EFFECTS OF LANDLOCKED ALEWIFE INTRODUCTION
ON
WHITE BASS AND WALLEYE POPULATIONS, CLAYTOR LAKE, VIRGINIA
by
John Lee Boaze
Thesis submitted to the Graduate Faculty of the
Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of
MASTER OF SCIENCE
in
Wildlife Management
(Fisheries Option)
APPROVED:
Robert T. Lackey, Chairman
Senry S. Mosby/I Kenneth L. Dickson
May 1972 Blacksburg, Virginia 24061 l
ACKNOWLEDGMENTS
I wish to express my appreciation to the Virginia Cooperative
Fishery Unit, the Division of Forestry and Wildlife Sciences, and the
Biology Department, Virginia Polytechnic Institute and State University for use of facilities and equipment. The author is indebted to
, Chief, Fish Division, Virginia Commission of Game and Inland
Fisheries for making the project possible; , for serving as graduate counnittee chairman until his transfer; R. T. Lackey for his chairmanship of the graduate committee; K. L. Dickson, Biology Depart- ment, and H. S. Mosby, Division of Forestry and Wildlife Sciences for their cooperation in all phases of the work including reviewing of the manuscript; , Division of Fishery Services, United States
Bureau of Sport Fisheries and Wildlife, for the use of equipment and for his valuable instructions; American Electric Power Company, for assistance in analyzing water samples. In addition, the following assisted in various capacities and their aid is greatly appreciated: , ., and Sincere thanks is also extended to the many sportsmen who cooperated with the investigation and contributed valuable information.
ii /
TABLE OF CONTENTS Page ACKNOWLEDGMENTS • ...... • • • • • • • • 11 LIST OF FIGURES . . . vi LIST OF TABLES vii
LIST OF APPENDIX TABLES • x
INTRODUCTION 1
Reason for the Study • • • • • • 1
Management History of Claytor Lake • • • • • 1
LITERATURE REVIEW • • • • • • • • • • • 5
MATERIALS AND METHODS • 8
Study Area • • • 8
Sampling Stations 8 Fish Population Sampling Stations • 8 ·water Temperature and Dissolved Oxygen Stations • 11 Sampling Methods • • • • • • • • • • • 11
Fish Population Sampling 11 Vertical Gill Netting • • • 13 Water Temperature and Dissolved Oxygen Determination. 13 Age Determination • • • • 15 Growth Analysis • • 16 Length-Weight Relationship 17 Coefficient of Condition 17
Comparison of Growth Rates 17
iii iv
TABLE OF CONTENTS - continued Page RESULTS • • • • • • • • • • • • ...... 19 Fish Population Studies ...... 19 Vertical Gill Netting ...... 24 Fish Fauna of Claytor Lake • 29
Water Temperature and Dissolved Oxygen 32
Age Determination 34
Growth Analysis 38 Length-Weight Relationship • ...... 48 Coefficient of Condition • ...... 48 Comparison of Growth Rates • ...... 59 Alewife Utilization 59 DISCUSSION ...... 63 Fish Population Studies • ...... 63 Vertical Gill Netting . . . . 64 Fish Fauna of Claytor Lake • 66
Water Temperature and Dissolved Oxygen • 67 Age Determination • • • • • ...... 68 Growth Analysis • • • • • • • • • • • • • • • 70
Length-Weight Relationship 74 Coefficient of Condition • ...... 75 Comparison of Growth Rates • 75
Alewife Utilization 76 v
TABLE OF CONTENTS - continued
Page
RECOMMENDATIONS 78
REFERENCES CITED 79 APPENDIX 84
VITA 103 LIST OF FIGURES
Figure Page
1. The geographic location of Claytor Lake • . • . • 9 2. Location of sampling stations, Claytor Lake, 1971 • 10 3. Position of vertical gill nets ...... : 14 4. Depth distribution of fish taken in vertical nets, Claytor Lake, 1970-1971 • ...... 28 5. Zone of trout water in Claytor Lake, July 23, 1971 33 6. Zone of trout water in Claytor Lake, September 19, 1971 ...... 35 7. Distribution of sex and age class of 279 walleye, Claytor Lake, 1971 ...... 36 8. Distribution of sex and age class of 543 white bass, Claytor Lake, 1971 ...... 37 9. Distribution of age class of 244 alewives, Claytor Lake, 1971 ...... 39
vi LIST OF TABLES Table
1. The number of fish stocked by year in Claytor Lake
from 1939 to 1971 • • • • • • • • • • • • • • • 2
2. The number and weight of fish taken by rotenone
sampling in Claytor Lake population studies,
October 16-18, 1970, reported as number and weight
per acre 20
3. The IU!lber and weight of fish taken by rotenone
sampling in Claytor Lake population studies,
June 29-July 1, 1971, reported as number and
weight per acre 22
4 . The total number and weight of fish collected during
each day of cove sampling in Claytor Lake, 1970-1971. • 25
5. Fish species and number of individuals caught by
vertical gill net in Claytor Lake, 1970-1971 26
6. List of the common and scientific names of fishes
found in Claytor Lake and their relative abundance
in 1950 and 1971 30 7 • Average calculated total length in millimeters at
successive ages by age groups of 279 walleye,
Claytor Lake, 1971 • • • • • • • • • • • • • 40
8. Average calculated total length in millimeters at
successive ages by age groups of 167 male walleye,
Claytor Lake, 1971 41
vii viii
LIST OF TABLES - continued
Table
9. Average calculated total length in millimeters at
successive ages by age groups of 84 female walleye,
Claytor Lake, 1971 42
10. Average calculated total length in millimeters at
successive ages by age groups of 543 white bass,
Claytor Lake, 1971 • . . • • • . • • . • • • . • 45
11. Average calculated total length in millimeters at
successive ages by age groups of 265 male white bass,
Claytor Lake, 1971 • • • . • • • . • • . . • • 46
12, Average calculated total length in millimeters at
successive ages by age groups of 249 female white bass,
Claytor Lake, 1971 . • . • • • . • • . • • . . • . 47
13. Average calculated total length in millimeters at
successive ages by age groups of 244 alewives,
Claytor Lake, 1971 49
14. Average K(TL)-factor for male walleye by month and
twenty millimeter total length intervals, Claytor Lake,
for the months of April through October, 1971 • . 50
15, Average K(TL)-factor for female walleye by month and
twenty millimeter total length intervals, Claytor Lake,
for the months of April through October, 1971 .• 52 ix
LIST OF TABLES - continued
Table Page
16. Average K(TL)-factor for male white bass by month
and twenty millimeter total length intervals,
Claytor Lake, for the months of April through
October, 1971 • • • • • • • • ••• 55
17. Average K(TL)-factor for female white bass by month and
twenty millimeter total length intervals, Claytor Lake,
for the months of April through October, 1971 • • • 57
18. Total length of each annulus formation for walleye
before and after the stocking of alewives, with "t"
values indicating significance of difference,
Claytor Lake, 1971 • • • • • • • • • • • • • • • • • 60
19. Total length at each annulus formation for white bass
before and after the stocking of alewives, with "t"
values indicating significance of difference,
Claytor Lake, 1971 • • • • • • • • • • • 61 20. Growth rates of walleye from Claytor Lake, 1971
compared with that of other populations 71
21. Growth rates of white bass from Claytor Lake, 1971
compared with that of other populations 73 LIST OF APPENDIX TABLES
Table
I. Size classes used in summarizing fish population
data from Claytor Lake • • • • • • • • • • • 85
II. The numbers and weights of fish taken by Commission
personnel from two 1/3-acre coves in Claytor Lake,
August, 1961 • • • • • • • • • • • • 86
III. The numbers and weights of fish taken by Commission
personnel from two 1/3-acre coves in Claytor Lake,
July, 1962 87
IV. The numbers and weights of fish taken by Commission
personnel from two 1/2-acre coves in Claytor Lake,
September, 1964 • • • • • •••••• 88
V. The numbers and weights of fish taken by Commission
personnel from two 1/2-acre coves in Claytor Lake,
August, 1965 89
VI. Seasonal depth distribution of alewives in Claytor
Lake, 1970-1971 • • • • • • 90
VII. Seasonal depth distribution of channel catfish in
Claytor Lake, 1970-1971 • • • • • • • • . • • • • • • • • 91
VIII. Seasonal depth distribution of white crappie in
Claytor Lake, 1970-1971 ••.•.••.. 92
IX. Seasonal depth distribution of white bass in
Claytor Lake, 1970-1971 • • . • • • • • • 93
x xi
LIST OF APPENDIX TABLES - continued
Table Page
x. Seasonal depth distribution of walleye in
Claytor Lake, 1970-1971 • ...... 94 XI. Water temperature in C and dissolved oxygen in mg/l for Claytor Lake, July 23, 1971 . . . . . 95 XII. Water temperature in C and dissolved oxygen in mg/l for Claytor Lake, August 21, 1971 . . . . . 97 XIII. Water temperature in C and dissolved oxygen in mg/l for Claytor Lake, September 19, 1971 • . . . . . 99 XIV. Abridged life table for both sexes of white bass, 1971 ...... 101 xv. Abridged life table for both sexes of walleye, Claytor Lake, 1971 ...... 102 INTRODUCTION
Reason for the Study
The interest in a study of Claytor Lake was prompted by local sportsmen groups and the Blue Ridge Project Pump Storage Proposal of
Appalachian Power Company. The concensus of the interested parties was that a study should be made to define the fishery and evaluate the effects of landlocked alewife introduction on the white bass and the walleye populations of the lake. Further, these groups proposed that the study should evaluate the changes in fish population struc- ture over the past twenty years.
Management History of Claytor Lake
Following the complete clearing and flooding of the Claytor Lake basin in 1939, a stocking program was initiated by the Virginia
Commission of Game and Inland Fisheries and the United States Depart- ment of Interior, Fish and Wildlife Service. Between 1939 and 1946, walleye, bluegill, longear sunfish, largemouth bass, smallmouth bass, and white crappie were planted (Table 1). During 1947 and 1948, the
Commission planted Daphnia as an invertebrate fish food organism.
The Commission of Game and Inland Fisheries in 1946, under pressure from local sportsmen, passed a regulation prohibiting all fishing on the lake between December 31 and the opening of the regular bass season on June 10. Many fishermen hoped that, by eliminating fishing in the reservoir during winter and spring, the bass population would be less susceptible to poaching. However, the extended
1 2
Table 1. The number of fish stocked by year in Claytor Lake from 1939 to 1971 (Data from Commission of Game and Inland Fisheries records)
Year Species Number
1939 Walleye 250,000 Bluegill 10,649 Longear sunfish 3,040 Largemouth bass 7,620
1940 Walleye 200,000 Bluegill 10,650 Largemouth bass 4,694
1941 Bluegill 8,525 Largemouth bass 700
1942 Walleye 150,000 Bluegill 9,400 Largemouth bass 9,300
1943 Largemouth bass 1,960 White Crappie 2,400
1944 Bluegill 6,300 Longear sunfish 1,000 Largemouth bass 2,994 Smallmouth bass 2,000
1945 Walleye 25,000 Bluegill 15,600 Longear sunfish 8,000 Largemouth bass 1,780 Smallmouth bass 1,000
1946 Walleye 25,000 Largemouth bass 1,400 White crappie 279
1952 Largemouth bass 1,400
1958 Largemouth bass 880
1959 'White bass 99 3
Table 1. The number of fish stocked by year in Claytor Lake from 1939 to 1971 (Data from Commission of Game and Inland Fisheries records) (Continued)
Year Species Number
1963 Muskellunge 10
1964 Muskellunge 200 Threadfin shad *
1965 Thread fin shad *
1966 Muskellunge 200
1967 Muskellunge 400
1968 Muskellunge 200 Striped bass 5,000 Hybrid bass (white X striped) 200 Alewives 60,000
1969 Muskellunge 400 Northern pike 6,280 Smallmouth bass 5,000 Hybrid bass (white X striped) 500 Striped bass 1,300 Rainbow trout 22,000 Alewives 50,000
1970 Muskellunge 50 Striped bass 1,500 Brown trout 67,000 Rainbow trout 22,103
1971 Striped bass 23,275
*Unknown 4
closing of the lake did not result in an increase in the bass popula- tion (Roseberry 1950).
The Commission sponsored a study from July 1, 1948 to November 1,
1949 by Dean A. Roseberry on the fish population of Claytor Lake.
Roseberry (1950) concluded that nutrients released from decaying plants resulted in high fertility of the reservoir and supported an excellent fishery immediately following impoundment.
In 1959 a single introduction of 99 white bass established a population of these fish in the lake (Martin 1970). The establishment of the white bass population is somewhat unusual due to the lack of a forage species such as threadfin or gizzard shad (Tatum 1957).
Threadfin shad were introduced into the lake in 1964 and 1965 in an attempt to establish a forage fish, but the winters probably proved too cold for these fish. Threadfin shad usually die if the water temperatures drop below 9.0 C (Strawn 1963). The introduction of alewives to Claytor Lake in 1968 and 1969 represented an attempt to establish a forage species that could tolerate existing temperatures and could utilize the plankton.
Striped bass stockings were made in 1968 through 1971. The Com- mission hopes to plant sufficient numbers of striped bass to establish a fishery within the next two or three years (Neal 1972).
Muskellunge, northern pike, and hybrid (white X striped) bass have been introduced into the lake, but with little or no success in establishing a fishery of these species (Table 1). A fishery being defined as one in which the fishermen actively seek a given species of fish. LITERATURE REVIEW
The use of various members of the Clupeidae (herring family) as a planktivorous forage fish is an established fisheries management practice (Taylor 1956). Therefore they are often able to strengthen the link in the food chain between the plankton community and the piscivorous fish community. In addition, rather high fecundity and small size (especially of threadfin shad and alewives), make them excellent forage fish (Everhart 1971). Tatum (1957), in studying factors affecting the establishment of a white bass fishery in North
Carolina, found a shad population existed in the reservoirs where white bass were established.
The alewife, which is being widely used as a forage species for both warm water and cold water fishes, originally was an anadromous species confined to the northern Atlantic coast of the United States
(Threinen 1958). Landlocked populations have been established in the northeastern United States and Canada through introductions and by natural spread through the canal systems. The oldest known landlocked population of alewives is in Lake Hopatcong, New Jersey (Gross 1953).
Invasion of the Great Lakes by alewives has occured since 1930
(Miller 1957). According to Smith (1970), the alewife failed to appear or to become abundant in any of the Great Lakes while the lakes supported a large population of predatory fish. In southeastern United
States, only Virginia has introduced and established a landlocked population o·f alewives (Hoffman 1971).
5 6 l
Ripe anadromous alewives have been stocked into lakes to spawn.
The young provide an immediate forage food, but this procedure must be repeated annually because of winter die-off of both young and adults (Foye 1956). Recently hatched anadromous alewives have also provided substantial forage for landlocked Atlantic salmon
(Lackey 1972).
There are advantages and disadvantages to the use of alewives as a forage species. Wagner (1972) found that the alewife served as food for inshore piscivorous fishes such as the walleye and smallmouth bass especially in the summer. The absence of yellow perch in the stomachs of walleyes indicated the alewife could be buffering the predation of walleyes on yellow perch. He further reported that the above normal growth of northern pike in Little Bay de Noc, Michigan was probably due to the presence of alewives.
