LAKE TANEYCOMO 211 ANNUAL LAKE REPORT Shane Bush Fisheries Management Biologist Missouri Department of Conservation Southwest Region March 1, 212
EXECUTIVE SUMMARY Lake Taneycomo was formed by the construction of Powersite Dam (Ozark Beach Dam) in 1913 and is Missouri's oldest hydroelectric reservoir. It is owned and operated by Empire Distric Electric Company (EDEC). The lake is riverine in nature, 22 miles in length, and encompasses 2,8 surface acres. Prior to 1958, Lake Taneycomo supported one of Missouri's best warm-water fisheries. This changed in 1958 when Table Rock Dam, located in the headwater of Lake Taneycomo, began discharging cold hypolimnetic water into Lake Taneycomo. The discharge of cold water changed Lake Taneycomo into a cold-water environment, providing good conditions for trout. Rainbow trout were first stocked into Lake Taneycomo in 1958. Brown trout were first stocked in 198. Since that time more than 3 million rainbow and brown trout have been stocked. Lake Taneycomo is Missouri's largest and most popular trout fishery. It annually receives in excess of 135, fishing trips and anglers catch an estimated 6, trout annually. The Missouri Department of Conservation (MDC) coordinates fisheries management activities following the lake management plan that was updated in February 21. Much like 28 and 29, 211 was characterized by high water during much of the year. Table Rock Lake reached a record level of 935.3 feet on April 28, 211 as a result of 13 inches of rain that fell from April 23 through April 28. As a result, record water releases occurred at Table Rock Dam in April 211. All ten of the flood gates were opened four feet each on April 26, releasing 68, cfs of water through the turbines and floodgates combined. These increased flows through the dam enabled the tailwater elevation of Lake Taneycomo to reach a record level of 728 feet, causing widespread flooding and damage lake-wide (Figure 1). When the floodwaters receded, MDC received numerous reports of stranded fish in road ditches and low lying areas. MDC staff spent two days on two separate occasions rescuing stranded fish and returning them to Lake Taneycomo. Approximately 8 trout were returned to the lake. A spring electrofishing survey was conducted in the lower portion of Lake Taneycomo on May 12, 211. Largemouth bass and bluegill were collected in 1.1 hours of electrofishing. The 211 Lake Taneycomo trout electrofishing survey was conducted August 17, 211. With the cooperation of the Corps of Engineers (COE) and Southwest Power Administration (SWPA), hydropower releases were terminated at 2 hours and sampling began at 213 hours. Twenty MDC staff from SW Fisheries, Shepherd of the Hills and Chesapeake hatcheries assisted with the sample. Experienced crew members from previous years (along with favorable weather conditions) helped to make the sample a great success. Sampling was completed by 3 hours on August 18, 211. Rainbow Trout Rainbow trout were captured at a rate of 32 fish per hour, well within the range of normal variation (Table 1, Figure 2). Size structure remains excellent with PSD and RSD values among the highest on record. Body condition has decreased from 21 and is similar to other recent high water years with relative weights averaging 88 for all sizes (Table 2). Relative weights were 88 for each of the upstream zones 1, 2, and 3, but were
