HomeMy WebLinkAboutNC0004987_Assessment of Balanced & Indigenous Populations_Lake Norman near Marshall Steam Station 2014_20141015 ASSESSMENT OF BALANCED AND INDIGENOUS POPULATIONS
IN LAKE NORMAN NEAR MARSHALL STEAM STATION
NPDES Permit No. NC0004987
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
October 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 Monitoring
field staff in carrying out a complex, multiple-discipline sampling effort that provides the
underpinning of this report. Glenn Long, David Horne, and Courtney Flowe contributed to
water quality sample collections. Mark Auten, Kim Baker, Bob Doby, and David Coughlan
contributed to fisheries collections and sample processing. James Hall, Aileen Lockhart,
Shannon McCorkle, and Jan Williams contributed in macroinvertebrate sampling, sorting and
taxonomic processing.
We would also like to thank multiple reviewers including Jason Brown and Tom Thompson.
ii
TABLE OF CONTENTS
EXECUTIVE SUMMARY iv
LIST OF TABLES vi
LIST OF FIGURES vii
CHAPTER 1- INTRODUCTION 1-1
CHAPTER 2- STATION OPERATION 2-1
BACKGROUND INFORMATION 2-1
THERMAL DATA 2-2
CONCLUSIONS 2-3
CHAPTER 3- MACROINVERTEBRATES 3-1
MATERIALS AND METHODS 3-1
RESULTS AND DISCUSSION 3-2
Substrate 3-2
Water Quality 3-2
Taxa 3-2
Density 3-3
Major Taxonomic Groups 3-3
EPT Densities and Taxa Richness 3-5
CONCLUSIONS 3-6
CHAPTER 4- FISH 4-1
MATERIALS AND METHODS 4-1
Spring Electrofishing Surveys 4-1
Summer Electrofishing Surveys 4-1
Fall Hydroacoustic and Purse Seine Surveys 4-2
Balanced and Indigenous Assessment 4-2
RESULTS AND DISCUSSION 4-3
Spring Electrofishing Surveys 4-3
Summer Electrofishing Surveys 4-4
Fall Hydroacoustic and Purse Seine Surveys 4-5
CONCLUSIONS 4-5
LITERATURE CITED L-1
iii
EXECUTIVE SUMMARY
Annual monitoring of physicochemical characteristics and assessments of macroinvertebrate
and fish populations at selected locations in Lake Norman continued through 2013, in
accordance with Duke Energy's agreement with the North Carolina Department of
Environment and Natural Resources. This report presents data collected from 2009 through
2013. Results of data analyses completed since submittal of the previous report in 2008 are
reported and support renewal of the existing permitted thermal limits for Marshall Steam
Station(MSS).
The continuous operation of MSS from 2009 through 2013 was similar to previous years.
Monthly average discharge water temperatures at MSS were in compliance with National
Pollution Discharge Elimination System (NPDES) permitted thermal limits of 93.9 °F (34.4
°C) from July 1 through October 31, and 91.9 °F (33.3 °C) the rest of each year, over this
five-year period.
Sampling of macroinvertebrate communities continued during 2009 — 2013. Water
temperatures and dissolved oxygen levels, measured at each location since 2005, do not
suggest any negative impact to the benthic communities. Macroinvertebrate data exhibit
substantial variability; however, the variability is consistent with that observed for historical
data. Although taxa numbers were somewhat lower during 2009—2013 as compared to 2004
— 2008, macroinvertebrate densities were generally similar between the two study periods.
Current study results indicate that, overall, the macroinvertebrate densities and taxa diversity
observed during 2009 — 2013 at locations uplake, downlake, and in the vicinity of MSS are
indicative of balanced and indigenous macroinvertebrate populations.
A diverse fish community was present in the littoral surveys of Lake Norman near MSS from
2009 to 2013. Spring and summer electrofishing surveys documented 28 and 19 species,
respectively, both numerically dominated by centrarchids, especially bluegill. Pollution-
tolerant species comprised less of the spring MSS fish population relative to the reference
area, and comprised only 16.6% of individuals collected during summer surveys. The
assorted fish species typically found in Lake Norman near MSS encompass multiple trophic
guilds (i.e., insectivores, omnivores, and piscivores) supporting a balanced fish community.
Non-indigenous species such as spotted bass and green sunfish are abundant near MSS, but
are also prevalent throughout Lake Norman.
iv
Annual hydroacoustic estimates from fall 2009 to 2013 showed the regular availability of
pelagic forage fish near MSS. Fall purse seine surveys indicate that threadfin shad continue
to dominate the Lake Norman forage fish community with a consistent alewife composition
of approximately 5% after 2004. Based on the catch per unit effort of littoral fish during
spring, total length distributions of resident important species during summer, and the regular
availability of forage fish, it is concluded that the thermal discharge of MSS has not impaired
the Lake Norman fish community.
Comparison of MSS operation and environmental monitoring data indicate that balanced and
indigenous populations of macroinvertebrates and fish continue to exist in Lake Norman in
the vicinity of MSS. This supports a conclusion that the present thermal limits should be
maintained when the MSS NPDES permit is renewed.
v
LIST OF TABLES
Table Title Page
1-1 Description of Lake Norman sampling locations in the vicinity of the MSS,
Catawba County,NC. 1-2
2-1 Marshall Steam Station CCW flow rate for each unit for 1, 2, and 3-pump
operation 2-4
3-1 General descriptions of the substrate found at Locations A,B,F, and E in the
vicinity of MSS during July of 2009—2013. Substrates are listed in order of the
most prevalent type first. Organic matter(om)is typically composed of small
sticks, leaf and/or grass fragments, etc 3-8
3-2 Dissolved oxygen and temperature measured near the sediments at the time of
macroinvertebrate collection from locations A, B, F, and E from July 2009—
2013 3-8
3-3 Macroinvertebrate taxa and densities (No./m2) from each Lake Norman sampling
location during summer sampling in 2009. 3-9
3-4 Macroinvertebrate taxa and densities(No./m2)at each Lake Norman sampling
location during summer sampling in 2010 3-11
3-5 Macroinvertebrate taxa and densities(No./m2)at each Lake Norman sampling
location during summer sampling in 2011. 3-13
3-6 Macroinvertebrate taxa and densities (No./m2) at each Lake Norman sampling
location in during summer sampling in 2012 3-15
3-7 Macroinvertebrate taxa and densities (No./m2) at each sampling location in Lake
Norman during summer sampling in 2013 3-17
4-1 Total number of individuals,percent composition, and total number of species in
spring electrofishing surveys from two areas(MSS and REF)in Lake Norman,
1993 — 1997 and 1999, 2000—2003, 2004—2008, and 2009—2013. 4-6
4-2 Total number of individuals,percent composition, and total number of species in
summer electrofishing surveys from three areas near MSS (above,in the vicinity
of, and below the discharge canal)in Lake Norman, 1991 — 1993, 1994— 1999,
2000—2003, 2004—2008, and 2009—2013. 4-7
4-3 Pelagic forage fish species composition from purse seine surveys in Lake
Norman, 1993 —2013 4-8
vi
LIST OF FIGURES
Figure Title Page
1-1 Sampling locations on Lake Norman. Duke Energy historical sampling location
numbers are listed in parentheses 1-3
2-1 The monthly average water temperature of the condenser cooling water
discharged from MSS from January 1,2009 through December 31, 2013 2-5
3-1 Total number of taxa collected annually from Lake Norman in the vicinity of
MSS from 2009 to 2013 3-19
3-2 Densities (No./m2)of macroinvertebrates collected annually from Lake Norman
in the vicinity of MSS from 2009 to 2013. 3-19
3-3 Densities(No./m2)of Oligochaeta collected annually from Lake Norman in the
vicinity of MSS from 2009 to 2013. 3-20
3-4 Densities(No./m2)of Chironomidae collected annually from Lake Norman in
the vicinity of MSS from 2009 to 2013. 3-20
3-5 Density(No./m2)of Oligochaeta, Diptera, and Corbicula collected annually from
Location F (mid-lake near MSS) from 2000—2008 3-21
3-6 Densities (No./m2)of Corbicula collected annually from Lake Norman in the
vicinity of MSS from 2009 to 2013. 3-21
3-7 Densities(No./m2) of Ephemeroptera collected annually from Lake Norman in
the vicinity of MSS from 2009 to 2013. 3-22
3-8 Densities(No./m2)of Trichoptera collected annually from Lake Norman in the
vicinity of MSS from 2009 to 2013. 3-22
3-9 Densities (No./m2)of Megaloptera from Lake Norman in the vicinity of MSS
from 2009 to 2013 3-23
3-10 Annual densities(No./m2)of Spheariidae from Lake Norman in the vicinity of
MSS from 2009 to 2013. 3-23
3-11 Annual densities of Ephemeroptera,Plecoptera, and Tricoptera(EPT in no./m2)
from Lake Norman in the vicinity of MSS from 2009 to 2013. 3-24
3-12 Annual Ephemeropteran/Plecopteran/Trichoptern(EPT)richness from Lake
Norman in the vicinity of MSS from 2009 to 2013. 3-24
4-1 Locations associated with spring electrofishing and fall purse seine surveys, and
zones associated with fall hydroacoustic survey of Lake Norman. 4-9
4-2. Total number of fish collected in spring electrofishing surveys from two areas
(MSS and REF)in Lake Norman, 1993 — 1997 and 1999—2013. 4-10
4-3 Biomass of fish collected in spring electrofishing surveys from two areas(MSS
and REF) in Lake Norman, 1993 — 1997 and 1999—2013. 4-10
4-4 Total number of fish species collected in spring electrofishing surveys from two
areas(MSS and REF)in Lake Norman, 1993 — 1997 and 1999—2013 4-11
4-5 Length distribution of bluegill among survey locations in summer electrofishing
surveys near MSS in Lake Norman, 2009—2013. 4-11
vii
LIST OF FIGURES (continued)
Figure Title Page
4-6 Length distribution of redbreast sunfish among survey locations in summer
electrofishing surveys near MSS in Lake Norman, 2009—2013. 4-12
4-7 Length distribution of spotted bass among survey locations in summer
electrofishing surveys near MSS in Lake Norman, 2009—2013. 4-12
4-8 Pelagic forage fish density estimates by zone in Lake Norman, late summer/early
fall 1997—2013. 4-13
viii
CHAPTER 1
INTRODUCTION
Annual monitoring of physicochemical characteristics and assessments of macroinvertebrate
and fish populations at selected locations in Lake Norman continued from January 2009
through December 2013 (Table 1-1 and Figure 1-1), in accordance with Duke Energy's
agreement with the North Carolina Department of Environment and Natural Resources
(NCDENR). Physicochemical and biological data were collected at locations near Marshall
Steam Station (MSS) and included a location upstream of the facility (Location A), two sites
within the immediate projected impact of MSS's discharge (Locations B and C) and three
downstream recovery sites (Locations D, E, and F), presumably outside the influence of the
effluent plume(Figure 1-1).
