ML19309F820
| ML19309F820 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 04/02/1980 |
| From: | Jason White VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | |
| Shared Package | |
| ML19309F818 | List: |
| References | |
| NUDOCS 8005010374 | |
| Download: ML19309F820 (400) | |
Text
{{#Wiki_filter:. - - . - . ... .-- . . gou5010 ' Y 9 < Virginia Electric and Power Company-North Anna Power Station 1979 Non-Radiological Environmental Operating Report Units 1 and 2 Volumes 1, 2 and 3 Recomend Approval: d h, Q f Station Biologist Date: 3/24/20
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Approved by: -
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7 Executive Manager Environmental Services ( Yd2l /986 Date: > f Approved by: ND bb Vtation Manager \' i . North Anna Power Station Date: d-2-8D
O - ENVIR0hMENTAL STUDY'0F LAKE ANNA, VIRGINIA ANNUAL REPORT
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January 1, 1979 - December 31, 1979 l (. l Prepared for: The Virginia Electric and Power Company
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l l Prepared by: James R. Reed and Associates, Inc. Environmental Testing and Consulting 813 Forrest Drive Newport News, Virginia 23606 O
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March 31, 1980 s
1 l l l l () . ENVIRONMENTAL STUDY OF LAKE ANNA, VIRGINIA ANNUAL REPORT ' January 1, 1979 - December 31, 1979 l l TABLE OF CONTENTS Page Table of Contents . . . . . . . . . . . . . . . . . . 11 List of Tables. . . . . . . . . . . . . . . . . . . , . v. List of Figures . . . . . . . . . . . . . . . . .'. . ix Acknowledgements. . . . . . . . . . . . . . . . . . . Xi General Introduction. . . . . . . . . . . . . . . . . xii i Summary . . . . . . . . . . . . . . . . . . . . . . . 0-1 Chapter 1 Heavy Metals and Nutrients 1.1 Intoduction . . , . . . . . . . . . . . . . . 1-1 1.2 Methods and Materials . . . . . . . . . . . . 1-2 1.2.1 Heavy Metals. . . . . . . . . . . . . . . 1-2 1.2.2 Nutrients . . . . . . . . . . . . . . . . 1-4 1.2.3 Station Descriptions. . . . . . . . . . . 1-6 1.3 Results . . . . . . . . . . . . . . . . . . . 1-8 1.3.1 Heavy Metals. . . . . . . . . . . . . . . 1-8 1.3.2 Nutrients . . . . . . . . . . . . . . . . 1-13 k' l.3.2.1 Nitrate Nitrogen. . . . . . . . . . . 1-13 1.3.2.2 Ammonia Nitrogen. . . . . . . . . . . 1-13 1.3.2.3 Phosphate . . . . . . . . . . . . . . 1-13 1.3.2.4 Sulfate . . . . . . . . . . . . . . . 1-16 1.4 Summary . . . . . . . . . . . . . . . . . . . 1-16 1.5 References. . . . . . . . . . . . . . . . . . 1-17 Chapter 2 Chlorophyll, Primary Productivity and Temperature Analyses 2.1 Introduction. . . . . . . . . . . . . . . . . . 2-1 2.2 Methods and Materials . . . . . . . . . . . . 2-2 2.2.1 Chlorophyll . . . . . . . . . . . . . . . 2-2 t 2.2.2 Primary Productivity. . . . . . . . . . . 2-4 l 2.2.3 Temperature . . . . . . . . . . . . . . . 2-8 2.3 Results and Discussion. . . . . . . . . . . . 2-8 l 2.3.1 Chicrophyll . . . . . . . . . . . . . . . 2-8 s 2.3.2 Primsry Productivity. . . . . . . . . . . 2-15 2.3.3 Temperature . . . . . . . . . . . . . . . 2-18 l x' 11 l w , --
O . Page 2.4 Summary . . . . . . . . . . . . '. . . . . . . 2-19 2.4.1 Chlorophyll . . . . . . . . . . . . . . . 2-19 2.4.2 Primary Productivity. . . . . . . . . . . 2-19 2.4.3 Temperature . . . . . . . . . . . . . . . 2-20 2.5 References. . . . . . . . . . . . . . . . . . 2-21 . Chapter 3 Phytoplankton . 3.1 Introduction. . . . . . . . . . . . . . . . . 3-1 3.2 Methods and Materials . . . . . . . . . . . . 3-1 3.3 Results and Discussion. . . . . . . . . . . . 3-3 3.4 Summary . . . . . . . . . . . . . . . . . . . 3-17 3.5 References. . . . . . . . . . . . . . . . . . 3-18 Chapter 4 Zooplankton Studies 4.1 Introduction. . . . . . . . . . . . . . . . . 4-1 4.2 Materials and Methods . . . . . . . . . . . . 4-1 4.2.1 Sampling Procedure. . . . . . . . . . . 4-1 4.2.2 Statistical Analyses. . . . . . . . . . 4-3 (]) 4.3 Results and Discussion. . . . . . . . . . . . 4-4 4.4 Summary . . . . . . . . . . . . . . . . . . . 4-17 4.5 References. . . . . . . . . . . . . . . . . . 4-20 Chapter 5 Macrobenthos 5.1 Introduction. . . . . . . . . . . . . . . . . 5-1 5.2 Methods . . . . . . . . . . . . . . . . . . . 5-1 5.3 Results . . . . . . . . . . . . . . . . . . . 5-5 (_ . 5.3.1 Sample Collection . . . . . . . . . . . . 5-5 5.3.2 Density and Percentage Composition. . . . 5-5 5.3.3 Diversity . . . . . . . . . . . . . . . . 5-15 5.3.4 Horizontal Distribution . . . . . . . . . 5-15 5.3.5 Vertical Distribution . . . . . . . . . . 5-18 5.3.6 Surface Community . . . . . . . . . . . .
- 5-18 5.4 Summary . . . . . . . . . . . . . . . . . . . 5-18 5.5 References. . . . . . . . . . . . . . . . . . 5-21 Chapter 6 Fish 6.1 Introduction. . . . . . . . . . . . . . . . . 6-1 6.2 Methods . . . . . . . . . . . . . . . . . . . 6-1 6.2.1 Fish Collection Techniques and Station Designations. . . . . . . . . . . 6-1 6.2.2 Water Quality Analyses. . . . . . . . . . 6-4 6.2.3 Abundance and Distribution of Populations . . . . . . . . .
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() . , Page 6.2.4 Age and Growth of Largemouth Bass . . . 6-5 6.2.5 Fecundity and Gonad Development . . . . 6-7 6.3 Results . . . . . . . . . . . . . . . . . . . 6-9 i 6.3.1 Physical and Chemical . . . . . . . . . 6-9 ! 6.3.2 Relative Abundance Based on Gill Net observations. . . . . . . . . . . . . . 6-22 6.3.3 Cove Rotenone Studies . . . . . . . . . 6-42 6.3.4 Gonosomatic.Index.cf the Female, Micropterus salmoides . . . . . . . . . 6-57 6.3.5 Fecundity - Micropterus salmoides . . . 6-57 6.3.6 Egg Size - Micropterus salmoides. . . . 6-60 6.3.7 Fingerling Production . . . . . . . . . 6-60 (- u 6.3.8 Growth of Year Class O Largemouth Bass (Micropterus salmoides) . . . . . . . . 6-65 6.3.9 Condition Factors of Selected Species in Lake Anna. . . . . . . . . . . . . . 6-70 6.3.10 Age and Growth of the Largemouth Bass I ^ (Micropterus salmoides) . . . . . . . . 6-77 6.4 Summary . . . . . . . . . .
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'. . . . . . . . . . 6-86 6.4.1 Physical and Chemical . . . . . . . . . 6-86 6.4.2 Relative Abundance Based on Gill Net
- O Observations. . . . . . . . . . . . . . 6-89 6.4.3 Cove Rotenone Studies . . . . . . . . . 6-89 6.4.4 Gonosomatic Index of the female,
! Micropterus salmoides . . . . . . . . . 6-90 6.4.5 Fecundity, Micropterus salmoides. . . . 6-90 6.4.6 Egg Size, Micropterus salmoides . . . . 6-91 6.4.7 Fingerling Production . . . . . . . . . 6-91 6.4.8 Growth of Year Class O Largemouth Bass
(_ . Micropterus salmoides . . . . . . . . . 6-91 6.4.9 Condition Factors of Selected Species . 6-91 6.4.10 Age and Growth of the Largemouth Bass, Micropterus salmoides . . . . . . . . . 6-92 6.4.11 Food Habits of the Largemouth Bass, Micropterus salmoides . . . . . . . . . 6-92 6.5 References. . . . . . . . . . . . . . . . . . 6-93
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O . 1 LIST OF TABLES Number Title Page l l 1.2.1.1 Average Detection Limits for Heavy 1 Metals in Lake Anna Water Samples 1979. . . 1-2 l 1.2.2.1 Nutrient Methodology. . . . . . . . . . . . 1-4 1.2.2.2 Average Detection Limits for Nutrients. . . 1-4 1.3.1.1 A Comparison of Mean Heavy Levels in Lake Anna Water from 1975-1979 . . . . . . . . . 1-9 l.3.1.2 Lead Concentration in Fourth Quarter Water Samples . . . . . . . . . . . . . . . 1-12 1.3.2.1 A Comparison of Mean Anion Levels in Lake i Anna Water 1975-1979. . . . . . . . . . . 1-14 2.2.2.1 Analytical Procedure for Determiniation Oi of Water Quality Parameters at Productivity Stations. . . . . . . . . . . . . . . . . . 2-6 2.3.1.1 Comparison of Average Chlorophyll a Concentrations at the Productivity' Stations. . . . . . . . . . . . . . . . . . 2-10 2.3.2.1 Comparison of Mean Primary Productivity Rates . . . . . . . . . . . . . . . . . . . 2-16 (_. 3.3.1 Phytoplankton Taxa and Corresponding Unit Volumes. . . . . . . . . . . . . . . . 3-4 3.3.2 Percent Composition of. Total Phytoplankton Densities for Each Sampling Station at Each Sampling Date. . . . . . . . . . . . . 3-11 3.3.3 Percent Composition of Total Phytoplankton Volumes for Each Sampling Station at Each Sampling Date . . . . . . . . . . . . . . . 3-12 3.3.4 Percent Composition of Total Phytoplankton Densities and Volumes for Each Division at Each Sampling Station . . . . . . . . . . . 3-13 O V
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O Number Title Page 3.3.5 Percent Composition of Total Phytoplankton Densities and Volumes for Each Division at Each Sampling Date . . . . . . . . . . . 3-14 4.3.1 Duncan's Multiple Range Test of Continuous Data, Date by Station. . . . . . 4-5 4.3.2 Duncan's Multiple Range Test of Discrete Data, Date by Station. . . . . . . 4-6 (' 4.3.3 Relative Abundance Ranking of Rotifera Density by Station . . . . . . . . 4-7 4.3.4 Duncan's Multiple Range Test for Continuous Data, Station by Date. . . . . . 4-9 4.3.5 Percentage of tne Total 1979 Zooplankton Population Represented by O March . . . . . . . . . . . . . . . . . . . ' 4-10 4.3.6 Duncan's Multiple Range Test of Discrete Data, Station by Date. . . . . . . 4-11 4.3.7 Student T-test of Continuous and Discrete Sampling . . . . . . . . . . . . . 4-12 7- 4.3.8 A Comparison of Mean Densities by s.. Station using a Duncan's Multiple Range Test. . . . . . . . . . . . . . . . . . . . 4-12 4.3.9 Mean Density by Station for Rotifera, Cladocera and Copepoda. . . . . . . . . . . 4-13 4.3.10 Duncan's Multiple Range Test, Area by Station . . . . . . . . . . . . . . . . . . 4-14 4.3.11 Zooplankton Master List . . . . . . . . . . 4-18 5.3.2.1 Density and Percentage Composition of Dominant Macrobenthos During 1979 . . .. . 5-7 5.3.2.2 Taxonomic List of Macrobenthic organisms Collected . . . . . . . . . . . . . . . . . 5-11 O vi
( . l Number Title Page 5.3.4.1 Horizontal Distribution of Dominant Macrobenthos . . . . ........... 5-16 5.3.5.1 vertical Distribution.of Dominant Macrobenthos . . . . ........... 5-19 6.3.1.1 Temperature (OC) at Surface, Mid and , Bottom by Station and Month. . . . . . . . 6-10 6.3.1.2 Dissolved Oxygen and Percent Saturation (w at Surface, Mid and Bottom by Station and
\_ Month. . . . . . . . ........... 6-16 6.3.1.3 Mean Turbidity Values (NTU) at Surface, Mid and Bottom Depths. . .. . . . . . . . . 6-20 6.3.1.4 Mean Alkalinity values by Station. . . . . 6-23 6.3.1.5 Mean Hardness Values by Station. . . . . . 6-25 6.3.2.1 Catch Per Net Day in Number of Individuals by Species, 1973-1979. . . . . . . . . . . 6-27 6.3.2.2 Catch Per Net Day as Expressed by Weight, 1975-1979. . . . . . ........... 6-35 6.3.2.3 Total Catch Per Net Day Expressed as
(]) Numbers of Individuals, 1973-1979. . . . . 6-43
- 6.3.2.4 Total Catch Per Net Day Expressed as Weight, 1975-1979. . ........... 6-44 6.3.3.1 Fish Standing Crop Estimates Based Upon Cove Rotenone Samples by Species . . . . . 6-45 6.3.6.1 Egg Size of the Female Largemouth Bass at Mid-Reservoir. . . . ........... 6-62 6.3.6.2 Egg Size of the Female Largemouth Bass in the WHTF . . . . . . ........... 6-63 6.3.8.1 Year Class O Largemouth Bass, Mean Length During Rotenone Collection . . . . . . . . 6-69 vii
O . Number Title .Page 6.3.9.1 R2 Values for Largemouth Bass k/ length Regression Equations for 1976-1979 . . . . . 6-71 6.3.9.2 Mean Condition Factors by Species for Upper, Lower and WHTF. . . . . . . . . . . . 6-76
, 6.3.10.1 Back Calculated Length Attained by Each Year Class of Largemouth Bass. . . . . . . . 6-79 6.3.10.2 Back Calculated Length Attained by Each
{} Year Class of Largemouth Bass. . o . . . . . 6-81 6.3.10.3 Back Calculated Length Attained by Each Year Class of Largemouth Bass. . . . . . . . 6-83 I 6.3.11.1 Gut Content of the Largemouth Bass . . . . . 6-85 6.3.11.2 Gut Content of the Largemouth Bass in the WHTF and Reservoir . . . . . . . . . . . . 6-87 (} 6.3.11.3 Fish Species List. . . . . . . . . . . . . . 6-88 , (* I O viii
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( . LIST OF FIGURES Number Title Page 1.2.1.1 Approximate Location of Sampling Stations for Heavy Metals . . . . . . . . . . . . . 1-3 1.2.2.1 Nutrient Sampling Locations. . . . . . . . 1-5 2.2.1.1 General Location of Chlorophyll Sampling Stations . . . . . . . . . . . . . . . . . 2-2
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2.2.2.1 General Location of Primary Productivity Sampling Stations. . . . . . . . . . . . . 2-5 (. 2.2.3.1 General Location of Physical and Chemical Sampling Stations. . . . . . . . . . . . . 2-9 3.2.1 General Location of Phytoplankton Sampling Stations. . . . . . . . . . . . . 3-2 4.2.1.1 Zooplankton Sampling Stations. . . . . . . 4-2 5.2.1 Location of Macroinvertebrate Stations . . 5-2 5.2.2 Diagram of a Typical Benthic Station . . . 5-4 6.2.1.1 General Location of Gill Netting Stations. 6-2 6.2.1.2 General Location of Rotenone Stations. . . 6-3 4 , N/ 6.3.1.1 Temperature at Weekly Intervals Mid-Reservoir. . . . . . . . . . . . . . . . . 6-13 6.3.1.2 Temperature at Weekly Intervals, WHTF Station R. . . . . . . . . . . . . . . . . 6-14 6.3.1.3 Temperature at Weekly Intervals, WHTF Discharge Canal. . . . . . . . . . . . . . 6-15 1 6.3.4.1 Gonosomatic Index (GSI%) of Female Largemouth Bass, Mid-Reservoir . . . . . . 6-58 6.3.4.2 Gonosomatic Index (GSI%)' of Female Largemouth Bass, WHTF.- . . . . . . . . . . 6-59 6.3.5.1 Fecundity vs. Weight for the Largemouth Bass . . . . . . . . . . . . . . . . . . . 6-61 ! ix e
O . Number Title Page 6.3.7.1 Number of Young of the Year Largemouth Bass by Station . . . . . . . . . . . . . . 6-64 6.3.7.2 Number of Young of the Year Bluegill by Station. . . . . . . . . . . . . . . . . 6-66 6.3.7.3 Number of Young of the Year Chain Pickerel by Station. . . . . . . . . . . . . . . . . 6-67 6.3.7.4 Number of Young of the Year White Perch r by Station. . . . . . . . . . . . . . . . . 6-68 i 6.3.9.1 Condition (K) vs. Length for Largemouth Bass,1976-1979, WHTF. . . . . . . . . . . . 6-72 6.3.9.2 Condition (K) vs. Length for Largemouth Bass, 1976-1979, Lower Reservoir. . . . . . 6-74 6.3.9.3 Condition (K) vs. Length for Largemouth Bass, 1976-1979, Upper Reservoir. . . . . . 6-75 k-l l l n v X e
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() . l ! ACKNOWLEDGEMENTS' The project manager would like to acknowledge the support ' of the followir, individuals in the completion of this project: Mr. Charles A. Sledd and Mr. Daniel Shuber, Virginia Commission of Game and Inland Fisheries, for their cooperation and assis-cance in fishery surveys; Mr. James McNeal, Virginia State i Water Control Board, for providing information and assistance in fish studies; Mr. Jud White, Mr. Jeff Jones, Mr. Frank Massie, Mr. William Taylor, Mr. Rick Willis, and Mr. Robert S..Andrews, l biologists with Virginia Electric and Power Company at the ( North Anna Power Station for their cooperation in all phases of the study; Mr. James Price for assistance in the statistical analysis of the data. The following James R. Reed and Associates, Inc. personnel participated in the various activities of this project. Primary Productivity Zooplankton Diane I. Switzer - Supervisor John B. Bailey - Supervisor Anna E. Tuerk Robert G. Cox Denise Davis Druce E. Sawyer Nutrients Guy G. Lawrence Joyce L. Barton - Supervisor Fisheries
, James W. Bandelean - Supervisor Stanford R. Wells - Supervisor Benthics Mark A. Harrison Dale A. Dobroth - Supervisor Water Chemistry David V. Grimes Judith Davis Project Manager Darryl Whitmore Grace Hornby Leo D. Montroy, Ph.D.
Principal in Charge James R. Reed, Jr., Ph.D. O xi
O . GENERAL INTRODUCTION
. i Lake Anna Reservoir with a surface area of approximately 3 24 x 10'+ hectares is utilized to provide cooling water for the Virginia Electric and Power Company's second nuclear facility, the North Anna Power Station. It is divided into a waste heat treatment system which comprises 8.4 x 103 hectares and the main Reservoir containing 2.4 x 10 hectares.
(- To avoid confusion, the following tenninclogy will be used to refer to the different, or collective, water bodies: Lake Anna - Both reservoirs or the entire project; Reservoir - Main body of Lake Anna; O Upper Reservoir - Lake above Rt. 208 bridge; Lower Reservoir - Lake below Rt. 208 bridge; Waste Heat Treatment Facility (WHTF) - Lagoon complex the smaller reservoir or lagoons. The Reservoir and WHTF were filled from separate drainage basins. Very little mixing has occurred between waters of the u WHTF and of the Reservoir due to earthen dikes between them. In addition, the area of the WHTF was not directly subjected to acid and metal mine' drainage from Contrary Creek, a site of pyrite mining until the 1920's. This study summarizes the ecological and water quality studies carried out from January 1, 1979 through December 31, 1979 and is intended to supplement previous Virginia Electric and Power Company Preoperational Environmental Reports. O xii
O Summary
- r. 0-1 Heavy Metals and Nutrients
( l. There is no evidence to indicate that the operation of the reactor unit at the North Anna power station had any effect on water quality in Lake Anna in 1979.
- 2. Iron levels have increased in the Upper Reservoir and Contrary Creek areas from 1978 to 1979.
() 3. Copper and lead appear to be decreasing overall in Lake Anna, however, March Contrary Creek samples showed elevated levels for zinc and lead.
- 4. December lead values were unusually high, however, con-tamination of the samples is suspected and following March 1980 analysis of metal samples, this hypothesis will be confirmed or disclaimed.
5. Earch levels for nitrate nitrogen were significantly higher in the Upper Reservoir than in other areas at any other sampling date during 1979.
- 6. The sulfate content in Lake Anna was lower in 1979 than in previous years except at station 223 in Contrary Creek.
l 0.2 Chlorophyll, Primary Productivity and Temperature
- 1. Comparisons of chlorophyll concentrations between 1978 and 1979 data show.significant increases at stations 211 and 212.
All other stations did not differ significantly between 1978 and 1979.
- 2. The two Upper Reservoir stations 211 and 212 experienced the highest chlorophyll concentrations of all stations sampled.
C in 1979. 0-1 . s
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- 3. Generally, chlorophyll concentrations appeared to be lower -
in the Lower Reservoir stations 241 and 243 than in the Waste Heat Treatment Facility stati'ons.
- 4. Comparisons of primary productivity rates between 1978 and 1979 show significant decreases at station 132, 241 and 243.
- 5. Greater light intensity on 1979 sampling dates is believed to be the major factor in lower primary productivity rates than in 1978.
- 6. For most sampling dates, all stations were not significantly c.
different in 1979 primary productivity rates.
- 7. Comparisons between 1978 and 1979 data show no significant differences in temperature.
- 8. Comparisons between stations and dates in 1979 show no significant differences between the Waste Heat Treatment Facility and the Lower Reservoir.
{} 0.3 1. Phytoplankton Comparisons between 1978 and 1979 data show that phyto-plankton densities were significantly decreased at station 211. For all other stations, there was no significant difference between years.
- 2. In general, the five primary productivity stations were comparable in phytoplankton densities during 1979.
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- 3. For most of the year blue-green algae dominated at stations 211, 212 and 223.
- 4. Green algae dominated during the winter and late spring months.
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- 5. Diatoms dominated the phytoplankton community from March through May.
- 6. Blue-green -1gae dominated in the late summer and early fall months.
0.4 Zooplankton l~. Characteristics that occurred in Lake Anna zooplankton in both 1978 and 1979. ( a. Stations 211, 212 ane. 221 had the highest mean densities of zooplankton. 0-2
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- b. The month of March had the lowest mean density.
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- c. Rotifera were numerically dominant.
- 2. There was no significant difference in mean densities between 1978 and 1979.
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- 3. Stations 223 and 111 showed consistantly lower numbers of.
zooplankton compared to other stations. 0.5 Macrobenthos
- 1. During 1979 the density of the macrobenthos increased I
,s throughout the reservoirs. The density in the Lower Reservoir was significantly highe" (Students t-test,
, * = .05) in 1979 than 1978. The Upper Reservoir showed no significant difference ate 4= .05.
- 2. During 1979 the density of the macrobenthos increased in the WHTF, although there was no significant difference from 1978 at *L= .05.
() 3. Trichoptera continued to increase in dominance in the Reservoir through the year and in the WHTF through August.
- 4. Pelecypoda replaced Trichoptera as the most abundant organism in the WHTF for the last three sampling periods in 1979.
(J S. 1979 was the first time Corbicula, the Asiatic clam, has l been reported in Lake Anna.
- 6. In 1979 Isopoda were again collected in Lake Anna, however their densities were extremely low.
0-6 Fish - Physical and Chemical
- 1. Disolved oxygen values were generally high throughout the water column at all fish stations for 1979.
- 2. Turbidity values for the Upper Reservoir fish stations, at the mid and bottom depths, were significantly higher than all other sampling stations.
- 3. The mean alkalinity values for surface, mid and bottom depths at station M were significantly lower at the 95% confidence level than the remaining stations.
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- 4. The mean hardness values for station Z at surface, mid and bottom depths were significantly lower than all other stations. .
Relative Abundance Based on Gill Net Observations
- 1. The gizzard shad increased in gill net catches since its appearance from 3.1 to as much as 68% of the total catch.
A gradual decline in relative abundance of shad was noted in recent years.
- 2. The chain pickerel has suffered a decline in numbers through- .
out the study. .
,.. 3. The carp has displayed an increase in catch per day as well .~ . as kg per net day. -
- 4. The creek chubsucker has declined steadily in relative abundance chroughout the study period.
- 5. The brown bullhead and the yellow bullhead have shown a de-crease in catch per unit effort during the study period.
() 6. 'The channel catfish has shown an increase in catch per unit effort in the WHTF and the Lower Reservoir at ' station S near the WHTF discharge area.
- 7. The largemouth bass displayed an increase in relative abundance in the WHTF in 1979.
- 8. The white perch has shown a marked increase in relative abundance over the study period.
- 9. The striped bass has shown an increase in catch per unit effort in the WHTF, perhaps due to the attraction of the artifical current.
- 10. The WHTF-produced higher values for kg of fish caught per net day than the other study areas.
! Cove Rotenone Studies l
- 1. In Lake Anna no significant changes between years were found to exist throughout the study period for gizzard shad, al-though there appeared to be a decline in mean standing corp of this species.
- 2. The gizzard shad was the most important fish in terms of s standing crop.
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- 3. The Upper Reservoir displayed the highest value for stand-ing crop of gizzard shad.
- 4. The carp has increased in standing.' crop and was shown to be significantly higher in kg/ hectare in the Pamunkey Creek Arm.
- 5. The creek chubsucker was collected at more stations than other suckers, but this species remains on a steady decline.
- 6. The channel catfish has steadily increased in standing crop over the past two years in the WHTF, but Pamunkey Creek and the Mid-Reservoir stations remained significantly higher ,
than all other stations for this species.
- 7. The white perch displayed an increase in standing crop during 1979.
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- 8. No significant difference occurred between years but Pamunkey Creek displayed significantly higher standing crop values than all other stations.
- 9. Changes in standing crop observed at the species level appear to be more important in predicting the impact of heated
(]) effluent than observing total standing crop. Gonosomatic Index of the female, Micropterus sa.1moides.
- 1. During 1979, female bass at the M!d-Reservoir electrofishing station displayed a peak of gonad development in the third week of April, but female bass observed in the WHTF reached their peak gonad development during the last week of March.
- 2. Female bass were observed in the " squeeze ripe" or spawning condition in the WHTF on April 9, 1979, wherease the female bass collected in the Reservoir started spawning three weeks later on April 26, 1979.
Fecundity, Micropterus salmoides
- 1. There appears to be a steady decline observed in fecundity from 1976-1979 in the WHTF.
- 2. The Mid-Reservoir station during 1979 displayed high pre-dictive values for fecundity when compared to the WHTF.
Egg Size, Micropterus salmoides
- 1. Female largemouth bass in the WHTF reached a peak egg size in the last week of March and retained a relatively large 0-5
4 mhmgwse a 6e ,. *- () - 1 egg size until the first week of May, whereas female bass l in the Mid-Reservoir sampling station did not attain a mature egg size until the third week of April. Fingerling Production
- 1. The largemouth bass produced extremely high numbers of young of the year during 1978.
2. 1 Generally, whenever there was a peak in bluegill production
. the fingerling bass population was depressed. )
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- 3. Chain pickerel seemed to have a higher reproductive success '
rate during 1978-1979 because of the increase in fingerlings
, observed for this species.
- 4. Young of the year white perch have displayed a marked in-crease in numbers from 1976-1979.
Growth of Year Class O Largemouth Bass, Micrcpterus salmoides
- 1. The year class O bass collected at the WHTF : stations and the 4
() NAR arm of the Upper Reservoir were significantly longer than the young bass collected at the remaining stations. Condition Factors of Selected Species in Lake Anna
- 1. The largemouth bass in Lake Anna displayed an increase in K with length.
- 2. During the operational year 1979, the condition of the smaller
, bass was higher than that observed in previous years sampled
~
in the WHTF.
- 3. Young largemouth bass collected in the Lower Reservoir during 1976 displayed significantly higher condition factors than young bass collected in other years.
- 4. In 1979 the gizzard shad had significantly higher values for condition in the WHTF as compared to all other study areas.
- 5. In 1979 the bluegill population in the Upper Reservoir had significantly lower values for condition than the other two study areas and the mean condition of the bluegill in the WHTF for 1979 was greater than the other areas.
- 6. The operation of unit one appeared to produce no adverse effects on the condition of the black crappie in the WHTF.
0-6
c. O Age and Growth of the Largemouth Bass, Micropterus salmoides
- 1. The 1979 Lake Anna largemouth bass population was putting on more weight with length than the national average.
- 2. The age I largemouth bass in the WHTF grew significantly faster than the first year bass in the other sampling locations.
Food Habits of the Largemouth Bass, Micropterus salmoides 1. Throughout the study period from 1977-1979, it was evident that the family Clupeidae, represented by the single species
Dorosoma cepedianum, was the most frequently selected forage fish in the diet of the largemouth bass in Lake Anna.
- 2. The 1979 operational year did not affect the food habits of the largemouth bass.
O i 4 0 0-7
O . 1.0 Heavy Metals and Nutrients - 1.1 Introduction As of four major areas. in the past, Lake Anna is defined in terms The Upper Reservoir represented by stations 211 and 212, is characterized by the relatively shallow arms (8 meters or less) of the North Anna River and Pamunkey Creek, both of which feed into the reservoir. Progressing down the reservoir, Contrary Creek is the next area to beand 224, 225, encountered, 231. represented by stations 221, 222, 223, () According to the Virginia State Water Control Board (1976), there are three now inactive pyrite mines and mining spoils piles that are contributing high concentrations of dissolved metals Lake Anna. and acid leachate to Contrary Creek, and ultimately to The Board is developing a feasibility study to address the dissolved metals problem, and is using an EPA Demonstration the water quality Grant to reclaim the mine waste areas and abate problem. s' The board speculates deleterious effects on the reservoir's biotic components from significant concentrations of dissolved heavy metals and mentions the problems that could arise from the use of the reservoir as a thermal collector during power plant operations, but does not elaborate with any specific in-formation in their 1976 Inventory Report. One warning made, however, regards massive uncontrolled development of the sur-rounding land, which could produce siltation problems, was.e-water loadings, and water quality degradation unless prevent-ative steps are taken. The Waste Heat Treatment Facility (WHTF) is on the receiving end of the discharge canal from the North Anna Power and 132.Station and is represented by stations 111, 121, 131, The Lower Reservoir, the furthest downstream point, is () represented by stations 241 and 243, where the waters from the WHTF return to the main body of the reservoir. 1-1
. - . = -- . .
O - The purpose of this sampling program was to provide enough data to characterize the existing water quality situ-ation in Lake Anna and detect trends.
- 1.2 Methods and Materials 1.2.1 Heavy Metals Thirty-six water samples were collected quarterly from Lake Anna and the WHTF (Figure 1. 2.1.1) during 1979 and analyzed for iron, copper, zinc and lead. Samples were drawn from three depths where possible: surface (epilimn-ion), middle (metalimnion) and bottom (hypolimnion). Bottom samples were taken 1 meter from the bottom to avoid disturbing sediments which could give inaccurate readings for the metal content of the water column. Metalimnion samples were not taken from stations 111, 131, 211, 212, 222 and 223 because the depths
(]. were less than 8 meters. A non-metallic Niskin water sampler (General Oceanics) was used in obtaining the samples, which were placed in acid-cleaned, i sample-rinsed polyethylene bottles. A pH reading was taken to l ' correspond with each metals sample, then the samples were volume-trically preserved with nitric acid, filtered through acid-cleaned filtering apparatus using 0.45 micron filter membranes, () and were returned to their original containers. Blank samples and standards were prepared and carried through with each set of samples. An atomic absorption spectrophotameter (Instrument-ation Laboratories Medel 251) was utilized for the analyses of iron, copper and zinc. An attachment unit (Flameless Model 455) was also used for the detection of leac. The sample concentrat-ions were calculated from the least-squares line of best fit of the standatds for each analysis. One way ANOVA using Duncan's significant means tests were employed in data analysis for
- s. nutrients and heavy metals using the Statistical Analysis System computer program. Metals in water are expressed as mg/l (parts per million).
A zero value indicates that the metal content was below the detectable level. Detection limits are given in Table 1.2.i.1. Table 1.2.1.1. Average Detection Limits for Heavy Metals in Lake Anna Water Samples in 1979. Detection Limit
- (mg/1) l Iron (Fe) 0.01 Copper (Cu) 0.06 Zinc (Zn) 0.01 Lead (Pb) 0.002 O .
1-2 . 9 m - - --
i o ( O a O
~
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- CONT LEY CREEK 4-211 LOWER 221 RESERVOIR 4
I
' 225 7
ta 223
. 224 1 b
UPPER I
- RESERVOIR 22 y
. 241 %
111 WHTF
- 21. 2436 l
13
- 6 131 ,m Fi 7ure 1.2.1.1. Approximate location of sampling stations b for heavy metals in Lake Anna, 1979.
O 1.2.2 Nutrients Water samples were collected quarterly in conjunction with the metals samples and analyzed for ammonia nitrogen, nitrate nitrogen, total phosphate, orthophosphate, metaphosphate, and sulfate. Samples were collected at four depths (0, 2, 4, and 6 meters) from the stations shown in Figure 1.2.2.1, yielding a total of 40 nutrient samples per collection. Sazples were placed into acid-cleaned, sample rinsed, brown polyethlene bottles. In the laboratory, dupli-cate samples were prepared for each analysis to insure accu-rate results, and were analysed according to the methods summarized in Table 1.2.2.1. Table 1.2.2.1. Nutrient Methodology ,_ Analysis Method I (_' Ammonia Nitrogen Phenate Method, p. 416. Nitrate Nitrogen Cadmium Reduction Method, p. 413. Total Phosphate Persulfate Digestion, P. 476. < and Ascorbic Acid Method, P. 481. Orthophosphate Ascorbic Acid Method, p. 481. Metaphosphate Subtration, p. 469. (} Sulfate 1 Turbidimetric Method, p. 496. Standard Methods for the Examination of Water and Wastewater, 14th. Edition, 1975. Detection limits are shown in Table 1.2.2.2. Table 1.2.2.2. Average Detection Limits for Nutrients in Lake Anna Water Samples in 1979. C Detection Limit
, (mg/1)
Ammonia (NH4+) 0.01 Total Phosphate (T-PO4) 0.01 Orthophosphate (0-PO4) 0.01 Nitrate (NO3) 0.01 Sulfate (du a) 0.3 l Ammonia nitrogen was determined directly using the color-imetric Phenate Method. Levels of ammonia were low and inter-ferences few enough to eliminate the need for predistillation. Nitrate nitrogen was determined by reducing nitrate to nitrite
,) through a culumn of amalgamated cadmium filings and measuring colorimetrically.
