BRUNSWICK STEAM ELECTRIC PLANT 

2008 BIOLOGICAL MONITORING REPORT 

Prepared by: 

 Environmental, Health and Safety Services Section 

 Progress Energy Carolinas, Inc. 

 Raleigh, North Carolina 

December 2009 
Brunswick Steam Electric Plant 2008 Biological Monitoring Report 

 

Progress Energy Carolinas, Inc. i Environmental, Health and Safety Services Section

Preface

This copy of the report is not a controlled document as detailed in the Biology Program 

Procedures Manual and Quality Assurance Manual. Any changes made to the original of this 

report subsequent to the date of issuance can be obtained from: 

 Director 

Environmental, Health and Safety Services Section 

Progress Energy Carolinas, Inc. 

410 South Wilmington Street 

Raleigh, North Carolina 27601 
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Table of Contents

 Page 

Preface ................................................................................................................................. i 

Table of Contents.................................................................................... ii 

List of Tables ...................................................................................................................... iii 

List of Figures ..................................................................................................................... iv 

List of Appendices .............................................................................................................. v 

Metric-English Conversion and Units of Measure ............................................................. vi 

Common and Scientific Names of Species Used in this Report ........................................ vi 

Executive Summary ............................................................................................................ vii 

1.0 INTRODUCTION ............................................................................................... 1-1 

2.0 MONITORING PROGRAM RESULTS ............................................................. 2-1 

2.1 Introduction .......................................................................................................... 2-1 

2.2 Methods................................................................................................................ 2-1 

2.3 Results and Discussion ........................................................................................ 2-2 

2.3.1 Water Quality ....................................................................................................... 2-2 

2.3.2 Dominant Species ................................................................................................ 2-3 

2.3.3 Seasonality and Abundance ................................................................................. 2-4 

2.3.4 Fine-Mesh Screens and Cooling Water Flow ...................................................... 2-5 

2.3.5 Survival Estimates ............................................................................................... 2-6 

2.4 Summary and Conclusions .................................................................................. 2-6 

3.0 REFERENCES .................................................................................................... 3-1 
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List of Tables

Table Page 

2.1 Annual mean density and percent of total for the ten most abundant taxa 

 collected during entrainment sampling at the Brunswick Steam Electric 

 Plant during 2007 and 2008 ................................................................................. 2-7 

2.2 Total number of the ten most abundant taxa estimated for larval impingement 

sampling at the Brunswick Steam Electric Plant during 2007 

and 2008 ............................................................................................................... 2-8 

2.3 Total number, total weight, and percent of total of the ten most 

abundant juvenile and adult organisms collected in the 

 Brunswick Steam Electric Plant impingement samples during 2008 .................. 2-9 

2.4 Entrainment densities of selected taxa at the Brunswick Steam Electric 

 Plant during 2008 ................................................................................................. 2-10 

2.5 Entrainment rates of selected taxa at the Brunswick Steam Electric Plant 

 during 2008 .......................................................................................................... 2-11 

2.6 Estimated total number of selected taxa collected with monthly larval 

impingement sampling at the Brunswick Steam Electric Plant during 2008 ....... 2-12 

2.7 Density and modal length for selected species collected with juvenile 

 and adult impingement sampling per month at the Brunswick Steam 

 Electric Plant during 2008 ................................................................................... 2-13 

2.8 Mean density and biomass of selected juvenile and adult organisms indicating 

reductions in density and biomass impinged during 2008 as a result of the 

 Fish diversion structure. ....................................................................................... 2-14 

2.9 Percent effectiveness of fine-mesh screens in reducing the number entrained 

 per day for selected taxa at the Brunswick Steam Electric Plant 

 during 2008 .......................................................................................................... 2-15 

2.10 Estimated numbers and percent survival of selected larval organisms 

collected during impingement sampling at the Brunswick Steam Electric Plant 

during 2008 .......................................................................................................... 2-16 

2.11 Estimated numbers, biomass, and percent survival of selected juvenile 

and adult organisms collected during impingement sampling at 

the Brunswick Steam Electric Plant during 2008. ............................................... 2-17 
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List of Figures

Figure Page 

1.1 Location of the Brunswick Steam Electric Plant near 

Southport, North Carolina .................................................................................... 1-2 

1.2 Location of the fish diversion structure, fish return flume, return basin, and 

 sampling locations at the Brunswick Steam Electric Plant during 2008 .............. 1-3 

2.1 Mean daily freshwater flow to the Cape Fear Estuary and monthly intake 

 canal salinity at the Brunswick Steam Electric Plant during 2008 ...................... 2-18 

2.2 Mean annual freshwater flow to the Cape Fear Estuary, 2004-2008 ................... 2-18 

2.3 Mean monthly intake canal water temperature at the 

 Brunswick Steam Electric Plant during 2008 ...................................................... 2-19 

2.4 Mean winter and summer intake canal water temperatures 

 at the Brunswick Steam Electric Plant, 2004-2008 ............................................. 2-19 

2.5 Number of taxa collected in entrainment and larval impingement 

 samples at the Brunswick Steam Electric Plant during 2008 ............................... 2-20 

2.6 Annual number of total organisms entrained at the Brunswick Steam 

 Electric Plant and percent reduction from baseline entrainment estimates, 

 1979-2008 ............................................................................................................ 2-21 

2.7 Annual number of total organisms entrained at the Brunswick Steam 

 Electric Plant, 1979-2008 and the annual mean density of total larval 

 organisms collected during larval fish sampling in the 

 Cape Fear Estuary, 1979-1993. ............................................................................ 2-21 
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List of Appendices

Appendix Page 

1 Summary of historical environmental studies conducted in association 

 with the Brunswick Steam Electric Plant, 1968-2008 .......................................... A-1 

2 Number of larval organisms collected during entrainment and larval 

 impingement sampling at the Brunswick Steam Electric Plant during 2008 ....... A-3 

3 Number and biomass of juvenile and adult organisms collected during 

 impingement sampling at the Brunswick Steam Electric Plant during 2008 ....... A-6 
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Metric-English Conversion and Units of Measure 

Length

1 micron (μm) = 4.0 x 10-5 inch 

1 millimeter (mm) = 0.001 m = 0.04 inch 

1 centimeter (cm) = 10 mm = 0.4 inch 

1 meter (m) = 100 cm = 3.28 feet 

1 kilometer (km) = 1000 m = 0.62 mile 

Volume

1 milliliter (ml) = 0.034 fluid ounce 

1 liter = 1000 ml = 0.26 gallon 

1 cubic meter = 35.3 cubic feet 

1 cubic foot per sec. = 448.8 gallons per min. 

Area 

1 square meter (m2

) = 10.76 square feet 

1 hectare (ha) = 10,000 m2

 = 2.47 acres 

Temperature

Degrees Celsius (°C) = 5/9 (°F-32) 

Weight

1 microgram (μg) = 10-3 mg or 

 10-6 g = 3.5 x 10-8 ounce 

1 milligram (mg) = 3.5 x 10-5 ounce 

1 gram (g) = 1000 mg = 0.035 ounce 

1 kilogram (kg) = 1000 g = 2.2 pounds 

1 metric ton = 1000 kg = 1.1 tons 

1 kg/hectare = 0.89 pound/acre 

 

Common and Scientific Names of Species Used in this Report

Atlantic sharpnose shark Rhizoprionodon terraenovae Gobies Gobionellus spp.

Smooth butterfly ray Gymnura micrura Gobies Gobiosoma spp.

Atlantic stingray Dasyatis sabina Atlantic cutlassfish Trichiurus lepturus

Atlantic menhaden Brevoortia tyrannus Harvestfish Peprilus alepidotus

Anchovies Anchoa spp. Flounder Paralichthys spp. 

Bay anchovy A. mitchilli Southern flounder P. lethostigma.

Striped anchovy A. hepsetus Blackcheek tonguefish Symphurus plagiusa

 Shrimp Litopenaeus & 

Farfantepenaeus spp. 

Silversides Atherinidae Brown shrimp F. aztecus

Searobin Prionotus spp. Pink shrimp F. duorarum 

Pinfish Lagodon rhomboides White shrimp L. setiferus

Star drum Stellifer lanceolatus Hardback shrimp Trachypenaeus spp. 

Silver perch Bairdiella chrysura Grass shrimp Palaemonetes spp. 

Weakfish Cynoscion regalis Swimming crab larvae Portunid megalops 

Spot Leiostomus xanthurus Blue crabs Callinectes spp. 

Croaker Micropogonias undulatus Blue crab C. sapidus

Striped mullet Mugil cephalus Lesser blue crab C. similis

Combtooth blennies Blennidae Brown bar crab Portunus spp. 

 

 
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Executive Summary

 Biological monitoring of the Cape Fear Estuary (CFE) at Progress Energy Carolinas, Inc. 

(PEC) Brunswick Steam Electric Plant (BSEP) was conducted in 2008 as part of the National 

Pollutant Discharge Elimination System (NPDES) permit requirements. Entrainment and 

impingement studies monitored the effectiveness of the intake modifications in reducing 

entrainment and impingement of fish and shellfish. 

 The fish diversion structure excluded most large organisms and many of the impinged 

larval, juvenile, and adult organisms were successfully returned alive to the estuary by using 

fine-mesh traveling screens and the fish return system. Evidence for this success includes 

species composition and abundance of organisms entrained and impinged. Anchovies, gobies, 

spot, croaker, pinfish, shrimp and crabs were the dominant larvae entrained and impinged. Use of 

fine-mesh screens has decreased the risk of entrainment for spot, croaker, pinfish, shrimp and 

crabs. These organisms potentially may be at greater risk of being entrained since they are 

spawned offshore and must pass by the plant intake in order to reach the nursery areas in the 

CFE. Anchovies and gobies on the other hand are at reduced risk because these species are 

estuarine residents and spawning occurs throughout the entire estuary. Overall reductions in the 

annual number entrained due to a combination of fine-mesh screens, the fish return system, and 

reduced cooling water flow have ranged from 57% to 87% since 1983. Based on survival 

estimates data, approximately 44% of the larval species historically tested for survival were 

returned alive to the estuary. Larval survival was greatest (> 90%) for the shrimp and crab 

larvae, the most valuable commercial taxa. 