Gross (1953) found that the landlocked alewife did not compete with game fish for food or spawning area because they were pelagic fish.
Wagner (1972), however, believed the alewife competed with game fish fry for food. Priegal (1969) considered walleyes under 75 mm (3 inches) to be piscivorous if forage fishes were extremely abundant. Davis
(1965) recommended that when walleye fingerlings reached a length of
38-51 mm (1.5-2.0 inches), they should be stocked in a pond with a suitable forage fish.
Species, other than walleye and smallmouth bass, found to prey on the landlocked alewife include lake trout (Webster et al 1959), landlocked Atlantic salmon (Lackey 1969). brook trout (Lackey 1969), 7
and brown trout (Gross 1953). Gross also found that the alewife com- prised 55.6% of the pickerel diet and that the alewife in Boonton
Reservoir, New Jersey caused the pickerel to move from shallow water to deeper water. l
MATERIALS AND METHODS
Study Area
Claytor Lake is located on the New River in Pulaski County,
Virginia (Figure 1). The lake was formed as a result of the con- struction of a hydro-electric dam by Appalachian Power Company. The dam is located at 37° 05 1 north longitude, 80° 35' west latitude. The resulting reservoir has approximately 1820 surface ha (4,495 acres) and some 161 km (100 miles) of shoreline. Commercial operation of the hydro-electric plant began on August 1, 1939 and the normal pool elevation of 662.66 m (1,846 feet) above mean sea level was reached on
April 20, 1940 (Roseberry 1950).
Claytor Lake is a dimictic lake, having spring and fall turnovers.
During the warm months of the year, this oligotrophic reservoir con- tains two layers of water with distinct temperature differences. The epilimnion supports populations of warm water fishes, while the hypo- limnion usually contains insufficient amounts of oxygen to support cold water fishes.
The only significant source of domestic waste entering into
Claytor Lake is the Pulaski sewage treatment plant effluent which enters the lake via Peak Creek.
Sampling Stations
Fish Population Sampling Stations
Sites for conducting rotenone sampling were the same as those used by the Commission of Game and Inland Fisheries in their population studies (Figure 2). Each of the two coves contained approximately 0.405
8 9
VIRGINIA
------~f- RADFORD -L-~~~~~~~..;::::=---===ccLAYTOR LAKE
LITTLE r--RIVER
N CJ)
0 FEET 21000
CLAYTOR LAKE RESERVOIR
FIG. I. THE GEOGRAPHIC LOCATION OF CLAYTOR LAKE (SIMMONS 1968) 6
PEAK CREEK ROTENONE SITE
ALLI SONIA
LOWMAN S FERRY, RT ·~o672 , CREEK
STATlON 5 3 ...... 0
MAIN CHANNEL ROTENONE
LAKE STATE PARK
STATION I o VERTICAL GILL NET STATION o. TEMPERATURE 8 DISSOLVED OXYGEN 8z
FIG. 2. LOCATION OF SAMPLING STATIONS, CLAY TOR LAKE, 1971
,• 11
surface ha (1 acre). The surface area was determined by use of an
aerial photograph enlarged to a scale of 1:400. For the purpose of
determining the standing crop of fishes, 0.405 ha (1 acre) was
selected as the sampling area for each cove.
Claytor Lake is a difficult reservoir to sample due to the steep
shoreline and the small number of coves similar both in size and in
depth. The· sampling of the lake was not conducted in such a manner
as to be statistically significant according to Hayne, Hall, and
Nichols (1967).
Four stations were chosen for investigating the vertical distri-
bution of the fishes in the lake. Each of the permanent stations was
placed in a different representative area of the lake where the
maximum fishing depth could be obtained (Figure 2). The decision to
use only four stations was influenced by the available equipment, the
limited manpower for checking the nets, and the heavy pleasure-boat
traffic during most of the year.
Water Temperature and Dissolved Oxygen Stations
Stations for sampling water temperature and dissolved oxygen are
shown on Figure 2. Each of the stations was selected to correspond to
stations chosen by Roseberry (1950). Some of the stations were located
at or near permanent markers in the reservoir, while others were
located by sighting between two shore markers.
Sampling Methods
Fish Population Sampling
I· Cove-rotenone samples of the fish population were taken in 12
October, 1970, and June, 1971. The method for cove sampling as described by Swingle and Swingle (1967) was used in this study.
Each cove was blocked off the day before the sample was to be taken by use of a 1/4-inch mesh nylon net, 15 feet deep, 300 feet long.
Diver's then checked the lead line to make sure it was lying on the bottom of the cove. One hundred fish were collected outside the cove, marked, and placed inside the cove in order to establish a gauge of the recovery success after treatment. Each of the coves was treated with emulsifiable rotenone (5%) at a calculated concentration of 2 mg/l and the chemical was dispensed by means of a weighted hose attached to an electric water pump. Fish in distress were collected as soon as possible. The collection of fish from the cove continued for two consecutive days following treatment. At the end of the third day's pick-up, the block net was removed from the cove.
All fish were sorted according to species, weighed, and measured.
Scale samples were taken from a representative sample of all game fish in the first day's collection. All fishes were classified according to size into three categories: fingerling, intermediate, or harvest- able, using a modification of the techniques established by Surber
(1959). Criteria for this classification are summarized in Appendix
Table II.
Records were obtained from the Commission for fish population studies on Claytor Lake for 1961, 1962, 1964, and 1965. These collections were made at various times during the summer in the same coves, but without the use of block-off nets and using a smaller size cove. -1
I 13
Vertical Gill Netting
Vertical gill netting was carried out during the first twenty days of December, 1970, March, 1971, June, 1971, and September, 1971.
Two gill nets were suspended from net racks (Figure 3) at each of
the 4 sample stations in the lake (Figure 2). Each net was 24-feet wide and had a 1/2-, 1-, or 2-inch stretch mesh. The nets were checked daily, weather permitting, and each captured fish was recorded
to as species, length, weight, depth caught, and mesh size in which
it was collected. Scale samples were taken from all game fish.
Water Temperature and Dissolved Oxygen Determination
Temperature and dissolved oxygen determinations were made monthly at 2-foot intervals from the top to the bottom of the lake at each of
7 stations (Figure 2) by means of a Yellow Springs Instrument Company
oxygen analyzer and thermistor, model 54. Graphs developed from these
data were used in the analysis of Claytor Lake for a "two-story"
fishery. The term "two-story" fishery refers to a lake in which the
upper portion is occupied by warm water species and the lower portion
is inhabited by cold water species (Kirkland and Bowling 1966). The
criteria for determining the suitability of Claytor Lake for a "two-
story" fishery was that used by Boles (1970) and Kirkland and Bowling
(1966). They reported the establishment of successful rainbow and
brown trout fisheries in reservoirs in Tennessee and Georgia having
a layer of water with a maximum temperature of 21 C (70 F) and at
least 3 mg/l dissolved oxygen. WARNING TRAFFIC CONE j -
....~ - -
- - POSITION OF VERTICAL GILL NETS 15
For the purpose of this study, only water temperatures and dissolved oxygen data for July, August, and September, 1971, are presented. This was the critical period in determining whether or not a lake would support a year-round trout fishery. Water temperature and dissolved oxygen data for the months of November 1970 to July 1971 and from October 1971 to April 1972 are filed with the Commission of
Game and Inland Fisheries, Richmond, Virginia.
Age Determination
Scale samples were used for age determination of walleye, white bass, and alewives. Scale samples were collected by use of gill nets, rotenone, fishermen's creels, and annual die-offs in the case of the alewives. Scales from the walleye and white bass were collected from the body near the tip of the right pectoral fin (Lagler 1956). Scales from the alewives were taken from the midline just above the insert of the anal fin (Rothschild 1963). The scales were placed in coin envelopes with the following information recorded on the outside: species, located, date, total length, weight, sex, maturity, and gear used to collect the specimen. Stomach contents were recorded for only the fish taken during gill netting operations.
Three scales from each fish were cleaned and mounted between two microscope slides. They were then read using an Eberbach model 2700 microprojector at 40X magnification. The distance from the focus to each annulus was recorded to the closest millimeter. Fish collected during early spring (March 1) were assumed to have completed their growth for the previous year. Therefore an annulus mark was placed at the anterior margin of the scale. 16
Growth Analysis
All data were key-punched on computer cards for use in back calculation of growth rates. Since scale size is rarely proportional to the length of the fish and it is unwise to apply an ~ value derived from another population (Hile 1970), an intercept value~ was determin- ed by fitting a body-scale straight line regression (Van Oosten 1929) utilizing a standard computer regression program. The resulting intercept value for a was then substituted into the following equation: s L a + .....!!. (L - a) n = - S c - c where: L is the length of the fish at the time n of formation of the annulus, n.
a is the intercept value determined by fitting
a body-scale straight line regression.
S is the scale measurement to a given annulus, n. n S is the scale measurement from the focus to the c anterior margin.
Lc is the length of the fish at the time of
capture.
A computer program developed by of the
Engineering Department and of the Biology
Department of Tennessee Technological University was used for back calculating mean total lengths at successive annuli for each age class of each sex and combined sexes. The foregoing formula was used in this program. 17
Length-Weight Relationship
In expressing the length-weight relationship for walleye, white bass, and alewives, the following formula was used:
Log W = a + n Log L where: W is the weight in grams.
L is the length in millimeters.
a is a constant.
n is a constant.
All the fish were combined to determine the length-weight relationship as suggested by Hile (1954).
Coefficient of Condition
A program developed by (unpublished) was used to calculate coefficient of condition values. The formula used in the program was
K(TL) = w ~os L where: W is the weight in grams.
L is the total length in millimeters.
105 is a factor to bring the value of K(TL)
near unity (Carlander 1969).
All fish were separated into sex, 20 mm total length intervals, and one month intervals of capture to yield the best results as described by Lagler (1956).
Comparison of Growth Rates
Scales obtained prior to the 1970 study were collected by the
Virginia Commission of Game and Inland Fisheries. The total length -1
I 18
and weight of these fish samples were converted from the English to
the metric system. Collections made by the writer provided the scale data following the 1969 stocking of alewives. These data were used to compare growth rates of walleye and white bass before and after alewife introduction. Information collected during the 1971 study was also used to compare the observed current growth of walleye now with the growth reported by Roseberry (1950). A two-sample "t"
test was run on the prestocking and poststocking growth rates of each year class to determine if there was a statistically significant difference. RESULTS
Fish Population Studies
The results of the fish population studies are shown in Tables 2 and 3 for October 1970 and June 1971 respectively. Appendix Table II contains the criteria used in grouping the fishes as to fingerlings,
intermediates, or harvestables. Results of the fish population
studies conducted by the Commission are given in Appendix Tables III- VI.
The two fish population samples taken during this study differ considerably in total weight of fish collected. The 1970 rotenone
study yielded 24.4 pounds of fish/acre sampled while the 1971 study
showed 53-2 pounds of fish/acre sampled. Although the total weight differs, the percent of total wieght composed of game fish is very
similar for 1970 and 1971, 56.96%-and 58.93% respectively. The total
percentages of non-game fish and forage fish taken in the rotenone
sample are also in close agreement. In 1970, the percentage by weight
of non-game fish and forage fish was 43.04%, while in 1971 the per- centage by weight was 41.07%.
The total number of fish taken by rotenone in 1970 was 581/acre
sampled. The 1971 study resulted in 831.5 fish/acre sampled from the
same two coves. As with the wieghts, the percent of total game fish
and percent of total non-game fish and forage fish are in close agree- ment. In 1970, 82.83% of the total number of fish were game fish and
in 1971, 80.46% of the total number of fish were game fish.
19 Table 2. The numbers and weights of fish taken by rotenone sampling in Claytor Lake population studies, October 16-18, 1970, reported as number and weight per acre*
Finger lings Intermediates Harvestables Total Species Percent of Total No. Lb. No. Lb. No. Lb. No. Lb. No. Lb.
Game fish Largemouth bass 1.0 0.050 1.0 0.225 -- -- 2.0 0.275 0.34 1.13 Smallmouth bass 3.5 0.400 4.0 1.675 0.5 0.300 8.0 2.375 1.38 9.73 Spotted bass 7.0 0.150 1.5 0.600 -- -- 8.5 0.750 1.46 3.07 White bass ------0.5 0.775 0.5 0.775 0.09 3.18 Bluegill 136.0 0.575 37.0 2.225 25.5 4.150 198.5 6.950 34.17 28.48 Pumpkin seed 4.5 0.075 1.5 0.075 3.0 0.725 9.0 0.875 1.55 3.59 N Green sunfish 235.0 1.300 13.0 0.525 -- -- 248.0 1.825 42.68 7.48 0 White crappie 4.5 0.050 ------4.5 0.050 0.77 0.20 Rock bass 0.5 0.025 ------0.5 0.025 0.09 0.10 Sub-total 392.0 2.625 58.0 5.325 29.5 5.950 479.5 13.900 82.53 56.96
Non-game fish
Flathead catfish 2.5 0.050 0.50 0.100 0.5 7.150 3.5 7.300 0.60 29.92 Channel catfish ------0.5 0.150 0.5 0.150 0.09 0.62 Yellow perch -- -- 1.50 0.075 7.0 0.650 8.5 0.725 1.46 2.97 White sucker ------1.0 1.650 1.0 1.650 0.17 6.76 Sub-total 2.5 0.050 2.00 0.175 9.0 9.600 13.5 9.825 2.32 40.27
Forage fish Spottail shiner 6.5 0.025 ------6.5 0.025 1.12 0.10 Alewife 80.5 0.550 1.0 0.100 -- -- 81.5 0.650 14.03 2.67 Table 2. The numbers and weights of fish taken by rotenone sampling in Claytor Lake population studies, October 16-18, 1970, reported as number and weight per acre* (Continued)
Finger lings Intermediates Harvestables Total Percent of Total Species No. Lb. No. Lb. No. Lb. No. Lb. No. Lb.
Sub-total 87.0 0.575 1.0 0.100 88.0 0.675 15.15 2. 77
GRAND TOTAL 481.5 3.250 61.0 5.600 38.5 15. 550 581. 0 24.400 100.00 100.00
*12% recovery of marked fish
...... N Table 3. The numbers and weights of fish taken by rotenone sampling in Claytor Lake population studies, June 29-July 1, 1971, reported as number and weight per acre*
Finger lings Intermediates Harvest ables Total Percent of Total Species No. Lb. No. Lb. No. Lb. No. Lb. No. Lb.
