EPA 660/2-74-064
July 1974
Environmental Protection Technology Series
Pollution Aspects of Catfish Production
-—Review and Projections
Office of Research and Development
U.S. Environmental Protection Agency
Washington, O.C. 20460
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and
Monitoring, Environmental Protection Agency, have
been grouped into five series. These five broad
categories were established to facilitate further
development and application of environmental
technology. Elimination of traditional grouping
was consciously planned to foster technology
transfer and a maximum interface in related
fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
H. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL
PROTECTION TECHNOLOGY series. This series
describes research performed to develop and
demonstrate instrumentation, equipment and
methodology to repair or prevent environmental
degradation from point and .non-point sources of
pollution. This work provides the new or improved
technology required for the control and treatment
of pollution sources to meet environmental quality
standards.
EPA REVIEW NOTICE
This report has "been reviewed by the Office of Research and
Development, EPA, and approved for publication. Approval
does not signify that the contents necessarily reflect the
views and policies of the Environmental Protection Agency,
nor does mention of tr-ade names or commercial products consti-
tute endorsement or recommendation for use.
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EPA-660/2-74-064
July 1974
POLLUTION ASPECTS OF CATFISH PRODUCTION--REVIEW AND PROJECTIONS
By
James C. Barker
Jerry L. Chesness
Ralph E. Smith
Project 801662
Program Element 1BB039
Project Officer
Lee A. Mulkey
United States Environmental Protection Agency
Southeast Environmental Research Laboratory
College Station Road
Athens, Georgia 30601
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20JQ2 - Price $1.65
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ABSTRACT
A literature review and field study was undertaken to determine
the waste concentrations and discharge loadings occurring in the
waters from catfish-culturing ponds and raceways. Water quality
analyses were performed on samples taken during a 240-day growing
season and at drawdown (assuming drainage at harvest).
The natural biological degradation of the raw wastes in the
ponds and raceway systems resulted in BOD reductions of 96.8% and
98.0% respectively when compared to waste levels produced in indoor
single pass tank systems with no waste removal facilities. Reduc-
tions in total nitrogen of 97.2% and 97.7% occurred in ponds and
raceways respectively, while ammonia nitrogen was reduced by 97.4%
and 99.4% respectively. Sedimentation and biodegradation resulted in
an 83.6% reduction in suspended solids in ponds and an 86.2% sus-
pended solids reduction in raceways. Total phosphate levels were
reduced by 98.5% and 97.4% in ponds and raceways respectively.
This report was submitted in fulfillment of Grant No. 801662
under the sponsorship of the Office of Research and Development,
United States Environmental Protection Agency.
ii
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CONTENTS
Page
Abstract ii
List of Figures iv
List of Tables v
Acknowledgments vii
Sections
I Conclusions 1
II Recommendations 3
III Introduction 5
IV The Present Status of Catfish Culture 9
V Catfish Wastes and Wastewater Quality 24
VI Research Methods and Facilities 36
VII Results 45
VIII References 89
IX Glossary 98
X Appendices LOO
iii
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FIGURES
No. Page
1 Flow Diagram for Raceway System E 41
2 Flow Diagram for Raceway System TR 43
3 BOD Concentration in Ponds 46
4 COD Concentration in Ponds 47
5 Total Kjeldahl Nitrogen Concentration in Ponds 48
6 Ammonia Nitrogen Concentration in Ponds 49
7 Nitrite + Nitrate - Nitrogen Concentration in Ponds ^0
8 Total Solids Concentration in Ponds 51
9 Total Volatile Solids Concentration in Ponds ^2
10 Total Suspended Solids Concentration in Ponds ->3
11 Settleable Solids Concentration in Ponds 54
12 Total Phosphate Concentration in Ponds 55
13 Orthophosphate Concentration in Ponds 56
14 BOD Concentration of Raceway Effluent 69
15 COD Concentration of Raceway Effluent 70
16 Total Kjeldahl Nitrogen Concentration of Raceway Effluent 71
17 Ammonia Nitrogen Concentration of Raceway Effluent 72
18 Nitrate + Nitrite - Nitrogen Concentration of Raceway Effluent 73
19 Total Solids Concentration of Raceway Effluent 74
20 Total Volatile Solids Concentration of Raceway Effluent 75
21 Total Suspended Solids Concentration of Raceway Effluent 76
22 Settleable Solids Concentration of Raceway Effluent 77
23 Total Phosphate Concentration of Raceway Effluent 78
24 Orthophosphate Concentration of Raceway Effluent 79
IV
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TABLES
No. Page
1 Catfish Effluent Water Quality 28
2 Pond Descriptions 37
3 Raceway Descriptions 39
4 Pond C and W Range and Mean Concentrations 58
5 Pond C and W Mean Surface, Mid-depth and Bottom Concentrations 59
6 Pond Harvest Data 60
7 Water Quality During Harvest Drawdown for Pond System C 62
8 Pond C Parameter Concentrations at Different Sampling Depths 64
9 Waste Discharge Potential of Mid-depth vs. Bottom Discharge
from Pond C 65
10 Raceway ED and TR Mean Diurnal Variations in Effluent Cone 67
11 Raceway EG, EF, ED and TR Mean Influent and Effluent Cone 80
12 Raceway Harvest Data 83
13 Pounds Parameter Discharged from Raceway System E 85
14 Waste Production from Different Fish Culture Systems 86
15 Water Quality Data, Ponds, 7/IS/73 101
16 Water Quality Data, Ponds, 8/14/73 1°2
17 Water Quality Data, Ponds, 9/4/73 103
18 Water Quality Data, Ponds, 9/25/73 104
19 Water Quality Data, Ponds, 9/25/73 105
20 Water Quality Data, Ponds, 10/18/73 106
21 Water Quality Data, Ponds, 11/9/73 1°7
22 Water Quality Data, Ponds, Harvest, 10/3/73 108
23 Water Quality Data, Raceways, 6/13/73 109
24 Water Quality Data, Raceways, 6/25/73 HO
25 Water Quality Data, Raceways, 7/9/73 HI
26 Water Quality Data, Raceways, 7/25/73 H2
27 Water Quality Data, Raceways, 8/9/73 113
28 Water Quality Data, Raceways, 8/17/73 n4
v
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No. Page
29 Water Quality Data, Raceways, 8/23/73 H5
30 Water Quality Data, Raceways, 9/6/73 116
31 Water Quality Data, Raceways, 9/19/73 117
32 Water Quality Data, Raceways, 8/14/73 118
33 Water Quality Data, Raceways, 9/4/73 119
34 Water Quality Data, Raceways, 10/3/73 120
35 Water Quality Data, Raceways, 10/18/73
vi
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ACKNOWLEDGEMENTS
This project was/funded by United States Environmental
Protection Agency Grant 801662.
The assistance provided by the Environmental Protection
Agency and Mr. Lee A. Mulkey are deeply appreciated.
vii
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SECTION I
CONCLUSIONS
1. None of the water quality parameter concentrations recorded during
the study period interfered with or presented difficulties in the
culturing of catfish.
2. All pond water parameters except ammonia nitrogen when expressed
as pounds parameter per 100 fish show decreasing trends as the
culture season progressed. This is a result of the decrease in
unit metabolic waste production as the fish increase in size.
When the parameter concentrations are expressed as milligrams
per liter the levels show an increasing trend as the season
progresses.
3. Samples taken near the bottoms of ponds have, in general, the
highest parameter concentrations. The lowest levels occur at
mid-depth while those from the surface are in between. For ex-
ample COD values from bottom, surface, and mid-depth were 41.0
mg/1, 35.0 mg/1 and 30.8 mg/1 respectively.
4. The total pounds of each parameter released from the pond during
the drawdown for harvest can be closely estimated by using the
mean of the surface, mid-depth and bottom concentrations in the
pond prior to drawdown.
5. If preharvest drawdown requires drainage only to the mid-depth
level, a plight reduction in total quantities of waste discharged
can be attained by removing water from the mid-depth level as
I
opposed to the bottom. For example a 2.5% BOD reduction and 8.4%
total Kjeldahl nitrogen reduction were attained in this study.
6. Ponds have a high biological assimilative capacity for the wastes
produced during the culture of catfish. BOD and total nitrogen
levels are reduced by 96.8% and 97.2% respectively from the raw
waste levels recorded in tank studies.
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7. Pond drainage should be discontinued during seining operations.
The waters discharged during harvest operations have the highest
waste concentrations. Organic parameter concentration can be as
much as 30% higher in the discharge occurring during seining.
8. Raceway water quality parameter concentrations when expressed as
a function of fish density showed a slight tendency to increase
during the growing season. This indicates that the systems did not
have the biological capability to assimilate all of the wastes
resulting in a net buildup of nutrients.
9. Recirculation raceway systems provide the highest degree of waste
stabilization of any of the systems studied. For example, BOD,
total nitrogen, and total solids were reduced by 98.0%, 97.7%,
and 48.4% respectively when compared with the raw waste levels
in tanks. This increase in waste reduction can be attributed
to the increased mixing and aeration received by the water dur-
ing pumping and gravity flow through the raceway.
10. Physical settling basins are not an effective means of removing
suspended organic solids from the "continuous" flow in raceway
systems for catfish production. Based on model studies a 78-ft.
long trapezoidal shaped settling basin would remove only 47» of
the total organic solids.
11. With the exception of ammonia nitrogen and total phosphate all
water quality parameter concentrations obtained from ponds and
raceways during the growing season were well within the permis-
sible criteria for raw surface water for public supplies as set
forth by the Federal Water Pollution Control Administration
(FWPCA) in 1968.
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SECTION II
RECOMMENDATIONS
1. Where topography and economics permit, effluents from catfish
production ponds at the time of harvest should be released into
a holding pond. This is especially important with regards to
the final 2 to 3 feet of drawdown water which contains a higher
waste concentration. The effluent in the holding pond should be
retained until biodegradation of wastes improves the water quality
to the extent that next season's fish crop could be stocked in
these waters or the waters released to a receiving stream.
2. When the harvest of catfish production ponds can be achieved by
draining to the mid-depth level the drain pipe intake should be
located at mid-depth and not the bottom. This will reduce the
waste discharge from the pond during drawdown.
3. Water should not be released from the pond during harvest operations.
The physical agitation caused by the fish and the seining operation
increase the solids and other waste parameter concentrations in the
water. Allowing this water to remain in the pond for a month or
more after harvest would allow sedimentation and biodegradation to
take place prior to final drainage.
4. Further research is needed to establish the effectiveness and
techniques for land disposing and land filtration (overland flow
prior to entering receiving stream) of the drainage waters from
catfish production ponds. This would prove to be an effective
alternative to holding ponds for renovation of drainage waters.
I
5. Raceway systems for catfish production should be of the closed-loop
recirculation type. When a recirculation reservoir does not have
sufficient biodegradation capacity to prevent certain waste
parameters from reaching toxic levels periodic wasting or drainage
should be kept to a minimum.
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6. Further research is needed in order to develop biological
filtration and polyculture systems suitable for outdoor warm-
water-culture raceway systems. If this can be successfully
accomplished then it should be possible to increase the stocking
intensities per unit of total water volume.
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SECTION III
INTRODUCTION
"Fish" to the average reader, has a recreational connotation.
To a small and rapidly expanding group, however, it has a vastly
more important implication: the production of food and income. It
has been demonstrated that a ton of fish may be produced in an area
capable of yielding only 800 pounds of corn or 80 pounds of beef.
The Chinese began developing the art of fish farming into a science
more than 2000 years ago. Only in the past two decades, however, has
intensive fish culture came into focus in the United States. Today's
fish farmer is in the same position as the poultry farmer of 20 years
ago who was changing from the back-yard flock to the highly specialized
commercial poultry production we know today.
A sound catfish industry has great potential for meeting the
growing demands for increased food supply at reasonable costs. Cat-
fish, compared to other animals, are relatively efficient converters
of feed to meat. The product, if properly produced and marketed, is
a highly nutritious food—high in vitamins, minerals, and protein;
yet low in carbohydrates and cholesterol. In 1970 approximately
45,000 acres were devoted to catfish farming primarily in one to
twenty acre ponds in the southern states. This acreage yielded 54
million pounds of undressed catfish worth 35.7 million dollars on the
retail market. The projected value of production in 1975 is 88 million
dollars. Emphasis was placed on high-density production of catfish in
flowing water earthen raceways in Georgia in 1969.
The mushrooming development of catfish farming has been paralelied
by a strong supporting program of research with work on spawning of
catfish, biological investigations, economics, and applied research
as well as follow-up studies of all subjects of concern to catfish
culturists . The primary emphasis of water quality work to date has
been on the effects of pollutants on fish, rather than the effects of
fish cultural activities on other beneficial uses downstream. The
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almost complete absence of literature on the subject suggests that
the quality of effluents from catfish culture operations has not
been considered a serious enough problem to warrant investigation.
However, in 1970, an estimated 185,000 acre-feet of water was being
used for catfish production with a projected usage of 400,000 acre-
feet by 1975. This quantity of water qualifies the catfish industry
as a significant water user. As a result of public interest in the
discharge of wastes into natural waters, much concern has arisen in
the nature of effluents from fish cultural activities. Due to threat-
ening water shortages and water pollution control laws, maximum
efficiency in the use of water for fish culture is being sought.
Cultured fish produce a relatively large amount of organic wastes
(uneaten feed and metabolic byproducts). Murphy and Lipper (1970)
indicated that the BOD production in a raceway containing 100,000 one-
pound catfish would equal that of a flock of 150,000 one-pound chickens,
1,500 one-hundred-pound hogs, or 480 one-thousand-pound steers. The
quantity of waste to be handled then is considerable irregardless of
the type of culture system in use. These wastes will inhibit growth
and create an environment conducive to disease problems or oxygen
depletion.
The pollution potential could have decided effects on the quality
of waters receiving fish culture effluents. A major portion of the
catfish producers in Georgia harvest their ponds by releasing the con-
tents (5-100 acre-feet) over a three- or four-day period into a small
receiving stream nearby. This practice has the potential to create an
immediate shock-loading effect on the receiving ecosystem. Chronic
effects of waste water from open raceways flowing into small receiving
streams are little understood. Concern regarding the release of such
materials into the environment must be considered, as well as the
biological effects of having such compounds remain in the system as is
the case with closed raceway systems. Producers are asking if the
water from cultural activities is nutrient-enriched, and if so, what
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should be done to minimize these pollutants and increase fish
production.
There are three broadly grouped categories of factors associated
with fish cultural effluents that have potential or known existing
detrimental effects on the quality of the receiving waters. The first
category includes pathogens and parasites passing from the fish pro-
duction unit into natural waters. A second category consists of
chemicals and drugs employed to control either prophylactically or
therapeutically, diseases and parasites. The third group of factors
include those that contribute to chemical and/or physical change of
water quality. The first and second categories are sporadic in nature
while the third group constitutes the most suspect and possibly sig-
nificant sources of pollution.
OBJECTIVES
This study was initiated to present a state-of-the-art review of
catfish cultural activities with regard to the production of water-
borne waste and its ultimate disposition. The specific objectives
follow:
1. To obtain a compilation and review of present information on
the pollution aspects of commercial catfish production.
2. To survey and analyze representative effluent samples of
various segments of the catfish production enterprise for
the characterization and quantification of fish production
wastes .
3. To evaluate pollution1control methods and make research
projections for the management of catfish production wastes.
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SECTION IV
THE PRESENT STATUS OF CATFISH CULTURE
Despite its virtual overnight development in the United States,
catfish culture is one of the most thoroughly documented forms of
intensive fish culture. Success, however, is not inevitable for every
farmer who stocks a pond. As the industry has progressed, four methods
of catfish culture have developed (1) pond culture, (2) raceway cul-
ture, (3) cage culture, and (4) tank culture. However, the majority
of cultured catfish are produced by the first three methods. Specific
requirements of a fish farm depend upon local situations, but general
management guidelines for the pond, raceway, and cage culture systems
have been established.
SELECTION OF CATFISH SPECIES
Three principal species of catfish are adaptable to intensive
culture—blue, white, and channel catfish. Of these three, the most
widely used is the channel catfish (Ictalurus Punctatus) partly due to
their superior taste, fast growth from feeding, resistance to crowding,
and availability of information known about their culture. On the other
hand, channel catfish are difficult to train to surface-feed, and
they have a nervous temperament causing problems when handled.
Blue catfish (Ictalurus Furcatus) grow more uniformly, yield a
marketable portion of about 60-62% of live weight compared to 56-58%
for channel catfish, readily adapt to surface-feeding enabling the
farmer to inspect his fish for health and feeding habits daily, and
are easy to harvest by seining. Major disadvantages, however, are
poorer conversion of most artificial feeds, greater age at maturity,
and high mortality rates during handling and transportation. The
white catfish (Ictalurus Catus) are among the hardier species of cat-
fish, withstanding crowding, low dissolved oxygen concentrations, tur-
bidity, and high temperatures much better than channel catfish. However,
they dress out at less poundage than the other types of fish and do not grow
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nearly £S rapidly as channel catfish. Hybridization is gaining in
popularity with the most promising hybrid thus far being a male blue
catfish crossed with a female channel catfish. This hybrid grows
more uniformly and has shown 11-65% better growth rates than the parents
SITE SELECTION AND DESIGN CRITERIA
Pond Culture
Geographic areas with long periods of warm temperatures are best
suited for catfish culture. Optimum rates of growth require a water
temperature of over 70°F for 180-210 days per year. Close proximity
of fish farm to market eliminates long-distance fish transportation.
Site selection depends primarily on soil characteristics, topography,
water supply, and drainage-protection areas. A heavy soil capable of
holding water is necessary to prevent seepage losses. Land previously
used for crops has the advantage of being cleared of brush, trees, and
roots, but there is the chance of residual herbicides and insecticides
in the soil which may be toxic to fish. A thorough test of the soil
is necessary for a fish operation planned on cropland where chlorinated
hydrocarbon pesticides have been used.
Topography of the proposed pond-site should be suitable for proper
drainage of the pond and adequate flood protection. Generally, flat
well-drained land affords the most economical pond construction, but
sufficient elevation is required so that each pond can be drained com-
pletely into an adequate disposal outlet. Pond construction may be
simplified by placing a dam across a natural drainage basin, however,
the main course of a stream should be avoided because of its flooding
characteristics. On large watersheds, flood channels or diversion
ditches that bypass the ponds may be necessary for protection of the
structures against excessive overflow and loss of fish. On sloping
lands ponds should be designed to fit the contour of the land and make
maximum use of the water supply.
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The shape and arrangement of catfish ponds affects their effective-
ness and efficiency of production. A square-shaped pond is less expensive
to construct, because it requires less levee than a rectangular pond for
the same number of acres of water. Economy of harvesting plus a greater
feed area usually favor rectangular-shaped ponds since less seine is
required for harvesting. To secure the best aeration benefits, the
pond should be laid out with the longer axis parallel with the prevail-
ing wind direction. Larger ponds need a certain amount of protection
from these winds, however, since wind traveling over a long water sur-
face will create waves and erode the dams or levees.
In order to prevent loss of fish, spillways of dams should be wide
enough to hold the depth of overflow to six inches or less during
excessive rainfall and filling. Storage of storm water can be provided
by setting the overflow pipe at a lower elevation than the spillway. To
prevent trash fish from entering the pond from downstream, an overfall
or weir constructed on the back slope of the spillway is essential.
All slopes, tops of dams and levees, and disturbed areas should be
vegetated immediately after construction to prevent erosion.
