EPA-600/3-76-113
December 1976
Ecological Research Series
DISSOLVED OXYGEN, TEMPERATURE,
SURVIVAL OF YOUNG AT FISH
SPAWNING SITES
Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Duluth, Minnesota 55804
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into five series. These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to develop and
demonstrate instrumentation, equipment, and methodology to repair or prevent
environmental degradation from point and non-point sources of pollution. This
work provides the new or improved technology required for the control and
treatment of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/3-76-113
December 1976
DISSOLVED OXYGEN, TEMPERATURE, SURVIVAL OF YOUNG AT FISH SPAWNING SITES
John J. Peterka
James S. Kent
Department of Zoology
North Dakota State University
Fargo, North Dakota 58102
Grant No. R801976
Project Officer
Richard Siefert
Environmental Research Laboratory
Duluth, Minnesota 55804
ENVIRONMENTAL RESEARCH LABORATORY—DULUTH
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
DULUTH, MINNESOTA 53804
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DISCLAIMER
This report has been reviewed by the Environmental Research Laboratory -
Duluth, U.S. Environmental Protection Agency, and approved for publication.
Approval does not signify that the contents necessarily reflect the views
and policies of the U.S. Environmental Protection Agency, nor does mention of
trade names or commercial products constitute endorsement or recommendation
for use.
ii
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FOREWORD
Our nation's freshwaters are vital for all animals and plants, yet our
diverse uses of water for recreation, food, energy, transportation, and
industry physically and chemically alter lakes, rivers, and streams. Such
alterations threaten terrestrial organisms, as well as those living in water.
The Environmental Research Laboratory in Duluth, Minnesota develops methods,
conducts laboratory and field studies, and extrapolates research findings
—to determine how physical and chemical pollution affects
aquatic life
—to assess the effects of ecosystems on pollutants
—to predict effects of pollutants on large lakes through
use of models
—to measure bioaccumulation of pollutants in aquatic
organisms that are consumed by other animals, including
man
This report provides measurements of fluctuations of dissolved oxygen and
water temperature adjacent to embryos and sac larvae of northern pike,
bluegills, and pumkinseeds in their natural spawning sites. It also
describes field experiments designed to determine the effects of brief
exposure of various concentrations of dissolved oxygen on early life stages
of northern pike, bluegill, and smallmouth bass in their natural habitat.
Donald I. Mount, Ph. D.
Director
Environmental Research Laboratory
Duluth, Minnesota
iii
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ABSTRACT
Fluctuations of dissolved oxygen concentrations and water temperatures in
their natural spawning sites were measured during embryo through larva
stages of northern pike (Esox lucius) , and during embryo and sac larva
stages of bluegills (Lepomis macrochirus) and pumpkinseeds (Lepomis
gibbosus). At northern pike sites, dissolved oxygen concentrations from
combined measurements 1 and 10 cm from the bottom ranged from 0.0-16.6
mg/liter, and water temperatures from 2.5-23.0 C; average daily fluctua-
tions were 3.0 mg/liter and 1.6 C. For bluegill and pumpkinseed nests,
dissolved oxygen concentrations 1 cm from the bottom ranged from 2.4-18.2
mg/liter and water temperatures from 15.0-27.5 C, with average daily
fluctuations of 4.4 mg/liter and 3.3 C. In field experiments to deter-
mine acute effects of a single exposure to low dissolved oxygen concen-
trations, tolerance decreased from embryo to larva stages for northern
pike and from embryo to sac larva stages for bluegills and smallmouth
bass (Micropterus dolomieui).
This report was submitted in fulfillment of Grant Number R801976, by
the Department of Zoology, North Dakota State University, under the
partial sponsorship of the Environmental Protection Agency. Work was
completed August 1976.
iv
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CONTENTS
Page
Foreword iii
Abstract iv
Figures vi
Acknowledgments vii
1. Introduction 1
2. Conclusions 2
3. Recommendations 3
4. Methods 4
5. Results 8
6. Discussion 20
References
Appendices
A. Dissolved Oxygen Concentrations and Water Temperatures
in a Northern Pike Spawning Marsh 23
B. Dissolved Oxygen and Water Temperatures
in Centrarchid Nests 26
C. Northern Pike Oxygen Tolerance Experiments 28
D. Centrarchid Oxygen Tolerance Experiments 31
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FIGURES
No. Page
1 Siphoning apparatus to collect water samples 5
2 Dissolved oxygen concentrations in a northern pike spawning
marsh 9
3 Water temperatures in a northern pike spawning marsh 10
4 Water temperatures and dissolved oxygen concentrations
measured 5 cm from the bottom by two Delta recorders in a
northern pike spawning marsh 11
5 Mean water temperatures and dissolved oxygen concentrations
1 cm from the bottom in bluegill and pumpkinseed nests 14
6 Water temperatures and dissolved oxygen concentrations
measured 5 cm from the bottom by two Delta recorders in
bluegill spawning areas 15
7 Survival of northern pike embryos, sac larvae and larvae
exposed for 8 h to various concentrations of dissolved
oxygen 17
8 'Survival of smallmouth bass and bluegill embryos and sac
larvae exposed for 6 h and for 4 h, respectively, to
various concentrations of dissolved oxygen 18
vi
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ACKNOWLEDGEMENTS
The authors thank the Minnesota Department of Natural Resources, Detroit
Lakes Fish Hatchery for permitting us to conduct studies at Crane Lake and
the spawning marsh at Silver Lake; the U.S. Fish and Wildlife Service for
use of hatchery ponds at the Valley City National Fish Natchery; and both
the above as well as the North Dakota Game and Fish Department, Spiritwood
Lake Fish Hatchery for providing fish embryos and larvae.
vii
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SECTION 1
INTRODUCTION
In their extensive review of dissolved oxygen requirements for fishes,
Doudorof f and Shumway (1) reported that the contradictory results in many of
the studies could be lessened through controlled experiments in which natural
conditions are closely simulated. Our purpose was to contribute to the design
of such experiments at the Environmental Research Laboratory—Duluth,
Minnesota by providing measurements of fluctuations of dissolved oxygen and
water temperature adjacent to embryos and sac larvae of northern pike (Esox
lucius), bluegills (Lepomis macrochirus), and pumpkinseeds (Lepomis gibbosus)
in their natural spawning sites. We studied embryos and sac larvae because
they are relatively immobile and therefore unable to avoid exposure to
extremes, and because there is a lack of detailed information on dissolved
oxygen concentrations and water temperatures encountered by these stages.
To assess how low dissolved oxygen concentrations observed in the field
influenced hatching success and survival we conducted field experiments with
embryos, sac larvae, and larvae of northern pike, and embryos and sac larvae
of bluegills and smallmouth bass (Micropterus dolomieui) . Except for the
brief exposure times to various levels of dissolved oxygen, all fish were
kept in their natural surroundings where they were exposed to fluctuating
environmental factors; differences in survival from controls were then
attributed to effects of dissolved oxygen concentrations used in the treat-
ments.
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SECTION 2
CONCLUSIONS
In a northern pike spawning marsh, average dissolved oxygen concentrations
and water temperatures measured at combined depths of 1 and 10 cm from the
bottom, increased from morning to afternoon, respectively: 4.8 to 8.1
ing/liter and 6.1 to 7.3 C during the embryo stage, 3.3 to 6.6 mg/liter and
8.3 to 10.3 C during the sac larva stage, and 2.8 to 5.3 mg/liter and 8.2
to 9.8 C during the larva (free swimming) stage. Dissolved oxygen concen-
trations 1 and 10 cm from the bottom were 1.0 mg/liter and less in 7% of the
measurements made during embryo stages and in 18% of the measurements during
sac larva stages; their maximum duration was 10 h in a 24 h period.
In bluegill and pumpkinseed nests, average dissolved oxygen concentrations
and water temperatures 1 cm from the bottom during embryo through sac larva
stages increased from morning to afternoon and were, respectively, 7.1 to
11.5 mg/liter and 20.0 to 23.3 C; values measured at 10 cm from the bottom
and at the surface were similar. Dissolved oxygen concentrations during
embryo through larva stages were 4.0 mg/liter or less on only 5 of 53 days;
supersaturation occurred in the afternoons on 48 of 53 days. The presence
of males guarding the nests did not appear to affect oxygen levels; oxygen
concentrations adjacent to the nests were similar to those inside.