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O Total phosphate (total filtrable and nonfiltrable phos-phate) samples were treated with a mild persulfate digestion to release all bound forms of phosphate to the liberated orthophosphate form, and were then determined colorimetrically using the Absorbic Acid Method. Orthophosphate (total filtr-able or dissolved phosphate) samples were filtered, and the
._Itrates were retained for analysis by direct colorimetry.
Metaphosphate (total nonfiltrable or particulate phosphate) concentrations were obtained by subtracting the concentration of filtrable phosphate from the total filtrable and nonfiltr-able phosphate. Sulfate was measured by nephelometry, i.e. The absorbance of a b4rium sulfate suspension from which the natural turbidity of the sample was subtracted. 1.2.3 Station Descriptions
'- Station 243 is the furthest down-stream station on Lake Anna and is in the Old North Anna river channel about 450m (1500 ft) from the dam. The reservoir at this point is approximately 2.1 km (1.3 mi) wide and 21 m (70 ft) deep in the channel, however deeper soundings have been recorded off the ao.ithwest corner of the dam at a quarry site. This station i:. located about 1.2 km (.8 mi) from the center of dike at Rock creek, and is approximately 4.3 km (2.7 mi) downstreem O from stattun 241, nearly 8.8 km (5.5 mi) from the power station.
This area is fairly < posed to wind conditions due to the lack of prominent shorelines. Statien 241 is located approximately halfway between the power station and the dam in the reservoir. It is 4.6 km (2.8 mi) from the power station, just downstream from Duke's Creek and about 230 m (750 f t) southwest of a point of shore. The d. pth at this station is about 16m (42 f t) and lies in the s- original channel of the North Anna River. intako, Station 231 is located about 460 m (1500 f t) from the to the power station in water approximately 8 m (25 f u de.v. The reservoir is almost 1.2 km (.8 mi) wide l in this area. Tne midehannel depth at the power station is about 15 m (50 ft). This site is located just downstream from Sturgeon Creek. Station 225 is located on the original channel of the North Anna River approximately 1.7 km (1.0 mi) upstream from Station 231. It is beneath power lines crossing the reservoir, off the southern shore about 38 m (125 f t) . The depth of the water is 15 m (50 f t) , and the span across the reservoir is about 300 m (1000 f t) . It is approximately 1.,2 km (.8 mi) downstream from Contrary Creek. O - i s 1-6
l i l Station 224 is in the lower reaches of Contrary Creek, approximately .9 km (.6 mi) from the mouth. It is about 9 m (30 ft) from the northwest shore at the' site of rock outcropp - ings. The depth here is 12 m (40 f t) , located over the original creekbed, and the width of the impoundment is about 380 m l (1250 f t) . i Station 223 is midway between the Route 652 bridge over ' Contrary Crcek and station 224, in an enlarged bay-like area, l approximately 1.2 km (,8 mi) from each of these sites. The stations site is slightly off-center over the original creek-bed in water that is about 8 m (26 ft) deep. The width of this bay-like area is close to 610 m (2000 ft). Station 222 is the uppermost station on Contrary Creek, (' just downstream from the bridge crossing of Route 652. The water is about 8 m (26 f t) deep, and impoundment reaches approximately 2.3 km (1. 4 mi) upstream. . Freshwater Creek empties into Contrary Creek upstream from Station 222 and I could be diluting the effects of mine dumps along the creek-bed of Contrary Creek about.4.6 km (2.8 mi) upstream. O Station 221 is upstream from the mouth of Contrary Creek just below the Route 208 bridge on the original North Anna River channel in 15 m .(50 f t) of water. The reservoir is approximately 1.1 km (.7 mi) wide at station 221. This is the approximata midpoint in the length of the Reservoir, and is about 3. 4 km (2.1 mi) upstream from the power ststion. Station 211 is located approximately 10.5 km (6.5 mi) upstream from the Power station, just below the Route 719 bridge on the North Anna arm of the reservoir. The depth of the water is about 7 m (23 ft), and the width of the impound-l ment is around 300 m (1000 f t) . Station 212 is located just downstream from the Route 719 bridge crossing of the Pamunkey Creek arm of the reservoir. The water is nearly 9 m (30 f t) deep and the area is about 115 m (375 ft) wide. This station is about the same distance from the power .atation as is station 211. - l Stations 111, 121, 131, and 132 are located in the Waste Heat Treatment Facility. Station 111 is located at the end of the dischargi. canal from the power station in the vicinity of the original Sedges Creek channel. It is 1.4 km (.9 mi) from the discharge point at the reactor site. The water is approxi-mately 8 m (26 f t) deep at this point and 300 m (1000 f t) wide. p>, Station 121 is approxiamte.fy 300 m (1000 ft) from the dike on Elk Creek'in water 18 m (60 tc) deep, and the width of the s 1-7 s
- ~ - - ~ ~
_. . J._ . .7.-.. -. _. O . impoundment is .8 km ( . 5 mi) . This station is 5.8 km (3.6 ! mi) from the power station discharge. ' Station 131 is near the end of the third canal where it empties into Coleman Creek. The impoundment is constricted here, approximately 300 m (1000 f t) wide and 7 m (23 f t) deep. A strong flow in the direction of the third dike persists when the station pumps are functioning. This station is about 10.1 km (6.3 mi) from the power station discharge point. Station 132 is located 300 m (1000 f t) from the dike near the original Rock Creek basin. The water is 15 m (50 f t) deep and the distance from shore to shore is about . 9 km ( . 6 mi) . This station is about 12.8 km (8.0 mi) from the power station discharge point. From this station, cooling water from the [, WHTF reenters the reservoir and may recirculate up to the power station. The entire recirculation distance is approxi-mately 22.0 km (13.6 mi). 1.3 Results . 1.3.1 Heavy Metals From 1978 to 1979 the overall water temperature decreased approxiamtely 10C. The seasonal water () temperatures overall were lower in 1979 except during March. The greatest temperature difference from 1978 to 1979 occurred in the Upper Reservoir, while the smallest change in temperature occurred in the WHTF and Lower Reservoir. Station 111, nearust the discharge point at the power station exhibited the most elevated temperature, followed by stations 121, 131, and 132 consecutively. Upper Lake station 212 had the coolest waters in the reservoir. In spite of the changes, there was no sign-ificant differences between 1978 and 1979 temperatures (Section
., 2.3.3.).
The pH decreased slightly overall from 1978 to 1979. The average pH in all areas except Contrary Creek is 6.8, while Contrary Creek averages 6.4. Station 222 exhibited the lowest average pH of 5.5. The lowest pH value recorded (pH=4.2) occurred at station 222 in March. Table 1.3.1.1 is a comparison of mean heavy metal level
- in Lake Anna water from 1975-1979 for each station. The over-all iron concentration in the reservoir (excluding WHTF) has increased from 1978 to 1979 and increased at all stations except 111 and 131. Mean iron levels in the Upper Reservoir doubled while in the Contrary Creek area they tripled. The lower Lake and WHTF water changed very little in iron con-centration from 1978 to 1979. The highest level of iron detected in, Lake Anna water during 1979 (22.15 mg/1) occurred 1-8
./
s
. --. - _. _:.=-..._
O in a 14 meter hypolimnion sample from station 221 in September. In fact, the seasonal maximum for iron (1.87 mg/1) occurred in i September. Generally, the highest levels of iron were detected
)
in hypolimnetic Contrary Creek samples.' Iron is widely dis-tributed in nature, generally as bivalent ferrous Fe++ or trivalent ferric Fe+++. In the epilimnion of a lake in the presence of oxygen, trivalent Fe+++ is present as a colloidal complex in combination with other inorganic ions or decomposit-ion materials. During summer stagnation, with the accompanying oxygen depletion in the hypolimnion, the trivalent ferric form is reduced to the bivalent ferrous form, the latter going into l solution. As a result of the reduction of the ferric complex, the concentration of iron as well as silicate, phosphate, and bicarbonate is frequently increased (Reid, 1961; Wetzel, 1975). Station 223 exhibited the highest station mean overall (3.39
,s mg/1). Iron was detected in over 88% of the samples n.t'.lyzed.
(_ The Virginia State Water Control Board (1976) has a reference i level based on drinking water quality criteria of 0.3 mg/l for iron, and approximately 58% of the Lake Anna water samples ex-ceeded the reference level. However, these are not unusual iron levels for lake waters (Reid, 1961). Table 1.3.1.1. A Comparison of Mean Heavy Metal Levels in Lake Anna Water From 1975-1979 for each station. Fe Cu Zn Pb Station Year (mg/l) (mg/1) (mg/1) (mg/1) 111 1975 0.37 0.01 0.01 0.04 ; 1976 0.80 0.014 0.0 0.001 I 1977 0.53 0.0 0.0 0.0 1978 0.74 0.002 0.004 0.002 1979 0.38 0.0 0.0 0.0 v 121 1975 0.21 0.01 0.0 0.04 ! 1976 0.39 0.007 0.001 0.002 ; 1977 0.50 0.0 0.0 0.0 1 1978 0.14 0.0 0.0 0.0 1979 0.35 0.0 0.001 0.003 131 1975 0.33 0.01 0.01 0.07 1976 0.04 0.015 0.0 0.004 1977 0.94 0.0 0.0 0.0 1978 0.90 0.0 0.007 0.001 1979 0.60 0.0 0.0 0.0 132 1976 0.59 0.013 0.0 0.0 1977 0.82 0.0 0.0 0.0 1978 0.33 0.001 0.004 0.002 {) 1974 0.48 0.0 0.0 0.005 l l l-9 l
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O . Table 1.3.1.1 (Cont.). i Fe Cu ' Zn Pb I Station Year (mg/1) (mg/1) ' (mg/1) (mg/l) 211 1975 2.17 0.01 0.0 0.03 1976 0.33 0.007 0.002 0.0 1977 0.45 0.0 0.001 0.0 1978 0.69 0.0 0.0 0.001 1979 1.33 0.0 0.0 0.001 212 1975 1.20 0.02 0.01 0.02 , 1976 0.30 0.009 0.003 0.0 1977 0.60 0.0 0.0 0.0 1978 0.56 0.0 0.0 0.001
,. 1979 0.73 0.0 0.0 0.0
(' 221 1975 1.70 0.01 0.02 0.04 1976 0.70 0.021 0.0 0.003 1977 0.86 0.0 0.0 0.0 1978 0.42 0.001 0.003 0.001 1979 2.75 0.0 0.016 0.001 222 1975 1.59 0.065 0.19 0.06 O 1976 1977 0.47 1.67 0.076 0.047 0.0 [ 0.059 0.030 0.0 1978 0.80 0.051 0.182 0.007 1979 1.48 0.180 0.239 0.001 223 1976 0.19 0.043 0.022 0.0 l 1977 1.11 0.036 0.019 0.0 l 1978 0.60 0.005 0.012 0.001 e' (; 1979 3.39 0.026 0.162 0.006 224 1976 1.47 0.020 0.002 0.0 1977 1.82 0.027 0.011 0.0 1978 0.93 0.037 0.132 0.005 1979 1.51 0.002 0.068 0.002 225 1975 1.63 0.01 0.02 0.09 1976 1.02 0.012 0.0 0.0 1977 0.77 0.005 0.0 0.0 1978 0.52 0.004 0.0 0.001 1979 0.90 0.0 0.009 0.001 231 1976 0.46 0.05 0.0 G.0 1977 1978 0.48 0.006 0.0 0.002 1979 0.62 0.0 0.002 0.0 0 - 1-10
]
Table 1.3.1.1 (Cont.). , l Fe Cu Zn Pb Station Year (mg/1) (mg/1) (mg/l) (mg/1) 241 1975 0.51 0.01 0.01 0.97 l 1976 0.76 0.042 0.0 0.0 ' 1977 0.20 0.0 0.0 0.0 1978 0.91 0.001 0.0 0.001 1979 1.04 0.0 0.0 0.0 243 1975 0.75 0.03 0.02 0.94 1976 3.24 0.015 0.002 0.004 1977 0.23 0.0 0.0 0.0 1978 0.50 0.0 0.004 0.002 1979 0.57 0.001 0.001 0.0 ( . Copper levels decreased overall from 1978 to 1979, except at stations 222 and 223, where levels increased. The highest concentration of copper was detected in a hypolimnetic sample from station 223 in December (0.12 mg/1). Copper was only detected in 5% of the samples analyzed. The VSWCB (1976) has a reference level of 1.0 mg/l for copper based on drinking O water quality criteria. No values for copper exceeded this reference level in Lake Anna water tested in 1979. Levels of zinc in 1979 Lake Anna water overall remained near those observed in 1978. Contrary Creek zinc levels were slightly elevated over 1978 levels, with station 222 having the highest station mean. Zinc, found in 24% of the samples, was more prevalent in hypolimnetic water samples and the high-est seasonal average occurred in March. Contrary Creek levels (_- of zine wet 2 significantly higher in March than during other sampling periods. The VSWCB (1976) reference level of 5.0 mg/l for zine was not exceeded by any levels of zine obtained in 1979 Lake Anna water samples. , f.ead levels decreased overall in Lake Anna water from 1978 to 1979. Lead was detected in 18% of the samples collected for the first three quarters. Contrary Creek hypolimion samples for stations 223 and 225 were elevated in March. Lead was de-tected in Lt metalimnion samples from stations 121 and 132 in the WHTF in ptember. The VSWCB (1976) reference level for , lead is o.0. mg/1, and none of the Lake Anna water samples collected during March, June or September 1979 were above this level. December lead values (4th Quarter) were un6sually high (Table 1. a.1. 2) . This data was not analyzed with preceeding O- 1979 lead values, because of the possibility of contamination 1-11
.. --- -:= .: :_ : . ..- . _ _ --- - - - - - - - - - - - - - - - - - -
l l O . from sample containers. A statement will be submitted follow- , ing the analysis of March 1980 samples to support or disclaim ' this hypothesis. These values are muchihigher than the typ-ical lead values found in Lake Anna. Table 1.3.1.2 Lead Concentration (mg/l) in Fourth Quarter
- l Water Samples Lake Anna 12/17/79.
. Depth
- Station (meter) Level
- Lead 111 0 S 0.100 7 B 0.024 121 0 S 0.013 5 M 0.002 s 10 2 0.032 131 0 S 0.036 7 B 0.040 132 0 S 0.038 t
5 M 0.042 10 B 0.033 211 0 3 0.111 6 B 0.056 212 0 S 0.028 9 B 0.024 221 0 'S 0.005 6 M 0.017 12 B 0.032 222 0 S 0.023 5 B 0~031 223 0 S 0.041 8 B 0.072 k 224 - 0 S 0.005 3 M 0.027 6 B 0.083 225 0 S 0.046 - 8 M DL 16 B 0.046 231 0 S DL i l 6 M- 0.019 12 B 0.018 241 0 S 0.029 8 M 0.019 16 B 0.039 243 0 S 0.029 8 M 0.089 16 B 0.003
- S = Surface M = Middle O B = Bottom 12 .
_. = .- =. - ---
. .= ,_ _ - . -- . _ . - .-
O . 1.3.2 Nutrients 1.3.2.1 Nitrate Nitrogen The overall mean for nitrate nitrogen in Lake Anna water in 1979 is approximately 0.16 mg/l and is nearly unchanged from 1978 levels. Increases did occur at stations 211, 212, 241 and 132 and decreased at stations 111, 121 and 231 (Table 1.3.2.1). March levels for nitrate were significantly higher in the Upper Reservoir (0.29 mg/1) than in other areas at any other sampling dates during 1979. Nitrate nitrogen was detected in 99% of the samples analyzed, and the highest value recorded (0.49 mg/1) occurred in the surface sample at Upper Reservoir station 212 in March. None of the levels by recorded exceeded the reference level of 0.9 mg/l given the VSWCB (1976) Water Quality Inventory. According to Lee (1977), inorganic nitrogen levels as high as 0.3 mg/l could lead to deteriorated water quality in summer due to excessive algal growth. In fact, increased phytoplankton densities were recorded at Upper Lake stations during March (Section 3.3). 1.3.2.2 Ammonia Nitrogen Ammonia levels have. continued to decrease in Lake Anna water. The overall mean of 0.04 mg/l is O well below the reference level of 0.29 mg/l given in the VSWCB (1976) Water Quality Inventory. Ammonia was detected in only 22% of the samples analyzed. Upper Lake station 212 hypoll-metric samples exhibited the hf; hest levels of ammonia in March and June (0.16 mg/l and 0.21 mg/l consecutively). Station 212 was the only station showing ammonia levels higher in 1979 than in 1978 (Table 1. 3. 2.1) . In surface water, ammonia concentrat-ions were normally 0.1 mg/l or less as nitrogen. Higher levels are usually indicative of sewage or. industrial contamination I (National Academy of Science, 1972). l.3.2.3 Phosphate Total phosphate levels for 1977 were con-sistent with 1978 levels overall. Upper Reservoir and Contrary l Creek total phosphate levels increased slightly from 1978 to 1979, but Lower Reservoir and WHTF levels are the same. The seasonal maximum occurred in December (0.06 mg/1) and station 211 had the highest station mean (0.07 mg/1) for total phosphate (Table 1. 3. 2.1) . The highest level of total phosphate during 1979 (0.21 mg/1) occurred once at station 212 in September, and once at station 223 in December, both in hypolinnion samples. The reference level given by the VSWCB (1976) Water Quality Inventory for phosphates in 0.3 mg/1. Whib total phosphate was detected in 98% of the samples analyzed in 1979, orthophosphate (soluable inorganic phosphate) was detected in only 1% of the 160 samples. These very low (]) levels (0.01 mg/1) were found at station 211 in Decembar. l
- 1-13
^ ._ _ ._ . ....__..._;._ _. - _ __-~~ '~ ~ ~
l '() - 1 Table 1.3.2.1. A Comparison of Mean Anion Levels (mg/1) in Lake Anna Water, 1975 - 1979. Station Year NH4 + 0-PO4 T-PO4 NO3- SO4 = 111 1978 0.07 0.0 0.04 0.23 9.9 1979 0.04 0.0 0.03 0.17 8.1 l 121 1975 0.488 0.02 0.11 0.238 9.0 1976 0.138 0.01 0.14 0.440 9.0 1977 0.086 0.01 0.30 0.256 11.9 1978 0.04 0.0 0.03 0.19 9.6 1979 0.03 0.0 0.02 0.17 d.4 . f 132 1975 0.411 0.02 0.10 0.226 9.0 1976 0.157 0.01 0.18 0.343 9.0 1977 0.100 0.02 0.37 0.205 10.4 1978 0.05 0.0 0.03 0.14 11.1 1979 0.02 0.0 0.03 0.17 8.4 4 l 211 1975 l 0.515 0.06 0.26 0.135 10.0 1976 0.135 0.06 0.19 0.790 10.0 ,Q 1977 1978 0.118 0.06 0.02 0.0 0.29 0.254 16.7 0.04 0.07 7.9 1979 0.03 0.0 0.07 0.11 5.7 212 1975 0.709 0.09 0.25 0.155 19.0 1976 0.215 0.05 0.21 0.750 9.0 1977 0.117 0.03 0.38 0.211 18.8 1978 0.03 0.01 0.05 0.07 8.4 1979 0.07 0.0 0.06 0.16 6.0 ks 221 1975 0.585 0.02 0.16 0.147 10.0 1976 0.251 0.02 0.16 0.523 10.0 1917 0.160 0.02 0.40 0.221 10.8 1978 0.06 0.01 0.03 0.16 9.3 1979 0.05 0.0 0.5 0.16 8.0 223 1976 0.113 0.03 0.14 0.245 19.7 1977 0.088 0.02 0.35 0.019 15.5 1978 - - - - - 1979 0.05 0.0 0.06 0.12 16.0 231 1978 0.07 0.0 0.03 0.18 10.0 1979 0.04 0.0 0.05 0.17 8.5 l l lO ' 1-14 L -.W.-
~
O . Table 1.3.2.1 (CONT.). Station Year NH 4 + O-PO4 T-PO4 NO 3- SO4= 241 1975 0.507 0.02 0.11 0.l'39 9.0 1976 0.215 0.02 0.13 0.605 9.0 1977 0.115 0.02 0.48 0.245 8.7 1978 0.07 0.0 0.03 0.17 9.7 1979 0.02 0.0 0.04 0.18 8.7 243 1975 0.504 0.02 0.12 0.114 10.0 1976 0.108 0.02 0.18 0.594 10.0 1977 0.067 0.02 0.39 0.237 8.7 1978 0.08 0.0 0.05 0.17 9.6 - 1979 0.03 0.0 0.04 0.17 8.5 k. O O
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O 1.3.2.4 sulfate The sulfate content of Lake Anna water for 1979 was lower than previous years. All stations (Table 1.3.2.1) show decreases except station 223 in Contrary Craek. Contrary Creek is still the area with the highest sulfate content (10.9 mg/1) while the Upper Reservoir is the area with the lowest sulfate content (5.8 mg/1). The higest recorded ! value occurred at station 223 in March (21.0 mg/1). Sulfate is widely found in nature and my be present in surface waters - in concentrations ranging from a few to several thousand mg/l (APHA, 1975). 1.4 Summary
- Heavy Metals and Nutrients
'~ 1. There is no evidence to indiccte that the operation of the reactor unit at the North Anna power station had any effect on Water quality in Lake Anna.in 1979.
( 2. Iron levels have increased in the Upper Reservoir and Contrary Creek areas from 1978 to 1979.
- 3. Copper and lead appear to be decreasing overall in Lake O Anna, however, March Contrary Creek samples showed elevated levels fer zine and lead.
- 4. December lead values were unusually high, however, con-tamination of the samples is suspected and following March 1980' analysis of metals samples, this hypothesis !
will be confirmed or disclaimed. ' l 5. March levels for nitrate nitrogen were significantly (,) I higher in the Upper Reservoir than in other areas at any other sampling date during 1979.
- 6. The sulfate content in Lake Anna was lower in 1979 than in previous years except at station 223 in Contrary Creek.
0 1-16 ,
() . 1.5 References American Public Health Association, Ameri6an Water Works Association, Water Pollution Control Federation. Standard methods for the examination of water and wastewater, 14th Edition, Washington, D.C.; 1976. Lee, G. F Critical levels of phosphorus and nitrogen in Texas impoundments. Texas J. of Science. XXVIII (1-4); 347-350; 1977. National Academy o5 Sciences; National Acad.amy of Engineering. Water quality criteria, 1972. Washington, D.C.: EPA-R3 033; 1973.
; Reid, G. K. Ecology of inland waters and estuaties. New York:
D. Can Nostrand Company; 1961. Simmons, G. M., Jr. Annual report 19'/6. Preoperational environ-mental study of Lake Anna, Virginia. Richmond,TD(: Virginia Electric and Power Company; 1977. Annual report 1977. Preoperational () environmental study of Lake Anna, Virginia. Richmond, VA: Virginia Electric and Power Company; 1978. Virginia State Water Control Board. Water quality inventory (305 (b) Report) , Virginic, 1976 Report to EPA Administrator and Congress. Information Bullentin 526. 313-342: 1976.
/
l O l-17
. s l
O . 2.0 Chlorophyll, Primarv Productivity and Temperature Analyses 2.1 Introduction The thermal profile of the resetvoir and waste heat treatment facility is of primary interest when con-sidering the acute and chronic relations of biotic and abiotic components in the aquatic system. Most studies of thermal effects on algae are focused on the measurement of primary pro-ductivity, i.e., the rate of photosynthesis (Gurtz and Weiss 1972). Primary production in phytoplankton is dependent upon a number of variables such as changes in temperature, light and available nutrient supply (McMahon and Docherty 1975) . In this study, primary productivity determinations and temperature pro-O files were utilized in correlating observed trends. Chlorophyll studies are useful in determining algal stand-ing crop and in the trophic system of lake classification. Thus far, Lake Anna has been classed as an mesotrophic lake based upon its chlorophyll and phytoplankton composition (VEPCO 1976). Chlorophyll analysis was undertaken and the results evaluated in relation to phytoplankton, primary productivity and physical
; ' factors.
2.2 Methods and Materi'als 2.2.1 Chlorophyll At the five primary productivity stations (121, 132, 221, 241, 243), (Fig. 2.2.1.1) water samples were drawn at one-meter inte.vals from zero to five meter depths. Only surface samples ware drawn at the remaining five product-ivity stations (111, 211, 212, 223, 231) (Fig. 2.2.1.1). All chlorophyll stations are located in open water areas with the exception of 211 and 212, which are located near the Rt. 719 bridges in the North Anna and Pamunkey rivers, respectively. Sampling frequency was once per month with the exception of June, July and August when samples were drawn twice per month. Collections were made between 0830 and 1130 hours using a plastic watet sampler. Magnesium carbonate (MgCO3) was added to the samples O following the procedure outlined in Standard Methods for the s 2-1
O C O ' O l 2 1 0 2 !!! w ll.
; 212 Kilometers .1 I 6 i l I
l I li Rt.719 i 1 Rt. ~208 i f i 21 i i 211
- 241 223 .
w e b 231 Power / i Station , 11 l 243 e 121 132 l. i l Figure 2.2.1.1 General location of chlorophyll sampling i station in Lake Anna, 1979. Primary i productivity stations are underlined. j i
l 1 l (:) - Examination of Water and Wastewater (APHA, 1976). From January to June, sample filtration occurred at the North Anna Environ-I mental Laboratory. Beginning in July, cooled samples were trans- , ported to the James R. Reed and Associates, Inc. biological l laboratory in Newport News, Virginia for filtration. Samples l were filtered onto glass fiber filters which were then placed into centrifuge tubes containing 10 ml. of 90% acetone (V/V). The tubes were kept at 00C overnight during the extraction process, then centrifuged at 500 x G for twenty minutes. The chlorophyll extract was decanted into graduated centrifuge tubes
.and absorption readings were taken on a Turner Model 350 Spectro-photometer. .
In determining the amount of chlorophyll (mg/m3), the fol-lowing calculations were used (APHA, 1976): Chl. a concentration in sample = ll.64D663-2.16D645-0.10D630 Chl. b concentration in sample = 20.97D645-3.94D663-3.66D630 Chl. c concentration in sample = 54.22D630-14.81D645-5.55D663 Chl. n - (mg/1) x Extract Vol. (ml.) (]} Chlorophyll n (mg/m3) = Filtered Volume (liters) where D = Optical Density (Absorbance) n = a, b or c Student's t-tests, ANOVA, Duncan's Multiple Range Tests and partial correlations were performed using a SAS test package and ( run on an IBM 370 computer. Both chlorophyll a and total chlorophyll data were analyzed by running ANOVA and Duncan's Multiple Range tests for dates within stations and stations within dates. The data for each was then grouped according to the location of stations in order to test for any significant differences between station 221 (located about 2.5 miles above the power station site), the Lower Reservoir (stations 241 and 243) and the Waste Heat Treat-ment Facility (stations 121 and 132). ANOVA and Duncan's Mul-tiple Range tests kere conducted for areas within dates and dates within areas. " Chlorophyll a data was used for whole and partial cor-relations with primary productivity rates, phytoplankton densities and physical-chemical measurements. l l
]' 1978 and 1979 data were compared by Student's t-tests to
' determine whether there were any significant changes in stations or in months from year to year. 2-3
O 2.2.2 Primary Productivity At primary productivity stations (121, 132, 221, 241, 243) (Fig. 2.2.2.1), samples for primary productivity, total alkalinity, pH and background readings were drawn with a non-metallic water sampler at one-meter intervals from depths of zero to five meters. Sampling frequency was twice per month in June, July and August and once per month at , all other times in 1979. All primary productivity stations are located in open water areas with an average depth of 14 meters. Total alkalinity was determined by potentiometric titrat-ion to pH = 4.5 (APHA 1976) . Both alkalinity and pH measure-ments were made with a Corning Model 5 pH Meter. Primary productivity analysis was performed following the procedure outlined in' Standard Methods for the Examination of Wa'ter and Wastewater (APHA, 1976). Samples from eacn depth were placed into light and " dark" bottles (300-ml. BOD bottles painted black then wrapped with duct tape) containing a broken ampoule of 5 uCi of 14C (labelled as NaH14 CO3 ) . .The samples were then placed at the depths from which they were drawn via an anchored and buoyed hanger. Hangers were set between 0830 and 1130 hours and left for a four hour in situ incubation period. Each background, light and dark subsample was filtered onto (]) a 0.45 um pore size membrane filter and rinsed with 5% hcl. After drying, the filters were placed into scintillation vials containing 10 ml. of scintillation cocktail (scintillation grade toluene and Liquifluor (NEN)). The samples were then counted by either Analytics Laboratory in Richmond, Virginia or Inter-Science Research in Norfolk, Virginia. The following equation was used to analyze primary pro-ductivity (Vollenweider 1969, Lind 1974, and APHA 1976) :
\_i Net Lcpm-(Dcpm+ BKGepm)
Photosynthetic Rate = x 1.06 l E x Alk. x C (mgC/m3/hr) 1.11 x 107 dpm where: L cpm, D cpm, BKGcpm = counts per minute as recorded by the scintillation counter E = scintillation counter efficiency 1.06 = compensation for slower uptak e of 14 C molecule in relation to 12 C (]) 1.32 x 107 = disintegration per minute of 14 C added 2-4
F i O O O
]
2 Kilometers i l ' i , R . 208 - I l t 221 e lI 241 Y l
- Power
- j Station d I
i l \ '
, e- 243 b
e f 21 [ 132 Figure 2.2.2.1 General location of primary productivity sampling stations in Lake Anna, 1979. I i
.i 9
= . - . - .;
O Table 2.2.2.1. Analytical procedure for determination of water quality parameters at productivity stations. Parameter Method Solar Radiation Belfort Instrument Company Pyr-i heliometer i 1 Light Penetration Model LMD-8A Whitney Photometer (Montedoro - Whitney Corporation) l i Transparency Secchi disc (20 cm. diameter) Alkalinity APHA Standard Methods, 1976 (' pH Corning Model 5 pH Meter Dissolved Oxygen Yellow Springs Instrument Model S4 Oxygen Meter Temp ature Yellow Springs Instrument Model 54 Oxygen Meter () Chlorophyll a, b and c Spectrophotometric Determination of Chlorophyll a, b and c, APHA Standard Methods, 1976 Primary Pruddetivity Carbon 14 Method, APHA Standard Methods, 1976
/
i 1 1 O 2-6
./
--m - -
,.e,.y- -
~ - - - -
t O . Alk. = recorded as mg/ liter Bottled Vol. C= , (0.25) ( Filtered Vol. ) (1000) (Alk. correction factor) where: 0.25 = factor to reduce measurement to an hourly rate 1000 = factor to convert measurement to m3 Alk. correction factor = dependent upon l temperature and pH reading To assess other factors influencing primar'y production, solar radiation, light penetration and dissolved oxygen were also measured. A Belfort Instrument Company pyrheliometer (Model 5-3850A) measured solar radiation (gm cal /cm2/ day) for i (_ a 36 hour period during productivity sampling. Light pene-tration was determined using a Model LMD8A Whitney photometer (Montedoro-Whitney Corporation), and transparency was measured with a secchi disc. Dissolved oxygen readings were taken via a Yellow Springs Instrument company, Inc. Model 54A Dissolved oxygen Meter. Table 2.2.2.1 lists methods and equipment uti-lized in the course of productivity analysis. General climatic conditions such as wind velocity, precipitation and cloudiness , s were also noted to aid in data interpretation. These conditions are stated in the physical-chemical portion of the Data Base l (A2-25). Analysis of variance (ANOVA), Student's t-tests, Duncan's Multiple Range Tests, and whole and partial correlations (0.05 level of significance) were performed using a Statistical Analysis System (SAS) test package, SAS Institute, Raleigh, L' Nnrth Carolina and run on an IBM 370 computer. ANOVA and Dun-l can's Multiple Range Tests were performed on the 1979 primary productivity data to test for significant differences of sam-pling dates within stations and stations within dates. Primary l productivity data was then grouped according to the location of l the respective sampling stations in order to test for any signi-ficant differences between the Waste Heat Treatment Facility (Statiuns 121 and 132) , the Lower Reservoir (Stations 241 and 243) and Station 221 which is located near the Rt. 208 bridge about 2.5 miles above the reactor site. Duncan's Multiple Range tests were performed for the purpose of grouping stations that l ~ were comparable in values. Data was incorporated into whole and partial correlation tables along with chlorophyll, phyto-plankton and physical-chemical parameter data. The 1979 prim-ary productivity rates for each station and for each date were com-pared with 1978 rates by Student's t-tests, in order to recog-nize if there w*ere any alterat. ions in the primary productivity rates in individual stations of months from year to year. O 2-7 1
O 2.2.3 Temperature Temperature readings were taken from surface to bottom at one-meter intervals at all productivity stations (Fig. 2.2.3.1). All stations were located in open water areas with the exception of stations 211 and 212 which were located near the Rt. 719 bridges in the North Anna and Damunkey rivers, respectively. Data was collected twice per month in June, July and August and once per month during the remainder of 1979. Sampling was usually performed between the hours of 0830 and 1200. A Yellow Springs Instrument Company, Inc. Model 54A Dis-solied Oxygen Meter was used in the determinations. The data was statistically evaluated by Analysis of Variance, Student's t-tests and whole and partial correlations utilizing the SAS test package oa an IBM 370 computer. Student's t-tests were used to compare the mean temperatures of stations for each sampling date in 1979. Temperature values for 1978 and 1979 i.' were compared using monthly readings for each station. Whole and partial correlations for each date and station as well as for the entire year of 1979 were performed using temperature, phytoplankton densities, primary productivity, chlorophyll and other physical-chemical data. 2.3 Results and Discussion () 2.3.1 Chlorophyll Chlorophyll a b, c and-total chlorophyll (the sum of chlorophyll a, b, and,cT determinations for all sam-ples are given in the Data Ease Section. ANOVA and Duncan's Multiple Range tests were run on both chlorophyll a and total chlorophyll values. In comparing chlorophyll a and total chlorophyll readings for both 1978 and 1979, there was a significant increase in stations 211 and 212 in 1979. At all other stations there was i \_ no significant difference between years. Table 2.3.1.1 illu-strates the mean chlorophyll a concentrations for stations and dates in 1978 and 1979. Comparisons were also made between the months in which the first reactor unit was either operating or nonoperating. No significant differences were observed when grouping either all primary productivity sampling stations together or all stations at which only surface samples were drawn. ANOVA and Duncan's Multiple Range tests were run on chloro-phyll a and total chlorophyll values for the five primary pro-ductivIty stations by sampling dates. (Data Base page A2-71). In most cases the statistical results pertaining to stations and sampling dates when analyzing chlorophyll a alone were no diff-erent than when analyzing total chlorphyll. For this reason, the general term chlorophyll will be used in the following discussion unless there is a specific reference to chlorophyll a. 2-8 -
o i O ( O n 2 1 0 2 N ' 212 Kilometers ,! I N .. Rt. 719 . 1 I;. i'
/ t. 208 L
& o i q
/ ** 21 .
