LOUISIANA DEPARTMENT OF
WILDLIFE & FISHERIES
OFFICE OF FISHERIES
INLAND FISHERIES SECTION
PART VI -B
WATERBODY MANAGEMENT PLAN SERIES
TOLEDO BEND RESERVOIR
WATERBODY EVALUATION &
RECOMMENDATIONS
2
CHRONOLOGY
May 2010 - Prepared by
Ricky Yeldell, Biologist Manager, Toledo Bend Research Station
November 2013– Updated by
Ricky Yeldell, Biologist Manager, Toledo Bend Research Station
November 2015 – Updated by
Jason J. Brancamp, Biologist Manager, District 10
October 2017 – Updated by
Villis Dowden, Biologist Manager, District 10
October 2019 – Updated by
Villis Dowden, Biologist Manager, District 10
Brittainey Thaxton, Biologist, District 10
Will Romero, Biologist, District 10
October 2021 – Updated by
Villis Dowden, Biologist Manager, District 10
Brittainey Thaxton, Biologist Supervisor, District 10
Will Romero, Biologist, District 10
3
TABLE OF CONTENTS
WATERBODY EVALUATION .................................................................................................. 4
STRATEGY STATEMENT ....................................................................................................................................... 4
Recreational........................................................................................................................................................... 4
Commercial ........................................................................................................................................................... 4
Species of Special Concern .................................................................................................................................... 4
EXISTING REGULATIONS ..................................................................................................................................... 4
Recreational........................................................................................................................................................... 4
Scuba Diving Season ............................................................................................................................................. 4
Commercial Fishing Regulations .......................................................................................................................... 5
SPECIES EVALUATION ........................................................................................................................................... 5
Recreational Species .............................................................................................................................................. 5
Commercial Species ............................................................................................................................................ 23
Species of Special Concern .................................................................................................................................. 28
HABITAT EVALUATION ....................................................................................................................................... 29
Aquatic Vegetation .............................................................................................................................................. 29
Durable Natural Structure ................................................................................................................................... 32
Substrate .............................................................................................................................................................. 32
Artificial Structure ............................................................................................................................................... 32
CONDITION IMBALANCE / PROBLEM ............................................................................................................. 33
Federal Energy Regulatory Commission (FERC) Project Relicensing ............................................................... 33
Invasive Aquatic Vegetation ................................................................................................................................ 33
CORRECTIVE ACTION NEEDED ........................................................................................................................ 34
RECOMMENDATIONS ............................................................................................................ 34
LITERATURE CITED ............................................................................................................... 37
APPENDIX I ................................................................................................................................ 38
APPENDIX II .............................................................................................................................. 40
APPENDIX III ............................................................................................................................. 41
4
WATERBODY EVALUATION
STRATEGY STATEMENT
Recreational
Largemouth Bass (LMB) are managed to provide the opportunity to catch fish of greater than
average size. Sunfish, catfish, and crappie are managed to provide a sustainable population
while providing anglers the opportunity to catch or harvest numbers of fish.
Commercial
Catfish, buffalo, Freshwater Drum and bowfin are managed to provide sustainable populations.
Species of Special Concern
Paddlefish Polyodon spathula are managed to provide the greatest opportunity to restore the
population to a viable fishery.
The Sabine Shiner Notropis sabinae is a species of interest and occurs throughout the reservoir.
Suckermouth Minnows Phenacobius mirabilis occur in this waterbody and are listed as a species
of conservation interest.
EXISTING REGULATIONS
Recreational
Current Texas regulations may be viewed at the Texas Parks & Wildlife website:
http://www.tpwd.state.tx.us/publications/annual/fish/.
Current Louisiana recreational fishing regulations may be viewed at the link below:
http://www.wlf.louisiana.gov/regulations
Scuba Diving Season
A special season for scuba diving (spear fishing) for Largemouth Bass, crappie, and Lepomis
species resulted from the passage of Act No. 323 of 1984 and was initiated on July 3, 1985. This
season was in effect only for Toledo Bend Reservoir south of Highway 6 on the Louisiana side
of the reservoir. The season ran from sunrise on June 1
st
to sunset the last day of September. A
special permit was required of participants, and a monthly report had to be filed in order to keep
the permit. Limits were five Largemouth Bass, 25 crappie, and 50 Lepomis spp. (bream). In
addition to the special permit, participants could not have other types of fishing gear in the boat
at the time and were required to have a valid recreational fishing license.
The special scuba diving season on Toledo Bend was amended by the LWFC in May 1989
(Appendix I) to only allow the take of crappie and Lepomis spp. (sunfish or bream). In January
2013, the Louisiana Wildlife and Fisheries Commission abolished the special scuba diving season
on Toledo Bend. Therefore, the take of any freshwater gamefish with scuba diving equipment is
not allowed. Take of catfish or any non-gamefish with scuba diving equipment is allowed on the
Louisiana side of the reservoir.
5
Commercial Fishing Regulations
Texas commercial regulations may be viewed at the Texas Parks & Wildlife website:
http://www.tpwd.state.tx.us/publications/annual/fish/.
While current Louisiana commercial fishing regulations may be viewed at the link below:
http://www.wlf.louisiana.gov/regulations
SPECIES EVALUATION
Recreational Species
Largemouth Bass Recreational Angler Surveys
The current daily Largemouth Bass limit for Toledo Bend, Texas and Louisiana is eight bass, 14
inches minimum length. Creel survey data obtained during the ramp access creel from January
1, 2019 to December 31, 2019 indicate that 75% of all angling efforts on the waterbody were
directed toward black bass. Anglers surveyed on the Louisiana side of the reservoir caught 0.56
Largemouth Bass per hour of angling effort during the survey period. A total of 397 Largemouth
Bass anglers were interviewed during 72 creel days with 6 creels days per month. Retention rate
of legal sized Largemouth Bass >14” caught by anglers was 16% of the total catch within the
creel period.
Largemouth Bass Electrofishing samples
Electrofishing samples for Largemouth Bass are gathered in the fall (September-November) or
spring (March-May). Each of the last six spring sample periods were taken during two separate
three-year waterbody and population assessments, 2010-2012 and 2018-2020 respectively. The
Louisiana side of the reservoir is divided into three zones for electrofishing with eight stations
within the northern zone, 12 stations in the middle zone and ten stations located in the southern
zone, for a total of 30 electrofishing stations each sample period. Zones located north to south
include Float-Road Boat Pass to Converse Boat Lane, Converse Boat Lane to Pendleton Bridge,
and Pendleton Bridge to Toledo Bend Dam. Sample times each fall or spring are 15 minutes per
station for a total of 7.5 hours of sample time for the entire fall or spring period. Deviations from
sample station areas have occurred during low water in the fall, but seldom during the spring
when water levels are generally closer to pool and more stable. Electrofishing gear for black bass
is most effective in 6 feet of water or less.
Largemouth Bass Relative Abundance and Relative Weight
Spring electrofishing data from Toledo Bend Reservoir reveals relatively constant Catch Per Unit
Effort (CPUE, number per hour) values for LMB over time. Relative abundances of both quality-
size (> 12 in total length) and preferred-size (≥ 15 in. total length) Largemouth Bass were
consistent during the 2010-2012 assessment. CPUE increased slightly in 2018,much more so in
2019 and similar values in 2020 as 2010 (Figure 1). Both quality and preferred size classes during
2019 showed the highest numbers recorded during the last eight sample periods, with 114 quality
LMB per hour and 49 preferred LMB per hour. The CPUE values for memorable size LMB ( ≥
20 in. total length) for years 2008, 2009, 2010, 2011, 2012, 2018, 2019 and 2020 were 0.5, 0.3,
0.7, 0.3, 1.0, 2.1,2.0 and 0.7 LMB per hour, respectively.
6
Figure 1. Spring electrofishing CPUE (± SE) for LMB of stock-, quality-,
preferred-, and memorable- size fish sampled in years 2008-2020.
Normally, CPUE of Age-1 Largemouth Bass is calculated to assess recruitment of
young of the year fish from the previous year. With the last two assessments being
six years apart, a single Age-Length Key along with Mean Annual Pool Stage to
backlog recruitment prior to the 2018-2020 and previous sample periods was
assigned. Daily elevation data and yearly mean pool stage were pooled from
USGS 08025350. The following CPUE by Age Key (Age-5) represents that cohort
of older individuals sampled in 2019 (Figure 2). Mean pool stage was close to 2
feet below 172’ MSL throughout 2014, 3-Years following the historic low mean
pool stage of 162.5 in 2011. Both 2013 and 2014 each had the highest number of
Age-5 cohorts (green dots on the Figure 2) sampled in 2018 and 2019, likely as a
result of good spawning cover in 2013 and 2014 following such a long, low water
period where close to 1/3 of the reservoir was exposed to aerobic conditions for
over 12 months. Similar increases in Age-5 cohorts can be observed following
previous long low water periods in 1996 and 2006.
Figure 2. Age-5 cohort Largemouth Bass CPUE and mean annual pool stage
from 2012 earlier and 2018-2020.