For all species tested, tolerance to low dissolved oxygen concentrations
decreased from embryo to larva stages. While northern pike embryos exposed
for 8 h to 0.6 mg/liter survived as well as controls, larvae required con-
centrations of 2.0 mg/liter and greater, and exposure for only 2 h to 0.8
mg/liter drastically reduced their survival. Larvae exposed for 8 h re-
quired oxygen concentrations of 4.0 mg/liter and greater. For smallmouth
bass exposed for 6 h, embryo hatching success at 1.0 mg/liter and greater
and sac larva survival at 2.2 mg/liter and greater was similar to controls.
Compared with controls, bluegill embryos exposed for 4 h tolerated concen-
trations as low as 0.5 mg/liter, and sac larvae tolerated levels as low as
1.8 mg/liter; survival of sac larvae was drastically reduced by exposure
for 2 h to 0.5 mg/liter of dissolved oxygen.
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SECTION 3
RECOMMENDATIONS
Because marked stratification of dissolved oxygen concentrations and water
temperatures occurred in spawning sites of northern pike, we found it
necessary to take samples manually at depths near and just above the bottom
to represent conditions to which embryos and sac larvae were exposed; marked
stratification was not found in bluegill or pumpkinseed nests. We found 20
ml water samples for dissolved oxygen determinations were the smallest we
could take and still retain accuracy. Delta dissolved oxygen recorders
provided useful information regarding daily and seasonal trends and durations
of extremes, but we did not find them consistent enough to provide accurate
measurements. The continuous movement of water caused by the stirring
mechanism affected micro-stratification.
It is feasible to use field-based experiments to determine effects of dis-
solved oxygen concentrations on survival of early life-stages of northern
pike, bluegills and smallmouth bass. However, we found it difficult to
maintain fish from embryo to early feeding stages. Future experiments
should be designed to provide a minimum handling of fish, particularly during
daily counts, in order to minimize shock.
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SECTION 4
METHODS
DISSOLVED OXYGEN AND WATER TEMPERATURE
Dissolved oxygen and water temperatures were measured in a northern pike
spawning marsh, Silver Lake, Clay County, and in bluegill and pumpkinseed
nests, Crane Lake, Ottertail County, Minnesota. Northern pike were studied
from mid-April, when spawning began, until mid-May when fry were observed,
1974 and 1975. Adult northern pike were stocked and marsh water levels
were controlled by fisheries personnel of the Minnesota Department of
Natural Resources. For bluegills and pumpkinseeds, dissolved oxygen and
water temperatures were measured from the time a nest was first seen until
the male fish abandoned the nest. Measurements were made from early June
until mid-July, 1973 and 1974.
In 1973, we determined, from samples collected every 2 h for several days
in Crane Lake, that lows of dissolved oxygen occurred at 0800-0900 (CDST)
and highs at 1600-1700. We confirmed these times both there and in the
Silver Lake marsh in 1974 with continuous records of dissolved oxygen con-
centrations. Daily samples were taken during these periods to provide
measurements of extremes in dissolved oxygen concentrations. Dissolved
oxygen was measured from water samples collected at the surface with a
van Dorn sampler and from those siphoned 1 and 10 cm from the bottom
through Tygon tubing (inside diameter of .24 cm) into 20 ml glass-stoppered
weighing bottles. To develop siphons, we placed sample bottles in a
weighted plastic pail to allow the bottles and tips of siphon tubes to be
lowered below the water's surface [Magnuson (2)] (Fig. 1). Sampling depths
of 1 cm from the bottom were chosen to represent dissolved oxygen concen-
trations adjacent to embryos and larvae of northern pike on the bottom;
those at 10 cm to represent conditions adjacent to embryos and sac larvae
on vegetation above the bottom.
At each depth duplicate samples were prepared by thoroughly flushing the
siphon tubes and replacing the volume of the sampling bottles at least twice.
Samples were fixed using the azide modification of the Winkler method
[A.F.H.A. (3)]. Chemicals for fixing the 20 ml samples were used in reduced
volumes (0.1 ml); 8.2 ml of fixed sample was titrated with 0.002 N Na2S203 in
a buret with graduations of 0.05 ml. Dissolved oxygen was measured to the
nearest 0.1 mg/liter. Where discrepancies greater than 0.3 mg/liter between
duplicate samples occurred, a third titration was run using the mixed re-
mainders of the two samples; means were determined from the closest two out
of three measurements. To provide a check on the accuracy of dissolved
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WATER
LEVEL
SUPPORT ROD
SCREENED
OPENING
TUBING
CONNECTOR
WEIGHTED PAIL
SAMPLE
BOTTLE
TYGON TUBING
X
Figure 1. Siphoning apparatus to collect water samples.
5
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oxygen determinations in small samples, duplicate macro samples (200 ml) and
small samples (8.2 ml) were prepared from water collected at the surface.
Any differences of dissolved oxygen in macro and small samples were used to
adjust dissolved oxygen values for all small samples, assuming the dissolved
oxygen in macro samples to be correct. The mean difference between duplicate
macro samples was 0.03 mg/liter (N=30).
To reduce disturbance from sampling of any dissolved oxygen or water tempera-
ture stratification, siphon tubes extended 1-2 m from each station. A
tubing connector at the intake end of each siphon tube was cut at a 45°
angle. Because tests in laboratory aquaria using methylene blue crystals as
tracers showed water was drawn to the tip of the connector we positioned
the connector 10 cm from the bottom to draw water from above the connector
tip, and the connectors 1 cm from the bottom to draw water from below the
connector tip to help prevent disturbance of any oxygen stratification due
to slight currents created by siphoning (Fig. 1). Each tubing connector-end
was covered with 3l6y Nitex netting to prevent entrance of detritus.
Water temperatures to the nearest 0.5 C were measured with thermistors at
times and depths dissolved oxygen samples were collected. As with siphon
tubes, thermistor probes were left in place to prevent any disturbance of
water during sampling.
Two Delta (Model 3610) recorders were used in 1974 to provide a continuous
record of dissolved oxygen and water temperatures. Probes were placed 5 cm
from the bottom, and dissolved oxygen was recorded to the nearest 0.2
mg/liter and water temperature to the nearest 1 C. The meters provided a
good indication of daily trends and duration of extremes, but problems with
the need for frequent calibration led us to discontinue their use after one
year.
We measured water movement near the bottom of spawning sites of northern pike
by timing the drift of plumes from methyl ene blue crystals which were dropped
on a metal grid placed on the bottom. Observations of the plumes were made
with a glass-bottomed pail.
Durations of early stages of northern pike development were estimated from
field observations of hatching of embryos and development of sac larvae
and larvae.
OXYGEN TOLERANCE EXPERIMENTS
In field experiments, early stages of northern pike, smallmouth bass and blue-
gills were exposed to dissolved oxygen concentrations ranging from no oxygen
to saturation for periods ranging from 1-8 h (8 h was the longest period
during which dissolved oxygen concentrations measured remained below 1.0
mg/liter in the northern pike spawning marsh) .
Northern pike, obtained from the National Fish Hatchery, Valley City, N.D.
and from N.D. State Hatchery, Spiritwood, ranged from 1-day-old embryos to
larvae. Smallmouth bass embryos and sac larvae were obtained from nests in
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spawning ponds at the National Fish Hatchery, Valley City. Bluegill embryos
and sac larvae were obtained from nests at Crane Lake, Minnesota.
Chambers containing embryos, sac larvae or larvae were returned to natural
surroundings following each treatment where they were elevated on racks to
prevent disturbance of the bottom and avoid siltation. Survival was measured
daily by counting live and dead fish in the chambers. For experiments with
embryos, survival was recorded until hatching was complete. Survival of sac
larvae and larvae was recorded until most in control chambers died. Northern
pike embryos were treated in solutions of 1:600 formalin for 16 min about
every two days (method used at the National Fish Hatchery, Valley City, N.D.)
when fungused embryos were observed. Fungus was not a problem with centrar-
chids because of short incubation periods.
