by
GARY WILLIAM ISAAC
A THESIS
submitted to
OREGON STATE COLLEGE
in partial fulfillment of
the requirements for the
degree of
MASTER OF SCIENCE
June 1960
APPROVED:
Redacted for privacy
Professor and Head of Department of Fish & Gene M*nageaet
In Charge of Major
Redacted for privacy
Chaira
f-Sckoo-.raduate Committee
Redacted for privacy
Dean of Graduate School
Date thesis is presented
Typed by Cliatie Stoddard
ACK1OWLEDG1 ENTS
Acknowledgement is gratefully extended to the pond owners
for the excellent cooperation accorded me during the farm fish
pond population studies.
Thanks are extended to Andrew S.
Landforce, Extension Wildlife Management Specialist, who furnished
aluab1e information concerning the history of the ponds.
I am indebted to C. David Mclntire, Research Assistant, for his
assistance in planning and conducting the farm pond population
studies.
Particular thanks are extended to Carl E. Bond, Associate
Professor of Fish and Game Management, and to Professor R. E,
Dimick, aead of the Department of Fish and. Game Management, for
their guidance during the study and for their criticism of the
manuscript.
Dr. Max Katz, Fisheries Biologist, U. S. Public
Realth Service, deserves acknowledgement for his constructive
criticism of the Manuscript.
Thanks are extended to Charles E.
Warren, Associate Professor of Fish and Game Management, for his
suggestions concerning the calculation of fish production.
I sincerely appreciated the assistance of Dr. Lyle Calvin,
Statistician of the Oregon Agricultural Experiment Station, for
his help in the statistical analysis, and for his suggestions
concerning the preparation of the manuscript.
Special thanks
are extended to Thomas L. Jackson, Associate Professor of Soils,
for his recommendations concerning fertilizers and their application.
52
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APPDIXES
ESTIMATES PRODUCTION FISH OF DISCUSSION
'
a
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bluegills
juvenile of Schooling
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bluegills juvenile of Growth
bluegills adult for condition of Coefficient
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a
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production
fish and organism8 Benthic
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*
a
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bluegiUs adult of Production
ESTIMATES PR0DTYCION FISH OF RESULTS
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*
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.3
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a
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25
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-,
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...
a
a
IBLIOGRAPH! B
ISTIMATES PRODUCTION FISH FROM CONCLUSIONS
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'+5
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39
38
37
32
32
29
2
2
26
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20
18
18
18
13
15
15
13
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Sampling
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Stocking
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a
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Fertilization
ponds of location and Description
PONDS CREEK SOAP TH± IN PRODUCTION FISH
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ESTIMATES CROP STANDING FROM CONCLUSIONS
,
ESTIMATIONS CROP STANDING OF DISCUbSION
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*
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estimates population of Reliability
present vertebrates aquatic other with Ponds
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other with Ponds
present fish of species
............
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a
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Bluegiliponds.
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ponds, Base
ponds bluegill and Bass
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301
13
ponds farm Valley Willaaette in fish of crops Standing
0*3a
as
ass. Oregonfarmponds.
13
a
a
a
a
a
a ,,.,,
southern in bluegills and bass of crops Standing
a
a
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as
Oregonfaraponds.,
central in bluegills and bass of crops Standing
a
a
a
a
a
a
a
a
ESTIMATES CROP STANDING OF RESULTS
...........
M.THODZ
.*,..ae.,ss.,.,'... REVIEWOFLITERATURE
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INTRODUCTION
Page
CONTENTS 01 TABLE
LIST O
TABLES
TABLE
1.
2.
3.
4.
5,
Standing crops of bass and bluegills in three
a
.
central Oregon farm ponds . .
.
.
.
Standing crops of bass and bluegille in three
southern Oregon farm ponds . . . . . . a .
Standing crops of fish in Willamette Valley
farm ponds . .
.
.
a
,
a
a
,
a
7-.
8-.
a
a
a
Populations of the water newt in four newlyconstructed Willamette Valley ponds .
.
a
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a
a
Reliability of population estimate in pond 18 .
a
.
16
17
19
-
Average standing crops of bass and bluegills
from ponds in different climatic areas of Oregon
a
.
.
a
(lbs./surface acre) . . . . , . . . .
a
-
a
19
21
23
a
Selected morphological characteristics of the
Soap Creek ponds at maximum
(March1959)
.
a
a
.
ter volumes
a
a
a
a
a
a
a
*
9. Pounds of fertilizer and nutrients added to the
Soap Creek ponds from May to October 1959
a
10.
.
14
-a
Populations of the water newt in three old
Willamette Valley pOnds a a . a a a a
a
a
.
6.
.
a
a
a
a
a
27
a
a
2
Computation of production and net gain or loss in
weight of adult bluegills, Soap Creek ponds, May
throughNovemborl959. as...... .......
34
U. Comparison of dry weight of benthic organisms
(eight Ekman dredge sampies from each pond,
September 21-22) with fish production
a
a
37
Mean condition coefficients for adult bluegills
in the Soap Creek ponds, May through November 1959.
-.
39
Numbers of juvenile bluegilla sampled and mean
weights (in ng.), Soap Creek ponds, August through
.
October 1959 . . . .
a
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a
41
September1959 .............-....a.
44
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12.
13.
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a
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14.
Mean weights of juvenile bluegilla (in ag.) from
different depths, Soap Creek ponds, August through
LIST OF FIGURES
Pag
FIGURE
1.
2.
Mean condition coefficients for adult bluegill,
Soap Creek ponds, May through November 1939
.
Growth ratea of newly-hatched bluegill, Soap
Creek ponds, August through October 1939 . .
.
.
*
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1+3
LIST OF APPENDIXES
JPPNDIX
A
Page
Corznion and scientific uaaee of aquatic
bratesdiscuased. ..
B
C
.
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erte-
. .. . ''U,.
53
Description of ponds where fish population
estimateeweremad, ..............,
5k
Tables of anal7sis of variance calculations
for determining the schooling habits of
juvenile bluegills in the Soap Creek ponds .
55
.
.
INTRODUCTION
This study was designed to measure fish population densities
in representative Oregon farm ponds and to determine the effects
of artificial fertilization on fish production.
To accomplish
these aims, the standing crops of fish in representative farm
ponds in three of the matn climatic areas of Oregon were measured
and evaluations of fish production were made in four experimental
ponds in the Willamette Valley.
The study was conducted in 1958 and 1959 as an integral part
of the Oregon State College Agricultural £xperiment Station
Project 29k, "Determination of Fish Species and Management Practices Best Suited to Farm Ponds in Oregon."
The first phase of
the project involved surveys of representative Oregon ponds in
195? and 1958 to determine general limnologica]. characteristics
and fish growth in different climatic areas of Oregon (11, p. 156) and (12, p. 1-k].).
The definitions of the terms "standing crop" and "production"
as used in this paper may assist in understanding the scope of
this study.
The standing crop is the poundage of fish in a pond
at any particular time.
Production is "the total elaboration of
new body substance in a stock in a unit of tine irrespective of
whether or not it survives to the end of that time" (18, p. 20).
The standing crop, or population density at any particular
time, is an inportant management tool for evaluating the statue
of the fish population at the time the crop is estimated.
Radi-
cal seasonal fluctuations in population numbers makes estimation
of the standing crop inadequate for predicting what any one pond
may be eapable of producing for a sustained period.
For this
reason, standing crop estimations in Oregon ponds were coupled
with estimations of production of fish in four artificially enriched ponds near Corvallis, Oregon.
Oregon is generally divided into several broad climatic
regions.
Three of these regions were used in this study for
comparison of standing crops.
These areas were southern Oregon,
central Oregon, and the Willamette Valley.
The purpose of se-
lecting these particular climatic divisions was to formulate, if
possible, management policies that would apply to an entire climatic area.
Zouthern Oregon is characterized by a growing season
of 126 to 180 days.
Temperatures range from winter averages of
3k to ko° F. to a summer average of 67° 7.
Central Oregon has a
growing season of about 150 days and the temperatures range from
winter averages of 31 to 38° 7. to summer averages of approximately 69° F.
The Willamette Valley has a growing season of
approximately 189 days and the temperature ranges from an average
of 1I6° F. in winter to an average of 6k° F. in summer (25, p.
1075-1086).