Grune fish Largemouth bass 104.5 0.200 0.5 0.150 2.0 4.250 107.0 4.600 12.87 8.65 Smallmouth bass 22.5 0.100 4.5 1. 325 0.5 0.200 27.5 1.625 3.31 3.05 Spotted bass 2.0 0.200 4.0 1.100 -- -- 6.0 1.300 o. 72 2.44 White bass ------12.0 5.200 12.0 5.200 1.44 9. 77 Bluegill 298.5 2.325 84.0 6.150 45.5 7.875 428.0 16.350 51.48 30.73 Pumpkinseed 7.5 0.200 2.5 0.125 -- -- 10.0 0.325 1.20 0.61 Green sunfish 65.5 0.750 10.0 0.550 -- -- 75.5 1.300 9.08 2.44 Redbreasted sunfish------0.5 0.200 0.5 0.200 0.06 0.38 N White crappie 0.5 0.025 0.5 0.025 0.5 0.100 1.5 0.150 0.18 0.28 N Rock bass ------0.5 0.250 0.5 0.250 0.06 0.47 Rainbow trout ------0.5 0.050 0.5 0.050 0.06 0.10 Sub-total 501.0 3.800 106.0 9.425 62.0 18.125 669.0 31.350 80.46 58.93
~on.=a_~rne _fi2~ Flathead catfish ------2.0 7.350 2.0 7.350 0.24 13.81 Channel catfish -- -- 2.0 0.400 2.0 0.700 4.0 1.100 0.48 2.07 Yellow perch 0.5 0.025 25.0 o. 775 0.5 0.050 26.0 0.850 3.13 1.60 Carp ------1.0 6.900 1.0 6.900 0.12 12.97 Sub-total 0.5 0.025 27.0 1.175 5.5 15.000 33.0 16.200 3.97 30.45
Forage fish
Alewife 111.5 4.150 17.0 1.450 1.0 0.050 129.5 5.650 15.57 10.62 I
Table 3. The numbers and weights of fish taken by rotenone sampling in Claytor Lake population studies, June 29-July 1, 1971, reported as number and weight per acre* (Continued)
Finger lings Intermediates Harvestables Total Percent of Total Species No. Lb. No. Lb. No. Lb. No. Lb. No. Lb .
Sub-total 111.5 4.150 17.0 1. 450 1.0 0.050 129.5 5.650 15.57 10.62
GRAND TOTAL 613.0 7.975 150.0 12.050 68.5 33.175 831.5 53.200 100.00 100.00
*21% recovery of marked fish
N w 24
In 1970 there were 0.275 pounds (1.13% of total) or 2.0 (0.34% of total) largemouth bass/acre sampled in Claytor Lake. For 1971, there were 4.6 pounds (8.65% of total) or 107 (12.87% of total) largemouth bass per acre sampled.
Alewife reproduction was observed both years. In 1970, there were 80.5 fingerling alewives/acre sampled, while in 1971 there were
111.5 fingerling alewives/acre sampled.
The recovery rates by days are given in Table 4. The highest percent recovery by weight (47.1%) and numbers (43.3%) occured on the first day. This was followed by a decreasing percentage of weight and numbers recovered for the second and third days. The 1970 recovery rate for marked fish was 12% and in 1971 the recovery rate was 21%.
The water temperature within the sample area was 18.5 C in 1970 and in 1971 it ranged from 27.0 C to 22.3 C for the main channel area.
A thermocline was present at a depth of 3-4 m in this cove. The Peak
Creek sample area had water temperatures ranging from 26 C to 23 C on the bottom. A thermocline was present in this cove at 4-6 m.
Vertical Gill Netting
A summary of the fish species and numbers of each caught by vertical gill nets are shown in Table 5. The alewife was the dominant species collected in the nets. There were 1310 alewives collected representing 67.70% of the total number of fish captured. Channel catfish were next with 11.32% (219) of the total sample. The third most numerous species collected was the white crappie, 11.27% (218) of the total collection. Other species captured, in order of abundance, 25
Table 4. The total numbers and weights of fish collected during each day of cove sampling, using rotenone, in Claytor Lake, 1970-1971
Collected* Percent Day No. Lb. No. Lb.
First day 1252 73.10 44.3 47.1
Second day 905 44.85 32.0 28.9
Third day 668 37.25 23.7 24.0
TOTAL 2825 155.20 100.0 100.0
*Based on four samples 1970-1971 26
Table 5. Fish species and number of individuals caught by vertical gill net in Claytor Lake, 1970-1971
Total Species Number Percent
Alewife (Alosa pseudoharengus) 1310 67.70
Channel catfish (Ictalurus punctatus) 219 11.32
White crappie (Pomoxis annularis) 218 11.27
White bass (Morone chrysops) 64 3.31
Walleye (Stizostedion v. vitreum) 52 2.69
Flathead catfish (Pylodictis olivaris) 20 1.03
Black crappie (Pomoxis nigromaculatus) 14 o. 72
Carp (Cyprinus carpio) 11 0.57
Yellow perch (Perea flavescens) 9 0.47
Bluegill (Lepomis macrochirus) 8 0.41
Golden shiner (Notemigonus crysoleucas) 4 0.21
Smallmouth bass (Micropterus dolomieui) 3 0.15
Muskellunge (Esox masquinongy) 1 0.05
Rainbow trout (Salmo gairdneri) 1 0.05
Spotted bass (Micropterus punctulatus) 1 0.05
TOTAL 1935 100.00 27 were the white bass, walleye, flathead catfish, black crappie, carp,
yellow perch, bluegill, golden shiner, smallmouth bass, muskellunge,
rainbow trout, and spotted bass. The single muskellunge taken in
the vertical nets was captured in November after a release into the
lake of 50 of these fish one month earlier. Appendix Tables VI-X
show the numbers of alewives, white crappie, channel catfish, white
bass, and walleye collected in all sample periods.
The highest concentration of alewives was between 1 and 2 m (4-7
ft) in December and moved down to between 9 and 10 m (30-33 ft) in
March. In June, the alewives showed a tendency to move to the upper
10 m (33 ft) of the lake and remain there until after September
(Figure 4).
Channel catfish were collected in a vertial distribution pattern
similar to the alewives. The concentration of channel catfish was
within 2 m (7 ft) of the alewife for all sampling periods (Figure 4).
Only 2% (4) of the channel catfish were taken in zones that did not
contain alewives.
Walleye did not follow any clear pattern of depth distribution
(Figure 4), except during September when all the fish were near the
surface of the lake.
White crappie showed a gradual downward movement in the lake from
December to September (Figure 4). In December, most white crappie were collected at 6-7 m (20-23 ft). In the March sample, these fish
had moved down to 7-9 m (23-30 ft) in the lake. In June, when other
fishes were moving up near the surface, the concentration of white
crappie was seeking deeper waters in the lake. This was true in DEPTH (M)
(JJ I\) I\) OJ (JI (JI 0 'Tl 0 (JI 0 01 0 I I I I G> I I ~ I z 0 0 0 :; 111 111 111 'Tl G) CHANNEL CATFISH -I '"'O (") CJ'J -I ::c ~ :::c ::!! CJ'J 0 WHITE CRAPPIE (") Q :::c 0 r CJ'J z )> -I (") -< :ti 111 -i - z om s: -i ;o ~ )> ;o CHANNEL CATFISH :ti )> 0 (") -I N rZ ::c WALLEYE ~~~~ 00 )> 0 ::;s; z WHITE I'll 0 ~ 'Tl
z ALEWIVES CHANNEL < CJ'J 111 fTl :ti ~ -I 0 WHITE )> r 29
September also. Of the 218 white crappie collected, 98% (213) were collected in the same vertical region as alewives.
White bass were collected only during June and September (Figure
4). The depth distribution was found to range from the surface to 10 m
(33 ft) in June, and from the surface down to 14 m (46 ft) in September.
In both sample periods, the largest grouping of white bass was found at the surface of the lake where a majority of alewives occurred.
Combining the channel catfish, walleye, white crappie, and white bass as a unit, they seem to occupy approximately the same vertical region in the lake. Of the 553 fish taken during the vertical gill netting operation, 544 were taken within the vertical region occupied by the alewife.
Preferences for temperature and dissolved oxygen could not be determined for any of the species collected due to the limited amount of data for these two parameters.
Fish Fauna of Claytor Lake
Table 6 lists the fishes collected in Claytor Lake during this study and the investigation conducted by Roseberry (1950). The relative abundance of each species is also given based on the total number of each species collected in all samples. All common and scientific names are in accordance with the American Fisheries Society (1970). The list does not include species of fish that were introduced and apparently failed to establish themselves in the lake.
There were 25 species of fish collected during this study. Five of these species (alewife, rainbow trout, muskellunge, white bass, and l
30
Table 6. List of the common and scientific names of fishes found in Claytor Lake and their relative abundance in 1950 and 1971
Relative Abundance Common name Scientific Name 1950 1971
Alewife Family - Cluperidae Alosa pseuchoharengus (Wilson) * A Rainbow trout Family - Salmonidae Salmo gairdneri Richardson * R Muskellunge Family - Esocidae Esox masquinongy Mitchell * R Family - Cyprinidae Carp CyPrinus carpio Linnaeus A c Satinfin shiner Notropis analostanus (Girard) R * Spottail shiner Notropis hudsonius (Clinton) R R
Family - Catostomidae White sucker Catostomus commersoni (Lacipide) * R Hog sucker Hypentelium nigricans (Lesueur) C R
Family - Ictaluridae Channel catfish Ictalurus punctatus (Rafinesque) A A Flathead catfish Pylodictis olivaris (Raf inesque) R c
Family - Percichthyidae White bass Morone chrysops (Rafinesque) * A Striped bass Morone saxatilis (Walbaum) * R Family - Centrarchidae Rock bass Ambloplites rupestris (Rafinesqu~R R Redbreasted sunfish Lepomis auritus (Linnaeus) * R Green sunfish Lepomis cryanellus (Rafinesque) C A Pumpkinseed Lepomis gibbosus (Linnaeus) C A Bluegill Lepomis macrochirus Rafinesque A A Smallmouth bass Micropterus dolomieui Lacipide A A Spotted bass Micropterus punctulatus (Rafinesque) A c Largemouth bass Micropterus salmoides (Lacipide) R A White crappie Pomoxis annularis Rafinesqu~ A A Black crappie Pomoxis migromaculatus (LeS'.Jeur) R A l 31
Table 6. List of the common and scientific names of fishes found in Claytor Lake and their relative abundance in 1950 and 1971 (Continued)
Relative Abundance Common name Scientific Name 1950 1971
Family - Pericidae Yellow perch Perea flavescens (Mitchell) R A Walleye Stizostedion v. vitreum (Mitchell) A A
* Not reported A Abundant--200 or more specimens collected C Common--16-100 specimens collected R Rare--less than 15 specimens collected 32
striped bass) were introduced into the lake by the Commission of Game and Inland Fisheries after 1950.
Excluding the five introduced species, there were two new species identified in this study for Claytor Lake. The two new species were the white sucker, Catostomus commersoni, and the red- breasted sunfish, Lepomis auritus.
The four species which have become well established in the lake over the past 20 years are the flathead jatfish, Prylodictus olivaris, largemouth bass, Micropterus salmoides, yellow perch, Perea flavescens, and black crappie, Pomoxis nigromaculatus. These four species were taken both in gill nets and in rotenone sampling.
The one specimen of the hog sucker, Hypentelium nigricans, captured in a gill net during this investigation reflects the very low popula- tion of these fish in Claytor Lake. It is now listed as a rare species.
Only a small percentage (1-2%) of the fish collected during this study were spotted bass, Micropterus punctulatus. It has apparently decreased in numbers and is now listed as common.
Water Temperature and Dissolved Oxygen
Appendix Tables XI-XIII summarize the water temperature and dissolved oxygen data for July 23, August 21, and September 19, 1971.
Assuming that trout require water of 21 C or less, which contain
3 mg/l of oxygen, data for this period of 1971 showed Claytor Lake to have a zone of trout water present on 23 July from 22-25 m (72-80 ft) at station 1 (Figure 5). The zone of trout water at station 2 ranged from 17 to 20 m (56-66 ft). If any trout water occurred above station
2, it could not be detected. On 21 August, water 21 C or less which STATION 2 3 4 5 6 0
5
10
15 .....~ :I: 20 ..... Q.. w w w 0 25~ ~ • TROUT WATER
30
35
FJG. 5. ZONE OF TROUT WATER IN CLAYTOR LAKE, JULY 23, 1971 34 contained 3 mg/l or more of oxygen was not present at any of the stations. By 19 September, water with the above criteria had re- appeared in the lake at stations 2, 3, and 4 (Figure 6).
Age Determination
During this investigation a total of 279 walleye were collected for use in age determination. The dominant age class was II, having 137 fish or 49% of the total sample (Figure 7). The second largest group was age III. A total of 104 fish, or 37% of the sample, were in this age group. The remaining fish were distributed in age groups as follows: I, 1 (1%); IV, 26 (9%); V, 9 (3%); and VI, 2 (1%).
Age-class II was dominant for the male walleye (Figure 7). It contained 109 fish (65%). Numbers of fish in other age classes and their percentages of the total were as follows: III, SO (30%);
IV, 7 (4%); and V, 1 (1%).
Of the 84 female walleye aged, 42 (5%) were in age class III
(Figure 7). Age classes II and IV consisted of 16 and 17 walleye respectively. Each of the two preceding age classes held 19% of the female walleye sample. Strengths of the remaining classes were V,
7 (9%) and VI, 2 (3%).
A total of 543 white bass were used in age class analysis. The strongest age class was III, having 354 fish (65%) (Figure 8). Age class II had 84 fish (15%). The remaining age class strengths and the percentages of the total were as follows: 0, 2 (2%); IV, 65 (12%);
V, 20 (4%); and VI, 3 (2%). STATION 2 3 4 5 6 0
5
10
~ 15
w :r 20 U1 I- l a. w 0 25 L • TROUT WATER
30
35
FIG. 6. ZONE OF TROUT WATER IN CLAYTOR LAKE,
SEPTEMBER 19, 1971 36
150
J: ~125 LL ~ FEMALE ~100 a:: f2I MALE CDw75 ~ 0 TOTAL ::> z 50
25
0 I Il m AGE CLASS
FIG.7. DISTRIBUTION BY SEX AND AGE CLASS OF 279 WALLEYE, CLAYTOR LAKE, 1971 37
375
350
275
250 J: (/) u:: 225
LL 0200 a: ~175 ~ :::> Zl50
125 £21 MALE g FEMALE 100 0 TOTAL 75
5
AGE CLASS FIG. 8. DISTRIBUTION BY SEX AND AGE CLASS OF 543 WHITE BASS, CLAYTOR LAKE, 1971 38
For the male white bass collected during this project, age classes II and III were dominant (Figure 8). These age classes con- sisted of 53 and 184 fish respectively. This represented 20% age II and 68% age III male white bass in the sample. The remaining age class strengths and the percentages of the total were as follows:
I, 4 (2%); IV, 19 (7%); V, 4 (2%); and VI, 1 (1%).
Age class III was the prevailing group for the female white bass (Figure 8). This age class had 162 fish, 65% of the total.
Other year class strengths and percentages of total were found to be: I, 7 (3%); II, 17 (7%); IV, 46 (18%); V, 15 (6%); and VI, 2 (1%).
For the total sample of white bass aged, 84% (455) were in age class III or less, and 16% (88) were above three years of age. The oldest fish taken was in age class VI.