Chambers were constructed of PVC pipe with an inside diameter of 4.3 cm and a
length of 2.3 cm with covers of 316u opening Nitex netting. To permit
development of northern pike sac larvae to the feeding stage where any
delayed exposure effects could be observed, we used large holding chambers
constructed of 13.2 liter (3 gal) and 22.0 liter (5 gal) polyethylene tubs
with openings covered with 750y Nitex netting.
During treatment, chambers were placed in 22.0 liter polyethylene buckets
filled with lake water in which dissolved oxygen was controlled by bubbling
various mixtures of compressed nitrogen and air. The buckets were kept in
the lake to maintain natural temperatures. Gas mixtures were adjusted by
flow meters and a gas manifold. Dissolved oxygen and water temperatures were
recorded at about 1 h intervals during the experiments. The change in pH due
to bubbling nitrogen gas in the northern pike marsh water was from 8.5 to 8.7
at a concentration of 0.3 mg/liter of dissolved oxygen; the pH of water in
Crane Lake changed from 8.4 to 8.9 at a concentration of 0.3 mg/liter
dissolved oxygen. We did not consider these changes in pH to affect sur-
vival of fish.
Analysis of variance with replications and with treatments fixed was used in
the experiments. When zero values occurred, 1.0 was added to each value
for computation of sums of squares. Duncan's Multiple Range Test was used
to determine significant differences among means [Steel and Torrie (3)].
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SECTION 5
RESULTS
DISSOLVED OXYGEN AND WATER TEMPERATURE--NORTHERN PIKE
Dissolved oxygen in 1974 and 1975 generally was lowest at 1 cm from the
bottom and highest at the surface. Dissolved oxygen concentrations were
lower in the morning than in the afternoon at all water depths measured, and
decreased at a given depth from embryo to larva stages (Fig. 2; Appendix A,
Table 1). Daily fluctuations in dissolved oxygen and differences between
morning and afternoon measurements during the embryo and sac larva stages
were less in 1975 than in 1974.
Dissolved oxygen concentrations at all depths fluctuated markedly from day to
day and from morning to afternoon (Fig. 2) . The maximum day-to-day decreases
in 1974 were from 14.7 to 3.8 and from 10.2 to 2.7 mg/liter at 10 and 1 on
from the bottom, respectively, from the afternoon of 26 April to the after-
noon of 27 April. In 1975, a decrease at 10 cm from 9.8 to 6.2 mg/liter and
at 1 cm from 6.5 to 2.9 mg/liter from the afternoon of 6 Hay to the afternoon
of 7 May was the largest measured. The greatest differences between morning
and afternoon concentrations on the same day were 3.5 to 15.0 mg/liter at 1
cm on 23 April 1974, and 3.2 to 9.4 mg/liter at 10 cm on 5 May 1975.
Mean dissolved oxygen concentrations measured 5 cm from the bottom with Delta
oxygen recorders at two stations from 23 April to 12 May 1974, were lowest
at 0800-0900 and highest at 1600-1700 COST (Fig. 4). Because daily patterns
of dissolved oxygen fluctuations were similar, we chose 2 days to illustrate
data from continuous recordings: 24 April, when highest concentrations of
dissolved oxygen occurred, and 28 April, when lowest concentrations occurred
(Fig. 4). Dissolved oxygen was 0.0 mg/liter for 6 h on 28 April and was less
than 0.6 mg/liter for 8 h. We observed that oxygen increased slightly before
and then decreased at sunrise on 8 mornings from 27 April-13 May at one of
the recorders and on 6 mornings from 24 April-8 May at the other recorder
(Fig. 4) . The weather from 24 April-13 May was windy and cloudy with much
rain which could have caused the pre-sunrise increases of dissolved oxygen.
Dissolved oxygen concentrations measured by the recorders were similar to
averages of manual measurements made 10 cm from the bottom. Means of dis-
solved oxygen determined with recorders for embryos, sac larvae, and larvae,
respectively, were 7.4, 6.5, and 5.5 mg/liter; those for manual measurements
were 7.6, 6.0, and 5.1 mg/liter (Appendix A, Table 1) .
Average daily water temperatures generally increased from April to May in
1975, whereas in 1974 they remained rather uniform (Fig. 3) . Water
8
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Figure 2. Dissolved oxygen concentrations in a northern pike spawning
marsh. Each point represents the mean determined from measure-
ments at two stations at the surface, and at 10 and 1 cm from
the bottom. Broken line represents measurements at 0800-0900
(CDST), and solid line represents measurements at 1600-1700.
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Figure 3.
Water temperatures in a northern pike spawning marsh. Each
point represents the mean determined from measurements at two
stations at the surface, and at 10 and 1 cm from the bottom.
Broken line represents measurements at 0800-0900 (CDST), and
solid line represents measurements at 1600-1700.
10
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io
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-^ •— • — •— •
0-1
3-4
23-24
Figure 4. Water temperatures and dissolved oxygen concentrations measured 5 cm
from the bottom by two Delta recorders in a northern pike spawning
marsh. A. -28 April 1974, day of highest water temperature. B. -Average water
temperature from 23 April-12 May 1974. C.-23 April 1974, day of lowest water
temperature. D.-24 April 1974, day of highest dissolved oxygen. E. -Average
dissolved oxygen from 23 April-12 May 1974. F. -Average dissolved oxygen from
1-4 May 1974, indicating an increase in dissolved oxygen before sunrise, fol-
lowed by a decrease at sunrise. G.-28 April 1974, date of lowest dissolved oxygen.
11
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temperatures for combined depths 10 and 1 cm from the bottom in 1974 ranged
from 3.5-12.8 C during the embryo, 5.0-11.2 C in the sac larva, and 5.0-9.0 C
in the larva stages; in 1975 the ranges were 3.5-8.5 C, 6.2-14.5 C, and
8.8-16.2 C. Water temperature fluctuations from morning to afternoon were
greater in 1974 than in 1975.
Embryo
Because embryos and sac larvae were observed on vegetation, dissolved oxygen
concentrations and water temperature measured in 1974 and 1975 at 1 and
10 cm from the bottom are used to describe conditions experienced by these
stages. Dissolved oxygen concentrations during the northern pike embryo
stage ranged from 0.3-16.6 mg/liter 1 cm from the bottom and 1.2-15.0 at
10 cm (Appendix A, Table 1) . Mean dissolved oxygen concentrations at 10 and
1 cm, respectively, were 6.0 and 3.5 mg/liter in the morning and 9.3 and 6.9
mg/liter in the afternoon. When measurements at the 10 and 1 cm levels were
combined, concentrations less than 1.0 mg/liter occurred in 107. (6 out of 60)
of the morning measurements or 5 of the 15 mornings; concentrations of
1.1-2.0 mg/liter occurred in 18% of the morning measurements or 7 of the 15
days. Supersaturation occurred in 14% (9 out of 64) of the afternoon
measurements or 6 of 16 afternoons.
Water temperatures from combined measurements 10 and 1 cm from the bottom
ranged from 2.5-16.0 C (Appendix A, Table 2). Mean water temperatures at 10
and 1 cm, respectively, were 6.5 and 5.6 C in the morning and 8.0 and 6.6 C
in the afternoon.
Sac Larvae
During northern pike sac larva stages in 1974 and 1975, dissolved oxygen
concentrations ranged from 0.0-13.4 mg/liter (Appendix A, Table 1) . Mean
dissolved oxygen concentrations at 10 and 1 cm, respectively, were 4.4 and
2.2 mg/liter in the morning and 7.6 and 5.6 mg/liter in the afternoon. Of 74
morning measurements at 10 and 1 cm, concentrations of 1.0 mg/liter and less
occurred in 24% of the measurements (13 of the 18 days) ; concentrations of
1.1-2.0 mg/liter occurred in 9.5% of the morning measurements (9 of the 18
days). Of 72 afternoon measurements supersaturation occurred in 9.8% (6 of
the 18 days) .
