Depths ranged from 1.3 m at Location 69.0 in November, to 3.5 m at Locations 11.0 and 9.5 in February and May, respectively (Table 3-1). The lakewide mean Secchi depth during 2012 was the highest yet recorded since measurements were first reported in 1992 (Duke Energy 2011).

Community Composition One indication of "balanced indigenous populations" in a reservoir is the diversity, or number of taxa observed over time. Lake Norman typically supports a rich community of phytoplankton species. This was certainly true in 2012. Ten classes comprising 97 genera and 263 species, varieties, and forms of phytoplankton were identified in samples collected during 2012, as compared to 107 genera and 279 species, varieties, and forms of phytoplankton identified in 2011 (Appendix Table 3-1).

The 2011 total represented the 3-5

highest number of taxa recorded in any year since monitoring began in 1987 (Duke Energy 2012). Eleven taxa previously unrecorded during the Lake Norman Maintenance Monitoring Program were identified during 2012.

Species Composition and Seasonal Succession The phytoplankton community in Lake Norman varies both seasonally and spatially.

Additionally, considerable variation may occur between years for the same months sampled.

During February 2012, cryptophytes (Chryptophyceae) dominated densities at all locations (Table 3-4; Figures 3-7 through 3-11).

During most previous years, cryptophytes and occasionally diatoms (Bacillariophyceae) dominated February phytoplankton samples in Lake Norman.

The most abundant cryptophyte during February 2012 was the small flagellate, Rhodomonas minuta, one of the most common and abundant forms observed in Lake Norman samples since the Maintenance Monitoring program began in 1987.

In May, diatoms dominated samples at all locations (Table 3-4; Figures 3-7 through 3-11).

The most abundant diatoms were Tabellaria fenetrata at Locations 2.0, 5.0, and 11.0 and Fragillaria crotonensis at Locations 9.5 and 15.9.

Diatoms have typically been the predominant forms in spring periods of previous years; however, cryptophytes were dominant in May 2008 and May 2011, and often dominated May samples from 1988 to 1995 (Duke Energy 2012).

During August 2012, green algae (Chlorophyceae) dominated densities at all locations (Table 3-4; Figures 3-7 through 3-11).

The most abundant green alga was the small desmid, Cosmariumr asphearosporum var. strigosum. Prior to 1999, green algae were the primary constituents of summer phytoplankton assemblages, and the predominant green alga was also C. asphearosporum var. strigosum (Duke Power 1999).

During August periods of 1999 through 2001, Lake Norman summer phytoplankton assemblages were dominated by diatoms, primarily the small pennate, Anomoeoneis vitrea (Duke Power 2000, 2001, 2002).

The possible causes of this significant shift in summer taxonomic composition during 1999 -

2001 were discussed in earlier reports and included deeper light penetration, extended periods of low water due to drawdown, and shifts in nutrient inputs and concentrations (Duke Power 2000, 2001, 2002).

Whatever the cause, the phenomenon was lakewide and not localized near MNS or Marshall Steam Station; therefore, it was most likely due to a combination of natural environmental factors, and not station operations.

Since 2002, 3-6

taxonomic composition during the summer has shifted back to green algae predominance (Duke Energy 2012).

During November 2012, diatoms dominated densities at all locations and the most abundant species at all locations was T. fenestrala at all locations (Table 3-4; Figures 3-7 through 3-11). Diatoms have typically been dominant during past November periods, with occasional dominance by cryptophytes (Duke Energy 2012).

Blue-green algae, which are often implicated in nuisance blooms, were not abundant in 2012 samples. Their overall contribution to phytoplankton densities have seldom exceeded 4% of totals (Duke Energy 2012). Prior to 1991, blue-green algae were often dominant at uplake locations during the summer (Duke Power Company 1988, 1989, 1990, 1991, 1992).

SUMMARY

Lake Norman continues to be oligo-mesotrophic based on long-term, annual mean chlorophyll concentrations. Individual chlorophyll concentrations during 2012 were within historical ranges.

Lakewide mean chlorophyll a increased from the annual minimum in February to the annual peak in August, and then declined November.

Some spatial variability was observed in 2012; however, maximum chlorophyll concentrations were most often observed uplake at Locations 15.9 (November) and 69.0 (May and August), while minimum chlorophyll a concentrations were recorded from downlake at Locations 2.0 (November), 5.0 (August) and 8.0 (May). The highest chlorophyll value recorded in 2012 (12.14 gig/L at Location 69.0 in August) was well below the NC State water quality standard of 40 gg/L.

Most phytoplankton standing crops in 2012 were lower than in 2011.

Phytoplankton densities and biovolumes during 2012 never exceeded the NC guideline for algae blooms of 10,000 units/mL density and 5,000 mm 3/m 3 biovolume. Standing crop values in excess of bloom guidelines occurred during eight previous years of sampling.

As in past years, standing crop spatial distribution typically mirrored that of chlorophyll, with high values usually observed at uplake locations, while comparatively low values were noted downlake.

Seston dry and ash-free weights were most often higher in 2012 than in 2011. The trend of increasing values from downlake to uplake was generally apparent during most sampling 3-7

periods. Maximum dry and ash-free weights were consistently observed at uplake Location 69.0. Minimum values were most often noted at downlake Locations 2.0 through 9.5.

Secchi depths often reflected suspended solids, with shallow depths loosely related to high dry weights. The lakewide mean Secchi depth in 2012 was one of the highest recorded since 1992.

Diversity, or the number of phytoplankton taxa identified in 2012 was lower than in 2011, but still among the highest yet recorded. The taxonomic compositions of phytoplankton communities during 2012 were similar to those of most previous years.

Diatoms were dominant during May and November, while cryptophytes were dominant during February.

During August, green algae consistently dominated algal assemblages. Contribution of blue-green algae to total densities seldom exceeded 4%.

The most abundant algae during 2012 were: the cryptophyte, Rhodomonas minuta in February; the diatom Tabellaria fenestrata in May and November; and, the green alga, Cosmarium asphearosporum var. strigosum in August. All of these taxa have been common and abundant throughout the Lake Norman Maintenance Monitoring Program.

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

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

3-8

Table 3-1.

Mean chlorophyll a concentrations (jig/L) in composite depths (m) observed in Lake Norman in 2012.

samples and Secchi Sample Month =

Feb May Aug Nov Location Chlorophyll 2.0 5.14 4.41 4.58 2.18 5.0 4.67 4.47 4.04 2.99 8.0 5.06 4.01 4.15 3.39 9.5 3.12 4.13 5.75 3.70 11.0 2.28 4.63 4.67 5.35 13.0 2.07 4.93 3.79 6.29 15.9 1.94 5.59 4.79 8.26 69.0 1.75 5.77 12.14 2.95 Sample Month Feb May Aug Nov Location Secchi Depth 2.0 3.0 3.4 2.2 2.3 5.0 3.2 2.9 2.1 1.8 8.0 3.4 3.0 1.9 2.2 9.5 3.1 3.5 2.5 2.6 11.0 3.5 3.0 2.2 2.0 13.0 1.8 2.9 1.6 1.8 15.9 2.6 3.2 1.8 2.2 69.0 2.3 1.4 1.4 1.3 Annual mean from all Locations =

2.45 3-9

Table 3-2.

Mean phytoplankton densities (units/mL) and biovolumes (mm 3/m 3) by location and sample month from samples collected in Lake Norman during 2012.

Density Locations Month 2.0 5.0 9.5 11.0 15.9 Mean Feb 827 714 607 561 504 643 May 999 983 918 1,219 1,802 1,184 Aug 1,293 1,203 1,683 1,687 2,047 1,583 Nov 478 528 934 1,550 2,288 1,156 Biovolume Locations Month 2.0 5.0 9.5 11.0 15.9 Mean Feb 275 211 148 188 187 202 May 1,034 807 773 1,306 1,538 1,092 Aug 673 852 1,158 1,175 1,939 1,159 Nov 504 672 1,540 2,594 3,521 1,766 Table 3-3. Total mean seston dry and ash free-dry weights (mg/L) from samples collected in Lake Norman during 2012.

Dry weights Locations Month 2.0 5.0 8.0 9.5 11.0 13.0 15.9 69.0 Mean Feb 1.48 1.45 1.40 1.52 1.57 2.32 2.04 3.20 1.87 Jun 1.13 1.22 085 1.09 1.35 1.17 1.45 5.82 1.76 Aug 4.58 4.04 4.15 5.75 4.67 3.79 4.79 12.14 5.49 Nov 2.03 1.81 1.94 2.82 2.08 2.66 2.74 4.68 2.60 Ash-free dry weights Month Feb 0.50 0.45 0.47 0.45 0.51 0.63 0.63 0.90 0.57 Jun 0.66 0.64 0.45 0.62 0.72 0.63 0.91 1.36 0.75 Aug 1.34 1.05 1.28 1.39 1.38 1.00 1.09 2.81 1.42 Nov 0.63 0.82 0.86 1.01 0.87 0.86 0.99 1.15 0.88 3-10

Table 3-4. Dominant classes, their most abundant species, and their percent composition (in parentheses) at Lake Norman locations during each sampling period of 2012.

Location Feb May 2.0 Cryptophyceae (78.1)

Bacillariophyceae (53.2)

Rhodomonas minuta (74.1)

Tabellaria fenestrata (28.9) 5.0 Cryptophyceae (74.7)

Bacillariophyceae (50.1)

R. minuta (73.3)

T. fenestrata (24.7) 9.5 Cryptophyceae (59.0)

Bacillariophyceae (43.2)

R. minuta (57.1)

Fragillaria crotonensis (16.4) 11.0 Cryptophyceae (69.8)

Bacillariophyceae (40.4)

R. minuta (67.7)

T. fenestrate (26.5) 15.9 Cryptophyceae (73.0)

Bacillariophyceae (51.4)

R. minuta (68.0)

F. crotonensis (35.2)

Aug Nov 2.0 Chlorophyceae (63.2)

Bacillariophyceae (59.2)

Cosmarium asphearosphorum v.