REVIEW 07 LITERATURE
The interest in the field of farm fish ponds has increased
As
tremendously in the United States during the last 20 years.
the interest in farm and ranch ponds has increased, biologists
have been confronted with the problem of finding satisfactory
ways to successfully manage farm ponds.
Particular attention
has beefl paid to the problem of increasing fish production in
ponds.
Pioneer work in the Jnited States in the use of ferti-
Users for increasing the production of fish food organisms and
fish has been done by Smith and Swing].. (23, p. 309-315),
Using
15 ponds, each approximately 3 feet deep and about 334 square
feet in surface area, they were able to study the effects of
different nutrients on plankton and fish production in Alabama
ponds.
3all established that fertilizing with 100 pounds per
acre (per application) of inorganic fertilizer containing 10
percent nitrogen, 6 percent available phosphoric acid, and 14 per-
cent potassium, increased the total weight of all aquatic organisms produced in Michigan ponds (1, p. 19).
An excellent review
of the literature on pond and lake fertilization has been compiled by Maciolek (14, p. 1-43.).
One of the most important management problems that baa been
encountered by pond owners is the over-population of ponds with
small, unharvestable fish.
To evaluate the problem of over-
population or unbalance, Swing].., in Alabama has prescribed a
LI
number of ratios (2k, p. 1-7k).
These ratios have been used as
indices to the status of fish populations in Alabama and other
southern states.
The F/C ratio, for example, is the total pounds
of forage fish divided by the total pounds of carnivorous fish.
Other approaches to the problem of evaluating the status of
fish populations in ponds have been the estimations of standing
crops by the multiple recapture method, by poisoning, or by
draining.
The multiple recapture method, as used in this study,
is a refinement of the method described by C, G. S. Petersen.
According to Ricker (18, p. 81), Petersen used mark and recapture
methods for studying the yearly immigration of young plaice into
the Limfjord from the German Sea (17, p. 1-k8).
The next re-
corded use of the recapture method for estimating animal numbers
was described by Lincoln (13, p. 1-k) for waterfowl populations.
Es used the ratio of the banded ducks killed to unbauded ducks
killed to estimate the continental duck population.
Recent re-
finements and modifications to meet fisheries problems have been
made by Delury (10, p. 281-307); Schumacher and
p. 228-2k9); and Scluzabel (21, p. 3k8-352).
schneyer (22,
The Schnabel
(multiple recapture) method of estimation was used in this study.
It is based on the weighted average of a series of separate popu
latton estimates.
yisheriee workers in many states have estimated the standing
crops of fish in lakes and ponds.
Ball (2, p. 268) found that
the standing crops of fish in l4icbigan ponds ranged from 193 to
721 pounds per surface acre and averaged 313 pounds per acre.
Clark (9, p. 265) reported that the total poundage of fish per
acre in unfertilized IContucky ponds ranged from 200 to 1000
pounds.
Bennett (½, p. 251) has fc'und that Illinois ponds sup-
ported fish populations which varied between 71 and 1,145 pounds
per acre.
The fish populations in ½2 Iowa ponds have been esti
mated by various workers, and the results summarized by Carlander
and Moormam (7, p. 659.668), who found that bluegill1 standing
crops were usually over 100 pounds per acre and that the standing
crops of bass generally ranged between 10 and ½]. pounds per acre.
I(uch of the available information on the standing crops of fish
in lakes and ponds has been summarized by Carlander (6, p. 566).
He concluded:
(1) there was no correlation between standing
crop per acre and the area of the pond;
(2) there was a positive
correlation between carbonate content and standing crop;
(3) there were greater standing crops in ponds containing pri-
marily herbivores than in ponds containing species with predatory
food habits; and (½) there was an increase in standing crop as
the number of species increased; however, maximum standing crops
were found in ponds with not more than two species.
Wohiechiag and Woodhull (26, p. 5-kk) estimated the fish
populations in Salt Springs Valley Reservoir in Calaveras
1cientific names of all aquatic vertebrates discussed are recorded in Appendix A.
County, California.
The populations in this 900-acre (spiliway
acreage) reservoir were estimated by the Schuabel method.
The
per acre of bluegill
reservoir supported approximately 25 pauud
and k.O pounds per acre of largemouth ba8s.
Poundages of other
species were estimated, and the difficulties involved in seining
and trapping fish in a large reservoir were discussed.
Although the term production has been used by many fisheries
workers, it has been used in different ways.
Smith and Swingle,
in Alabama, have used the term production to describe the tots).
pounds of fish. removed after draining a pond (23, p. 313).
Ba].?
(1, p. 10-18) in Michigan has used production in a similar manner.
Probably the first attempt to measure fish production as defined
earlier in this paper was by Ricker and Foerster (19, p. 173-211),
who measured the production of young sockeye salmon in Cultus
Lake, British Columbia.
following:
They found it necessary to know the
(1) the number and weight of the fish present at some
time during the year; (2) the rate of growth during successive
short periods throughout the year; and (3) the rate of mortality
during the same periodse
The number and weight of the young sockeye was obtained from
direct enumeration of the fish as they left the lake.
Estimates
of the growth rates of the salmon were obtained from samples taken
from the stomachs of piseivorous fishes.
Estimates of seasonal
mortality rates were made Iron data based on the survival of
marked fish released at various times during the year.
The
ethod8 of coiputation used have been summarized in the handbook
by W. 1. Ricker 'Randbook of Computations for Biological. Statia-
tics of Fish Populations" (18, p. 32).
MET0DS
The methods used to study farm fish ponds included interviews with the pond owners, limnologica]. sampling, and standing
crop determinations.
The owners of the ponds surveyed were inter-
viewed to find out items of interest about the ponds, such as,
stocking history, fishing pressure, winter or summer kills,
aquatic weed problems, spawning success, and the owner's opinion
of the pond.
The ponds were then sampled with hook and line,
when time permitted, to ascertain angling potential, and also to
encourage the pond owners to fish the ponds frequently and with
techniques other than the traditional bobber and worm method.
Water samples were then taken to determine some of the unnological characteristics of the ponds.
These water samples were
analysed for dissolved oxygen, surface and bottom alkalinity,
total dissolved solids, and total phosphorous.
Temperatures were
taken at two-foot intervals, and samplea of plankton and benthic
organisms were collected (15).
Estimation of the standing crops of fish was the final stp
in the analysis of ponds.
The ponds were seined with either a
60-foot seine, 6-feet deep, with a 10-foot bag, or a 100-foot
seine, 6-feet deep, or with a 200-foot seine, 10-feet deep with a
10-foot bag.
The seine used depended upon the size of the pond,
the species of fish present, and the quantity of aquatic plants
in the pond.
The sizes of fish which were included in the estimates
varied with each pond.
The objective was to estimate the stand-
ing crops of only those fishes which were sufficiently large to
handle and fin-clip without injury.
These sizes (total length)
were normally three inches for bluegills and four to five inches
for largemouth bass.
Although some ponds contained multitudes
of tiny bluegille, the numbers of these email fish could not be
readily estimated.
After seining, the various species were separated and were
placed in large tubs.
each species collected was weighed in the
aggregate, marked by clipping the upper lobe of the caudal fin,
and immediately released.
Sufficient numbers of fish were
weighed to insure an accurate estimate of the mean weight.
The
numbers weighed depended on uniformity in sizes--usually 100 fish
of each species was considered an adequate sample.
Seining and
marking was continued until approximately one-third to one-half
of the fish in a seine haul were found to have been previously
marked.
The population was then estimated by the Schnabel method
(21, p. 31+8_352),
The formula used to make this estimation is
represented by the following expression;
where
P is the estimated number of fish of a particular species,
A is the number of fish handled,
B is the number of marked fish at large in the pond, and
C is the number of marked fish recaptured.
The poundage of fiah present was then determined by multi-
plying the mean weight per fish by the estimated number of fish
present in the pond.
The poundage per surface acre was obtained
by dividing the estimated total poundage by the surface acreage.
Confidence limits for the estimated numbers of each species
present were calculated for ponds where the multiple recapture
technique was employed.
No direct method is available for de-
termining the standard error of the estimates when Schnabel's
formula is used, but it has been pointed out by Schaefer (20,
p. 198) that the Schumacher and Eschmeyer method, and the
Schnaboi. method are equally efficient when B/P is equal to 0.25.
This condition was approximately satisfied during this study,
therefore, the standard error of the Schumacher and Eschmoyer
estimate was used to determine the standard error of the Sebnabel
estimate.