0
50
100
150
200
250
300
350
400
2008 2009 2010 2011 2012 2018 2019 2020
Catch/Hr
Year
Spring CPUE Stock (equal or over 8")
Spring CPUE Quality (equal or over 12")
Spring CPUE Preferred (equal or over 15")
Spring CPUE Memorable Memorable (equal or over 20")
0
1
2
3
4
5
6
7
8
9
10
11
162
163
164
165
166
167
168
169
170
171
Relative Cohort CPUE (Age
-5)
Mean Annual Pool Stage
Year
Pool Stage
CPUE
7
Proportional stock density (PSD) (Anderson 1976) and relative stock density
(RSD) (Gablehouse 1984) are indices used to numerically describe length
distribution (frequency) data. These indices can provide not only an understanding
of the size structure of the bass population for biologists, but can also help anglers
form expectations as to what type of angling experience they may expect from a
given waterbody. Proportional stock density compares the number of fish of
quality size (greater than 12 inches for Largemouth Bass) to the number of bass of
stock size (8 inches in length). The formula for Largemouth Bass PSD is given as:
Number of bass>12 inches
PSD12 = ———————— x100
Number of bass>8 inches
Stock size fish are the fish in a population that would be considered to be of
“catchable” size. The PSD is expressed as a percentage. A fish population with a
high PSD consists mainly of larger individuals, whereas a population with a low
PSD consists mainly of smaller fish. For example, the chart below indicates a PSD
of 59 for Largemouth Bass at Toledo Bend LA, in 2020 (Figure 3). The number
indicates that 59% of the bass stock (fish over 8 inches) in the sample were at
least 12 inches or longer.
For more detailed discussion of the proportion of sizes greater than 12 inches, we
may look at relative stock density (RSD). The RSD may be used to discuss the
proportions of the “catchable” fish population that belong to any length group of
interest. Typically, RSD values are used to discuss three size groups of
Largemouth Bass. Those groups are preferred (≥15”), memorable (≥20”) and
trophy (≥25”). In the case of Toledo Bend LA, the Largemouth Bass RSD values
for preferred, memorable and trophy sizes during 2020 were 22, 1 and 0,
respectively. These values suggest that of the fish sampled, 22% of the “catchable”
size Largemouth Bass were over 15 inches but less than 20 inches in length, while
1% of fish were recorded that were longer than 20 inches. Consequently, 77% of
the “catchable” Largemouth Bass sampled were between 8 and 11.99 inches. RSD
of Largemouth Bass between 15 and 20-inches fell 6 % in 2020 from 2019 values.
The formula for RSD (preferred) is given as:
Number of bass>15 inches
RSD15 (preferred) = ———————————— x100
Number of bass>8 inches
8
Figure 3. The relative stock densities and proportional stock densities of Largemouth Bass
collected during spring electrofishing sampling at Toledo Bend, Louisiana, from 2009-2020.
Median relative weights for different size groups of LMB sampled from Toledo Bend Reservoir
during the fall in years 2009 – 2010 are stock size – 103.3, quality size – 102, preferred size –
104.3, and memorable size – 97.7. Relative weight data for Largemouth Bass are depicted in
Figure 4.
Figure 4. The relative weights of Largemouth Bass by stock-, quality- and preferred-
size fish sampled at Toledo Bend Reservoir, Louisiana, from fall electrofishing 2002
– 2010.
85
90
95
100
105
110
115
120
125
2002 2003 2004 2005 2006 2007 2008 2009 2010
Relative Weight
Year
Stock (equal or over 8") Quality (equal or over 12") Preferred (equal or over 15")
9
Relative weights for LMB collected in spring 2020 are slightly higher for stock, quality and
preferred size LMB than those found in 2019 sampling efforts. Relative weights in 2020 were
also slightly higher than median Wr from 2010-2019 for stock, quality and preferred size groups
indicating stable body condition and weights for all size groups of LMB (Table 1).
Table 1. Largemouth Bass relative weights for spring 2020 electrofishing samples compared
to average Largemouth Bass relative weights for samples collected from 2010 – 2019.
LMB Size
Group
2010-2019 Median
Wr
2020 Wr
2020 Wr vs. 2010-2019
Median Wr
Stock
98.1
98.8
+0.7%
Quality
99.2
99.6
+0.4%
Preferred
98.2
99.2
+1.0%
Memorable
103.5
103.5
0.0%
Seine sampling results from Toledo Bend, although quite variable from year to year, show a mean
catch of 5.7 young-of-the-year (YOY) Largemouth Bass per seine haul during the period from
1990 -2010. Summer seine samples have not been utilized as frequently since 2010 due to Age-
1 CPUE LMB values that also detail year to year recruitment using electrofishing equipment.
Values for LMB caught per seine sample appear in Figure 5.
Figure 5. Catch per seine haul of YOY Largemouth Bass in Toledo Bend Reservoir,
Louisiana, from 1990-2010.
Largemouth Bass Age, Growth, and Mortality
From 2010 – 2012 and 2018 - 2020, LDWF conducted two intensive studies of the Toledo Bend
Reservoir LMB population. Population dynamics including relative abundance, spawning
success, growth, body condition, mortality, and longevity were measured. Toledo Bend anglers
were also surveyed to determine their collective influence on the LMB population. An angler
opinion survey was included to provide information and angler feedback concerning current
Largemouth Bass regulations of eight LMB daily and >14-in length compared more restrictive or
limited daily creel limits.
Length and weight measurements were recorded for every fish. Ear bones (called otoliths) were
removed from 32% of the sampled fish during the 2010 -2012 sample and 41% of the sample
during the 2018 – 2020 study for age and growth analyses. Annual growth rings on the otoliths
provide an accurate measurement of fish age. Size and age for all of the sampled fish were
combined to generate estimates of average growth rate and longevity. Angler surveys were
0
2
4
6
8
10
12
Number Caught Per Sample
Year
10
conducted during the sample period in 2019 to document fishing effort, angler catch rate and
harvest rates. A separate opinion survey for bass anglers was conducted with willing anglers
regarding the current Largemouth Bass daily limit of eight bass, 14” minimum length.
Figure 6 illustrates that Toledo Bend supports a healthy bass population that includes some large
individuals. Good representation of fish in the 7 to 14-inch range was observed for each year in
2010-2012. Higher numbers of preferred sized LMB within the 15-20-inch range were observed
in the 2018-2020 study, indicating excellent recruitment conditions three to six years earlier. It
is important to note that spring sampling typically does not include fingerling size bass being one
year later than the previous spawning occurrence. The sample size of age-1 LMB was slightly
lower in the 2018-2020 study. However, the recurring presence of age-1 bass indicates successful
reproduction (Figure 7).
Figure 6. Annual length distributions of LMB Catch Per Unit Effort, collected from Toledo
Bend Reservoir, Louisiana, during spring electrofishing surveys in 2010-2012 and 2018-
2020.
Age structure of each electrofishing sample (2010-2012) and (2018-2020) is shown in Figure 7 and
8. The majority of the age 6+ fish were females. While bass up to 11 years old were found in each
study, only a small percentage of Toledo Bend LMB 6 years and older were included in the samples
which is typical with electrofishing gear. Average length at age for Toledo Bend bass during each
separate study is provided in Table 2. A Toledo Bend LMB typically reaches 14” TL within three
years.
11
Figure 7. CPUE for LMB by age class for Toledo Bend Reservoir, Louisiana,
from spring electrofishing results, (2010 - 2012) and (2018 - 2020).
Table 2. Length at age, in inches, for LMB from Toledo Bend Reservoir, LA, 2010 – 2012 and
2018 - 2020.
Growth of LMB is fast through Age-5, but then slowed to only 1.2 inches or less per
year during the 2010-12 study. The 2018-20 study showed slightly faster growth
through Age-4, but slowed considerably to 1/2 inches or less per year for LMB older
than Age-6 (Table 2 and Figure 8). Body condition for Toledo Bend bass can be
described as robust in each study. Good physical condition of bass generally is the
product of an adequate food supply, readily available to predation. One of the more
significant findings is the stable recruitment of Age-1 LMB into the Toledo Bend
population (Figures 7 and 8). Contributing factors include annual water fluctuation,
quality spawning substrate, and adequate cover for fingerlings while water levels are
close to normal Pool 172’ MSL in late spring and summer. CPUE of Age-1 LMB
has varied very little from year to year, and differs from 28-30 bass per hour which
is very stable compared to other waterbodies in Louisiana.
0
10
20
30
40
50
60
70
0 1 2 3 4 5 6 7 8 9 10 11
CPUE
Age (years)
2010-2012
2018-2020
Age
Length (2010-2012)
Length (2018-2020)
0
1.92
0.06
1
7.24
7.50
2
11.19
12.06
3
14.12
14.85
4
16.29
16.56
5
17.89
17.61
6
19.08
18.25
7
19.97
18.65
8
20.62
18.89
9
21.10
19.03
10
21.46
19.13
11
21.73
19.18
12
21.92
19.21
13
22.07
19.24
14
22.18
19.25
15
22.26
19.26
12
Figure 8. Total length at capture by age for 1,444 Toledo Bend Reservoir LMB
(2018-2020).
