Growout channel catfish stocking evaluation of Oklahoma's small impoundments

              W 2800.7 F532r/w no.32
F-50-R-17 2010 c.1
FINAL REPORT
FEDERAL AID GRANT NO. F-50-R-17
Fish Research for Oklahoma Waters
PROJECT NO. 32
Growout channel catfish stocking evaluation of Oklahoma's small
impoundments
OKLAHOMA DEPARTMENT OF WILDLIFE CONSERVATION
JANUARY 1, 2010 through DECEMBER 31, 2010
FINAL REPORT
State: Oklahoma Grant Number: F-50-R-17
Grant Title: Fish Research for Oklahoma Waters
Project Number: 32
Project Title: Growout channel catfish stocking evaluation of Oklahoma's small
impoundments
Project Leader: Greg Summers
Contract Period: From: January l, 2010 to: December 3l, 2010
I. Project Objective: Determine/calculate 1.) catch rates, length frequencies, condition, and
age structure on nine small lakes before and after experimental stocking rate
manipulations and 2.)angler catch rates and satisfaction before and after stocking rate
manipulations on nine small lakes.
II. Summary of Progress
A. Introduction
Channel catfish (lctalurus punctatus) are stocked in small impoundments throughout
Oklahoma as put-grow-take or put-take fisheries. These stockings are necessary to
sustain an acceptable sport fishery as natural recruitment of channel catfish in small
impoundments is often low (Santucci et. al. 1994). It is important these stockings make a
significant contribution to the fishery as the Oklahoma Department of Wildlife
Conservation (ODWC) invests considerable resources in them.
Channel catfish are difficult to sample in small impoundments with most gear types. As
a consequence, the ODWC has conducted few catfish surveys on small lakes. Recently,
tandem hoop nets (3 tied in a series) have been used to effectively collect these fish in
small impoundments (Flamming and Schultz 2007, Michaletz and Sullivan 2002).
Tandem hoop nets collect channel catfish more efficiently than gill nets or electrofishing
and also produce representative samples offish >250 mm (Buckmeier and Schlechte
2009, Michaletz and Sullivan 2002).
Many small impoundments are stocked annually with growout (229 mm) channel catfish
at rates as high as 99 fish/ha. It is possible that some of these small bodies of water are
overstocked as stocking rates remain high and the number of catfish anglers in Oklahoma
have decreased since 1996 (US. Dept. ofInterior et. al. 2006). Michaletz (2009) found
size structure, condition, and growth to be highly variable on 60 small impoundments in
Missouri; therefore he suggested that stocking rates be individually determined for each
lake.
The population structure of channel catfish in department lakes needs to be determined as
well as stocking rates evaluated. Since channel catfish are one of the few species
managed in small impoundments by stocking, the number of fish stocked can have a
direct effect on angler catch rates and satisfaction. Reduced stocking rates could
potentially improve the size structure of overcrowded populations and in turn increase
angler satisfaction. Unless angler catch rates and satisfaction are negatively impacted,
reduced stocking rates could also potentially free hatchery ponds and resources for
production of other species.
B. Methods
Population characteristics
Nine small impoundments, American Horse, Burtschi, Dahlgren, Evan Chambers, Hall,
Nanih Waiya, Ozzie Cobb, Raymond Gary, and Watonga, were sampled with tandem
hoop nets (three in a series) during July and August 2009. Historically these lakes have
been stocked annually in August through October with growout (229 mm) channel catfish
at the rate of 99 fishlha. These impoundments are highly diverse, ranging geographically
from the panhandle in Northwest Oklahoma to Southeast Oklahoma. The nine lakes
range in size from 14 to 96 ha and encompass trophic levels from oligotrophic to
hypereutrophic. In addition to channel catfish, these impoundments primarily support
populations of sunfish, largemouth bass, and crappie.
Each tandem hoop net set consisted of three hoop nets that were approximately 3.4 m
long with seven fiberglass hoops. The largest hoop was .8 m in diameter at the mouth
and successive hoops slightly decreased in size to the cod end. Two hoop nets with 25-
mm-bar mesh and one hoop net with 12.5-mm-bar mesh were randomly ordered in each
series. Hoop nets were connected mouth to cod end by bridles that were l.8 m total
length. This allowed nets in a series to be fished approximately 0.9 m apart. Each net
was baited with approximately 0.9 kg of cheese log in a 907 g plastic sample jar with
approximately 25 to 30 holes that were 6 mm in diameter.