Tabellaria fenestrata (35.1) strigosum (30.3) 5.0 Chlorophyceae (62.0)

Bacillariophyceae (53.6)

C. asphear. v strig. (28.2)

T. fenestrata (31.7) 9.5 Chlorophyceae (59.7)

Bacillariophyceae (65.5)

C. asphear. v strig. (31.6)

T. fenestrata (21.5) 11.0 Chlorophyceae (67.6)

Bacillariophyceae (77.3)

C. asphear. v strig. (30.8)

T. fenestrata (41.1) 15.9 Chlorophyceae (52.6)

Bacillariophyceae (62.9)

C. asphear. v strig. (16.8)

T. fenetrata (22.5) 3-11

14 12 10

_1 L,

00.

8 6

4 2

0 12.41 pgfL-Lay 1997 176.

D6 plL-lNa 1999 Feb May Aug Nov Maxirrm Minimum 2012 Mean I

Figure 3-1.

Lake Norman phytoplankton chlorophyll a seasonal maximum and minimum lakewide means since August 1987 compared with the long-term seasonal lakewide means and lakewide means for 2012.

3-12

10 Chlorophyll (pg/L)

Density (units/mL) 14 12 0.........................--------------------

80 6

4 2

0 1

-~

(N LA cf O

Seston Dry Weight (mg/L) 12 10 8

~

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

12o 0,

(N

) CD 0D

)

C') C3) 10 2,400 2.000 1,600--------------

iooo ~--

1,200 800 4 0 0 0

PC P

U C?

0F)

(Nj t)

0)

)

Biovolume (mm 3lm3) 4,000 3,500 3.000 2 75 0 0 2.000 1,500 1.500

~~

I1.000 500 o

0Lto CD CI

0) -

U Locations Feb May Aug Nov

-4 X

Figure 3-2.

Phytoplankton chlorophyll a, densities, biovolumes, and seston dry weights at locations in Lake Norman in February, May, August, and November 2012.

3-13

20

-5 0

1 20 18 16 12 -

4 2

0

.. P&YAMZQPV._

I --- ------

J \\----------

87 88899091 929394 959697 98 99000102 03 04050607 0809 1011 12 Years I

8 0

-- 0-95 5 20 18-16 6-4 2

0 878889990 9192 93 949596 97 9899 00 010203 0405 0607 0809 10 11 12 Years S

-,-..---110

--'==-130 20 18 16

.. 14 12 10

--A

I -..

87 88 89 9091 92 93 94 959697989900 01020304 05 0607 0809 10 11 12 Years 1

159 690 30 25 20 7-15 0

5 10 5

0 87 88 89 9091 92 93 94 95 9697 9B 99 00 01 02 03 04 05 0607 08 09 10 11 12 Years Figure 3-3.

Phytoplankton mean chlorophyll concentrations by location for samples collected in Lake Norman from February 1988 through 2012 (Note: change in axis for 15.9 and 69.0, and that clear data points represent long-term maxima).

3-14

30 25 20 15 P10 5

1

-20

-*- 50 Mixing Zone I

0 87 88 89909192 93 9495 9697 9899 0001 020304 05 0607 08 0910 11 12 Years L

-.- BO

-95 30 -r 25 -

20

~15-10-5 J -----

0 87 88 8990 9192 93 9495 96 97909900 01 0203 04 050607 08 0910 11 12 Years 1

- 11 0

--o-130 1

30 25 e20 15 10 5-0- 8 30 25 20 10-5 0

7 8889 909192 93 94 96969798 9900 0102 03 04OS 0607 0809 10 11 12 Y.."s 159

-w-69 0 1

I........

11 1 I~......

_ýW;-rv4v 8 7 8889 909192 9394 9596 9798 99 0001 02 03G4 05 06 07080910 11 12 Years Figure 3-4.

Phytoplankton mean chlorophyll concentrations by location for samples collected in Lake Norman from May 1988 through 2012 (Note: clear data points represent long-term maxima).

3-15

-20

.50 7

30 25 0o

-15 10 5

0 30 25 20 p-15 10 5

0 Mixing Zone 87 88 89 90 91 92 93 94 95 96 97 98 99 00 0102 03 04 05 06 07 08 09 10 11 12 Years F

-.80

~9 5 87 88 89909192 9394 9596 9798 99 00 010203 04 05 0607 080910 11 12 Years 1,0

-w-13 0 1

30 25 20

~15 45 10 0

87 88 8990 9192 93 94 959697 989900 0102 03 04 050607 08 091011 12 Year.

159

-a*-69 0 1

35 30 25 20 a 15 510 5

0 878889990 91 9293 9495 9697 98 99000102 0304 05 0607 0809 1011 12 Yea's Figure 3-5.

Phytoplankton mean chlorophyll concentrations by location for samples collected in Lake Norman during August 1987 through 2012 (Note: change in axis for 15.9 and 69.0, and that clear data points represent long-term maxima).

3-16

20 18-16

~14-12 I-10 2

8 S6-C-)

1

.- 2,0

-0n-50 Mlixong Zoo.

AJ.Y...... --

A -------

4 2

0 87 88 89 9091 92 93 949S 96 97 98 99 00O102O03O04O06070809 1011 12 Year.

1

.- 80

-i-m-95 1

20 18 16 14

_12-2 8

r6-4 2

0 20 18 16 14 12 L-10 CL 8

16 4

2 0

20 18 16 4 14

-12

~10 p8 4

2 0

ep 7 08 89 9091 9293 9495 96 9798 99 00 102 03D405 6 0708O09 1011 12 Years E1788 89 909192 9394 9596 9798 9900 0102 03 0405 0607 0809 10 11 12 Years 87 8889 9091 9293 94 9596 97 9899 00010203 0405 06 0708 091011 12 Years Figure 3-6.

Phytoplankton mean chlorophyll concentrations by location for samples collected in Lake Norman during November 1987 through 2012 (Note that clear data points represent long-term maxima).

3-17

2000 0

--L Chrysophyceae

Cryptophyceae a Myxophyceae

Dinophyceae 1,800 --

mOther 1,600-----------------------------------

E1.400 -----------------------------------------------------------------------------------

E 12400 120-------------------------------------

800 600 ------------------------------------------

400 200 Feb May Aug Nov 1,2 0 0 -.--

18000 -

E E

600 -..............----------------------.

0

.2 4 0 0 200 -

Feb May Aug Nov Figure 3-7.

Class composition of phytoplankton standing crop parameters (mean density and biovolume) from euphotic zone samples collected at Location 2.0 in Lake Norman during 2012.

3-18

2,000 -

1,800 -

1 600

-J E 1,400 1.200 -

1 000 800 600 400 200 0

Chlorophyceae O3Chrysophyceae

Myxophyceae mOther

Bacillariophyceae

Cryptophyceae

Dinophyceae I ---------------------------------------------------------------------------------

I ----------

Feb May Aug Nov 1 200 1,000 E

800 E

E 600 0

400 ra 200 0

U Feb May Aug Nov Figure 3-8.

Class composition of phytoplankton standing crop parameters (mean density and biovolume) from euphotic zone samples collected at Location 5.0 in Lake Norman during 2012.

3-19

3.000 M Chlorophyceae o Chrysophyceae

" Myxophyceae

" Other OBacillariophyceae

=Cryptophyceae mDinophyceae 2 500 -

.-J E Z000 CD S1 ý500 C

o1,0002 500o I

U Feb May Aug Nov 3.500 3.000 E

E E

4 2Z000 E

"0 1 500 A

Q I AA I 1JJI I,UUU 500 0

Nov Feb May Aug Figure 3-9.

Class composition of phytoplankton standing crop parameters (mean density and biovolume) from euphotic zone samples collected at Location 9.5 in Lake Norman during 2012.

3-20

3000 M Chlorophyceae 0 Bacillariophyceae 0 Chrysophyceae 2 --

Cryptophyceae w Myxophyceae

Dinophyceae 2.500 lmOther

2000 t-Cn t1-C 1.0 0 0 500 Feb May Aug Nov 3,500 -..----------------------------------------------------------

3.000-------------------------------

E 2,5 0 0 -.-.----------------------

EE 2 000 E

~1500 -------------------------------------------------------------------------

.0 a 1.000 500 Feb May Aug Nov Figure 3-10.

Class composition of phytoplankton standing crop parameters (mean density and biovolume) from euphotic zone samples collected at Location 11.0 in Lake Norman during 2012.

3-21

3000-2 500 ES 2000

'1 500 CD 0

0) o I ooo m Chlorophyceae T a Cryptophyceae a

Other oBacillaflophyceae aMyxophyceae o Chrysophyceae a Dinophyceae I

I Nov 500 -

0 1

-I-No Feb May Aug 4,000 -

3,500 E 3,000 E 2.500 CD E 2,000

> 1,500 0

~-----

1,000 --------------------------------------

I

[ - ----

500 "

Feb May Aug Nov Figure 3-11.

Class composition of phytoplankton standing crop parameters (mean density and biovolume) from euphotic zone samples collected at Location 15.9 in Lake Norman during 2012.

3-22

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

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

2. compare and evaluate, where possible, zooplankton data collected during 2012 with historical data collected during the period 1987 - 2011.

Studies conducted between 1973 and 1985 using primarily monthly zooplankton data from Lake Norman, showed that zooplankton populations demonstrated a bimodal seasonal distribution with highest values generally occurring in the spring and a less pronounced fall peak (Duke Power Company 1976, 1982, 1985).

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). Since quarterly sampling began in August 1987, distinct bimodal seasonal distributions have been less apparent due to the lack of transitional data between quarters.

METHODS AND MATERIALS Duplicate 10 m to surface and bottom to surface net tows were taken at Locations 2.0, 5.0, 9.5, 11.0, and 15.9 in Lake Norman (Figure 2-1) during each season: winter (January through March), spring (April through June), summer (July through September), and fall (October through December) 2012. For discussion purposes the 10 m to surface tow samples are called "epilimnetic" samples and the bottom to surface net tow samples are called "whole-column" samples. Locations 2.0 and 5.0 are defined as the "mixing zone" and Locations 9.5, 11.0, and 15.9 are defined as "background" locations.

Field and laboratory methods for zooplankton standing crop analysis were the same as those reported in Hamme (1982).

4-1

Zooplankton standing crop data from 2012 were compared with corresponding data from quarterly monitoring begun in August 1987.

RESULTS AND DISCUSSION Total Abundance Epilimnetic zooplankton densities during 2012 ranged from a low of 16,374/mi3 at Location 2.0 in February, to a high of 245,455/M3 at Location 11.0 in May (Table 4-1). During 2012, there was some of spatial variability in annual maxima and minima among Lake Norman locations, but generally densities increased from downlake to uplake (Table 4-1; Figures 4-1 and 4-2). Over the long-term, the highest epilimnetic zooplankton densities at Lake Norman locations have predominantly occurred in the spring, with winter peaks observed about 25%

of the time. Peaks were observed only occasionally in the summer and fall (Duke Energy 2012).