Water temperatures in 1974 and 1975 from combined measurements 10 and 1 cm
from the bottom ranged from 4.0-17.0 C (Appendix A, Table 2) . Mean water
temperatures at 10 and 1 cm, respectively, were 8.5 and 8.0 C in the morn-
ings and 10.9 and 9.7 C in the afternoons.
Larvae
In 1974 and 1975, dissolved oxygen concentrations ranged from 0.0 at 1 cm
from the bottom to 12.0 mg/liter at the surface (Appendix A, Table 1). Mean
dissolved oxygen concentrations at 10 and 1 cm, respectively, were 3.8 and
1.9 mg/liter in the morning and 6.4 and 4.2 mg/liter in the afternoon; at the
surface means were 5.8 (morning) and 8.3 mg/liter (afternoon). Although
concentrations of 2.0 mg/liter and less occurred in 25% of the morning
12
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measurements, mostly at 1 cm from the bottom, higher oxygen concentrations
were present at other depths.
Water temperatures ranged from 4.0-22.5 C (Appendix A, Table 2) . Mean water
temperatures for the three depths ranged from 8.0-8.3 C in the mornings and
from 9.1-13.2 C in the afternoons.
DISSOLVED OXYGEN AND WATER TEMPERATURE—CENTRARCHIDS
In general, dissolved oxygen concentrations and water temperatures measured
in nests of bluegills and pumpkinseeds in 1973 and 1974 were higher at a
given depth in the afternoon than in the morning; measurements taken at the
surface in water depths of about 0.7 m differed only 0.6 mg/liter and 0.4 C
from measurements taken 1 cm from the bottom (Appendix B) , and daily
fluctuations and mean values were similar in both years (Fig. 5) .
Because, unlike the northern pike studied, embryos and sac larvae were found
only at the bottom, and because no stratification occurred we will limit our
discussion here to measurements 1 cm from the bottom. The mean dissolved
oxygen concentration 1 cm from the bottom was 7.1 mg/liter in the morning and
11.5 mg/liter in the afternoon with a range of 2.4-18.2 mg/liter (Appendix B,
Table 1) . In spite of this large range, 71% of the morning measurements were
6.1-9.0 mg/liter and 61% of the afternoon measurements were 9.1-13.0 mg/liter.
Super saturation occurred on 18 of 53 mornings and on 48 of 53 afternoons.
The low of 2.4 mg/liter of dissolved oxygen was measured in one pumpkinseed
nest found in very shallow water of 0.3 m. Both maximum and minimum
dissolved oxygen concentrations were recorded at stations on the lee side of
the lake. Mean water temperatures at 1 cm from the bottom were 20.0 C in
the morning and 23.3 C in the afternoon with a range of 15.0-27.5 C (Appen-
dix B, Table 2) .
Mean dissolved oxygen concentrations measured 5 on from the bottom with Delta
recorders at 2 stations from 9 June to 5 July 1974, were lowest at 0800-0900
and highest at 1700-1800 CDST (Fig. 6). The lowest dissolved oxygen concen-
tration, 5.0 mg/liter, was recorded on 21 June, and highest, 16.0 mg/liter,
on 26 June.
To determine if nest-guarding activities of male fish affected dissolved
oxygen levels, we measured dissolved oxygen with manual methods in 8 nests
and 1 m outside each of these nests in 1974. Average dissolved oxygen con-
centrations 1 cm from the bottom were 7.5 mg/liter inside the nests (morn-
ings) ; this was not significantly different (P < .01, N » 43) from 7.2
mg/liter outside the nests. Means of the afternoon measurements were 11.9
mg/liter (N = 39) both inside and outside the nests.
OXYGEN TOLERANCE EXPERIMENTS—NORTHERN PIKE
Embryo
A 77% hatching success occurred with embryos exposed for 8 h on the 7th day
after fertilization to dissolved oxygen of 0.6 mg/liter, which was similar to
hatching success of 80-93% in the higher concentrations tested (Fig. 7;
13
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30 JULY 10
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TIME, days
Figure 5. Mean water temperatures ana dissolved oxygen concentrations 1 cm trom the bottom in bluegill
and pumpkinseed nests. Broken line represents measurements at 0800-0900 (CDST), and solid line
represents measurements at 1600-1700. Each point represents the mean determined from 1-3 nests.
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0-1
3-4
7-1
11-12
TIME, k
15
19 20
23-24
Figure 6. Water temperatures and dissolved oxygen concentrations measured
5 cm from the bottom by two Delta recorders in bluegill spawning
areas from 9 June-5 July, 1974. Broken lines represent days of
highest and lowest temperatures and dissolved oxygen concentra-
tions.
L5
-------
Appendix C, Table 1) . Hatching began 10 days after fertilization; all
embryos had hatched by the 12th day following fertilization.
Sac Larvae
Mean survival of sac larvae, exposed 1 day after hatching for 8 h to dis-
solved oxygen concentrations of 0.3 mg/liter in two experiments was 51%.
This was significantly lower (P < .01) than the 87-97% survival in the high-
er concentrations tested (Fig. 7; Appendix C, Table 2) . Mean total lengths
of sac larvae measured 8 days after hatching were similar (F < .05) in the
first experiment; no lengths were measured in the second experiment.
Because survival was reduced when we exposed sac larvae to 0.3 mg/liter of
dissolved oxygen for 8 h, we tried to assess effects of various durations of
exposure to low dissolved oxygen concentrations. No sac larvae treated 3
days after hatching in dissolved oxygen concentrations of 0.8 ing/liter sur-
vived exposure for 6 h, 6% survived for 4 h, 14% survived for 2 h, and 88%
survived in the controls (Appendix C, Table 3). Survival in the controls was
higher (P < .01) than in all treatments; survival in the treatments was not
different at the .01 level, but at the .05 level, survival after 2 h exposure
was greater than after 6 h.
Larvae
All larvae that had just reached the feeding stage died after 8 h in dis-
solved oxygen concentrations averaging 1.6 mg/liter (Fig.7; Appendix C,
Table 4). Survival in controls and in treatments where dissolved oxygen
ranged from 3.5-9.3 mg/liter was 93-100%. High mortality of larvae in con-
trols prevented assessment of survival for more than 1 day following treat-
ment.
OXYGEN TOLERANCE EXPERIMENTS—CENTRA.RCHIDS
Smallmouth Bass—Embryo
Two-day-old embryos exposed to 0.5 mg/liter of dissolved oxygen for 6 h died
before hatching (Fig. 8; Appendix D, Table 1) . Mean hatching success of
69-91% was similar (P < .01) in higher concentrations tested of 1.8-7.9
mg/liter.
Smallmouth Bass—Sac Larvae
No sac larvae survived at a dissolved oxygen concentration of 0.5 mg/liter
when treated 1 day after hatching for 6 h (Fig. 8; Appendix D, Table 2) .
Mean survival of 53-83% was similar (P < .01) in the higher concentrations
tested of 2.2-9.0 mg/liter. In another experiment, survival of sac larvae
treated with dissolved oxygen levels of 1.0-2.0 mg/liter for 6 h was 85%;
this was not significantly different (P < .01) from the 95% survival in con-
trols.
16
-------
20 _
1 2 3 4 S 6 7 8 9
DISSOLVED OXYGEN, rug/liter
10 11 CONTROL
Figure 7. Survival of northern pike embryos, sac larvae and larvae exposed
for 8 h to various concentrations of dissolved oxygen. A.
-Hatching success of embryos exposed 7 days after fertilization.
B.-Survival of sac larvae exposed 1 day after hatching. C.-Sur-
vival of larvae exposed in early feeding stage. Stars indicate
significant differences from controls. Detailed information
found in Appendix C.
17
-------
S 100
o
£
w
BLUEGIll
_ — — - *
if,
1234SI7IIU MNTM1
men.