The rate at which fish die each year is referred to as mortality. Results of the 2010-2012 study
indicate that the total annual mortality rate for Toledo Bend LMB was 64% per year. At that rate,
if you start with 100 age-1 Toledo Bend LMB, only 1.7 fish will remain alive by age 5. Annual
mortality decreased to 49% during the 2018-2020 study. Compared with initial study results, if
you now start with 100 age-1 Toledo Bend LMB, 6.8 fish will remain alive by Age-5. The
differences in CPUE within inch groups between each of the two studies is shown in Figure 9.
Total combined CPUEs were similar (166 vs 157 bass/hour) with larger numbers of 3-11-inch
bass sampled in 2010-2012 compared to larger numbers of 12-21-inch bass sampled in 2018-
2020. With the increased sample size of Age 4-11 LMB, Total mortality (A) decreased 15%
annually during the most recent study.
Figure 9. Catch Per Unit Effort (hour) by inch group for each 3-Year Largemouth Bass
study, Toledo Bend, Louisiana.
0
5
10
15
20
25
0 2 4 6 8 10 12
Total Length (inches)
Age (years)
Observed (n=1,444) Expected
Linf = 19.27
K = 0.49
t0 = -0.01
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0 2 4 6 8 10 12 14 16 18 20 22 24
%Frequency
Inch Group
2010-12
2018-20
13
The results of this study suggest that the Toledo Bend LMB population has a total mortality that
that decreased between 2012 and 2020. The decrease in mortality within legal sized LMB > 14”
also suggest lower fishing mortality. The 2019 creel survey results suggest that Toledo Bend bass
anglers harvest a lower percentage of LMB than they release (16% of legal-size LMB are kept).
Summary of Studies:
Comparing each study, the Toledo Bend Reservoir LMB population has a high maximum age,
moderate growth rate, stable relative weights, a mortality rate that decreased 15%, and a good
annual recruitment of Age-1 fish. The Toledo Bend Reservoir LMB fishery had an 84% voluntary
catch and release rate of legal Largemouth Bass during the 2019 angler creel survey. The Toledo
Bend Reservoir LMB fishery is currently managed with a 14-inch minimum length limit (MLL)
and an eight fish per day harvest limit. Given the dynamics of the Toledo Bend Reservoir LMB
population and fishery, the existing eight LMB at 14 inch MLL size regulation still appears
beneficial. Annual recruitment and growth within all size classes has shown to be highest
following long periods of water levels 3-8 feet below 168’ MSL.
Largemouth Bass Genetics
Toledo Bend has been stocked with Florida-strain Largemouth Bass since 1984. Florida-strain
Largemouth Bass are stocked into the reservoir to incorporate a genetic trait associated with larger
maximum-sized adult fish. Stocking rates are 20 fingerlings per habitat acre. LDWF typically
stocks over 800,000 FLMB fingerlings annually, with over 40,000 habitat acres estimated within
Toledo Bend, LA. As of spring 2021, Toledo Bend Reservoir has been stocked with over 40
million Florida strain Largemouth Bass by both TPWD and the LDWF. Genetic analysis of
Largemouth Bass taken by electrofishing (Table 3) shows that, over time, the percentage of bass
with Florida genetics has ranged from 1.1% (1989) to 48% (1988). Analysis also indicates that
Largemouth Bass with the genetic signature defined as pure Florida has ranged from 1.1 % (1989-
1990) to 18% (2001-2002).
Table 3. Genetic analysis of Largemouth Bass taken by electrofishing from Toledo
Bend Reservoir, Louisiana, 1988 – 2019.
Year
Number
Northern
Florida
Hybrid
Florida Influence
1988
Unknown
52%
11%
37%
48%
1989
89
98.9%
1.1%
0
1.1%
1990
Unknown
84%
2%
14%
16%
1992
Unknown
85%
3%
11%
14%
1994
Unknown
86.4%
7.2%
6.3%
13.5%
1999
148
68%
8%
24%
32%
2000
50
80%
2%
18%
20%
2001
104
65%
18%
20%
38%
2002
118
61%
16%
23%
39%
2003
170
57%
11%
32%
43%
2004
176
76%
9%
15%
24%
2005
170
67.3%
5.8%
26.9%
32.7%
2006
181
68.50%
4.97%
25.41%
30.38%
2007
171
64%
4%
32%
36%
2009
106
71%
3%
26%
29%
2010
383
71%
7%
22%
29%
14
Year
Number
Northern
Florida
Hybrid
Florida Influence
2011
382
74.5%
4%
21.5%
25.5%
2012
364
67.3%
4.1%
28.6%
32.7%
2018
454
62.5%
9.5%
28.0%
37.5%
2019
580
65.5%
7.6%
26.9%
34.5%
2020
437
71.1%
6.0%
22.9%
28.9%
On October 7, 2000, results of a survey conducted by Texas A & M University were published in
Characteristics, Participation Patterns, Attitudes, Management Preferences, Expenditures, and
Economic Impacts of Toledo Bend Reservoir Anglers: Texas and Louisiana. Mail surveys were
sent to 1,045 Toledo Bend anglers who fished between October 1998 and September 1999
(Thailing & Ditton, 2000). The anglers were interviewed as part of the creel survey conducted
by Texas Parks & Wildlife and the Louisiana Department of Wildlife & Fisheries. One angler per
fishing party was randomly selected to receive the mail survey. Anglers were asked questions in
reference to their satisfaction with fishing at Toledo Bend Reservoir. Opinions in reference to
existing and proposed management regulations were solicited as was a description of their trip in
progress, including species targeted and fishing-related expenditures.
Relevant data from these studies are considered to represent public opinion regarding current
fishing regulations at Toledo Bend Reservoir. Anglers were asked whether they supported or
opposed current or proposed fishing regulations at Toledo Bend Reservoir. Responses to the
questions concerning Largemouth Bass regulations appear in Tables 4 and 5 and Figure 10.
Table 4. Angler support or opposition to current Largemouth Bass fishing regulations at
Toledo Bend Reservoir, Louisiana, 2000.
2000 Opinion Survey of All Anglers to 14 inch minimum length limit for Largemouth Bass
(%)
Strongly
Support
Support
Neutral
Oppose
Strongly
Oppose
All Anglers
43.8
36.4
9.5
6.4
3.9
2000 Opinion Survey of Anglers by State to 8-fish daily bag limit for black basses in any
combination (%)
Strongly
Support
Support
Neutral
Oppose
Strongly
Oppose
Louisiana anglers
37.6
39.8
10.5
7.3
4.8
Texas anglers
30.7
36.8
13.2
10.4
8.9
Table 5. Angler opinion survey of current Largemouth Bass regulations during 2019 angler creel
survey January-December 2019 (Do you Support or Oppose the Current Largemouth Bass Daily
Creel Limit of 8 bass, 14 inches minimum length?).
2019 Opinion Survey of Largemouth Bass Anglers for existing Regulations of 8-bass, 14
inches minimum length limit.
Support
Oppose
Neutral
Bass anglers
119
85
37
Of the 85 bass anglers that opposed the current creel regulations, 33 suggested a 5 bass daily
limit, 6 suggested less than 8, 7 suggested a slot limit, 3 suggested 10 and 1 suggested to remove
15
the size limit on Largemouth Bass altogether.
Figure 10. Percentage of angler support or opposition to current Largemouth Bass regulations at
Toledo Bend Reservoir, Louisiana, 2019.
With regard to the Largemouth Bass length limit regulation at the time of the creel survey in 2019,
almost half of the anglers surveyed supported or strongly supported the current regulations, while
more than one-third of the anglers opposed or strongly opposed the current
regulations.Largemouth Bass
Sunfish (Bluegill & Redear)
Creel survey data from 2009-2010 indicate that 8% of angler-hours on the Louisiana side of the
reservoir are directed toward sunfish. Sunfish provide an excellent opportunity to introduce new
anglers to sportfishing due to their generous abundance and their willingness to accept lures.
Sunfish also make up a significant portion (43.7% in 2010) of available forage for predatory sport
fish species. Creel survey data further shows that Louisiana anglers seeking sunfish caught 4.7
sunfish per hour of angling effort during the survey period. The creel survey data in 2019 showed
lower interest toward sunfish, with 1.58% of the 316 total anglers interviewed targeting either
Bluegill or bream.
Crappie
Current daily crappie regulations for Toledo Bend Reservoir, Texas and Louisiana are 25 crappie
with no minimum length limit. The 2010-2011 creel survey data show that crappie anglers
contributed 18% of all angling effort hours on the Louisiana side of the reservoir. Louisiana
crappie anglers caught 2.0 crappies per hour of angling effort during the 2010-2011 creel survey
period. The more recent 2019 creel survey data showed that angling effort was slightly less, with
12% directed toward crappie and 1.61 crappies caught per hour of angling.
Crappie Relative Abundance, Length Distribution and Size Structure Indices
Total gill net sampling catch-per-unit-of-effort (number of fish caught per 100’ of net per net
night) values for 2002-2019 are provided in Figure 11. These values indicate a slightly increasing
population over time. Both crappie species are known to exhibit cyclical population patterns and
such fluctuations are depicted by the gillnetting data.
Support
49%
Do Not Support
35%
Neutral
16%
2019 Toledo Bend Bass Angler Opinion Survey
Concerning LMB Regulations of 8 bass, 14" MLL
16
Figure 11. The CPUE (number caught)/100’/Net Night of White Crappie and Black
Crappie in Toledo Bend Reservoir, Louisiana, by gillnet sampling 2002-2021.
