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ABSTRACT

THE EFFECT OF NUTRIENT ENRICHMENT ON PRIMARY
PRODUCTION IN MICHIGAN FARM PONDS

By
Albert Massey

Three farm ponds were fertilized with phosphorus and nitrogen
to determine the response of the primary producers. One was fertil-
ized with phosphorus and nitrates to approximate enrichment with
primary sewage effluent; another to approximate secondary sewage
effluent; a third to approximate tertiary effluent; and a fourth was
unfertilized to serve as a control.

Water samples were monitored for temperature, dissolved oxy-
gen, pH, alkalinity, soluble phosphorus, total phosphorus and nitrate.
Primary producers were also monitored. Changes in water chemistry
were exhibited by all the treated ponds. In general, the severity of
the changes produced by the treatments was relative to the nutrient
load received. The highest nutrient loading rate caused the greatest
fluctuations in mean dissolved oxygen concentrations, pH and alka-
linity.

The phosphorus and nitrogen concentrationS'hithe fertilized
ponds never reached the theoretical concentration and decreased

rapidly, shortly after fertilization. The rapid decline of phosphate

Albert Massey

was probably due to a comination of factors, including bacterial
activity, absorption, intake by plants and precipitation with Ca++.
The decline in nitrate was biogenic in origin.

Fertilizer-induced changes in productivity or standing crop
of the macrophytes, phytoplankton and periphyton were observed under
the conditions of the study. Results indicate that the highest
nutrient loads favored the production of phytoplankton, and the
lower nutrient loads favored the production of periphyton. Macro-

phyte production was highest in the control pond.

THE EFFECT OF NUTRIENT ENRICHMENT ON PRIMARY
PRODUCTION IN MICHIGAN FARM PONDS

By

Albert Massey

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE

Department of Fisheries and Wildlife

T976

ACKNOWLEDGMENTS

I extend my sincere thanks and appreciation to Dr. Robert C.
Ball for his assistance, guidance and encouragement throughout my
graduate program. Also, I would like to thank Drs. Niles R. Kevern
and Frank M. D'itri for their assistance and for serving as committee
members.

I greatly appreciate the understanding and assistance given
by my wife Louise.

Finally, I am very grateful to the Agriculture Experiment
Station of Michigan State University for their financial support

throughout my graduate program.

ii

TABLE OF CONTENTS

Page
LIST OF TABLES . . . . . . . . . . . . . . . . v
LIST OF FIGURES . . . . . . . . . . . . . . . . vii

INTRODUCTION . . . . . . . . . . . . . . . . . l
LITERATURE REVIEW . . . . . . . . . . . . . . . 3
DESCRIPTION OF STUDY AREA . . . . . . . . . . . . ll
METHODOLOGY . . . . . . . . . . . . . . . . . l6

Fertilization Rates . . . . . . . . . . . . 16

Phosphorus Application . . . . . . . . . . . l6
Nitrogen Application . . . . . . . . . . . . l9

Water Exchange . . . . . . . . . . 20
Physical and Chemical Parameters . . . . . . . . 2l
Temperature . . . . . . . . . . . . . . 2l

Dissolved Oxygen . . . . . . . . . . . . 2l
pH . . . . . . . . . . . . . . . . . 22
Alkalinity . . . . . . . . . . . . . . 22
Phosphorus . . . . . . . . . . . . . . 22
Nitrate—Nitrogen . . . . . . . . . . . . 23
Biological Parameters . . . . . . . . . . . . 24
Macrophytes . . . . . . . . . . . . . . 24
Phytoplankton . . . . . . . . . . . . . 25
Periphyton . . . . . . . . . . . . . . 27

RESULTS AND DISCUSSION . . . . . . . . . . . . . 29

General Ecological Considerations . . . . . . . 29
Physicochemical Characteristics of Pond A . . . . . 30
Temperature . . . . . . . . . . . . . . 30
Oxygen . . . . . . . . . . . . . . 33
Alkalinity and pH . . . . . . . . . . . . 35
Phosphorus Concentrations . . . . . . . . . 36
Nitrogen . . . . . . . . . . . . . . . 37
Macrophytes . . . . . . . . . . . . . . 4l
Phytoplankton . . . . . . . . . . . . . 45
Periphyton . . . . . . . . . . . . . . 48

Physicochemical Characteristics of Pond B . . . . . 50

Temperature . . . . . . . . . . . . . . 50
Oxygen . . . . . . . . . . . . . . SO
Alkalinity and pH . . . . . . . 5l

Phosphorus and Nitrate Concentrations . . . . . 52
Macrophytes . . . . . . . . . . . . . . 52
Phytoplankton . . . . . . . . . . . . . 58
Periphyton . . . . . . . 59
Physicochemical Characteristics of Pond C . . . . . 60
Temperature . . . . . . . . . . . . . . 60
Oxygen . . . . . . . . . . . . . . 6l
Alkalinity and pH . ' . . . . . 6l
Phosphorus and Nitrate Concentrations . . . . . 63
Macrophytes . . . . . . . . . . . . . . 63
Phytoplankton . . . . . . . . . . . . . 68
Periphyton . . . . . . . 68
Physicochemical Characteristics of Pond D . . . . . 69
Temperature . . . . . . . . . . . . . . 69

Oxygen . . . . . . . . . . . . . . 69
Alkalinity and pH . . . . . . . . 7l
Phosphorus and Nitrate Concentrations . . . . . 7l
Macrophytes . . . . . . . . . . . . . . 72
Phytoplankton . . . . . . . . . . . . . 76

Periphyton . . . . . . . . . . . . . . 76

GENERAL RESULTS . . . . . . . . . . . . . . . . 77
Dissolved Oxygen . . . . . . . . . . . . . 77
Phosphorus . . . . . . . . . . . . . . 80
Primary Production . . . . . . . . . . . . . 93

SUMMARY . . . . . . . . . . . . . . . . . . 104

LITERATURE CITED . . . . . . . . . . . . . . . 106

iv

LIST OF TABLES

Table

1. Physical Dimensions of Lake City Experimental Ponds,
Lake City, Michigan, 1970 . . . . .

2. Aquatic Plants in Lake City Ponds, June, l97O .

3. Dates of Nutrient Enrichment and Quantities Added in
Experimental Ponds . . . . . . .

4. Concentration of Selected Chemical Constituents in
Pond A, Lake City, Michigan, l97O .

5. Observed and Theoretical Total Phosphorus Concentra-
tions in Pond A, Lake City, Michigan, l97O

6. Standing Cr0p (biomass) of Primary Producers in Pond A,
Lake City, Michigan, 1970 . . . .

7. Concentration of Selected Chemical Constituents in
Pond 8, Lake City, Michigan, l97O

8. Observed and Theoretical Total Phosphorus Concentra-
tions in Pond 8, Lake City, Michigan, l97O

9. Standing Crop (biomass) of Primary Producers in Pond B,
Lake City, Michigan, l97O . . . . .

lO. Concentration of Selected Chemical Constituents in
Pond C, Lake City, Michigan, l97O . .

ll. Observed and Theoretical Total Phosphorus Concentra-
tions in Pond C, Lake City, Michigan, 1970

l2. Standing Crop (biomass) of Primary Producers in Pond
C, Lake City, Michigan, l970 . .

l3. Concentration of Selected Chemical Constituents in
Pond D, Lake City, Michigan, l970 .

l4. Standing Crop (biomass) of Primary Producers in Pond
D, Lake City, Michigan, 1970 . . . .

Page

14
15

18

34

38

44

53

54

57

62

64

67

70

73

Table
15. Percent Dissolved Oxygen Saturation in Michigan
State University, Lake City Experiment Ponds,
l97O . . . . . . . . . . .
l6. Mean and Range of Total and Soluble Phosphorus Con-

centrations in Michigan State University
Experimental Ponds, l97O .

l7. Estimate of Mean Standing Crop of Primary Producers
in Lake City, Michigan Ponds, l97O . .

vi

Page

79

81

94

LIST OF FIGURES

Figure Page

l. Location and diagram of the Michigan State Univer-
sity Experimental Ponds at Lake City, Michigan,
l97O . . . . . l2

2. The daily maximum and minimum air and water tempera-
tures in Lake City ponds during. the study period,
l97O . . . . . 3l

3a. Macrophyte standing crop in Pond A, Lake City,
Michigan, 1970 . . . . . . . 42

3b. Phytoplankton standing crop as determined by
chlorophyll a concentrations in Pond A, Lake City,
Michigan, l97O . . . . . . . . . . . . 42

3c. Periphyton production rates and standing crop in
Pond A, Lake City, Michigan, 1970 . . . . . . . 42

4a. MacrOphyte biomass (dry weight) in Pond 8, Lake
City, Michigan, l97O . . . . . . . 55

4b. Phytoplankton biomass as determined by chlorophyll
concentrations in Pond 8, Lake City, Michigan,
l97O . . . . . . . . . . . . . . . 55

|m

4c. Periphyton production rates and standing crop in
Lake City, Michigan, 1970 . . . . . . . . . 55

5a. Macrophyte biomass (dry weight) in Pond C, Lake
City, Michigan, l97O . . . . . . . 65

5b. Phytoplankton biomass as determined by chlorophyll
concentrations in Pond C, Lake City, Michigan,
l97O . . . . . . . . . . . . . . . 65

In:

5c. Periphyton production rates and standing cr0p in
Pond C, Lake City, Michigan, 1970 . . . . . . . 65

6a. Macrophyte biomass (dry weight) in Pond D, Lake
City, Michigan, l97O . . . . . . . 74

vii

Figure

6b.

6c.

10.

Phytoplankton biomass as determined by chlorophyll a_

concentration in Pond D, Lake City, Michigan,
1970 . . . . . . . .

Periphyton production rates and standing crop in
Pond D, Lake City, Michigan, 1970 . .

Total phosphorus concentrations observed in experi-
mental ponds in Lake City, Michigan, 1970

Standing crop of macrophytes (biomass) observed in
Lake City, Michigan Experimental Ponds, 1970

Standing crop of phytoplankton (biomass) observed
in Lake City, Michigan Experimental Ponds, 1970

Standing crop of periphyton observed in Lake City,
Michigan Experimental Ponds, 1970.

viii

Page

74

74

82

96

99

101

 

INTRODUCTION

Eutrophication (enrichment) of natural waters is one of the
most significant causes of water quality problems in North America
(Lee, 1970). The term is usually defined as meaning an enrichment
of water by plant nutrients through either man-created or natural
means (Mackenthun, 1968). Man, with his current waste disposal and
farming practices, has accelerated this natural process with the
result being increased primary production (Lee, 1973).

Primary production is the process by which plants change
inorganic matter and solar energy into energy containing material
which acts as the base for the aquatic food chain. Primary producers
can be separated into three general categories: (1) phytoplankton,
(2) periphyton, (3) higher aquatic plants (Wetzel, 1964).

Primary producers play a vital role in the aquatic environ-
ment (Mulligan, 1969). Some of the functions primary producers per-
form are to oxygenate the water, serve as a base for the food web,
convert inorganic material to organic material, and store plant
nutrients. However, excessive growth of higher aquatic plants and
algae can have a detrimental effect on the aquatic community. Exces-
sive primary production can result in the destruction of fisheries
(Scultorpe, 1967), block irrigation ditches (Nestlake, 1960), inter-
fere with navigation (Boughey, 1963), affect public health (Holm

 

gt 11., 1969), and affect the recreational uses of a body of water
(Little, 1966).

Scientists agree that the way to slow cultural eutrophica-
tion is to find the key factor limiting primary production and limit
its input to our waterways.

The question of "What limits the primary producers?" is com—
plicated by the fact that the aquatic ecosystem is a multifactor
system which is in dynamic equilibrium. The equilibrium is estab-
lished by the particular geochemical character and biota of the lake
and as a result the isolation of a single limiting factor from various
lake types has proved a difficult and confusing task.

The objectives of this research project were:

1. To conduct an in sitg_bioassay to determine if

phosphorus and nitrogen are the factors limiting
primary production in typical Michigan farm
ponds.

2. To quantify the biological response of primary

producers to various concentrations of growth
limiting nutrients.

LITERATURE REVIEW

Part I of this research project is based on Liebig's law of
the minimum which states that "growth is limited by the substance
that is present in minimal quantity in respect to the needs of the
organism" (Liebig, 1840).

Investigators do not always agree on the element limiting
primary production. These are reasonable findings because any one
of the fifteen major elements needed for growth which is in short
supply may limit growth. Due to particular geochemical situations
some of the following have been found to be limiting: nitrogen,
phosphorus, iron, sodium, silicon, copper, carbon and vitamin 812
(Vollenweider, 1968). If any one of these elements which is in short
supply is added to an aquatic system, primary production will increase
until some other element becomes limiting.

One of the confusing factors of the nutrient controversy is
that algae and aquatic plant species vary in their nutritive require~
ments. Minor changes in nutrient levels may bring about succession
of one species by another because of slight physiological advantages
in competition for nutrients (Hutchinson, 1944). As trophic levels
change, i.e., from oligotrophic to eutrophic, plankton populations
become more and more dominated by less desirable species of algae

such as the bluegreens (Rawson, 1956).

Netzel (1965) points out that in the past the problem has
been attacked by determining as many physical and chemical parameters
as possible and then seeking correlation between these fluctuating
parameters and oscillations in the growth of algae. He further
states that the relationship is not simply related to a single domi-
nant influencing factor. The instantaneous concentrations may
also indicate actual influencing quantities of a limiting factor or
be the resultant product of a regeneration of a declining population
peak. Problems of rapid turnover, re-utilization, and even storage
of some materials negate the value of results of the analysis to a
large extent. Some critical factors such as dissolved organic com-
pounds are ignored because of the present inability or difficulty in
determining their concentrations. In natural situations, limiting
factors are relative and highly dynamic.

This is in agreement with Moss (1967) who points out chemical
analysis of lake waters will not necessarily indicate potentially
limiting nutrients since the environment is a dynamic system with
constant interaction between biotic and abiotic factors.

Phosphorus usually occurs in natural waters in the form of
phosphates. Biologically, phosphorus is one of the most important
elements. Phosphorus is necessary to create high energy phosphate
bonds. Adenosine diphosphate (ADP) converted to adenosine triphos-
phate stores energy which is later released and is the fuel for all
biochemical work within cells. The photosynthetic fixation of carbon
would be fruitless if it were not followed by the phosphorylation

of the sugar product. Thus, one atom of phosphorus per molecule of

adenosine is absolutely necessary. No organism could live without
phosphorus (Deevey, 1970).

The theory that phosphorus is the limiting element in the
aquatic ecosystem has been in existence since the infancy of lim-
nology. Atkins (1923) postulated that phosphorus might be the
limiting factor in phytoplankton production in the sea. In 1931
Prescott found acorrelation between the phosphorus content and
production of plankton in Iowa lakes. He went on to theorize that
the type of flora in a lake might be influenced by the difference in
phosphate content. Yoshimura (1932) concluded that total phosphate
was the limiting factor during certain periods of the year. Chu
(1942, 1943), while trying to develop a culture medium for optimum
algae growth, found that algae were limited when the concentration
of nitrogen and phosphorus dropped below 0.1 mg/l and 0.009 mg/l,
respectively.

Investigations of Wisconsin lakes by Sawyer gt 21, in 1945
popularized the idea that phosphorus was the limiting element in
the growth of algae. Of the 17 lakes studied, a concentration of
0.015 mg/l inorganic phosphorus at the time of the spring turnover
seemed to be the value below which few blooms of algae would develop.
Although it was never Sawyer's intention to set a minimum concentra-
tion for which phosphorus would be limiting, many authorities have
used this concentration for a standard. Numerous investigations
(Ball, 1948; Rodhe, 1948; Hasler and Einsele, 1948; Hutchinson and
Bowen, 1950; Thomas, 1953; Ketchum, 1954; Sawyer, 1954; Gerloff and
Skoog, 1957; Putnam and Olson, 1960; Hooper and Ball, 1964; Netzel,

1966; Edmondson, 1970) have, through independent research, found that
phosphorus is usually the element limiting the growth of algae and
aquatic plants. Over 40 years of research has led investigators to
the understanding that phosphorus is the limiting factor in most
aquatic systems.

However, there have been findings from limnologists which do
not agree that phosphorus is the limiting element. Due to shifting
equilibrium, phosphorus may be limiting at one time during the year
and nitrogen at another time (Yoshimura, 1932). In other situations
where large amounts of phosphorus are available, nitrogen may become
limiting (Shapiro and Ribeiro, 1965).

Investigators have found that tr0phic increases in Lake
Michigan have led to a change in the silicon cycle. The diatom popu-
lation in the last 20 years has utilized silicon at a greater rate
than the amount supplied from all sources relative to other essential
nutrients. Continued depletion of silicon will tend to favor pro-
liferation of phytoplankton other than diatoms and could result
in blooms of blue-green or other undesirable algae (Schelske and
Callender, 1970).

Blue-green algae, which cause most noxious blooms, have the

ability to fix atmospheric nitrogen. Nostoc paludosum was found to

 

fix atmospheric nitrogen as long as there was a sufficient supply of
phosphorus. Low nitrate values are commonly associated with blooms

of blue-green algae, presumably due to the ability of these algae to
fix nitrogen and flourish when nitrogen is in short supply for other

algae (Schelske _e_i_; g” 1970).

The nitrate nitrogen concentration in the Upper Great Lakes
can be used to show that nitrogen is not the primary factor in the
eutrophication of the Great Lakes. Lake Superior was found to have
the highest nitrate concentration of the Great Lakes (Putnam and
Olson, 1960); however, the nitrate was not used because the low
phytoplankton population was limited by some other factor, probably I
phosphorus. In the other Great Lakes the nitrate concentrations were
lower due to utilization by phytoplankton. Lake Michigan studies

show that when phosphorus was added the algae were able to use the

 

nitrogen (Schelske and Stoermer, 1971).