The size of a pond for catfish production may be a case of neces-
sity rather than choice and will vary according to the slope and size
of the site available. Ponds of less than one acre to more than 100
acres have been used for catfish production, but usually, a pond of
5-20 surface acres is characteristic of a successful operation. Small
ponds are more expensive to construct and utilize more space for levees,
but they provide more flexibility for management, harvesting, overcoming
oxygen shortages, and treating f'or diseases and parasites. They also
can be drained and refilled quickly. Recommended depths for catfish
production ponds are 3-6 feet -- not less than 2 feet or more than 8
feet. A minimum depth of two feet is required to control vegetation.
Ponds deeper than 6 feet are difficult to seine, drain slowly, and cost
more to refill. However, depths of 6-8 feet may be necessary in states
north of Arkansas to prevent winter kill.
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After construction, the bottom of the pond is graded smooth
with a slope of 0.2 ft. fall per 100 linear feet toward the deep
end or harvesting basin. To facilitate harvesting, a harvest basin
is constructed in the deep end of the pond 18-24 inches below the
drainpipe base. A satisfactory harvest basin contains about 10% of
the total bottom area in the pond. Ponds should be equipped with
drainpipes large enough for prompt and complete drainage. One such
device is a three-ring, turn-down pipe which acts as an overflow and
drainpipe and can be adjusted to maintain desired water levels.
Raceway Culture
The production of catfish in earthen raceways is a new kind of
fish culture in America referred to as "intensive production." To
understand this type of flowing water culture, the following general
definitions are helpful:
1. Raceway - A channel with a continuous flow of water constructed
for growing fish.
2. Raceway Unit - One of the segments into which a raceway is
divided by screen partitions or water control structures.
3. Open raceway system - An installation in which water flows
from the water supply source through the raceways and waste treatment
facilities without recirculation.
4. Closed raceway system - An installation in which water is
recirculated from the water supply reservoir through the raceways and
waste treatment facilities and returned to the supply reservoir.
The water temperature of raceways is influenced by the water
source more than the external environment. Unless some form of heated
water is available, raceway culture of catfish is restricted to the
extreme southern states due to relatively cool water temperatures
experienced in other geographical locations. Rough terrain with cross
slopes greater than 7% should be avoided, otherwise excessive land
grading is required and objectionable cuts and fills are necessary.
Other geographic, topographic and soil characteristics and require-
ments are much the same as for pond culture-
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Most raceways usually consist of from 10-20 rectangular units each
100 feet long. All channels should be aligned as straight as possible
to achieve uniform flow throughout the channel cross section. Necessary
curves should have a relatively flat curvature to avoid eddy flow and
dead areas. The recommended channel grade is from l-27». Channel flow
is dependent on weir flow and the volume of water moved through the
system rather than the channel grade. Typical channel cross sections
are trapezoidal and consist of a 10-foot bottom width, 4-foot maximum
depth, and 1:1 side slopes. Low channel velocities of 0.025 feet per
second result from a recommended raceway flow of 530 gallons per minute.
At this exchange rate, each raceway unit has a water retention time of
approximately one hour. The dike crowns should have a minimum width
of 12 feet to allow service vehicle access.
Water control structures are installed to provide water aeration,
to subdivide the raceway into 100-foot units, and to create channel
flow. A water fall of 1-2 feet per raceway unit is recommended. Water
discharge from each raceway unit should be taken from near the channel
bottom elevation to aid in flushing metabolic wastes and to remove water
with a low level of dissolved oxygen. A vertical adjustable baffle
located on the upstream side of the water control structure serves this
purpose. Some of the more successful water aerators are the conven-
tional splash board, a transversely corrugated inclined plane with holes,
and a riser pipe with perforated collars.
An alarm system should be installed on each raceway to notify the
operator of any flow stoppage. In the event of a power failure, an
auxiliary pumping system or a'storage reservoir capable of supplying a
12-hour emergency supply of water by gravity is imperative to prevent
rapid oxygen depletion and fish kills.
Cage Culture
Cage culture is used mostly in natural bodies of water such as rivers,
lakes, reservoirs, rock quarries, canals, and ponds that are otherwise
13
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unsuitable because of poor harvesting capabilities, excessive flooding,
and the presence of other undesirable fish. Adequate circulation of
water supplies or supplemental aeration is necessary to maintain suf-
ficient levels of oxygen and to avoid a buildup of body wastes and
parasites. The influence of the geographic area is the same in cage
culture as in pond culture of catfish. Other advantages of cage cul-
ture include less expensive treatment for parasites and diseases, com-
plete harvesting, manipulation of harvest to meet market demands, and
ease of observation.
The most popular cage size appears to be 36 cubic feet with
dimensions of 3 ft. x 4 ft. x 3 ft. deep. Depth in water may exceed
three feet in very clear lakes where adequate oxygen is known to exist.
Cage materials are usually one-half by 1-inch square mesh aluminum or gal-
vanized wire attached to wooden or steel rod frames. Vinyl or "net set"
coatings should prolong the life of any material used. The top should
be constructed of some light solid material such as marine plywood or
aluminum sheeting. Styrofoam, small drums, or other buoyant material
provide flotation for the cages which are anchored or tied to a cable
spanning the water impoundment.
WATER MANAGEMENT
Water Supply
Water, to a fish farmer, is what soil is to the rowcrop farmer.
A dependable supply of good quality water is essential for catfish
culture since it is the medium in which the fish lives, reproduces, and
grows. Well water and spring water are the most dependable sources
of good quality water since they are usually free of such impurities
as parasites, diseases, pesticides, turbidity, and trash fish. Well
water may be deficient in oxygen and supersaturated with nitrogen,
carbon dioxide, and iron. Aeration of the water by splashing the flow
over baffles and screens before it enters the culture system increases
the oxygen content and significantly decreases the nitrogen and carbon
14
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dioxide levels. Well water is usually more expensive than other
sources because of drilling and pumping costs. Spring water has the
same characteristics as well water and may be used if an adequate
volume is available year round. Springs, however, tend to yield
water which is too cold for catfish culture unless some type of warm-
ing procedure is employed.
Runoff, streams, and reservoirs provide the most economical
sources of water, however, the best known management precautions should
be understood and followed. Runoff from cropland and watersheds may
carry pesticide residues and may not provide an adequate amount of
water. Water secured from streams or reservoirs may introduce diseases,
parasites, sediment-laden water, or undesirable fish. The impurities
may be toxic to fish, reduce production, or cause a bad taste in the
fish flesh. Meshed screen or saran sock filters may be placed over
the ends of water inlets to prevent the entry of trash fish.
Water Quantity
The amount of water needed for growing catfish depends on the
size of the fish farm and the type of operation, that is, pond or
raceway. Enough water is required for filling ponds in a reasonable
time and for replacing water lost through evaporation and drainage
when oxygen depletion occurs. A normal water requirement is 25-30
gallons per minute (gpm) per surface acre of pond culture. A well
producing 1,000 gpm will produce 4.4 acre-feet in 24 hours. A 1,000-
1,200 gpm well is generally considered adequate for a 40-acre catfish
farm.
Raceways with 100-foot segments use a flow rate of 530 gpm with
i
a unit retention time of 60 minutes. When supply reservoirs are
utilized the storage capacity should be sufficient to fill the race-
ways and auxiliary pools, offset evaporation and seepage losses, and
maintain a reasonable volume of storage below the pump intake to avoid
reservoir pollution. Storage reservoirs should provide a minimum of
one acre-foot of water for every 4,500 cubic feet within a closed race-
way system. When the source is from wells, springs, or streams, open
15
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raceway systems should be designed to keep within the minimum
seasonal flow.
In summary the average volume of water needed during a growing
3
season to grow a harvestable crop of catfish is: (1) 85 ft /lb fish for
3 "}
ponds, (2) 60 ft /lb fish for raceways, and (3) 1.7 ft /lb for tanks.
Water Quality
Whatever the source of water, its quality should be carefully
checked. Well and spring water usually has excessive carbon dioxide,
nitrogen, or iron. Catfish can withstand 12-15 parts per million (ppm)
of carbon dioxide but will usually die if concentrations exceed 25-30
ppm. Toxicity of ammonia nitrogen depends upon water pH. Total ammonia
concentrations above 2-4 ppm may be toxic if the pH is above 8.5. The
most toxic form of ammonia, un-ionized ammonia, becomes toxic to salmo-
nids at levels of 0.5 ppm and greater. The amount of total ammonia
that is in the un-ionized form increases as the pH increases. Combi-
nations of low oxygen and high carbon dioxide and nitrogen gases are
usually lethal to catfish. Waters which contain high ferrous iron con-
centrations can cause mortality by iron oxidizing and settling on the
gills in amounts that interfere with fish respiration. Aeration of the
water usually eliminates excessive amounts of carbon dioxide and nitrogen.
Water hardness is expressed as the amount of calcium carbonate in
the water. Desirable ranges for catfish culture are 20-150 ppm total
hardness and 30-200 ppm total alkalinity. If water is too soft (less
than 15 ppm total hardness) the addition of agricultural limestone or
hydrated lime is recommended. Sulfate of ammonia fertilizer may be
used for water which is too hard (more than 200 ppm). Rapid changes
in pH may severely stress the fish. Toxic levels are below 4 and above
11 with the desirable pH range being 6.5 - 8.5 for catfish production.
Chlorides in water combine with sodium, potassium, and magnesium
to form salts. Catfish, when slowly acclimated, have been raised
successfully in water averaging 2,500 ppm of salt as NaCl. Chlorine
16
-------
may be a problem where municipal water supplies are used for fish
production since toxic levels to catfish are 0.1-0.2 ppm and above.
Hydrogen sulfide is sometimes found in bottom water of ponds low in
oxygen and high in organic matter. In such cases 1-2 ppm may be toxic
to catfish, especially smaller ones.
Catfish take food very sparingly at water temperatures below 60°F
and grow most efficiently at temperatures between 75°F and 85°F. Dur-
ing periods of higher water temperatures, feeding rates should be
regulated to the amount the fish will eat. Muddy water may reduce fish
yields and impart an undesirable flavor to the fish. Proper pond and
raceway construction should include complete grass coverage of all
bare or disturbed areas. Ponds may be cleared of muddiness by scattering
hay on the water around the pond edges every 10 days except during hot
weather. Gypsum may also be scattered over the surface at rates of
200-800 pounds per acre at 7-10 day intervals. Density of plankton and
algae growth is a good index to water quality. A bright object immersed
in water should be visible to a depth of 12 inches. Deterioration of
a dense bloom of algae could cause an oxygen depletion.
Oxygen Maintenance
Oxygen depletion is the most common cause of sudden massive fish
kills. Fish will die when the dissolved oxygen level falls below 1.0
ppm. Water should contain 4-5 ppm oxygen at 6 inches below the surface
of the water for optimum fish growth. Decaying organic matter such as
weeds, leaves, feed, and metabolic wastes as well as a sudden die-off
of plankton and algae tend to rapidly deplete oxygen from water. A
heavy fish population may use oxygen faster than it is added. Chemical
reactions tend to tie up elemental oxygen. Water at 80°F when in
atmospheric equilibirum, will hold only 8.1 ppm dissolved oxygen, whereas
at 40°F it will hold 13.0 ppm. Water can be supersaturated with oxygen
produced by algae to levels of 20-30 ppm. Adding water which is
initially low in oxygen to a production unit reduces the amount of
dissolved oxygen per volume of water'.
17
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Oxygen should be monitored at dawn since concentrations are
usually lowest at this time because aquatic plants and animals have
been using it during darkness without replenishment. Sunlight permits
photosynthetic aeration, and, also at dawn a slight wind usually occurs
physically mixing air with water at the water surface. Oxygen concen-
trations are highest at midafternoon and begin decreasing. Photosyn-
thesis does not occur during the night causing reduced oxygen levels from
plant and animal respiration. Oxygen depletions can take place most
readily during hot cloudy days with very little wind.
When fish show signs of distress and oxygen levels fall below 3
ppm, measures should be taken immediately to restore oxygen to the
water. One of the most common ways of supplying oxygenated water is
to remove the lower dead water from the pond bottom and add fresh water
high in oxygen to the surface. Pumps are used to aerate the water by
spraying it into the air or splashing it off boards or concrete. Mechan-
ical devices attempt to mix air with water or bubble air through perfo-
rated hoses located on the pond bottom, but these methods are quite
expens ive.
STOCKING
Prior to stocking any pond, all trash fish present should be
destroyed. A growing season of 180-210 days is usually required for
growing marketable size catfish. The spring months of March and April
are the most preferable stocking times since water temperatures are
increasing to the point where fingerlings start feeding immediately.
When there is a significant difference in water temperatures, it is
important to acclimate the fish when moving them from one impoundment
to another.
Fingerlings for stocking should be carefully selected according
to uniformity of size, health conditions, and reputation of fingerling
producer. Uniformity in size at stocking results in equal competition
for food and better feed utilization. Also, a uniform harvest of
18
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marketable-sized fish is achieved. Fingerlings which are 4-6 inches
in length are preferable for stocking. Catfish fingerlings should be
obtained only from reliable sources where treatments are provided for
diseases and parasites. Treatment again at stocking time is desirable.
The preferred rate of stocking open growing ponds without aeration
ranges between 1,500 and 2,500 fingerlings per surface acre of water.
The beginning fish culturist should not stock more than 1,500 fish per
acre because higher stocking rates tend to decrease water quality, in-
crease disease problems, and give less efficiency in feed conversion.
At this stocking rate for a 210-day growing season, fish will average
1.25 pounds at harvest. As the culturist gains experience a stocking
rate of 2,000 per acre will yield more total pounds per acre but each
fish will be smaller (about 1 pound). Stocking rates of 3,000-4,000
per acre are possible where there is adequate controlled flow through
the pond or if aeration is provided.
The stocking density for flowing raceways should not exceed one
pound of fish per 2 cubic feet af water at a flow rate of 530 gallons
per minute. For a raceway unit 100 feet long, 10-foot bottom width,
1:1 side slopes, and a water depth range of 2-4 feet, the approximate
volume of storage ts 4,000 cubic feet. Therefore, 2,000 fingerlings
stocked in this unit and fed properly for 210 days should yield 2,000
pounds of marketable-size fish. Cages can normally support 10 pounds
or more of fish per cubic foot of enclosed water. The production
potential of cage culture is approximately the same as that of open
pond culture (1,500-2,000 pounds per surface acre).
FEEDS AND FEEDING
Catfish grown on fish farms are placed in ponds at high population.
densities, thus making the supply of food naturally available inadequate
to meet the needs of the fish. Sufficient protein in the form of supple-
mental feeding of commercially prepared feed rations must be supplied.
Good growth is obtained when catfish are fed diets containing 28-3270
19
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protein. Common sources of protein from both plant and animal origin
are fish meal, corn gluten meal, soybean meal, feather meal, blood
meal, and poultry by-product meal. The amount of fish meal used in a
feed ration should not exceed 127., as larger amounts may cause excessive
accumulation of fat and strong flavors in fish. Raceway and cage cul-
ture requires more nutritionally complete feeds containing about 3670
protein. A vitamin premix, when added to commercial rations, may
improve catfish growth by as much as 15%.
Many fish culturists prefer floating feeds, because they can readily
observe the amount of feed being utilized and can adjust feeding rates
accordingly. Floating feeds cost about 10% more than sinking feeds but
permit better feed utilization and less wasted feed. Catfish are
usually fed by hand, by mechanical blower-feeders, or by self feeders
or demand feeders. If fed by hand, fish should be fed at the same time
and location each day and in shallow water along entire sides of ponds.
Catfish can cause the release of feed from demand feeders by bumping
trigger mechanisms when hungry. Advantages of self feeders include an
avoidance of overfeeding and a reduction in labor. A disadvantage in
some cases is reluctance of the channel catfish to adapt to self-feed-
ing thereby failing to achieve optimum growth due to insufficient feed.
Overfeeding wastes feed and increases the chances of oxygen deple-
tion. Catfish should be fed only what they will consume in 15-20 minutes
and should never be fed more than 35 pounds of feed per surface acre
per day in a stillwater pond. Feeding in raceway units should not exceed
one pound of feed per 100 cubic feet of water per day at a flow rate
of 530 gallons per minute. Catfish consume the most feed and make the
best gains when the water temperature is between 70 and 90°F. Within
this temperature range the fish are fed at the rate of 2.5%-3.5% of
their body weight daily with the proportion decreasing as the fish gTow
larger in size. Samples of fish should be seined and accurately
weighed regularly to determine the amount of feed to be fed. Catfish
should be fed every day in the early morning and late afternoon during
20
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warm weather and only in the late afternoon during cool weather. When
the water temperature falls below 60°F, catfish feed sparingly and
should be fed only on warm days once or twice per week at a rate not
more than 0.57» of their body weight. The rate of feeding may also be
reduced during unusually warm weather, rainy days, or when plankton
bloom is heavy.
The feed conversion ratio refers to the amount of feed required
to produce one pound of fish. Since pond waters provide a limited
amount of natural food an incomplete ration is generally fed to cat-
fish of this culture with an average feed conversion of 2.0:1. More
intensive culture systems (raceway and cage) require nutritionally
complete rations with a 1.5:1 feed conversion. Feed utilization depends
to a large extent on management practices.
DISEASES AND PARASITES
The intensive culture of catfish tends to enhance the incidence
and spread of fish diseases and parasites. The best chance of avoid-
ing a disease problem is by stocking properly treated fish that are
free of diseases. Stress caused by low oxygen, high temperature,
malnutrition, excessive handling, and poor water quality are major
causes of fish diseases. Diseased catfish show a number of symptoms
such as changes from normal behavior, reduced vitality, failure to
consume feed, lesions, and death. The most common bacteria -diseases
are hemorrhagic septicemia, columnaris (saddleback) disease, gill
disease, and fin and tail rot. The channel catfish virus disease is
highly infective and contagious. There is no known treatment for this
disease and the only methods of control are isolation and sanitary
measures designed to prevent further spread. Fungus infections are
usually secondary, taking place in necrotic tissue associated with
injuries or other diseases.
The losses due to parasites in food fish production are usually
not as great as with diseases, except with "Ich" disease. More channel
21
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catfish die because of Ichthyophtirius multifilis (Ich) than all
other diseases combined. Other important protozoan parasites
especially troublesome in raceways are Trichodian, Scyphidia,
Trichophrya, Chilodonella, Costia, and gill worms.
Prevention is the best treatment for disease problems. Many
authorities recommend prophylactic treatments monthly or bi-monthly
to prevent serious outbreaks. Before any treatment can be considered,
a thorough knowledge of the water chemistry, fish, disease, and treat-
ment agent is essential since interactions can produce unwanted effects
When a problem is suspected, the fish culturist should get the advice
of a fisheries consultant on the type of dis-ease and administration
of treatment.
HARVESTING.
For complete fish harvest, the only effective method available is
seining. Seining can be done in ponds up to 8 feet deep without de-
watering or can be combined with pond drainage. Draining water from
ponds so that the catfish are concentrated in a small area or catch
basin is a widely used practice for small operations and in ponds that
cannot be drag seined because of obstructions and hangs. Small seins
and dip nets are then used to remove the fish from the pond for trans-
port. Draining usually produces a higher percentage of the fish than
other methods, but it also presents some disadvantages. The major
disadvantage is that water is wasted necessitating a rather rapid
and costly refilling operation with good quality water. Pumping
costs for water range between $3 and $15 per acre-foot, thus to fill
a 10-acre pond to a depth of 4 feet would cost between $120 and $600.
