&EPA
United States
Environmental Protection
Agency
Environmental Research
Laboratory
Duluth MN 55804
EPA-600/3-80-009
January 1980
Research and Development
Spatial
Distribution and
Temperature
Selection of Fish
Near the Thermal
Outfall of a Power
Plant During Fall,
Winter and Spring
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EPA-600/3-80-009
January 1980
SPATIAL DISTRIBUTION AND TEMPERATURE SELECTION OF FISH
THE THERMAL OUTFALL OP A POWER PLANT DURING FALL, AID
by
M. J. Ross
D. B. Siniff
University of Minnesota
Minneapolis, Minnesota 55455
Contract No. 68-03-2145
Grant No. R804997Q1G
Project Officer
J, Howard McCormick
Environmental Research Laboratory
Duluthj Minnesota 55804
This study was conducted in cooperation with the
University of Minnesota, Minneapolis, Minnesota 55455.
ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
DULUTH, MINNESOTA 55804
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DISCLAIMER
This report has been reviewed by the Environmental Research
Laboratory-Buluth, Duluth, Minnesota, U.S. Environmental Protection
Agency, and approved for publication. Approval does not signify that the
contents necessarily reflect the views and policies of the U.S.
Environmental Protection Agency, nor does mention of trade names or
eomereial products constitute endorsement or recomendation for use.
ii
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FOREWORD
The studies reported were initiated to determine the degree of
concern that should be rendered yellow perch inhabiting an environment
receiving a heated water discharge. A portion of the upper Mississippi
River near Cohasset, Minnesota, receiving a heated discharge from a
coal-fired power plant, was chosen for the study site. The study was
initiated after completion of two laboratory studies; one determined that
yellow perch required a winter chill period of a relatively long duration
for successful spring spawning to take place; and another determined that
the species, even in winter, preferred water temperatures well In excess
of those leading to successful spring spawning.
The study site provided options between various habitats including
those that would promote normal reproduction and those artificially
heated such as to inhibit spawning success. The consequences of various
thermal experiences for given periods were known from laboratory data.
Thus, it was necessary to determine what thermal experience the fish
would choose when given the options. It was further desirable to
determine the area of influence and the portion of the yellow perch
population affected by the introduced environmental perturbation.
Conventional sampling methods were not adequate for this project
since instantaneous positioning of a fish reveals little about cumulative
thermal experiences of individuals. The cumulative thermal experience is
a reflection of both changes in positions of individuals and changes in
water temperature gradients both away from and with reference to the
heated effluent. Thus single time or widely time spaced locating of
individuals was not adequate. To accomplish the goals of this research
it was necessary to employ telemetry techniques that allowed continuous
monitoring of movements and thermal experiences encountered during
extended periods. The findings are not unexpected in retrospect, but
very thought-provoking, and emphasize the importance of field validation
of at least representative categories of pollution discharges into
ecosystems similar to those likely to receive those discharges.
J. David Yount
Deputy Director
Environmental Research Laboratory - Duluth
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ABSTRACT
The movement patterns of 4 fish species; yellow perch (Perca
flavgscens), northern pike (Esox lucius), largemouth bass (Micropterus
salmoides) and walleye CStizostedion vitreum) were monitored by radio
telemetry near the thermal discharge of a power plant (AT 15°C
nominal). Fish movements relative to depth, temperature, center of the
home range, discharge point, and release location are examined. Near
thermally altered areas northern pike exhibited the greatest amount of
movement followed by yellow perch, walleye and largemouth bass. Except
for largemouth bass, thermal experience was found to be transitory. An
overall mean winter temperature selection of 5.4°C was determined for
yellow perch. While only in the thermally altered area yellow perch had
a slightly higher mean thermal experience, 6.3°C. Yellow perch were
not found to be attracted from the surrounding areas into the heated
waters of the discharge bay during the cooler months. Not until spring
was a population concentrating influence observed and that was believed
due to indirect influences; more cover due to greater available light in
the ice free area contributing to a higher standing stock of aquatic
vegetation.
We concluded that temperature, when in concert with numerous other
environmental variables, did not alter the distribution of yellow perch
from that predicted on the basis of laboratory temperature preference
studies. Furthermore, movement patterns of northern pike, walleye and
largemouth bass were found to be relatively similar to those reported
from thermally unaltered areas.
iv
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TABLE OF COM-TENTS
Foreword Hi
Abs tract iv
List of fables. vli
List of Figures fx
Acknowledgments ^j
1. Introduction j_
2. Conclusions 5
3. Reeon»eodations g
4. Study Area 7
5, Methods 10
Collecting and Tagging . 10
Fish Transmitters 12
Tracking and Recording 15
Data Analysis: Distribution 16
Data Analysis: Temperature 17
Autumn Fish Distribution 18
Associated Studies ig
6. Results 19
Yellow Perch Temperature 19
Summary 23
Winter Fish Distribution 23
Home Range 23
Mobility 27
Temperature 2?
Depth 43
Similtaneous Tracking . 43
Sunmary 43
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Autumn Distribution Results
Sunnna ry................
Associated Observations
Yellow Perch Length and Weight ...
GonadalSomatic Indices ..,....,..,
Winter Trap Netting ..............
Spawning Condition and Sex Ratios
Recapture Results ................
7. Discussion.
References
Appendices
A. Studies to determine the effect of radio
transmitters on yellow perch and largemouth bass.
B. Temperature transmitter design and development.
C. Automatic receiving and recording system.......
D. Fish tagged, tracking period and number of
observations ..............................
E. Accuracy of locating radio tagged fish by
triangulation
vi
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LIST OF TABLES
Number Page
1, Fish radio tag specifications 14
2. Overall yellow perch winter temperature
selection (degrees celsius) 20
3. Overall yellow perch winter temperature selection
grouped at the P=0,05 level by analysis of variance 21
4. Yellow perch winter temperature selection
in thermally altered areas.. 24
5. Yellow perch winter templerature selection
in thermally altered area grouped at the
P=0.05 level by analysis of variance. 25
6. Diel winter perch mean temperatures....................... ^o
7. Adjusted minimum area winter home rages 32
8. Fish mobility as mean distance moved per day
and mean distance moved from center of home
range and release site 33
9. Mean fish distance from discharge point 37
10. Fish movement with respect to thermally
altered and unaltered areas.... 40
11. Amount of time fish were located in the discharge bay
as a percent of the entire individual tracking periods ... 42
12. Depth selection by fish in the discharge area,
13. A summary of results for two periods when
fish were tracked concurrently.
46
14. Autumn yellow perch movement 51
15. fellow perch standard length and weight
observations, April 30, to May 5, 1975....... 57
vii
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C range under natural conditions. The work of Barans and Tubb (1973)
using yellow perch acclimated to seasonal ambient temperatures of Lake
Erie concluded that selected temperatures changed from one time of the
year to the next. They reported fall, winter, and spring selected
temperature ranges for adult yellow perch of; 13-21°C, 12-16°C, and
10-14°C respectively. Temperature preference studies performed by
McCauley (1977) using a horizontal gradient tank found adult yellow perch
temperature preference changed with acclimation. At 5°C acclimation
the selected temperatures ranged from 12.3 to 23.8°C while at 20°C
acclimation selected temperatures ranged from 16.1 - 24.2°C. These
values were not found to change seasonally, and all were well above the
maximum temperatures available under natural winter conditions throughout
the species range.
With the introduction of a thermal discharge into an environment,
seasonal ambient water temperature options previously unavailable to the
indigenous fishes become available. The subsequent question which arises
is then, what will be the responses of fishes to these new options?
These studies have concentrated on examining responses of yellow perch to
a thermal discharge into an upper Mississippi River ecosystem during the
cooler portions of the year, those seasons when heated waters are most
attractive are when least field work has traditionally been conducted.
Concern for the reproductive success of yellow perch when provided with
the option of heated water during the winter months stems from research
conducted at the EPA Environmental Research Laboratory - Duluth, where it
was learned that maximum reproductive success of the species followed
over wintering at temperatures of 4°C for 185 days and that little or
no success resulted when over winter was at 10°C (Jones et al, 1977).
The significance of this seemed accentuated when it is considered that
the distribution of the species is associated with that portion of the
country where ice cover is expected during the winter months. With this
fact in mind it becomes apparent that the species is adapted to winter
temperatures not greater than 4°C, the wannest possible water under ice
cover. The concern for the reproductive success of the species was
further accentuated when laboratory gradient tank studies revealed that
adult yellow perch, after acclimation to 5°C, have preferenda in excess
of 10°C (McCaully 1977). Under natural conditions, this would not pose
a concern as there is no heated water available. However, when a heated
water supply is provided the question arises as to what will be the
response of the fish to a choice between natural 4°C maximum
temperature or some other temperature more nearly approaching their
winter preferendum.
The next question is; if fish are attracted to the unseasonally
elevated temperatures, what is the area of the thermal influence, and
what kind of population concentrating effect can be expected? Or in
other words, what portion of the population in the vicinity of the heated
discharge can be expected to be affected by that discharge? This
potential concentrating effect has, in addition to the potential spawning
inhibition, the potential of concentrating a major portion of the endemic
perch spawning stock in a relatively small area. Also, the area is
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particularly vulnerable to chemical alteration from condenser and cooling
tower anti-fouling agents as well as to cold shock should the artificial
heat source be abruptly shut down.
Conventional fisheries methodology was not well suited to answering
these questions since it was not only necessary to know that a fish was
present at a given location in respect to the heated discharge but also
to know where it had been previously and where it would be at subsequent
times. Biotelemetry is uniquely suited to such problem solving and was
employed in these studies. Short exposures to elevated temperatures of
the magnitude involved at this site would not have adverse effects; it is
only the accumulated thermal exposure that would inhibit reproductive
potential. The study of population concentrating effects is also
facilitated by being able to follow the movements of individual fish into
the heated water zone or out again.
Biotelemetry methods have proven successful in tracking several
free-ranging species of fish including largemouth bass, Micropterus
saImpides, and rainbow trout, Salmo gairdneri, (Winter 1976), Also,
Cluggston (1973) and Warden and Lorio (1975) have used biotelemetry
methods to observe the behavior of largemouth bass relative to
environmental alterations.
The major objectives of our research were:
- Determine the winter temperature selection of adult yellow perch
in the vicinity of a thermal effluent.
- Determine the distribution and movements of fishes, particularly
yellow perch, relative to a thermal discharge during the fall,
winter and spring.
Determine population concentrating influences of a thermal
discharge on yellow perch during the season when discharge
temperatures approached laboratory determined preferenda more
closely than seasonal ambient water temperatures.
This study was accomplished with three subprojects. First, fish were
equipped with radio transmitters and tracked in the thermal discharge
area to determine winter distribution and associated temperatures.
During this phase of the study, temperature-sensitive transmitters and an
automatic recording system were put into operation. Secondly, fish from
outside of the discharge area were equipped with radio transmitters and
tracked in an attempt to more fully explain distribution and observe
population concentrating influences of the discharge. The third
subproject was a series of associated observations made in conjunction
with the above radio tracking studies, in order to substantiate our
telemetry inferences. These include mark-recapture operations,
comparative survey information, catch per unit effort, sex ratio,
spawning condition, and gonadalsomatic indices of yellow perch within and
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SECTION 5
METHODS
COLLECTING AMD TAGGING
Fish for radio tagging were collected principally with five single
pot trap nets set between 1 m and 3 n deep. Nets were inspected every
morning during trapping periods, weather permitting. All fish were
removed and the numbers of each species recorded for survey information.
Fish retained for tagging were transported in tubs via boat to a holding
tank. Occasionally fish were provided by anglers, commercial fishermen,
Wapora Inc. trap nets and Minnesota Power and Light Company
electrofishing operations.
Fish to be tagged were held in a 600 liter stainless steel tank
equipped with a heater and aerator. We attempted to maintain
temperatures in the holding tank approximately the same as the
temperature of the water where fish were collected by utilizing various
combinations of insulation, heating, aeration, and freshwater flow from
the Mississippi River.
Prior to the tagging operation fish were weighed, measured, sexed,
and a scale sample taken. For tagging, fish were placed in a trough and
kept moist by dripping water from a wet towel. Radio tags were applied
externally by a subdorsal fin mount (Fig. 2). Using either a hypodermic
needle or a surgical needle two teflon-coated wires protruding from the
transmitter were threaded through the supporting tissue between
pterygiophores immediately ventral from the dorsal fin (Fig. 2a), A
plastic plate was installed on the opposite side of the fish and the
attachment wires were tied and the excess clipped off (Fig. 2b). Total
time for the tagging operation averaged 3.5 minutes. At no time,
however, was a fish held out of water more than 2 minutes before being
submerged for a time and the operation continued to completion. Fish
tagged during the fall and spring months were sedated with Tricaine
Methanesulfonate (MS-222) and given a static one hour treatment with
Aureomyein (20 ppm). Fish tagged during winter months were not treated
chemically.
Fish generally acclimated to the tag within 0 to 25 minutes i.e.,
they regained equilibrium and swam normally in the holding tank.
Appendix A discusses the bio-effects of external tags on small fish.
Following an acclimation and observation period of two to four hours,
radio tagged fish were released at their respective trapping sites.
10
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a) Feeding attach-
ment wire through
muscle tissue.
b) Attaching
plastic backing
plate.
c) Sub dorsal
mount.
Figure 2, Attaching radio transmitter.
11
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FISH TRANSMITTERS
Two types of 53 MHz radio frequency transmitters were used during
this study. Initially a transmitter circuit similar to that described by
Cochran and Lord (1963) was ttodified and moisturized by the Oniversity
of Minnesota's Cedar Creek Bioelectronics Laboratory. Secondly, a
temperature-sensing transmitter was designed, miniaturized, field tested,
and drift tested by this laboratory for use in the yellow perch studies.
The location transmitter circuit and component arrangement are shown
in Figure 3. The original design was for a continuous wave ("whistling")
signal. Capacitor €3 and resistor R2 were added to cause the
transmitter to emit a pulsed signal. Pulsing signals reduced power
consumption and therefore increased transmitter life. The pulse width
(on time) of our transmitters was 0.02-0,025 seconds and the pulse rate
was between 60 and 120 pulses per minute. The duty cycle or ratio of on
time to total time was 3% +^ 1%.
Technical specifications for the location transmitter are summarized
in fable I, Transmitter life, size and range are parameters of most
concern to biologists. The theoretical life based on a transmitter
current drain of 0.3 - 0.4 m,a. with a Mallory 675 battery was
approximately 30 days. Actual life averaged 33 days. It should be
noted, however, that the average actual life was biased to the low range
as during certain tracking periods we could not always determine if the
transmitter had stopped because the battery expired or if the fish had
simply moved out of range or was captured and the tag not returned. Size
of perch location transmitters averaged 3.3 cm long, 1.3 cm wide, and 0*6
cm deep. The final weight of the transmitter on the fish, i.e.,
components plus encapsulating material minus excess attachment wires
minus water volume displaced, averaged 3.5 g. Maximum range was
difficult to determine exactly as range varied with depth of the fish,
meteorological conditions, water conductivity, and radio frequency
interference. However an approximate range of 0.7 to was determined.
For the temperature transmitter we added a thermistor and control
circuitry to a location transmitter, resulting in a pulse rate that was
temperature-dependent. Pulse width remained constant but the spacing
between pulses varied with temperature.
Table 1 summarizes technical specifications of the temperature
transmitter. Theoretically life and range parameters should have been
similar to those of the location transmitter as the temperature-sensing
circuitry only consumed 0.005 to 0.01 ma. The current drain of the
entire unit varied with temperature; i.e., as temperature increased,
pulse rate increased which increased the current drain. Current drains
of 0.3 to 0.7 ma were typical. However, we found that increased loading
of the transmitter antenna in water caused a reduction in power output.
We needed to lower base resistor Rg from 100 k ohms to 47 k ohms to
increase power output. Therefore, early models with the 100 k ohm Rg
had greatly extended life of 100 - 120 days, but a range of only
12
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BAT ±
c WHIP ANTENN
CIRCUIT DIAGRAM
COLLECTOR
EiTTER
BASE TAB
CASE GROUND
CUT OFF
TRANSISTOR LEAD CONFIGURATION
AMPEREX A4t5
ANTENNA
BATTERY
ATTACHMENT WIRE
COMPONENT ARRANGEMENT
Figure 3. Transmitter circuit diagram and cGnponent arrangement,
13
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Table 1. FISH RADIO TAG SPECIFICATIONS
Frequency:
Battery:
Dimensions,
Location
Transmitter:
Dimensions,
Temperature
Transmitter;
Potting Compound:
Backing washer:
Attachment wires:
Antenna:
Approx. life and
range:
53 to 54 mhz.
Mallory 625, 675, RM-1
(Experimentally, lithium cells)
(using 675 battery)
3.3 cm X 1.1 cm X 0.9 cm
dry weight 6,0 g to 6.5 g
weight in water 3.5 g
4.6 cm X 1.2 cm X 0.9 cm
dry weight 9.5 g - 11.0 g
weight in water 4.9 g
size and weight include transmitter potted and
sealed and backing washer.