In Lake Erie blue-green algae populations most likely would
not be reduced by the control of inorganic nitrogen, since blooms
presently occur after this nutrient has all but disappeared from the
lake in summer. It appears, however, that maximum populations, but
not period of dominance, can be limited by phosphorus control
(Hartley and Potos, 1971).

Three recent papers concerning the importance of carbon in
biological systenm.(Kuentzel, 1969, 1970, 1971) have been widely pub-
licized. The papers are basically literature reviews. They propose
that carbon, not phosphorus, is the key limiting factor. Kerr gt_al,
(1970) conducted a bioassay study on laboratory medium and infertile
pond waters. Under the conditions of the study, where other nutri-
ents were in adequate supply, carbon was limiting.

King (1970) comes to the conclusion that carbon can be limit-
ing in situations where phosphorus and nitrogen are in adequate

supply. In oligotrophic, mesotrophic and many eutrophic waters the

carbon supply (from inorganic sources in the water, daily increment,
the atmosphere, bacterial degradation of autochthonous and alloch-
thonous material) would be more than adequate to force some other
factor to be limiting (Goldman gt al., 1971). In any event, the
overwhelming bulk of evidence indicates that in aquatic systems
normally encountered in nature, phosphorus limits primary production.

Part II of this project deals with the response of the pri-
mary producers to nutrient enrichment. Most of the research which
has been done on the effect of enrichment has been done in ponds in
relation to fish production. The fertilization of ponds to increase
fish production dates back to the early days of China (Swingle gt 11.,
1963). Nutrient enrichment increases primary production. The end
result is an increase in food available to all higher trophic levels.

However, fertilization appears to affect the components of
the primary producers in various ways. In the southeastern United
States the fertilization of ponds with phosphorus, nitrogen and
potassium is used to control macrophytes (Smith and Swingle, 1942).
Fertilization proved to be effective in producing a rapid growth of
phytoplankton which, by shading out sunlight, prevented the growth
of submerged macrophytes. Fertilization of ponds in the southeast
was for the purpose of increasing fish production and to control
aquatic plants.

Not all enrichment studies have resulted solely in an increase
in phytoplankton. Neess (1949) found that phosphate fertilizer often
would stimulate the growth of macrophytes. Another difficulty fre-

quently experienced has been the appearance of a heavy growth of

filamentous algae which is detrimental to the designated use of the
ponds.

Fertilizer applied in the early spring or late winter stimu-
lated the growth of cold water filamentous algae (Swingle gt_gl.,
1963). Fertilization studies by Surber (1945) in ponds and Hasler
and Jones (1949) in artificial ponds resulted in the growth of fila-
mentous algae. Patriarche and Ball (1949) working on Michigan
ponds were unable to produce a phytoplankton bloom with fertilizer
until late in the summer. Their ponds contained large beds of rooted
aquatic plants prior to fertilization. Instead of a plankton bloom
a heavy growth of filamentous algae was produced which resulted in
elimination of most of the submerged macrophytes.

I Later, Ball and Tanner (1951) while working on a small warm
water lake in northern Michigan found that three applications of
fertilizer during the summer resulted in an increase in phytoplankton,
yet a fourth application caused a filamentous algae bloom. During
three years of work on a small marl lake in Michigan, Hooper and Ball
(1964) were unable to stimulate a bloom of photoplankton. However,
a rise in the production of the benthic community was noted.

More recently Mulligan and Baranowski (1969) conducting
experiments at Cornell University found that high nutrient levels
(5.0 mg/l phosphorus and 15-50 mg/l total nitrogen) cause an
increased turbidity of the water, increased chlorophyll a_and
increased dry weight of phytoplankton. Lower levels of nutrient
enrichment (0.17—1.5 mg/l nitrogen and 0.065-0.51 mg/l phosphorus)

caused an increase in the production of macroscopic filamentous

10

algae. The lowest fertilization levels tested stimulated the growth
of higher aquatic plants. High yields of macrophytes never coincided
with large phytoplankton populations.

Hetzel and Hough (1973) suggest that as nutrient limitations
are decreased there is an increase in macrophyte production. At some
point, as nutrient loading increases, there is a shift in production
with attached and eulittoral algae playing a more important role.
During this time Span, when the attached and eulittoral algae were
increasing, phytoplankton production also increases.

There appears to be a number of factors which control the
component of the primary producers which will respond to nutrient
enrichment. Some of these factors appear to be: season in which
enrichment was started, water temperature, sunlight, standing crop
of macrophytes prior to enrichment, rate of nutrient loading, concen-

tration of fertilizer in the water and availability of carbon.

DESCRIPTION OF STUDY AREA

This study was conducted at the Michigan State University
Experiment Station two miles south of Lake City, Missaukee County,
Michigan. Michigan State University owns and operates an 850-acre
farm as an agricultural experimental research station. Four man-made

ponds, a laboratory and living facilities are maintained by the Fish-

 

eries and Wildlife Department for field research.

Construction of the ponds began in 1942. The original ponds
were below a beaver dam on Mosquito Creek. However, the beaver dam
proved unreliable and an earthen dam with concrete structures which
allow control of water levels in the ponds was completed in 1945.
The control structures allow the water level in each pond to be
maintained independently of the other ponds (Figure l).

Mosquito Creek is an outlet for Missaukee Lake. High water
levels in the lake during recent years had resulted in increasing
amounts of water passing through Mosquito Creek. The high water
levels insured an adequate supply of water to the ponds during the
study period.

The ponds were assigned the letters A, B, C and D (Figure 1).
The physical dimensions of the ponds are listed in Table l. The
ponds were originally constructed with gravel bottoms. However,
over the years sediments composed of silt, muck and decaying aquatic

vegetation covered sections of the ponds. During the study period

11

12

.omm_ .cmmweowz .xbwu axes be mecca
Pmucmewcmaxm xuwmcm>wcs mpmum cmmecuwz mnp mo Emcmmwu new :owpmooq

.P mc:m_m

 

 

 

 

in E 39.3:

14

Table 1. Physical Dimensions of Lake City Experimental
Ponds, Lake City, Michigan, 1970.

 

 

Pond Acres Average Depth Acre Feet
(feet)

A 0.36 3.2 1.152

B 0.46 3.3 1.518

C 0.17 3.4 0.578

D 0.19 3.2 0.608

 

every attempt was made to avoid disturbing the sediments. Aquatic

plants present at the onset of the study are listed in Table 2.

15

Table 2. Aquatic Plants in Lake City Ponds, June, 1970.

 

Pond A.
Chara
Elodea canadensis

Najas flexilis

 

Potamogeton natans

Pond B.
9.62::
Elodea canadensis
Najas flexilis
Potamogeton natans

Pond C.
£116.22
Potamogeton natans
Potamogeton paraelongus
Elodea canadensis
Nymphaea ordorata

Pond D.
Potamggeton amphifolius
Potamogeton natans
Najas flexilis

Elodea canadensis

 

 

METHODOLOGY

Fertilization Rates

 

The fertilization schedule for Pond A was modeled to simulate
the rate of enrichment which would occur if three million gallons a
day of primary wastewater treatment plant effluent, which contained
5 mg/l total phosphorus and 30 mg/l total nitrogen, were discharged
to a 12.7 acre pond six feet deep.

The enrichment in Pond B simulated the nutrient load a 13.3
acre pond six feet deep would receive if three million gallons a
day of wastewater treatment plant effluent containing 2.5 mg/l of .
total phosphorus and 15 mg/l total nitrogen were discharged into it.

Pond C received a nutrient load proportional to that which
would occur if three million gallons a day of wastewater treatment
plant effluent, which contained 1.25 mg/l of total phosphorus and
7.0 mg/l total nitrogen, were discharged into a 5.6 acre pond six
feet deep.

Pond D was not fertilized and contained natural levels of

total phosphorus and total nitrogen.

Phosphorus Application
Phosphorus as P205 is a well known fertilizer for terrestrial
plants. Triple superphosphate which is 46 percent available P205
was used as a phosphorus source. The fertilizer was purchased

locally in fifty-pound bags. Phosphorus was added at a rate which

16

17

would bring the initial concentration of phosphorus in the pond
water to the following levels. Subsequent applications would

increase the phosphate concentration.

 

 

Amount of Phosphorus Added Theoretical
Eggg_ (pounds) (kg) (lb/acre foot) Concentration
A 1.85 0.84 1.60 0.59 mg/l
B 1.2 0.54 0.79 0.29 mg/l
C 0.52 0.24 0.90 0.33 mg/l
D 0.0 0.0 0.0 0.0

At 0900 on July 7, 1970, the first phosphorus application was
made to Pond A. Prior to application the phosphorus was placed in
10 gallons of water in a plastic container overnight. One gallon of
the phosphorus solution was then placed with four gallons of water
in a manually operated water pump. The pump and operator were then
rowed around the pond in a small boat. While the boat was moved
around the pond the operator directed the nozzle of the pump at the
water's surface. This process was repeated until all 10 gallons had
been used. Every attempt possible was made to spread the phosphorus
evenly. In addition, the boat was rowed around the pond for an
additional 10 minutes to aid in mixing. Due to water quality prob-
lems discussed in the nitrogen section, phosphorus was not added on
JUIY 15, l7and at only one-half the original rate on July 18 and 20.

The initial application was made to Ponds B and C on July 14
and July 17, respectively. Dates of fertilization and quantities

added are shown in Table 3.

18

 

Table 3. Dates of Nutrient Enrichment and Quantities ‘ Added in Experimental Ponds

Date Pond A Pond B Pond C Pond D
July 7, 1970 1.60 phosphorus 0.0 0.0 0.0
10.57 nitrogen 0.0 0.0 0.0
July 8, 1970 1.60 phosphorus 0.0 0.0 0.0
10.57 nitrogen 0.0 0.0 0.0
July 9, 1970 1.60 phosphorus 0.0 0.0 0.0
10.57 nitrogen 0.0 0.0 0.0
July 10, 1970 1.60 phosphorus 0.0 0.0 0.0
10.57 nitrogen 0.0 0.0 0.0
July 11, 1970 1.60 phosphorus 0.0 0.0 0.0
10.57 nitrogen 0.0 0.0 0.0
July 14, 1970 1.60 phosphorus 0.79 phosphorus 0.0 0.0
10.57 nitrogen 4.65 nitrogen 0.0 0.0
July 15, 1970 1.60 phosphorus 0.79 phosphorus 0.0 0.0
10.57 nitrogen 4.65 nitrogen 0.0 0.0
July 16, 1970 1.60 phosphorus 0.79 phosphorus 0.0 0.0
0.0 nitrogen 0.0 nitrogen 0.0 0.0
July 17, 1970 0.0 phosphorus 0.0 phosphorus 0.90 phosphorus 0.0
0.0 nitrogen 0.0 nitrogen 2.99 nitrogen 0.0
July 18, 1970 0.80 phosphorus 0.79 phosphorus 0.90 phosphorus 0.0
5.28 nitrogen 4.65 nitrogen 2.99 nitrogen 0.0
July 20, 1970 0.80 phosphorus 0.79 phosphorus 0.90 phosphorus 0.0
5.28 nitrogen 4.65 nitrogen 2.99 nitrogen 0.0
July 23, 1970 1.60 phosphorus 0.79 phosphorus 0.90 phosphorus 0.0
10.57 nitrogen 4.65 nitrogen 2.99 nitrogen 0.0
July 27, 1970 1.60 phOSphorus 0.79 phosphorus 0.90 phosphorus 0.0
10.57 nitrogen 4.65 nitrogen 2.99 nitrogen 0.0
July 29, 1970 1.60 phosphorus 0.79 phosphorus 0.90 phosphorus 0.0
10.57 nitrogen 4.65 nitrogen 2.99 nitrogen 0.0
August 1, 1970 1.60 phosphorus 0.79 phosphorus 0.90 phosphorus 0.0
10.57 nitrogen 4.65 nitrogen 2.99 nitrogen 0.0
August 3, 1970 1.60 phosphorus 0.79 phosphorus 0.90 phosphorus 0.0
10.57 nitrogen 4.65 nitrogen 2.99 nitrogen 0.0
August 19, 1970 1.60 phosphorus 0.79 phOSphorus 0.90 phosphorus 0.0
10.57 nitrogen 4.65 nitrogen 2.99 nitrogen 0.0

3 pounds per acre-foot

19

Nitrogen Application

Nitrogen in the form of urea and potassium nitrate are well
known fertilizers for terrestrial plants. Initially in the study
urea was used as a fertilizer. The urea was 45 percent NH3, by
weight.

A build-up of ammonia nitrogen levels was determined to be
stressing fish in Pond A on July 16, 1970. On July 18, 1970, the
nitrogen source was changed from urea to potassium nitrate. Potas-
sium nitrate was purchased locally in 50-pound bags which contained
33 percent nitrate nitrogen by weight. Nitrogen was added at a rate
which would bring the water to the following concentrations. Subse-

quent applications would increase the nitrate concentration.

 

 

Eggg (poufigggnt 0(k31tr116/ggggdfoot) c62633§1§§16n
A 11.05 5.02 10.57 3.52 mg/l
B 7.05 3.20 4.65 1.71 mg/l
C 3.2 1.45 2.99 1.1 mg/l
D 0.0 0.0 0.0 0.0 mg/l

At 0900 on July 7, 1970, the first application of urea was
made to Pond A. Prior to application the urea was placed in 10 gal-
lons of water to which the phosphorus had already been added and
left to stand overnight. One gallon of the phosphorus-nitrogen
solution was then placed with four gallons of water in a manually
operated water pump. The pump and operator were then rowed around

the pond in a small boat. While the boat was rowed around the pond

20

the operator directed the spray from the nozzle of the pump at the
water's surface. This process was repeated until all 10 gallons of
solution had been applied. Every attempt was made to spread the
solution evenly. In addition, the boat was rowed around the pond
for an additional 10 minutes to aid mixing.

Due to the ammonia problem discussed earlier in this section,
nitrogen was not added to Ponds A and B on July 16 and 17. On
July 18 and 20, nitrogen loading was reduced by one-half in Pond A.

Initial application was made on Ponds B and C on July 14 and

A

17, respectively. Dates of fertilization and concentrations are

shown in Table 3.

Water Exchange

 

Rate of water flow through the ponds was monitored by con-
structing straight notch weirs below the outlet structures of each
pond. Boards on the inlet structures were adjusted to allow a suf-
ficient water flow through the ponds to conform with a predetermined
retention time. The retention time of the pond was calculated using

the following formula:

.o|<

where t is the theoretical retention time in days, v is the volume
of the pond in millions of gallons and q is the rate of flow in

millions of gallons. The theoretical retention time is the time in
which there is complete replacement of all water in the pond. How-

ever, this is a volumetric replacement and not molecule for molecule

21

replacement. Therefore, some water was not replaced. The the-
oretical retention times for the ponds were:

Pond A, 8.3-days

Pond B, 8.7 days

Pond C, 3.7 days

Pond D, 4.0 days

Physical and Chemical Parameters

 

Temperature

 

Water temperature in the ponds was monitored with a Taylor
continuous recording thermometer. The sensor for this unit was
placed in four feet of water near the outlet of Pond B. Weekly
inspection of the recorder chart indicated the maximum and minimum
temperatures which had occurred on any date. On several occasions
water temperatures in all ponds were checked with a hand-held ther-
mometer to determine if temperatures in Pond B were similar to
temperatures in Ponds A, C and 0. Ambient air temperature was
recorded at and obtained from the weather station at the Lake City

Experiment Station.

Dissolved Oxygen

Dissolved oxygen concentrations were determined between
10:00 and 11:00 A.M. using the azide modification of the Winkler
method (Anon., 1965). Due to its chemical stability, phenylarsene
oxide was substituted for sodium thiosulfate in the oxygen determina-
tions. Water samples for determination of dissolved oxygen and the

r‘f-Bmcainder of the chemical parameters were taken at three-day intervals

22

from June 29 to August 8, 1970. From August 8 until August 22 a
four-day sampling interval was used. Water samples were also ana—
1yzed on the initial day of fertilization in Ponds A, B and C and

on August 24 and September 4, 1970.

RE
A Beckman pH meter was used to measure hydrogen ion concen-

tration on the sample dates indicated in the dissolved oxygen section.

The instrument was standardized at regular intervals.

A1ka1inity_

Phenolphthalein alkalinity is a measure of the concentration .
of carbonate (CO3): and hydroxide (0H)‘ ions in the sample. The
amount of carbonate and hydroxide are determined by titration with
an acid to the phenolphthalein end-point at pH 2 8.3, while the total
alkalinity was titrated to the color end-point of pH between 4.5 and
5.4 using methyl orange as a color end-point indicator (yellow to
pink).

Total and phenolphthalein alkalinity were measured following

the procedures outlined in Standard Methods (Anon., 1965).

Phosphorus
The concentrations of orthophosphate and total phosphate were

determined in all ponds at predetermined intervals. Orthophosphate
was determined spectrophotometrically using the stannous chloride
mathod (Anon., 1965). Under acid conditions orthophosphate forms a

.YE1low complex with molybdate ions. The phosphate-molybdate complex

23

was then reduced to a highly colored blue complex by the addition
of stannous chloride. The color is proportional to the phosphate
concentration. The blue color was then measured at 690 u on a
Beckman Model B spectrophotometer.

Total phosphate was determined spectrophotometrically using
the stannous chloride method after an initial acid hydrolysis step
(Anon., 1965). Boiling with acid for 90 minutes hydrolyzed poly-
phosphates, insoluble phosphates and some organic phosphates to
orthophosphates. Orthophosphate was then determined as outlined
above.

Samples for phosphorus determinations were taken in 250-ml
glass-stoppered, acid-washed bottles. Samples were returned to the
laboratOry and processed within two hours. Water samples for phos-
phorus analysis were taken on the schedule outlined under dissolved
oxygen. This sampling schedule was designed to monitor changes in

phosphorus concentrations in pond waters.