The fish diversion structure and fish return system, when considered together, substantially 

reduced the impingement mortality of larger organisms due to cooling water withdrawal. The 

fish diversion structure excluded many of the larger fish and shellfish from the canal. Those that 

did get in and subsequently became impinged were returned alive to the CFE by the fish return 

system. Installation of the fish diversion structure significantly reduced the number of larger 

organisms impinged by as much as 99%, depending upon species. In addition to a reduction in 

numbers, a shift to the impingement of smaller finfish has resulted as well. This is important 

because the larger individuals that are not impinged are the reproducing members of the 

population. The species composition of organisms collected with impingement samples also 

shifted to a greater percentage of shrimp and blue crab rather than larger finfish as a result of the 

fish diversion structure which is significant because these species exhibit excellent survival in 

the fish return system (> 90%). 

 Despite some variability in entrainment rates due to environmental and plant operating 

conditions there has been no evidence of long-term environmental impact. Prior to the 

installation of fine-mesh screens and the fish return system, data from intensive sampling 

throughout the 1970s indicated that operation of the plant had no measurable adverse effect on 

fish and shellfish populations in the CFE. More recent fish and shellfish population studies 

conducted during 1999, 2001 and 2002 indicated no declines in abundance of any species or 

shifts in species composition. 
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1.0 INTRODUCTION

Progress Energy Carolinas, Inc. (PEC), formerly doing business as Carolina Power & 

Light Company (CP&L), was issued an NPDES permit in December 1974. The permit allowed 

for once-through cooling water, withdrawn from the CFE, to be discharged into the Atlantic 

Ocean (Figure 1.1). A stipulation of the NPDES permit required biological monitoring to 

provide sufficient information for a continuing assessment of power plant impacts on the marine 

and estuarine fisheries of the CFE. Data were reported annually and provide an assessment of 

the effectiveness of the fish diversion structure, fine-mesh screens, and seasonally based flow 

minimization in reducing the entrainment and impingement of organisms. 

A stipulation of the renewed NPDES permit, issued in 1981, and subsequent permits was 

the implementation of power plant modifications to reduce entrainment and impingement of 

estuarine organisms resulting from the intake of cooling water. A permanent fish diversion 

structure was constructed across the mouth of the intake canal in November 1982 to reduce 

impingement by preventing larger fish and shellfish from entering the intake canal (Figure 1.2). 

In addition, the fish diversion structure significantly reduced the numbers of threatened and 

endangered sea turtles entering the intake canal. To reduce the entrainment of larvae, 1-mm 

fine-mesh screens were installed on two of the four intake traveling-screen assemblies of each 

unit in July 1983 and on a third assembly per unit in April 1987. At that time, the NPDES permit 

required that three of the four intake traveling-screen assemblies on each unit be covered with 

fine-mesh screens. In August 2003, the NPDES permit required two full fine-mesh screens 

along with two 50% fine-mesh screens on the four intake traveling screens per unit. Organisms 

retained on either the fine mesh or coarse mesh traveling screen panels are gently washed into a 

fiberglass fish return system and are subsequently returned alive to the CFE (Figure 1.2). 

Under the current permit, a maximum intake flow of 26.1 cubic meters per second (cms) 

per unit is allowed from December through March and 31.1 cms per unit is allowed from April 

through November. Normally two full fine-mesh screens and one 50% fine mesh screen are used 

during these periods of maximum intake flow. The flow of one unit may be increased to 

34.8 cms during July, August, and September. Seasonal flow minimization during December 

through March is a measure, in addition to fine-mesh screens, to reduce operational impacts on 

the large numbers of commercial finfish larvae recruiting to the estuarine nursery areas during 

that time of year. 

Environmental studies associated with the BSEP began in 1968 before the plant began 

withdrawing cooling water from the estuary. Intensive physical, chemical, and biological studies 

of the estuary and near-shore ocean were conducted in the mid and late 1970s. These original 

studies were followed by a long-term monitoring program through the early 1990s aimed at 

monitoring fish and shellfish populations within the estuary and documenting the effectiveness 

of the intake modifications at reducing the entrainment and impingement of organisms. A 

detailed summary of historic environmental studies can be found in Appendix 1. 

Beginning in 1994, PEC reduced the biological monitoring program with the concurrence 

of the North Carolina Department of Environment & Natural Resources. Based on almost two 

decades of operation with no detectable adverse impact on fish and shellfish populations in the 

CFE, the monitoring program was modified to concentrate on the impingement and entrainment 
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of organisms (Figure 1.2). This report presents data for 2008 on impingement and entrainment 

rates of larval, juvenile, and adult fish and shellfish and evaluates the effectiveness of the 

NPDES-required intake modifications. 

Atlantic Ocean

Ocean 

Discharge 

Area

Dutchman Creek

Plant Site

Walden 

Creek

Cape Fear River

Intake 

Canal

Southport

Visitors 

Center

NORTH 

CAROLINA

Brunswick 

Steam Electric 

Plant

N

Kilometers

Miles

0 2 4

0 2

Fish- return flume

Discharge weir *

Fish-diversion 

structure

*

Figure 1.1 Location of the Brunswick Steam Electric Plant near Southport, North 

Carolina.
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Intake structure

Fish return flume

Intake canal

Nancy's Creek Gum Log Branch Access road

Fish

diversion 

structure

Walden Creek

Cape Fear River

Return basin

N

0

0 1000 2000 3000

500 1000

meters 

feet 

Plant area

Discharge

Weir

Larval Impingement Sampling

Fish Return Flume

Impingement Sampling

Fish Return Flume

Entrainment Sampling

Discharge Weir

Figure 1.2 Location of fish diversion structure, fish return flume, return basin, and 

sampling locations at the Brunswick Steam Electric Plant during 2008. 
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2.0 MONITORING PROGRAM RESULTS

2.1 Introduction

Past data indicated that the impingement of large fish and shellfish of the CFE was reduced 

as a result of the 9.4-mm (3/8-inch) mesh screening on the fish diversion structure (CP&L 1984, 

1985a, 1985b). Organisms small enough to enter the intake canal through the fish diversion 

structure may be impinged on the plant intake screens and returned to the CFE via a fish return 

flume or they may be entrained through the plant. Similarly, previous studies have documented 

a reduction in the entrainment of small organisms due to the installation of fine-mesh screens at 

the intake structure and the subsequent survival of a percentage of impinged larvae returned to 

the CFE via the fish return flume (Hogarth and Nichols 1981; CP&L 1989; PEC 2008). 

Entrainment sampling during 2008 documented the species composition, seasonality, and 

abundances of larval and postlarval organisms passing through the cooling system. The larval 

impingement study evaluated the success of the fine-mesh screens in reducing entrainment of 

these organisms. Juvenile and adult (J/A) impingement sampling documented species 

composition, densities, weights, and lengths of juvenile and adult organisms impinged during 

2008 and provided evidence of the continued effectiveness of the fish diversion structure. Note 

that the J/A impingement study addressed the impingement of organisms that would typically be 

impinged on conventional 9.4-mm (3/8-inch) mesh traveling screens. Survival study results 

from previous years were used to estimate the effectiveness of the return system for returning 

impinged organisms alive to the CFE (CP&L 1987, 1988). 

2.2 Methods

Intake canal water temperature and salinity measurements were collected from the fish return 

flume during impingement sampling. Daily freshwater flow values presented in the report were 

downloaded from the United States Geological Survey website. Total freshwater input to the 

CFE was estimated using data from stream gaging stations in the Cape Fear, Northeast Cape 

Fear, and Black Rivers according to the methods presented by Giese et al. (1979, 1985). 

The collection gear used for entrainment and impingement sampling has remained 

unchanged since 1984 (CP&L 1985a). Entrainment sampling was conducted in the discharge 

weir (Figure 1.2). Larval impingement and J/A impingement sampling were conducted in the 

fish return flume. The J/A impingement program included fish and shrimp ≥ 41 mm, portunid 

crabs ≥ 25 mm, and eels and pipefish ≥ 101 mm. Impinged organisms smaller than these size 

limits would have been entrained without use of fine-mesh screens and were analyzed with the 

larval impingement sampling program. 

Densities calculated for all larval organisms were averaged to obtain a mean number per 

1,000 m3

 of water entrained through the plant per sampling date. Densities for J/A organisms 

impinged on each sampling date were calculated by dividing the total number of organisms 

collected by the volume of water pumped through the plant. Densities were expressed as the 

number per million cubic meters of water pumped through the plant during each 24-hour 

sampling period. 
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For both entrainment and larval impingement sampling, rates and densities of total number 

of organisms and selected taxa collected were expanded to give an estimate for 24 hours. 

Entrainment and larval impingement rates per 24-hour sampling period during 2008 were 

summed to find the total number of larvae affected. The percent effectiveness (how successfully 

the organisms were kept from being entrained) of fine-mesh screens was calculated as the ratio 

between the larval impingement rate and the total number (entrainment plus larval impingement) 

affected for each sampling trip. 

An overall assessment of reductions in entrainment due to fine-mesh screens, fish return 

system, and NPDES permit limitations on Plant cooling-water flow was conducted using 

historical entrainment data collected from 1979 through 2008. However, data from 1983 were 

excluded from the analysis since fine-mesh screens and the fish return system were not fully 

operational for a portion of that year. Both of these intake modifications were completed during 

June 1983. However, data prior to 1983 can be used to estimate annual numbers entrained 

during a period with no controls in place (i.e., no fine-mesh screens, fish return system, or 

NPDES permit limitations of flow). Mean daily entrainment densities were multiplied by design 

cooling water flow and summed to obtain an annual estimate of total number entrained. Design 

flow is the rated flow of all main cooling water pumps per unit plus service water and screen 

wash flows. The summation of these flows result in a total design flow of 84.15 cms. Details 

and rated pump capacities can be found in the Proposal for Information Collection compiled as 

required by the phase II 316(b) rule (PEC 2005). Linear interpolation was used to estimate 

entrainment rates on non-sampling days. Annual numbers entrained after 1983 were calculated 

in a similar fashion with the exception that actual cooling-water flow was used. A calculated 

annual baseline entrainment rate was obtained by averaging the annual number entrained for the 

years 1979 through 1982. The estimated annual number entrained each year after 1983 was 

subtracted from the annual baseline estimate to obtain a percentage reduction from baseline due 

to the installation of fine-mesh screens, fish return system, and reduced cooling-water flow. 