Scotch Cast epoxy sealed with a final coat
of clear fingernail polish.
1.6 mm-low density polyethylene cut and
ground to proper size and shape.
24 ga. silver-copper conductor wire covered
with extruded teflon.
Teflon covered twist-o-flex dental type
stainless steel.
(675 battery) - 0.7 km.
30 to 40 days
14
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approximately 150 meters. Later model transmitters had life and range
parameters similar to location transmitters. With the added circuitry,
perch temperature transmitters were slightly larger than location
transmitters. Size of perch temperature transmitters averaged 4,6 era
long, 1.2 cm wide and 0.9 cm deep. The final weight in water of the
temperature transmitter averaged 4.9 g. Appendix B elaborates on the
design and development of the temperature transmitter circuit.
After construction a numbered identifier label with tag return
information was taped to the crystal. Transmitters were then
encapsulated in Scotch cast #5 electrical resin (3M Company). This
compound made the units watertight and supported all components. After
the resin hardened the excess was ground off and the tranmitter package
streamlined with a electric grinder. After allowing the tags to
stabilize 24 hours, temperature tranmitters were calibrated in agitated
water from 0 - 20°C. Immediately prior to fish tagging, the final
battery connection was completed and a coat of quick-drying final sealant
was painted on the entire transmitter. Marine epoxy was used initially
as a final sealant; however, it tended to become cloudy with age. Clear
fingernail polish was found to dry faster and remain transparent, thus,
tags could be more easily identified.
TM.CK.lfC AM> RECORDING
Fish location and temperature information were collected using 53 MHz
radio frequency receivers in conjunction with yagi and loop antennas. An
important feature of radio frequency telemetry is the flexibility
available for data collection. Locations were obtained by triangulation
from shore towers and aebile tracking equipment. Temperature information
was collected at a remote recording station, and manually with a stop
wa tc h.
Fifty three MHz receivers used for location and manual temperature
information were constructed by the Cedar Creek Bioelectronic
Laboratory. These receivers were capable of distinguishing 100 different
transmitters (fish) spaced 10 KHz apart. Animals were located by
triangulating from three, 4 element yagi antennas mounted on 7 m
semi-permanent shore towers around the discharge bay as described by
Winter et al. (1978). Shore towers were calibrated by placing
transmitters at known locations and taking bearings to these locations.
Correction factors were then added or subtracted to fish bearings. When
fish left the immediate discharge area, they were located with respect to
landmarks by handheld and airplane mounted loop antennas and truck and
boat mounted yagi antennas.
We usually attempted to locate all fish at least once a day.
Priority was given to those individuals in the iimediate discharge area;
often these fish were located 3 to 4 tines a day. On several occasions,
"round-the-clock* tracking at 2 to 3 hour intervals was attempted;
however, sporadic radio frequency interference limited the success of
these attempts. When fish were located their positions were noted in
reference to gridded maps of the area.
15
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Fish temperature data were collected in 2 ways. Temperature
transmitter pulse rates were monitored manually with a stopwatch when
location data were being obtained. However, the principal source of fish
temperature information was an automatic monitoring and recording system
designed for this project. The system consisted of a 53 MHz
channel-scanning receiver coupled to a pulse rate decoder and strip chart
recorder. The equipment was housed in a remote recording shack near the
shore of the discharge bay. We found that a. near-shore location and low
3 m antennas optimized the signal to interference ratio. The recording
system is more fully described in Appendix G, The entire
receiving-recording system was powered by a 12 v automobile battery.
Generally we adjusted the receiver scanning rate to monitor each
temperature transmitter (fish) for a period of 4 minutes once every 64
minutes. In conjunction with the scanning system, a second continuous
receiving-recording system was installed. This system monitored
temperature for a selected individual continuously for 24 hour periods.
DATA ANALYSIS.' DISTRIBUTION
Fish located by triangulation were plotted on grid maps of Cohasset
area. Winter and spring telemetry data were analyzed by individual fish
with existing University of Minnesota computer programs for home range,
distance moved from center of home range, release site and between
consecutive sites, distance from discharge point and changes in this last
parameter with changing plant operations.
Home range was defined by Hayne (1949) as the area utilized by an
animal in the course of normal movements excluding migrations and
occasional wanderings. Several methods for determining home range areas
have been proposed including home range rectangle, summation of grid
squares and minimum area polygon. Our analysis was based on an adjusted
minimum area polygon method as determined by computer programs described
by Siniff and Tester (1963)'; This procedure was found to be most
compatible with non-automatic telemetry operations. To determine home
range with the minimum area polygon, all individual fish locations were
plotted and the area of the smallest convex polygon enclosing these fixes
was computed (Odum and Kuenzler 1955), This minimum area was then
adjusted by subtracting any portions that occured on land due to
shoreline irregularities. With sufficient location data, adjusted
minimum area approached the maximum area utilized by an animal.
Distance analysis for species mobility was accomplished in 2 manners;
first, by defining a fixed point i.e., discharge point, release site etc.
and entering this point with all locations for an individual fish on a
'fixed point problem1 computer program. Secondly, the distance between
consecutive locations was determined by entering all individual fish
locations on a 'moving point1 computer program. Only those fish with a
minimum of 2 days between fixes while they were in the discharge area
were analyzed with this method. The mean distance moved per day was then
calculated as the total distance moved between fixes divided the number
of days an individual was tracked.
16
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All home range and mobility results were obtained by calculating a
mean for each individual under consideration and then averaging these
means for an overall species ffleao. Fish considered in this analysis were
those fish maintaining a winter hoiae range at least partially within the
discharge area.
Discharge area temperatures were obtained with a Yellow Springs
electrical resistance type thermometer. The discharge point and 3
transects with 5 equidistant stations per transect were monitored at 0.5
m intervals from surface to bottom on a weekly basis. Winter isotherm
maps were constructed from these data for the upper 1.5 m of the
discharge bay.
Winter distribution with respect to temperature was analyzed for
movement between the discharge bay and thermally unaltered areas by
plotting consecutive fish locations on a map of mean winter isotherms.
This information was divided into 2 different types of movement. First,
movement between the thermal discharge bay and unaltered areas when
individuals were either maintaining a home range at least partially
within the thermally affected areas or returned at a later date to the
discharge area were termed 'crossings'. Secondly, movements froa the
discharge bay to unaltered areas, when the fish did not return to the
discharge bay were termed 'dispersals'.
Depth selection was determined by overlaying a transparent
bathymetric map of the discharge area on individual fish location
co-ordinates,
DATA AHM.YSIS; TEMPEEATURI
Recording tapes were read hourly and winter temperature data were
analyzed to the nearest 0.1°C. Temperatures collected manually served
to augment and verify those recorded automatically. We also attempted to
monitor fish that had moved out of recording range on a daily basis.
Yellow perch winter temperature data were analyzed in several manners
with standard (SPSS) statistical programs. First, all winter temperature
data were lumped to obtain an overall group mean regardless of fish
location. This method ignores the fact that several fish transmitters
did not record well due to limited ranges; consequently, these
individuals have a limited effect on the mean. Perch such as 1837, 1838
and 1842 that recorded for extended periods contribute proportionately
more to the lumped mean. Therefore, a second method was used to
determine overall perch winter mean temperature selection. Individual
mean temperatures were calculated for fish with more than 20
observations. These means were then averaged so that each individual
contributed equally to the overall mean.
To determine mean winter temperature selection when perch were in
thermally altered waters, all temperature data greater than 1°C were
analyzed with the sane 2 methods as presented above.
17
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Diel winter temperature selection was determined by analyzing mean
diurnal and nocturnal temperatures for those perch with more than 20
observations in each period. This analysis was performed on both overall
data and discharge area data.
AUTUMN FISH DISTRIBUTION
Autumn fish distribution was determined by plotting individual fish
locations on gridded maps with respect to average fall isotherms.
ASSOCIATED STUDIES
Several other studies were carried out in conjunction with our perch
telemetry operations. The purpose of these observations was to collect
data in order to more fully understand the impact of the thermal
discharge on the fish community and correlate it to our perch telemetry
observations.
Largemouth bass, northern pike and walleye were also equipped with
radio transmitters. Transmitter size and configuration varied. Several
models were used including a lithium cell powered unit. Capture,
transport, tagging, tracking, recording and data analysis methods for
these fish were essentially identical to those used for yellow perch.
Yellow perch, largemouth bass, northern pike and walleye not utilized for
telemetry purposes were treated in one of two manners. First, length and
weight measurements were taken, and then fish were tagged with numbered
Atkins tags for mark-recapture information. These fish were handled
similarly to telemetry fish,* however, tagging time was reduced and
because of the larger numbers involved, individuals were anesthetized
with MS-222. Finally, samples of yellow perch were preserved for later
anatomical observations. Laboratory studies on preserved specimens
involved comparing the gonado-somatic indices of yellow perch collected
in the discharge bay with t;hose of perch collected during the same time
period from unaltered waters. Gonado-somatic indices were obtained by
weighing individual fish then excising and weighing gonads. The index is
the ratio of gonad weight to whole body weight expressed as a percent.
Survey information recorded each time nets were pulled included net
location and numbers of each species. As spawning season approached,
yellow perch sex ratios and spawning condition were also noted.
18
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SECTION 6
RESULTS
During the autumn, winter and early spring of 1975 and 1976, 116
yellow perch, 13 walleyes, 8 northern pike and 2 largemouth bass were
equipped with radio frequency transmitters. Winter and early spring
fishes from the discharge area were monitored for comparative
distribution relative to the thermal plume. Included in this group were
24 perch, 2 walleye and 1 northern pike equipped with temperature sensing
transmitters. Autumn fishes were captured, tagged and released outside
of the discharge area to determine attraction, if any, that the heated
area had for fish that came under its influence. Attraction was
suspected since discharge temperatures were closer to the reported
temperature preference of yellow perch at a time when normal seasonal
water temperatures were declining. Tables 1 to 4 in Appendix D summarize
data concerning numbers of fish, period of observation and quantity of
information collected.
YELLOW PERCH TEMPERATURE RESULTS
Analysis of yellow perch winter temperature distribution data
Indicated a high degree of variability between Individuals and no
significant dial difference within individuals. Table 2 presents overall
perch winter temperature distribution data. Mean temperature selection
ranged from 1.1°C to 9.2°C for 10 individuals. Analysis of variance
indicated a significant difference among average temperatures for
individual perch (p < 0.05). Table 3 presents the results of 3 different
multiple comparison tests to separate significant groups of means. The
least significant difference procedure was considered a liberal test and
indicated that the 10 perch winter temperature means with 20 or more
observations per individual could be separated into 7 different groups.
The more conservative Student-ffewman-Kuels' procedure also separated the
individual means into 7 groups, while the Scheffe procedure, a very
conservative test, divided the individual overall winter means Into 6
subsets with a maximum of 4 fish in a group.
The perch overall winter temperature frequency distribution was
bimodel with peaks at 0°C and 8°C (Figure 4). The lower mode
reflected the large number of temperature observations on fish that moved
into unaltered waters. The 8°C mode represented the most commonly
encountered temperature only while yellow perch were in the discharge
affected areas. The mean overall temperature selection for yellow perch
determined by averaging individual means was found to be 5.4°C,
19
-------
Table 2. OVERALL YELLOW PERCH TOTTER TEMPERATURE SELECTION (°C)
Fish
Id. No.
1833
1834
1836
1837
1838
1842
1843
1844
1847
1848
No, of
Observations Mean
97
160
23
1110
342
353
92
38
29
121
3.4
5.0
5.0
7,4
4.8
6.6
1.1
2.5
9.2
8.5
Standard
Deviation
2.6
3.0
3.0
2.2
2.9
2.6
1.8
2,5
4.3
2.6
Minimum
0
0
0
0
0
0
0
0
0
0
Maximum
9.3
12.8
8.6
13.0
12.9
14.4
10.1
8.8
14.6
14.1
95% Confidence Interval
2.9
4.5
3.8
7.3
4.5
6.3
0.7
1.6
7.6
8.1
- 4.0
- 5.5
- 6.4
- 7.5
- 5.1
- 6.9
- 1.5
- 3.3
- 10.9
- 9.0
Total 2365
Mean by averaging individual means: 5.4 C
Mean by grouped data: 6.3 C
-------
A large number of winter perch temperature observations were
collected from fish outside of the discharge area. Therefore, the
overall winter temperature data did not reflect the temperature selection
of perch located only in the discharge bay since every fish resided in
unaltered waters at least briefly, as noted by a minimum temperature of
0°C (Table 2). Winter mean temperature selection of yellow perch
confined to discharge affected areas was obtained by analyzing
temperatures greater than 1°C, thus eliminating data from outside of
the thermal plume.
Table 4 presents temperatures selected by yellow perch while in the
discharge area. ¥ariability among individual perch remained
substantial. The multiple comparison test using the "Scheffe* procedure
separated the 10 individuals into 5 significantly (P < C.05) different
subsets (Table 5). The mean temperature selection for yellow perch while
in the discharge affected areas only, as determined by averaging
individual means, was 6.3°C.
Because of the high degree of temperature variability among the
individual perch, winter diet temperature selection was examined on an
individual basis. Diurnal and nocturnal temperature data were analyzed
for all data and for the discharge area observations. Results are
presented in Table 6. A t-test on individual perch winter day and night
mean temperatures indicated no significant (p < 0.05) difference.
However, when the data were analyzed for perch only in discharge areas, 2
of 6 individuals preferred significantly warmer areas during the day but
the diurnal means were only 0.7°C and 0.6°C higher for the 2
significant individuals.
Summary
A high degree of variability was detected among individual perch with
respect to temperature selection. In general yellow perch selected
relatively cool winter temperatures from the 0°C to 15°C gradient
available to them. An overall winter mean of 5.4°C was found for all
data with a mean of 6.3°C observed for fish in discharge affected areas
only. Yellow perch varied slightly but not significantly, with respect
to diel temperature selection.
WINTER DISTRIBUTION RESULTS
HomeRange
A comparative analysis of home range and movement data for yellow
perch, northern pike, walleye and largemouth bass indicated interspecific
distribution differences with respect to biotic and physical factors. By
comparing home range size and utilization, and location points with
respect to temperature, depth, release site and center of home range a
description of the respective winter distribution of the 4 species was
made.
23
-------
Table 4. YELLOW PERCH WINTER TEMPERATURE SELECTION (°C) IN THERMALLY ALTERED AREAS
KJ
*»
Fish
Id. No.
1833
1834
1836
1837
1838
1842
1843
1844
1847
No, of
Observations Mean
74
130
18
1096
274
343
35
28
75
4.5
6.2
6.5
7.5
5.9
6.8
2.8
3.2
10.7
Standard
Deviation
2.0
2.0
1.4
2.0
1.9
2.4
1.9
2.5
2.4
Minimum
1.1
3.9
4.1
1.2
1.1
1.4
1,2
1.2
6.9
Maximum
9.3
12.8
8.6
13.0
12.9
14.4
10 1 1
8.8
14.6
95% Confidence Interval
4.0 -
5.8 -
5.7 -
7.4 -
5.7 -
6.5 -
2.1 -
2.3 -
9.7 -
5.0
6.5
6.5
7.6
6.2
7.1
3.4
4.2
11.7
Total 2143
Mean by averaging individual means: 6.3
Mean by grouped data: 7.0
-------
Table 5. YELLOW PERCH SELECTION IN
AREA GROUPED AT THE P = 0.05 LEVEL BY ANALYSIS
OF VARIANCE
Schef f e * Procedure
Subset No,
1
2
3
4
5
Fish Id, No.
1843
1844
1833
1833
1838
1834
1836
1834
1836
1842
1836
1842
1837
1848
1847
Mean Temp, (°C)
2.8
3.2
4.5
4.5
5.9
6.2
6.5
6,2
6.5
6.8
6.5
6.8
7.5
8.6
10.6
25
-------
Table 6, DIEL WINTER PERCH MEAN TEMPERATURES C C)
Overall
In DiBcharge
ON
Pish
Id. No.
1833
1834
1837
1838
1842
1843
1848
Diurnal
Mean
3.3
4.2
7.4
4.7
6.7
1.5
8.1
Nocturnal
Mean
3.8
6.1
7.4
4.8
6.5
0.3
8.8
Calculated
Test
Statistic
0.3
1.4
0.0
0.0
0.1
0.7
0.3
Fish
Id. No.
1833
1834
1837
1838
1842
1848
Diurnal
Mean
4.6
6.0
7,6
6.3
7.1
8.1
Nocturnal
Mean
4.3
6.3
7.4
5.6
6,5
8.9
Calculated
Test
Statistic
0.8
0.9
0.9
*
3.1
*
2.3
1.89
Cltical "t-test" statistic of 1.98 has been exceeded at P = 0.05,
-------
Figures 5 to 12 illustrate examples of consecutive locations and home
ranges for yellow perch, northern pike, largemouth bass and walleye in
the vicinity of the thermal discharge. Table 7 presents home range
information. Northern pike had the largest mean winter home ranges (18.7
ha) followed respectively by yellow perch (10.6 ha), largemouth bass (3.7
ha) and walleye (2.2 ha). However, there was a good deal of variability
within each group and the number of instrumented individuals was large
only for perch.