Age class I was the strongest class for the 244 alewives aged
(Figure 9). Included in this age class were 122 fish, 50% of the sample analyzed. Other age class strengths and the percentages of the total were as follows: O, 77 (32%); II, 43 (17%); and III, 2 (1%).
Growth Analysis
The growth rate of the walleye population of Claytor Lake was calculated using 279 fish and an "a" value of 14.6. Individual growth rates for males and females were calculated with a sample size of 167 and 84 fish, respectively. The growth for the combined sexes of walleye is presented in Table 7. Table 8 contains the growth for the males, and the growth for the females is sho~~ in Table 9. 39
...
150
:r:125 ... Cl)
~ ~100 0 a: 75 - l&J CD ::E 50 "' => z 25
0 0 I n m AGE CLASS FIG. 9. DISTRIBUTION BY AGE CLASS OF 24 4 ALEWIVES, CLAYTOR LAKE, 1971 ------,
Table 7. Average calculated total lengths in millimeters at successive ages by age groups of 279 walleye, Claytor Lake, 1971
. Age Number of Mean length Mean calculated total length (mm) at annulus class fish at capture I II III IV v VI
I 1 325 161 (12.8)* (6.3) II 137 371 194 353 (14.6) (7.6) (13. 9) III 104 449 198 320 420 (17. 7) (7.8) (12.6) (16.5)
26 526 208 333 430 492 ~ IV 0 (20. 7) (8.2) (13 .1) (16.9) (19.4) v 9 594 211 352 451 521 570 (23.4) (8.3) (13.9) (17.8) (20.5) (22.4) VI 2 642 207 327 433 512 565 617 (25.3) (8 .1) (12.9) (17. O) (20.2) (22.2) (24.3) Weighted mean total length 197 339 424 500 569 617 (7.8) (13.3) (16. 7) (19.7) (22.4) (24.3) Mean annual increment of total length 197 142 85 76 69 48 (7. 8) (5.6) (3.3) (3.0) (2. 7) (1.9) Percent of growth per year of life 32 23 14 12 11 8
* Total length in inches Table 8. Average calculated total length in millimeters at successive ages by age groups of 167 male walleye, Claytor Lake, 1971
Age Number of Mean length Mean calculated total length (mm) at annulus) class fish at capture I II III IV v
I 0 0 0
II 109 374 194 360 (14.7)* (7. 6) (14.2)
III 50 436 197 318 416 (17.2) (7. 8) (12.5) (16.4) .i:- t--' IV 7 507 215 350 431 482 (20.0) (8.5) (13.8) (17. 0) (19.0) v 1 579 198 308 401 467 519 (22.8) (7 .8) (12.2) (15.8) (18.4) (20.4)
Weighted mean total length 196 347 417 480 519 (7. 7) (13. 7) (16.4) (18.9) (20.4)
Mean annual increment of total length 196 151 70 63 39 (7. 7) (5.9) (2.8) (2.5) (1.5)
Percent of growth per year of life 38 29 13 12 8
* Total length in inches Table 9. Average calculated total length in millimeters at successive ages by age groups of 84 female walleye, Claytor Lake, 1971
Age Number of Mean length Mean calculated total length (nnn) at annulus class fish at capture I II III IV v VI - I 0 0 0
II 16 372 197 324 (14.6)* (7.8) (12.8)
III 42 466 200 328 426 (18.3) (7 .9) (12.9) (16. 8)
IV 17 535 205 328 433 497 .J:- (21.1) (8.1) (12.9) (17.0) (19.6) N
v 7 585 200 348 447 516 565 (23.0) (7.9) (13. 7) (17.6) (20.3) (22.2)
VI 2 642 207 327 433 512 565 617 (25.3) (8.1) (12.9) (17.0) (20.2) (22. 2) (24.3)
Weighted mean total length 200 329 430 503 565 617 (7 .9) (13.0) (16.9) (19. 8) (22.2) (24.3)
Mean annual increment of total length 200 129 101 73 62 52 (7.9) (5 .1) (4.0) (2.9) (2 .4) (2.0)
Percent of growth per year of life 32 21 16 12 10 9
··------·-·-~ -- --·---- *Total length in inches 43
Walleye in Claytor Lake were 197 mm (7.8 inches) at the end of their first year of growth. This represented 32% of the total growth.
In their second year of growth they were 339 mm (13.3 inches). The increase of 142 mm (5.6 inches) from age I to age II was reflected as
23% of the growth in the life span. At age III, the walleye were 424 mm (16.7 inches). The 85 mm (3.3 inches) accounted for 14% of the growth. The increase from 424 mm (16.7 inches) at age III to 500 mm
(19.7 inches) at age IV represented 12% of the growth. Eleven percent
(69 mm, 2.7 inches) of growth was acquired between ages IV and V.
The remaining 8% (48 mm, 1.9 inches) of the growth occurred between ages V and VI. Age VI walleye in Claytor Lake had a calculated total length of 617 mm (24.3 inches).
The calculated growth for male and female walleye was approxi- mately the same at the end of age I. The males were 196 mm (7.7 inches) and the females were 200 mm (7.9 inches). Male walleye were larger at age II (347 mm, 13.7 inches) than females (329 mm, 13.0 inches) of the same age. From age III to age V the female fish exhibited a faster growth rate than the males. Females were 430 mm
(16.9 inches) at age III, 503 mm (19.8 inches) for age IV, and 565 mm
(22.2 inches) at age V. Males had obtained a length of 417 mm (16.4 inches) by age III, 480 mm (18.9 inches) at age IV, and 519 mm (20.4 inches) when five years old. Male walleye age II had a greater mean length at capture (374 mm, 14.7 inches) than the females (372 mm, 14.6 inches), while the females exhibited greater mean length at capture than the males for age classes II through V. 44
The results for the back calculation of growth rates, using a = 38.4, for 543 white bass from Claytor Lake are shown in Table 10. Table 11 presents the growth rates for the males, and the female growth rates are shown in Table 12. White bass from Claytor Lake were 145 mm (5.7 inches) at the end of the first year of growth and
235 mm (9.3 inches) at the end of the second growing season. The growth in the first year of life represented 35% of the total growth.
Growth in the second year of life represented 22% (90 mm, 3.5 inches) of the total growth. Age III white bass were 300 ~ (11.8 inches).
There was a 16% (65 mm, 2.6 inches) increase in growth from age II to age III. Four year old white bass were found to be 351 mm (13.8 inches) long. The increase of 51 mm (2.0 inches) between ages III and IV was reflected as 12% of the growth. Age V fish had a greater increase in growth (13%) than the age IV fish. The five year old fish were 404 mm (15.9 inches) with an annual increment of 53 mm
(2.1 inches). The total length of the white bass was calculated to be 412 mm (16.2 inches). They exhibited an annual increment between ages V and VI of 8 mm (0.2 inches) or 2% of their total length.
The average calculated size of the female was larger than the average calculated size of the male at each annulus. The females showed a greater annual increment of growth in age classes I through V, but the males exhibited a larger growth increment in age Class VI.
The mean length at capture was greater for the males (225 mm, 8.9 inches) than for the females (219 mm, 8.6 inches) at age I. The mean length of capture for females was greater in age classes II through VI than for the males of the same age •
• Table 10. Average calculated total length in millimeters at successive ages by age groups of 543 white bass, Claytor Lake, 1971
Age Number of Mean length Mean calculated total length (mm) at annulus) class fish at capture I II III IV v VI
0 2 147 (5.8)* I 15 224 153 (8.8) (6.0) II 84 271 147 245 (10.7) (5.8) (9.6)
III 354 311 144 228 297 .i:- (12.2) (5. 7) (9.0) (11. 7) VI IV 65 357 147 249 309 343 (14.1) (5.8) (9.8) (12.2) (13.5) v 20 415 157 266 332 375 406 (16.3) (6.2) (10.5) (13 .1) (14.8) (16.0) VI 3 416 149 262 324 366 395 412 (16.4) (5. 9) (10.3) (12.8) (14.4) (15.6) (16.2) Weighted mean total length 145 235 300 351 404 412 (5. 7) (9.3) (11.8) (13 .8) (15.9) (16.2) Mean annual increment of total length 145 90 65 51 53 8 (5. 7) (3. 5) (2.6) (2 .0) (2.1) (0.3) Percent of growth per year of life 35 22 16 12 13 2
*Total length in inches ------,
Table 11. Average calculated total length in millimeters at successive ages by age groups of 265 male white bass, Claytor Lake, 1971
Age Number of Mean length Mean calculated total length (mm) at annulus class fish at capture I II III IV v VI
I 4 225 151 (8. 9) * (5. 9) II 53 268 149 249 (10.6) (5. 9) (9.8)
III 184 306 144 229 295 (12.0) (5. 7) (9. O) (11. 6) .&::- °' IV 19 355 149 250 309 344 (14. 0) (5.9) (9.8) (12.2) (13.5) v 4 378 151 234 299 346 374 (14.9) (5. 9) (9.2) (11. 8) (13.6) (14. 7)
VI 1 403 144 245 313 346 386 396 (15.9) (5.7) (9.6) (12.3) (13.6) (15.2) (15.6)
Weighted mean total length 145 234 297 345 377 396 (5. 7) (9.2) (11. 7) (13.6) (14.8) (15.6)
Mean annual increment of total length 145 89 63 48 32 19 (5. 7) (3. 5) (2.5) (1. 9) (1.3) (O. 7)
Percent of growth per year of life 37 22 16 12 8 5
* Total length in inches ------,
Table 12. Average calculated total length in millimeters at successive ages by age groups of 249 female white bass, Claytor Lake, 1971
Age Number of Mean length Mean calculated total length (mm) at annulus class fish at capture I II III IV v VI
I 7 219 159 (8.6)* (6.3)
II 17 275 145 248 (10.8) (5. 7) (9.8)
III 162 318 144 229 299 (12.5) (5.7) (9. 0) (11.8) ...... r::-- IV 46 357 147 248 308 343 (14.0) (5.8) (9.8) (12.1) (13. 5) v 15 421 157 269 336 379 411 (16.6) (6.2) (10.6) (13. 2) (14. 9) (16. 2)
VI 2 423 151 271 330 377 400 420 (16.7) (5. 9) (10. 7) (13.0) (14.8) (15. 7) (16.5)
Weighted mean total length 146 237 304 353 409 420 (5.8) (9.3) (12.0) (13. 9) (16.1) (16.5)
Mean annual increment of total length 146 91 67 49 56 11 (5.8) (3.6) (2.6) (1.9) (2. 2) (0.4)
Percent of growth per year of life 35 22 16 12 13 2
* Total length in inches 48
Using an "a" value of 16.8, back calculations of the total length were conducted for 244 alewives (Table 13). The young-of- the-year alewives were found to have a mean length of 81 mm (3.2 inches) at capture. One year old alewives were 145 nnn (5.7 inches) total length. The alewives attained 65% of their growth the first year of life. Age II alewives had a weighted mean total length of
179 mm (7.0 inches). Alewives in age class II displayed an annual increment between ages I and II of 34 mm (1.3 inches). This repre- sented 16% of the growth per year of life. The two age III fish used in the calculations had a weighted mean total length of 222 mm (8.7 inches). Age III alewives showed a 19% (43 mm, 1.7 inches) increase in growth between age II and age III.
Length-Weight Relationship
The length-weight relationship as determined from a sample of 243 walleye (sexes combined) for Claytor Lake was log W = -5.69978 +
3.25378 log T.L. From a sample of 511 white bass of both sexes from
Claytor Lake, the length-weight regression was calculated as being log W = -4.60826 + 2.87194 log T.L. The relation between length and weight for 364 alewives from Claytor Lake was found to be as follows: log W = -5.28911 + 3.06370 log T.L.
Coefficient of Condition
Coefficient of condition factors [K(TL)-factor] are given for male walleyes in Table 14 and for female walleye in Table 15. Each sex was grouped into 20 Illill total length intervals by month. Male condition factors have a tendency to increase from spring to fall with length. I
I
Table 13. Average calculated total length in millimeters at successive ages by age groups of 244 alewives, Claytor Lake, 1971
Age Number of Mean length Mean calculated total length (mm) at annulus class fish at capture I II III
0 77 81 (3.2)*
I 122 154 133 (6.1) (5.2)
II 43 187 150 179 (7.4) (5. 9) (7. 0) ~ '° III 2 225 120 184 228 (8. 9) (4. 7) (7.2) (8. 7)
Weighted mean total length 145 179 222 (5. 7) (7 .0) (8. 7)
Mean annual increment of total length 145 34 43 (5. 7) (1.3) (1. 7)
Percent of growth per year of life 65 16 19
* Total length in inches
_J Table 14. Average K(TL)-factor for male walleye by month and twenty millimeter total length intervals, Claytor Lake, for the months April through October, 1971
Twenty millimeter April May June July total length "K" Number "K" Number "K" Number "K" Number intervals factor fish factor fish factor fish factor fish
280-299 ------1.73 l 300-319 0.83 l 320-339 0.96 4 ------0.93 3 340-359 0.84 15 -- -- 0.85 l 0.95 1 360-379 0.86 34 0,87 1 380-399 0.86 32 0.83 1 -- -- 0.99 1 400-419 0.90 11 0.85 1 1.28 2 0.97 2 420-439 0.80 2 \II ------0 440-459 0.95 2 -- -- 0.94 2 0.94 1 460-479 0.87 2 0.99 2 0.96 3 0.87 1 480-499 ------1.00 3 500-519 ------0.83 2 520-539 ------0.96 1 540-559 560-579 0.39 1 ------1.13 1
Total 0.86 104 0.91 5 0.98 10 1.02 15 Table 14. Average K(TL)-factor for male walleye by month and twenty millimeter total length intervals, Claytor Lake, for the months April through October, 1971 (Continued)
Twenty millimeter August September October Total total length "K" Number "K" Number "K" Number "K" Number intervals factor fish factor fish factor fish factor fish
280-299 ------1. 73 1 300-319 ------0.83 1 320-339 0.84 1 ------0.94 8 340-359 0.99 1 ------0.85 18 360-379 0.69 2 ------0.85 37 380-399 1.02 1 -- -- 1.03 1 0.87 36 400-419 0.92 1 1.09 1 0.98 1 0.96 21 Vt 420-439 -- -- 1.07 1 1.00 1 0.92 4 .... 440-459 ------0.93 3 0.94 8 460-479 0.92 1 -- -- 1.04 6 0.97 15 480-499 1.01 1 ------1.01 4 500-519 1.00 2 -- -- 1.03 1 0.94 5 520-539 -- -- 0.93 2 -- -- 0.90 3 540-559 560-579 ------0.76 2
Total 0.91 10 1.00 4 1.00 15 0.90 163 Table 15. Average K(TL)-factor for female walleye by month and twenty millimeter total length intervals, Claytor Lake, for the months of April through October, 1971
Twenty millimeter April May June July total length "K" Number "K" Number "K" Number "K" Number intervals factor fish factor fish factor fish factor fish
280-299 ------1.00 1 300-319 320-339 0.93 1 ------0.86 1 340-359 ------0.99 1 360-379 -- 380-399 1.17 1 0.91 3 -- -- 0.98 2 400-419 VI ------N 420-439 1.04 1 -- -- 0.89 1 440-459 -- -- 0.89 1 0.95 3 460-479 -- -- 1.06 2 o. 98 4 0.98 1 480-499 ------0.95 3 1.00 2 500-519 -- -- 1.08 4 -- -- 1.00 8 520-539 1.15 1 ------1.11 1 540-559 560-579 0.58 1 -- -- 0.59 1 580-599 600-619 ------0.99 1 620-639 -- -- 1.03 1 640-659 -- -- 0.94 1
Total 0.98 5 1.00 12 0.93 13 1.00 17 Table 15. Average K(TL)-factor for female walleye by month and twenty millimeter total length intervals, Claytor Lake, for the month of April through October, 1971 (Continued)
. Twenty millimeter August September October Total total length "K" Number "K" Number "K" Number "K" Number intervals factor fish factor fish factor fish factor fish
280-299 ------1.00 1 300-319 320-339 ------0.90 2 340-359 0.91 2 ------0.94 3 360-379 0.91 2 ------0.91 2 380-399 0.95 1 ------0.97 7 VI 400-419 0.90 1 ------0.90 1 w 420-439 1.20 2 ------1.00 4 440-459 0.98 1 0.95 1 -- -- 0.94 6 460-479 1.02 4 0.97 1 1.03 2 1.01 14 480-499 -- -- 1.09 1 1.02 2 1.00 8 500-519 -- -- 1.10 2 1.03 2 1.04 16 520-539 1.12 2 -- -- 1.00 2 1.08 6 540-559 1.07 1 ------1.07 1 560-579 1.07 1 -- -- 1.10 1 0.83 4 580-599 1.09 1 -- -- 1.12 2 1.11 3 600-619 ------0.99 1 620-639 ------1.05 1 1.04 2 640-659 ------0.94 1
Total 1.00 18 1.04 5 1.05 12 1.00 82 54
The females exhibited a similar tendency with increase in condition factors from spring to fall and with increase in length. Condition factors for males ranged from 1.73 for one male in the 280-299 mm interval in July to 0.39 for one male in the 560-579 mm group taken in April. Female condition factors ranged from a high of 1.17 for one female in the 380-399 mm class collected in April to a low of 0.58 for one female in the 560-579 mm class interval taken in
April.