211 241 I u 223
- 4 -
231 , l Power -
* ,j-.
Statio.n ,
')
P ! l 111 ' 243 121 132 Figure 2.2.3.1 General location of physical and chemical sampling stations in Lake Anna, 1979. Primary Productivity stations are underlined. j
O Table 2.3.1.1 Comparison of average Chlorophyll a concentrations at the productivity stations. Chlorophyll a = mg/m3, Station Month 1978 1979 111* March 1.20 4.96 April 2.37 1.95 { 7.96 0.00 June 0.86 3.73 July 2.28 0.00 August 1.26 0.51 September 0.00 1.46 October 0.00 1.00 November 1.30 1.00 (.. ~ 121 March 5.12 7.12 April 2.35 2.33 May 8.94 1.15 June 0.71 4.66 July 2.69 0.92 August 2.65 0.97 September C.29 () October November 0.50 1.31 1.78 1.74 0.84 132 March 8.79 6.29 April 2.91 2.28 May 6.56 0.38 June 2.07 4.39 July 2.88 1.14 s August 1.30 0.55 September 0.37 1.40 October 0.97 0.80 November 2.50 1.36 211* March 4.99 2.68 April 6.52 7.58 May 2.87 17.32 June 2.62 16.81 July 5.08 5.03 August 4.83 8.39 - September 6.09 6.38 t October 8.13 11.28 November 10.24 10.86 O 2-10 -
.i
O . Station Month 1978 ;979 212* March 3.99 3.t0 April 3.68 8.80 May 5.82 0.26 June 3.49 11.78 July 5.24 1.36 August 3.68 5.37 September 3.28 6.94 October 3.08 11.93 November 4.84 9.23 221 March 1.97 6.11 e April 2.29 4.42 (.. May 6.31 0.07 June 1.62 4.27 July 2.28 1.57 August 1.28 1.68 September 0.66 3.52 October 0.79 3.56 November 0.94 1.37 () 223* March April 0.00 0.00 1.56 0.00 May 0.66 0.00 June 1.57 5.75 July 2.20 2.28 August 3.92 1.93 September 1.54 2.37 October 0.61 2s97 November 0.70 1.07 v 231* March 4.78 5.79 April 0.63 4.10 May 8.39 0.00 June 2.21 3.81 July 2.86 1.93 August 0.79 0.99 September 0.00 1.66 October 0.56 2.15 November 0.94 0.10 241 March 1.56 8.19 April 2.81 0.36 May 6.84 0.00 June 1.89 2.64 July 2.15 0.65 l n August 1.19 0.76 U September' O.37 1.01 October 0.00 0.83 November 1.24 1.24 2-11 _ ,-- , r
O . Station Month 1978 1979 243 March 4.72 8.39 April 2.81 0.51 May 6.76 0.00 June 1.12 3.72 July 1.92 0.94 August 1.00 0.38 September 0.10 0.88 October 0.41 0.89 November 0.67 1.39 s.
- Stations at which only surface samples are drawn.
O - t O i 2-12 _-- _ _ _ _ _ _ _ _ _ _ _ - - - _ _ _ _ _ _ _ _ . . -- __ _ _ _ _ . . _ . .1
N.. r ~- l O . For two stations in the Waste Heat Treatment Facility (WHTF), 121 and 132, chlorophyll values were significantly higher in March than all other sampling dates for these stations with respective mean chlorophyll a concentrations of 7.12 and 6.29 mg/m3 The second sampling in June with mean chlorophyll a concentrations of 4.66 and 4.39 mg/m3 was signif- l icantly higher for both of these stations than the remaining l sampling dates. The first July analysis shows the lowest read-ings of the year for the WHTF stations with 0.58 and 0.34 mg/m3, At the two stations in the Lower Reservoir, 241 and 243, the analysis for March and the second sampling in June also resulted in the highest concentrations for the year. The mean chlorophyll a concentrations for March and June 19 at station 241 were 8.li and 2.64 mg/m3 . The readings for station 243 on these dates were 8.39 and 3.72 mg/m3 . At station 221, the first June and the January samplings were significantly higher than the remaining dates with mean calorophyll a concentrations of 17.78 and 17.50 mg/m3, respect-ively. The five primary productivity stations were compared for (]) each sampling date by ANOVA and Duncan's Multiple Range test. The results were also grouped according to station location so that general comparisons could be made between the Waste Heat Treatment Facility, the Lower Reservoir and Station 221, located near the Rt. 208 bridge abc.ut 2.5 miles above the reactor site. During January, Station 221 was significantly higher than all other stations in mean chlorophyll values with a chlorophyll a concentration of 17.50 mg/m3 as compared with mean values of (_ 7.2 to 3.0 mg/m3 at other stations. In March, stations 241 and 243 (in the Lower Reservoir) were higher in chlorophyll than the WHTF stations, while in April station 221 was rated significantly higher than the WHTF. The Lower Reservoir stations were significantly lower than both station 221 and the WHTF area. Station 121 was significantly higher in May in chlorophyll content than the other four stations. The WHTF area was also significantly higher than the Lower Reservoir and station 221. During the first sampling in June, station 221 had signif-icantly higher chlorophyll content than the other two areas, although later in the month, the WHTF was comparable to station I 221 and bota were significantly higher than the Lower Reservoir stations. l () . s 2-13
- - + - - --- - - - - - *
- .. . . 2: 2. - _ _ - - --
l O In July all stations were roughly comparable in chlorophyll concentration, but with the first August sampling the Lower Reservoir was significantly lower in mean chlorophyll values ( than the other areas. The results for the second sampling in
- August, September and October show that station 221 was signif-icantly higher in chlorophyll concentration than the WHTF and the Lower Reservoir. During these months the mean values for station 121 and for the WHTF area were greater but usually not significantly higher than each of the remaining three stations or the Lower Reservoir.
There was no significant difference among the individual stations or the general areas in November, while in December station 221 was significantly higher than the other stations ~ and areas. The Lower Reservoir stations were significantly lower in mean chlorophyll concentrations. ( ~ Chlorophyll a concentrations were correlated with depth, phytoplankton densities, primary productivity and physical-chemical factors. The whole and partial correlation tables for stations, dates and for 1979 are presented in Data Base (page A3-234, A3-249, A3-264). Chlorophyll a concentrations in phytoplankton appears to be correlated to many variables including phytoplankton densities, primary productivity, dis-() solved oxygen, pH, temperature and depth. Chlorophyll e concentrations increase gradually during the _ winter months 6o reach a peak in March. This coincides with
- months.
the increase in diatoms (Bacillariophyto) in the early spring Chlorophyll e is found mainly in diatoms, thus it is possible to trace the fluctuation of this algal using data deriven from chlorophyll c analysis. Chlorophyll a is found in green algae (Chlorophyta) and is the or.ly chlorophyll type found in blue-green algae (Cyano-phyta). Chlorophyll a also occurs in diatoms. As it is not possible to diffentiate between chlorophyll a from different divisions of algae, phytoplankten identification becomes necessary. Geneially, chlorophyll concentrations appeared to be lower in Lue Lower Reservoir stations than in the Waste Heat Treatment Facility stations. 1979 is the first year for which this observation is noted and it will be of interest to see if this is a developing trend. The difference in chlorophyll concentration is not attributable to any factor or factors at this time. The two Upper Reservoir stations, 211 and 212, experienced the highest, chlorophyll concentrations of all stations sampled. 2-14 s __.______E--------
l () l There is generally a high input of organic material in runoff i from cow pastures and farmland near these stations, i With the exception of the two upper stations, chlorophyll analysis indicates that Lake Anna has not changed in its trophic state as mesotrophic from 1978 through 1979. Each year was characterized by operation of Unit 1 during only a portion of the year, thus precluding any estimations of significant alterations in chlorophyll concentrations due to increased thermal influences. 2.3.2 Primary Productivity Primary productivity estimates for stations and dates sampled are given in the Raw Data Section. Associated physical and chemical parameters necessary for deter-minations are also presented. ANOVA and Duncan's Multiple Range
,- tests were performed on the data. Duncan's tables of the sta-(_ tistical analyses are located in the Data Base (page A2-139, A2-145, A2-160).
The five primary productivity stations (Fig. 2.2.2.1) were compared for each sampling date. The stations were also grouped according to station location so that comparisons would be pos-sible between the Waste Heat Treatment Facility (stations 121 and 132), the Lower Reservoir (stations 241 and 243) and station
,,/ 221 (located near the Rt. 208 bridge about 2.5 miles above the reactor site). -
In January, station 221 was significantly higher in mean l primary productivity rates than the Waste Heat Treatment Facil-ity (WHTF) and the Lower Reservoir. All stations were generally comparable for the remainder of the year, with the exception of May in which station 221 again was significantly higher in mean primary production. Sampling dates were compared for each station with results showing no significant differences or specific trends in sampl-ing dates. The Duncan's tables illustrate a great deal of over-lapping in months of similar production rates. , Average promary production rates for 1978 and 1979 for i sampling stations are presented in Table 2.3.2.1. When average primary production rates of 1979 were compared with those of ' 1978, it was found that 1979 rates were significantly lower than those of 1978 at stations 132, 241 and 243. Photosynthetic rates are influenced by many variables such as temperature, light intensity, nutrient availability, phyto-plankton density and alkalinity. In comparing pyrheliometer charts, photometric readings and climate accounts, it is esti-rN d mated that aclar radiation and light penetration were greater on sampling days in 1979 than in 1978. Overoptimum light 2-15
O . Table 2.3.2.1 Comparison of mean primary productivity rates (mg C/m3/hr). Station Month 1978 1979
. March 2.793 8.211 April 20.631 14.044 May 13.087 5.348 i June 14.337 6.938 121 July 6.384 2.282 August 9.817 0.638 September 7.924 12.374 October 6.109 6.291 November 4.990 2.230
{' December 7.397 1.322 March 5.160 5.547 April 18.811 9.296 May j
- 12.404 7.819 ;
June 14.050 9.752 132 July 6.801 2.096 () August September October 8.472 13.206 6.090 2.298 9.274 3.173 November 5.736 3.071 December 7.649 1.236 March 1.232 2.868 April 15.035 18.083 May 12.017 16.190 June 7.878 11.568 t 221 July 5.054 5.379 August 12.192 1.919 September 7.134 9.179 October 6.714 12.463 November 4.798 7.614 December 6.248 ' 2.692 March 1.791 6.012 April 16.047 8.247 i May 11.767 7.389 l June 9.164 4.881 241 July 4.772 3.507 August 10.367 1.582 September 7.853 4.287 October 3.716 2.762 November 4.841 2.964 December 5.133 0.766 2-16
__ r._ _ _ () -
)
l , Station Month 1978 1979 \ March 3.580 7.133 April 18.563 9.192 May 13.610 9.253 June 8.838 7.637 243 July 3.906 4.153 l . August 5.357 3.567 l September 12.455 5.539 October 5.676 3.214 , November 4.023 3.693 December 6.141 1.146 i O l l l . O 2-17
~
~
e w - -- , - - - - - - - - -
. . . . ~ . - .
l O co.nditions can provoke a reduction in photosynthetic rates ! (Wetzel 1975, Prescott 1968, Tilzer and Horne 1979). The de-l crease in primary production is associat'ed with photo-oxidative l destruction of enzymes and does not involve destruction of the chlorophyll (Wetzel 1975). This observation by investigators perhaps explains the reduction in primary productivity from l 1978 through 1979 while chlorophyll concentrations were not significantly different. l l Generally, moderate increases in temperature stimulates photosynthesis, however, the effects of light and temperatures on phytosynthesin and growth of algae are inseparable lecause of the interrelationships in metabolism and light saturation. In his investigations of the effects of thermal effluents upon phytoplankton populations, Lind found that a definite light-('- temperature relationship existed (Lind 1974). A common change in photosynthetic rates of phytoplankton is an increase in the rate at which light saturation occurs at higher temperatures (Wetzel 1975). Primary productivity rates were correlated with other data as presented in the tables in Data Base (page A3-234). At most O- stations light penetration, depth, dissolved oxygen and temper-ature were most correlated with photosynthetic rates. Phyto-plankton density and chlorophyll concentrations were, in most cases, less important than physical and chemical factors. The relatively greater importance of light, temperature and other physical factors over phytoplankton density has been concluded by many investigators in the field of aquatic primary product-ivity (Marcus 1972, Wetzel 1975. Brock 1975, Gurtz and Weiss 1972). s Estimation of primary productivity rates is of importance in analyzi i the state of an aquatic system as algal photo-synthesis is the major process in which energy is supplied for higher trophic levels such as zooplankton and fish (Wetzel 1975). There is a limited number of invest.igations based on long term, monstant exposure of an aquatic ecosystem to thermal effluent and cycling associated with nuclear reactor sites such as Lake Anna. The comparisons of data within and between repott years afforas observations useful in projecting trends as con-l struction of the reactor site progresses toward completion. 2.3.3 Temperature Temperature data for all stations and sampl-ing dates are listed in the Physical and Chemical tables of the Data Base Section (page A2-25) . Data was analyzed by perform-ance of Student's t-tests, ANOVA and correlations with phyto-plankton and other physical and chemical factors. 2-18
O There was no significant difference in temperatures between 1978 and 1979. When stations were compared, there was no significant difference between stations in the Waste Heat Treatment Facility and the Reservoir. The highest temperature recorded during sampling was 350C on the first August sampling date at station 111. The first reactor unit had been operating at near 100% capacity since May. At temperatures greater than 350C, blue-green algae are generally the predominant phytoplankton as temperature tolerance limits for other types of algae are exceeded (Brock 1975). Unfortunately, it is not possible to analyzed any thermal effects on the phytoplankton population at station 111 i t during that time as the increase in blue-green algae which occurred in late summer and early fall is part of the usual { phytoplankton cycle in Lake Anna. Of the many variables affecting primary productivity, temperature and light are considered to be the two most im-portant (Gurtz and Weiss 1972, Lind 1974). Although these are somewhat related, light is generally the most cricical ( factor in influencing production rates (Prescott 1968, Wetzel l 1975). However, in the late spring and early summer months (]) of 1979, temperature was otten more highly correlated with primary produ: tion than was light. - This might be associated with reactor Unit 1 going off-line on March 30 and back on-line May 2, .979. l Summary 2.4 2.4.1 Chlorophyll (' 1. Comparisons of chlorophyll concentrations between 1978 and 1979 data show significant increases at stations 211 and 212. All other stations did not differ significantly between 1978 and 1979.
- 2. The two Upper Reservoir stations 211 and 212 experienced the highest chlorophyll concentrations of all stations sampled in 1979.
- 3. Generally, chlorophyll concentrations appeared to be lower in the Lower Reservoir stations 241 and 243 than in the Waste Heat Treatment Facility stations.
2.4.2 Primary Productivity
- 1. Comparisons of primary productivity rates between 1978 and 1979 show significant decreases at stations 132, 241 and
(]) 243. 2-19 O q em e 9 9 n y. -- --"'
.- : ~ ~ :. . ;- -
~
T-- ..:- ... 17'- --'
.=.. ~ ' ~ ~ ' ~
O .
- 2. Greater light intensity on 1979 sampling dates is believed l
to be the major factor in lower primary productivity rates than in 1978. -
- 3. For most sampling dates, all stations were not significantly different in 1979 primary productivity rates.
2.4.3 Temperature
- 1. Comparisons between 1978 and 1979 data show no significant differences in temperature.
- 2. Comparisons between stations and dates in 1979 show no significant differences between the Waste Heat Treatment Facility and the Lower Reservoir.
S 9 O t_ l . O - 2-20
; -2.__._
{ l ( - 2.5 References A. P. H. A., et.al. Standard Methods for the Examination of Water and Wastewater. 14th edition; Washington, D.C.; 1976. . Brock, T.D. Predicting the ecological consequences of thermal pollution from observations on geothermal habitats. Environmental Effects of Cooling Systems at Nuclear Power Plants; International Atomic Energy Agency; Vienna; 1975. Gurtz, Martin E. and Charles M. Weiss. Field investigations of the response of phytoplankton to thermal stress; E.S.E. Pablication No. 321; December 1972. Illinois Natural History Survey; Lake Sangchris Project. Annual
\. Report for Fiscal Year 1974. Urbana, Illinois; 1974.
Located: Illinois Natural History Survey, Urbana, Illinois. Lind, Owen T. Handbook of Common Methods in Limnology; The C.V. Mosby Company; Saint Louis, Mo.; 1974.
, B.J. Venables, Mark Wysong and D.L. Lukins. The
(~' relationship of electric power station thermal circulation to biological productivity of reservoirs; Baylor University; Project Number B-091-TEX; January 1974. Marcus , Miu.ael D. An Ecological Evaluation of a Thermal Dis-l charge. Part II: The distribution of phytoplankton and primary productivity near the western shore of Lake Erie. Technical Report No. 14: Thermal Discharge Series; Institute of Water Research; Michigan State University;
, May 1972.
McMahon, J.W. and A.E. Docherty. Effects of heat enrichment on species succession and primary production in fresh-water plankton. Enviroplental Effects of Cooling Systems at Nuclear Power Plants; Symposium IAEC; 1975. Prescott, G. W. The Algae: a Review. Houghton Mifflin Company; Boston, Mass; 1968. Tilzer, M.M. and A.J. Horne. Diel patterns of phytoplankton productivity and extracellular release in ultra-oligo-tropic Lake Tahoe. Int. Revue ges. Hydrobiol. 64(2):157-176; 19/9. Vollenweider, Richard A. A Manual on Methods for Measuring Primary Production in Aquatic Environments, IBP Handbook No. 12; F.A. () Davis Company; Philadelphia, Pa.; 1969. Wetzel, Robert G. Limnology. W.B. Saunders Company; 1975. 2-21
./
O - 3.0 Ph'ytoplankton 3.1 Introduction Phytoplankton, microscopic free-floating algae, are an important component of the aquatic ecosystem, (_ performing the vital ecological function of photosynthesis (the storage of solar energy through the synthesis of organic matter from carbon dioxide and water). They are positioned at the base of the aquatic food web and as such are a necessary focal point for studies of thermal effects upon aquatic commun-ities (Gurtz and Weiss, 1972). 3.2 Methods and Materials Individual 60-ml. phytoplankton O samples were drawn at one-meter intervals from depths of zero to five meters at the primary productivity stations (121, 132, 221 241, 243), (Fig. 3.2.1). At each of the remaining pro-ductivity stations (111, 211, 212, 223, 231), a composite 250-ml. sample from 0, 2, 4 and 6-meter depths was formed. All phytoplankton sampling stations were located in open water areas with the exception of stations 211 and 212, which were located near the Rt. 719 bridges in the North Anna and Pamunkey river area of the impoundment, respectively. Data was k- collected twice per month in June, July and August and once per month ut all other times of the year. In most cases, sample collection took place between 0800 and 1200 hours. A non-metallic water sampler was used for collection purposes. The samples were preserved with 4% Lugol's and 30% formalin. Each sample was introduced into a 50-ml. settling column positioned on plate chambers (Wild Heerbrugg Instruments, Inc.) and allowed to settle for a minimum of eight hours. A Wild Heerbtugg Model M40 Inverted Microscope with phase con-trast cptias and 10X, 40X and 100X objectives was used in identifying and enumerating phytoplankton. Standard keying I. texts were utilized to assist in identification (Whitford and Schumacher 1973, Cocke 1967, Prescott 1970, and Smith 1950). With few exceeptions taxonomic classifications were made to the genus level. After analysis, the sample was then transferred to a 10-ml. vial for the reference collection. O Data was s 3-1 -
O ( o ' o 2 1 0 2 I
# 212 I Kilometers i l N,
Rt.719 % 1 R .208 - j L i
< i . I 21 211 , l f
241
^
223 i y , . N 231 i Power .
- Station ]
' 111
- e 243 a *
- e 121
.132 Figure 3.2.1. General location of phytoplanktop sampling stations in Lake Anna, 1979. Primary i
productivity stations are underlined. 4
p . . .---.- l
)
1 l reported as number of organisms per milliliter of sample. Analysis of Variance, Student's t-tests, Duncan's Multiple Range tests, whole and partial correlations were performed uti-lizing the Statistical Analysis System (SAS), SAS Institute, Raleigh, North Carolina and run on an IBM 370 computer. Phytoplakton densities were analyzed by comparing stations within dates and dates within stations. The data was then grouped according to station location so as to compare station 221 (located about 2.5 miles above the reactor site), the Waste Heat Treatment Facility (stations 121 and 132) and the Lower Reservoir (stations 241 and 243). Whole and partial correlat-ions were performed with phytoplankton densities, primary pro-ductivity, chlorophyll a and physical-chemical factors. Phytoplankton volumes were determined for each station, sampling date and taxonomic division so that comparisons be-tween densities and volumes would be possible. Phytoplankton densities for 1979 were compared with those for 1978 by sampling dates within stations so that year to year
- changes could be observed.
3.3 Results and Discussion Phytoplankton densities (number /ml) for all dates and stations sampled are presented in the Data Base (page A3-1). Genera identified during 1979 and their respective volumes are listed in Table 3.3.1. ANOVA and Duncan's Multiple Range tests were conducted on data by stations and sampling dates, and were also grouped according to station location for the purpose of comparing the Lower Reservoir (stations 241 and 243), the Waste Heat Treatment Facility (WHTF), (s station 221 and the Upper Stations (211 and 212). Duncan's tables are p esented in Data Base (A3-206, A3-212, A3-228) . The five primary productivity stations (Fig. 3.2.1) were I compared for cach sampling date. In January, station 221 was significantly higher in mean phytoplankton density than the other four stations, while in March it was significantly lower. On the AUG 2 sampling, stations 221 and 121 were significantly higher than the remaining stations. Station 221 was again significantly higher in mean algal density in October, followed by station 121. For all other sampling dates, the five pri-mary productivity stations were generally comparable in phyto-plankton density. ANOVA and Duncan's Multiple Range tests were performed on the density data. In the WHTF, February, AUG 1 and September collections show the highest phytoplankton densities for the (]) Lower Reservoir stations 241 and 243. At station 221, January - 3-3 .
, , _ _ 94D + ab e6 s>* ese , - e.e e 8""'"ee** " * * * * '
I O Table 3.3.1. Phytoplankton taxs and corresponding unit volumes found in Lake Anna, 1979. , Taxa Unit Volumes (um3) Division Cyanophyta Order Chroccoccales Family Chroococcaceae Genus Agmenellum 3.0 Ay hanocapsa 4.0
. . . .. Aphanothece 13.0 k~ -
Chroccoccus 905.0 Dactylococcopsis 77.0 Gloeocapsa 19.0 Gloeothece 15.0 0 - Microcystis 1.2 Entophysalis 40.0 Order Oscillatoriales (Hormogonales) Family Oscillatoriaceae L Genus Arthrospira 41.0 Lyngbya 4.7 Oscillatoria 18.0 l Spirulina 39.3 Trichodesmium 300.0 Order Nostocales Family Nostocaceae 270.0 Genus Anabena 270.0 0 - 3-4 *
./
O Taxa Unit volume (um3) Division Chlorophyta 350.0 Order Volvocales Family Chlamydomonadaceae Genus Chlamydomonas 384.0 Family Volvocaceae Genus Eudorina 65.0 Order Tetrasporales
~ \_
Family Cocc.omyxaceae Genus Elakatothrix 16.0 Order Microsporales Family Microsporaceae () Genus Microspora 430.0 Order Chlorococcales Family Micractiniaceae Genus Golenkinia 180.0 .
, Family Coelastraceae Genus Coelastrum 115.0 Family Hydrodictyaceae
- Genus Pediastrum 79.0 Family Occystaceae Genus Ankistrodesmus 105.0 Chodatella 167.0 Closteriopsis 1,232.0 '
Dictyosphaerium 14.0 () ' Franceia 190.0 Kirchneriella 43.0 3-5
O Taxa Unit Volume (um3 ) Nephrocytium . 65.0 oophila 1,300.0 Pachycladon 400.0 Quadriquia 115.0 Schroederia 140.0 Selenastrum 126.0 Tetraedron 179.0 ( Eemily Scenedesmaceae Genus Actinastrum 400.0 Crucigenia 32.0 Scenedesmus 135.0 () Tetradesmus 150.0 Tetrastrum 134.0 order Zygnematales , 700.0 Family Desmidiaceae (- Genus Arthrodesmus 188.0 Closterium 2,048.0 _ Cosmarium 2,027.0 Cosmocladium 400.0 E,uactrum 1,827.0 Groenbladia 475.0 Hyalotheca 1,454.0 Micrasterias 26,546.0 Pleurotaenium 552,905'.0 () ' Spondylosium 624.0 Staurastrum 3,190.0 3-6 .
--~
() .
. Taxa [ nit Volume (um3)
Division Chrysophyta . Order Ochromonadales Family Ochromonadaceae Genus Ochromanas 85.0 Family Dinobryonaceae , Genus Dinobryon 93.0 Famiily Synuraceae ([ Genus Synura 87.0 Order Mischococcales Family Sciadaceae , Genus 'Ophiocytium 289.0 () Division Bacillariophyta Order Eupodiscales Family Coscinodiscaceae Genus Cyclotella 292.0
, Melosira 216.0 v
Order , Fragilariales Family Fragilariaceae Genus Asterionella 600.0 Diatoma 2,937.0 Fragilaria 150.0 Synedra 250.0 Tabe11 aria 775.0 - Order Achnanthales I () Family Cymbellaceae Genus Amphora 200.0 3-7 . O i +h., __9-_=a_e.m m_.-.Av.?'.Q__'_ ser____--_ Q ^ ~ ^ ~ - ~
O Taxa Unit Volume (um3) Cymbella 300.0 ; Family Gomphonemaceae , Genus Gomphonema 176.0 . Family Naviculaceae Genus Navicula 168.0 Pinnularia 1,080.0 Order Surirellales (]) Family Surirellaceae Genus Surirella 3,800.0 Order Nitzschiales Family Nitzschiaceae (]) Genus Nitzschia 240.0 Division Euglenophyta Order Euglenales Family Euglenaceae
, Genus Lepocinclis 1,800.0 \-
Phacus 14,807.0 Trachelomonas 10,016.0 Division Pyrrophyta Order Gymnodiniales Family Gymnodiniaceae Genus Gymnodinium 194,052.0 rder Peridiniales Family Certiaceae () ' Genus Ceratium
~
10,513.0 3-8 .
- ' ~ ~ -
i O l Taxa dnitvolume (um3) Family Peridiniaceae , ! Genus Peridinium 3,889.O Division Crytophyta i ! Order Cryptophyceae Family Cryptochrysidaceae Genus Cryptomonas 550.0 I O , u O - l i 3-9 l - - - - - -
O and AUG1 had the highest phytoplankton densities. The Upper Reservoir stations 211 and 212 showed the highest phytoplankton densities in January, also. While the Upper Reservoir and station 221 exhibited lowest densities in March, the remaining stations had lowest algal counts in December. Stations 211 and 212 were analyzed with the primary productivity stations although their sampling techniques differed in that composite samples were drawn. For the pur-pose of comparing mean densities, stations 111, 223, and 231 were also analyzed in this manner. Tables 3.3.2 and 3.3.3 show the percent composition of total algal density and volume for each station on each sampling date. Station 111 had the highest density and volume in March. Although station 223 had the highest phytoplankton density in the JUL1 sampling with 19.90% it only totaled 9.93% of the total volume. (' October, station 223 had only 10.89% of total density but it comprised the largest portion of total volume with 21.89%. In Station 231 had the greatest algal density of all ten stations on the AUG1 sampling with 17.4% of total density. Comparisons were made between 1978 and 1979 for each of the ten phytoplankton sampling stations. There was a sign-ificant decteaue in densities at station 211, while chlorophyll O concentrations were significantly increased. Comparison of algal genera and cell volumes for each year show that there was a substantial decttase in the number of small algae such as Microcystis and increases in Chroccoccus, Ankistrodesmus and Cyclotella, which may account for the occurence of de-creased total densities and increased chlorophyll concentrat- . ions. s (, The percent of total density and volumes of algal div-isions for each station is presented in Table 3.3.4. Blue-green algae (Cyanophyta) and green algae (Chlorophyta) com-prise most of the algaA community at each station when pooled for the entire year. Station 211, 212 and 223 are composed of far greater percentages of blue-green algae than green algae. The blue-greens are more likely to tolerate fluctuations in pH that can occur at station 223 due to acid-mine drainage in . Contrary Creek and may actually dominate at this station due to the lower pH, since it has been shown that blue-greens out-compete greens at lower pH values (Brock 1973, Shapiro 1973). Stations 211 and 212 are in turbid water with high nutrient in-put and low light penetration conditions that reduce species diversity and favor blue-green populations (Wetzel 1975). The percent composition of total phytoplankton densities and volume for each division at each sampling date is presented in Table 3.3.5. In January, members of the division Chloro-O phyta such as Ankistrodesmus, Microspora and Groenbladia appeared 3-10
a o c o n o I Table 3.3.2. Percent composition of total phytoplankton densities for each Sampling f Station at each sampling date. ' l [ Stations l 111 121 132 211 212 221 223 231 241 243 ! 1 ! i' JW4 6.08 3.77 4.42 4.43 39.19 29.88 2.26 2.96 2.46 4.58 \ . MAR 28.64 19.72 14.57 1.84 10.95 1.53 2.13 2.07 9.25 9.31 l. APR 11.59 16.15 15.90 11.15 5.11 7.03 2.09 6.08 12.08 12.81 i' ? MAY 8.78 8.02 6.21 29.78 12.76 10.18 8.71 7.39 4.42 3.75
*JUN 1 2.34 3.65 3.62 2.32 48.28 4.21 23.85 1.56 5.13 5.05 w
h JUN 2 8.64 7.99 7.19 11.39 28.94 7.04 9.07 6.24 6.53 6.98 e JUL 1 4.72 9.81 8.13 18.91 15.01 8.12 19.90 3.06 5.83 6.51 AUG 1 9.75 6.65 9.35 3.93 15.41 13.26 3.63 17.43 12.30 8.28 AUG 2 6.56 8.66 5.82 10.54 34.17 9.21 5.27 9.62 4.82 5.35 SEP 7.26 8.21 8.04 16.33 ,27.80 8.69 4.37 7.96 4.38 6.97 OCT 7.59 12.85 4.52 10.76 2.73 21.74 10.89 16.82 7.14 4.94 NOV 2.53 8.12 7.96 31.82 14.19 9.16 6.87 8.12 4.74 6.49 4
*JUN 1 refers to the first sampling in June.
l
- O F O O O l
l
- i l Table 3.3.3. Percent composition of total phytoplankton volumes for each Sampling i
Station at each sampling date. i. Stations 111 121 132 211 212 221 223 231 241 243 JAN 0.41 0.45 0.87 0.21 47.99 48.54 0.37 0.25 0.25 0.65
.?
MAR 22.49 13.42 10.02 1.29 20.31 3.43 1.29 2.35 17.15 8.25
-}
APR 10.68 13.87 17.14 5.66 7.23 10.25 1.86 8.92 10.51 13.89 1 MAY 7.41 10.80 12.03 25.04 8.78 8.37 7.84 8.31 6.75 4.66
*JUN 1 3.54 9.39 7.76 4.08 6.80 7.94 2.88 3.57 37.78 16.26 JUN 2 9.20 11.16 11.52 9.48 8.93 11.20 8.16 9.40 '11.57 9.38 JUL 1 7.39 10.87 10.30 11.74 11.56 7.20 9.93 5.05 15.45 10.50 ij AUG 1 7.17 6.83 16.08 3.95 13.03 10.25 7.63 14.78 11.33 8.93 l AUG 2 11.68 '
7.72 7.74 5.51 23.35 8.08 14.47 8.46 6.23 6.77 ll SEP 8.59 11.08 11.22 7.50 23.02 8.62 6.34 5.91 6.94 10.77 OCT 5.74 17.25 6.87 4.09 3.33 18.77 21.89 10.38 5.86 5.82
~
NOV 5.90 8.59 5.38 35.68 10.52 11.70 3.35 4.48 4.53 9.86 , t
*Jun 1 refers to the first sampling date in June.
O
O r O O O Table 3.3.4. Percent composition of total phytoplankton densities and volumes for each Division at each sampling station. I CYANO. CIILORO. CHRYSO. BACILL. EUGLEN. PYRRO. CRYPTO. 111' %D 34.01 51.24 0.95 13.71 0.01 0.08 0.01
%V 7.72 84.82 0.07 6.68 0.12 0.59 0.00 ,,
121 %D 42.62 42.78 ,0.86 13.72 0.00 0.00 0.00 l
%V 8.90 83.96 0.06 6.82 0.03 0.23 0.00 132 %D 40.57 44.59 0.92 13.88 0.00 0.05 0.00
%V 8.48 84.12 0.05 6.21 0.03 1.10 0.00 -
t 211 %D 62.92 29.90 5.38 1.71 0.00 0.08 0.00
%V 27.40 41.71 5.74 2.14 0.00 23.01 0.00 ;
Y e-. 212 %D 74.80 20.68 3.22 1.28 0.00 0.01 0.00 " l
%V 6.21 90.41 1.37 0.96 0.00 1.04 0.00 ,
,l 221 %D 39.98 52.98 0.70 6.27 0.00 0.06 0.00 'l
%V 3.76 93.79 0.05 1.56 0.01 0.84 0.00 ,
223 %D 70.07 17.67 1.00 11.15 0.00 0.11 0.00 I'
%V 37.40 38.84 0.31 21.44 0.00 2.02 0.00 231 %D 40.90 47.43 1.18 10.37 0.00 O.10 0.01
%V 35.10 37.92 0.29 18.09 0.00 8.58 0.02 241 %D 42.76 42.64 1.91 12.51 0.00 0.18 0.00
%V 20.02 64.04 0.26 13.27 0.10 2.30 0.90 243 %D 48.31 38.16 0.93 12.56 0.00 0.04 0.00
%V 29.46 52.77 0.18 16.06 0.00 1.53 0.00
/
O c O o O Table 3.3.5. Percent composition of total phytoplankton densities and volumes for each Division at each sampling date. t CYANO. Cil LORO. CilRYSO. BACILL. EUGLEN. PYRRO. CRYPTO. JAN %D 9.32 83.41 0.31 6.95 0.00 0.00 0.00 ,
%V 0.34 98.85 0.00 0.80 0.00 0.01 0.00 .