Fish populations were determined by' draining whenever possihi.,
Each species of fish was weighed in the aggregate, and an
accurate measure of the standing crop in pounds per acre was
readily obtained.
Ponds in which the water volume could not be
reduced sufficiently to recover all the fish were treated with
rotenane (five percent active powder).
atiaations of the fish populations in ponds involved the
repeated sampling of the populations; therefore, certain assump
tiona concerning the enumeration method bad to be satisfied if a
reliable estimate was to be expected.
follows:
The assumptions are as
(1) that the marked fish are caught with the same
probability as the unmarked; (2) that there is no mortality or
recruitment to the population during the period of study;
(3) that the marked fish do not lose their marks; (k) that all
marks are recognized and reported on recovery; and (3) that
marked fish become randomly mixed with, the unmarked; or that the
distribution of fishing effort (in subsequent sampling) is pro
portional to the number of fish present in different parts of the
body of water.
The moat serious problems involved in the estimation of fish
populations in Oregon ponds were concerned with satisfying
assumptions number one and five.
Marked fish were not caught
with the same probability as unmarked fish in some ponds.
Large
mouth bass were extremely difficult to recapture after they had
been marked.
This made the estimation of the bass populations
difficult in same ponds and impossible in others.
Carlander and
Moorman (7, p. 665) have reported this same problem in estimating
the bass populations in Iowa ponds.
The assumption that marked fish distribute themselves at
random upon release in the pond was difficult to satisfy.
Most
12
population estimates were made during the spring and 3U1U15' When
adult fish were concentrated in the shallows for spawning.
The
fish in these ponds were not distributed at random before the
seining was begun, and the marked fish upon release frequently
returned immediately to the site of capture, which in many instances was the spawning nest.
In all instances, attempts were
made to distribute both the fishing effort and the marked fish
o that the above asaumption could be satisfied, and a reliable
estimate expected.
The other assumptions (numbers two, three and four) were not
difficult to satisfy because the duration of time necessary to
complete the sampling was short (one or two days).
RESULTS O' STANDING CROP ESTIMATES
crops of bass and bluegills j
Ztandjn
central Oregon farm ponds
The fish populations in three central Oregon farm ponds in
Jefferson County were studied to determine some of the general
characteristics of populations in that area.
Descriptions of
these ponds (7, 8 and 10) are given in Appendix B.
The average
standing crop of bluegille for these ponds was 110.0 pounds per
The range in standing crops was from 7.9 to 226.9 pounds
acre.
per acre.
The average standing crop of bass was 218.1 pounds per
acre, and the range was from 72.6 to 365.7 pounds per acre as recorded in Table 1.
Standing crops of base and bluegifle in southn 0re
farm ponds
Standing crops were estimated for three southern Oregon
ponds.
County.
Pond 5 is in Lake County, while 11 and 12 are in Josephine
The descriptions of these ponds are given in Appendix B.
Standing crops were estimated by the Schztabel method for
ponds 5 and 11.
The crop in pond 12 was determined by draining.
The average standing crop of bluegills for these ponds was 151.9
pounds per acre and ranged from k5.5 to 363.3 pounds per acre.
The standing crop of bass averaged 79.7 pounds per acre, and
ranged from 73.1 to 86.2 pounds per acre.
The average standing
crop of bass was calculated from only two ponds (5 and 12).
The
numbers of bass captured in pond 11 were insufficient to give a
Table 1.
Standing crops of baas and blusgills in three central Oregon farm ponds
S
'rf
S
44
O,-4
Pond
no.
Species of
fish present
4)
0
0
No. of
samples
95% coaf.
limits
Lbs.!
acre
Dates of
estimates
9-23 59
*7
Bluegill
Largemouth bass
2
2
453
572
184
231
22
23
21k?
3526
1317-3233
2243-5507
226.9
365.7
8
Bluegill
Largemouth baas
4
10k
510
70
328
12
53
214
1082
126-302
361-1803
7.9
72.6
10
Bluegill
Largemouth bass
4
29
32
30
4
3
55
126
16-9k
20-232
95.1
216.0
4
26
* Confidence li*.tta determined by method described by Chapman (8, p. 69-85) for single
recapture estimates.
9_59
9 24-59
The population estimates are given in Table 2.
reliable estimate.
Standing crops of fish in Wilamette Valley farm pon4a
Fish populations were estimated for 1k ponds in the
These included 13 ponds in the Willamette
Willamette Valley.
Valley proper (Salem to Harrisburg) and one pond near Rainier in
the lower Columbia region.
given in Appendix B.
The descriptions of these ponds are
Because of the diversity of pond populations
in this area, the ponds were divided into groups on the basis of
the species present.
Standing crop estimations for the ponds
surveyed are given in Table 3.
Bass and bluegil1 ponds.
The standing crops of base and
bluegills in ponds 2 and 19 were estimated by the Schnabel method.
The standing crop for pond 13 was determined by draining.
The
standing crop in pond 18 was estimated by both the Schnabel method
and by draining.
The average standing crop of bluegill was 169.5
pounds per acre, and ranged from 2k.2 to 5k3.9 pounds per acre.
The average standing crop of bass was 75.7 pounds per acre,
ranging from 25.k to 192.k pounds per acre.
Baae ppnda.
The standing crop of bass in pond 6 was esti-
*ated by the Schuabel uethod.
The pond contained no other species
of fish, and the bass population was composed mostly of one-year
old fish which ranged from k to 6 inches in total length.
standing crop was 62,0 pounds per acre in this pond.
The
Table 2.
Standing crops of bass and bluegils in three southern Oregon farm ponds
S
4p,
rl
0
;4.
Species of
fish present
0
0
0r4
Pond
no.
S
5
0
No. of
samJ1es
95% cant.
limits
Bluegill
Largesouth bass
6
6
166
47
111
33
23
2
487
367
287-687
Bluegill
Largemouth basa
4
290
801
-
138-1464
-
241
-
43
4
Bluegill
Largemauth bass
10
10
198
176
5
**
-
-
2725
-
Blue
Lergeaouth bass
-
-
-
-
8612
15
-
-
Lba./
acre
Dates of
estimates
53
86.2
-
7-13-59
146,9
7
-
363.3
73.1
10-29-58
* Pond population determined by draining.
** Inaufficient numbers of recaptured fish to determine confidence limits of estimate.
*11* Insufficient numbers of bass captured to determine population.
58
Table 3.
Standing crops of fish in Willamette Valley farm 1:onds
0
0o
S41
44.)
0
Cj.40
Or-I
Pond
Species of
fish present
no.
*1
No. of
samples
Rainbow
Cutthroat
Bluegill
-
C1
0
0
0-ri
0r4
-
i
95% conf.
limits
Lbs./
acre
Dates of
estimates
8.6
8.9
16.3
1-30-58
79
83
-
-
-
19k
-
-
-
-
-
-
-
-
-
Largemouth bass
Bluegill
5
291
153
76
352
287-k17
190.0
Bluegill
k
329
137
k1
552
523-581
89.7
5-25-58
Largemouth bass
Bluegill
Brown bullhead
-
-
-
79
329
-
56.7
93.3
63.3
5-2k-58
-
-
6
Largeniouth bass
k
211
115
1].
lOok
669-1339
62.0
6-25-59
9
Bluegill
k
1737
5k1
303
2293
1621-2965
231.6
7-28-59
Bluegill
Largomouth bass
-
-
-
-
829
315
-
89.2
33.0
10-26-57
'lkSl
Bluegill
-
-
-
-
3k0
-
32.0
ll-k-59
*1532
Bluegill
-
-
-
-
578
-
30.1
11-6-59
'1633
Bluegill
-
-
-
-
6k2
-
50.8
11-9-59
*173k
Bluegill
-
-
-
-
14.71
-
78.0
11-12-59
Bluegill
Largemouth bass
k
Bluegill
Largemouth bass
-
Bluegill
Largemouth bass
* * '2
3
'13
2106
18
53
136.6
1+56
99
17
8
9700
38
-
-
-
7565
63
-
103.7
11
11
593
27
538
1+1
1
337k
276
1192-5556
21+
51+3.9
192.1+
Bluegill
Largemouth bass
1+
21
19
-
-
3
-
133
-
31-235
1+
Bluegill
Largemouth bass
6
31+9
68
957
205
2k'4-1670
6
293
55
1+6
19
Bluegill
White crappie
Coarse scale sucker
1+
10k
1526
2k
72
1+
793
261+_l322
1+9.3
20
1026
1k
11+6
1+792
1+33.0
3
56
3873-5751
38-7k
18
1+
1+
1+
8
7k9k-11,906
**
**
-
25-385
* Pond populations determined by draining.