Figure 8. Survival of smallmouth bass and bluegill embryos and sac larvae
exposed for 6 h and for 4 h, respectively, to various concentra-
tions of dissolved oxygen. A.-Hatching success of smallmouth bass
embryos exposed 2 days after fertilization. B.-Survival of
smallmouth bass sac larvae exposed 1 day after hatching. C.-
hatching success of bluegill embryos exposed 1 day after fertili-
zation. D.-Survival of bluegill sac larvae exposed 1-4 days after
fertilization. Stars indicate significant differences from
controls. Detailed information in Appendix D.
18
-------
Bluegill—Enibryo
Mean hatching success of embryos, exposed for 4 h in two experiments to 0.5
rag/liter of dissolved oxygen was 40%; this was not significantly different
(P < .05) from 44-50% hatched in concentrations of 2.1-7.8 tag/liter (Fig. 8;
Appendix D, Table 3) .
Bluegill—Sac Larvae
In four out of five experiments no sac larvae, 1-4 days after hatching, sur-
vived when exposed for 4 to 6 h to a dissolved oxygen concentration of
0.5 mg/liter. Mean survival ranged from 65-74% in the higher concentrations
tested of 1.8-8.0 mg/liter (Fig. 8, Appendix D, Table 4). Exposure for 6 h
rather than 4 h in one experiment did not reduce survival, which in this
experiment was second highest of the five experiments. In concentrations of
more than 1.8 mg/liter of dissolved oxygen, mean survival in water tempera-
ture of 26 C was 89% and was significantly higher (P < .01) than the mean
survival of 56% in water temperature of 21-22 C. Mean survival of sac larvae
exposed to dissolved oxygen concentrations of 0.5 mg/liter for periods rang-
ing from 1-4 h was 0, 1, 11% for the 4, 3, 2 h exposures, respectively, and
was lower (P < .01) than the 71, 79% survival in the 1 h exposure and in the
control (Appendix D, Table 5). Although there was a significant interaction
between experiments and treatments, this was probably due to the low survival
of the controls in one of the five experiments. When this experiment is
eliminated from the analysis, the interaction was non-significant.
19
-------
SECTION 6
DISCUSSION
DISSOLVED OXYGEN AND WATER TEMPERATURE
Northern Pike
We measured dissolved oxygen concentrations and water temperatures in a
northern pike spawning site during 2 years of extremely different weather
conditions. In 1974 warm water temperatures during spawning were followed
by cooler temperatures, and there were extreme day-to-day and morning-to-
afternoon fluctuations of dissolved oxygen concentrations and water tempera-
ture. In 1975 there was a gradual wanning trend from spawning to larva
stages, and fluctuations of temperature and of dissolved oxygen were less
than in 1974. In both years dissolved oxygen concentrations decreased from
embryo to larva stages. The decrease was probably due to decomposition of
grasses that had grown when the marsh bottom was dry during the preceding
summer and fall.
Natural reproduction was measured from counts of numbers and wet weights of
fingerlings released to Silver Lake when the marsh was drained in the summer
(Detroit Lakes Fish Hatchery, Minnesota Department of Natural Resources).
Estimated numbers of fingerlings resulting from 12 to 15 female northern pike
in 1974 and 1975, respectively, were 3190 and 2500; the average wet weights
were 1.6 and 2.7 g. The estimate for 1975 is believed to be low because
large flows of water over the retaining wall dam during the spring permitted
fingerlings to escape before the census was taken.
The two stations where manual measurements were taken had different expo-
sures to wind, sunlight, and water currents which affected dissolved oxygen
concentrations and water temperatures. Station A was sheltered from the wind
and shaded in the afternoon by trees and cattails; water currents near the
bottom on a calm day were 0.05 cm/sec. Station B was exposed to wind and
afternoon sunlight; located near the main channel draining the marsh, its
water current was 0.23 cm/sec. The faster movement of water at Station B
was probably the reason the mean dissolved oxygen concentration at that
station, 5.6 mg/liter, was greater than the 4.9 mg/liter mean at Station A.
Both means are of measurements at combined depths 1 and 10 cm from the
bottom. Exposure to afternoon sunlight was responsible for warmer average
water temperatures from the combined depths 1 and 10 cm from the bottom of
9.0 C at Station B compared to 7.5 C at Station A. The faster water currents
and afternoon sunlight also caused the frost to leave the bottom muds of
Station B sooner than at Station A.
20
-------
Centrarchids
In Crane Lake, where centrarchids were studied, dissolved oxygen concentra-
tions and water temperatures during the spawning seasons 1974 and 1975 were
similar and were characterized by low day-to-day fluctuations, little strat-
ification with depth, and generally high concentrations of dissolved oxygen;
super saturation occurred on 907=, of the days sampled. Lows of less than 4.0
rag/liter of dissolved oxygen were found on 10% of the mornings. We found
dissolved oxygen concentrations on cloudy days to be lower than on clear
days, but there were too few cloudy days to make statistical comparisons.
No differences were found in dissolved oxygen inside and outside of bluegill
nests guarded by male fish.
OXYGEN TOLERANCE EXPERIMENTS
For 8 h exposures to various levels of dissolved oxygen, survival was simi-
lar to that in the controls for northern pike embryos treated at concentra-
tions of 0.6 mg/liter, for sac larvae treated at concentrations of 2.0
ing/liter and greater, and for larvae treated at concentrations of 4.0
mg/liter and greater. Apparently, tolerance to low dissolved oxygen con-
centrations decreases from embryo to larva stages. Even the age of sac
larvae influenced tolerance to low dissolved oxygen concentration as no
3-day-old sac larvae survived a 6 h exposure to a concentration of 0.8
mg/liter, whereas 51% of 1-day-old sac larvae survived an 8 h exposure at
0.3 mg/liter. Survival of 3-day-old sac larvae was drastically reduced
by exposure to 0.5 mg/liter of dissolved oxygen for only 2 h.
Siefert, Spoor, and Syrett (5) found that constant exposure to dissolved
oxygen concentrations of about 5.0 mg/liter would permit good survival of
northern pike from the embryo state through first feeding of larvae. Be-
cause of short exposure times to low dissolved oxygen concentrations used in
our experiments, it is difficult to make comparisons with results from other
studies. However, during embryo through larva stages, dissolved oxygen
concentrations at combined depths 1 and 10 cm from the bottom were less than
5.0 mg/liter in 70% of the morning measurements and in 30% of the afternoon
measurements indicating that naturally-occurring dissolved oxygen concen-
trations are frequently lower than concentrations reported necessary for
good survival determined from laboratory experiments.
Hatching success of smallmouth bass embryos exposed for 6 h at concentrations
of 1.0 mg/liter and greater of dissolved oxygen was similar to controls, as
was survival of smallmouth bass sac larvae treated at 2.2 mg/liter and
greater. Smallmouth bass embryos died when exposed to 0.5 mg/liter for 6 h.
Siefert, Carlson, and Herman (6) found that after constant exposure of small-
mouth bass embryos and larvae to various levels of dissolved oxygen, hatch-
ing took place at 2.5 mg/liter but death occurred by the fifth day of expo-
sure; embryos treated with 1.2 mg/liter failed to hatch.
Hatching success of bluegill embryos exposed for 4 h at concentrations of
0.5 mg/liter was similar to controls; for sac larvae, survival was similar to
controls at 1.5 mg/liter and greater. Survival of bluegills sac larvae was
severely reduced by exposure to 0.5 mg/liter of dissolved oxygen for only 2 h.
21
-------
REFERENCES
1. Doudoroff, P. and D. L. Stunnway. Dissolved Oxygen Requirements of
Freshwater Fishes. Food and Agriculture Organization of the United
Nations, Rome, Italy. Technical Paper Number 86. 1970. 291 p.
2. Magnuson, J. J. and W. E. Stuntz. A Siphon Water Sampler for Use
Through the Ice. Limnol. Oceanogr. ^5:156-158, January 1970.
3. Standard Methods for the Examination of Water and Wastewater.
American Public Health Association, New York. 1971. p. 477-481.
4. Steel, R. G. D. and J. H. Torrie. Principles and Procedures of
Statistics. McGraw-Hill Book Company, Inc., New York. 1960. p. 132-156.