Lead net samples
Lead net surveys are conducted from September through November. Zones located North
to South include Float-Road Boat Pass to Converse Boat Lane, Converse Boat Lane to
Pendleton Bridge and Pendleton Bridge to Toledo Bend Dam. There are a total of 48 net
samples within 24 sets. Two nets are set close to one another for one set. There are six sets
within the Northern zone, ten within the middle zone and eight in the Southern zone. Nets
are usually set on a Thursday and pulled the following Monday for close to 90 hours of
sample time per net. Inch-group compositions of crappie samples taken by lead net sampling
show slight variation from year to year. Over time, crappies collected by lead net sampling
are clustered primarily within the seven-inch to 11-inch range, with the most commonly
captured group being eight- inch. In 2018, there were more crappie captured in the ten inch
– twelve-inch range. In 2019, there was a large group of individuals in the seven – nine-
inch range, and in 2020 there were more crappie within the ten – eleven-inch range than any
other sample period. This indicates favorable spawning conditions for recruitment and
abundant forage availability for growth as each cohort moves through the population
(Figures 12 and 13). Water level and other physical changes do have some effect on CPUE
(hour). For example, in Fall 2009, water levels were above 172’ Pool and CPUE was less
than other periods.
0
0.2
0.4
0.6
0.8
1
1.2
01-02 02-03 03-04 04-05 05-06 06-07 07-08 08-09 09-10 10-11 11-12 18-19 19-20 20-21
Number Caught
Year
White Crappie Black Crappie
17
Figure 12. The CPUE by inch group for crappies collected by lead net sampling at
Toledo Bend Reservoir, Louisiana, in years 2007-2020.
Figure 13. Annual length distributions of Crappie Catch Per Unit Effort, collected from Toledo
Bend Reservoir, Louisiana, during each Fall lead net survey in 2018-2020.
Figure 14 depicts the catch per unit effort (CPUE) for crappies collected in lead net sampling.
CPUE values are given for stock-size, quality-size, preferred-size and memorable-size groups.
As previously stated, crappie populations are known to be cyclical. Changes in crappie
populations typically correspond to strong year classes produced when habitat conditions favor
crappie recruitment. Gillnet and lead net sample data bear out this cyclical pattern with strong
stock size classes moving into both quality and preferred classes the following years.
0
0.05
0.1
0.15
0.2
0.25
4 Inch
5 Inch
6 Inch
7 Inch
8 Inch
9 Inch
10 Inch
11 Inch
12 Inch
13 Inch
14 Inch
15 Inch
Catch Per Hour
Size Group
2009 2010 2011 2018 2019 2020
18
Figure 14. The catch per unit effort of selected crappie size groups caught in Toledo
Bend Reservoir, Louisiana, by lead net sampling 2007 – 2020.
Relative stock density (RSD) and proportional stock density (PSD) values for crappies are also
derived from lead net sampling data. These stock density indices are illustrated in Figure 15.
Figure 15. Structural stock density indices for crappies caught in Toledo Bend
Reservoir, Louisiana, by lead net sampling 2007 – 2020.
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2007 2008 2009 2010 2011 2018 2019 2020
CPUE (Hour)
Year
STOCK > OR = 5" QUALITY > OR = 8" PREFERRED > OR = 10" MEMORABLE >OR = 12"
31
22
45
26
21
45
30
52
0
10
20
30
40
50
60
70
80
90
0
10
20
30
40
50
60
2007 2008 2009 2010 2011 2018 2019 2020
P
S
D
R
S
D
Year
RSD PREFERRED > OR = 10" RSD MEMORABLE >OR = 12"
RSD TROPHY > OR = 15" PSD
19
Upon examination of the CPUE values from both gillnetting and lead netting, it appears that overall
abundance of crappies within the preferred and memorable size categories increased during the
period from 2011 to 2020. A corresponding decrease in PSD and RSD values for crappies from
2009-2011 may be a reflection of a population increase within the lower size groups. The CPUE
for 2018 - 2020 lead net and 2019 -2021 gill net samples also indicates a population that is still
increasing in the preferred- and memorable-size groups with higher stock densities.
Recruitment is measured within the inter annual variability in Age-1 CPUE to index how stable
spawning conditions are. Fall 2019, Age-1 CPUE data was more than 150% greater than the next
highest years of 2020 and 2011. That 2019 Age-1 class is almost 3 years old now in 2021 and
over 11 inches in length (Figure 16).
Figure 16. Mean Age-1 CPUE of crappie within Toledo Bend Reservoir, La to
assess recruitment variability.
Crappie Age, Growth, and Mortality
Crappie species are annually surveyed for age and growth information during each assessment.
Black Crappie and White Crappie length at age for the period 2018 - 2020 is shown in Figure 17.
Since regulations for both species are the same, the data sets were combined to generate age,
growth, and mortality results.
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
2009 2010 2011 2018 2019 2020
Mean Age
-1 CPUE
Year
20
Figure 17. Observed and predicted total length at age of Toledo Bend Reservoir
crappie (2018-2020). Von Bertalanffy parameter estimates and sample sizes (n)
are presented in each graphic.
Age analyses revealed that the Toledo Bend crappie population is primarily comprised of age-1
and age-2 fish (Figure 18). These crappies are subject to relatively moderate annual mortality
rates (Figure 19). Additionally, coefficients of variation between each assessment (CV)
describing the magnitude of variation in mean annual age-1 crappie catches in lead nets indicate
a very stable recruitment of crappies into the population (CV =76%).
Figure 18. The age frequency of all crappies (black and white combined)
collected with lead nets from Toledo Bend Reservoir, Louisiana, 2018 – 2020.
0
1000
2000
3000
4000
5000
6000
0 1 2 3 4 5 6 7 8 9
Total Number Sampled
Age (Years)
n = 7,908
21
Figure 19. Annual mortality and corresponding survival rate of crappie (black and
white) from Toledo Bend Reservoir, Louisiana, derived from lead net samples
collected in 2018 – 2020.
In Figure 19, the un-aged fish in samples were assigned ages from an annual age-length-key.
The catch curve equation and coefficient of determination (R
2
) are presented in graphic. Z =
slope of descending catch curve; S = survival rate; AM = annual mortality (which includes
mortality due to fishing and natural causes); N = sample size. The annual mortality rate of
crappie between each study was very similar, with a rate of 75% in 2009-2011 and 71% in
2018-2020. Much like the results of the 3-Year LMB assessment, the additional older
individuals within the sample decreased annual mortality.
Catfish
Catfish are traditionally known as a commercial species in Louisiana. However, a recreational
catfish fishery does exist statewide. For that reason, catfish are discussed in both the recreational
and commercial sections of this document. Creel data for the Louisiana side of the reservoir show
that during the 2009-2010 survey period, recreational anglers who targeted catfish caught 1.96
catfish per hour of effort. Catfish angler effort comprised 3.28% of all angling effort on the
reservoir. Creel data for catfish anglers in 2019 decreased to 0.63%.
Recreational catfish regulations have undergone several changes at Toledo Bend in recent years.
Current regulations allow for 50 fish daily in aggregate of Channel Catfish and blue catfish, with
no more than five fish over 30 inches in total length. Recreational regulations for Flathead Catfish
are ten fish daily with an eighteen-inch minimum length limit.
LDWF routinely samples Toledo Bend with gillnetting gear to assess catfish, among other
species. Gillnetting data for all three species of catfish from a fifteen-year period are shown in
Figure 20.
22
Figure 20. Catch per unit effort (pounds per net night/100 net) of catfish by species
collected in Toledo Bend Reservoir, Louisiana, by gillnet sampling 1997 – 2021.
Table 4 compares the most recent gillnetting CPUE (Pounds) for the major catfish species found
in the reservoir to the mean CPUE (Pounds) values for the last ten sampling periods.
Table 4. Gillnetting CPUE for three catfish species collected at Toledo Bend Reservoir, Louisiana,
from 2002 – 2021
Species
Mean CPUE 2002-
2021
CPUE 2020-2021
2020-2021 CPUE
VS
Mean CPUE 2002-
2021
Channel Catfish
0.06
0.46
+648%
Blue Catfish
4.33
5.55
_+28%
Flathead Catfish
0.79
0.39
-51%
Forage
Forage fish are those that are available for use as food by predatory fishes. In general, all
individuals up to six inches in length are considered forage fish. Fall electrofishing community
assemblage samples from 2001 through 2010 show that the reservoir yields an average of 68.5
pounds of forage per hour. Figure 21 depicts the percentage of total forage poundage for each of
the major forage species collected during spring electrofishing sampling in 2019.
0
1
2
3
4
5
6
7
8
9
CPUE (Pounds)
Year
Channel Catfish Blue Catfish Flathead Catfish
23
Figure 21. Percentage by pounds of forage species collected by electrofishing
on Toledo Bend Reservoir, Louisiana, in year 2019.
Commercial Species
Data gathered by LDWF during standardized gillnet sampling is presented in the following
graphs. Standardized sampling involves the use of 100 yards each of 2.5-inch, 3-inch, 3.5-inch
and 4-inch monofilament gill nets at each sampling station.