Effort at each lake was determined by lake size: <20 ha -3 series, ::::2:0 and <61 ha - 5
series, :::::61to <1Olha - 8 series, :::::1 01ha - 10 series (Kline et al. 1995). Sites were
randomly selected in the littoral zone at each lake. Nets were set parallel to the shoreline
in 2.4 to 3.7 m of water to limit by-catch of turtles. If insufficient depth or anoxic
conditions were encountered « 4mg/ml in 8 to 12 feet of water), nets were set
shallower. Shorelines with more than a 45° slope were avoided to keep hoop nets from
rolling to deeper water. Tandem hoop nets were fished for 72 h before being retrieved.
All channel catfish collected were measured (mm.TL), and 20 fish from each 20 mm
length group were weighed and retained for age determination by lapilli (Long and
Stewart 2010) otoliths. All other fish were released back into the lakes. Catches were
recorded separately by each net but were pooled by series to express CPUE as number
of channel catfish per series.
CPUE and mean length were calculated at each lake and compared among lakes. Size
structure at each lake was analyzed by length frequency histograms and PSDs. In
addition relative weights (Wr) were determined for the overall population as well as
specific length groups. Mean length at age was determined from age analysis oflapilli
otoliths using methods described by Mauck and Boxrucker (2005). Since some lakes
were stocked with fish from one cohort in different years, Von Bertalanffy growth
curves were used to estimate length at age in the respective year. Total annual
mortality was determined from catch curve data.
Angler survey
In order to assess channel catfish angler catch rates and satisfaction, a survey box was
placed in a high traffic area at each lake at the beginning of October 2010. A sign was
attached above each survey box to encourage catfish anglers to complete a survey
(Figure 1). Survey cards briefly explained the purpose of the survey and asked party
size, hours spent fishing, number of channel catfish caught and kept, length of fish
caught and kept, and satisfaction of number and length of fish caught (Figure 2).
Anglers were given the choice to either drop the completed survey in the box or mail it
in with prepaid postage.
The total number of anglers, hours of angling effort, and number of fish
caught/kept were summarized for each lake. The number of angling hours required per
fish, mean length of fish caught/kept, percentage of fish caught that was kept, and mean
satisfaction for number and length of fish were also calculated for each lake.
C. Results/Discussion
Population characteristics
Overall, the nine lakes sampled yielded a mean catch rate of 80 fish/series with 3,922
channel catfish being caught from the nine lakes in 2010. Catch rates varied substantially
among lakes. Raymond Gary and Ozzie Cobb produced the lowest CPUE (5 fish/series,
n=54 and 18 fish/series, n=90, respectively) while Burtschi and Watonga had the highest
CPUE (172 fish/series, n=I,372, and 135 fish/series, n=676, respectively). The other
lakes yielded catch rates between 51 and 103 fish/series (Table 1). Mean length among
lakes ranged from 374 mm at American Horse to 293 mm at Burtschi (Table 1).
Growth seemed to be negatively correlated with relative abundance suggesting density
dependence. Results from length at age data suggest channel catfish from American
Horse and Raymond Gary had the highest mean length at age while channel catfish from
Evan Chambers and Burtschi grew slowest (Table 2). Fish stocked in Dahlgren, Nanih
Waiya, and Ozzie Cobb, reached 305 mm within one year after being stocked. Lakes
American Horse and Raymond Gary were similar in length after the first year of growth
at 301 and 299 mm respectively. Channel catfish at lakes Burtschi, Hall, and Watonga
did not reach 305 mm until the third year after being stocked, while it took fish at Evan
Chambers five years to reach this size. Catch curve analysis from length at age data
indicated mortality was moderately high and similar among lakes (44%-59%) except at
Chambers where it was 34% (Table 1).
Length frequencies and low PSDs further indicated a proportionally large number of
small individuals in lakes Burtschi, Chambers, Hall, and Watonga (Figure 3, Table2). In
addition, Dahlgren and Nanih Waiya also had a low proportion of quality size individual
as indicated by PSDs (Table 4). Low PSDs are often an indication of slow growth (Guy
and Brown 2007). Channel catfish populations at American Horse, Ozzie Cobb and
Raymond Gary had higher PSDs and resembled more of a balanced population.