/ i MAR %D 10.22 53.84 7.32 28.55 0.00 0.06 0.00 }*
%V 2.97 78.57. 0.58 15.89 0.00 1.99 'O.00 APR %D 2.27 40.32 1.37 56.00 0.00 0.05 0.00
%V 1.11 31.99 0.12 51.02 0.00 15.73 0.00 MAY %D 30.70 36.57 0.18 32.50 0.00 0.05 0.00 l-
%V 5.55 35.06 0.01 40.78 0.00 18.60 0.00 8
*JUN 1 %D 80.56 14.80 0.90 3.71 0.00 0.03 0.00
[ 0.80 0.00
%V 16.10 76.65 0.30 6.15 0.00 ,
JUN 2 %D 55.51 34.07 0.97 9.36 0.00 0.09 0.00 i
%V 36.30 52.41 0.15 9.76 0.00 1.37 0.00 JUL 1 %D 60.05 27.62 3.84 8.13 0.00 0.35 0.00 ;
%V 21.61 58.12 1.69 11.93 0.00 6.65 0.00 i AUG 1 %D 40.80 54.12 3.17 1.90 0.00 0.01 0.00
- %V 37.77 54.22 3.03 2.91 0.15 1.92 0.00 AUG 2 %D 70.97 24.24 2.91 1.86 0.00 0.02 0.00 -
%V 54.62 29.75 3.96 3.54 0.19 7.93 0.00 i
SEP %D 83.73 12.04 3.45 0.71 0.00 0.06 0.00
%V 71.70 19.55 5.08 1.21 0.00 2.46 0.00 9
i
O C O n O CYANO. CHLORO. Cif RYSO. BACILL. EUGLEN. PYRRO. CRYPTO. . OCT %D 72.89 23.18 0.86 3.04 0.00 0.04 0.00
%V 51.96 38.97 0.80 5.57 0.00 2.70 0.00 NOV %D 64.93 28.37 2.88 3.81 0.00 0.01 0.00
%V 20.76 70.93 2.31 4.72 0.00 1.27 0.00 .i
- JUN 1 refers to the first sampling in June.
g .s I - I 0
.I
;l
- l' l
I O e
~
. _._ .; - - .7__ .]
)
\
l
\
C) to dominate at most stations. Diatoms (Bacillariophyta) in-creased in density and volume composition throughout the late winter and early spring and represented the greater percentage of phytoplankton volume during April and May. Throughout March, April and May, Tabellaria and Asterionella had a relat-ively greater abundance than green algae. Cold water temper-atures and increasing light are believed to be the major factors influencing the increase in diatom numbers in the late winter and their dominance in the spring (Marcus 1972, Wetzel 1975) . From June through Novemebr, blue-green organisms generally comprised the greater percent. age of phytoplankton density and blue-green volumes exceeded those of other divisions from August throt'gh October. Microcystis, Aphanocapsa, Oscillatoria,
-Chroccoccus and Aqmenellum were the most common blue-greens i
(, \ while Quadrigula was the most abundant green alga during late summer and early fall. The predominance of Cyanophyto in the late summer and early fall months is generally expected in the annual cyclic fluctuations of this group (Kreh 1973, Wetzel 1975, Shapiro 1973; Illinois Natural History Survey 1974). Since blue-greens are able to withstand higher temperatures than other algae. They are generally the only algal organism tolerant of ( temperatures greater than 350C (Wetzel 1975). Station 111, located at the mouth of the discharge canal reached a temper-ature of 350C for only a short period of time in the beginning of August. During this time blue-greens were present but a green algae, Quadrigula, was dominate. The diatoms Cyclotella and Tabellaria were also present in smaller numbers. There-fore the short period of time in which temperatures approached
,- the limits of tolerance for all groups other than blue-greens (s did not appear to influence the population cornosl. ion of the algal community at the mouth of the discharge canal.
In December Chlorophyta appeared to be increasing in density with Microspora, Crucigenia and Groenbladia as dominates, while blue-green algae decreased in numbers. . Phytoplankton densities were correlated with other pro-ductivity and physical-chemical variables (Data Base A3-234). Generally, phytoplankton most closely correlated with temper-l ature and pH and, to a lesser degree, with alkalinity. The phytoplankton community is an appropriate target for dynamic investigation in that algae are the primary sources of energy for other trophic levels and that they have tae capacity at high bloom densities of raising the pH values of water through the removal of carbon dioxide during growth resulting s in die-offs ,of zooplankton (Pulis 1971) . In the most severe s) situations, changes in the composition of the algal community 3-16 . I
O can disturb the base of the normal aquatic food web, perhaps eliminating many consumer species and resulting in the destruct-ion of the existing food web and the construction of new webs of less value. In cases where nuisance species dominate due to a lack of consumer species capable of utilizing them, the formation of obnoxious blooms is possible. The production of extracellular substances and products of decaying algae on a large scale may be toxic to other aquatic life (L1rcus 1972) . Investigating the postoperational effects on the phyto-plankton community of a power plant during its first year of operation, Kreh (19/3) observed no influence of plant operation on algae numbers, biomass, species composition and diversity. For Lake Anna, there also appears to be no observable impact of the operation of Unit 1 upon the algal community, although both 1978 and 1979 were characterized by operation of the re-(~ actor during only a portion of the year. Until full or con-stant power generatien occurs, conclusions about ecological impacts must be reserved. 3.4 Summary
- 1. Comparisons between 1978 and 1979 data show that phyto-O plankton densities were significantly decreased at station 211. For all other stations, there was no significant i difference between years.
- 2. In general, the five primary productivity stations were comparable in phytoplankton densities during 1979.
- 3. For most of the year blue-green algae dominate'd at stations 211, 212 and 223.
(/ 4. Green algae dominated during the winter and late spring montha.
- 5. Diatoms dominated the phytoplankton community from March through May.
- 6. Blue-green algae dominated in the late summer and early fall months.
o . 3-17
- - - - - - - - - - - - - _ - - . _ , _ _ . - - - _ - - - - -----.+e-- ,
, - - ---,,g -- ,
. . . . . . -- - ^ r_ . ?. . - - - - . - -
~ ' ~
l 1 () 3.5 References Brock, T.D. Lower pH limit for the existence of blue-green algae: Evolutionary and ecological implications. Science 179: 480-483. 1973. , Cocke, Eltun C. The Myxophyceae of North Carolina. Wake Forest University; Winston-Salem, North Carolina; 1967. i Gurtz, Martin E. and Charles M. Weiss. Field investigations of I l the response of phytoplankton to thermal stress; E.S.E. Publication No. 321; December 1972. Illinois Natural History Survey. Lake Sangchris Project. Annual Report for Fiscal Year 1974. Urbana, Illinois; 1974. -) Located: Illinois Natural History Survey, Urbana, Illnois. (. Kreh, Thomas V. An Ecological Evaluation of a Thermal Discharge. Part VII: Postoperational effects of a power plant on phytoplankton and community metabolism in western Lake Erie. Technical Report Number 321; Institute of Water Research; Michigan State University; July 1973. . 1 Marcus, Michael D. An Ecological Evaluation of a Thermal () Discharge. Part II: The distribution of phytoplankton and primary productivity near the western shore of Lake Erie. Technical Report No. 14; Thermal Discharge Series; Institute of Water Research; Michigan State University; May 1972. Prescott, G.W. How to Know the Freshwater Algae. Wm. C. Brown Company Publishers; Dubuque, Iowa; 1970. (}j Pulis, L.C. The influence of stream condenser effluent on freshwater phytoplankton. Cornell University; Ithaca, N.Y.; January 1971. Shapiro, J. Blue-green algae: Why they become dominant. Science 179: 382-384. 1973. Smith, Gilbert M. The Fresh-water Algae of the United States. Second edition; McGraw-Hill Book Company, Inc.; N.Y.; 1950. Virginia Electric and Power Company. North Anna Power Station Preoperational Environmental Report. A report of VPI & SU and Virginia Commonwealth Univ. for Virginia Electric and Power Company; 1976. Located at Virginia Electric and
- Power Company, Richmond,. Virginia.
Wetzel, Robert G. Limnology. W.B. Saunders Company; 1975. Whitford, L.A. and G.J. Schumacher. A Manual of Fresh-water Algae. Sparks Press; Raleigh, N.C.; 1973. 3-18
() . 4.0 Zooplankton Studies 4.1 Introduction This study was performed to determine the (';
'- effects of the power station on the zooplankton population of Lake Anna. It was an important study in that zooplankton are a major aquatic food source and they are among the organisms iden-tified as having "the greatest potential'for being affected by t
station operation" (Nuclear Regulatory Commission,1977) . l 4.2 Materials and Methods - () 4.2.1 Sampling Procedure Zooplankton samples were collected in accordance to Environmental Technical Specifications for Virginia Electric Power Company (Nuclear Regulatory Commission, 1977). The samples were collected at the surface and at one meter intervals to a depth of five meters at stations 121, 13 2, 2 21., 2 41 and 2 4 3. Samples were taken at the surface and at even meter depths to a depth of six meters at stations 111, 211, 212, 223 and 231 (Figure 4. 2.1.1) , i, (, The samples were collected using a 5 liter Niskin sampler. The 5 liter samples were filtered through funnels with 37 aun nylon mesh glued to a pair of " windows" cut out of each funnel. The funnels were plugged and held in place on ring stands with clamps. After filtering, the concentrated samples were then drained into i 4 ounce glass sample jars. The funnels were rinsed into sample jars using distilled water. Two milliliters of club soda were added immediately and the samples were preserved as soon as pos-sible with 2 ml of 30% formalin. The addition of club soda acts, to relax the zooplankton so they do not contract when the formalin is introduced. After~ allowing the samples to settle 2-3 days they were drawn down to approximately 30 ml and another 2 ml of 30% formalin were added. Two complete Sedgwick-Rafter cell counts were made under 4X magnification for each sample collected. The 1 ml aliquot sub-sample for the counts was obtained using a Hensen-Stemple pipet. l ' s_). After two 1 ml aliquots were removed, the remaining sample volume was determined with a graduated cylinder and used to estimate 4-1
./
o o o e O - O ' ' 4 2 1 0 2 . I Pamunkey Creek 1 212 - t l 221 211 ', North Anna River 241 , i , 223 i 231 , l e Power
- 6 Station . 243 11 I
/ .
11 ' 132 . 1 Figure 4.2.1.1 Zooplankton sampling stations on Lake Anna, ' 1979. b . 1
O zooplankton density per liter. This volume was returned to the sample jar and all. owed to resettle 2-3 days. Using a pasteur pipet, the settled zooplankton were transferred to 10 ml vials for long-term storage. The identification of zooplankton was performed to the lowest taxa feasible. 4.2.2 Statistical Analyses The technical specifications of tha monitoring program required two types of sampling; continuous iad discrete. Data was collected from 0, 1, 2 , 3, 4 and 5 m depthe for continuous sampling while discrete sampling collected cata from 0, 2, 4 and 6 m. The continuous data stations were 121, 132, 221, 241 and 243 and the discrete data stations were 111, 211, 212, 223 and 231. Each type of sampling required a separate statistical design to analyze and interpret the data.
- f. Stations subject to similar environmental pressures were
~ grouped i.:to areas and analyzed. Area one consisted of the two upper lake stations 211 and 212; area 2 included the two lower laxe stations, 241 anc 243; and area three included the WHTF stations 111, 121 and 132 The continuou4 discrete and area data were analyzed using an
(' ANOVA and a Duncan's Multiple Range Test (alpha = 0. 05) . The te~st package used was the Statistical Analysis System, SAS Institute, Raleigh, N.C. and run on an IBM 370 computer. Due to ice cover in February, only stations 111, 121, 132 and 221 were sampled. For the remainder of the year data were collected at all stations. An ANOVA of the zooplankton density by date by station was performed on both continuous and discrete data. These results ks were Duncan's then Test. placed into statistically significant groups using the Stations that are not significantly different were groupcu together by a horizontal line. A space separating two lines indicates that the two groups are statistically different. It is possible for two groups to overlap and a sta-tion may be included in two or more groups. An ANOVA of the zooplankton densities by station by date was also performed. These results were grouped using a Duncan's Test and reported in a similar fashion. was performeu on areas 1, 2 and 3. A final ANOVA and Duncan's Three stations (111, 223 and 231) were selected to compare 1979 and 1978 data using a Student t-test. These were of interest ) because of the physical or chemical parameters that may have in-fluenced the stations throughout the year. The com analysed by a Duncan's Test on the mean density of*plete of allyear was stations. O Finally'a comparison of mean densities and percentages of Rotifera, Cladocera and Copepoda at all stations was calculated. 4-3 e
..__.._______.__~--- . _ . _ . . _ . . -
O 4.3 Results and Discussion The ANOVA of continuous (station 121, 132,221, 241 and 243) data for date by station is summa-rized in Table 4.3.1. and ordered the stationsAby Duncan's Test statistically grouped decreasing mean density. The com-plete ANGVA data is listed in the Data Base. Station 221 had the highest mean density for almost half the year, which was not the case in 1978 (Vepco, 1979). In the fall and winter this station had the highest mean density for six consecutive months from August through January (Table 4.3.1). The abundance was largely due to the Rotifera popu-lation, which made up 83% of the total zooplankton population for 1979. Copepoda contributed 126 while Cladocera only contributed S% of the population (Data Base, page A4-146).
- Station 121 had the lowest mean density during six samplings k and was in the lowest Duncan's grouping in all, but four sam-pling dates.
This was caused by a much lower Rotifera popu-lation at station 121 than at other continuous stations. A comparison of Rotifera, Cladocera and Co'epoda p populations at stations 221 and 121 shows the percentage approximately equal, ! but in each double that case the total of station 121numbers at station 221 were almost (Data Base, page A4-146). k O 4-4
~- -- *
O Table 4.3.1 Duncan's Multiple Range Test of Continuous Data, . Date by Station, Lake Anna 1979. JANUARY 221 243 241 121 132 FEBRUARY 132 121 221 MARCH 132 121 243 241 221 APRIL 241 132 121 243 221 MAY 241 221 243 121 132 V'- JUNE 1 132 221 241 243 121 JUNE 2 121 132 221 241 243 JULY l 243 132 241 221 121 () JULY 2 243 221 241 132 121 AUGUST 1 132 221 121 243 241
\UGUST 2 221 132 121 241 243 SEPTEMBER 221 132 243 121 241
, {'; OCTOBER 221 243 132 241 121 NOVEMBER 221 243 241 132 121-DECEMBER 221 241 243 132 121 The complete numerical data is presented on page A4-166.
, O - 4-5
- -- -. _ --_._________________m _ _ _ - _ , _ _ _ _ _. --
l l Table 4.3.2 Duncan's Multiple Range Test of Discrete Data, Date by Station, Lake Anna 1979. JANUARY 211 231 212 111 223 l FEBRUARY 111 - MARCH 212 211 111 231 l APRIL ?ll 231 111 212 223 1 MAY 211 212 231 111 223 s JUNE 1 212 211 231 111 223 JUNE 2 , 211 231 212 111 223 JULY l 211 212 231 223 111 JULY 2 212 211 223 231 111 AUGUST 1 21,2, 211 223 111 231 AUGUST 2 211 212 223 231 111 SEPTEMBER 211 212 2_31 111 223 (, OCTOBER 231 211 212 223 111 NOVEMBER 212 223 231 211 111 DECEMBER 212 211 231 223 111-l The complete numerical data is presented on page A4-172. I O 4-6 e
O Discrete data (stations 111, 211, 212, 223 and 31) were analyzed in a similar fashion as continuous data and are pre-sented in Table 4.3.2. The upper lake stations were domina. with station 211 having the highest mean density seven times and station 212 having the highest for six samplings. The Duncan's Test placed station 211 in the highest group for -' every sampling except February when ice prevented sampling at the upper lake stations. Station 212 was placed with 211 in the highest grouping for ten sampling dates. The difference between the upper lake stations and other discrete stations can be traced to the sheer number of Rotifera present (Table 4.3.3.). The lowest mean densities for discrete data were exhibited by stations 223 and 111 in all months but March (Table 4. 3. 2) . Here again the key factor appeared to be Rotifera abundance. Both stations 223 and 111.showed a lower abundance of rotifers when compared to the rest of the stations (~\
~
(Table 4. 3. 3) . Stations 211, 212 and 223 were consistant with 1978 data in that they recorded high and low densities respec-tively in 1978 as in 1979 (Vepco, 1979). Table 4.3.3 Relative Abundance Ranking of Rotifera Density by Station, Lake Anna 1979 () Station 211 212 221 243 132 241 231 121 111 223 number /l 935 766 432 333 332 331 296 248 173 139 The ANOVA of continuous data for station by date is pre-sented in Table 4.3.4. The sampling in March is of particular
~. interest because it showed the lowest mean dunsity for all stations except 132, which had March as its second lowest density. This low density for March was also recorded in 1978 (Vepco, 1979). March sampling contributed no more than 1.6%
of the zooplankton population at any station (Table 4.3.5). This may be explained by the change of seasons where cold water populatione are declining and warm water populations have not yet developed. The ANOVA for discrete data by station by date is, presented in Table 4.3.6 and indicates results similar to continuous data for March. The only exception is at station i 212 lowest. where March exhibits the second lowest mean density, not the A comparison of all the stations necessitated a student t-test and f-distribution to determine if the variances between continuous and discrete data were equal. The F-distribution showed a very low probability (0.0001) of finding of F'value greater than.3.33 (Table 4.3.7) . This low probability indicates s 4-7
./
. . l l
l O that the variance densities are equal. between continuous and discrete station mean A comparison of the mean densities for all stations for the year was performed and is presented in Table 4.3.8. A Duncan's Test shows stations 211 and 212 having significantly major mean densities than the rest of the stations in the lake, which had similar densities. Relative abundance for the complete year showed: Rotifera 83%, Cladocera 5% and Copepoda 12% (Table 4. 3. 9) . Looking specifically at Rotifera, 42% of the rotifers occurred at sta-tions 211 and 212. Stations 111 and 223 contributed only 8% of the rotifer population. While sheer numbers of Rotifera may be impressive, it is suggested by Hutchinson that in terms of bio-mass the Rotifera population may be insignificant (Hutchinson, 1967). Cladoceran and Copepod abundance was spread out evenly r-
' between stations. When the mean densities per station were ranked, stations 211 and 212 showed the greatest numbers of both Rotifera and Copepoda. For Cladocera these two stations were ranked midway and were therefore less influential in the Cladoceran population (Table 4.3.9) .
An ANOVA of the three areas by station mean densities was () performed (Table 4.3.10) . Area 1 (stations 211 and 212) there ' was no significant difference between either station, nor in Area 2 (stations 2 43 and 241) . In area 3 (stations 111, 121, 132) it was shown that station 132 had a significantly higher mean density than either station 121 or 111. e e O ' s 4-8 s
- e~ - - - - - - - ~ '-r
O r O o O L t
. i Table 4.3.4 Duncan's Multir.le Range Test for Continuous Data, Station by Date, Lake Anna 1979.
'l Station :!
121 JUN2 MAY JUL1 APR JUN1 DEC AUG1 SEP AUG2 JAN JUL2 ' NOV FEB OCT MAR 132 JUN1 JUN2 JUL1 APR SEP OCT MAY AUG1 AUG2 JUL2 DEC JAN NOV MAR FEB 221 OCT JUN2 MAY JUN1 DEC JUL1 JAN SEP JUL2 AUG2 APR NOV AUG1 FEB MAR w 241 MAY JUN2 APR JUL1 JUN1 DEC JUL2 OCT JAN SEP AUG2 NOV AUG1 MAR 243 JUL1 JUN1 JUN2 MAY OCT APR JUL2 DEC JAN NOV SEP AUG1 AUG2 MAR t The complete numerical data is presented on page A4-178. -
- * ~ ~ ..
O . Table 4.3.5 Percentage of the total 1979 zooplankton population . represented by March, Lake Anna 1979. " Station 111 121 132 211 212 221 223 231 241 243 Percent 1.5 1.6 1.6 0.7 1.3 0.2 N/A 0.4 0.6 1.0 t O I ~ 1 O 4-10
Table 4.3.6 Duncan's Multiple Range Test of Discrete Data - Station by Date, .i Lake Anna i 17 9. jj:
'l Station l' 111 JUN1 JUN2 MAY JUL1 JUL2 DEC SEh APR AUG1 JAN AUG2 OCT FEB NOV MAR '
211 SEP JUL1 JUN1 MAY AUG2 JUN2 JUL2 JAN OCT AUG1 DEC APR NOV MAR 212 JUN1 JUL1 SEP AUG1 JUL2 MAY AUG2 OCT JUN2 DEC NOV JAN MAR APR r 223 JUL2 JUL1 JUN? OCT AUG2 AUG1 DEC SEP NOV MAY JtlN1 APR JAN MAR 231 JUN2 MAY OCT JUN1 JUL1 APR JUL2 DEC AUG2 JAN SEP AUG1 NOV MAR I The complete numerical data is presented on page A4-195. t f I O
O o O o O L Table 4.3.7 Student t-test of continuoui, and discrete sampling, Lake Anna 1979. Siimpling .. Mean Std Dev I Prob .lTI. F Prob F { Discrete 280 554.2 636.2 3.66 0.0003 3.3 - 0.0001 Continuous 438 419.4 348.5 , 1 Table 4.3.8 A comparison of mean densities by station using a Duncan's Multiple I Range Test. Station 211 212 221 243 241 231 132 121 111 223 i f*ean density 1032.6 861.0 517.8 429.7 426.8 415.2 410.1 314.1 245.8 214.5 (number / liter) 8 Duncan's Test ! 211 212 221 243 241 231 132 121 111 223 S 4
~
4 o c- O O O [ l l Table 4.3.9 Mean density by station for Rotifera, Cladocera and Copepoda, Lake Anna 1979. l Rotifera Total % l Station 211 212 221 243 132 241 231 121 111 223 . f . Mean density 935.0 766.0 431.7 333.4 332.1 331.1 296.4 248.5 172.7 138.9 4000.8 83 (4/1) l Cladocera t Station 241 243 231 212 221 211 132 111 121 223 i Mean density 37.1 31.9 29.6 27.0 26.0 24.7 24.4 21.6 19.7 16.8 258.8 5 [ (4/1) Copepoda ' Station 211 212 221 243 231 241 132 111 223 121 . i Mean density 78.6 76.6 62.6 58.6 58.3 53.6 50.6 47.5 43.1 38.8 568.3 12 (#/1) r r
~ ~ ~ ~ ~
. . , . . . .~ . _ .
O - t Table 4.3.10 Duncan's Multiple Range Test, Area by Station, Lake Anna 1979. l Area 1 211 212 Mean density 1032.6 861.0 Duncan's Test 211 212 Area 2 243 241 Mean density 429.7 426.8 (], ' Duncan's Test 243 241 Area 3 132 121 111 Mean density 410.1 314.1 245.8 Duncan's Test 132 121 111 O The complete numerical data is presented or page A4-211. ( e l \ O - 4-14
-- , - , > . , . - - - - , , - , , , . _ . , , , . , , - - . _,.r.- ., ,
O . Student t-test were performed on three stations, which are particularly interesting due to their respective environments. The three stations are 111, 223 and 231. Station 111 is the ~ first to receive thermal effluent, 223 (Contrary Creek) is sub-ject to the influence of Srid mine drainage and 231 represents the water column before it enters t'he reactor cooling system. The t-tests compared 1978 to 1979 mean density data and results
.were all less than 2.064, which indicates no significant difference in zooplankton densities between 1978 and 1979 at these stations.
A characterization of zooplankton-populations of stations 121 and 243 is presented below to compare 1978 and 1979. This offers a descripcion of two open water stations, station 121 in the WHTF and station 243, the first lake station to receive WHTF water. (- The mean the JUN2 zooplankton sampling of 1979. density for station 121 peaked during The mean density at that time was 1040 zooplankton per liter. Rotifera dominated with Kertella, Polyarthra next and Conochilus contributing 890 of the 1040. The and earlysignificant summer group monthsof sampling dates encompassed the spring (Table 4.3.4). MAY was second to JUN2 () in mean density (590 per liter) with Polyarthra as the dominants (Data Base, page A4-159). A complete list of genera identified in 1979 is presented in Table 4.3.11. and Conochilus l In 1978 station 121 peaked during the same sampling (JUN2 ) as in 1979 with 635 zooplankton per liter. Again, as in 1979, the spring and summer months were in the highest group of mean densities. Total numbers were roughly similar between years and Rotifera dominated in 1978 as in 1979. Keratella contribut-ed 543 of the 635 zooplankton per liter, while Polyarthra and (_ Conochilus did not play a major role (Vepco Report, 1979). The mean density of station 243 peaked during the JUL1 ~ sampling of 1979 with 1244 zooplankton per liter. As at station 121, Rotifera were numerically dominant with,Keratella and Polyarthra accounting for 971 of the 1244 zooplankton per liter. The next significant grouping included the summer months with JUN1, highest at 627 zooplankton per liter. This decrease in mean density is associated with a decrease in Rotifera, espec-ially Polyarthra (Data Base, page A4-159). 709 In 1978, density zooplankton per at station 243 peaked during August, with liter (Vepco, 1979) . As in 1979, Rotifera were the predominant zooplankton at this station with Keratella and Polyarthra contributing 621 of the 709 zooplankton per liter Both stations (121, 243) () the large numbers of Rotifera preseat.in 1978 and 1979 were influenced by At each station the 4-15
O . densities were less in 1978 than in 1979, but a statistical comparison of all stations indicates no difference between years. During 1979 both stations 121 and 243 showed higher numbers of Polyarthra and Keratella. It is known that Polyarthra maior, Keratella cochlearis and Asplancha sg. increase in numbers in thermally enriched waters, but with no permanent change in diversity (McMahon, 1975). This increase in Polyarthra and Keratella cannot be correlated to the temperature in Lake Anna because there is no signif-icant difference in temperatures between 1978 and 1979 (Section 2. 3. 3) . The effects of thermal loading on the zooplankton population appears to be minimal with only one reactor on line. The temper-atures at station 111 peaked at 35 C on August 7, 1979. This is (, close 33;8 to the tolerance limit 0for certain Cladocerant, which is
+ 2.50C ,and 32.9 + 2.5 C for 48 and 72 hour periods respec-tively~(Carson ~
1972). Copepoda shows a temperature tolerance ranging from 3-330C. This degree of thermal flexibility allows it(Bradely, to acclimate to 1975). a wide variety of thermal, environments The depth of the thermal effluent is important in that if it is (]) confined to the surface water, many zooplankton have the ability to select a preferred depth. Depth selection would have to take into account food availability and predator influences. The result of a higher temperature may be increased metabolic activity and therefore decrease the developmental stages of eggs (Gallager, 1974). Temperature plays a critical role in the development of diapausing eggs in copepods. Should the adults not survive the winter and not produce subitaneous eggs, then the spring cohort would result from overwintering, diapausing eggs. This would not g
- necessarily change the generic richness, only the type of copepod eggs that reach maturity (Cooley , 1978 ) .
A study of temperature verses zooplankton densities in Lake Erie showed that cladocerans, copepods and total zooplankton correlated highly to temperatuce. In the same study zooplankton density and biomass were compared with primary productivity, fish biomass and density, oxygen concentration, temperature, particu-late organic carbon and suspended solids. The three that cor-related best to zooplankton density were primary productivity, fish biomass and density and oxygen concentration (Nalepa , 197 0) . While direct monitoring of zooplankton productivity was not performed in this study, it is known that filter-feeding zooplank-ton are more productive than predaceous zooplankton (Wetzel, 197 5) . This is significant in that 83% of the zooplankton present in 1979 were rotifers, which are in large part filter-feeders. Filter-() feeding zooplankton are known to correlate directly with primary 4-16
~ ~ T ~ ~ l._n--
. _ _ [_ - __ _ . _ _ _
O . 1 productivity (Wetzel, 1975) and with no significant change in primary productivity in 1979 it may be that the numbers of herbivorous zooplankton did not change appreciably. This is supported by the fact that there is no significant change in the total zooplankton numbers from 1978 to 1979. The zooplankton community in Lake Anna can be divided into two feeding classes: filter-feeding and raptorial (piercing). The majority of rotifers are filtering or sedimentary suspension , l feeders, as are the cladocerans and calanoid copepods (Hutchinson, ' 1967). The f'ew raptorial types include cyclopold copepods and j rotifers such as Asplanchna, Ascomorpha and Synchaeta. ' Trophic relationships can be characterized by the feeding types. Among the Rotifera there are fine detrital filter-feeders such as Filinia and Conochilus and live algal filter-feeders such as Polyarthra. Filter-feeding cladocerans and copepods tend to be larger and live longer than the rotifers,and therefore influence the food availability for other filter- , feeders. The raptorial copepods and rotifers represent the predaceous input of zooplankton trophic relationships (Hutchinson, 1967). The zooplankton population.of Lake Anna has all the above feeding types present in the water column. The filter-feeders (~' are numerically dominant which is evident by '59 fact that 83% of the zooplankton are rotifers. It follows enat a lower number of predaceous zooplankton should exist at the trophic level above herbivorous zooplankton, and is demonstrated in that 12% of the population were copepods (Table 4. 3. 9) . 4.4 Summary
- 1. Characteristics that occurred in Lake Anna zooplankton in both 1978 and 1979.
- a. Stations 211, 212 and 221 had the highest mean densities of zooplankton.
- b. The month of March had the lowest mean density.
- c. Rotifera were numerically dominant.
- 2. There was no significant difference in mean densities between 1978 and 1979.
- 3. Stations 223 and 111 showed consistantly lower numbers of l zooplankton compared to other stations.
i 1 4 17
O Table 4 3.11 Zooplankton Master List for Lake' Anna 1979. Phylum Rotifera . Class Monogononta Order Ploima Family' Brachionidae Genus Brachionus Kellicottia Keratella r Lepadella Family Lecanidae Genus Lecane Monostyla Family Notommatidae Genus Cephalodella . Family Trichocercidae {; Genus Trichocerca Family Gastropidae Genus Ascomorpha Gastropus Family Asplanchnidae Genus Asplanchna Family Synchaetidae Genus Polyarthra Synchaeta Pleosoma 4-18
. - . . - . - a: . . = = ---:__.. _ . _ . ._
O Table 4.3.11 (CONT.)
- Family Conochiloidea ,
Genus Conochilus Collotheca Order Flosculariaceae Family Testudinellidae Gen,us Filinia Family Hexarthridae ( Genus Hexarthra Phylum Arthropoda Class Crustacea Order Cladocera () Family Sididae Genus Diaphanosoma Family Holopedidae Genus Holopedium Family Daphnidae (_..- Genus Ceriedaphnia Daphnia Family Bosminidae Genus Bosmina Order Copepoda Suborder Calanoida Suborder Cyclopoida . l O
~
4-19
~~ ~ - - ~ ~ - - ~
l l O . 4.5 Reference Bradely, B.P. Adaption to copepod populations of thermal stress. College Park, MD. Water Resources Research Center; 1975. Cars'on, D.M. Geographical variation in upper thermal tolerances of a planktonic cladoceran. Ithaca, New York. Cornell University; 1972. Cooley, J.M. The effect of temperature on the development of diapausing and subitaneous eggs in several freshwater copepods. Crustaceana 35, vol. 1; 1978. Edmondson, W.T., editor. Fresh-water biology, 2nd ed. New York: John Wiley & Sons, Inc.; 1959. C Gallager, B.J. Lake Sangchris: Case History of an Illinois Cooling Lake. Proceedings of a Symposium on Energy Produc . tion and Thermal Effects. Ann Arbor, Michigan. Science Publishers, Inc.; 1974. Hutchinson, G.E. A Treatise on Limnology. Vol. 2. New York: John Wiley & Sons, Inc.; 1967. McMahon, J.W.; Docherty, A.E. Effects of heat enrichment on species succession and primary production in freshwater plankton. Proceedings of a symposium on the environmental effects Austria. of cooling systems at nuclear power plants. Vienna, International Atomic Energy Agency; 1975. Nalepa, T.F. An ecological evaluation of a thermal discharge: Part III: The distribution of zooplankton along the western k shote of Lake Erie. East Lansing Michigan. Institute of Water Research Center, University of Michigan; 1972. Nuclear Regulatory Commission. Environmental Technical Specifi- ' cations for Virginia Electric Power Company North Anna Power Station, Units 1 and 2. Appendix B Nos. 50-338, 50-339. 1977. Located at Virginia Electric Power Company, Richmond, Virginia Pennak, R.W. Fresh-water invertebrates of the United States. New York: The Ronald Press Co.; 1953. Rutter - Kolisko, A. Plankton rotifers, biology and taxonomy. Dietenheim, Germany: Gebruder Ronz; 1974. l \ - N 4-20 l
I O . Virginia Electric and Power Company. Environmental St'Idy of Lake Anna, Virginia: January 1, 1978 - December 31, 1978. A report of James R. Reed and Associates, Inc. to the Virginia Electric and Power Company. March 1979. Located at Virginia Electric and Power Company, Richmond, Virginia. Wetzel, R.G. 1975. Limnology. Philadelphia: W . ll . Saunders Company;
^
7 , N.. O l . i L i e O 4-21 - m - -- ,
1_ __ . . _ _ _ _ . _ _ _ _ . . _ . _ e 5.0 Macrobenthos 5.1 Introduction The objective of the sampling program for macroinvertebrates in Lake Anna during 1979 was to provide data to evaluate the effects of operation of the North Anna i (N ' Power Station upon this element of the aquatic community. . Biological information including dominance, frequency of occ-urrence and diversity of the benthic organisms was considered.. 52 Methods The locations of the benthic stations were in accordance with North Anna Environmental Technical Specificat-ions.and are shown in Figure 5.2.1. O Individual station descriptions are as follows: Station A - This station is located in the Sedges Creek Arm of the WHTF. The bottom at 2 meters is firm clay with a ' shallow layer of sediment and detritus and a considerable amount of submerged aquatic vegetation, often completely covering the baskets and transect line. At 4 and 7 meters the bottom is also firm clay but with little sedimentation (, evident. Current is noticable at all three depths but is more pronounced at the 4 and 7 meters. Station B - This station is located in the Elk Creek Arm of the WHTF. The bottom at all three depths is firm clay, with some submerged aquatic vegetation at 2 meters, although not as much as 2 meters, at station A. There is no noticeable current at this station. Station C - This station is located in thIe Coleman Creek Arm of the WHTF. The substrate at this station is unlike that found at any of the other stations. There is a considerable amount of detritus at 2 meters with a lesser amount being pre-sent at 4 and 7 meters. The bottom is strewn with boulders and rocks at all three depths. Current is noticeable at all depths and is stronger here than at any other station. () Station D - This stati:n is on the southern side of the Lower Reservoir and near the dam. The substrate at this station 5-1
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I O is very hard clay with little or no sedimentation at iun( depth." Theres is often a noticeable current at seven meters. Station E - This station is located on the northern shore of tne lower reservoir across from Duerson Point. Substrate at this station is of moderate firmness and is composed of gravel and soil. The slope is steeper at this station than any of the others. There is no noticeable current at this station. Station F - This station is located on the western shore of the Lower Reservoir across from Stugeon Creek. Substrate at , this station is firm clay with some gravel. ! Station H - This station is located on the southwestern shore of the Upper Reservoir just downstream from Marshall Creek. l l The bottom at 2 meters is gravel and granular clay. At 4 and 7 meters the bottom is firm clay with some sedimentation. {-} Station J - This station is located on the northeastern shore in the Pamunkey Arm of the Upper Reservoir just downstream i from the 719 bridge. The bottom at 2 meters is clay, gravel and silt, at 4 meters is clay and silt and is deep silt at 7 meters. l () Station K - This station is located on the northern shore in the North Anna Arm.of the Upper Reservoir just downstream from the 719 bridge. The substrate at 2 meters is soil and clay and becomes progressively more silty at 4 and 7 meters. t l Divers located these stations by lining up specific land-i marks and swimming out from shore until crossing the 2 meter transect line. These transect lines were nylon rope placed at es the 2, 4 and 7 meter contours. The lines were held in place (_/ 0.5 meter or less off the bottom with wooden stakes, located approximately 5 meters apart, which also served as markers for the placement of the artifical substrate samplers. All three transect lines were connected at one end with another length of rope resulting in what appeared to be a large underwater E, ! (Figurc 5 2.2). This line enabled the divers to swim directly from the 2 meter line to the 4 and 7 meter transect lines. The artifical substrate was 3M Corporation No. 200 Conservatieo Webbing, which is no longer available. Four 10.2 cm squares were placed in baskets made from 2 quart round plas-tic containers with lids. These containers were 11.4 cm tall with a diameter of 16 cm at the top and 13.5 cm at the bottom. A total of twenty-two (22) 3.8 cm holes were cut in the top, buttom and sides of each basket. Two baskets containing the substrete were placed on the bottom in the vicinity of each wooden stake, and were held in place by one or more cross shaped (]) stakes. The long arm of the cross was pushed into the bottom until the other arm rested firmly on the top of the basket. 5-3 TM _ _ . _ _ _ _ _ _ _ . _ -
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O . All of the substrate baskets for the entire year were put in place over a,3-5 day period during the first part of Sept-ember. Colonization of the substrate took place over the next 5-8 week period. The first samples were collected in November and monthly thereafter. After divers located the samples, they were very carefully placed in muslin bags. An overhand knot was then tied around the neck of the bag to help prevent the escape of organisms during transport. At the surface, samples were placed in large plastic l 1 trash cans, with a minimum amount of water to keep the samples I moi.st but not covered. It was found if the samples were com-(_ pletely covered with water and left overnight that the dissolved oxygen would be depleted and many of the organisms would die. This problem was lessened in the moist environment. In addition to the artificial substrate samples, one D-frame kick sample was taken at each station in 0.5 meter of water near the shore by having someone shuffle their feet while walking backwards, dislodging the organisms from the () various substrates (Reed 1977). The organisms were collected in the net which was held flush with the bottom and fairly close to the feet. The day after collection, the entire contents of the bags were washed through a 0.5 mm selve. The webbing and seived materials were covered with 90% isopropanol in quart containers. For sorting, the materi'als were placed in enamel pans and flood-ed with a salt solution (Nacl sp. gr.=1.12) which caused the (_., organisms to float to the surface. All materials and webbing were examined under magnification to insure maximum retrieval. The organisms were identified to genus or species, whenever possible using the following keys Edmondson (1959), Merritt and Curmins (1978), Needham and Westfall (1954), Pennak (1953), Torre-Bueno (1978), Usinger (1956) and Wiggins (1977). 5.3 Results 5.3.1 Sample Collection In 1979 Macrobenthic samples were collected at the 9 stations shown in Figure 5.2.1. Monthly samples were collected at each station, except during October when recolinization of the sub' strate took place. Stations J and K were not sampled in February due to ice cover. All data collected in 1979 are presented in the Data Base (page AS-1) . , 5.3.2 De'sity and Percentage Composition O composition and temporal distribution of the 11 dominant macro-Density, percentage !