Whole-column densities ranged from a low of 19,418/mi3 at Location 2.0 in February to 216,690/mi3 at Location 15.9 in May (Table 4-1 and Figure 4-1). Spatial and temporal trends among whole-column densities were typically similar to those of epilimnetic densities During 2012, as has been the case in all past years, total zooplankton densities were most often higher in epilimnetic samples than in whole-column samples (Duke Energy 2012).

This relates 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).

Since epilimnetic zooplankton communities are far more representative of overall seasonal and temporal trends, most of the following discussion will focus primarily on zooplankton communities in this area of the water column.

Epilimnetic zooplankton densities during all seasons of 2012 were generally within historical ranges (Figures 4-3 through 4-6). The exceptions were record low values from Locations 2.0 and 9.5 in Febraury. The highest winter densities recorded from Locations 2.0 and 11.0 occurred in 1996, while the winter maximum at Location 9.5 was recorded in 1995 (Figure 4-3). The winter maximum from Location 5.0 occurred in 2004, while the long-term winter maximum from Location 15.9 occurred in 2011. Long-term maximum densities for spring 4-2

occurred at Locations 2.0 and 5.0 in 2005, while the highest spring values from Locations 11.0 and 15.9 occurred in 2002. The highest spring peak at Location 9.5 was observed in 2005 (Figure 4-4). Long-term summer maxima occurred in 1988 at Locations 2.0, 5.0, and 11.0, while summer maxima at Locations 9.5 and 15.9 occurred in 2007 and 2003, respectively (Figure 4-5). The long-term maxima for the fall occurred at Locations 2.0 and 5.0 in 2009 and Locations 9.5 and 11.0 in 2006, while the fall maximum at Location 15.9 occurred in 1999 (Figure 4-6).

Year-to-year fluctuations of epilimnetic densities among background locations, particularly Locations 11.0 and 15.9 have generally been far more apparent than in the mixing zone (Figures 4-3 through 4-6). These uplake locations are far more susceptible to hydrological fluctuations associated with the more riverine zone of the reservoir that can have direct influences on phytoplankton communities (see Chapter 3). These impacted phytoplankton communities subsequently provide a

food source for zooplankton, particularly microcrustaceans. Conditions at Locations 2.0 and 5.0 in the mixing zone are less variable due to the dampening influences of the Cowans Ford Dam.

Community Composition Since the Lake Norman Maintenance Monitoring Program began in August 1987, 131 zooplankton taxa have been identified (Table 4-2). During 2012, 56 taxa were identified, as compared to 50 recorded in 2011 (Duke Energy 2012). Four taxa, previously unrecorded during the Maintenance Monitoring Program were identified during 2012. The number of taxa identified during 2012 was within ranges of previous years.

During 2012, rotifers were dominant in 75% of the samples (Table 4-1). Copepods were dominant in both epilimnetic and whole-column samples at Locations 5.0 and 9.5 in the winter and Location 5.0 in the fall. Copepods were also dominant in epilimnetic samples from Location 2.0 in the winter and fall, respectively.

Cladocerans, typically the least abundant forms, were dominant in one winter sample, Location 2.0-bottom (Table 4-1).

During most years, microcrustaceans (copepods and cladocerans) dominated mixing zone samples, but were less important among background locations (Figures 4-7 and 4-8).

Compared to 2011, rotifers increased in relative abundances in both the epilimnetic and whole-column samples of the mixing zone and background locations during 2012. Rotifer percent compositions were in the high historical range (Figures 4-7 and 4-8).

4-3

Copepoda As has always been the case, immature forms (primarily nauplii) consistently dominated copepod populations during 2012. Adult copepods seldom comprised more than 7% of the copepod densities at any location.

In order of seasonal importance, Epishura was most common adult among winter and spring samples, while Mesocyclops and Tropocyclops were most important among spring assemblages (Table 4-3). During the summer and fall periods, Tropocyclops was the most important constituent in all samples. Similar patterns of copepod taxonomic distributions occurred in previous years (Duke Energy 2012).

Copepods tended to be more abundant among background locations than among mixing zone locations during 2012 (Figure 4-9). Copepods peaked in the mixing zone during winter and at background locations in the spring. During most past years, peaks from both areas were observed in the spring (Duke Energy 2012).

Cladocera Bosmina was the most abundant cladoceran observed in 2012 samples, as has been the case in most previous studies (Duke Energy 2012 and Hamme 1982). Bosmina often comprised greater than 70% of the cladoceran densities in both epilimnetic and whole-column samples, especially during winter and fall (Table 4-3). Bosminopsis was most often the dominant cladoceran in summer samples. Similar patterns of cladoceran dominance occurred in past years (Duke Energy 2012).

Long-term seasonal trends of cladoceran densities were variable and described in detail in previous maintenance monitoring reports (Duke Energy 2012). During 2012, cladocerans were generally more abundant at background locations. Maximum densities in the mixing zone and at background locations occurred the spring (Figure 4-10). Cladoceran peaks were most often in the winter and spring, with occasional peaks recorded in the summer and fall (Table 4-1; Figure 4-2).

Rotifera Keratella and Conochilus were the most abundant rotifers at most locations in the winter of 2012 (Table 4-3). Kellicotia dominated most rotifer populations during the spring, while Ptygura dominated most summer populations. Polyarthra and Keratella were each dominant 4-4

in four fall samples, while Conochilus and Conochiloides were each dominant in one fall sample.

All of these taxa are important constituents of rotifer populations, as well as zooplankton communities, in previous studies of Lake Norman (Duke Energy 2012; Hamme 1982).

Long-term tracking of rotifer populations indicated high year-to-year seasonal variability.

Peak densities have most often occurred in the winter and spring, with occasional peaks in the summer and fall (Figure 4-11). During 2012, peak rotifer densities occurred in the spring.

SUMMARY

During 2012, seasonal maximum densities among zooplankton assemblages varied considerably and no consistent seasonal trends were observed. Historically, maxima most often occurred in winter and spring, while minima most often occurred in the fall. As in past years, epilimnetic densities were higher than whole-column densities. Mean zooplankton densities tended to be higher among background locations than among mixing zone locations during 2012, as has often been the case in previous years. Spatial trends of zooplankton populations were generally similar to those of phytoplankton, with increasing densities from downlake to uplake.

Long-term trends showed much higher year-to-year variability at background locations than at mixing zone locations, likely due to the influences associated with uplake riverine conditions as opposed to relatively stable conditions in the main area of the reservoir. Epilimnetic zooplankton densities were within ranges of those observed in previous years, with the exceptions of record low zooplankton densities from Locations 2.0 and 9.5 in Febraury 2012.

Since the Lake Norman Maintenance Monitoring Program began in 1987, 131 zooplankton taxa have been recorded from Lake Norman. During 2012, 56 taxa were identified, as compared to 50 in 2011. The number of taxa recorded for 2012 was within the historical range.

Rotifers were dominant in 75% of all samples and their overall relative abundances increased since 2011 in epilimnetic and whole-column samples from mixing zone and background locations.

Overall, relative abundance of copepods decreased from 2011 to 2012.

The relative abundance of all microcrustaceans (copepods and cladocerans) decreased throughout 4-5

the lake in 2012 and their percent compositions at these locations were within historical ranges.

Historically, copepods and rotifers have most often shown annual peaks in the spring, while cladocerans continued to demonstrate year-to-year variability.

Immature forms dominated copepod populations with adults rarely accounting for more than 7% of zooplankton densities. The most important adult copepods were Tropocyclops and Epishura, as was often the case in previous years. Bosmina was the predominant cladoceran, as in most previous years of the Program. Bosminopsis dominated cladoceran populations during the summer. The most abundant rotifers observed in 2012, as in many previous years, were Keratella, Conochilus, Ptygura, and Kellicotia.

Lake Norman continues to support a highly diverse and longitudinally variable zooplankton community. No discernible impacts of plant operations were observed.

4-6

Table 4-1.

Total zooplankton densities (No. X 1000/mr3), densities of major zooplankton taxonomic groups, and percent composition (in parentheses) of major taxa in the epilimnion and whole-column net tow samples collected from Lake Norman in winter (February), spring (May), summer (August), and fall (November) 2012.

Locations Season and Sample Type Taxa 2.0 5.0 9.5 11.0 15.9 Sample Date Epilimnion Copepoda 8.27 7.18 15.23 42.15 67.22 Winter (50.5)

(41.4)

(62.9)

(45.4)

(32.4) 2/2/13 Cladocera 5.13 4.62 5.14 15.18 22.67 (31.3)

(26.7)

(21.2)

(16.3)

(10.9)

Rotifera 2.98 5.53 3.86 35.51 117.58 (18.2)

(31.9)

(15.9)

(38.3)

(55.7)

Total 16.37 17.33 24.24 92.84 207.45 Whole-column 2.0 5.0 9.5 11.0 15.9 Depth 30 m 18 m 21 m 25 m 21 m Copepoda 7.00 7.86 22.01 34.64 40.62 (36.0)

(41.3)

(74.0)

(41.9)

(29.2)

Cladocera 7.90 7.26 4.83 13.19 9.76 (40.7)

(38.1)

(16.2)

(15.9)

(7.0)

Rotifera 4.52 3.93 2.91 34.88 88.79 (23.3)

(20.6)

(9.8)

(42.2)

(63.8)

Total 19.42 31.60 29.75 82.71 139.16 Locations Season and Sample Type Taxa 2.0 5.0 9.5 11.0 15.9 Sample Date Epilimnion Copepoda 15.52 15.73 22.65 30.94 32.10 Spring (8.1)

(7.1)

(17.9)

(12.6)

(13.8) 5/10/12 Cladocera 13.05 11.43 13.12 33.09 76.43 (6.8)

(5.2)

(10.3)

(13.5)

(32.9)

Rotifera 163.51 194.14 91.10 181.42 123.69 (85.1)

(87.7)

(71.8)

(73.9)

(52.3)

Total 192.08 221.30 126.87 245.46 232.22 Whole-column 2.0 5.0 9.5 11.0 15.9 Depth 31 m 21m m18 26 m 22 m Copepoda 13.66 16.37 15.53 19.90 36.93 (13.9)

(11.2)

(31.41)

(19.2)

(17.0)

Cladocera 9.85 11.88 12.08 18.43 66.66 (10.0)

(8.15)

(24.43)

(17.8)

(30.8)

Rotifera 74.83 117.58 21.84 65.50 113.11 (76.1)

(80.63)

(44.16)

(63.1)

(52.2)

Total 98.33 145.84 49.46 103.84 216.69 4-7

Table 4-1. (Continued).

