Aquaculture Feeding and Growth Experiments Comparing Bluegill and F,
Hybrid Sunfish (male bluegill x female green sunfish)
An Honors Thesis (HONORS 499)
by
Kenton J. Hanauer and Mary M. Picconatto
Ball State University
Muncie, Indiana
April 1992
Expected Date of Graduation May 1992
-
Aquaculture Feeding and Growth Experiments Comparing Bluegill and F,
Hybrid Sunfish (male bluegill x female green sunfish)
An Honors Thesis (HONORS 499)
by
Kenton J. Hanauer and Mary M. Picconatto
Thesis Advisor
(Dr. Thomas Mc Cornish)
~_L/M*~
Ball State University
Muncie, Indiana
April 1992
Expected Date of Graduation May 1992
-
-.
THESIS ABSTRACT
! ; / - ....... ·\.<7
Thesis:
Aquaculture feeding and growth experiments comparing bluegill
and F1 hybrid sunfish (male bluegill x female green sunfish)
Students:
Kenton J. Hanauer and Mary M. Picconatto
Degree:
Bachelor of Science
College:
Ball State University
Date:
April 1992
Pages:
64
Possible differences in food consumption, growth, and food
conversion comparing groups of six bluegill (Lepomis macrochirus) to six
hybrid sunfish (male bluegill x female green sunfish (Lepomis cyanellus))
were evaluated over a 64 day total period from December 12, 1991 to
February 14, 1992. Each fish was held in an individual aquarium with a
daily 1 2 hour photoperiod of natural light supplemented with overhead
fluorescent
li~lhting.
Daily maximum and minimum water temperatures
ranged from S8 to 69 0 F. Fish were fed an ad libitum ration of frozen brine
shrimp (Arternia sp.) twice daily between 0700-1000 hours and 1600
-1900 hours. The 64 day total period was divided into sequential 22, 20,
and 22 day periods with fish weighed and measured at the beginning and
i
at the beginning and end of each period. Examination of data revealed a
significant difference (l-test; P<O.OS) in the amount of food consumed for
all periods with bluegill consuming more food than hybrid sunfish.
There
were no significant differences observed between bluegill and hybrid
sunfish in conversion efficiencies for any of the three experimental
periods Ct.-test; P>O.OS). Evaluation of weight gain and length gain per day
revealed no significant differences (l-test; P>O.OS) except in period 1
with bluegill
~lrowing
more than hybrid sunfish.
These results must be
interpreted with care since fish were isolated and social mechanisms
excluded.
Social interactions appeared to have some importance in the
feeding behaviors of the fish, particularly the hybrid sunfish.
A follow up
test using all twelve of the original experimental fish together in the
main raceway tank provided insight into this phenomenon.
ii
TABLE OF CONTENTS
Page
ABSTRACT........ ".................................................................................................................. i
TABLE OF CONl-ENTS....................................................................................................... iii
LIST OF FIGURES................................................................................................................ iv
LIST OF TABLES................................................................................................................ vii
INTRODUCTION................................................................................................................... 1
ACKNOWLEDGEMENTS...................................................................................................... 2
LITERATURE RE\/IEW ........................................................,. ............ ............ ....... .......... .... 3
MATERIALS AN[) METHODS............................................................................................ 6
Tank Description............. ..... ......... ..................... .... ........ .... ................... ....... ........ 6
Conditioo~.............................. ...............................................................................
8
Data Collection..................................................................................................... 11
RESULTS............ ".................................................................................................................. 14
Water Quality Analysis.... ........ ......... ..................... ......... ....... ............ ............... 14
Feeding Results for Bluegill and Hybrid Sunfish ................................... 27
DiSCUSSiON ........................................................................................................................ 51
CONCLUSiONS..................................................................................................................... 62
LITERATURE OTED........................................................................................................... 63
iii
LIST OF FIGURES
Figure
1.
Mean water temperature, and mean high and low temperatures
observed in the main raceway tank for five day intervals.. ....... ....... 1 6
2.
Individual site locations for measurements of pH: tap,
dechlorination exit, tank, and aquarium #9....... ........ ....... .......... ........ ...... 17
3.
Dissolved oxygen high, low, and mean values at tap,
dechlorination exit, tank, and aquarium #9 ............................................. 19
4.