Relative weights ranged from 93 at Burtschi to 79 at Raymond Gary (Table 3). Body
condition did not seem to be associated with growth as Raymond Gary, Ozzie Cobb,
Dahlgren, and Nanih Waiya. All had substantially lower relative weights than the other
populations. At the time of sampling, these four lakes were all stratified at <3 m with no
dissolved oxygen in the hypolimnium while the other lakes supported dissolved oxygen
at depths >5 m. Thermal stress and reduced dissolved oxygen may have exacerbated the
poor body condition of channel catfish in these lakes.
Angler survey
Twenty-nine angler surveys were received between October and December 2009. Lake
Burtschi had the highest number of respondents (n=8) while no surveys were received
from Lake Ozzie Cobb. The mean catch rate (no./hour) channel catfish was lowest at
Watonga (0.014). The other lakes were substantially higher ranging from (0.125 at Nanih
Waiya to (0.667) at Raymond Gary and Burtschi. Mean length offish caught by anglers
at each lake was similar to mean length obtained from tandem hoop net samples. Anglers
from American Horse, Nanih Waiya, and Raymond Gary kept an average of>67% of the
fish they caught while all other lakes kept <20% of fish caught. Satisfaction for number
offish caught and length offish was highest at Lake Nanih Waiya and lowest at Lake
Watonga.
D. Conclusions/Recommendations
• Relative abundance, as measured by tandem hoop nets, was highly variable
among lakes. Growth seemed to be negatively correlated with relative abundance
suggesting density dependence.
• Length frequencies and low PSDs further indicated slow growth at Lakes
Burtschi, Evan Chambers, Hall, and Watonga.
• Relative weights (Wr) were not associated with growth. Environmental
conditions such as temperature and dissolved oxygen may be related to body
condition.
• The angler survey should continue through September 2011. If angler survey
returns continue to be low, interviews will be conducted to increase the number of
respondents.
• All nine lakes should be sampled in 2011 to determine catch rates, length
frequencies and body condition.
• Lakes with slow growth and high relative abundance (Burts chi, Evan Chambers,
Hall, and Watonga) should be stocked with 13 fish/ha while lakes with fast
growth rates and moderate abundance (American Horse, Dahlgren, and Nanih
Waiya) should continue to be stocked with 99 fishlha. Stocking rates at Raymond
Gary and Ozzie Cobb should be increased to 150 fish/ha as they exhibited fast
growth but had low relative abundance.
III. Significant Deviations: None
Preparedby: _
Chas Patterson, Senior Fisheries Biologist
Date:
Approved by:_---'-"0IY<!i?:;c_-=-=--------'------'Cb_'-----=~=___J__ _
Fisheries Administration
Oklahoma Department .f Wildlife Conservation -:r' ,~ John Stafford
Federal Aid Coordinator
Oklahoma Department of Wildlife Conservation
IV. Literature Cited
U.S. Department of the Interior, Fish and Wildlife Service, and U.S. Department of
Commerce, U.S. Census Bureau. 2006. 2006 National Survey of Fishing,
Hunting, and Wildlife-Associated Recreation.
Buckmeier, D. L., and J. Warner. 2009. Capture efficiency and size structure of channel
catfish and blue catfish sampling gears. North American Journal of Fisheries
Management. 29 :404-416
Flamming, M. K., and R. Schultz. 2007. Evaluation of hoop-net size and bait selection
for sampling channel catfish in Iowa impoundments. North American Journal of
Fisheries Management. 14:781-789
Kline, D., B. DeCook, L. Mitzner, J. Pitlo, J. Schwartz, G. Sobotka, and L. Squibb. 1995.
Standard gear and techniques for fisheries surveys in Iowa. Des Moines, Iowa
Long, J. M. and D. Stewart. 2010. Verification of otolith identity used by fisheries
scientists for aging channel catfish. Transactions of the American Fisheries
Society. 139: 1775-1779
Mauck, P. and J. Boxrucker. 2005. Abundance, growth, and mortality of the Lake
Texoma blue catfish population: implications for management. Proceedings of
the Annual Conference of the Southeastern Association ofFish and Wildlife
Agencies. 58:57-65
Michaletz, P. H., and K. Sullivan. 2002. Sampling channel catfish with tandem hoop
nets in small impoundments. North American Journal of Fisheries Management.