Locations Season and Sample Type Taxa 2.0 5.0 9.5 11.0 15.9 Sample Date Epilimnion Copepoda 26.27 19.90 14.47 10.58 25.94 Summer (29.5)

(35.4)

(8.9)

(6.4)

(17.6) 8/8/12 Cladocera 8.71 0.81 24.16 10.99 32.75

_9.8)

(1.4)

(14.8)

(6.7)

(22.2)

Rotifera 53.82 35.57 124.46 143.67 88.97 (60.5)

(63.2)

(76.3)

(86.9)

(60.2)

Total 64.03a 56.28 163.09 165.24 147.66 Whole-column 2.0 5.0 9.5 11.0 15.9 Depth 30 m 20 m 17 m 25 m 21 m Copepoda 11.68 16.95 8.50 8.22 18.40 (36.3)

(47.2)

(11.6)

(15.5)

(25.8)

Cladocera 3.71 0.50 13.07 4.44 15.66 (11.5)

(1.4)

(17.8)

(8.3)

(21.9)

Rotifera 16.83 18.37 51.96 40.36 36.52 (52.2)

(51.1)

(70.7)

(75.9)

(51.2)

Total 32.22 3 5.9 5b 73.52 53.160 7 1.3 7d Locations Season and Sample Type Taxa 2.0 5.0 9.5 11.0 15.9 Sample Date Epilimnion Copepoda 13.33 18.10 25.66 20.96 24.02 (46.8)

(44.6)

(38.1)

(25.4)

(13.0)

Cladocera 4.22 11.68 4.80 9.13 3.98 (15.4)

(28.8)

(7.1)

(11.1)

(2.2)

Rotifera 9.89 10.78 36.90 52.38 156.68 (36.1)

(26.6)

(54.8)

(63.5)

(84.8)

Total 27.44 40.56 67.36 82.47 184.67 Whole-column 2.0 5.0 9.5 11.0 15.9 Depth 31 m 19 m 17 m 24 m 22m Copepoda 12.72 12.99 32.72 24.24 21.05 (40.5)

(52.8)

(40.6)

(22.3)

(130)

Cladocera 5.80 7.61 3.87 11.22 4.38 (18.4)

(30.9)

(4.8)

(10.3)

(2.7)

Rotifera 12.94 3.99 43.95 73.03 136.67 (41.1)

(16.3)

(54.6)

(67.3)

(84.2)

Total 31.46 24.59 80.54 108.48 162.33

' = Chaoborus (227/m3, 0.3%)

b = Chaoborus (129/M 3, 0.4%)

= Chaoborus (153/m 3, 0.3%)

d = Chaoborus (776/M3, I. 1%)

' = Chaoborus (232/m 3,0. 1%)

4-8

Table 4-2. Zooplankton taxa identified from samples collected quarterly on Lake Norman from 1987 - 2012.

Taxon 87-97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 Copepoda C7vc/ops thomasi Forbes X

X X

X C. vernalis Fischer X

C. spp. 0. F. Muller X

X x

X X

x x

Diaplomus birgei Marsh X

X D. nississippiensis Marsh X

X X

X D. pallidus Herick X

X X

X D. reighardi Marsh X

D. spp. Marsh X

X X

Epishurafluviatilis Herrick X

X X

X Ergasilus spp. Smith X

X Eucyclops agilv (Koch)

X E. prionophorus Kiefer X

Mesocyclops edax (S. A. Forbes)

X X

M spp. Sars X

X X

X Paracyclopsfimbriarus v. poppei X

Tropocyclops prasinus (Fischer)

X X

T. spp. (Fischer)

X X

X Cladocera Alona spp.Baird X

-X X

X Alonella spp. (Birge)

X X

Bosmina longirostris (0. F.M.)

X X

B. spp. Baird X

X X

Bosminopsis dietersi Richard X

X X

X Ceriodaphnia dubia X X C. lacustris Birge X

X X

C. spp. Dana X

X X

X Chydorus spp. Leach X

X X

Daphnia ambigua Scourfield X

X X

X D. calawba Coker X

X X

X D. galeata Sars X

D. laevis Birge X

I IX X

X D. longiremis Sars X

X X

D. lumholzi Sars X

X X

D. mendotae (Sars) Birge X

X X

X D. parvula Fordyce X

X XX X X X X X

X X X X

X X X D. pulex (de Geer)

X X

X D. pulicaria Sars X

D. retrocurva Forbes X

X X

X D. schodleri Sars X

D. spp. Mullen X

X X

X X X X

X X

X X X

X X

X Diaphanosoma brachyurum X

X X

X X 7 D. spp. Fischer X

X X

4-9

Table 4-2. (Continued).

Page 2 of 4 Taxon 87-97 98 99 00 01 02 03 04 05 06 07 09 09 10 11 12 Disparalona acutirostris (Birge)

X Eubosmina spp. (Baird)

X Holopedium amazonicum Stin.

X X

X H. gibberum Zaddach X

X H. spp. Stingelin X

X X

X Ilyocryptus sordidus (Lieven)

X I. spinifer Herrick X

L. spp. Sars X

X X

Latona setifera (O.F. Muller)

X Leptodora kindiii (Focke)

X X

Leydigia acanthoceroides (Fis.)

X L. spp. Freyberg X

X X

x X X

X Moina spp. Baird X

Monospilus dispar Sars X

Oxurella spp. (Sars)

X Pleuroxus hamulatus Birge X

X P. spp. Baird X

Sida crystallina 0. F. Muller X

Simocephalus expinosus (Koch)

X Simocephalus spp. Schodler X

Rotifera Anuraeopsisfissa (Gosse)

X X

A. spp. Lauterborne X

X X

Ascomorpha ecaudis Perty X

A.

spp. Perty X

Asplanchna brightwelli Gosse X

X A. priodonta Gosse X

X X

A. spp. Gosse X

X XX X

X X

Brachionus angularis Gosse X

X B. calvciflomrs Pallas X

B. caudata Bar. & Dad.

X B. bidentata Anderson X

B. havanensis Rousselet X

B. patulus 0. F. Muller X

X X

B. spp. Pallas X

X X

Chromogaster ovalis (Berg.)

X X

X C. spp. Lauterborne X

Collotheca balatonica Hanring X

X X

C. mutabilis (Hudson)

X X

C. spp. Harring X

X X

Colurella spp. Bory de St. Vin.

X Conochiloides dossuarius Hud.

X X

C. spp. Hlava X

X X

X Conochihls unicornis (Rouss.)

X X

C spp. Hlava X

X X

Filinia spp. Bory de St. Vincent X

X X

X Gastropus stylifer lmhof X

X X

G. spp. Imhof X

X X

4-10

Table 4-2. (Continued).

Page 3 of 4 Taxon 87-97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 Hexarthra mira Hudson X

X X

X X H. spp. Schmada X

X X

Kellicottia bostoniensis (Rou.)

X X

K. longispina Kellicott X

X X

X K. spp. Rousselet X

X X

X Keratella americana Carlin x

K. cochlearis Raderorgan X

X X

K. quadrata Mannchen X

X X

K. taurocephala Myers X

X x

X X

X K. spp. Bory de St. Vincent X

X X

Lecane luna 0. F. Muller X

Lecane spp. Nitzsch X

X X

Lophocharis spp. (?) Ehenberg x

Macrochaetus subquadratus P.

X X

M. spp. Perty X

X X

X Monommala spp. Bartsch x

X Monostvla stenroosi (Meiss.)

X M. spp. Ehrenberg X

X X

X x

Notholca spp. Gosse X

X Platyias patulus Harring X

Ploesoma hudsoni Brauer X

X X

X P. truncatum (Levander)

X X

P. spp. Herrick X

X X

X Polyarthra euryptera (Weir.)

X X

X P. major Burckhart X

X X

X P. vulgaris Carlin X

X X

P. spp. Ehrenberg X

X X

X Pompholyx spp. Gosse X

Proales spp. (?) Gosse X

Ptygura libra Meyers X

X X

X P. spp. Ehrenberg X

X X

X Scalpholeberis aurita Fischer IdX Svnchaeta spp. Ehrenberg X

X X

X Trichocerca capucina (Weir.)

X X

X x

T cylindrica (Imhof)

X X

X XX X

X X

X T. longiseta Schrank X

X X

X T. multicrinis (Kellicott)

X X

T. porcellus (Gosse)

X X

X T, pusilla Jennings x

T. similis Lamark X

T. spp. Lamark X

X X

X X X

X X

Trichotria spp. Bory de St. Vin.

X X

X Unidentified Bdelloida X

X X

X Unidentified Monogonata X

Unidentified Philodinidae X

X Unidentified Rotifera X

X X

X Insecta Chaoborus spp. Lichtenstein X

X X

X XX X I X

X X

X 4-11

Table 4-2. (Continued).

Page 4 of 4 Taxon 87-97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 Ostracoda (unidentified)

X X

X 4-12

Table 4-3. Dominant copepod (adults), cladoceran, and rotifer taxa and their percent composition (in parentheses) of the copepod, cladoceran and rotifer densities by location and sample period in Lake Norman in 2012.