Nitrate-Nitrogen

Nitrate was determined spectrophotometrically using the brucine
method (Anon., 1965). Brucine is an organic compound which reacts
with nitrates under acid conditions and at elevated temperatures
develops a yellow color. The color of the resulting complex was
measured at 410 u on a Beckman Model B spectrophotometer. There are
two factors which cause difficulty when this method is used: (1) The
color development does not obey Beer's law. A curve rather than a

straight line is obtained from graphing a set of standard solutions.

24

(2) The intensity of color development is a function of time and
temperature. Temperature and time during analysis were carefully
controlled. For each series of analysis a set of nitrate standard
solutions was also analyzed. To insure accuracy, after analysis a
new calibration curve was developed from the standard solutions.
Water samples for nitrate analysis were taken at the inter-

vals indicated under the dissolved oxygen section. Samples for
analysis were taken in 250-ml acid-washed bottles and returned to
the laboratory. Analysis was undertaken within two hours.

. Ammonia nitrogen was determined on July 17, 1970 in Pond A

using the Nessler method (Anon., 1965).

Biological Parameters

Macrophytes

 

The standing crop of macrophytes was measured gravimetrically
after the whole plant including the roots was cropped (Penfound,
1956; Sculthorpe, 1967). With the aid of stakes on shore to locate
coordinates, all ponds were divided into one-meter square plots.
Plots which contained emergent or floating aquatic plants or were
within one meter of shore were not sampled. Each pond was sampled
at seven-day intervals, with a plot to be sampled being selected
using a table of random numbers. Ropes were stretched between
coordinating stakes, thus locating the plot. Three 625 square
centimeter subsamples were taken from each square meter plot.

Plants were harvested by placing a square (25 cm x 25 cm)
foams within the one meter plot and removing all plants. An attempt

was made to remove all plant roots. The plants were removed by.

25

hand with the worker hanging over the side of the boat wearing

scuba gear or with the diver free in the water. Plant samples were
washed in fresh water, blotted dry, then placed in a constant tem-
perature oven (50°C) for 48 hours (Wetzel, 1960). Plants were then
placed in a desiccator, cooled to room temperature and weighed on an
analytical balance.

Sculthorpe (1967) lists four aquatic plant species found in
the study ponds as containing from 14 to 23.9 percent of their dry
weight as ash free dry weight. Tesar (1973) reported the ash free
weight of macrophytes ranged from 29 to 43 percent of the net weight.
A mean of 19.5 percent was calculated from the work of Sculthorpe
and used to estimate ash free dry weight in the study. This calcula-
ted mean is similar to the 20 percent ash free weight from dry weight

reported by Slédecek and Sladedkova (1964).

Phytoplankton

In this study phytoplankton was defined as the free floating
algae which could be removed from the water by filtration with a
0.45 p Millipore R Filter. This group would include the tychoplankton
which is normally found free floating with other vegetation, usually
macrophytes, in the littoral zone (Hutchinson, 1957). No attempt
was made to trace the change in species produced in the ponds since
greater importance was attached to the total quantity of plankton
Produced.

The standing crop of phytoplankton was measured in each pond
at four-day intervals. Chlorophyll p_was used to determine standing

CTTJp and was measured spectrophotometrically using the methods of

26

Parsons and Strickland (1963) as modified by Moss (1967). Samples
were obtained from all ponds between 10:00 A.M. and 12:00 noon on
sampling days. This was done to reduce the possibility of diurnal
changes in chlorophyll concentration (Yentsch and Ryther, 1957). To
insure that the phytoplankton sample was representative of the
plankton population, eight one-liter samples from various locations
in the ponds were placed in a plastic bucket and mixed. A one-liter
subsample was then removed and used for analysis. A water sample
between 25 ml and 500 ml was filtered through an H.A. 0.45 i 0.02 p
Millipore R Filter (Millipore Filter Corp., Bedford, Mass.) upon
which three drops of MgCO3 had been placed. Care was taken to keep
the filter vacuum below 15 inch Hg. to avoid damage to the algal
cells and loss of cell contents (Wetzel, 1964). The amount of sample
filtered was dependent upon the plankton population present with high
plankton densities reducing the volume of sample filtered.

After filtration the filter was placed in a mortar and ground
vigorously with a pestle for two minutes in 2 ml of 90 percent
redistilled acetone. The mixture was rinsed with 4 m1 of acetone
into a 15-ml glass-stoppered centrifuge tube. The centrifuge tube
was then placed in a dark refrigerator for 24 hours prior to analysis
for chlorophyll p_and its degradation products. Chlorophyll p_con~
centrations were determined with the aid of a Beckman Model B spec-
trephotometer.

Ash free dry weight was estimated using the values reported
by Grzenda and Brehmer (1960). Theyreported that phyto-pigments

constituted 1.3 percent of the ash free dry weight. These findings

27

are in agreement with Weber (1973) who estimated the chlorophyll

content of a cell to be 1 to 2 percent of the ash free dry weight.

Pepiphyton

Studies have shown the amount of biomass of periphyton is
directly related to the amount of chlorophyll p_present in a sample
(Weber, 1973; Grzenda and Ball, 1968). Standing crop and coloniza-
tion rates of this community can be measured and sample sites com-
pared if the quantity of chlor0phyll per unit area is known.
Artificial substrates (plexiglass) were provided for periphyton
growth, then the growth measured at predetermined time intervals.

Clear plexiglass plates with a total exposed surface area of
l40‘square centimeters (2" x 5" x 1/4") were used to collect periphy-
ton growth. The plates were attached to a horizontal crossbar with
Acco #1125 spring clips. The crossbar was attached to a wooden pole
driven into the pond bottom. In each pond a total of 16 plates were
held 12 inches below and with the flat surface parallel to the
water's surface (King and Ball, 1966).

At four-day intervals duplicate samples were removed from
each pond. By measuring the amount of biomass accumulation between
sampling dates an estimate of the colonization rate was calculated.
In this manner plates which had been in the ponds for time intervals
0f from 4 to 32 days were compared. At the end of the first 32-day
Period (July 28) all plates were replaced and the 32-day cycle
restarted.

The plexiglass plates were removed from the clamps, placed

in 'individual light-proof containers and taken directly to the

28

laboratory for immediate processing. The plexiglass plates were
scraped into a mortar to remove the periphyton community which had
colonized it. The plexiglass slide was then rinsed with 2 ml of

90 percent redistilled acetone into the same mortar. An additional
5 m1 of acetone was placed into the mortar. The periphyton-acetone
mixture was vigorously ground with a pestle for one minute. The con-
tents of the mortar were then rinsed with 3 mls of acetone into a
15-ml glass-stoppered centrifuge tube. The centrifuge tube was
refrigerated at 6°C for 24 hours. After 24 hours the sample was
examined spectrophotometrically for chlorophyll p_as outlined by
Parsonsand Strickland (1963) and its degradation products (Moss,
1967).

Ash free dry weight was estimated using the values reported
by Grzenda and Brehmer (1960). They reported that phytopigments
constituted 1.3 percent of the ash free dry weight. These findings
are in agreement with Weber (1973) who estimated the chlorophyll

content of a cell to be 1 to 2 percent of the ash free dry weight.

RESULTS AND DISCUSSION

General Ecological Considerations

It is a well established ecological observation that indi-
viduals of a p0pulation in order to grow and multiply must be sup-
plied with certain essential materials. Not only must specific
essential elements be present, but each element to which the organism
responds has a maximum and minimum limiting effect. These observa-
tions are usually stated as Liebig-Blackman law and Shelford law
(Boughey, 1968). The former states that growth of an organism is
dependent on the amount of foodstuff (e.g., inorganic, or organic)
or level of factor (e.g., light, temperature) present in minimum
quantity to the organism relative to the availability of essential
elements and factors in the organism's environment and the propor-
tionate cellular requirements of the organism. Shelford's law goes
on to recognize the effect of an excess of one element or factor has
on the growth of an organism. That is, Shelford recognized the
growth or metabolism of an organism is injured when an element is
supplied above or below a certain concentration (Bowen, 1966).
Thus, an organism's success in populating a given ecosystem is con-
trolled by the quantity and variability of materials for which there
is a minimum requirement and physical factors which are critical and
by the limits of tolerance of an organism to these factors and com-

Peting organisms (Odum, 1971).

29

30

The presence or success of a population of organisms in a
given ecosystem is based on the completeness of a complex of condi-
tions. What is essential is the identification of the operationally
significant factors on the organism's growth from the array of pos-
sible controlling factors. Environmental factors that have been
experimentally demonstrated to exert control on the growth and
metabolism of plant and animal populations in aquatic ecosystems
include light, temperature, organic compounds, dissolved oxygen,
salinity, dissolved inorganic constituents, and suspended solids.

In discussing the abundance of the primary producers and
causal factors responsible for the observed population shifts, it
will be done in light of these ecological principles (Liebig and
Shelford laws). They provide the framework to understand the chance
of an organism to thrive and grow in a given environment and not in

another (Odum, 1971).

Physicochemical Characteristics of Pond A

 

Pond A was the first pond to be fertilized (July 7, 1970).
It also received the highest rate of nitrogen and phosphorus loading,

5.02 (3.52 mg/l) and 0.84 kg (0.59 mg/l), respectively.

Igmperature

The temperature in the four ponds followed similar patterns.
Temperatures during the study ranged from a maximum of 28.1°C
(82.5°F) on June 30 down to a minimum of 13.7°C (56.9°F) on August 31,
1970 (Figure 2). The maximum diurnal change in water temperature from

a daytime high to a nighttime low was 5.0°C (9.9°F) and occurred on

31

Figure 2. The daily maximum and minimum air and water temperatures

in Lake City ponds during the study period, 1970.
(Maximum and minimum water temperatures are stippled;
maximum and minimum air temperatures are clear.)

32

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33

July 23. The maximum diurnal change in surface air temperature from
a daytime high to a nighttime low was 23.9°C (43°F) and occurred on
August 27, 1970. The stable temperature in the waters (1/5 the vari-
ation of the air) is due to the specific heat capacity of water
(Hutchinson, 1967). The ecological importance of temperature lies
in the seasonal and daily variation within the ponds. This flux is
what directly affects the metabolic activities of the existing plant
and animal communities.

Organisms such as algae may be greatly influenced by tempera-
ture (Hutchinson, 1967). Blue-green algae are very tolerant of high

temperature. Diatoms such as Fragilaria crotonensis, however, grow

 

best between l3-16°C. In most years Fragilaria crotonensis and other

 

diatoms are largely replaced in the summer by blue-green algae
(Wesenberg-Lund, 1904). Algae encountered in this study would be
from the mesothermal temperature spectrum (ls-30°C) (Lowe, 1974).
The solubility of oxygen in water varies inversely with tem-
perature. In fresh water, the solubility of atmospheric oxygen is
decreased by about 55 percent as the temperature increases from 0°C
to 40°C (Mackenthun and Ingram, 1967). Therefore, high temperatures
indirectly affect organisms by controlling the amount of oxygen

available to them at a time when their metabolic rates are high.

Oxygen

Oxygen concentrations averaged 8.2 mg/l (94 percent satura-
tion). An oxygen maximum appeared very early in the study (July 19)

during the peak of the phytoplankton standing crop (Table 4). Levels

34

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35

of 19 mg/l (186 percent saturation) of oxygen were reached throughout
the shallow pond. Following this peak in productivity, oxygen levels
within the pond were reduced but still remained between 120 and 152
percent saturation at the existing temperatures. The very intensely
developed oxygen maxima began in mid-July, persisted until late July
and remained below 100 percent saturation throughout August. The
primary productivity of the pond was particularly intense throughout
the periods of the maxima in direct correlation with the development
of high oxygen concentrations. These findings are similar to those
reported by Wetzel (1966) in hypereutrophic Sylvan Lake. He reported
a maximum oxygen concentration of 16.6 mg/l and 189.5 percent satura-

tion during July.

Alkalinity and pH

Experimental Pond A at Lake City had an average total alka-
linity of 90 mg/l. This is similar to the findings of Sohacki (1965)
for the same ponds. It can be classified as a hardwater pond
(Ruttner, 1940). Alkalinity is the buffering capacity of a body of
water, i.e., its ability to withstand changes in pH. Alkalinity is
imparted by the proton accepting species in the water, usually the
bicarbonates, carbonates and hydroxide components of the water body.
As plants remove C02 from the water for use in photosynthesis, a
new chemical equilibrium must be established. Carbon dioxide is
utilized by primary producers causing a loss of bicarbonate, and
carbonate and hence a reduction in buffering capacity. A change in

pH may result if the buffering capacity is exceeded.

36

Total alkalinity in Pond A ranged from 82 to 107 mg/l with
a mean of 90.3 mg/l. Total alkalinity concentrations were slightly
elevated on July 13, 16, and 19. The elevation was probably due to
the potassium nitrate fertilizer used to enrich the ponds. Potassium
would dissociate from the nitrate and be available to form potassium
bicarbonate andcarbonate (Hutchinson, 1957). Potassium bicarbonate
and carbonate would increase the buffering capacity of the water.
Barrett (1957) found that when fertilizer containing potassium was
added to the lake it did go into solution but was only a small frac-
tion of the amount already occurring in the lakes.

Phenolphthalein alkalinity was 0.0 except on several occasions I
when a supersaturation of dissolved oxygen and high pH values (> 8.9)
occurred. The absence of phenolphthalein alkalinity indicates all
of the alkalinity was due to bicarbonates. High primary production
resulted in the loss of C02, high pH values and a supersaturation of
dissolved oxygen. As a result of the loss of C02, the concentration
of bicarbonate was lowered (indicated by increased phenolphthalein
alkalinity) and could not effectively act as a buffer for hydroxyl
ions produced by the photosynthetic uptake of C02. As a result,
hydroxyl ions accumulate accounting for a dramatic rise in pH

(Vallentyne, 1974).

Phosphorus Concentrations

 

The total phosphorus concentration in Pond A ranged from less
than 0.01 mg/l on July 4 to 2.12 mg/l on July 16, 1970 (Table 4).

The total phosphorus concentration increased immediately after

37

fertilization to 0.45 mg/l which is somewhat lower than the theoreti-
cal concentration expected (O.59 mg/l). On July 11 after five days
of receiving 1.85 pounds of phosphorus per day, an algal bloom began
to develop. Fertilization was halted on July 12 and July 13. Fer-
tilization was resumed on July 14, 15 and 16. On July 16, total
phosphorus reached the highest concentration during the study period
(2.12 mg/l). This value was, however, less than the expected the-
oretical value of 2.73 mg/l. Observed total phosphorus values
ranged from 60 to 96 percent of the theoretical values (Table 5).
The phosphorus maxima coincided with the maximum standing crop of
phytoplankton.

Soluble phosphorus concentrations ranged from less than 0.01
mg/l on several occasions to 1.98 mg/l on July 16, 1970. Soluble
phosphorus concentrations followed the same general pattern as total
phosphorus concentrations, i.e., increased with fertilization,
decreased when enrichment was halted.

Soluble phosphorus ranged from 93 percent of the total phos-
phorus, on the first day of the study, to 16 percent total phosphorus
on the last day sampled (September 4, 1970).

Nitrogen

Although air contains 79 percent nitrogen, only a few organ-
1 sun can use nitrogen in this form. Nitrogen is present in the
aquatic ecosystem in the following forms: N2, NH3, NO', N03. Most
Primary producers are only able to utilize nitrogen that has been

fixed (incorporated in a chemical compound). Therefore, most primary

38

 

 

 

 

 

Table 5. Observed and Tgeoreticala Total Phosphorus
oncentrations 1n Pond A, Lake City,
Michigan, 1970.

Theoretical Observed Observed ,
thg_ Concentration Concentration Percent(lheoreticali
July 7 0.59 0.45 76
July 10 1.96 1.29 65
July 13 1.76 1.34 76
July 16 2.73 2.12 78
July 19 2.08 1.61 77
July 23 2.01 1.69 84
July 25 1.54 1.20 78
July 28 1.54 1.26 82
July 31 1.49 1.17 79
August 3 2.04 1.59 78
August 6 1.37 1.11 81
August 10 0.80 0.75 94
August 14 0.47 0.44 94
August 18 0.27 0.26 96
August 22 0.56 0.49 88
August 27 0.27 0.23 79
September 4 0.10 0.06 60

aTakes into account flushing rate of pond.

bmg/l .

><|

80.3 percent

39

producers are unable to use atmospheric nitrogen. Nitrogen is one
of the key elements in the building of amino acids.

Certain bacteria and some algae are capable of utilizing and
incorporating it into protein. Nitrogen compounds are then released
as waste products or at the death of the organism through decomposi-

tion. Bacteria convert protein to NH3 which plants and algae can

 

then use as a nutrient. If the NH3 is not used, the Nitrosomonas
group of bacteria under aerobic conditions will convert NH3 to NOE.
If the nitrite is still unused the Nitrobacter group of
bacteria convert it into nitrate.
The nitrogen cycle is a gaseous cycle. Nitrogen may be lost
or added, to or from the atmosphere at any point in the cycle as a
gas. The nitrogen fertilizer originally used in Pond A was urea.
Urea is converted to ammonia which can be toxic to aquatic organisms
and becomes more toxic as the pH value increased above 8. On July 16,
1970, fish in Pond A were observed to be in distress. Fish had con-
gregated at the inlet of the pond and were near the surface apparently
under some physiological stress. Water samples were immediately taken
and analyzed for ammonia-nitrogen. The results revealed that 0.5 mg/l
of ammonia was present in the water. At a pH of 9.1 enough of the
non-ionized ammonia would be present to be toxic to fish (Ball, 1967).
Approximately 238 bass, bluegills, and bullheads were removed from
the pond and released. An additional 35 fish died in the pond. Fish

were not completely eradicated from the pond: several bluegills were

seen later in the summer.

