RECOVERY OF GRASS CARP, CHANNEL CATFISH, AND
CENTRARCHIDS IN ARTIFICIAL CENTRAL ARIZONA PONDS
PAUL C. MARSH
Center for Environmental Studies
Arizona State University
Tempe, AZ 85287
W. L. MINCKLEY
Department of Zoology
Arizona State University
Tempe, AZ 85287
ABSTRACT
Seven small, artificial ponds at Sun Lakes in central Arizona were reclaimed with rotenone in April 1978. Mean total
fish biomass was 532 kg/ha comprised of grass carp (Ctenopharynogodon idella, 67%), channel catfish (Ictalurus punctatus,
30%), largemouth bass (Micropterus salmoides, 3%), and green sunfish (Lepomis cyanellus, <1%). Greatest total biomass
was 1,159 kg/ha in a 0.44-ha pond, comparable to some commercial culture operations. Standing crops of grass carp and
largemouth bass were positively correlated, perhaps owing to essentially complete vegetation removal by the former and
consequent prey vulnerability to the latter. Pond area and fish yield were unrelated. Differential angler harvest and water
quality may have been factors resulting in observed differences in yield among ponds.
INTRODUCTION. — Grass carp (Ctenopharyngodon idella)
has for years been touted as an effective biological control
agent for nuisance aquatic plants. Although banned in
Arizona because of unknown potentials for environmental
disturbance, grass carp nevertheless has been imported and
stocked or escaped in several places (Marsh and Minckley
1982, 1983). Channel catfish (Ictalurus punctatus) and
largemouth bass (Micropterus salmoides) are popular
introduced sport fishes in the southwestern United States.
Both have been extensively stocked in public waters by the
Arizona Game and Fish Department (AZGF), and into private ponds by the U.S. Soil Conservation Service and
private individuals and organizations.
Not unexpectedly, grass carp, channel catfish, and
largemouth bass have been introduced together in an
attempt to satisfy needs for both vegetation control and
recreational fishing. Such was the case in a series of small,
artificial ponds at the town of Sun Lakes, Arizona. We
report on community structure and species-biomass of
fishes in those ponds.
AREA AND METHODOLOGY. — Sun Lakes, Arizona, is a
retirement community with a population of about 5,000
and is located 32 km SSW of Phoenix, in central Arizona
(T2S, R5E, S31-32, Maricopa Co.). Eight artificial ponds
are situated within "green belt" and golf course areas at
Sun Lakes (Fig. 1). Ponds are generally kidney shaped,
Figure 1. Sketch map of artificial ponds (1-8) at Sun
Lakes, and inset showing location in central Arizona.
Numbers are total fish biomass (kg/ha), arrows indicate
direction of water flow. Pond 1 is at highest elevation, 3 is
lowest. Ponds 1-4 were closed to angling during daylight
hours, 5-8 were open to fishing 24 hours daily.
Marsh, P.C. and W. L. Minckley. 1983. Recovery of grass carp, channel catfish, and centrarchids in artificial central Arizona
ponds. Journal of the Arizona-Nevada Academy of Science 18:47-51.
47
48
VOL. 18
JOURNAL OF THE ARIZONA-NEVADA ACADEMY OF SCIENCE
sions and meshes) for a period of one to three weeks to
obtain brood stocks of all but grass carp for re-introduction. Numbers and weights of fishes so removed from
ponds 1 and 5-6 were not recorded, but constituted a minor
fraction of totals present. Ponds were then treated by
applying 7.5% active-ingredient rotenone to obtain a concentration of 2 mg/l. Fishes were collected for three consecutive days following rotenone application. All specimens from seven ponds (the eighth, originally a fishless
pond, was used to hold fish to be re-stocked) were identified and enumerated, and those taken on the day of poisoning also were measured (total length, TL, in cm) and
weighed (nearest 1 or 10 g, depending on equipment).
Total biomass was estimated from mean weights of fishes
collected on day 1 and total numbers collected over the
three-day pick-up period.
Simple linear regressions of the form y = mx + b were
used to examine relations between species biomasses and
between lake areas and biomass.