Locations Winter Spring Summer Fall Copepoda:

Epilimnion 2.0 Epishura (5.8)

Epishura (2.7)

Tropocyclops (9.4)'

Tropocyclops (5.7)'

5.0 Tropocyclops (2.0)

Tropocyclops (2.4)

Tropocyclops (15.7),

Mesocyclops (1.0) 9.5 Epishura (8.6)

No adults present Tropocyclops (10.0)'

Tropocyclops (16.0) 11.0 Epishura (6.6)

Mesocyclops (2.1)

Tropocyclops (6.1)'

Tropocyclops (10.5) 15.9 Epishura (4.4)

Mesocyclops (5.4)

Tropocyclops (8.5)'

Tropocyclops (9.1)

Copepoda:

Whole-column 2.0 Tropocyclops (12.2)

Tropocyclops (1.5)

Tropocyclops (3.8)

Tropocyclops (2.3) 5.0 Epishura (7.0)

Cyclops (2.0)'

Tropocyclops (3.4)

Tropocyclops (5.6) 9.5 Epishura (8.5)

Mesocyclops (3.2)'

Tropocyclops(13.2)'

Tropocyclops (24.1) 11.0 Epishura (8.6)

Mesocyclops (1.9)

Tropocyclops (8.8)

Tropocyclops (9.2) 15.9 Epishura (5.8)

Epishura (6.4)

Tropocyclops (4.1)

Tropocyclops (4.5)

Cladocera:

Epilimnion 2.0 Bosmina (100.0)

Bosmina (88.6)

Bosmina (73.2)

Bosmina (83.6) 5.0 Bosmina (98.5)

Bosmina (93.4)

Bosmina (55.8)

Bosmina (89.5) 9.5 Bosmina (74.6)

Bosmina (67.0)

Bosminopsis (66.1)

Bosmina (70.4) 11.0 Bosmina (72.7)

Daphnia (48.7)

Bosminopsis (79.5)

Bosmina (62.2) 15.9 Bosmina (56.6)

Bismina (50.4)

Bosminopsis (99.0)

Bosmina (81.7)

Cladocera:

Whole-column 2.0 Bosmina (93.5)

Bosmina (71.9)

Bosmina (50.6)

Bosmina (69.1) 5.0 Bosmina (95.1)

Bismina (77.5)

Bosmina (55.5)

Bosmina (53.6) 9.5 Bosmina (69.9)

Daphnia (40.8)

Bosminopsis (71.6)

Bosmina (77.4) 11.0 Bosmina (72.0)

Daphnia (45.9)

Bosminopsis (86.7)

Bosmina (65.4) 15.9 Bosmina (45.9)

Bosmina (44.7)

Bosminopsis (91.7)

Bosmina (87.4) 4-13

Table 4-3. (Continued).

Locations Winter Sprin Summer Fall Rotifera:

Epilimnion 2.0 Keratella (51.2)

Conochilus (47.9)

Ptygura (72.1)

Polyarthra (43.7) 5.0 Keratella (75.7)

Conochilus (65.0)

Ptygura (85.0)

Polyarthra (42.3) 9.5 Keratella (42.5)

Kellicotia (42.8)

Ptygura (72.1)

Conochiloides (40.2) 11.0 Conochilus (84.7)

Kellicotia (66.3)

Ptygura (77.0)

Keratella (54.6) 15.9 Conochilus (43.4)

Kel/icotia (62.9)

Conochioides(33.7) Keratella (43.8)

Rotifera:

Whole-column 2.0 Keratella (29.3)

Ke/icotia (42.7)

Ptygura (62.5)

Polyarthra (40.5) 5.0 Polyarthra (49.9)

Conochilus (62.1)

Ptygura (37.5)

Polyarthra (61.3) 9.5 Polyarthra (55.9)

Kellicotia (50.2)

Ptygura (72.0)

Conochilus (45.3) 11.0 Conochilus (82.4)

Kel/icotia (61.1)

Ptygura (75.0)

Keratella (67.2) 15.9 Conochilus (47.2)

Kellicotia (54.3)

Conochilus (45.1)

Keratella (57.0) 4-14

Epilimnetic

-*-Winter Spring --

Summer -

Fall E

0 x

6zZ)

C*

0 300 250 200 150 100 50 0

9 --------

7 ------------------

.7.......

ý-ýý --------------------

'19

^ - --

M T

2.0 5.0 9.5 Location Whole-column 11.0 15.9 I-Winter Spring --,-Summer Fall I 300 E 250 0

0 o 200 6 150 z

100 50 0

1%-------------------------------------------------------------------------------------------------

Ti -----------------------------------------------------------

2.0 5.0 9.5 Location 11.0 15.9 Figure 4-1.

Total zooplankton density by location for samples collected in Lake Norman in 2012.

4-15

300 250 0

80 200 6

150 zZ*" 100~

50 o

50 0

Winter BRofers nCladocerans opepods.

Spring 300

,Rotifers oCladocerans *Copepodsj I

= -

250 '

E 0o 200

-- 6 150 z

100-C:

100...

-J 0

2.0 50 95 110 15.9 Location 20 5.0 9ý5 110 15.9 Location Summer 300 300 3 Routers OCladocerans EVopepods.....

250 250 0

8200...........-------0200 z

z 2I 100 -

100 O

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

50 C

Z 50 50 0

0 20 5.0 9.5 110 15.9 Location Fall eRotifers 0 Cladocerans ECopepods

.I --

U&, :7t"!717 20 50 95 110 159 Location Figure 4-2.

Zooplankton community composition by sample period and location for epilimnetic samples collected in Lake Norman in 2012.

4-16

Winter Mixing Zone Locations 300

--*-20 "--50 1 E

0 0

0 z

C)

C a) 250 200

.1 150 100 50 7'

17 ----------------

0 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 Year Background Locations E

0 0

X 6z 0

300 250 200 150 100 50 0

88 89 90 91 92 93 94 95 96 97 98 9900 01 02 03 04 05 06 07 08 09 10 11 12 Year Figure 4-3.

Total zooplankton densities by location and year for epilinmetic samples collected in Lake Norman in the winter periods of 1988 - 2012 (clear data points represent long-term maxima).

4-17

Spring Mixing Zone Locations 00 0

6 z

Ca))

600 500 400 300 200 100 0

88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 Year Background Locations 0

0 0

06 z

Ca) 600 500 400 300 200 100

.~.......................................................................................

-0 1. a 0

88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 Year Figure 4-4.

Total zooplankton densities by location and year for epilimnetic samples collected in Lake Norman in the spring periods of 1988 - 2012 (clear data points represent long-term maxima).

4-18

300 E 250 0

o 200 X

6 150 z

.1 100 o

50 0

Summer Mixing Zone Locations I--

2.0 --m-5.0 I I

I I

,I I

1 1

I I..

1 I

I I,,

,.I......

I I..

87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 Year Background Locations 300 E 250 000 200 o 150 z

100 o

50 n

"-'r ---------------------------

"=;;

1 -

95 -'-w11. -15.91

-I--

--A A---

87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 Year Figure 4-5.

Total zooplankton densities by location and year for epilimnetic samples collected in Lake Norman in the summer periods of 1987 - 2012 (clear data points represent long-term maxima).

4-19

Fall Mixing Zone Locations E

0 6z a) 0 300 250 200 150 100 50 1 -- 2,0 5.0 A A L w,--a 0

87 88 89 90 91 92 93 94 95 96 97 98 990001020304050607080910 11 12 Year Background Locations 500 9.5 110 -*-159 E

0 C

0 400 300 200 100 0

87 88 89 90 91 92 93 94 95 96 97 98 990001020304050607080910 11 12 Year Total zooplankton densities by location and year for epilimnetic samples collected in Lake Norman in the fall periods of 1987 - 2012 (clear data points represent seasonal maxima).

Figure 4-6.

4-20

Mixing Zone. Epilimnion U Rotifers 01 Cladocerans 0 Copepods 100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0%

TT 11 U 88899091929394959697989900010203040506070809101112 Mixing Zoneý Whole-column 100%

90%

80%

70%

60%

50%

40%

300`

20%

10%

0%

IIIilHHlhll ii IlHllihHHHl 88899091929394959697989900010203040506070809101112 Years Figure 4-7.

Annual percent composition of major zooplankton taxonomic groups from mixing zone locations (Locations 2.0 and 5.0 combined) during 1988 - 2012 (Note: does not include Location 5.0 in the fall of 2002 or winter samples from 2005).

4-21

Background. Epilimnion 100% L 90%0 80%

70%0 60%

50%

40%

30%

20%

10%

0%0 E Rotifers 01 Cladocerans MCopepods IIII~iIIilllIJI

-1lI---

tH

=jI:Iu:Inummmuuuuunm*

I..

-F I A-- I F-r I~ I I- -I 1--i FA I-A ý- A ý- 4 f-A t-41-4 1 A f-+9-44-44-4 1 A P-4 88899091929394959697989900010203040506070809101112 Background Whole-column 100%0/

90%

80%

70%

60%

50%

40%

30%

20%

10%

0%

III l liii iIt --

t iI m

n.

.a 6iýz"

-_ ;_- ZZ =

=

88899091929394959697989900010203040506070809101112 Years Figure 4-8.

Annual percent composition of major zooplankton taxonomic groups from background locations (Locations 9.5, 11.0, and 15.9 combined) during 1988 -

2012 (Note: does not include winter samples from 2005).

4-22

1 20 4

--Mixing Zone

-u--Background Locations E~

80 0

X t

0+4~+44

+4 -

444

+tI44 4

+-4--+--4-4 f$+

4 +-4 4-+

44 z

Z.

20 0

c L

.EL

..L c~

L c EL..

.c E..

E.

c E.

EL

.ri

...cEL

..I L

E.

.EL

..EL

.d

-=4 A

1996 I

M' 1999 2,,

2

0° I20 2D-3 2.(4 Z5° a.16 2X7' 20: 16 ZOL9 2 1l 2011 220;2 Seasons and Years Figure 4-9.

Copepod densities during each season of each year among epilimnetic samples collected in Lake Norman from 1994 2012 (mixing zone =mean of Locations 2.0 and 5.0; background =mean of Locations 9.5, 11.0, and 15.9).

60 T.

lw = :

MixingZone

-&-BackgroundLocations i

i 5 0.-.-.-.-.--- :-:-:---:-

T -T --------

T 40 i I i

" 0

.,-¢ -- ' -i - - ' -.- L $ - -:

i : : i ::i i

I I it it it i

i i I

i I :

..l

. I...............

~

40

"-÷----4 i 1 - '--i-"--' ---;--- 4--÷----÷-4-=--4----4...........

4

-i;-- ----

,- ---:---*---',--.4---;--,-4---4 4---..--........;---*-*-,-

0 30 1

1-"..1-.4-"-4 I

'II I

I I

T1 ij I

6 C 20,,

it ii!

iit

! i i ii:

I t :,

i:it ~

=

0 - - -r

-+--

.L..

-J..

L I.