93 and 98 in the downstream zones 4A and 4B. It is possible that record level water releases from Table Rock Dam in April 211 moved a substantial amount of gravel and invertebrates downstream into Zone 4. Rainbow trout were collected at a rate of 338 fish per hour in the special regulation zone above Fall Creek (Table 3, Figure 3). In this same area, RSD 13 and RSD 16 were 6% and 16%, respectively. Rainbow trout were collected at a rate of 97 fish per hour below Fall Creek (Table 3, Figure 4). RSD 13 and RSD 16 values were 44% and 15%, respectively. The special management zone has now been in place for 14 years in upper Lake Taneycomo. Since the special regulations were implemented in 1997, the rainbow trout population has increased 1-fold (Table 3). Size structure, in general, has greatly benefited as well. The percentage of stock-size rainbow trout at or exceeding 16 inches has increased above Fall Creek. Currently, RSD 16 of 16% exceeds the 5-1% objective listed in the current management plan. Body condition of rainbow trout has fluctuated over the past few years. The average relative weight of 88 in 211 was the same body condition that was observed during other recent high water years, such as 28 and 29. 27 and 21 were characterized by lower water flow through Table Rock Dam and relative weights during these years were noticeably higher. An additional 666,992 rainbow trout were stocked into Lake Taneycomo in 211 (Table 6). Brown Trout The catch per unit effort (CPUE) of brown trout was 23 fish per hour which is the lowest rate observed since 198 (Table 4, Figure 5). Brown trout stocked in June 211 comprised the majority of the catch (9-12 ). RSD 13 was 45%, which is below average from 1997-29. However, RSD 16 of 37% was above average and RSD 2 of 2% is the highest on record. Body condition of brown trout has decreased from 21, but remains above normal with average relative weight of 17 (Table 5). CPUE of brown trout > 2 was 2%, which is below the management objective of 3-6%. CPUE of brown trout continues to decline. This could be attributed to the above average water temperatures in 28 and 29, creating poor water quality conditions in Lake Taneycomo which could have resulted in poor survival of stocked fish. In addition, high water flows at Powersite Dam during brown trout stockings in 28 and 29 washed many stock size brown trout into Bull Shoals Lake. Many ten inch brown trout were observed during a walleye electrofishing sample below Powersite Dam in March 21. Size structure of brown trout has improved during the past six years. Although overall numbers of brown trout are low compared to previous years, numerous fish greater than 2 inches are available providing the opportunity to catch a true trophy. Angler catch rates of these larger fish will likely decline within the next few years due to the lack of intermediate sized fish (15-18 ) in the population. However, catch rates should rebound once the large year class of brown trout from 21 reach the legal size limit. An additional 15,254 brown trout were stocked into Lake Taneycomo in 211 in an effort to improve brown trout numbers in the lake (Table 6). It is recommended that the increased
brown trout stocking rate of 15, per year be continued through 213 as fish are available. Largemouth Bass A total of 11 largemouth bass were captured in 1.1 hours of electrofishing for a CPUE of 1 largemouth bass per hour (Figure 6). More largemouth bass were collected than in 29, likely due to higher water temperatures during the samples. Most of the largemouth bass collected came from Bull Creek, which was much warmer at the time of the sample than the other sampling coves near Powersite Dam. The water temperature was 6 degrees F in Bull Creek and 52 degrees F around Powersite Dam. RSD 12 and RSD 15 values were 6% and 29%, respectively. The size structure still remains favorable and within the established management objectives. Bluegill A total of 67 bluegill were captured in 1.1 hours of electrofishing for a CPUE of 61 bluegill per hour (Figure 7). Size structure has remained relatively consistent each year since 28. PSD 6 values were 38% and still slightly higher than the management objectives. General Lake Activities The low dissolved oxygen (DO) season began much earlier in 211 than