*1 Insufficient recaptures to estimate confidence interval.
" Insufficient recaptures to estimate the number of bass present.
7-10-58
15.1+
25.1+
2k.2
-
66.0
51.9
28.8
557
8-21-58
8-10-59
7
k 59
7-17-59
Bluegill ponds.
Six of the ponds surveyed in the Willamette
Valley contained only bluegills.
The populations in all six
ponds were composed primarily of small, unharvestable fish which
averaged less than 3 inches in total length.
The average stand-
ing crop was 85.1+ pounds per acre and ranged from 30.1 to 231.6
pounds per acre.
Pond8 with other species of fish present.
Fish populations
were estimated in three ponds (1, 1+ and 20) in the Willamette
Valley that contained species other than largemouth bass and/or
bluegill sunfish.
Pond 20 contained largeinoutb bass, white
crappiee, bluegiils, coarse-scale suckers, and equawfisb.
Stand-
ing crops were estimated for bluegills, white crappies, and
coarse-scale suckers, as these were the only recies present in
large numbers.
The estimated poundages of bluegills, white
crappies, and coarse-scale suckers were 1+9.3, 1+33.0 and 28.8
pounds per acre, respectively.
Pond 1 contained bluegills, rain-
bow trout and cutthroat trout.
The standing crops were 16.3
pounds of bluegill per acre, 8.6 pounds of rainbow trout per
acre, and 8.9 pounds of cutthroat trout per acre.
Pond 1+ con-
tained 56.7 pounds of largemouth bass per acre, 93.3 pounds of
bluegill per acre and 63.3 pounds of brown bullhead per acre.
Ponds with other aquatic vertebrates presJ. Four newlyconstructed ponds (11+51, 1552, 16s3, and 17Sk) and three older
ponds (1, + and 18) in the Willamette Valley contained populations
19
of water newts in addition to the fish populations present.
The
standing crops of newts in these ponds are presented in Tables
4 and 5.
The average standing crop for the three older ponds
was 133.1 pounds per acre.
examinations of the stomach contents
of sev-eral newts indicated that they were feeding primarily on
aquatic insect larvae and were therefore competing with pond
fishes for food.
One pond, 1k81, was fenced before it was filled
with water in January 1959 to determine if newts could be kept
out of the pond,
The fence was constructed of window screen 12
inches high held upright by 2k-inch supports of heavy-gauge wire.
The pond was drained in November of 1959 and no newts were re-.
covered.
Table 4.
Populations of the water newt in three old Willamette
0
0
1582
1
0.11
1683
3
0.38
1.93
1784
3.3
* Newt control by fencing before the pond was filled.
20
Reliabi4ty of population estimates
A check on the reliability of the population estimate in
Thompson's pond (number 18) near Sweet Home was conducted in
April and May 1957, as recorded in ¶able 6.
The pond was seined
on April 30, 195?, and the population estimated by the Schnabel.
method.
The estimated standing crop of bluegilla was 136.6 pounds
per acre (9700 fish).
A total of 103.7 pounds per acre of blus
gills (7565 fish) was recovered when the pend was drained on
May +, 1957.
were from 7k9
(7565).
The 95 percent confidence limits of the estimate
to 11,906 and included the number actually present
No check could be made on the reliability of the bass
estimate as insufficient numbers of bass were recaptured to de..
termine the confidence limits.
Reliability of population estimate in pond 18
Table 6.
Species of
fish present
Type of
estimate
o mabS 1
Bluegill
Largemouth bass
g
Bluegill
Largemouth bass
Population
estimate
9700
38
-
95% conf.
limits
7k9k-ll,906
No. recovered
upon draining
Lbs./
acre
-
136.6
15.k
**
7565
3
Dates of
estimates
103.7
25.
Insufficient numbers of marked fish recaptured to determine confidence limits.
ru
I-'
22
DISCUSSION OF STANDING CROP ESTIMATIONS
A comparison was made of the average standing crops of base
and bluegills in the three climatic areaa of Oregon surveyed.
The results recorded in Table 7 indicate that the average stand-
ing crop of bluegiU was greater than 100 pounds per acre for ail
three areas, while the average standing crop of bass was greater
than 60 pounds per acre.
The Willemette Valley bass-bluegill
ponds surveyed were supporting the highest average standing crop
of bluegills (169.3 pounds per acre).
Central Oregon ponds were
supporting the highest average standing crop of bass (218.1
pounds per acre).
The poundages of bluegill in Oregon ponds were
similar to those reported by Ball (2, p. 266-269) for Michigan
ponds and by Carlander and Moorman (7, p. 659-668) for Iowa ponds.
Central Oregon ponds were supporting greater poundages of bass
than ponds in Iowa and Michigan.
The highest bass population
estimate in the Oregon ponds surveyed was 365.7 pounds of bass
per acre for pond 7 (central Oregon).
Carlander has repoited 80
pounds per acre as the highest bass population estimated in Iowa
ponds.
This population was composed primarily of k to 6 inch
bass, as was the population in the most productive Oregon pond
surveyed, but the poundage was nearly five times greater in the
Oregon pond.
Central Oregon ponds appear to be capable of sup
porting greater standing crops of bass than southern Oregon ponds,
Willamette Valley ponds, and ponds in Michigan and Iowa.
The chemical, physical, end biological characteristics of
the climatic regions surveyed undoubtedly effected the standing
crops of fish present in the areas.
Unfortunately, there was
only limited information available on limnological eharacterism
tics of ponds in the areas surveyed, and no definite relation-s
ships between these characteristics and the standing crops of
fish could be established,
Central Oregon
3
110.0
218.1
Southern Oregon
3
151.9
79.7
Willamette Valley
5
169.5
75.7
Large populations of the water newt were found in three
WiUametto Valley ponds (1, k and 18).
Since newts were appar.*
ently oompeting with pond fish for food, it seemed advisable to
attempt to prevent their movement into newly-constructed ponds.
Pond lkSl was fenced with window screen before it was filled,
and no newts were recovered when the pond was drained 11 months
later.
Although this method proved to be effective for con.
trolling newts, more information on the extent of the competition
between newts and fish is needed before control is recommended.
Management practices probably bad a greater influence on
population size than any other single tactor
Ponds in the three
climatic areas appeared to be capable of producing only a limited
poundage of fish when left in an unmanaged condition.
Suitable
stocking rates and ratios were believed to be necessary for the
maximum yield of pan..sized fish in Oregon ponds,
Central Oregon
pond owners have greater difficulty obtaining fish for planting
and are inclined to follow present stocking recommendations.
In
contrast, Willamette Valley pond owners find it less difficult
to obtain fish and in some instances do not follow stocking
recommendations.
tor example, pond 9 was
tooked with a "bucket-
full" of bluegills and was supporting a large poundage of small,
unharveatable fish under 3 inches in total length when the population was estimated (Table 3, page 1?).
fishing intensity also appeared to have an important influ
enoe on the sizes of fish present in Oregon ponds.
Interviews
with pond owners indicated that the pond fish populations in mU
areas were improperly harvested,
Central Oregon ponds, however,
did appear to be more adequately harvested than ponds in southern
Oregon and the Willamette Valley.
This may be a partial explana-.
tion as to why the central Oregon ponds surveyed were supporting
the highest poundages of bass.
Although harvesting fish crops in
ponds can be compared with harvesting other farm commodities, it
was difficult to convince pond owners that they should fish their
ponds intensely to provide maximum yields of pan-sized fish.
25
CONCLUSIONS I'ROM STANDING CROP ESTIMATES
1.
Standing crops of bluegills in Oregon ponds were
similar to those reported for other states.
2.
Average bluegill standing crops were similar in central
Oregon, southern Oregon, and in the Willametto Valley.
3.
Largemouth bass standing orops appeared to be greater in
Oregon ponds than in Michigan and Iowa ponds.
1+.
The central Oregon ponds surveyed were supporting larger
standing crops of bass than ponds in southern Oregon and the
Willamette Valley.
5.
Water newts were present in sufficient numbers in some
Willamette Valley ponds to be important competitors with fish for
food organisms.