')

1 E

E 2

E E

E E I

, 1a oa I, Al I 11 I*

i 1r 1ut iti I I,, II Io-96 1 9I-1 199-2 2V51 2DI2 2Y43 II 4

2.06 2,c6 2YO 2,06 2'.09 2 I Il 2 0; 1I 21 12 Seasons and Years Figure 4-10. Cladoceran densities during each season of each year among epilimnetic samples collected in Lake Norman from 1990 -

2012 (mixing zone = mean of Locations 2.0 and 5.0; background = mean of Locations 9.5, 11.0, and 15.9).

60

-3,

- -r-Ii' 5 0 HI 111,?

0 Seasons and Years Figure 4-11.

Rotifer densities during each season of each year among epilimnetic samples collected in Lake Norman from 1994 -

2012 (mixing zone =mean of Locations 2.0 and 5.0; background =mean of Locations 9.5, 11.0, and 15.9).

t'J t-Jb

CHAPTER 5 FISHERIES INTRODUCTION In accordance with the Lake Norman Maintenance Monitoring Program for the McGuire Nuclear Station (MNS) NPDES permit, and associated requirements from the North Carolina Wildlife Resources Commission (NCWRC), Duke Energy personnel monitored specific fish population parameters in Lake Norman during 2012. The components of this program were:

1. spring electrofishing survey of littoral fish populations with emphasis on age, growth, size distribution, and condition of black bass (spotted bass Microplerus punctulatus and largemouth bass M salmoides);

2. summer striped bass Morone saxatilis mortality surveys;

3. winter striped bass gill net survey with emphasis on age, growth, and condition; and

4. fall hydroacoustic and purse seine surveys of pelagic forage fish abundance and species composition.

METHODS AND MATERIALS Spring Electrofishing Survey An electrofishing survey was conducted in Lake Norman in March at three areas (Figure 5-1): near Marshall Steam Station (MSS, Zone 4), a reference (REF, Zone 3) area located between MNS and MSS, and near MNS (Zone 1).

Ten 300-m shoreline transects were electrofished in each area and were identical to historical locations sampled since Duke Energy began standardized spring electrofishing surveys of multiple reservoirs in 1993.

Transects within each area included habitats representative of those found in Lake Norman.

Shallow flats where the boat could not access within 3 to 4 m of the shoreline were excluded.

All sampling was conducted during daylight, when water temperatures were expected to be between 15 and 20 'C.

Surface water temperature (°C) was measured with a calibrated thermistor at each location. Stunned fish were collected by two netters and identified to 5-1

species. Fish were enumerated and weighed in aggregate by taxon, except for black bass, where total length (TL, mm) and weight (g) were obtained for each individual collected.

Catch per unit effort (CPUE, number of individuals/3,000 m and kg/3,000 m) and the number of species were calculated for each sampling area. Sagittal otoliths were removed from all largemouth bass ? 150 mm and a subsample of spotted bass (4 from each 25-mm TL size class 150-350 mm per area and all > 350 mm) and sectioned for age determination (Devries and Frie 1996). Black bass < 150 mm were assumed to be age 1 because young-of-year bass are not historically collected during spring surveys. Condition (Wr) based on relative weight was calculated for spotted bass and largemouth bass >_ 150 mm long, using the formula Wr =

(W/W,) x 100, where W = weight of the individual fish (g) and W, = length-specific mean weight (g) for a fish as predicted by a weight-length equation for each species (Anderson and Neumann 1996). Growth rates were compared between species and among areas.

Summer Striped Bass Mortality Surveys Mortality surveys were conducted at least weekly during July and August to specifically search for dead or dying striped bass in Zones I to 4. All observed dead and dying striped bass were collected and a subsample of individual TLs was measured prior to disposal.

Striped Bass Netting Survey Striped bass were collected in early December for age, growth, and condition determinations.

Fish were collected from local anglers and in monofilament gill nets. The nets measured 76.2 m long x 6.1 m deep and contained two 38.1-in panels of either 38-and 51-mm square mesh or 63-and 76-mm square mesh. Nets were set overnight in areas where striped bass were previously located.

Individual TL and weight were obtained and sagittal otoliths removed and sectioned for age determination (Devries and Frie 1996). Growth and condition (Wr) were determined as described previously for black bass.

Additionally, all catfish collected were identified, measured, and enumerated by species.

Fall Hydroacoustics and Purse Seine Surveys Abundance and distribution of pelagic forage fish in Lake Norman were determined using mobile hydroacoustic (Brandt 1996) and purse seine (Hayes et al. 1996) techniques. The 5-2

lake was divided into six zones (Figure 5-1) due to its large size and spatial heterogeneity. A mobile hydroacoustic survey of the lake was conducted in September with multiplexing, side-and down-looking transducers to detect surface-oriented fish and deeper fish (from 2.0 m depth to the bottom), respectively.

Annual purse seine samples were also collected in September from the epilimnion of downlake (Zone 1), midlake (Zone 2), and uplake (Zone 5) areas of Lake Norman. The purse seine measured 122.0 x 9.1 m, with a mesh size of 4.8 mm. A subsample of forage fish collected from each area was used to estimate taxa composition and size distribution.

RESULTS AND DISCUSSION Spring Electrofishing Survey Spring 2012 electrofishing resulted in the collection of 6,658 individuals (15 species and two centrarchid hybrid complexes; Table 5-1) weighing approximately 226.3 kg at average water temperatures of 20.8 'C (MSS), 19.6 'C (REF), and 20.0 'C (MNS).

Bluegill Lepomis macrochirus dominated samples numerically while spotted bass dominated samples gravimetrically. The survey consisted of 2,919 individuals (14 species and two centrarchid hybrid complexes) in the MSS area, 1,978 fish (14 species and two centrarchid hybrid complexes) in the REF area, and 1,761 individuals (15 species and two hybrid centrarchid complexes) in the MNS area.

There is no apparent temporal trend in the number of individuals collected within or among areas since 1993 (Figure 5-2a).

Total biomass of fish during 2012 was approximately105.3 kg in the MSS area (uplake), 59.3 kg in the REF area (midlake), and 61.7 kg in the MNS area (downlake), different from the spatial trend of previous years (Figure 5-2b) with the lowest total biomass from the MNS area. Typically, spring electrofishing data showed a trend of increasing fish biomass with increased distance uplake. Similar spatial heterogeneity was noted by Siler et al. (1986) whose authors reported that fish biomass was higher uplake than downlake due to higher levels of nutrients and resulting higher productivity uplake versus downlake. The spatial heterogeneity is further evident by higher concentrations of chlorophyll a, greater phytoplankton standing crops, and elevated epilimnetic zooplankton densities in uplake compared to downlake regions of Lake Norman (see Chapters 3 and 4). There is no apparent temporal trend in the biomass of fish collected within each area since 1993.

5-3

Spotted bass, thought to have originated from angler introductions, were first collected in Lake Norman in the MNS area during a 2000 fish health assessment survey. The number of individuals and biomass of spotted bass collected have increased since 2001 (Figure 5-3a and b). Spotted bass were most abundant in the MSS area in 2012, although a temporal trend is not evident among areas. Spotted bass biomass was highest in the MSS area, similar to recent years. Small spotted bass (< 150 mm) dominated the black bass catch in all areas in 2012 (Figures 5-4a and b).

Spotted bass (> 150 mm) mean Wr ranged from 67.0 for fish 200 to 249 mm in the MNS area to 78.0 for fish 300 to 349 mm in the REF area (Figure 5-5a). Overall, spotted bass (> 150 mm) mean Wr values were similar in the MSS (76.1, 0.5 SE) and REF areas (75.6, 0.8 SE) and lowest in the MNS area (71.2, 0.8 SE) which were within the range of observed historical values (70.5 to 82.3) (Duke Power 2004a, 2005, unpublished data; Duke Energy 2006, 2007, 2008, 2009, 2010, 2011, 2012).

The number of individuals and biomass of largemouth bass collected from all areas in 2012 marked historical lows continuing a downward temporal trend (Figure 5-6a and b). As in most years, the number of individuals and biomass of largemouth bass were highest in the MSS area in 2012. Typically, the number of individuals and biomass were intermediate in the REF area and lowest in the MNS area following a longitudinal gradient reported from similar reservoirs in Georgia (Maceina and Bayne 2001) and Kentucky (Buynak et al. 1989).

However, the low number of largemouth bass collected from Lake Norman in 2012 and recent years diminishes the significance of this comparison.

Largemouth bass (> 150 mm) were distributed across all size classes only from the MSS area (Figure 5-4b) with most size classes represented by four or fewer individuals. The mean Wr ranged from 78.4 for two fish > 450 mm collected in the MSS area to 91.3 for a single fish 350 - 399 mm collected in the REF area (Figure 5-5b). The low number of largemouth bass collected diminishes the significance of these comparisons. Overall, largemouth bass (> 150 mm) mean Wr values were not significantly different in the REF (86.5, 4.8 SE), MNS (83.9, 1.3 SE), and MSS areas (82.7, 1.2 SE). Mean Wr values were within the range of observed historical values (76.0 to 89.9; Duke Power 2004a, 2005, unpublished data; Duke Energy 2006, 2007, 2008, 2009, 2010, 2011, 2012).

5-4

Largemouth bass numbers in 2012 were inadequate for growth rate comparisons with spotted bass or with previous years of largemouth bass data (Table 5-2). Spotted bass growth for all areas was fastest through Age 3 and slowed with increasing age as in previous years.

Largemouth bass population parameters from surveyed areas have declined sharply in recent years likely due to congeneric competition from the introduced spotted bass (Sammons and Bettoli 1999; Long and Fisher 2000; Pope et al. 2005). However, other introduced species (eg., alewife Alosa pseudoharengus and white perch Morone americana) may have contributed to these declines (Kohler and Ney 1980; Madenjian et al. 2000).

Summer Striped Bass Mortality Surveys A total of 835 dead striped bass were collected during July and August 2012 surveys (Figure 5-7). Thirty of the fish were collected from the MNS intake and not attributed to a specific date. This total represents an increase over 2011 (395), but is much lower than the largest recorded die-off of this Lake Norman sport fish species in 2010 (6,981). Since the survey began in 1983, summer mortalities in excess of 50 striped bass also occurred in 1983 (163),

2004 (2,609), and 2009 (362).