The objectives of this on-going monitoring program are to provide an assessment of the
balanced and indigenous nature of the biological populations in Lake Norman with respect to
the thermal discharge from MSS and evaluate renewal of thermal limits at the station. The
thermal limit for MSS is a monthly average discharge (i.e., end-of-pipe) temperature limit of
93.9 °F (34.4 °C) from July 1 through October 31, and 91.9 °F (33.3 °C) the rest of each
year.
Regulatory review of past studies has determined, pursuant to Section 316(a) of the Clean
Water Act, that the thermal discharge of MSS ensures the protection and propagation of
balanced, indigenous populations in Lake Norman. This report presents data collected since
submittal of the previous summary reports (Duke Power Company 1994; Duke Power 1999,
2004a; Duke Energy 2009a) and includes data collected from 2009 through 2013. These data
were also compared with other past and present on-going environmental monitoring
programs conducted in this watershed.
1-1
Table 1-1. Description of Lake Norman sampling locations in the vicinity of MSS, Catawba County,NC.
Approximate
River Miles
Report Upstream of
Location Duke Energy Cowans Ford
Designation Location No. Location Description County Hydro Longitude Latitude
The first cove on the left upstream from MSS
A 15.5 intake cove. Catawba 16.9 -80.9461 35.6163
First cove along northern shoreline going into the
B 14.7 MSS CCW discharge cove. Catawba 13.9 -80.9573 35.5942
C 14.5 Inside MSS discharge canal. Catawba 13.9 -80.9644 35.5951
Large cove halfway between channel markers 14
D 13.0 and 15 on the west side of the channel. Catawba 12.7 -80.9527 35.5753
Cove formerly proposed for power plant site
E 19.0 intake or discharge. Iredell 9.0 -80.9301 35.5297
Left shoreline, approximately 100 m uplake of
F 34.0 Channel Marker 13. Catawba 11.5 -80.9569 35.5544
N
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Cowans Ford Hydro
■
McGuire Nuclear Station
Figure 1-1. Sampling locations on Lake Norman. Duke Energy historical sampling location numbers
are provided in parentheses.
1-3
CHAPTER 2
STATION OPERATION
BACKGROUND INFORMATION
Marshall Steam Station (MSS) is located on the western shore of Lake Norman (Figure 1-1)
just north of Charlotte, NC, in Catawba County. Its four generating units have a combined
operating capability of 2,090 MWE-net. Units 1 and 2 are each rated at 385 MWE-net and
began commercial operation in 1965 and 1966, respectively. Units 3 and 4 are each rated at
660 MWE-net and began commercial operation in 1969 and 1970,respectively.
MSS receives once-through condenser cooling water (CCW) from below a skimmer wall
located at the mouth of a 1.3-mi- (2.1-km-) long cove. The surface area of the cove is about
200 ac (81 ha) and its volume is approximately 250 million ft3(7 million m3). The skimmer
wall was designed to retain the upper 60 ft (18.3 m) of water on the lake side of the wall at
full pond. The opening below the skimmer wall through which the station CCW is
withdrawn is about 10 ft(3 m)high and 270 ft(82.3 m)wide.
Units 1 and 2 each have two condenser cooling water pumps, and Units 3 and 4 each have
three condenser cooling water pumps. Typically, only one pump per generating unit is used
during the cool winter months or when the unit is operating at reduced load. During the
warmer summer months when units are operating at full-load, either two or three pumps per
unit are generally used, depending on which units are operating. Maximum rates of cooling
water flow are 423 cfs (12.0 cms) each for Units 1 and 2, and 709 cfs (20.1 cms) each for
Units 3 and 4. Thus, the maximum possible station CCW flow rate is 2,264 cfs (64.1 cms).
Under one-pump-per-unit operation, the maximum CCW flow rate for the entire station is
1,230 cfs (34.8 cms). Refer to Table 2-1 for a listing of CCW flow rates for each unit under
one-, two-, and three-pump operation.
The CCW from MSS is discharged into a one-mile- (1.609 m-) long cove. The discharge
cove varies from a width of 75 ft (22.9 m) and depth of 33 ft (10.1 m) at the discharge
structure to a width of 850 ft (259.1 m) and a depth of 50 ft (15.2 m) at the mouth of the
discharge cove. The total area of the discharge cove is about 75 ac(30.4 ha).
2-1
Lake Norman was recently classified as oligotrophic, or of low nutrient content and algal
productivity, based on year 2012 water quality monitoring performed by the North Carolina
Department of Environment and Natural Resource (NCDENR) in association with the Lake
Assessment Program, which is conducted on a five-year cycle (NCDENR 2013). This
classification is consistent with earlier assessments (NCDENR 2003, 2008) indicating that
despite increases in population growth in the upper Catawba River Basin over the last two
decades, Lake Norman continues to effectively assimilate nutrient inputs into the reservoir
from the surrounding watershed.
Nutrient and algal biomass data, collected monthly from May through September 2012,
ranged from low to moderate levels, with higher values reported in the upper portions of the
reservoir, combined with progressively decreasing concentrations in the lower sections of the
reservoir (NCDENR 2013). Turbidity levels were also low and Secchi depths ranged from
1.0 to 4.0 m, indicating very good water clarity. Surface dissolved oxygen (DO)
concentrations ranged from 5.8 to 8.8 mg/L and surface water temperatures ranged from
76.1 °F to 94.28 °F (24.5 to 34.6 °C). Overall, these results are similar to those previously
reported by the State (NCDENR 2003, 2008) and to other studies (MCDEP 2003, 2007;
Duke Power Company 1994; Duke Power 1999, 2004a; Duke Energy 2008, 2009d, 2011,
2012, 2013) on Lake Norman.
THERMAL DATA
Duke Energy operates MSS as a base-load generating facility and station operation during
the period from January 2009 through December 2013 was similar to previous years (Duke
Power Company 1994; Duke Power 1999, 2004a; Duke Energy 2009a). From 2009 through
2013, MSS was operated continuously with peak pumping of CCW during the summer.
The seasonal cycle of discharge water temperatures at MSS over the period January 2009
through December 2013 was also similar to that observed in previous years (Figure 2-1;
Duke Power Company 1994; Duke Power 1999, 2004a; Duke Energy 2009a). Monthly
average discharge water temperatures at MSS were in compliance with NPDES-permitted
thermal limits of 93.9 °F(34.4 °C) from July 1 through October 31, and 91.9 °F (33.3 °C)the
rest of each year, over this five-year time period (Figure 2-1). Discharge water temperatures
ranged from a minimum monthly average of 62.4 °F (16.9 °C) in February 2011 to a
2-2
maximum monthly average of 93.9 °F (34.4°C) in August 2011 (Figure 2-1). Discharge
temperatures are linked to a combination of local meteorological conditions and electrical
generation.
CONCLUSIONS
MSS operated continuously from 2009 through 2013 and station operation during this period
was similar to previous years. Monthly average discharge water temperatures at MSS were
in compliance with NPDES-permitted thermal limits of 93.9 °F (34.4 °C) from July 1
through October 31, and 91.9 °F (33.3 °C)the rest of each year,over this five-year period.
2-3
Table 2-1. Marshall Steam Station CCW flow rate for each unit for one-,two-, and three-
pump operation.
Unit One-Pump CCW Two-Pump CCW Three-Pump CCW
Number Flow Rate(cfs) Flow Rate(cfs) Flow Ratelcfs)
1 281 423 (423)
2 281 423 (423)1
3 334 564 709
4 334 564 709
Station Total 1,230 1,974 2,264
1 Units 1 and 2 have only two CCW pumps available.
2-4
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2-5
CHAPTER 3
MACROINVERTEBRATES
MATERIALS AND METHODS
Benthic macroinvertebrate sampling was conducted annually in the summer of each year
from 2009 to 2013 as part of the continuing monitoring program for Marshall Steam Station
(MSS). As in previous years, samples were collected from four locations on Lake Norman:
Location A (uplake of MSS), Location B (MSS discharge canal), Location F (just north of
Channel Marker 13), and Location E (downlake of MSS) (Table 1-1 and Figure 1-1).
A petite Ponar dredge (15.3 x 15.3 cm) was used to collect five sample replicates at each
location. Samples were collected at depths ranging from 2 to 3 m to bracket the depth of
peak benthic abundance commonly associated with lakes and reservoirs (Brinkhurst 1974).
Samples were washed through a 500-µm mesh sieve and individually preserved with 70%
ethanol containing rose bengal stain. The substrate at each location was visually identified
and recorded during the sieving process. Organisms were sorted in the laboratory and
identified to the lowest practicable taxon. Macroinvertebrate densities were determined from
each replicate, averaged and expressed in No./m2.
The NCDENR requested additional analyses to be performed based on their review and
response to the 2009 MSS report (Duke Energy 2009a; NCDENR letter of November 19,
2009). In addition to current analyses, NCDENR requested additional information on the
following groups: Non-chironomid Diptera, Ephemeroptera, Plecoptera, Trichoptera,
Coleoptera, Megaloptera, Odonata, Crustacea, and Mollusca.
Ephemeroptera/Plecoptera/Trichoptera (EPT) densities and taxa richness were also requested
for additional assessment of the balanced and indigenous nature of the benthic community in
the vicinity of MSS. No Coleoptera, or Crustacea have been collected at locations in the
vicinity of MSS in the last 10 years and Plecoptera were only collected once during 2006
(Duke Energy 2009a). The only Mollusca collected were represented by Corbicula and
Spheariidae,which are addressed separately in this report.