)
5-5
./
benthic taxa are given in Table 5.3.2.1. Comparison of 1979 data with data from 1978 (VEPCO, 1979) show a reversal of the three year decline in density. The data reflect an almost 2-fold increase in the number of organisms collected compared to last year. Table 5.3.2.2 is a taxanomic list of all organ-isms collected in 1979. In the reservoir there was the typical decline in density through the summer months which was attributable to the de-l crease in numbers of chironomids present. The sharp decline l in numbers of organisms in February is probably the result of i stations J and K not being collected, as these stations have l the most dense population of Chironomidae. The density in the Lower Reservoir was significantly higher (Students t-test,
- A= .05) in 1979 than 1978 while the Upper Reservoir showed
!x no significant difference at A = .05.
~
The 1979 densities in the WHTF displayed increases of up to five times the number of organisms when compared to 1978 data. These increases were due to a greater number of Trichoptera and Pelecypoda being collected. The density in the WHTF displayed no significant difference between 1978 (} and 1979 (Student t-test,6 = . 05) l In contrast to the past four years Trichoptera, not i Chitonomidae, were the most abundant organisms in Lake Anna, followed by Chironomidae then Pelecypoda. l Trichoptera represented 10.5% - 55.4% of the organisms collected in the Reservoir and 32.3% - 86.6% of the organ-isms in the WHTF. These ranges are higher than 1978 in both {, the Reservoir and WHTF. As in 1978, Cernotina was the most abundant Trichoptera followed by Cyrnellus. Chiromimidae were the most abundant organisms in the Reservoir, representing 26.1% - 74.6% of the total and 1.2%- 23.3% in the WHTP. These lower ranges reflect the fact that Chironomidae was no longer the most abundant organism in Lake Anna (Reservoir plus WHTF). Pelec'rpoda, displayed a substantial increase in density and percentage composition in both the Reservoir and WHTF. In 1978 they represented 0.1% - 14. 5% of the population in the Reservoir and 0.0% - 0.5% of the population in the WHTF. It is important to note that even though Pelecypoda did represent 14.5% of the total organisms in the reservoir in l August 1978, during no other month were they responsible for i more than 4.9% of the population. In 1979 Pelecypoda account-({} ed for between 1.7 and 23.2 percent of the organisms collected in the Reservoir and between 0.0 and 66.1 percent of those organisms collected in the WHTF. This large shift in community 5-6
O Table 5.3.2.1. Density and percentage composition of dominant macrobenthos in Lake Anna during 1979. Density is expressed as the number of organisms per web sampler. Values in parentheses are percent composition. An asterisk (*) denotes less than 1%. Jan. Feb. Mar. Res. WHTF Res. WHTF Res. WHTF Turbe11 aria 1.11 - 0.67 - 2.75 - (**) (-) (**) (-) (2.2) (-) _ Oligochaeta 0.58 - 0.17 * * - l,, (**) (-) (**) (**) (**) (-) l Hirudinia 0.17 - 0.13 - 0.11 - (**) (-) (**) (-) (**) (-) Gastropoda- 0.94
- 0.13 - * -
(**) (**) (**) (-) (**) (-) O ~ re1ecreade 5.25 0.17 4.9e - 12.17 0.33 (4.1) (**) (6.7) (-) (10.7) (**) Amphipoda 0.50 - * - 0.36 - (**) (-) (**) (-) (**) (-) Isopoda - - - - - - (-) (-) (-) (-) (-) (-) Ephemeroptera 2,56 1.11 4.04 0.11 2.67 0.67 (2.0) (1.2) (5.4) (**) (2.2) (**) Odonata 1.25 2.44 3.33 2.72 1.42 1.11 (**) (2.7) (10.2) (2.9) (1.1) (1.2) Trichoptera 27.97 66.83 40.79 69.06 25.72 66.39 j (21.9) (73.7) (55.4) (75.2) (20.8) (74.4) Chironomidae 87.81 20.00 19.21 19.83 77.17 20.83 (68.7) (22.0) (26.1) (21.6) (62.5) (23.3) All Othets2 0.11
- 0.13 0.11
- 0.11
(**) (**) (**) (**) (**) (**) Total urganisms 127.77 90.66 73.58 91.88 '123.5 89.38 O i 5-7 \ .
cr_-~~ _ _ _ . _ . . . . .~~~..';___._-- ~ ~ ' ~ ~~ - ' "- - ~~ ~ l l O - l l l Apr. May June Res. WHTF Res. WHTF Res. WHTF Turbellaria * - 0.56 0.11 0.50 - (**) (-) (**) (**) (**) (-) Oligochaeta 0.33 - 0.67 - - - ! (**) (-) (**) (-) (-) (-) Hirudinia * - * - 0.28 - (**) (-) (**) (-) (**) (-) Gastropoda * - 0.14 * ,( (**) (-) (**) (-) (-) (**) Pelecypoda l 1.89 0.17 6.78 0.28 21.31 0.78 (1.7) (**) (5.1) (**) (23. 2) (1.6) Amphipoda 0.25 - 0.28 - * - (**) (-) (**) (-) (**) (-) O z=ogeae - (-) (-) (**) (-) (-) (-) Ephemeroptera 1.83 0.50 1.31 0.61 1.03 0.39 (1.7) (**) (**) (**) (1.1) (**) Odonata 1.33 2.00 1.17 2.11 1.00 1.17 (1.2) (1.3) (**) (1.8) (1.1) (2.4) b Trichoptera 34.50 128.67 46.19 98.61 26.14 41.44 (39. 3) (83.7) (35.0) (86.6) (28.5) (86.4) l Chironomidae 69.97 22.33 74.75 12.00 41.44 4.11 (63.4) (14.5) (56.6) (10,5) (4 5. 2) (8.6) All Others2 _ * , , , _ (-) (**) (**) (**) (**) (-) Total Organisms 110.27 153.72 131.97 113.72 91.75 47.94 5-8
O July Aug. Sept. Res. WHTF Res. WHTF Res. WHTF Turbellaria 0.56 - - - - - (**) (-) (-) (-) (-) (-) Oligochaeta 0.28
- 0.22 0.50 -
(**) (-) (**) (**) (**) (-) Hirudinia 0.11 - * - * - (**) (-) (**) (-) (**) (-)
- 7. Gastropoda ,
0.11 - - * - (**) (**) (-) (-) (**) (-) Pelecypodal 32.69 6.28 21.58 7.22 18.36 23.06 (38.8) (11.8) (38.0) (18.9) (29.8) (42.2) ! Amphipoda - - - - - - l (-) (-) (-) (-) (-) (-) Isopoda - - - - - - (-) (-) (-) (-) (-) (-) Ephemeroptera 0.53
- 0.22 0.17 0.56 0.67
(**) (**) (**) (**) (**) (1.2) Odonata 0.44 0.89 0.97 1.06 0.58 4.78 (**) (1.7) (1.7) (2.8) (**) (8.7) i Trichoptera 8.92 44.72 7.83 23.22 14.58 21.72 (10. 5) ( 8 4. 5) (14.2) (60.7) (23.7) (39.8) Chire.aomidae 40.39 6.94 25.69 6.06 26.56 . 4.33 (47. 9) (13.1) (45.2) (15.8) (43.1) (7. 9) All Others2 0.31
- 0.42 0.33 0.39 *
(**) (**) (**) (**) (**) (**) Total Organisms 84.25 52.94 56.80 38.27 61.61 54.61 O 5-9 9-
....=.__. - - -T. . . .
-- - ~ ~ ' ~ '
_ _ _ _ ~. n
~ ' -" ~
l O Oct. Nov. Dec. Res. WHTF Res. WHTF Res. WHTF Turbe11 aria 0.61 .- 0.86 - (**) (-) (**) (-) oligochaeta - - 0.25 - (-) (-) (**) (-) Hirudinia - - * - (-) (-) (**) (-) Gastropoda - - - * (-) (-) (-) (**) Pelecypoda l 2.92 49.22 8.5 55.1 (2. 9) (66.1) (7.7) (56.8) Amphipoda 1.36 - 1.03 0.17 (1.4) " (-) (**) (**) Isopoda - - - - (-) (-) (-) (-) Ephemeroptera 0.69 0.17 1.97 1.28 (**) (**) (1.8) (1.3) Odona t.a 0.86 0.11 0.75 1.22 (**) (**) (**) (1.3) Trichoptera 19.03 24.06 21.14 33.00 (19. 0) (32.3) (19.3) (34.0) Chircnomidae 74.83 0.89 75.14 6.17 (74.6) (1.2) (68.5) (6.4) All Others2 . . . . (**) (-) (**) (-) Total Organisms 100.36 74.44 109.69 97.00 1 Taxon title prior to 1978 was Sphaeriidae now to include Unionidae and Corbiculidae. , 2 Includes C.haoborus which were considered as a separate ; taxa price. to 1978. O . l 1 5-10 .
-n
. _ . . . - . . . . . . . I . . . -- . - _ . .. . .--.. _. 1 l
l O . Table 5.3.2.2. Taxonomic list of macrobenthic organ-isms collected in Lake Anna from January 1, 1979 to January 1, 1980. Phylum: Platyhelminthes l Class: Turbellaria Phylum: Annelida
, Class: Hirudinea Class: Oligochaeta -
( Phylum: Mollusca Class: Gastropoda Order: Pulmonata l , Family: Physidae ( Physa sp. Family: Planorbidae Helisoma sp. Class: Pelecypoda y , Order: Heterodonta Family: Sphaeriidae Family: Corbiculidae Order: Eultmellibranchia Family: Unionidae Phylum: Arthropoda l Class: Crustacea Order: Isopoda Family: Asellidae () ' Asellic 5-11 .
.. -..m. ..-_. _ _ , ., _ -
1 () . Order: Amphipoda Family: Talitridae Hyalella azteca Order: Decapoda Family: Astacidae Class: Insecta Order: Ephemeroptera . Family: Ephemeridae Hexagenia munda Family: Caenidae Caenis amica Family: Ephemerellidae ( Ephemerelia sp. Family: Baetidae Baetis sp. Family: Heptageniidae Stenonema Order: Odonata Suborder: Anisoptera l Family: Gomphidae l Progomphus i Dromogomphus spinosus Hagenius brevistylus Family: Libellulidae
' Epicordulia princeps l
, P) b Tetragoneuria cynosura 5-12 *
. = - _ _ .--
l I ($) Macrochemis sp. Plathemis sp. Neuro cordula sp. i Family: Macromildae l Macromia sp. Didymops sp. Suborder: Zygoptera
~
Family: Coenagrionidae Argia sp. Enallagma sp. Ischnura sp. Orders Megaloptera O Family: Sialidae Sialis sp. Order: Coleopter Family: Dytiscidae L Order: Trichioptera Family: Polycentropodidae . Cyrnellus fraternus Cernotina sp. Phylocentropis placidus Family: Hydropsychidae l Chemumatopsyche sp. Family: Hydroptilidae Hydroptila sps 5-13
O . Family: Phryganeidae Phryganea sayi Family: Leptoceridae Leptocella sp. Oecetis sp. Mystacides sp. l l Triaenodes sp. Family: Molannidae 1 C Molanna sp. Order: Diptera Chaoborus sp. Family: Sciaridae Family: Similiidae Family: Ceratopogonidae Family: Chironomidae o I O 5-14 t
\
1
. = _ _ - _- . _.--- - - _ _ _ -x_-_-______. - -- ..
i (:) structure, especially in the WHTF, was the result of the appearance and rapid increase in numbers of Corbicula. Sickel (1973) suggested that Corbicula may cause eco-logical problems as a result of competition with native ' molluscs. Economic problems such as fouling cooling systems or interferring with gravel operations have been noted by Sinclair and Isom (1963a, 1963b) and Goss and Cain (1975). The spread and abundance of Corbicula continues to cause concern resulting in ongoing research centering on develop-ment of control procedures (Bre11enthine 1979) and population dynamics and dispersal studies (Dreier 1978). Corbicula was first reported in Virginia in ths James River between Richmond and Hog Island in the fall of 1971 e' (Diaz 1974). Roagers (1977) has since reported Corbicula in the New River, Virginia. " Corbicula was first collected at station C in the WHTF in July 1979 and was found at all stations except A by l December 1979. It has also been collected in the North Anna River. Other groups of organisms considered relatively abundant in Lake Anna were Turbe11 aria, oligochaeta, Hirudinea, Os Gastropoda, Amphipoda, Ephemeroptera and Odonata. Temporal j distribution and dominance of organisms in these groups changed little from 1978. 5.3.3 Diversity Diversity values for 1979 were calculated for all stations using the Sequential Comparison Technique (Cairns and Dickson, 1971). Diversity values were similar to those reported in 1978 and ranged from 0.90 to 0.02. Over-(_') all dis ersity values were somewhat higher than 1978 (VEPCO, 1979) possibly as a result of increased density of all organ-isms as well as a decline in the dominance of Chironomidae. In the Data Base (page AS-35) the category entitled " number of taxa with greatest abundance" is defined as the smallest number of taxa necessary to account for 50% or more of the total number of organisms. As in 1978 this value never ex-ceeded 2 at any depth at any station. 5.3.4 Horizontal Distribution The horizontal distribution of the dominant macrobenthos is summarized in Table 5.3.4.1. Turbellaria, Oligochaeta, Hirudinea, Gastropoda and Amphipoda were found at fewer stations in 1979 than in 1978. Pelecypoda were found at all stations in 1979, but were absent from station C in 1978. The presence of Pelecypoda (Corbicula) at station C is significant in that Corbicula were present in substantial numbers (21.7% of the total number of organisms O 5-15
~
O O O D O Table 5.3.4.1. Horizontal distribution of dominant macrobenthos in Lake Anna from January - December, 1979. Density is expressed as the number of organisms per web sampler. As asterisk (*) denotes less than 0.1
. organism / sampler.
WitTP Station!. Reservoir Stations i. I! Taxa A B C D E F H J K Turbellaria - - - - - 0.39 0.70. 0.98 2.20 i, Oligochaeta * -
- 0.41
- 0.11 0.09
- 0.55 f
, Ilirudinia - - - - - -
0.11
- 0.33 l
?
Gast moou * * * - - 0.23 Pelecypoda l
- 1.92 36.97 22.74 32.06 7.62 4.79 2.97 2.66 Amphipoda - - *
- 0.15 1.09 0.16 0.35 0.22 Isopoda - - - - - - - -
- Ephemeroptera
- 1.29 0.35 0.44 2.36 0.85 1.97 0.93 1.31 Odonata 1.85 1.26 1.26 0.23 2.68 0.85 0.93 0.58 0.52 i
, Trichoptera 4.29 36.. 127.65 , 60.12 21.91 30.11 19.71 5.13 4.42 e
e
l O C O o O 1 h ' i 1.dTF Stations j Reservoir Stations
?
l Taxa A B C D E F H J K 1 Chironomidae 7.45 23.38 4.06 4.27 11.18 13.41 16.44 167.73 113.92 All Others2 - *
- 0.11 0.12 0.23
- 0.27 0.32 l
Total Organisms 13.74 64.17 170.43 88.39 70.50 54.65 44.98 179.12 126.73 NLmber of Months y sampled 11 11 11 11 11 11 11 10 10 ; U j 1 Taxon title prior to 1978 was Sphaeriidae now to include Unionidae and Corbiculidae. : J 2 Includes Chaoborus which were considered as a separate taxon prior to 1978. B G G
_ .~_ O . at this station in 1979). Ephemeroptera, Trichoptera, Odonata and Chironomidae were present'at all stations in 1979 as in 1978. l Ephemeroptera were similar in abundance and distribution l in 1978 and 1979. Trichoptera were down in abundance at i Station A and up at all others. The density of Trichoptera was greatcst at station C and, as in 1978, Cyrnellus was the dominant genera. Cyrnellus, a net spinning caddis fly, is generally carviverous. A rock rubble substrate provides necessary points of attachment for its nets and a current is necessary to sweep food into these nets. Only station C , provides an abundance of this type habitat. Numbers of i (' Odonata werre down at station D and up at all others. Odonata l community structure was similar to that reported by Voshell l (1978) for Lake Anna. Numbers of Chironomidae were up at stations i., B, E, J and K. Density of the total number of organis...s was up at 5 out of 9 stations in 1979 when compared to 1978. 5.3.5 Vertical Distribution Vertical distribution of the (]) eleven major macrobenthic taxa is shown in Table 5.3.5.1. Seven of the eleven major taxa decreased in density as the depth Ancreased. Included in this trend were: Turbellaria, Amphipoda, Isopoda, Ephemeroptera, Odonata and Chironomidae. 1 Turbellaria, Ephemeroptera and Odonatat are the only three l orders wha h have consistantly followed this pattern for the ! last 5 years. As in 1978, Oligochaeta were most dense ut 4 meters followed by 2 meters and then 7 meters. Also followiny this pattern were Hirudinea, Pelecypoda and C Tr,1choptera.
~
5.3.6 Surface Community As in 1978, surface samples were collected at all stations using a D-frame dip net technique and a one minute sampling period. As in past years the density of these samples was r;uite variable and ranged from 0 to 233 organisms. The 1979 data are quite similar to 1978 data, not only with regards to density but also to community structure, as Chironomidae were the most abundant organism followed by Amphipoda and Trichoptera. As in 1978 Amphipoda and Trichoptera were most abundant in or near aquatic macro-phytes. Isopoda, which were absent in 1978, were collected again in 1979. 5.4 Summary ,
- 1. During 1979 the density of the macrobenthos increased O
throughout the reservoirs. The density in the Lower ' N
~
5-18
./
O Table 5. 3.5.1. Vertical distribution of dominant macrobenthos in Lake Anna from January - December, 1979. Density is expressed as the number ,of organisms per sampler. An asterisk (*) denotes less than 0.1 organisms / sampler. Taxa 2 meters 4 meters 7 meterc Turbe11 aria 1.08 0.16 0.16 Oligochaeta 0.18 0.26
- Hirudinia
- 0.12 0.36 Gastropoda I Pelecypoda l 13.55 13.81 6.43 Amphipoda 0.51 *
- Isopoda
- _ -
Ephemeroptera 2.20 0.88 0.24 () Odonata 1.87 0.96 0.68
- Trichoptera 42.41 45.73 25.84 Chironomidae 56.22 41.59 26.83 All Others2 0.17 0.15
- Total Organisms 120.27 101.45 63.26 1 Taxon title prior to 1978 was Sphaeriidae now to include Unionidae and Corbiculidae.
2 Includes Chaoborus which were considered as a separate taxon prior to 1978. O 5-19
O
- 1 Reservoir was significantly higher (Students t-test,
*( = .05) in 1979 than 1978. The Upper Reservoir showed
- no significant difference ats< = .05.
- 2. During 1979 the density of the macrobenthos increased in the WHTF, although there was no significant difference from 1978 ate (= .05.
- 3. Trichoptera continued to increase in dominance in the Reservoir through the year and in the WHTF through August. ;
- 4. Pelecypoda replaced Trichoptera as the most abundant l i
organism in the WHTF for the last three sampling periods
, in 1979. *
- 5. '
1979 was the first time Corbicula, the Asiatic clam, has been reported in Lake Anna.
- 6. In 1979 Isopoda were again co lected in Lake Anna, however their densities were extremely low.
O (:) i O 5-20 G
-.- __..-* w?** m _.
O . 5.5 References Brellenthin, J.B., Biologist for Tennessee Valley Authority. (Letter to Dale A. Dobroth, James R. Reed and Assoc. Inc.). 1979 September 18. Cairns, J., Jr.; Dickson, K.L. A simple method for the bio-logical assessment of the effect of waste discharges on aquatic bottom dwelling organisms. J. Water Pollut. Coutr. Fed. 43(5):755-772; 1971. Commonwealth Edison Company. Annual Report For Fiscal Year 1976 ~ Lake Sangchris Project. A report by Illinois Natural History Survey to Commonwealth Edison Company. February 1977. ~ Located at Commonwealth Edison Company, Chicago, Illinois. O Diaz, R.J. Asiatic Clam, Corbicula manilensis (Philippi), in the Tidal James River, Virginia. Chesapeake Science 15(2):118-120; 1974. l i Edmondson, W.T., editor. Freshwater biology, 2nd ed. New York: l John Wiley and Sons; 1959.. ~ () Goss, L.B.; Cain C.,Jr. Power plant condenser and service water system fouling by Corbicula, the Asiatic Clam. Biofouling Workshop: Electric Power Research Institute and Maryland Power Plant Siting Program; 1975 June 16-17; Baltimore, MD. Johns Hopkins University; 1975. Merritt, R.W.; Cummins, K.W., editors. An introduction to the aquatic insects of North America. Dubuque, IA: Kendall/ Hunt Publishing Co.; 1978. { Needham, J.G. ; Westfall, M.J. , Jr. A manual of the dragonflies I of North America (Anisoptera). Berkeley, CA: University l of California Press; 1954. l Pehnak, R.W. Fresh-water invertebrates of the United States. l New York: The Ronald Press Co.; 1953. Reed, J.R., Jr. Stream community response to road construction sediments. Blacksburg, VA; Va. Water Resources Research Center; 1977. Rodgers, J.H.; et al. The invansion of th( Asiatic Clam, ! Corbicula manIIensis, in the New River, Virginia. The i Nautilus Vol. 91(2):43-46; 1977. O 5-21
.- . _ . .. ._ . -. - .x _ _ .._-
-~~
O . Sickel, J.B. A new record of Corbicula manilensis (Philippi) in the southern Atlantic slope region of Georgia. The Nautilus 87 (1) : 11-12; 1973. Sinclair, R.M. Effects of an introduced clam (Corbicula) on the water que.lity in the Tennessee River Valley. Second ) 1 Annual 5anitary Engineering Conference; 1963 May 3C 31 Nashville, Tn. Vanderbilt University; 1965. 1
; Isom B.G. Further studies on the Asiatic Clam (Corbicula) in Tennessee. Nashville, Tn: Tennessee Stream Pollution Control Board Tennessee Department of Public Health; 1963 (Reprinted 1978); 78 p. Available from Tennessee Department of Public Health, Nashville, Tn.
(,', Torre-Bueno, J.R. de la, F.R.E.S. A glossary of entomology. New York: New York Entomological Society; 1978. Usinger, R.L., Editor. Aquatic insects of California. Berkeley, CA: University of California Press; 1956. Virginia Electric and Power Company. Environmental Study of () Lake Anna, Virginia: January 1, 1978-December 31, 1979. A report of James R. Reed and Associates, Inc. to the Virginia Electric and Power Company. March 1979. Located at Virginia Electric and Power Company, Richmond, Vir-ginia. Voshell, J.R., Jr.; Simmons G.M., Jr. The Odonata of a new reservoir in the southeastern 7 (1) : 67-76; 1978. United States. Odonatologica gs Wiggins, G.B. Larve of the North American Caddisfly Genera l (Trichoptera) . Toronto: University of Toronto Press; 1977. () - 5-22
./
() , 6.0 Fish 6.1 Introduction Studies of fish populations in water receiv- {-- ing heated effluent from power plant discharges have been ex-tensively documented and have produced varying results (Bennett and Gibbons, 1975; Marcy, 1976; Bennett and Gibbons, 1974; Larimore and Tranquilli, 1977; Gammon, 1973; Larimore, 1975; Goldstein, 1976; Proffitt, 1969; Neill and Magnuson,1972). The need for additional information to supplement existing studies is essential to more accurately define the impacts of power plant discharges on fish populations. This study is designed to provide information relating to the impact of the O North Anna Nuclear Power Plant on the fish community of Lake Anna, Virginia and is carried out in accordance with the guidelines set forth in the technical specifications as pro-mulgated by the Nuclear Regulatory Commission. 6.2 Methods 6.2.1 Fish Collection Techniques and Station Designations. ( Locations of all fish collection sites are shown on Figures 6.2.1.1 and 6.2.1.2. In general, habitats at all stations ware similar, although some slight variations did occur. Bottom types varied from submerged brush, decaying vegetation, and fallen logs to detritus and clay. Aquatic macrophytes were encountered in some shallow areas and the shoreline terrestrial vegetation varied from open pastures and old fields to near climax deciduous oak forests. Experimental gill nets were set, as often as conditions allowed, near littoral drop off areas where, as discovered from previous sampling, fish tend to move more frequently. . Depth selection was aided by a Ray Jefferson depth sounder (Model 5270) to standardize the depth at each separate sampling period. During periods of thermal stratification, nets were set above the thermocline which usually ranged from six to eight meters in depth. Generally, the best possible habitats were exploited at each station depending on time of year, O' weather conditions,and other physical and chemical factors. All sites in the reservoir were similar except Contrary Creek. 6-1
, t !' .'
o ' 3 R J((N .
- d. ~
T i TNI N s r 2M 0 e t e m 8 0 o 1 Ml o i 2 t R s
/ n 2MK 7 ri o
s et n wa ' o
, ot PS i
t a t s O a g n i t t i e r l l ZI. i g, f c , o n Y o i t . aa cn on lA l e ak ra - eL n en Gi 1 1 2 6 e O _ r _ u g i F u
t '
. ;I I e
v o o C . D/ m _ a v l r i o yl v de r oe e J or s MC R e - d - i*
. i s M -
r o 2C 0 t e e m 8 0 2 Nl o d 1 t r i R nk n 2 u K s Vn o l. oe pe l r lc i M s n
. o i
t a O t s e n o n. Rm e9 Ar t7 NA o9 r1 f - o ( 5 _ n7 _ o9 i1
- t aa cn on yk
\ lA l e ee ak ke ra nC eL u n m en a - Gi P
2 1 2 6 9 e O r u g i F iu
() ! which was notably different due to a greater transparency of the water and lower alkalinity and pH values than other areas of the reservoir. Collecting methods included the use of experimental gill l nets that were 91.44 m in length and 1.83 m deep. Each net consisted of six panels 15.24 m long with respective mesh sizes of 1.27, 2.54, 3.81, 5.08, 6.35 and 7.62 cm bar mesh. One net i was set at each station on a quarterly basis. Gill nets tend to be selective and are more efficient in capturing fish with external roughness, teeth,. spines, etc. (Lagler, 1968) and they tend to catch larger fish (Yeh, 1977) . Fishing success of passive nets depends on fish movements and (~- their efficiency and selectivity may be subject to abrupt changes from shifts in barometric pressure, wind-driven cur-rents, water level fluctuations, turbidity and transmitted light (Lagler, 1968). The limitations of collection methods were considered when the data were analyzed. Several samples were taken and the mean catch reported and compared between l l sites. The use of experimental gill nets with varying mesh minimized the sampling bias. No matter what type of sampling technique is employed, each has its own degree of selectivity O depending upon the situation (Lagler, 1968). Therefore, in this study a variety of techniques were used including seines and electrofishing. Electrofishing was done using a pulsed D.C. boat shocker. These samples were taken prior to and during the spawning period of the largemouth bass to obtain information relating to the reproduction of this fish and also to supplement age and (y growth data. Bass were collected from the Reservoir and the WHTF during the same day to reduce bias. Cove rotenone samples are taken in August, 1979 to obtain information on standing crop, young of the year and population structure. Six coves were selected, surveyed and blocked off with a 300' x 25' x 1/2" blocker net. Divers were sent down to insure the net was secure on bottom. 100-125 fish were collected by electrofishing, fin clipped, recorded and released inside the blocker net to facilitate a tag return estimated to test the effectiveness of the rotenone. Rotenone was added at a concentration of one part per million and the fish were col-lected, measured, sorted by size class and weighed. 6.2.2 Water Quality Analyses Selected physical and chemical measurements were performed at the time the fish collections were made. Interpretation of these data were discussed-in relation to the fisheries data. [} 6-4
.I
l .- - - . . . - . . . _ 1 O l Temperature and dissolved oxygen were taken at one meter intervals throughout the water column at each station with a Yellow Springs Instrument Company Model $4 dissolved oxygen / temperature meter. Alkalinity (CACO 3 ) and hardness (EDTA) were measured at the surface, mid and bottom depths (Standard Methods, Amer. Publ. Health Assoc. et al., 1975). Turbidity
- was monitored at the surface, mid and bottom depths utilizing a Coleman Nephocolorimeter and recoded in nephelos units (ETU)
(Amer. Publ. Health Assoc. et al., 1975). 6.2.3 Abundance and Distribution of Populations Changes in relative abundance and species composition were based upon a l standardized netting program as well as summer rotenone samples. I Rotenone provided information on standing crop as well as young (~ . of the year fishes and species composition. This method in conjunction with the standardized netting program has proven to be effective in obtaining valid information concerning the abundance and distribution of fish populations in Lake Anna. Relative abundance values were determined based on catch per unit fishing effort (c/f), on the basic assumption that unit effort can be calculated on any method as long as effort (*) v (f) is in the same units, and is most commonly used for making year to year comparisons as part of a monitoring program (Lackey, 1974). Catch per net day (c/f) for samples obtained from experi-mental gill nets provided the basis for determining changes in the relative abundance of fish species. One net day was equivalent to 91.44 meters of experimental gill net set for one overnight period (approximately 18-20 hours) . Relative abund-(..' ance values were calculated on the basis of numbers of individ-ual species and weight of individual species. In addition to providing supplemental information on relative abundance, the rotenone samples were analyzed for standing crop (biomass or kg/ hectare). Standing crop was based on a tag return estimate l utilizing a mark and recapture technique and was calculated us-ing surface area. From these data, individual species weight and numbers were multiplied by a correction factor to obtain the estimated standing crop (kg/ hectare). 6.2.4 Age and Growth of Largemouth Bass, Micropterus Salmoides. Age and growth of Micropterus salmoides from the Reservoir and WHTF were evaluated from individuals collected throughout the study period. Upon capture, individuals were weighed, a measure of total length was taken using a conventional fishery measuring board, and scale samples were collected. Total length (T.L.) (as opposed to standard length (S.L.)) was used because-it is O more representative in length-weight functions (Royce, 1942), is easier to measure in tha field, can be measured more accurate-ly than S.L. (Carlander and Smith, 1945) and is more commonly 6-5
l 1 () . l l used by fisherman and fishery biologists (Ricke:J and Merriman, 1945). Approximately 12 scales were remqved from the shoulder l at the lateral line below the origin of the dorsal fin on the l left side. Scale samples were placed in an anvelop.e on which date, collection method, location, weight, length, as well as sex of the fish when noted, were recorded. Permanent mounts
- of scales were made in the laboratory, and impressions were made by placing scales between two pieces of cellulose acetate, each approximately 0.5 mm thick, and pressed in an Ann Arbor Rollerpress.