Individual site locations for measurements of dissolved oxygen:
tap, dechlorination exit, tank, and aquarium #9 .................................... 20
5.
Individual site locations for measurements of oxygen saturation:
tap, dechlorination exit, tank, and aquarium #9 ..................................... 21
6.
Alkalinity high, low, and mean values at tap, dechlorination
exit, tank, and aquarium #9.................... ................................... ...................... 22
7.
Individual site locations for measurements of alkalinity: tap,
dechlorination exit, tank, and aquarium #9 .............................................. 23
8.
Chlorine high, low, and mean values at tap, dechlorination exit,
tank, and aquarium #9............ ..................................... ....................................... 24
9.
Individual site locations for measurements of chlorine: tap,
dechlorination exit, tank, and aquarium #9............................................. 25
10.
Mean chlorine level, and mean high and low chlorine levels
observed from the tap for five day intervals..........................................
26
Nitrate high, low, and mean values at tap, dechlorination exit,
tank, and aquarium #9..................... ................... ......... .......... .................. .........
28
Individual site locations for measurements of nitrate: tap,
dechlorination exit, tank, and aquarium #9............................................
29
11.
12.
-
Page
iv
Figure
-
Page
13.
Nitrite high, low, and mean values at tap, dechlorination exit,
tank, anel aquarium #9 ...................................................................................... 30
14.
Individual site locations for measurements of nitrite: tap,
dechlorination exit, tank, and aquarium #9 ............................................ 31
15.
Total food consumed by hybrid sunfish for periods 1, 2, and 3,
by individual fish........................................................ ........................................ 36
16.
Food consumed per day by individual hybrid sunfish for periods
1,2, and 3, including average food consumed per day........................ 37
17.
Total food consumed by bluegill for periods 1, 2, and 3, by
individual fish......................................... .... ......................................................... 38
18.
Food consumed per day by individual bluegill for periods 1, 2,
and 3, including average food consumed per day.................................. 39
19.
Total weight gain by hybrid sunfish for periods 1, 2, and 3,
by individual fish............................................................................................... 40
20.
Weight 9ain per day by individual hybrid sunfish for periods 1,
2, and 3, including average weight gain ................................................... 41
21 .
Total weight gain by bluegill for periods 1, 2, and 3, by
individual fish.................. ......... ...................................... ......... ............................ 42
22.
Weight ~~ain per day by individual bluegill for periods 1, 2, and 3,
including average weight gain..................................................................... 43
23.
Total length increase by hybrid sunfish for periods 1, 2, and 3,
by individual fish............................................................................................... 45
24.
Length increase per day by individual hybrid sunfish for periods
1, 2, and 3, including average length increase ....................................... 46
25.
Total length increase by bluegill for periods 1, 2, and 3,
by individual fish......................................................... ...................................... 47
v
Figure
Page
26.
Length increase per day by individual bluegill for periods 1, 2,
and 3, including average length increase.................................. ............... 48
27.
Food conversion efficiency by hybrid sunfish for periods 1, 2,
and 3, by individual fish ................................................................................... 49
28.
Food conversion efficiency by bluegill for periods 1, 2, and 3,
by individual fish....... ..... ..... ............................. ................... .......... .......... ........... 50
29.
Average food consumed per day comparing hybrid sunfish and
bluegill with 95% confidence intervals................................................... 52
30.
Average weight gain per day comparing hybrid sunfish and
bluegill with 95% confidence intervals.............. ......... ............ ....... .... ....
53
31.
Average length increase per day comparing hybrid sunfish and
bluegill with 95% confidence intervals ................................................... 54
32.
Food conversion efficiency comparing hybrid sunfish and
bluegill with 95% confidence intervals................................................. 55
33.
Average length increase per day comparing hybrid sunfish and
bluegill with 95% confidence intervals, for experimental
period February 28 to March 19, 1992 ..................................................... 59
34.
Average weight increase per day comparing hybrid sunfish and
bluegill with 95% confidence intervals, for experimental
period February 28 to March 19, 1992..................................................... 61
vi
LIST OF TABLES
Table
Page
1.
Water chemistry during fish growth experiments by date and
site for temperature, pH, dissolved oxygen, alkalinity, nitrate,
and nltnte.......................................................................................... ................... 1 5
2.