3-1
Beginning in 2005, in conjunction with macroinvertebrate sampling, a calibrated YSI Model
55 handheld DO meter was used to measure water temperature and DO just above the
sediment at each of the four sampling locations. Starting in 2008, water temperatures and
DO concentrations were measured, in situ, using a calibrated Hach® HQ40d water quality
meter.
RESULTS AND DISCUSSION
Substrate
Substrates at Lake Norman sampling locations consisted of varying amounts of silt, sand,
organic material, and clay. Silt was the predominant component at most locations, while
comparatively high amounts of clay and sand were often observed in the substrates at
Location E (Table 3-1).
Water Quality
Water temperatures observed during sampling from 2009 to 2013 ranged from 26.4 to 31.1
°C (Table 3-2). No consistent spatial patterns among maximum and minimum temperatures
were observed during 2009—2013 and temperatures at Location B in the discharge were not
notably different from those at other sampling locations.
The DO concentrations observed during 2009 —2013 ranged from 1.0 to 8.7 mg/L (Table 3-
2). Minimum DO concentrations were most often recorded from Location B in the
discharge, while maximum DO readings were most often observed at Location A. The
comparatively high DO recorded in 2013 may have been due to the unusually cool and wet
summer of that year, with a much higher level of water column mixing. Additionally, with
the cool, wet conditions, MSS may have minimized operations. Minimum DO
concentrations at the discharge were likely due to low-DO water from beneath the skimmer
wall being entrained through MSS during summer periods of 2009 through 2012.
Taxa
The number of macroinvertebrate taxa collected at a location is typically a good indicator of
the overall diversity and the presence of a balanced indigenous population. Taxa abundance
3-2
from 2009 to 2013 varied temporally and spatially at Lake Norman (Tables 3-3 through 3-7
and Figure 3-1). Taxa abundance during 2009 — 2013 was slightly lower than during the
2004 — 2008 reporting period (Figure 3-1), with total taxa numbers ranging from 18 to 36.
Temporally, taxa numbers generally declined from 2009 through 2011, and then increased
between 2011 and 2013. Spatial maxima occurred at Location A in 2013, Location B in
2011, and Location F in 2009, 2010, and 2012. Spatial minima occurred at Location E in
2009, 2010, and 2011, and Location B in 2012 and 2013.
Density
During 2009 - 2013, overall annual macroinvertebrate densities varied substantially
temporally and spatially, and total densities were not appreciably different from densities
during 2004—2008 (Tables 3-3 through 3-7 and Figure 3-2). Macroinvertebrate densities in
Duke Energy's piedmont reservoirs are typically characterized by very high temporal and
spatial variability (Duke Energy 2009a, 2009b, 2009c, 2011). This was also true of the
densities of major taxonomic groups. Variability may be due to macroinvertebrates and
sediments not being homogenously distributed on the substrates. High spatial and temporal
variability can often mask short-term or long-term environmental impacts. Total densities
ranged nearly an order of magnitude from minimum to maximum during 2009 — 2013. As
with total taxa numbers, densities generally declined from 2009 through 2011, and then
increased between 2011 and 2013. No consistent trend in spatial maxima was observed.
Minimum spatial densities were consistently recorded from Location E well downlake of the
MSS discharge(Figure 3-2). This was also the case during the 2004—2008 reporting period.
It is unlikely that thermal impacts would be manifested at this location to a greater extent
than at other locations since no consistent temporal or spatial temperature patterns were
observed (Table 3-2). The predominance of less suitable substrates (clay in 2009 and 2010,
sand in 2011 — 2013), as well as substrate patchiness, may have resulted in less suitable
conditions for benthic macroinvertebrate colonization and growth at Location E (Table 3-1).
Major Taxonomic Groups
Considerable variability was also observed among major taxonomic groups. Oligochaeta
densities during 2009—2013 varied nearly 50 times from minimum to maximum (Tables 3-3
through 3-7 and Figure 3-3). Oligochaetes were dominant in Lake Norman
macroinvertebrate samples approximately 40% of the time. Maximum oligochaeta densities
occurred at Location B in 2009, 2012, and 2013, and they were most abundant at Locations
3-3
A and F in 2010 and 2011, respectively. Higher oligochaeta densities at the discharge were
indicative of tolerance for the low DO conditions typically observed there. The lowest
oligochaeta densities consistently occurred at Location E (Figure 3-3). The majority of
oligochaetes at all locations were the Tubificidae. Milligan (1997) stated that Tubificids
frequently form dense populations in organically enriched habitats with a silty or muddy
substrate tending toward anoxic conditions. Sediment composition at most locations
consisted primarily of silt with organic matter and some sand, while at Location E, clay and
sand were often among primary components (Table 3-1). Oligochaeta densities showed an
overall decline from 2009 through 2011, followed by increases between 2012 and 2013.
The family Chironomidae represents a ubiquitous and widespread group of insects that can
be found in a broad variety of aquatic habitats. The Chironomidae tended to show temporal
and spatial variability at Lake Norman, and densities during 2009 — 2013 were similar to
those observed during 2004 — 2008 (Figure 3-4). Densities ranged nearly six fold from
minimum to maximum during 2009 — 2013 (Tables 3-3 through 3-7 and Figure 3-4).
Chironomids constituted the most abundant taxonomic group at Lake Norman locations, and
were dominant in approximately 60% of samples collected during 2009 — 2013. Maximum
chironomid densities were observed at Location F in 2009, 2010, and 2012; while maxima at
Locations A and B were observed in 2011 and 2013, respectively. Minimum densities were
most often recorded from Location E.
Non-chironomid dipteran taxa densities showed considerable variability, ranging from 0/m2
up to over 600/m2 (Tables 3-3 through 3-7 and Figure 3-5). In most cases, total densities
were less than 50/m2. Densities tended to decline from 2009 through 2012, followed by an
increase in 2013. No consistent spatial trends were observed.
Mean annual densities of Corbicula during 2009 — 2013 tended to be lower than those
recorded during 2004 — 2008 (Figure 3-6). Spatial maxima most often occurred at Location
F, while minimum densities were generally recorded from Location B. Data from the
previous 10 years show there has been an apparent long-term decline in clam densities since
2008. Densities ranged from 0/m2 to over 1,300/m2 and during most years from 2009
through 2013, Corbicula densities were less than 500/m2(Tables 3-3 through 3-7).
Mean annual densities of Ephemeroptera during 2009 — 2013 were generally higher than
those of 2004 — 2008 (Figure 3-7), ranging from 0/m2 to nearly 400/m2 (Tables 3-3 through
3-7). The overall trend seemed to indicate increased densities through 2011, followed by a
3-4
decline through 2013. This was the opposite of what was observed among total densities at
Lake Norman locations (Figure 3-2). No consistent spatial trends were observed (Figure 3-
7).
Mean annual densities of Trichoptera during 2009—2013 were somewhat higher than during
the previous five-year sampling period (Figure 3-8). Densities ranged from 0/m2 to over
100/m2 (Tables 3-3 through 3-7). No consistent temporal or spatial trends were observed
among Trichoptera during 2009—2013.
The presence and abundance of Megaloptera and Spheariidae were sporadic during 2009 —
2013 (Figures 3-9 and 3-10). Megaloptera were only observed at Locations A and E, and
densities were always less than 45/m2 (Tables 3-3 through 3-7). Overall densities were
slightly higher during 2009 — 2013 than during the previous five-year period (Figure 3-9).
No Spheariidae were collected in 2010 or 2011, and overall densities were lower during
2009 — 2013 than during 2004 — 2008 (Figure 3-10). Odonata were observed infrequently
during 2004 — 2008 and no odonates were collected in Lake Norman samples during 2009 —
2013 (Tables 3-3 through 3-7).
EPT Densities and Taxa Richness
Densities of EPT taxa (Ephemeroptera and Trichoptera only, no Plecoptera were collected
during 2009—2013) showed slightly higher densities during 2009—2013 than during 2004—
2008 (Figure 3-11). EPT densities ranged up to over 45 fold from minimum to maximum
during 2009 — 2013 (Tables 3-3 through 3-7). Generally, densities appeared to increase
between 2009 and 2011, and then decline from 2012 to 2013. No consistent spatial trends
were observed among EPT densities.
The EPT taxa richness values during 2009—2013 were typically higher than during the 2004
— 2008 sampling period (Figure 3-12). Most taxa richness ratings ranged from Fair to
Excellent. Excellent EPT richness was observed at Location A in 2010, Location B in 2011,
and Location F in 2011 and 2013. Poor richness ratings were recorded from Location B in
2009 and 2012, at Location E in 2010 and 2011, and at Location F in 2012. Low ratings at
Location B (the discharge) may have been due to low DO conditions (Table 3-2), while the
low ratings at Location E may have resulted from substrate patchiness and occasionally poor
substrate conditions. EPT richness ratings appeared to increase substantially from 2009
3-5
through 2011, and then decline at all but Location E in 2012. Ratings increased again
through 2013 at all but Location E.
CONCLUSIONS
Substrates at Lake Norman locations generally consisted of varying proportions of silt, sand,
organic matter and clay with somewhat higher composition of clay and sand at Location E.
The water quality parameters (temperature and DO) taken at the time of macroinvertebrate
collections did not suggest any negative impact to the benthic communities. The only water
quality issue may be related to the low DO values at most times of sampling at Location B,
which could be expected since MSS withdraws its condenser cooling water from the bottom
of Lake Norman via an intake canal skimmer wall (Chapter 2).
The common characteristic among macroinvertebrate communities at Lake Norman locations
was the high variability among total densities and the densities of major taxonomic groups.
This is common at sampling locations on other piedmont reservoirs in North Carolina.
Although taxa numbers were somewhat lower during 2009 — 2013 as compared to 2004 —
2008, macroinvertebrate densities were generally similar between the two study periods.
Both taxa numbers and densities showed an apparent decline from 2009 through 2011,
followed by an increase from 2011 through 2013. No consistent spatial trends in maximum
densities were observed. Minimum taxa numbers were recorded at Location E during three
of the five years represented, while minimum densities were consistently reported from this
location.