Mobility
Indices of nobility were determined by considering the distribution
of distances between locations and release site, locations and geometric
center of the home range, and distance between consecutive fixes (Table
8). Northern pike exhibited the greatest mobility with respect to all 3
parameters. They moved at a daily rate more than double that of bass and
walleye. Northern pike and yellow perch moved at a more rapid daily rate
and substantially further from the release site and geometric center of
their home ranges than the walleye or bass. Figure 13 presents distance
from geonetric center of home range data at 50 ia intervals. Ninety
percent of the walleye locations were within 100 m of the geometric
center of the home range. Localized movement was also apparent from the
largeaouth bass frequency distribution. Over 501 of both northern pike
and yellow perch locations were further than 100 m from the home range's
geometric center.
Temperature
When individual fish locations were mapped over average winter
isotherms in the upper 1.5 m of the discharge bay (Figures 14 to 17),
largemouth bass were found in the warmest areas. Yellow perch were
generally located in intermediate areas and northern pike moved across
all discharge affected areas. Mean distance from discharge was computed
for each species (Table 9) and was as follows: largemouth bass, 322 m;
perch, 411 mj and northern pike, 411 m. Mean walleye distance for one
individual was 404 m; however, a high percentage of these locations were
in the center, deeper area of the discharge bay. These areas were
considerabley cooler than the upper 1.5 m (Figure 18).
It seemed that variations in power plant operations would cause
changes in thermal discharge temperature which could result in changes in
fish distribution. Individuals could have maintained a constant
temperature by moving closer to or further away from the discharge point
depending on the type and magnitude of power plant alteration. Distance
froa individual perch locations to the discharge point were determined
for 3 discharge temperatures; 5°-9°C, 10°C-13°C and
14°-18°C. These temperature classes roughly corresponded to 1 unit
operating, both units operating less than full capacity and both units
operating full capacity respectively. Limited location data were
available because when temperature transect data were being collected
fish tracking data were not taken. However, 36 perch locations which
27
-------
Discharge !ni!;;£!;!:;:^;^:!:i!in!;H;N;; Discharge
Figure 5. Movement pattern of yellow perch No, 107.
Figure 6. Home range of yellow perch No. 107,
28
-------
Discharge [|l !iiH;i!l!!!iiiH!i!i!!i!^^ Discharge
i canal •::!H;il!!iy;i:iliiii^i^"^Nt Baypiii
Figure 7. Movement pattern of northern pike No. 102. (©, capture location)
.. _ , r: I:::::::::::::::::
il Canal ::::::::•: -i^]^*
Figure l». Home range of northern pike No. 102. (o, capture location).
29
-------
'
'
Figure 9. Movement pattern of largemouth bass No. 1011, (o, capture location )
Figure 10. Howe range of largemouth bass No. 1011. (©» capture location)
30
-------
;::•;•:••:•;;! I'DiBcharae
Miss. R
Figure 11. Movement pattern of walleye No. 1081. (o, capture location).
Figure 12. Home range of walleye No. 1081. (© , capture location).
31
-------
table 7. ADJUSTED AHEA.VXNTER
Yellow Northern Largemouth
Perch Pike Bass Walleye
Fish
Id, No.
107
108
110
111
113
1009
1014
1017
1033
1833
1834
1837
1838
1840
1841
1842
1843
1847
Mean
Home Home Home Home
Range Fish Range Fish Range Fish Range
(ha.) Id. No. (ha.) Id. No. (ha,) Id. No. (ha.)
8.5 101 11.4 104 7.0 1081 2.2
11.4 102 30.8 1011 013
17.8 103 15.5
22.0 106 16.5 Mean 3.7
14.0 1012 27.0
9.1 1015 12.6
15.4
13.0 Mean 18.9
9.2
5.2
11.2
7.3
13.7
7.4
11.0
6.8
1.6
6.0
10.6
32
-------
Table 8. FISH MOBILITY AS MEAN DISTANCE MOVED PER DAY AND MEAN DISTANCE MOVED FROM CENTER OF HOME
RANGE AND RELEASE SITE
Mean distance moved
from release site
(meters).
Mean
Dlstance
74
No.
Indi-
vlduals
Walleye
Mean
Distance
75
No.
Indi-
viduals
Perch Northern Pike
No.
Mean Indi-
Distance vlduals
219
No.
Mean Indl-
Distance viduals
19 297
Mean distance moved
from geometric
center of hom&
range (meters).
63
59
109
19
183
Mean distance moved
per day (meters) .
89
91
175
14
251
-------
50
™
Q 30
a:
yj 20
O.
10
NORTHERN PIKE
120 Observations
i i
50
40
30
20
10
YELLOW PERCH
666 Observations
!OO 200 300 400 >500
100 200 300 >350
U)
*»
2
UJ
O
a:
50
40
20
10
LARGE MOUTH BASS
125 Observations
4-
50
40
30
20
10
WALLEYE
20 Observations
100 200 300 400 500
METERS
IOO 200 30O 400
METERS
Figure 13. Distribution of fish distances from geometric center of home range.
-------
Figure 14. Yellow perch No. 113 locations relative to average winter isotherms. (°C),
•IgurelS. Northern pike No. 102 locations relative to average winter isotherms (°C).
35
-------
Figure 16. Largemouth bass No. 104 locations relative to average winter isotherms .CO
iiisiH=£-' p-iH- Discharge;;
Figure 17. Walleye No. 1081 locations relative to average winter isotherms. (°C).
36
-------
Table 9, MEAN FISH DISTANCE FROM DISCHARGE POINT (METERS)
Yellow
Perch
Mean
Fish Ms-
Id. No. tance
Northern
Pike
Mean
Fish Dis-
Id.No. tance
Largemouth
Bass
Mean
Fish Dis-
Id.No. tance
Walleye
Mean
Fish Dis-
Id.No, tance
107
108
110
III
113
1009
1014
1017
1033
1183
1833
1834
1837
1838
1840
1841
1842
1843
1847
Mean
537
438
489
434
368
429
381
432
342
433
393
299
465
428
290
459
483
470
254
411
101
103
106
1012
Mean
556
311
307
471
411
104
1011
Mean
229
345
322
1081
404
37
-------
UJ
yj
Q.
yj
Q
0
1.0
3,0
4,0
5,0
6,0
6789
TEMPERATURE (°C)
10
Figure 18. Discharge area mean winter water temperatures
vs, depth,
38
-------
were obtained within 24 hours of monitoring a discharge temperature
between 5°C and 9°C had a mean distance of 467 m from the discharge
point. Eight perch locations obtained at temperatures between 10°C and
13°C were found to average 341 m from the discharge point. Sixty-four
locations obtained at discharge temperature between 14°C - 18°C were
determined to be mean distance of 384 m from the discharge point.
Analysis of variance showed these means were not significantly different
(P < 0.05) and there was no apparent pattern to perch distribution with
respect to alteration in plant operations.
Table 10 presents results for fish movement between thermally
modified and unaltered waters. Nineteen of 31 winter perch crossed
between altered and unaltered waters at least 1 time while in the
vicinity of the thermal discharge during winter months. Eighteen of 31
perch dispersed from the discharge bay during winter months. Only 2 of
31 perch remained entirely within thermally altered areas during the
winter tracking period. Eight perch exhibited crossing and eventually
dispersed. Eight additional perch were tracked after the peak of
spawning in April 1976. All fish in this group dispersed from the
discharge bay within 16 days after tagging. Of the 26 perch observed to
disperse from the discharged bay 58% moved upstream 35% moved downstream
and 8X moved into unaltered areas of Jay Gould Lake.
All northern pike tracked for more than 4 days moved between
discharge and unaltered waters. Three individuals crossed and 3
exhibited both crossing and dispersal behavior. All 3 winter walleyes
tracked also moved between altered and unaltered waters. One individual
crossed 7 times. The remaining 2 walleyes exhibited both crossing and
dispersal behavior. Both largeaouth bass remained entirely within the
discharge bay during winter months. The average number of crossings per
individual for each species were; northern pike 8.5, perch 3.9, walleye
3.7, and largemouth bass 0,
The high percentage of fish, other than largemouth bass, observed
crossing between thermally modified and unaltered areas, and the large
numbers of perch, northern pike and walleye observed dispersing from the
discharge bay implied that the thermal experience was generally
transitory. This was further substantiated by looking at the number of
days an individual was located in or near the discharge area as a percent
of the total period the fish was tracked. For the purposes of this
analysis fish that briefly crossed into nearby unaltered waters and
returned to the discharge bay were counted as discharge area fish. Table
11 presents these results. The percent column may appear deceptive.
Many of the fish with relatively short tracking periods remained near the
discharge area. However, a strong bias toward discharge area locations
existed because all fish were captured and released in the discharge
bay. Additionally, tracking periods could only extend to the life of the
transmitter. If thermal experience was transitory, a better indicator
should have been found by limiting the analysis to those fish that were
tracked for protracted time periods. Only 1 of 3 northern pike tracked
39
-------
Table 10. FISH MOVEMENT WITH RESPECT TO THERMALLY ALTERED AND UNALTERED
AREAS
Fish
Id. No.
Yellow
107
108
109
110
111
113
1009
1013
1014
1016
1017
1018
1032
1033
1153
1159
1183
1833
1834
1836
1837
1838
1839
1840
1841
1842
1843
1844
1846
1847
1848
1850
1851
1852
1853
1854
1855
1856
1857
Cros-
sings
Perch
8
7
8
22
4
10
2
0
12
4
10
4
6
2
2
2
9
0
0
0
0
0
0
0
3
0
6
0
0
2
0
Dispersal
Date
3/15/75
4/6/75
4/24/75
4/27/75
4/24/75
5/10/75
4/29/75
5/4/75
1/20/76
2/16/76
3/26/76
3/23/76
2/25/76
2/28/76
2/25/76
1/21/76
2/27/76
4/7/76
4/18/76
4/26/76
4/23/76
4/18/76
4/15/76
4/15/76
It/21/76
4/24/76
Dispersal Location
River River Jay Gould
Downstream Upstream Lake
X
X
X
X
X
„ -X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
C N
o (3
en QJ
0)
tO v3
IA
s<
I-t
«y
c
*
\o
0%
H
0)
4-1
C
JSS
JS
CTi
Mi
C
M
a
40
-------
fable 10, (continued) FISH MOVQCENT WITH RESPECT TO THERMALLY ALTERED
AND UMALTERED AREAS _____^_^^_^.
Dispersal Location
Fish Cros-
Id.No. sings
Northern Pike
101 6
102 26
103 5
106 4
1012 2
1015 6
Halleye
100 7
1057 2
1081 2
Largemouth Bass
104 0
1011 0
Dispersal River River Jay Gould
Date DownstreaB Upstream Lake
4/6/75 X
4/27/75 X
4/27/75 X
4/15/75 X
5/9/75 X
Season
& Year
Winter 1975
41
-------
Table 11. AMOUNT OF TIME FISH WERE LOCATED IN THE DISCHARGE BAY AS A PERCENT OF THE ENTIRE
INDI?IDUAL TRACKING PERIODS
Yellow Perch
Fish
Id , No .
107
108
109
110
111
113
1009
1013
1014
1016
1017
1018
1032
1033
1153
1159
1183
Days
Tracked
28
33
38
26
38
33
17
39
31
26
41
15
29
29
28
27
28
Days
in dis-
charge
28
33
20
26
38
29
17
21
31
17
41
14
28
19
4
8
28
Percent
In dis-
charge
100%
1.00%
53%
100%
100%
88%
1001
54%
100%
651
100%
93%
97%
66%
14%
30%
100%
Yellow Perch
Fish
Id. No.
1833
1834
1836
1837
1838
1839
1840
1841
1842
1843
1844
1846
1047
1848
Days
Tracked
58
20
119
125
66
28
14
50
29
30
65
72
53
46
Days
in dis-
charge
15
20
17
56
25
27
14
25
17
30
13
1
53
13
Percent
in dis-
charge
26%
100%
14%
45%
38%
96%
100%
50%
59%
100%
30%
1%
100%
28%
Northern Pike
Days
Fish
Id. No,
102
103
106
1012
1015
101
100
1057
1081
104
1011
Days in dis-
Tracked charge
89
31
15
26
42
43
_____Walley_e
10
12
22
Largetnouth
60
51
53
31
15
25
18
43
6
1
21
Bass
60
51
Percent
in dis-
charge
60%
100%
100%
96%
43%
100%
60%
81
95X
100%
100%
-------
Figure 19. Largemouth basa No. 104 locations relative to depth.
Si Discharge:;;;:: Discharge!;
Figure 20. Walleye No. 1081 locations relative to depth.
44
-------
for longer than a month remained near the discharge area. Similarly only
4 of 14 perch tracked for more than 31 days remained near the discharge
bay. Although the longest tracking period for a walleye was 22 days none
of the 3 individuals remained entirely in the discharge area.
Selected individual fish locations mapped over depth contours are
depicted in Figures 19 to 22 and summarized in Table 12. A chi-square
test showed the species distributions to be significantly different (P <
0.05}. Largemouth bass selected significantly shallower, near shore,
areas than other fish. For example, 95% of all largemouth bass locations
were found at a depth less than 1.5 m. Walleyes selected substantially
deeper areas; 58% of all walleye locations were found in the center areas
of the discharge bay, an area with depths greater than 3 m. Northern
pike and yellow perch were intermediate with respect to depth selection.
They prefered shallow areas, but not to the extent that largemouth bass
did.
Simultaneous Tracking
There may have been some bias in comparing species that were not
tracked during the same time periods or were tracked considerably longer
than others. Therefore an attempt was made to isolate this bias. Table
13 presents summary results for 2 time intervals when fish of various
species were tracked over similar time periods. First 1 largemouth bass,
1 northern pike and 2 perch tracked in late February and March were
compared. We selected the least mobile northern pike and most mobile
largemouth bass, a worst case situation} to determine if relative
distribution results were consistent with overall estimates. In general,
the results compared favorably with overall distribution results.
Largemouth bass had the smallest home range, least mobility, fewest
crossings and shallowest depth distribution closest to the discharge.
Perch were intermediate with respect to home range size and mobility.
Northern pike and perch crossed into unaltered waters and preferred
somewhat deeper areas which were further from the discharge than
largemouth bass. A second period from April 12 to May 4, 1975 was
selected to compare walleye to perch distribution parameters. Here
again, perch preferred areas away from the discharge point, exhibited
more mobility, had greater home range sizes and selected shallower depths
than the walleye. When mid-winter perch from the first time period were
compared to the late winter individuals, the only parameters noticeably
different were distance from the release and discharge points. Home
range, mobility, depth selection and movement between altered and
unaltered waters appeared to be similar.
Summary
Comparative species distribution results must be interpreted with a
certain degree of caution. Obviously, a larger number of fixes over a
protracted time period could result in larger home ranges, more
43
-------
••
O\ Discharge (II ill DIs char geliiiiil
Miss. R
Jay Gould L
Figure 21. Yellow perch No. 113 locations relative to depth.
Figure 22. Northern pike No. 102 locations relative to depth.
45
-------
Table 12. DEPTH SELECTION BY FISH IN THE DISCHARGE AREA
Depth
0.0-1. 5m
1.5-3. Om
> 3.0ro
Perch
No. of Par-
Observations cent
541 71%
122 16%
97 13%
Northern Pike
No. of
Observations
154
34
10
Per-
cent
78%
17%
6%
Largemouth Bass
No. of Per>-
Observations cent
130 96%
5 31
1 1%
Walleje
No. of Pei>
Observations cent
7 241
5 17%
17 59%
Chi-Square 0.95, 6 D.F. - 12.6.
-------
Table 13. A SUMMARY OF RESULTS FOE TWO PERIODS WHEN FISH WERE TRACKED CONCURRENTLY
b j:ua r y 26 to M arch 22, 19 7 5
Fish
Species Id. No,
Yellow
Perch 107
108
X
Northern
Pike 103
Largemouth
Bass 104
Yellow
Perch 1017
1033
X
Walleye 1081
Tracking
Period
No, No.
Days Locations
25 55
25 51
25 53
16 32
25 48
Apr
Home
Range
(ha)
8.5
LI. 4
9.9
L4.1
3.3
i 1 3
23^ 38
20 38
22 38
18 23
L2.4
9.1
L0.8
2,5
Mobility gj ^ g,
4-> Q) O O O d
C o Q) 6 fl) «S
4J wof-i wocg
WOrt -H!-ial *H^!UO
OS« Qfc« on-low
(meters
§ a) Temp
J-i W>
IW J-l
rt
. je
4J U
as en
•H -H
O P
Cros'-
/day) (meters) (meters) (meters) sings
230 312 112
2,21 268 125
226 290 119
237 365 174
132 123 99
.2 to May 4, 197
215 152 114
203 123 108
209 138 109
73 74 64
534 8
437 5
495 7
306 2
279 0
6
423 10
342 2
387 6
409 0
Depth
0.0-1,5 1,5-3,0 > 3.0
(tneters) (meters) (meters)
35 1 3
33 3 13
34 2 8
30 1 1
46 2 0
16 11 9
30 4 4
23 8 7
5 2 16
-------
crossings, higher daily movements, etc. The tracking period was
determined fay the transmitter life as determined by the battery size an
individual could carry. Also, fish were tracked over non-coincidental
time intervals on an irregular schedule. However, each time fish were
tracked we attempted to locate all individuals regardless of species
which minimized bias.