5. Siefert, R. E., W. A. Spoor, and R. F. Syrett. Effects of Reduced
Oxygen Concentrations on Northern Pike (Esox lucius) Embryos and Larvae.
J. Fish. Res. Board Can. 30:849-852, June 1973.
6. Siefert, R. E., A. R. Carlson, and L. J. Herman. Effects of Reduced
Oxygen Concentrations on the Early Life Stages of Mountain Whitefish,
Smallmouth Bass, and White Bass. Prog. Fish Cult. ^6 (4):186-190,
October 1974.
22
-------
APPENDIX A
DISSOLVED OXYGEN CONCENTRATIONS AND WATER TEMPERATURES IN A NORTHERN PIKE
SPAWNING MARSH DURING THE EMBRYO, SAC LARVA, AND LARVA STAGES
MEASUREMENTS TAKEN AT 0800-0900 AND AT 1600-1700 CDST AT THE SURFACE AND AT
10 AND 1 cm FROM THE BOTTOM AT 2 STATIONS IN 1974 AND 1975. MEAN WATER
DEPTHS WERE 0.5 m AND RANGED FROM 0.46 TO 0.58 m.
TABLE A-l. DISSOLVED OXYGEN CONCENTRATIONS (mg/liter) IN A NORTHERN PIKE
SPAWNING MARSH DURING THE EMBRYO, SAC LARVA, AND LARVA STAGES,
AND THE FREQUENCY AT WHICH VARIOUS DISSOLVED OXYGEN CONCENTRA-
TIONS OCCURRED
Dissolved Oxygen
Morning
Depth
Surface
10
1
Total
No.
30a
30
30
90
Average
7.4
6.0
3.5
5.6
S.D.
2.58
2.76
2.65
3.08
Embryo
Range
2
1
0
0
.4-12
.2-10
.3- 9
.3-12
.4
.4
.6
.4
Afternoon
No,. Average
32B
32
32
96
10.3
9.3
6.9
8.9
S.D.
2.23
3.24
4.62
3.75
Range
5.
8.
0.
0.
6-15.8
5-15.0
8-16.6
8-16.6
Sac Larva
Surface
10
1
Total
37C
37
37
111
6.4
4.4
2.2
4.3
0.96
1.56
2.03
2.33
3
1
0
0
.3- 8
.3- 7
.0- 7
.0- 8
.2
.4
.0
.0
36d
36
36
108
9.1
7.6
5.6
7.4
1.21
2.17
3.65
2.91
7.
2.
0.
0.
4-13.1
8-12.6
6-13.4
6-13.4
Larva
Surface
10
1
Total
23e
23
23
69
5.8
3.8
1.9
3.8
1.24
1.62
1.56
2.14
3
1
0
0
.6- 8
.0- 6
.0- 4
.0- 8
.4
.8
.8
.4
22
22
22
66
8.3
6.4
4.2
6.3
1.74
1.63
2.34
2.56
5.
2.
1.
1.
5-12.0
9- 9.1
0-11.0
0-12.0
(continued)
23
-------
APPENDIX A - TABLE A-l (continued) .
Frequency
of Dissolved Oxygen in the Marsh
Morning
Dissolved
Oxygen
(mg/ liter)
0.0- 1.0
1.1- 2.0
2.1- 3.0
3.1- 4.0
4.1- 5.0
5.1- 6.0
6.1- 7.0
7.1- 8.0
8.1- 9.0
9.1-10.0
10.1-11.0
11.1-12.0
12.1-13.0
13.1-14.0
14.1-15.0
15.1-16.0
16.1-17.0
Totals
Embryo
No.
6
11
4
7
10
11
8
7
11
11
2
1
1
0
0
0
_0
90
7.
6.7
12.2
4.4
7.8
11.1
12.2
8.9
7.8
12.2
12.2
2.2
1.1
1.1
0
0
0
0
100
Sac
No.
18
7
9
12
10
20
27
7
1
0
.0
0
0
0
0
0
JO
111
Larva
7»
16.2
6.3
8.1
10.8
9.0
18.0
24.3
6.3
0.9
0
0
0
0
0
0
0
0
100
Larva
No.
10
7
6
10
16
9
7
3
1
0
0
0
0
0
0
0
0
69
7.
14.5
10.1
8.7
14.5
23.2
13.0
10.1
4.3
1.4
0
0
0
0
0
0
0
0
100
Embryo
No.
1
4
5
2
1
6
9
9
6
17
12
7
3
3
7
3
1
96
7o
1.0
4.2
5.2
2.1
1.0
6.3
9.4
9.4
6.3
17.7
12.5
7.3
3.1
3.1
7.3
3.1
1.0
100
Afternoon
Sac
No.
2
4
6
3
6
11
9
12
19
20
10
2
2
2
0
0
0
108
Larva
7o
1.9
3.7
5.6
2.8
5.6
10.2
8.3
11.1
17.6
18.5
9.3
1.9
1.9
1.9
0
0
0
100
Larva
No.
0
3
6
4
6
10
12
7
11
3
1
3
0
0
0
0
0
66
7o
0
4.5
9.1
6.1
9.1
15.2
18.2
10.6
16.7
4.5
1.5
4.5
0
0
0
0
0
100
a7 mornings from 23-30 April in 1974 and 8 mornings from 25 April -
2 May in 1975.
b
8 afternoons from 23-30 April in 1974 and 8 afternoons from 24
April - 1 May in 1975.
1975.
in 1975.
1975.
in 1975.
"8 mornings from 1-8 May in 1974 and 10 mornings from 3-12 May in
*8 afternoons from 1-8 May in 1974 and 10 afternoons from 2-12 May
"7 mornings from 9-16 May in 1974 and 4 mornings from 13-16 May in
6 afternoons from 9-16 May in 1974 and 4 afternoons from 13-16 May
24
-------
APPENDIX A (continued)
TABLE A-2. WATER TEMPERATURES (C) IN A NORTHERN PIKE SPAWNING MARSH DURING
THE EMBRYO, SAC LARVA, AND LARVA STAGES
Water Temperatures
Morning
Depth
Surface
10
1
Total
Surface
10
1
Total
Surface
10
1
No.
30
30
30
90
37
37
37
111
23
23
23
Average
7.2
6.5
5.6
6.4
8.8
8.5
8.0
8.4
8.2
8.3
8.0
S.D.
3.21
2.46
2.22
2.71
2.29
2.38
2.39
2.36
3.14
3.36
3.08
Embryo
Range
3.5-15.0
3.5-14.0
2.5-12.0
No.
32
32
32
2.5-15.0 96
Sac Larva
5.0-13.0
5.0-12.5
4.0-12.5
4.0-13.0
Larva
4.0-14.0
5.0-14.5
5.0-14.0
36
36
36
108
22
22
22
Afternoon
Average
11.1
8.0
6.6
8.6
14.4
10.9
9.7
11.7
13.2
10.0
9.1
S.D.
5.27
2.94
2.65
4.22
4.46
3.04
2.50
3.95
5.39
4.18
3.39
Range
5.0-22.0
4.7-16.0
3.5-14.0
3.5-22.0
7.0-23.0
6.0-17.0
5.0-15.0
5.0-23.0
6.0-22.5
5.0-17.5
5.0-15.0
Total
69
8.2
3.15 4.0-14.5
66
10.8 4.68
5.0-22.5
25
-------
APPENDIX B
DISSOLVED OXYGEN CONCENTRATIONS AND WATER TEMPERATURES IN
CENTRARCHID NESTS DURING EARLY-LIFE STAGES
MEASUREMENTS TAKEN AT 0800-0900 AND AT 1600-1700 COST AT THE SURFACE AND AT
10 and 1 cm FROM THE BOTTOM AT UP TO 3 STATIONS IN 1973 AND 1974. MEAN
WATER DEPTHS WERE 0.7 m AND RANGED FROM 0.27 TO 1.07 m.