Chironomids were the most abundant macroinvertebrates at most locations during 2009 —
2013, while oligochaetes constituted the second most abundant forms. The majority of
oligochaetes were Tubificids, which often formed dense concentrations in organically
enriched habitats. Chironomid maxima were most often recorded from Location F, while
maximum oligochaete densities (mostly Tubificids) were most often recorded from Location
B in the discharge. Comparatively high oligochaeta densities in the discharge were likely
due to their tolerance of the low DO conditions observed there. Minimum densities of both
groups typically occurred at Location E. Low total densities, as well as minimum densities
of chironomids and oligochaetes at this location, may have been due to less suitable substrate
and/or substrate patchiness.
3-6
Non-chironomid Diptera, Corbicula, Ephemeroptera, and Trichoptera densities showed
considerable variability and few consistent spatial or temporal patterns were observed during
2009 — 2013. The presences and abundances of Megaloptera and Spheariidae were
extremely sporadic during the recent five-year monitoring period, and no odonates were
collected during 2009—2013.
EPT taxa richness and densities during 2009 — 2013 were typically higher than in 2004 —
2008 and most richness ratings during 2009—2013 were from Fair to Excellent. Poor ratings
were observed occasionally from the discharge location and from Location E. This was
likely due to low DO conditions in the discharge and possible poor substrate or substrate
patchiness at Location E.
Some impacts were noted at the MSS discharge location due to low DO conditions; however,
based on macroinvertebrate densities, total taxa numbers, and EPT densities and taxa
richness observed during 2009 — 2013, it is concluded that thermal discharges from MSS
have not impaired macroinvertebrate communities in the vicinity of the station.
3-7
Table 3-1. General descriptions of the substrate found at Locations A, B, F, and E in the
vicinity of MSS from July 2009 - 2013. Substrates are listed in order of the
most prevalent type first. Organic matter (om) is typically composed of small
sticks, leaf and/or grass fragments, etc.
Year Location A Location B Location F Location E
silt silt silt clay
2009 om clay om silt
sand om sand om
sand sand
silt silt silt silt
2010 om sand om clay
sand om sand om
silt silt silt silt
2011 sand sand om sand
om om sand
silt silt om silt
2012 sand sand silt sand
om om
silt silt silt silt
2013 om om sand sand
sand om om
Table 3-2. DO and temperature measured near the sediments at the time of
macroinvertebrate collection from locations A, B, F, and E from July 2009-
2013.
Year Location A Location B Location F Location E
2009 8.3 mg/L 1.6 mg/L 7.1 mg/L 8.2 mg/L
28.1 °C 27.1 °C 27.5 °C 26.4 °C
2010 8.6 mg/L 1.3 mg/L 7.0 mg/L 8.2 mg/L
29.9 °C 31.1 °C 30.2 °C 30.0 °C
2011 7.7 mg/L 1.0 mg/L 7.1 mg/L 7.7 mg/L
28.0 °C 28.2 °C 29.0 °C 29.2 °C
2012 7.5 mg/L 1.8 mg/L 8.1 mg/L 8.0 mg/L
30.1 °C 29.4 °C 30.0 °C 30.8°C
2013 8.7 mg/L 5.3 mg/L 8.2 mg/L 7.9 mg/L
28.7°C 28.6 °C 28.5°C 28.0°C
3-8
Table 3-3. Macroinvertebrate taxa and densities (No./m2) from each Lake Norman sampling
location during summer sampling in 2009.
2009 Locations
Taxa A B F E
Diptera
Ceratopogonidae
Palpamyia-Bezzia complex TT 17 17 17
Chaoboridae
Chaoborus spp. 585 112 26
Chironomus spp. 9 52
Claadgpelma spp. 17 112
Cladotanytarsus spp. 732 17 887
Cryptodhiranamus app. 26 9 138 17
Cryptotendpes spp. 34 362 189 60
Diaotenaihpes neornodestus 26
Nilothauma spp. 9
Pagastiedla spp. 17 77 26 9
Paralauterbomiella nigmhalteralis 9 9 9
Paratendipes spp. 9
Polypedilum halterale gr. 250 17 43
Polypedilum scalaenum gr. 9 9 26
Pseudodriron mus spp. 17 112
Stempellina spp. 26 17
Stenochironomus spp. 17 43
Stictochiranamus spp. 258 121 103
Tanytarsrs spp. 310 60 336 43
Chiron
Parakiefferiella spp. 17
Ablabesmyia annulata 9 17
Ablabesmyia mallochi 9 9
Ablabesmyia ramphe gr. 9
Clinotaanypus spp. 172
Coelotanypus spp. 86 172 60
Djalmabatista puldna
Prodadius spp. 241 697 112 121
Ephemeroptera
Caenidae
Caenis spp. 60
Ephemeridae
l-lexagenia spp. 26 17 9
Megaloptera
Sialidae
Sialis spp. 26
Oligochaeta
Naidldae 9 60
Dern trifida 9 146
3-9
Table 3-3. (Continued).
2009 Locations
Taxa A B F E
Oligochaeta
Nais spp. 52 34
Nais pardalis 9 26
Tubiicidae 870 1,093 456 155
Aulodrilus limnobius 43 250 138
Autodrilus pigueti 9 4,830
Branchirua sowverbyi 17
Other
Glossiphoniidae
Helobdella stagnalis 43 422 319 17
Planariidae
Cura formanii 9 69
Sabellidae
Maneyunkia speciosa 508 818 43
Tetrastemmatidae
Prostana graecens 69
Nematoda 86 534 77
Pelecypoda
Corbiculidae
Corbicula flumina 146 827 284
Sphaeriidae
Sphaerium spp. 310 215
Trichoptera
Leptoceridae
Oecetis spp. 17 17 17 43
Triaenodes igniters 26
Polycentropodidae
Nyclophylax spp. 26
Polycentropus spp. 17 17
Total Density for Year 4,022 9,652 5,356 1,550
Total Taxa for Year 27 27 36 24
3-10
Table 3-4. Macroinvertebrate taxa and densities (No./m2)at each Lake Norman sampling
location during summer sampling in 2010.
2010 Locations
Taxa A B F E
Diptera
Ceratopogonidae
Palpamyra-Bezzia complex 17 17 26
( omidae-Chironominae
Axarus spp.
Chiranornus spp. 95
Cladopelma spp. 9 34
Cladotanytarsus spp. 723 17 ;•;7 TT
Cryptochiranomus spp. 69 284 69
Cryptotendipes app. 7T 413 336 9
Dicrotendipes neomodestus 60
Nilothauma spp. 9
Pagastiella spp. 103
Paralauterbamiella nigrohalteralis 43 60
Polypedilum halterale gr 43 9 43 26
Polypedilum scalaenum gr 9 77
Stempellina spp. 17 146
Stenochironomus app. 241 43 9 9
Stictochiionomus app. 17 207
Stictochironamus caffranius 9 9
Tanytarsus app. 422 34 189 34
Chiron 17 9
Paraldefferiella spp. 26
Ablabesmyia annulata 9 60
Ablabesmyia ramphe gr 52 17 26
Coelotanypus spp. 43 181 69
Djalmabatista pulchra 9
Parclad►us spp. 155 422 26 138
Ephemeroptera
Baetidae
Pseudvdoeon app. 86 198
Caenidae
Caenis app. 241
Ephemeridae
Hexagenia spp. 26 103 9
Megaloptera
Sialidae
Sialis app. 43 34
Oligochaeta
Naididae 9 69
Arcteonais lomondi 9
Dem app. 17
Dero digitata 95 9
3-11
Table 3-4. (Continued).
2010 Locations
Taxa A B F E
Oligochaeta
Dery bifida 155 439
Nais spp. 9
Nais partialis 9
llncinais uncinata ___ 9
Tubth1
cidae .903 121 250 207_
Aulockilus limnobius 801 34 232 52
Aulodrilus pigueti 138 844
Branchirua sowerbyi 232 34 43 172
Illyvdrilus templetoni 60
Limnodrilus hoffineisterei 26 9
Tubifer tubifex 43
Other
F linea
Glossiphoniidae
Helobdella stagnalis 336 26 34
SabeTidae
Manayunkia speciosa 26 336
Nematoda 164 77
Pelecypoda
Corbicubdae
Corbicula flumina 551 1,369 34
Trichoptera
Leptoceridae
Oecetis spp. 9 9
Triaenodes spp. 17
Polycentropodidae
Aalycentrvpus spp. 17
Total Density for Year 6,338 3,125 5,468 1,130
Total Taxa for Year 29 28 31 21
3-12
Table 3-5. Macroinvertebrate taxa and densities (No./m2) at each Lake Norman sampling
location during summer sampling in 2011.
2011 Locations
Taxa A B F Lijara
Ceratopogonidae
Palpomyia-Bezzia complex 26 9 26 34
Chironomidae-Chironominae
Ghironomus spp. 9
Cladopelma spp. 9 26
C2adotanytarsus spp. 164 17 319 26
Cryptochirtnnus spp. 9 69 26
Cryptotendpes spp. 9 551 121. 26
Dic otendpes spp. 9 95
Nilothauma spp. 9
Pagastiella spp. 9 26
Paralauterbomiella niujohalteralis 26
PclyperWum halterale gr. 17 164 34 9
Pblypedlum scalaenum gr 43
Stempellina spp. 9 9 26
Stictochironomus spp. 146
Sticto iironomus spp. 9 646
Stictochiranomus caffranius 103
Tanytarsus spp. 112 77 43 17
Chiron
Paraloefieriella spp. 17
Chironomidae-Tanypodnae
Ablabesmyia annulata 34 17
Ablabesmyia mallochi 9
Ablabesmyia ramphe gr. 9 9
Coelotanypus spp. 405 232 26 284
Prodadius spp. 250 284 77
Ephemeroptera
Baetidae
Pseudodoean spp. 9 276 387
Caenidae
Caenis spp. 34
Ephemeridae
Ibxagenia app. 34 43 43
Megaloptera
Sialidae
Sialis app. 9
Oligochaeta
Naiddae 26 17
Arcteonais lomandi 9
Dero spp. 9
Dero digitata 267
Dero bifida 26 474
3-13
Table 3-5. (Continued).