The nature of telemetry limits the number of individuals that can be
tracked at a given timej thus, fish had to be grouped wihout regard to
size or sex. All fish analyzed were adults grouped by species and
season. This fact probably accounts for a portion of the intraspecific
variability and the lack of more clear-cut interspecific differences.
However, the overall results generally agreed with those obtained by
selecting limited periods when the species were tracked concurrently.
Our radio tags did not transmit depth data per se. Depth was
inferred from location. Conceivably, an individual could have been at
any depth in the water column at a given location. However, as Holt et
al. (1977) pointed out, walleyes are a demersal species and the
probability that this species was near the bottom at any given time was
high. Erikson (1975) found that during the winter Perca fluviati^lis (a
closely related European perch species) remained at the bottom of a
laboratory tank. Therefore, the assumption in determining comparative
depth data was likely valid for these species.
In general, perch were found to have a home range size less than
northern pike and greater than largeatouth bass and walleye. This species
preferred shallow areas distal from the discharge point. A high
percentage of the individuals either crossed between the discharge bay
and unaltered waters or dispersed from the discharge bay. Perch mobility
as measured by distance moved from center of home range, release site and
daily movement rates was determined to be less than northern pike and
greater than walleye or largemouth bass. Perch locations with respect to
changes in plant operations showed no significant difference or pattern.
northern pike generally exhibited the largest mean home range and
were the only species to have mean home range size larger than the
discharge bay. This species also preferred relatively shallow areas.
Northern pike showed the greatest variability with respect to distance
from the discharge and were found to virtually cover the entire discharge
bay. They demonstrated the most nobility and crossed between thermally
altered and unaltered waters more often than any other species. No
northern pike tracked for more than 4 days remained entirely in the
discharge bay.
Largemouth bass had a small home range and preferred significantly
shallower areas closer to the discharge than northern pike or yellow
perch. Largemouth bass movement from center of the home range, release
site and daily movement rates were determined to be substantially less
than that of northern pike and yellow perch. The 2 largeraouth bass
remained entirely within thermally altered areas during their tracking
periods.
48
-------
Limited data were available on walleye as only 1 individual was
successfully tracked while maintaining a home range in the discharge
bay. This individual had a small home range in the center deep area of
the discharge bay. Mobility was less than that of perch and northern
pike. All 3 walleyes tracked during winter months moved between
thermally altered and unaltered areas. Two individuals dispersed shortly
after instrumentation.
AUTUMN DISTRIBUTION RESULTS
The high percentage of yellow perch observed dispersing from the
discharge area during the late winter and early spring months resulted in
an expansion of the project. We speculated yellow perch would return to
thermally altered areas the following autumn as the river cooled, and the
fish followed the thermal gradient to maintain temperatures closer to
reported temperature preferenda. Fish approaching the discharge
confluence with the river could have reacted positively and moved into
the discharge bay, A negative reaction would have been observed if the
fish encountered the gradient and either turned back or continued moving
through the periphery to thermally unaltered areas. Figure 23 presents
average fall isotherms in °C above ambient, depicting the gradient
present during this phase of the investigation.
During the fall months of 1975 and 1976, fish were trapped and
released in areas where radio tagged fish had dispersed the previous
spring. We tracked 62 yellow perch and 3 walleyes captured in areas
upstream and downstream from the thermal discharge and 2 walleyes from
the discharge area for a minimum of 7 days. Table 14 suraaarizes the
results. Autmm cracking cowienced in September 1975 when the normal
river temperature was 13°C and discharge temperature was 20°C.
Tracking continued until December when normal river temperatures had
dropped to 0°C and discharge temperatures to 10°C. Nine yellow perch
were tracked upstream from the discharge. Figure 24 depicts the
distribution of daily locations of a typical perch upstream from the
thermal discharge. All individuals remained in waters under normal
seasonal temperature conditions. Only 1 fish made a substantial move
downstream toward the discharge area, however, this perch moved into the
thermally unaltered area of Jay Gould Lake, Three perch moved into the
northwest bay of Blaekwater Lake that supplies water to the intake of the
power plant. The remaining 5 perch remained in shallow areas of
Blaekwater Lake upstream from the discharge.
Nine perch and 1 walleye were radio tagged downstream during the
Autumn of 1975. Figure 25 shows a typical location pattern of a perch
downstream from the discharge. Initially fish trapping below the
discharge and mixing zones was difficult due to strong currents. Thus, 4
of 9 'downstream' perch were not radio tagged until November 27. By this
time, normal river temperatures had cooled to 0°C. Discounting these
last 4 perch, 3 of 5 perch moved through the mixing zone during the
autumn cooling period. Two individuals subsequently moved into thermally
49
-------
Figure 23. Average fall Isotherms (°C above ambient). (Modified from HP & L» by permission.)
-------
Table 14. AUTUMN YELLOW PERCH MOVEMENT
1975
1976
No.
Tracked
9
No . moved
toward
Discharge
1
Per-
cent
III
No . moved
into Per-
Discharge cent
0 0%
No,
Tracked
5
48
No » moved
toward
Discharge^
3
32
Per^
cent
60%
67%
No, moved
into
Dischayge
1
1
Per"
cent
201
27,
Total
11%
53
35
661
4%
-------
MINNESOTA
POWER & LIGHT
CAPTURE &
RtLEASe
MJSSISSIPP1 RIVER
N
500 in
Figure 24. Movement of perch Ho. 1813 from October 7S to
November 19, 1975 as it remained upstream from the discharge area.
52
-------
APTURE &
RELEASE
Figure 25. Movement of yellow perch No, 1817 from October 9
to November 1, 1975 as it aoved upstream from below the nixing
zone into Jay Gould Lake.
53
-------
unaltered areas of Jay Gould Lake. Only 1 individual continued to move
up the gradient into the discharge area. This perch remained in the
discharge area for a 5 day period after which it also moved into Jay
Gould Lake. Due to these observations, we shifted all future autumn work
downstream.
One walleye (no. 1814) which was radio tagged below the discharge
moved upstream through the nixing zone and continued upstream 2.5 kn
beyond the confluence of discharge and river. This individual
subsequently maintained a location centered around a 3.5 m deep bend in
the meandering river channel between Blackwater and Cutoff Lakes. Two
walleyes radio tagged in the discharge bay moved back and forth between
the bay and thermally unaltered areas of Jay Gould Lake.
Fifty-six yellow perch and 2 walleyes were captured and radio tagged
below the thermal discharge between September 10 and December 1, 1976.
River temperatures dropped from 19°C to 3°C and discharge
temperatures fell from 27°C to 12°C. Forty-eight perch were tracked
successfully. Thirty-two of these 48 perch moved upstream and
encountered the mixing zone. Only 1 fish visited the discharge bay and
it for only 1 day prior to moving into thermally unaltered areas of Jay
Gould Lake. The remaining 31 individuals moved into thermally unmodified
areas of Jay Gould Lake, Little Jay Gould Lake, Pokegama Lake and the
Mississippi River above the confluence with discharge waters, or returned
downstream below the mixing zone. Figure 26 depicts river temperature
and the autumn 1976 perch movement upstream as a percent of the total
number of perch transmitting downstream from the confluence of the
discharge and Mississippi River on a given day. The greatest upstream
movement occurred between October 13 and Ifovember 3, with a peak of 291
(2 of 7 individuals) occurring on October 16. At this time downstream
river temperatures were dropping rapidly, relative to other Autumn
periods. The only perch that entered the discharge area during the fall
of 1976 moved upstream into the discharge bay during this period.
Two 1976 walleyes which were tagged below the discharge moved into
the discharge bay within a day of release. Subsequently, 1 of these fish
moved between discharge and thermally unaltered areas. The other moved
upstream to the same 3.5 m deep bend in the river channel that walleye
no. 1814 had occupied the previous fall.
Summary
The results of two autumn seasons fish tracking outside of the
thermal discharge bay indicated 35 of 53 perch tracked below the
discharge moved upstream through the mixing zone. Only 2 of the 35
continued in a positive direction through the thermal gradient into the
discharge bay. Furthermore, these 2 perch remained in the thermally
modified area only for a short period of tine, tone of the 9 perch
tracked above the discharge - river confluence moved into thermally
altered waters. Five walleyes tagged during the fall months appeared
either to oscillate between discharge and thermally unaltered waters or
to move upstream beyond the mixing zone.
54
-------
Ill o
feL20
cc
5
C0
I
10
o
40
z
O 20
K
yj
Q-
o
JL
_ "*
2 2
gii T . 10
"* . 1
I]
~ 12
12
0
J
T
0
J
' €
f
_
5
<•*
1
"i
1
3 "
r
r ;
_ c
•
15 I'
2
T
»
j r
51
5
Mi
151
5 1
r
10 20 30
SEPTEMBER
10 20 30
OCTOBER
10 20
NOVEMBER
30
Figure 26. Autumn 1976 Downstream River Temperature (°C).
Autuma 1976 yellow perch moving upstream as a percent of the total number of radio tagged perch
monitored downstream from the discharge area each day.
-------
ASSOCIATED OBSERVATIONS
Yellow Perch_ Length and Weight
Length and weight observations from yellow perch captured in
commercial fishing operations between April 30 and May 5, 1975, are
presented in Table 15. A t-test indicated neither standard length nor
weight varied significantly between perch of the sane sex captured in the
discharge area compared to the Mississippi River immediately upstream.
GonadalSomatic Indices
Prespawning gonadalsonatic indices of yellow perch captured between
April 7, 1975 and May 5, 1975 were similar for fish collected in
thermally modified and unmodified areas. Indices for 20 females from
modified areas ranged from 2.8Z to 26.31 with a mean of 17.7%. Indices
for 27 females from unmodified areas ranged from 1.7% to 23.3% with a
mean of 16.8%. Similarly, indices for 13 males from modified areas
ranged from 0.8% to 5,3% with a mean of 2.5% compared to a range of 0.4%
to 3.7% and a mean of 1.9% for males from unheated waters. These figures
compared closely to mean gonadalsomatic indices of 16.2% for female and
3.9% for male perch from Minnesota Department of Itotural Resources traps
at Little Cutfoot Sioux Lake on May 9, 1975. These perch were from a
thermally unmodified area approximately 50 km north of the study area.
Eighteen percent of females over 150 g from Little Cutfoot Sioux Lake
were considered undeveloped; the ovary weight was less than 10% of the
whole body weight. This compares to 202 undeveloped females from the
discharge area and 14.8% undeveloped females from unaltered waters near
the discharge.
Winter Trap Netting
Winter trap netting catch rates from the discharge bay are presented
in Table 16. Bullheads, rockbass, dogfish and bluegill sunfish were the
most eonBonly encountered species. Walleye, largeaouth bass, white fish,
tullibee and burbot were among the least frequently encountered. Dogfish
and bluegill sunfish trapping rates dropped substantially from 1975 to
1976 while yellow perch and rock bass rates increased. Winter and spring
yellow perch catch rates in the discharge area are plotted in Figure 27.
Catch per trap night increased in 1976. However, catch rates peaked both
years near the spawning season.
Spawning Conditionand Sex Ratios
Figure 28 presents spawning condition and sex ratios of yellow perch
collected by coaanercial fishermen fron the discharge and unmodified areas
in 1975. Data from natural areas were only available after the ice was
out. A high percent of discharge area males were ripe over the entire
spawning period. Females were generally green before April 30. Changes
56
-------
Table 15. YELLOW PERCH STANDARD LEHGTH AMD WEIGHT OBSERVATIOHS, APRIL 30, TO MAY 5, 1975
Unmodified Areas
ThermalIgAl tered Areas
Ln
Female
Mean
No . Obs er vat ions
Standard
Deviation
Weight
(s)
299
77
87
Length
ton)
21.9
76
2.0
Male
Weight
Cg)
197
23
64
Length
(cm)
19.6
25
1.8
Female
Weight
Cg)
289
36
77
Length
tcm)
22.3
35
2.0
Male
Weight
Cg)
176
19
62
Length
Ccm)
19.3
22
1.9
-------
Table 16. WINTER 1975 AMP 1976 CATCH RATES FOR THE DISCHARGE AREA
Ui
oc
«
JC
»
*(-!
ss
"***.
a
to
N
H
Winter 1975
Totals : 90
Winter 1975,
Catch /Trap
Night :
Winter 1976
Totals: 249
Winter 1976,
Catch/Trap
Night:
43
to
•H
M-i
OQ
O
o
450
5.0
199
0,8
is.
**3
t^
9
f
iH
H
3
W
2043
22.7
4399
17.6
C l^
O (U O
§4J fM
*H CJ
o Jd 3
o 5 to
18
0.2
13
0.05
P
C
CU
45
4J ^)
M Ai
O «H
29
0.3
103
0.4
QJ
<0
t^H
63
S
3
0,03
4
0.2
^
O 4^
i-» O
0) CU
25
0.3
248
1.0
*£*
4J
3
O
E
i
00 OJ
>-. CO
-------
I3
QL
a:
h-
X 9
o c
cr
UJ
a.
1 ,
1976
1-1516-30 1-15 16-28 1-15 16-31
JAN FEB MAR
1-15 16-30 1-15 16-30
APRIL MAY
Figure 27.
and 1976.
Yellow perch catch per trap night In discharge area for 1975
59
-------
DISCHARGE AREA
UNALTERED AREAS
Oh
g 3
< 2
CC
X |
0
100
80
z 60
LJ
DC 40
LU
a.
20
GREEN
RIPE---
SPENT-
100
80
I 6°
u
cr 40
Q.
20
0
"-, A
Cf
5 10 15 20 25 30 5 8 tO IS 20 25 30 5
APRIL MAY APRIL MAY
Figure 28. Sest ratios and spawning condition of yellow perch from discharge
and unaltered areas 1975.
60
-------
in sex ratios indicated that males moved into spawning areas in the
discharge by April 21, followed shortly thereafter by females. The peak
of spawning occurred between April 30 and shortly after May 5, 1975 in
both discharge and unmodified areas. Similar data were not available for
1976; however, by April 20, 15 of 19 female perch collected by
electrofishing in both modified and unaltered areas were spent. Also
after April 19 catch rates in discharge area nets dropped to O.I
perch/trap night. They had been 3.3 from April 1 to 6, 1976. For the
sane time intervals ca'tch rates in unaltered areas climbed from 6 to 9.4
perch/trap night, apparently indicating that perch were leaving the
discharge area for unaltered waters.
Recaptures
The recapture of both radio and Atkins tagged fish provided valuable
information (Table 17). Recapture rates for radio tagged fish were
similar to Atkins tagged individuals. Nine radio tagged yellow perch
recaptured in nets had an average of 11 other perch of various sizes in
the same net. Ten recaptured transmitter tagged perch were in good
condition with no debris or vegetation entangled with the transmitter.
Transmitter and backing washers generally remained firmly attached and
little, if any, abrasion was noted around the transmitter or attachment
washer. One female tagged prior to spawning and recaptured 45 days later
had released its eggs. The peak of spawning also occurred during this
time period. A radio tagged walleye recaptured after 166 days had
abrasions and lesions near the anterior end of the attachment backing
washer. A radio tagged northern pike recaptured 11 months after tagging
appeared to be in good condition. The skin under both the transmitter
and attachment backing washer had abrasions, but there was no obvious
infection. This 5.67 kg female had maintained its weight over the 11
month period.
While trapping downstream from the mixing zone during the fall of
1976 a yellow perch Atkins tagged in the discharge bay the previous
winter was collected.
Angler returns of Atkir.s tagged fish provided insight into long term
movement. A yellow perch tagged in the discharge bay December 10, 1975
was caught 7.2 km upstream in the Mississippi liver during the summer of
1976. Another perch tagged 0.8 km above the discharge on May 3, 1975 was
caught June 24, 1976 6.2 km further upstream. A yellow perch tagged
April 21, 1975 in the discharge bay was caught 6 km downstream below the
Pokegama Dam on June 18, 1975. Angler returns of 2 walleyes showed even
further long term movement. A 312 g walleye tagged 0.8 km above the
discharge on May 3, 1975 was caught approximately 16 km further upstream
on October 12, 1975. A 1.59 kg walleye tagged December 2, 1975 in the
discharge bay was caught 7.2 km downstream, below the Pokegama Dan on
July 9, 1976.
61
-------
Table 17, YELLOW PERCH RECAPTURE DATA
_ a_^^ :^= JE_ ,_^r= _ Returns^
No.