Crowding the fish into a small area for seining increases the danger
of oxygen depletion.
In large operations where the costs of drainage are prohibitive,
large seines are used to drag the entire pond without water drawdown.
Seines are made of 1 inch bar mesh nylon material with floats located
22
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at the top and weights at the bottom to keep the seine upright. Seines
are normally 10 feet wide and in 200-foot sections. Usually about three
feet of seine is required for every 2 feet of pond width. In larger
ponds seines are usually pulled by mechanical equipment to the collec-
tion area. Fish are dipped from the collection area into brailing
baskets and lifted by a powered boom into hauling trucks. Mechanical
harvesting by seining reduces labor requirements, conserves water, and
eliminates the danger of oxygen depletion due to overcrowding. Complete
harvest usually is not achieved, however, since 15-3070 of the fish may
escape seining.
Movement of fish over long distance requires good hauling facilities
and good handling techniques. Truck-mounted tank compartments equipped
with agitators or aerators generally permit the transport of up to 8
pounds of 1-2 pound fish per gallon of water at 65°F. Fish should not
be fed for 24 hours before handling and transport to prevent a buildup
of fecal material and wasted feed in the transport water. At lower
temperatures more fish can be hauled successfully, and usually short-
distance transport would require only the placement of fish on ice.
23
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SECTION V
CATFISH WASTES AND WASTEWATER QUALITY
In properly managed ponds, wastes are diluted and gradually reduced
to harmless materials or cycled back into phytoplankton or other plant
or animal life. However, organic materials may build up faster than
they can be reduced due to overfeeding or crowding and eventually lead
to oxygen depletion. Feed should not be fed in amounts more than the
fish can clean up or more than the pond can assimilate. If the oxygen
supply problems are overcome, the next limiting factor will likely be
metabolic wastes. Ammonia, hydrogen sulfide, and to a lesser extent
carbon dioxide, are directly toxic to fish.
In open flowing water systems, wastes are flushed out with the
waste water. These systems require large volumes of water and will
subject the downstream environment to a pollutional loading. However,
a continuous water supply may not be available, or the economic utili-
zation of water and nutrients in water may demand that the water not
be wasted. Closed system recirculation and/or biofiltration minimizes
both the amount of water used and downstream pollution. In most exist-
ing closed raceway systems large reservoirs are utilized to assimilate
wastes retained within the system and reduced them to harmless products.
Closed tank and cage culture systems employ mechanical and biological
filtration to break down nitrogenous products such as ammonia. Filtra-
tion, however, is an area that is open for development.
PRODUCTION OF METABOLIC WASTES
Murphy and Lipper (1970) determined the solid waste and BOD pro-
duction of two adult channel catfish each weighing approximately 1,840
grams and maintained in a 250-gallon recirculating tank under controlled
conditions. They found that the channel catfish produced 4.9 grams BOD
and 92 milliliters solids per kilogram live weight per day. These wastes
occurred in two forms: a soluble form comprising 58% of the total
waste BOD and a flocculate that settles readily in still water com-
prising the remaining 42% of the total. Compared with commercial
24
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animals, they found channel catfish waste to have about one and one-
half times the pollution potential of poultry and swine wastes and
about five times that of beef cattle on a per-kilogram live-weight basis.
Harris (1972) conducted a laboratory investigation to determine the
levels of BOD and oxygen utilization, ammonia, and suspended solids
produced by catfish in a single pass tank system. Four plywood tanks
8 feet long by 20 inches wide by 14 inches deep were stocked with
approximately 25 pounds of channel catfish each. The fish had an
average weight of 150 grams. The fish were fed 1% of their body weight
per day for seven days and then 2% for seven days.
At the 1% feeding rate the suspended solids production was 0.35 Ibs/
100 Ibs. fish/day on a fish weight basis or 0.36 Ibs/lb. food/day on a
fish food weight basis. The 2% feeding rate resulted in a suspended
solids production of 0.801bs/100 Ibs. fish/day or 0.41 Ibs./lb. food/day.
The suspended solids production peaked approximately 4-6 hours after
each feeding period.
BOD production at the 1% feeding rate was 0.40 Ibs./lOO Ibs fish/
day or 0.40 Ibs/lb. food/day. At the 2% rate 0.91 Ibs BOD/100 Ibs fish
or 0.46 Ibs BOD/lb food were produced per day. It was found that any
"uneaten food exerts the same BOD per pound as the fecal material but
with no resultant weight gain to the fish and no reduction through fish
metabolism.
Ammonia nitrogen was produced at the rate of 0.019 lbs/100 Ibs fish/
day or 0.019 Ibs/lb food/day at the 1% feeding rate while at the 2% rate
0.024 lbs.NH3-N/lOO Ibs fish or 0.013 Ibs NH3~N/lb food were produced
per day. Harris concluded that the waste parameters measured per pound
of fish food were independent of the feeding rate. More emphasis should
be placed on the mas,s balance concept of determining the pollutional
potential of a fish production system.
25
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In a recent study, Page and Andrews (1973) analyzed effluents from
high density tank culture of channel catfish to determine the production
of metabolic wastes by catfish. Duplicate sets of tanks containing
3.0 cubic meters (793 gallons) of water each were stocked with 160 large
catfish and 1,200 small catfish averaging 940 grams and 60 grams,
respectively. The daily BOD production rate was determined to be 3.5
grams per kilogram fish for 60-gram fish and 1.1 gram per kilogram for
940-gram fish. These values are lower than that reported by Murphy and
Lipper (1970). This difference is probably due to the fact that Murphy
and Lipper's work was restricted to only two fish under laboratory
conditions, whereas, this study was performed under simulated commercial-
type high density conditions.
When the data from Page and Andrews' study were expressed as grams
waste product per day per kilogram fish, production rates in most cases
were higher for 60-gram fish than for 940-gram fish. When results
were expressed as grams waste product per day per kilogram feed, produc-
tion rates approached the same value for both size fish. These
observations tend to support the belief that the quantity of metabolic
waste products is directly proportional to the amount of food eaten
and inversely proportional to the size of fish. Average values (grams
per day per kilogram feed) for both size fish were as follows:
Ammonia Nitrogen (as N) 20
Nitrate Nitrogen (as N) 100
Nitrite Nitrogen (as N) 1
BOD 98
Total Solids 180
Total Nitrogen (as N) 67
Total Phosphorus (as P) 15
Total Potassium 18
26
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The production of solid wastes was dependent on feeding time with the
highest production immediately following feeding. BOD, ammonia, and
nitrate levels peaked only in late afternoon approximately 6-8 hours
after feeding. The solids contained relatively high levels of nitro-
gen and phosphorus while most of the potassium was in the filtered
water.
CATFISH EFFLUENT WATER QUALITY
Very little information is available on the discharge water from
intensive culture of catfish. Such data would be useful in determining
the effect of effluents from commercial catfish production units on
stream water quality and in the design of wastewater treatment systems.
The available effluent water quality data along with the results of this
study are presented in Table 1.
In 1970 the Soil conservation Service and the University of Georgia
Agricultural Experiment Station cooperated in a joint field trial to
determine the effects of production of channel catfish in earthen race-
ways upon dissolved oxygen, temperature, pH, carbon dioxide, BOD, total
hardness, nitrates, and water turbidity. The study was made on three
catfish farms with closed raceway systems ranging from 17-25 units per
raceway. The method of aeration was water pouring over the top of the
control weir, falling one foot, and splashing on a board the length of
the weir. Chapman et al. (1971) reported the results of this study
and indicated that the present recommended level of stocking (one-
half pound fish per cubic foot of water) did not overtax the raceway
systems' ability to maintain desired oxygen levels. Raceways where
sinking feed was fed had 15 inches of waste deposited in the lower
ends of ,the units at harvest. These raceways exhibited the poorest
water and fish quality, slowest rate of fish growth, and highest
plankton fertility. Where floating feeds were fed, only three inches
of waste were deposited in the lower ends of the raceway units.
27
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ro
CO
Table 1.
WATER QUALITY
^
Fish Density
Dissolved Oxygen
BOD
COD
KJaldahl Nitrogen
Organic Nitrogen
Annonla Nitrogen
Nltrate+Nitrlte-N
total Solids'
Dissolved Solids
Volatile Solids
Suspended Solids
Settleable Solids
Total Carbon
Dissolved Carbon
Carbon Dioxide
Total Phosphorus
Orthophosphate
Turbidity
pH
Hardness
Alkalinity
Chlorides
Water Temp.*F
Total Collform
Fecal Collform
Barker
"et.al.
T974
Tond
"Tjpen
0.0097
6.4
33.
8.21
7.44
0.77
0.12
140.
78.
80.
63.
44.
0.'24*
0.08
7.4
64.0
14.1
Beasley
& Allen
1973
Pond
Open
0.014
6.5
55.
0.09
1.27
275.
134.
56.
0.17
8.2
3300
2.0
Greene Greene
1969 1968
Pond Pond
Closed Closed
Filtered Filtered
0.038 0.024
4.2 7.5
14.2 7.85
13.3 7.40
0.92 0.45
0.63
87.7 91.8
33.8 41.1
•
29.2 22.4
7.7
78.9
Barker Allen Harris Chapman Parker Broussard Murphy Murphy
et.al. et.al. & Simco et.al. & Llpper Llpper
1974 1974 1972 1971 1973 1973 197J2 1970
Raceway Raceway Raceway Raceway Raceway Tank Tank Tank
Closed Closed Open Closed Closed Closed Closed Closed
OxPond OxPond OxPond Filtered Filtered Filtered
0.34 3.0 1.9 0.37 7.2 3.1
7.3 5.2 4.4 6.1 7.2 5.0
7.0 5.9 8.0 10.1
37.
9.28
8.66
0.62 0.43 0.25 1.00 1.50
0.24 0.29 2.16
165.
98.
84.
69. 29.
48.
17.4 1.0 32.0
0.76
0.11
43.4 19.1
7.2 7.1 6.9 8.7 7.0
44.2 27.7 162.
31.5
12.2
82. 73. 81. 71.
32900
3.1 0.24
5.6 6.3
rj.i 19.1
0.62 0.30
1.10 1.46
29.4 26.2
6.8 7.2
80. 75.
(a) All parameter units are in mg/1 except coliform and turbidity
(b) Number of marketable-size fish per ft. of water
(c) Jackson Turbidity Units
(d) Number of bacteria colonies per 100 ml of sample
-------
Indications were that closed systems with storage capacities less than
one acre-foot of water for every 4,500 cubic feet within the raceway
reached high fertility and algae buildup early in the growing seasons.
Where supply reservoirs were fertilized and/or stocked with fish, poor
water quality resulted.
Beasley and Allen (1973) analyzed water samples collected from
several catfish ponds in both the Mississippi and Arkansas Delta areas
for chemical, biochemical, and physical characteristics. The ponds
ranged in size from 10-40 acres, and the stocking rates included 1,800,
2,000 and 3,000 catfish per acre. Samples were collected prior to
harvesting and draining periods. They found that the pond water quality
usually met or exceeded standards set forth for recreational waters by
the Mississippi Air and Water Pollution Control Commission. The few
exceptions occurred when the pH exceeded the allowable standard of 8.5
or when there was high turbidity caused by heavy algae blooms or muddy
water. There was almost a total absence of fecal coliform bacteria
which would indicate no sewage pollution. Most of the coliform bacteria
present were probably soil bacteria. Ponds stocked at higher rates
usually had slightly higher levels of BOD, nutrients, and total solids.
Samples collected near the bottoms of ponds exhibited slightly higher
parameter concentrations than those taken at the surface.
Boyd (1973), Department of Fisheries and Allied Aquaculture at
Auburn University, evaluated the contribution of phytoplankton, to the
COD of pond waters and the amount of oxygen required ±o completely
decompose various organisms. Thirteen of the ponds investigated received
daily applications of fish feeds, 11 received inorganic fertilization,
and two received no nutrient addition. In the ponds which received
applications of feed, plant production within the pond was the major
source of COD. Water samples contained fairly unialgal blooms of
green or blue-green algae, blooms containing several species of green
-------
algae, and mixed-species phytoplankton communities of low density.
The COD of high protein content fish feeds was similar to that of
phytoplankton. The soluble organic matter in pond waters had an
average COD of 19.9 mg/liter.
Allen (1974), Fisheries Biologist at Fish Farming Experiment
Station near Stuttgart, Arkansas, studied the effects of stocking
size and rate on the growth of channel catfish using mini-raceways
approximately 9 feet long, 1.5 feet wide, and 0.75 foot deep. Each
raceway unit had an approximate water inflow of 6 gallons per minute
which was recycled through three acres of ponds and back into the
raceways. Raceway containers were stocked with 2-4 pounds of catfish
per cubic foot of water. Lower stocking rates and stocking larger-
sized fish yielded larger fish at harvest. Water quality data
showed that orthophosphate and pH were negatively correlated with
standing fish crop, and total coliform bacteria and alkalinity were
positively correlated. Maximum BOD added to the environment was 1 kg
per 100 kg of fish per day.
BIOLOGICAL FILTRATION
Green (1970), in an experiment at Auburn University, investigated
the use of biofilters, settling basins, and aeration for renovating
wastewater from recirculating catfish culture systems. Replicate
rectangular concrete ponds with capacities of 4,080 gallons were stocked
with 2,000 pounds per acre (low rate) and 4,000 pounds per acre (high
rate) of catfish. Each pond had a filter with a surface area of 15
square feet filled with 2"-4" gravel to a depth of 4 feet. Water was
pumped from the pond and sprayed continuously over the gravel at the
rate of 650 gallons per hour. In a biofilter, or trickling filter, the
wastewater is sprayed over filter media that is coated with a living
film of aerobic microorganisms actively feeding upon and oxidizing the
organic matter and ammonia in the water. Recirculation and biofiltra-
tion of the water in fish ponds yielded a net production of over 19,300
30
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pounds per acre with channel catfish and white catfish responding
similarly. Filtration improved the water quality in the pond by
reducing the levels of ammonia, organic carbon, nitrate, and tur-
bidity, and possibly increasing dissolved oxygen. At the high stock-
ing rate, a settling basin in series with the filter had no effect on
the fish production, but it did cause a 20% increase in production at
the low stocking rate.
Three types of biofilters in a recirculating-water fish production
system were compared by Murphy and Lipper (1971). Wastewater passed
through rock filters, settled in rectangular sedimentation tanks, and
percolated through sand filters before returning to a common reservoir.
Flow rates through the filtering systems were approximately 3.3 gal-
lons per minute. Average fish density was 103 pounds of fish per 250-
gallon tank.
The filter material providing the best substrate for the decrease
of BOD and conversion of ammonia to nitrates was the one-half-inch
rock according to Murphy and Lipper's results. Sand percolation removed
a high percentage of BOD while the filter was building up to a stable
bacterial population. However, it soon became a trap for dead bacterial
masses which added pollutional load on the system and could only be
removed by backwashing. The one-half-inch rock biofilter was self-
cleaning in that it had large enough voids to allow bacterial masses
to be washed through without additional backwashing. Problems encoun-
tered included a high ammonia concentration which developed due to a
i
collapse of the bacteria population in the biofilters. Subsequent
investigation revealed that the bacteria normally present on the rock
surfaces had been devoured by the larvae of the common "filter fly".
A solution to this problem was to completely submerge the biofilters
which worked.satisfactorily until another buildup of ammonia caused
another major fish kill. The submerged biofilter had trapped the
solids in the rocks, and excess ammonia resulted from the breakdown of
the solids. Larger rocks would have prevented this problem. Based on
the results of their study, Murphy and Lipper suggested that a
31
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biofilter operating under a normal fish load should maintain the
water at about 0.5 mg/1 ammonia nitrogen, 5 mg/1 dissolved oxygen,
1.1 mg/1 nitrate nitrogen, 20 mg/1 carbon dioxide, and 15 mg/1 BOD.
Fish densities in excess of 7 pounds per cubic foot of water
have been obtained by Parker and Simco (1973) in recirculating systems
employing biological filters, settling chambers, and foam strippers.
Fish survival during the 142-day study was more than 99% with a net
gain of 318 pounds and a standing crop density of 7.2 pounds per
\
cubic foot. Average food conversion for the growing period was 1.75.
Parker and Simco concluded that the simplest and least expensive
method of solids removal was sedimentation. A mechanically cleaned
settling chamber with large internal surface areas separated by weirs
allowed for the progressive removal of solids from the water. Nitrogen
levels decreased as water passed through the filter since biofilters
can detoxify ammonia through the nitrogen cycle first to nitrites and
then to nitrates in the presence of oxygen. Dissolved oxygen levels
decreased as water passed through the updraft filter but increased after
passing through the trickling filters.
Final clarifiers removed particulate matter and extended the life
of the biofilters. The addition of foam strippers for the removal of
foam caused by vigorous agitation of water high in organic matter con-
tent reduced the BOD load in the system. Water exchange rates of 6-7
minutes per tank maintained adequate water quality, but lower rates
allowed waste metabolites to accumulate. In any recirculating system
water quality is controlled by the fresh water inflow or exchange rate,
the flow rate per tank, and the filter size.
Andrews et al. (1970) investigated two pilot model culture systems
at Skidaway Institute of Oceanography. A rectangular concrete block
culture pool had a total volume of 164 cubic feet. Water from this
tank circulated through two rock and gravel filters having a combined
filter area of 25 square feet. These filters were replaced during the
32
-------
study with a B. F. Goodrich PVC artificial media filter containing a
settling basin. The systems were initially stocked at a density of
10 channel catfish per cubic foot of water with an average weight of
276 grams each. After the gravel filter' became functional, a filtra-
tion rate of one gallon per minute per square foot of filter area was
maintained.
Experimental results of Skidaway Institute indicated that although
aerated water was added to the top of the gravel and oyster shell fil-
ters, conditions became anaerobic near the bottom and ammonia was pro-
duced rather than removed. It was necessary to remove the solids before
addition of the wastewater to the filters and to continuously inject
air into the bottom of the filters to keep the system aerobic. The
artificial media filtration system offered several advantages over the
gravel system. At high ammonia levels the artificial media filter was
more efficient for removing ammonia than the gravel type- The arti-
ficial media was much easier to clean requiring less water, however,
daily backflushing was still recommended. The most important advan-
tage of the artificial media filter system was its reliability.
Researchers at Skidaway determined that 1.0 ppm ammonia is a level
that is acceptable for catfish culture, and a commercial recirculating
system should be designed with this in mind. At 1.0 ppm ammonia in the
system, the artificial filter media will remove ammonia at a rate suf-
ficient to accommodate 40 pounds of fish per square foot of filter area
based on data which indicate the channel catfish produce approximately
0.1 mg ammonia per minute per pound of fish. Results from other studies
indicated that about 5 pounds of fish per cubic foot of water was the
maximum practical stocking density of intensive culture of catfish.
Assuming a culture pool depth of 4 feet, 5 pounds of fish per cubic
foot of water, and a filter system approximately 5 feet deep, the ratio
of filter to pool on a surface area basis should be 0.5:1 Supplemental
aeration will be needed in the system to maintain a minimum dissolved
33
-------
oxygen level of 5 ppm.
The prototype for an environmentally controlled closed loop
catfish production system was designed and constructed by Hall (1972)
and associates at Macomb, Illinois. Steel tanks stacked five high
inside an insulated building provided fish with a constant fresh
water supply. A sand filter removes solid wastes which are back-
flushed to a septic tank where they are anaerobically biodegraded
before being conveyed to an aerobic lagoon outside the building. A
limestone-filled biofilter removes soluble wastes from the circulated
water. The unit has proved that fish can be successfully grown in a
closed-loop confinement system.