 

40

Subsequent applications were made using potassium nitrate.
Nitrate is quite soluble in water, easily used by aquatic plants and
algae and relatively chemically stable. Nitrate concentrations in
the ponds were always lower than the theoretical concentrations cal-
culated. This is probably due to the luxury consumption of aquatic
plants, phytoplankton and periphyton (Gerloff, 1960). Maximum con-
centration of nitrate observed during the study was 6.46 mg/l which
occurred on August 3, 1970 (Table 4).

The concentrations of available nitrate should not have
limited primary production. However, nitrogen can limit primary
production.

Yoshimura (1932) found phosphorus may be limiting at one time
of the year and nitrogen at another. In other situations where large
amounts of phosphorus are available, nitrogen may become limiting
(Shapiro and Ribeiron 1965). Thomas (1953) concluded that (1) phos-
phorus was the minimum factor in oligotrophic lakes, and (2) there
are lakes in which, according to the weather, phosphorus may be
limiting one year and nitrogen may be limiting the next.

There were other significant sources of nitrogen to the
ponds. Precipitation in the form of rainfall and snowfall is a sig-
nificant source of nitrogen in some parts of the world. In the mid-
\~est, average rainfall contains on the order of 1 mg/l of nitrate
nitrogen. When this is compared to the normal 0.3 mg/l often cited
as the critical concentration of nitrogen, rainfall rather than
ciiluting the nutrients in a lake is actually contributing to them

(l_ee, 1970; Pecor pt 21., 1973).

41

Macrophytes

 

The standing crop of hydrophytes in Pond A remained rela-
tively constant during the first three sampling periods (June 29,
.July 8 and July 15) of the summer (Figure 3a, Table 6). These same
phenomena were observed by Penfound (1956); i.e., the productivity
of macrophytes was highest in spring and lowest during the summer.
Low productivity was due primarily to the relatively low photo-
synthesis compared with that of respiration during hot summer
weather. Forsberg (1959) observed production rates of submerged
macrophytes were higher in spring, lower in summer and negative in
the fall. Aquatic macrophyte standing crop on the three above
mentioned dates was 239.6 with a 8.0. 7.6 g/mz. There was no appar-
ent stimulation of plant growth when enrichment began on July 7.

The July 15 sample from Pond A was obtained with a great
deal of difficulty. The water was extremely turbid making collection
of the macrophytes difficult. Plants which were sampled were found
to be in poor physiological condition. Macrophytes sampled on
July 22 were difficult to locate in the turbid water and those which
were located were in a degenerated condition. Standing crop had
been reduced to 132 g/m2.

By the July 29 sampling date only a few plant fragments
«could be located anywhere in Pond A. The rate at which the aquatic
Plants degenerated was calculated to be 17 percent per day. These
‘findings are higher but in agreement with those observed by Jewell
(1970) who found degeneration of hydrophytes at 18°C to be about

9 percent per day. The decline in macrophyte standing crop may have

 

42

Figure 3a. Macrophyte standing cr0p in Pond A, Lake City, Michigan,
1970.

Figure 3b. Phytoplankton standing crop as determined by chlorophyll
p_concentrations in Pond A, Lake City, Michigan, 1970.

Figure 3c. Periphyton production rates and standing crop in Pond A,
Lake City, Michigan, 1970.

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SUBSTRATE
err-nary p

Table 6.

Date

6/29/70
6/30/70
7/ 1/70
7/ 2/70
7/ 3/70
7/ 4/70
7/ 5/70
7/ 6/70
7/ 7/70
7/ 8/70
7/ 9/70
7/10/70
7/11/70
7/12/70
7/13/70
7/14/70
7/15/70
7/16/70
7/17/70
7/18/70
7/19/70
7/20/70
7/21/70
7/22/70
7/23/70
7/24/70
7/25/70
7/26/70
7/27/70
7/28/70
7/29/70
7/30/70
7/31/70
8/ 1/70
8/ 2/70
8/ 3/70
8/ 4/70
8/ 5/70
8/ 6/70
8/ 7/70
8/ 8/70
8/ 9/70
8/10/70
8/11/70
8/12/70
8/13/70
8/14/70
8/15J70
8/16/70
8/17/70
8/18/70
8/19/70
8/20/70
8/21/70
8/22/70
8/23/70
8/24/70
8/25/70
8/26/70
8/27/70
8/28/70
8/29/70
8/30/70
8/31/70
9/ 1/70
9/ 2/70
9/ 3/70
9/ 4/70
9/ 5/70
9/ 6/70
9/ 7/70

Fertilizer Added

><><><><><

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44

Phytoplankton
Mean
Standing Crop
ug/l chlorophyll a

<5

<5

53

95

80

72

55

48

PPT

52

29

25

<5

(5

10

16

12

StandingfiCrop (biogass) of Primary Producers in Pond A.

Periphyton

Mean

Standing Crop

Ps/cm

2

chlorophyll a

1.2

Lost

7.3

10.1

9.0

Macrophytes
Mean
Standing Crop

Azjm

238

233

248

134

Decomposed

0.0

Lake City, Michigan, 1970.

Chemistry
X

X

45

been due to plant growth being inhibited by high phosphate concentra-
tions. Wetzel (1968) reported increasing phosphate levels
above those found in natural waters results in a slight but consist-
ent inhibition of certain species of aquatic plants. He reported
0.305 mg/l as being inhibiting the growth of some aquatic plant
species.

The response of gha£§_to phosphate levels above 30 ug/l was
found to be distinctly inhibitory (Forsberg, l964). The decline in
the macrophyte population corresponded to an increase in the phyto-

plankton population.

Phytoplankton

The phytoplankton population of Pond A showed an immediate
response to enrichment. Phytoplankton standing crop increased from
7 ug/l chlorophyll g_on July 7 to 53 ug/l on July ll (Figure 3b). A
number of researchers (Hutchinson and Bowen, l950; Hayes and Phil-
lips, 1958) have found that phytoplankton can absorb nutrients very
quickly. Phytoplankton response to nutrients can be measured in a
matter of minutes (Coffin gt 11., l949) and blooms of phytoplankton
in natural waters have been reported to appear very quickly (Comita
and Anderson, l959). The phytoplankton biomass in Pond A continued
to increase until the maximum standing crop (95 ug/l chlorophyll a)
was observed on July 15. Chlorophyll values were indicative of
highly eutrophic (productive) waters which have a high concentration
of phosphorus (Bachmann and Jones, l974; EPA, 1974). Using the

relationship between total phosphorus and average chlorophyll

46

concentrations suggested by Dillon and Rigler (l974), the concentra-
tion of total phosphorus observed on July 16 (2.12 mg/l) could have
resulted in over l000 ug/l of chlorophyll a, The vertical extinCtion
of light is effectively accomplished by dense phytoplankton popula-
tions and is directly density dependent. The rapid diminishment of
light intensity, and consequent increase in photo-inhibition by high
biogenic turbidity is probably a very important factor in the high
levels of photosynthesis achieved in the first few centimeters of
water in a hypereutrophic situation (Wetzel, l966).

The self-shading effect described by Wetzel may be the factor
limiting the phytoplankton population to 95 ug/l chlorophyll a_making '
the l000 ug/l suggested by Dillon and Rigler unobtainable. The
. highest chlorophyll a_concentration observed in 150 Michigan lakes
surveyed during 1974 was 125 ug/l (Michigan Department of Natural
Resources Unpublished Data, l975) indicating that indeed the phyto-
plankton population may be self-limiting.

Chlorophyll concentrations remained high until August 8 when
a decline was noted. Turbidity decreased and chlorophyll concentra-
tions remained low until August 20. The next application of fertili-
zerstimulated a small pulse of phytoplankton (maximum of l6 ug/l
chlorophyll a).

The reduction in phytoplankton biomass with an apparent
excess of available Phosphorus (Table 4) may possibly be accounted
for by examining the food web in the pond. Phytoplankton is normally
consumed by zooplankton which are consumed by fish. Due to some yet

undetermined set of physical, chemical and biological circumstances

47

the phytoplankton were able to respond to the fertilization by very
quickly increasing their biomass. A time lag could be expected for
the zooplankton population to increase in size for the available food
supply (Comita and Anderson, 1959). The increase in the zooplankton
population could be expected to increase rapidly due to the fish kill
which occurred on July 18. The removal of almost all fish from the
pond would remove predator pressure from the zooplankton, allowing
for a very rapid population expansion.

A reciprocal relationship between zooplankton and phyto-
plankton was indicated by Wright (1965). He found that during
periods when zooplankton were increasing there was a simultaneous
decrease in phytoplankton biomass (as measured by chlorophyll a)

' becoming practically zero at the height of the zooplankton pulse.
Following the decline of the zooplankton, the population of phyto-
plankton increased. A very large but undetermined number of 200-
plankters were observed in Pond A from August 3 through August 10.

During the period of high phytoplankton populations, macro-
phyte biomass continued to decline. The decline in macrophyte
biomass may be attributed to the increased phytoplankton reducing
.the light intensity or possibly changing the spectral qualities of
light reaching the plants. Shading with phytoplankton is a common
method used to control macrophytes in the southeastern United States
(Swingle gt_al., 1963).

Knight gt a1. (1962) suggest that aquatic macrOphytes have
several adaptive mechanisms which allow them to grow in luxuriant

beds at high light intensities which may have caused phytoplankton

48

to be light inhibited. He felt that starting ponds (flooding) in
early summer when there is little cloudiness may favor the growth
of aquatic macrophytes as compared to phytoplankton, whereas the
lower light intensities of a cloudy spring may favor growth of
phytoplankton.

Weather records obtained from the Lake City Weather Station
indicate cloudy, mostly cloudy or overcast weather from July 7
through July 11, clear skies on July 12 and overcast on July 13 and
14. The author speculates that overcast skies may have reduced
light intensities sufficiently to allow the phytoplankton population,
with nutrients available, to rapidly increase in biomass until they

become self-limiting.

Periphyton

 

The periphyton community in Pond A responded to enrichment
by an increase in production. The artificial substrate method does
not truly measure production; it measures the rate of colonization
(Wetzel, 1964). The estimate of colonization or production is the
additional ug/cmz/day of chlorophyll a_which has occurred by attach-
ment and growth of organisms since the last sample was taken. The
two Sampling dates prior to enrichment had production rates of 0.30
and 0.33 ug chlor0phyll a_cm2/day. One day after fertilization pro-
duction was determined to be 1.12 pg chlorophyll a_cm2/day. Standing
crop of periphyton for the next 16 days averaged 9.2 ug chlorophyll
Ԥ_cm2. TheSe findings are similar to those of Szczepanski and

Szczepanska (1966) who measured chlorOphyll content of algae on

49

slides exposed for various times. They found a rapid rise in the
amount of chlorophyll for the first two weeks or so, then a period
of about five weeks of more or less constant chlorophyll levels.
The carrying capacity or maximum biomass of periphyton which could
utilize the artificial substrate was determined to be approximately
9 ug chlorophyll 2 cm2. Slade‘c‘ek and Slade‘c’kvoé (1964) defined
turnover time as the time needed for renewal of the periphyton com-
munity. The turnover time for the periphyton community in Pond A
with the first set of substrates was 16 days.

Artificial substrates were replaced on July 28. On August 1
when the first samples were taken, the rate of production was 0.56 ug
chlorophyll g_cm2/day. This low rate even with excessive nutrients
available was probably the result of initial colonization. During
the first three days of exposure, substrates placed in artificial
streams by Kevern (1962) showed little or rm) measurable periphyton
growth. He subtracted the three days from total exposure time for
calculating production rates. This situation did not appear to hold
completely true for the nutrient enriched Pond A.

Due to a laboratory accident, the samples for August 5 were
destroyed. Production rates on August 9 and 13 were 0.63 and 0.70 pg
chlorophyll a_cm2/day, respectively. These rates were slightly
lower than those observed during the first exposure period. Carry-
ing capacity averaged 9.4 ug chlorophyll a_cm2. Turnover time was
16 days. In 1968 Gehring (1969) found the turnover time for these
same ponds to be 16-22 days.

50

Differences in periphyton standing crop and production are
apparent from Figure 3C. Standing cr0p is the quantity or biomass
of material which was present when the sample was taken, and produc-
tivity is the increase in biomass between sampling dates. Produc-
tivity was high (July 5-10 and August 1-13) when biomass was being
accumulated on the plexiglass plates. On July 20 and August 15,
productivity appeared to decline to near zero while the standing
crop remained fairly constant. However, production was taking place
to make up for losses from the standing crop. Materials can be lost
from the standing crop via grazing organisms, cell sluffing and cell
decay. Production of the periphyton community was approximately

equal to the loss of material from the standing crop.

Physicochemical Characteristics of Pond B

 

Fertilization of Pond B was begun on July 14, 1970, seven
days after the fertilization of Pond A started. It received the
second highest rate of nitrogen and phosphorus loading, 3.20 and

0.54 kg, respectively.

Temperature

 

A complete description of the temperature variation observed
during the study and its impact on the ecosystem can be found in the

temperature section of the Results and Discussion, Pond A (page 30).

Oxygen

Prior to enrichment, oxygen concentrations averaged 9.1 mg/l

(104 percent saturation). The maximum observed concentration of

51

oxygen occurred late in July (between July 19 and 28). Levels of

13 mg/l (142-155 percent saturation) of oxygen were reached on two
occasions in the pond. Following this peak, oxygen levels declined
below 100 percent saturation and remained there for the balance of
the study period. Primary production, as estimated by standing crop,
was particularly intense during the periods of the maxima in direct
correlation with the development of high oxygen concentrations.

The low values for dissolved oxygen occurred on August 18
when levels of dissolved oxygen and percent saturation were 5.9 mg/l
and 65 percent, respectively. These reduced levels of dissolved
oxygen occurred during a period when there was a high standing crop
of filamentous algae covering much of the surface of Pond B. It can
be theorized that the floating algae which was beginning to decay
exerted a high 8.0.0. on the pond water, reducing the dissolved oxy-
gen. In addition, the floating algae may have effectively kept

light from reaching other primary producers (shading effect).

Alkalinity and pH

Experimental Pond B contained hardwater with a total alka-
linity which ranged from 61 to 108 mg/l and a mean of 77 mg/l. Total
alkalinity was elevated on July 19, probably due to the use of
potassium nitrate fertilizer used to enrich the ponds. Phenolphtha-
lein alkalinity was low (< 10) except for a 9-day period near the
end of July when it averaged 24 mg/l.

The elevated phenolphthalein alkalinity occurred during a

period of high pH values (> 9.1) and high phytoplankton standing

 

52

crop. The depletion in the bicarbonate alkalinity occurred in the
pond during the period of maximal productivity. Such removal of

bicarbonate from the water is largely biogenic in origin.

Phosphorus and Nitrate Concentrations

Total phosphorus concentrations in Pond B ranged from 0.01
mg/l on July 13 to 0.75 mg/l on August 8. Total phosphorus measure-
ments were always somewhat lower than the expected theoretical con-
centration (Table 8). Observed concentrations of total phosphorus
ranged from 48 to 85 percent of the theoretical values. A question-
able value of 31 percent was observed but not used. Soluble phos-

phorus ranged from less than 0.01 mg/l to 0.65 mg/l (Table 7).

Macrophytes

 

Standing crop of macrophytes in Pond B remained relatively
constant after fertilization began, x = 201 g/m2 (Figure 4, Table 9).
Biomass appeared to have increased on the August 12 sampling date;
however, the addition was not due entirely to macrophyte growth. A
bloom of filamentous algae occurred the week before and it was
impossible to remove all of this material from the plants prior to
their being dried and weighed. The periphyton material which
remained on the aquatic plants accounted for some of the weight
addition. Subsequent sampling of the macrophytes found the plants to
be heavily overgrown with filamentous algae and in poor physiological
condition. From August 12 until the termination of the study, the
macrophyte population continued to decline. The biomass on the last

sampling date (September 1) had been reduced to 120 g/m2.

53

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00.0 00.0 00.0 0.00 0.00 0.0 00000 0.00 00\0N\0
00.0 00.0 00.0 0.00 0.00 0.0 00000 0.00 00\0N\0
00.0 00.0 00.0 0.00 0.00 0.0 00: 0.2 0200:
00.0 00.0 00.0 0.0 0.00 0.0 00000 0.00 00\0_\0
00.0 00.0 NNHO 0.0 0.00 0.0 A0000 0.00 00\00\0
00.0 00.0 00.0v 0.0 0.00 0.0 00000 0.00 00\00\0
00.0 00.0 00.0v 0.0 0.00 0.0 00000 0.0 00\0_\0
00.0 00.0 00.00 0.0 0.00 0.0 0000 0.0 00\0\0
00.0 00.0 00.0v 0.0 0.00 0.0 0000 0.0 00\0\0
00.0 00.0 00.0v 0.0 0.00 0.0 M000w 0.0 00\_\0
00.0 00.0 00 0v 0.0 0.00 0.0 0 000 0.0 0:000
00m00002-000c002 mscommcoza mzcomm0000 >u00000xp< >0000~0¥~< In, cmmxxo 00>Fommwo 0009
00000 -00000 000000000000000 00000
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54

 

 

 

 

 

Table 8. gbserved and TBeoreticala Total Phosphorus
oncentrations in Pond b, Lake City,
Michigan, 1970.
Date Clgeoretical Observed. Percent(0bserved )
_____ centration Concentration Theoretical
July 14 0.29 0.24 83
July 16 0.77 0.45 58
July 19 0.77 0.63 82
July 23 0.93 0.72 77
July 25 0.71 0.56 79
July 28 0.73 0.58 79
July 31 0.71 0.53 75
August 3 0.99 0.75 76
August 6 0.67 0.54 81
August 10 0.39 0.27 69
August 14 0.23 0.11 48
August 18 0.13 0.04 31
August 22 0.26 0.21 81
August 27 0.13 0.11 85
September 4 0.05 0.04 80

¥

aTakes into account

bmg/l.

flushing rate of pond.