TABLE B-l. DISSOLVED OXYGEN CONCENTRATIONS (mg/liter) IN BLUEGILL
AND PUMPKINSEED NESTS DURING EMBRYO AND SAC LARVA
STAGES, AND THE FREQUENCY AT WHICH VARIOUS DISSOLVED
OXYGEN CONCENTRATIONS OCCURRED
Dissolved Oxygen
Morning
Depth
Surface
10
1
Total
No.
145a
145
145
435
Average
7
7
7
7
.7
.5
.1
.5
S.D. Range
1.31 4
1.35 4
1.57 2
1.43 2
.8-13.2
.6-13.5
.4-12.6
.4-13.5
Afternoon
No. Average S.D.
144b
144
144
432
12.1
12.2
11.5
12.0
1.76
1.99
2.53
2.13
Range
7.1-16
6.8-19
4.8-18
4.8-19
.5
.2
.2
.2
Dissolved
Oxygen
(ing/ liter)
2.1- 3.
3.1- 4.
4.1- 5.
5.1- 6.
6.1- 7.
7.1- 8.
8.1-9.
9.1-10.
10.1-11.
11.1-12.
12.1-13.
13.1-14.
14.1-15.
0
0
0
0
0
0
0
0
0
0
0
0
0
1
No.
2
3
8
17
39
34
30
8
2
1
1
0
0
Frequency
Morning
of Dissolved Oxygen
Afternoon
cm Total
7.
1.4
2.1
5.5
11.7
26.9
23.4
20.7
5.5
1.4
0.7
0.7
0
0
No.
2
3
12
43
109
111
109
32
8
3
1
2
0
%
0.5
0.7
2.8
9.9
25.1
25.5
25.1
7.3
1.8
0.7
0.2
0.5
0
1
No.
0
0
3
2
3
1
5
16
25
28
20
13
17
cm
Total
7o
2
1
2
0
3
11
17
19
13
9
11
0
0
.1
.4
.1
.7
.5
.1
.4
.4
.9
.0
.8
No.
0
0
3
2
5
3
12
34
74
95
75
59
40
%
0
0
0.7
0.5
1.2
0.7
2.8
7.9
17.1
22.0
17.4
13.7
9.3
(continued)
26
-------
APPENDIX B - TABLE B-l (continued)
Frequency of Dissolved Oxygen
Morning
Dissolved
Oxvsen
vs.ti.jr 5*^11
(mg/liter)
15.1-16.0
16.1-17.0
17.1-18.0
18.1-19.0
19.1-20.0
Sum
1 cm
No.
0
0
0
0
0
145
7.
0
0
0
0
0
100
Total
No.
0
0
0
0
0
435
%
0
0
0
0
0
100
Afternoon
1 cm
No.
7
1
2
1
0
144
7o
4.9
0.7
1.4
0.7
0
100
Total
No.
18
6
4
1
1
432
%
4.2
1.4
0.9
0.2
0.2
100
22 mornings from 4 June to 5 July in 1973 and 31 mornings from
7 June to 8 July in 1974.
25 afternoons from 4 June to 5 July in 1973 and 28 afternoons from
7 June to 8 July in 1974.
TABLE B-2. WATER TEMPERATURES (C) IN BLUEGILL AND PUMPKINSEED NESTS
DURING EMBRYO AND SAC LARVA STAGES
Water Temperature
Morning
Depth
Surface
10
1
Total
No.
145
145
145
435
Average
19.7
20.0
20.0
19.9
S.D.
2.60
2.59
2.54
2.58
Range
14.0-25
15.0-26
15.0-25
14.0-26
.0
.5
.5
.5
No.
144
144
144
432
Afternoon
Average
23
23
23
23
.7
.3
.3
.4
S.D.
2.73
2.42
2.44
2.53
Range
18
18
18
18
.0-29.0
.5-27.5
.5-27.5
.0-29.0
27
-------
APPENDIX C
RESULTS OF NORTHERN PIKE OXYGEN TOLERANCE EXPERIMENTS
TABLE C-l. HATCHING SUCCESS OF NORTHERN PIKE EMBRYOS EXPOSED
7 DAYS AFTER FERTILIZATION FOR 8 h AT 10 C TO
DISSOLVED OXYGEN CONCENTRATIONS LISTED
Fifteen Embryos Initially in Each Chamber. Exposures
Made on 7 May, and Survival Recorded 5 Days Later,
Average Dissolved Oxygen
(rag/liter)
Range of Dissolved Oxygen
(ing/liter) 0
Percent Survival
Days to First Hatch
Days to 90% Hatch
0.6 1.8
.5-0.7 1.0-2.0
77 80
10 10
11 11
2.6
2.5-4.5
93
10
11
8.0 Control
7.0-9.5 Control
83 80
10 10
11 11
Analysis of Variance
sov df
Treatment 4
Error 15
Total 19
88
14.800
36.000
50.800
TABLE C-2. SURVIVAL OF NORTHERN PIKE SAC LARVAE
ms
3.700
2.400
EXPOSED 1
F
1.542 N.S.
DAY AFTER HATCH-
ING FOR 8 h AT 8-11 C TO DISSOLVED OXYGEN CONCENTRATIONS LISTED
Fifteen Sac Larvae Initially in Each
Survival Recorded
Duncan's Multiple Range Test*
Average Dissolved
Oxygen (mg/liter) 0.3
Range of Dissolved
Oxygen (mg/liter) 0.2-0.5
Average Length (mm) 10.63
Percent Survival13 51
.05
8 and 4 Days After
2.0 Control
1.5-2.0 Control
10.85 10.73
87 91
Chamber .
Treatment
4.8
3.0-6.5
10.87
91
In Two Experiments
•
10 . 1 Control
9.0-11.0 Control
10.83 10.73
92 97
.01
(continued)
28
-------
APPENDIX C - TABLE C-2 (continued).
Analysis of variance0
sov
Subgroups
Treatments
Experiment
Interaction
Error
Total
df
11
5
1
5
23
34
ss
219.417
192.917
8.028
18.472
129.333
348.750
ms
19.417
38.583
8.028
3.649
5.623
F
10.445*
1.428 N.S.
0.657 N.S.
Underlined values not different at 0.05 and 0.01 levels.
Percentages given are for combined survival rates of two experiments.
c
Because of zero readings, 1 was added to all values for computation of
ss.
TABLE C-3. SURVIVAL OF NORTHERN PIKE SAC LARVAE EXPOSED 3 DAYS AFTER
HATCHING AT 12-13 C TO LOW DISSOLVED OXYGEN CONCENTRATIONS
OF 0.8 mg/liter FOR TIMES LISTED
Fifty Sac Larvae Initially in Each Chamber. Treatment Given
on 14 May, and Survival Recorded 3 Days Later.
Duncan's Multiple Range Testa
Exposure Time 6 h 4 h 2 h Control
Percent Survival 0 6 14 88
.05 _
.01
Analysis of Variance
sov df ss ms
Treatment 3 2530 843.333 187.407**
Error 4 18 4.500
Total 7 2548
Underlined values not different at 0.05 and 0.01 levels.
Because of zero readings, 1 was added to all values for computation of
ss.
(continued)
29
-------
APPENDIX C (continued)
TABLE C-4, SURVIVAL OF NORTHERN PIKE LARVAE, EXPOSED AT EARLY FEEDING STAGE
FOR 8 h AT 10-14 C TO DISSOLVED OXYGEN CONCENTRATIONS LISTED
Ten Larvae Initially in Each Chamber. Treatment Given on 20 May
and Survival Recorded 1 Day Later.
Duncan's Multiple Range Test
Average Dissolved
Oxygen (rag/liter) 0.5 1.6
Range of Dissolved
Oxygen (mg/liter) 0.5 1.0-2.0
Percent Survival 0 0
.05
8.9 Control Control 4.0
8.2-9.3 Control Control 3.5-4.5
93 93 97 100
.01
Analysis of Variance
sov df
Treatments 5
Error 12
Total 17
ss ms F
368.278 73.656 441.885**
2.000 0.129
370.278
of ss.
Underlined values not different at 0.05 and 0.01 levels.