2011 Locatins
Taxa A B F E
Oligochaeta
Tubihcidae 835 112 740 129
Aulodnlus limnobius 52 60 86
Autodrilus piquet' 491
Limnodrilus horfineisterei 9 9
Other
Glossiphonidae
I welobdella stagnalis Ti 77 370 17
Planariidae
Cora fonnanii 9 34
Nematoda 95 129 293 9
Pelecypoda
CorbicuGdae
Corbicula flumina 138 422 465
Trichoptera
Hopes
Hydroptila spp. 17
Leptoceridae
Oecetis spp. 43 17 26
Polycentropoddae
Polycentropus spp. 9
Total Density for Year 2,517 3,119 4,238 1,326
Total Taxa for Year 24 30 24 18
3-14
Table 3-6. Macroinvertebrate taxa and densities (No./m2) at each Lake Norman sampling
location in during summer sampling in 2012.
2012 Locations
Taxa A B F E
Diptera
Ceratopogonidae
Palpomyia-Bezzia complex 9 60
Chaoboridae
Chaoborus spp. 26
Chironorridae-Chirawminae
Chironomus spp. 9 17
Ciadopelma spp. 9
C adotanytarsus spp. 103 577 9
Cryptochiranornus spp. 43 164 52
Cryptotendipes spp. 17 9 215 103
Dicrotendipes neomodestus 34
Pagastiella spp. 9 9 17
Paralauterbomiella nigrohalteiralis 26
Polypedilum halter-ale gr. 121 26
Polypedilum scalaenum gr. 69 52
Stempellina spp. 17
Stictochironomus spp. 379 189 172
Tanytarsus spp. 17 293 52
Ch'uono
Paraldefferiella spp. 9
Chironomidae-Tanypodinae
Ablabesmyia annulata 9 9
Ablabesmyia mallochi 9 34
Coelotanypus spp. 112 9 138
Djalmabatista pukka 17
Procladius spp. 577 26 103
Ephemeroptera
Baetidae
Pseudoclbecn spp. 26
Caenidae
Caenis spp. 77
Ephemeridae
Hexagenia spp. 9 9 181
Megaloptera
Sialidae
Sialis spp. 34
Oligochaeta
Naididae 86
Arcteonais lomondi 9 250 69
Bratislavia unidentata
Dem spp. 34 9
Dego digitata 1,825
3-15
Table 3-6. (Continued).
2012 Locations
Taxa A B F E
Oiigochaeta
Ndae
Dero bifida 95 121 17
Nais spp_ 43
Nais partialis 17
PristineJlajenkinae 52
Uncinais uncinata 456 990
Tubifcidae 964 611 1,558 26
Aulodn7us limnobius 34 43
Aulodrilus pigueti 9 1,171
Aulodrilus pluriseta 9 43
Branchirua sowerbyi 86 482 207 26
Other
Glossiphoniidae
flelobdella stagnalis 17 26
Glossiphonndae
Heiobdelia stagnalis 241
Planarndae
Cura formanii 34
Tetrastemmatidae
Prostoma graecaens 9
Nematoda 26 52 293 26
Pelecypoda
CorbicuGdae
Corbicula flumina 69 52 86 34
Sphaeriidae 17 121
Trichoptera
Leptoceridae
Oecetis spp_ 34 17
Polycentropadidae
Polycentropus spp. 9 9
Total Density for Year 2,634 5,116 5,703 1,353
Total Taxa for Year 21 20 30 27
3-16
Table 3-7. Macroinvertebrate taxa and densities (No./m2) at each sampling location in
Lake Norman during summer sampling in 2013.
2013 Locations
Taxa A B F E
Diptera
Ceratopogonidae
Palpcmyia-Bezzia complex 9 164 52 17
Chaoboridae
Chaobonrs app. 9 9
Chironornidae-Cturonominae
Chiranomus app. 26 86
Cladopelma spp. 9 17
Cladotanytarsus spp. 689 207 69
Cryptochironomus spp. 52 34 43 26
Cryptotendrpes spp. 103 250 86 34
Hamischia spp. 17
Abcrochironomus spp. 9
Nilothauma spp. 9
Pagastiella spp. 9 52 17
Paralauterbomiella nigrohalteralis 112 17 95 9
Polypedilum halterale gr. 129 198 52
Polypedilum scalaenum gr. 43
Stempellina spp_ 9 17 9 9
Stictochironomus spp. 697 534 86
Tanytarsus spp. 362 215 77 224
Chiron '
Nanodadius spp. 9
Chironomidae-Tanypodinae
Ablabesmyia annulata 34 43 17
Ablabesmyia mallochi 26
Coelotanypus spp. 284 112 52 86
Djalmabatista puk rra 9
Prodadius spp. 396 525 52 267
Ephemeroptera
Baetidae
Pseudocloeon spp. 26 17 138 9
Caenidae
Caenis spp. 26
Ephemeridae
Hexagenia spp. 34 17 9 43
Megaloptera
Sialidae
Sialis spp. 17 9
011gochaeta
Naididae 86
Arcteonais lomondi 103 9 95
Dero spp. 17
Dem digitata 52 17
Dem bifida 69 224 17
Uncinais uncinata 69 413 34
3-17
Table 3-7. (Continued).
2013 Locations
Taxa A B F E
Oligochaeta
Tubiicidae 1,576 947 1,395 603
Aulodrilus limnabius 77 319 542
Aulodrilus pigueti 34 3,384
Aulodrilus plurisefa 34
Branchirua sowerbyi 387 1,128 620
Branchirua sowerbyi 60
illyodrilus templetoni 129 69
Limnodrilus hoffineisterei 34
Other
Glossiphoniidae
Helobdella sfagnalis 232 1,240 465 52
Placabdella spp. 9
Planariidae
Curs formanii 17
Sabetidae
Manayunlda speciosa 26 43
Talitridae
Hyalella azteca 43
Nematoda 284 456 482 121
Pelecypoda
Corbiculidae
Corbicula flumina 112 9 758 26
Sphaeriidae
Sphaerium spp. 43 26 353
Trichoptera
Hydroptilidae
Hydroptila sPp- 9
Leptoceridae
Oecetis spp. 69 34 95 17
Total Density for Year 6,318 9,300 5,515 3,686
Total Taxa for Year 36 27 29 34
3-18
❑A ❑ B ❑ F ❑ E
45 —
40
=
I
35
U
CJ 25ca
x
20 — ^—
Ta
►- 15
10
5
0 f '
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Figure 3-1. Total number of taxa collected annually from Lake Norman in the vicinity of
MSS, 2004— 2008 and 2009— 2013.
OA ❑ B ❑ F ❑ E
10,000 T
9,000
8,000
7,000
E 6,000 —
5,000 - — —
4,000 —
3,000 - --
2,000 '
-
1,000 /
p ,
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Years
Figure 3-2. Densities (No./m2) of macroinvertebrates collected annually from Lake
Norman in the vicinity of MSS, 2004—2008 and 2009 — 2013.
3-19
OA EIB OF OE
if Oligochaeta
7,000
at
6,000 .4
.-4
5,000
o 4,000
- -
1- 3 000
,
0 2,000 • •
1,000 • — I —
0 + - • _
2004 2005 2006 2007 2008 2009 2010 2011 20:2 2013
Years
Figure 3-3. Densities (No./m2) of Oligochaeta collected annually from Lake Norman in the
vicinity of MSS, 2004—2008 and 2009—2013.
DA DB OF OE
Chironomidae
3,000
2,500
N
E 2,000
— 1,500
c 1,o00 _ –
w
–
SOO _ —
2004 2005 2005 2007 2008 2009 2010 2011 2012 2013
Years
Figure 3-4. Densities (No./m2) of Chironomidae collected annually from Lake Norman in
the vicinity of MSS, 2004—2008 and 2009—2013.
3-20
DA BB OF OE
Non-Chironomids
300
250
II
h
E 200 i
o I
-- 150 i . .. .. _._
Zvi
c 100
a _
S0 '«;
0 .f ri0 ,� 0i®. r .11 w I j11° L , 0 ° + r 1i
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Years
Figure 3-5. Densities (No./m2) of non-chironomid taxa from Lake Norman in the vicinity
MSS, 2004—2008 and 2009—2013.
DA OB OF DE
Corbicula
2,500 -
N
N
I
o
2 000 _ .J (»
z 1,soo II,
Z
.N 1,000
c i r —
C.)
—
500- 'a
x
0 r'l + Ork al le 1
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Years
Figure 3-6. Densities (No./m2) of Corbicula collected annually from Lake Norman in the
vicinity of MSS, 2004—2008 and 2009—2013.
3-21
NIA ® B OF DE
Ephemeroptera
450
400
_ 350 -
N
E 300 )11
-.
Z 250 -.
Z' 200
150 -. — — —
0 '- —
SO -1 •
0 0 tO
2004 2005 2006 2007 2006 2009 2010 2011 2012 2013
Years
Figure 3-7. Densities (No./m2) of Ephemeroptera collected annually from Lake Norman in
the vicinity of MSS, 2004—2008 and 2009—2013.
BA BB OF DE
Trichoptera
120
100
E 8o _.
Z 60 g
C 40 —
0 —
20 _
C CC
0
2004 2005 2006 2007 2006 2009 2010 2011 2012 2013
Years
Figure 3-8. Densities (No./m2) of Trichoptera collected annually from Lake Norman in the
vicinity of MSS, 2004—2008 and 2009—2013.
3-22
OA OB BF DE
Megaloptera
45
40
35
30
z25
Z" 20
1/1
0 15 -.
0
10 -
5 0 ;.0 OHOI 0 00 000! 000 000 , 0 0 ' 00 000 101
0
20C4 2005 2006 2007 2008 2009 2010 2011 2012 2013
Years
Figure 3-9. Densities (No./m2) of Megaloptera from Lake Norman in the vicinity of MSS,
2004—2008 and 2009—2013.
OA MB OF OE
Spearidae
500
m
400
6 300 -
Z
200 -
100
0
00 0000 0000 00]
0 -1=1 • I1J LI L
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Years
Figure 3-10. Annual densities (No./m2) of Spheariidae from Lake Norman in the vicinity of
MSS, 2004—2008 and 2009—2013.
3-23
DA ❑ B OF El
500
400
E 300
o
z
•w
c
0 200
100 — —
0 _-1-, _ _ n [ _ —
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Years
Figure 3-11. Densities (No./m2) of EPT from Lake Norman in the vicinity of MSS, 2004 —
2008 and 2009—2013.