Harry Dupree (1972) conducted research in 5-foot diameter fiber-
glass raceway tanks. Water for the tanks was obtained from a screened
box located in a 4-acre earthen pond adjacent to the tank site. To
remove waste materials, and to retard the large fluctuations in water
temperature and pH, the pond was permitted to grow up with native
forms of rooted and submerged vegetations including hyacinths, paspalm,
smartweed, and Najas. Water was pumped from the screened box and
jetted through various si.zed orifices into each tank before draining
back into the pond. The earthen oxidation pond proved satisfactory
for waste removal in a closed catfish production system.
The effect of water hyacinth on water quality and subsequent plant
production in conjunction with fish culture was pursued by Wahlquist
(1972). Nine 0.1 acre ponds were stocked with water hyacinths and nine
ponds without plants served as controls. The water hyacinths were con-
2
fined within floating wooden rafts (495 ft ) covering 11.3% of the
pond.'s total surface area. Data presented in the study indicated that
the plants did not create water quality parameters that were detri-
mental to the fish.
The South Carolina Agricultural Experiment Station at Clems on '
University conducted similar experiments with Chinese water chest-
nuts as a means of increasing production of pond-raised catfish.
34
-------
Chinese water chestnut corms were planted in rafts filled with ver-
miculite and floated near the surface of pools in which channel
catfish were fed from March through October. The plants grew well and
mature corms were produced by September with an average production of
2,835 pounds per acre. Average production of channel catfish was 1,100
pounds per acre in control pools and 1,740 pounds per acre in pools
with water chestnuts.
35
-------
SECTION VI
RESEARCH METHODS AND FACILITIES
The commercial catfish installations selected for this study
included four ponds located in the Coastal Plains area of south
Georgia. Three of these ponds produced food-fish and were harvested
by drawdown and seining. The fourth pond contained several pairs of
broodfish used for spawning. In addition, two flowing water earthen
raceway systems located in central and south Georgia were selected
for study. All installations were stocked with channel catfish
fingerlings and produced crops of marketable size fish in one growing
season. These six installations were chosen because they represent
a diversity of production levels, feeding programs, and operational
practices.
POND DESCRIPTIONS
Table 2 provides a physical description of the commercial cat-
fish production ponds used in this study.
Pond GK was rectangular shaped and stocked with 36 pairs of brood
fish. This pond was used for spawning and fingerling production
utilizing demand type feeders. Samples were collected from the pond
during the growing season to compare the water quality parameter con-
centrations with those of food fish production ponds.
Pond C was a 4-acre production pond located below three
smaller food fish ponds (all in series) which drained into it. The
smaller ponds (which were not sampled) had a combined surface area of
3.5 acres and a total water volume of 7.5 acre-foot. The large pond
(C)was stocked January 1, 1973 with 8,000 channel catfish fingerlings
approximately 6 inches in length. The pond was irregular in shape and
had an effective water depth of 4-6 feet. The ponds were filled by
introducing well water into the initial small pond of the series and
successfully filling each of the subsequent ponds. After the initial
filling, only enough fresh water was added to the ponds during the
36
-------
Table 2. POND DESCRIPTIONS
Sample Sample
No. Collection
Point
GKS Surface
GKB Bottom
CS Surface
CB Bottom
BS Surface
BB Bottom
WS Surface
WB Bottom
Pond
Location
(Ga.)
Quitman
Morven
Sylvester
Rochelle
Surface
Area
(acres)
1.25
4
10
10
Effective
Depth
(ft.)
5
5
6
8
Volume
of Water
(ac.-ft.)
5
15
36
48
Stocking
Rate
(no. fish
per acre)
30 prs.
2000
1600
1800
-------
growing season to offset evaporation and seepage losses. One serious
oxygen depletion during the summer killed about 2,000 fish in Pond C.
Emergency aeration was achieved by spraying water from the pond into
the air with a tractor-driven irrigation pump. Feed was introduced
through demand type feeders.
Pond B was a new pond in its second year of catfish production with
a surface area of 10 acres. The pond surface was triangular in shape,
and the water depth ranged from 3-8 feet. Well water was used to fill
the pond and maintain the water level. Pond B was stocked with 16,000
channel catfish fingerlings on April 1, 1973. A massive fingerling
kill occurred soon after stocking, most probably due to stresses
incurred during stocking and the lack of medicated feeding. This
occurrence emphasizes the importance of purchasing fingerlings from
a reliable source where treatments for parasites and diseases have
been provided. Another loss of fish through an unscreened emergency
spillway occurred early in the season during a period of heavy rainfall.
The extent of the losses was not known until harvest, but due to the
lack of feed being consumed from the demand feeders, it was suspected
that the majority of the fish had either died or been washed out the
spillway.
Pond W was a 10-acre food fish pond which has been in production
several years. It was the deepest pond of the study with a depth
range of 5-12 feet. The grower believes that the added depth is needed
to effectively assimilate wastes from the catfish- Water from a nearby
well was used for filling and water level maintenance. The pond was
stocked April 1, 1973 with 18,000 channel catfish fingerlings.
RACEWAY DESCRIPTIONS
Table 3 presents a summarized description of the flowing water
earthen raceway systems used in this study. Raceways EG, EF, and ED
were part of a large commercial catfish production facility located
in central Georgia. A line diagram and flow chart for the system is
38
-------
Table 3. RACEWAY DESCRIPTIONS
vo
Sample
No.
EG1
EG8
EF1
EF11
EDI
ED17
TR1
TR8
Sample
Collection
Point
Inf luent
Effluent
Inf luent
Effluent
Influent
Effluent
Influent
Effluent
Raceway
Location
(Ga.)
Mayfield
Mayfield
Mayfield
T if ton
No. of
100-ft
units
7
10
16
8
Effective
Depth
(ft.)
4
4
k
3
Volune of Water
Per
100-ft.
unit
(ft.3)
5600
5600
5600
4800
Total
System
(ac-ft)
30.6
31.0
65.5
21.0
Flow
Rate
(gpm)
350
350
350
530
Stocking
Rate
(no.
fish
per
unit)
2000
2000
1500
2250
-------
shown in Figure 1. The operation is corporation-controlled and con-
sists of its own brood ponds, hatchery, fingerling ponds, food fish
production units, and processing plant. The semi-closed-loop system
utilizes supply reservoirs to furnish water to the raceways and oxi-
dation ponds to store the raceway effluents for recirculation. The
system is not completely closed since periodically a portion of the
wastewater is released to an adjoining stream and replenished by fresh
water from upstream.
A 9.5-acre-foot reservoir supplies water to two 7-unit (EG) and
six 10-unit raceways (EF) at the rate of 350 gpm per raceway. Each
raceway unit is 100 feet long, 10 feet wide, 4 feet deep, and has a
1:1 sides lope. Each unit has an approximate water holding capacity
of 5,600 cubic feet and a hydraulic detention time of two hours. Water
aeration is achieved by an 18-inch waterfall between each unit. Some
weirs have conventional splash boards with bottom-water take-off sleeves
installed. The effluent from these raceways is collected by a 20.2
acre-foot oxidation pond where it has a 1.6-day detention time before
being pumped back to the supply reservoir for recirculation. Each
unit of Raceways EG and EF were stocked April 1, 1974 with 2,000 five-
inch channel catfish fingerlings.
A 16.5-acre-foot reservoir supplies water to eight 16-unit raceways
(ED) at a flow rate of 350 gpm. The units were identical to those in
the 7 and 10-unit raceways except that each unit was stocked with 1,500
fingerlings. The effluent was collected by a 47 acre-foot oxidation
pond where it had a detention time of 3.8 days before being returned
to the supply reservoir.
No rigid schedule was adhered to for replacing the recirculating
water with fresh water, however, it was estimated that one quarter of
the total system capacity was replaced at a frequency of once every
i
two weeks. Therefore, the entire system water capacity would be
exchanged once every two months.
40
-------
Pump Location
* Sampling Location
Figure 1. Flow diagram for Raceway System E
4.1
-------
Aa experimental raceway system (TR) was put into catfish pro-
duction in the summer of 1971 at the University of Georgia Coastal
Plains Experiment Station, Tifton, Georgia. The raceway (Figure 2)
is a closed-loop recirculation system with a very minimum of over-
flow (from watershed) being discharged to the waterway below the
system. Water from a nearby 600-gpm well is used to maintain the
water level in the system reservoir which serves as a source of
recirculating water and as an effluent collector for waste assimila-
tion.
The system reservoir has a surface area of 5 acres and a water
holding capacity of 20 acre-feet. This provides an 8.5-day hydraulic
detention time for a 530-gptn raceway pumping rate. The raceway is
an earthen channel with a bottom slope of 1.5 percent divided into
8 units. Each unit has a 100-foot length, 10-foot bottom width, 3-foot
depth, and 2:1 sides lopes. The units have a water holding capacity of
4,800 cubic feet and a hydraulic detention time of slightly more than
one hour. Water from the reservoir is pumped into the initial unit
through a 12-foot high corrugated metal riser pipe fitted with three
aeration collars. Each raceway unit is separated by a concrete head-
wall provided with a weir over-flow notch. Affixed to the downstream
side of each headwall is a transversely corrugated inclined plane
aerator. A bottom-water take-off sleeve is attached to the upstream
side of each headwall to force water with the lowest dissolved oxygen
concentration at the channel bottom to flow up and over the weir and
aerator. The raceway was stocked April 1, 1974 with an average of
2,250 eight-inch channel catfish fingerlings per unit.
WATER QUALITY MEASUREMENTS
Water quality samples were collected from the surface and near the
bottom of each pond on the average of every three weeks during the
growing season. These samples were "grab" samples collected near mid-
day from two to four locations (horizontal) over the pond. The
42
-------
RACEWAY SYSTEM 1
VALVE & METER
\\X\\\\\\\\\\\\\\\\\\\ \\Vv\\\\\\\\\\
Figure 2. Flow diagram for Raceway System TR
-------
composite samples (comprising the grab samples) were stored in poly-
propylene gallon jugs and "iced down" for transportation back to the
laboratory. At harvest time composite samples were obtained during
pond drawdown. All samples were analyzed within 72 hours after col-
lection.
Raceway influent and effluent composite samples were collected
and analyzed on a bi-weekly basis. Additional samples over a 24-hour
period were also taken to determine if diurnal changes in the effluent
composition occurred. Dissolved oxygen and water temperatures were
measured at the raceway sampling points using a YSI Model 51A Oxygen
Meter.
Samples were analyzed at the Agricultural Engineering Center
Laboratory for BOD, COD, total Kjeldahl nitrogen, ammonia nitrogen,
nitrate nitrogen, complete residue analysis, total and orthophos-
phate, pH, total hardness, and chlorides. Analysis was according
to procedures outlined in Methods for Chemical Analysis of Water and
Wastes (1971) and Standard Methods for the Examination of Water and
Wastewater (1971).
The numbers and total weights of the fish at stocking and at
harvest were recorded for each pond and raceway. At the Tifton race-
way the average weight of the fish was determined weekly. The pounds
of feed fed at each installation during the growing season was also
recorded.
44
-------
SECTION VII
RESULTS
POND WATER QUALITY DURING GROWING SEASON
The basic water quality data collected during the growing
season in the ponds are presented in the Appendix. The water quality
parameter concentrations were converted from units of milligrams per
liter (mg/1) to pounds parameter per 100 pounds of fish for each
sampling date. Parameter concentrations were also calculated in
terms of pounds parameter per pound of feed fed on each sampling date.
Figures 3-13 graphically present the parameter concentrations in
pounds per 100 pounds of fish as a function of the fish density in
pounds of fish per acre-foot of water. The fish densities represent
the estimated standing weight of fish on each sampling date and in-
crease as the growing season progresses. Data presented are the mean
values (for bottom and surface) for five sampling dates for Pond C
and 6 sampling dates for Pond W covering the period from July 8, 1973
to November 9, 1973. Pond GK and Pond B were excluded from these
calculations since Pond GK was a brood pond and Pond B had so few
fish due to a massive fish kill early in the season. A linear
regression analysis was run to obtain the curve of best fit for the
plotted values. Correlation coefficients averaged 0.58 and ranged
from 0.20 to 0.81. The reader is reminded at this point that the
curves presented in Figures 3 through 24 should not be used for pre-
diction purposes. They are intended only to show possible trends
in parameter concentrations during the growing season.
The parameter concentrations expressed as milligrams per liter
generally increased during the growing season, however, when expressed
as pounds per 100 pounds fish, the concentrations decreased as fish
densities increased. This trend supports the belief that smaller fish
produce more metabolic waste products on a per-pound basis than do
larger fish. The exception to this trend was ammonia nitrogen which
45
-------
cn
0.62
300 400 500
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 3. BOD concentration as a function of standing fish density in ponds
600
-------
Q
©
©
l
300 400 500
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 4. COD concentration as a function of standing fish density in ponds
600
-------
9 . ..
S 7
in
<-> c
O; 6
o
o
D-
®
r = 0.81
rr-
©
200
300 400 500
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 5. Total Kjeldahl nitrogen concentration as a function of standing fish density in ponds
600
-------
1.0
.0.8
O
2 0.6
o
2 0.4
IP 0.2
200
®
©
0
O
300
r =0.21
400 500
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 6. Ammonia nitrogen concentration as a function of standing fish density in ponds
500
-------
0
r =0.76
0
300 400 500 600
POUNDS FISH ON HAND/ACRE-FOOT.WATER
Figure 7. Nitrite + nitrate-nitrogen concentration as a function of standing fish density in ponds
-------
en
CO
o
o
o
CO
to
o
Q.
150
130
no
90
70
_ ©
50 _
200
®
®
®
r =0.73
©
1
®
300 400 500 - 600
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 8. Total solids concentration as a function of standing fish density in ponds
-------
TOO
en
ro
O
CO
2
O
O
CO
3
Q.
80
60
40
20
©
0
©
0
O
0.71
i i . i I I I I L
200 300 400 500 600
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 9. Total volatile solids concentration as a function of standing fish density in ponds
-------
en
CO
100 _
80
©
©
r = 0.54
GO
Q
60
00
CO
to
20
®
G
©
©
200 300 400 500 600
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure LO. Total suspended solids concentration as a function of standing fish density In ponds
-------
100
ui
.£»
CO
o
Q.
o
o
co
LU
CO
CO
a
80
LI 60
©
40
20
®
0.46
©
200 300 400 500 600
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 11. Settleable solids concentration as a function of standing fish density in ponds
-------
en
0.25
0.20
§
£
z
o
DC
E 0.15
to
Q
z
8
Q.
O
O
^ 0.1
I 0.05
a.
©
®
€>
200 300 400 500
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 12. Total phosphate concentration as a function of standing fish density in ponds
600
-------
0.10
or
O.Ofi
o
0.06
O
CL.
O
O
O
°r
o
0.04
0.02
r = 0.69
200 300 400 500
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 13. Orthophosphate concentration as a function of standing fish density in ponds
600
-------
showed a slight increase in parameter concentrations as fish density
increased.
The mean and extreme parameter concentrations for Ponds C and W
are presented in Table 4. Average concentrations and average fish
weights for the sampling period from July 18, 1973 to November 9, 1973
were used to calculate the means and extremes. The BOD/COD ratio was
0.19 which compares favorably with that of livestock wastes. A residue
analysis revealed that approximately 62% of the total solids were
volatile, 52% were suspended, and 36% settled in one hour. Total
Kjeldahl nitrogen determinations indicated a ratio of 0.072 pounds
nitrogen per pound total solids. Approximately 92.4% of the total
Kjeldahl nitrogen was organic with the remaining 7.6% in the form of
ammonia nitrogen. It is difficult to explain the high percentage of
organic nitrogen although the same trend was observed by Greene
(Table 1) . Perhaps the abundant algae growth is a major contributor
to the high organic nitrogen values. Further analyses indicated 0.0009
pounds nitrate plus nitrite nitrogen per pound total solids. The pond
water contained approximately 0.002 pounds total phoephate per pound
of total solids. Approximately 26% of the total phosphate existed in
the form of orthophosphate.
Surface, Middepth, and Bottom Concentrations
Table 5 lists surface, mid-depth, and bottom water quality of Pond C
and Pond W for the sampling period of July 18, 1973 to November 9, 1973.
Bottom samples showed a 23% increase in organic parameter concentra-
tions when compared to surface samples. This increase was primarily
due to settling of metabolic waste products and uneaten feed. The
presence of algae in the surface layer of the ponds probably influenced
the COD and the solids concentrations. The total solids content of
the bottom samples increased by 35%, and the suspended and settleable
solids concentrations nearly doubled. This increase could again be
attributed to settling and bottom sediment disturbance by the fish.
The ammonia nitrogen concentrations of the bottom samples were nearly
57
-------
Table 4. POND C AND W RANGE AND MEAN CONCENTRATIONS1
cn
00
Parameter
BOD 5
COD
TKN
Utl U
ntiA B
urt 4. un -L w
nu^ ~ w-*_ T n
TS
TDS
TVS
TFS
TSS
Sett. S.
Total P
Ortho - PO,
PH
Hardness
Chloride
Parameter
Min
1.0
20.
2.47
0.
0.05
40."
18.
24.
14.
12.
3.
0.06
0.
6.9
5.
7.5
Concentration,
Mean
7.4
39.
9.26
0.77
0.12
132.
66.
81.
51.
66.
46.
0.24
0.07
7.3
53.
12.5
rng/1
Max
15.6
84.
17.58
2.99
0.39
242.
120.
145.
117.
157.
122.
0.55
0.35
8.1
90.
25.0
Ibs. Part
Min
0.91
11.2
1.79
0.
0.03
56.0
11.0
30.0
15.0
6.00
1.00
0.02
0.
6.9
7.00
5.44
imeter/100
Mean
5.77
30.0
6.93
0.53
0.09
97.0
47.0
60.0
37.0
50.0
35.0
0.180
0.048
7.3
36.0
9.16
Ibs. Fish
Max
13.8
63.8
13.4
1.83
0.100
184.
84.0
110.
75.0
111.
93.0
0.450
0.215
8.1
65.0
15.4
Iba . Pa rar
Mln
0.620
5.33
1.21
0.
0.018
29.0
5.00
17.0
7.00
3.00
0.500
0.010
0.
6.9
5.00
2.81
neter/lb.
Mean
3.36
17.6
3.96
0.310
0.050
56.0
27.0
34.0
22.0
29.0
20.0
0.100
0.028
7.3
21.0
5.35.
Feed
Max
9.30
35.3
7.09
0.970
0.090
101.
46.0
70.0
45.0
75.0
49.0
0.310
0.102
8.1
44.0
10.4
(a) Values are from five sampling dates in pond C and six in W.
(b) Sums of TVS + TFS and TDS + TSS do not necessarily equal TS for mln and max values since extremes were from
two different ponds.
(c) As CaCO,
-------
Table 5. POND C AND W; MEAN SURFACE, MIDDEPTH, AND BOTTOM CONCENTRATIONS
Parameter
BOD5
COD
TKN
NH3 - N
N03 + N02 - N
TS
TDS
TVS
TFS
TSS
Sett. S.
Total P
Ortho - PO.
4
PH
Hardness
Chloride
Concentrations ,
Surface
6.9'
35.
8.69
0.37
0.10
114.
67.
76.
38.
47.
34.
0.17
0.05
7.6
47. '
12.4
Mid depth
5.8
31.