in previous years. The vacuum breaker vents were blocked open at Table Rock Dam on June 23 and restrictions were placed on generation on August 1. Generation restrictions were lifted on December 1 and the vents were closed on December 15. Cooperation between the COE, SWPA, EDEC, and MDC on water releases at Table Rock Dam was critical to the health of the trout in Lake Taneycomo during the 211 low DO season. Zebra mussels have been known to be present in Lake Taneycomo since September 27. Three zebra mussel sampling devices were placed at Empire Electric Dam, the City of Branson boat dock, and Cooper Creek boat dock in August 29. Two of the three sampling devices were washed downstream in the spring of 211. However, the remaining sampling device at Rockaway Beach was checked in 211 and no zebra mussels were found. An angler reported seeing zebra mussels attached to woody debris in Bull Creek in September 211. MDC staff investigated this report and found no evidence of zebra mussels in Bull Creek. Additionally, MDC staff took advantage of a lake drawdown in October 211 to search for zebra mussels near Powersite Dam. No zebra mussels were found during these investigations. In February 211, MDC staff gathered algae samples from Lake Taneycomo between Outlet 2 and the Shepherd of the Hills boat ramp that were suspected to be Didymo. Further analysis by Dr. Rhodes at Missouri State University found that the algae were Gomphonema and did not pose a threat to Lake Taneycomo. Two wader wash stations were built and installed along Lake Taneycomo at outlets 1 and 2 at Shepherd of the Hills
Hatchery in January 211 in an effort to prevent Didymo from entering Lake Taneycomo. As a further Didymo preventative measure, a regulation banning the use of felt soled waders in Lake Taneycomo will go into effect on March 1, 212. Trout habitat improvements were completed in October 211 using funding from the National Fish Habitat Initiative (NFHI). A total of 71 boulder clusters were placed in the upper mile of Lake Taneycomo from Outlet 1 to the Shepherd of the Hills boat ramp. The habitat project was completed during a two week period of lake drawdowns requested by EDEC to replace the wooden flashboards on Powersite Dam with operational flood gates. The angler creel survey that began in February 28 concluded in January 21. Survey results will be described in an addendum once data is summarized in 212. Management Recommendations 1) Continue to collect trout population information annually and black bass and bluegill population information every three years for regulation and monitoring purposes. 2) Continue to stock approximately 7, rainbow trout. 3) Request an increase in brown trout stocking from 1, to 15,, as available, in 212. 4) Summarize 28-21 creel survey information to measure fishing pressure and angler catch and harvest rates. 5) Cooperate in ongoing efforts to monitor and enhance water quality and flow regimes. 6) Continue efforts through education of boaters and anglers to prevent the spread of zebra mussels, Didymo, and other aquatic nuisance species from and to Lake Taneycomo. 7) Review and comment on permit applications for boat dock construction and dredge and fill activities.
Table 1. Electrofishing capture rates and size structure indices of rainbow trout in August electrofishing samples, 1979-211. Year Number/Hour RSD-13 RSD-16 RSD-2 1979 256 14 3 1 198 14 24 4 1 1981 85 19 6 1 1982 95 7 1 <1 1983 165 47 9 2 1984 191 8 <1 1985 13 13 5 1986 135 5 1987 76 19 1 1988 11 8 1 <1 1989 74 1 1 199 73 19 1991 68 <1 1992 43 8 1993 99 33 2 1994 44 32 2 1 1995 56 25 2 <1 1996 23 1 1997 11 3 2 <1 1998 117 46 5 1999 23 53 9 <1 2 185 24 3 21 175 31 5 <1 22 274 59 12 <1 23 219 52 13 24 277 43 9 25 276 57 11 26 175 52 6 <1 27 259 55 4 28 157 66 7 29* 313 57 9 21 245 7 18 211 32 6 16 1 For Zones 1, 2, and 4b only