Age determination of fish and measurements of scales for back-calculation were accomplished with a Bausch and Lomb Tri-Simplex projector at a magnification of 43X. All scales were (]' aged a minimum of two times and at least four scales were ex-amined from each individual. Regenerated scales were disre-garded. The method proposed by Hile (1941) designating January 1, as a universal fish birthday was employed in aging. The formula used for back-calculating of body length is: L'=C+lI-(L-C) l () where l L' = length of a fish when annulus X was formed; L = length of fish at time scale sample was obtained; S' = length of scale radius to annulus X; 5 = length of total scale radius; C = intercept as calculated from the regression of scale length vs bcdy length. k- This equation was employed because it accounted for a greater amount of the variability than other methods attempted. Hile (1941) presents a detailed discussion on various methods of back-calculation of growth and where each should be employed. Other discussions on these techniques and their use with various species of fish have been presented by many authors (LeCren, 1947; Nicholls, 1957; Padfield, 1951; Ricker, 1969; Bennett, 1937; Weatherly, 1972; Everhart, et al., 1975; Carlander, 1977). Computation of weight from length was based on the length-l weight relationship. log W = log a + b log L where: log W = predicted log weight () log log a b
=
=
y intercept slope of the line log L = actual log length 6-6
Data for largemouth bass were examined from each of the study areas to determine if any variation existed between fish populations present there. i Condition factors were calculated for the largemouth bass collected from each study area of the Reservoir. Since the weight of a fish varies with the cube of its length, provided the shape and specific gravity remain the same,.any change in the shape or relative plumpness of a fish will cause a change in the value of c in the formula (Carlander, 1977): W = cL 3 Fishery biologists have used this fact in describing the (}. condition, plumpness, or well being of a fish. The coefficient of condition, K, or Fulton's condition factor (Carlander, 1977), has been widely used and was utilized in this study: 5 K = K10 L3 where W = weight in grams . L = length in millimeters 105 = a factor to bring the values of K near unity (Carlander, 1977) . 6.2.5 Fecundity and Gonad Development During 1979, studies were performed to aid in the characterization of the Micropterus l salmoides populations. These included determination of fecun-dity, egg size and gonad development for this important game fish species. Only the yolk-laden eggs (greater than 0.75 mm in diameter) were counted when determining the fecundity estimate. When fish were collected in the running rip 0 condition, egg counts were disregarded. The fish used in fecundity estimates were collect-ed prior to spawning' activity to insure an accurate fecundity estimate. The gonads of both sexes of M. salmoides were excised and weighed in the field. In addition 7 fish were measured for total length (Ricker and Merriman, 1945), weighed, and a scale sample taken so that condition and age of the fish could be calculated. The gonads used for fecundity and egg size studies were immed-iately stored in jars containing Gilson's fluid for subsequent analysis (Simpson,1959; Ricker, 1968). The Gilson's fluid contained twice the amount of acetic acid to harden the eggs and facilitate further their separation 6-7
O - from the ovarian tissue, i.e. (Simpson, 1959): I 100 ml 60% propanol (v/v) 885 ml water 15 ml 80% nitric acid (v/v) , 18 ml glacial acetic acid 20 gm mercuric chloride The closed jars were shaken vigorously to assist the pene-tration of the fluid, and then allowed to stand at least 24 hours or until such time as analysis could be facilitated. This technique allowed the eggs to be stored several weeks with- . out any deterioration. (} When the eggs were ready for analysis, the Gilson's fluid was replaced by water, and each jar was shaken vigorously, liberating the majority of the eggs from the ovarian tissues. The ovarian tissue, free of eggs, floated to the top and was decanted. The jar was then refilled with water, and the shak-ing process repeated until all ovarian tissue was removed. After settling to the bottom the mature ova were transferred to small jars from which the egg sub-sample for counting was taken. (} The one milliliter sub-sample of eggs was transferred to a Petri dish and counted. These eggs were then returned to the original sample. The total number of eggs from each individual pair of ovaries was then calculated volumetrically (Burrows, 1961) in a graduated cylinder and the fecundity estimated by multiplying the total volume of eggs by the number of eggs in
- c. one milliliter.
\-
Fecundity of the female M. salmoides was plotted against length of the fish, (Bagenal, 1966) and were plotted (fecundity vs. length) by the log / log least squares regression method as follows: log F = log a + n log L where F = fecundity; a = a constant; n = exponent; L = length of each individual fish. After taking the antilog, a second equation is generated which is useful in describing and predicting fecundity values. (]) A one milliliter sub-sample of eggs was accurately measured utilizing a 10 ml graduated cylinder. The egg sub~uumple was s 6-8
, , , - _ .gy _ _ . _ _ _-,~y . , - - - - . --
l l O . taken with an open glass rod after stirring the eggs to obtain a random sample of all sizes of mature oya. Egg size was mea-sured by employing the use of a microscope stage micrometer. M. salmoides eggs were placed directly on the slide while wet l and a random sample of 20 eggs were measured per ovary.
~
( 6.2.6 Statistical Analyses A simple one-way classification ANOVA and Duncan's Multiple Range test was used for testing selected fish sp6 ?.es biomass between years, first year growth, alkalinity, hardness and turbidity between locations (Steel and Torrie, 1960; Zar, 1974). All ninety-five percent confidence intervals (mean + t (Standard errer)) were also plotted follow-ing Steel and Torrie (1960). 6.3 Results (~' 6.3.1 Physical and Chemical Temperatures were taken monthly [ at one meter intervals at each fish station except where ice cover prevented sampling at some stations in January and Feb-ruary (Table 6.3.1.1) . Since gill nets were set at generally shallow depths only the surface, mid and bottom temperatures were reported. The temperature data as reported in meter in-tervals will be found in the Data Base (page A6-26). Temperatures at the WRTF gill netting stations were generally higher than at the Reservoir gill netting stations (Table 6. 3.1.1) . Data received from VEPCO biologists stationed at the North Anna Nuclear Facility demonstrate the weekly changes in temperature experienced at the electrofishing stations throughout the year (Figures 6.3.1.1, 6.3.1.2 and 6.3.1.3). The higher temperatures noted in the WHTF during the early spring ([- subsequently affected the spawning of the largemouth bass as will l be noted later in the report. Dissolved oxygen levels observed at the surface, mid and bottom were generally high with corresponding values of satur-ation at all fish stations throughout the year (Table 6.3.1.2) . Dissolved oxygen data recorded at meter intervals can be found in the Data Base (page A6-30). Some super saturation levels were encountered during the summer months and the lowest value for dissolved oxygen (1.8 ppm @ 20% saturation) was recorded during July at station Y. This value was taken at a bottom depth which typically has low oxygen during the summer months. l Turbidity in the Upper Reservoir stations for surface and i mid-depths was significantly higher than all other fish sampl-i n V ing stations (Table 6.3.1.3). An ANOVA and Duncan's Multiple i Range test demonstrated the following relationships for turbidity 6-9
O C O n O l Table 6.3.1.1 Temperature (c) at surfac'e, mid, and bottom by station and month for Lake Anna, 1979. Lower Reservoir Upper Reservoir Wi!TF l Station I Date Depth S T V M Y Z N R 1/23 S 6.2 5.0 3.0 6.0 6.0 '
- M 5.5 5.0 3.0 6.0 6.0 l
B 5.2 5.0 3.0 6.0 6.0 2/22 S 8.8 6.5 P d M 7.2 5.8 o - i B 7.0 5.5 , f 3/20 S 10.0 9.0 7.8 9.0 9.0 8.8 12.5 12.5 M 10.0 9.0 7.0 7.0 9.0 8.8 11.5 12.0 B 9.0 9.0 7.0 6.8 7.0 8.8 11.5 12.0 4/18 S 12.5 13.0 12.9 13.5 13.0 13.1 13.0 .13.2 M 12.5 13.0 12.0 13.0 13.0 12.8 13.0 13.5 B 12.5 12.0 12.0 12.9 13.0 12.5 13.0 13.0 9
o c. o - o . O Temperature (C) at surface, mid, and bottom by station and month for Lake Anna, 197 9. - (Cont. ) ; Lower Reservoir Upper Reservoir WiiTF Station Date Depth S T V M y Z N R . 5/14 S 19.5 19.0 20.5 I 21.0 22.0 22.0 21.5 21. j M 18.8 18.5 20.5 21.5 22.5 22.5 21.0 22.0 B 18.8 18.0 19.0 22.0 18.0 19.0 20.0 22.0 6/13 S 22.0 22.2 23.0 24.0 23.5 24.0 26.2 25.0 i p M 22.0 22.0 22.5 23.5 23.2 23.0 26.5 25.0 B 22.0 22.0 22.0 21.3 19.5 21.5 26.0 25.0 , 7/18 S 26.5 26.3 27.0 27.0 26.5 26.8 -29.5 28.0 M 26.5 26.0 26.8 27.0 25.0 26.0 29.0 28.0 B . 25.8 24.0 26.5 26.5 23.0 24.0 28.5 28.0 8/28 S 25.5 25.5 26.8 28.0 26.0 27.0 29.5 29.0 M 25.5 25.8 26.0 27.0 26.2 26.5 29.8 29.0 B 25.5 25.8 26.0 27.0 25.0 25.5 29.5 28.0 i 1 .
o o O n O
' Temperature (C) at surface, mid, and bottom by station and month for Lake Anna, 1979. (Cont.i Lower Reservoir Upper Reservoir WitTF Station
- Date Depth S T V M Y Z N R 9/.'.9 S 23.8 24.0 24.0 22.5 21.5 21.9 24.9 23.8 .
M 24.0 24.1 23.8 23.0 22.0 22.0 25.0 24.0 B 24.0 24.0 23.5 23.0 22.0 22.0 25.0 24.0 10/16 S 16.5 16.0 16.0 16.0 15.0 15.0 16.0 16.5 i.r M 16.5 16.2 16.0 16.0 11,3 15.0 w - 17.0 16.5 I B 16.5 16.2 16.0 15.5 13.0 12.5 17.0 16.0 11/27 S 11.5 12.2 12.0 12.0 12.0 12.0 12.5 11.0 1 M 11.5 11.5 12.0 11.5 10.5 11.0 12.0 11.0 B 11.0 11.5 11.5 11.0 9.5 11.0 12.0 11.0
- 12/17 S 9.2 10.2 10.1 9.2 . 7. 8 7.5 8.5 8.2 i
M 10.0 10.2 10.1 9.2 8.3 7.8 8.5 i '8.2 B 10.1 10.2 10.3 9.3 8.5 7.9 8.5 8.2 l l
O i O n O
- ___ surface
_ ._._. mi d bottom 8 reactor down
+ ice cover O high wind no data 30 - -
s#~'s /\
/ s'~ .' ~~ s.\
.u e
es w e
# / 's '
- - N
'\%'.s g
@ , *~~',.* =***s./*_,/ *\
g s e W B-e f' i ,. . s
.s
-t u 4 e I
~
m I
~~N.' s Ei,
/ ,, *j s%
e s, ~ En ,A s- s *--%'~ 16-- /, .~$ ' q
// s.s
, ' i,- n^
y_+
- s. ,,
s i .
' s = , . . . . . . .
Jan Mar May MONT!! Jul Sep Notr FIGURE 6.3.1.1. Temperature at weekly intervals Lake Anna 1979 Mid-Reservoir e
o r, o ^, o
----- su r f a ce mid g bottom 4 reactor ice cover down A high wind no data
\ 1 ~ ~ _%.
f,'*\,%/,
,- g 4 1% / *\
/ %/
, \,%.1 r\
.~.e",'
g l5 - j/ s \.\g
, aV i /
y u i E 6 *
* ! ./.
* #i- - ' t s M10 -
es 4 /N ' . e . ' ./ E 9 /s . .> t-e ' s N # ,' / e-/-{/ .
\
j's.k& o 5 +
+ '
Jan e a Mar e i i e i e i e i s' ! May Jul Sep Nov '
, MONTli FIGURE 6.3.1.2. Temperature at weekly intervals Lake Anna 1979 WilTF-STATION R i . . .
I q
O O O ' O L
- ----- sur f ace
_._. _. m id bottom l
# reactor down
.g. ice cover 35 -
A high winds
- no data i
/ " < Y.s
/., N% .4 sp%%
~~
p $ a,5 2,m _ s)' E.s o <r $- sg
*25-
/ I#' i -
!d f '9' t b,s E
l/ %
$ p-N ,- A- ,/ hw ,
f 15 - /'
'4,' I g f,'e- \, #
i
- 7 4 :
E 'g ils g l.
, , e.= /r[ ' .g. .g f,/ I,g I
S- $.g ,.//
, k ,
+ + :
= = . . . . , , , - - - , , ,.
Jan Mar May Jul Sep Nov MONTH , i FIGURE 6.3.1.3. Temperature at weekly intervals Lake Anna 1979 WHTF-DISCHARGE CANAL s
*\
e
s O O O n - O . Table 6.3.1.2 - Dissolved oxygen and percent saturation at surface, mid, and bottom by station and month for Lake Anna, 1979. l Lower Reservoir Upper Reservoir WilTF I Station Date Depth S T V M Y Z N R . I 1/23 D.O. S 11.0 10.8 11.8 11.8 11.6 -
% Sat. 88 84 87 94 93 D.O. M 11.0 11.0 11.8 11.6 11.6
% Sat. 86 86 87 93 93 D.O. B 9.5 10.8 12.0 11.4' 11.4
, t Sat. 74 84 89 91 91 e
[ 2/22 D.O. S ' 12.0 12.0
% Sat. 103 96 D.O. M ~ 41. 8 11.9
% Sat. 96 95 i
i D.O. B 9.8 11.4 !. % Sat. 80 89 3/20 D.O. S 11.8 11.6 12.2 10.9 11.0 10.6 11.6 11.6
% Sat. 104 100 102 94 95 91 107 107 D.O. M 11.6 11.6 12.0 10.6 10.8 10.6 11.4 11.4
% Sat. 102 100 98 86 93 91 102 105 D.O. B 10.8 11.2 11.6 10.2 8.6 10.2 11.2 11.0
% Sat. 93 96 95 83 70 85 100 101 e
O 'I O O O . Dissolved oxygen and percent saturation at surface, mid, and bottom by station and month for Lake Anna, 19 79. (Cont. ) Lower Reservoir Upper Reservoir WitTF Station Date Depth S T V M Y Z N R 4/18 D.O S 9.8 9.9 9.9 9.3 10.8 10.4 11.6 11.6
% Sat. 90 93 93 87 101 98 109 109 , *D.O. M 9.7 9.8 9.8 9.2 10.6 9.6 11.4 11.4 l t Sat. 90 92 90 86 '100 90 107 107 D.O. D 9.7 9.8 9.6 9.0 10.2 9 '.1 11.2 11.4
- 7. % Sat. 90 92 88 84 96 84 105 107 U
5/14 D.O. S 7.6 8.4 9.0 9.0 - 8. 5 8.7 8.5 8.3
% Sat. 80 89 97 100 96 98 94 92 l
l D.O. M 7.6 8.0 9.0 9.0 8.3 8.6 8.0 8.2 l % Sat. 80 84 97 100 94 97 88 93 lI l D.O. B 7.5 7.7 8.3 9.0 3.7 5.1 7.2 8.0
% Sat. 79 81 88 102 39 54 78 91 6/13 D.O. S 8.3 8.5 8.4 9.2 8.1 8.4 8.9 8.2
% Sat. 94 96 96 108 93 98 108 97 D.O. M 8.3 8.4 8.3 9.0 7.0 6.7 8.9 8.2
% Sat. 94 95 94 103 80 77 108 97 D.O. B 8.3 8.4 8.2 8.3 4.1 5.2 8.9 8.1
% Sat. 94 95 93 92 47 57 108 96
G O O n O Dissolved oxygen and percent saturation at surface, mid, and bottom by station and month for Lake Anna, 1979. (Cont.) i Lower Reservoir Upper Reservoir WiiTF Station Date Depth S T V M Y Z N R 7/18 D.O. S 7.2 7.4 8.2 8.5 8.1 8.3 7.0 7.1
% Sat. 88 90 101 105 98 102 89 90 D.O. M 6.6 6.9 8.0 8.5 5.4 5.7 7.2 6.8
% Sat. 80 84 97 105 65 69 92 86 D.O. B 6.3 5.9 8.0 8.4 1.8 2.3 7.1 6.2
,f n Sat. 77 73 97 102 20 27 89 78
- 8/28 D.O. S 6.0 6.9 7.7 8.6 '8.4 8.8 7.4 7.5
% Sat. 72 83 SS 108 102 108 96 96 D.O. M 6.0 6.8 7.6 8.5 8.1 6.4 - 7. 4 7.5
% Sat. 72 83 92 105 . 98 78 97 96 ;
D.O. B 6.0 6.6 7.5 7.9 2.1 0.9 7.7 6.4
, 1 Sat. 72 80 91 97 25 10.8 100 81 9/19 D.O. S 6.5 7.1 7.2 7.8 7.5 8.6 -
7.6 7.5 ; 1 Sat. 76 83 84 89 84 97 90 87 i e ( D.O. M 6.5 6.8 7.0 7.7 7.5 8.2 7.7 7.5
% Sat. 76 80 82 88 85 93 91 88 ,
i D.O. B 6.3 6.5 6.2 7.7 7.4 5.1 7.7 7.3 4 Sat. 74 76 72 88 84 56 91 85
O C O o O Dissolved oxygen and percent saturation at surface, mid, and bottom by station and month for Lake Anna, 1979. (Con t. ) Lower Reservoir Upper Reservoir Wi!TF Station Date Depth S T V H Y Z N R 10/16 D.O. S 7.5 7.4 7.3 7.9 8.8 8.3 8.5 8.1 1 Sat. 76 74 73 79 86 81 85 82 t D.O. M 7.5 7.3 7.3 7.6 6.5 8.5 7.2 7.1 . 1 Sat. 76 73 73 76 62 82 74 79 D.O. B 7.4 7.4 7.2 6.8 6.0 6.6 7.1 7.3 l y 1 Sat. 75 74 72 67 56 61 73 73 - j r 11/27 D.O. S 9.3 9.8 9.7 9.9 11.0 11.4 9.9 9.2 I
% Sat. 85 91 89 91 101 105 92 83 D.O. M 9.3 9.7 9.8 9.4 10.2 10.6 9.8
. 9.2 ,
t Sat. 85 89 91 86 91 95 97 83 l D.O. B 9.3 9.6 9.7 8.8 9.7 10.2 9.6 8.6
% Sat. 84 88 89 79 86 91 88 77 12/17 D.O. S 10.6 10.4 10.3 10.1 11.5 11.7 9.3 9.6 t Sat. 91 92 91
- l 87 97 97 79 80
~
D.O. M 10.7 10.1 10.2 10.0 11.5 11.6 9.3 9.6
% Sat. 93 89 90 86 96 97 79 80 D.O. B 10.6 9.9 10.0 9.9 11.6 11.3 9.3 9.6
% Sat. 93 87 88 86 99 95 79 30
O C O o O Table 6.3.1.3 Mean turbidity values (NTU) at surface, mid, and bottom depths for Lake Anna, 1979. j 95% Standard Confidence Intervals Station Depth Mean Error Lower Upper l S S 3.15 0.652 1.68 4.62 : 1 M 3.05 0.466 2.00 4.10 l 1 B 16.50 7.520 0.69 33.49
/
T S 2.54 0.434 1.56 3.52 4 M 2.84 0.565 1.57 4.11 7. g B 13.65 6.610 0.00 28.58 V S 2.37 0.539 1.16 3.58 M 2.77 0.517 1.61 3.93 ., B 20.00 6.250 5.88 34.12 N S 2.80 0.464 1.77 3.83 , M 2.79 0.475 1.74 3.84 B 12.63 4.960 1.62 23.64 .
\
r
O O O O O Mean turbidity values (NTU) at surface, mid, and bottom depths for Lake Anna, 1979. (Cont.) 95% Standard Confidence Intervals Station Depth Mean Error Lower Upper R S 3.38 0.697 1.84 4.92 1 M 3.44 0.685 1.92 4.96 B 5.23 1.200 2.57 7.89 Z S 8.12 3.550 0.00 16.28 M 8.40 3.29U 0.84 15.96 ; fi B 18.93 6.430 4.15 33.71 Y S 7.51 2.430 1.78 13.24 M 8.08 2.200 2.89 13.27 - B 18.33 5.340 5.73 30.93
- M S 4.06 1.390 0.87 7.25
. M 4.01 1.290 1.05 6.97 B 6.90 3.230 0.00 14.32 -
4 I
(:) . i values at the 95% confidence level: Z Y M R S d T V 8.12 7.51 4.06 3.38 3.15 2.80 2.54 2.37 A one way classification ANCVA and Duncan's Multiple Rangs test revealed the following trend for alkalinity values in Lake
. Anna for 1979:
Y Z V R N S T M 16.30 15.60 15.36 15.08 14.66 14.63 14.63 10.40 The mean alkalinity values for surface,mid and bottom depths at station M'were significantly lower at the 95% confid-ence level than the ramaining stations. Even though the Upper I_ Reservoir stations exhibited higher alkalinity values than the remaining stations (Table 6. 3.1. 4 ) statistical evidence indi-cated no significant difference in 1979 as did 1978 data. Mean hardness values are shown in Table 6.3.1.5 for the fish sampling stations by month. A one way classification ANOVA and Duncan's Multiple Range test revealed the following relationship between stations: R T M S V Y N Z 22.16 22.00 21.90 21.63 21.45 21.40 20.33 18.10 The mean hardness values for station Z at surface, mid , and bottom were significantly different than all other stations at the 95% confidence level. This phenomenon has not been ob-served in past studies. (s 6.3.2 Relative Abundance Based on Gill Net Observations Throughout the sampling period between 1973-1979, all fish col-lected utilizing gill nets were counted to facilitate estimation of relative abundance in terms of numbers of individuals (Table 6.3.2.1). Beginning in 1975-1979 composite weights were also taken and expressed in terms of kg/ net day to yield data on bio-mass of fish collected (Table 6. 3. 2. 2) . The gizzard shad, Dorosoma cepedianum, was discovered in Lake Anna in 1974 and as increased in gill net catches from 3.1 and 7.3% up to as much as 68% of the catch per net day (Table 6.3.2.1). This species has been shown to dominate fish collect-ions in both the hot water and control arms in a cooling reser- ! voir and contributed from 34.5-79.1% of the total catch (Witt, Campbell, ana Whitley, 197u). The gizzard shad in Lake Anna has proven to be the dominant fish in terms of numbers, even in * (Table 6. 3. 2.1) . The dis-O years with reduced catch per net daytibution clear trend with the exception of a gradual decline in numbers of the gizzard shad in Lake Anna appe 6-22
O O O n O Table 6'.3.1.4 Hean alkalinity values (mg/l CACO 3 ) by station at : surface, mid, and bottom for Lake Anna, 1979. Confidence Interval . Standard 95% C.I. Station Depth Mean Error Lower Upper S S 14.63 0.464 13.60 15.66 l M 14.72 0.531 13.55 15.90
- B 14.81 0.527 13.65 15.97 T S 14.63 0.883 12.67 16.60
, M 15.00 0.871 13.07 16.93 J
[j B 14.63 0.578 13.35 15.91 V S 15.36 1.060 13.01 17.71 M 14.18 0.441 13.20 15.15 , S 15.36 1.050 13.03 17.70 N S 14.66 0.766 12.98 16.34 M 14.58 0.965.. 12.46 16.70 B 13.25 0.828 11.43 15.07 - e t 1
o c' o 7 o Mean' alkalinity values (mg.1 Ca CO 3
) by station at surface, mid, and bottom for Lake Anna, 1979. (Cont.)
Confidence Interval Standard 95% C.I. Station Depth Mean Error Lower Upper R S 15.08 0.519 13.80 16.22 M 14.25 0.554 13.04 15.46 B 14.16 0.471 13.13 15.19 Z S 15.60 0.997 13.35 17.85 M 15.10 0.940 12.98 17.22 i, y B 17.30 1.550 13.80 20.80 M S 10.40 1.660 6.65 14.15
- M 10.50 1.160 7.88 13.12 ., i B 11.00 1.310 8.04 13.96 Y S 16.30 1.570 12.76 19.84 M 14.60 1.640 10.90 , 18.30 B 19.60 1.530 16.15 23.05 -
1
O c O n O Table 6.3.1.5 Mean hardness values (mg/l EDTA) by station at ' surface, mid, and bottom for Lake Anna, 1979. ' Standard 95% C.I. ' Station Depth Mean Error Lower Upper - S S 21.63 0.620 20.26 23.00 M 19.27 1.430 16.10 22.44 B 21.36 0.633 19.96 22.76 T S 22.00 0.771 20.29 23.71
. M 23.10 1.520 19.73 26.47 8
$ B 22.00 0.727 20.39 23.61 V S 21.45 0.371 20.62 22.27 -
M 21.72 0.60A 20.38 23.06 - B 21.63 0.671 20.14 23.11 Y S 21.40 . 1.160 18.78 24.02 M 20.60 0.404 19.68 21.51 B 24.40 0.929 22.31 26.49 - i 4 e
j cj o c-, o Mean hardness values (mg/l EDTA) by station at surface, mid, and bottom for Lake Anna, 1979. (Cont.) 95% C.I. Station Depth Mean Error Lower Upper N S 20.33 0.461 19.32 21.34 . t M 20.66 0.593 19.36 21.96 i B 21.33 0.638 19.93 22.73 R S 22.16 0.762 20.49 23.83 M 21.00 0.440 20.03 21.96 i gl B 20.83 0.438 19.86 21.79 M S 21.'90 ' O.699 20.33 23.47 M 20.60 0.569 19.32 21.88 . l B 19.40 1.980 14.93 23.87 Z S 18.10 1.840. 13.95 22.25 - M 21.40 0.635 20.12 22.83 B 22.10 0.830 20.23 23.97 - 9
O O O O O Table 6.3.2.1 Catch per net day as expressed in numbers of individuals by species from 1973-1979, for Lake Anna.
% Lower % Upper 1 WHTP Total Reservoir Total Reservoir Total Anguillidae Anguilla rostrata 1973 1974 0.1 0.2 1975 1976 1977 /-. 0.1 0.2 1978 1979 i w Clupeidae w
Dorosoma cepedianum 1973 '
~
1974 3.5 7.3 4.7 7.3 l.1 3.1 . 1975 5.3 13.2 10.7 25.0 13.7 31.2 1976 20.8 38.3 18.5 44.1 14.0 27.2 1977 1978 25.4 6.9 68.0 32.5 13.3 18.5 53.8 54.6 14.7 6.7 42.7 25.0 '! l' 1979 5.8 28.3 5.4 25.5 4.2 14.5 Esocidae . Esox niger
- 1973 8.4 9.8 6.2 8.5 8.4 8.4 1974 7.1 14.8 3.1 4.8 ,
1.0 2.8 I 1975 2.8 7.0 1.6 3.7 1.5 3.4 4 9
O (- O o O
% Lower % Upper %
WitTP Total Reservoir Total Reservoir Total Esox niger 1976 2.3 4.2 1.7 4.0 1.2 2.3 l 1977 1.0 2.6 dL O.1 0.2 0.7 2.0 1978 0.1 0.4 1979 0.2 0.8 0.3 1.5 0.2 0.6' Cyprinidae Cyprinus carpio 1 1973 0.1 0.1 2.4 3.3 8.7 8.7
. 1974 1.0 2.0 1.5 2.3 0.5 1.4
- s. 1975 1.4 3.5 1.4 3.2 1.4 3.2
$ 1976 0.5 0.9 1.3 3.1 1.6 3.1 1977 0.7 1.8 0.8 3.2 1.6 4.7 1978 1.6 7.5 1.9 5.6 0.6 2.2 1979 1.1 5.3 0.8 4.0 1.7 5.7 Notemigonus crysoleucas 1973 40.8 48.0 29.2 40.1 27.2 27.2 1974 1.0 2.0 16.1 25.2 1.1 3.1 1975 0.4 1.0 .e 0.1 40.1 0.4 0.9 1976 0.6 1.1
- 4 0.1 4 0.1 0.6 1.1 1977 0.4 1.0 dL 0.1 0.2 2.1 6.1 ,
1978 40.1 0.2 0.2 . 0.6 1979 Catostomidae Catostomus commersoni 1973 0.2 0.2 1974 1975 0.1 0.2 0.1 0.2
o c, o ~, o
% Lower % Upper %
WilTP Total Reservoir Total Reservoir Total Catostomus commersoni 1976 < 0.1 < 0.1 < 0.1 < 0.1 0.8 0.2 1977 <.0.1 < 0.1 0.5 1.4 1978 <t0.1 0.3 1979 Erimyzon oblongus 1973 9.9 11.6' 5.5 7.5 12.4 12.4 1974 12.8 26.7 12.8 20.8 3.9 11.1 1975 13.2 33.0 5.5 12.8 5.3 12.1 1976 10.3 18.9 4.2 9.9 5.7 11.0 1977 2.1 5.7 1.3 5.0 2.3 6.7 y 1978 0.1 0.4 0.2 0.6 w m 1979 < 0.1 0.4 < 0.1 0.2 Moxostoma macrolepidotum 1973 0.1 0.1 0.1 ~ 0.1 1974 0.1 0.1 0.2 0.5 i 1975 0.1 0.2 0.6 1.3 ; 1976 <C0.1 0.1 1.0 1.8 i 1977 0.1 0.1 0.1 ' O.4 1.2 3.4 ' I 1978 <C O.1 0.1 1.4 5.3 1979
- i Ictaluridae . j Ictalurus natalis 1973 3.8 4.4 1.5 2.0 4.4 4.4
, 1974 2.5 5.2 2.1 3.3 1.5 4.3 l 1975 2.5 6.2 0.4 0.9 1.5 3.4 i 1976 1.7 3.0 0. 2 0.3 12 2.2
O O O n O
% Lower % Upper %
WiiTF Total Reservoir Total Reservoir 'l o tal I. natalis 1977 0.6 1.6 0.7 2.0 1978 < 0.1 0.1 0.3 1.3 1979 <C 0.1 0.4 0.4 1.4 I_ . nebulosus i 1973 12.9 15.1 16.5 22.6 30.1 30.1 1974 14.2 29.6 16.3 25.5 22.8 52.0 1975 8.2 20.5 14.7 34.3 12.2 27.8 m 1976 10.9 20.0 11.2 26.6 15.8 30.6 1 o 1977 3.2 8.5 1.8 7.0 4.6 13.4 g 1978 1.6 7.5 2.4 7.1 2.1 8.1 : 1979 0.3 1.6 1.0 4.7 0.9 3.1 , I. punctatus ... 1973 0.1 0.1 1974 0.2 0.4 0.3 0.4 0.5 1.4 1975 0.4 1.0 0.6 . 1.4 0.8 1.8 1976 0.1 0.2 0.4 1.0 0.9 1.6 1977 0.3 0.8 0.4 1.6 0.6 1.6 1978 1.2 5.4 1.3 3.9 0.4 1.6 1979 2.4 11.9 1.7 8.2 0.6 - 2.0 Centrarchidae Lepomis gibbosus 1973 0.7 0.8 0.2 0.2 0.3 0.3 1974 ' 0.1 0.1 0.1 0.2 1975 O.1 0.2 < 0.1 < 0.1 0.2 0.4
. 1976 < 0.1 0.1 0.3 0.4 4
o o o o o 1 1 l l
% Lower % Upper %
WiiTF Total Reservoir Total Reservoir- Total L. gibbosus 1977 < 0.1 0.1 < 0.1 0.2 < 0.1 0.1 197C < 0.1 0.3 1979 < 0.1 0.4 0.2
- 0.8 < 0.1 0.3 L. gulosus 1973 0.1 0.1 0.1 0.1 1974 0.4 0.8 1975 < 0,1 <. 0 .1 0.2 0.4 i 1976 0.1 0.1 U 1977 0.1 0.4 1978 < 0.1 0.1 0.2 0.6 1979 0.1 -
0.6 <00.1 0.3 L. macrochirus 1973 0.9 1.0 0.7 0.9 0.7 0.7 1974 0.4 0.8 1.5 2.3 0.1 0.2 1975 0.3 0.7 1.3 3.0 0.6 1.3 1976 ' O.7 1.2 0.5 1.0 0.5 0.9 1977 0.3 0.6 0.3 1.2 0.4 1.2 1978 0.5 2.1 0.4 1.2 0.4 1.6 1979 0.3 1.8 1.0 4.5 0.7 2.3 L_ . microlophus 1973 1974 0.1 0.2 < 0.1 < 0.1 1975 < 0.1 < 0.1 0.4 0.9 0.1 0.2 1976 < 0.1 0.1 < 0.1 0.1 < 0.1 < 0.1 1977 0.1 0.2 <00.1 0.1
O O O O O
% Lower % Upper %
WitTP Total Reservoir Total Reservoir Total L. microlophus 1978 0.2 0.7 1979 < 0.1 0.2 Micropterus salmoides 1973 6.9 8.1 6.6 9.0 1.5 1.5 1974 3.4 7.0 1.9 2.9 0.4 1.1
, 1975 3.1 7.7 1.9 4.4 1.0 2.2 j 1976 4.1 7.6 1.1. 26.0 0.8 1.5 i
.i 1977 1.7 4.5 1.1 4.4 0.8 2.1 j y 1978 4.9 23.3 1.2 3.7 0.6 2.2 i 1979 3.4 16.8 1.0 4.5 0.6 2.0 Pomoxis nigromaculatus 1973 0.7 0.8 '2.8 3.8 '.5 4
~
4.5 1974 1.5 3.1 2.7 4.2 1.8 5.1 1975 2.0 5.0 3.1 7.2 4.4 10.0 l 1976 1.3 2.3 1.5 3.5 6.1 11.7 . 1977 0.7 1.8 20 7.8 3.2 9.2 1978
- 2.2 10.2 2.5 7.2 11.3 42.5 1979 1.8 8.7 1.3 5.9 8.9 30.4 l
Fcrcidae Perca flavescens 1973 0.1 0.1 0.3 0.4 0.4 0.4 . 1974 0.1 0.2 0.5 0.7 0.2 0.5 , t 1975 0.5 1.2 1.0 2.3 0.1 0.2 l
O C O '"' O
% Lower % Upper %
WitTF Total Reservoir Total Reservoir Total Perca flavescens 1976 0.6 1.1 0.7 1.7 0.6 1.8 1977 0.4 1.0 2.0 8.0 0.3 0.9 1978 0.5 2.5 1.5 4,5 0.3 1.3 1979 0.2 0.8 1.3 5.9 0.4 1.6 Stizostedium g trem 1973 1974 i 1975 h 1976 1977 0.3 0.8 1.1 4.4 0.3 0.9 1978 0.1 0.5 0.3 1.0
- 1979 0.2 0.8
~
Percichthyidae Morone americana 1973 1974 ., 1975 1976 < 0.1 . 0.1 - 1 1977 0.3 1.2 <;0.1 0.1 , 1978 1.8 8.4 3.5 10.4. 1.8 6.6 l 1979 4.1 20.1 6.6 30.9 10.6 36.1 M. saxatilis 1973 1974 1975
< 0.1 < 0.1 0
o c o o l
% Lower % Upper %
WiiTP Total Reservoir Total Reservoir Total M. saxatilis i 1976 0.1 0.1 0.3 0.7 1977 0.1 0.3 0.1 0.3 ,. 1978 0.1 0.5 0.S 1.6 F 1979 0.7 3.3 , 0. 3 1.8 i I m . I La b 9 6 9 4
O C O O O 4
*1'able 6. 3. 2. 2 Catch per net day as expressed by weight (kg) of individuals by species for 1975-1979 for Lake Anna.