Table 16 summarizes condition factors for male white bass and
Table 17 presents the condition factors for the female white bass.
Grouping of the data was the same as described for the walleye. It is possible male white bass condition factors may have been lower in May and June than either April or July. From July to October condition factors increased from 1.22 to 1.37. An increase in condition factor with length could not be detected. The range for male white bass condition factors was from 1.44 for one fish in the
200-219 mm class to 0.98 for five fish in the 360-379 mm interval.
The condition factors for female white bass seemed to have followed the same pattern as the males. Condition factors for April and July may have been higher than either May or June. A small decrease in the condition factor may possibly be noted for those fish over 360 mm as compared with those under 360 mm. Female white bass condition factors varied from a high of 1.51 for three fish collected in
October in the 300-319 mm group to a low of 0.40 for one female taken in October in the 560-579 mm. range. Table 16. Average K(TL)-factor for male white bass by month and twenty millimeter total length intervals, Claytor Lake, for the months of April through October, 1971
Twenty millimeter April May June July total length "K" Number "K" Number "K" Number "K" Number intervals factor fish factor fish factor fish factor fish
200-219
220-239 1.20 5 240-259 1.24 13 -- -- 1.11 1 1.23 2
260-279 1.12 35 1.06 7 1.16 2 V1 -- -- \J1 280-299 1.15 31 1.07 4 -- -- 1.21 7 300-319 1.20 72 1.12 3 -- -- 1.23 5 320-339 1.19 15 1.08 2 -- -- 1.24 5 340-359 1.07 4 360-379 o. 98 5 ------1.21 2 380-399 -- -- 1.02 1
Total 1.17 180 1.09 10 1.07 8 1.22 23 Table 16. Average K(TL)-factor for male white bass by month and twenty millimeter total length intervals, Claytor Lake, for the months of April through October, 1971 (Continued)
Twenty millimeter August September October Total total length "K" Number "K" Number "K" Number "K" Number intervals factor fish factor fish factor fish factor fish
200-219 1.44 1 ------1.44 1 220-239 ------1.20 5 240-259 1.36 1 ------1.24 17 260-279 1.11 44 ------IJ1 0\ 280-299 1.22 2 ------1.15 44 300-319 1.23 2 1.37 1 1.41 1 1.20 84
320-339 1.32 12 1.36 4 1.36 5 1.26 43
340-359 1.32 3 1.22 1 1.38 4 1.25 12 360-379 1.16 1 ------1.06 8 380-399 1.27 2 ------1.19 3
Total 1.30 24 1.34 6 1.37 10 1.19 261 I
I
Table 17. Average K(TL)-factor for female white bass by month and twenty millimeter total length intervals, Claytor Lake, for the months April through October, 1971
Twenty millimeter April May June July total length "K" Number "K" Number "K" Number "K" Number intervals factor fish factor fish factor fish factor fish
160-179 ------1.30 1 180-199 -- -- 1.16 1 -- -- 1.35 1 200-219 ------1.24 1 220-239 240-259 1.06 5 -- -- 1.12 1 260-279 1.14 7 1.12 2 1.08 2 1.22 3 280-299 1.14 8 1.03 1 -- -- 1.32 6 VI 300-319 1.14 43 1.10 8 -- -- 1.19 5 ...... 320-339 1.16 31 1.11 2 -- -- 1.24 5 340-359 1.32 2 1.12 3 -- -- 1.21 3 260-379 1.07 4 1.08 1 -- -- 1.17 2 380-399 0.87 3 0.95 2 -- -- 1.08 3 400-419 1.07 5 ------1.10 4 420-439 ------1.15 1 440-459 0.99 1 560-579
Total 1.13 109 1.09 20 1.09 3 1.21 35
_J I
Table 17. Average K(TL)-factof for female white bass by month and twenty millimeter total length intervals, Claytor Lake, for the months April through October, 1971 (Continued)
Twenty millimeter August September October Total total length "K" Number "K" Number "K" Number "K" Number intervals factor fish factor fish factor fish factor fish - 160-179 ------1.30 1 180-199 ------1.25 2 200-219 ------1.24 1 220-239 240-259 1.37 2 ------1.15 8 260-279 1.40 1 ------1.16 15 280-299 1.23 1 ------1.21 16 VI 300-319 1.33 9 1.30 1 1.51 3 1.18 69 CX> 320-339 1.33 19 1.29 2 1.35 6 1.23 65 340-359 1.33 13 1.29 4 1.41 5 1.30 30 360-379 1.17 5 1.37 4 -- -- 1.19 16 380-399 1.20 2 -- -- 1.10 2 1.03 12 400-419 1.20 2 1.28 1 -- -- 1.12 12 420-439 ------1.15 1 440-459 ------0.99 1 560-579 ------0.40 1 0.40 1
Total 1.31 54 1.32 12 1.31 17 1.20 250 59
Comparison of Growth Rates
Comparison of the growth rates of walleye before and after the introduction of the alewife into Claytor Lake is shown in Table 18.
In comparing ages I through IV, no significant difference was noted between the growth rates. Comparison of the growth rates of white bass before and after the introduction of the alewife into Claytor
Lake is given in Table 19.
Alewife Utilization
In examining the stomach contents of various species of predators in Claytor Lake as an incidental part of this study, alewives were found on one or more occasions in the following [number of stomachs examined in parentheses]: walleye (64), white bass (43), smallmouth bass (8), channel catfish (20), flathead catfish (18), black crappie
(13), white crappie (11), and yellow perch (9).
Alewives were the only fish found in the 16 walleye stomachs containing food. The alewives taken by the walleye ranged from 76 111111
(3.0 inches) to 187 111111 (7.4 inches) in total length.
Thirty-four white bass stomachs contained food. Only crayfish were present in four of the stomachs; crayfish and alewives were found in three of the stomachs; and, only alewives were noted in 27 stomachs.
Size range for the alewives taken by white bass was from 50 111111 (2.0 inches) to 120 111111 (4.7 inches) total length.
Because the alewife and crayfish seem to be the principle sources of food for the walleye and white bass in Claytor Lake, an analysis of the food value of each was made using a bomb calorimeter. The alewife I
Table 18. Total length at each annulus formation for walleye before and after the stocking of alewives, with "t" values indicating significance of difference, Claytor Lake, 1971
Mean calculated total length at annulus (mm)
Annulus 1 2 3 4 Before stocking (1962-67) 204(17)* 352(10) 430(7) 536(2) (8.o)+ (13.8) (16. 9) (21.1) After stocking (1971) 197 (279) 339(278) 424(141) 500(37) (7 .8) (13.3) (16.7) (19.7)
Calculated "t" 0.93 NS 0.89 NS 0.31 NS 0. 93 NS Q\ 0
* Number of fish used in each comparison + Total length in inches Table 19. Total length at each annulus formation for white bass before and after the stocking of alewives, with "t" values indicating significance of difference, Claytor Lake, 1971
Mean calculated total length at annulus (mm)
Annulus 1 2 3 4
Before stocking (1962-67) 147(81)* 246(62) 295(37) 331(10) (5 .8)+ (9. 7) (11.6) (13.0)
After stocking (1971) 145(541) 235(526) 300(442) 351(88) (5.7) (9.3) (11.8) (13 .8)
Calculated "t" 1.06 NS 3.846 1.50§ l.97t °'.....
* Number of fish used in each comparison
+ Total length in inches 6 Significant at the 99.9 percent level § Significant at the 90.0 percent level
t Significant at the 95.0 percent level 62 yielded a total of 5.301 Cal/g dry weight and the crayfish had a value of 3.202 Cal/g dry weight. DISCUSSION
Fish Population Studies
Based on the two rotenone samples taken during this study, the standing crop of fishes in Claytor Lake is below that of most other reservoirs. Estes (1971) reported there was a high of 2119 fish weighing 246.2 pounds collected/acre sampled in Leesville Lake for 1969.
Although the standing crop of fishes in Leesville was much higher than for Claytor Lake, the percentage of game fish was in close agreement.
Leesville had a high of 48.0% game fish/acre sampled. Henley (1966a) reported the standing crop of fish in Lake Cumberland, Kentucky varied from 91.7 pounds/acre in 1964 to a high of 175.3 pounds/acre in 1960.
Douglas Reservoir, Tennessee (Hayne et al 1967) had a standing crop of 145.4 pounds and 4869 fish/acre. They reported an average of 12.9 pounds of largemouth bass or 96 fish/acre, comprising 1.1% of the total number and 8.4% of the total weight in Douglas Reservoir. The difference between the 1970 and 1971 samples for Claytor Lake may be due to the time of year the samples were taken. The 1970 sample was collected in mid-October and the bass had probably moved out of the cove areas while the 1971 sample was conducted in late June when the bass were still in the coves.
Alewife reproduction as revealed by cove samples was higher during
1971 than in 1970. However, this could be attributed to the time of the year that the respective samples were taken. The June 1971 sample was collected shortly after spawning of the alewives; therefore, they had not moved out of the shallow areas.
63 64
The percent recovery by days was lower for this study than that reported by Henley (1966b) •. He reported 53.2% of the total numbers and 64.1% of the weight was recovered on the first day, followed by a decrease in recovery for the second and third days. Using scuba gear to evaluate the percent of numbers and weight of fish lost due to the failure of the fish to come to the surface, he reported a
25.6% loss of total numbers and 5.0% loss of total weight in rotenone cove sampling. The poor rate of recovery of marked fish in this study was probably due to either the deep coves sampled or the lower water temperatures at the bottom of the sample coves.
Vertical Gill Netting
Vertical distribution of the alewives in Claytor Lake seems to follow the general pattern described in other studies. Lackey (1970) reported that the landlocked alewives in Echo Lake, Maine, occupied the upper depths of the lake during summer and fall. During winter and early spring the alewife was found on or near the bottom of the lake. Reigle (1969) studied the depth distribution of the alewife in southern Lake Michigan with a bottom trawl and found the alewife to be in deeper water (35 fathoms or more) from January to April.
From July through September, the alewife was vertically scattered in southern Lake Michigan. In contrast, the alewives in Claytor Lake seemed to concentrate in the upper depths of the lake (0-10 m or 0-33 ft) in the summer. This variation could probably be explained with regard to size and location of the lakes involved. Results reported ~I
I 65
by Galligan (1962) and Gross (1953) showed a similar summer con- centration of alewives near the surface.
The concentration of channel catfish near the alewives and the presence of alewives in stomach samples indicated the utilization of the alewife as forage. Borges (1950) reported the channel catfish in the Lake of the Ozarks to be distributed at all depths during the sununer months which paralleled the distribution of the gizzard shad in the lake. He noted the presence of the large (177 mm and greater) channel catfish nearer the surface at depths of 1.5 to 4.6 m (5 to
15 ft). Bryan and Howell (1946) found most of the channel catfish taken in lower Wheeler Reservoir, Alabama, to be in depths of 3.1 to
6.1 m (10 to 20 ft) during late summer and fall which was fairly close to the distribution of the forage fish.
Grinstead (1969) reported the white crappie seemed to be influenced by light and this appeared to be true in Claytor Lake also. Based on secchi disk readings, as the lake became clearer, the white crappie were concentrated at greater depths. The white crappie in Claytor Lake followed a pattern similar to the pattern reported by Borges (1950). He found that the white crappie ranged from the surface to 8.5 m (28 ft) during June and early July. In
September he found the white crappie to inhabit depths similar to those for June and early July.
There were insufficient numbers of white bass taken to show any clear depth preference in this study. The vertical distribution of the white bass in Claytor Lake did exceed that reported for the Lake 66 of the Ozarks by Borges (1950). He noted the white bass as being no deeper than 3.1 to 4.3 m (10-14 ft), while in Claytor Lake, the white bass was taken to depths of 14 m (46 ft). Bryan and Howell
(1946) found the distribution of white bass to be similar to Borges
(1950) and this study. They reported the white bass as being found mostly in water 0.3 to 3 m (1-10 ft). The white bass distribution appeared to follow the depth distributions of the alewife in June and
September. Eley, Carter, and Dorris (1967) found that white bass of
Keystone Reservoir had a vertical distribution similar to gizzard shad.
The absence of white bass from the sample in March was attributed to their migration up the New River to spawn.
Fish Fauna of Claytor Lake
Roseberry (1950) found 17 fish species in Claytor Lake. The only species listed by Roseberry (1950), but not found in this study, was the satinfin shiner, Notropis analostamus. The two new species found in the lake may have immigrated from the river.
Each of the four species (flathead catfish, largemouth bass, yellow perch, and black crappie) that have become well established in
Claytor Lake were listed as rare in relative abundance during the study by Roseberry (1950). Gasaway (1970) found that the flathead catfish population increased over a 16 year period. He further reported the decline in largemouth bass in Lake Francis Case, South
Dakota. The increase in yellow perch and black crappie may be due to their affinity for clearer water (Trautman 1957; Walburg 1964). 67
It is not known if Claytor Lake is clearer now than in 1950, but this possibility does exist.