Summary of results for experimental period 1, December 12,
1991, to January 2, 1992 (22 days).........................................................
32
Summary of results for experimental period 2, January 3 to
January ,~2, 1992 (20 days).........................................................................
33
Summary of results for experimental period 3, January 23 to
February 13, 1992 (22 days).......................................................................
34
Data for follow up experimental period, February 28 to
March 19, 1992..................................................................................................
58
3.
4.
5.
vii
1
,-
INTRODUCTION
The aquaculture industry has been a growing part of the agriculture
industry in the United States since the early 1980's. In light of this
expansion, aquaculture experiments were initiated in September of 1991
at Ball State University.
Sunfish present an appealing option for
aquaculture in Indiana and the region, because they exhibit growth
characteristics compatible with regional conditions while being perceived
as a desirable food and sport fish by the public.
Experiments with bluegill (Lepomis macrochirus) and Fl hybrid
sunfish (male bluegill x female green sunfish (Lepomis cyanellus)), were
initiated to evaluate potential differences between the two species with
regard to the suitability of the fish for aquaculture.
The bluegill was
chosen because of it's popularity as a sport fish. The hybrid was selected
because of it's potential hybrid vigor and supposed better growth
associated with aggressive feeding.
Differences in food consumption,
growth (weight and length), and food conversion were evaluated in the
comparison.
2
-
ACKNOWLEDGEMENTS
We would like to thank Allan Winters and Janet Tuhey, for their help
in maintaining the greenhouse tank, feeding the experimental fish during
periods when we couldn't be present, and allowing us to share their space
in the greenhouse.
Thanks are also in order for Scott Tollentino and Kevin Mc Keag.
Without their help and patience we would still be writing.
Special recognition is given to the Honors College and the Biology
Department for their support and encouragement. It is not often that
undergraduates are given the opportunity to conduct this type of research.
Finally, al special thank you to Dr. Thomas S. Mc Comish, for keeping
us on top of things and pushing us to achieve. His guidance and support
have been mOire important than he will ever know.
-
3
LITERATURE REVIEW
Aquacuilture is a rapidly growing industry.
An indication of its
expansion is the increased number of journal publications dealing with
aquaculture.
These include Water Farming Journal, Catfish Aquaculture
News, The Aquaculture News, and North Central Regional Aquaculture
Center (NCRAC) Journal.
Expansion has occurred as a result of an
increased demand for fisheries products, a leveling off of commercial
landings, and the ability of the industry to produce high quality products
at competitive prices (Broussard 1991).
Sunfish are considered desirable as food and sport fishes by the
public (Kaufman 1 973).
Additionally, they exhibit growth characteristics
compatible with conditions in our region.
For these reasons, the sunfish
present an appealing option for aquaculture in this state and region.
Two sunfish species present in Indiana are the bluegill and the
green sunfish,
Bluegill have historically been an important fish in pond
management (Carlander 1977). Additionally,
the species has value in
being highly adaptable to diverse conditions (Kaufman 1973).
An example
of this adaptability is the ability of the species to alter niches as a
response to competition.
Bluegill forage primarily in the littoral zone,
their preferred habitat (Werner and Hall 1979). However, in the presence
4
of competitive species, they have the ability to migrate to the open water
and utilize zooplankton as their food source (Werner and Hall 1976).
Furthermore, they are highly regarded as a sport and forage fish.
Green sunfish
are efficient at foraging and use resources more
effectively than bluegill (Werner and Hall 1979). Under identical densities
in preferred habitat, green sunfish exhibit significantly greater growth
and therefore, presumably greater fitness (Werner and Hall 1977).
Additionally, they are more aggressive.
Green sunfish clearly dominate
bluegill of the same size in aquaria to the point that cohabitation is not
possible (Greenberg 1947).
However, as a food and sport fish the green
sunfish is not considered as desirable as the bluegill.
Under natural
conditions, the green sunfish rarely reaches a size considered to be of
interest for a food or sport fish (Carlander 1977).
What seems the ideal, then, would be a combination of bluegill size
and adaptability characteristics with green sunfish aggressiveness and
foraging characteristics.
The hybridization of bluegill and green sunfish
might accomplish this ideal. According to Hubbs (1 955), hybrids are
intermediate in taxonomic characters between parental species.