6.
pOflde.
Water newts can be ezoluded by fencing newlyconstruCted
26
flSR PRODUCTION IN THE SOAP CREEK PONDS
Calcu1ations of fish production in the four experimental
ponds near Corvallis were made during the summer of 1959.
The
purpose of the study was to experiment with some of the techniques
used in estimating production, to determine the effects of arti.
ticial fertilization upon production of bluegills, and to deter-
mine if the calculations of production would furnish useful information regarding farm pond fish populations.
Description and location of pon4
A series of four rectangular ponds were excavated during
July 1958 approximately 100 yards west of Soap Creek, about 15
miles north of Corvallis, Oregon.
The ponds were designated as
lkSi, 1532, 1633, and 173k in the preceding section, but to keep
the numbering system consistent with that of Nclntire (16), who
made limnological studies in the same ponds, the prefixes have
been dropped.
Zn the subsequent discussion, the ponds are num-
bered SI, $2, $3, and 3k.
The ponds were filled by run-off water draining east to Soap
Creek.
The water was collected behind a diversion terrace which
was designed to guide water into the ponds.
The ponds were cant-
pletely filled by January 9, 1959.
Pond Si is nearly 200 f..t Long and 100 feet wide; while 32,
33 and Sk are approximately 250 feet long and 100 feet wide.
west end of the pond is ebalow, and the bottom of each pond
The
27
elopes gently toward the deeper east end.
Some of the important
morphological characteristics of each pond during maximum water
volume are given in Thble 8.
The ponds had lost considerable water by early summer.
81,
being the smallest, was most adversely effected by the loss of
water.
The water level had dropped from a depth of 5 feet in
early March to a depth of 3.5 feet by July.
At that time, it be-
came necessary to pump water into Si from Soap Creek.
The changes
in the limnological characteristics of SI brought about by the
addition of this supplementary water were recorded by Mclntire
(16).
ab].s 8.
Se1,ctet morphological characteristics of the Soap
Creek ?onde at maximum water volumes (March l99)
Average
depth (feet)
Water volume
(acrs.teet)
0.38
2.7
1.026
82
0.60
3.3
1.980
83
0.49
3.8
1.862
84
0.47
3.5
1.645
Pond
number
Surface area
81
(acres)
Fertilization
The soil in the Soap Creek drainage was known to be deficient in nitrogen and phosphorous, therefore, the ponds were
treated with combinations of these nutrients.
Single superphos-
phate was used as the phosphorous source and urea was used as the
28
nitrogen source.
These nutrients were available as commercial
grade fertilizers from local distributors%
No recommendations were available regarding the fertilization of Oregon ponds, therefore, the poundages of fertilizers
applied to one pond, 83, approximated those used by Ball and
Tanner in their Michigan studiee (3, p. 7).
They applied
lO.6..k (N..P2OçK2O) at a rat, of 100 pounds per acre every three
weeks for five months (May through September).
Pond S3 received
approximately this same amount of nutrients.
Fertilization was begun on May 1 and continued monthly, ext-
cept for July, until the last application on October 1, 1939.
The July omission was made to avoid fish mortalities which might
have occurred from oxygen depletioa.
Dense blooms of phytoplank-
ton were present, and dissolved oxygen was less than 2.0 milli-
grams per liter near the bottoms of 53 and 84.
The pounds of
commercial fertilizer added monthly and the total pounds of nu-
trients added are given in Table 9.
Pond 82 received nitrogen
only, 83 received nitrogen and phosphorous (same rate as Michigan
ponds), 54 received nitrogen and phosphorous at twice the rate
applied to 83.
81 was used as the control pond, receiving no
fertilizer.
Stocking
Adult bluegills were obtained from the William Ieimer pond
near Perrydale, Oregon, in early May 1.959.
The ponds were
length-weight a is later, discussed is coefficient,which condition
The
coefficients. condition mean calculate to planting of time
the at taken were fish 15 of lengths standard nd
weights The
May. in begun was populations fish adult the of Sampling
Sampling
evident. been
have would production in differences no and ponds the of any in
limiting been have not might food available understocked, were
ponds the ±f that believed was It
acre-foot. per fish email
125 is rate stocking recommended present The
poad. Oregon
for recommended presently that times four approximately was rate
stocking This
respectively. fish 732 and 835, 876, 461, ceivod
re Sk and S3, 52, Si,
acre-foot. per fish 450 approximately
of rate a at 8) (Table volume water of basis the on stocked
none
none
none
none
16,7
none
25.0
16.7
25.0
50.0
33.4
50.0
75.2
53
37.6
Si.
none
52
37.6
Nitrogen
lrea
50 2
phate
superphosSingle
monthly added
added_ nutrients
pounds Total
fertilizer Pounds
Pertilization
number
Pond
1959 October to Ma from ponds Creek
Soap the to added nutrients and fertilizer of Pounds
9. Table
relationship.
It was used to measure the "plumpness" of the fish
during the study period.
The mean weight per fish at the time of
stocking was calculated from a randomly selected sample of 87
fish.
Severity-five fish were marked with a left-ventral clip to
estimate mortality.
The next sampling was conducted during the
first week in July.
Approximately 100 fish from each pond were
seined with a 100-foot seine and the mean weights determined.
Twenty-five fish were weighed and measured individually to determine mean condition coefficients.
Seventy-five fish were marked
with a right-ventral fin clip to estimate mortality.
This pro-
cedure was repeated in mid-August for additional growth information, and another 25 fish from each pond were weighed and measured
for condition coefficient analysis.
Au additional 75 fish were
marked with a both-ventral clip to estimate mortality.
There was
no further sampling of the adult fish until the ponds were drained
in November and the entire fish populations were recovered.
On July 31, newly-hatched bluegifls were observed in all
four ponds.
These fish were found by ?lclntire (16) to be utiliz-
ing zooplankton and benthic organisms present in the ponds.
A
sampling method was established to estimate the growth rates of
these newly-hatched bluegills in each pond.
The sampling was be-
gun on August 13 and was terminated on October 13.
eight sampling
stations were located on the periphery of each pond, starting with
station 1 at the shallow southwest corner of each pond and moving
clockwise around the pond.
Station 2 was at the northwest corner,
31
3 and 4 on the north side, 5 in the northeast corner, 6 in the
southeast corner, and 7 and 8 on the south side of each pond.
One seine haul was made at each station with a 10-foot
seine, and all captured bluegiUs counted and weighed in the
aggregate.
This procedure was used during the first sampling,
but a further refinement was made when it was suspected that
the young fish were schooling in size groups in the different
areas of the ponds.
During subsequent sampling, eight seine
hauls were made, as before, but each seine haul was divided in
the center with a wooden lath.
Thus, each seine haul contained
two "aub-seine hauls" which were counted and weighed as before.
This made possible the determination of schooling habits of the
juvenile bluegills by comparing the variations in mean weight
within a single seine haul, and among several seine hauls.
This
sampling procedure was continued at approximately two-week in..
tervals from late August to mid-October.
At that time the young
bluegille became difficult to capture in adequate numbers and
sampling was discontinued.
RESULTS 07 FISH PRODUCTION ESTIMATES
Production of adult blueills
Production is the total elaboration of new body substance
in a fish stock in a unit a! time, irrespective of whether or
not it survives to the end of that time.
Fish production can
be computed when growth rates and mortality rates are known and
average standing orops have been computed.
The instantaneous
growth rates were computed for each time interval from the initial
and final mean weights of the fish by the following expression for
exponential growth:
5gt
we
where
g is the instantaneous growth rate,
is the initial weight in grams,
is the final weight in grams, and
t is the tine interval.
The total time involved from Nay to November was considered
as t m 1.
terval (t
The time from May 8 to July 2 was the first time in..
O.1); the time from July 2 to August 20 wae the
second interval (t
0.27); and the time from August 20 to
November 10 was the third interval (t = O.2).
The computed
instantaneous growth rates for each of these time periods for
each pond are presented in Table 10. The computation of those
growth rates was a necessary intermediate in the computation of
fish production.
These instantaneous growth rates indicate the
pattern of growth during the time intervals if the rates of
growth are assumed constant during the intervals.
In SI and
33 there was negative growth during the second time interval;
and there were negative rates of growth during two of the time
periods (July Z to August 20, and August 20 to November 10) in
32.