The decrease in the hog sucker population is probably due to the loss of habitat for this fish. Roseberry (1950) reported catching numerous specimens during April, May, and June.
The spotted bass population in Claytor Lake may have been under estimated due to gear selectivity. However, the writer does not think there are sufficient numbers of these fish present now to conduct a study on spotted bass as was done by Roseberry (1950). It is possible some unfavorable environmental change has taken place in the lake resulting in the decline of the spotted bass population.
Other species such as the walleye and channel catfish seem to be at approximately the same population level as was described by Rose- berry (1950). Therefore, the environment for these species is still present.
Water Temperature and Dissolved Oxygen
The absence of trout water (maximum 21 C and at least 3 mg/l oxygen) in Claytor Lake during parts of August and September leads the writer to believe this lake is not suitable for a "two-story" fishery. The absence of the trout water, using the previously stated criteria, was verified from data of the Virginia State Water Control Board (Unpublished). Simmons (1968) reported a similar finding in Claytor Lake on August 16, 1965. When the water temperature was at the maximum of 21 C for trout, the dissolved oxygen concentration 68 was 0 111g/l and when the dissolved oxygen was 3 mg/l, the water
temperature was 25 C.
Water suitable for trout again occurred between September 14 and
19. Virginia Water Control Board (Unpublished) data taken on 14
September indicated the absence of trout water in the lake, but data collected for this study on 19 September showed a zone of trout water
to again be present in the lake.
Age Determination
The age structure of the present walleye population appears to be very similar to the structure reported by Roseberry (1950). He found only three walleye above age V, with the dominant age class
being age II. In this study, the two oldest fish were age VI, while
in Roseberry's (1950) study, the oldest fish was in age class VIII.
Vidal (1962) reported the average life span for walleye as being 10 to 12 years and a maximum age of 18 to 20 years. No fish
from this study or from the 1950 study approximated these old ages.
Carlander (1953) cites only one example of age XVIII walleye. Priegel
(1970) reported finding age X males and females in the Wolf River
drainage above Lake Winnebago, Wisconsin, during spawning season. In
Lake Winnebago, the oldest fish taken between 1964 and 1967 was eight
years old. The oldest fish taken during this study were two females six years old. An abridged life table, beginning at age class II,
for the combined sexes of ages II through VI walleye is given in
Appendix Table XIV. 69
The difference in dominant age classes for the males and females was probably due to sampling of a large number of age 11 male walleye on the spawning grounds. The ratio of the males to females checked on the spawning ground over a five week period was 21:1.
The white bass population in Claytor Lake has an age structure very similar to that of other populations of this species, as reported in the literature. The majority (82%) of the population was in age
111 or less. Based on the 542 fish used in age and growth analysis,
90% of the sample consisted of age 111 and younger fish for Center
Hill Reservoir, Tennessee (Webb and Moss 1967). Myhr (1971) reported similar findings. Ninety-six percent of the white bass population in Dale Hollow Reservoir were age 111 and younger. The white bass population of Bull Shoals Reservoir, Arkansas, exhibited an age class structure very near that of Claytor Lake, with 86% of the white bass being age 111 or less (Houser and Bryant 1970). The close agreement between this study and the Bull Shoals Reservoir study is due to the aging technique. All fish captured between 1 January and the time of actual annulus formation were assigned an additional annulus at the margin of the scale. In the two Tennessee studies, fish were not assigned to the next age class until actual annulus formation occurred on the scale. The total sample of white bass taken for age and growth studies is considered to be nonrandom in regard to age composition of the younger fish due to gear selectivity. But random sampling was reflected with regard to the male-female of 1.1:1 ratio in Claytor 70
Lake. Sigler (1949) reported a ratio of 1 male to 1.1 females in
Spirit Lake, Iowa and Van Oosten (1942) reported a ratio of 1:1 for
Lake Erie White bass in Claytor Lake may live as long as six years, but few of either six normally live longer than three years. Fitz
(1965) drew similar conclusions with regard to eleven east Tennessee reservoirs. An abridged life table for the combined sexes of age III through VI white bass is given in Appendix Table XV.
Because the alewife population is new and probably still expanding in Claytor Lake, the writer does not consider reported age-class strengths to be accurate. The presence of age class 0 does indicate reproduction is taking place in Claytor Lake. Most of the samples for this class were collected during January, 1971. Since the Commission did not stock alewives in Claytor Lake during 1970 these fish would have to come from either the 1968 or the 1969 stock of fish.
One five year old fish was taken in the sample but was excluded because of its age. The oldest fish spawned in Claytor Lake could not exceed age III because the first introduction did not occur until
April 1968. Therefore, the longevity of alewives in Claytor Lake can- not yet be stated.
Growth Analysis
The calculated growth for walleye in Claytor Lake was less than for other waters in the southeastern U. S. (Table 20). The slower growth of walleye may be due to environmental factors, such as water temperature in the lake. The walleye exhibited a slower growth in this study than was reported by Roseberry {1950) (Table 20). A 71
Table 20. Growth rates of walleye from Claytor Lake 1971 compared with that of other populations
Mean calculated total length (mm) at annulus Location I II III IV v VI Reference
Claytor Lake, 197 339 424 500 569 617 Present Virginia (7 .8)* (13.3) (16. 7) (19. 7) (22.4) (24.3) study
Claytor Lake, 252+ 386 503 589 663 760 Roseberry Virginia (9.9) (15.2) (19.8) (23.2) (26.1) (29.9) 1950
Dale Hollow 228 357 487 554 634 Range Reservoir, TN (8.4) (14.1) (19.2) (21.8) (25.0) 1971
Average for eleven east TN Valley 244 396 483 556 617 716 Fitz Reservoirs (9.6) (15.6) (19.0) (21. 9) (24.3) (28.2) 1965
Approximate 206 297 356 409 460 480 Vidal U.S. average (8 .1) (11. 7) (14.0) (16.1) (18 .1) (18.9) 1962
* Total length in inches + Converted from inches to millimeters 72
reasonable explanation cannot be offered for the difference in growth rates in 1971 as compared with 1950.
The faster growth rate of the females over the males is not restricted to the Claytor Lake walleye population. Eschmeyer (1950),
Vidal (1962), and Mraz (1968) reported similar findings in regard to the faster growth of females compared with that of males.
The reverse of "Lee's phenomenon," as was the case of the walleye growth rates in this study, may have arisen from size-selective mortality that was reflected more heavily on the smaller fish at an age group (Ricker 1968).
The comparison of white bass growth rates for Claytor Lake with those of other waters is shown in Table 21. The growth rates of white bass for this study seem to fit between those reported for the more southern populations and those of the more northern populations.
The difference between the lengths of the growing season may account for this variation between populations.
The higher growth rates for females as compared with males of the sample population are characteristic of nearly all white bass populations. Houser and Bryant (1970), Myhr (1971), and Ruelle (1971) reported that females were longer and heavier than the males of the same age. The deviation from this characteristic was noted at age VI for the Claytor Lake fish. This was probably due to the small number of males and females in that age class.
The presence of "Lee's phenomenon," noted in age class I, was not present in age class II, while the reverse seemed to be present in 73
Table 21. Growth rates of white bass from Claytor Lake 1971 compared with that of other populations
Location Mean calculated total length (mm) at annulus I II III IV V VI Reference
Claytor Lake, 145 235 300 351 404 412 Present Virginia (5. 7)* (9.3) (11.8) (13.8) (15.9) (16.2) study Average for eleven east TN Valley 201+ 312 363 391 439 460 Fitz Reservoirs (7.9) (12.3) (14.3) (15.4) (17 .3) (18.1) 1965 Dale Hollow 193 346 390 415 443 Myhr Reservoir, TN (7. 6) (13 .6) (15.4) (16.3) (17.4) 1971 Pool 19, 139 210 244 272 382 Pelren Miss. R, IA (5.5) (8.3) (9.6) (10. 7) (15 .0) 1970 Lewis and Clark Reser- 108 239 297 323 353 362 Ruelle voir, N.D. (4.3) (9.4) (11. 7) (12. 7) (13. 9) (14.3) 1971
*Total length in inches
+Con~erted from inches to millimeters 74
age classes III - V. The presence of the reverse of "Lee's phenom- enon" in these age classes was probably due to gear selectivity. A large number of the fish in the sample were taken in gill nets which may have a tendency to capture larger members of an age class.
The growth rates of the alewives in Claytor Lake are still under- going changes due to the age of the population. Therefore, a comparison with other, more established, populations would not be meaningful.
The large population of small fish should be an advantage to the predator populations since the predators should be able to utilize a larger portion of the small-size alewife population.
Length-Weight Relationship
The value of the constant !!. will usually be near 3.00 when using the metric system, because the weight of an object varies as the cube of its length if shape and specific gravity remained the same
(Carlander 1969). The value of!!. for the walleye population in
Claytor Lake was calculated to be 3.25378. Because the calculated value of !!. was found to be greater than 3.00, it can be concluded the walleye were becoming relatively heavier with length (P < 0.1).
Roseberry (1950) reported the length-weight relationship for walleye to be log W • -5.08049 + 3.096735 log S.L. The n value for white bass from Claytor Lake was found to be 2.87194. White bass of Claytor Lake were becoming relatively lighter with increase in length (P < 0.02).
The n value for alewives from Claytor Lake was calculated to be
3.0637. The alewives from Claytor Lake were found to be relatively heavier with length (P < 0.02). 75
Coefficient of Condition
Both male and female walleye exhibited a tendency to have an increased condition factor with length from spring to early fall.
On the average, condition factors were higher for females than males.
This was true for monthly and interval totals.
Male and female white bass had a higher condition factor in April than either May or June. The decrease in condition factors and then the increase was probably due to the fish being heavier during spawning season. The fairly large increase in condition factor from June to
July may have been influenced to some degree by the alewives spawning in the middle of June.
Comparison of Growth Rates
The failure to determine any significant difference in the weighted mean total lengths of walleye before and after the introduction of the alewife was probably due to the small number of samples for the prestocking period. Only 17 walleye were available for the pre- stocking period and seven of these fish were in age class I.
The absence of a significant growth rate difference in age class
I may be due to the white bass not feeding on alewives during this period in their life history. The fish may not have been feeding on the alewife long enough to show an increase in growth due to foraging on the alewife.
The significant decrease in the mean calculated total length at age II of the poststocking sample may be due to an error in growth calculations. 76
Fish in age classes III and IV clearly exhibited an increase in total length following the introduction of the alewife. Because the only change known to have taken place in Claytor Lake, other than natural change due to the passage of time, is the introduction of the alewife. The writer believes that the increase in total length was attributable to the utilization of the alewife by the white bass.
Houser and Bryant (1970) reported that the growth rate of white bass in Bull Shoals Reservoir, Arkansas, increased significantly following the introduction of a forage fish (threadfin shad) in the reservoir.
Myhr (1971) reported a similar finding for the white bass in Dale
Hollow Reservoir, Tennessee, following the stocking of threadfin shad.
Alewife Utilization
Although no conclusions can be drawn from the stomach analysis due to the small number of samples taken, some generalizations can be inferred. A large number of the predator species have taken the alewife as food one or more times.
The popular food of the walleye in other populations is yellow perch, which, although present in the lake, were not found in the 16 stomachs examined. Roseberry (1950) reported finding bluegills, white crappie, channel catfish, bass, walleye, and yellow perch in walleye stomachs. Eschmeyer (1950) and Dobie (1966) reported heavy predation of the walleye on yellow perch.
White bass seem to be taking the alewife a large percentage of the time, although they are still utilizing the crayfish to some extent. 77
The high percentage of empty stomachs was probably due to the fact that nearly all fish taken for stomach analysis were taken by use of gill nets.
Based on the results of the one test made for the food value of the alewife and the crayfish, it would seem that the utilization of alewives over crayfish would be beneficial to the fish. The caloric value/g dry weight was found to be much higher for the alewife. RECOMMENDATIONS
1. Further studies should be conducted to determine the interrelation-
ship of the alewife with the predator species such as the large-
mouth bass, smallmouth bass, spotted bass, white crappie, and
black crappie.
2. A study should be conducted beginning in 1974 to determine if the
striped bass are reproducing in Claytor Lake.
3. The creel limit on white bass should be removed.
4. The study of the effects of the alewife upon the walleye and
white bass populations should be repeated in five years to
determine if the negative results of this study were valid.
5. No attempt should be made to impose further restrictions in the
way of seasons, size limits, or reduced creel limits on the
established fishes of Claytor Lake.
6. The stocking of trout in Claytor Lake should be discontinued.
78 REFERENCES CITED
American Fisheries Society. 1970. A list of common and scientific names of fishes from the United States and Canada. Spec. Publ. No. 6. Amer. Fish. Soc., Washington, D. C. 3rd ed. 150 p.
Boles, H. D. 1970. Personal communications.
Borges, J. M. 1950. Fish distribution studies, Niangua Arm of the Lake of the Ozarks, Missouri. J. Wildl. Mgmt. 14(10):16-33.
Bryan, P. and H. H. Howell. 1946. Depth distribution of fish in lower Wheeler Reservoir, Alabama. Rept. Reelfoot Lake Biol. Sta., 10:4-9 (Reprinted in J. Tenn. Acad. Sci., 21(1):4-9).
Carlander, K. D. 1953. First Supplement to Handbook of Freshwater Fishery Biology. Wm. C. Brown Co., Dubuque, Iowa. 429 p.
1969. Handbook of Freshwater Fishery Biology. Iowa State Univ. Press, Ames, Iowa. 752 p.
Davis, H. S. 1965. Culture and Diseases of Game Fishes. Univ. of Calif. Press, Berkeley. 332 p.
Dobie, J. 1966. Food and feeding habits of the walleye, Stizostedion y. vitreum, and associated game and forage fishes in Lake Vermilion, Minnesota, with special reference to the tullibee, Coregonus (Leuchichthys) artedi. Minn. Fish. Invest. No. 4:39-71.
Eley, R. L., N. E. Carter, and T. C. Dorris. 1967. Physicochemical limnology and related fish distribution of Keystone Reservoir, p. 229-243. In Reservoir Fishery Resources Symposium. Res. Comm. So. Div-:--Amer. Fish. Soc.
Eschmeyer, P. H. 1950. The Life History of the Walleye in Michigan. Mich. Dept. of Conserv., Inst. Fish. Res. Bull. 3. 99 p.
Estes, R. D. 1971. The effects of the Smith Mountain pump storage project on the fishery of the lower reservoir, Leesville, Virginia. Ph. D. Thesis. V.P.I. & S.U., Blacksburg, Va. 151 p.
Everhart, W. H. 1971. Fishery Science: Its Principles and Applications. Colo. State Univ. 231 p. mimeographed.
Fitz, R. B. 1965. Growth of fishes in Eastern Tennessee Valley reser- voirs. Tenn. Valley Auth. Norris, Tenn. 1 p. mimeographed.
Foye, R. E. 1956. Reclamation of potential trout ponds in Main. J. Wildl. Mgmt. 20:389-398.
79 80
Galligan, J. P. 1962. Depth distribution of lake trout and associated species in Cayuga Lake, New York. J. N. Y. Fish and Game 9(1):44-68.