Dead striped bass TL in 2012 varied (465-690 mm) with a subsample (n = 98) mean of 582 mm. Most mortalities were collected from Zone 1 (Figure 5-1) as fish trapped below the anoxic metalimnion were prone to hypolimnetic dissolved oxygen concentrations (DO) below 2.0 mg/L during the natural summer stratification of lower Lake Norman (NCDENR 2012; also see Chapter 2 including Figure 2-11). Although some mortalities were likely incidental (i.e., hooking-related mortalities associated with the capture of meta-and hypolimnetic striped bass from cooler depths and release in warm epilimnetic waters), this number was indeterminate. Death of Lake Norman striped bass at approximately 2.0 mg/L further supports the lethal DO component of the striped bass habitat "squeeze" model (Coutant 1985) as measured hypolimnetic temperatures were non-stressful (< 20 0C).

Continuous water quality monitoring in Lake Norman throughout the year and a rigorous schedule during summer since 1983 have shown that preferred striped bass habitat has remained fairly constant and within a range of historical bounds (see Chapter 2). While similar DO regimes have been observed since 1983, their potential detrimental impact on striped bass survival appears to be linked to the colonization of Lake Norman by alewife.

Adult alewife, first detected in Lake Norman in 1999 (Duke Power 2000), seek cool water in summer and are a significant nutritive improvement over the typically smaller, threadfin shad 5-5

Dorosoma petenense which prefer warm water and dominate the forage community (Table 5-4; Brandt et al. 1980). The presence of large adult alewives in cool hypolimnetic waters during summer attracts striped bass, which may get trapped as the habitat "squeeze" progresses. As recent research by Thompson (2006) has implicated a forage fish component to the stressful habitat "squeeze" period, the presence of striped bass in the hypolimnion during warm summer months appears to be a logical and recent occurrence. Slight nuances in the progression and severity of the metalimnetic oxygen minima from year to year may mean the difference between the deaths of large numbers of striped bass or few to none (Dr.

James Rice, NC State University, personal communication). A thick and anoxic metalimnion may trap and kill striped bass while a thin or hypoxic metalimnion may allow fish to escape and attempt to survive the summer in warmer epilimnetic waters. Whatever the mechanism, while striped bass deaths can be attributed to this temperature-oxygen "squeeze", their attraction into the hypolimnion is primarily due to the presence of adult alewife stocked by anglers.

A total of 1,204 dead catfish were collected from Zone 1 between July 27 and August 23, with most fish collected after August 13.

A toxicology report from Auburn University concluded that examined specimens were in overall good health and that mortalities were likely due to coinciding anoxic to severely hypoxic conditions (< 0. 35 mg/L). Blue catfish Ictalurus furcatus (n = 926), originally stocked as a sportfish by the NCWRC in 1966, dominated the mortalities although channel catfish 1. punctatus (n = 276) and two flathead catfish Pylodictis olivaris were also collected. Although stomach analyses indicated that catfish also foraged upon alewife in the hypolimnion, it is not known why catfish died in appreciable numbers in 2012 and not prior years.

Winter Striped Bass Netting Survey Striped bass (81 via gill netting, 5 from anglers) collected in December 2012 ranged in TL from 330 to 650 mm and were dominated by age 1 fish (Figure 5-8). Striped bass growth was fastest through age 4 and slowed with increasing age, although the low number of older striped bass collected diminishes the significance of this comparison. Mean Wr was highest for age 1 fish (89.3) and remained between 80.0 and 83.0 for Age 2-6 fish. Mean Wr was 84.4 (0.8 SE) for all striped bass in 2012, within the range of observed historical values (78.5 to 86.1).

Growth in 2012 was also consistent with historical values measured since consistent annual gillnetting began in 2003, given the preponderance of young fish (Duke Power 2004a, 2005; Duke Energy 2006, 2007, 2008, 2009, 2010, 2011, 2012).

5-6

The December striped bass gillnetting also yielded 149 catfish. Blue catfish (183) dominated the catch and ranged in length from 298 to 968 mm. Flathead catfish (37) and channel catfish (10) were less numerous and ranged in length from 332 to 837 mm and 268 to 488 mm, respectively.

Fall Hydroacoustics and Purse Seine Surveys Mean forage fish density estimates in the surveyed zones of Lake Norman ranged from 6,542 (Zone 1) to 11,549 (Zone 4) fish/ha in September 2012 (Figure 5-9). Zone 6 fish densities were indeterminate using hydroacoustics due to the shallow nature of the riverine habitat.

Zones 3 and 4 had the highest forage fish density estimates with most zones having much higher densities than historical values. The annual forage fish population survey of Lake Norman has demonstrated considerable variability within and among zones since 1997.

Threadfin shad dominated the epilimnetic Lake Norman forage fish community purse seine survey in mid-September 2012 (93.6%), similar to surveys since 1993 (Table 5-3). The modal length class of threadfin shad collected in 2012 was 46 to 50 mm indicating most fish to be young-of-the-year (Figure 5-10).

Alewife comprised at most 25.0% (2002) of the pelagic forage fish surveys. The percent composition of alewife has remained relatively low from 2005 to 2012 (range = 1.5 to 6.4%) with a noticeable exception in 2009 (11.6%).

SUMMARY

In accordance with the Lake Norman Maintenance Monitoring Program for the MINS NPDES permit, specific fish monitoring programs continued during 2012.

Spring electrofishing indicated that 14 to 15 species of fish and two hybrid complexes comprised diverse, littoral fish populations in the three survey areas. The number of individuals and biomass of fish in 2012 were generally similar to those noted annually since 1993.

Collections were numerically and gravimetrically dominated by centrarchids.

Largemouth bass number of individuals and biomass were the lowest recorded since surveys began in 1993. Spotted bass number of individuals and biomass decreased from 2011 levels, but remain high, likely displacing largemouth bass. Introductions of other non-native species (e.g., alewife, flathead catfish, and white perch) likely contributed to changes in the composition and distribution of indigenous and stocked sportfish in Lake Norman.

5-7

In 2012, striped bass mortalities (805) during summer stratification were the third highest number ever collected, ranging in TL from 465 to 690 mm. Striped bass populations through 2003 existed through most summer periods by residing in warm epilimnetic waters near their physiological tolerance limits.

The introduction of alewife by anglers provided an alternative, and larger, prey item resulting in a significant redistribution of striped bass.

During natural summer stratification, striped bass began following alewife into the hypolimnion after 2003. In some years (2004, 2009 - 2012), striped bass became trapped by the temperature-oxygen "squeeze", and died. Alewife further impaired the marginal striped bass habitat of Lake Norman into one that periodically causes the deaths of large numbers of this stocked sport fish species.

A total of 1,204 dead catfish were collected from Zone 1 between July 27 and August 23, with most fish collected after August 13. Mortalities were likely due to coinciding anoxic to severely hypoxic conditions (< 0.4 mg/L), although it is not known why catfish died in appreciable numbers in 2012 and not prior years.

Winter mean Wr (84.4) of striped bass was similar to historical values although dominated by age 1 and 2 fish. The hydroacoustic survey of the Lake Norman forage fish population in 2012 further demonstrated the considerable variability within and among zones evident since 1997. Alewife percent composition in fall purse seine surveys was 6.4% and modal threadfin shad TL class was 46 to 50 mm. Temporal fluctuations in clupeid densities contribute to the variable nature of forage fish populations.

The present study adds another year of comparable data to past studies indicating that the Lake Norman fish community is composed mostly of indigenous species expected from a reservoir located in the NC piedmont. Some indigenous species (e.g., largemouth bass and yellow perch) exhibit reduced CPUE compared to historical surveys as a result of competition and predation by invasive species introduced by anglers (e.g., alewife, spotted bass and white perch). Other non-indigenous species (e.g., blue catfish and striped bass) were stocked by NCWRC to improve sportfish opportunities. Regardless of the introductory source, and based on the diversity and numbers of individuals in the littoral fish community during spring and the regular availability of forage fish to limnetic predators, it is concluded that the operation of MNS has not impaired the Lake Norman fish community.

5-8

Table 5-1. Number of individuals (No.) and biomass (Kg) of fish collected from electrofishing ten 300-m transects each, at three areas (MSS, REF, MNS) in Lake Norman, spring 2012.

MVSS RW MNS Total Scientific nane Conmsn narme N.

Kg Nb.

Kg No.

Kg Clupeidae Dorosoma cepedianum Gizzard shad 6

3.01 2

1.21 13 7.57 21 11.78 Cyprinidae Cyprinella chloristia Greenfin shiner 3

0.01 3

0.01 2

0.00 8

0.02 Cyprinella nivea Whitefin shiner 1

0.01 1

0.00 1

0.00 3

0.02 Cyprinus carpio Conmon carp 5

18.75 1

4.44 1

3.38 7

26.57 Catostomidae Carpiodes cyprinus Quillback 1

0.98 I

0.98 Ictaluridae Ictalurus punctatus Channel catfish 3

1.25 4

1.87 1

0.04 8

3.16 Pylodictis oIivaris Flathead catfish 3

1.07 4

0.59 6

7.07 13 8.73 Centrarchldae Lepomnis auritus Redbreast sunfish 130 3.00 404 6.42 342 5.22 876 14.64 Lepornis cyanellus Green sunfish 187 2.99 340 4.36 47 0.61 574 7.96 Lepomis gulosus Warnouth 11 0.07 8

0.08 18 0.14 37 0.29 Lepomis hybrid Hybrid sunfish 51 2.17 64 1.61 51 1.25 166 5.03 Lepornis macrochirus Bluegill 2,284 19.92 1,040 11.52 1,167 10.42 4,491 41.86 Lepomnis microlophus Redear sunfish 39 4.21 19 3.37 12 0.98 70 8.55 MicrOpterus punctulatus Spotted bass 159 32.06 85 22.69 92 19.20 336 73.95 Micropterus salmoides Largermouth bass 32 15.12 2

0.98 5

3.44 39 19.54 Micropterus hybrid Hybrid black bass 1

0.39 1

0.84 2

1.22 Pomoxis nigromaculatus Black crappie 4

1.30 1

0.18 1

0.54 6

2.02 Total 2,919 105.31 1.978 59.33 1,761 61.66 6,658 226.31 Total no. species 14 14 15 Mean water tern perature (C) 20.8 19.6 20.0 Table 5-2.

Mean TL (mm) at age (years) for spotted bass and largemouth bass collected from electrofishing ten 300-m transects each, at three areas (MSS, REF, MNS) in Lake Norman, spring 2012.