Taggejd Netting Elect w^ftahJMg Angling Totjtl^ Percent Return
M Radio 116 911 9.51
Atkins 903 61 3 5 7,72
-------
SECTION 7
DISCUSSION
Habitat selection is a complex and dynamic process. The habitat a
fish selects is influenced by many variables including light,
temperature, depth, ice cover, dissolved and suspended chemicals,
vegetation, predators, prey and competition. Furthermore, the relative
importance of each parameter may vary with species, time of day, weather
patterns, season, and environmental alterations. This study evaluated
the comparative impact of an industrial perturbation on the habitat
selection of yellow perch and three other fishes as determined by
distribution and temperature selection.
The telemetry results indicated that each species reacted
differently. With the exception of largemouth bass, the thermal
experience appeared to be transitory. Temperature most likely played a.
relatively minor role in the autumn, winter and early spring habitat
selection of yellow perch. Habitat selection of northern pike was also
found little if at all effected. Additonally, observations on recaptured
animals suggested that neither radio tagging nor handling adversely
affected behavior or survival.
The nature of telemetry studies limits researchers to making numerous
observations on relatively few animals. An implicit assumption is that
tagged animals behave similarly to the remainder of the population. Our
tagged perch indicated that activity and survival of radio tagged fish
were similar to perch marked with standard fisheries methods. Due to
size limitations of the radio transmitter, we usually tagged large perch
that were almost always female. However, the fact that an average of 11
other yellow perch of various sizes were in the same net with 9
recaptured perch suggested that large radio tagged females were not
segregated from the other portions of the yellow perch population.
Finally, observations on recaptured fish indicated that radio tagged fish
suffered limited physical injury due to externally applied radio
transmitters. Appendix A more fully discusses the impact of radio
transmitters on small fish. Although limited data are available, it
appears that properly applied small radio transmitters do not interfere
with short term fish behavior of the nature involved in this study during
the cool and cold water seasons of the year.
63
-------
Our observations that largeraouth bass had a small home range entirely
within the discharge area in shallow relatively warm water compare
favorably with those in the literature. Winter (1977) determined that
95% of the largemouth bass locations were less than 3 m deep during the
summer in an unaltered Minnesota lake. Relative to yellow perch and
walleye, largemouth bass were reported to have the highest final
temperature preferenduo (Coutant, 1975). Clugston (1973) found
largemouth bass moving in and out of a thermal discharge; however,
minimum ambient water temperatures in his study were 11° +_ 2°C,
considerably warmer than the 0°C temperatures found in our study area,
Largemouth bass movement rates reported by Clugston (1973) and Peterson
(1976) were higher than the winter rates we found, but our determinations
were a minimum daily rate because fish were not tracked continuously.
Walleyes tagged in the thermal discharge were found either to confine
most of their winter movements to the deeper cooler areas of the
discharge or to leave the discharge areas shortly after tagging. Little
data exist in the literature concerning the effect of thermal discharges
on walleye behavior. However, Holt et al. (1977) found that the mean
depths in which walleyes were found in an unaltered lake was 2.8 to 7.2
m. This agrees well with the depth selection of the only walleye we
aion'itored in the discharge area for an extended period. Both localized
short term activity (Kelso 1976a) and rapid movement between areas (Bahr
1977) have been observed for walleyes. Perhaps the relatively small
amount of area greater than 3 m deep in the discharge bay limited the
number of walleyes that remained in the discharge bay during winter
months. These fish exhibited localized activity confined to the center,
deeper areas. Other walleyes left the discharge area rapidly for
thermally unaltered waters.
Apparently temperature preference did not subtantially influence
habitat selection in the 5 walleyes tracked during autumn months.
Individuals moved between altered and unaltered waters, The only site
specificity observed was a large bend in the meandering river channel
approximately 2.5 km above the discharge confluence with the river.
As with walleyes little information is available concerning northern
pike behavior near thermal discharges. However, the relatively high
amount of movement, large home range and shallow depth selection of
northern pike agree with the winter observations of Diana et al. (1977)
for a thermally unmodified area. They noted that pike were generally
found in near shore areas less than 4 m deep. Also, this species did not
develop a well defined home range; daily movements ranged from 0 to 4000
m and 70% were more than 200 m.
Yellow perch behavior relative to thermal discharges has been studied
more extensively. Our observations concur with those of Storr and
Schlenker (1973) and Kelso (1976b). In general the thermal discharge had
little long term effect on the behavior and distribution of yellow
perch. Perhaps the key to this conclusion was the high degree of
64
-------
variability noted between individual yellow perch with respect to winter
temperature selection. However, many other observations supported this
hypothesis. The low overall winter temperature preference, the high
amounts of movement between thermally altered and unaltered areas, the
transitory nature of thermal experience and the failure of yellow perch
to ascend an autumn temperature gradient were all behavioral indications
that factors other than or in addition to temperature preference
contributed significantly to habitat selection. Similar physiological
observations on perch from altered and unaltered areas with respect to
length, weight, spawning condition and timing suggested that thermal
effects, if any, were limited.
The scope of this investigation was confined to thermal effects,
However, telemetry, trapping and field observations can potentially
elucidate environmental factors other than temperature to more fully
explain the observed distribution of yellow perch. Trapping data
indicated higher numbers of ictalurids, centrarchids, and dogfish in the
discharge bay. Perhaps competition from these more therraophilic species
accounted for the lack of positive thermal response observed in yellow
perch. Secondly, perch may have preferred the comparative darkness
offered by ice cover during winter months when vegetation cover was at a
minimum. Telemetry data indicated that northern pike, a visual feeder
and major predator on yellow perch, preferred aany of the same shallow
areas away from the discharge point, where perch were most often located
when in discharge affected areas. Spring trapping data suggested that
perch moved into the relatively higher standing stock of aquatic
vegetation to spawn in the discharge bay. Both trapping and telemetry
observations indicated that a high percentage of these fish subsequently
dispersed shortly after spawning. The observed autumn distribution and
movement patterns could have been a response to the aquatic vegetation
dying and washing away in the narrow river channel downstream from the
confluence with the thermal discharge. Perch situated upstream from the
discharge did not encounter as severe a loss of habitat because this area
was characteristically a wide shallow environment where the river channel
meandered through wild rice beds.
Behavior with respect to food and water chemistry was not evaluated;
no data were gathered relative to the abundance of food organisms. While
a good deal of literature is available concerning toxicity of various
levels of chemicals on growth and survival, little is known of the
chemical effects on fish behavior. Furthermore, a real paucity of
information exists relative to the synergistic effects of temperature and
various water chemistry parameters on fish behavior. Therefore, the
chance that power plant induced alterations in water chemistry could
account for the lack of positive thermal response remains a possibility
until further research is performed.
In stiamary thermal effects appeared to restrict walleye movement in
the discharge area and maintained conditions in shallow areas preferred
by largemouth bass. Northern pike movement was not limited to nor
specific for any portion of the discharge area. On a relative basis,
65
-------
movement patterns of largemouth bass, walleye and northern pike were not
substantially altered from those reported in the literature from
thermally unaltered areas. Finally, the results indicated that an
elevated temperature in conjuction with the numerous other environmental
variables in a dynamic river system did not alter the distribution of
yellow perch as would be predicted on the basis of laboratory temperature
preference experiments. Interpretation of cause and effect data gathered
independently is difficult; however, environmental factors such as
competition, predation and the dynamics of suitable aquatic vegetation
habitat could more fully account for the observed fall, winter, and early
spring distribution of yellow perch.
66
-------
REFERENCES
Bahr, D.M. 1977. Homing, swimming behavior, range, activity patterns
and reaction to increasing water levels of walleyes (Stizostedion
yicreum vitreum) as determined by radio telemetry in navigational
pools 7 and 8 of the upper Mississippi liver during spring 1976,
M.S. Thesis University of Wisconsin - LaCrosse. 67 pp.
Barans, C.A. and R.A, Tubb. 1973. Temperatures selected seasonally by
four fishes from western Lake Erie. J, Fish. Res. Board Can.
30(1L):1697-1703.
Bennett, G.W. 1970. Management of lakes and ponds. Second edition.
Von Nostrand Reinhold Co., New York. 375 pp.
Brett, J.R. 1956. Some principles in the thermal requirements of
fishes. Quart. Rev. Biol. 31(2):75-87.
Brungs, W.A. and B.R. Jones. 1977. Temperature criteria for freshwater
fish: protocol and procedures. U.S.EPA Ecol. Res. Ser. EPA
600/3-77-061.
Clugston, J.P. 1956. Some effects of heated effluents from a nuclear
reactor on species diversity, abundance, reproduction and movement of
fish. Ph.D. Thesis. University of Georgia. 104 pp.
Cochran, W.W. and R.D. Lord, Jr. 1963. A radio-tracking system for wild
animals. J. Wildl. Manage. 27(l):9-25.
Coutant, C.C, 1969. Thermal pollution - biological effects. In; A
review of the 1968 literature on wastewater and water pollution
control. J. Water Poll. Contr. Fed, 41(6):1036-1053.
Coutant, C.C. 1970. Thermal pollution - biological effects. In; A
review of the 1969 literature on watewater and water pollution
control. J. Mater Poll. Contr. Fed. 42(6):1025-1057.
Coutant, C.C,, 1975. Temperature selection of fish - a factor in power
plant impact assessments. Symposium on the physical and biological
effects on the environment of cooling systems and thermal discharges
at nuclear power stations. IAEA-SM-187/11. Oslo, 26-30 August 1974.
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Coutant, C.C. and C.P. Goodyear. 1972, Thermal effects - reviews. In:
1971 water pollution control literature review. J. Water Poll.
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Coutant, C.C,, and H.A. Pfuderer. 1973. Thermal effects - a review of
the literature of 1972 on waste water pollution control. J. Water
Poll. Contr. Fed. 45(6);1331-1369.
Coutant, C.C., and H.A. Pfuderer. 1974. Thermal effects. J. Water
Poll. Contr. Fed. 46(6):1476-154Q.
Diana, J.S., W.C. Mackay and M. Ehraan. Movements and habitat preference
of northern pike (Esojc lucius) in Lac Ste. Anne, Alberta. Trans. An.
Fish. Soc. 106(6)J560-565.
Dobie, J. 1966. Food and feeding habits of the walleye Stizostedion v.
vitreum, and associated game and forage fishes in Lake Vermillion,
Minnesota, with special reference to the tullibee, Coregonus
(Leucichthys) artedi. Minn. Fish. Invest. No. 4:39-71.
Eriksson, L.O, MS. 1974. Diel and seasonal activity rhythms and
vertical distribution in the perch, Perca f luviatjLlus at the Arctic
Circle. Ms. Report, Univ. Umea, Sweden. 10 p. +2 Tab. and 6 Fig.
Ferguson, R.E. 1958. The preferred temperature of fish and their
midsummer distribution in temperate lakes and streams. J. Fish, les.
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Gibbons, J.W., J.F. Hook and D.L. Forney. 1972. Winter responses of
largemouth bass to heated effluent from a nuclear reactor. The
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Hayne, D.W. 1949. Calculation of size of home range. J. Mammal.
30(13:1-18.
Hokanson, K.E.F. 1977. Temperature requirements of some percids and
adaptations to the seasonal temperature cycle. J. Fish. Res. Board
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6. Fed. Water Poll. Contr. Adm. Cincinnati, Ohio.
Holt, C.S., G.D.S. Grant, G.P. Oberstar, C.C. Oakes, and D.W. Bradt.
1977. Movement of walleye, Stizostedion vitreum, in Lake Bemidji,
Minnesota, as determined by radio-biotelemetry. Trans. Ao. Fish.
Soc. 106(23:163-169.
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temperature requirements for maturation and spawning of yellow perch
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mankind, Proc. World Conf., Vol. 3.; Biological Balance and Thermal
Modifications M. Marios (Ed.). 189-192.
68
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Kelso, J.R.M. 1976a. Diel movement of walleye Stizostedion vitreum
vitreuBi, in West Blue Lake, Manitoba, as determined by ultrasonic
tracking. J. Fish. Res. Bd. Can. 33:3070-3072.
Kelso, J.R.M. 1976b. Movement of yellow perch (Perca flavescens) and
white sucker (Catostonms commersoni) in a nearshore Great Lakes
habitat subject to a thermal discharge. J. Fish. les. Bd. CAn,
33:42-53.
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interrelationships of walleye and yellow perch, especially during
their first summer, in two Minnesota lakes. Trans. Am. Fish. Soc.
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the heated discharge of a nuclear power plant. J. Fish. Biol.
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yellow perch, Perca flavescens. U.S. EPA Ecol. Res. Ser. EPA
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in support of Minnesota Power and Light Company's application for
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Mississippi River. Minn. Dept. Cons. Invest. Rpt. No. 255.
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93(3):267-285.
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noVOTent data obtained by telemetry. Bioscience 15(2):1Q4-108.
Storr, J.F. and G. Schlenker. 1973. Response of perch and their forage
to thermal discharges in Lake Ontario. Proc. of Symp. Thermal
Ecology, Augusta, Georgia, May 3-5, 1973.
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U.S. Dept. of the Interior. 1957. A special report oa the Mississippi
liver Headwater reservoir system. Bureau of Sport Fisheries and
Wildlife. Mpls., MS.
Warden, R.L. Jr. and W.L. Lorio. 1975. Movements of largeaouth bass
(Micropterus salmoides) in impounded waters as determined by
underwater telemetry. Trans. Am. Fish, Soc. 104(45:696-702.
Winter, J.D. 1976. Moveaents and behavor of largemouth bass
(Micropt erus salBoides) and steelhead (Salao ga^irdneri) determined by
radio telenetry. Ph.D. Thesis. Oniv. of Minn. 195 pp.
Winter, J.D. 1977. Summer home range and habitat use by four largenouth
bass in Mary Lake, Minnesota. Trans. Am. Fish. Soc. 106(4):323-330.
Winter, J.D., V.B. Ruechle, D.B. Siniff and J.I. fester. 1978.
Equipment and methods for radio tracking freshwater fish. Bniv. of
Minn. tnst. of Ag. Misc. Bui. 152. 45 p.
70
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APPENDIX A
STUDIES TO DETERMI« THE EFFECT OF RADIO TRANSMITTERS ON YELLOW PERCH
(Perca flavescens) AM) LARGEMOUTH BASS (Micropterus salmoides)
Radio and ultrasonic telemetry have been utilized extensively to
monitor movements, activity, and reactions of both free-ranging and
captive animals to environmental variables. While terrestrial biologists
have the opportunity to locate and visually observe their study animals,
fisheries researchers rarely have the same opportunity. Because
behavioral characteristics of tagged specimens are studied for the
purpose of extrapolation to non-tagged individuals, the effect of the tag
and tagging process must be known before such extrapolation can be made
with confidence,
Transmitter attachment procedures have differed among telemetry
studies depending on the species, environment, type of research, and
state of the art. Winter (1976) and Morris (1976) discussed various
internal and external attachment methods and the respective advantages
and problens associated with each. Several authors, including Bahr
(1977), Hart and Susimerfelt (1975), Henderson et ai. (1966), Warden and
Lorio (1975), Winter (1977), Young et al. (1972), and Ziebell (1973) have
discussed the effect of transmitters on fish relative to one or more of
the following; swimming ability, feeding behavior, survival, and tag
retention. Although there is a good deal of indirect information as to
the effect of transmitters on fish, much of it is subjective or derived
from short term observations. Furthermore, even less is known concerning
physiological effects and the effects of package weight.
Laboratory studies indicate that both physostomes and physoclists can
re-adjust their buoyancy to neutral after radio tagging. Fried et al.
(1976) reported that by gulping air, Atlantic salmon smolts (Salmo salar)
adjusted for negative buoyancy induced by transmitter tag weight.
Neutral buoyancy was regained in physoclistic fish in less than 24 hours
by secreting gas into the air bladder to adjust for transmitter weight
(Gallepp and Magnuson 1972). However, McCleave and Stred (1975)
determined that larger internal and external tags caused a significant
decrement in swimming ability in stamina chambers. Wrenn and Hackney
(1976), using dummy radio transmitters surgically implanted in sauger
(Stizostedion canadenae) concluded that some mortality could be expected,
but that long-term growth and general condition of fish that survive
would not be affected. However, further investigations of this nature
are warranted as the state of the art of electronics for telemetry has
surpassed our knowledge of the bio-effects of transmitter packages.
71
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This paper reports on several studies which have been carried out to
determine the effect of the radio transnitter package on behavior,
physiology, and predator-prey relationships on yellow perch and
largenoutfa bass. These studies were conducted in laboratory situations
and others were done in large outdoor ponds.