Gasaway, C. R. 1970. Changes in the fish population in Lake Francis Case in South Dakota in the first sixteen years of impoundment. U. S. Bur. Sport Fish. and Wildl. Tech. Papers No. 56. 30 p.
Grinstead, B. G. 1969. The vertical distribution of the white crappie in the Buncombe Creek Arm of Lake Texoma. Okla. Dept. of Wildl. Conserv. Bull. No. 3. 37 p.
Gross, R. W. 1953. Some observations of the landlocked alewife, Pomolobus pseudoharengus (Wilson), in New Jersey. N. J. Fish. Surv. Rept. (2):157-164.
Hayne, D. W., G. E. Hall, and H. M. Nichols. 1967. An evaluation of cove sampling of fish populations in Douglas Reservoir, Tennessee, p. 244-297. In Reservoir Fishery Resources Symposium. Res. Comm. So. Div. Amer. Fish. Soc.
Henley, J. P. 1966a. Lake Cumberland Investigations. Ky. Dept. of Fish and Wildl. Res., Fish. Bull. No. 28. 26 p.
1966b. Evaluation of rotenone sampling with scuba gear. S. E. Assoc. Game and Fish Comm., Proc. 20:439-446.
Hile, R. 1954. Fluctuation in growth and year-class strength of the walleye in Saginaw Bay. U. S. Bur. Sport Fish. and Wildl., Fish. Bull. 56:7-79.
1970. Body-scale relation and calculation of growth in fishes. Amer. Fish. Soc., Trans. 99(3):468-474.
Hoffman, J. M. 1971. Personal communication.
Houser, A., and H. E. Bryant. 1970. Age, growth, sex composition, and maturity of white bass in Bull Shoals Reservoir. U. S. Bur. Sport Fish. and Wildl. Tech. Papers No. 49. 10 p.
Kirkland, L., and M. Bowling. 1966. Preliminary observations on the establishment of a reservoir trout fishery. S. E. Assoc. of Game and Fish Comm., Proc. 20:364-374.
Lackey, R. T. 1969. Food interrelationships of salmon, trout, alewives and smelt in a Main lake. Amer. Fish. Soc., Trans. 98(4):641-646. 81
1970. Seasonal depth distribution of landlocked Atlantic salmon, brook, landlocked alewives, and American smelt in a small lake. J. Fish. Res. Board Canada 27(9):1656-1661.
1972. Personal communication.
Lagler, K. F. 1956. Freshwater Fishery Biology. Wm. C. Brown Co., Dubuque, Iowa. 2nd ed. 421 p.
Martin, R. G. 1970. The Claytor Lake fishery. Va. Wild!. 32(7):18-19.
Miller, R. R. 1957. Origin and dispersal of the alewife, Alosa pseudoharengus, and the gizzard shad, Dorosoma cepedianum, in the Great Lakes. Amer. Fish. Soc., Trans. 86:97-111.
Mraz, D. 1968. Recruitment, growth, exploitation and management of walleyes in a southeastern Wisconsin lake. Dept. Nat. Res. Bull. No. 40. 38 p.
Myhr, A. I., III. 1971. A study of the white bass, Morone chrysops (Rafinesque), in Dale Hollow Reservoir, Tennessee, Kentucky. M. S. Thesis. Tenn. Tech. Univ., Cookeville, Tenn. 58 p.
Neal, W. E. 1972. Personal communication.
Pelren, D. W. 1970. Age and growth of white bass from Pool 19 of the Mississippi River. Iowa State J. Sci. 44(4):471-479. Priegel, G. R. 1969. Food and growth of young walleyes in Lake Winnebago, Wisconsin. Amer. Fish. Soc., Trans. 98(1):121-124.
1970. Reproduction and early life history of the walleye in the Lake Winnebago region. Wis. Dept. Nat. Res. Tech. Bull. No. 45. 105 p.
Range, J. D. 1971. The possible effect of the threadfin shad, Dorosoma petenense (Gunther), on the growth of five species of game fish in Dale Hollow Reservoir. M. S. Thesis. Tenn. Tech. Univ., Cookeville, Tenn. 52 p.
Reigle, N. J., Jr. 1969. Bottom trawl exploration in southern Lake Michigan, 1962-65. U. S. Fish Wild!. Serv. Bur. Com. Fish Circ. 301. 35 p. Ricker, w. E. (ed.). 1968. Methods for Assessment of Fish Production in Fresh Waters. IBP Handbook No. 3. Blackwell Scientific Publ., Oxford, England. 306 p. 82
Roseberry, D. A. 1950. Game fisheries investigations of Claytor Lake: A main stream impoundment of New River, Pulaski County, Virginia, with emphasis on Micropterus punctulatus (Rafinesque). Ph. D. Thesis. V.P.I., Blacksburg, Va. 268 p.
Rothschild, B. J. 1963. A critique of the scale method for determining the age of the alewife, Alosa pseudoharengus (Wilson). Amer. Fish. Soc., Trans. 92:409-413.
Ruelle, R. 1971. Factors influencing growth of white bass in Lewis and Clark Lake, p. 411-423. In Reservoirs Fisheries and Limnology. Spec. Publ. No. 8-.- Amer. Fish. Soc. Washington, D. C.
Sigler, W. F. 1949. Life history of the white bass, Lepibema chrysops (Rafinesque) of Spirit Lake, Iowa. Iowa Agri. Exp. Sta., Iowa State College Res. Bull. 366:203-244.
Simmons, G. M., Jr. 1968. Investigation of limnetic inorganic carbon assimilation in a mainstream and pumped storage impound- ment. Ph. D. Thesis. V.P.I., Blacksburg, Va. 235 p. Smart, C. w. Unpublished. Computer program for coefficient of condition on file with Va. Coop. Fish. Unit.
Smith, S. H. 1970. Species interactions of the alewife in the Great Lakes. Amer. Fish. Soc., Trans. 99(4):754-765.
Strawn, K. 1963. Resistance of threadfin shad to low temperatures. S. E. Assoc. Game and Fish Comm., Proc. 17:290-293.
Surber, E. W. 1959. Suggested standard methods of reporting population data for reservoirs. S. E. Assoc. Game and Fish Comm., Proc. 19:313-325.
Swingle, H. S., and W. E. Swingle. 1967. Problems in dynamics of fish populations in reservoirs, p. 229-243. In Reservoir Fishery Resources Symposium. Res. Comm. So. Div. Ame-r: Fish. Soc.
Tatum, B. L. 1958. Introduction and success of white bass in North Carolina. S. E. Assoc. Game and Fish Comm., Proc. 11:185-192.
Threinen, C. W. 1958. Life history, ecology, and management of the alewife Pomolobus pseudoharengus (Wilson). Publ. Wis. Cons. Dept. No. 223. 8 p.
Trautman, M. B. 1957. The Fishes of Ohio. Ohio State Univ. Press, Columbus, Ohio. 683 p. 83
Van Oosten, J. 1929. Life history of the lake herring (Leucichthys artedi Le Sueur) of Lake Huron as revealed by its scales, with a critique of the scale method. U. S. Bur. Fish. Bull. 44:265-428.
1942. The age and growth of the Lake Erie white bass, Lepibema chrysops (Rafinesque). Papers of the Mich. Acad. Sci., Arts, and Letters 27:307-332.
Vidal, P. 1962. Walleye and sauger facts. Ill. Dept. Cons. Div. Fish. Fish. Mgmt. No. 31. 3 p. mimeographed.
Virginia State Water Control Board. Unpublished. Claytor Lake investigation data.
Wagner, W. C. 1972. Utilization of alewives by inshore piscivorous fishes in Lake Michigan. Amer. Fish. Soc., Trans. 101(1):55-63.
Walburg, C. H. 1964. Fish population studies, Lewis and Clark Lake, Missouri River, 1956 to 1962. U. S. Fish and Wildl. Serv., Special Sci. Rept. No. 482. 27 p.
Webb, J. F., and D. D. Moss. 1967. Spawning behavior and age and growth of white bass in Center Hill Reservoir, Tennessee. S. E. Assoc. Game and Fish Conun., Proc. 21:343-357.
Webster, D. A., W. G. Bentley, and J. P. Galligan. 1959. Management of the lake trout fishery of Cayuga Lake, New York, with special reference to the role of hatchery fish. Cornell Univ. Exp. Sta. Mem. 357. 83 p. APPENDIX
84 85
Appendix Table I. Size classes used in sunnnarizing fish population data from Claytor Lake
Species Fingerling Intermediate Harves table
Game fish Inch Inch Inch
Largemouth bass 0-5.5 5.6-10.5 10.6 and over Smallmouth bass 0-5.5 5.6-10.5 10.6 and over Spotted bass 0-5.5 5 .6-10 .5 10.6 and over WM.te bass 0-3.5 3.6-5.5 5.6 and over Rock bass 0-3.5 3.6-5.5 5.6 and over White crappie 0-3.5 3.6-5.5 5.6 and over Bluegill 0-3.5 3.6-5.5 5.6 and over Pumpkinseed 0-3.5 3.6-5.5 5.6 and over Redb re as ted sunfish 0-3.5 3.6-5.5 5.6 and over Green sunfish 0-3.5 3.6-5.5 5.6 and over Warmouth 0-3.5 3.6-5.5 5.6 and over Rainbow trout 0-3.5 3.6-5.5 5.6 and over
Non-game fish
Flathead catfish 0-5.5 5.6-10.5 10.6 and over Channel catfish 0-5.5 5 .6-10 .5 10.6 and over Yellow perch 0-3.5 3.6-5.5 5.6 and over Carp 0-5.5 5.6-10.5 10.6 and over White sucker 0-5.5 5.6-10.5 10.6 and over
Forage fish
Spot tail shiner 0-3.5 3.6-5.5 5.6 and over Alewife 0-3.5 3.6-5.5 5.6 and over Threadfin shad 0-3.5 3.6-5.5 5.6 and over Appendix Table II. The numbers and weights of fish taken by Commission personnel from two 1/3-acre coves in Claytor Lake, August, 1961
Species Finger lings Intermediates Harvestables Total Percent of Total No. Lb No. Lb No. Lb No. Lb No. Lb
Game fish ---siiiallmouth bass 24 0.20 9 1.60 1 0.50 34 2.30 5.87 8.70 Spotted bass -- -- 1 0.20 -- -- 1 0.20 0.17 0.76 White bass 93 0.90 -- -- 3 1.00 96 1.90 16.58 7 .18 Walleye ------1 0.90 1 0.90 0.17 3.40 Bluegill 216 1.50 77 1.87 35 8.61 328 11.98 56.65 45.29 Pumpkinseed 1 0.05 8 0.60 -- -- 9 0.65 1.55 2.46 Green sunfish 47 0.45 13 0.60 -- -- 60 1.05 10.36 3.97 00 Crappie* 13 0.10 ------=....._!1 0.10 2.25 0.38 a- Sub-total 394 3.20 108 4.87 40 11.01 542 19.08 93.60 72.14
Non-game fish Channel catfish -- -- 2 0.10 5 6.70 7 6.80 1.21 25.71 Yellow perch 24 0.20 1 0.05 3 --0.30 -28 0.55 4.84 2.08 Sub-total 24 0.20 3 0.15 8 7.00 35 7.35 6.05 27. 79
Forage fish Threadfin shad 2 0.02 ------2 0.02 0.35 0.07 Sub-total 2 0.02 ------2 0.02 0.35 0.07
GRAND TOTAL 420 3.42 111 5.02 48 18.01 579 26.45 100.00 100.00
*Includes black and white crappie Appendix Table III. The numbers and weights of fish taken by Commission personnel from two 1/3-acre coves in Claytor Lake, July, 1962
Finger lings Intermediates Harvestable Total Percent of Total Species No. Lb No. Lb No. Lb No. Lb No. Lb - Game fish --r:8"rgemouth bass -- -- 1 0.20 -- -- 1 0.20 0.28 0.88 Smallmouth bass 10 0.05 20 1.50 -- -- 30 1.55 8.45 6.80 Spotted bass 38 0.88 4 1.00 -- -- 42 1.88 11.83 8.24 White bass 21 0.25 - -- 10 4.62 31 4.87 8.74 21.36 Bluegill 87 0.75 29 1.50 36 7.75 152 10.00 42.82 43.86 Pumpkinseed 1 0.05 2 o.os 3 0.10 0.84 0.44 -- -- 00 Green sunfish 46 a.so 5 0.25 -- -- 51 0.75 14.37 3.29 ...... Sub-total 203 2.48 61 4.50 46 12.37 310 19.35 87.33 84.87
Non-game fish Channel catfish 1 0.10 -- -- 2 2.25 3 2.35 0.84 10.31 Yellow perch 21 0.25 10 0.25 11 0.60 42 1.10 11.83 4.82
Sub-total 22 0.35 10 0.25 13 2.85 45 3.45 12.67 15.13
GRAND TOTAL 225 2.83 71 4.75 59 15.22 355 22.80 100.00 100.00 Appendix Table IV. The numbers and weights of fish taken by Conunission personnel from two 1/2-acre coves in Claytor Lake, September, 1964
Finger lings Intermediates Harvestable Total Percent of Total Species Lb Lb No. Lb -- No. No. Lb No. Lb -~· Game fish -r:8:rgemouth bass 50 1.40 12 4.00 6 3.20 68 8.60 4.09 11.95 Smallmouth bass 6 0.40 -- -- 4 2.40 10 2.80 0.60 3.89 White bass 30 0.90 26 1.60 26 13.40 82 15.90 4.93 22.10 Walleye -- -- 1 0.10 1 1.00 2 1.10 0.12 1.53 Bluegill 1112 14.80 108 7.60 64 8.40 1284 30.80 77 .16 42.81 Pumpkin seed 4 0.10 4 0.20 -- -- 8 0.30 0.48 0.42 Green sunfish 104 1.20 22 1.10 126 2.30 7.57 3.20 -- -- 00 Crappie* ------2 0.40 2 0.40 0.12 0.55 00 Sub-total 1306 18.80 173 14.60 103 28.80 1582 62.20 95.07 86.45 Non-game fish Channel catfish 6 0.10 2 0.10 12 9.00 20 9.20 1.20 12. 79 Yellow perch 50 0.30 10 0.20 ------60 0.50 3.61 0.69 Sub-total 56 0.40 12 0.30 12 9.00 80 9.70 4.81 13.48 Forage fish Shiner Spp. 2 0.05 ------2 0.05 0.12 0.07 Sub-total 2 0.05 ------2 0.05 0.12 0.07