The growth rates were positive in Sk for all three inter-
vals.
The computation of instantaneous mortality rates was also
necessary for the estimation of fish production.
Mortality rates
could not be computed for each time interval from the numbers of
marked fish recovered upon draining since mortality was introduced, apparently b
the marking procedure.
Therefore, the
total instantaneous mortality rate was computed from the numbers
stocked and the numbers recovered from each pond by the following expression:
N
t=e -it
where
i
is the instantaneous mortality rate,
is the initial numbers of fish present,
Nt is the final numbers of fish present, and
t
is the time period.
Table 10.
Pond
no. and
fertilizer
applied
Computation of production and net gain or loss in weight of adult bluegilla, Soap
Creek ponds, May through November 1959
Time
period
1
a
None
3
Totals
82
Nitrogen
1
2
only
Totals
3.
a
Nitrogen
and phosphorous
Totals
2(aitrogen and
phosphorous
Initial
standing crops
in kg.
6.572
6.692
5,852
-12.487
14.853
10.190
-
11.903
18.960
13.584
--
1
10.435
2
14.906
3
15.811
Totals
--
Instan-
Instan..
taneous
mortality
rate
i
taneous
growth
rate
g
Average
standing crops
in kg.
6.638
kg.
-
1.o86
13.612
12.711
9.147
4.08k
-2.669
-0.457
2.314
k.o68
-2.012
---
--
--
0.958
-3.766
-4.296
0.47
-0.20
14,557
16.617
13.584
6.842
-3,323
1.494
5.677
-4.487
0.000
--
5.013
1.190
12.491
15.368
16.301
5.996
2.766
3.912
4.372
0.922
0.978
--
12.674
6.272
-
0.13
0.11
0.17
0.30
-0.21
-0.05
0.43
(g-i)i
0,39k
--
0.13
0.12
o.i8
Actual
net
gain or
loss in
0.039
0.30
0.26
Computed
net gain
or loss
in kg.
0.113
-o.881
-0.318
-0.06
0.07
o.o8
0.07
0.11
kg.
g
0.09
o.o8
0.13
0.41
Production in
0.11.
o,u
-
o.48
0.18
0.24
6.k
5.680
0.730
-0.375
..i,o58
-
--
0.776
----
6,195
35
The assumption was made that the rate of mortality was con-
stant during the entire study (May to November) and the total
mortality rate was then divided into three instantaneous mortality rates on the basis of the length of the different time
intervals.
o.k3 for
The total mortality rates were 0.30, o.ki, 0.26, and
l, 82, 83, and 8k respectively.
The total instantane-
ous mortality rate for each pond, and the corresponding rates
for each time interval are recorded in ¶able 10.
The rate of
mortality appears to be greater during the third period (August
to November) for all four ponds, but this is due entirely to
the length of this interval (t
0.142).
The total mortality
rates were greater in 82 and 8k than in $3. and 83.
Although no
excessive mortality was observed in 82 or 8k, conditions near
the bottom were found by Malntire (16) to be submarginal for
over two months (1.5 milligrams per liter dissolved oxygen).
This may have bee* partially responsible for the high mortality
in these ponds.
The average standing crops for each time interval were also
necessary for the computation of production.
The average stand-.
jag crops were determined for each pond by using the computed
instantaneous growth and mortality rates for each pond and the
standing crops at the beginning of the time periods as indicated
by the following expression.
=w0 (e-.l)
g-i
36
where
W is the average standing crop for the time period,
is the standing crop at the beginning of the time
period, and
g and i are the instantaneous growth and mortality rates
for the time period.
The meaning of the average standing crop can be seen from
the preceding equation.
The initial standing crop for any time
interval changes during the time involved as the fish change in
weight (growth) and as the numbers of fish decrease (mortality).
The computed average standing crops for each pond and for each
time period are recorded in Table 10.
The production of adult bluegills was calculated by multiplying the average standing crop
for each interval times the
instantaneous growth rate g for that interval.
values for each interval,
are presented in Table 10.
The computed
nd the total production for each pond
The total production is the sum of
the production for each period.
The production for any particu-
lar time interval wifl be negative if the instantaneous growth
rate is negative.
For example, in S2 the growth rates and the
production were negative for the second (t = 0.27) and third
(t = 0.ka) interval.
The total production was 0.39k, 0.958,
3.013, and 12.67k kilograms for 81, 82, S3, and 8k respectively.
Benthic
and fish production
Examination of the stomach contents of five adult bluegille
from each pond indicated that aquatic Diptera of the family
Tendipedidas were the only important food item in the diet of
the fish in the experimental ponds.
The total dry weight, in
milligrams, of tendipedid larvae removed from the stomachs of
five adult bluegills taken from each pond on August 19 were
1.7, 1.4, 3.6, and 85.5 milligrams for ponds Si, 52, 53, and 54
respectively,
The total dry weight of benthic organisms (in
mg.) for one sampling period (September 21-22) consisting of
eight Ekman dredge samples of one-fourth square foot each was
compared with the total kilograms of fish produced in each pond.
The results presented in Table U indicate that there was a
direct relationship between the abundance of tendipedid larvae
and fish production in all four ponds..
81
19.4
0.394
52
32.9
0.958
53
161.0
5.013
84
314.4
12.674
38
ills
Coefficient of condition for adult
The coefficient of condition K, expressed in metric units,
as described by Carlander (5, p. 8) was used to determine the
condition of the adult bluegills at each sampling.
The ex
pression for the condition coefficient is:
K = W 10
,
L3
Th]
W is the weight n grams,
L
1O
is the standard length in millimeters, and
is a factor to bring the value of K near unity.
The mean K for 15 representative bluegilla at the time of
stocking on May 8 was 3.22.
This was a composite sample taken
before the fiah were placed in the ponds, therefore, the initial
K was 3.22 for each pond.
Carlander (5, p. 178) has reported a
mean condition coefficient of 3.72 for 136 bluegills from Iowa
ponds.
Mean values of 1( were computed from samples of approxi-
mately 25 fish from each pond on July 2, August 20, and
November 10.
The tabulated values (Thble 12) of the least
significant difference at the five percent significance level
(LSD) indicate that adult bluegills in s4 wore in better eon
dition than the fish in any other pond at all periods of sampling.
On July 2 and August 20, the mean condition was better in 83 than
in Si and 82.
The mean conditions for fish in Si and 82 ware not
39
table 12,
Pond
number
Mean condition coefficients for adult bluegilla in
the Soap Creek ponds, May through November 1959
Time of aa*pling
August 20
July 2
My 8
November10
Si
3.22
3.19
2.65
2.9?
£2
3.22
3.1k
2.68
2.82
83
3.22
3.31
2.87
3.02
3k
3.22
3.55
3.5k
3.k2
0.13
0.13
0l2
L3D,03
-
significantly different on either of these dato,
When the ponds
were drained, the fish in Si and 83 were in bettex condition than
the fish in 32.
The general trends in mean condition coeffici-
ents are presented in ?igur, 1.
Growth of juvenile
1ls
Newly-hatched bluegills were present by mid-July in all
ponds.
The growth rates of these small fish were estimated every
two weeks by sampling at eight locations around the ponds as
previously described.
The differences in mean weights at the
initial sampling (Table 13) indicated that spawning and/or hatching had occurred at different times in the four ponds.
The
initial mean weight in B]. and 82 was similar (approximately 100
mg.), but the initial mean weight was extremely different in 33
(300 mg.) and 24 (25 ag.).
The mean weights of the small fish
in 31, 82, and 83 remained relatively constant, but the mean
ALL
C
0
PONDS I
POND
SI
POND
$2 rwd&
POND
$3 DCCV\/\/V
S
4.0
z
'a
U
U.
UIii
8
3.5
z
0
I
a
z
0
U
3.0
z
4
'a
2.5
May 8
FIGURE I
July 2
Aug.
MEAN
CONDITION
ADULT
BLUEGILL
CREEK
PONDS,
20
Nov. 10
COEFFICIENTS FOR
SOAP
SUNFISH,
MAY
NOVEMBER
1959
THROUGH
Table 13.
Numbers of juvenile bluegifla sampled and mean weights (in mg.), Soap Creek ponds,
August througb October 1959
no.
33
August 28
August 13
Pond
September 11
September 29
October
3
No.
Wt,/fish
No.