DA OB OF DE
Excellent
30
Good
25
20
—
2 Good tan
15 —
x
cv
W 1p -Fair
—
0 ' -1 — _
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Years
Figure 3-12. EPT taxa richness from Lake Norman in the vicinity of MSS, 2004 — 2008 and
2009—2013.
3-24
CHAPTER 4
FISH
MATERIALS AND METHODS
Spring Electrofishing Surveys
Annual (2009 — 2013; current National Pollution Discharge Elimination System permit
cycle)boat electrofishing surveys were continued in Lake Norman in March or April near the
thermal influence of Marshall Steam Station (MSS; Zone 4 in Figure 4-1) and at a reference
area (REF, Zone 3) located between MSS and McGuire Nuclear Station. Ten 300-m
shoreline transects were surveyed in each area and were identical to historical locations
surveyed since 1993. Transects included littoral habitats representative of those found in
Lake Norman. All sampling was conducted when surface water temperatures were expected
to be 15—20 °C.
Stunned fish were collected by two netters and identified to species. Fish were enumerated
and weighed in aggregate by taxon, except for spotted bass (Micropterus punctulatus) and
largemouth bass (M. salmoides), where total length (TL, mm) and weight (g) were obtained
for each individual collected. Surface water temperature(°C)was measured with a calibrated
thermistor at each transect. Annual catch per unit effort (CPUE per 100 m) was determined
by area for number of individuals,biomass, and number of species collected. Condition(Wr)
based on relative weight was calculated for spotted bass and largemouth bass > 150 mm TL,
using the formula Wr = (W/Ws) x 100, where W = weight of the individual fish and Ws =
length-specific mean weight for a fish as predicted by a weight-length equation for each
species (Neumann et al. 2012). Resulting metrics were compared between areas using a t-
test(P < 0.05).
Summer Electrofishing Surveys
Annual (2009 — 2013) boat electrofishing surveys were continued in Lake Norman in July
near the thermal influence of MSS. Ten 100-m shoreline transects were surveyed to
represent three areas (Figure 1-1): two transects above the MSS discharge canal (Location
4-1
A), four in the vicinity of the discharge canal (Locations B and C), and four below the
discharge canal (Locations D and E). Transects were identical to historical locations
surveyed since 1991 and independent of spring transects. Surface water temperature and
dissolved oxygen (DO, mg/L) were measured with a calibrated thermistor and DO probe,
respectively, at each location. Stunned fish were collected by two netters, identified to
species, and measured for TL. Representative and Important Species (RIS) were selected
based upon abundance, distribution, and ecological significance as a prey (bluegill [Lepomis
macrochirus] and redbreast sunfish [L. auritus])or predator(spotted bass) species.
Fall Hydroacoustic and Purse Seine Surveys
Density and distribution of pelagic forage fish in Lake Norman were determined using
mobile hydroacoustic (Rudstam et al. 2012) and purse seine (Hayes et al. 2012) techniques.
The lake was divided into zones (Figure 4-1) due to its large size and habitat spatial
heterogeneity. An annual mobile hydroacoustic survey was conducted in mid-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 mid-September from the epilimnion of
downlake (Zone 1), midlake (Zone 2), and uplake (Zone 5) areas in water deep enough for
unhindered net deployment. 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 TL size distribution.
Balanced and Indigenous Assessment
Annual surveys are used to assess the balanced and indigenous nature of the Lake Norman
fish community and provide information relative to the potential thermal influence of MSS.
The assessment includes comparisons of spring electrofishing CPUE (spatially and
temporally) and of summer electrofishing RIS length distributions. Results from both
seasonal surveys were examined according to species pollution tolerance and trophic guild.
Hydroacoustic and purse seine surveys of pelagic forage fish were examined for trends.
4-2
RESULTS AND DISCUSSION
Spring Electrofishing Surveys
Spring electrofishing surveys from 2009 to 2013 were conducted at average water
temperatures ranging from 15.9 to 21.1 °C. Surveys resulted in the collection of 11,682
individuals comprising 26 species at the MSS area and 10,251 individuals comprising 21
species at the REF area (Table 4-1). The number of individuals per 100 m ranged from 47.3
to 143.3 at the MSS area and from 59.2 to 77.2 at the REF area (Table 4-1 and Figure 4-2).
Fish biomass per 100 m ranged from 3.5 to 7.1 kg at the MSS area and from 2.0 to 3.9 kg at
the REF area (Figure 4-3). The number of species per 100 m ranged from 14 to 20 at the
MSS area and from 14 to 19 at the REF area (Figure 4-4). Since 1993, both biomass and
number of species collected from the MSS area were significantly greater than those from the
REF area. When limited to the current permit cycle, the biomass collected from the MSS
area was significantly greater than from the REF area.
The number of individuals in spring electrofishing surveys from 2009 to 2013 was dominated
by centrarchids (MSS-95.9%, REF-93.7%), with clupeids (MSS-1.5%, REF-3.3%) and
cyprinids (MSS-1.4%, REF-2.3%) greater than 1.0% each, and the remaining families
representing less than 1.0% of individuals combined (Table 4-1). Green sunfish (Lepomis
cyanellus) exhibited a considerable (and similar) increase in relative abundance at both areas
compared to the 2004 - 2008 study period. Overall, current species composition data are
similar to previously reported spring electrofishing data near MSS (Duke Power Company
1994; Duke Power 1999, 2004a; Duke Energy 2009a) and from other Catawba River
reservoirs (Duke Power 2004b, 2004c; Duke Energy 2009b, 2009c).
Species considered pollution tolerant for wadeable stream assessments (e.g., longnose gar
[Lepisosteus osseus], goldfish [Carassius auratus], common carp [Cyprinus carpio], golden
shiner [Notemigonus crysoleucas], white catfish [Ameiurus catus], redbreast sunfish, green
sunfish, and hybrid sunfish; NCDENR 2013) represented 19.7% of MSS and 27.5% of REF
individuals during spring 2009 - 2013, similar to spring 2004 - 2008 (MSS-18.1%, REF-
24.2%) and spring 2000-2003 (MSS-15.4%, REF-17.0%).
Species considered insectivorous for wadeable stream assessments (NCDENR 2013)
represented 86.0% of MSS and 86.3% of REF from 2009 to 2013. Species considered
4-3
piscivorous (MSS-11.2%, REF-8.8%) and omnivorous (MSS-2.8%, REF-4.9%) also
reflected similar guild contributions when comparing areas from 2009 to 2013.
No significant difference existed between areas for spotted bass mean Wr (MSS-77.2, REF-
77.1). Largemouth bass from MSS (84.5) had a higher mean Wr than from REF (82.8);
however, the continued downward trend in the number of largemouth bass collected from
Lake Norman in recent years diminishes the significance of a statistical comparison.
Summer Electrofishing Surveys
Summer electrofishing surveys from 2009 to 2013 resulted in the collection of 2,967
individuals comprising six families, 19 species, and two hybrid centrarchid combinations
(Table 4-2). The species composition for the combined summer electrofishing surveys was
dominated by centrarchids (93.2%), followed by clupeids (4.9%), and cyprinids (1.2%). The
remaining families represented less than 1.0% of individuals combined. Previously reported
summer data also documented dominance by centrarchids during 2004 — 2008 (90.4%) and
2000 — 2003 (77.0%). Spotted bass have steadily increased in percent composition from
being absent prior to 2005 to approximately 9.5% of individuals collected during summer
2009 —2013. Overall, current CPUE and species composition data are similar to previously
reported summer electrofishing data near MSS (Duke Power Company 1994; Duke Power
1999, 2004a; Duke Energy 2009a) and from other Catawba River reservoirs (Duke Power
2001a, 2001b, 2004b, 2004c; Duke Energy 2009b, 2009c).
Pollution-tolerant species represented 16.6% of the collected fish during summer 2009 —
2013 surveys, similar to summer 2004 — 2008 (12.2%) and summer 2000 — 2003 (18.2%).
Insectivorous (78.2%), piscivorous (15.8%), and omnivorous (6.0%) species from 2009 to
2013 surveys had guild contributions similar to summer 2004 — 2008 (79.4%, 12.3%, 8.3%)
and summer 2000—2003 (81.6%, 12.9%, 5.6%),respectively.
The TL distributions of RIS (i.e., bluegill, redbreast sunfish, and spotted bass) during
summer 2009 — 2013 surveys (Figures 4-5 to 4-7) indicated successful reproduction and
multiple age groups from above, in the vicinity of, and below the MSS discharge canal.
Although the discharge canal consistently had the highest temperature (as high as 36.8 °C)
and lowest DO (as low as 0.5 mg/L), it maintained RIS TL size class distributions similar to
areas above and below the discharge canal.
4-4
Fall Hydroacoustic and Purse Seine Surveys
Annual hydroacoustic estimates near MSS (Zone 4) from 2009 to 2013 indicated the regular
availability of pelagic forage fish with no temporal trend in density (range = 1,564 — 11,551
fish/ha; Figure 4-8). Threadfin shad (Dorosoma petenense) continued to dominate annual
purse seine surveys of the Lake Norman forage fish community from 2009 to 2013,
comprising 88.4 — 98.3% of fish collected (Table 4-3). Alewife (Alosa pseudoharengus),
first detected in low numbers in 1999 (Duke Power 2000), have comprised as much as 25.0%
(2002) of mid-September pelagic forage fish surveys, but percent contribution has remained
relatively low since 2005 (range= 1.5— 11.6%).
CONCLUSIONS
A diverse fish community was present in the littoral surveys of Lake Norman near MSS from
2009 to 2013. Spring and summer electrofishing documented 28 and 19 species,
respectively, both numerically dominated by centrarchids, especially bluegill. Pollution-
tolerant species comprised less of the spring MSS fish population (19.7%) relative to the
REF area (27.5%), and comprised only 16.6% of individuals collected during summer
surveys. The assorted fish species typically found in Lake Norman near MSS encompass
multiple trophic guilds (i.e., insectivores, omnivores, and piscivores) supporting a balanced
fish community. Non-indigenous species such as spotted bass and green sunfish are
abundant near MSS,but are also prevalent throughout Lake Norman.
Annual hydroacoustic estimates from 2009 to 2013 showed the regular availability of pelagic
forage fish near MSS. Purse seine surveys indicate that threadfin shad continue to dominate
the Lake Norman forage fish community with a consistent alewife composition of
approximately 5% after 2004. The introduction of alewife and inherent, temporal
fluctuations in clupeid densities contribute to the variable nature of forage fish populations.