% Lower % Upper %
WHTF Total Reservoir Total Reservoir Total Anguillidae Anguilla rostrata , 1977 < 0.1 : Clupeidae Dorosoma cepedianum iw 1975 1.6 10.8 2.3 18.5 2.3 19.3 1976 3.8 23.8 2.3 18.4 2.8 16.5 ; 1977 1.8 22.2 1.1 16.1 1.2 10.1 1978 0.5 5.6 1.3 15.1 0.5 8.9
- 1979 0.5 6.3 0.4 6.4 0.4 5.6 Esocidae ;
Esox niger 1975 1.6 10.8 0.9 i.4 0.9 7.7 1976 1.3 8.1 1.4 . t .1 1.0 6.1 1977 0.8 9.9 0.1- L. 3 0.9 1.7 1978 0.1 1.1 1979 0.1 0.7 0.3 4.0 0.2 2.2 Cyprinidae Cyprinus carpio 4 1975 3.4 23.0 2.9 23.3 3.0 25.2 1976 1.3 8.0 3.1 24.8 3. 9 _ 23.0
O C O D O
% Lower % Upper %
WHTF Total Reservoir Total Reservoir Total
'Cyprinus carpio , . 1977 1.8 22.4 1.9 28.1 3.5 30.5 1978 4.2 45.8 2.1 24.4 1.4 26.3 1979 3.0 36.2 2.3 35.7 4.1 60.0 1
Notemigonus crysoleucas
' ~
1975 < 0.1 0.1 0.1 0.1 0.1 0.1 197. 0.1 0.4 0.1 0.1 0.1 0.2
.- 1977 <. 0.1 0.5 0.1 0.2 0.2 1.4 I
6- 1978 0.1 0.1 0.1 0.3 m 1979
- Catastomidae I Catostomus commersoni i 1975 0.1 0.4 0.6 4.7 1976 <C 0.1 0.2 0.1 0.2 0.7 4.1 '
1977 0.1 0.8 0.5 3.9 : 1978 0.1 1.7 '! 1979 Erimyzon oblongus l l 1975 4.1 27.8 2.4 19.3 2.0 16.8 > 1976 3.9 24.3 2.3 18.1 2.5 15.0 , 1977 1.0 12.7 0.7 11.1 1,3 11.6 l 1978 0.1 0.8 0.2 1.4 l 1979 < 0.1 0.5 0.1 0.1 i
O O O O O . i
% Lower % Upper %
WilTF Total Reservoir Total Reservoir Total , Ictaluridae
,Ictalurus natalis 1975 0.7 4.8 0.1 0.9~ 0.2 1.3 1976 0.7 4.3 0.1 0.5 0.4 2.6 1977 0.2 2.4 0.2 1.6 1978 0.1 0.1 0.1 1.1 1979 0.1 0.1 0.2 2.2 I. nebulosus ,
$ (
l i 1975 0.9 6.2 1.4 11.3 1.2 10.1 , d 1976 1.0 6.5 1.3 10.2
~
1.5' 8.9
- 1977 0.4 4.4 0.2 3.2 0.5 4.6 1978 0.1 1.4 0.5 5.9 0.4 6.8
1979 <00.1 0.4 0.1 1.7 0.5 7.5
~
i
-I. punctatus t
1975 0.3 2.2 0.3 2.7 . 0.9 7.8 1976 0.2 1.0 0.4 2.8 1.4 8.5 ? 1977 0.5 6.4 0.6 8.4 0.9 7.8 4 1978 1.7 13.3 2.0 23.2 0.4 8.7 i
- 1979 0.5 5.5 1.4 21.6 J.6 9.1 I i . -
Centrarchidae Lepomis gibbosus 1975 < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 0.1 1976 < 0.1 <~0.1 0.1 0.4 4 1
O O O O O l
% Lower % upper %
WilTF Total Reservoir Total Reservoir Total Lepomis gibbosus 1977 < 0.1 0.1 < 0.1 0.2 < 0.1 0.1 1976 <;0.1 0.1 197') < 0.1 0.1 < 0.1 0.3 < 0.1 < 0.1 L_ . gulosus 1975 < 0.1 < 0.1 < 0.1 0.1 1976 < 0.1 < 0.1 . m 1977 < 0.1 0.2 ', 1 1978 < 0.1 0.1 < 0.1 0.5 m 1979 < 0.1 0.1 < 0.1 < 0.1 L_ . macrochirus . 1975 < 0.1 0.1 0.2 1.5 < 0:1 0.2 1976 < 0.1 0.3 < 0.1 0.2 < 0.1 0.1 1977 < 0.1 0.3 < 0.1 0.3 0.1 0.4 1978 < 0.1 0.3 < 0.1 0.3 < 0.1 0.3 , 1979 < 0.1 0.2 0.1 1.0 < 0.1 0.2
-L. microlophus t
1975 < 0.1 < 0.1 < 0.1 0.2 < 0.1 ' < 0 .1 ' 1976 <.0.1 0.1 <.0.1 0.1 <. 0 . 1 < 0.1 ' 1977 < 0.1 0.2 < 0.1 < 0.1 1978 <00.1 0.2 , 1979 <.0.1 0.3 i
.i
.t
O c. o 7 0 I
% Lower % Upper &
WHTF Total Reservoir Total Reservoir Total Micropterus salmoides 1975 1.8 12.2 1.3 10.5 0.4 3.7 1976 3.4 21.4 0.9 7.4 1.1 6.3 1977 0.9 11.2 0.8 12.0 0.5 4.7 1978 1.0 11.3. 0.8 9.3 0.2 4.2 1979 1.3 16.0 0.6 w.5 0.1 1.5 Pomoxis nigromaculatis I. 1975 0.2 1.6 0.3 2.6 0.2 2.0 !
- i. 1976 0.2 1.3 0.2 1.5 0.4 2.4 g 1977 0.1 1.5 0.2 3.2 0.2 1.8 .
1978 1.0 10.4 0.2 2.4 0.6 11.0 1979 0.1 0.6 0.1 1.3 0.4 5.8 Percidae .- Perca flavescens j
?
1975 0.1 0.3 0.2 1.2 < 0.1 < 0.1 ; 1976 <. 0 .1 0.2 0.1 0.7 0.1 0.8 : 1977 0.1 0.9 0.1 0.9 . 0.1 0.4 1978 < 0.1 0.3 0.1 1.4 < 0.1 0.2 1979 < 0.1 < 0.1 0.1 1.1 < 0.1
- 0.1 Stizostediun vitrem 1975 1976 ,
1977 0.2 2.0 0.8 12.2 0.2 2.1 e
l i O c o o O i
% Lower % Upper %
WiiTP Total Reservoir Total Reservoir Total Stizostediun vitrem t . 1978 0.1 1.3 0.4 4.5 1979 0.2 2.4 Percichthyidae Morone americana e 4 1975 ! m 1976 < 0.1 0.1 l J. 1977 0.1 0.9 < 0.1 0.1 o 1978 0.2 1.8 0.3 2.9 0.1 2.1 1979 0.2 2.6 0.5 7.4 0.6 8.2 , i M_ . saxatilis 1975 1976 < 0.1 0.3 0.3 2.2 1977 <;0.1 0.1 0.1 0.6 1978 0.3 3.7 0.6 7.5 1979 2.6 30.8 0.3 4.4 -
F . . . . .. -. . . - - - - - . . . l (2) and kg/ net day noted form 1978-1979 (Table 6. 3. 2.1 and 6. 3. 2. 2) . The chain pickerel, Esox niger, has' suffered a general de-cline in numbers and biomass in gill net catches throughout the study (Table 6. 3. 2.1 and 6. 3. 2. 2) . This decline can be related to the fact that aquatic vegetation along the shore and in low areas is restricted and this species depends on aquatic vegeta-tion and low lying swampy areas for reproduction (Mansueti and Hardy, 1967). The carp, Cyprinus carpio, has displayed an overall uni-form increase in percentage of total catch per net day as well as kg per net day (Table 6.3.2.1 and 6.3.2.2) in the WHTF as well as the Reservoir stations. This species typically has comprised from 23% to as much as 60% of the total biomass of (. fish caught per net day (Table 6. 3. 2. 2) . Erimyzon oblongus, the creekchub sucker, has shown a natural decrease in numbers and biomass over the years as the reservoir aged (Table 6.3.2.1). This species is typically associated with rivers and streams and was expected to display a decline in population. The shorthead redhorse, Moxostoma (]) macrolepidatum, however, increased in numbers and bicmass in the Upper Reservoir during 1979 (Table 6. 3. 2.1 and 6. 3. 2. 2) . " Ictalurus natalis and I. nebulosus, of the family Icaluri-dae, displayed a decrease in cacch per unit effort throughout 1979 (Table 6. 3. 2.1) . The channel catfish, I. punctatus, how-ever, has shown a marked increase in catch per unit effort in the WHTF and Lower Reservoir, especially at stations just be-I ~ yond the outfall of the WHTF. It has been demonstrated that ( L-channel catfish have unusually good reproduction in a reser-voir receiving heated effluent due to the increased temperature and artificial current produced in the cooling lake (Larimore and Tranquilli, 1977). Gammon (1973) reported that flathead catfish and perhaps channel catfish increased reproduction and density in thermally affected areas of the Wabash River and it appears that, at this point, channel catfish have increased in number and biomass in the area affected by heated effluent and artificial currents in Lake Anna. l The sunfish family, Centrarchidae, generally was . not caught in great numbers with gill nets because they typically occupy littoral areas that were inaccessable to gill netting. The largemouth bass, Micrepterus salmoides, and the black crappie, Pomoxis nigromaculatus, however, were well represented in the gill not catches (Table 6.3.2.1). The largemouth bass displayed a marked increase in numbers and biomass in the WHTF ({) (hotwater stations). Neill and Magnuson (1972) reported th:tt bluegill, pumpkinseed and largemouth bass were 14gnificantly higher in terms of catch per unit effort (c/f) in heated areas 6-41
- - . . --. _ . .- =
i I (2) than reference areas. Three times as many bass were reported taken in a hotwater arm than in a control arm in a heated effluent study (Witt, Campbell and Whitley, 1970)'.and Lake Anna appears to be following a similar pattern. - The black crappie, Pomoxis nigromaculatus, displayed a slight decrease in the heated areas and the Upper Reservoir stations in c/f, but the decrease in kg/ net day was much.less in 1979 than previous years (Table 6. 3. 2.1 and 6. 3. 2. 2) . Black crappie have been shown to avoid areas affected by heated effluent (Ruelle, Lorenzen and Oliver, 1977), but no clear trend for this species can be determined at this point in time for Lake Anna. The yellow perch, Perca flavescens, generally displayed erratic results and, therefore, no trend can be established. {- The white perch, Morone americana, demonstrated a marked increase in catch per net day in all study areas of Lake Anna (Table 6. 3. 2.1) . The striped bass, M. saxatilis, showed an in-crease in c/f in the WHTF, perhaps due to attraction of the artificial current. (:) - In terms of total catch per net day the WHTF displayed the lowest value during 1975 for numbers of individuals caught per net day, but the kg/ net day was higher in the WHTF than the other two areas (Table 6.3.2.3 and 6.3.2.4). 6.3.3 Cove Rotenone Studies Results from cove rotenone samples are given in Table 6.3.3.1. Included in this table are the mean standing crop estimates by species and area for the years 1975 _ through 1979. A total of 26 coves were sampled throughout this (, period and all values have been converted to kg/hectre for pur-poses of comparison. Clupeids were the most frequently impinged fish at southern power plants and made up 40-55% of the biomass in cove rotenone samples (Jenkins, 1977). If power plant induced mortalities have in fact affected fish populations in the receiving water, it should be first detected by changes in the Clupeid standing crop (Jenkins, 1977). In Lake Anna, no significant changes between years were found to exist throughout the study period although there appeared to be a decline in mean standing crop (Table 6. 3. 3.1) . This population decline was also demonstrated in the relative abundance data (Table 6. 3. 2.1 and 6. 3. 2. 2) . In a heated effluent study in South Carolina it was reported that the threadfin shad, Dorosoma getenense, population re-mained constant (Ruelle, Lorenzen and Oliver, 1977), whereas () in Lake Sangchris, Illinois the gizzard shad population stand-1.1g crop continued to increase (Larimore, 1975). In Lake Anna i the shad population appears to be relatively constant statisti-cally. 6_42
- ' ~ -
-+r 4 -m--- - ,,,
O O O n O Table 6.3.2.3 Total catch per net day expressed as numbers of individuals for Lake Anna, 1973-1979. Region 9 Lower Upper Year WiiTF Reservoi- Reservoir 1973 85.09 72.86 100.00 1974 47.90 63.72 34.93 1975 40.00 42.82 43.88 1976 54.24 41.93 51.43 g 1977 37.38 24.70 34.44 1978 21.00 33.95 26.67 , 1979 20.34 21.25 29.28 .- , 4 9 e l . I e 5 4 i
O O O O O I i Table 6.3.2.4 Total catch per net day expressed as weight (kg) for Lake Anna, 1975 - 1979. l Region Lower Upper Year WHTF Reservoir
- Reservoir i 1975 14.75 14.72 11.90 . ;
i 1976 15.90 12.50 16.90 i 1977 7.96 6.57 11.43 {
^
1978 9.16 8.50 5.12 1979 8.35 6.33 6.73 e e e
,i h
I
O O O n o i Table 6.3.3.1 Fish standing crop estimates based upon cose rotenone samples by species j from Lake Anna (mean kg/ hectare), 1975 - 1979. ; i WitTF Lower Reservoir Upper Reservoir ; I
. Moody Millpond Dam Mid NAR Pamunkey Mean !
Creek Creek Cove Lake Arm Creek Anguillidae ; i Anguilla rostrata , 1975 0.90 0.45 1976 0.19 2.06 0.37 *0.25 0.52 ,. 1977 0.75 0.23 il 1978 0.20 0.68 0.15 i 1979 0.01 1.18 0.19 a Clupeidae 1 Dorosoma cepedianum 1975 190.90 146.10 168.50 1976 144.48 56.60 40.54 138.54 *153.83 114.64 1977 52.93 78.32 134.71 103.24 159.56 182.87 118.60 1978 39.63 144.57 44.16 80.21 247.95 71.00 104.59 - 1979 42.64 41.96 55.25 86.82 137.06 157.32 86.84 Esocidae Esox niger 1975 2.90 2.30 2.60 1976 1.17 2.90 0.10 1.82 *1.69 1.54 ! 1977 1.71 0.22 0.23 1.04 0.67 0.00 0.64 1978 0.94 7.59 2.04 0.05 0.08 0.00 1.78 1979 1.75 1.86 0.41 3.47 2.01 0.54 1.67
O C O O O WilTF Lower Reservoir Upper Reservoir Moody Millpond Dam Mid NAR Pamunkey Mean Creek Creek Cove Lake Arm Creek E. lucius 1976 2.72 0.90 Cyprinidae ' f
.l Cyprinus carpio j
l 1
1975 1.70 0.00 0.85 1976 37.64 0.00 13.45 3.67 *7.84 12.52 1977 0.00 0.00 0.00 13.26 0.00 94.42 17.94 1978 35.43 13.83 0.00 24.97 13.52 87.85 29.27 1979 19.41 4.32 0.00 27.67 0.00 ,22 13 12.25 - Notemigonus crysoleucas # 1975 0.50 0.25 t 1976 2.92 2.45 '0.39 *l.60 1.49 : 1977 1.21 1.23 1.21 0.46 0.86 0.85 1978 1.28 2.25 0.77 1.41 1.86 0.54 1.35 1979 2.73 0.69 0.30 1.58 0.48 1.05 . 1.13 Notropis analostanus ; 1977 0.03 0.12 0.02 1978 0.01 0.12 0.05 - e
O r O ' O WitTF Lower Reservoir Upper Reservoir T Moody Millpond Dam Mid NAR. Pamunkey Mean Creek Creek Cove Lake Arm Creek i N. procne 1977 0.02 0.05 0.01 j 1978 0.01 0.01 0.01 1 1979 0.01 0.01 Catostomidae '? i 4; Catostomus commersoni ' i 1977 8.55 1.43 , 1978 2.53 19.04 3.60 j 1979 2.00 0.33 'j i Erimyzon oblongus ' 1975 . 23.90 17 10 20.50 1976 3.07 0.32 3.35 12.37 *3.18 5.66 g 1977 1.15 1.43 0.74 1.08 0.02 3.10 1.25 . 1978 0.37 1.12 3.21 0.93 0.39 1.33 1.23 1979 0.00 0.06 0.12 0.00 0.80 2.90 - 0.64 Moxostoma macrolepidotum 1975 4.10 2.05 ' 1976 1977 l 1 1.68 8.69 1.73 , 1978 4.51 0.75 1979 ! 2.18 3.30 0.91 .
. ?
6' i
I l o o o n o l WHTF Lower Reservoir Upper Reservoir Moody Millpond Dam Mid NAR Pamunkey Mean Creek Creek Cove Lake Arm Creek Aphredoderidae Aphredoderus sayanus 1975 0.01 0.01 0.01 0.01 1976 1977 0.01 m Ictaluridae
!l a " Ictalurus natalis 1975 0.80 1.30 1.05 1976 6.57 2.65 1.87 4.33 *4.38 ... 3.96 1977 7.36 2.08 0.77 0.45 0.25 1.58 2.08 1978 3.93 1.77 0.39 0.54 1.56 0.95 1.52 1979 2.42 2.11 0.31 0.30 1.62 2.17 1.48 t
I. nebulosus j i 1975 6.40 0.60 3.50 ; 1976 35.02 0.41 17.45 0.53 *6.09 - 11.90 1977 0.10 0.60 0.41 0.90 1.71 5.90 1.60 1978 0.91 1.87 0.07 11.60 0.60 4.25 3.22 1979 3.86 14.94 0.66 4.13 0.22 2.40 4.37
O n O 7 O l1 l ' i WilTP Lower Reservoir Upper Reservoir Moody Millpond Dam Mid NAR Pamunkey Mean Creek Creek Cove Lake Arm Creek I. punctatus 1975 2.60 0.80 1.70 1976 2.09 0.00 6.57 7.63 *1.01 3.46 1977 0.00 0.00 0.57 10.83 1.73 10.25 3.89 1978 0.03 0.02 0.00 9.55 2.76 1.06 2.24 1979 3.90 0.76 0.80 10.61 2.28 12.48 5.13 m Noturus insignis t $ 1976 0.01 0.01 1979 0.01 0.01 Centrarchidae .- l Acantharchus pomotis 1975 0.10 0.05 1976 0.02 0.01 1977 . 0.02 1.80 0.30 : 1978 0.03 0.04 0.01 't 1979 - 0.00 l Enneacanthus gloriosus 1976 0.01 0.01 i 1977 0.01 0.01 0.01 1979 0.02 0.01 , i w
O O O O O : i WIITF Lower Reservoir Upper Reservoir Moody Millpond Dam Mid NAR Pamunkey Mean Creek Creek Cove Lake Arm Creek Lepomi_s auritus 1975 0.07 0.60 0.34 1976 1.24 0.62 *0.75 0.52 1977 0.49 0.76 3.88 1.69 0.48 1.21 1979 0.56 0.76 0.94 0.38 1979 0.17 1.37 2.91 0.90 0.90 1.04 m L. gibbosus in m o 1975 5.00 6.30 5.65 : 1976 14.76 6.94 3.60 5.24 *25.87 11.28 1977 17.75 14.35 4.70 5.96 21.77 27.11 15.27 1978 4.68 10.67 3.96 4.93 12.80 10.02 9.51 1979 4.07 5.42 2.26 3.95 11.22 19.41 7.72 ] , L. gulosus 1975 0.50 0.80 0.65 1976 0.63 0.14 1.98 3.20 *2.75 1.74 L 1977 3.03 3.43 0.99 2.92 1.67 3.36 2.57 1978 2.76 7.37 0.59 1.53 3.11 1.96 - 2.89 1979 4.82 5.55 0.91 1.78 4.16 5.17 3.73 L. macrochirus 1975 28.10 33.40 30.75 1976 80.07 29.14 36.42 78.82 *79.79 60.85 1977 148.41 117.97 22.12 41.62 66.34 196.08 98.75 1978 57.21 71.17 28.89 24.65 68.68 135.49 64.35 1979 68.84 65.58 17.03 32.56 50.71 133.54 61.37
O c O o O WitTF Lower Reservoir Upper Reservoir Moody Millpond Dam Mid NAR Pamunkey Mean Creek Creek Cove Lake Arm Creek L. microlophus 1975 0.20 0.30 0.25 l 1976 0.01 0.55 1.00 0.12 *0.04 0.03 1977 5.55 0.36 0.60 0.18 1.98 1.44 1978 0.50 0.80 0.04 1.94' O.40 0.56 0.71 , 1979 0.39 2.72 0.41 1.07 0.54 0.85 i Micropterus salmoides
? -
1975 3.00 4.30 3.65 1976 7.13 4.70 2.18 5.18 *6.85 5.21 1977 5.97 14.12 2.60 3.32 5.97 9.16 6.85 1978 5.46 4.94 2 . 7.3 9.45 9.07 . 7 59 6.44 1979 7.12 10.75 0.25 4.43 5.00 13.84 6.89 , Pomoxis nigromaculatus l 1975 7.50 6.00 6.75 i 1976 35.45 12..]2 73.14 26.78 *29.1.1 35.36 l 1977 23.23 13.37 3.67 59.57 1.36 20.07 19.88 l 1978 8.37 4.25 0.12 5.81 2.83 6.20 4.60 1979 'j l 50.53 5.27 0.13 4.65 1.50 7.91 11.66 , I l Jorcidae 1 i Perca flavescens i j 1975 3.80 2.50 3.15 i 1976 5.12 2.70 14.48 20.62 *18.84 11.64 12.35 ( I l
i i O C O 3 O I l l l I WHTF Lower Reservoir Upper Reservoir ! Moody Millpond Dam Mid NAR Pamunkey Mean l Creek Creek Cove Lake Arm Creek . l P. flavescens , 1977 5.16 23.27 19.72 17.94 13.83 11.64 15.26 1978 3.11 3.59 3.86 18.42 9.30 12.75 8.51 1979 6.66 4.55 1.44 15.71 6.43 18.02 8.80 Stizostedian vitreum m 1975 1.90 0.95
$ 1976 0.14 3.64 *0.74 0.88 .N Etheostoma olmstedi 1977 0.04 .,. 0.01 1978 0.01 0.01 0.01 0.01 1979 0.01 0.03 0.01 0.01 Parciphthyidae Morone americana .
1976 0.47 *0.02 - 0.09 :- 1977 0.01 0.03 0.46 0.17 1.54 0.37 ! 1978 0.01 0.02 3.05 0.48 4.17 1.29 0 1979 0.75 0.01 7.73 0.79 7.10 2.73 M_ . saxatilis ' 1976 0.10 0.02 1977 a
O 0 c O 3 WitTF Lower Reservoir Upper Reservoir Moody Millpond Dam Mid NAR Pamunkey Mean Creek Creek Cove Lake Arm Creek M. saxatilis 1978 0.03' O.01 1979 0.08 0.01 0.01 Total Specles
.1975 '
279.97 227.60 253.90 I T' 1976 373.41 124.35 220.80 313.61 *353.36 277.10 un 1977 272.87 271.60 191.90 269.58 279.05 587.63 311.91 9 1978 164.84 275.84 93.41 199.74 376.19 380.25 248.43 1979 219.89 166.70 81.73 210.65 227.36 412.72 219.41
- Mean for two coves sampled on the North Anna River arm during 1976. ,,,
O l e
;__..._~
O The gizzard shad in Lake Anna comprised from 38-66% of the total mean standing crop in 1979.and was found to be the most important fish in the lake in terms;of standing crop. Differences between stations were observed at the 95% confidence level for standing crop values. A Duncan's Multiple Range test revealed the following relationships: NAR Pamunkey Mid Millpond Moody Dam Arm Creek Reservoir Creek Creek Cove 171.91 137.48 119.94 80.36 69.92 68.66 l The Upper Reservoir generally produced higher gizzard ! shad standing crop values with the WHTF and Dam Cove producing the lowest standing crop values for this species. The family Esocidae, represented by the single species Esox niger was found to have significantly different standing crop values between years. A Duncan's Multiple Range test revealed the following relationship: 1975 1978 1979 1976 1977 O The years 1978 and 1979 are grouped with the highest year, 1975, which demonstrates an increase in standing crop for this species. l The carp, Cyprinus carpio, increased in biomass throughout the study from 4.2% up to 11.77% of the total standing crop of fish taken from Lake Anna. In similar studies the carp accounted k_ for 34-46% of the standing crop of fish (Goldstein, 1976; Witt, Campbell and Whitley, 1970). The population of carp in Lake Anna has not reached these proportions, but it has been reported the the spawning of carp in Lake Sangchris was initiated two weeks earlier in heated areas than in ambient areas (Larimore, 1975) which could produce a positive effect on the standing crop of this , species in the WHTF in the future. In addition, carp appear to l exhibit a distinct preference for the warmest zones (Gammon , 1973; j Neil and Magnuson,0 1972) and have been found in senmer tempera-turas exceeding 33 C in an effluent canal discharging into the White River, Indiana (Proffitt, 1969). In one study, however, carp were picked up less in heated areas than in c'ontrol areas (Witt, Campbell and Whitley, 1970). In Lake Anna, carp standing crop values were significantly higher in the Pamunkey Creek arm than in the WHTF heated areas. The sucker family, Catostomidae, was well represen~ted in (]) the Upper Reservoir with higher standing crop values and more sucher species than other locations sampled (Table 6. 3. 3.1) . Even 6-54 .
{_ 1 I (~3 l kJ l l th'ough Erimyzon oblongus was collected a,t more stations than other suckers, this species remains on a. steady decline. This is not unusual since this fish is typically a river form and would be expected to decline in a lentic situation due to the lack of proper habitat. An analysis of variance proved signif-icant between years and a Duncan's Multiple Range Test demon-strated that the years 1975 and 1976 were significantly higher than the later years 1977-1979. It has been documented that the family Ictaluridae (cat-fishes) are highly tolerant of heated discharges associated with power plant operations (Dryer and Benson, 1957; Marcy, 1976; Gammon, 1973) and channel catfish have shown exceptional
~
reproduction in a power plant study at Lake Sangchris, Illinois (Larimore and Tranquilli, 1977). Brown bullheads in the Con-necticut River moved into the heated effluent discharge canal of the Connecticut Yankee Atomic Power Co.'s Haddam Neck Plant in large numbers and comprised 67% of the total catch and 68% of the total catch in the winter (Marry, 1976). The optimum temperatures for channel catfish, Ictalurus punctatus, in the Wabash River were reported to lie in the range between 30-320C (Gamman , 1973) and the temperature tolerance for brown bullheads was reported to be 330C, in addition, this species will enter 400C water for food (Marcy, 1976). The three species of cat-fish in Lake Anna, which include the yellow bullhead, Icalurus natalis, the brown bullhead, I. nebulosus and the channel cat-fish, I. punctatus, have dispTayed a marked increase in stand-ing crop in the WHTF during the first operational years of 1978-1979 (Table 6. 3. 3.1) . The channel catfish in particular has steadily increased in standing crop over the past two years in the WHTF, but Pamunkey Creek and the Mid-Reservoir stations (,j remained significantly higher than all other stations for this species. The sunfishes (Centrarchidae) in general have displayed higher densities or catch rates in areas affected by heated effluents from power plants than in control areas (Witt, Camphell and Whitley, 1970; Neill and Magnuson, 1972). Black crappie young of the year have been shown to be inversely re- ) lated to power plant generation, especially in the hot water areas whereas other sunfish ycung of the year were uniformly distributed between hot and cold water stations (Ruelle, Lorenzen and Oliver, 1977). Although sunfish appear to tol-erate and even be attracted to areas affected by heated efflu-ent elevated temperatures have been shown to adversely affect bluegill eggs (Banner and Van Arman, 1973) which could affect the standing crop of this species in the WHTF in subsequent years. (]) 6-55
O - The pumpkinseed, Lepomis gibbosus, has been cited as one of the more tolerent of the sunfish species to thermal effluent l and has been collected in water up to 400C (Marcy , 197 6 ) . In ' Lake Anna, however, the pumpkinseed appear to inhabit the teio upper arms of the reservoir more extensively than the WuTY as indicated by the standing crop values throughout the study period (Table 6.3. 3.1) . An analysis of variance and Duncan's Multiple Range test revealed the following relationship for standing crop of this species at the 95% confidence level. , Pamunkey NAR Moody Millpond Mid Dam l Creek Arm Creek . Creek Reservoir Cove 1 0 Bluegills comprised from 12% up to 31.6% of the standing crop in Lake Anna from 1975-1979 with a mean of 23.88%. In a similar rotenone study performed on a lake receiving heated effluent bluegills only comprised 8.6% of the total standing crop (Witt, Campbell and Whitley, 1970). The Upper Reservoir contains the highest standing crop of bluegills with Pamunkey Creek significantly higher than all other stations. An ANOVA s/ an'd Duncan's Multiple Range test revealed the following relat-ionship for data form 1975-1979. Pamunkey Moody NAR Millpond Mid Dam Creek Creek Arm Creek Reservoir Cove 155.03 88.63 56.78 57.47 41.15 26.12 The black crappie, Pomoxis nigromaculatus, showed no sign-({ ificant differences in standing crop between years or stations. Yellow perch, Perca flavescens, generally have displayed less abundance in thermally affected areas than do most other species found in southern reservoirs (Ruelle, Lorenzen and Oliver, 1977) and also this species was shown to be less abund-ant in Lake Monona, Wisconsin near thermal outfall areas (Neill and Magnuson, 1972). In Lake Anna the yellow perch displays a high standing crop value at the mid-t-aservoir station, but no significant differences exist between stations or years. The white perch, Morone americana, has exh,1bited an in-crease in standing crop during 1979 (Table 6.3.3.1). In terms of total standing crop no significant differences occurred between years for Lake Anna, but an ANOVA and.a Duncan's Multiple Range test revealed the following relation by station ( at the 95% confidence level. 6-56 .
1 l O Pamunkey NAR Moody Mid Millpond Dam Creek Arm Creek Reservo}r Creek Cove 460.20 292.71 257.75 254.71 209.62 146.96 Pamunkey Creek station was shown to be significantly higher than the ramainder of the stations which has historically been the case. Since only one reactor unit was operational and because its on-line time was sporatic, creating no constanct effects, no overall statistical change in total standing crop occurred during 1979. However, some changes at the species level have been observed, notably that the catfishes and the largemouth p1 bass increased in the WHTF. Other species remained constant
\ and yet others declined such as the gizzard shad. The changes observed at the species level could ultimately prove to be the most important in predicting the overall impact of heated efflu-ent on the fishes of Lake Anna.
6.3.4 Gonosomatic Index of the Female, Micropterus salmoides. The mean gonosomatic index (gonad weight / body weighr) was ob-O served throughout the spawning season for the female largemouth bass (Figures 6. 3. 4.1 and 6. 3. 4. 2) . Historically the female bass have reached a peak of gonad development in the Reservoir and WHTF from mid to late April. During 1979, female bass at the Mid-Reservoir electrofishing station displayed a peak of gonad development in the third week of April, but female bass observed in the WHTF reached their peak gonad development dur-ing the last week of March (Figure 6.3.4.2). In addition, female bass were observed " squeeze ripe" in the WHTF on April s- 9 whereas they were not observed in spawning condition (squeeze ripe) at the Mid-Lake station until April 26, 1979. This diff-erence in spawning time between the Reservoir and the WHTF app-ears to be due to the operation of the reactor unit. The WHTF remained ice free during the winter and warmed much faster than the Reservoir (Figure 6.3.1.3), which was ice covered during the winter. Apparently this was enough to affect a difference in spawning times between these two study areas. This pheno-menon has been noted in past thermal effluent studies (Witt, Campb211 and Whitley, 1970; Larimore, 1975; Bennett and Gibbons, , 1975). l l 6,3.5 Fecundity - Micropterus salmoides Fecundity equations generated by the least squares regression method for fecundity vs. length and fecundity vs weight for 1976-1979 are as follows: () Fecundity vs. Length 1976 WHTF F = (0.000013) L 3.62 R 2 =9.738 y 6-57 ,
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(6) 6 -- -- (2) (4) p in GSI% __ so < 6 (1) 4 __ l-I 2 __ i i I I I I I e a a I , 5 5 5 5 I I I I s I 3/22 3/29 4/5 4/12 4/19 4/26 5/3 5/10 5/17 5/24 i FIGURE 6.3.4.2. Gonosomatic Index (GSIt)of female largemouth bass Lake Anna 1979 WHTF (sample size in parentheses) March - May 1979 , e
(:) . 1 2 2 1977 WHTF F = (0.0257) L .327 R =0.766 1 197 8 WWJF F = (35.08) L l '.0 6 R2=0.368 I 1 1979 WHTF F = (0.04i6) L .103 2 g 230.456 I 5.55 ) 1979 Mid-Reservoir F = (3.28 x 10-11) L R 2 =0.747 Fecundity vs. Weight 1976 WHTF F = (24.6) W1 .09 g 2=0.795 - 2 1977 WHTF F = (1399.58) WO .4438 R =0,.749 ! r- , 1978 WHTF F = (1640.589) WO .354 R 2 =0.493 2 1979 WHTF F = (68.7) WO .728 R =0.710 2 1979 Mid-Reservoir F = (0.0602) W1 .698 R =0.792 The equation for fecundity vs. weight generated the best correlation coefficients, so these data are presented in O Figure 6.3.5.1. There appears to be a steady decline observed in fecundity from 1976-1979 in the WHTF. The years 1978 and 1979 show a leveling off in egg number, although 1979 values are somewhat lower. The Mid-Reservoir station during 1979 displayed high predictivs values for fecundity w%en compared to the WHTF. 6.3.6 Egg Size - Micropterus salmoides Mature and maturing egg size of the largemouth bass Micropterus salmoides, was ( averaged and presented by date to observe the evolution of the bass egg from its initial development stages until the closing weeks of the spawning season Tables 6.3.6.1 and 6.3.6.2. Female largemouth bass in the WHTF reached a peak egg size in the last week of March and retained a relatively large egg size until the first week of May, whereas female bass in the Mid-Reservoir sampling station did not attain a mature egg size until the third week of April. These data are con-sistant with the 1979 gonosomatic index data indicating a separation in gonad development and spawning times for the WHTF when compared to the mid-reservoir sampling stations. l
- 6.3.7 Fingerling Production The largemouth bass produced l cxtremely high numbers of young of the year during 1978, r'T t
N/ especially in the WHTF and Mid Reservoir stations (Figure 6.3.7.1). The lowest numbers of young bass recorded isre during 1976, and in 1979 the WHTF at Millpond Creek produced the most fingerling bass per hectare. These fluctuations in 6-60 1
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./ ' 77 WilTF
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I FIGURE 6.3.5.1. Fecundity vs. weight for the largemouth bass, Micropterus salmoides Lake Anna 1976- 1979 i
O O o 1 O I l Table 6.3.6.1 Egg size (rmn) of the female largemouth bass, Micropterus salmoides, at the Mid-Reservoir Station, Lake Anna, 1979. 95% Mean Confidence Limits Range Fish T.L. Date Number Egg Size Upper Lower (ima) Range 4-5 4 1.245 1.283 1.206 0.962 1.389 400 - 435 4-17 4 1.370 1.397 1.342 1.285 1.428 420 - 512 4-26 4 1.348 1.408 1.287 1.246 1.417 470 - 580 I 5-3 4 1.304 1.349 1.258 1.205 1.442 360 - 542 5-10 3 1.314 1.338 1.289 1.213 1.403 425 - 530 S' 5-17 2 1.349 1.388 1.309 1.274 1.424 475 - 510 0 t 5-25 2 1.227 1.265 1.188 1.180 1.276 350 - 415 p l
. i l
3
O c O O . O Table 6.3.6.2 Egg size (mm) of the female largemouth bass, Micropterus salmoides, in the WitTP, Lake Anna, 1979.