GRAND TOTAL 1364 19.25 185 14.90 115 37.80 1664 71.95 100.00 100.00
*Includes black and white crappie Appendix Table V. The numbers and weights of fish taken by Commission personnel from two 1/2-acre coves in Claytor Lake, August, 1965
Finger lings Intermediates Harvestable Total Percent of Total Species No. Lb No. Lb No. Lb No. Lb No. Lb -- Game fish ----Largemouth bass ------1 0.60 1 0.60 0.13 1.81 Smallmouth bass 18 0.40 3 1.00 -- -- 21 1.40 2.80 4.22 Spotted bass 19 0.30 -- -- 1 1.30 20 1.60 2.66 4.83 White bass -- -- 22 0.90 40 17 .10 62 18.00 8.26 54.30 Walleye 1 0.05 ------1 0.05 0.13 0.15 Bluegill 519 4.00 46 2.60 11 2.50 576 9.10 76.70 27.45 Pumpkinseed 31 6 37 0.50 4.93 1.51 ()0 0.30 0.20 -- -- \C) Warmouth 3 0.10 ------3 0.10 0.40 0.30 Sub-total 591 5.15 77 4.70 53 21.50 721 31.35 96.01 94.57
Non-game fish Channel catfish 7 0.10 2 0.20 2 1.20 11 1.50 1.46 4.52 Yellow perch 14 0.10 4 0.10 1 0.10 19 0.30 2.53 0.91
Sub-total 21 0.20 6 0.30 3 1.30 30 1.80 3.99 5.43
GRAND TOTAL 612 5.35 83 5.00 56 22.80 751 33.15 100.00 100.00 90
Appendix Table VI. Seasonal depth distribution of alewives in Claytor Lake, 1970-1971
Number of Fish Collected Depth (m) December March June September
0-1 26 159 12 1-2 27 224 24 2-3 5 61 29 3-4 3 150 26 4-5 2 1 120 18 5-6 1 2 51 11 6-7 5 1 51 2 7-8 1 14 5 8-9 37 7 9-10 4 18 8 10-11 1 7 2 11-12 12 5 12-13 1 7 2 13-14 1 14 14-15 8 8 15-16 3 9 16-17 1 11 17-18 1 18-19 7 19-20 2 1 20-21 3 21-22 23-24 1 24-25 1 91
Appendix Table VII. Seasonal depth distribution of channel catfish in Claytor Lake, 1970-1971
Number of Fish Collected Depth (!!!_) December March June September
0-1 4 12 4 1-2 4 13 4 2-3 2 14 4 3-4 2 9 2 4-5 4 1 15 3 5-6 1 1 6 3 6-7 4 5 10 3 7-8 1 2 3 2 8-9 4 6 1 9-10 5 6 10-11 8 5 3 11-12 2 3 2 12-13 6 1 13-14 8 5 2 14-15 1 3 1 15-16 1 2 16-17 1 17-18 1 18-19 1 19-20 2 1 20-21 21-22 22-23 23-24 24-25 92
Appendix Table VIII. Seasonal depth distribution of white crappie in Claytor Lake, 1970-1971
Number of Fish Collected Depth (m) December March June September
0-1 4 1-2 1 2-3 4 1 3-4 1 2 7 1 4-5 12 1 5-6 2 5 2 6-7 4 1 9 7-8 1 2 11 8-9 2 2 19 4 9-10 1 23 2 10-11 1 10 1 11-12 1 12 6 12-13 10 3 13-14 2 10 8 14-15 11 4 15-16 3 16-17 1 6 17-18 18-19 1 3 19-20 20-21 21-22 1 22-23 23-24 24-25 1 93
Appendix Table IX. Seasonal depth distribution of white bass in Claytor Lake, 1970-1971
Number of Fish Collected Depth (m) December March June September
0-1 3 11 1-2 1 6 2-3 4 3-4 7 4-5 1 2 5-6 6 6-7 3 7-8 1 1 8-9 1 9-10 1 7 10-11 3 11-12 3 12-13 2 13-14 1 14-15 15-16 16-17 17-18 18-19 19-20 20-21 21-22 22-23 23-24 24-25 94
Appendix Table X. Seasonal depth distribution of walleye in Claytor Lake, 1970-1971
Number of Fish Collected Depth (~) December March June September
0-1 6 3 1-2 2 2-3 4 2 3-4 2 7 4-5 2 1 5-6 1 1 1 6-7 1 2 7-8 1 1 8-9 1 9-10 1 10-11 1 11-12 1 2 12-13 1 13-14 1 1 14-15 1 1 15-16 1 16-17 1 17-18 18-19 19-20 20-21 2 21-22 22-23 23-24 24-25 I
Appendix Table XI. Water temperature in C and dissolved oxygen in mg/l for Claytor Lake, July 23, 1971
Station 1 Station 2 Station 3 Station 4 Station 5 Station 6 Peak Ck. Depth(m) Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. ill_ ~mg/12 ill_ (mg/12 fil_ (mg/12 fil_ ~mg[l2 fil_ (mg/12 fil_ ~mg/12 Jf)_ (mg/l)
1 25 11.0 25 9.9 26 9.6 26 9.1 26 8.0 26 9.7 26 9.1 2 26 11.0 24 9.7 26 9.8 25 9.1 25 7.9 23 9.3 25 9.1 3 25 10.7 24 8.7 25 9.8 25 8.7 25 7.6 23 8.9 25 9.1 4 24 9.7 24 8.2 24 8.6 25 8.1 25 7.2 23 8.4 25 8.3 5 24 8.3 24 8.2 24 7.9 25 7.9 25 7.0 22 7.4 25 7.2 \C) 6 24 7.8 24 7.9 24 7.6 25 7.8 25 6.9 25 6.6 U1 7 24 7.8 24 6.1 24 7.2 24 7.2 25 6.8 24 5.2 8 23 5.3 24 6.1 24 6.8 24 7.0 24 6.6 24 4.3 9 23 4.3 23 5.2 24 5.1 24 6.1 24 6.6 24 4.6 10 23 2.6 23 4.4 23 3.7 24 6.0 24 6.5 23 3.2 11 23 2.6 22 3.6 23 3.7 23 5.8 24 5.8 23 3.2 12 23 1.6 22 3.5 23 3.5 23 5.7 23 5.4 23 3.1 13 22 1.8 22 2.7 22 2.8 23 5.7 23 5.4 22 1.2 14 22 1.5 '•22 2.5 22 1.8 22 4.8 22 5.3 20 0.4 15 21 0.9 21 1. 9 21 1.6 22 2.4 23 4.2 20 1.3 16 21 1.6 21 1.8 21 1.9 22 1.4 19 1.7 17 20 2.5 20 2.9 20 2.5 21 2.4 19 1.6 18 19 2.5 21 2.9 20 2.3 21 2.3 18 0.3 19 18 1.8 20 2.9 20 1.9 20 2.3 18 0.3 20 18 2.2 20 3.0 19 1. 7 20 1.8 17 0.3 21 17 1.5 19 2.5 19 0.5 16 0.3 22 15 2.6 19 1.4 19 0.5 16 0.3 23 13 2.9 16 0.4 18 0.5 16 0.3 24 12 3.4 16 0.3 25 12 2.2 16 0.3 I
I
Appendix Table XI. Water temperature in C and dissolved oxygen in mg/1 for Claytor Lake, July 23, 1971 (Continued)
Station 1 Station 2 Station 3 Station 4 Station 5 Station 6 Peak Ck.
Depth(m) Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. - fil (mg/l) fil (mg/1) fil (mg/1) (C) (mg/1) fil (mg/l) (C) (mg/1) (C) (mg/1)
26 11 1.6 27 10 0.3 28 9 0.3 29 8 0.3 30 7 0.2 31 7 0.2 32 7 0.2 \0 °' Appendix Table XII. Water temperature in C and dissolved oxygen in mg/l for Claytor Lake August 21, 1971
Station 1 Station 2 Station 3 Station 4 Station 5 Station 6 Peak Ck. Depth(P!) Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. (C) (mg/12 (C) (mg/12 fil (mg/12 fil (mg/l) fil (mg/l) fil (mg/l) fil (mg/l) 1 26 7.6 26 8.7 26 8.8 25 8.8 24 8.2 24 8.9 26 9.7 2 26 7.8 25 8.9 26 8.8 25 8.8 24 8.1 23 8.9 25 9.9 3 26 7.8 25 9.1 25 8.8 25 8.8 24 8.1 23 8.8 25 9.9 4 25 7.8 24 7.8 24 7.6 24 6.5 24 7.9 22 8.5 25 9.1 5 25 7.8 24 7.4 24 7.0 24 6.0 23 6.6 24 7.5 6 25 8.0 24 7.3 24 6.8 24 5.9 23 6.6 24 5.1 7 25 8.0 24 6.4 24 6.6 24 5.6 23 6.6 24 5.2 8 25 8.1 24 6.4 24 6.6 24 5.6 23 6.5 24 5.2 \0 9 24 6.5 24 6.3 24 6.3 24 5.3 23 6.2 23 4.7 '-J 10 24 5.4 24 6.1 24 5.4 23 5.1 23 6.3 23 4.2 11 23 3.8 24 6.1 24 4.6 23 5.1 23 5.9 23 3.9 12 23 3.5 24 6.0 23 4.5 23 5.0 23 5.7 23 3.8 13 23 3.4 23 5.1 23 4.3 23 4.9 22 5.4 23 3.4 14 22 3.2 23 5.1 23 4.3 23 4.7 22 5.4 23 3.3 15 22 2.6 23 4.7 23 4.4 23 4.7 22 5.4 23 1.1 16 22 2.6 23 4.5 22 4.3 23 4.7 23 0.9 17 22 1.4 23 4.4 22 4.3 23 4.9 23 0.7 18 22 1.3 23 4.3 22 4.3 22 4.7 23 0.5 19 21 1.3 23 4.3 22 3.8 22 4.6 23 0.3 20 21 0.9 22 4.3 22 3.6 22 4.6 22 0.3 21 20 0.4 22 4.3 22 3.2 22 0.2 22 20 0.3 22 4.3 22 1.0 20 0.2 23 19 0.3 22 4.3 22 1.0 17 0.3 24 17 0.2 22 3.4 25 15 0.2 22 2.6
_J Appendix Table XII. Water temperature in C and dissolved oxygen in mg/l for Claytor Lake August 21, 1971 (Continued)
Station 1 Station 2 Station 3 Station 4 Station 5 Station 6 Peak Ck. Depth(!!!,) Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. fil ~mg/12 fil (mg/12 fil ~mg/12 fil (mg/12 fil ~mg/l) fil (mg/l) fil (mg/l)
26 12 0.2 21 2.6 27 11 0.2 19 0.4 28 10 0.2 13 0.4 29 10 0.2 13 0.4 30 9 0.2 12 0.4 31 9 0.2 12 0.5 \b 32 9 0.2 11 0.5 00 Appendix Table XIII. Water temperature in C and dissolved oxygen in mg/l for Claytor Lake, September 19, 1971
Station 1 Station 2 Station 3 Station 4 Station 5 Station 6 Peak Ck. Depth Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D. O. .
l 23 6.0 23 6.5 23 6.3 23 6.0 23 5.6 2 23 5.9 23 6.7 23 6.3 23 5.7 23 5.4 3 23 5.9 23 6.7 23 6.3 23 5.7 23 5.4 4 23 5.7 23 6.8 23 6.1 23 5.8 23 5.3 5 23 5.7 23 6.8 23 6.1 23 5.8 23 5.0 6 23 5.7 23 6.7 23 6.0 23 5.5 23 4.9 7 23 5.6 23 6.7 23 6.0 23 5.5 23 4.6 ID 8 23 5.5 23 6.7 23 5.9 23 5.5 23 4.6 \0 9 23 4.1 23 5.0 23 5.2 23 5.5 22 3.8 10 23 3.2 23 3.8 22 4.6 23 5.5 22 3.3 11 23 3.0 23 3.1 22 4.2 23 5.5 22 3.3 12 22 2.3 23 2.8 22 4.2 22 5.2 22 3.0 13 22 1.8 22 2.9 22 4.9 22 4.9 22 2.7 14 22 1.6 22 3.9 22 4.4 22 3.9 22 2.7 15 22 1.2 22 4.5 22 4.3 22 4.0 22 2.9 16 22 1.1 22 4.8 21 4.3 21 4.0 21 2.9 17 22 0.6 22 4.2 21 4.3 21 4.2 21 4.0 18 22 0.3 22 4.2 21 4.3 21 4.1 21 4.0 19 21 0.2 22 4.5 21 3.8 21 4.0 20 20 0.3 21 4.6 21 2.9 20 3.7 21 20 0.2 21 4.9 20 2.8 22 20 0.2 20 4.9 20 2.8 23 19 0.3 20 3.9 20 0.3 24 18 0.2 19 0.4 19 0.3 25 14 0.2 15 0.2 26 13 0.2 14 0.2 I
Appendix Table XIII. Water temperature in C and dissolved oxygen in mg/l for Claytor lake, September 19, 1971 (Continued)
Station 1 Station 2 Station 3 Station 4 Station 5 Station 6 Peak Ck. Depth Temp .. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. Temp. D.O. hl _fil (mg/l) fil (mg/l) fil (mg/l) _ill (mg/l) (C) (mg/l) (C) (mg/l) (C) (mg/l)
27 12 0.2 28 11 0.2 29 10 0.2 30 10 0.2 31 10 0.2 32 9 0.2
t..i 0 0 Appendix Table XIV. Abridged life table for both sexes of white bass, Claytor Lake, 1971
Age No. deaths No. dying No. sur- Mortaility Average Mean in age- in age viving . rate per No. living expect- class x interval at begin- 1000 at between ation of per 1000 ing of beginning two age life age class of age intervals remain- per 1000 interval ing
III 354.0 800.9 1000.0 800.9 599.5 0.76 IV 65.0 147.1 199.1 738.6 125.6 0.80
...0 v 20.0 45.2 52.0 869.6 29.4 0.63 ...... VI 3.0 6.8 6.8 1000.0 3.4 0.50 Appendix Table XV. Abridged life table for both sexes of walleye, Claytor Lake, 1971
Age No. deaths No. dying No. sur- Mortaility Average Mean in age- in age viving rate per No. living expect- class x interval at begin- 1000 at between ation of per 1000 ing of beginning two age life age class of age intervals remain- per 1000 interval ing
II 125.0 498.0 1000.0 498.0 751.0 1.19
III 92.0 366.5 502.0 703.2 318.7 0.87 ....0 IV 24.0 95.6 135.5 705.9 87.6 0.85 N v 8.0 31.9 39.8 800.0 23.9 0.70 VI 2.0 8.0 8.0 1000.0 4.0 0.50 The vita has been removed from the scanned document EFFECTS OF LANDLOCKED ALEWIFE INTRODUCTION ON WHITE BASS AND WALLEYE POPULATIONS, CLAYTOR LAKE, VIRGINIA
by
John Lee Boaze
(ABSTRACT)
The effects of the landlocked alewife introduction on the white bass and walleye populations were evaluated. Only white bass in age classes III and IV clearly exhibited an increase in total length following the introduction of landlocked alewives. Age and growth analysis for walleye, white bass, and alewives are given. Condition factors for walleye and white bass are reported by sex, month, and twenty millimeter total length intervals. Alewives were found in the stomach contents of eight species of piscivorous fishes. The vertical distributions by season of alewives, channel catfish, white crappie, walleye, and white bass are given. Each of the predator fishes seem to be found in close proximity to the alewife.
Changes in the fish fauna of Claytor Lake between 1950 and 1971 are discussed. Based on the two rotenone samples taken during this study, the standing crop of fishes in Claytor Lake is below that of most other reservoirs.