Past studies have indicated that a balanced indigenous fish community exists near MSS
(Duke Power Company 1994; Duke Power 1999, 2004a; Duke Energy 2009a). The present
study adds more years of comparable data, reinforcing that conclusion. Based on the CPUE
of littoral fish during spring, TL distributions of RIS during summer, and the regular
availability of forage fish, it is concluded that the thermal discharge of MSS has not impaired
the Lake Norman fish community.
4-5
Table 4-1. Total number of individuals,percent composition, and total number of species in spring electrofishing surveys from two
areas (MSS and REF)in Lake Norman, 1993 - 1997 and 1999, 2000-2003,2004-2008, and 2009-2013.
Spmg 1993-1997,1999 Sprig 2000-2003 Sprig 2004-2008 Sprig 2009-2013
PASS REF PASS REF MSS REF PASS REF
Sclen9Fk:nano Comrcn name No. % No. % Pb. % Pb. % Pb. % -Pb. % _ Pb. % Pb. %
Lepisostsldas
Lepiaoaeea oeseua Lo gnoseger 2 0.03% 1 0.01% 1 0.01% 1 0.01% 5 0.05%
Clupildas
Alosspseudo5arengua Alewife 45 0.51% 57 0.77% 1 0.01% 51 0.53% 2 0.02% 1 0.01%
Don ecma cepedanum Gizzard shed 81 0.94% 50 0.72% 30 0.34% 94 1.27% 27 0.32% 38 0.39% 84 0.72% 60 0.59%
Darosanapitenenae TMeedfinshad 944 10.98% 1,515 21.72% 840 9.46% 58 0.78% 127 1.51% 523 5.43% 86 0.74% 276 2.69%
Cyprinidae
Cyprineda ch/aieda Greenfin shier 22 0.26% 12 0.17% 50 0.56% 153 2.07% 43 0.51% 38 0.39% 16 0.15% 49 0.48%
Cy4nelladnee WnhfInshimer 734 &54% 586 8.40% 1257 14.18% 1,470 19.89% 228 2.72% 353 3.67% 28 0.22% 44 0.43%
Cyprinua caplo Connor cap 157 1.83% 168 2.41% 190 2.14% 51 0.69% 58 0.69% 48 0.50% 99 0.85% 20 0.20%
H18ogne(Mis regius Eastern savary ninnow 2 0.02%
Nocaas lsptocephdus Behead chub 1 0.01%
NotaTgars s ayadsucas Golden shies 8 0.09% 5 0.07% 4 0.06% 2 0.03% 7 0.08% 1 0.01% 1 0.01%
Nobrophehudsonlus Spottal shiner 414 4.81% 67 0.98% 472 5.32% 561 7.59% 240 2.86% 184 1.91% 21 0.18% 119 1.16%
Notropisprocne Swallowtail shiner 1 0.01% 1 0.01%
Pfinephales prame/as Fathead minnow 1 0.01%
Catostom Mae
Cwpodes cgxinua Oulback 5 0.06% 6 0.09% 3 0.03% 3 0.04% 2 0.02% 4 0.04% 3 0.03%
M orostoma mapdepidofum ShorOwd redhase 2 0.02% 4 0.06% 4 0.05% 1 0.01%
Moxostune npiscartes Striped}arprock
id. 1 0.01%
Ictalur
Amedu u8 calm MAW catfish 1 0.01%
Amalwus nebWosua Brown bullhead / 0.01%
Iclalurus*rcalua Beep catfish 2 0.02% 8 0.11% 1 0.01% 3 0.03% 1 0.01%
Icialuruspunctau8 Channel catfish 22 0.26% 14 0.20% 37 0.42% 40 0.54% 16 0.19% 24 025% 35 0.30% 27 0.26%
Pyfcisesdiwris Hothead catfish 7 0.08% 4 0.06% 14 0.16% 6 0.06% 9 0.11% 14 0.15% 21 0.18% 40 0.39%
Salmonidae
Oncorhynchua myklsa Rainbow trout 2 0.02% 1 0.01%
Moronklaa
Moron americana Wide perch 8 0.09% 103 1.16% 4 0.05% 8 0.10% 17 0.18% 66 0.56%
Morse cirysops Mlle bass 6 0.07% 4 0.06% 2 0.02% 3 0.04%
Morme saxadlla Striped bass 6 0.07% 3 0.03% 2 0.03% 1 0.01% 1 0.01% 10 0.09% 3 0.03%
Centrarchldae
Lspomisavdua Redbreast sunfish 1,398 1626% 1,017 14.58% 957 10.78% 1,004 13.59% 1,110 13.24% 1,925 19.99% 587 5.02% 1,408 13.74%
Upends cyarellua Green sunfish 129 1.54% 12 0.12% 1,373 11.75% 1,084 10.57%
Lepania gibbosue Rarpkeeeed 4 0.05%
Wanes guloaus Wamou h 63 0.73% 95 1.36% 150 1.69% 118 1.60% 111 1.32% 225 2.34% 69 0.59% 125 1.22%
Lepamis hybrd Hybdd sunfish 219 2.56% 207 2.97% 213 2.40% 197 2.67% 340 4.06% 360 3.74% 245 2.10% 306 2.99%
Worlds mecroderus Bkregi 2,731 31.76% 1.939 27.80% 3.418 38.51% 2,622 36.48% 4,600 54.85% 4,735 49.16% 7,424 63.55% 5,634 54.96%
Lepomis miaoicphus Pledger sunfish 111 1.29% 174 2.49% 468 5.27% 477 6.45% 559 6.67% 558 5.79% 300 2.57% 199 1.94%
Mrcrcptaus punctdalus Spaded bass 15 0.17% 12 0.16% 304 3.63% 198 2.06% 929 7.95% 750 7.32%
MOcropterus salmoides Largemouth bass 1,349 15.69% 911 13.06% 573 6.46% 420 5.68% 408 4.87% 270 2.80% 221 1.89% 73 0.71%
M9cropterus hybrid HMO beck bass 19 0.23% 11 0.11% 43 0.37% 18 0.18%
Ponexis ammlais Meds crappie 3 0.03%
Pbmaris dgramacdaus Beck crappie 51 0.59% 118 1.69% 1 0.01% 19 0.26% 19 0.23% 22 023% 12 0.10% 8 0.06%
Partial..
a3heoebrre Maihxme Swamp darter 1 0.01%
Maxims dmsted Tessellated dater 1 0.01% 1 0.01% 1 0.01% 3 0.04% 3 0.04% 4 0.04% 1 0.01%
Percy Bawacene Yellow perch 256 2.98% 80 1.15% 17 0.19% 3 0.04% 8 0.10% 13 0.13% 1 0.01%
Total 8,599 100.00% 6,976 100.00% 6,876 100.00% 7,390 100.00% 8,388 100.00% 9,631 100.00% 11,682 100.00% 10,251 100.00%
Total no.speedos 24 21 26 27 26 25 26 21
LT
Table 4-2. Total number of individuals,percent composition, and total number of species in summer electrofishing surveys from three
areas near MSS (above,in the vicinity of, and below the discharge canal)in Lake Norman, 1991 - 1993, 1994- 1999,
2000-2003, 2004-2008, and 2009-2013.
Sumner 1991-1993• Sumner 1994-1999° Sumner 2000-2003 Sumner 2004-2008 Sumner 2009-2013
Scientific name Corroon name Pb. % No. % No. % Pb. % Pb. %
Leplsosteidas
Lepisosteus osseus Longnose gar 11 0.26% 3 0.09% 3 0.10%
Clupeldae
Alosa pseudoharengus Alewife 5 0.16% 2 0.07%
Darosoma cepedlennum Gizzard shad 11 0.72% 38 0.91% 4 0.19% 6 0.19% 12 0.40%
Darosome petenense Threadfin shad 5 0.33% 355 8.54% 60 1.88% 130 4.38%
Cyprinidae
Carassius auratus Goldfish 1 0.03% 1 0.03%
Cyprinella chlorlstie Greenfin shiner 15 0.98% 54 1.30% 28 1.32% 53 1.66% 7 0.24%
Cyprinella nivee Whitefin shiner 170 11.10% 469 11.28% 257 12.09% 58 1.82% 1 0.03%
Cyprinus cerplo Conran carp 53 3.46% 94 2.26% 11 0.52% 3 0.09% 7 0.24%
Notemigonus crysoleucas Golden shiner 5 0.12%
Notropis hudsonius Spottal shiner 29 0.70% 157 7.39% 100 3.14% 20 0.67%
Catostomides
Carpiodes cyprinus Callback 5 0.12%
Monostoma macrdepidolum Shorlhead red arse 7 0.33% 5 0.16%
Moxostoma sp. Brassyjunprock 6 0.14%
Ictaluridae
Ictalurus punctatus Channel catfish 11 0.72% 10 0.24% 4 0.19% 7 0.22% 8 0.27%
Pylodctis olivaris Flathead catfish 16 0.38% 2 0.09% 3 0.09% 7 0.24%
PoecIlldae
Gambusia holbrooki Eastern rrosqutofish 5 0.33% 3 0.10%
lloronidae
Marone americana White perch 8 0.38%
Moron.chrysops White bass 5 0.12%
Centre/chides
Lepornis aurilus f2adereast sunfish 119 7.77% 261 6.28% 317 14.92% 272 8.53% 155 5.22%
Lepomis cyanellus Green sunfish 5 0.33% 1 0.05% 58 1.82% 286 9.64%
Leponds gibbosus f'unpkinseed 5 0.33%
Lepomis gulosus Warnouth 26 1.70% 91 2.19% 42 1.98% 74 2.32% 88 2.97%
Lepomis hybrid Hybrid sunfish 5 0.33% 99 2.38% 58 2.73% 53 1.66% 37 1.25%
Lepomis macrochirus Bkregll 926 60.44% 1,829 43.98% 900 42.35% 1,957 61.41% 1,703 57.40%
Lepamis microlophus Redear sunfish 5 0.33% 71 1.71% 78 3.67% 65 2.04% 38 1.28%
Micropterus punctulatus Spotted bass 86 2.70% 282 9.50%
Micropterus salmoides Largennulh bass 133 8.68% 422 10.15% 240 11.29% 313 9.82% 170 5.73%
Micropterus hybrid Hybrid black bass 2 0.06% 7 024%
Pomoxlsnigromeculatus Black crappie 6 0.14% 1 0.05%
Percldas
Etheostoma olmstedi Tessellated darter 20 1.31% 26 0.83%
Perca Bavescens Yelow perch 18 1.17% 257 6.18% 10 0.47% 3 0.09%
Total 1,532 100.00% 4,159 100.00% 2,125 100.00% 3,187 100.00% 2,967 100.00%
Total no.species 16 21 17 20 19
A •locations B and E w ere not sarrpled in 1992.location B was not sanpied in 1993
J °location B w as not sampled in 1994,locations A and B were not sampled in 1995
Table 4-3. Pelagic forage fish species composition from purse seine surveys in Lake
Norman, 1993 -2013.