Additional insight was obtained by comparing annual entrainment estimates to the mean annual 

density of larvae entering the estuary from 1979 through 1993. 

 Survival in the return system was determined for selected size classes of the dominant 

organisms that have been impinged at the BSEP in past years (CP&L 1985a, 1986, 1987, 1988). 

Survival estimates were calculated using survival rates determined during previous studies for 

fast-screen rotation (CP&L 1987, 1988). 

2.3 Results and Discussion 

2.3.1 Water Quality 

•Intake canal salinity ranged from a low of 12 ppt during September to a high of 34 ppt 

during January (Figure 2.1). Freshwater input varied sporadically during 2008 with 

peak flows occurring during March, April, September, and December. Except for 

2006, the annual mean freshwater input to the CFE remained relatively low from 

2004-2008 when compared to the long-term annual mean flow of 270 cms from 

1980-2003 (Figure 2.2). 
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•Intake canal water temperature ranged from 12.2°C during January and December to a 

high of 29.8°C during August (Figure 2.3). Mean water temperature during the peak 

recruitment season for most winter spawners (January-March) was relatively warm 

during 2006, 2007 and 2008 compared to the previous two years (Figure 2.4). Little 

difference was evident for mean summer water temperature (June-August) among 

these years. 

2.3.2 Dominant Species 

•Anchovies, Gobiosoma spp., pinfish, spot, and croaker were the most abundant taxa 

collected in entrainment samples during 2008 (Table 2.1). Shrimp larvae, Atlantic 

menhaden, portunid crab megalops, and Blennidae were also among the 10 most 

numerous taxa entrained entrained during 2008. A complete species list showing 

numbers collected can be found in Appendix 2. The annual mean density of total 

organisms collected in entrainment samples during 2008 was approximately 50% 

greater than that collected during 2007. 

•Ten taxa accounted for 96% of the total larval organisms collected in larval 

impingement samples during 2008 (Table 2.2). The most dominant larvae impinged 

were shrimp, croaker, Anchoa spp. (≥ 13 mm), spot, and pinfish. Portunid crab 

megalops, Atlantic menhaden, Blennidae, hardback shrimp, and Gobionellus spp.

were also among the top ten larval taxa impinged during 2008. Although the relative 

ranking has varied, the same ten most abundant species have generally dominated 

larval impingement samples each year since 1984. A complete species list showing 

numbers collected can be found in Appendix 2. 

•Commercially and recreationally important taxa dominated larval impingement samples 

indicating that use of fine-mesh screens successfully reduced the entrainment of these 

important taxa. The number of taxa collected in larval impingement samples by 

month was generally greater than the number collected in entrainment samples 

during 2008 due to the use of fine-mesh screens (Figure 2.5). This relationship is 

important because it indicates that use of fine-mesh screens reduces the risk of 

entrainment for the larvae found in the CFE. 

• During 2008, J/A impingement samples were numerically dominated by bay anchovy, 

white shrimp, brown shrimp, pink shrimp, and lesser blue crab (Table 2.3). Spot, 

striped anchovy, brown bar crab, blue crab, and rough silverside were also among the 

top ten species collected during 2008. These top ten species accounted for 95% of 

the number collected and approximately 89% of the biomass collected during 2008. 

Prior to intake modifications in 1983, Atlantic menhaden and larger finfish, such as 

spot and croaker, dominated both the number and biomass collected with J/A 

impingement sampling (CP&L 1980a, 1980b, 1982, 1983). This shift in species 

composition was a result of the exclusion of larger finfish by the fish diversion 

structure. This shift is significant because impingement samples have become 

dominated by shrimp and crabs. Both these taxa exhibit relatively high survival in 

the fish return system. Additional species that contributed to the biomass impinged 

include pinfish (7.8 kg), blackcheek tonguefish (7.3 kg), brief squid (6.1 kg), fringed 
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flounder (5.3 kg), threadfin shad (5.3 kg), and Atlantic cutlassfish (4.3 kg). A 

complete species list showing numbers and weights collected can be found in 

Appendix 3. 

•No rare, threatened or endangered species were collected with entrainment or 

impingement sampling during 2008. 

2.3.3 Seasonality and Abundance

•Seasonal variations for larvae entrained and impinged in 2008 were similar to seasonal 

variations observed in previous years and corresponded to the seasonality of larval 

fish in the CFE (Tables 2.4, 2.5, and 2.6; CP&L 1994). This observation is important 

since it indicates that recruitment to and within the estuary is functioning normally 

and has not been disrupted by cooling water withdrawal or other environmental 

perturbations. Minor changes in peaks of abundance in entrainment and 

impingement of organisms are normal and can be influenced by environmental 

conditions such as changing freshwater discharge to the estuary, operating fewer 

fine-mesh screens, increasing or decreasing the flow of cooling water as determined 

by plant operational needs, and sampling period (Blumberg et al 2004; Copeland et 

al. 1979; Lawler et al 1988; Thompson 1989). 

•The typical winter and summer periods of abundance observed during 2008 in the 

entrainment program were also observed in the larval impingement program 

(Table 2.6). Atlantic menhaden, spot, croaker, and pinfish, all ocean-spawned 

species, were most abundant during winter and early spring. Shrimp larvae were most 

abundant during spring, summer, and early fall. Estuarine-spawned species (e.g., 

anchovies, Gobiosoma spp., and Blennidae) were most abundant during the spring 

and summer. The period of abundance for portunid crab megalops occurred during 

the fall and early winter. Larval Gobionellus spp. was present year-round. 

•Seasonality of larger individuals collected during J/A impingement sampling were 

consistent with previous years and the natural seasonality reported for these species 

in the lower CFE by Schwartz et al. (1979). Results indicate that impingement of 

finfish was comprised mostly of young-of-year individuals too small to be excluded 

by the fish diversion structure. Impingement of significant numbers of larger fish has 

been virtually eliminated by the installation of the fish diversion structure. Atlantic 

menhaden abundant during May, June, and December were young-of-year 

individuals as indicated by modal lengths ≤ 70 mm (Table 2.7). Peak densities of 

spot and croaker collected during May, June, and September also consisted of youngof-year individuals. Bay anchovy, collected year round, was most abundant during 

the winter and spring when past data indicated that most of the individuals 

comprising the population had grown to a size large enough to be impinged on the 

coarse-mesh traveling screens. The striped anchovy was most abundant during late 

summer. Peak densities of white, brown, and pink shrimp occurred during the 

summer recruitment period. Blue crab was also abundant during the summer and 

early fall. 
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•The seasonality for total number of all organisms impinged was driven by the large 

numbers of bay anchovy collected (Table 2.7). Once bay anchovy is excluded, a 

pattern emerges where the greatest number impinged by month occurred during the 

summer months. Shrimp and blue crab were the dominant organisms impinged 

during the summer. This is significant because both taxa are characterized by high 

survival rates in the fish return system. (CP&L 1987, 1988). 

• Installation of the fish diversion structure resulted in a decline in the densities of most 

J/A organisms impinged. Species that dominated impingement prior to installation 

of the diversion structure include Atlantic menhaden, spot, croaker, and blue crabs. 

During 2008, the mean density of these species collected with J/A impingement 

sampling has been reduced by 64% for blue crabs to 99% for Atlantic menhaden in 

comparison to the average baseline density (Table 2.8). The average biomass 

(weight per million cubic meters of water) impinged for these species was reduced by 

approximately 60% for blue crabs to 99% for Atlantic menhaden when compared to 

the baseline biomass. 

2.3.4 Fine-Mesh Screens and Cooling Water Flow

•The overall effectiveness of fine-mesh screens in reducing entrainment for total 

organisms ranged from 5% in May to 53% in April (Table 2.9). The variability of 

their effectiveness in reducing entrainment was influenced by the number of finemesh screens operating, species composition, seasonality, and organism size. Species 

body size and shape have been shown to have an effect on screening efficiency for 

other species of larval fish (Tomljanovich et al. 1978; Stone & Webster Engineering 

Corporation 1984). 

• By taxon, the overall annual effectiveness ranged from 1% for Anchoa spp. (< 13 mm) 

and Gobiosoma spp. to 52% for portunid crab megalops, a valuable commercial 

species. During March and April, when fine-mesh screen efficiencies were highest, 

Unit 2 (Unit 1 refueling outage) was operating with two fine-mesh screens and one 

50% fine-mesh screen. The dominant larvae at that time were shrimp, croaker, and 

spot (Tables 2.4, 2.5, 2.6, and 2.9). The lowest fine-mesh screen efficiencies for the 

year were recorded during May when non-commercially important taxa such as goby 

(Gobiosoma spp.) and anchovy larvae (Anchoa spp. < 13 mm) were numerically 

dominant (these taxa exhibit relatively poor fine-mesh screen efficiency).

• The percentage reduction in entrainment from baseline for total organisms has ranged 

from 57% to 87% since 1983 (Figure 2.6). This meets the entrainment reduction 

thresholds (60-90%) proposed by the phase II 316(b) rule currently in revision. 

Comparison of the annual number entrained to the mean annual larval density from 

1979 through 1993 indicated that the reductions in entrainment were due to the 

installation of the fine-mesh traveling screens and the fish return system plus reduced 

cooling water flow and not due to any declines in the abundance of larvae in the CFE 

(Figure 2.7). Although there was normal inter-annual variability in the density of 

larvae collected from the CFE through 1993 there was no decreasing trend in density.
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Progress Energy Carolinas, Inc. 2-6 Environmental, Health and Safety Services Section

2.3.5 Survival Estimates

•Fourteen of the most commonly impinged larval taxa were previously tested for 

survival on fast-screen rotation speed (Table 2.10). These fourteen taxa accounted 

for approximately 87% of the total larval impingement catch. Survival during fastscreen rotation ranged from approximately 1% for anchovies (Anchoa spp. ≥ 13 mm) 

to approximately 96% for pink and white shrimp. 