Wt./fish
No,
Wt./fish
No,
Wt,/fish
473
79.7
64
108.0
709
143.3
630
170.8
733
161.3
8k
96.4
884
99.1
802
107.1
484
127.1
632
137.2
309
312.3
436
354.2
634
317.7
389
440.1
81
339.5
1043
26.1
832
102.4
785
238.6
780
330.5
6o6
307.8
No.
Wt./f ish
three all at hauls seine individual within than hauls seine among
variation more significantly was There
occurring. was groups
size by schooling that observation the substantiated periods
sampling three for c) (Appendix calculations variance of Analysis
hauls. seine within weight in variation the than greater be to
expected was hauls seine different among weight mean in variation
the groups, size by schooling were fish young the If
hauls.
several among variation the and hauls seine individual of halves
separate the within weight mean in variation the analyze to
possible was it method, this Using
described. previously as lath
wooden a with divided were samples subsequent in hauls seine
observation, this support To
groups. size different in ing
school- were fish small the that indicated 13) (August conducted
was growth for 8ampling first the when observations Field
bluegills jvenile of
olin
another. one from different significantly not were $3 and $2,
Si, in rates growth The
ponds. three other the in than
84 in
better significantly was growth of rate the that indicated cance
signifi- of test A
milligrams .k3
respectively. 24 and 83, 82, 31, for day per
and 2.30, 0.87, 1.36, were growth of rates The
day. per milligrams in rate growth the is which pond, each for
b, coefficient regression the by substantiated was This
rapidly.
grew fish young the which in pond only the was 3k Apparently
2. figure in illustrated as considerably increased 5k in weight
3
500
400
POND
SI
POND
S2
POND
S3 ---------
PONDS4 - - - - *
- -
- S
- -
-
300
LI-
200
x
100
z
4
Lu
Z
0
0
TIME
FIGURE 2
30
20
P0
OF
SAMPLING
GROWTH
RATES
SUNFISH,
SOAP
IN
40
DAYS
50
60
OF NEWLY-HATCHED BLUEGILL
AUGUST
CREEK PONDS,
THROUGH
OCTOBER
(959
sampling periods,
Unfortunately, the method of analysis does
not indicate the sizes of fish which were schooling together,
nor does it indicate the location of the different size groups
around the pond peripheries.
Smaller fish appeared to be more
abundant in seine hauls from the shallower portions (west ends)
of the ponds.
This was substantiated by determining the mean
weight per fish from seine hauls in the shallow and deep ends
of the ponds as presented in Table 1k.
The mean weight of the
young fish from the shallow ends of the ponds was less than the
mean weight of fish taken from the deeper ends in all instances
except on September U and 29 for S2.
?able 1k.
Mean weights of juvenile bluegills (in mg.) from
Si
100.7
117.8
136.2
153.k
165.8
176.6
82
99,6
lOk.9
118.7
111.6
l%.1
89.5
83
31+0.8
372.7
276.0
302.3
381.2
336.1
sk
88.6
12k.9
17k.3
269.0
295.6
1+06.1
DISCUSS ION OF FISH PRODUCTION
STIMATF.8
The addition of nutrients, particularly nitrogen and phoe
phorous, had a pronounced effect upon the ability of the Soap
Creek ponds to produce fish.
The chemical, physical, and bio
logical changes in the pond environments accompanying fertiliza
tion were recorded by Mclntire (16). AU of these changes
following fertilization effected the production of new body subsstance in the ponds.
Fish production was increased as the application of ferti..
users increased.
(0.39k kg.)
The control pond (Si) had the lowest production
Pond $2 (nitrogen only) produced slightly more new
body substance (0.958 kg.), but the greatest production occurred
in $3 and Sk which received both nitrogen and phosphorous fertilizers.
Production in 23 (5.013 kg.) was approximately four times
greater than in the control pond (Si) and production was nearly
twelve times greater in 8k than in the control.
The addition of
both nitrogen and phosphorous to $3 at a rate of 37.6 pounds
nitrogen and 25.0 pounds available phosphoric acid per season
apparently was adequate to increase fish production.
Molntire
has recorded that 33 maintained high plankton populations during
the summer (16).
He has also shown that benthic populations did
not become established as quickly in 33 as in 5k.
The major food
item found in the stomachs of adult bluegills from all ponda was
benthic organisms (tendipedid larvae).
Therefore, it was
reasonable to suspect that a scarcity of this particular food
during the early portion of the study limited fish production In
83,
Doub1in
the rate of application of nitrogen and phosphorous
in 8k had a pronounced effect upon the production of fish as presented in Table 10 (page 3k).
The high production in 8k was
apparently duo in part to the early establishment of fish food in
this pond.
A tendipedid population had become established in the
shallow end of sk by July 21 and bad not developed in appreciable
numbers in the other ponds (16).
Production could only be estimated after the ponds were
drained in November, therefore, condition coefficients wore com-
puted to determine the changes in condition during the study
(Table 12, page 39, and Figure 1, page 1+0).
ccndition followed an interesting pattern.
The changes in mean
From the time of
stocking (May 8) to the second sampling (July 2), the mean oon
dition dropped in Si and S2, and increased in 83 and 81+.
Spawn-
ing had occurred in all ponds by the third sampling period
(August 20); and mean condition had dropped markedly in all ponds
except 81+.
When the ponds were drained in November, the mean
condttion had increased to some extent in Si, 32, and 23 and had
decreased slightly in 81+.
This pattern of changes in condition
can best be explained by the early establishment of benthic
organisms in 84,
Sufficient food was available in 51 by July
and the mean condition coefficient of bluegiUs in the pond was
k7
significantly greater than the sean condition in the other ponde.
This initial advantage was never overcome; and even after spawning in July, the condition of b].uegills in 3k did not decrease as
it did in the other ponds Oiguz'e 1, page 40).
The slight de-
crease in mean condition in $4 recorded in November was apparently due to the onset of winter.
Juvenile fish growth was significantly better in s4 than in
the other ponds (Tigiue 2, page 43).
Th. early establishment of
a suitable food supply in Sk stimulated by the addition of nitrogen and phosphorous (twice the rate of $3) was believed to be
responsible for the increased rate of growth in this pond.
CONCLUSIONS FROM FL3H PRODUCTION ESTIMATES
1.
Fish production in 33 and sk was increased from four to
twelve times by the addition of nttrogen and phosphorous ferti
lizers.
2.
The better condition of adult bluegills in 3k apparently
resulted from the early establishment of food supplies stimulated
by doubling the rate of application of nitrogen and phosphorous
fertilizers.
3.
The growth rate of newly-hatched bluegilis was signifi-.
cantly better in 3k than in the other three ponds.
k.
Newly-.hatched bluegills were schooling in different size
groups in the various areas of the ponds, and the smaller fish
were more abundant in the shallow ends than in the deep eade.
3.
Estimation of fish production appeared to be an ex-
cellent technique for studying fish populations in ponds since
production accounts for both the growth and death of fish during
the period of study.
BIBLIOGRAPHY
1.
Ball, Robert C. Experimental use of fertilizer in the production of fish-food organisms and fish. east Lansing,
(Michigan1 Agricultural Experiment Station.
19k9. 28 p.
Technical Bulletin 210)
2.
Ball, Robert C. Farm pond ianagemeut in Michigan.
of Wildlife Management 16:266-269. 1952.
3.
Ball, Robert C. and Howard A. Tanner. The biological
effects of fertilizer on a warm-water lake, East Lansing,
(Michigan. Agricultural Emperiment Station.
1951. 32 p.
Technical Bulletin 223)
k.
Pond management in Illinois.
Bennett, George
of Wildlife Management l6:21+9253. 1952,
5.
Carlander, Kenneth D. Handbook of freshwater fishery
biology. Dubuque, Iowa, William C. Brown Company, 1950.
281 p.
6.
Carlander, Kenneth D. The standing crop of fish In lakes.
Journal of the Fisheries Resear*h Board of Canada 12:543570. 1955.
7,
WI
Journal
Journal
Carlander, Kenneth D. and Robert B. Moox'man, Standing crops
of fish in Iowa ponds. Proceedings of the Iowa Academy of
Science 63:659668. 1956.
8.
Chapman, B. G. A mathematical study of confidence limits of
salmon populations calculated from sample tag ratios. In:
Problems in enumeration of populations of spawning sockeye
(Intersalmon, New Westminster, B. C., 1948.
p. 69-85.