Carp
While Common Carp (Cyprinus carpio) are not subject to species specific management, they are
monitored as they occur in standardized sampling efforts directed toward other species. Figure 22
depicts total CPUE of common carp collected during gillnet sampling at Toledo Bend Reservoir.
Figure 22. Total catch per unit effort (pounds per net night) of common carp
taken by gillnet sampling in Toledo Bend Reservoir, Louisiana, from 2002 -
2021.
0
2
4
6
8
10
12
14
02-03 03-04 04-05 05-06 06-07 07-08 08-09 09-10 10-11 11-12 18-19 19-20 20-21
CPUE (POUNDS)
Year
Carp Total CPUE (Pounds)/100'/Net Night
24
Catfish
All catfish species are managed to provide a sustainable population. Although the three major
catfish species (Channel Catfish Ictalurus punctatus, Blue Catfish Ictalurus furcatus, and
Flathead Catfish Pylodictis olivaris) exhibit some fluctuations in population numbers annually,
these fishes are certainly being sustained within the waterbody. Data from standardized gillnet
sampling relative to these species is presented in Figures 23-21.
Figure 23. Total CPUE (pounds per net night/per 100 ft. net) of Channel Catfish
taken by gillnet sampling in Toledo Bend Reservoir, Louisiana, from 2002 - 2021.
While the CPUE value for Channel Catfish collected by gill net sampling remains small,
the species’ frequency remains fairly consistent during gillnet sampling at this reservoir. It
is understood that large specimens of Channel Catfish are not common at Toledo Bend
Reservoir. The low CPUE for gillnet sampling from 2002 through 2019 is likely due to
gear bias against smaller specimens. The 2020-2021 gill net efforts did produce larger
individuals that were able to stay entangled within that gear type and were the largest
sample size in 18 years. Figure 23 depicts the total CPUE of Channel Catfish during gillnet
sampling at Toledo Bend Reservoir.
Figure 24. Total CPUE (pounds per net night/100 ft. net) of blue catfish taken
by gillnet sampling in Toledo Bend Reservoir, Louisiana, from 2002 - 2021.
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
02-03 03-04 04-05 05-06 06-07 07-08 08-09 09-10 10-11 11-12 18-19 19-20 20-21
CPUE (POUNDS)
Year
Channel Catfish
0
1
2
3
4
5
6
7
8
9
02-03 03-04 04-05 05-06 06-07 07-08 08-09 09-10 10-11 11-12 18-19 19-20 20-21
CPUE (POUNDS)
Year
Blue Catfish
25
Gillnetting CPUE indicates that Blue Catfish increased in abundance from 2003-2010, and have
remained stable at Toledo Bend Reservoir. Blue Catfish are the most commonly collected catfish
species in LDWF samples. Figure 24 depicts the total CPUE of Blue catfish during gillnet
sampling at Toledo Bend Reservoir.
Figure 25. Total CPUE (pounds per net night/100 ft. net) of Flathead Catfish taken
by gillnet sampling in Toledo Bend Reservoir, Louisiana, from 2002 - 2021.
Flathead Catfish increased in abundance through 2012, with pounds per net hour in 2021
similar to 2009. CPUE within other gear types such as lead nets is also stable, and there are
no concerns with the population. Figure 25 depicts the total CPUE of Flathead Catfish
during gillnet sampling at Toledo Bend Reservoir.
Freshwater Drum
Freshwater Drum Aplodinotus grunniens has sustained a population in the reservoir for many
years. Related data derived from gillnet sampling at Toledo Bend Reservoir is presented in Figure
26.
Figure 26. Total CPUE (number per net night and pounds per net night) of freshwater
drum taken by gillnet sampling in Toledo Bend Reservoir, Louisiana, from 2002 - 2021.
0
0.2
0.4
0.6
0.8
1
1.2
02-03 03-04 04-05 05-06 06-07 07-08 08-09 09-10 10-11 11-12 18-19 19-20 20-21
CPUE (POUNDS)
Year
Flathead Catfish
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
02-03 03-04 04-05 05-06 06-07 07-08 08-09 09-10 10-11 11-12 18-19 19-20 20-21
CPUE (POUNDS)
Year
Freshwater Drum Total CPUE (Pounds)/100'/Net Night
26
Gillnetting data for Freshwater Drum indicate a healthy population within the reservoir. Peaks in
the pounds per net night data likely represent the presence of older fish with higher individual
weights. Figure 26 depicts the total CPUE of Freshwater drum during gillnet sampling at Toledo
Bend Reservoir.
Smallmouth Buffalo
The reservoir’s Smallmouth Buffalo Ictiobus bubalus population has remained relatively stable
over time, though some fluctuations are noted in the poundage values for this species. The
majority of these fluctuations can be attributed to periods when age classes reach maximum size
and exert great influence upon sampling values. Smallmouth Buffalo data are provided in Figure
27.
Figure 27. Total CPUE of Smallmouth buffalo taken by gillnet sampling in Toledo
Bend Reservoir, Louisiana, from 2002 - 2021.
Bowfin
Bowfin Amia calva is not a major commercial species in Toledo Bend Reservoir. Bowfin are
occasionally collected during standardized sampling, but do not appear in significant numbers.
However, Bowfin do sustain themselves in this waterbody and no problems exist related to them.
Gillnet sampling data for Bowfin are shown in Figure 28.
0
2
4
6
8
01-02 02-03 03-04 04-05 05-06 06-07 07-08 08-09 09-10 10-11 11-12 18-19 19-20 20-21
CPUE (POUNDS)
Year
Smallmouth BuffaloTotal CPUE (Pounds)/100'/Net Night
27
Figure 28. Total CPUE of Bowfin taken by gillnet sampling in Toledo Bend Reservoir, Louisiana,
from 2002 - 2021.
Garfish
Longnose Gar Lepisosteus osseus constitutes the majority of garfish poundage collected during
standardized gillnet sampling in Toledo Bend Reservoir. Spotted Gar Lepisosteus oculatus occur
frequently but do not attain the size and weight of Longnose Gar or Alligator Gar Atractosteus
spatula. All three species remain at relatively constant abundance from year to year. Gillnetting
data for these species are depicted in Figure 29.
Figure 29. Total CPUE (pounds per net night) of garfish taken by gillnet sampling in Toledo Bend
Reservoir, Louisiana, from 2002 - 2019.
0
0.05
0.1
0.15
0.2
02-03 03-04 04-05 05-06 06-07 07-08 08-09 09-10 10-11 11-12 18-19 19-20 20-21
CPUE (POUNDS)
Year
Bowfin Total CPUE (Pounds)/100'/Net Night
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
02-03 03-04 04-05 05-06 06-07 07-08 08-09 09-10 10-11 11-12 18-19 19-20 20-21
CPUE (POUNDS)
Year
Alligator Gar Total CPUE (Pounds)/100'/Net Night
Spotted Gar Total CPUE (Pounds)/100'/Net Night
Longnose Gar Total CPUE (Pounds)/100'/Net Night
28
Species of Special Concern
Paddlefish Polyodon spathula occur in Toledo Bend and are listed as a species of concern. They
are rarely seen by Toledo Bend anglers. In 2003-2004 gill net sampling, two specimens were
captured. In 2004-2005 gill net sampling, three specimens were captured. Of these five fish, the
largest was collected near Fisherman’s Wharf, and weighed 43 lbs. The remaining four specimens
were captured in gill nets north of San Patricio Bay. One Paddlefish was collected in 2007-2008
gill net sampling. Five specimens were collected in 2010 – 2011 samples and two specimens
were collected in the 2011 – 2012 samples. Six large specimens were collected in 2018-2019,
with four individuals weighing over 70 lbs., resulting in a greatly increased CPUE. Gillnetting
data for Paddlefish is in Figure 30.
Figure 30. Total CPUE (pounds per net night) of Paddlefish in Toledo Bend
Reservoir, Louisiana by gillnet sampling from 1993 – 2019.
The Sabine Shiner Notropis sabinae is a species of interest and occurs throughout the reservoir.
Sabine Shiners are occasionally collected during shoreline seine sampling. Collection years and
(number collected) are as follows; 2003 (6), 2004 (6), 2005 (1), 2006 (2), 2007 (3), 2008 (2).
Five Suckermouth Minnows Phenacobius mirabilis were captured in the 2002 seine haul sample
at Bass Haven Resort just above the dam. This is also a species of interest and has not been
recorded since 2002.
Grass Carp Ctenopharyngodon idella have been collected in gill net samples as well as reported
by anglers and bow fishermen. One grass Carp was collected during gill net sampling in 2002-
2003, one in 2006-2007, and one in 2008-2009. No individuals have been collected or reported
since 2009.
0
0.2
0.4
0.6
0.8
1
1.2
93-
94
94-
95
95-
96
96-
97
97-
98
98-
99
99-
00
00-
01
01-
02
02-
03
03-
04
04-
05
05-
06
06-
07
07-
08
08-
09
09-
10
10-
11
11-
12
18-
19
19-
20
20-
21
CPUE (POUNDS)
Year
Paddlefish Total CPUE (Pounds)/100'/Net Night
29
HABITAT EVALUATION
Aquatic Vegetation
Hydrilla (Hydrilla verticillata) is a significant submersed aquatic plant in Toledo Bend Reservoir.