Age (years)

Taxa Area 1

2 3

4 5

6 7

8 9

10 Spotted MSS 177 253 330 367 409 407 bass REF 159 262 331 382 391 423 MNS 203 279 346 369 426 492 Mean TL (mm) 179 265 336 373 408 415 492 Largemouth MSS 186 287 319 351 429 447 420 439 bass REF 337 510 MNS 379 Mean TL (mm) 186 312 319 365 429 447 510 420 439 5-9

Table 5-3. Number of individuals (No.), percent composition of forage fish, and threadfin shad modal TL class collected from purse seine surveys in Lake Norman during late summer/early fall, 1993 - 2012.

Species composition Threadfin shad modal Year No.

Threadfin shad Gizzard shad Alewife TL class (mm) 1993 13,063 100.00%

31-35 1994 1,619 99.94%

0.06%

36-40 1995 4,389 99.95%

0.05%

31-35 1996 4,465 100.00%

41-45 1997 6,711 99.99%

0.01%

41-45 1998 5,723 99.95%

0.05%

41-45 1999 5,404 99.26%

0.26%

0.48%

36-40 2000 4,265 87.40%

0.22%

12.37%

51-55 2001 9,652 76.47%

0.01%

23.52%

56-60 2002 10,134 74.96%

25.04%

41-45 2003 33,660 82.59%

0.14%

17.27%

46-50 2004 21,158 86.55%

0.24%

13.20%

51-55 2005 23,147 98.10%

1.90%

36-45 2006 14,823 94.87%

5.13%

41-45 2007 27,169 98.34%

1.66%

41-45 2008 47,586 95.58%

4.42%

41-45 2009 16,380 88.40%

11.60%

46-50 2010 15,860 95.38%

0.36%

4.26%

41-45 2011 24,837 98.32%

0.15%

1.52%

41-45 2012 23,719 93.60%

6.40%

46-50 5-10

Zone 6

i*¸ IV 0

Purse seine locations Electrofishing transects

-k

-~

'I' Zone 5 A

3~3~

~

\\- A>

~3\\

Mrs*;aIl Steam Station

'/-

6*

0, 0

0' 0

0 Zone 4 Zone 3 Zone 2 N

00.51 2

3

-Miles 0

1 2

4 Kilometers Figure 5-1.

Sampling locations Norman.

Zone1 Cowans Fortd Dam*

1 LJ>

McGuire Nuclear Station and zones associated with fishery assessments in Lake 5-11

5,000 4,500 4,000 3,500 E

oo 3,000 -

2,500 0

2,000 LL 1,500 1,000 500 0

MSS REF MNS a

I I

C')

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(D rI-0 0

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Year Figure 5-2. Total number of individuals (a) and biomass (b) of fish collected from electrofishing ten 300-m transects each, at three areas (MSS, REF, MNS) in Lake Norman, spring 1993 - 1997 and 1999-2012.

5-12

300 T MSS REF 250 t MNS CU 0) 0)

UI) 200 4-150 +

a 100 +

50-0 I

I I

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Year 70.

M SS REF MNS b

60 +

Eý 50.

0 0

0 40 m 30

. 20 U)

1-

+I 4-10 0

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Year Figure 5-3.

Total number of individuals (a) and biomass (b) of spotted bass collected from electrofishing ten 300-m transects each, at three areas (MSS, REF, MNS) in Lake Norman, spring 2001 - 2012.

5-13

60 T SIMSS 1 REF a

50 0 MNS 30 20 o

40 30

.0 o

20

<150 150-199 200-249 250-299 300-349 350-399 400-449

Ž450 TL class (mm) 8 IMSS b

7 DREF o' MNS E

6 0

0 5

4 3

0Ea)Lm 2

0

<150 150-199 200-249 250-299 300-349 350-399 400-449

>450 TL class (mm)

Figure 5-4.

Size distributions of spotted bass (a) and largemouth bass (b) collected from electrofishing ten 300-m transects each, at three areas (MSS, REF, MNS) in Lake Norman, spring 2012.

5-14

0 EMSS a

85 +

[]REF 0 MNS E

(n 80 +

75 +

70 t 65 -I-150-199 60 4-200-249 250-299 300-349 350-399 400-449

?450 TL class (mm) b E

-C 0E 2'

100 95 90 85 80 75 70 65 60 150-199 200-249 250-299 300-349 350-399 400-449

>450 TL class (mm)

Figure 5-5.

Condition (Wr) for spotted bass (a) and largemouth bass (b) collected from electrofishing ten 300-m transects each, at three areas (MSS, REF, MNS) in Lake Norman, spring 2012.

5-15

300

....... MSS a

REF E 250 MNS o

150 0E() 100 50 Ce)

'T t)

C*

N-

0) 0 N"

V) t U')

CD C-O

0) 0

-V

0)

)

0 0

M0 0

0 0

0

~-

3 0-(N (N

(

(C)

C (N

O 0

N 0

(

C N

(N Year 70

....... MSS 60 REF b

-M

MNi, 0

50

40.

50 S

N 4 0 "Y_--

N\\

30 Ea) 2' 20%

10 Mv

) OW N-0M 0

M I) 0 )

P N 0 0 C

0) 0 M

0)

0) 0 0

0 0

0 Year Figure 5-6.

Number of individuals (a) and biomass (b) of largemouth bass collected from electrofishing ten 300-m transects each, at three areas (MSS, REF, MNS) in Lake Norman, spring 1993 - 1997 and 1999 - 2012.

5-16

0 E

0.

1,000

2004(n =2,588) *2009(n = 362) 12010(n = 6,981) 02011 (n = 395) 02012(n = 805) 900 800 700 600 500 400..

0 0-------

IJ

,WII W,.

Date

e 5-7. Number of striped bass mortalities by date in summer 2004, 2009 - 2012.

Figur 700 650 600 EE

.-J 550 C

500 450 400 100 95 90 85 80 75 70 65 60 CD W

1 2

3 4

5 6

7 Age (years)

Figure 5-8.

Mean TL and condition (Wr) by age of striped bass collected in Lake Norman, winter 2012. Numbers of fish by age are inside bars.

5-17 I

25,000 T Zone 1

-A-Zone 3 x Zone 5

-Zone 2

eZone 4 20,000 6 15,000

-o 10,000 (n

a) 0 LL 5,000 0

I.

I I

I i -

C O

0 C

CN M~

-t LO W~

r-M M

0CO M,

0)

M~0 0

0 0D 0D 0D 0D 0

0 C

CD M

oD o0 0

0 0

0 0S o0 N

04 -

cj cC" YJ 04r N

('

(N Cq C

CN Year Figure 5-9.

Zonal density estimates of pelagic forage fish in Lake Norman, late summer/early fall 1997 - 2012.

5-18

300

Threadf in shad 0 Alewif e 250 200 0C-150 0) 0L. 100 50 0

f A

TL class (mm)

Figure 5-10.

Number of individuals and size distribution of threadfin shad and alewife collected from purse seine surveys in Lake Norman, September 2012.

5-19

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19 th Edition. APHA. Washington, DC.

Analytical Software. 2008, Statistix 9. Analytical Software. Tallahassee, FL.

Anderson, RA and RM Neumann. 1996. Length, weight, and associated structural indices.

Pages 447-482 in BR Murphy and DW Willis, editors.

Fisheries techniques.

American Fisheries Society. Bethesda, MD.

Brandt, SB. 1996. Acoustic assessment of fish abundance and distribution. Pages 385-432 in BR Murphy and DW Willis, editors. Fisheries techniques. American Fisheries Society. Bethesda, MD.

Brandt, SB, JJ Magnuson, and LB Crowder. 1980. Thermal habitat partitioning by fishes in Lake Michigan. Canadian Journal of Fisheries and Aquatic Sciences. 37:1557-1564.

Buynak, GL, LE Komman, A Surmont, and B Mitchell. 1989. Longitudinal differences in electrofishing catch rates and angler catches of black bass in Cave Run Lake, Kentucky. North American Journal of Fisheries Management. 9:226-230.

Cole, TM and HH Hannan.

1985. Dissolved oxygen dynamics. in Reservoir limnology:

ecological perspectives. KW Thornton, BL Kimmel and FE Payne, editors. John Wiley & Sons, Inc. New York, NY.

Coutant, CC.

1985.

Striped bass, temperature, and dissolved oxygen: A speculative hypothesis for environmental risk. Transactions of the American Fisheries Society.

114:31-61.

Devries, DR and RV Frie. 1996. Determination of age and growth. Pages 483-512 in BR Murphy and DW Willis, editors. Fisheries techniques. American Fisheries Society.

Bethesda, MD.

Duke Energy. 2006. Lake Norman maintenance monitoring program: 2005 summary. Duke Energy Corporation, Charlotte, NC.

Duke Energy. 2007. Lake Norman maintenance monitoring program: 2006 summary. Duke Energy Corporation, Charlotte, NC.

Duke Energy. 2008. Lake Norman maintenance monitoring program: 2007 summary. Duke Energy Corporation, Charlotte, NC.

Duke Energy. 2009. Lake Norman maintenance monitoring program: 2008 summary. Duke Energy Corporation, Charlotte, NC.

L-1

Duke Energy. 2010. Lake Norman maintenance monitoring program: 2009 summary. Duke Energy Corporation, Charlotte, NC.

Duke Energy. 2011. Lake Norman maintenance monitoring program: 2010 summary. Duke Energy Corporation, Charlotte, NC.

Duke Energy. 2012. Lake Norman maintenance monitoring program: 2011 summary. Duke Energy Corporation, Charlotte, NC.

Duke Power. 1997. Lake Norman maintenance monitoring program: 1996 summary. Duke Energy Corporation. Charlotte, NC.

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MNS-14-018, Lake Norman Maintenance Monitoring Program: 2012 Summary

Contents

Text

SUMMARY

SUMMARY

SUMMARY

SUMMARY

SUMMARY

References:

2.0 LOCATION

Background

Background

1.0 LOCATION

Background

Background

Background

Background

SUMMARY

SUMMARY

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SUMMARY

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MNS-14-018, Lake Norman Maintenance Monitoring Program: 2012 Summary

Text

SUMMARY

SUMMARY

SUMMARY

SUMMARY

SUMMARY

References:

2.0 LOCATION

Background

Background

1.0 LOCATION

Background

Background

Background

Background

SUMMARY

SUMMARY

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=

SUMMARY

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