72
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Methods
Five studies were conducted to evaluate radio package effects, The
general design of these studies was to contrast the physiological and
behavioral responses of control fish to those of dummy radio tagged
and/or sham tagged fish when exposed to similar environmental conditions
and challenges. Control groups were usually tagged with Atkin's tags
(small plastic tags) attached into the upper back portion immediately
anterior to the dorsal fin. Dummy radio tagged fish were also equipped
with an external, simulated radio tag fitted immediately ventral of the
dorsal fin. Dummy radio tags were designed to weigh approximately 1% of
the fish's weight. Sham tagged individuals were processed identically to
the dummy tagged fish except that after processing the tag was removed
and the experiment carried on. The 5 experiments were as follows; (1)
survival of dummy radio tagged versus control yellow perch; (2) some more
subtle effects of transmitter attachment as measured via differential
mortalities between dummy radio tagged and untagged fish when exposed to
predation by northern pike," (3) feeding rates of control and dummy radio
tagged largemouth bass; (4) respiration, feeding, and growth rates of
control, sham tagged and dummy tagged yellow perch; and (5) the influence
of different tag weight to yellow perch weight to determine the maximum
load carrying capacity.
(1) Survival
Equal numbers of dummy radio tagged and Atkin's tagged perch were
released into a 0.5 ha, 2 m deep pond at the EPA Environmental Research
Laboratory Duluth, Minnesota. The study pond bottom was gravel with
several inches of silt and submerged vegetation although the shallows
supported growths of filamentous algae. Substantial amounts of
planktonic algae were noted throughout the summer. Temperatures in the
pond averaged 22°C at the surface and 19°C at the bottom. Dissolved
oxygen in the pond was very low at the bottom, averaging 1.4 parts per
million in August and reaching a low of 0,1 part per million early in the
month. Fish were picked in an unbiased manner for assignment into the
transmitter and control group. Tagged and control fish were released on
3 different occasions during August, 1975.
(2) Predation
The predation experiment was carried out in an adjacent small pond
about 0.05 ha in area and 1 m deep. The bottom was bedrock and gravel
with very little silt and about 70 percent was covered with dense aquatic
vegetation. The water was very clear throughout the experiment and no
major algal blooms were observed. Temperature averaged 20.5°C.
Because of the shallow depth, dissolved oxygen, though not measured, was
assumed to be near saturation. In this case 66 yellow perch were used as
prey species and 5 northern pike (Esox lucius) were used as the
predator. On 3 different occasions during August and September 1975
equal numbers of dummy tagged and control yellow perch were released into
73
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this pond. Shoreline observations of the pond were made about every 2
days for mortality and the pond was seined twice during the experiment.
It was completely drained on September 12, 1975 and all surviving fish
were sacrificed for examination. The northern pike stomachs were
examined for evidence of predation.
(3) Feeding - Largemouth Bass
The feeding experiment with largemouth bass was carried out in the
Duluth Environmental Research Laboratory. Ten laboratory reared and 12
wild-caught largemouth bass were divided equally among a dummy tagged
group and a control group. After tagging, all fish were given a
Terramyctn treatment and during the next nine days given two formalin and
one Roccal treatment. Fish were fed a measured amount of minnows once
every other day from September 8 through September 13. The fish were
allowed to feed for alternately 1-hour and 6-hour periods with the
remaining minnows removed from the tanks after these time limits,
(4) Respiration, Feeding and Growth
Further experiments on yellow perch measuring respiration rates,
feeding rates, and growth were carried out at our field laboratory in
Cohasset, Minnesota from September 28, 1976 to November 7, 1976. The
fish were kept in a 600 liter stainless steel holding tank supplied with
untreated Mississippi River water. The temperature in the tank varied
with the river temperature. The fish were divided into 3 separate groups
consisting of control, dummy radio tagged, and sham-tagged fish with five
individuals in each group. Each individual was weighed and measured
prior to and after the 6-week experiment. Each group was supplied with
10 minnows each day and the number consumed was tallied the following
day. The respiration rate of each fish was counted daily using the
number of operculum cycles for a 30-second interval. Notes on survival
and tag retention were kept throughout the experiment.
(5) Maximum Loading
The maximum dummy radio tag weight an individual could carry was
determined for 5 yellow perch. Fish were equipped with small dummy radio
tags and the weight of the tag increased by adding brass washers and nuts
to protruding bolts until the individual could no longer maintain
equilibrium or swim normally in a holding tank.
74
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Results
(1) Survival
When the 0,5 ha pond was drained on November 1 (86 days after initial
release), only 2 of 28 duamy radio-tagged fish were recovered while 23 of
28 controls survived (Table A-l). Between August 11 and September 10, 9
dead dummy tagged fish and 2 dead control fish were found in the pond.
Four of the 9 dummy tagged fish had enlarged holes around the attachment
wires, and filamentous algae caught between the fish and the anterior end
of the tag. One of the observed mortalities was a dummy-tagged fish that
had lost its tag. The holes were evident where the tag had pulled
through the body and the dorsal fin.
(2) Predation experiment
Table A-2, summarizes the results of the predation experiment.
Observed mortalities were subtracted from the total fish released to
obtain the number of fish available to predators. Twenty-nine out of 31
control fish were recovered and 11 out of 27 tagged fish were recovered.
Dummy radio tagged fish had a significantly higher mortality rate (P <
0.001). Mortalities cannot be confirmed as due entirely to predation,
but that predation was at least partially involved was evidenced when on
capture the largest pike regurgitated a partially digested dunmy radio
tagged perch. When the 0.05 ha. pond was drained, 5 duway radio tags
were found on the bottom with no tissue attached. One had been seen
several days earlier on a living perch. The stomach of another pike
yielded a radio tag with a snail amount of tissue still attached,
suggesting that the other tags retrieved from the bottom of the pond may
have represented egesta of previous prey fish.
(3) Largemouth bass feeding experiment
Figure A-l summarizes the results of the feeding experiment. For the
laboratory fish, controls consumed more minnows than radio-tagged fish in
13 out of 13 trials. For the wild fish, controls ate more minnows than
dummy tagged fish in 10 out of 13 trials. Controls seemed more active
than tagged fish, but tagged fish seemed to have no difficulty in feeding
and were observed feeding 12 hours after they were tagged. When the fish
were examined on September 13 and November 2, sores were observed under
the tag and attachment plate. Dumay radio tags had loosened during the
experiment chafing the underlying surface. Some fungus was present on
the tags and around the attachment wires, but there were some fungus
infections on the control fish also. One tagged fish had shed its tag.
The wound had healed, leaving only a slight scar and a torn section of
the dorsal fin.
75
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Table A-l. SURVIVAL RESULTS ON YELLOW PERCH (PERCA
FLAVRSCEME) RELEASED INTO
THE LARGE
Atkin's Tag
Released
August 6, 1975
August 7, 1975
August 30, 1975
Total released
Recovered (pond drained)
November 1, 1975
Not recovered
Observed mortality
Unobserved mortality
Total not recovered
Percent survival
11
4
13
28
23
2
3
5
82%
POND
Dummy Radio
11
4
13
28
2
9
17
26
7%
Table A-2. RESULTS OF PREDATION
Released
August 7, 1975
August 29, 1975
September 7, 1975
Total
Observed mortalities
(not due to predatlon)
Total available to predators
Recovered
August 19, 1975
September 5, 1975
September 12, 1975
Total
Percent survival
Control
10
12
9
31
0
31
7
0
22
29
94%
Tagged
10
12
9
31
4
27
0
1
10
11
41%
-------
1501
ISO-
n
Laboratory Reared
19 21 23 25 27 29 2 5 8 9 10
AUGUST SEPTEMBER
Q minnows presented
EJ minnows consumed by tagged fish
minnows consumed by control fish
!3
19
21 23 25 27 29
AUGUST
8 9 10
SEPTEMBER
minnows presented
minnows consumed by tagged fish
minnows consumed by control fish
13
Figure A-l. Feeding of laboratory reared and wild largemouth bass under laboratory conditions.
-------
At the beginning of the experiment, there was no significant
difference between the mean weights, and lengths of controls and dutnny
tagged fish (Table A-3). Growth in both length and weight was
significantly less (P < 0.05) for the tagged fish between August 6 and
September 13 in both laboratory reared and wild-caught groups.
(4) Respiration, Feeding and Growth
Sespiration rates in duuray radio tagged, shan tagged and control fish
varied with temperature independent of treatment (Fig. A-2). A single
factor analysis of variance indicated no difference in respiration rate
over the 6-week period. However, due to the great deal of variability
caused by temperature fluctuation in the tank, respiration rates were
also analyzed on a daily basis. Significant differences (P <0.05) were
observed between groups on only 3 of 33 days as follows: October 6, dummy
radio tagged and sham tagged greater than controlsj October 7, sham
tagged lower than controls; October 10, dummy radio tagged lower than
controls. We concluded there was no apparent pattern in these
differences.
Feeding and growth rates in the three groups were not found to be
significantly different (P < 0.05), Table A-4 summarizes the results.
While sham-tagged individuals consumed considerably fewer minnows, a Chi
square test showed no difference (P < 0.05). Initially there was no
significant weight difference between the treatment groups (P < 0.05).
While weight changes did not occur similarly between the treatment
groups, the weight changes were not significantly different from initial
weights in any group (P < 0.05, Table A-4). Two of 6 dummy radio tagged
perch died during the 6 week respiration-feeding study. Sham-tagged and
control fish did not suffer any mortality. One of the dumny radio tag
mortalities had a fungal infection near the anterior attachment site.
The other mortality also had a large fungal infection, however, it was
located ventrally from the tag and not associated with the tagging site.
The anterior attachment wire separated from 1 dummy radio tag. This
break occured at the junction of the wire and the epoxy shield covering
the transmitter.
(5) Maximum Loading
We used 5 yellow perch to determine the maximum package weight that
could be carried without loss of equilibrium. Results are presented in
Table A-5. A linear regression of package weight (in water) plotted
against fish weight indicated that for fish in the 140 g to 300 g size
range, the transmitter should weigh no more than 2% of the fish's weight.
Discussion
The nature of telemetry studies is generally one of collecting a
large number of observations on relatively few individuals. The
necessary assumption follows that tagged animals behave similarly to the
78
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Table A-3. A COMPARISON OF WEIGHT, AND LENGTH OF LARGEMOUTH BASS BEFORE AND AFTER THE FEEDING
EXPERIMENT (MUMBER OF FISH EXAMINED IN PAREMHESES)
Date
8/6/75 Average weight (g)
Range
Standard deviation
Average total length (cm)
Range
Standard deviation
8/13/75 Average weight (g)
Range
Standard deviation
Average total length (cm)
Range
Standard deviation
Change in weight (g)
Change in length (cm)
Lab Reared
Control (5)
364.9
277-506
97.2
28.3
26-31
2.2
450.9
282-639
138.9
29.5
27-33
2.7
+ 86.0
+ 1.3
Group
Tagged (5)
410.8
335-549
81.0
29-1
28-32
1.8
432.4
321-611
109.7
29.6
28-33
1.9
+ 21.6
+ 0.5
Wild
Control (6)
211.3
131-287
64.2
24.2
21-27
2.4
250.8
178-324
56.2
25.3
22-28
2.2
+ 39.5
+ 1.1
Group
Tagged (6)
288.5
84-439
118.5
24.6
18-30
3.9
227.6
99-435
113.7
24.7
19-30
3.8
- 0.9
+ 0.1
-------
TanK Temperature
Control
-• Sham Tagged Fish
• •• Radio Tagged Fish
28 30
SEPT
8
10
12 14 16
OCTOBER
18 20 22 24 26 28 30
3
NOV
Figure A-2. Tank temperature and respiration rates of control, sham tagged, and dummy radio
tagged perch.
-------
Table A-4. YELLOW FEEDING AMD GROWTH.
11. 1976.
28 TO
Number Mean
Minnows Initial
Consumed Weight (g)
Dummy
radio 53 245
Sham tag 25 270
Control 55 263
Mean Mean
Final Weight
Weight (g) Change %
251 + 2%
245 - 9%
249 - 5%
Table A-5. MAXIMUM WEIGHT OF TAG RESULTING IN LOSS OF EQUILIBRIUM
AMONG YELLOW PERCH OF SIZES
142
218
283
283
283
Tag Height (g)
5.1
5.1
7.5
10.5
10.5
Tag Weight
in Water (g)
3.3
3.3
5.3
7.0
7.0
Tag Weight in
Water as Percent
of Fish Weight
2.4%
1.7%
1.9%
2.5%
2.5%
81
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rest of the population. These studies contrasting the responses of dummy
radio tagged fish to those of untagged fish revealed that the basic
assumption upon which radio telemetry studies is founded may be accepted
with reservations. These reservations point to the essential need to
know that the answers to the questions being asked are not biased by the
processes of capturing, tagging and carrying the transmitter package.
The bioeffects of an external transmitter were revealed in these studies
to be composed of several elements. One was a weight element, where
transmitter (weight in water) burdens greater than 2% of fish weight were
found excessive.
Low dissolved oxygen concentrations in addition to the trauma of
handling and tagging contributed to the high incidence of mortality in
large pond survival study, indicating that radio tagged fish are more
susceptible to environmental stresses that compound tagging effects.
Survival was also compromised by entanglement of external transmitters in
dense aquatic vegetation. Survival of radio-tagged fish appears to be
much greater under more favorable conditions. Studies with yellow perch
in the upper Mississippi have resulted in a 9,62 recapture rate of 115
radio-tagged perch, compared to a 7.7% recapture rate of 903
Atkins-tagged perch (Ross, 1978). Furthermore, the recaptured
radio-tagged perch had an average of 11 other non-tagged individuals in
the same net, Haynes (1978) reported that 47% of radio-tagged chinook
salmon (Oneorhynchus tshawy t s c h a) reached Lower Graite Dam on the Snake
River, compared to 33% of controls. Indirectly, the effect of the radio
tag appears no greater than that of standard fisheries tags.
Virtually every telemetry study involving more than a very few
individuals can anticipate some mortality. Mortality rates may be
increased due to handling and tagging. These studies revealed that
survival may be decreased due to selective predation on radio tagged
fish. The problem facing the researcher is to account for these
eventualities in experimental design and ensure that telemetry data
differentiates between moribund or dead and normally active individuals.
Generally moribund individuals can be detected simply by their lack of
movement. Thus the data from such immobile individuals can be removed
prior to analysis.
Laboratory experiments indicated that yellow perch respiration rates,
growth and feeding behavior were not altered by dummy tags. While
respiration rates varied with temperature, little difference was observed
among control, sham tagged and dummy tagged fish. This implies to us
that tagged fish were not required to alter their metabolic rates in
order to carry the transmitter. Also, the lack of variation among groups
over changing temperatures indicated a similar physiological response to
this environmental variable. However, the largemouth bass study found
feeding and growth to be nearly always greater among non-tagged fish.
These findings may indicate a species specific response or merely that at
the lower temperatures in the perch experiment more time may have been
required to detect statistically significant differences.
82
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In spite of Che problems revealed in these studies radio telemetry
may be the best or the only means available Co answer some types of
questions. In these cases it is essential to know of the shortcomings
and to take them into consideration when interpreting the findings.
However, many very inportant ecological questions can apparently be
addressed by this technology without any or with only slight technology
induced bias. The Mississippi liver mark and recapture studies (loss,
1978) produced overnight fyke net catches of both tagged and non-tagged
perch, suggesting that they move in the same areas and essentially in the
same time frame. Further these catches produced nearly equal percentage
recapture ratios between actual radio tagged fish and Atkin's tagged
fish. These findings also indicate that in the less restricted natural
environment during the cooler months, differential mortalities between
tagged and non-tagged groups may not be as serious as suggested by our
pond studies. Both of these findings give support to the primary premise
that at least gross movements of tagged fish are representative of those
of non-tagged fish*
83
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References
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and reaction to increasing water levels of walleye (Stizostedion
vitreua vitreua) as determined by radio telemetry in navigation pools
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by Atlantic salmon (Salmo salar) smolts tagged internally with dummy
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Gallepp, G.W., and J.J. Magnuson. 1972. Effects of negative buoyancy on
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127 p.
Warden, R.L., Jr., and W.L. Lorio, 1975. Movements of largemouth bass
(Micropterus salmoides) in impounded waters as determined by
underwater telemetry. Trans. Am. Fish. Soc. 104(4):696-702.
84
-------
Winter, J,D, 1976. Movements and behavior of largemouth bass
(Micropterus salmoides) and sceelhead (Salmo gairdneri) deterained by
radio telemetry. Ph.D. thesis, Univ. of Minn. 197 p.
Winter, J.D. 1977, Sunmer hone range movements and habitat use by four
largeiaouth bass in Mary Lake, Minnesota. Trans, Am, Fish. Soc.
106(4).-323-330.
Wrenn, W.B. and P.A. Baekney, MS 1976. Growth and survival of sauger
(Stizostedion canadense) with surgically implanted model
transmitters. Biothermal Research Station, Tennessee Valley
Authority. (Unpublished Manuscript).
Young, A.H., P. Tytler, F.G.J. Holliday, and A. MacFarlene, 1972. A
small sonic tag for measurement of locomotor behavior in fish. J.
Fish. Biol. 4;57-65.
ZiebeLl, C.D., 1973. Ultrasonic transmitters for tracking channel
catfish. Prog. Fish. Cult., 35(l):28-32.