0.44-1.02 ha (1.09-2.51 ac) surface area, 34-4.3 m (1114 ft) maximum depth, and with low shoreline development. They are sealed with clay or plastic liners, overlain
by silt-sand substrate; gravel and larger particles are rare.
Ponds are supplied with water from a well, reclaimed wastewater, and infrequent local runoff, and are interconnected
by underground pipes (Fig. 1).
Unknown numbers of fingerling (76-102 mm; 3-4 in)
channel catfish and largemouth bass and juvenile (152203 mm; 6-8 in) grass carp were stocked in 1971-1972. At
least two silver carp (Hypopthalmichthys molotrix) also
were introduced, presumably as contaminants with grass
carp (Marsh and Minckley 1983). Also stocked at unknown
dates and sizes were green sunfish (Lepomis cyanellus),
fathead minnow (Pimephales promelas), common carp
(Cyprinus carpio), and goldfish (Carassius auratus).
In April 1978, personnel from Arizona State University, under direction of AZGF, reclaimed the ponds. Fishes
were initially netted (trammel, hoop, seine; various dimen-
Table 1. Density (No/ha), standing stock (kg/ha) and percentage of standing stock (in parentheses) of fish in 7 ponds at
Sun Lakes, central Arizona.
Pond
Area (ha)
1
3
0.44
1.02
4
0.46
5
6
7
8
Total
Mean
0.59
0.61
0.95
0.70
4.77
0.68
No/ha
Grass carp
120
71
67
53
59
26
40
436
62
Channel catfish
443
275
167
80
249
93
247
1554
222
Largemouth bass
489
89
93
151
43
26
16
907
130
5
157
80
14
38
109
27
430
61
1057
592
407
298
389
254
330
3327
475
Green sunfish
TOTAL
kg/ha (%)
Grass carp
879
(76)
289
(50)
330
(66)
583
(83)
224
(52)
95
(55)
108
(57)
2508
(67)
358
Channel catfish
254
(22)
268
(46)
148
(30)
84
(12)
200
(46)
71
(41)
76
(40)
1101
(30)
157
26
(2)
16
(3 )
17
(3 )
32
(5 )
6
(1)
6
(3 )
3
(2)
106
(3 )
15
Green sunfish
0.2
(<0.1)
4.4
(1)
3.0
(1)
<0.1
(<0.1)
0.7
(<1)
2.4
(1)
0.6
(<1)
11
(<1)
TOTAL
1159
577
699
431
174
188
Largemouth bass
498
3726
532
ISSUE 2, 1983
49
RECOVERY OF GRASS CARP, CHANNEL CATFISH, AND CENTRARCHIDS
RESULTS. - Total fish biomass ranged from 174 to 1,159
kg/ha, with a mean of 532 kg/ha. Grass carp comprised
50-83% (Ii = 67%), channel catfish 12-46% OE = 30%),
largemouth bass 1-5% (Ft = 3%), and green sunfish <0.1-1%
(rc < 1) (Table 1). Other species were represented by only a
few individuals and negligible biomass.
Mean TL of grass carp was 63-93 cm among ponds
(Table 2), with low variability (coefficient of variation,
CV, 0.07). Overall limits were 53-102 cm TL. Mean individual weights (WT, Table 2) ranged from 2.7-11.1 kg, with
at most 0.25 CV in any pond. Although there were substantial differences in both mean TL and WT among ponds,
there was high uniformity within each pond.
Channel catfish was numerically predominant in four
of seven ponds. Mean TL was 33-50 cm among ponds, and
individuals ranged from 13-56 cm (Table 3). Mean individual WT by pond was 0.310-1.060 kg (overall range 0.015-
2.20 kg). CV in TL was at most 0.23, and as high as 0.43
in WT. Diversity in size was as great within as among ponds.
Presence of small fish in two ponds suggested some natural
recruitment.
Largemouth bass was the most abundant species in
two ponds. Mean TL ranged from 19-27 cm (CV = 0.13),
with overall limits of only 17-29 cm (Table 4). Mean
individual WT was less uniform, 0.054-0.226 kg (CV =
0.25), with a range of 0.036-0.266 kg. Substantial differences in size occurred among ponds.