Because of zero readings, 1 was added to all values for computation
30
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APPENDIX D
RESULTS OF CENTRARCHID OXYGEN TOLERANCE EXPERIMENTS
TABLE D-l. HATCHING SUCCESS OF SMALLMDUTH BASS EMBRYOS EXPOSED 2 DAYS AFTER
FERTILIZATION FOR 6 h AT 20-23 C TO DISSOLVED OXYGEN CONCENTRA-
TIONS LISTED
Fifteen Embryos Initially in Each Chamber. Treatment Given in
Two Experiments, and Survival Recorded When Hatching was Complete.
Duncan's Multiple Range Test
Average Dissolved Oxygen
(mg/liter)
Range of Dissolved Oxygen
a
0.5
1.8
3.5
Control
7.9
(mg/ liter)
Percent Survival
.05
.01
0.5 1.0-2.0
0 69
3.0-5.0 Control 7.5-9.0
87 89 91
Analysis of Variance0
sov
Subgroups
Treatments
Experiment
Interaction
Error
Total
df
9
4
1
4
24
33
ss
976.326
943.314
14.860
18.152
114.377
1090.703
ms F
108.408
235.829 57.967**
14.860 3.118 N.S.
4.538 .952 N.S.
4.766
i
Underlined values not different at 0.05 and 0.01 levels.
Percentages given are for combined survival rates of two experiments.
°Because of zero readings, 1 was added to all values for computation
of ss.
(continued)
31
-------
APPENDIX D (continued)
TABLE D-2. SURVIVAL OF SMALLMOUTH BASS SAC LARVAE EXPOSED 1 DAY AFTER HATCH-
ING FOR 6 h AT 17 C TO DISSOLVED OXYGEN CONCENTRATIONS LISTED
Ten Sac Larvae Initially in Each Chamber. Treatment Given on
30 May, and Survival Recorded 2 Days Later.
0.5
Duncan's Multiple Range Test
Average Dissolved Oxygen
(rag/liter)
Range of Dissolved Oxygen
(ing/liter) 0.3-0.6
Percent Survival 0
.05
.01
2.2
4.2
Control 9.0
2.0-2.5 3.5-4.5 Control 8.5-9.5
53 73 77 83
Analysis of Variance
sov df
ss
ms
Treatments
Error
Total
4
10
14
138.267
48.666
186.933
34.567
4.867
7.103**
&Underlined values not different at 0.05 and 0.01 levels.
Because of zero readings, 1 was added to all values for computation
of ss.
(continued)
32
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APPENDIX D (continued)
TABLE D-3. HATCHING SUCCESS OF BLUEGILL EMBRYOS EXPOSED 1 DAY AFTER FERTI-
LIZATION FOR 4 h AT 25-28 C TO DISSOLVED OXYGEN CONCENTRATIONS
LISTED
Fifteen Embryos Initially in Each Chamber. Survival Recorded
1 Day After Treatment When Hatching was Complete.
Average Dissolved Oxygen
(mg/liter) 0.5 2.1 3.0 7.8 Control
Range of Dissolved Oxygen
(mg/liter)
Percent Survival8
0.5 1.5-2.5
40 46
2.5-3.5 7.5-9.5 Control
50 47 44
Analysis of Variance
sov
Subgroups
Treatments
Experiments
Interaction
Error
Total
df
9
4
1
4
18
27
ss
20.700
7.533
4.033
9.134
48.667
69.367
ms F
4.140
1.883 0.824N.S.
4.033 1.491 N.S.
2.284 0.845 N.S.
2.704
Percentages given are for combined survival rates of two experiments.
(continued)
33
-------
APPENDIX D (continued)
TABLE D-4. SURVIVAL OF HLUEGILL SAC LARVAE EXPOSED 1-4 DAYS AFTER HATCHING
FOR 4 h AT 21-26 C TO DISSOLVED OXYGEN CONCENTRATIONS LISTED
Ten Sac Larvae Initially in Each Chamber. Survival Recorded 1
Day After Treatment in Five Experiments.
Duncan's Multiple Range Testa
Average Dissolved Oxygen
(mg/liter) 0.5 3.7 8.0 1.8 Control
Range of Dissolved Oxygen
(mg/liter)
Percent Survival
.05
.01
0.5
1
2.5-4.5
65
7.4-9.0
69
1.5-2.5
70
Control
74
Analysis of Variance0
sov
Subgroups
Treatments
Experiments
Interaction
Error
Total
df
24
4
4
16
49
73
ss
707.187
561.587
77.987
67.613
155.833
863.020
ms
29.466
140.397
19.487
4.226
3.180
F
33.224**
6.131**
1.329 N.S.
Underlined values not different at 0.05 and 0.01 levels.
b
Percentages given are for combined survival rates of five experiments.
Because of zero readings, 1 was added to all values for computation of
ss.
(continued)
34
-------
APPENDIX D (continued)
TABLE D-5. SURVIVAL OF BLUEGILL SAC IARVAE EXPOSED 1-4 DAYS AFTER HATCHING
AT 23-28 C TO LOW DISSOLVED OXYGEN CONCENTRATIONS OF 0.5 tng/liter
FOR TIMES LISTED
Ten Sac Larvae Initially In Each Chamber. Survival Recorded
1 Day After Treatment In Five Experiments.
Duncan's Multiple Range Test8
Treatment Time 4 h
Percent Survival1* 0
.05
3 h 2 h 1 h Control
1 11 71 79
.01
Analysis of Variance0
sov df
ss
ms
Subgroups
Treatments
Experiment
Interaction
Error
Total
24
4
4
16
49
73
1001.013
923.147
8.631
69.253
86.667
1087.680
41.708
230.787
2.153
4.328
1.769
53.320 **
1.217 N.S.
2.447 *
Underlined values not different at 0.05 and 0.01 levels.
Percentages given are for combined survival rates of five experiments.
cBecause of zero readings, 1 was added to all values for computation
of ss.
35
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/3-76-113
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Dissolved Oxygen, Temperature, Survival of
Young at Fish Spawning Sites
5. REPORT DATE
December 1976 (Issuing Date)
6. PERFORMING ORGANIZATION CODE
AUTHOR(S)
John J. Peterka and James S. Kent
8. PERFORMING ORGANIZATION REPORT NO.
PERFORMING ORGANIZATION NAME AND ADDRESS
Department of. Zoology
North Dakota State University
Fargo, North Dakota 58102
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
R 801976
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Research Laboratory - Duluth, Minn.
Office of Research and Development
U.S. Envlronment al Pro te ction A*ency
Duluth MN 55804
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/03
5. SUPPLEMENTARY NOTES
6. ABSTRACT
Fluctuations of dissolved oxygen concentrations and water temperatures in
their natural spawning sites were measured during embryo through larva
stages of northern pike (Esox luciusl, and during embryo and sac larva stages
of bluegills (Lepomis macrochirusl and pumpkinseeds (Lepomis gibbosus).
At northern pike sites, dissolved oxygen concentrations from combined
measurements 1 and 10 cm from the bottom ranged from 0.0-16.6 mg/liter, and
water temperatures from 2.5-23.0 C; average daily fluctuations were 3.0 mg/liter
and 1.6 C. For bluegill and pumpkinseed nests, dissolved oxygen concentrations
1 cm from the bottom ranged from 2.4-18.2 mg/liter and water temperatures from
15.0-27.5 C, with average daily fluctuations of 4.4 mg/liter and 3.3 C. In
field experiments to determine acute effects of a single exposure to low
dissolved oxygen concentrations, tolerance decreased from embryo to larva stages
for northern pike and from embryo to sac larva stages from bluegills and
smallmouth bass (Micropterus dolomieui).
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lOENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
'Dissolved gases, *Temperature,
*Embryos, *Larvae, Bass, Fishes,
Mortality, Fresh water, Bioassay
Dissolved oxygen,
Fluctuations,
Spawning, Esocidae,
Centrarchidae,
Natural habitat
06/F
8. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
44
"20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (»-73)
•OJS. GOVERNMENT PRINTING OFFICE: 1977-7S7-OS6/SS04
36
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