7.86
0.72
0.09
116.
78.
77.
39.
38.
25.
0.18
0.06
7.5
45.
9.5
mg/1
Bottom
7.6
41.
10.53
1.15
0.12
145.
61.
90.
55.
84.
58.
0.33
0.10
7.0
51.
11.5
Ibs Parameter Per 100
Surface
5.66
27.9'
6.48
0.31
0.08
82.0
48.0
52.0
30.0
34.0
24.0'
0.14
0.03
7.6
35.0
9.68
Middepth
4.58
24.0
5.62
0.52
0.07
84.0
56.0
54.0
30.0
28.0
18.0
0.15
0.04
7.5
32.0
7.04
Ibs Fish
Bottom
5.88
32.2
7.38
0.75
0.10
111.
46.0
68.0
43.0
65.0
46.0
0.23
0.06
7.0
37.0'
8.64
-------
2.5 times greater than those of the surface samples primarily due to
the lack of oxygen at the lower depths necessary for nitrification.
Selected sampling of the mid-depths of Pond C and Pond W indi-
cated that the water quality here was higher than either the surface
or bottom layers. Organic parameter concentrations and total solids
were approximately 57o lower at mid-depth than at the surface. A more
vigorous growth of algae in the surface layer near the sunlight would
probably explain why the middle layer of water was of higher quality
Suspended solids levels were approximately 127o lower, and settleable
solids were 1.570 lower in the middle layer than near the surface.
Ammonia nitrogen and pH were exceptions, since ammonia levels increased
and pH decreased from surface to bottom.
POND HARVEST AND WASTE QUANTITIES
Harvest
The harvest weight of fish, feeding rate and feed conversion for
Ponds C and B are shown in Table 6.
Table 6. POND HARVEST DATA
Pond Harvest Weight Average Feeding Feed
Lb. Fish Lb. Fish Rate (70 of Body Conversion
Per Acre Per Ac-Ft. Wt . Per Day) (Lb . Feed/Lb. Grain)
B 150 42 0.91
C 2250 600 2.11
1.60
2.00
Pond B was drained for harvest on January 2, 1974 through an eight-
inch drain pipe and by a tractor-driven irrigation pump. The pond was
drained completely except for two one-acre catch basins which collected
the fish and contained about 18 inches of water. Only 1,500 pounds of
fish were harvested each weighing about 32 ounces and only 2,400 pounds/
of feed were fed during the growing season. Since this did not repre-
sent a normal harvest (due to the earlier fish kill) no water quality
measurements were made during drawdown.
60
-------
Pond W was originally scheduled for harvest in the fall of 1973
but a prolonged dry spell forced cancellation of pond drawdown because
of the economics of complete refilling from the well. The fish remain
unharvested as of this writing. At the end of the sampling period
approximately 15 tons of feed had been fed through demand feeders. An
estimated nine tons of fish remained in the pond at this time. No
drawdown water quality data was available for Pond W.
Pond C was harvested on October 3, 1973. Approximately 9,000
pounds of fish averaging 28 ounces each were harvested from the pond
by drawing the pond down and seining. Drawdown was accomplished
through a drain pipe discharging water from the pond at a depth of
one foot above the bottom. Two weeks prior to the harvest of Pond
C the three smaller ponds in series above Pond C were harvested.
Harvest of these ponds was accomplished by lowering the water level
in Pond C ; and then draining each small pond into the succeeding pond
and finally into Pond C. The three smaller ponds yielded a total of
10,000 pounds of fish. The complete drawdown and harvest time for the
system was less than three weeks.
Waste Quantities
Water quality and total pollutional loading for the entire system
were evaluated (Table 7) in the following manner: water quality sam-
ples were collected from the bottom of Pond C prior to the initial draw-
down (for accomodating the drainage of the three smaller ponds above).
The parameter concentrations for these samples were then determined
(column one Table 7). After harvest of the three smaller ponds the
final drawdown of Pond C (for its harvest) was carried out. Water
samples were collected prior to this drawdown, during this drawdown,
during seining and immediately after fish harvest. The composition
of these samples is also presented in Table 7. The total pounds of
parameter discharged from the system (column nine) was obtained by
summing the poundage in the initial drawdown volume and each of the
61
-------
Table 7. WATER QUALITY DURING HARVEST DRAWDOWN FOR POND SYSTEM C
Parameter
Feet of Drawdown
Ac-ft of Discharge
BOD
COD
TKN
NH3-N
N03 + N02 - N
TS
TDS
TVS
TSS
Sett. S.
Total P
Ortho - PO,
PH
Hardness
Chloride
Concentrations (mg/1)
Drawdown
of 3
small ponds
7.5
7.2
32.
14.50
0.84
0.07
128. ,
92.
88.
36.
28.
0.55
0.10
7.3
40.
15.0
Initial Drawdown
1.0
3.8
9.6
48.
9.33
1.21
0.29
130.
82.
81.
48.
13.
0.12
0.04
6.8
70.
15.0'
2.0
3.4
8.4
51.
11.92
0.84
0.25
135.
111.
94.
24.
19.
0.21
0.01
6.9
60.
15.0
3.0
3.0
10.4
41.
8.58
0.93
0.23
161.
103.
82.
58.
32.
0.11
0.06
6.6
90.
25.0
4.0
2.6
10.4
58.
10.25
1.12
0.39
215.
108.
98.
107.
86. '
0.28
0.05
6.3
90.
15.0
Drawdown
During
Seining
4.1
0.24
12.8
72.
12.58
1.49
0.47
245.
117.
133.
128.
123.
0.45
0.19
6.1
70.
15.0
4.2
0.235
11.2
60.
10.67
1.21
0.33
208.
117.
118.
91.
71.
0.27
0.04
6.2
85.
15.0
Drawdown
After
Seining
4.3
0.23
8.6
52.
8.25
0.19
0.13
146.
93.
83.
53.
50.
0.28
0.16
6.2
55.
12.0
Total Ibs
Parameter
Discharged
from Pond
System
21.00
502.
2481.
665.
54.7
12.0
8415.
5560.
5075.
2855.
1906.
17.9
3.64
6.9
3597.
936.
Ibs of
Parameter
Per 100
Ibs of fish
Discharged
2.64
13.0
3.50
0.288
0.0632
44.2
29.2
26,7
15.0
10.0
0.0942
0.0192
6.9
18.9
4.93
-------
final drawdown increments. The pounds of parameter discharged per
100 pounds of fish (column 10) was based on the total fish produc-
tion for the entire system (19,000 pounds).
During the final drawdown of Pond C the organic parameter con-
centrations of the bottom discharge increased by 377, over the levels
present in the pond prior to drawdown. This increase could be
attributed to flushing of bottom deposits through the drainpipe. Total
solids increased by 10%, suspended solids by 28%, and settleable solids
by 87o- Ammonia levels decreased by 14% during drawdown possibly due
to partial aeration at the discharge outlet of the drainpipe. Dur-
ing drawdown the only parameter to exceed the mean concentration level
recorded during the growing season was nitrate nitrogen.
The dragging of the seine across the pond floor plus the turbu-
lence of men wading and excited fish caused considerable agitation of
bottom sediment and waste deposits during seining. Discharge during
seining caused the BOD to increase by 12%, COD by 23.% total Kjeldahl
nitrogen by 4.8%, and total solids by 26.4% over those values recorded
during the initial drawdown. Other parameters showed smaller increases
Approximately two hours after the third and final seining, most dis-
charge parameter levels were less than half their peak values.
Oftentimes it is difficult to be at a particular pond during pre-
harvest drawdown and to spend the time and obtain the necessary sam-
ples during the entire drawdown period. Consequently just prior to
the final harvest drawdown for Pond C water quality samples were taken
from the bottom, mid-depth and surface. In Table 8 the waste quan-
tities calculated from these concentrations and the mean concentration
are compared with those based on drawdown concentrations. The waste
discharge quantities calculated from mean (depth) concentrations in
the pond prior to drawdown compare closely with those measured in the
discharge water.
The effect of depth-of-removal on the total waste discharged
during harvest drawdown can be ascertained from the data in Table 9.
63
-------
Table 8. POND C PARAMETER CONCENTRATIONS AT DIFFERENT SAMPLING DEPTHS
Parameter
BOD
COD
TKN
NH3 - N
N03 + N02 - N
TS
TDS
TVS
TFS
TSS
Sett. S.
Total P
Ortho - PO,
PH
Hardness
Chloride
Ibs.
Parameter Per
Concentration Prior to Drawdown
Surface Middepth Bottom
2.83
11.90
2.90
0.15
0.039
42.5
38.6
24.2
18.3
3.90
1.00
0.019
0.003
8.2
20.90
4.83
2.58
10.60
2.67
0.360
0.035
41.2
34.1
23.5'
17.7'
7.10
4.50
0.019
0.010
7.5
22.50
4.83'
2.96
12.60
3.30
0.600
0.035
48.3
23.5
28.0
20.3
24.8
21.3
0.032
0.013
7.0
27.40
4.03
100 Ibs. Fish
Mean
2.79
11.70
2.96
0.370
0.037
44.0
32.1
25.2
18.8'
11.9'
8.90
0.024
0.009
7.6
23.60
4.56
Drawdown Discharge
Concentration
2.64
13.10
3.50
0.290
0.063
44.3
29.3
26.7
17.6
15.0
10.0
0.094
0.019
6.9
18.90
4.93
ON
•P-
-------
Table 9. WASTE DISCHARGE POTENTIAL OF MID-DEPTH VS. BOTTOM DISCHARGE FROM POND C
Parameter
BOD
COD
TKN
NH3 - N
NO + NO. - N
J £»
TS
TDS
TVS
TFS
TSS
Sett. S.
Total P
Ortho - PO,
Hardnes s
Chloride
Total Ibs. Parameter in Upper
Half of Pond
175.
730.
179.
13.6
2.39
2667.
2361.
1517..
1150.
306.
129.i
1.22
0.33
1356.
306..
Total Ibs. Parameter in Lower
Half of Pond
178.
749.
194.
32.4
2.24
2890.
1742.
1666.
1223.
1146.
945.
1.73
0.74
1618.
274.
Cn
-------
The average depth of Pond C is five feet. If we assume that
draining the pond to the mid-depth level is sufficient for sein-
ing we can compare the total waste discharges for the drain outlet
at mid-depth and at the bottom. This was done by developing a
stage-storage curve for the ponds- Bottom, mid-depth and surface
concentrations were weighted according^ to the volume representation
indicated from the stage-storage curve. The results from this analysis
are presented in Table 9. The reduction in pollutional loading to a
receiving stream by mid-depth drainage is not large. This reduction
would amount to 1.7% for BOD, 2.6% for COD, 8.4% for total Kjeldahl
nitrogen and 8.4% for total solids as an example.
RACEWAY WATER QUALITY DURING GROWING SEASON
Diurnal Variations in Effluent Composition
Grab sampling can present certain limitations in that diurnal
and hydrologic fluctuations in effluent composition are not always
accounted for. However, grab sampling does make it possible to
test many more systems in a shorter time span than would be possible
employing composite (time-wise) sampling.
Grab samples were collected at six-hour intervals over a 24-hour
period for three sampling dates at Raceway TR and one at Raceway ED.
Table 10 presents the mean diurnal variations of the sample concen-
trations and the overall 24-hour mean values. Most organic parameter
concentrations peaked in the afternoon and evening hours probably due
to the fish and feeding activities during the day. The solids concen-
trations tended to be highest following the morning and afternoon
feeding periods. Ammonia peaked during the early morning hours before
daylight.
The mean values when compared with the interpolated (linear) values
between 12 noon and 2 PM were in close agreement. Consequently all
raceway water quality sampling was done by grab sampling during this
time period.
66
-------
a b
Table 10. RACEWAY ED & TR - MEAN DIURNAL VARIATIONS IN EFFLUENT CONCENTRATIONS
Parameter
BOD5
COD
TKN
NH3 - N
N03 + N02 - N
TS
TDS
TVS
TFS
TSS
Sett. S.
Total P
Ortho - PO,
PH
Hardness
Chloride
Concentrations (mg/1)
5 AM 11 AM 5 PM 11 PM
6.3
36.
9.19
0.95
0.28
169.
114.
66.
66.
55.
31.
1.01
0.11
7.1
57.
14.4
4.3
35.
7.85
0.65
0.27
179.
124.
76.
103.
55.
42.
0.87
0.13
7.1
56.
12.5
6.7
40.
11.87
0.67
0.19
188.
102.
90.
86.
86.
66.
1.07
0.12
7.3
51.
13.1
7.3
39.
10.44
0.87
0.21
178.
113.
96.
82.
64.
47.
0.75
0.12
7.4
56.
14.4
Mean
6.2>
37.
9.84
0.78
0.24
179.
113.
83.
84.
65.
47.
0.93
0.12
7.2
55.
13.6
(a) One sampling date
(b) Three sampling dates
-------
Water Quality
The raceway effluent parameter concentrations are presented in
Figures 14 through 24. The data is presented in terms of pounds of
parameter per 100 pounds of fish per day as a function of the fish
density in pounds fish per acre-foot of water in the total system.
The volume of water in the total system was used rather than that of
the individual raceway units. In a closed-loop recirculating system
the metabolic and feed wastes are retained within the entire system.
Fish densities represent the estimated standing weight .of fish in the
raceway units on each sampling date- A regression analysis was used
to obtain a best-fit curve to the plotted values. This was done not
for prediction purposes but only to show trends. Correlation coef-
ficients ranged from 0.05 to 0.47 with a mean of 0.18.
The parameter concentrations expressed as pounds per 100 pounds
fish per. day generally showed a slight tendency to increase as fish
density increased. These trends emphasize the point that, even though
larger fish produce less waste per pound than smaller fish, the sys-
tem reservoirs and oxidation ponds do not have the capacity to effec-
tively assimilate all of the waste products from intensive fish pro-
duction resulting in a net buildup of certain parameters within the
system during the growing season. The closed-loop system of Raceway
TR yielded consistently higher parameter concentrations than did the
semi-closed-loop systems of Raceways EG, EF, and ED. The lower con-
centrations in system E was the result of periodic wasting of water
to a nearby stream. Ammonia nitrogen was an exception to the above
trends showing a slight decrease in concentration as fish density
increased.
Influent and Effluent Composition
Table 11 presents the mean parameter concentrations and differences
for the influent and the effluent from Raceways EG, EF, ED, and TR dur-
ing the growing season.
68
-------
0.5_
0.4
i - 0.05
0.3
3
o
o
§
E
OL.
0.2
0.1
9
9
» ®
200
1 I
300
1 I
5009Ui
900
400 500 600 700 800
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 14. BOD concentration of raceway effluent as a function of standing fish density
1000
-------
2.5
2.0
1.5
~~~ 9
CO
CO
a
1 1.0
o
o
0.5
200
300
400
r = 0.20
500 "TOO"BOO"
g0o
500 600 700 Ml
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 15. COD concentration of raceway effluent as a function of standing fish density
1000
-------
0.5 ._
0.4
0.3
in
o
1 0.2
o
o
0.1
I
r = 0.16
200
300
400
500
500
700 800
900
1000
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 16. Total Kjeldahl nitrogen concentration of raceway effluent as a function of standing
fish density
-------
po
0.05 _
0.04
0.03
CO
0
s
°- 0.02
o
o
0.01
O
Q Q
r = 0.19
200 300
900
1000
400 500 600 700 800
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 17. Anmonia nitrogen concentration of raceway effluent as a function of standing fish density
-------
CO
0.025 _
0.02
~ 0.015
0.01
i
CM
0.005
o ©
1
I
200
300
r = 0.08
e
400 .500 600 700 800
POUNDS FISH ON HAND/ACRE-FOOT WATER
900
1000
Figure 18. Nitrate + nitrite-nitrogen concentration of raceway effluent as a function of standing
fish density
-------
10
•CO
t-t
u.
o
o.
§
r « 0,06
& &
50070C
200 300 400 500"" BOO TOO " 960 ' 900 fOOO
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 19. Total solids concentration of raceway effluent as a function of standing fish density
-------
5.0 —
en
4.0
Q
1
z
o
3C
CO
3.0
r = 0.16
2.0
o
o
1.0
I I I I I I J
200300400500655706BOfl900TOOO
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 20. Total volatile solids concentration of raceway effluent as a function of standing fish density
-------
5.0
4.0
1
§ 3.0
2.0
o
o
1 1.0
§
a.
r=0.06
200 300
900 1000
400 500 600 700 800
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 21. -Total suspended solids concentration of raceway effluent as a function of standing fish density
-------
5.0
o
—
o
o
3:
CO
co
o
o
0.
o
o
i
CO
§
3
4.0
3.0
2.0
1.0
r = 0.21
o <•>
200 300 400 500 600 700 800 900 TOGO
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 22. Settleable solids concentration of raceway effluent as a function of standing fish density
-------
oo
0.05_
0.04
5 0.03
1-4
u_
I
I
§ 0.02
g
0.01
r = 0.47
I
200 300
900
1000
400 500 600 700 800
POUNDS FISH ON HAND/ACRE-FOOT WATER
Figure 23. Total phosphate concentration of raceway effluent as a function of standing fish density
-------
0.0175
•VI
10
0.010
I
o
to
o
a.
o
o
a.
o
I
o
0.0075
0.0050
0.0025
r = 0.23
300
900
1000
400 500 600 7QO 800
POUND? FISH ON HAND/ACRE-FOOT WATER
Figure 24. Orthophosphate concentration of raceway effluent aa a function of standing fish density
-------
Table 11. KACKWAYS KG, F.F, Kl), AND TK MKAN INKI.UKNT AMI) KFFl.UIWi' CONCENTRATIONS
(a)
oo
o
Parameter
BOD-
COD
TKN
NH- - N
N03 + N02 - N
TS
TDS
TVS
TFS
TSS
Sett. S.
Total P
Ortho - PO^
pH
Hardness
Chloride
Concentration (mg/1)
Influent
6.2
23.8
6.71
0.345(b)
0.225
139.
' 83.
65.
74.
56.
34.
•0.570
0.103
-7.5
33.8'
6.90
Effluent
6.9
32.0
8.29
0.518
0.283
163.
91.
74.
89.
72.
50.
0.600
0.103
7.3
33.3
8.30
E-I
0.7
8.2.
1.58
0.173
0.058
24.
8.
9.
15.
16.
16.
0.030
0.
-
-
-
Ibs Parameter/ 100 Ibs
Influent
0.20
0.86
0.238
0.012
0.008
5.18
3.09
2.46
2.72
2.09
1.34
0.019
0.003
7.6
1.40
0.39
Effluent
0.26
1.25
0.354
0.022
0.010
6.56
3.31
3.06
3.50
3.25
1.97
0.022
0.005
7.4
1.37
0.39
Fish/Day
E-I
0.06
0.39
0.116
0.010
0.002
1.38
0.22
0.60
0.78
1.16
0.63
0.003
0.002
-
-
-
Ibs Parameter /lb Feed/Day
Influent
0.14
0.61
0.163
0.009
0.005
3.60
2.18
1.74
1.86
1.42
0.92
0.013
0.002
7.6
1.04
0.28
Effluent
0.18
0.88
0.249
0.016
0.007
4.65
2.37
2.19
2.46
2.28
1.39
0.015
0.004
7.4
1.02 -
0.27
E-I
0.04
0.27
0.086
0.007
0.002
1.05
0.19
0.45
0.06
0.86
0.47
0.002
0.002
-
-
-
(a) Mean values from eight sampling dates for System E and five for System TR.