Green sunfish was numerically dominant in only one
pond. Mean individual WT was 0.005-0.070 kg. Biomass
of green sunfish was small (0.1-4.4 kg/ha) and contributed
at most 1.4% to total biomass in any pond.
There were no significant correlations between species
or total biomasses (kg/ha, dependent variable) and pond
size (ha); correlation coefficients (r) were -0.04 to -0.60
Table 2. Mean (1 1 SD) and range of total length (TL, cm) and weight (WT, kg) of grass carp in 7 ponds at Sun Lakes, central
Arizona.
POND
3
4
5
6
7
8
72 ± 4
74 ± 5
93 1 5
69 1 4
67 1 3
63 1 3
Min
63
62
86
60
60
53
Max
80
85
102
76
72
66
7.3 ± 1.4
4.1 ±0.6
4.9 *1.1
11.1 ±2.7
3.8 ±0.5
3.6 ±0.5
2.7 ±0.4
Min
3.75
2.80
3.33
7.86
2.43
2.62
1.48
Max
9.80
5.00
7.46
16.13
4.85
4.86
3.28
43
63
28
31
25
24
19
1
TL
WT
Table 3. Mean (± 1 SD) and range of total length (TL, cm) and weight (WT, g) of channel catfish in 7 ponds at Sun Lakes,
central Arizona.
POND
1
3
4
5
6
7
8
42 ± 2
45 ± 9
50 ± 5
49 ± 5
41 ± 8
41 / 7
33 / 8
Min
38
27
39
36
15
26
13
Max
48
56
56
56
52
53
44
570 ± 120
970 ± 320
890 ± 370
1060 1 250
800 1 300
760 1 330
310 1 130
TL
WT it
Min
330
70
80
450
20
140
15
Max
910
1300
1670
1640
1690
2200
710
131
161
42
39
72
71
102
50
JOURNAL OF THE ARIZONA-NEVADA ACADEMY OF SCIENCE
VOL. 18
of the most productive commercial ponds, is well within
the range for world aquacultural production (31 countries)
of 55 to 6,000 kg/ha (Pillay 1973).
Standing stocks of fishes in natural, low-desert streams
of southwestern United States range from 30 to 1,670
kg/ha (Minckley 1981), and in a southwestern canal from
490 to 1,020 kg/ha (Minckley et al., 1983). Standing crops
of fishes in streams of other regions rarely exceed 300
kg/ha (Minckley 1981). We have no comparable data for
southwestern lakes or ponds. Fish biomass from Sun Lakes
is thus near maxima in other southwestern aquatic systems,
well above those outside the region, and demonstrates a
generally high production in low-desert aquatic habitats.
Investigations of the effects of grass carp on other
species, including channel catfish, largemouth bass, and
other centrarchids, have produced variable results (Bailey
1978, Forester and Lawrence 1978, Lewis 1978). In some
cases effects were positive, in others negative, and in some
no effect was observed. In Sun Lakes, largemouth bass and
grass carp biomasses were directly proportional. We attri-
(Table 5). The only significant species-biomass correlation
was that of largemouth bass (dependent) and grass carp
(y = 0.034X + 2.645, r = +0.87, N = 7), which suggests that
largemouth bass standing stock increased linearly as a function of grass carp biomass.
DISCUSSION. — Mean standing crops of channel catfish,
largemouth bass, "sunfishes", and common carp in North
American lakes and reservoirs are approximately 15, 17,
45, and 115 kg/ha, respectively, with maxima near 65, 65,
225, and 675 kg/ha (Carlander 1955). Compared to these
lentic habitats, standing crops of Sun Lakes channel catfish
were at or above maxima, largemouth bass were about
average, "sunfish" were relatively low, and grass carp (compared with common carp) were exceptionally high. Intensive commercial polyculture ponds may produce tens of
thousands of kg/ha (Hepher and Pruginin 1981, Hickling
1968), and under ideal conditions of monoculture, yields
as high as 2 million kg/ha/yr have been achieved (Hickling
1968). Total fish yield from Sun Lakes, while below that
Table 4. Mean (+ 1 SD) and range of total length (TL, cm) and weight (WT, g) of largemouth bass in 7 ponds at Sun Lakes,
central Arizona.