22:870-878
Michaletz, P. H. 2009. Variable responses of channel catfish populations to stocking
rate: density dependent and lake productivity effects. North American Journal of
Fisheries Management. 29:177-188
Santucci, V. J., D. Wahl, and T. Storck. 1994. Growth, mortality, harvest, and cost-effectiveness
of stocked channel catfish in a small impoundment. North
American Journal of Fisheries Management. 14:781-789
Table 1. Sample size, CPUE (fish/series), mean length (mm), annual mortality, and PSDs
of channel catfish from nine Oklahoma small impoundments in July and August
2010.
Lake SaSmizpele CPUE lMenegatnh Annual PSD
(mm)
mortality
American
Horse 257 51 374 46 19
Burtschi 1372 172 275 59 2
Evan
Chambers 498 100 293 34 6
Dahlgren 244 81 352 45 5
Hall 310 103 302 54 3
Nanih Waiya 426 85 333 55 6
Ozzie Cobb 90 18 367 44 28
Raymond
Gary 54 5 348 58 33
Watonga 676 135 318 47 6
Table 2. Mean lengthatage (mm) of channel catfishfrom nine smallimpoundments acrossOklahoma in2010. Lengths noted with *
were derivedfrom Von Bertalanffygrowth curves.
Year American Evan
stocked Horse Burtschi Chambers Dahlgren Hall
2009 301 262 275 330 281
2008 401* 275* 277* 336* 304*
2007 462* 309* 299* 378* 335*
2006 509 273 279 349 381
2005 582 396 350 506 380
2004 660 421 337 490 480
2003 320 326
2001 505 630 371
2000 450 439
1999 410
1998 408
1997 387
1996 430
1995 440
1994
1993 350
Naniah
Waiya
Ozzie
Cobb
Raymod
Gary Watonga
313
324
368
449*
498*
319
343
429
446*
473*
454
299
393
461
532*
601*
392
265
290*
325*
352
392
432
520
576
570 580
Table 3. Relative weights (W;.) of channel catfish from nine small impoundments in Oklahoma in July and August 2010.
Mean Relative Weights (WrJ
Sub- Stock Quality Preferred
stock (2:281 (~411 to (~611 to s Memorable
(:::;280 to s 410 :::;610mm 710mm (~ 711 to :::;
Lake Overall Wr mmTL) mmTL) TL) TL) 910 mm TL)
American
Horse 90 117 87 88 91 94
Burtschi 93 98 86 89 104
Dahlgren 80 83 79 80
Evan
Chambers 88 92 86 84
Hall 90 97 86 83
Nanih Waiya 83 90 82 84 72
Ozzie Cobb 82 95 82 80
Raymond
Gary 79 80 78 82
Watonga 87 99 84 80
Table 4. Summary of angler survey responses administered at nine Oklahoma small impoundments starting in October 2010.
Satisfaction was ranked on a scale from 1 to 5 with 1 being dissatisfied and 5 being satisfied.
Nanih Ozzie
American Burtschi Chambers Dahlgren Hall Wayia Cobb Raymond Watonga
Horse n=4 n=8 n=4 n=3 n=l n=l n=O Gary n=4 n=4
Total # of anglers 9 17 7 9 2 2 4 14
Total angling effort (hrs) 91.2 52.5 39.0 17.5 8.0 18.5 72.0
Total # fish caught 44 35 6 3 0 1 12 1
Angling hours/fish 2.1 1.5 6.5 5.8 8.0 1.5 72.0
Total # fish kept 30 6 1 0 0 1 8
% fish kept that were caught 68 17 17 0 0 100 67 0
Mean length of fish caught
(in) 13-16 8-12 8-12 13-16 13-16 13-16 8-12
Mean length of fish kept (in) 13-16 8-12 8-12 13-16 13-16 13-16 8-12
Mean satisfaction of #
caught 3.3 2.6 1.8 4.0 5.0 3.5 1.0
Mean satisfaction of length 1.8 1.9 1.7 3.0 5.0 3.5 1.0
Figure 1. Sign specifications used above channel catfish survey box at nine small impoundments in Oklahoma starting in October
2010.
f------------- 24·' ----------------j ~---------------.--"'\ ______TTENTION:
,..--- -atfish Anglers
LEASE FILL OUT SURVEY
below
Figure 4. Channel catfish survey administered at nine small impoundments across
Oklahoma starting in October 2010.