This
intermediate condition displays characteristics that cannot be attributed
to either parel1t and is thought to be a result of hybrid vigor or heterosis.
5
Heterosis accounts for several characteristics of hybrids.
Among these
are an increased growth rate, higher adaptive plasticity, and a more rapid
sexual maturaltion (Bennett 1971). These attributes make the hybrid
favorable for the demands of fish management.
available niches that other fish cannot utilize.
Hybrids may also fill
It has been noted that
native game fish utilize only 25% of the water volume in aquatic systems,
where hybrids increase water usage, foraging in less used areas of a pond,
lake, or stream (Dalrymple 1986).
Another characteristic of hybrids is
the acceptance of supplemental food such as pelleted prepared food
(Lewis and Heidinger 1971), making them acceptable for use both in
aquaculture and as experimental fish.
One such hybrid is the result of a cross between male bluegill and
female green sunfish.
This cross exhibits rapid growth (Childers 1967),
as well as probable hybrid vigor including increased aggression.
In fact,
the bluegill x green sunfish hybrids exceeded the average growth for
bluegill in Illinois ponds (Brunson and Robinette 1986).
Additionally, the
cross produces mostly male offspring (Brunson and Robinette 1986). This
increased growth and aggression may be desirable for aquaculture as well
as use in farm ponds, urban-metro lakes, and youth fishing programs
(Dalrymple 1986).
-
6
MATERIALS AND METHODS
Tank Description
Aquaculture experiments were conducted in a raceway tank located
in the northeast section of the Ball State Greenhouse. The concrete tank
measured 118 cm x 338 cm and 116 cm deep (46 in x 133 in and 45 in
deep). The tank was lined with clear plastic to seal it and to provide a
smooth, cleanable surface safe for fish and other aquatic organisms.
A
flow-through system was utilized in which tap water entered through a
dechlorination chamber at the west end of the tank, flowed into the main
raceway, and exited through a drainage standpipe at the east end.
Dechlorination of water occurred in a partitioned chamber 118 cm x
89 cm and 116 cm deep (46 in x 35 in and 45 in deep) at the west end of
the system. A plastic netting and sheet were held as a screen by a wooden
frame painted with gray enamel, forming the barrier between the main
tank and the dechlorination chamber.
Water flow between these areas was
restricted to the narrow (up to 10 mm; 3/8 in) spaces at the junction of
the partition and the tank walls.
Dechlorination was achieved using a
series of two, 121 L plastic containers.
Tap water entered the first
container from the faucet, and partial dechlorination was achieved there
through vigorous aeration.
The partially dechlorinated water then flowed
7
through two pipe connectors (10 mm; 3/8 in diameter) from the first
container into the second where aeration continued. Water exited the
second container through a single drain pipe (10 mm; 3/8 in diameter),
dropping 21.0 cm (8.3 in) to the water level in the partitioned chamber.
Further aeration continued with multiple airstones at various locations
within the chamber.
Finally, dechlorinated water entered the main tank
through the spaces (up to 10 mm; 3/8 in) at the junction of the partition
and the tank walls.
Supplemental aeration in the main tank was provided
by four airstones, one in each corner. On the average, 26-27 L per hour
flowed from the second plastic container into the partitioned chamber and
through the main tank.
This flow provided a theoretical turnover of water
in the tank every five days.
A floating frame (71 cm wide x 140.5 cm long; 28 in wide x 55.3 in
long) constructed of wood, and painted with gray enamel, held twelve
individual wastebasket aquaria in two rows of six.
The frame with
aquaria was positioned in the main raceway tank using ties so that it was
free floating, yet remained close enough to the edge to allow observations
while feeding.
Dimensions of the main raceway (west end) were 118 cm x
249 cm and 116 cm deep (46 in x 98 in, and 45 in deep). Each individual
aquarium was 19.5 cm x 24.9 cm and 30.7 cm deep (7.7 in x 9.8 in, and 12.1
-
8
in),
holding approximately 17.5 L of water.
Water was allowed to flow
freely through individual aquaria through multiple (52) 6 mm (1/4 in)
holes in all four sides of the basket, starting approximately 50 mm (2 in)
above the bottom of the aquarium and ending just below the surface of the
water.