POND
1
3
4
5
6
7
8
19 ± 1
25 ± 1
25 1 1
25±1
23 1 3
27 1 1
25±2
Min
17
21
21
21
21
25
22
Max
20
27
27
27
27
29
27
54 ± 9
175 1 29
175 1 25
210 1 31
131±19
226 ± 23
166 1 42
Min
36
107
104
112
100
174
119
Max
72
235
210
244
160
266
222
43
54
25
69
8
16
8
TL
WT ii
Table 5. Coefficients for slope (m) and intercept (b) of simple linear regressions of the form y = mx + b, and correlation
coefficients (r), for species biomass (kg/ha) or surface area (ha) of fish from 7 ponds at Sun Lakes, central Arizona. (n = 7
in each case).
y (dependent)
x (independent)
Largemouth bass
Grass carp
0.0343
Channel catfish
Grass carp
0.1345
Largemouth bass
Channel catfish
0.0309
Largemouth bass
Area
-20.97
Channel catfish
Area
-17.01
Grass carp
Area
-744.84
level
2.6453
0.8724
0.025
0.4481
NS
10.063
0.2364
NS
29.216
-0.4285
NS
168.86
-0.0455
NS
865.00
-0.5980
NS
109.06
ISSUE 2, 1983
RECOVERY OF GRASS CARP, CHANNEL CATFISH, AND CENTRARCHIDS
bute this to vegetation removal by grass carp, which presumably enhanced vulnerability of prey for largemouth
bass. Vegetation was virtually absent in Sun Lakes ponds,
as were forage fishes. The last suggests that largemouth
bass may have effectively depleted their forage base.
Although we have no data on angler effort or harvest,
we know that ponds at Sun Lakes received at least moderate pressure from residents and guests. Four ponds (5-8,
Fig. 1) that were open to 24-hour fishing produced an
average of 373 kg/ha total biomass, while those closed to
fishing during daylight hours yielded an average of 745
kg/ha, twice that of the open ponds. Both largemouth
bass and channel catfish similarly occurred at about twice
the biomass in closed as in open ponds (19.5 vs. 11.5 and
223 vs. 108 kg/ha, respectively). It is tempting to attribute
these differences to differential angling pressure. However,
such may not have been the case since grass carp, which
was not taken by fishermen, showed the same trend (500
vs. 252 kg/ha in closed vs. open ponds).
Pond 1 is at highest elevation and is the only pond that
receives well-water input (Fig. 1). It had the highest per
unit area biomass. Downflow there was a sequential reduction in biomass from pond 1 to ponds 5, 6, 7 and 8. This
reduction may have been due to deteriorating water quality, nutrient uptake in upper ponds that limited primary
production in those lower on the system, or to other factors that directly or indirectly limited fish production.
Along this continuum, ponds 4 and 3 should have yet
smaller biomasses. They did not. However, pond 4 received nutrient-enriched, reclaimed wastewater that enhanced algal and macrophyte production, thus presumably
enhancing relative fish production. Other factors such as
feeding of grass clippings by groundsmen (C. Wright, pers.
comm.) and inputs of inorganic fertilizers with runoff from
surface irrigation of golf course greens introduce variables
we cannot assess. Growth of Sun Lakes grass carp showed
trends among ponds parallel to those of standing stock
(Marsh and Dhaenens 1984), presumably due to similar
factors.
It is not possible from our data to evaluate Interactive effects of grass carp and other species. Total standing stocks were certainly extraordinary, and grass carp
effectively controlled aquatic vegetation. Grass carp had
not recruited in any pond, and recruitment to channel catfish and centrarchid populations was minimal. We have no
evidence that grass carp did or did not impact reproductive
success of other fishes, yet whether directly or indirectly,
51
such may have been the case. Absence of small fishes of
any species indicated low recruitment of the population
as a whole.
LITERATURE CITED
BAILEY, W. M. 1978. A comparison of fish populations
before and after extensive grass carp stocking. Transactions of the American Fisheries Society 107(1):181206.
CARLANDER, K. D. 1955. The standing crop of fish in
lakes. Journal of the Fisheries Research Board of
Canada 12(4):543-569.