Species composition
Year Threadfin shad Gizzard shad Alewife
1993 100.00%
1994 99.94% 0.06%
1995 99.95% 0.05%
1996 100.00%
1997 99.99% 0.01%
1998 99.95% 0.05%
1999 99.26% 0.26% 0.48%
2000 87.40% 0.22% 12.37%
2001 76.47% 0.01% 23.52%
2002• 74.96% 25.04%
2003 82.59% 0.14% 17.27%
2004 86.55% 0.24% 13.20%
2005 98.10% 1.90%
2006 94.87% 5.13%
2007 98.34% 1.66%
2008 95.58% 4.42%
2009 88.40% 11.60%
2010 95.38% 0.36% 4.26%
2011 98.32% 0.15% 1.52%
2012 93.60% 6.40%
2013 93.50% 6.50%
4-8
Zone 6
• Purse seine locations
• Electrofishing transects
Zone 5
�
� 9
;
Marshall Steam Station �"
N. L
• • Zone 4
r7 •
gam```1
414: h h
Zone 2
• •
Zone 3
•
$Y' Lt,
fe
_± •, ,
0 0.5 1 2 3 �' •
Miles • e Zone 1
0 1 2 4
— Cowans Ford Dame •
Kilometers McGuire Nuclear Station -
Figure 4-1. Locations associated with spring electrofishing and fall purse seine surveys, and
zones associated with fall hydroacoustic survey of Lake Norman.
4-9
160 —
-MSS
140 —
f REF
120 —
- 100 —
80 —
0
r 60 —
40 —
20 —
0 1 + + + + + 1 1 + + + 1 + + 1 1 + + + 1 i
co La Co f� co a) o N M 1.0 O CO O O N M
O O O O O O O O O O O O O O O O O
O O 6) O O 67 O O O O O O O O O O O O O O O
N N N N N N N N N N N N N N
Year
Figure 4-2. Total number of fish collected in spring electrofishing surveys from two areas
(MSS and REF) in Lake Norman, 1993 — 1997 and 1999—2013.
14 —
MSS
12 — —f—REF
10 —
E
0 8 —
0
m
6 —
N
LL
4 —
r . •
2 —
co '• O co on o N M Li CD f� CO O O N
O 0) 0) O O O O O O O O O O O O O
o O O Cr) 0) O O O O O O O O O O O O O O O
NNNNNNNNNNNNNN
Year
Figure 4-3. Biomass of fish collected in spring electrofishing surveys from two areas (MSS
and REF) in Lake Norman, 1993 — 1997 and 1999 —2013.
4-10
30 -
+MSS
25 - -t-REF
20 -
0
el\ ViVq6%j- 15 -
o)
0
'U
N
s 10 —
ii
5 -
0 I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
M v' it) (O Co O o N M O ti CO O O '- N CO
Cn C7) O) O Cn O 0) O O O O O O O O O O .-
O O O O CS) O CS) O O O O O O O O O O o O O o
N N N N N N N N N N N N N
Year
Figure 4-4. Total number of fish species collected in spring electrofishing surveys from two
areas (MSS and REF) in Lake Norman, 1993 — 1997 and 1999—2013.
16% -
■Above ■Discharge ■Below
14% -
12%
-y 10% —
0
0 8% —
c
v 6%
a�
o-
4% ill"
2%0% -I' I L .Y I1Iki _L all I_ 1 _
O o o O o 0 0 0 0 0
N CD Co O N CO Co
r r r r r N
IL class(mm)
Figure 4-5. Length distribution of bluegill among survey locations in summer electrofishing
surveys near MSS in Lake Norman, 2009—2013.
4-11
25% —
■Above ■Discharge ■Below
20%
c
0
15% - -
0.
E
0
0
t00i 10% - -
a
5% —
tII 11111111111111 11111 I 11111 11
NO COO coo O N COO co O
N
TL class(mm)
Figure 4-6. Length distribution of redbreast sunfish among survey locations in summer
electrofishing surveys near MSS in Lake Norman, 2009—2013.
30% —
■Above ■Discharge ■Below
25% —
0 20% —
U,
0
o 15%
c I
a10% —
::: :
-
+� lir I I III I'I 1111111 It, li ; , I I11
O O O O O O O o O O O O O O
N CO CO O N CO CO N N N N CO M
TL class(mm)
Figure 4-7. Length distribution of spotted bass among survey locations in summer
electrofishing surveys near MSS in Lake Norman, 2009—2013.
4-12
25,000 —
—a—Zone 1 —A—Zone 2
—A—Zone 3 Zone 4
Zone 5
20,000 —
cT
s
°c 15,000
C 7
a)
r 10,000 —
w
a)
f2 —van. N4414
O) ` v
5,000 — `0f»�''\ /'/
0 I I I I I I E t I I I I I I I I I
N. co 0) O — N Cr) U) CO f- co C) O N M
C) C) C) 0 0 0 0 0 0 0 0 0 0 A- A- A- e-
C) C) C) 0 0 0 0 0 0 0 0 0 0 0 0 0 0
a- a- a- N N N N N N (N N N N N N N N
Year
Figure 4-8. Pelagic forage fish density estimates by zone in Lake Norman, late
summer/early fall 1997—2013.
4-13
LITERATURE CITED
Brinkhurst, RO. 1974. The Benthos of Lakes. The MacMillan Press, London. 190 pp.
Duke Energy. 2008. Lake Norman maintenance monitoring program: 2007 Summary.
Duke Energy. 2009a. Assessment of balanced and indigenous populations in Lake Norman
near Marshall Steam Station. Duke Energy, Charlotte,NC.
Duke Energy. 2009b. Assessment of balanced and indigenous populations in Lake Wylie
near Allen Steam Station. Duke Energy, Charlotte,NC.
Duke Energy. 2009c. Assessment of balanced and indigenous populations in Mountain
Island Lake near Riverbend Steam Station. Duke Energy, Charlotte,NC.
Duke Energy. 2009d. Lake Norman maintenance monitoring program: 2008 Summary.
Duke Energy, Charlotte,NC.
Duke Energy. 2011. Lake Norman maintenance monitoring program: 2010 Summary.
Duke Energy, Charlotte,NC.
Duke Energy. 2012. Lake Norman maintenance monitoring program: 2011 Summary.
Duke Energy, Charlotte,NC.
Duke Energy. 2013. Lake Norman maintenance monitoring program: 2012 Summary.
Duke Energy, Charlotte, NC.
Duke Power. 1999. Assessment of balanced and indigenous populations in Lake Norman
near Marshall Steam Station. Duke Power, Charlotte,NC.
Duke Power. 2000. Lake Norman maintenance monitoring program: 1999 summary. Duke
Power, Charlotte,NC.
Duke Power. 2001 a. Assessment of balanced and indigenous populations in Lake Wylie
near Plant Allen. Duke Power, Charlotte,NC.
Duke Power. 200lb. Assessment of balanced and indigenous populations in Mountain
Island Lake near Riverbend Steam Station. Duke Power, Charlotte,NC.
Duke Power. 2004a. Assessment of balanced and indigenous populations in Lake Norman
near Marshall Steam Station. Duke Power, Charlotte,NC.
Duke Power. 2004b. Assessment of balanced and indigenous populations in Lake Wylie
near Plant Allen. Duke Power, Charlotte,NC.
L-1
Duke Power. 2004c. Assessment of balanced and indigenous populations in Mountain
Island Lake near Riverbend Steam Station. Duke Power, Charlotte,NC.
Duke Power Company. 1994. Assessment of balanced and indigenous populations in Lake
Norman near Marshall Steam Station. Duke Power Company, Charlotte,NC.
Hayes, DB, CP Ferrier, and WW Taylor. 2012. Active fish capture methods. Pages 267-304
in AV Zale, DL Parrish and TM Sutton, editors. Fisheries Techniques, 3"1 edition.
American Fisheries Society, Bethesda, MD.
Mecklenburg County Department of Environmental Protection (MCDEP). 2003. Lake
monitoring data summary for 2001-2002. Charlotte,NC
MCDEP. 2007. Lake monitoring report for 2007. Charlotte,NC.
Milligan,MR. 1997. Identification manual for the Oligochaeta of Florida. Vol. 1. 187 pp.
Neumann, RM, CS Guy, and DW Willis. 2012. Length, weight, and associated indices.
Pages 637-676 in AV Zale, DL Parrish and TM Sutton, editors. Fisheries
Techniques, 3'edition. American Fisheries Society, Bethesda, MD.
North Carolina Department of Environment, and Natural Resources (NCDENR). 2003.
Basinwide assessment report; Catawba River Basin. North Carolina Department of
Environment and Natural Resources Division of Water Quality. 203pp.
NCDENR. 2008. Lake and reservoir assessments; Catawba River Basin. North Carolina
Department of Environment and Natural Resources Division of Water Quality.
Environmental Sciences Section. 21pp
NCDENR. 2013. Standard operating procedure. Biological monitoring: stream fish
community assessment program. NCDENR, Division of Water Resources,
Environmental Sciences Section, Biological Assessment Branch. Raleigh, NC.
Rudstam, LG, JM Jech, SL Parker-Stetter, JK Horne, PJ Sullivan, and DM Mason. 2012.
Fisheries acoustics. Pages 597-636 in AV Zale, DL Parrish and TM Sutton, editors.
Fisheries Techniques, 3'h edition. American Fisheries Society, Bethesda, MD.
L-2