Aeration and circulation of water were promoted by a single
airstone positioned near the bottom of each aquarium.
Conditions
The experimental period was 64 days long, beginning December 12,
1991 and ending February 14, 1992. It was broken into three sequential
22, 20, and 2;~ day periods designated period 1, period 2, and period 3.
Additional experimentation in the main raceway tank took place between
February 28 and March 19, 1992.
Analysis of water quality was used to monitor environmental
conditions of the system.
Analyses of pH, dissolved oxygen, alkalinity,
chlorine, nitrate, and nitrite concentrations were completed four times
during the experimental period, approximating the beginning or end of each
sample period.
Additional testing of chlorine was completed on a
continuous basis approximately every five days.
Samples were collected
from four separate sites for all tests. These were at the tap (source of
9
the water at faucet) flowing into the first plastic container of the
dechlorinator, at the exit pipe of the second plastic container into the
dechlorination chamber, at the standpipe at the east end of the main
raceway tank, and from aquarium number nine as a representative
aquarium sample.
Maintenance of water quality was facilitated by the
flow-through nature of the tank.
The complete theoretical turnover of
water helped to reduce the build-up of waste materials (i.e.
nitrites).
nitrates,
Additionally, supplemental aeration in the main tank was used
to facilitate the breakdown of waste materials and to maintain dissolved
oxygen near saturation levels.
A twelve hour photoperiod was maintained by natural light·
supplemented with four, adjacent, overhead, cool, white, fluorescent
lights of 40 watts each. The supplemental lights were regulated by a
Paragon Electric Timer, model 4005-00S, set to turn on lights at 0700 h
and to turn off lights at 1900 h.
Fifteen hybrid sunfish were introduced to the raceway tank on
September 20, 1991. Bluegill introduction occurred on October 25,
however only three survived. A subsequent attempt at introduction of
bluegill occurred on October 30.
Fish in this assemblage were acclimated
to the tank water between 1145 hand 1 61 5 h and then released into the
10
system. On November 1, 1991, both hybrid sunfish and bluegill were
seined from the raceway tank and placed into individual wastebasket
aquaria.
Twelve experimental fish were held in isolation, with one in each
wastebasket aquarium, for a total of six hybrid sunfish (fish 1-6), and six
bluegill (fish l-12).
Isolation allowed known amounts of food to be fed to
each fish whHe inhibiting the transfer of excess food between aquaria.
Additionally, isolation eliminated social interaction and competition as a
variable to feeding.
The fish were fed weighed portions of frozen brine
shrimp (Arternia sp.) in near ad libitum amounts twice daily between 0700
- 1000 hand 1600 - 1900 h. Prior to feeding, frozen portions were
weighed to the nearest 0.01 g on a Mettler top pan balance, recorded, and
placed in plastic food containers for storage.
All weighed portions were
stored as frozen cubes in a standard freezer.
Near ad libitum feeding was
accomplished through the introduction of small portions of shrimp (about
5 mm x 5 mrn) cut from each frozen cube with a knife and fed to each fish.
When the total amount in the weighed portion for an individual was
consumed, another weighed portion was assigned to the same fish and then
fed. The feeding process was continued in each daily period until each
fish no longer accepted the small cut portion of shrimp or spit it out.
11
Excess food was returned to the freezer. At the end of each period,
uneaten portions were weighed, subtracted from the total weighed food or
sum of all portions for each fish, with the total representing the
estimated amount of food consumed by each individual fish. It should be
noted that some food was uneaten but it was minimal. No attempt was
made to quantify uneaten food, thus food consumed was always an
overestimate.
Data Collection
Water quality analyses were completed four times during the
experimental period; December 18, January 3, January 27, and February 13.
Water taken fl'om each of the four experimental sites was placed in 3.8 L
jars and transported to the laboratory for analysis.
The pH was determined using a Beckman model 21 portable digital pH
meter. The meter was standardized using a pH 8.3 standard solution.
Dissolved oxygen was determined according to a slightly modified
Standard Winkler Method (Standard methods 1971). Four 300 mL BOD
bottles were filled; one at each sample site.
First, 2 mL of manganous
sulfate solution and 2 mL of alkaline iodide sodium azide solution were
added to each bottle. The bottles were stoppered, gently mixed, and
allowed to settle.