><|

72.3 percent

55

Figure 4a. Macrophyte biomass (dry weight) in Pond 8, Lake City,
Michigan, 1970.

Figure 4b. PhytOplankton biomass as determined by chlorophyll a
concentrations in Pond 8, Lake City, Michigan, 1970.

Figure 4c. Periphyton production rates and standing crop in Lake
City, Michigan, 1970.

Pond B as determined by chlorophyll a_concentration
astanding crop; -------------- production).

 

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Table 9.

Date

6/29/70
6/30/70
7/ 1/70
7/ 2/70
7/ 3/70
7/ 4/70
7/ 5/70
7/ 6/70
7/ 7/70
7/ 8/70
7/ 9/70
7/10!7O
7/11/70
7/12/70
7/13/70
7/14/70
7/15/70
7/16/70
7/17/70
7/18/70
7/19/70
7/20/70
7/21/70
7/22/70
7/23/70
7/24/70
7/25/70
7/26/70
7/27/70
7/28/70
7/29/70
7/30/70
7/31/70
8/ 1/70
8/ 2/70
8/ 3/70
8/ 4/70
8/ 5/70
8/ 6/70
8/ 7/70
8/ 8/70
8/ 9/70
8/10/70
8/11/70
8/12/70
8/13/70
8/14/70
8/15/70
8/16/70
8/17/70
8/18/70
8/19/70
8/20/70
8/21/70
8/22/70
8/23/70
8/24/70
8/25/70
8/26/70
8/27/70
8/28/70
8/29/70
8/30/70
8/31/70

Fertilizer Added

><><><><><

X

9/
9/
9/
9/
9/
9/
9/

1/70
2/70
3/70
4/70
5/70
6/70
7/70

Phytoplankton
Mean
Standing Crop
4pg/1 chlorophyll a

<5

12

28

25

42

30

21

24

16

22

14

10

57

Standing Crop (biomass) of Primary Producers in Pond 3.
Dates of Fertilization and Water Chemistry Analysis Indicated.

Periphyton
Mean
Standing Crop
pg/cn2 chlorophyll a

<1

10.6

11.5

2.24

15.4

7.8

Macrophytes
Mean
Standing Crop

431m

183

212

187

240

212

Lake City. Michigan, 1970.

Chggistry
x

X

58

Ball and Tanner (1951) reported a similar occurrence while
fertilizing a small lake. They observed that after fertilization a
bloom of filamentous algae appeared and covered the submerged vege-
tation. The combination of reduced light and the burden of the fila-

mentous algae all but destroyed the Chara and potamogentons.

4|

Phytoplankton

 

Phytoplankton standing crop in Pond B responded immediately

to enrichment. Chlorophyll a_increased from 7 ug/l on July 11 to a

 

maximum of 42 ug/l on July 27. During this same time period, total
phosphorus concentration increased from < 0.01 mg/l to 0.55 mg/l.
Phytoplankton biomass gradually declined reaching 6 ug/l chlorophyll
g_on August 12. This decrease in phytoplankton biomass corresponds
with the appearance of the filamentous algae bloom described in the
preceding section. Estimates were that about 25 percent of the sur-
face area of the ponds was covered with mats of floating algae.
From August 7 until August 12 approximately 33 cubic feet of algae
(wet) were removed from the pond's surface. The 25 percent of the
pond surface which was covered by floating mats of algae resulted in
the shading out of light to other primary producers. Hence, the
decrease in phytoplankton may have been the result of decreased
availability of light. No dramatic increase in the zooplankton popu-
lation was visible, unlike the pulse of zooplankton noted in Pond A.
An increase in the phytoplankton standing crop was noted as

the filamentous algae bloom subsided and fertilization was resumed.

59

Periphyton

 

Periphyton in Pond B had an accrual rate of less than 0.20
ug/cmZ/day chlorophyll a_prior to enrichment. Accrual rate increased
to 2.0 after enrichment then decreased as the substrate reached its
carrying capacity estimated to be 10.6 ug/cm2 chlorophyll a, Turnover
time was determined to be 20 days.

The second set of substrates in Pond B had a higher initial
accrual rate than the previous set (0.56 compared to < 0.20). Turn-
over time was less than 16 days and the substrate carrying capacity
was greater (11.4 ug/cm2 compared to 10.6 ug/cm2 chlorophyll 3).

During the second colonization study, a filamentous algae
bloom appeared. The filamentous algae bloom occurred during a period
when water temperatures were high and relatively stable. Ball and
Tanner (1951) while fertilizing a small lake observed that filamentous
algae occurrence was more conspicuous during a period in early August,
when there was a prolonged period of hot quiet weather. At Lake
City, filaments were visible on the artificial substrates during the
bloom. However, the exact quantification of this material was not
possible. The filamentous form of algae did not appear to be
anchored securely to the substrates. Pieces of the mats were observed
on several occasions to break from the substrate and float to the
surface. When maximum care was taken in removing the substrates for
analysis, some material was observed to be lost. Evidence of this
can be seen in large variation in the biomass on the last six sam-

pling dates.

60

Although no exact measurement of the quantity of filamentous
algae produced during the bloom was made, approximately 33 cubic
feet of filamentous algae was removed. Most of the filamentous algae
produced stayed in the pond. A great deal of it could be observed in
various stages of decomposition throughout the pond after the bloom
had subsided. This material contributed to total pond primary pro-
duction, but was not accurately measured.

Pieczynska (1971) reported that filamentous algae growing on
and around plants in the shallow zone of a lake may produce 750 mg/dm2
of material (dry weight) and contributes significantly to the total
primary production of some lakes.

Initial response to enrichment in Pond B was an increase in
phytoplankton biomass followed by a bloom of filamentous algae. The

filamentous algae subsequently caused a reduction in both the phyto-

plankton and macrophyte standing craps.

Physicochemical Characteristics of Pond C

 

Pond C was the last pond to be fertilized (July 17, 1970),
ten and three days, respectively, after Ponds A and B were first
fertilized. It received the lowest rate of nitrogen and phosphorus

loading, 1.45 and 0.24 kg, respectively.

Temperature

 

A complete description of the temperature variation observed
during the study and its impact on the ecosystem can be found in the

temperature section of the Results and Discussion, Pond A (page 30).

 

61

mg
Enrichment had no apparent effect on the dissolved oxygen
concentration in Pond C (Table 10). Prior to fertilization, oxygen
concentrations averaged 9.1 mg/l (105 percent saturation). The
maximum observed dissolved oxygen concentration occurred in mid-July
(on July 13 and 17). Levels of 11.2 mg/l (133 percent saturation)
of oxygen were reached in the pond. On July 8, 1970, a heavy rain-
storm occurred at Lake City; 0.42 inches of rain fell on that date.

Between July 13 and 17, 0.49 inches of rain fell on the Lake City

 

Experiment Station. Rainfall can carry substantial quantities of
nutrients (Neibel, 1969). It is possible that the natural nutrient
contributions in rainfall stimulated productivity in the pond
increasing the dissolved oxygen concentration. Following this peak ,
and the commencement of enrichment, percent saturation of dissolved

oxygen declined, averaging 97 percent for the remainder of the study.

Alkalinity and pH

 

Experimental Pond C had an average total alkalinity of 82
mg/l, and is classified as hard water. Phenolphthalein alkalinity
'was low (< 10) except for two occasions when it rose to 10 and 11
mg/l. During this same time interval, dissolved oxygen levels were
10.2 and 11.0 mg/l. High pH levels (> 8.5) occurred simultaneously.
The depletion of the bicarbonate alkalinity and rise in pH occurred

in the pond during periods of high productivity.

62

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00.00 00.0 00.00 0.0 0.00 0.0 0000 0.0 0000000
00.0v 00.0 00.0V 0.0 0.00 0.0 00000 0.0 00000\0
00.0. 00.0 00.0 0.0 0.00 0.0 0000 0.0 0000000
00.0 00.0 00.0 0. 0.00 0.0 0000 0.0 00\0\0
00.0 00.0 00.0 0.0 0.00 0.0 1000 0.0 00\0\0
00.0 00.0 00.0 0.0 0.00 0.0 1000 0.0 0000000
00.0 00.0 00.0 0.00 0.00 0.0 00_0V 0.00 00\00\0
00.0 00.0 00.0 0.0 0.00 0.0 00000 0.0 0000000
0.0 00.0 00.0 0.0 0.00 0.0 0000 0.0 00\00\0
00.0 00.0 00.0 0.0 0.00 0.0 0000 0.0 0000000
00.0 00.0 00.0 0.0 0.00 0.0 00000 0.00 0000000
00.0 00.0 00.0. 0.0 0.00 0.0 10000 0.00 00\0_\0
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000000Fz-0000002 0000000000 000000W000 000000000< 000000000< :0 cmmxwo 00>00000o 0000
00000 -00000 00000000000000 00000
000050000

.0000 .00000000 .0000 0000 .0 0000 00 0000000000000 00000000 00000000 00 0000000000000 .00 00000

63

Phosphorus and Nitrate Concentrations

Total phosphorus concentrations in Pond C ranged from 0.0l
mg/l prior to enrichment to a maximum of 0.51 mg/l on August 3.
Total phosphorus concentrations were always lower than the expected
theoretical concentration. Observed concentrations of total phos-
phorus ranged from 85 to 93 percent of the theoretical concentra-
tions (Table ll). Soluble phosphorus ranged from less than 0.01
mg/l to 0.5l mg/l (Table l0).

Maximum nitrate nitrogen values (1.07 mg/l) occurred on
July 19. Successive applications of nitrogen fertilizer did not
result in the "build-up" in the nitrate concentration. A "build-up"

of nitrate over the sample period did occur in Ponds A and B.

Macrophytes

 

The standing crop of macrophytes in Pond C was increasing
prior to enrichment and continued to increase for the first week
after enrichment (Figure 5, Table l2). The July 30 sample contained
slightly less biomass than the sample from the previous sampling
period. This may be due to the lack of homogeneity in natural condi-
tions which reduces the quantitative validity that can be attained
with this sampling technique. Biomass appeared to have increased on
the August 12 sampling date. The addition was not due entirely to
macrophyte growth. The filamentous algae bloom described in Pond B
also occurred in Pond C. An attempt was made to remove as much of
the filamentous algae from the harvested plants as was possible.

‘However, it was impossible to remove all the algae from the

64

Table 11. Observed and TBeoreticala Total Phosphorus
Concentrations in Pond C, Lake City,
Michigan, 1970

 

 

 

 

 

Theoretical Observed Observed
gate. Concentration Concentration Percent(Theoretical)
July 17 0.33 0.28 85
July 19 0.43 0.40 93
July 23 0.61 0.56 92
July 25 0.34 0.31 91
July 28 0.39 0.35 90
July 31 0.35 0.32 91
August 3 0.66 0.57 86
August 6 0.28 0.24 86
August 10 0.08 0.07 88
August 14 0.03 0.03 --

August 18 0.00 0.03 -
August 22 0.14 0.12 86
August 27 0.03 0.03 -
Septenber 4 0.01 0.03 -
x' 89 percent

 

aTakes into account flushing rate of pond.

bmg/l.

65

Figure 5a. Macrophyte biomass (dry weight) in Pond 0. Lake City,
Michigan, 1970.

Figure 5b. Phytoplankton biomass as determined by chlorophyll 3
concentrations in Pond C, Lake City, Michigan, 1970.

Figure 5c. Periphyton production rates and standing cr0p in Pond C,
Lake City, Michigan, 1970.

 

( standing crop; ---------- production rate)

66

 

 

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SUBS'RATES
REPLACE?-

- -——-‘ L—‘~H WW“?

67

Table 12. Standing crop (biomass) of Fri-cry Producera in Innd C. Lake City. Michigan. 1970.
Dates of Fertilization and Hater Chemistry Analynia Indicated.

Phytoplankton Periphyton Macrophytes
Mean Mean Mean
Standing Crop Standing Crop Standing Crop
Dates Fertilizer Added pg/l chlorophyll a pg/cm2 chlorophyll a gig: Chemistry,

6/29/70 <5 x
6/30/70 <1

7/ 1/70 320 x
7/ 2/70

7/ 3/70 5

7/ 4/70 <1 x
7/ 5/70

7/ 6/70

7/ 7/70 <5 X
7/ 8/70 <1 290

7/ 9/70

7/10/70 x
7/11/70 8

7/12/70 1.1

7/13/70 x
7/14/70

7/15/70 <5 360

7/16/70 1.2 x
7/17/70
7/18/70
7/19/70 9 x
7/20/70 x 1.8

7/21/70

7/22/70 375 x
7/23/70 x 8

7/24/70 3.2

7/25/70 X
7/26/70

7/27/70 x 9

7/28/70 4.9 x
7/29/70 x 360

7/30/70

7/31/70 11 X
8/ 1/70 x, 2.4

8/ 2/70

8/ 3/70 x X
8/ 4/70 15 _

8/ 5/70 — 430

8/ 6/70 x
8/ 7/70

8/ 8/70 16

8/ 9/70 8.4

8/10/70 X
8/11/70

8/12/70 7 382

8/13/70 8.8

8/14/70 x
8/15/70

8/16/70 <5

3/17/7‘0 9.3

8/18/70 X
8/19/70 x 285

8/20/70 8

8/21/70 10.5

8/22/70 x
8/23/70

8/24/70 5

8/25/70 11.1

8/26/70 210

8/27/70 X
8/28/70 <5

8/29/70 11.7

8/30/70

8/31/70

9/ 1/70 6

9/ 2/70

9/ 3/70 200

9/ 4/70

9/ 5/70

9/ 6/70 <5 X
9/ 7/70

><><

68

macrophytes prior to their being dried and weighed. Subsequent sam-
pling of the macrophytes found the plants to be heavily overgrown
with filamentous algae and in poor physicological condition. From
August 12 until termination of the study the macrophyte population
continued to decline. Biomass on the last sampling date was 200

gm/mz. Macrophyte biomass was reduced 37.5 percent during the study.

Phytoplankton

Phytoplankton standing crop showed little initial response
to the addition of nitrogen and phosphorus. Biomass as measured by
chlorophyll g_concentration did increase to a maximum of 16 ug/l on
August 8. By August 8, a bloom of filamentous algae was spreading
throughout the pond and subsequent sampling of phytoplankton showed
a decrease in the biomass. The phytoplankton population increased
to prefertilization levels after the bloom and remained at the low

levels for the remainder of the season.

Periphyton

 

Periphyton in Pond C had a maximum accrual rate of 0.43
ug/cmzlday chlorophyll a, The 28-day time interval the first series
of substrates was submerged was not sufficient to establish the
turnover time or substrate carrying capacity with such a slow
accrual rate.

During the second colonization study a filamentous algae
bloom began to materialize. Initial rate of periphyton colonization
was 0.6 ug/cmZ/day. The sample taken at the onset of the bloom
showed a rate of 1.5 ug/cmZ/day. This rate was in all probability

 

69

higher. Some filaments of periphyton were always observed to be lost
when the substrates were removed for analysis. Substrate carrying
capacity was determined to be 10.85 ug/cmz. Turnover time was 24
days. During the period when the maximum bloom was in progress,
approximately 21 cubic feet of algae (wet weight) was removed from
the surface of Pond C.

The response in Pond C to enrichment was a doubling of the
phytoplankton biomass followed by a bloom of filamentous algae which

resulted in a decline in the macrophyte and phytoplankton standing

 

crop.
Physicochemical Characteristics of Pond D
Pond 0 served as a control during the study and was not
fertilized.
Temperature

 

A complete description of the temperature variation observed
during the study and its impact on the ecosystem can be found in the

temperature section of the Results and Discussion, Pond A (page 30).

Oxygen

Average oxygen concentration during the study period was 8.0
mg/l with 96 percent saturation (Table 13). The maximum observed
concentration of oxygen occurred in mid-July. A maxima of 10.9 mg/l
(130 percent saturation) was reached on July 13. The maximum oxygen
concentration_observed in Pond D coincided with that observed in

Pond C. These maxima were probably the results of climatic conditions

.covumcsumm nematode

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71

favoring high production during this period. The standing crop of
phytoplankton as estimated by chlorophyll a concentration was near
the maximal observed during this study on July 13. The high oxygen
concentrations were caused by high primary production during this
period. Following this peak, oxygen levels in the pond were slightly
reduced but still remained between 86 and 110 percent saturation for

the remainder of the study.

Alkalinityiandgpfl

Experimental Pond 0 contained hard water with a total alka-
linity which ranged from 65.0 to 80.0 mg/l and a mean of 73 mg/l.
Phenolphthalein alkalinity was elevated on those occasions when pH
was elevated. The increases in pH and phenolphthalein alkalinity

were biogenic.

Phosphorus and Nitrate Concentrations
Total phosphorus concentrations in Pond D ranged from 0.01

to 0.04 with a mean value of 0.02 mg/l. This value is in agreement
for phosphorus concentrations found in natural waters. Juday and
Birge (1931) determined the mean phosphorus concentration of 479
Wisconsin lakes to be a mean value of 0.023 mg/l. Ten years later,
Hutchinson (1941) found phosphorus concentration of Linsley Pond to
be 0.021 mg/l.

‘ Soluble phosphorus was below the level of detectability
(< 0.01 mg/l) during the study period. Armstrong and Schindler
(1971) reported an average dissolved phosphorus concentration of

0.007 mg/l from 40 small lakes within a small area of the Canadian

72

shield in northwestern Ontario. Total and soluble phosphorus levels
do not appear to be elevated beyond the levels which naturally occur
in the surface water of this region.