Table 2. Relative weights of rainbow trout from Lake Taneycomo, 1993-211. Year Relative Weight by Length Class (Inches) All Sizes <13. >13. >16. 1993 111 11 112 118 1994 95 95 97-1995 111 19 117 124 1996 16 17 1-1997 12 11 12 12 1998 17 17 17 19 1999 14 14 13 14 2 95 96 9 81 21 112 11 114 113 22 112 19 114 116 23 11 11 1 99 24 99 99 99 98 25 96 1 94 92 26 85 86 84 86 27 96 97 95 94 28 88 88 88 85 29 88 91 87 84 21 98 96 1 11 211 88 88 89 92
Table 3. Electrofishing capture rates and size structure indices of rainbow trout in August electrofishing samples, taken above and below Fall Creek, 1996-211. Year Number/Hour RSD-13 RSD-16 Above Fall Creek Regulation Area 1996 27 9 1997 121 31 2 1998 147 47 5 1999 238 54 9 2 22 25 3 21 25 34 5 22 334 62 13 23 26 55 14 24 331 44 1 25 315 59 12 26 226 53 6 27 32 56 4 28 187 67 7 29* 449 62 11 21 275 72 19 211 338 6 16 Below Fall Creek Non-Regulation Area 1996 1 1997 38 11 1998 18 14 1999 5 19 4 2 78 5 2 21 64 3 1 22 86 31 3 23 65 17 2 24 64 29 4 25 125 17 2 26 38 46 8 27 55 32 28 45 53 7 29 122 28 21 12 43 6 211 97 44 15 *For Zones 1 and 2 only
Table 4. Electrofishing capture rates and size structure indices of brown trout in August electrofishing samples, 1979-211. Year Number/Hour RSD-13 RSD-16 RSD-2 1979 2 6 4 4 198 1 6 7 1981 51 4 11 1 1982 132 1 4 1 1983 225 38 1 <1 1984 16 33 8 1 1985 188 14 6 <1 1986 273 24 2 <1 1987 134 6 14 1988 66 57 29 2 1989 73 37 17 2 199 24 4 13 2 1991 62 44 16 1 1992 71 45 11 3 1993 133 57 15 3 1994 113 38 15 3 1995 145 58 2 2 1996 12 32 13 2 1997 175 42 13 2 1998 93 51 17 2 1999 124 37 1 2 2 1 59 15 3 21 12 36 8 1 22 125 52 14 1 23 84 59 16 3 24 8 67 23 3 25 77 91 45 2 26 11 76 33 4 27 9 82 39 5 28 41 66 3 5 29* 33 87 35 6 21 29 98 67 12 211 23 45 37 2 *For Zones 1, 2, and 4b only
Table 5. Relative weights of brown trout from Lake Taneycomo, 1993-211. Year Relative Weight by Length Class (Inches) All Sizes <13. >13. >16. 1993 94 93 94 96 1994 1 14 95 9 1995 1 12 99 99 1996 95 96 94 89 1997 96 98 96 96 1998 92 95 91 9 1999 92 97 87 79 2 91 93 89 83 21 95 97 93 89 22 96 14 92 91 23 95 97 94 89 24 92 94 92 89 25 113 17 113 123 26 15 99 17 11 27 15 12 15 17 28 14 12 15 15 29 19 91 11 16 21 131 1 132 137 211 17 13 128 133
Table 6. 211 monthly stocking rates in Lake Taneycomo. Month Rainbow Trout Brown Trout January 46,85 February 39,1 March 56,873 April 47,56 May 34,377 June 88,27 15,254 July 81,527 August 81,8 September 67,28 October 6,174 November 4,918 December 23,1 TOTAL 666,992 15,254
Figure 1. Daily pool and tailwater elevations at Table Rock Lake and Lake Taneycomo from April 22 through April 28.
Fish/Hr Fish/Hr Fish/Hr 5 45 4 35 3 25 2 15 1 5 Effort = 5.6 hr. 32 Total RBT/hr. N = 1689 PSD (13) = 59% RSD (16) = 16% RSD (2) = 1% Rainbow Trout Length Frequency Taneycomo - 211 3 6 9 12 15 18 21 5 45 4 35 3 25 2 15 1 5 Rainbow Trout Length Frequency Taneycomo - 21 Effort = 4.3 hr. 245 Total RBT/hr. N = 156 PSD (13) = 7% RSD (16) = 18% 3 6 9 12 15 18 21 5 45 4 35 3 25 2 15 1 5 Effort = 3.6 hr. 313 Total RBT/hr. N = 1134 PSD (13) = 57% RSD (16) = 9% Rainbow Trout Length Frequency Taneycomo - 29 3 6 9 12 15 18 21 Figure 2. Length frequencies for rainbow trout sampled in all zones 29-211.
Fish/Hr Fish/Hr Fish/Hr Rainbow Trout Length Frequency Management Zone - Taneycomo 211 7 6 5 4 3 2 1 Effort = 4.8 hr. 338 Total RBT/hr. N = 161 PSD (13) = 6% RSD (16) = 16% RSD (2) = 1% 3 6 9 12 15 18 21 24 27 7 6 5 4 3 2 1 Rainbow Trout Length Frequency Management Zone - Taneycomo 21 Effort = 3.5 hr. 275 Total RBT/hr. N = 956 PSD (13) = 72% RSD (16) = 19% 3 6 9 12 15 18 21 24 27 7 6 5 4 3 2 1 Rainbow Trout Length Frequency Management Zone - Taneycomo 29 Effort = 2.1 hr. 449 Total RBT/hr. N = 949 PSD (13) = 62% RSD (16) = 11% 3 6 9 12 15 18 21 24 27 Figure 3. Length frequencies for rainbow trout sampled above Fall Creek 29-211.