After floc settled, 2 mL of concentrated sulfuric acid
12
were added.
At this point, the mixture was stable and ready for titration.
From each BOD bottle, 1 00 mL portions were taken and placed into
separate 300 mL erlenmeyer flasks.
Using a standard stabilized 0.025 N
Sodium Thiosulfate solution, the samples were titrated to a pale yellow.
Two mL of starch indicator solution were added which caused the solution
to change from yellow to blue. Titration was then completed using the
Sodium Thiosulfate solution read to 0.05 mL on the buret. Dissolved
oxygen in parts-per-million (ppm) was equal to 2 x the mL amount of
Sodium Thiosulfate used in the titration.
The temperature of each sample
was also recorded in order to calculate percent saturation.
Readings were
taken using a mercury thermometer, and saturation was determined using
a nomogram (Rawson 1944).
Alkalinity was determined through titration of water samples with
0.02 N sulfuric acid. A 50 mL water sample was placed into 250 mL
flasks and four drops of Phenophthalein indicator were added.
The mixture
was titrated to a faint pink color (pH 8.3) using the sulfuric acid. Next,
four
drops of Brom Cresol Green-Methyl Red indicator were added
producing a blue color.
-
Titration was continued with sulfuric acid until
the solution changed from blue to faint pink (pH 4.8). Total alkalinity was
then reported in ppm calcium carbonate by mUltiplying the total amount of
13
sulfuric acid used by 20.
Chlorine, nitrate, and nitrite were analyzed using a Hach portable
colorimeter and United States Environmental Agency approved tests.
All
tests used were as outlined in the Hach procedures manual for the
portable colorimeter models DR/1 A and DREL/1 C. The methods used for
each were total chlorine (DPD method), nitrogen nitrate (Nitraver 5), and
nitrogen nitrite (Nitriver III).
Experim,ental fish were measured and weighed at the beginning and
end of each experimental period.
Fish were removed from individual
aquaria, blotted to consistent wetness using a damp chamois, and weighed
to the nearest 0.01 9 using a Mettler top pan balance. They were then
measured to the nearest mm in an extended, relaxed position, from the tip
of the closed mouth to the tip of the lower caudal fin lobe. Measurements
of length were made using pointed dividers.
Following measurements, fish
were returned to the assigned aquaria with a soft net to minimize excess
handling and stress.
14
RESULTS
Water Quality Analysis
Complete water chemistry data for temperature, pH, dissolved
oxygen, alkalinity, chlorine, nitrate, and nitrite were summarized
according to date and location (Table 1).
The daily water temperature ranged between 580F and 69 oF, with an
average of 63oF. Fluctuations in the temperature were apparent (Figure 1).
High, low, and mean values were observed over five day increments,
measured at the east end of the tank near the standpipe. Water
temperature of the system was influenced by factors beyond control
during the experiment such as tap water fluctuations, environmental
temperature variation, etc.
The pH in all sample locations throughout experimental periods
remained relatively constant.
The tank maintained a basic pH ranging
between 7.6 and 8.5 standard units.
Individual variation according to
sample location was observed (Figure 2). Low and high pH values at
specific sites were as follows: tap 7.6-7.8; dechlorination chamber exit
8.1-8.5; tank at standpipe 8.2-8.5; aquarium nine 8.2-8.5.
Dissolved oxygen also remained relatively constant.
Averages for
individual sites were 10.4 ppm at tap, 9.2 ppm at dechlorination chamber
15
-
Table 1. Water chemistry during fish growth experiments by date and
site, for temperature, pH, dissolved oxygen, alkalinity, nitrate,
and nitrite.