Bulletin
no.
national Pacific Salmon Fisheries Commission,
2, pt. 2)
9.
Clark, Minor. Kentucky's farm fish pond program.
of Wildlife Management 16:262-266. 1952.
10.
Journal
Delury, B. B. On the planning of experiments for the estimation of fish populations. Journal of the Fisheries Research Board of Canada 8:281-307. 1951.
Liaanology of selected Oregon farm fish
ponds, Master's thesis. Corvallis, Oregon State College,
56 numb, leaves.
1958.
U. Kendle, Earl R.
12.
Xlavano, Wayne C. Age and growth of fish from Oregon farm
ponds. Master's thesis. Corvallis, Oregon State College,
1958. ki numb, leaves,
13.
Lincoln, F. C. Calculating waterfowl abundance on the basis
of banding returns. Washington, 1930. k p. (U. S. Department of Agriculture. Circular 118)
1k.
Macielek, John A. Artificial fertilization of lakes and
(U. S. Fish and Wildlife
ponds. Washington, 195k. ki p.
Service. Special Scientific Report-Fisheries 113)
15.
!4clntire, Charles D. Unpublished research on the limnology
of Oregon farm ponds. Corvallis, Oregon State College,
Department of Fish and Game Management, 1959-60.
16.
Mclntire, Charles D. Effects of artificial fertilization
on plankton and benthos production in four experimental
ponds. Master's theais. Corvallis, Oregon State College,
1960. 76 numb, leaves.
17.
Petersen, C. 0. J. The yearly immigration of young plaice
into the Limfjord from the German Sea, etc. report of the
Danish Biological Station for 1895, 6:1-kB. Cited in: W.
E. Ricker's Handbook of computations for biological statistics of fish populations. Ottawa, 1958. 300 p.
(Fisheries Research Board of Canada. Bulletin 119)
18.
Ricker, W. E. Handbook of computations fez' biological sta
tistics of fish populations. Ottawa, 1958. 300 p. (Fisheries Research Board of Canada. Bulletin 119)
19.
Ricker, W. E. and R. E. Yoerster, Computation of fish production. Bulletin of the Bingha* Oceanographic Collection,
Yale University. Peabody Museum of Natural History. Bingham Oceanographic Foundation. 11(k) :173-2U. 19k8.
20.
Schaefer, Mj3.ncr 3, Estimation of size of animal populations by marking experiments. Washngtou, 1951. p. 191w
Fishery Bulletin
(U. S. Fjh and. Wildlife Service.
203.
69 from Fishery Bulletin of the Fish and Wildlife Service
Vol. 52)
21.
Solinabel, Zoo E.
tion of a lake.
1938.
The estimation of the total fish populaAmerican Mathematical Monthly. k5:38-352.
22.
Schunacher, F. X. and R. W. Escbmeyer. The estivate of fish
population in lakes and ponds. Journal of the Tennessee
Acadenty of Science l8:228.ak9. 19k3.
23.
$ith, £. V. and H. S. Swingle. The relationship between
plankton production and fish producUon in ponds. ?ranaactIons of the American Fisheries Socist 68:309.315. 1938.
24.
Swingle, H. S. Relatiønships and dynamics of balanced and
unbalanced fish populations. Auburn, 1950. 74 p.
(Alabama. Agricultural Experiment Station. Bulletin 274)
23.
U. S. Department of Agriculture. Climate and man: !earbook
of Agriculture, 1941. Wasbington 1941. 1248 p.
a6.
Wohlschlag, Donald E. ad Chester A. Woodhi1l. The fish
populations of Salt Springs Valley 1sseroir, Calaveras
County, California. California Fish and Game 39:5..kk. 1953.
5,
APPEIWXX A.
Common and scientific names of aquatic vertebrates
discussed
Sockeye salmon, Oncor}tynehus nerka nerka, Walbaum
Coastal cutthroat trout, Salmo clarki clarki, Richardson
Rainbow trout, Salmo
Richardson
Columbia coarse-scale sucker, Catostomus macrocheilus, Girard
Richardson
Columbia squawfish, Ptychocheilu
Brown bullhead, Ictalurus nebulosus, LeSueur
largemouth bass, Micropterus salmoides, Lacepede
Bluegill, Lepomis mach.rochirua, Rafinesque
White crappie, Poniozia annu3s, Rafineeque
Water newt, Tazicha
Skilton
APPENDIX B.
Pond name
Cronemiller
Lake
Baker
Clay
Description of ponds where fish population estimates were made
Pond
no.
1
Location
Near Corvallis
Surface
area
(acres)
1.90
2
Harrisburg
0.22
3
Hoskins
0.20
hverage
depth
Record of stocking
No.
8.0
5-7-57
697
700
15
Fingerling
Fingerling
Adult
Cutthroat
Rainbow
Bluegill
4.2
29
9 15-56 11+00
Fingerling
Fingerling
Largemouth bass
Bluegill
-
3.3
355
5-8-54
Cleveland
1+
Belifountain
0.30
5
Lakeview
0.85
5.0
Durlam
6
Sodaville
0.68
3.8
7
Madras
0.50
3.8
Link
8
Madras
2.20
4.0
Reimer
9
Perrydale
0.25
5.0
Sandoz
10
Madras
0.35
4.0
Schutzwohl
Schutzwohl
Skean
11
12
13
Grants Pass
Grants Pass
0.45
3.7
Bluegill
Largemouth bass
Brown bullhead
Fingerling
Fingerling
Largemouth bass
Bluegill
8-21-56
400
Fingerling
Largemouth bass
8 19 54
30
300
Fingerling
Fingerling
Largemouth bass
Bluegill
8 15
600
200
Fingerling
Fingerling
Bluegill
Largemouth bass
-
-
Fingerling
Bluegill
9-?-54
300
15
Fingerling
Adult
Bluegill
Largemouth bass
54
20
20
Adult
Fingerling
Bluegill
Largemouth bass
7-?-53
528
250
125
Fry
Fry
Fry
Bluegill
Brown bullhead
Largemouth bass
1+1+7
Fingerling
Fingerling
Largemouth bass
Bluegill
3.5
0.28
-
Bluegill
Cutthroat
100
500
4.9
Rainier
Fingerling
Fingerling
Species
8 -?-51
-.
0.94
1+0
-
-
2.5
Crurnmett
Farrell
Size
Date
(ft.)
5 15-54
86
Soap Creek
lkSl
Near Corvallis
0.38
2.7
5-15-59
1+61
Adult
Bluegill
Soap Creek
1552
Near Corvallis
0.60
3.3
5-15-59
876
Adult
Bluegill
Soap Creek
16S3
Near Corvallis
0.55
3.8
5-15-59
835
Adult
Bluegill
Soap Creek
17S4
Near Corvallis
0.47
3.5
5-15-59
732
Adult
Bluegill
0.67
4.8
50
100
Adult
Adult
Largemouth bass
Bluegill
375
Fingerling
Adult
Adult
Largemouth bass
Largemouth bass
Bluegill
Thompson
18
Sweet Home
9-15-57
Walton
19
Turner
0.50
5.0
Willamette
20
Corvallis
0.1+3
7.0
-
21
50
-
-
-
APPENDIX C.
Table 1.
Analysis of variance ea1cu&tons for schooling of
juvenile b1ueil1Agst 28,1959
Variation
due to:
Ponds
Hauls in ponds
Within hauls
Total
Table 2.
Degrees of
freedom
Sum of
squares
Mean
square
3
798,0145.00
266,015.00
28
303,158.00
10,827.00
32
65,501.00
2,0147.00
63
1,166,7014.00
3.
Ana3.sia of variance calculations for schooling of
iuveui1s b1ue1s, September l,939
Variation
due to:
Degrees of
freedom
Ponds
Sum of
squares
Mean
square
3
331,557.76
110,519.25
Hauls in ponds
28
11,329.82
6,1476.07
Within hauls
32
39,699.7k
1,2140.62
63
352,587.32
Total
Table 3.
F
5.221
Analy-sis of variance calculations for schooling of
juven4e b1uoil1s, September29, 1959
Variation
due to:
Ponds
Degrees of
freedom
Sum of
squares
Mean
square
3
1,197,863.08
399,287.69
Hauls in ponds
28
1418,1493.97
114,946.21
Within hauls
32
113,820.85
3,556.90
63
1,730,177.90
Total
1Significant at the five percent signi±icance level.
F
4.201