(b) Values are shown with .three digits to the right of decimal for calculation purposes.
-------
The mean water temperature of the raceway effluents during the
sampling period was 81°F. The dissolved oxygen levels of the raceway
effluents averaged 6.9 mg/1 and ranged from 5.5 to 7.5 mg/1. The
BOD/COD ratio of 0.20 was approximately the same as that computed for
the ponds. Approximately 47% of the total solids were volatile, 51%
were suspended, and 30% settled out in one hour. The decrease in
volatile solids when compared to pond concentrations was probably due
to sediment and inorganic matter being stirred-up by fish in the race-
way units. A ratio of 0.054 pounds total Kjeldahl nitrogen per pound
total solids was again less than that obtained in stillwater ponds.
Approximately 93.8% of the nitrogen was organic, and 6.2% was in the
form of ammonia (about the same percentages as found in ponds). The
nitrate plus nitrite nitrogen ratio was 0.0015 pounds per pound total
solids considerably higher than that of ponds. The increase in
nitrates could be coupled with increased nitrification of ammonia by
aerobic bacteria. The raceway effluent contained 0.0034 pounds
total phosphate per pound total solids of which 237o were in the form
of orthophosphate. Again the total phosphate percentage was con-
siderably higher than in ponds because of the sweeping of sediment and
suspended matter by the flowing water. Phosphate ions become affixed
to sediment and are relatively insoluble thereafter.
Comparing differences between influent and effluent concentra-
tions shows that overall the organics in the water increased by 32%.
Total solids increased by 27% while suspended solids increased 62%
and settleable solids by 47%. Frequently the total solids concentra-
tions of the influent to Raceways EG, EF, and ED were slightly higher
than the effluent concentrations. This was attributed to the sweeping
of sediment from the floor of the supply reservoir by bottom water
intake structures. Suspended particles could be readily observed in
the raceway effluents. Ammonia levels increased by 83% as water flowed
through the fish production units, however, the highest concentration
81
-------
recorded (1.96 mg/1) was still less than levels at which total ammonia
becomes toxic to catfish. The pH showed a slight decrease from 7.6 to
7.4.
Settling Basin Analysis
A trapezoidal-shaped settling basin model was designed and tested
for the removal of suspended wastes in recirculation raceway systems
by Chesness et al. (1974). In the recirculating, warm-water catfish
production system at Raceway TR, filterable solids have been averaging
39% of the total solids. The removal of these solids by gravity
settling could result in a significant improvement in water quality.
If the settling basin proved effective, the most practical adapta-
tion would be to use (with modifications for cleaning) the last unit
or portion of the raceway as a basin. A 1/12 scale model of a 54-foot
long raceway unit was selected with a flow velocity 1/144 that of the
prototype. A slatted baffle arrangement produced uniform, streamline
flow through the basin. The effluent was discharged uniformly from
the surface of the settling zone by means of a weir. Field evalua-
tions were made by diverting effluent from the last unit of Raceway
TR through the model.
A settling column analysis was performed for each field test on
a single composite water sample made up from the model inlet grab
samples. Grab samples were taken periodically of the basin effluent,
and at the end of each flow test the sediment collected in the basin
was recovered. COD and residue analyses (total, volatile, and sus-
pended solids) were performed on the samples. In the third and final
field test the basin model length was increased to simulate a full
length (100-foot) raceway unit.
The average removal of filterable solids for the basin with a
33.9-in. long settling zone was 43.2%. When the settling zone length
was increased 2.5 times to 78 in. the actual removal increased to only
57.3%.
82
-------
Even though the basin removed an average of 48% of the filterable
solids, this represented less than a 67» reduction in effluent COD.
The reason for this was evident—only 16% of the sediment in the basin
was organic. The low percentage of volatile (organic) solids in the
sediment from the basin is apparently a characteristic of recircula-
tion raceway systems used for warm-water fish culture. The higher
water temperatures (75°F to 86°F) and increased sunlight intensity
and duration combined with recirculation apparently result in increased
biological activity and the subsequent breakdown (or dissolution) of
waste particulates (fecal and waste feed).
RACEWAY HARVEST AND WASTE QUANTITIES
Harvest
The harvest weight of fish, feeding rate and feed conversion for
Raceways EG, EF, ED and TR are presented in Table 12.
Table 12. RACEWAY HARVEST DATA
Kaceway 11 / .. 11 / ,-. 3 • • ^
Ib/unit Ib/ft in unit
EG
EF
ED
TR
2500
2500
1875
2380
0.45
0.45
0.34
0.50
lb/ac-ft(total) f %ra*e R ^ ^eed .
Feeding Rate Conversion
(% of body (Ib feed/
wt/day) Ib gain)
572
806
458
907
1.59
1.59
1.59
1.23
1.75
1.75
1.75
1.25
• Harvesting of the fish began November 1, 1973 with Raceways EG and
EF and continued through January 1974 with Raceway ED. Harvesting was
accomplished by successively draining each unit (beginning at lower end)
of a raceway and seining the fish. This method was utilized for each
succeeding unit until the entire raceway was harvested. Approximately
95% of the fish that were stocked were harvested at an average weight of
20 ounces each. Raceway EG yielded 2,500 pounds of fish per unit for a
83
-------
total weight of 17,500 pounds. Raceway EF yielded a total weight of
25,000 pounds while Raceway ED yielded 30,000 pounds. These fish were
hand-fed daily a total of 63.5 tons of catfish ration during the grow-
ing season.
Raceway TR yielded an average of 2,380 pounds per unit for a total
weight of 19,050 pounds of fish averaging 17 ounces each. Approximately
10.5 tons of a commercial high protein trout ration were hand-fed twice
daily during the growing season. Good management practices resulted
in a 99.6 percent survival and recovery at harvest on October 18, 1973.
Waste Quantities
Raceway systems EF, EG, and ED are semi-closed recirculation
systems. During the course of the growing season the total volume of
water in each system was replaced four times with river water. By
assuming the parameter concentrations for the raceway influent were
equal to those of the oxidation pond discharge it was possible to
calculate the quantities of wastes released each time the oxidation
ponds were drained. Summing these values for the entire growing
season results in the total waste discharge figures presented in
Table 13.
WASTE LOADINGS FROM PONDS, RACEWAYS AND TANKS
By combining the results of this study with several of those
reported in the literature it was possible to compare waste load-
ings resulting from three different types of catfish production
systems. The results of this analysis are presented in Table 14.
The values represent the total waste production from each culture
system per 100 pounds of fish (mean weight of 1.25 Ibs. each) pro-
duced during a 240-day culture period. These waste concentrations would
represent the loading to a receiving stream if the ponds were com-
pletely drained for harvest, the raceway water volume was exchanged
four times and the tanks were in effect indoor single pass raceways
with no waste removal facilities.
84
-------
Table 13. POUNDS PARAMETER DISCHARGED FROM RACEWAY SYSTEM E
oo
Ul
Parameter
BOD5
COD
TKN
NH3 - N
N03 + N02 - N
TS
TDS
TVS
TFS
TSS
Sett. S.
Total P
Ortho - PO,
PH
Hardness
Chloride
Raceway System
Total Ibs. Parameter
Discharged
6,886.
29,563.
9,019.
273.
364.
171,700.
91,715.
79,475.
92,225.
79,985.
44,867.
671.
61.2
7.5
30,287.
12,394.
E(a)
Ibs. Parameter Discharged
Per 100 Ibs. Fish
1.62
6.95
2.12
0.064
0.086
40.4
21.5
18.7
21.7
18.8
10.5
0.158
0.014
7.5
7.12
2.92
(a) 477 acre-feet discharged during growing season; 425,000 Ibs. fish
on hand at harvest.
-------
Table 14. WASTE PRODUCTION FROM DIFFERENT FISH CULTURE SYSTEMS
Parameter
BOD5
COD
TKN
NH3 - N
N03 + N02 - N
TS
TDS
TVS
TFS
TSS
Sett. S.
Total P
Ortho - PO,
Hardness
Chloride
Ibs. Parameter Per 100 Ibs. Fish on Hand for 240-Day Growing Season
Page & Andrews
Tank
67.6
48.5
14.8
49.0
78.3
6.10
Harris
Tank
96.7
4.56
136.
Tank
Means
82.1
48.5
9.71
49.0
78.3
136.
6.10
Barker et al. ,
Pond System C
2.64
13.0
3.50
0.29
0.06
44.2
29.2
26.7
17.5
15.0
10.0
0.09
0.02
18.9
4.93
Barker et al. .
Pond System
2.61
23.5
1.91
0.41
0.06
76.1
41.6
38.7
37.3
34.4
18.4
0.15
0.03
61.6
6.34
Beasley 6. Allen
Ponds
2.69
20.1
0.04
* 0.52
103.
86.5
53.5
50.3
17.3
0.04
Pond
Means
2.65
18.9
2.70
0.25
0.21
74.7
52.5
39.6
35.0
22.2
14.2'
0.09
0.02
40.2
5.64
Barker et al.
Raceway System E
1.62
6.95
2.12
0.06
0.09
40.4
21.5
19.2
22.2'
18.8
10.5
0.16
0.01
7.12
2.92
00
-------
Representative data on raw waste (feed and metabolic) composi-
tion and production for catfish was extremely limited. Utilizing
mean values from Page and Andrews' and Harris1 works it was possible
to arrive at certain raw waste production values for catfish. With
this data it is possible to assess the waste assimilative capacities
of the pond and semi-closed raceway systems.
The waste production from ponds represents data from eight ponds
with stocking densities ranging from 1,800 to 3,000 fish/surface-acre.
It is assumed that all pond waters had zero waste levels at the time
of stocking. General agreement between the three sets of values is good.
Perhaps the two most significant differences occur in COD and total solids
values. For Pond C COD is 40% less and total solids 103% less than the
respective mean values for the other ponds. The mean values given in
column four should be a reasonably accurate representation of potential
waste discharge loadings from pond culture systems for catfish.
The waste stabilization effect by the natural biological processes
occurring in the ponds is very pronounced. BOD and TKN have been
reduced by 96.8% and 94.9% respectively when compared to the mean raw
waste levels reported from tank studies. Assuming a 4.5 pound oxygen
demand per pound of TKN this means a total oxygen demand (on natural
waterways) reduction of 95.4%.
The semi-closed Raceway System E shows the positive effects of
increased physical (mixing and aeration) and biological activity on
waste stabilization. When compared with the mean values for the ponds,
BOD and TKN loadings are further reduced by 38.9% and 14.5% respectively.
During the stabilization process in the ponds and raceways total
suspended solids are reduced by an average of 85% when compared with raw
waste quantities from tanks. This is further evidence that physical
settlement is not likely to affect much improvement in water quality in
the culture of warm water fish in ponds or raceways.
In our discussion of waste production and possible discharge
loadings to streams it is important that we reconsider our earlier
87
-------
assumption of zero concentration levels at the start of production.
If a catfish producer must remove production wastes from the water
he uses before discharging it he should not be held accountable for
the initial waste loadings in the water. Consequently, additional in-
formation is needed to determine the general background or initial
waste level of the water sources used for catfish production.
88
-------
SECTION VIII
REFERENCES
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Allen, K. 0. 1974. Fisheries Research Biologist with U. S. Bureau of
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Bardach, J. E., J. H. Ryther, and W. 0. McLarney, 1972. Aquaculture—
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89
-------
Boyd, C. E. 1973. The Chemical Oxygen Demand of Waters and Biological
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Boyd, C. E. 1971. Phosphorus Dynamics in Ponds. In: Proceedings of
the 25th Annual Conference of the Southeastern Association of Game and
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Boyd, C. E. 1970. Influence of Organic Matter on Some Characteristics
of Aquatic Soils. Hydrobiologia (The Hague). 36(1): 17-21.
Boyd, C. E. and C. P. Goodyear. 1971. Nutritive Quality of Food in
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Broussard, M. C., Jr., N. C. Parker, and B. A. Simco. 1973. Culture of
Channel Catfish in a High Flow Recirculating System. Memphis State
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Brown, E. E. 1971. Economics of Catfish. In: Proceedings of the Cat-
fish Farmers of Georgia, Schuler, G- A. and J. L. Byford (eds.). Athens
University of Georgia Cooperative Extension Service, p. 39-42.
Busch, C. D., J. L. Koon, and R. Allison. 1973. Aeration, Water Quality
\
and Catfish Production. Auburn University Agricultural Engineering
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Chapman, S. R., J. L. Chesness, and R. B. Mitchell. 1971. Design and
Operation of Earthen Raceways for Channel Catfish Production. Soil
90
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Conservation Service. (Presented at Joint Meeting of Southeast
Region Soil Conservation Society of America, and Southeast Region
American Society of Agricultural Engineers. Jacksonville. January
31 - February 3.) 12 p.
Chesness, J. L., J. L. Stephens, and T. K. Hill. 1972. Gravity Flow
Aeration for Raceway Fish Culture Systems. University of Georgia
Agricultural Experiment Station, Athens, Georgia. Research Report
No. 137. 21 p.
Chesness, J. L. and J. L. Stephens. 1971. A Model Study of Gravity
Flow Aerators for Catfish Raceway Systems. Transactions of the ASAE .
14(6): 1167-1169, 1174.
Chu, C. L. and G. N. Greene. 1966. Experiments on the Use of a
Biofilter to Remove Wastes from Fish Tanks. In: Proceedings of the
20th Annual Conference of the Southeastern Association of Game and
Fish Commissioners, Webb, J. W. (ed.). Auburn, Auburn University
Fisheries Laboratory, p. 446-455.
Container Culture of Catfish and Removal of Excess Nutrients from
Fish Pond. 1973. Excerpts from FAO Aquaculture Bulletin. April-July
Issue, p. 7-8.
Culley, D. D-, Jr. 1973. Raceways; Exotic Species Most Affected by
Proposed EPA Discharge Permits. The American Fish Farmer & World
Aquaculture News. 4(8):9-12.
Davis, J. T. and J. S. Hughes. 1970. Channel Catfish Farming in
Louisiana. Louisiana Wildlife and Fisheries Commission, Baton Rouge,
Louisiana. Wildlife Education Bulletin No. 98. 48 p.
91
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Dupree, H. K. 1972. Evaluation of an Oxidation Pool to Remove Wastes
in a Closed System for Raising Fish. Southeastern Fish Cultural
Laboratory, Marion, Alabama. Technical Assistance Project No.
14-16-0008-571. U. S. Department of the Interior, p. 49-62.
Environmental Protection Agency. 1971. Methods for Chemical Analysis
of Water and Wastes. Washington, D. C., U. S. Government Printing
Office. 312 p.
Federal Water Pollution Control Administration. 1968. Water Quality
Criteria. Washington, D. C., U. S. Government Printing Office. 234 p.
Gray, D. L. 1973. The Biology of Channel Catfish Production. Uni-
versity of Arkansas Cooperative Extension Service, Fayetteville,
Arkansas. Circular No. 535. U. S. Department of Agriculture. 16 p.
Greene, G. N. 1969. Biological Filters for Increased Fish Production.
Auburn University Agricultural Experiment Station. (Prepared by
Auburn University Agricultural Experiment Station. Auburn). 15 p.
Grizzell, R. A., Jr. 1967. Pond Construction and Economic Considera-
tions in Catfish Farming. Soil Conservation Service. (Presented at
21st Southeastern Association of Game and Fish Commissioners. New
Orleans. September 25-27.) 5 p.
Grizzell, R. A., Jr., 0. W. Dillon, Jr., and E. G. Sullivan. 1969.
Catfish Farming - A New Farm Crop. Soil Conservation Service, Wash-
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of Agriculture. 22 p.
Hach Chemical Company. 1969. DR-EL Methods Manual. Seventh Edition,
Ames, The Iowa State University Press. 68 p.
92
-------
Hall, M. D. 1972. The Fish Barn. Agricultural Engineering. 53:16.
Harris, J. C. 1972. Pollution Characteristics of Channel Catfish
Culture. Unpublished Masters Thesis. The University of Texas at
Austin. 94 p.
Hastings, W. H. 1972. Feeding Domestic Freshwater Fish. Agricultural
Engineering. 53:16-17.
Hatcher, R. M. 1972. Catfish Farming in Tennessee. Tennessee Game
& Fish Commission, Nashville, Tennessee. Report No. 5-72-5M (Second
Edition). 47 p.
Hill, T. K., J. L. Chesness, and E. E. Brown. 1973. A Two-Crop Fish
Production System. Transactions of the ASAE. 16(5):930-933.
Hinshaw, R. N. 1973. Pollution as a Result of Fish Cultural Activities.
Utah State Division of Wildlife Resources, Salt Lake City, Utah. Environ-
mental Protection Agency. 209 p.
Hubert, W. A. 1973. Evaluation of Intensive Catfish Culture Systems
for Potential Valley Use. Tennessee Valley Authority. (Prepared by
Division of Forestry, Fisheries, and Wildlife Development. Muscle
Shoals. April.) 27 p.
Hubert, W. A., W. T. Morgan, and A. 0. Smith. 1972. A Description of
the Fish Culture Industry in the Tennessee River Valley and A Review
of the Major Cause of Fish Loss - Oxygen Depletion. Tennessee Valley
Authority, Norris, Tennessee. Technical Note No. B3. 21 p.
Jeffrey, N. B. 1969. Some Aspects of the Ecology of Fish Ponds. In:
Proceedings . • • 1969 Fish Farming Conference. College Station,
Texas Agricultural Extension Service, p. 40-42.
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Knepp, G. L. and G- F. Arkin. 1972. Ammonia Toxicity Levels and
Nitrate Tolerance for Channel Catfish (Ictaluras Punctatus). Uni-
versity of Illinois. (Presented at 1972 Annual Meeting American
Society of Agricultural Engineers. Hot Springs. June 27-30). 6 p.
Liao, P. B. 1970. Salmonid Hatchery Wastewater Treatment. Water
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Liao, P. B. 1970. Pollution Potential of Salmonid Fish Hatcheries.
Water & Sewage Works. August Issue, p. 291-296.
Lee, J. S. 1971. Catfish Farming ... A Reference Unit. Mississippi
State University. (Published by Mississippi State University Curri-
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College.) 103 p.
Lewis, S. D. 1971. Effect of Selected Concentrations of Sodium
Chloride on the Growth of Channel Catfish. In: Proceedings of the
25th Annual Conference Southeastern Association of Game and Fish Com-
missioners, Webb, J. W. (ed.). Carbondale, Southern Illinois Fisheries
Research Laboratory, p. 459-466.
Lovell, R. T. 1973. Put Catfish Offal to Work for You. Fish Farming
Industries. October - November Issue. 3 p.
Lovell, R. T. 1972. Fight Against Off Flavors Inches Ahead. Fish
Farming Industries. February Issue. 3 p.
Mack, J. 1971. Catfish Farming Handbook. San Angelo, Info Books.
195 p.
94
-------
McCoy, E. W. 1973. Catfish Marketing and Related Production Factors.
Auburn University Agricultural Experiment Station, Auburn, Alabama.
Circular No. 206. 23 p.
Montfort, W. W., Jr., K. L. Anderson, and W. J. Lorie. 1969. Pro-
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State College, Mississippi. Publication No. 622. U. S. Department
of Agriculture. 16 p.
Murphy, J. P. and R. I. Lipper. 1972. 1971 Confinement Rearing of
Channel Catfish. Kansas State University, Manhattan, Kansas. KCREA
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Page, J. W. and J. W. Andrews. 1973. Chemical Composition of Effluent
from High Density Culture of Channel Catfish. Skidaway Institute of
Oceanography. (Presented at Summer Meeting of American Society of
Agricultural Engineers. Lexington. June 17-2Q.) 11 p.