Site/Parametel'
12/18/91
Date
1/3/92
1/27/92
2/13/92
Tap
-
Temperature (oF)
pH (St. units)
Dissolved Oxygen
Nitrate (ppm)
Nitrite (ppm)
Alkalinity (ppm)
Chlorine (ppm)
Dechlorination Exit
Temperature (oF)
pH (St. units)
Dissolved Oxygen
Nitrate (ppm)
Nitrite (ppm)
Alkalinity (ppm)
Chlorine (ppm)
Tank Standpipe
Temperature (oF)
pH (St. units)
Dissolved Oxygen
Nitrate (ppm)
Nitrite (ppm)
Alkalinity (ppm)
Chlorine {ppm)
Aquarium #9
Temperature (OF)
pH (St. units)
Dissolved Oxygen
Nitrate (ppm)
Nitrite (ppm)
Alkalinity (ppm)
Chlorine (ppm)
(ppm)
(ppm)
(ppm)
(ppm)
56
7.6
10.0
3.3
0.01
282
0.6
58
7.6
10.4
2.5
0.01
278
1.4
57
7.7
10.4
6.9
0.01
230
1.2
58
7.8
10.8
3.5
0.01
246
1.4
61
8.1
9.6
3.5
0.01
280
0.8
62
8.4
9.0
3.0
0.01
280
1.0
61
8.3
9.0
5.7
0.01
224
0.7
58
8.5
9.0
3.8
0.01
246
0.9
62
8.2
9.0
3.6
0.02
270
0.1
64
8.4
8.8
2.9
0.01
272
0.1
61
8.3
8.8
3.9
0.07
250
0.0
59
8.5
8.8
4.9
0.05
244
0.0
64
8.2
9.4
3.5
0.02
296
0.1
62
8.5
8.2
3.2
0.01
274
0.1
62
8.2
8.4
4.9
0.03
248
0.0
59
8.5
8.2
4.2
0.05
244
0.0
)
)
MEAN 5 DA Y TEMPERATURES AND MEAN HIGH AND LOW
OBSERVED BY SAMPLE PERIOD
-=
'-
75l
73
71
69
01.1..1
ell:
I-
67
1.1..1
65
63
I:
61
I-
59
57
c
I:X
~
1.1..1
55
LI)
0
I
...0
LI)
0
N
0
t<1
N
...0
N
LI)
N
I
LI)
t<1
I
...0
0
"'1'
LI)
"'1'
...0
t<1
LI)
LI)
I
I
t<1
0
LI)
"'1'
"'1'
...0
I
...0
"'1'
0
...0
...0
LI)
LI)
...0
DAYS
Figure 1.
Mean water temperature and mean high and low temperature
observed in the main raceway tank for five day intervals.
I-'
0'1
17
10
TAP pH
-
8 -
:::c
11:1.
6
4
2
0
01/03
12/18
01/27
02/14
DECHLORINATION EXIT pH
10
8
:::c
11:1.
6
4
2
0
12/18
01/03
01/27
02/14
TANK pH
10
8
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6
4
2
0
12/18
01/03
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02/14
AQUARIUM #9 pH
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01/27
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12/18
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01/27
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01/03
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18
exit, 8.9 ppm in tank at standpipe, and 8.6 ppm in aquarium nine (Figure 3).
Variation at these sites was slight (Figure 4).
Dissolved oxygen during
experiments ranged between 8.2 ppm and 10.8 ppm. Saturation was
estimated as between 83% and 109% for the system.
Percent saturation
was usually between 90-100% (Figure 5).
Alkalinity exhibited only slight changes throughout the system.
Averages for individual sites were 259 ppm at tap, 257 ppm at
dechlorination exit, 259 ppm in tank at standpipe, and 265 ppm in
aquarium nine (Figure 6). The alkalinity throughout the system ranged
between 224 ppm and 296 ppm (Figure 7).
Chlorine levels remained below 0.1 ppm in the main raceway tank.
Averages for the individual sites based on the four periods evaluated were
1.2 ppm at tap, 0.9 ppm at the dechlorination chamber exit, less than 0.1
ppm at the tank at standpipe, and less than 0.1 ppm in aquarium nine
(Figure 8).
Oiifferences at individual sites were highest at the tap and
dechlorination exit, but other sites were low and relatively uniform
(Figure 9).
Additionally, chlorine was monitored from the tap on a
consistent basis every 5 - 10 days. Results of these measurements
-
demonstrate only slight fluctuations in chlorine levels (Figure 10).
The rangle for nitrate concentrations was between 2.5 ppm and 6.9
)
DISSOL VED OXYGEN
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Figure 3.
AVE.
HIGH
LOW
DECHL.
TANK
AQ. #9
Dissolved oxygen high, low, and mean values at tap,
dechlorination exit, tank, and aquarium #9.