Nitrate nitrogen concentrations ranged from 0.02 mg/l to 0.04
mg/l with a mean value of 0.025 mg/l. On July 1, 10 and 25, nitrate
levels were 0.04 mg/l. On these dates, or within 48 hours preceding
these dates, rainfall of 0.20, 0.42 and 0.55 inches, respectively,
was recorded. This may well account for the slight elevations in
nitrate concentrations.

Mean nitrate concentrations of 0.02 mg/l are in agreement
with the data reported by other researchers in natural lentic waters ‘
of this region. Armstrong and Schindler (1971) reported mean nitrate
nitrogen values of 0.01 mg/l (range < 0.001 to 0.04 mg/l) for surface

samples taken in 1968 and 1969 from ten Canadian Experimental Lakes.

Macrophytes

Standing crop of macrophytes in Pond 0 increased at the onset
of the study from 277 g/m2 to 330 g/m2 (Table 14). A slight decline
in biomass was noted for the next two sampling dates (Figure 6).
Macrophyte biomass increased from July 21 until the termination of
the study. A maximum standing crop of 380 g/m2 was observed on
September 3, 1970. The net primary production of the higher aquatic
plant community as determined by the harvest method was 1.69 g/mzl
day. These findings are in strong agreement with those reported by
Knight, Ball and Hooper (1962), who reported a primary production
rate of 1.45 g/mZ/day in a Lake City pond used as a control during

another study.

73

Tabla 16. Standing Crop (biomaaa) of Primary Producara in Pond D. Laka City. Michigan. 1970.
Dataa of Fertilization and water Chaniatry Analyaia Indicated.

 

Phytoplankton Periphyton Macrophyte-
Hean Mean Mean
Standing Crop Standing Crop Standing Crop

n

QgSa Fertilizer Added pgll chlorophyll a pgllcn chloroghxll ; g7 Chaniatrz

6/29/70 <5 x
6/30/70 <1

7/ 1/70 277 x
7/ 2/70

7/ 3/70 <5

7/ 4/70 <1 x
7/ 5/70

7/ 6/70

7/ 7/70 5 x
7/ 8/70 1.0 330

7/ 9/70

7/10/70 X
7/11/70 7

7/12/70 1.1

7/13/70 X
7/14/70

7/15/70 5 305

7/16/70 1.2 x
7/17/70

7/18/70

7/19/70 <5 X
7/20/70 1.3

7/21/70

7/22/70 260 x
7/23/70 6

7/24/70 1.5

7/25/70 X
7/26/70

7/27/70 7

7/28/70 1.8 X
7/29/70 271

7/30/70

7/31/70 3 X
8/ 1/70 <1

8/ 2/70

8/ 3/70 X
8/ 4/70 5

B/ 5/70 --- 293

8/ 6/70 X
8/ 7/70

8/ 8/70 <5

8/ 9/70 <1

8/10/70 X
8/11/70

8/12/70 <5 350

8/13/70 1.0

8/14/70 X
8/15/70

8/16/70 , <5

8/17/70 1.0

8/18/70 x
8/19/70 348

8/20/70 6

8/21/70 1.1

8/22/70 X
8/23/70

8/24/70 7

8/25/70 1.0

8/26/70 362

8/27/70 X
8/28/70 5

3/29/70 1.1

8/30/70

8/31/70

9/ 1/70 8

9/ 2/70

9/ 3/70

9/ 4/70

9/ 5/70 7 X
9/ 6/70

9/ 7/70

 

74

Figure 6a. Macrophyte biomass (dry weight) in Pond 0, Lake City,
Michigan, 1970.

Figure 6b. Phytoplankton biomass as determined by chlorophyll a_
concentration in Pond 0, Lake City, Michigan, 1970.

Figure 6c. Periphyton production rates and standing crOp in Pond 0,
Lake City, Michigan, 1970.

 

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76

Phytoplankton

The phytoplankton population, as determined by chlorophyll 1
concentrations, ranged from below the level of detectability (< 5 poll)
to 8 ug/l with a mean of 4.6 ug/l (Figure 6B). This mean is probably
an underestimate of the actual chlorophyll concentration. When the
mean was calculated, values below the level of detectability were
assigned a numerical value of 1.0 ug/l.

Bachmann and Jones (1974) suggest a direct relationship
between chlorophyll §_concentration and total phosphorus concentra-
tion. Using their model, a mean chlorophyll a_concentration of 4.6
ug/l should have a total phosphorus value of 0.015 mg/l. Pond 0
contained a mean total phosphorus concentration of 0.02 mg/l and is

in agreement with their model.

Periphyton

The periphyton community of Pond D was initially colonized
very slowly (Figure 6C). There was a lO-day time lag between the
placement of the substrates and the first detectable level of chloro-
phyll g_(> 1 ug/cmz). Kevern (1962) found a 3-day period after
substrate placement when little growth occurred. He subtracted the
first 3 days from total exposure time for calculating production
rates. Lag time was not subtracted in this study, so these results
would be comparable with the other ponds.

The maximum standing crop of periphyton observed was 1.8

2 and occurred during the first exposure period. Maximum

ug/cm
colonization rate was 0.08 ug/cmZ/day. It appears as if the turnover

time was greater than the 28-day exposure period.

GENERAL RESULTS

Dissolved Oxygen

 

A number of factors affect the concentration of dissolved
oxygen in the water, two of which are temperature and the biota.
Temperature affects the solubility of dissolved oxygen and the meta-
bolic rate of organisms. Temperature can affect the seasonal and
daily concentrations of dissolved oxygen, but it has a more pro-
nounced effect on the seasonal variation of oxygen than on daily
fluctuations.

Daily fluctuations in dissolved oxygen occur and they are in
part related to the photosynthesis and respiration of the aquatic
community (Odum, 1956). Oxygen is released into the water by pri-
mary producers as a by-product of photosynthesis during daylight.

' During darkness, the primary producers as well as the remainder of
the aquatic community utilize dissolved oxygen for respiration. In
addition, there is some exchange of oxygen with the atmosphere. The
direction of exchange depends on the saturation gradient.

Diurnal fluctuations in dissolved oxygen are an indication
of the amount of photosynthetic activity (primary production) being
carried out by the aquatic community (Verduin, 1956; Ryther, 1956).
Diurnal fluctuations were not monitored during this study. However,
percent saturation of dissolved oxygen was calculated.

Percent saturation is the amount of oxygen which is dis-
solved in a volume of water compared to the maximum which could be

77

78

dissolved in the same volume of water at the same temperature and
pressure.

Supersaturation is a situation where greater than the maxi-
mum amount of a substance has been dissolved at standard temperature
and pressure. With dissolved oxygen, this is an unstable condition
and the oxygen tends to escape from solution until a new equilibrium
is established near 100 percent saturation. In an aquatic system
where plants and algae produce oxygen through photosynthesis, the
amount of dissolved oxygen added to the water can often exceed the
expected capacity of the water and it becomes supersaturated with
oxygen (Pecor _t_al,, 1973). 1

Oxygen supersaturation is often attributable to photosyn-
thesis by primary producers. Consequently, marked oxygen super-
saturation is commonly associated with highly productive waters
(Hutchinson, 1957).

At the beginning of this project it was assumed that primary
production in the four ponds would be similar. With the exception
of nutrient loading, all ponds were exposed to the same chemical,
physical and environmental variables. Therefore, water samples taken
at the same time from all ponds and analyzed for dissolved oxygen
and percent saturation should, in gross terms, reflect the relative
production of oxygen by aquatic macrophytes and algae.

The results of this comparison are presented in Table 15.
Pond A, which received the greatest amount of enrichment and hence

was assumed to have the highest productivity, had a mean dissolved

oxygen saturation value of 107 percent.

 

Table 15.

Date

6-29
7-1
7-4

7-10
7-13
7-16
7-19
7-23
7-25
7-28
7-31
8-3

8-6

8-10
8-14
8-18
8-22
8-27

Pond A

97
100
83
96
76
182
185
186
k52
127
122
136
92
94
57
61
58
52
79

1' = 107
Range 57-186

S.D. = 42.0

79

M
108
107

87
95
104
120
128
142
136
122
155
95
86
93
78
73
65
64
87
2': 102.

Range 64-155

S.D. = 25.0

m
96
97
84

100
106
133
122
88
99
100
118
99
92
96
95
110
97
78
83
Y'= 99

Range 83-133

S.D. = 13.0

Percent Dissolved Oxygen Saturation in Michigan State
University, Lake City Experiment Ponds, 1970.

£911.42.
96
98
84
99
96
130
110
98 ‘
90
95
99
95

92

98

104

92

87

91
§'= 96
Range 86-130
S.D. = 9.0

80

A decrease in mean percent saturation occurred with a
decrease in nutrient loading. Pond B was greater than Pond C which
was greater than Pond D. The mean percent saturation of Ponds B, C
and D was 102, 99 and 96, respectively.

The range and standard deviation of the four ponds indicate
that the stability of the pond decreased with increased nutrient load-
ing. Pond A had a larger range and standard deviation than Pond B
which was larger than C which was larger than D. The large standard

deviation was caused by the response of the aquatic community to

 

reach a new equilibrium with changing levels of nutrient availability.

Phosphorus

 

The mean and range of total and soluble phosphorus concentra-
tions in Ponds A, B, C and D are given in Table 16. Total phosphorus
concentrations are graphically presented in Figure 7. Ponds B and C
followed patterns similarix>those described in Pond A, i.e., total
phosphorus being always lower than the theoretical value and soluble
phosphorus being some fraction of total phosphorus. The mean
observed total phosphorus values were 80.3 (Pond A), 72.3 (Pond B)
and 89 (Pond C) percent of the theoretical values (Tables 5, 8 and
11).

Total phosphorus levels in Pond D were within the range of
values commonly found in Michigan inland lakes (Michigan Department
of Natural Resources, 1975 unpublished data). Therefore, this con-
centration encountered could be considered a natural level. Soluble
phosphorus concentrations were always below the level of detect-

ability (< 0.01 mg/l).

81

 

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84

Some explanation of the phosphorus cycle may explain why
concentrations of phosphorus in the enriched ponds were lower than
theoretical values.

The decline of phosphorus concentrations after fertilization
has been noted by many scientists (Zeller, 1952; Hepher, 1958).

Under normal conditions phosphate is found in aquatic systems
due to natural and man-made activities. Distribution may depend to
a great degree on basin form, chemical composition of the surround-
ing terrain, land use, waste disposal practices, watershed size,
behavior of other substrates in the particular body of water (Reid,
1961).

Phosphate, pyrophosphate, tripolyphosphate and polyphosphate
anions are known to form complexes, chelates and insoluble salts
with a number of metal ions. How much complexing and chelating goes
on will depend on the concentrations of phosphates and metal ions,
the pH and the presence of other factors in the water (Stumm and
Morgan, 1970).

Three forms of phosphates are commonly found in natural
waters: soluble inorganic, soluble organic, and organic. Many
researchers studying aquatic systems employ the molybdenum blue
method of measuring orthophosphate. Rigler (1968) questions whether
this method really measures orthophosphate. He postulates that the
concentration of inorganic phosphate in lakewater is much lower than
indicated by this method. Hydrolysis of organic compounds may be
the source of error. The measurement of total and soluble phosphorus

in the Lake City study would eliminate this error.

85

Watt and Hayes (1968) concluded analytical techniques can
measure only net changes in phosphorus and cannot provide information
about an equilibrated cycle. A steady state may exist such that
during the period between two sets of observations, no change can be
found in the phases of phosphorus. This does not mean that exchanges
have not taken place, but rather that all changes are compensated--
the system is in a state of dynamic equilibrium.
The following chemical explanations are given for the lower 1
than theoretical concentrations of phosphate in the water column. 1
Large quantities of phosphorus are consistently found
deposited in lake muds, but often the quantities of soluble inor-
ganic phosphorus found in water are very small (Zicker gt a_l., 1956).
Insoluble ferric phosphate is precipitated when ferric iron
and inorganic phosphate occur together under alkaline aerobic condi-
tions. When oxygen is added to the system, any excess iron is pre-
cipitated out as ferric hydroxide. When oxygen is lacking in the
bottom muds, iron is reduced from ferric to the ferrous state and
phosphorus is free to go into solution (Hutchinson, 1957).
Mortimer (1941) is in basic agreement with these findings.
He concluded that most lake muds just below the surface are anaerobic
and contain ferrous iron which is soluble. Ferrous iron cannot exist
in oxygenated water, but is precipitatedin ferric form on the mud
surface carrying phosphorus with it. In a later paper, Mortimer
(1942) elaborates on the mud-water relations. The thickness of the
surface-oxidized layer decreases, adjusting to the new balance of

supply and demand. The decrease in thickness takes place from below

86

and results in the liberation of some previously adsorbed or pre-
cipitated ions (Fe, Mn, P02).

Hutchinson (1957) agrees, stating that in productive lakes
with clinograde oxygen curves there is an increase in soluble phos-
phate in the oxygen deficient part of the hypolimnion. This is in
part due to decomposition of sinking plankton, but in most cases is
primarily caused by liberation of phosphate from sediments under
reducing conditions.

Excess ferric hydroxide forms a gel which while precipita-
ting out of solution, also adsorbs phosphates on its surfaces
(Zicker gt al., 1956). They also concluded that calcium carbonate
had a depressing effect on the concentration of soluble phosphate.
By adding calcium carbonate to a lake containing 8 ppb soluble phos-
phorus, the water concentration was reduced to 0.5 ppb. This reduc-
tion may have been accomplished in two ways: (1) formation of a new
compound such as hydroxylapatite, and (2) phosphate ions being
adsorbed on the surface of the CaCO3 crystals. The crystals that
settle to the mud surface act in two ways: (1) fonn a seal that
restricts the diffusion of phosphate ions released by the mud, and
(2) some of the calcium particles entering the mud can convert some
of the iron and aluminum held phosphates to calcium phosphates. If
the pH is lowered, as may happen during anoxic conditions, some of
the phOSphorus is released.

The effect of high calcium concentrations on phosphorus
concentrations was also investigated by Otsuki and Wetzel (1972).

They considered chemical precipitation, without the agency of living

87

organisms, responsible for several marl lakes in Indiana. By
evaporation of natural waters, CaCO3 is deposited and takes soluble
salts with it. Even a change in temperature or free CO2 concentra-
tion can cause precipitation.

Hepher (1958) felt that in hardwater ponds phosphorus added
to the water in soluble forms disappears rapidly from the water
mainly by being precipitated as calcium phosphate. He felt the
process is influenced by pH and alkalinity of the water. The high
pH values and moderately hard water in the ponds would account for
some of the phosphorus loss.

Hooper and Ball (1964), while fertilizing marl lakes to
increase primary production, concluded that a decrease in suspended
carbonate and phosphorus coincided with an increase in transparency;
it seemed as if phosphorus settled along with considerable marl.

The addition of living organisms to the cycle serves to
clarify what may be happening. Fertilization of eutrophic lakes
will very often cause increased primary production. At times, the
increase is in phytoplankton (Swingle et 91., 1963) or periphyton
population (Hooper and Ball, 1964). At other times, it is displayed
in the macrophytes (Mulligan and Baranowski, 1969). This may be due
to the fact that macrophytes seem unable to utilize organic phosphate
compounds (Hayes and Phillips, 1958). When Hayes §t_al, (1952) added
large amounts of inorganic phosphate to a lake, it was found that
the rooted aquatic Ericaulon sp. had taken up phosphorus in hours.
Examination revealed that the leaves showed uptake before the roots.

It appears that material does not have to go through the roots in

88

order to reach the leaves. The concentration in the plant tissue
can be correlated with the concentration in the water (Lee, 1969).
Hutchinson and Bowen (1950) reported that within one week, some

species of Potamogenton in fertilized water can concentrate phos-

 

phorus in their tissue 1000 times that found in the tissue of simi-
1ar plants in unfertilized water. H
Hutchinson and Bowen (1950) relate that when inorganic phos- I
phate is added to a lake, almost immediately all of the phosphorus
is taken up by the phytoplankton which can then easily be sedimented

 

out of the epilimnion. Hayes and Phillips (1958) found that t:

Chlamydomonas dysosmos established a new phosphorus equilibrium

 

within 2.5 minutes after the addition of phosphorus. Under natural
conditions, such microorganisms can very rapidly make over any inor-
ganic phosphorus present into an organic form. The microorganisms
then return a fraction of the phosphorus via cell leakage and meta-
bolic by-products to the water where it can be used by other organ-
isms. In all cases, there was a rapid loss of phosphorus from the
open water of the lake, the loss being due not only to storage by
phytoplankton, but also the 200p1ankton and littoral vegetation.

-Mackereth (1952) thought the uptake of phosphorus may be a
purely physical phenomenon by adsorption on some part of the algae
cell.

Chu (1946) tested to see if phytoplankton could use various
forms of phosphorus. The following forms were tested: orthophos-
phate, phytin (a stable organic phosphorus compound of plant origin)

and pyrophosphate. The results were: (1) orthophospate--plankton

89

grew well; (2) phytin--plankton grew well; (3) pyrophosphate--there
was some conversion to orthophosphate, but not enough to sustain
growth. Therefore, the change of dissolved organic phosphorus may
follow two courses: (1) turning into orthophosphate and (2) being
absorbed and utilized directly by living organisms.

,This is in keeping with the findings of Karl-Kroupa §t_gl,
(1957). The findings indicate that polyphosphates, which are stable
compounds, are easily converted to orthophosphates by living organ-
isms (plants and bacteria).

Hayes and Phillips (1958) do not believe that any specific
natural physiochemical or bacteriological layering of the muds in
lakes is important. The dominant role in exchange was previously
attributed to the state of oxidation or reduction with bacteria only
playing a minor role but their results indicate that bacteria can
to a high degree suppress the classical inorganic mechanism.

Macpherson gt_al. (1958) found that when inorganic phosphate
is added to water, a large part is likely to be quickly converted
to an organic form by bacteria. If bacteria are absent, plants
rapidly absorb it. Therefore, under conditions in nature, only a
minOr fraction is likely to be left for the mud adsorption reaction.

