to the 2014 Lake Taneycomo Annual Report
Transcription
to the 2014 Lake Taneycomo Annual Report
LAKE TANEYCOMO 2014 ANNUAL LAKE REPORT Shane Bush Fisheries Management Biologist Missouri Department of Conservation Southwest Region March 1, 2015 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 District Electric Company (EDEC). The lake is riverine in nature, 22 miles in length, and encompasses 2,080 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 1980. Since that time more than 30 million Rainbow and Brown Trout have been stocked. Lake Taneycomo is Missouri's largest and most popular trout fishery, but it also contains an excellent warmwater fishery in the lower sections of the lake. It annually receives in excess of 140,000 fishing trips and anglers catch an estimated 500,000 trout annually. The Missouri Department of Conservation (MDC) coordinates fisheries management activities following the lake management plan that was updated in February 2010. A spring electrofishing survey was conducted in the lower portion of Lake Taneycomo on May 8, 2014 with water temperatures ranging from 65 to 72 degrees F. Largemouth Bass and Bluegill were the primary species sampled in 1.96 hours of electrofishing. The 2014 Lake Taneycomo trout electrofishing survey was conducted September 4, 2014. With the cooperation of the Corps of Engineers and Southwest Power Administration, hydropower releases were terminated at 1900 hours and sampling began at 2100 hours. A crew of 20 Missouri Department of Conservation staff from Fisheries, Private Lands Services, and Forestry all assisted with the sample. Sampling was completed by 0130 hours on September 5. Rainbow Trout Rainbow Trout were captured at a rate of 202 fish per hour in all zones combined, well within the range of normal variation (Table 1, Figure 1). Size structure continues to be good with PSD13 and PSD16 values of 57% and 9%, respectively. Body condition of Rainbow Trout remains good with relative weights averaging 98 for all sizes (Table 2). Rainbow Trout were collected at a rate of 225 fish per hour in the special regulation zone above Fall Creek (Table 3, Figure 2). In this same area, PSD13 and PSD16 were 60% and 9%, respectively and well within the established management objectives (Appendix A). Size structure has remained steady and fluctuated very little in this area during the past 17 years following the regulation changes, indicating that the regulations are working. Rainbow Trout were collected at a rate of 94 fish per hour below Fall Creek (Table 3, Figure 3). PSD13 and PSD16 values were 17% and 0% respectively in this stretch, and closely resemble that of a put and take fishery. A total of 708,619 Rainbow Trout were stocked into Lake Taneycomo in 2014 (Table 4). Brown Trout The catch per unit effort (CPUE) of Brown Trout was only 36 fish per hour, which is higher than in 2009-2011, but lower than the previous two years (Table 5, Figure 4). Size structure of Brown Trout was good with PSD13 and PSD16 values measuring 79% and 44%, respectively. PSD20 of 12% is well above the established management objectives and signifies that the increased stockings of Brown Trout following the floods of 2008 and 2011 have finally brought the numbers of legal sized fish back into the population. Body condition of Brown Trout was well above average with an average relative weight of 115 for all sizes and 124 for Brown Trout greater than or equal to 16 inches (Table 6). The increase in stocking of Brown Trout from 10,000 to 15,000 in the past four years has contributed greatly to the rebound of this fishery and should be continued in 2015 as fish are available. The biggest Brown Trout collected in the 2014 trout sample measured 29.0 inches and weighed 20.8 pounds (Figure 5). A total of 10,007 diploid Brown Trout were stocked into Lake Taneycomo in 2014. A total of 5,089 triploid Brown Trout were stocked in 2014 as part of the 15,000 fish commitment, bringing the total number of triploids stocked into Lake Taneycomo since 2013 to 10,089. Only 33 triploid Brown Trout were captured during the 2014 trout sample with PSD13 and PSD16 values measuring 50% and 8%, respectively (Figure 6). It is unknown why so few triploid Brown Trout were captured in the trout sample, but may be attributed to the lack of reproductive potential of these fish making them remain in the lower sections of the lake where