•Approximately 44% of the selected larval organisms were returned alive to the estuary. 

•Eleven taxa of the dominant J/A organisms impinged were previously tested for 

survival during fast-screen rotation (Table 2.11; CP&L 1987, 1988). In addition, 

survival of star drum and silver perch was estimated using data for two closely 

related species (croaker and spot). These eleven taxa accounted for approximately 

93% of the total number collected and 90% of the total weight collected. 

•Excluding bay anchovy, survival ranged from 16% for Atlantic menhaden to 96% for 

blue crabs. The most valuable commercial species (shrimp and blue crabs) exhibited 

the highest survival rates. Survival estimates indicated that 91% of the total number 

and 92% of the total biomass of organisms impinged, excluding bay anchovy, were 

returned alive to the estuary during 2008. 

2.4 Summary and Conclusions

The Brunswick Steam Electric Plant intake modifications and operational measures 

continued to be effective in reducing the number of organisms affected by the withdrawal of 

cooling water from the Cape Fear Estuary. Evidence supporting this conclusion includes species 

composition and abundance of organisms entrained and impinged. Anchovies, gobies, spot, 

croaker, pinfish, shrimp and crabs were the dominant larvae entrained and impinged. Use of finemesh screens has decreased the risk of entrainment for spot, croaker, pinfish, shrimp and crabs. 

These organisms may potentially be at more risk of being entrained since they are spawned 

offshore and pass by the plant intake in order to reach the nursery areas in the Cape Fear Estuary. 

Conversely, anchovies and gobies are at less risk since they are estuarine residents and spawning 

occurs throughout the entire estuary. Overall, use of fine-mesh screens has reduced the numbers 

of all organisms entrained by up to approximately 52%. The greatest reductions in entrainment 

due to fine-mesh were evident for shrimp and crab larvae, the most valuable commercial species. 

Larvae that would have been entrained were returned alive by the fish return system to the CFE 

in significant numbers. Overall reductions in the annual number entrained due to a combination 

of fine-mesh screens, the fish return system, and reduced cooling water flow ranged from 57% to 

87% since 1983. Based on survival estimates data, approximately 44% of the larvae tested for 

survival were returned alive to the estuary. The most valuable commercial taxa, shrimp and crab 

larvae, exhibited the greatest survival (> 87%). 

Considered together, the fish diversion structure and fish return system has substantially 

reduced the impingement mortality of larger organisms due to cooling water withdrawal. The 

fish diversion structure excludes many of the larger fish and shellfish from the canal. Those that 

do get in and subsequently become impinged are returned alive to the CFE by the fish return 
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system. Installation of the fish diversion structure significantly reduced the number of larger 

organisms impinged at the plant. Conservative estimates of the effectiveness were between 

64%-99% for the historically dominant species impinged. In addition to a reduction in numbers, 

a shift to the impingement of smaller finfish has resulted as well. This shift to smaller 

individuals is important because the larger individuals that are being excluded (saved) are the 

reproducing members of the population. In addition, the natural mortality rates (predation, 

weather, tides, etc.) of smaller individuals is relatively high compared to the natural mortality 

rates of older, larger individuals so many of the smaller individual would not survive to maturity 

even in the absence of Plant operation. The species composition of organisms collected with 

impingement sampling also shifted to a greater percentage of shrimp and blue crabs rather than 

larger finfish as a result of the fish diversion structure. This shift in species composition is 

significant since juvenile and adult shrimp and crabs exhibit excellent survival in the fish return 

system (> 90%). 

 There has been no evidence of long-term environmental impact despite some variability 

in entrainment rates due to environmental and plant operating conditions. The seasonality of 

organisms collected in the entrainment, larval impingement, and J/A impingement studies during 

2008 were similar to previous years and corresponded to the natural seasonality of larval 

organisms in the Cape Fear Estuary. Fish population studies conducted during 1999, 2001 and 

2002 indicated no declines in abundance of any species or shifts in species composition 

compared to long-term data collected from the 1980s through 1993 even for bay anchovy, a 

species exhibiting poor survival in the fish return system. Intensive assessments throughout the 

1970s, before the installation of fine-mesh screens and the fish return system, indicated that 

cooling-water withdrawal had no measurable adverse effect on fish and shellfish populations in 

the Cape Fear Estuary. Annual population levels in the Cape fear Estuary were determined by 

temperature, freshwater flow, and salinity. 
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Table 2.1 Annual mean density (no./1000 m3) and percent of total for the ten most 

abundant taxa collected during entrainment sampling at the Brunswick 

Steam Electric Plant during 2007 and 2008 (based on ranking for 2008).

 

 2007 2008 

 Annual mean Annual mean 

Taxon density Percent density Percent

 

Anchoa spp. (> 13 mm) 4.0 4.3 28.8 20.8

Gobiosoma spp. 10.1 11.1 22.7 16.4 

Pinfish 0.8 0.9 20.8 15.0 

Spot 40.5 44.0 15.1 10.9 

Croaker 10.2 11.1 14.8 10.7

Anchoa spp. (< 13 mm) 7.9 8.6 11.4 8.2 

Shrimp 4.2 4.6 8.0 5.8 

Atlantic menhaden 0.7 0.8 3.2 2.3 

Portunid crab megalops 2.6 2.8 2.5 1.8 

Blennidae 0.9 1.0 1.5 1.1 

Other taxa (n = 39 for 2007) 7.5 6.6 9.9 7.1 

 (n = 35 for 2007) 

 

Total organisms+

 92.1 100.0 138.7 100.0 

 

+ Total may vary from summation due to rounding of individual taxon. 
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Table 2.2 Total number of the ten most abundant taxa estimated for larval 

impingement sampling at the Brunswick Steam Electric Plant during 2007 

and 2008 (based on ranking for 2008). 

 

 2007 2008 

Taxon Total number+

 Percent Total number+ Percent 

 

Shrimp 2.2 x 106

 16.6 3.0 x 106 24.4 

Croaker 2.6 x 106 19.4 2.3 x 106 19.0

Anchoa spp. (≥13 mm) 1.0 x 106

 7.7 2.3 x 106 18.9 

Spot 4.6 x 106

 34.9 1.8 x 106 14.3

Pinfish 1.0 x 105

 0.8 9.9 x 105 8.1 

Portunid megalops 7.8 x 105

 6.0 4.6 x 105 3.8

Atlantic menhaden 1.5 x 105 1.2 4.0 x 105 3.3 

Blennidae 2.4 x 104 0.2 2.6 x 105 2.2 

Hardback shrimp 2.2 x 105 1.6 1.4 x 105 1.2 

Gobionellus spp. 1.1 x 105 0.9 1.3 x 105 1.0 

Other taxa (n = 51 for 2007) 1.4 x 106

 10.8 4.9 x 105 4.0 

 (n = 51 for 2008) 

 

Total& 13.1 x 106 100.0 12.2 x 106 100.0 

+

Total number is a sum of the twelve sampling-day totals. 

&

Total may vary from summation due to rounding of individual taxon. 
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Table 2.3 Total number, total weight, and percent of total of the ten most abundant 

juvenile and adult organisms collected in the Brunswick Steam Electric Plant 

impingement samples during 2008.

 

Taxon Number+

 Percent& Weight (kg)+ Percent&

 

Bay anchovy 82,442 44.9 70.9 10.1

White shrimp 39,334 21.4 335.0 47.5 

Brown shrimp 29,645 16.1 80.4 11.4 

Pink Shrimp 6,533 3.6 11.0 1.6 

Lesser blue crab 5,525 3.0 41.4 5.9 

Spot 2,950 1.6 17.4 2.5 

Striped anchovy 2,285 1.2 7.2 1.0 

Brown bar crab 2,053 1.1 4.9 0.7 

Blue crab 1,598 0.9 59.2 8.4 

Rough silverside 1,488 0.8 2.2 0.3 

Other taxa (n = 72 for 2008) 9,821 5.3 76.0 10.8 

 

Total 183,673 100.0 705.5 100.0

 

+

Numbers and weights are sums of the twelve sampling day totals. 

&

Percentages may not add up to 100 due to rounding. 
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Table 2.4 Entrainment densities (mean no./1000 m3 per sampling day) of selected taxa+

at the Brunswick Steam Electric Plant during 2008. 

Month

Taxa Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 

 

Anchoa spp. 

(< 13 mm) 

0 0 0 0 870 133 38 30 5 17 0 0

 

Anchoa spp. 

(> 13 mm) 

1,764 14 41 21 61 175 0 47 351 186 23 81

 

Spot 16 1,053 236 143 0 0 0 0 0 0 0 0

Pinfish 50 1,924 0 18 0 0 0 0 0 0 0 3

Atlantic croaker 417 208 238 417 3 0 0 0 44 35 20 39

 

Atlantic menhaden 9 58 108 131 0 0 0 0 0 0 4 0

 

Combtooth 

blennies 

0 0 0 0 52 43 34 12 2 0 0 0

Gobionellus spp. 5 6 3 33 6 0 0 12 7 4 0 3

 

Gobiosoma spp. 0 0 0 0 666 1,154 122 151 90 0 0 0

 

Portunid crab 

megalops 

 0 2 0 3 6 22 7 6 1 0 195 0

Shrimp 19 35 77 322 21 152 86 29 14 0 16 0

 

Hardback shrimp 0 0 0 0 0 53 3 9 0 0 0 0

Total organisms 2,302 3,324 752 1,178 1,861 1,966 376 355 554 252 266 134

+

Selected taxa comprised ≥ 1% of the total sampled in either entrainment or larval impingement 

sampling.
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Table 2.5 Entrainment rates (million per sampling day) of selected taxa+ at the 

Brunswick Steam Electric Plant during 2008. 

Month

Taxa Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 

 

Anchoa spp. 

(< 13 mm) 

0 0 0 0 4.599 0.703 0.208 0.162 0.027 0.090 0 0 

 

Anchoa spp. 