Hayes §t_al. (1958) concluded that bacteria appear to be
the principal dynamic agents that affect the redox conditions of the
mud. The lower strata of muds are at all times reduced but the
layer at the interface may be oxidized by the water above, but this
oxidized layer is never more than 1 mm thick. Pomeroy gt a1. (1965)

present a conflicting view of the exchange mechanism. They feel

90

exchange consists of a two-step ion exchange between clay minerals
and water, plus a minor exchange between interstitial microorganisms
and water.

Hayes and Phillips (1958) found that more total phosphorus
remains in water at equilibrium when bacteria were present than when
they were absent. The ability of bacteria to keep phosphorus in
water has been explained in two ways: (1) by an acceleration of the
rate of phosphorus return from the sediments to the water by bac-
teria in the mud decomposing dead or decaying organic matter;

(2) by rapid uptake of the phosphorus, it is held from chemical or
colloidal adsorption mechanisms of mud and water.

Kuznetsov (1968) provides some interesting material on bac-
teria. The mineralization of iron humates and the oxidation of
ferrous forms of iron with subsequent sedimentation are, to a con-
siderable extent, the result of certain species of iron bacteria.
There are also bacteria capable of reducing ferric to ferrous com-
pounds; these can filter through the silt surface and form an iron
nodule. This indicates that these bacteria can affect the iron con-
centration directly and the phosphorus concentration indirectly.

.Hargrave and Geen (1968) found that the regeneration of
inorganic phosphorus by zooplankton is also of great importance.

The daily phosphate requirements of phytoplankton were compared with
phosphorus released by zooplankton. The rates of excretion and the
abundance of zooplankton were used to calculate an average daily
addition of inorganic phosphorus to the photic zone. In one lake

the zooplankters released twice the average daily phytoplankton

 

91

phosphorus requirement, but in a pond only one-fifth was supplied
by animal excretion.

As Wetzel (1960) points out, primary producers affect marl
deposition in lakes. Autotrophic and heterotrophic bacteria are
capable of withdrawing CO2 and causing a chemical precipitate.
ghgrg, some filamentous algae and all macrophytes can also perform
this task. This precipitation can then remove inorganic phosphate
which is necessary for their growth. This is partially counter-

balanced by another plant mechanism. Dissolved organic material

 

excreted by the primary producers can act as a chelator for metal ‘0
ions (Wetzel, 1968). Chelation, an equilibrium reaction between a
metal ion and an organic chelating agent, results in the formation

of a stable ring structure incorporating the metal ion. It assumes
importance in marl lakes that exhibit many chemical characteristics
unfavorable to high sustained productivity. Many essential ions such
as iron and phosphorus are usually precipitated out of the aerobic
zone and become unavailable for plant use. Chelation by dissolved
organic matter can maintain metallic ions complexed in a soluble
state and are available for metabolism. The organic chelate can
successfully compete for cations such as Ca++ from Ca3(PO4)2 and
release the phosphate for use.

The biologic cycle as outlined by Rigler (1956) is the uptake
of inorganic phosphate by plankton and bacteria which settle to the
bottom. They are decomposed and their nutrients released. There
then appears to be a horizontal movement of the nutrients to the

littoral area via bacteria and plankton. Once in the littoral areas

92

the macrophytes utilize them. The macrophytes in turn release phos-
phorus to the open water to complete the cycle. Hayes and Phillips
(1958) conclude there is five times as much participating inorganic
phosphorus in the mud phase as in the water (obtained from the sedi-
mentation of phytoplankton and bacteria). The ratio of soluble
organicix>inorganic phosphorus in water is also 5 to 1. Hayes and
Phillips (1958) combine the ratios and it is seen that the phos-
phorus exchange in the mud is about equal to the total phosphorus in
the water. If the mud phosphorus were released, it would double the
supply (this would then trigger more equilibrium reactions with
underlying mud).

Watt and Hayes (1968) state that when an aquatic biological
system approaches a relatively stable condition, the distribution of
dissolved inorganic phosphorus, particulate phosphorus, and dissolved
organic phosphorus may be dealt with as though it were the result of
the equilibrium of a chemical exchange system. This statement is
in line with Rigler's (1964) observations that in eight of the nine
lakes studied, the proportions of inorganic, soluble organic and
organic phosphorus were almost identical.

There is a strong interaction between the physical environ-
ment and its biological components. I

In this study it appeared only a small portion of the added
nutrients would contribute to the continued development and suste-
nance of the primary producers. A major quantity of the phosphorus
and nitrogen added could not be accounted for as having left the

pond via the outflow. Most phosphorus remained in the pond presumably

93

sedimented in the bottom and unavailable to plants and algae. How-
ever, certain rooted aquatic plants can obtain phosphorus from the
sediments via their root systems. Certain conditions prevailed
throughout the study and contributed to the return of the ponds to
prefertilization nutrient levels. The shallow study ponds remained
in an oxidized state, so that the added phosphorus, which did not
leave via the outfall, could be held out of the biologic cycle as

poorly soluble ferric phosphate.

Primary Production

 

An examination and comparison of the total primary produc-
tion in each pond would indicate whether fertilizer had increased ‘
the amount of plant material in each pond or whether it had just
favored one component of primary producers over another. Estimated
ash free dry weight of each component of primary producer was com-
pared (Table 17). Pond13,which received the smallest of the three
artificial nutrient loads, had the highest mean standing crop (ash
free dry weight). Using this criterion, the second most productive
pond was 0 which was unfertilized and acted as a control. In all
cases, the bulk of the standing crop came from the macrophytes. The
macrophytes appear to be the most important component in the produc-
tion of organic material in this pond situation.

However, care must be taken when using mean standing crop to
estimate production. Macrophytes, while difficult to measure, are
relatively stable throughout the growing season. Phytoplankton and

periphyton are less stable and pulses in populations may appear and

 

94

Table 17. Estimate of Mean Standing Cropa of Primary
Producers in Lake City, Michigan Ponds, 1970.

 

 

 

 

 

 

COMPONENT Pond A Pond B Pond C Pond D
Macrophytes

g/m2 day wt. 85.311085 l98.41-_40.5 319.21704 317.5:393
g/m2 ash free dry wt.b 16.6 38.7 62.2 51.9
Phytoplankton .
ug/l chlorophyll a 31.2:29.8 15.9_+_10.6 6.8:4.3 4,213.1
g/m2 ash free dry wt.b 2.40 1.22 0.52 0.32
Periphyton

ug/cm2 chlorophyll a 7.5129 7.6_+_4.68 5014.3 6.87:0.56
g/mz ash free dry wt.b 5.77 5.85 3.85 0.67

Total 24.8 45.8 66.6 62.9

 

atone standard deviation.

bEstimated ash free dry weight.

95

disappear between sampling dates. Phytoplankton standing crop may
appear stable between sampling dates, yet this may be an entirely new
population. Production of phytoplankton can be high with little
change in standing crop. Periphytic growth in the form of fila-
mentous algae which was removed during a bloom from Ponds B and C

was not added to the estimates. This would add to the total stand- f
ing crop for Ponds B and C, but insufficient comparable data were
collected for quantification. ‘ .:

The physical removal of the floating filamentous algae from

 

Ponds B and C during the bloom (August 5) may have had a substantial
yet undetermined effect on the ponds. If this material had been
allowed to remain in the ponds, it may have shaded out the macro-
phytes and algae, caused the ponds to go anaerobic, or the fila-
mentous algae may have had an antagonistic effect on the plants and
phytoplankton. The mean standing crop of primary producers as dis-
cussed in the previous section, as well as the individual results
in Ponds B and C, may have seriously been affected by this
manipulation.

The response of the primary producers in each pond has
already been discussed. The results of each fraction (i.e., macro-
phytes, phytoplankton and periphyton) in the four ponds will now be
compared.

The response of the macrophyte community in the four ponds
varied with the nutrient loading (Figure 8). Pond A which received
the highest nutrient loading had the lowest standing crop of macro-

phytes at the end of the sampling season. Smith (1969), while

96

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98

studying changes in the biota of a lake after fertilization,
reported that healthy macrophytes increased in abundance after years
when algae blooms had occurred as a result of fertilization. How-
ever, during the fertilization and algal blooms, macrophytes died

or appeared moribund.

Ponds B and C which received lower nutrient loading had
higher standing crops of macrophytes. Pond D which was not enriched
contained the largest standing crop and highest production rate of
any study pond. Phytoplankton populations in the four ponds did not
fOllow a similar pattern.

Phytoplankton standing crop, as determined by chlorophyll 2;
concentrations, appeared to be directly related to the rate of
nutrient loading. Standing crap in Pond A was greater than Pond B >
Pond c > Pond 0 (Figure 9). '

These findings are in agreement with those of Mulligan and
‘ Baranowski (1969). While conducting bioassays 0n the effects of
various phosphate and nitrate concentrations on primary production,
they reported the amount of chlorophyll g_in the water was highest
in heavily fertilized treatments, lowest in control treatments and
slightly higher in low fertilizer treatments. They also describe a
pattern for periphyton development which was observed at the Lake
City study.

The periphyton community of the ponds responded quickly to
enrichment. Highest average rate of accrual occurred in Pond B,
which received an intermediate rate of enrichment (Figure 10).

Pond A had the next highest mean accrual rate. Much of the

99

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.m mczmwm

100

   

 

101

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cmmw;o_z .XHPU mxmo :0 um>cmmno cepxcawcmq eo 00cc mcwccmpm

.0_ 0000_o

102

 

 

 

an: / Du: — '3 ‘1'1AH60801HD

103

periphyton accrual occurred after the phytoplankton standing crop
had begun to decline. Smith (1969) described similar results. He
reported that immediately after fertilization there was a pulse of
phytoplankton. However, after a time blooms of filamentous algae
appeared.
In conclusion, the results of this study found the highest

loading of phosphorus and nitrogen used favored the phytoplankton {‘
community to the detriment of the macrophyte community. 'Filamentous

algae appears to have been most abundant at the intermediate loading

 

rates. The natural macrophyte community of the ponds produced the

l ’IMIE “ IL'. Ina..—

greatest biomass under "natural" or control conditions.

These findings are supported by Mulligan and Baranowski
(1969) in their field and laboratory studies. Wetzel and Hough
(1973) in an assessment of the role of macrophytes in lakes suggest
a similar relationship. They suggest that as nutrient limitations
are removed, phytoplankton and periphytic algae are capable of
responding quickly and increasing primary production. However, cer-
tain types of macrophytes can respond at high nutrient levels.

McNabb (1975) presented a similar theory. He observed that
the initial response to increasing nutrient levels was an increase
in macrophyte biomass and changes in the macrophyte community. As
nutrient levels increase, he observed an increase in the importance
of the periphyton community. At the highest nutrient levels he sug-

gests an increase in the dominance of the phytoplankton community.

SUMMARY

The primary production was measured on four farm ponds from
June 26, 1970, through September 3, 1970, at the Michigan State
University, Lake City, Michigan experimental field station. Three
ponds were enriched with different concentrations of phosphorus and
nitrogen. The fourth pond served as a control.

Chlor0phyll a_was used to estimate standing crop of phyto-
plankton and periphyton. In addition, it was used to determine rate
of colonization of the periphyton community. Macrophyte standing
crop was determined gravimetrically. Water chemistry was monitored
fer pH, alkalinity, soluble and total phosphate, nitrate and dis-
'solved oxygen.

An investigation of the data showed that the phosphorus and
nitrogen added to the ponds did not result in the theoretical con-
centration of these constituents. Due to chemical and biological
conditions operating in the ponds, the nutrients did not remain in
solution for any length of time.

Under the environmental conditions operating in the ponds
during the study, it appeared as if high nutrient loading rates
favored the production of phytoplankton and periphyton. However,
the results of the project may have been an artifact caused by the
manipulation of the primary producers. The physical removal of a

portion of the periphyton community during the filamentous algae

104

 

105

bloom placed an undetermined influence on the other primary pro-
ducers in the pond. If left in the pond, the macrophyte and phyto-
plankton populations may have responded in a manner other than the
one observed.

Macrophyte production was highest in the control pond, and
was adversely affected in the other ponds by the conditions imposed
by the experiment.

Additional research is needed to determine the exact set of
physical, chemical and biological variables operating at the time
of this investigation. Insufficient data was collected to signifi-

cantly quantify the effect of each of these parameters.

 

 

LITERATURE CITED

106

 

LITERATURE CITED

Anonymous, 1965. Standard Methods for the Examination of Water and
Wastewater, 12th Ed. American Public Health Assoc., N.Y.
769 pp.

Armstrong, F. A. J., and D. W. Schindler, 1971. Preliminary chemical
characterization of waters in the Experimental Lakes Area,
northwestern Ontario. J. Fish. Res. Bd. Can., 28: 171-187.

Atkins, W. R. 0., 1923. The phosphate content of fresh and salt
waters in its relationship to growth of algal plankton.
J. Mar. Bio. Assoc., 13: 110-150.

 

Bachmann, R. W., and J. R. Jones, 1974. Phosphorus inputs and
algal blooms in lakes. Iowa State J. of Res., 49: 155-160.

Ball, 1. R., 1967. The relative susceptibilities of some species
of freshwater fish to poisons. I. Ammonia. Water Res.,
1: 767-775.

Ball, R. C., 1948. Fertilization of natural lakes in Michigan.
Trans. Am. Fish Soc., 78: 145-155.

Ball, R. C., and H. A. Tanner, 1951. The biological effects of fer-
tilizers on a warm-water lake. Mich. State College.
Agricult. Exp. Stat. Techn. Bull., 223: 1-32.

Barrett, P. H., 1957. Potassium concentrations in fertilized trout
lakes. Limnol. Oceanogr., 3: 287-294.

Boughey, A. S., 1963. The explosive development of a floating weed
vegetation on Lake Kariba. Adansonia, 3: 49-61.

Boughey, A. S., 1968. Ecology of Populations. Macmillan Company,
London. 133 pp.

Bowen, H. J. M., 1966. Trace Elements in Biochemistry. Academic
Press, New York. 235 pp.

Chu, S. P., 1942. The influence of the mineral composition of the

medium on the growth of planktonic algae. 1. Methods and
Culture Media. J. Ecol., 30: 284-325.

107

108

Chu, S. P., 1943. The influence of the mineral composition of the
' medium on the growth of planktonic algae. II. The influence
of the concentration of inorganic nitrogen and phosphorus.
J. Ecol., 31: 109-148.

Chu, S. P., 1946. The utilization of organic phosphorus by phyt0--
plankton. J. Mar. Biol. Assoc. U.K., 26: 285-295.

Coffin, C. C., F. R. Hayes, L. H. Godrey, and S. G. Whiteway, 1949.
Exchange of materials in lakes as studied by the addition
of radioactive phosphorus. Can. J. Res., 27: 207-222.

Comita, G. W., and G. C. Anderson, 1959. The seasonal development
of a population of Diaptomus ashlandi Marsh, and related
phytoplankton cycles in Lake Washington. Limnol. 0ceanogr.,
4: 37-52.

 

Deevey, E. 5., Jr., 1970. Mineral cycles. Sci. Amer., 223: 148-158.

Dillon, P., and F. Rigler, 1974. The phosphorus-chlorophyll rela-
tionship in lakes. Limnol. 0ceanogr., 19: 767-773. .

Edmondson, W. T., 1970. Phosphorus, nitrogen and algae in Lake
Washington after diversion of sewage. Sci., 169: 690-691.

Environmental Protection Agency, 1974. An approach to a relative
trophic index system for classifying lakes and reservoirs.
National Eutrophication Survey Working Paper #24. 44 pp.

Forsberg, C., 1959. Quantitative sampling of subaquatic vegetation.
0ikos., 10: 233-240.

Forsberg, C. 1964. Phosphorus, a maximum factor in the growth of
Characeae. Nature, 201: 517-518.

Gehring, J. R., 1969. Primary Photosynthetic Productivity of Two
Michigan Ponds. Master's thesis, Mich. State Univ. 71 pp.

Gerloff, G. C., and F. Skoog, 1957. Nitrogen as a limiting factor
for growth of Microcystis aeruginosa in Southern Wisconsin
Lakes. Ecol., 38: 556-561.

 

Gerloff, G. C., 1960. Evaluating nutrient supplies for the growth
of aquatic plants in natural waters. IN: Eutrophication:
National Academy of Sciences, pp. 537-555.

Goldman, J. C., D. B. Porcella, E. J. Middlebrooks and D. F. Toerien,
1971. The effect of carbon on algal growth . . . its rela-
tionship to eutrophication. Utah Water Research Laboratory/
College of Engineering, Occasional Paper #6. 56 pp.

 

— wgu’

 

i

109

Grzenda, A. R., and R. C. Ball, 1968. Periphyton production in a
warm-water stream. Mich. Ag. Exp. Stat. Quarterly Bulletin,
50: 296-303.

Grzenda, A. R., and M. L. Brehmer, 1960. A quantitative method for
the collection and measurement of stream periphyton. Limnol.
Oceanogr., 5: 190-194.

Hargrave, B. T., and G. H. Geen, 1968. Phosphorus excretion by zoo-
plankton. Limnol. Oceanogr., 13: 332-342.

Hartley, R. P., and C. P. Potos, 1971. Algae-temperature-nutrient
relationships and distribution in Lake Erie. Environmental
Protection Agency, Water Quality Office. Region V, Lake
Erie Basin. 87 pp.

Hasler, A. 0., and W. G. Einsele, 1948. Fertilization for increasing
productivity of natural inland waters. Trans. 13th N. Amer.
Wildl. Conf., March 8, 9 and 10, pp. 527-555.

Hasler, A. 0., and E. Jones, 1949. Demonstration of the antagonistic
action of large aquatic plants on algae and rotifers. Ecol.,
30: 359-364.