sampling is not conducted. An additional 5,000 triploid Brown Trout are planned to be stocked in Lake Taneycomo in 2015 as part of this ongoing study. Additional Brown Trout length and weight data was collected from fish ascending the ladder at Shepherd of the Hills Fish Hatchery in the fall of 2014. The size distribution of Brown Trout ascending the fish ladder closely resembled that of Brown Trout collected during the trout sample on Lake Taneycomo, with the exception that few of the Brown Trout stocked in 2014 (9-11 inches) ascended the fish ladder (Figure 7). Collecting this data in the future should provide quality supplemental data to the electrofishing samples greatly help inform future management decisions regarding the Brown Trout population in Lake Taneycomo. Additionally, collecting this data could provide a cheap and effective method to assess the status of the Brown Trout population in Lake Taneycomo during years such as 2014 when electrofishing catch rates of Brown Trout were relatively low. Largemouth Bass A total of 219 Largemouth Bass were captured in 1.96 hours of electrofishing for a CPUE of 112 Largemouth Bass per hour (Figure 8). Size structure of Largemouth Bass was excellent and exceeded the established management objectives with PSD12 and PSD15 values were 79% and 39%, respectively. Relative weight of Largemouth Bass was excellent as well averaging 97 for all sizes (Table 7). Bluegill A total of 340 Bluegill were captured in 1.96 hours of electrofishing for a CPUE of 173 Bluegill per hour (Figure 9). Size structure has remained relatively consistent each year since 2009 that sampling has been conducted. The PSD6 value was 30% in 2014 and right in line with the established management objectives. Crappie Black Crappie were caught via angling in February 2014 and otoliths were taken for age and growth analysis. The length frequency distribution of Black Crappie caught was favorable and varied among several different size classes (Figure 10). Otolith examination of 46 fish indicated that Black Crappie grow well in Lake Taneycomo and average 10.2 inches at age 4 (Table 8). General Lake Activities The low dissolved oxygen (DO) season in 2014 was not nearly as severe as it was in 2013. The low DO season began on August 19 when DO levels dropped below 6 mg/L in the tailwater of Table Rock Dam and the vacuum breaker vents were opened. Dissolved oxygen conditions began to improve on November 18 and the vacuum breaker vents were closed at Table Rock Dam on December 17. No fish mortality was reported in 2014 as a result of low DO conditions. Aquatic vegetation treatments were conducted on lower Taneycomo at Empire Park and Rockaway Beach on June 3, 2014. With MDC providing advice and logistical support, Midwest Lake Management, Inc. treated several submergent species of aquatic vegetation including: Curlyleaf Pondweed, Coontail, Southern Naiade, and Elodea by using a mix of Tribune® and Cutrine Plus®. This was the second year of treatments at Empire Park and the first year of treatment at Rockaway Beach. Treatments were highly effective at killing the vegetation in both areas, but seemed to be slightly more effective at Empire Park following the second year of treatment (Figures 11-12). Empire District Electric Company (EDEC) staff plan to hire Midwest Lake Management, Inc. again in the spring of 2015 to treat the vegetation as it begins to grow and will likely continue treatments in the future to keep the plants under control. MDC and EDEC also worked together to compose a set of guidelines for the general public to use for treatment of the aquatic vegetation in Lake Taneycomo (Appendix B). Management Recommendations 1) Collect trout population information annually for regulation, monitoring, and triploid study evaluation. 2) Continue to stock 700,000 Rainbow Trout and 15,000 Brown Trout annually, including 5,000 triploid Brown Trout annually through 2015. 3) Work with MDC Resource Science Division to develop a plan to document the effects of low DO levels and trout mortality during the low DO season. 4) Cooperate in ongoing efforts to monitor and enhance water quality and flow regimes. 5) Continue efforts through education of boaters and anglers to prevent the spread of zebra mussels, Didymo geminata, and other aquatic nuisance species from and to Lake Taneycomo. 