(> 13 mm) 

7.957 0.064 0.091 0.055 0.324 0.926 0 0.256 1.854 0.985 0.123 0.365

 

Spot 0.070 4.751 0.533 0.377 0 0 0 0 0 0 0 0 

Pinfish 0.224 8.679 0 0.047 0 0 0 0 0 0 0 0.015

Croaker 1.883 0.936 0.536 1.101 0.016 0 0 0 0.231 0.185 0.104 0.177

Atlantic menhaden 0.040 0.263 0.243 0.345 0 0 0 0 0 0 0.021 0 

Combtooth 

blennies 

0 0 0 0 0.273 0.226 0.187 0.064 0.010 0 0 0 

Gobionellus spp. 0.021 0.028 0.007 0.086 0.031 0 0 0.064 0.039 0.019 0 0.015

 

Gobiosoma spp. 0 0 0 0 3.518 6.099 0.665 0.824 0.476 0 0 0 

Portunid crab 

megalops 

0 0.007 0 0.008 0.031 0.116 0.037 0.032 0.008 0 1.029 0 

Shrimp 0.086 0.159 0.173 0.852 0.110 0.802 0.471 0.161 0.072 0 0.086 0 

 

Hardback shrimp 0 0 0 0 0 0.280 0.016 0.048 0 0 0 0 

Total organisms 10.385 14.996 1.697 3.113 9.834 10.392 2.053 1.937 2.927 1.333 1.404 0.603

+

Selected taxa comprised ≥ 1% of the total sampled in either entrainment or larval impingement 

sampling. 
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Table 2.6 Estimated total number (million per sampling day) of selected taxa+ collected 

with monthly larval impingement sampling at the Brunswick Steam Electric 

Plant during 2008. 

Month

Taxa Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec 

 

Anchoa spp. 

(< 13 mm) 

0 0 0 0 0.038 0.009 0.001 0.003 0.001 0.005 0 0

 

Anchoa spp. 

(> 13 mm) 

1.350 0.340 0.017 0.040 0.043 0.069 0 0.013 0.177 0.097 0.049 0.113

 

Spot 0.044 0.959 0.392 0.346 0.010 0.001 0 0 0 0 0 0

 

Pinfish 0.068 0.906 0 0.011 0.002 0.001 0 0 0 0 0 0.001

 

Atlantic croaker 0.372 0.267 0.392 1.255 0.002 0 0 0 0.003 0.015 0.011 0.010

 

Atlantic menhaden 0.006 0.032 0.151 0.212 0.001 0 0 0 0 0 0 0

 

Combtooth 

blennies 

0 0 0 0 0.261 0.002 0 0 0 0 0 0

Gobionellus spp. 0.007 0.001 0.011 0.097 0.004 0 0 0 0.005 0.001 0 0.015

 

Gobiosoma spp. 0 0 0 0 0.013 0.023 0.001 0.013 0.013 0.001 0 0

 

Portunid crab 

megalops 

 0.025 0.998 0.010 0.087 0.082 0.015 0.014 0.005 0.019 0.003 0.090 0.014

Shrimp 0.054 0.079 0.381 1.323 0.049 0.478 0.442 0.076 0.074 0.012 0.012 0.002

 

Hardback shrimp 0 0 0.006 0 0 0.023 0.038 0.065 0.004 0.004 0 0.002

 

Total organisms 1.951 2.741 1.365 3.443 0.567 0.655 0.513 0.194 0.345 0.141 0.181 0.148

 

+

Selected taxa comprised > 1% of the total sampled in either entrainment or larval impingement 

sampling.
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Table 2.7 Density (no./million m3 of water entrained during each 24-hour sampling 

period) and modal length for selected species+ collected with juvenile and adult 

impingement sampling per month at the Brunswick Steam Electric Plant 

during 2008. 

Month

Taxa Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec 

 

Bay anchovy& 

density 1,385 470 581 481 508 1,356 10 28 1,202 74 2,386 9,325

 

Atlantic 

menhaden 

density 4 < 1 0 0 17 13 0 0 0 0 7 39

modal length 110 IN§ 50 50 50 65,70

 

Striped anchovy 

density 5 1 112 63 258 0 0 389 1,130 58 252 17

 

Spot 

density < 1 < 1 0 0 95 120 1 2 17 8 3 365

modal length IN IN 45 55 IN IN 110 95,100 IN 65

 

Croaker 

density 0 1 0 0 4 12 0 0 18 0 4 0

modal length IN IN 55 55 IN

 

White shrimp 

density 3 13 32 3 16 0 16 96 5,335 321 47 1,849

modal length IN 95 135 IN 160 55 45, 60 95 100 75 100

 

Brown shrimp 

density 0 0 0 0 3 5,390 42 94 49 22 5 0

modal length IN 70 95 110 70 70 45

 

Pink shrimp 

density 0 7 0 0 13 0 1 33 1,060 103 15 17

modal length 55 115 IN 60, 65 55 50 40 70, 85

 

Blue crab& 

density 

14 2 0 0 32 224 11 42 929 30 56 11

 

Total organisms 150 44 166 55 269 5,958 87 611 8,666 630 412 2,622

excluding bay anchovy 

 

Total organisms 1,535 514 747 536 777 7,314 97 639 9,868 704 2,798 11,947

+

Selected species, with the exception of bay anchovy, are commercially and recreationally important species that 

accounted for greater than 1% of the total catch by number or weight. 

&length-frequency analysis was not conducted on bay anchovy or blue crab data. 

§

IN= insufficient number collected for length-frequency analysis 
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Table 2.8 Mean density and biomass of selected juvenile and adult organisms indicating 

reductions in density and biomass impinged during 2008 as a result of the fish 

diversion structure. 

Density (number/million m3) + Biomass (kg/million m3) +

Taxa Pre-diversion& 2008 

Percent 

Reduction Pre-diversion& 2008 

Percent 

Reduction

 

Atlantic menhaden 5,481 7 99.9 38.8 0.04 99.9 

 

Spot 362 53 85.4 3.7 0.31 91.6 

 

Croaker 199 4 98.0 5.7 0.03 99.4 

 

Blue crabs 351 128 63.6 4.5 1.80 59.9 

 

 

Total 

Organisms 10,538 3,293 68.8 60.6 12.65 79.1 

+

Density and biomass are expressed as number and weight (kg) of organisms impinged per 

million m3 of water pumped by the plant. 

&

These values are means of all years (1977-1981) prior to completion of the diversion structure. 
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Table 2.9 Percent effectiveness+ of fine-mesh screens in reducing the number entrained 

per day for selected taxa at the Brunswick Steam Electric Plant during 2008. 

 Month 

Taxa Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Annual

 

Anchoa spp. 

(< 13 mm) NP& NP NP NP 1 1 0 2 4 5 NP NP 1 

 

Anchoa spp. 

(> 13 mm) 15 84 16 42 12 7 NP 5 9 28 24 15 23 

 

Atlantic 

menhaden 13 11 38 38 100 NP NP NP NP NP NP NP 31 

 

Spot 39 17 42 48 100 100 NP NP NP NP NP NP 23 

 

Croaker 16 22 42 53 11 NP NP NP 1 8 10 5 31 

 

Pinfish 23 9 NP 19 100 100 NP NP NP NP NP 6 10 

 

Combtooth 

blenny NP NP NP NP 49 1 0 0 0 NP NP NP 26 

 

Gobionellus spp. 22 15 42 56 11 13 44 NP NP 6 6 8 20 

 

Gobiosoma spp. NP NP NP NP < 1 < 1 < 1 2 3 100 NP NP 1 

 

Shrimp 39 33 69 61 31 37 48 32 51 100 12 100 50 

 

Hardback shrimp NP NP 100 NP NP 8 70 58 100 100 NP 100 29 

Portunid crab 

megalops 100 99 100 92 73 11 27 14 70 100 8 100 52 

 

Total 

Organisms 16 15 45 53 5 6 20 9 11 10 11 20 17 

+

Percent effectiveness = [no. collected in larval impingement samples/( no. collected in larval 

impingement samples + no. collected in entrainment samples)] x 100 

&

NP = Not Present. 
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Table 2.10 Estimated numbers and percent survival of selected larval organisms 

collected during fine-mesh screen sampling (larval impingement) at the 

Brunswick Steam Electric Plant during 2008. 

 Total Percent+ Number&

Taxa number survival survived 

 

Shrimp 2,981,376 90.3 2,692,183 

Croaker 2,327,616 33.7 784,407 

Anchoa spp. > 13 2,309,184 0.7 16,164 

Spot 1,750,896 29.4 514,736 

Portunid Megalops 463,104 87.0 402,900 

Atlantic menhaden 403,056 3.2 12,896 

Hardback shrimp 142,416 78.8 112,224 

Gobionellus spp. 125,568 15.4 19,337 

Blue crabs 69,696 91.7 63,911 

Flounder spp. 41,616 93.2 38,786 

Pink and white shrimp 14,832 95.8 14,209 

Weakfish 14,256 12.6 1,796 

Mullet 13,248 69.8 9,247 

Prionotus spp. 5,616 89.8 5,043 

 

 

Total selected taxa 10,662,480 44.0 4,687,869 

 

+

Reference: CP&L 1987 and 1988 (fast-screen rotation). 

 &The number survived is a total for the 12 sampling days and not the entire year. 
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Table 2.11 Estimated numbers, biomass (kg), and percent survival of selected juvenile 

and adult organisms collected during impingement sampling at the 

Brunswick Steam Electric Plant during 2008. 

 Total Total Percent Number Biomass 

Taxa number biomass survival+ survived& survived 

 

Bay anchovy 82,422 70.9 4.9 4,040 3.5 

Pink & white shrimp 45,867 345.9 93.7 42,977 324.1 

Brown shrimp 29,645 80.4 90.4 26,799 72.6 

Blue crabs 7,164 100.9 96.2 6,892 97.0 

Spot 2,950 17.4 60.4 1,782 10.5 

Blackcheek tonguefish 1,206 7.3 83.1 1,002 6.0 

Atlantic menhaden 392 2.5 15.6 61 0.4 

Croaker 202 1.8 45.1 91 0.8 

Star drum¶ 125 0.7 45.0 83 0.3 

Weakfish 100 0.6 35.0 35 0.2 

Silver perch¶ 74 2.3 60.4 45 1.4 

Striped mullet 25 0.2 92.0 23 0.2 

Flounder 11 0.4 71.1 8 0.3 

 

 

Total 170,263 631.1 83,838 517.4 

 

Percent survival 49.2 82.0 

(selected taxa) 

 

Percent survival 90.9 91.7 

(selected taxa excluding bay 

anchovy) 

+

Reference: CP&L 1988 (fast-screen rotation). 