85
-------
APPEH3IX B
TEMPERATURE T1AISMITTER DESIGN AM) DEVELOPMENT
Teaperature sensing transmitters used in Chis study were developed
for use on small fish and constructed by the University of Minnesota's
Cedar Creek Bioelectronics Laboratory. In the development of the
temperature transmitter circuit 3 areas were critical (Figure B-l).
First, the pulse rate had to remain constant with changes in power supply
voltage. This was especially critical when working with lithium 2,8 v
batteries. By inserting Rsj and Is2 (Figure B-l), pulse rates were
stabilized for changes in power supply voltage. Lithium batteries were
not used in this study; however, weight and life considerations make
lithium cells preferable for many aquatic applications and will be
utilized extensively when smaller sizes become available. A single 1.4
v. mercury cell (RM675) was used to power temperature transmitters used
in this study. Pulse rate voltage stability of the temperature-sensing
circuitry was found to be greater at this voltage eliminating the need
for Rsj and Rs2- Table B-l summarizes pulse interval variation
versus changes in supply voltage.
Second, long-term drift had to be minimal so that temperature
transmitters would retain their original calibration over the expected
life of the unit. Figure B-2 summarizes drift testing data. Worst case
drift was found to be 1°C at 0°C and generally much less. These
tests were made over a ten-week period, but shorter term observations
could be expected to measure temperature more accurately. Since the bulk
of the drift occurred during the first two weeks of testing, long-term
drift could probably be reduced by pre-aging tags before calibration.
The third design goal was to obtain a range of optimum sensitivities
fron 0 - 35°C, The actual pulse rate for a given temperature or range
of greatest sensitivity was determined by the thermistor-timing capacitor
combination. By varying this combination, the range of maximum
sensitivity could be optimized (Figure B-3).
86
-------
NOTE: 01, Q2, Q3, 04, AND
Dl ARE IN RCA
CA 3096A TRANSISTOR
ARRAY,
rn
Figure B-i, Temperature transmitter circuit.
-------
Table B-I, PULSE INTERVAL VA1IATION VERSUS SUPPLY VOLTAGE FOR
2.8 VOLT NOMINAL LITHIUM CELL. TIMING CAPACITOR 0.47 pf.
Battery Voltage
Thermistor
Resistance
488 k
1.0 M
1.5 M
1.04 M
2.5 M
PULSE INTERVAL
MERCURY CELL.
Thermistor
Resistance
470 K
680 K
1.0 M
1.5 M
2.2 M
3.3 M
2.6 2.8 3.0
Pulse Interval (Milliseconds)
656
1110
1552
2073
2518
656
1109
1548
2067
2510
656
1109
1548
2063
2507
VARIATION VERSUS SUPPLY VOLTAGE FOR 1.25
TIMING CAPACITOR 0.47 pf .
1.2
158
210
341
472
700
983
Battery
1.3
Pulse Interval
160
211
342
472
700
983
Voltage
1.4
(Milliseconds)
162
212
343
472
700
983
VOLT NOMINAL
1.5
165
214
346
474
700
983
88
-------
1600
0
0 4 8 12
TEMPERATURE DEGREES
16 20
CENTIGRADE
Figure B-2. Envelope of long term temperature transmitter
calibration drift. Calibration checked; 10/5/76, 10/19/76,
11/2/76, 11/17/76, 12/21/76.
89
-------
PULSE RATE VS TEMPERATURE
UJ
<
tr
UJ
CO
3500
3000
CO
o
z
o
o
UJ
CO
x: 2500
2000
1500
1000
500
Thermistor GA6IPZ, I Meg of 25° C
Thermistor GA55P2, 500K at 25°C
20 25 30 35 40
0
TEMPERATURE °C
Figure B-3. Temperature transmitter pulse rate vs. Temperature,
Thermistor-Capacitor combinations.
90
-------
APPENDIX C
TECHNICAL SPECIFICATIONS FOR AUTOMATIC
TEMPERATURE RECORDING EQUIPMENT
This appendix describes the automatic temperature recording system
used for the project. The system had three main components,* a 53 tnhz
programmable 16 channel scanning receiver, a pulse rate decoder and a
strip chart recorder. Following a brief technical description,
information on receiver controls and operating procedures is outlined.
Finally, circuit and block diagrams are presented.
The receiver is similar to the model used to monitor fish location
described on page 15. However, several changes and modifications were
made. Major design changes included the use of a memory into which
frequencies could be programmed and later recalled by means of a single
selector or scanned automatically by an interval timer. This option
proved valuable in 2 applications. First, in tracking from an aircraft
where it is necessary to scan for a number of animals in a short
period, individual animals could be tuned rapidly by means of a single
switch. Since all channels are locked to a single crystal there was no
need to search around a frequency to make sure that a transmitter had not
been missed. A second application, and a more important one, was in
unattended applications where the receiver could scan and record data
from the channels that were programmed into the memory. The scanning
rate could be pre-selected so that the receiver looked at 1 of 16
channels for periods ranging from 3.7s seconds to 1/2 hour. The receiver
had a phase locked loop to detect the signal sent to the decoder. Use of
a phase locked loop gave greater noise immunity and made transmitter
drift a minor problem because the loop detects a signal if it is within +
2.5 KHz from a set frequency.
Next, temperature transmitter signals from the receiver were sent to
a pulse rate decoder. The function of this unit was to measure pulse rate
and generate a signal to a recording apparatus. Since the pulses from
the receiver were not perfectly square, some error would result depending
on where the trigger level was set and how the pulse varied from pulse to
pulse. This potential error was reduced by averaging a number of
pulses. We did this in the decoder by counting the time for 10 pulses.
With this scheme we were dependent only on the triggering time of the
start pulse (Oth pulse) and of the stop pulse (10th pulse). In addition,
the error in these 2 pulses were divided by a factor of 10. Output of
91
-------
the decoder was available as a digital readout from the front panel, a
binary coded decimal signal and from the digital-to-analog (DA)
converter. The DA converter was an 8 bit integrated circuit type with
its output adjusted to 1 milliaapere full scale. The 8 bit converter was
capable of dividing the 0 to 1 ma scale in 2® or 256 parts.
For our application a Eustrak analog recorder was used. The
millianpere current generated by the pulse rate decoder DA converter was
sent to the Eustrak where it was recorded on a 3" per hour strip chart.
92
-------
''2» '*' ''**"*
gxoowcjxy
©
FROST PAH1L CONTROLS,
(I) Headset Impedance Selector
(2) Headset Jack
(3) Battery Charge/External
Power/Auxiliary Output
(k) Antenna Input Connector
(5) Pine Tune Control
(6) On/Off RP Gain Control
(7) Audio Gain Control
(8) Battery Status Indicator
(9) External 0-1 ma Recorder
Jack
(10) Signal Level Meter
(11) Frequency Selector
Switches
(12) Frequency Indicator
CONNECTORS AND INDICATORS
(13) Display On/Off Switch
(Ik} Memory Channel Selector
(15) Memory Bank Selector
(16) Memory Active/Bypass Selector
(17) Memory Read/Write Selector
(18) Memory Auto/Manual Selector
(19) (20) Memory Scan Interval
Control
(21) Signal Search Control
(22) Auto Scan Channel Indicator
(23) Signal Indicator From Phase
Lock Loop
(24) Auxiliary Outputs
93
-------
Function of Operator Controls
1. Headset Impedance Switch. This switch selects the best impedance
match between the 2000 ohm Telex headsets which are normally used and the
8 ohm Koss headsets which are used if anbient or wind noise is a problen.
2. Headset Jack. Provides receptable for headset or other listening
device. A standard monaural plug fits. Standard stereo plugs may be
used if both head pieces are wired to the tip.
3. Battery Charge/ExternalPower: Operional Input/Output. Provides
receptable for input power to recharge internal batteries and to provide
power from external 12 volt power supply. Extra pins may also be used as
optional input-outputs.
4. Antenna Input. Female BNC connector to provide for 50 ohm antenna
input.
5. Fine tune. Allows shifting the 1st converter crystal frequency to
provide fine tuning between the 1 KHz increments of the frequency
synthesizer. It allows the operator to tune to the frequency that can be
heard best or is the most comfortable.
6. On/Off - R.F. Gain. Turns power on and off from internal batteries
or external power supply. The variable resistance control varies the
R.F. gain in the input pre-anplifier to prevent signal overload on strong
signals. This prevents spurious signals from being generated by
intennodulation and cross Modulation. R.F. gain is Baxinum when the
control is fully clockwise.
7. Audio Cain._ Controls the audio level in the headset. This control
has very little effect on detectability of a signal. Maximum signal
level is with the control fully clockwise.
8. Battery Status Indicator. Indicates voltage level of internal
rechargeable batteries or external power source. It should be in the
white area for proper operation.
9. 0-1 caa External Recorder. Allows insertion of an external meter in
series with the internal meter to record signal strength on an external
paper recorder.
10. Signal Strength Meter. Provides an integrated indication of the
audio signal level.
11. Frequency Selectors. The three switches select which frequencies
are to be passed through the receiver and which are blocked. Frequency
can be selected in 1 KHz increments over a 1 MHz range. The 1 MHz range
is determined by selection of the preamp and first converter.
94
-------
12. Firequengjf=j|gdig,:g^gl£ Three digit display of the frequency. In the
manual mode the display will be the same as the frequency selector
switches (11). When in the memory active mode it will display the
frequency of the active channel.
13, Display on/off Switch; Turns off the display to save power when the
display is not needed.
14. Memory phanrteI_SeLector,^ Sixteen position switch to address which
channel is to be written or read into the frequency selector.
15. Memory Bank Selector: In 32 channel receivers the switch selects
channels 0-15 in position (A) or 16-31 in position (B).
16. Memory Active/Bypass Selector; This switch is used to transfer a
frequency selected by front panel switches (11) into the memory channel
selected by (A).
17. MemoryRead/WriteSelector; This switch is used to transfer a
frequency selected by front panel switches (11) into the memory channel
selected by (A).
18. Memory Auto Manual Selector; Selects whether the memory is to be
scanned by means of the channel selector (14) or automatically by an
internal timer.
19., 20. Memory Scan Interval^ontrql; Controls the rate of the
interval timer for the auto can mode.
21. Signal Search^Control; (Optional) With this signal in the lock
mode the receiver will scan until a signal is found. It will then remain,
locked on that channel as long as a signal is present.
22. Auto Scan Channel Indicator: Lights indicate which channel is
active in the auto scan mode. It is in binary code and can be converted
to decimal by adding the number below the lights that are on.
23. Signal Indicator From Phase-loeked-loop; Indicates a signal is
present if the light is on.
24. AUK i 1 i a_ry_ Ou t pu t s.'
95
-------
Operating Procedure
Once the function of each control is understood, operating procedure
follows quite easily.
(l)-(2) Headsej^Jack andHeadset Impedance Switch;
The headset or other audio output device is plugged into the headset
jack and the impedance switch is set to correspond to the impedance of
the headset used; 8 ohms for the Koss or other stereo types or 2 K for
relex or similar 2000 ohm headsets. Headsets or audio devices of other
impedance can be used with some loss in output level depending on the
impedence mismatch and power required. For devices other than 8 or 2000
ohms the impedance switch should be set for the best output level.
(6) On/Off R. F.Gain. The on/off switch controls the power to all
modules whether the receiver is operating on external batteries or is
using an external power source.
The R.F, gain control should be rotated fully clockwise so that R.F.
sections are operating a maximum gain to achieve maximum sensitivity. It
should be left at maximum sensitivity until the transmitter or signal
source can be heard. Once the signal is found, the gain should be
reduced to achieve a signal level where differences in signal amplitudes
can be easily detected. The gain should also be reduced as you move
toward a signal source to prevent overload of the input stages. Although
overload will cause no permanent damage to the receiver, it can cause
spurious signals to be generated from cross or intermodulation. These
spurious signals can cause confusion. Overload (spurious signals) can
cause signals to appear on channel locations where no signal sources are
supposed to be. This problem usually does not occur during normal
operation with perhaps 2 exceptions. 1) When attempting to determine
whether a transmitter is working on the test bench extraneous signals
may be detected while switching to the correct channel. Confusion may
also result while attempting to check out a number of transmitters for
test purposes. 2) Occasionally problems will be encountered while trying
to move in on a signal source. These can almost always be cleared up by
making sure the channel setting is correct for the signal source being
searched and reducing the signal level. The setting of the R.F, gain
control is probably the most critical for accurate and efficient signal
source location.
(7) Audio Gain. The audio gain should be set for a comfortable noise
level in the headset. Settling of the audio gain does not affect
sensitivity except as effects hearing sensitivity. The audio level does
not affect signal to noise ratio. It does affect the meter indication.
96
-------
(3) - (8) Jl^tt^er^^charge/^ex^ernal power; Battery level indicator. The
battery level indicator should be in the white region when the receiver
is turned on. If it is in the red region the internal battery voltage is
low and in need of recharge or the voltage of the external power source
is low. If an external power source is used, the receiver will switch
automatically frora internal to external power. The receiver is designed
for a negative ground system. The positive supply line should be
conected to pin 2 of the supply jack. If the polarities are reversed, a
protective diode will block the current to prevent damage to the
receiver. When external power is applied an audible click can be heard
as the internal relay switches from internal to external power.
Frequency selection switches (11) control the frequency to which the
receiver is tuned with the active-bypass switch (16) in the bypass
position, or the read-write switch (17) in the write position. The
receiver frequency will be displayed at (12) with the display switch (13)
in the on position. The display draws approximately 40 ma or 1/3 of the
current needed to operate the receiver. Power is saved with the display
off.
The auto-manual scan switch (18) determines how the memory is
addressed; by the channel switch (14) and bank switch (15), or the
automatic scanning circuitry.
To program the memory, place the manual-auto scan switch (18) in the
manual position. Set the channel (14) and bank (15) switches at the
desired locations. Place the read-write switch (17) in the write
position. Select the frequency desired with the frequency selector
switches (11). Change the channel switch to the next location and select
the next desired frequency. When finished programming be sure the write
switch (17) is set to read. With the read-write switch in the write
position the memory will record the frequency of the selector switches at
the channel addressed. Manually check the channels to be sure the
desired frequencies have been programmed in the memory. To change a
frequency on a given channel, address the channel, place read-write
switch to write, select desired frequency on selectors and switch back to
read.
The channels will be scanned automatically with the auto-manual scan
switch (18) in the auto position. The lights (22) indicate which channel
the scanning circuitry is addressing when the channel display switch (22)
is on. The time the receiver will remain on a channel is controlled by
(19) and (20). The X adjust (19) controls the basic scanning rate while
(20) selects a multiple of that rate. If X is adjusted to change
channels every second, the multiplier (20) can change the rate up to 512
seconds. The scanning circuitry scans sequentially. The scanner does
not stop scanning when the auto-manual switch is in the manual position,'
the memory, however, is addressed by the channel and bank switches.
Memory is retained when the receiver is off by a small internal power
source. This power source should last at least one year.
97
-------
RECEIVER FUNCTIONAL BLOCK DIAGRAM
vs
oa
ANTENNA
INPUT ~*
FINE
TUNE
jf < AUDIO
< n F. 6AIM > GAIN
< CONTROL 1 CONTROL
HREAMP AND IF. SAIN
Iff MIXER AND 2nd
•4
t
*s,
BJl/ ^Mi
BLOCK AUDIO -3 r- — ^. SWITCH AUDIO
--, j 3 £ X_ JACK
MIXER AMPLIFIER 3 C_ o til
>LI
\ #
FREQUENCY
SYNTHESIZER
111 1UI HI.
METER X^N.
AMPLIFIER J \ \ EXTERNAL
AND \ \J p=5 METER JACK
INTEGRATOR ^-^ /^
MiTER
- — w ** *^
\ \ \
METER LEVEL
CONTROL (INTERNAL)
FREQUENCY SELECTOR
SWITCHES
EXTERNAL POWER
RECHARGE JACK
EXTERNAL/ INTEMAL
POWER RELAY
OFF
SWITCH
TO ALL
MODULES
BATTERY STATUS
INDICATOR
-------
H
•-(-' Wv-fc
99
-------
fs. * s
i-s- "- ' —VVV—K S 2 H
100
-------
101
-------
JI-FROM MEMORY BOARD J2.