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Individual site locations for measurements of oxygen
saturation: tap, dechlorination exit, tank, and aquarium #9.
21
TAP OXYGEN SATURATION
,-~
120 -
z
CI
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80
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60
e
en
40
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II:IIi:
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12/18
01/27
01/03
02/13
DATE
DECHLORINATION EXIT OXYGEN SATURATION
120
z
CI
100
80
60
40
20
O~·~~~~--~~~~~~~~~~-L~~~~
12/18
01/03
01/27
02/13
DATE
TANK OXYGEN SATURATION
z
CI
100
80
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~
60
!;i
40
~
20
::.
en
o
12/18
01/27
01/03
02/13
DATE
OXYGEN SATURATION
AQUARIUM #9
120
z
CI
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100 80
60
40
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12/18
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01/27
01/03
DATE
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02/13
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ALKALINITY
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•
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AVE.
HIGH
LOW
•
200
TAP
Figure 6.
DECHL.
Alkalinity high, low, and mean values at tap, dechlorination
exit, tank, and aquarium #9.
N
N
Figure 7.
Individual site locations for measurements of alkalinity:
dechlorination exit, tank, and aquarium #9.
tap,
--
23
.-
TAP ALKALINITY
-
350 e 300
A.
A. 250
)200
!::
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12/18
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01/27
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EXIT ALKALINITY
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300
250
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-< 100
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0
12/18
01/03
01127
02/13
TANK ALKALINITY
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350
300
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50
0
12/18
-e
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01/03
01/27
#9 ALKALINITY
AQUARIUM
350
300
250
!:: 200
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c
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01/03
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CHLORINE
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Figure 8.
DECHL.
TANK
•
r::l
•
AQ. #9
Chlorine high, low, and mean values at tap, dechlorination exit,
tank, and aquarium #9.
tv
~
------------------------------------------------------
-',-#
---
Figure 9.
Individual site locations for measurements of chlorine:
dechlorination exit, tank, and aquarium #9.
tap,
-
,-
25
e
.:..
.:..
"'z"
ex:
CI
....I
:c:
u
TAP CHLORINE
1.6 1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
-
01/03
01/27
DECHLORINATION
EXIT
01/03
01/27
12/18
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ex:
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02/13
~HLORINE
1.6
1.4
1.2
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0.8
0.6
0.4
0.2
0.0
12/18
-
CHLORINE
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
12/18
-
02/13
01/03
01/27
AQUARIUM
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
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1 2/18
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CHLORINE
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01/03
01/27
DATE
02/13
)
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TAP CHLORINE
eA
A
-'
c.J
Q.
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1.8
1.6
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1.2 .
1.0
0.8
0.6
0.4
0.2
0.0
0
5
10
15
20
25
30
35
40
45
50
55
60
65
DAY
Figure 10. Mean chlorine levels, and mean high and low chlorine levels
observed from the tap for five day intervals.
N
en
27
ppm. Averages for individual sites were 4.1 ppm at tap, 4.0 ppm at
dechlorination chamber exit, 3.8 ppm in tank at standpipe, and 4.0 ppm in
aquarium nine (Figure 11). Variation was greatest at tap and
dechlorination chamber exit samples (Figure 12).
Nitrite was present only in trace amounts throughout the system
ranging from 0.01 ppm to 0.07 ppm.
Averages for individual sites were
0.01 ppm at tap, 0.01 ppm at dechlorination chamber exit, 0.03 ppm in tank
at standpipe, and 0.03 ppm in aquarium nine (Figure 13). There was a
tendency for some buildup of nitrite in the aquaria and in the tank (Figure
14).
Feeding Results for Bluegill and Hybrid Sunfish
Results of feeding experiments for periods 1,2 and 3 were evaluated
using the data base by period (Tables 2-4). Period 1 describes the dates
of December 12, 1991 through January 2, 1992, inclusive; period 2,
January 3 through January 22; and period 3, January 23 through February
14.
The total food consumed by hybrid sunfish in period 1 was 431 .28
grams; in period 2, 544.44 grams; and in period 3, 772.08 grams. Average
food consumed per day by period was 3.26 grams in period 1; 4.54 grams in
period 2; and S.85 grams in period 3. The total food consumed by bluegill