Channel Catfish Survey
The Oklahoma Department of Wildlife Conservation is evaluating the channel
catfish stocking program on Department lakes. Different stocking rates are being
tested to determine which best meets the needs of both anglers and fish
populations
Channel catfish anglers, we need your help! After you're done fishing today,
please fill out the attached survey and drop it in the box (or in the mail at your
convenience). We'd like you to complete this channel catflsh survey each time
you fish here during the next year '
We appreciate your support Thank you for taking tile time to complete a channel
catfish survey!
Sincerely,
Chas Patterson
Fisheries Biologist
(405) 325-7288
Date: . _ 2. Your home zip code: _
3. Did you fish for channel catfish today? 0 Yes 0 No ~ If no, survey is complete!
4. Number of people fishing for channel catfish in your group today:
5. What time did your group.
a) ..start fishing for catfish today? 0 a.rn. 0 p.rn
b) . finish fishing for catfish today? 0 a.rn 0 p.rn.
6. How many channel catfish did your group ..
a) ... catch today? (If zero, skip to question 8)
b) . keep today?
7 What was the average lengtll of channel catfish your group.
a) caught today? 0 8-12" 0 '13-'16" 0 17-20"
b) kept today? 0 8-12" 0 "13-'16" 0 '17-20"
020"+
020"+ o rva
8. How satisfied are you with ..
Number of channel catfish caught:
Length of channel catfish caught:
Dissatisfied
1
1
2
2
3
3
4
4
Satisfied
5
5
9. Comments: _
Figure 3. Length frequencies from nine Oklahoma small impoundments in 2010.
American Horse
20%
18%
16%
14%
.•..12% c:
~ 10%
~~~ .''''.luultultllll'J~.._...J..l~
140 170 220 250 280 310 340 370 400 430 460 530 560 600 630 730
lenght (mm)
16%
14%
12%
.•.. 10% c:
Q1): 8% Q) c.. 6%
4%
2%
0%
Burtschi
~ r' I 1 I r I r ~Tl 1111"
140 180 220 260 300 340 380 420 460 500 540 580 620 660 700
lenght (mm)
Dahlgren
20%
18%
16%
14%
.•..12% c:
~ 10%
~ 8% j
6% ;
4% 1
2%
0% '"
20%
18%
16%
14%
.c•.:. 12%
Q) o 10%
cQ.;. 8%
6%
4%
2%
0% ;-. ,.. ,..,.,
Evan Chambers
»l,.,a,.~~ ,1 '1'" - ("'1 1 r I' , 1 1'1 t r I r 11-, 1 1
140 180 220 260 300 340 380 420 460 500 540 580 620 660 700
lenght (m m)
140 180 220 260 300 340 380 420 460 500 540 580 620 660 700
lenght(mm)
Figure 3 continued. Length frequencies from nine Oklahoma small impoundments in 2010.
Hall Nanih Waiya
20%
18% i
16%
14%
i:: 12% !
~ 10%
~ 8%
6%
4%
2% !
0% I ,.,
20%
18%
16%
14%
•c::.•12%
~ 10%
Qc;. 8%
6%
4%
2%
0% ,IJ.,1. '#,-,I,.,..,.., '" , , ,.,..,.,..,,-, ,.,-, , , " , .J1J~I~d_~~~ .d
140 180 220 260 300 340 380 420 460 500 540 580 620 660 700
lenght (mm)
140 180 220 260 300 340 380 420 460 500 540 580 620 660 700
lenght (mm)
Ozzie Cobb
14% 12%
12% i • 10%
•.. 10% I I. •.. 8% c:: 8% 1 cQ:): Qo) II ~ 6% Q) •.. Qc). 6% c. 4%
4%
lilllJd . .JL
2% ,,,,,,,,,ftw, 2% 0% ,-- . 0% I
140 180 220 260 300 340 380 420 460 500 540 580 620 660 700 140
Raym ond Gary
J~.~L! lit I I I" rl 1,-' 11 J
lenght(mm)
180 220 260 300 340 380 420 460 500 540 580 620 660 700
lenght(mm)
Figure 3 continued. Length frequencies from nine Oklahoma small impoundments in 2010.
20%
18%
16%
14%
•.• 12%
c::
~ 10%
~ 8%
6%
4%
2%
0%
Watonga
140 180 220 260 300 340 380 420 460 500 540 580 620 660 700
lenght (mm)