Page, J. W. and J. W. Andrews. 1972. Efficiency of Two Types of
Microbiological Filters for Removing Ammonia from Effluents of High
Density Culture of Channel Catfdsh. Skidaway Institute of Oceano-
graphy. (Prepared by Skidaway Institute of Oceanography. Savannah.
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95
-------
Parker, N. C. and B. A. Simco. 1973. Evaluation of Recirculating
Systems for the Culture of Channel Catfish. Memphis State'University.
(Presented at 27th Annual Conference Southeastern Association of Game
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Patterson, D. W. 1973. Observations on Aerated Ponds for Catfish
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Condition of some Common Freshwater Fishes. Auburn University
Agricultural Experiment Station, Auburn, Alabama. Circular No. 183.
55 p.
96
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Tennessee Valley Authority. 1971. Producing & Marketing Catfish in
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Thornton, M. E. 1973. Oxygen Depletion: An Unnecessary Evil. The
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Kansas State University, Manhattan, Kansas. Bulletin No. 508. 24 p.
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Valley, Rouse, R< D. (ed.). Knoxville, Tennessee Valley Authority.
p. 84-87.
Wahlquist, H. 1972. Production of Waterhyacinths and Resulting
Water Quality in Earthen Ponds. Hyacinth Control Journal. 10:9-11.
Willoughby, H., H. N. Larsen, and J. T. Bowen. 1972. The Pollutional
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17(3):l-3.
97
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SECTION IX
GLOSSARY
SAMPLING LOCATIONS FOR WATER QUALITY DATA
EGFX - Outlet of oxidation pond serving Raceways EG and EF
EDX - Outlet of oxidation pond serving Raceway ED
TPO - Outlet of reservoir for Raceway TR at pump intake
TRT - Beneath riser aerator tower of Raceway TR
TDI - Raceway TR effluent during first fish harvest seining
of last unit of raceway
TD2 - Raceway TR effluent during second fish harvest seining
of last raceway unit
TD3 - Raceway TR effluent during third fish harvest seining
of last raceway unit
NS - Surface of catfish pay lake near Morven, Georgia
NB - Bottom of catfish pay lake near Morven, Georgia
GKM - Middepth of Pond GK
CM - Middepth of Pond C
BM - Middepth of Pond B
WM - Middepth of Pond W
GDI - Pond C discharge after 1 foot drawdown prior to fish
harvest
CD2 - Pond C discharge after 2 feet drawdown: prior to fish
harvest
CDS - Pond C discharge after 3 feet drawdown prior to fish
harvest
CD4 - Pond C discharge after 4 feet drawdown and at beginning
of first fish harvest seining
CDS - Pond C discharge during first fish harvest seining
CD6 - Pond C discharge during second fish harvest seining
CD7 - Pond C discharge two hours after third and final fish
harvest seining
ABBREVIATIONS FOR WATER QUALITY PARAMETERS AND OTHER VARIABLES
D.O. - Dissolved Oxygen
BOD - Five day Biochemical Oxidation Demand
COD - Chemical Oxidation Demand
98
-------
TKN - Total Kjeldahl Nitrogen (as N)
NH -N - Ammonia Nitrogen (as N)
NO -N - Nitrate plus Nitrite Nitrogen (as N)
TS - Total Solids
TDS - Total Dissolved Solids
TVS - Total Volatile Solids
TFS - Total Fixed Solids
TSS - Total Suspended Solids
Sett.S - Settleable Solids
Total P - Total Phosphate
Ortho-PO, - Orthophosphate
Hardness-Total Water Hardness (as CaCO )
Chloride - Chloride (as Cl)
Water Temperature - Water Temperature, °F
TOC - Total Organic Carbon
Stocking Rate - Number of fish stocked per production unit
(raceway) or per surface acre (pond)
Flow Rate - Gallons per minute (gpm)
Water Volume - Acre-feet at normal pool level
Fish Weight - Total pounds of fish in raceway or pond on
sampling date
Amount Fed - Total pounds of feed fed on sampling date.
-------
SECTION X
APPENDICES
The water quality parameter concentrations (mg/1) for each sample
collected from the ponds and raceways during the field study are
presented in Tables 15 through 35.
The parameter concentrations for surface (S suffix) and bottom
(B suffix) water samples for each pond visited on a given date are
presented in Tables 15 through 22. The parameter concentrations
obtained from water samples taken during the harvest drawdown of
Pond C are presented in Table 22.
Influent and effluent parameter concentrations for each raceway
sampled in System E are shown in Tables 22 through 31.
Parameter concentration data collected from Raceway System TR
are presented in Tables 32 through 35.
100
-------
Table 15. WATER QUALITY DATA, PONDS, 7/18/73
o
Parameter
Stocking Rate
Surface Area
Water Volume
Fish Weight
Amount Fed
BOD
COD
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrate «• Nitrite - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphate
PH
Hardness
Chloride
Pond
GKS
1.25
5
-
-
8.4
29
8.83
0.28
0.07
193
110
122
71
83
67
0.38
0.27
7.6
90
15.0
GKB
_
1.25
5
-
-
8.4
25
8.14
0.42
O.'O 8
172
86
90
82
86
58
0.90
0.55
7.2
100
15.0
CS
'2000
4
15
5364
113
15.6
84
17.05
0.14
0.16
208
103
-145
63
105
90
0.18
0.03
8.1
35
10.0
CB
2000
4
15
5364
113
9.2
81
17.58
0.42
0.15
242
110
143
99-
132
122
0.52
0.02
7.3
35
12.5
NS
2000
2
8
2682
40
8.8
49
12.89
0.28
0.17
126
79
_
-
47
11
0.08
0.07
7.6
5
7.5
NB
2000
2
. 8
2682
40
8.8
51
13.18
0.28
0.21
84
77
_
-
7
4
0.03
0.02
7.8
10
10.0
WS
1800
10
48
8839
131
8.8
29
7.11
0.28
0.09
38
26
24
14
12
4
0.08
0.06
7.7
10
7.5
WB
1800
10
48
8839
131
8.4
31
6.34
0.28
0.07
101
26
70
31
75
42
0.12
0.07
7.6
5
7.5
-------
Table 16. WATER QUALITY DATA, PONDS, 8/14/73
O
N>
Parameter
Stocking Rate
Surface Area
Water Volume
Fish Weight
Amount Fed
BOD
COD
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrate + Nitrite - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphate
pH
Hardness
Chloride
Pond
GKS
_
1.25
5
-
-
4.4
11
6.95
0.28
0.07
116
74
70
46
42
14
0.16
0.09
8.4
100
20.0
GKB
^
1.25
5
-
-
4.4
11
7.10
0.37
0.07
130
58
65
65
72
23
0.22
0.03
8.1
100
17.5
CS
2000
4
15
6639
140
6.4
20
8.58
0
0.08
100
18
70
30
82
67
0.13
0.05
8.5
50
15.0
CB
2000
4
15
6639
140
12.0
37
15.83
2.99
0.13
177
20
118 -
59
157
56
0.38
0.35
6.6
50
15.0
BS
1600
10
36
1293
11.8
8.4
8
8.44
0.37
0.11
120
97
74
46
23
15
0.08
0.02
6.9
20
12.5
BB
1600
10
36
1293
11.8
7.6
28
6.39
0.47
0.10
81
28
55
26
53
43
0.13
0.07
6.7
20
15.0
WS
1800
10
48
11,009
163
11.6
44
7.26
0.37
0.09
69
19
48
21
50
41
0.18
0.04
6.7
15
10.0
WB
1800
10
48
11,009
163
11.6
42
7.47
0.47
0.11
118
40
83
35
78
62
0.16
0.09
6.1
15
10.0
-------
TjbK- 17. WATKK QUALITY DATA, I'ONDS, 9/4/7!
Parameter
Stocking Rate
Surface Area
Water Volume
Fish Weight
Amount Fed
BOD
COD
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrate + Nitrite - N
Total Solids
Total Dissblved Solids
Total Volatile Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphate
PH
Hardness
Chloride
Pond
GKS
1.25
5
-
-
2.4
25
7.82
0.37
0.05
240
128
113
112
56
0.28
0.12
8.2
130
22.5
GKB
1.25
5
-
-
4.0
26
7.20
1.49
0.07
194
163
94
31
30
0.28
0.20
7.8
135
22.5
CS
2000
4
15
7631
161
3.6
21
9.67
0.56
0.10
140
93
112
47
24
0.17
0.12
7.6
40
17.5
CB
2000
4
15
7631
161
7.2
32
14.50
0.84
0.07
128
92
88
36
28
0.55
0.10
7.3
40
15.0
BS
1600
10
36
1343
12,3
4.8
30
7.26
0.75
0.01
107
48
61
59
50
0.15
0.04
6.8
15
15.0
BB
1600
10
36
1343
12.3
4.0
36
7.93
0.93
0.10
96
37
45
59
54
0.10
0.03
6.4
18
15.0
WS
1800
10
48
12,696
188
2.4
24
6.35
0
0.05
94
45
29
49
33
0.44
0.05
7.0
35
15.0
WB
1800
10
48
12,696
188
2.4
22
5.24
0.37
0.08
135
62
71
73
6-8
0.32
0.08
6.9
37
12.5
-------
Table 18. WATER QUALITY DATA, PONDS, 9/25/73
Parameter
Stocking Rate
Surface Area
Water Volume
Fish Weight
Amount Fed
BOD
COD
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrite + Nitrate - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphate
PH
Hardness
Chloride
Pond
GKS
_
1.25
5
-
-
5.6
17
5.67
0.65
0.08
194
156
85
109
38
30
0.15
0.06
8.3
120
20.0
GKM
_
1.25
5
-
-
5.0
15
5.28
0.84
0.07
182
155
69
113
27
15
0.15
0.08
8.7
135
22.5
GKB
_
1.25
5
-
-
6.8
25
7.82
0.93
0.09
216
155
67
149
61
34
0.28
0.07
8.5
170
25.0
CS
2000
4
15
8622
182
8.8
37
9.00
0.47
0.12
132
120
75
57
12
3
0.06
0.01
8.2
65
15.0
CM
2000
4
15
8622
182
8.0
33
8.30
1.12
0.11
128
106
73
55
22
14
0.06
0.03
7.5
70
15.0
CB
2000
4
15
8622
182
9.2
39
10.25
1.87
0.11
150
73
87
63
77
66
0.10
0.04
7.0
85
12.5
-------
Table 19. WATER QUALITY DATA, PONDS, 9/25/73
Parameter —
Stocking Rate
Surface Area
Water Volume
Fish Weight
Amount Fed
BOD
COD
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrite + Nitrate - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphat e
pH
Hardness
Chloride
Pond
BS
1600
10
36
1393
12.7
2.8
20
5.34
0.65
0.02
91
AS
69
22
43
31
0.25
0.05
7.1
50
15.0
BM
1600
10
36
1393
12.7
2.4
19
4.72
0.75
0.03
87
62
62
25
25
13
0.10
0.02
7.2
40
15.0
BB
1600
10
36
1393
12.7
6.0
37
7.42
0.93
0.12
101
63
72
29
38
33'
0.14
0.01
6.8
40
10.0
WS
1800
10
48
14,384
213
1.0
22
7.58
0.75
0.09
83
62
56
27 -
21
17
0.13
0
6.6
60
10.0
WM
1800
10
48
14,384
213
1.0
23
6.52
1.21
0.09
76
60
55
21
16
13
G.18
0
7.1
60
7.50
WB
1800
10
48
14,354
213
1.0
39
8.18
1.59
0.14
91
35
65
26
56
35
0.38
0
7.0
70
10.0
-------
Table 20. WATER QUALITY DATA, PONDS, 10/18/73
Parameter —
Stocking Rate
Surface Area
Water Volume
Fish Weight
Amount Fed
BOD
COD
Total Kjeldahl Nitrogen
Amnonia Nitrogen
Nitrate f Nitrite - N
Total, Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids-
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphate
PH
Hardness
Chloride
GKS
_
1.25
5
-
-
7.6
34
10.08
1.03
0.10
178
135
108
70
43
27
0.15
0.08
7.9
120
12.5
GKM
«.
1.25
5
-
-
4.8
27
7.03
1.03
0.10
158
134
77
81
24
19
0.11
0.08
8.0
105
15.0
GKB
_
1.25
5
-
-
6.8
53
7.53
1.21
0.11
194
121.
92
102
73
65
0.16
0.14
7.7
110
17.5
BS
1600
10
36
1448
13.2
3.2
21
7.20
1.40
0.02
123
54
67
56
69
68
0.23
0.03
7.5
30
15.0
Pond
BM
1600
10
36
1448
13.2
2.4
14
6.35
1.40
0.04
122
86
47
75
36
22
0.10
0
7.2
35
15.0
BB
1600
10
36
1448
13.2
5.6
32
7.87
1.68
0.14
153
60
69
84
93
37
0.11
0.06
6.5
60
10.0
ws
1800
10
48
. 16,232
240
4.8
31
7.00
0.84
0.11
110
85
92
18
25
13
0.20
0.05
7.7
75
10.0
WM
1800
10
48
16,232
240
4
25
5
0
0
99
83
76
23
16
8
0
0
7
70
5
.0
.74
.93
.10
.19
.05
.6
.0
WB
1800
10
48
16,232
240
6.
40
8.
1.
0.
136
72
87
49
64
43
0.
0.
7.
80
7.
4
83
12
12
34
08
0
5
-------
Table 21. WATER QUALITY DATA, PONDS, 11/9/73
Parameter
Stocking Rate
Surface Area
Water Volume
Fish Weight
Amount Fed
BOD
COD
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrate + Nitrite - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphate
PH
Hardness
Chloride
GKS
_
1.25
5
-
-
4.3
32
4.46
0.37
0.37
244
179
129
115
65
36
0.31
0.04
8.9
150
17.5
GKM
—
1.25
5
-
-
3.0
27
2.98
0.75
0.23
210
169
92
118
41
20
0.22
0.04
8.6
145 '
15.0
GKB
_
1.25
5
-
-
5.8
32
2.75
1.03
0.25
210
151
62
148
59
41
0.39
0.08
7.8
180
20.0
BS
1600
10
36
1500
13.7
4.4
33
2.76
0.47
0.19
130
69
73
57
61
46
0.23
0.02
7.7
30
15.0
Pond
BM
1600
10
36
1500
13.7
2.8
29
2.46
0.65
0.18
122
70
65
57
52
17
0.09
0.02
7.3
30
15.0
BB
1600
10
36
1500
13.7
7.2
41
5.27
0.84
0.53
139
62
52
87
77
56
0.16
0.03
6.6
45
15.0
WS
1800
10
48
18,000
266
2.
30
2.
0.
0.
101
66
59
42
35
21
0.
0.
7.
80
10.
8
47
37
05
20
01
8
0
WM
1800
10
48
18,000
266
2.4
29
2.40
0.65
0.05
98
74
51
47
24
17
0.16
0
7.5
80
5.0
WB
1800
10
48
18,000
266
4.
35
2.
0.
0.
109
79
48
61
60
30
0.
0.
6.
90
7.
4
79
75
13
21
01
7
5
-------
Table 22. WATER QUALITY DATA, POND HARVEST, 10/3/73
O
00
Parameter
Stocking Rate
Surface Area
Water Volune
Fish Weight
Amount Fed
BOD
COD
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrate + Nitrite - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended
Settleable Solids
Total Phosphate
Orthophosphate
PH
Hardness
Chloride
CS
2000
4
15
9000
189
8.8
37
9.00
0.47
0.12
132
120
75
57
12
3
0.06
0.01
8.2
65
15.0
CB
2000
4
15
9000
189
9.
39
10.
1.
0.
150
73
87
63
77
66
0.
0.
7.
85
12.
2
25
87
11
10
04
0
5
cm
2000
4
15
9000
189
9.6 <
48
9.33
1.21
0.29
130
82
81
49
48
13
0.12
0.04
6.8
70
15.0
CD 2
2000
4
15
9000
189
8.4
51
11.92
0.84
0.25
135
111
94
41
24
19
0.21
O'.Ol
6.9
60
15.0
Pond
CD3
2000
4
15
9000
189
10,
41
8.
0.
0.
161
103
82
79
58
32
0.
0.
6.
90
25.
4
58
93
23
11
06
6
0
CD4
2000
4
15
9000
189
10.4
58
10.25
1.12
0.39
215
108
98
117
107
86
0.28
0.05
6.3
90
15.0
CDS
2000
4
15
9000
189
12.8
72
12.58
1.49
0.47
245
117
133
112
128
123
0.45
0.19
6.1
70
15.0
CD6
2000
4
15
9000
189
11.2
60
10.67
1.21
0.33
208
117
118
90
91
71
0.27
0.04
6.2
85
15.0
CD7
2000
4
15
9000
189
8.6
52
8.25
0.19
0.13
146
93
83
63
53
50
0.28
0.16
6.2
55
12.0
-------
Table 23. WATER QUALITY DATA, RACEWAYS, 6/13/73
Parameter —
Stocking Rate
No. of Units
Flow Rate
Fish Weight
Amount Fed
Dissolved Oxygen
BOD
COD
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrite + Nitrate - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Or thophosphat e
PH
Hardness
Chloride
Water Temperature
Raceway
EG1
2000
7
350
6338
101
7.9
1.4
5
3.46
0.09
0.12
129
78
48
81
45
14
0.31
0.20
7.3
20
10.0
82
EG 8
2000
7
350
6338
101
8.1
2.0
9
4.65
0.09
0.17
117
72
50
67
51
34
0.17
0.16
7.2
15
10.0
82
EF1
2000
10
350
9054
144
8.2
1.9
7
4.87
0.28
0.11
147
87
32
115
23
15
0.42
0.06
7.4
10
5.0
83
EF11
2000
10
350
9054
144
7.2
2.6
10
4.08
0.28
0.12
100
85
55
45
60
23
0.24
0.05
7.2
10
7.5
82
EDI
1500
16
350
10,864
172
8.4
1.7
8
6.64
0.19
0.55
126
78
68
58
48
13
0.13
0.01
7.2
20
10.0
85
ED17
1500
16
350
10,864
172
7.9
2.7
18
9.56
0.37
0.83
168
72
78
90
96
71
0.43
0.03
7.2
20
7.5
85
-------
Table 24. WATKR QUALITY DATA, RACEWAYS, 6/25/73
Parameter
Stocking Rate
No. of Units ..
Flow Rate
Fish Weight
Amount Fed
Dissolved Oxygen
BOD
COD
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrite + Nitrate - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphate
PH
Hardness
Chloride
Water Temperature
Raceway
EG I
2000.
7.
350.
7288.
116.
6.8
6.3
20.
4. 94
0.09
o:il
78.
28.
37.
41.
50.
46.
0.13
0.07
7.4
20.
10.0
85.
EG8
2000.
7.
350.
7288.
116.
7.0
6.5
26.
5.63
0.09
0.15
98.
57.
42.
56.
41.
30.
0.08
0.06
8.1
15.
10.0
83.
EF1
2000.
10.
350.
10411.
165.
7.3
6.5
26.
5.48
0.19
0.09
98.
67.
26.
72.
31.
13.
0.14
O.Q4
'8.3
15.
5.0
86.
EF11
2000.
10.
350.
10411.
165.
6.7
7.3
31.
4.57
0.19
0.13
75.