FORESTER, T. S. and J. M. LAWRENCE. 1978. Effects
of grass carp and carp on populations of bluegill and
largemouth bass in ponds. Transactions of the American Fisheries Society 107(1):172-175.
HEPHER, B. and Y. PRUGININ. 1981. Commercial Fish
Farming. John Wiley & Sons, Inc., NY. 261 p.
HICKLING, C. F. 1968. The Farming of Fish. Pergamon
Press Inc., NY. 88 p.
LEWIS, W. M. 1978. Observations on the grass carp in
ponds containing fingerling channel catfish and hybrid
Transactions of the American Fisheries
sunfish.
Society 107(1):153-155.
MARSH, P. C. and M. A. DHAENENS. 1984. Growth of
grass carp, Ctenopharyngodon idella, in artificial central
Arizona ponds. California Fish and Game. In press.
MARSH, P. C. and W. L. MINCKLEY. 1982. Fishes of the
Phoenix metropolitan area in central Arizona. North
American Journal of Fisheries Mngmnt 2(4):395-402.
MARSH, P. C. and W. L. MINCKLEY. 1983. Escape of
hybrid grass x bighead carp into central Arizona. North
American Journal of Fisheries Mngmnt 3(2):216-217.
MINCKLEY, W. L. 1981. Ecological studies of Aravaipa
Creek, southeastern Arizona. Final Report to U.S.
Bureau of Land Management, Contract Number YA512-CT-698, Arizona State University, Tempe, AZ.
MINCKLEY, W. L., W. RINNE and G. MUELLER. 1983.
Fishery inventory of the Coachella Canal, southeastern
California. Journal of the Arizona-Nevada Academy of
Science. 18(2):39-45.
PILLAY, T.V.R. 1973. The role of aquaculture in fishery
development and management. Journal of the Fisheries Research Board of Canada 30(12, Part 2):22022217.
52
JOURNAL OF THE ARIZONA-NEVADA ACADEMY OF SCIENCE
VOL. 18
BOOK REVIEW
Tales from Tiburon: An Anthology of Adventures in Seriland. Edited by NEIL B. CARMONY and DAVID E. BROWN. The
Southwest Natural History Association, P.O. Box 35141, Phoenix, AZ 85069. ix + 146 pp; illus. Cloth, $15.75; paper, $9.95.
Being among the last hunter-gatherer groups on the continent, the Seri Indians of the Gulf of California coast and islands
have intrigued many with their apparent "wildness." Yet few first hand accounts of how the Seri lived prior to the Thirties
have been available in English. Although Tales of Tiburon has only short passages of ethnographic description among tales of
travel and travail in Seriland, it nevertheless helps fill a large void regarding the historic Seri. It is a beautiful, well-edited
book with immediate appeal to buffs of borderlands natural and cultural history.
Included in this anthology are selected excerpts of journals and articles regarding four adventures into Seri country:
Hardy's brief stay among Tiburon Island Comcaac in 1826; McGee's 1895 fieldnotes which contrast in tone with his ethnographic monograph; two reminescences of the ill-fated Grindell prospecting expedition of 1905; and the superlative journals
of naturalist-hunter Charles Sheldon, who stalked big game with the Seri in 1921. These four adventures are accompanied by
all-too-brief introductions on the environment by Raymond Turner, and the Comcaac or Seri People by Bernard Fontana;
by chapter introductions to place each adventure in historic perspective; and by a fine selection of photographs.
Overall, these journal accounts tell us as much about the observers as about the observed. Whereas the Grindell party
was poorly prepared, frightened and gullible, Sheldon's skill and patience endeared him to the Seri. Most of the accounts
emphasize terrestrial wildlife, waterhole locations, and Seri camp appearances to a greater extent than marine life, terrestrial
plants and their uses, or Seri religion and social organization. Nonetheless, the desert itself speaks through these accounts,
particularly in those where man meets his own mortality. Carmony and Brown are to be congratulated for juxtaposing these
interesting documents in a format worthy of their content.—Gary Nabhan, Office of Arid Lands Studies, University of
Arizona, Tucson.