Fish/Hr Fish/Hr Fish/Hr 7 6 5 4 3 2 1 Rainbow Trout Length Frequency Below Management Zone - Taneycomo 211 Effort =.8 hr. 97 Total RBT/hr. N = 79 PSD (13) = 44% RSD (16) = 15% 3 6 9 12 15 18 21 24 27 7 6 5 4 3 2 1 Rainbow Trout Length Frequency Below Management Zone - Taneycomo 21 Effort =.83 hr. 12 Total RBT/hr. N = 1 PSD (13) = 43% RSD (16) = 6% 3 6 9 12 15 18 21 24 27 7 6 5 4 3 2 1 Rainbow Trout Length Frequency Below Management Zone - Taneycomo 29 Effort = 1.5 hr. 123 Total RBT/hr. N = 185 PSD (13) = 28% RSD (16) = % 3 6 9 12 15 18 21 24 27 Figure 4. Length frequencies for rainbow trout sampled below Fall Creek 29-211.
Fish/Hr Fish/Hr Fish/Hr 1 9 8 7 6 5 4 3 2 1 Effort = 5.6 hr. 23 Total BNT/hr. N = 129 PSD (13) = 45% RSD (16) = 37% RSD (2) = 2% Brown Trout Length Frequency Taneycomo- 211 3 6 9 12 15 18 21 24 27 3 33 36 1 9 8 7 6 5 4 3 2 1 Effort = 4.3 hr. 29 Total BNT/hr. N = 125 RSD (13) = 98% RSD (16) = 67% RSD (2) = 12% Brown Trout Length Frequency Taneycomo - 21 3 6 9 12 15 18 21 24 27 3 33 36 1 9 8 7 6 5 4 3 2 1 Effort = 3.6 hr. 33 Total BNT/hr.. N = 119 PSD (13) = 87% RSD (16) = 35% RSD (2) = 6% Brown Trout Length Frequency Taneycomo - 29 3 6 9 12 15 18 21 24 27 3 33 36 Figure 5. Length frequencies for brown trout sampled in all zones 29-211.
Fish/Hour Fish/Hour Fish/Hour 1 8 6 4 211 LARGEMOUTH BASS LENGTH FREQUENCY LOWER LAKE TANEYCOMO Effort = 1.1 hr. 1 Total LMB/hr. N = 11 PSD (12) = 6% RSD (15) = 29% 2 3 6 9 12 15 18 21 24 1 8 6 4 29 LARGEMOUTH BASS LENGTH FREQUENCY LOWER LAKE TANEYCOMO Effort = 1.8 hr. 24 Total LMB/hr. N = 43 PSD(12) = 56% RSD(15) = 24% 2 3 6 9 12 15 18 21 24 1 8 6 4 28 LARGEMOUTH BASS LENGTH FREQUENCY LOWER LAKE TANEYCOMO Effort = 2.35 hr. 91 Total LMB/hr. N = 214 PSD(12) = 45.5% RSD(15) = 21% 2 3 6 9 12 15 18 21 24 Figure 6. Largemouth bass length frequencies 28-211.
Fish/Hour Fish/Hour Fish/Hour 1 8 6 Effort = 1.1 hr. 61 Total BG/hr. N = 67 PSD (6) = 38% RSD (8) = % 211 BLUEGILL LENGTH FREQUENCY LOWER LAKE TANEYCOMO 4 2 3 6 9 1 8 6 Effort = 1.76 hr. 35 Total BG/hr. N = 61 PSD (6) = 31% RSD (8) = % 29 BLUEGILL LENGTH FREQUENCY LOWER LAKE TANEYCOMO 4 2 3 6 9 1 8 6 Effort = 2.35 hr. 296 Total BG/hr. N = 696 PSD (6) = 4% RSD (8) = % 28 BLUEGILL LENGTH FREQUENCY LOWER LAKE TANEYCOMO 4 2 3 6 9 Figure 7. Bluegill length frequencies 28-211.