Hayes, F. R., J. A. McCarter, M. L. Cameron, and D. A. Livingstone,
1952. On the kinetics of phosphorus exchange in lakes.
J. Ecol., 40: 202-216.

Hayes, F. R., and J. E. Phillips, 1958. Lake water and sediment.
IV. Radio phosphorus equilibrium with mud plants and bacteria
under oxidized and reduced conditions. Limnol. Oceanogr.,
3: 459-475.

Hayes, F. R., B. L. Reid, and M. L. Cameron, 1958. Lake water and
sediment. II. Oxidation-reduction relations at the mud
waters interface. Limnol. Oceanogr., 3: 308-326.

Hepher, B., 1958. On the dynamics of phosphorus added to fish ponds
in Israel. Limnol. Oceanogr., 3: 84-100.

Holm, L. 0., L. W. Weldon, and R. 0. Blackburn, 1969. Aquatic plants.

Sci., 166: 699-709.

Hooper, F. F., and R. C. Ball, 1964. Responses of a marl lake to
fertilization. Trans. Am. Fish Soc., 93: 164-173.

Hutchinson, G. E. ,1941. Limnological studies in Connecticut.
IV. The mechanism of intermediary metabolism in stratified
lakes. Ecol. Monogr. ll: 21- 60.

 

 

110

Hutchinson, G._E., 1944. Limnological studies in Connecticut.
VII. A critical examination of the supposed relationship
between phytoplankton periodicity and chemical changes in
lake waters. Ecol., 25: 3-26.

Hutchinson, G. E., 1957. A Thesis on Limnology. Volume 1. Geography,
Physics and Chemistry. John Wiley and Sons, New York.
1015 pp.

Hutchinson, G. E., 1967. A Treatise on Limnology. Volume 11. Intro-
duction to Lake Biology and the Limnoplankton. John Wiley
and Sons, Inc., New York. 1115 pp.

Hutchinson, G. E., and V. T. Bowen, 1950. Chemical study of the
phosphorus cycle in Linsly pond. Ecol., 31: 194-203.

Jewell, W. J., 1970. Aquatic weed decay: dissolved oxygen utiliza-
tion and nitrogen and phosphorus regeneration. J. Water
Pollut. Control Fed., 43: 1457-1467.

Juday, C., and E. A. Birge, 1931. A second report on the phosphorus
content of Wisconsin lake waters. Trans. Wisc. Acad. of '
Sci. Arts and Letters, 26: 353-382.

Karl-Kroupa, E., C. F. Callis and E. Seifter, 1957. Stability of
condensed phosphates in very dilute solutions. Industr.
Eng. Chem., 49: 2061-2062.

Kerr, P. C., D. F. Paris and D. L. Brockway, 1970. The inter-
reaction of carbon and phosphorus in regulating heterotrophic
and autotrophic populations in aquatic ecosystems. Water
Pollut. Control Res. Series 16050. FGS 07/70. 53 pp.

Ketchum, B. H., 1954. Mineral nutrition of phytoplankton. A. Rev.
Plant Physiol., 5: 55-74.

'Kevern, N. R., 1962. Primary Productivity and Energy Relationships
in Artificial Streams. Ph.D. dissertation, Mich. State
Univ. 132 pp.

King, 0. L., and R. C. Ball, 1966. A qualitative and quantitative
measure of aufwuchs production. Trans. Amer. Micros. Soc.,
85: 232-240.

King, 0. L., 1970. The role of carbon in eutrophication. J. Water
Pollut. Control Fed., 42: 2035-2051.

Knight, A., R. C. Ball, and F. F. Hooper, 1962. Some estimates of
primary production rates in Michigan ponds. Mich. Acad.
Sci. Arts Letters, 47: 219-233.

 

111

Kuentzel, L. E., 1969. Bacteria, carbon dioxide and algal blooms.
J. Water Pollut. Control Fed., 41: 1737-1747.

Kuentzel, L. E., 1970. Bacteria-algae symbiosis--a cause of algal
blooms. Proceeding (if the National Symposium on Hydro-
biology "Bioresources of shallow water environments."
Proceeding Series #8, 321-334.

Kuentzel, L. E., 1971. Phosphorus vs carbon as a factor in algal
blooms and deterioration of water quality. Paper presented
to the Division of the Environmental Sciences of the New
York Academy of Sciences, N.Y. 1971.

- L "27..."! .IE‘

Kuznetsov, S. I., 1968. Recent studies on the role of microorganisms
in the cycling of substances in lakes. Limnol. Oceanogr.,
13: 211-224.

Lee, G. F., 1970. Eutrophication. University of Wisconsin Water
Resources Center Occasional Paper No. 2. 39 pp.

 

Lee, G. F., 1969. Analytical chemistry of plant nutrients. IN:
Eutrophication: causes, consequences, correctives. National
Academy of Sciences, N.Y., pp. 646-658.

Lee, G. F., 1973. Role of phosphorus in eutrophication and diffuse
source control. Water Res., 7: 111-128.

Liebig, J., 1840. Chemistry in Its Approach to Agriculture and
Physiology. Taylor and Walton, London. 4th Ed. as seen in
Odum, 1971.

Little, E. C. S., 1966. The invasion of man-made lakes by plants.
IN: MAN-MADE Lakes. InstituteirfBiOlogy Symposia #15.
ed. R. H. Lowe-McConnel. Academic Press. 847 pp.

Lowe, R. L., 1974. Environmental requirements and pollution tolerance
of freshwater diatoms. U.S. Environmental Protection Agency.
EPA 670.4 - 74-005. 333 pp.

Mackenthun, K. M., and W. M. Ingram, 1967. Biological associated
problems in freshwater environments: their identification,
investigation and control. Federal Water Pollution Control
Administration. Washington, D.C. 287 pp.

Mackenthun, K. M., 1968. The phosphorus problem. J. Amer. Water
Works Assoc., 60: 1047-1054.

Mackereth, F. J., 1953. Phosphorus utilization by Asterionella
formosa Hass., J. Exp. Bot., 4: 296-313.

Macpherson, L. B., N. R. Sinclair, and F. R. Hayes, 1958. Lake water
and sediments. III. The effect of pH on the partition of

112

inorganic phosphate between water and oxidized muds or its
ash. Limnol. Oceanogr., 3: 318-326.

McNabb, C. 0., Jr., 1975. Aquatic plant problems in recreational
lakes of southern Michigan. Report prepared for Michigan
Dept. of Natural Resources. 52 pp.

Mortimer, C. H., 1941-42. The exchange of dissolved substances between
mud and water in lakes. J. Ecol., 29: 280-329. 30: 147-201.

Moss, B., 1967. A spectrophotometric method for the estimation of
percentage degradation of chlorophylls to pheo-pigments in
extracts of algae. Limnol. Oceanogr., 12: 335-340.

Moss, B., 1967. Limitation of algal growth in some Central African
waters. Limnol. Oceanogr., 14: 591-601.

Mulligan, H. F., 1969. Management of aquatic vascular plants and
algae. IN: Eutrophication: causes, consequences, correc-
tives. National Academy of Sciences, N.Y. pp. 464-482.

Mulligan, H. F., and A. Baranowski, 1969. Growth of phytoplankton
and vascular aquatic plants at different nutrient levels.
Verh. Internat. Verein. Limnol., 17: 802-810.

Neess, John C., 1949. Development and status of pond fertilization
in central Eur0pe. Trans. Am. Fish. Soc., 76: 335-358.

Odum, E. P., 1971. Fundamentals of Ecology. W. B. Saunders, Phila-
delphia. 557 pp.

Odum, T. H., 1956. Primary production in flowing waters. Limnol.
Oceanogr., 11: 102-117.

Otsuki, A., and R. G. Wetzel, 1972. Coprecipitation of phosphorus
with carbonates in a marl lake. Limnol. Oceanogr., 17:
772-774.

Parsons, T. R., and Strickland, 1963. Discussion of spectrophoto-
metric determination of marine plant pigments. J. Mar. Res.,
21: 155-163.

Patriarche, M. H., and R. C. Ball, 1949. An analysis of the bottom
fauna production in fertilized ponds and its utilization by
young-of-the-year fish. Mich. Agr. Exp. Sta. Tech. Bull.
207, 1'3.

Pecor, C. H., J. R. Navy, 0. P. Tierney, and S. L. Vanlandingham,
1973. Water quality of Houghton Lake. Michigan Dept. of
Nat. Resources Tech. Bull. No. 73-7. 180 pp.

Penfound, W. T., 1956. Primary production of vascular aquatic
plants. Limnol. Oceanogr., 1: 92-101.

 

113

Pieczyhska, E. W. A., 1971. Mass appearance of algae in the lit-
toral of several Mazurian Lakes. Mitt. Internat. Versin.
Limnol., 19: 59-69.

Pomeroy, L. R., E. E. Smith, and C. M. Grant, 1965. The exchange
of phosphate between estuary water and sediments. Limnol.
Oceanogr., 10: 167-172.

Prescott, G. W., 1931. Iowa Lake Survey. A report to the Iowa
State Fish and Game Department relative to the conditions
of some Iowa lakes. Unpublished as seen in: Tucker, A., .
1957. The relationship of phytoplankton periodicity to the 1‘
nature of the physico-chemical environment with special
reference to phosphorus. Amer. Midland Nat., 57: 300-370.

Putnam, H. 0., and T. A. Olson, 1960. An investigation of nutrients
in western Lake Superior. School of Public Health, Univer-
sity of Minnesota. 24 pp.

 

Rawson, D. S., 1956. Algal indicators of trophic lake types.
Limnol. Oceanogr., 1: 18-25.

Reid, G. K., 1961. Ecology of Inland Waters and Estuaries. Rein-
hold Publishing Corp., N.Y. 375 pp.

Rigler, F. H., 1956. A tracer study of the phosphorus cycle in
lakewater. Ecol., 37: 550-562.

Rigler, F. H., 1964. The phosphorus fractions and the turnover
time of inorganic phosphorus in different types of lakes.
Limnol. Oceanogr., 9: 511-518.

Rigler, F. H., 1968. Further observations inconsistent with the
hypothesis that the molybdenum blue method measures ortho-
phosphate in lake water. Limnol. Oceanogr., 13: 7-14.

Rodhe, W., 1948. Environmental requirements of freshwater algae.
Symb. Bot. Upsal., 10: l-l49.

Ruttner, F., 1940. Fundamentals of Limnology. University of Toronto
Press. 295 pp.

Ryther, J. H., 1956. The measurement of primary production. Limnol.
Oceanogr., 1: 72-84.

Sawyer, C. N., 1954. Factors involved in the discharge of sewage
effluents to lakes. Sewage Ind. Wastes, 26: 317-328.

Sawyer, C. N., J. B. Lackey, and A. T. Lenz, 1945. Investigations of
the odor nuisances in the Madison Lakes, particularly Lake
_ Monona, Waubesa, and Kegosa from July 1943 to July 1944.
Report to Governor's Committee, Madison, Wisconsin. 92 pp.

114

Schelske, C. L., and E. Callender, 1970. Survey of phytoplankton
productivity and nutrients in Lake Michigan and Lake
Superior. Proc. 13th Conf. Great Lakes Res., 93-105..

Schelske, C. L., E. F. Stoermer, and L. E. Feldt, 1970. Inshore-
offshore differences in primary productivity and nutrients
in Lake Michigan as influenced by upwelling. Great Lakes
Research Division, University of Michigan. 28 pp.

Schelske, C. L., and E. F. Stoermer, 1971. Ph05ph0rus, Silica and
Eutrophication of Lake Michigan. Paper presented at Am. .F
Soc. of Limnol. Oceanogr., Symposium on Nutrients and .
Eutrophication, the limiting nutrient controversy. pp. 157-
171.

Sculthorpe, C. 0., 1967. The Biology of Aquatic Vascular Plants.
Edward Arnold Publishers, Ltd., London. 610 pp.

 

rig—:90;

Shapiro, J., and R. Ribeiro, 1965. Algal growth and sewage effluent
in the Potomac Estuary. J. Water Pollut. Control Fed., 37:
1034-1043. .

Siminon, H., 1973. Effects of Fertilization and Aeration on the
Ecology of Ponds. Master’s thesis, Mich. State Univ. 86 pp.

SladeEek, V., and A. Sladeckova, 1964. Determination of the periphy-
ton production by means of the glass slide method. Hydrobi-
ologia, 23: 125-158.

Smith, E. V., and H. S. Swingle, 1942. The use of fertilizer for
controlling several submerged aquatic plants in ponds.
Trans. Am. Fish. Soc., 71: 94-101.

Smith, M. W., 1969. Changes in environment and biota of a natural
lake after fertilization. J. Fish. Res. Bd. Can., 26:
3101-3132.

Sohacki, L. P., 1965. Ecological Alterations Produced by the Treat-
ment of Pond Ecosystems with Copper Sulfate and Sodium
Arsenite. Master's thesis, Mich. State Univ. 91 pp.

Stumm, W., and J. J. Morgan, 1970. Aquatic Chemistry. Wiley-
Interscience, New York. 583 pp.

Surber, E. W., 1945. The effects of various fertilizers on plant
growths and their probable influence on the population of
smallmouth black bass in hard-water ponds. Trans. Amer.
Fish Soc., 73: 377-393.

115

Swingle, H. S., B. C. Gooch, and H. R. Rabanal, 1963. Phosphate
fertilization of ponds. Proceedings of the Seventeenth
Annual Conference, Southeastern Assoc. of Game and Fish
Commissioners, September 29, 30; October 1, 2, 1963.
pp. 213-218.

Szczepanski,.A.,and W. Szczepanska, 1966. Primary production and
its dependence on the quantity of periphyton. Bull. Acad.
Pol. Sci. C1., 14: 45-50.

Tesar, F. J., 1971. Primary production in a Michigan Stream.
Master's thesis, Mich. State Univ. 953 pp. E-

Thomas, E. A., 1953. Zur Bekampfung der See-Eutrophierung: Empir-
ische and experimentelle Untersuchunger zur Kenntnis der
Minimumstoffe in 46 Seen der Schweiz and angrenzender

Begiete. Mluill. schweiz. Ver. Gas-u Wass Fachm Vr 2 and
3, 155.

 

Vallentyne, J. R., 1974. The algal b0wl--lakes and man. Ottawa,
Misc. Special Publ. 22, Dept. of the Environment. 185 pp.

Verduin, J., 1956. Primary production in lakes. Limnol. Oceanogr.,
1: 85-91.

Vollenweider, R. A., 1968. Scientific fundamentals of the eutrophi-
cation of lakes and flowing waters, with particular reference
to nitrogen and phosphorus as factors in eutrophication.
OECD. Paris, France. 237 pp.

Watt, W. 0., and F. R. Hayes, 1968. Tracer study of the phosphorus
cycle in sea water. Limnol. Oceanogr., 13: 276-285.

Weber, C. I., 1973. Recent developments in the measurement of the
response of plankton and periphyton to changes in their
environment. IN: Bioassay Techniques and Environmental
Chemistry. Ann Arbor Science Publishers, Inc., Ann Arbor.
pp. 119-138.

Weibel, S. R., 1969. Urban drainage as a factor in eutrophication.
IN: Eutr0phication: Causes, Consequences, Correctives.
Washington, D.C., National Academy of Sciences. pp. 383-403.

Wesenberg-Lund, C., 1904. Plankton investigations of the Danish
Lakes. Special Part. COpenhagen. (English summ. 44 pp.)

Westlake, D. F., 1960. Water weed and water management. J. Inst.
Public Health Eng., 59: 148-160.

Wetzel, R. G., 1960. Marl encrustration on hydrophytes in several
Michigan lakes. OIKOS., 11: 223-236.

Wetzel,

Wetzel,

Wetzel,

Wetzel,

Wetzel,

Wetzel,

Wetzel,

Wright,

116

R. G., 1964. A comparative study of the primary produc-
tivity of higher aquatic plants, periphyton, and phyto-
plankton in a large shallow lake. Int. Revue ges.
Hydrobiol., 49: 1-61.

R. G., 1965. Nutritional aspects of algal productivity in
marl lakes with particular reference to enrichment bioassays
and their interpretation. IN: Primary Productivity in

-Aquatic Environments. C. R. Goldman (ed.). pp. 137-160.

 

R. 0., 1966. Variations in productivity of Goose and hyper- '—
eutr0phic Sylvan Lakes, Indiana. Invest. Indiana Lakes

and Streams, 7, 5.

R. G., 1966. Productivity and nutrient relationship in marl

lakes of northern Indiana. Verh. Internat. Verein.Limnol., ;
16: 321-332. 1
R. G., 1968. Dissolved organic matter and phyt0plankton pro- 1,

ductivity in marl lakes. Mitt. Internat. Verein. Limnol.,
14: 261-270. .

R. G., 1969. Factors influencing photosynthesis and excre-
tion of dissolved organic matter by aquatic macrophytes in
hard water lakes. International Assoc. of Theoretical and
Applied Limnol. Proceedings, 17: 72-85.

R. G., and R. A. Hough, 1973. Productivity and role of
aquatic macrophytes in lakes: an assessment. Pol. Arch.
Hydrobiol., 20: 9-19.

J. C., 1965. The population dynamics and production of
Daphnia in Canyon Ferry Reservoir, Montana. Limnol.
Oceanogr., 10: 583-590.

Yentsch, C. 5., and J. H. Ryther, 1957. Short-term variations in

phytoplankton chlorophyll and their significance. Limnol.
Oceanogr., 3: 140-142.

Yoshimura, S., 1932. Seasonal variation in content of nitrogenous

Zicker,

compounds and phosphate in the water of Takasuka Pond.
Saitama, Japan. Arch. Hydrobiol. 24: 155-176.

E. L., K. C. Berger, and A. D. Hasler, 1956. Phosphorus
release from bog lake muds. Limnol. Oceanogr., 1: 296-303.

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