60.
33.
42.
15.
14.
0.22
0.22
8.2
20.
10.0
82.
EDI
1500.
16.
350.
12493.
198.
7.9
5.7
36.
9.30
0.19
0.19
108.
80.
68.
40.
28.
22.
0.12
0.08
8.3
15.
7.5
85.
EDI 7
1500.
16.
350.
12493.
198.
6.7
6.1
48.
12.41
0.47
0.26
202.
106.
82.
120.
96.
48.
0.17
0.05
8.6
15.
10.0
84.
-------
Table 25. WATER QUALITY DATA, RACEWAYS, 7/9/73
Parameter
Stocking Rate
No. of Units
Flow Rate
Fish Weight
Amount Fed
Dissolved Oxygen
BOD
COD
Total KJeldahl Nitrogen
Ammonia Nitrogen
Nitrite + Nitrate - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphate
PH
Hardness
Chloride
Water Temperature
Raceway
EG1
2000.
7.
350.
8396.
133.
8.9
5.2
21.0
7.12
0.14
0.27
180.
127.
71.
109.
53.
19.
0.13
0.05
7.8
15.
10.0
84.
EG8
2000.
7.
350.
8396.
133.
8.1
8.8
21.
15.86
1.12
0.32
218.
125.
78.
140.
93.
9.
0.13
0.03
7.8
20.
10.0
84.
EF1
2000.
10.
350.
11994.
190.
8.4
4.8
10.
10.54
0.98
0.27
153.
105.
41.
112.
48.
22.
0.32
0.20
7.8
18.
7.5
85.
EF11
2000.
10.
350.
11994.
190.
8.1
5.2
20.
9.66
1.22
0.33
176.
120.
66.
110.
56.
10.
0.20
0.08
7.8
17.
10.0
83.
EDI
1500.
16.
350.
14393.
228.
8.5
3.2
32.
9.90
0.30
0.14
168.
84.
109.
67.
84.
51.
0.08
0.05
7.9
15.
7.5
82.
EDI 7
1500.
16.
350.
14393.
228.
8.9
11.2
34.
13.20
0.56
0.21
219.
117.
86.
133.
102.
46.
0.61
0.03
7.8
17.
10.0
82.
-------
Table 26. WATER QUALITY DATA, RACEWAYS, 7/25/73
Parameter
Stocking Rate
No. of Units
Flow Rate
Fish Weight
Amount Fed
Dissolved Oxygen
BOD
COD"
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrate + Nitrite - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphate
PH
Hardness
Chloride
Water Temperature
EG1
2000
7
350
9662
153
8.4
5.2
34
7.78
0.19
0.15
154
77
69
85
77
67
0.83
0.45
7.3
20
7.5
84
EG8
2000
7
350
9662
153
7.4
4.4
44
9.16
0.09
0.19
240
121
96
144
119
61
0.17
0.12
7.3
25
10.0
83
EF1
2000
10
350
13,804
219
8.4
7.2
36
9.23
0.37
0.27
149
44
55
94
105
94
0.26
0.08
7.3
30
10.0
84
Raceway
EF11
2000
10
350
13,894
219
6.3
6.4
40
7.42
0.19
0.23
171
34
100
71
137
106
0.18
0.06
7.2
20
7.5
85
EDI
1500
16
350
16,564
263
7.6
3.6
24
7.28
0.09
0.21
123
30
70
53
93
30
0.04
0.02
7.3
20
10.0
86
ED17
1500
16
350
16,564
263
7.6
8.8
40
10.28
0.09
0.37
104
11
41
63
93
20
0.55
0.07
7.3
15
10.0
85
-------
Table 27. WATER QUALITY DATA, RACEWAYS, 8/9/73
Parameter —
Stocking Rate
No. of Units
Flow Rate
Fish Weight
Amount Fed
Dissolved Oxygen
BOD
COD
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrite + Nitrate - N
Total Solids >
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphate
pH
Hardness
Chloride
Water Temperature
Raceway
EG1
2000
7
350
10,929
173
6.8
3.6
14
7. '35
0.19
0.32
158
312
68
90
46
38
0.99
0.07
7.5
20
10.0
82
EG 8
2000
7
350
10,929
173
5.4
10.8
26
11.67
0.37
0.41
158
50
71
87
108
87
0.93
0.06
6.7
20
10.0
82
EF1
2000
10
350
15,613
248
6.4
5.6
19
9.37
0.28
0.34
147
80
44
103
67
45
0.78
0.02
7.3
15
7.5
83
EF11
2000
10
350
15,613
248
5.3
13.6
28
11.54
0.65
0.31
179
4&
106
73
133
112
0.94
0.08
6.8
25
12.5
, 82
Edl
1500
16
350
18,736
297
5.4
4.8
5
8.06
0.65
0.48
121
53
61
60
68
10
0.96
0.07
7.5
20
10.0
81
ED17
1500
16
350
18,736
297
4.0
5.2
7
11.92
1.40
0.65
131
64
57
74
67
46
1.18
0.03
7.1
20
10.0
82
-------
Table 28. WATER QUALITY DATA, RACEWAYS, 8/17/73
Parameter
Stocking Rate
No. of Units
Flow Rate
Fish Weight
Amount Fed
Dissolved Oxygen
BOD
COD
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrite + Nitrate - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphate
PH
Hardness
Chloride
Water Temperature
SAM
1500
16
350
19,686
312
-
2.0
28
9.58
1.12
0.69
116
60
31
85
56
31
1.07
0.02
7.4
25
10.0
-
Raceway
11AM •
1500
16
350
19,686
312
-
0.8
26
8.31
0.47
0.39
123
60
26
97
63
22
1.10
0.03
7.5
25
10.0
-
ED17
5PM
1500
16
350
19,686
312
-
3.6
27
8.79
0.19
0.29
180
47
52
128
133
79
0.81
0.03
7.6
25
12.5
—
11PM
1500
16
350
19,686
312
-
J.6
19
8.06
0.65
0.46
145
62
65
80
83
58
0.54
0.05
7.5
20
12.5
-
-------
Table 29. WATER QUALITY DATA, RACEWAYS, 8/23/73
Parameter
Stocking Rate
No. of Units
Flow Rate
Surface Area
Water Volume
Fish Weight
Amount Fed
D.O.
BOD
COD
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrate + Nitrite - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Or thophosphat e
PH
Hardness
Chloride
Water Temperature
Raceway
EG1
2000
7
350
-
-
11,958
190
8.5
12.4
30
5.14
0.09
0.24
118
22
44
74
96
88
0.87
0.06
9.2
30
7.5
76
EG8
2000
7
350
-
-
11,958
190
8.5
11.6
41
13.50
0.19
0.29
141
41
45
96
100
63
0.82
0.08
8.6
20
7.5
75
EF1
2000
10
350
-
-
17,083
271
8.3
11.2
44
5.52
0.09
0.23
110
62
29
81
48
26
0.88
0.07
8.6
20
10.0
77
EF11
2000
10
350
-
-
17,083
271
8.3
14.0
49
6.22
0.19
0.27
121
23
33
88
98
93
1.02
0.04
8.7
20
7.5
76
EDI
1500
16
350
_
-
20,500
325
8.0
8.4
19
4.87
0.19
0.25
90
13
47
43
77
60
1.35
0.02
7.0
20
10.0
78
EDI 7
1500
16
350
-
-
20,500
325
7.2
8.0
29
5.05
0.19
0.24
95
41
32
63
54
38
1.02
0.01
7.2
25
12.5
78
Oxidation Pond
EGFX
o
3.4
20.2
0
0
12.0
47
5.34
0.09
0.28
142
29
31
111
113
110
0.63
0.02
9.2
20
10.0
EDX
0
7.8
47.0
0
0
9.6
20
11.17
0.28
0.26
77
10
35
42
67
60
0.91
0.02
7.3
25
10.0
_
-------
Table 30. WATER QUALITY DATA, RACEWAYS, 9/6/73
Parameter
Stocking Rate
No. of Units
Flow Rate
Surface Area
Water Volume
Fish Weight
Amount Fed
D.O.
BOD
COD
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrate f 'Nitrite - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Ort hophosphat e
PH
Hardness
Chloride
'Water Temperature
Raceway
EG1
2000
7
350
-
-
13,067
207
7.2
6.4
8
4.16
0
0.17
152
66
82
70
86
59
0.60
0.04
8.4
30
5.0
84
EG8
2000
7
350
-
-
13,067
207
7.
8.
36
4.
0.
0.
147
42
86
61
105
91
0.
0.
6.
20
10.
84
2
0
23
09
22
60
07
9
5
EF1
2000
10
350
-
-
18,667
296
8
6
16
3
0
0
126
54
43
83
72
66
1
0
7
20
10
84
.1
.0
.40
.47
.18
.15
.06
,8
.0
EF11
2000
10
350
-
-
18,667
296
8.
7.
32
5.
0.
0.
138
105
97
41
133
133
0.
0.
7.
30
10.
84
1
6
18
75
15
75
36
0
0
EDI
1500
16
350
-
-
22,400
356
10.3
5.2
8
7.05
0.19
0.21
145
84
73
72
61
24
1.35
0.09
7.2
20
20.0
83
Oxidation Pond
ED17
1500
16
350
-
-
22,400
356
8.1
1.2
26
5.74
0.75
0.28
154
102
84
70
52
46
0.90
0.14
6.0
30
12.5
82
EGFX
0
-
-
3.4
20.2
0
0
-
10.0
40
4.07
0.37
0.29
174
75
76
98
99
34
1.31
0.02
6.5
40
10.0
-
EDX
0
-
-
7.8
47.0
0
0
-
1.2
23
3.49
0.37
0.19
119
79
60
59
40
31
0.07
0.04
6.5
17
8.5
-
-------
Table 31. WATER QUALITY DATA, RACEWAYS, 9/19/73
Parameter
Stocking Rate
No. of Units
Flow Rate
Surface Area
Water Volume
Fish Weight
Amount Fed
D.O.
BOD
COD
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrate -f Nitrite - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphat e
PH
Hardness
Chloride
Water Temperature
Raceway
EC1
2000
7
3?0
-
-
14,096
224"
8.8
5.6
8
5.85
0.19
0.17
126
62
si
75
64
13
0.65
0.06
7.7
30
10.0
77
EG 8
2000
7
350
-
-
14,096
224
8.2
9.2
35
7.93
0.47
0.32
177
94
82
95
83
50
0.79
0.04
6.8
31
8.5
76
EF1
2000
10
350
-
-
20,137
320
8.4
6.4
22
9.00
0.28
0.18
163
82
54
109
81
70
0.66
0
7.0-
38
9.5
77
EF11
2000
10
350
-
-
20,137
320
8.0
8.0
30
6.66
0.37
0.22
136
90
60
76
46
15
0.52
0.03
7.0
40
8.5
77
EDI
1500
16
350
-
-
24,164
384
9.0
6.4
41
7.47
0.37
0.34
141
94
60
81
47
17
0.49
0.03
7.4
40
12.5
77
Oxidation Pond
ED17
1500
16
350
-
-
24,164
384
7.8
8.0
42
7.47
0.75
0.41
169
61
63
106
108
63
0.24
0.03
7.1
30
10.0
77
EGFX
_
-
-
3.' 4
20.2
0
0
-
8.0
32
6.05
0.28
0.23
143
63
51
92
80
61
0.92
0.02
7.5
35
10.0
-
EDX
_
-
-
7.8
47.0
0
0
-
6.4
20
6.22
0.28
'0.24
126
91
44
82
35
17
0.35
0.08
7.6
30
12.5
-
-------
Table 32. WATER QUALITY DATA, RACEWAYS, 8/14/73
00
Raceway
Parameter
Stocking Rate
No. of Units
Flow Rate
Fish Weight
Amount Fed
D.O.
BOD
COD
Total Kjeldahl Nitrogen
Anmonla Nitrogen
Nitrate * Nitrite - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphat e
pH
Hardness
Chloride
Water Temperature
5
TR1
2250
8
530
12,983
159
-
7.5
31
5.76
0
0.11
147
116
82
65
31
5
0.64
0.11
7.1
70
17.5
-
AM
TR8
2250
8
530
12,983
159
-
3.3
39
8.17
0.65
0.13
189
138
133
56
51
28
0.62
0.17
6.8
80
15.0
-
11
TR1
2250
8
530
12,983
159
-
5.8
30
6.58
0.84
0.32
171
118
91
80
53
16
0.62
0.28
7.0
70
15.0
-
AM
TR8
2250
8
530
12,983
159
-
4.2
31
8.62
0.93
0.44
235
136
93
142
99
94
0.92
0.32
6.8
80
15.0
-
5 PM
TR1
2250
8
530
12,983 12
159
-
4.9
26
5.26
0.47
0.24
150
121
82
68
29
25
0.87
0.26
6.8
75
15.0
-
TR8
2250
8
530
,983
159
-
5.3
30
10.85
0.56
0.15
199
132
79
120
67
54
0.66
0.24
6.6
70
15.0
-
11
TR1
2250
8
530
12,983
159
-
4.1
21
4.42
0.56
0.11
144
117
78
66
27
26
0.44
0.07
7.1
80
15.0
-
PM
TR8
2250
8
530
12,983
159
_
6.1
33
10.70
0.75
0.13
179
113
82
97
66
61
0.60
0.20
6.9
70
15.0
-
-------
Table 33, WATER QUALITY DATA, RACEWAYS, 9/4/73
Raceway
Parameter
Stocking Rate
No. of Units
Flow Rate
Fish Weight
Amount Fed
D.O.
BOD
COD
Total KJeldahl Nitrogen
Ammonia Nitrogen
Nitrate + Nitrite - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphate
pH
Hardness
Chloride
Water Temperature
5 AM
TR1
2250
8
530
14,943 14
183
-
5.6
16
5.30
0
0.06
180
105
123
57
75
70
0.50
0,10
6.8
75
20.0
-
TR8
2250
8
530
,983
183
-
1.6
30
7.15
0.28
0.13
191
107
101
90
84
46
1.50
0.06
6.6
70
20.0
-
11 AM
TR1
2250
8
530
14,983
183
-
4.8
4
4.06
0.47
0.12
153
115
84
69
38
13
0.60
0.03
6.5
80
17.5
-
TR8
2250
8
530
14,983
183
.
3.2
31
5.57
0.56
0.10
171
145
83
88
26
22
0.70
0.07
6.5
75
15.0
-
5
TR1
2250
8
530
14,983
183
.
4.0
15
5.19
0.65
0.18
178
122
110
68
56
51
1.20
0.01
7.5
80
17.5
-
PM
TR8
2250
8
530
14.983
183
-
4.8
40
11.67
0.65
0.12
192
82
112
80
110
104
1.93
0.10
6.9
75
17.5
-
11
TR1
2250
8
530
14,983
183
-
4.4
17
5.02
0.47
0.07
188
88
135
53
100
78
0.98
0.03
7.0
80
17.5
-
PM
TR8
2250
8
530
14,983
183
-
7.2
43
10.08
0.56
0.14
202
131
117
85
71
42
1.10
0.13
7.4
75
20.0
-
-------
Table 34. WATER QUALITY DATA, RACEWAYS, 10/3/73
to
O
Parameter
Stocking Rate
No. of Units
Flow Rate
Fish Weight
Amount Fed
Dissolved Oxygen
BOD
COD
Total Kjeldahl Nitrogen
Ammonia Nitrogen
Nitrite + Nitrate - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixeft Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphate
PH
Hardness
Chloride
Water Temperature
TR1
2250
8
530
17,650
216
-
7.2
42
7.12
0.84
0.30
161
77
93
68
84
57
0.13
0
7.2
90
15.0
-
Raceway
TR8
2250
8
530
17,650
216
-
12.4
75
26.41
1.96
0.54
524
149
227
297
375
186
0.95
0.82
7.1
95
10.5
-
-------
Table 35. WATER QUALITY DATA, RACEWAYS, 10/18/73
Stocking Rate
No. of Units
Flow Rate
Surface Area
Water Volume
Fish Weight
Amount Fed
Dissolved Oxygen
BOD
COD
Total Kjeldahl Notrogen
Ammonia Nitrogen
Nitrite + Nitrate - N
Total Solids
Total Dissolved Solids
Total Volatile Solids
Total Fixed Solids
Total Suspended Solids
Settleable Solids
Total Phosphate
Orthophosphate
PH
Hardness
Chloride
Water Temperature
Reservoir
TPO
0
-
-
5
20 '
-
0
-
3.2
15
8.00
0.65
0.27
213
126
81
132
87
54
0.18
0.09
7.6
110
10.0
-
Raceway
TRT
2250
. 8
530
-
-
19,050
233
.
1.2
20
7.92
0.47
0.25
177
144
69
108
33
29
0.29
0.02
7.1
120
15.0
-
TR8
2250
8
530
-
-
19,050
233
_
3.2
39
7.82
0.93
0.33
218
131
89
129
87
54.
0.71
0.15
7.4
120
12.5
-
TD1
2250
8
530
-
-
19,050
233
_
7.2
62
9.58
1.77
0.48
292
118
69
223
174
80
1.32
0.65
6.9
135
15.0
-
TD2
2250
8
530
-
-
19,050
233
_
4.0
40
8.44
1.31
0.33
250
104
128
122
146
84
3.30
0.81
6.2
125
10.0
-
TD3
2250
8
530
-
-
19,050
233
_
10.0
76
9.67
2.52
0.58
292
136
77
215
156
136
2.40
1.30
7.3
150
10.0
-
-------
SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
.'. Re port No.
2.
w
5. Report Daie
6.
Pollution Aspects of Catfish Production—Review and Projections 8. i .--formi. g Org*..;z*titm
Author(s) Barker, James C., Chesness, Jerry L., and '
Smith, Ralph E.
Agricultural Engineering Department
University of Georgia
Athens, GA 30602
801662
j. Type. ;• Repo i and
Period Covered
12. Si>c>nsoria~ Oigani ztion __.
£iTA
15. .. ::•. ;, - Environmental Protection Agency Report Number EPA - 660/2 -
74 - 064, July 1974
A literature review and field study was undertaken to determine the waste
concentrations and discharge loadings occurring in the waters from catfish-culturing
ponds and raceways. Water quality analyses were performed on samples taken during
a 240-day growing season and at drawdown (assuming drainage at harvest).
The natural biological degradation of the raw wastes in the ponds and raceway
systems resulted in BOD reductions of 96.8% and 98.0% respectively when compared to
waste levels produced in indoor single pass tank systems with no waste removal
facilities. Reductions in total nitrogen of 97.2% and 97.7% occurred in ponds and
raceways respectively, while ammonia nitrogen was reduced by 97.4% and 99.4%
respectively. Sedimentation and biodegradation resulted in an 83.6% reduction in
suspended solids in ponds and an 86.2% suspended solids reduction in raceways.
Total phosphate levels were reduced by 98.5% and 97.4% in ponds and raceways
respectively.
This report was submitted in fulfillment of Grant No. 801662 under the sponsorship
of the Office of Research and Development, United States Environmental Protection
Agency.
17a. Descriptors
Catfish Production, Water Quality in Ponds and Raceways
17b. Identifiers
Waste Concentrations, Waste discharge, Biological organic removal
J7c. CO WRR Field & Group
18.
Security Class.
Repc: .«
Se • :ityC s.
21.
ffo. of
Pages
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
US DEPARTMENT OF THE INTERIOR
WASHINGTON. D C. 2O24O
Chesness. Jerry L.
IVRSiC 1C .-- REV INf i '-'
------- |