RECEIVER SYN. BOARD Jl.
o
TO LED
FREQUENCY
DISPLAY
FREQUENCY
DISPLAY
ON - OFF
SWITCH
27K
MULTIPLEX
TO P5 ON
AUTO SCAN
' tff iQX
.N BOARD
FREQUENCY DISPLAY BOARD
-------
SEC FROM C~C PlC
1C 8
o
La
RESET
FROM
P-D PII
LATCH
FROM
P-D PI2
D-A CONVERTER
MC14O8L-8
1 _1
t*uJ\L J*i J\ *
5.6K
^r
F.'.9-12
J»5 U5 J!i2 T*
T^C4<*6 rn sj/p5
J^Pf^2.7K r^TE--i
I JACK I
n
DIGITAL ANALOG CONVERTER BOARD
-------
o
*-
CHANNEL
SWITCH
MANUAL
AUTO
SCAN
SWITCH
SCAN
RATE
ADJUST
SCAN
RATE
SWITCH
O
AUTO SCAN
CARD
LED CHANNEL
DISPLAY
ACTIVE READ
BYPASS WRITE
SWITCH SWITCH
MEMORY
BOARD
OOO
FREQUENCY
SELECTOR
SWITCHES
RECEIVER
SYNTHESIZER
BOARD
DISPLAY
BOARD
788
LED FREQUENCY
DISPLAY
HP 5O82-740E
MEMORY BLOCK DIAGRAM
-------
o
U1
CHANNEL INPUT FROM AUTO SCAN BOARD Jl
j 3 12 13 11 S 10 14 15 16 1867 2345
INPUT FROM
FREQUENCY
SELECTOR
SWITCHES
Jl v
H
B 10
C 100
B i
D 1
A I
D 100
A 100
A IO
J4 12 13 II 9
23 22 21
3
4
5
6
7
8
9
to
1014 15 16
1 8 6 7
1 23 22 2t
1C 2
1C 6
1C 3
1C ?
2345
23 22 21 1 23 Z2 21
1C 4
1C 8
16
is
14
13
12
•
P4|
D IOO
A IOO
A 10
C 1
0 10
B IOO
C 10
OUTPUT TO JI
ON FREQUENCY
DISPLAY BOARD
^X
flCTIVE
1. 1C 1-8 ARE CO4O3iAO, RCA. '
2, 1C 1 -4, 5-8 INPUTS a OUTPUTS ARE |
COMMON. —
a. id as, zas, 3 a?, 4 a a CHANNEL INPUTS ARE COMMON.
16 CHANNEL MEMORY
-------
SIGNAL
FROM -
RECEIVER
SIGNAL
Oi SPLAY
PULSE
SHAPING
AND ERROR
DETECTION
J SEC.
GENERATOR
PULSE
COUNTER
COUNT
AND HOLD
OUTPUT
COUNT
DISPLAY
STOP RESET
AND RESTART
LOGIC
CONVERTOR
PULSE DETECTOR BLOCK DIAGRAM
-------
Table D-l. WIITER AND EARLY SPRING 1975, FISH RADIO TAGGED AMD
DATA COLLECTED
Species
Walleye
N. Pike
N. Pike
N, Pike
Lm. Bass
N. Pike
N. Pike
Perch
Perch
Perch
Perch
Perch
Perch
Perch
N. Pike
Perch
Lm, Bass
N. Pike
Perch
Perch
N. Pike
Perch
Perch
Perch
Perch
Perch
Walleye
Walleye
Perch
Perch
Perch
Perch
Walleye
Walleye
Walleye
Walleye
Fish
Id.
No.
100
101
102
103
104
105
106
107
108
109
110
111
113
114
1006
1009
1011
1012
1013
1014
1015
1016
1017
1018
1032
1033
1057
1081
1153
1159
1183
1214
1215
1794
1800
1801
Sex
F
F
M
F
F
F
F
F
F
F
F
F
M
F
F
F
F
F
F
F
F
F
M
M
M
F
M
F
M
F
F
F
Wt.
M
340
907
3969
5670
567
3062
4309
340
340
340
454
340
397
482
1588
284
928
3232
482
397
1764
425
454
454
340
284
709
482
312
567
340
340
1247
2495
2296
2778
Date
on
(1975)
2/5
2/4
2/13
2/16
2/16
2/18
2/20
2/25
2/24
2/24
2/26
2/26
3/9
3/16
4/2
4/3
4/2
4/2
4/4
4/4
4/10
4/11
4/10
4/10
4/12
4/12
4/14
4/19
4/25
4/26
4/25
5/3
4/30
5/13
5/13
5/19
Date
off
(1975)
2/14
3/18
5/12
2/18
4/16
2/19
3/6
3/24
3/28
4/2
3/23
4/5
4/10
3/16
4/3
4/19
5/22
4/27
5/12
5/4
5/2
5/6
5/20
4/24
5/10
5/10
4/25
5/9
5/22
5/22
5/22
5/21
5/4
5/21
5/22
5/21
frack
Perd.
J)stys_
10
43
89
31
60
2
14
28
33
38
26
39
33
1
2
17
51
26
39
31
42
26
41
15
29
19
12
22
28
27
28
19
5
9
10
3
So.
of
Loc,
23
24
104
44
104
3
28
61
66
57
43
61
51
1
4
32
35
23
43
52
48
31
55
27
42
37
9
28
23
18
37
8
4
10
9
3
Ho. of
Tenper a ture
Readings
103
15
28
6
109
-------
Table P-2. AUTUMN 1975, FISH TAGGED AMD DATA COLLECTED
Species
Perch
Perch
Perch
Perch
Perch
Perch
Walleye
Walleye
Walleye
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Fish
Id.
No.
1805
1807
1808
1810
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1824
1825
1826
1827
1828
1829
1830
1831
Sex
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
Wt.
is!
397
425
340
425
369
397
1588
3190
3062
454
340
397
340
340
482
397
510
482
482
340
340
340
312
Date
on
(1975)
9/26
10/3
10/3
10/3
10/3
10/3
10/7
10/9
10/9
10/9
10/9
10/16
10/16
10/26
11/4
11/4
11/5
11/5
11/5
11/27
11/27
11/27
11/27
Bate Track
off Perd.
(1975) Pays
10/31 36
10/3
11/15
11/7
11/14
11/19
11/20
11/19
11/12
11/1
11/23
10/24
12/11
11/26
11/9
12/20
12/16
12/12
12/14
1/1/76
12/18
1/1/76
12/23
0
44
36
43
48
45
42
35
24
46
9
56
32
6
47
42
38
40
36
22
36
27
No, No. of
of Temperature
Loe , Readings
29
0
41
27
39
44
46
39
34
20
44
9
51
29
5
41
20
35
35
25
19
22
23
110
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Table D-3. WINTER AMD EARLY SPRING 1976, FISH TAGGED AND DATA
COLLECTED
Species
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Fish
Id.
So.
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1850
1851
1852
1853
1854
1855
1856
1857
Sex
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
tft.
i£l
482
383
397
454
340
383
340
454
383
354
369
326
454
482
367
454
567
482
482
425
425
397
425
412
Date
OB
(1976)
1/5
1/11
1/17
1/29
1/29
1/29
1/29
2/3
2/3
2/8
2/8
2/8
2/21
2/26
2/27
3/25
4/11
4/11
4/11
4/11
4/11
4/21
4/21
4/23
Date
off
(1976)
3/3
1/30
1/17
5/27
5/2
4/4
2/25
2/16
3/24
3/8
3/9
4/13
2/21
5/9
4/20
5/9
4/18
6/2
5/9
6/2
5/9
6/2
5/16
4/27
Track
Perd.
"Days__
58
20
0
119
125
66
28
14
50
29
30
65
1
72
53
46
8
53
29
53
29
43
26
5
No,
of
Loc.
40
41
0
39
88
53
7
15
31
31
22
47
1
29
41
32
12
37
38
30
26
18
17
5
Mo. of
Temperature
Readings
79
130
0
48
1137
342
24
353
91
45
1
29
62
203
111
-------
Table D-4. AUTUMN 1976. FISH TAGGED AND DATA COLLECTED
Species
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Fish
Id,
No.
3001
3002
3003
3004
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3020
3021
3022
3023
3024
3026
3027
3028
3029
3030
3031
Sex
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
Wt.
lal
369
312
340
340
425
340
312
369
326
340
340
369
369
354
354
312
340
354
326
312
340
369
312
312
298
369
397
284
Date
on
(1976)
9/11
9/10
9/10
9/10
9/10
9/24
9/10
9/11
9/24
9/11
9/11
9/10
9/11
9/12
9/24
9/12
9/16
9/16
9/17
9/17
10/16
10/12
10/12
10/12
10/12
10/16
10/19
10/16
Date
off
(1976)
9/25
10/6
9/17
10/19
9/24
10/21
9/28
10/17
10/27
10/20
9/28
9/17
11/3
9/21
10/31
9/17
9/16
9/24
10/2
10/8
11/12
11/19
11/19
11/24
10/30
11/30
10/19
11/30
Track.
Perd.
Da^s___
15
27
8
40
15
28
19
37
34
37
18
6
54
10
38
6
0
9
17
22
28
39
39
44
19
46
0
46
No, of
Locations
12
25
5
34
12
28
16
34
32
40
14
5
48
7
37
5
0
6
14
20
25
30
30
31
19
25
0
25
112
-------
Table D -4. (CONTINUED)
COLLECTED
AUTUMN 1976, FISH TAGGED AND DATA
Species
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Walleye
Walleye
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Perch
Fish
Id.
No.
3032
3033
3034
3035
3036
3039
3040
3041
3042
3043
2048
3049
3050
3052
3054
3055
3056
3057
3059
3060A
3060B
3063
3065
3067
3068
3071
Sex
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
Wt.
i£l
298
369
340
369
397
354
284
298
340
284
1701
1361
284
284
284
312
326
354
354
312
397
383
383
539
439
397
Date
on
(1976)
10/20
10/16
10/16
10/16
10/20
10/20
10/20
10/20
10/20
10/20
10/16
10/16
10/23
11/6
10/23
11/6
11/6
11/6
11/6
11/6
11/6
11/6
11/6
11/6
11/6
11/6
Date
off
(1976)
11/30
11/19
11/30
11/3
11/7
11/30
11/30
11/30
10/20
11/9
11/15
11/2
11/30
11/30
11/24
11/30
11/30
11/30
11/30
11/19
11/30
11/30
11/30
11/24
11/30
11/30
Track.
Perd.
Dajs^
42
35
46
19
19
42
42
42
1
23
31
19
39
25
32
25
25
25
25
14
25
25
25
18
25
25
No. of
Locations
35
23
28
17
17
25
35
24
1
19
17
17
21
20
31
20
19
14
20
10
19
20
17
19
19
20
113
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APPENDIX E
ACCURACY OP LOCATING RADIO TAGGH) FISH BY TRIANGtJLATION
Accuracy and precision of animal tracking depend upon 3 major factors
as discussed by Heezen and Tester (1967) and Slade, et al, (1965): System
errors or the difference between tower determined bearing and the true
bearing to the animal could be caused by wind twisting the antennas,
inaccurate calibration and radio frequency interference. Reading errors
depended upon the ability of a person to detect signal nulls, resolution
of compass cards under differing light conditions and fatigue. Signal
nulls were the point at which a transmitter was no longer audible when
rotating a directional antenna. In general 2 nulls were located
symmetrically on either side of the peak signal. Nulls could be
discriminated with more precision than maximum signal strength. Thus,
determining maximum signal (the bearing to an animal) from 2 sytnetric
nulls was more reliable than attempting to discriminate actual signal
peaks. Finally, accuracy depended upon the animal's location and
movement with respect to the receiving antenna. Triangulation errors
increased in any direction from the 90° intersection of bearings at the
perpendicular bisector of the base line (an imaginary line connecting the
antennas). Also, readings to more distant animals inherently had a
greater error, as bearing error had greater significance as distance
increases.
Tests conducted on our shore tower array indicate bearing errors
caused less than 5 m location error at 100 m and 43 m at 800 m (Winter et
al. 1978). These results compare closely with Yagi accuracy tests
conducted by Marshall (1962 and 1963), and Slade, et al.(1965). To
determine precision of the system over time we routinely took location
bearings to a stationary reference transmitter in the discharge bay from
all 3 towers while tracking fish. When taking bearings from 3 locations
to a point, an error triangle was generated unless-all 3 bearings
coincided at exactly the sane point. The average size of the triangle
over time should have resulted in an area that came close to estimating
the precision of the system. We found this area to be 232.4 m^ or
approximately comparable to a circle with a 8.6 m radius. Actual
reference transmitter locations were plotted on an X, Y coordinate system
as the center of the error triangle. By summing the X and Y locations of
a stationary transmitter a standard error of the mean was found to be
6.9 m on the Y axis and 2.8 m on the X axis. The center of this
reference area was an average of 307 m from the 3 towers.
114
-------
Mobile tracking techniques offered the advantage of approaching an
animal closely and positioning bearings to cross closer to the optimum
90° intersection. However, reference positions of the antennas were
usually somewhat more difficult to determine especially under adverse
light and weather conditions, Winter et al. (1978) determined a 14 m
bearing error from a distance of 200 ra with a truck mounted Yagi. Loop
antennas can be very accurate, especially at close ranges. Verts (1963)
reported that triangulations from his truck mounted loop antenna were _+
7.6 m at 400 m and _+ 23 m from 800 m. Winter et al. (1978) reported 2~"
tests conducted with loop antennas. The results indicated a calculated
mean location error ranging from 0.79 m (5-15 m distance class) to 6.49 m
(76-92 m class). Our tests with mobile tracking equipment to a
transmitter at a fixed location indicted a standard error of the mean to
be 5.2 m on the X axis and 8.0 IB on the Y axis. In suawary, our tests
•and those in the literature indicated that in general, location errors
were less than 10% of the distance from the receiving antenna to the
transmitter.
115
-------
References
Heezen, K.L. and J.R. Tester. 1967. Evaluation of radio-tracking
triangulation with special reference to deer movements. J. Wildl.
Manage. 31(1) .-124-141.
Marshall, W.H. 1962. Development and use of short wave radio
transmitters to trace animal movements. Progress Report, Univ. of
Minn. 18 pp. (ttultilithed).
Marshall, W.H. 1963. Studies of movements, behavior and activities of
ruffed grouse using radio telemetry techniques. Progress Report,
Univ. of Minn. 30 pp. (mltilithed).
Slade, N.A., J.J. Cebula and R.J. Robel. 1965. Accuracy and reliability
of biotelemetric instruments used in animal movement studies in
prairie grasslands of Kansas. Trans. Kansas Acd. Sci. 68(1):173-179.
Verts, S.J. 1963. Equipment and techniques for radio-tracking striped
skunks. J. Wildl. Manage. 27(3);325-339.
Winter, J.D., V.B. Kuechle, D.B. Siniff and J.R. Tester. 1978.
Equipment and methods for radio tracking freshwater fish. Univ. of
Minn. Inst. of Ag. Misc. Bui. 152. 45 p.
116
-------
TECHNICAL RETORT DATA
(Pleae flwd Ins ouctions on the reverse before completing}
. REPORT NO, 2,
EPA-finn/3-sn~nn9
.TITLE AND SUBTITLE
Spatial Distribution and Temperature Selection of Fish
Near the Thermal Outfall of a Power Plant During Fall,
Winter and Spring
. AUTHOH(S)
M, J, Ross and D. B. Siniff
i, PERFORMING ORGANIZATION NAME AND ADDRESS
University of Minnesota
Minneapolis, Minnesota 55455
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Research Laboratory - Duluth, MN
Office of Research and Development
U.S. Environmental Protection Agency
Duluth, Minnesota 55804
3. RECIPIENT'S ACCESSION NO.
3, REPORT DATE
January 1980 issuing date
6, PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO.
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-03-2145
1804997010
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
EPA/600/03
15. SUPPLEMENTARY NOTES
16. ABSTRACT
The aoveaent patterns of 4 fish species; yellow p«rch (Perca flave»cen»), northern pike (Esox lycivn),
largeaouth bass (Hi crop t eru« ia lao idea) and walleye (Stitostedion vitreua) were «onitor«i by radio tclmecry
near the thermal discharge of » power plant (4 T 15°C nooinal). Fish movements relative to depth, temper-
ature, center of the home range, discharge point, and release location are examined. Near theraally altered
areas northern pik«s exhibited the greatest amount of movement followed by yellow perch, walleye and largeraouth
bass. Except for largemouth bass, thermal experience was found to be transitory. An overall mean winter
temperature selection of 5.4°C was determined for yellow perch. While only in the thermally altered area
yellow perch had a (lightly higher BMCI theraal experience, 6.3°C. Yellow perch were not found to be
attracted froa the uurrounding areas into the heated waters of the discharge bay during the cooler nonthi.
hot until spring was a population concentrating influence observed and that was believed due to indirect
influences; aore cover due to greater available light in the ice free area contributing to a higher standing
»tock of aquatic vegetation.
We concluded that temperature, when in concert with numerous other environmental variables, did not alter
the distribution of yellow perch to that predicted on the basis of laboratory temperature preference studies.
Furthermore, movement patterns of northern pike, walleye and largeaouth basg were found to b€ relatively
iiailar to those reported Iron thermally unaltered areas.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
Yellow perch Heated discharge
Morthern pike Freshwater fish
Walleye
Largemouth bass
Behavior
Temperature
Radio telemetry
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
b. IDENTIFIERS/OPEN ENDED TERMS
ftabitat-selection
Behavioral- thermoregulatio
Winter-movements
Attraction
19. SECURITY CLASS ("nit Report}
UNCLASSIFIED
20. SECURITY CLASS (This page]
UNCLASSIFIED
c, COSATI Field/Group
n
06/F
21. NO. OF PAGES
129
22. PRICE
EPA Form 2220-1 {Re*. 4-77)
PREVIOUS EDITION IS OBSOLETE
117
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