, 95%
Mean Confidence Limits Range Fish T.L. Date Number Egg Size Upper Lower , (mm) Range 3-22 6 1.256 1.289 ).222 1.078 1.371 360 - 552 3-29 4 1.427 1.454 1.399 1.287 1.506 432 - 465 , 4-5 2 1.354 1.423 1.343 1.332 1.377 459 - 542 i 4-19 6 1.392 1.404 1.379 1.303 1.444 385 - 520 ! 4-26 2 1.420 1.450 1.388 1.404 1.438 445 - 537 . t ' $ 5-3 4 1.310 1.350 1.269 1.224 1.378 410 - 494 5-10 1 1.386 1.426 1.344 440 5-17 4 1.269 1.298 1.239 1.181 1.427 43,3,-- 526 5-24 1 1.246 1.258 1.233 420 6 P
't a
i o C O '3 . O www.n, 1979 t 4
==== 1978 1977 1000 -
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" 1976 '
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l l I I I I I Moody M111 pond . Dam Mid NAR Pamunk(y
- i FIGURE 6.3.7.1. Number of young of t'ae year largemouth bass, Micropterus salmoides -
'; i by station: in Lake Anna. -
4 ~
' y
... ::.r . __
-~ -
O fingerling production can be best explained by observing the bluegill young of the year as shown in Ffgure 6.3.7.2. Gen-erally, whenever there was a peak in bluegill production the fingerling bass population was depressed. It has been noted that a dominant bluegill population may control bass reproduct-ion through predation on eggs and fry (Bennett, 1951). It was also reported that when there were 2800 or more small bluegills per hectare, bass fry survival was low (Bennett, A'dkins and Childress, 1969). This phenomenon appears to be true in the Lake Anna bass / bluegill community. No definite trends in fingerling production of bass or bluegills can be attributed to heated effluent to date. The chain pickerel, Esox niger, fingerlings appear to be (, generally increasing during 1978 - 1979. No young pickerel were collected during 1976 (Figure 6.3.7.3). Young of the year white perch, Morone americana, have had a drastic increase in numbers from 1976-1979. The Mid-Reser-voir station appears to be the most productive for this species,
~
hcwever, it was also collected in substantial numbers in the WHTF in 1979 at Moody Creek (Figure 6.3.7.4) . It has been shown that adult fishes usually demonstrate greater declines in areas affected by thermal effluent than do the young and, also, the young of certain species appear to tolerate higher temperatures in discharge canals than do the adults (Marcy, 1976). No particular trend has been noted to date for young / adult fishes in Lake Anna, and this condition will be ronsidered in future investigations.
'" 6.3.8 Growth of Year Class O Larc emouth Bass (Micropterus salmoides) A total of 339 indivic ual young of the year large-mouth bass were collected during the August rotenone sample in Lake Anna during 1979. The fish were measured to the nearest mm in the laboratory and the results are presented in Table 6.3.8.1. An ANOVA and Duncan's Multiple Range test displayed the following arrangement of means:
Moody NAR Millpond Pamunkey Dam Mid Creek Arm Creek Creek Cove Reservoir 88.586 83.14 78.00 64.66 64.00 59.27 the WHTF stations (Moody Creek and Millpond Creek) and the NAR Arm Upper Reservoir station were significantly different than the remaining stations. This difference was observed only for the NAR Arm during 1978 when the WHTF was not under any in-() fluence of heated discharge. It appears that during 1979 young bass at the WHTF stations were longer due to the earlier spawn induced by higher temperatures in the WHTF. Bennett and Gibbons (1975) also demonstrated this same phenomenon in a cooling s s 6-65 .
O ( O O O wwwnnan 1979 I
=""" 1978 s 1977 ;
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i j ' Moo'd y Mill' pond ' ' Da'm Mid'-R. NAR Pamunkey ! Creek Creek cove arm Creek ' FIGURE 6.3.7.2. Number of young of the year bluegill, Lepomis macrochirus ! l by station iniLake Anna. .
,j' 1
1 i t j I i f e , l l S: I I i
- O c O O O N 1979
.-= 1978 75 - ******* 1977 l 50 -
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I I l 7 Moody M111 pond Dam Mid-R. NAR Pamunkey - Creek Creek Cove arm Creek l-FIGURE 6.3.7.3. Number of young of the year chain pickerel, Esox niger, by station in' - Lake Anna, - - - i . e e e e g . 4 I h 4 L
O C O O O ! l 600 - l 500 _ ;
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==== 1978 E: .s "k 1977
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Creek Creek NAR Pamunkey ;
, . _ . . ..--- - 2 Cove arm Creek -
- - . .. . . ... - - . ~. ,
FIGURE 6.3.7.4. Number of young of the year White Perch, Morone americana, by station in - i T,ak p Anna. _
i O C O O O .. Table 6.3.8.1 Year class 0 largemouth bass (Micropterus salmoides) mean length in Lake Anna during August 1979 rotenone collection. 95% ' Mean Standard Confidence Limit Region Date Number (mm) Error Lower Upper : North Anna River Arm 8-14 42 83.41 2.14 74.81 87.47 Pamunkey ' Creek 8-16 60 64.66 1.86 60.93 68.40 m Mid i Reservoir 8-6 108 59.27 1.19 56.92 61.62 Lower Reservoir 8-8 54 64.00 1.43 51.13 56.87 Moody Creek - (WHTF) 8-20 46 88.58 3 04 82.43 94.73 M111 pond - Creek (WHTF) 8-22 29 78.00 4.04 69.72 86.28
() reservoir. The young bass in the WHTF apparently had more growing time than bass in the Reservoir. The young bass at the NAR rotenone station have historically begn longer due to some unexplained variable. More studies are in progress to asertain why the young bass in this Upper Reservoir station have a growth advantage. 6.3.9 Condition Factors of Selected Species in Lake Anna Condition factors have been utilized in thermal effluent studies to characterize the effects of high temperatures on the "well being" of fish populations. It has been reported that no pat-tern was evident to indicate that increased water temperature at any point in the cooling loop at Lake Sangchris affected the condition of gizzard shad, bluegill or yellow bass (Larimore and Tranquilli, 1977). Marcy (1976) demonstrated that brown bullheads had significantly lower conditions in heated dis-(m charge areas than in reference areas and Bennett and Gibbons (1974) stated that young bass had higher condition factora in heated areas than unheated reference stations. There seem to be mixed results concerning the condition of fishes affected by heated effluents. Prolonged heat stress can affect the metabolism of fishes expose to such stress this O in turn could affect the overall condition of the fish pop-ulation. In Lake Anna fish were collected from rotenone studies and electrofishing to obtain data for comparison of fish condition at the WHTF and reference stations. Trends in the condition of fish with length have been ob-served (Carlander, 1977) and in Lake Anna an increase in con-dition with length for the largemouth bass was observed. When condition for bass wrs plotted on length, significant slopes _ were evident with relatively high R2 values (Table 6.3.9.1). (_, The resulting equation K = mL + b was utilized to obtain a running average of mean K for all lengths where: K = predicted condition m = slope L = length b = Y intercept Bennett and Gibbons (1974) found that the condition of young bass was higher in heated areas than unheated aream, and in Lake Anna during the 1979 operational year, condition of the smaller bass in the WHTF was slightly higher than that of the previous years sampled (Figure 6. 3. 9.1) . Largemouth bass col-l lected in 1976 in the WHTF showed the predicted conQition of I bass longer than 300 mm was higher than the next three years sampled. A statistical ranking of the slopes by the Student, (]) Newman-Kuels Multiple Range test is as follows: 1976 1978 1977 1979 6-70
- :. w . . . .
- - - - - - - - -^
~
lO Table 6.3.9.1 R2 val.ues for largemouth bass K/ length regression equations for 1976 - 1979. Year WHTF Lower Reservoir Upper Reservoir 1976 0.76 0.58 0.81 1977 0.64 0.74 0.43 1978 0.64 0.77 0.71 1979 0.64 0.64 0.40 1 0
- o I
i l O l t 6-71 -- .
~
O c O O O
..... 1976
- 1977 a . 1978 mmmmmmmm197 9
~
2
,A n
5 .. *... c O m
- I M 4 H D
M a- - .* g**p* . O 3 O
*..*'*****,e
#,e* . ..
i
. e i I I I i I 3 i i 100 200 300 400 500 LENGTH (msa)
FIGURE 6.3.9.1. Condition (K) vs. Lake Anna 1976 - 1979 WHTF length for largemouth bass, Micropterus salmoides G e
1
, - - - n _ ,_ , n, ;_ --
O The 1976 slope for conditon vs. length of bass collected in the Lower Reservoir was significantly*different from all other years at the 95% confidence level.' The smaller bass dur-ing that year displayed a higher condition than bass collected in other years up to about 300 mm; as the fish increased in length beyond 300 mm their condition approached the condition of bass sampled in subsequent years (Figure 6. 3. 9. 2) . All bass sampled in the Lower Reservcir throughout the study period approached similar values for condition after they grew beyong 300 mm. The statistical ranking of the slopes between years for the Lower Reservoir in as follows: 1978 1977 1979 1976 (% s ,' The condition of the bass population in the Upper Reser-voir appeared to fluctuate more than the other two study areas between years (Figure 6. 3. 9. 3) , perhaps due to the smaller sample sizes obtained for that area. The condition factors for bass collected in 1979 appeared to be higher than those fis~h collected in other years, but the 1979 slope is not significant-ly different than the 1977 slope. The statistical ranking of O the slopes by year for the Upper Reservoir are as follows: 1978 1976 1977 1979 The gizzard shad, Dorosoma cepedianum shows no tendency for condition factors (K) to increase or decrease with length of the fish (Carlander, 1970) thus, the condition factors for gizzard shad in Lake Anna were averaged for all lengths and presented in Table 6.3.9.2. In Lake Anna, curing 1976, gizzard
shad collected at the Lower Reservoir station (Dam Cove) had a significantly higher mean condition factor than shad coll-ected st the WHTF or Upper Reservoir stations, but in 1977 the condition factor (K) of shad in the Lower Reservoir (Dam Cove) was significantly lower than the Upper Reservoir and WHTF stations. In 1979 the gizzard shad had significantly higher i
' values for condition in the WHTF as compared to all other study areas. No clear trends in condition factors were observed, how-ever, a significantly higher condition for shad in the WHTF was l evident in 1979, which was the first year of operation of the first reactor unit. Some populations of bluegill, Lepomis macrochirus, increase in condition (K) with length and other populations do not show this phenomenon (Carlander, 1977). In Lake Anna regressions of condition2 factors (K) on length of fish were run for bluegill and the R values were extremely low (0.00152); therefore, the O bluegill population in Lake Anna was considered uniform in condition throughout each size class and averaged accordingly (Table 6. 3. 9. 2) .
. 6-73
O C O ') O
..... 1976 1977
. . 1978 1979 2_ _
1 5 .*,,...****. ,*a ,e m c i j 1_ a.***...*...**. o w
* ,s#*
m o c
*p*e o
u d #+*# .-
**p
( l I i I I I I g IOO 200 300 400 500 t i LENGTH (mns) :- j FIGURE 6.3.9.2. Condition (K) vs. length for largemouth bass, Micropterus salmoides Lake Anna 1976 - 1979 Lower Rccervoir I, i
O c o 1 0 j
.....* 1976 m 1977 {
= = - 19 7 8 sammes 1979 2--
i
**..**..,* ,* ,d
.*.*..**..s*,# .
26 ...*** . . l
,f i, I n m
e o c ....**.. w lm u1__ ' M c
. #+*s 6
c o o * ..a.. . .
# . J
** e
***g* !
p e**, . I t I E 100 2C0 3( 0 4( 0 SC O , , ,
~~ '
! LENGTH (aus) ,
I : TIGURE 6.3.9.3. Condition (K) .vs. length for largemouth bass, Micropterus salmoides ' Lake Anna 1976 - 1979 Upper Reservoir g S 8
- pL e
-- _-- - - _ _ - - - - - - - - - - - - - - - - - - _ - - - _ - - _ _ - - - _ ~m-m
O C O O O Table 6.3.9.2 Mean condition factors by species-for Upper, Lower, and WiiTF Lake Anna, 1975 - 1977 and 1979. 1979 1977 1976 1975 Spccles WiiTF Lower Upper WitTF Lower Upper WiiTF Lower Upper Upper Lower Black Crappie 1.13 1.07 0.92 0.89 0.85 1.04 1.27 1.00 1.36 1.26 Blutgill 1.67 1.59 1.47 1.27 1.32 1.47 1.72 1.65 1.66 1.72 Purpkinseed 1.72 1.89 1.62 1.26 1.82 1.55 1.80 1.88 1.94 1.77 Gizzard shad 0.98 0.86 0.80 0.74 0.57 0.76 0.82 0.86 0.80 0.88 . I
- R:dnar 1.23 1.06 1.57 1.25 1.41 1.69 1.67 1.81 1.60 t,
- " Chain Pickerel 0.50 0.29 0.35 0.46 0.64 0.57 0.55 0.65 0.63 6
I i e 8 li
O In 1976 the WHTF stations displayed significantly lower l values for condition than other areas on the lake sampled. In 1 ! 1977 only the Upper and Lower Reservoir stations were recorded and no significant difference was observed in condition of the ) 1 bluegill population between these two areas. In 1979 the blue- l gill sampled in the Upper Reservoir had significantly lower I values for condition than the WHTF and Lower Reservoir and the l' mean condition of the bluegill in the WHTF for 1979 was higher than the other two study areas sampled (Table 6.3.9.2). l The pumpkinseed, Lepomis gibbosus, had significantly ' different values for mean condition between all three study areas during 1976. The Upper Reservoir was the highest and the WHTF had the lowest mean condition for that year (Table 6.3.9.2) and (i'- during 1975 the Upper Reservoir was significantly higher than the Lower Reservoir. During 1977 the Lower Reservoir has sign-ificantly higher condition values for this species than the NHTF and in 1979 the Lower Reservoir displayed significantly higher values for K than the other two study areas (Table
- 6. 3. 9. 2) . These results were too irratic to produce any stable trend in the condition of the pumpkinseed in Lake Anna.
O The black crappie, Pomoxis nigromaculatus, displayed no significant difference in condition between the Upper and Lower Reservoir for 1975, but during 1976 all stations were signif-l icantly different from each other. During 1977 no significant difference was noted between stations and in 1979 there was no significant difference between the WHTF and the Lower Reservoir station. The Upper Reservoir during that year had no data coll-ected for black crappie. The operation of unit one appeared to produce no adverse effects on the condition of the black crappie
'O in the WHTF.
6.3.10 Age and Growth of the Largemouth Bass, Micropterus salmoides Age was calculated utilizing scale samples, and in additon, length-weight regression equations were generated i to determine the overall development of this important game species. The relationship of length-weight was calculated for individ-uals to generate a curve for the purpose of obtaining weights where only lengths are known and also for interpretation of the exponen-tial growth function. These regression curves were generated separately for the WHTF, Upper and Lower Reservoir areas. Result-ing length-weight equations in logarithmic form are as follows: () Upper Reservoir log Wt = log - 12.28 + 3.18 log L Lower Reservoir log Wt = log - 12.76 + 3.28 log L 6-77 2______---
O WHTF , log Wt = log - 11.54 +.3.07 log L It has been stated that the length-weight regression equation slope will usually be above 3.0 because most fish be-come " plumper" as they grow (Carlander, 1977). The slopes cal-culated for 1979 have slopes well above the cube of the length. The mean slope for 116 largemouth bass populations was 3.08 (Carlander, 1977), therefore, in the 1979 Lake Anna bass pop-ulation more weight was being put on with length than the national average. Cellulose acetate impressions of scale samples were made for 307 bass in 1979. These were aged and distances to annuli ('
'- and interior scale radii were measured. Relation between scale radius and total body length was determined for bass from the WHTF, Upper and Lower Reservoir. The resulting relationships were linear, but not directly proportional. Consequently a Frazier-type correction (Ricker, 1968) was used and the follow-ing equations were employed to back calculate growth:
Upper Reservoir {) L' =
-4. 6 8 + ({' ) (L - (-4.68))
Lower Reservoir L' = -8.19 + ((') (L - (-8.19 ) ) , WHTF ( L' = -5.60 + (h') (L - (-5.6)) Growth rates were calculated for all year classes taken and are shown in table 6.3.10.1, 6.3.10.2 and 6.3.10.3. Using the mean calculated lengths for each group, ANOVA's were cal-culated to test for differences between location means. Age ' group I showed a significant difference between locations where-as the other age groups displayed no differences. A Duncan's Multiple Range test revealed the following relationship be-tween mean lengths for age' group I at the 95% confidence level: WHTF Upper Lower 152.35 128.33 115.95 The age I largemouth bass in the WHTF grew significantly l fastor than first year bass in the two other sample locations. l These data appear consistent with the 1979 data showing a dif-ference in growth of young of year bass in the WHTF. l I - W
o I c O o O :
.l I
l Table 6.3.10.1 Back calculated length attained by each year class of largemouth bass , at each annulus for fish collected from Lake Anna (Upper Reservoir, 1978). Mean Calculated Length at Annulus Year Class N1 i I II III IV y y1 yII yIII 1973 1 200.93 2 325.54 381.62 431.46 462.62 487.54 200.93 124.07 56.08 49.84 31.16 24.92 i 1974 2 170.58 261.30 306.52 366.48 420.54 i j 170.58 90.72 45.22 59.96 54.06 ! 1975 2 93.10 249.55 303.40 354.67 ; 93.10 156.45 53.95 51.27
... 1 1976 6 126.86 239.76 280.30 126.86 112.90 40.54 i 1977 12 105.46 230.83 -
105.46 125.37 -
'f . , i '
O O O n O Table 6.3.10.1 (CONT.) ; Mean Calculated Length at Annulus Year Class N1 i I II III IV V VI VII VIII 1978 19 128.33 128.33 I Mean Total Length 137.54 261.40 317.96 384.20 441.58 487.54 Mean Increment 137.54 121.90 48.94 53.39 42.61 24.92 o i 1 i Number of specimens in each age group 2 T.L. in mm *~ i 3 Mean increment for year class b l t
('. . 0 Table 6.3.10.2 Back calculated length attained by each year class of largemouth bass at each annulus for fish collected from Lake Anna (Lower Reservoir, 1979). l Mean Calculated Length at Annulus ;, Year Class 1 i N l I II III IV V VI VII VIII l 2 .. 1971 1 58.64 112.12 165.59 346.06 386.16 453.00 506.48 546.58 58.64 53.48 53.47 180.47 40.10 66.84 53.48 40.10 ! 1972 5 63.39 105.36 189.32 274.41 360.28 422.15 482.95 63.39 41.97 83.96 85.09 85.87 61.87 60.80 m i E 1973 12 102.40 202.07 292.16 354.58 409.20 446.72 F* 102.40 99.67 90.09 62.42. 54.62 37.52 1974 19 1. 105.49 204.76 301.77 377.76' 426.54 ' 105.49 99.27 97.01 75.99 48.78 *** j , 1975 16 88.39 188.53 289.88 353.40 88.39 100.14 101.35 63.52 1976 33 101.42 208.10 296.25 - 101.42 105.68 88.15' 1977 19 96.16 257.31 ' 96.16 101.15 i 9 e
p n O \ f Table 6.3.10.2 (CONT.) Mean calculated length at annulus Year Class N1 I II III IV V VI VII VIII 1978 13 115.95 i 115.95 .) Mean Total Length 91.48 182.60 255.83 341.24 395.54 440.62 494.71 546.58 Mean i Increment 91.48 94.48 05.67 93.50 57.34 55.41 *57.14 40.10 j m DJ 1 Number of specimens in each age group 2 ~~~ T.L. in mm ! 3 Mean increment for year class B i I
O O O O O l Taale 6.3.10.3 Back calculated length attained by each year class of largemouth bass - at each annulus for fish collected from Lake Anna (WHTF, 1979). Mean Calculated Length at Annulus Year Class NI 'I I II III IV V VI VII VIII ( 1971 1 68.082 128.37 202.06 262.35 362.83 423.12 496.31 537.00 68.083 60.29 73.69 60.29 100.48 60.29 73.69 40.19 I 1
. 1972 2 82.63 192.08 274.56 345.17 406.37 458.50 498.48
[ 82.63 109.45 82.48 70.61 61.20 52.18 39.98 - o i < 1973 12 90.46 177.13 257.25 335.49 410.39 471.42 90.46 86.67 80.12 78.24 74.90 61.03 j! 1974 19 81.08 156.49 254.59 346.09 414.46 81.08 75.41 98.10 91.50 68.37 1975 14 88.05 175.71 258.24 346.99 88.05 87.66 82.53 88.75 I 1976 34 104.21 199.25 282.24 104.21 95.04 82.99 . 1977 30 104.21 233.95 104.21 129.74 l
- l. ,
l
O G O o . O t Table 6.3.10.3 (CONT.) Mean calculated length at annulus Year Class N1 I II III IV V , VI VII VIII 1978 35 152.35 152.35 Hean Total Length 96.38 180.43 254.82 327.22 398.51 451.01 497.64 537.00 m i Mean 1n Increment 96.38 92.04 83.32 77.88 76.24 57.82 56.84 40.19 i 1 Number of specimens in each age group 2 T.L. 1 in mm ' 3 Mean increment for year class , i.
;*1 e
i e l i I 8 1 h 0 e 9
O O O O O Table 6.3.11.1 Gut content of the largemouth bass, Micropterus salmoides, in Lake Anna . 1979. (The presence of fish families found in.the gut is expressed as percent occurrence ) . FAMILY Month Clupeidae Ictaluridae Centrarchidae Percidae Crayfish Empty Unidentified : f March 12.50 12.50 25.00 37.50 12.50 April 32.00 28 57 10.70 3.57 25.00 May 31.81 13.63 41.00 13.63 Total 29.31 1.72 22.41 5.17 1.72 32.75 6.89 i i s e y . 9 i a
O 6.3.11 Food Habits of the largemouth bais, Micropterus salmoides A total of 58 largemouth bass were examined for gut contents during 1979 (Table 6.3.11.1). It was found that the gizzard shad constituted a majority of the forage base for the largemouth bass in Lake Anna during 1979. Centrarchids remain second in terms of frequency of occurrence, as has historically been the case. The families Ictaluridae and Percidae played a relatively minor role in the forage base for the largemouth bass and crayfish appeared as a minor food item during April (Table 6. 3.11.1) . , Throughout the study period trom 1977-1979, it was evident that the family Clupeidae, represented by the single species, Dorosoma cepedianum, was the most frequently selected forage (s fish in the diet of the largemouth bass in Lake Anna (Table 6.3.11.2). This may be attributed to the fact that the gizzard shad was found to be the most abundant fish in Lake Anna and was perhaps encountered by the bass more frequently than other prey species. D. cepedianum has also been noted as a valuable forage species In some other reservoir systems (Baker and Schmitz, 1971; Miller 1960; Jester and Hcnsen, 1972). By feeding on phytoplankton the gizzard shad has the advantage of shortening ( the food chain from the basic nutrients to the predator game fish level (Sandoz, 1956). This results in the transformation of living microscopic matter into flesh in one trophic step, which places D. cepedianum in an important position in the food chain of predatory fishes (Schneider, 1969). Therefore, the abundance of gizzard shad in Lake Anna may play.a key role in the maintenance of the largemouth bass population in this reser-voir. Any reduction in the shad population due to station oper-(; ation should be reflected in an alteration at food habits in the largemouth bass. The 1979 operational year did not appear to affect the food habits of the largemouth bass in Lake Anna. 6.4 Summary 6.4.1 Physical and Chemical
- 1. Dissolv ed oxygen values were generally high throughout the j water column at all fish stations for 1979.
- 2. Turbidity values for the Upper Reservoir fish stations, at the mid and bottom depths, were significantly higher than all other fish sampling' stations.
O 6-86
O O O O O Table 6.3.11.2 Gut content of the largemouth bass,.Micropterus salmoides, in the WitTF and Reservoir 1977-1979. (The presence of fish families found in the gut is expressed as percent (%) occurrence). 1979 1978 1977 FAMILY WIITF MID TOTAL WitTF MID TOTAL WilTF MID TOTAL Clupeidae 21.42 36.36 29.31 8.88 40.00 15.00 20.33 71.73 42.85 Ictaluridae 3.57 1.72 1.66 1.69 .95 Centrarchidae 14.28 23.27 22.41 2.22 20.00 8.33 11.86 2.17 7.61 Porcidae ' 9.09 5.17 6.66 1.66 3.38 1.90 6; Crayfish 3.57 1.72 8.88 5.00 - m i i Empty 53.57 18.18 32.75 68.88 33.33 61.66 50.84 23.91 39.04 Unidentified 3.57 9.09 6.87 11.11 6.66 11.86 2.17 7.61 Total 100% 100% 100% I l i I l l l l
O l Table 6.3.11.3 Fish Species List for Lake Anna, 1979. l s I Family Genus Species Common Name Anguillidae Angu;.la rostrata American eel Clupeidae Dorosoma cepedianum Gizzard shad Umbridae Umbra pygmaea Eastern mudminnow Esocidae Esox niger Chain pickerel Cyprinidae Cyprinus carpio Carp ("'-
'~
Notemigonus crysoleucas Golden shiner Notropis procne Swallowtail shiner Catostomidae Catostomus commersoni White sucker Erimyzon oblongus Creek chubsucker-l Moxostoma macrolepidotum Shorthead redhorse Ictaluridae O' Ictalurus natalis Ictalurus nebulosus Yellow bullhead Brown bullhead Ictalurus punctatus Channel catfish Noturus insignis Margined madtom Percichthyidae Morone americana White perch Morone saxatilis Striped bass Centrarchidae Enneacanthus gloriosus Bluespotted sunfish Lepomis auritus Redbreast sunfish (_. Lepomis gibbosus Pumpkinseed Lepomis gulosus Warmouth Lepomis macrochirus Bluegill Lepomis microlophus Redear Micropterus salmoides Largemouth bass Pomoxis nigromaculatus Black crappie l Percidae Etheos~toma ohnstedi Tessellated darter Perca flavescens Yellow perch O 6-88
O 3. The mean alkalinity values for surface, mid and bottom depths at station M was significantly lower at the 95% confidence level than the remaining stations. * ,
- 4. The mean hardness values for station Z at surface, mid and bottom depths were significantly lower than all other stations.
6.4.2 Relative Abundance Based on Gill Net Observations 1., The gizzard shad increased in gill net catches since its appearance from 3.1 and 7.5% to as much as 68% of the total catch. A gradual decline in relative abundance of shad was noted in recent years. 2. C' The chain pickerel has suffered a decline in numbers through-out the study. 3. Thekgcarp as per has displayed an increase in catch per day as well net day. 4. The creek chubsucker has declined steadily in relative {} abundance throughout the study period. 5. The brown bullhead.and the yellow bullhead have shown a de-crease in catch per unit effort during the study period. 6. The channel catfish has shown an increase in catch per unit effortthe near in WHTF the WHTF and the discharge area. Lower Reservoir at station S 7. (,; The largemouth bass displayed an increase ih relative abundance in the WHTF in 1979. 8. The white perch has shown a marked increase in relative abundance over the study period. 9. The striped bass has shown an increase in catch per unit effort in the WHTF, perhaps due to the attraction of the artificial current. 10. The WHTF produced higher values for kg of fish caught per net day than the other study areas. 6.4.3 Cove Rotenone Studies 1. In Lake Anna no significant changes between years were found I to exist throughout the study period for gizzard shad, al-(]) though of this there appeared species. to be a decline in mean standing crop x 6-89 .I
...-.--..- - ^^ -
~ '
O
- 2. The gizzard shad was the most import, ant fish in terms of standing crop. .
- 3. The Upper Reservoir displayed the highest value for stand-ing crop of gizzard shad.
- 4. The carp has increased in standing crop and was shown to be significantly higher in kg/ hectare in the Pamunkey Creek Arm.
S. The creek chubsucker was collected at more stations than i other suckers, but this species remains on a steady decline. l l
- 6. The channel catfish has steadily increased in standing crop
(~'. over the past two years in the WHTF, but Pamunkey Creek and the Mid-Reservoir stations remained significantly higher than all other stations for this species.
- 7. The white perch displayed an increase in standing crop dur-ing 1979.
- 8. No significant differences occurred between years but Pamunkey Os Creek displayed significantly higher standing crop values than all other stations.
- 9. Changes in standing crop observed at the species level appear to be more important in predicting the impact of heated effluent than observing total standing crop.
I 6.4.4 Gonosomatic Index of the female, Micropter2s salmoides. k-
- 1. During 1979, female bass at the.Mid-Reservoir electrofishing.
station displayed a peak of gonad development in the third ! week of April, but female bass observed in the WHTF reached i their peak gonad development during the last week of March. !
- 2. Female bass were observed in the " squeeze ripe" or spawning condition in the WHTF on April 9, 1979, whereas the female ;
l t bass collected in the Reservoir started spawning three weeks later on April 26, 1979. 1 6.4.5 Fecundity, Micropterus salmoides
- 1. There was a steady decline in fecundity observed from 1976-1979 in the WHTF.
(~} 2. The Mid-Reservoir station during 1979 displayed high pre-
\s dictive values for fecundity when compared to the WHTF.
, 6-90 y
_ . . . - . . . _: u_ O d.4.6 Egg Size, Micropterus salmoides
- 1. Female largemouth bass in the WHTF r$ ached a peak egg size in the last week of March and retained a relatively large egg size until the first week of May, whereas female bass in the Mid-Reservoir sampling station did not attain a mature egg size until the third week of April.
6.4.7 Fingerling Production
)
l
- 1. The largemouth bass produced extremely high numbers of )
young of the year during 1978. l l
- 2. Generally, whenever there was a peak in bluegill production the fingerling bass population was depressed.
- 3. Chain pickerel seemed to have a higher reproductive success rate during 1978-1979 because of the increase in fingerlings observed for this species.
1
- 4. Young of the year white perch,have displaysd. a marked in-crease in numbers from 1976-1979 ..
O 6.4.8 Growth of Year Class O Largemouth Bass, Micropterus salmoides t l 1. The year class O bass collected at the WHTF stations and the NAR arm of the Upper Reservoir were significantly longer than the young bass collected at the remaining stations. 6.4.9 Condition Factors of Selected Species in Lake Anna. O 1. The largemouth bass in Lake Anna displayed an increase in K with length.
- 2. During the operational year 1979, the condition of the smaller bass was higher than that observed in previous years sampled in the WHTF.
- 3. Young largemouth bass collected in the Lower Reservoir during 1976 displayed significantly higher condition factors than young bass collected in other years.
- 4. In 1979 the gizzard shad had significantly higher values for condition in the WHTF as compared to all other study areas.
- 5. In 1979 the bluegill population in the Uppe'r Reservoir had f' significantly lower values for condition than the other two
\ study areas and the mean condition of the bluegill in the WHTF for 1979 was greater than the other areas.
6-91
./
O
- 6. The operation of unit one appeared to produce no adverse '
effects on the condition of the black crappie in the WHTF. 6.4.10 Age and Growth of the Largemouth' Bass, Micropterus salmoides
- 1. The 1979 Lake Anna largemouth bass population was putting on I more weight with length than the national average.
- 2. The age I largemouth bass in the WHTF grew significantly faster than the first year bass in the other sampling locations. ;
6.4.11 Food Habits of the Largemouth Bass, Micropterus salmoides s 1. Throughout the study period from 1977-1979, it was evident that the family Clupeidae, represented by the single species, Dorosoma cepedianum, was the most frequently selected forage fish in the diet of the largemouth bass in Lake Anna.
- 2. The 1979 operational year did not affect the food habits of l the largemouth bass.
O 1 i l l
./ 6-92 )
' 1
O 6.5 References American Public Health Association; Amdpican Water Works Association. Water Pollution Centrol Federation. Stan-dard methods for the examination of water and wastewater. 15th ed. New York: Amer. Pub. Health Assoc.; 1975 Bagenal, T. B. The ecological and geographical aspects of fecundity of the plaice. J. Marine Bio. Assoc. U.K. 46: 161-186; 1966. l l Baker, C. D.; Schmitz, E.F. Food habits of adult gizzard shad I and.threadfin shad in two Ozark reservoirs. Reservoir Fisheries and Limnology. Spec. Publ. No. 8. Am. Fish. Soc. pp 3-11; 1971. Banner, A.; Van Arman, J.A. Thermal effects on eggs, larvae and juveniles of bluegill sunfish. Tech Report Office of l Research and Monitoring USEPA. Wash. D.C. 111 ages; 1973 Bennett, D.H.; Gibbons, J.W. Growth and condition of juvenile largemouth bass from a reservoir receiving thermal effluent O Thermal Ecology, A.E.C. Symp. Ser. (Conf. 730505) pp. 246-254; 1974.
; . Reproductive cycles of largemouth bass (Micropterun am1mniaan) in a cooling reservoir. Trans.
Am. Fish. Soc. 104: 77-82; 1975 Bennett, G.W. The growth of the largemouth black bass, Huro salmoides (Lacepede), in the waters of Wisconsin. Copeia. 1:104-118; 1937. U_
. Experimental largemouth bass management in Illinois. Tran. Am. Fish. Soc. 80:231-239; 1951.
; Adkins, H.W.; Childers, W.F. Largemouth bass and other fishes in Ridge Lake, Illinois, 1941-1963. Ill.
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