From 1985 through 2015, it was the dominant submersed aquatic plant in the reservoir. Hydrilla
is both beneficial as fish habitat and problematic to fishing and boating access. Coverage of
hydrilla significantly decreased in 2001 and 2002, likely due to lower lake levels necessitated by
dam repairs in 2001. Coverage remained stable from 2003 through 2010 with static water levels
and low turbidity. Coverage again decreased along the shoreline with record low lake levels in
2011, following dam repair and drought with new growth expanding into deeper areas of the
lakebed. Growth increased along the shoreline as the reservoir lake level slowly increased in
2012 and remained stable through February 2016. Following record floods and increased inflow
from March 2016 to 2019, hydrilla coverage has decreased considerably, probably due to the high
water levels and increased turbidity.
In 2017, researchers from the University of Georgia found the newly identified cyanobacterium
Aetokthonos hydrillicola (Figure 31), growing on hydrilla samples from Toledo Bend (Wilde et
al. 2017). The Latin name of the new species translates to “eagle killer growing on hydrilla” due
to the toxins produced by the cyanobacterium (Wilde et al. 2014).
30
Figure 31. Small colonies of the cyanobacteria Aetokthonos hydrillicola can be seen growing on
the leaves of hydrilla. Photo after Wilde et al. 2017.
Aquatic vegetation coverage is typically estimated in spring and fall seasons each year.
Additionally, more detailed surveys are periodically used to more accurately describe the
vegetative coverage at that particular time.
In October of 2003 and 2004, the lake was surveyed by LDWF aquatic vegetation personnel for
the presence of aquatic vegetation, mainly submersed plants, and spatial coverage of the major
species. Table 5 below shows the acreages for the major species found during these surveys along
with recent estimates for 2019. Both submersed and floating aquatic vegetation have significantly
decreased from 2015 to 2019.
In March 2005, an aerial survey of Toledo Bend was conducted to estimate the coverage of giant
salvinia (Salvinia molesta). A total of 2,150 acres of salvinia was estimated to be on the lake at
the time of the flight. It is also noted in this report that this plant can spread very rapidly and can
double in size every 7 to 10 days.
31
A second aerial survey was conducted on November 2, 2006. Coverage of 250 acres of giant
salvinia were noted on the Louisiana side of the reservoir.
Table 5. Total plant coverage in Toledo Bend Reservoir, Louisiana, during annual plant surveys,
2003 – 2020.
YEAR
HYDRILLA
COON-
TAIL
PONDWEED
AMERICAN
LOTUS
GIANT
SALVINIA
2003
1,600 acres
20 acres
60 acres
Not surveyed
0
2004
1,900 acres
30 acres
90 acres
Not surveyed
240 acres
2005
Not surveyed
Not
surveyed
Not surveyed
Not surveyed
2,150 acres
2006
Not surveyed
Not
surveyed
Not surveyed
Not surveyed
250 acres
2011
Not surveyed
Not
surveyed
Not surveyed
Not surveyed
25 acres
2012
(Fall
Estimates)
7,500 acres
1,000
1,200 acres
Not surveyed
1,200 acres
2013 Survey
conducted
09-05-13
6,288 acres
Not
surveyed
167 acres
896 acres
1,209 acres
2015
January
estimates)
5,650 acres
Not
surveyed
Not surveyed
Not surveyed
700
2016
(Fall
Estimates)
100
Not
surveyed
90
Not surveyed
410
2017 (Spring
Estimates)
200
Not
surveyed
18
Not surveyed
420
2018 (Fall
Estimates)
700
Not
surveyed
100
Not surveyed
350
2019 (Fall
Estimates
200
50
80
Not surveyed
350
2020 (Fall
Estimates)
5
25
100
40
350
The giant salvinia weevil (Cyrtobagous salviniae) is being used as a biological control for giant
salvinia at Toledo Bend Reservoir. The weevils have shown the ability to reduce the amount of
giant salvinia in areas where they have been released if conditions are conducive to their survival..
Through 2017, a total of 65 salvinia weevil releases have occurred. No weevil releases were made
in 2018 and 2019.
In 2021, the Department of Wildlife and Fisheries began conducting an aquatic habitat
propagation study to determine if 1) herbivory is impacting existing stock to the point that it
cannot increase beyond the current herbivore population, 2) there is a viable seed source of tubers
and turions within the substrate of areas that historically held good coverage of aquatic vegetation,
and 3) there is a successful aquatic vegetation species that can be propagated within any area or
the reservoir as a whole to improve habitat conditions (Figure 26). As of October 6, 2021, the
lake level reached 168’ MSL and generation ceased. Two of the planted exclosures were moved
to 167.5 MSL to retain enough moisture and were re-planted. Data collection is scheduled to
begin late October for a full calendar year.
32
Figure 32. LDWF staff propagate Vallisneria americana, American eelgrass, within exclosure and
study site in the Blue Lake area to examine growth and possible herbivory levels throughout Toledo
Bend Reservoir.
Durable Natural Structure
Much of the durable natural structure, such as standing trees, has decayed during the forty years
since impoundment of Toledo Bend Reservoir.
Substrate
Information from the Natural Resources Conservation Service shows that soils in the Sabine River
watershed range from a sandy type at higher elevations to a silt type at moderate elevations to a
clay type at lower elevations. Soil pH found at higher elevations ranges from 4.5 to 5.3. Soil pH
at slightly lower elevations is found to be 4.2. The soil pH of the lowest elevations is 4.6. All of
these soil types are classified as low in fertility.
Artificial Structure
LDWF has been involved in an artificial reef program since 2003 on Toledo Bend Reservoir. The
goal of this program is to increase angler success by providing underwater structure that attracts
forage fish and provides food and cover for game fish. These reefs are made of various materials.
Additionally, sand and gravel is being placed in locations that will attract spawning gamefish.
Currently, thirty-three artificial reefs and two sand and gravel beds have been placed in the
reservoir. Additional artificial reefs are planned. A table of artificial reef coordinates and
descriptions can be found in Appendix III of Toledo Bend Management Plan Part A.
33
CONDITION IMBALANCE / PROBLEM
Federal Energy Regulatory Commission (FERC) Project Relicensing
The Toledo Bend Project, of which Toledo Bend Reservoir is a part, is licensed by the Federal
Energy Regulatory Commission as Project No. 2305. The original license for the project was
issued on October 14, 1963. The license was for a fifty-year period with an expiration date of
September 30, 2013.
On August 29, 2014, the Sabine River Authority received notice from FERC that its license had
been renewed for an additional fifty years. This relicensing has an expiration date of July 31,
2064.
Invasive Aquatic Vegetation
Hydrilla was a significant submersed aquatic plant in Toledo Bend Reservoir. LDWF’s
September 5, 2013, vegetation survey recorded 6,288 acres of hydrilla on the Louisiana side of
the reservoir. Acreage of hydrilla continued to increase in 2014 with stable water levels and low
turbidity. The November 2015 estimate for hydrilla coverage decreased to 1,400 acres. LDWF’s
September 2018 vegetation survey recorded increasingly lower amounts, with only 700 acres of
hydrilla found on the Louisiana side of the reservoir. Abnormally high water levels with increased
turbidity from 2016 through 2019 have greatly reduced the total amount of hydrilla and other
submersed aquatic plants in the reservoir. Hydrilla is both beneficial as fish habitat and can be
problematic to fishing and navigation. Hydroelectric power generation has typically resulted in
routine water level fluctuations, which have limited the coverage of hydrilla and other submersed
aquatic vegetation prior to 2015. The effect of such water level fluctuation is most obvious along
the reservoir shoreline, being largely devoid of submersed plants. Hydrilla occasionally requires
control in public use areas such as boat ramps, boathouses and swimming areas. Many Toledo
Bend bass anglers welcome hydrilla as a complex structure plant which is utilized as cover by
Largemouth Bass. These anglers voice concern when they note a reduction of hydrilla coverage.
Giant Salvinia causes navigational problems in some areas of the reservoir. Localized
accumulations of the plant occasionally reach levels harmful to fisheries productivity. Although
giant salvinia has been present in the reservoir since 1998, it remains problematic only in areas
sheltered from wave action or water currents. Typical areal coverage of giant salvinia ranges
from 2%-3% on the Louisiana side of the reservoir. Drought conditions during 2011 drastically
reduced the areal coverage of the plant. The coverage of giant salvinia in September 2013 was
1,209 acres. The November 2015 estimate for giant salvinia coverage was 1,090 acres. Periodic
high water events followed by lowering of water levels from 2016 through 2019, further reduced
salvinia coverage to only 350 total acres. Foliar herbicide treatments for giant salvinia by LDWF
have decreased considerably on Toledo Bend since 2015.