&

Number and weight collected and survived are a total for the 12 sampling days and not the 

entire year. 

¶

Survival percentages for star drum and silver perch are estimates based upon data for similar 

species (croaker, spot) 

 
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Progress Energy Carolinas, Inc. 2-19 Environmental, Health and Safety Services Section

0

5

10

15

20

25

30

35

40

0

200

400

600

800

1,000

1,200

Salinity (ppt)

Freshwater Flow (cms)

Freshwater Flow Intake canal salinity

Figure 2.1 Mean daily freshwater flow to the Cape Fear Estuary and monthly intake 

canal salinity at the Brunswick Steam Electric Plant during 2008. 

0

100

200

300

2004 2005 2006 2007 2008

Freshwater Flow (cms)

270 cms = mean annual flow 1980-2003

Figure 2.2 Mean annual freshwater flow to the Cape Fear Estuary, 2004–2008.
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0

5

10

15

20

25

30

35

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

Temperature (°C)

Figure 2.3 Mean monthly intake canal water temperature (°C) at the Brunswick Steam 

Electric Plant during 2008. 

0

5

10

15

20

25

30

2004 2005 2006 2007 2008

Temperature (°C)

Winter Summer

Figure 2.4 Mean winter and summer intake canal water temperatures (°C) at the 

Brunswick Steam Electric Plant, 2004-2008. 
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14 15 14

20

23 23

16 17

20

12 12 12

53

13 15

10

13

24

19

12 13 14

7 9

6

46

0

10

20

30

40

50

60

70

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

Number of Taxa

Larval impingement

Entrainment

Figure 2.5 Number of taxa collected in entrainment and larval impingement samples at 

the Brunswick Steam Electric Plant during 2008. 

Photograph of February 2006 larval impingement sample.

These larvae would have been entrained without the use of fine-mesh screens 

Provided for information only and is not cited in the text. 

 
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0

20

40

60

80

100

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

197919801981198219831984198519861987198819891990199119921993199419951996199719981999200020012002200320042005200620072008

Percent Reduction

Number Entrained (millions)

Percent reduction

Baseline

Fine-mesh screens and return system installed 1983

Annual number entrained

Figure 2.6 Annual number of total organisms entrained at the Brunswick Steam Electric 

Plant and percent reduction from baseline entrainment estimates, 1979-2008. 

(Annual numbers entrained prior to 1983 were averaged to obtain the baseline 

entrainment estimate.) 

0

500

1000

1500

2000

2500

3000

3500

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

197919801981198219831984198519861987198819891990199119921993199419951996199719981999200020012002200320042005200620072008

Larval density (Nu./1000 m3)

Number Entrained (millions)

Annual number entrained

Mean annual larval density 

Figure 2.7 Annual number of total organisms entrained at the Brunswick Steam Electric 

Plant, 1979-2008 and the annual mean density of total larval organisms 

collected during larval fish sampling in the Cape Fear Estuary, 1979-1993 

(Estuarine larval fish sampling was discontinued after 1993) . 
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3.0 REFERENCES

Blumberg, A. F., D. J. Dunning, H. Li, D. Heimbugh, and W. R. Geyer. 2004. Use of a particle 

tracking model for predicting entrainment at power plants on the Hudson River. Estuaries. 27 

(3): 515 - 526 . 

CP&L. 1984. Brunswick Steam Electric Plant annual biological monitoring report, 1983. 

Carolina Power & Light Company, New Hill, NC. 

 .1985a. Brunswick Steam Electric Plant annual biological monitoring report, 1984. Carolina 

Power & Light Company, New Hill, NC. 

 . 1985b. Brunswick Steam Electric Plant Cape Fear Studies, Interpretive Report. Carolina 

Power & Light Company, New Hill, NC. 

 . 1986. Brunswick Steam Electric Plant annual biological monitoring report, 1985. Carolina 

Power & Light Company, New Hill, NC. 

 . 1987. Brunswick Steam Electric Plant annual biological monitoring report, 1986. Carolina 

Power & Light Company, New Hill, NC. 

 . 1988. Brunswick Steam Electric Plant annual biological monitoring report, 1987. Carolina 

Power & Light Company, New Hill, NC. 

 . 1989. Brunswick Steam Electric Plant annual biological monitoring report, 1988. Carolina 

Power & Light Company, Southport, NC. 

Copeland, B. J., R. G. Hodson, and R. J. Monroe. 1979. Larvae and postlarvae in the Cape Fear 

Estuary, North Carolina, during operation of the Brunswick Steam Electric Plant, 1974-1978. 

North Carolina State University, Raleigh, NC. 

Giese, G. L., H. B. Wilder, and G. G. Parker, Jr. 1979. Hydrology of major estuaries and sounds 

of North Carolina. United States Geological Survey. Water resources investigations 79-46. 

Raleigh, NC. 

 . 1985. Hydrology of major estuaries and sounds of North Carolina. United States 

Geological Survey. Water-supply paper 2221. Alexandria, Va. 

Hogarth, W. T. and K. L. Nichols. 1981. Brunswick Steam Electric Plant intake modifications to 

reduce entrainment and impingement losses. Carolina Power & Light Company, New Hill, NC. 

Lawler, J. P., M. P. Weinstein, H. Y. Chen and T. L. Englert. 1988. Modeling the physical and 

behavioral mechanisms influencing the recruitment of spot and Atlantic croaker to the Cape 

Fear Estuary. Am. Fish. Soc. Sym. 3: 115-131. 

PEC. 2005. Progress Energy Brunswick Steam Electric Plant proposal for information 

collection. NPDES Permit No. NC0007064. Progress Energy Carolinas Inc., Raleigh, NC. 
Brunswick Steam Electric Plant 2008 Biological Monitoring Report 

Progress Energy Carolinas, Inc 3-2 Environmental, Health and Safety Services Section

 . 2008. Brunswick Steam Electric Plant 2007 biological monitoring report. Progress Energy 

Carolinas Inc., Raleigh, NC. 

Schwartz, F. J., P. Perschbacher, L. Davidson, C. Simpson, D. Mason, M. McAdams, K. Sandoy 

and J. Duncan. 1979. An ecological study of fishes and invertebrate macrofauna utilizing the 

Cape Fear River Estuary, Carolina Beach Inlet, and adjacent Atlantic Ocean, 1973-1977. 

BSEP Cape Fear Studies, Volume XIV. Report to Carolina Power & Light Co., Institute of 

Marine Sciences, University of North Carolina, Morehead City, NC. 

Stone & Webster Engineering Corporation. 1984. Advanced intake technology study. Research 

project 2214-2. Prepared for the Electric Power Research Institute. Prepared by Stone & 

Webster Engineering Corporation. Boston, MA. 

Thompson, T. E. 1989. Factors limiting the movement of spot, Leiostomus xanthurus, into a 

freshwater-oligohaline tidal marsh. Master’s thesis. Department of Biological Sciences, 

University of North Carolina at Wilmington, Wilmington, N.C. 

Tomljanovich, D. A., J. H. Heuer, and C. W. Voigtlander. 1978. A concept for protecting fish 

larvae at water intakes. Trans. Amer. Fish. Soc. 30:105 - 106. 
Brunswick Steam Electric Plant 2008 Biological Monitoring Report 

Progress Energy Carolinas, Inc. A-1 Environmental, Health and Safety Services Section

APPENDICES 

Appendix 1. Summary of historical environmental studies conducted in association with 

the Brunswick Steam Electric Plant, 1968-2008. 

As part of the initial nuclear licensing efforts Carolina Power & Light Company (CP&L, 

predecessor to Progress Energy Carolinas, Inc) commenced environmental impact studies in 

1968. Physical/chemical studies included dye and flow studies, water chemistry, and thermal 

studies. Biological studies included phytoplankton, zooplankton, benthos and larval fish and 

shellfish diversity, distribution and abundance studies in the main stem of the estuary. Juvenile 

and adult fish and shellfish population studies were also conducted in the estuary. Special 

emphasis was placed on Walden Creek and Snow’s Marsh adjacent to the plant’s intake canal. 

Entrainment and impingement studies were also conducted after Unit 2 came online in 1974. In 

addition, thermal tolerance, swimming performance studies and marsh productivity studies were 

conducted. 

Studies were expanded and intensified in 1976 to address the potential adverse impact on 

the entire estuary by the intake under full 2-unit operation. These comprehensive studies were 

developed through an interagency review group assembled at CP&L’s initiative and included 

representatives of the EPA, NRC, National Marine Fisheries Service, United States Fish and 

Wildlife Service, North Carolina Division of Marine Fisheries, North Carolina Division of 

Environmental Management (predecessor to NC DENR), the League of Women Voters, and 

CP&L. Exhaustive dye tracer, hydrographic, tidal, temperature, and salinity studies were 

conducted to model estuarine flow dynamics relative to plant intake flows. Various gear 

efficiency and sampling methodology studies were conducted to ensure that statistically valid 

data were collected. The biological studies were modified to provide adequate data concerning 

the larval, juvenile, and adult fish and shellfish populations having the greatest potential to be 

adversely affected by plant operation. In addition to weekly entrainment and impingement 

studies, population studies were conducted in the near-shore ocean, main stem estuary, estuarine 

shallows, and tidal creek nursery areas from below Southport, NC upstream to the vicinity of 

Wilmington, NC. Specific criteria studied included species composition plus spatial, seasonal, 

and inter-annual abundance as well as age, growth, dietary, and tagging studies. The principal 

investigators from CP&L, NCSU, Institute of Marine Science and Lawler, Matusky and Skelly 

consultants used results of these studies to determine the mechanisms by which larvae enter and 

are retained in this intensively flushed estuary and to provide insight regarding the lack of any 

detectable adverse environmental impact on fish and shellfish populations due to cooling water 

withdrawal. Results of these studies were compiled in the 20 volume Cape Fear Studies. 

Beginning in 1980 and continuing through 1993, CP&L conducted a long-term 

Biological Monitoring Program that would provide for the continued assessment of the impact 

that the cooling water withdrawal might have on the Cape Fear River Estuary. Using historic 

biological study results as a guide, particular emphasis was placed on marine fisheries. With 

some modification, these Biological Monitoring Studies were a continuation of the studies 

conducted since 1976, thus, allowing for long-term trending of results. Certain studies were also 

expanded or added to address the effectiveness of the circa 1983 intake modifications in reducing 

the number of organisms entrained and impinged. Beginning in 1984 a larval impingement 

study was conducted in addition to the standard entrainment and impingement studies as 
Brunswick Steam Electric Plant 2008 Biological Monitoring Report 

Progress Energy Carolinas, Inc. A-2 Environmental, Health and Safety Services Section

Appendix 1. continued 

another means to assess the success of fine-mesh screens in reducing entrainment of larvae. 

Larval fish sampling was conducted in the ship channel and the mouths of two major tidal creek 

nursery areas. A larval fish discrete depth sampling study was conducted to better understand the 

distribution of larvae during recruitment to the estuary and to validate the standard larval fish 

study. A marsh nursery study using trawl, seine, and rotenone sampling was conducted to assess 

recruitment to and use of the tidal creek nursery areas with special interest placed on Walden 

Creek adjacent to the Plant’s intake canal and several nursery areas upstream of the intake canal. 

Sampling stations also included a location in the fish return basin. This station along with a 

special tagging study demonstrated that juvenile fish and shellfish used the return basin as a 

shallow water nursery area in a fashion similar to the headwaters of a natural tidal creek. A 

nekton study using trawl and gill net sampling was conducted to assess the populations of 

juvenile and adult fish and shellfish that could potentially be subject to impingement at the plant 

intake structure. Sampling stations in the CFE ranged from below Southport, NC to the vicinity 

of Wilmington, NC. Several sampling stations in the intake canal were used as an additional 

means of assessing the success of the fish diversion structure in reducing impingement. Survival 

studies were conducted in the fish return system to assess the success of the return system in 

returning larval, juvenile, and adult organisms alive to the estuary. A weekly temperature and 

salinity study was conducted along the main stem of the estuary since historic results indicated 

that freshwater flow, salinity, and temperature were the main determinants of fish and shellfish 

distribution and abundance in the estuary. 

Beginning in 1994 and continuing through the current permit cycle, the biological 

monitoring program was significantly reduced with the concurrence of State regulatory and 

resource agencies. Because of almost two decades of data demonstrating that the cooling water 

withdrawal has no adverse impact to the fish and shellfish populations in the estuary, the 

monitoring program was reduced to concentrate on entrainment and impingement only. This 

allowance was based on the fact that if the impingement mortality and entrainment performance 

remains relatively consistent then the environment remains protected. Sampling frequency was 

reduced to monthly sampling and results demonstrated the continuing effectiveness of the intake 

modifications in reducing entrainment and impingement of fish and shellfish. Periodic special 

study trawl surveys conducted in the marsh/tidal creek nursery areas continued to show no 

adverse impact on the recruitment to and use of these nursery areas by juvenile fish and shellfish. 

PEC believes over three decades of biological and environmental monitoring has resulted in one 

of the most extensive and informative data bases concerning our nation’s estuaries. These data 

can provide valuable insight regarding the ecology of our nation’s estuaries and any future phase 

II 316(b) regulations once the rule becomes finalized. 
Brunswick Steam Electric Plant 2008 Biological Monitoring Report 

Progress Energy Carolinas, Inc. A-3 Environmental, Health and Safety Services Section

Appendix 2. Number+of larval organisms collected during entrainment and larval 

impingement sampling at the Brunswick Steam Electric Plant during 2008. 

 

Number 

collected 

Number 

collected 

Scientific name Common name entrainment impingement 

 

Elopidae Tarpons 

Elops saurus (leptocephalus) Ladyfish (leptocephalus) 2 38 

Megalops atlantica (leptocephalus) Tarpon (leptocephalus) 0 0 

Anguillidae Freshwater eels 

Anguillia rostrata American eel 1 3 

Ophichthidae Snake eels 1 

Myrophis punctatus (leptocephalus) Speckled worm eel 17 154 

Myrophis punctatus Speckled worm eel 4 15 

Ophichthus gomesi Shrimp eel 0 1 

Clupeidae Herrings 

Brevoortia tyrannus Atlantic menhaden 120 740 

Engraulidae Anchovies 

Anchoa spp. < 13 mm Anchovy larvae < 13 mm 655 127 

Anchoa spp. ≥ 13 mm Anchovy larvae ≥ 13 mm 1,654 4,335 

A. mitchilli Bay anchovy 11 0 

A. hepsetus Striped anchovy 1 0 

Synodontidae Lizardfishes 

Synodus foetens Inshore lizardfish 1 1 

Ophidiidae Cusk-eels 

Ophidion welshi Crested cusk-eel 0 0 

Batrachoididae Toadfishes 

Opsanus tau Oyster toadfish 0 0 

Belonidae Needlefishes 

Strongylura marina Atlantic needlefish 0 0 

Exocoetidae Flying fishes 

Hyporhamphus unifasciatus Silverstripe halfbeak 0 1 

Cyprinodontidae Killifishes 

Cyprinodon variegates Sheepshead minnow 0 1 

Fundulus heteroclitus Mummichog 5 0 

Fundulus majalis Striped killifish 0 33 

Poeciliidae Livebearers 

Poecilia latipinna Sailfin molly 0 0 

Gadidae Codfishes 

Urophycis floridana Southern hake 0 1 

Atherinidae Silversides 56 2 

Menidia menidia Atlantic silverside 0 0 

Syngnathidae Pipefishes and seahorses 

Syngnathus spp. Unidentified pipefish 2 0 

S. fuscus Northern pipefish 3 9 

S. louisianae Chain pipefish 2 19 

Hippocampus erectus Lined seahorse 0 0 

Triglidae Searobins 

Prionotus spp. Searobin 5 10 

P. carolinus Northern searobin 0 1 

P. tribulus Bighead searobin 0 2 

Serranidae Seabasses 

Myctoperca spp. Grouper 0 0 

Percichthyidae Temperate basses 

Morone spp. Temperate bass 0 0 
Brunswick Steam Electric Plant 2008 Biological Monitoring Report 

Progress Energy Carolinas, Inc. A-4 Environmental, Health and Safety Services Section

Appendix 2 continued 

Number 

collected

Number 

collected

Scientific name Common name entrainment impingement

 

Carangidae Jacks 

Caranx hippos Crevalle jack 0 2 

Chloroscombrus chrysurus Atlantic bumper 1 0 

Selene vomer Lookdown 0 0 

Trachinotus carolinus Florida pompano 0 0 

T. falcatus Permit 0 0 

Oligoplites saurus Leatherjacket 0 0 

Lutjanidae Snappers 0 0 

Lutjanus griseus Gray snapper 0 0 

Centrachidae Sunfishes 

Lepomis spp. Sunfish larva 0 0 

Gerridae Mojarras 7 5 

Haemulidae Grunts 11 0 

Orthopristis chrysoptera Pigfish 27 41 

Sparidae Porgies 

Lagodon rhomboides Pinfish 1,242 1,743 

Archosargus probotocephalus Sheepshead 0 0 

Sciaenidae Drums 

Bairdiella chrysoura Silver perch 47 20 

Cynoscion nebulosus Spotted seatrout 33 4 

C. regalis Weakfish 17 25 

Leiostomus xanthurus Spot 781 3,108 

Menticirrhus spp. Kingfish spp. 6 0 

Micropogonias undulatus Atlantic croaker 678 4,215 

Sciaenops ocellatus Red drum 5 11 

Pogonias cromis Black drum 7 0 

Stellifer lanceolatus Star drum 2 0 

Ephippidae Spadefishes 

Chaetodipterus faber Atlantic spadefish 0 0 

Mugilidae Mullets 

Mugil cephalus Striped mullet 9 11 

M. curema White mullet 0 13 

Sphyraenidae Barracudas 

S. borealis Northern sennet 0 1 

Uranoscopidae Stargazers 

Astroscopus guttatus Northern stargazer 0 0 

Blenniidae Combtooth blennies 64 491 

Eleotridae Sleepers 

Dormitator maculatus Fat sleeper 0 1 

Eleotris pisonis Spinycheek sleeper 0 1 

Gobiidae Gobies 

Gobionellus spp. Goby 34 224 

Gobiosoma spp. Goby 1,004 163 

Microgobius spp. Goby 25 11 

Trichiuridae Snake mackerels 

Trichiurus lepturus Atlantic cutlassfish 0 1 

Stromateidae Butterfishes 

Peprilus alepidotus Harvestfish 0 0 

P. triacanthus Butterfish 0 0 

 

 
Brunswick Steam Electric Plant 2008 Biological Monitoring Report 

Progress Energy Carolinas, Inc. A-5 Environmental, Health and Safety Services Section

Appendix 2 continued 

Number 

collected

Number 

collected

Scientific name Common name entrainment impingement

 

Bothidae Lefteye flounders 

Citharichthys spp. Whiff larvae 10 37 

Paralichthys spp. larvae Flounder larvae 6 74 

Soleidae Soles 

Trinectes maculatus Hogchoker 18 11 

Gobiesocidae Clingfishes 

Gobiesox strumosus Skilletfish 19 4 

Cynoglossidae Tonguefishes 

Symphurus spp. Tonguefish larvae 1 2 

Balistidae Filefishes 

Monacanthus hispidus Planehead filefish 0 1 

Tetraodontidae Puffers 

Spheroides maculatus Northern puffer 0 2 

Chilomycterus schoepfi Striped burrfish 0 1 

 

Invertebrates 

 

Penaeidae Shrimp 

Penaeid shrimp larvae, postlarvae stage 

Shrimp larvae 

(pink, brown, white) 279 5752 

Farfantepenaeus aztecus Brown shrimp 0 0 

F. duorarum Pink shrimp 0 0 

Litopenaeus setiferus White shrimp 1 25 

Trachypeneus constrictus T-con or hardback shrimp 25 271 

Portunidae Swimming crabs 

Portunid crab < 10 mm Swimming crabs 2 134 

Portunid crab larvae, megalops stage Swimming crab megalops 68 1183 

Callinectes spp. < 20 mm Unidentified Callinectes crab 0 22 

 

Total organisms 6,969 23,103 

 

+

Numbers represent total number collected per 5-minute sample summed over all samples. 
Brunswick Steam Electric Plant 2008 Biological Monitoring Report 

Progress Energy Carolinas, Inc. A-6 Environmental, Health and Safety Services Section

Appendix 3. Number+ and biomass (g) of juvenile and adult organisms collected during 

impingement sampling at the Brunswick Steam Electric Plant during 2008. 