September 2018 acreage estimates were conducted for other nuisance aquatic vegetation species
including water hyacinth (Pontederia crassipes), alligator weed (Alternanthera philoxeroides),
and common salvinia (Salvinia minima). Water hyacinth coverage was estimated to be 0 acres,
alligator weed coverage was estimated to be 100 acres and common salvinia coverage was
estimated to be 0 acres. The latest estimates conducted in the fall of 2019 showed similar
coverage, with water hyacinth, alligator weed, and common salvinia covering approximately 0,
80, and 0 acres, respectively. A significant decrease in torpedo grass (Panicum repens) on the
Louisiana side was noticed from 2015 to 2019. Estimates of torpedo grass began at 350 acres in
the fall of 2015, and declined to 180 acres by the spring of 2017. The LDWF vegetation survey
in September 2018 recorded 300 acres of torpedo grass. Much of the torpedo grass became
uprooted during recent high water and wind events. Bass anglers have also voiced concern with
the reduction of torpedo grass utilized as cover for Largemouth Bass. While torpedo grass has
limited shoreline access with dense mats, it has also slowed erosion and wave action.
34
Reduced Durable Structure
Sixty years of impoundment have led to a reduction of complex woody structure through the
decay of submersed timber. While sufficient structure remains to sustain fisheries populations,
angler success has been reduced due to the loss of this woody structure.
Shoreline Stability
Recent high water levels throughout several months of the year have contributed to higher erosion
and loss of shoreline cover. Areas where erosion is most noticeable are high energy areas along
the main lake, including main lake points, deeper bays and bluffs that catch wave action. Loss of
shoreline cover and protective barriers have contributed to turbidity.
CORRECTIVE ACTION NEEDED
1. LDWF participated in the five-year FERC relicensing process (2008 – 2013) as a stakeholder.
This process included providing input on future operations of the project relative to population
stability of fisheries resources. LDWF will continue to provide input relative to future
reservoir operations as they relate to fisheries management.
2. Beginning in July 2016, the Sabine River Authorities will begin releasing increased ambient
surface water flows from Tainter gates six and seven in lieu of the original cold water releases
thru the sluice gates to maintain constant river discharge (Appendix III).
3. Bi-annual monitoring of aquatic plant species to identify problems related to these plants.
Appropriate use of herbicides, water level manipulation and biological agents to control
vegetation as needed.
4. Placement of artificial reef structures and publication of reef locations for anglers.
5. Continue Toledo Bend Habitat Propagation Study with different exclosure types to assess
if there is a viable seed source, successful aquatic vegetation species for propagation within
different portions of the reservoir, and if herbivory plays a key factor in limiting habitat
growth.
RECOMMENDATIONS
1. Discuss assessment and biological data with TPWD concerning fishery management
implications.
2. Continue providing input to involved agencies throughout FERC relicensing and Shoreline
Management Plan update and implementation process.
3. Continue an integrated management approach for Toledo Bend Reservoir to control nuisance
vegetation in areas where needed. Herbicide applications for aquatic plants will be submitted
according to the approved Aquatic Herbicide Application Procedures as adopted by the
LDWF Inland Fisheries Section (Table 6). LDWF personnel will continue to perform annual
surveys to monitor aquatic vegetation, and will update recommendations as necessary.
a. Hydrilla: Chemical treatments for hydrilla will be limited to critical areas such as boat
35
ramps and for shoreline angler access. Chemical treatments will be made with 4.0 ppm
of Aquathol Super-K. Chemical treatments are not recommended for large-scale or long-
term control of submersed aquatic vegetation. The cost for such control is prohibitive and
the control of hydrilla is short-lived.
Historically, drawdown measures have been unnecessary at Toledo Bend Reservoir due
to the water level fluctuations resulting from hydroelectric power generation and
drawdowns needed to perform repairs on the reservoir dam. However, the possibility of
future drawdowns for vegetation control does exist. Physical control of hydrilla and other
submersed aquatic vegetation (SAV) can be accomplished by means of lake drawdowns.
Drawdown measures will be considered when coverage of SAV exceeds 40% (72,600
acres) of total waterbody surface area.
Triploid grass carp are a potentially effective option for biological control of hydrilla.
Triploid grass carp are not recommended for Toledo Bend Reservoir. Complex cover is
directly related to sportfish productivity and angler success. Woody material in Toledo
Bend Reservoir is limited and complex cover is primarily comprised of submersed
aquatic vegetation. Excessive removal of submersed aquatic vegetation is not a
desirable management goal for Toledo Bend Reservoir. Efforts to introduce triploid
grass carp to manage submersed plant growth to a desired level of coverage have been
largely unsuccessful within other reservoirs. Recommendations for the introduction of
triploid grass carp into Toledo Bend Reservoir will be reserved until alternative control
options have been exhausted and until all stakeholder groups are aware of the potential
benefits and risks.
4. Continue to monitor all water quality parameters and lake levels throughout the reservoir in
order to document where and when beneficial vegetation used as complex cover by sportfish
decreases or increases.
5. Continue deployment of artificial reef structures.
6. Continue to propagate and assess various species of native aquatic vegetation following
guidelines for the 2021 LDWF Toledo Bend Habitat Propagation Study. Once study is
complete, further plantings and propagation should continue with Best Management Results
(BMR).
7. Consult and discuss LDWF’s data and projects with various user groups and organizations
to improve public awareness of any results and goals the Department would like to achieve
for the Toledo Bend Reservoir fishery and its watershed as a whole.
8. Continue to address “lake level management” with all authorities and user groups, to
improve fisheries habitat, shoreline stability, water quality and water conservation.
36
Table 6. LDWF Aquatic Herbicide Application Procedures.
Plant Species
Herbicide
Surfactant
Salvinia spp. Alternative 1
Common/Giant Salvinia
(April 1 to October 31)
Glyphosate (0.75 gal/acre)
Diquat (0.25 gal/acre)
Turbulence (or approved
equivalent, 0.25 gal/acre)
Salvinia spp. Alternative 2
Common/Giant Salvinia
(April 1 to October 31)
Glyphosate (0.75 gal/acre)
Flumioxazin (2 oz./acre)
Turbulence (or approved
equivalent, 0.25 gal/acre)
Salvinia spp. Alternative 3
Common/Giant Salvinia
(April 1 to October 31)
MSM (1 oz./acre)
Flumioxazin (1 oz./acre)
Turbulence (or approved
equivalent, 0.25 gal/acre)
Salvinia spp. Alternative 4
Common/Giant Salvinia
(November 1 to March 31)
Diquat (0.75 gal/acre)
Nonionic surfactant (0.25 gal/acre)
Salvinia spp. Alternative 5
Common/Giant Salvinia
(November 1 to March 31)
Flumioxazin (12 oz./acre)
Turbulence (or approved
equivalent, 0.25 gal/acre)
Water Hyacinth
2, 4-D (0.5 gal/acre)
Nonionic surfactant (1 pint/acre)
Water Hyacinth in waiver areas
(March 15 to September 15)
Glyphosate (0.75 gal/acre)
Nonionic surfactant (0.25 gal/acre)
Alligator Weed/Giant Cut Grass
(undeveloped areas)
Imazapyr (0.5 gal/acre)
Turbulence (or approved
equivalent, 0.25 gal/acre)
Alligator Weed/Giant Cut Grass
(developed areas)
Imazamox (0.5 gal/acre)
Turbulence (or approved
equivalent, 0.25 gal/acre)
American Lotus
2, 4-D (0.5 gal/acre)
Nonionic surfactant (1 pint/acre)
American Lotus in waiver areas
(March 15 to September 15)
Glyphosate (0.5 gal/acre)
Nonionic surfactant (0.25 gal/acre)
American Lotus in waiver areas
with potable water intakes
(March 15 to September 15)
Triclopyr (0.5gal/acre)
Turbulence (or approved
equivalent, 0.25 gal/acre)
Duckweed
Diquat (1.0 gal/acre) or
Flumioxazin (8 oz./acre)
Nonionic surfactant (0.25 gal/acre)
or Turbulence (or approved
equivalent, 0.25 gal/acre)
Cuban Bulrush (sedge)
2, 4-D (0.5 gal/acre)
Nonionic surfactant (1 pint/acre)
Cuban Bulrush (sedge) in waiver areas
(March 15 to September 15)
Glyphosate (0.75 gal/acre)
Nonionic surfactant (0.25 gal/acre)
Water Lettuce
Diquat (1.0 gal/acre) or
Flumioxazin (6 oz./acre)
Nonionic surfactant (0.25 gal/acre)
or Turbulence (or approved
equivalent, 0.25 gal/acre)
37
LITERATURE CITED
Thailing, Carol E. & Ditton, Robert B. 2000. Characteristics, Participation Patterns, Attitudes,
Management Preferences, and Economic Impacts of Toledo Bend Reservoir Anglers: Texas
and Louisiana. Department of Wildlife & Fisheries. Texas A&M University.
Texas Parks & Wildlife Department. 2009. 2009-2010 Texas Commercial Fishing Guide. Texas
Parks & Wildlife Department. Publication.
Wilde S. B., Jeffrey R. Johansen, H. Dayton Wilde, Peng Jiang, Bradley A. Bartelme1 & Rebecca
S. Haynie. 2014. Aetokthonos hydrillicola gen. et sp. nov.: Epiphytic cyanobacteria on
invasive aquatic plants implicated in Avian Vacuolar Myelinopathy. Phytotaxa 181:243 –
260.