 Total Total 

Scientific name Common name number weight (g) 

 

Carcharhinidae Sharks 

Rhizoprionodon terraenovae Atlantic sharpnose shark 0 0 

Dasyatidae Skates and Rays 

Dasyatis americana Southern stingray 2 310 

D. sabina Atlantic stingray 0 0 

Gymnura micrura Smooth butterfly ray 3 475 

Anguillidae Freshwater eels 

Anguilla rostrata American eel 0 0 

Elopidae Tarpons 

Elops saurus Ladyfish 0 0 

Ophichthidae Snake eels 

Myrophis punctatus Speckled worm eel 20 128 

Ophichthus gomesi Shrimp eel 1 205 

Clupeidae Herrings 

Alosa aestivalis Blueback herring 0 0 

A. sapidissima American shad 7 39 

Brevoortia tyrannus Atlantic menhaden 52 470 

Dorosoma cepedianum Gizzard shad 3 14 

D. petenense Threadfin shad 49 242 

Opisthonema oglinum Atlantic thread herring 5 23 

Engraulidae Anchovies 

Anchoa hepsetus Striped anchovy 189 945 

Anchoa mitchilli Bay anchovy 3,847 3,824 

Synodontidae Lizardfishes 

Synodus foetens Inshore lizardfishes 8 307 

Gadidae Codfishes 

Urophycis floridana Southern hake 1 13 

U. regia Spotted hake 1 15 

Ophidiidae Cusk-eels 

Ophidion welshi Crested cusk-eel 1 26 

Batrachoididae Toadfishes 

Opsanus tau Oyster toadfish 3 39 

Gobiesocidae Clingfishes 

Gobiesox strumosus Skilletfish 1 4.0 

Exocoetidae Flying fishes 

Hyporhamphus unifasciatus Silverstripe halfbeak 1 1 

Belonidae Needlefishes 

Strongylura marina Atlantic needlefish 1 85 

Cyprinodontidae Killifishes 

Fundulus heteroclitus Mummichog 12 28 

Fundulus majalis Striped killifish 1 6 

Atherinidae Silversides 

Membras martinica Rough silverside 61 119 

Menidia menidia Atlantic silverside 8 18 

Fistulariidae Cornetfishes 

Fistularia tabacaria Bluespotted cornetfish 0 0 

Syngnathidae Pipefishes 

Syngnathus fuscus Northern pipefish 38 46 

Syngnathus louisianae Chain pipefish 37 104 

Hippocampus erectus Lined seahorse 1 3 
Brunswick Steam Electric Plant 2008 Biological Monitoring Report 

Progress Energy Carolinas, Inc. A-7 Environmental, Health and Safety Services Section

Appendix 3 continued 

Total Total 

Scientific name Common name number weight (g) 

 

Scorpaenidae Scorpionfishes 

Scorpaena sp. Scorpionfish 1 25 

Triglidae Searobins 

Prionotus evolans Striped searobin 0 0 

Prionotus scitulus Leopard searobin 5 9 

Prionotus tribulus Bighead searobin 39 194 

Serranidae Sea basses 

Mycteroperca microlepis Gag 1 43 

Centropristis striata Black seabass 0 0 

Pomatomidae Bluefishes 

Pomatomus saltatrix Bluefish 1 38 

Rachycentridae Cobia 

Rachycentron canadum Cobia 2 189 

Carangidae Jacks 

Caranx hippos Crevalle jack 7 240 

Chloroscombrus chrysurus Atlantic bumper 4 75 

Oligoplites saurus Leatherjack 0 0 

Selene vomer Lookdown 8 115 

Trachinotus falcatus Permit 2 50 

Lutjanidae Snappers 

Lutjanus griseus Gray snapper 2 35 

Lobotidae Tripletails 

Lobotes surinamensis Tripletail 2 22 

Centrachidae Sunfishes 

Lepomis macrochirus Bluegill 1 3 

Gerridae Mojarras 

Diapterus auratus Irish pompano 1 1 

Eucinostomus argenteus Spotfin mojarra 0 0 

Haemulidae Grunts 

Orthopristis chrysoptera Pigfish 0 0 

Sparidae Porgies 

Archosargus probatocephalus Sheepshead 5 99 

Lagodon rhomboides Pinfish 126 957 

Sciaenidae Drums 

Bairdiella chrysoura Silver perch 12 270 

Cynoscion nebulosus Spotted seatrout 0 0 

C. regalis Weakfish 10 57 

Larimus fasciatus Banded drum 0 0 

Leiostomus xanthurus Spot 336 1,730 

Menticirrhus americanus Southern kingfish 1 5 

M. saxatilis Northern kingfish 0 0 

Micropogonias undulatus Atlantic croaker 19 501 

Sciaenops ocellatus Red drum 2 3 

Stellifer lanceolatus Star drum 21 88 

Ephippidae Spadefishes 

Chaetodipterus faber Atlantic spadefish 7 206 

Chaetodontidae Butterfly fishes 

Chaetodon ocellatus Spotfin butterflyfish 0 0 

Mugilidae Mullets 

Mugil cephalus Striped mullet 3 20 

M. curema White mullet 2 4 

 
Brunswick Steam Electric Plant 2008 Biological Monitoring Report 

Progress Energy Carolinas, Inc. A-8 Environmental, Health and Safety Services Section

Appendix 3 continued 

Total Total 

Scientific name Common name number weight (g) 

 

Sphyraenidae Barracudas 

Sphyraena barracuda Great barracuda 0 0 

S. borealis Northern sennet 0 0 

Labridae Wrasses 

Tautoga onitis Tautog 0 0 

Uranoscopidae Stargazers 

Astroscopus guttatus Northern stargazer 0 0 

A. y-graecum Southern stargazer 1 181 

Blenniidae Combtooth blennies 

Chasmodes bosquianus Striped blenny 0 0 

Hypsoblennius hentz Feather blenny 0 0 

H. ionthas Freckled blenny 0 0 

Eleotridae Sleepers 

Eleotris pisonis Spinycheek sleeper 0 0 

Gobiidae Gobies 

Gobionellus oceanicus Highfin goby 1 19 

Microdesmidae Wormfishes 

Microdesmus longipinnis Pink wormfish 1 4 

Trichiuridae Snake mackerels 

Trichiurus lepturus Atlantic cutlassfish 86 1618 

Scombridae Mackerels 

Scomberomorus maculatus Spanish mackerel 1 1 

Stromateidae Butterfishes 

Peprilus alepidotus Harvestfish 3 76 

P. triacanthus Butterfish 3 7 

Bothidae Lefteye flounders 

Ancylopsetta quadrocellata Ocellated flounder 1 4 

Citharichthys spilopterus Bay whiff 18 82 

Etropus crossotus Fringed flounder 15 127 

Paralichthys dentatus Summer flounder 4 236 

P. lethostigma Southern flounder 2 77 

Scophthalmus aquosus Windowpane 1 37 

Soleidae Soles 

Trinectes maculatus Hogchoker 0 0 

Cynoglossidae Tonguefishes 

Symphurus plagiusa Blackcheek tonguefish 44 277 

Balistidae Triggerfishes and filefishes 

Monacanthus hispidus Planehead filefish 1 5 

Aluterus schoepfi Orange filefish 1 1 

Tetraodontidae Puffers 

Chilomycterus schoepfi Striped burrfish 3 124 

Sphoeroides maculates Northern puffer 1 6 

 

Invertebrates Mollusks, shrimps, and crabs 

 

Aphysiidae Sea hares 

Aplysia sp. Sea hare 1 176 

Lologinidae Sea hares 

Lolliguncula brevis Squid 76 562 

Limulidae Horseshoe crabs 

Limulus polyphemus Horseshoe crab 0 0 

 
Brunswick Steam Electric Plant 2008 Biological Monitoring Report 

Progress Energy Carolinas, Inc. A-9 Environmental, Health and Safety Services Section

Appendix 3 continued 

Total Total 

Scientific name Common name number weight (g) 

 

Squillidae Mantis shrimps 

Squilla empusa Mantis shrimp 22 610 

Alpheidae Snapping shrimps 

Alpheus sp. Snapping shrimp 0 0 

Sicyoniidae Rock shrimps 

Sicyonia sp. Rock shrimp 0 0 

Penaeidae Prawns 

Farfantepenaeus aztecus Brown shrimp 1,597 5,548 

F. duorarum Pink shrimp 206 479 

Litopenaeus setiferus White shrimp 1,770 12,672 

Trachypeneus constrictus T-con or hardback shrimp 13 10 

Portunidae Swimming crabs 

Ovalipes sp. Lady crab 3 15 

Portunus sp. Swimming crabs 200 481 

P. spinimanus Brown bar crab 0 0 

Callinectes ornatus Shelligs crab 8 41 

C. sapidus Blue crab 133 7,176 

C. similus Lesser blue crab 243 1,871 

 

Reptiles 

 

Emydidae Emydiaeid turtles 

Malaclemys terrapin Diamondback terrapin 0 0 

 

Total organisms 108,668 273,412.3 

 

+

Numbers and biomass represent total number and weight collected per 24-hour sample summed 

over all sample dates.