Wilde, S. B., et al. 2017. Hiding in plain sight: A toxin produced by cyanobacteria is growing on
invasive aquatic plants and is moving up the food chain in Florida lakes. Aquatics, Vol. 39,
No. 3-4, pp. 21 – 25.
Yeldell, Ricky. 2006. Toledo Bend Crappie Regulations Opinion Survey Report. Louisiana
Department of Wildlife & Fisheries. Interagency Report.
38
Appendix I
113. Scuba Diving Game Fish Season
Pursuant to the authority granted under R.S. 56:320(E), the Louisiana Wildlife and Fisheries
Commission hereby continues the special scuba game fish season at Toledo Bend Reservoir, but
deletes black bass from the list of game fish eligible to be taken.
The rules regulating the special scuba game fish season as amended and re-enacted by the
commission are as follows:
(1) The special season shall be limited to Toledo Bend Reservoir, and only in that part of the
lake located south of Highway 6 (Pendleton Bridge) on the Louisiana side.
(2) The special season shall be for four months beginning at sunrise on the first day of June and
ending at sunset on the last day of September each year.
(3) The taking of game fish species shall be permitted during daylight hours only from sunrise
to sunset.
(4) Each diver harvesting game fish is required to have a special permit issued by the secretary
of the Louisiana Department of Wildlife and Fisheries, and the permit must be available for
inspection upon request.
(5) In addition to the special permit the permit holder must have a valid Louisiana sportfishing
license.
(6) Crappie and bream shall be the only game fish species allowed to be taken.
(7) The daily creel limit shall be 25 crappie and 50 bream; the possession limit shall be the same
as the daily creel limit.
(8) The scuba diver must be submerged in the water and use only standard underwater spearing
equipment.
(9) No permitted diver shall have in his possession (vessel or on his person) any other fishing
gear.
(10) Each permit holder shall submit to the Louisiana Department of Wildlife and Fisheries a
monthly report of game fish taken, and other information requested on the forms supplied by the
department; the report deadline for a specific month shall be on the fifteenth of the following
month. All reports should be sent to Bennie Fontenot, Louisiana Department of Wildlife and
Fisheries, Box 98000, Baton Rouge, LA 70898-9000. Each permit holder must submit the
monthly report whether they fish or not.
(11) A legal diving flag shall be conspicuously displayed while diving operations are taking
place.
(12) Permits will expire at the end of each season and shall be renewed on an annual basis.
(13) Failure of the permittee to adhere to any of the above stipulations shall result in the
revocation of the permit by the secretary of the department.
(14) The secretary of the department shall be authorized to recall permits and/or to close the
special season if deemed necessary.
AUTHORITY NOTE: Promulgated in accordance with R.S. 56:320(E).
HISTORICAL NOTE: Promulgated by the Department of Wildlife and Fisheries, Wildlife and
Fisheries Commission, LR 11:706 (July1985), amended LR 15:393 (May 1989).
Taking of other gamefish is prohibited as stated in current Louisiana Recreational Fishing
Regulations:
Skin divers fishing for sport in freshwater, when submerged in the water and using standard
spearing equipment, or any person using a bow and arrow, or any person using or possessing
nets or traps, including recreational hoop nets, recreational slat traps, recreational pipes,
recreational buckets, recreational drums, recreational tires, recreational cans, recreational wire
39
nets and recreational crawfish traps may not take or possess any Largemouth Bass (Micropterus
salmoides), spotted bass (M. punctulatus), black or white crappie (Pomoxis nigromaculatus, P.
annularis), white bass (Morone chrysops), yellow bass (M. mississippiensis), Striped Bass (M.
saxatilis), hybrid Striped Bass (Striped Bass-white bass cross), or any species of bream.
AMENDMENT: In January 2013, the LWFC abolished the special scuba diving season on
Toledo Bend. Therefore, the take of any freshwater gamefish with scuba diving equipment is
not allowed.
40
Appendix II
OPERATING GUIDE RULE CURVE
OPERATING GUIDE RULE CURVE
HYDROELECTRIC POWER PLANT, TOLEDO BEND DAM
MONTH
Reservoir Stage
Ft. MSL
PLANT OPERATION
October thru
December
Below 168
Above 168
No power generated.
Operate plant up to full capacity. *
January
Below 168.5
Above 168.5
No power generated.
Operate plant up to full capacity. *
February
Below 169
Above 169
No power generated.
Operate plant up to full capacity. *
March
Below 169.5
Above 169.5
No power generated.
Operate plant up to full capacity. *
April 1-15
Below 170
Above 170
No power generated.
Operate plant up to full capacity. *
April 15-30
Below 171
Above 171
No power generated.
Operate plant up to full capacity. *
May
Any stage Above 168 **
Above 172
Use Volume necessary to meet Prime Power
Schedule (see Note 2.)
Operate plant up to full capacity. *
June
Any stage Above 168 **
Above 172
Use Volume necessary to meet Prime Power
Schedule (see Note 2.)
Operate plant up to full capacity. *
July
Any stage Above 168 **
Above 172
Use Volume necessary to meet Prime Power
Schedule (see Note 2.)
Operate plant up to full capacity. *
August
Any stage Above 168 **
Above 172
Use Volume necessary to meet Prime Power
Schedule (see Note 2.)
Operate plant up to full capacity. *
September
Any stage Above 168 **
Use Volume necessary to meet Prime Power
Schedule (see Note 2.)
Notes:
1. Maximum turbine discharge, capacity 30 M Ac. Ft. per day.
2. In accordance with Section 5.05 of the Consolidated Power Sales Agreement, no more than 30,000,000 kWh of prime power
shall be scheduled during any one month of the Peaking Period, except with prior written consent of the Authorities.
3. Releases for downstream flows shall be in accordance with Section 5.10 of the Consolidated Power Sales Agreement.
4. When pool stage is at or above 172.5 and inflow is greater than power plant capacity, operate spillway in accordance with
“Guide on Spillway Gate Operation.”
5. Authorities will notify companies as to flow conditions in the Sabine River as required in Section 5.07 of the Consolidated
Power Sales Agreement.
6. Control stages set forth above are to be maintained only to the extent possible when making releases through the power plant.
Spillway gates are to be opened only when stages specified in the “Guide on Spillway Gate Operation” are reached.
7. During prime power season when stage of lake is near upper limit maintain close watch on inflow and make releases for
secondary power generation to avoid spillway releases if possible.
* Releases to be determined based on best judgment considering upstream conditions, stages at Ruliff and inflows below dam.
** No generation below the 168’ MSL except in the event of any of the following:
(1) the FERC, or successor agency orders or requires a reduction in the water level of the Reservoir for purposes of inspecting or
repairing the dam,
(2) an insufficient supply of electric power to the Companies’ firm or non-interruptible power users will result,
(3) non-use of the waters of the Reservoir for the generation of hydroelectric power will result in the failure to satisfy minimum
downstream flow requirements necessary to meet water sales from the diversion canals of the Authorities,
(4) non-use of the waters of the Reservoir for the generation of hydroelectric power will result in the failure to deter saltwater
encroachment into Sabine River Estuaries, or
(5) the Authorities fail to make all credits owed to the Companies or fail to make full reimbursements as required in Section 3.02A
and 3.07 of the Consolidated Power Sales Agreement within the time identified in the Amendment.
Effective date:
May 25, 2007
41
Appendix III
SPILLWAY CONTINUOUS FLOW RELEASE PLAN
On August 29, 2014 the Federal Energy Regulatory Commission (FERC) granted the Sabine River
Authorities of Louisiana and Texas a new 50 year operating license to operate the Toledo Bend
Hydroelectric Project (FERC Project No. 2305).
2.0 – LICENSE ARTICLE 402 AND 403 REQUIREMENTS
The Commission, under Article 403 of the License, required the Authorities, within 18-months
of License issuance, to file with the Commission for approval a flow release plan for releasing
and monitoring compliance with the continuous flow releases required at the project spillway
pursuant to Article 402. Article 402 of the License states:
Article 402. Continuous Releases from the Spillway. From the issuance date of the license through the
later of: (1) the end of the second year of the license term; or (2) 10 days following the Commission’s
approval of the flow release plan required by Article 403, the licensees must release continuous minimum
flows at the project spillway of 144 cubic feet per second (cfs). Such releases must be measured by a gage
that meets or exceeds the U.S. Geological Survey standards used for gage 08025360, Sabine River at the
Toledo Bend Reservoir tailrace. The licensees are not required to provide releases at the spillway greater
than 144 cfs, but may do so at their discretion.
Upon the later of: (1) the commencement of the third year of the license term; or (2) the Commission
approved schedule required by Article 403, the licensees must release continuous minimum flows at the
project’s spillway from a reservoir outlet structure with an elevation invert no lower than 145 feet above
sea level (msl) according to the flow release schedule in the table below. All flow releases in this table are
targeted, continuous values. Releases will occur thru tainter gates 6 and 7 or in the future a mini-hydro
electric generator if deemed feasible by the Authorities and approved by FERC.
Continuous Flow Releases at Spillway (cfs)
Reservoir Elevation
(msl)
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
At > 162
150
150
300
300
300
300
200
200
200
200
200
150
162 – 156
150
150
225
225
225
225
150
150
150
150
150
150
At < 156
150
150
150
150
150
150
150
150
150
150
150
150