6) Review and comment on permit applications for boat dock construction and dredge and fill activities. 7) Provide advice and logistical support to EDEC and other stakeholders related to nuisance aquatic vegetation problems on Lake Taneycomo. Table 1. Electrofishing capture rates and size structure indices of stock size Rainbow Trout (>11 inches) in August electrofishing samples, 1979-2014. back to text Year 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009* 2010 2011 2012 2013 2014 Number/Hour 256 140 85 95 165 191 103 135 76 101 74 73 68 43 99 44 56 23 101 117 203 185 175 274 219 277 276 175 259 157 313 245 302 248 233 202 *For Zones 1, 2, and 4b only PSD-13 14 24 19 7 47 8 13 5 19 8 10 19 <1 8 33 32 25 10 30 46 53 24 31 59 52 43 57 52 55 66 57 70 60 56 52 57 PSD-16 3 4 6 1 9 <1 5 0 1 1 1 0 0 0 2 2 2 0 2 5 9 3 5 12 13 9 11 6 4 7 9 18 16 9 6 9 PSD-20 1 1 1 <1 2 0 0 0 0 <1 0 0 0 0 0 1 <1 0 <1 0 <1 0 <1 <1 0 0 0 <1 0 0 0 0 1 <1 <1 0 Table 2. Relative weights of Rainbow Trout from Lake Taneycomo, 1993-2014. Year 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Relative Weight by Length Class (Inches) All Sizes <13.0 >13.0 111 110 112 95 95 97 111 109 117 106 107 100 102 101 102 107 107 107 104 104 103 95 96 90 112 110 114 112 109 114 101 101 100 99 99 99 96 100 94 85 86 84 96 97 95 88 88 88 88 91 87 98 96 100 88 88 89 92 94 89 97 99 96 98 101 96 back to text >16.0 118 124 102 109 104 81 113 116 99 98 92 86 94 85 84 101 92 85 93 96 Table 3. Electrofishing capture rates and size structure indices of stock size Rainbow Trout (>11 inches) in August electrofishing samples, taken above and below Fall Creek, 1996-2014. back to text Above Fall Creek – Regulation Area Below Fall Creek – NonRegulation Area *For Zones 1 and 2 only Year 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009* 2010 2011 2012 2013 2014 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Number/Hour 27 121 147 238 202 205 334 260 331 315 226 302 187 449 275 338 278 271 225 10 38 18 50 78 64 86 65 64 125 38 55 45 122 120 97 112 94 94 PSD-13 9 31 47 54 25 34 62 55 44 59 53 56 67 62 72 60 58 53 60 0 11 14 19 5 3 31 17 29 17 46 32 53 28 43 44 24 44 17 PSD-16 0 2 5 9 3 5 13 14 10 12 6 4 7 11 19 16 9 6 9 0 0 0 4 2 1 3 2 4 2 8 0 7 0 6 15 2 9 0 Table 4. 2014 monthly stocking rates in Lake Taneycomo. back to text Month Rainbow Trout Brown Trout January 52,802 10,007 February 39,204 March 54,641 April 60,118 1,963 May 67,102 3,126 June 81,002 July 83,010 August 81,041 September 67,115 October 60,180 November 39,198 December 23,206 TOTAL 708,619 15,096 Table 5. Electrofishing capture rates and size structure indices of stock size Brown Trout (>11 inches) in August electrofishing samples, 1979-2014. back to text Year 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009* 2010 2011 2012 2013 2014 Number/Hour 2 10 51 132 225 160 188 273 134 66 73 204 62 71 133 113 145 102 175 93 124 100 120 125 84 80 77 101 90 41 33 29 23 107 61 36 *For Zones 1, 2, and 4b only PSD-13 60 60 40 10 38 33 14 24 60 57 37 40 44 45 57 38 58 32 42 51 37 59 36 52 59 67 91 76 82 66 87 98 45 51 76 79 PSD-16 40 7 11 4 10 8 6 2 14 29 17 13 16 11 15 15 20 13 13 17 10 15 8 14 16 23 45 33 39 30 35 67 37 7 35 44 PSD-20 40 0 1 1 <1 1 <1 <1 0 2 2 2 1 3 3 3 2 2 2 2 2 3 1 1 3 3 2 4 5 5 6 12 20 2 3 12 Table 6. Relative weights of Brown Trout from Lake Taneycomo, 1993-2014. Year 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Relative Weight by Length Class (Inches) All Sizes <13.0 >13.0 94 93 94 100 104 95 100 102 99 95 96 94 96 98 96 92 95 91 92 97 87 91 93 89 95 97 93 96 104 92 95 97 94 92 94 92 113 107 113 105 99 107 105 102 105 104 102 105 109 91 110 131 100 132 107 103 128 103 99 107 114 103 116 115 103 119 back to text >16.0 96 90 99 89 96 90 79 83 89 91 89 89 123 110 107 105 106 137 133 110 119 124 Table 7. Lower Taneycomo Largemouth Bass relative weights 2014. back to text Table 8. Length at age data for Black Crappie collected via angling in 2014. Age Average Length N 2 7.7 9 3 8.8 12 4 10.2 16 5 11.7 7 6 12.0 1 TOTAL 45 back to text RAINBOW TROUT LENGTH FREQUENCY LAKE TANEYCOMO - 2014 Effort = 4.7 hr. 202 Total RBT/hr. N = 943 PSD (13) = 57% PSD (16) = 9% FISH/HR 50 45 40 35 30 25 20 15 10 5 0 0 3 6 9 12 15 18 21 24 Length (Inches) RAINBOW TROUT LENGTH FREQUENCY LAKE TANEYCOMO - 2013 Effort = 4.5 hr. 233 Total RBT/hr. N = 1041 PSD (13) = 52% PSD (16) = 6% FISH/HR 50 45 40 35 30 25 20 15 10 5 0 0 3 6 9 12 15 18 21 24 Length (Inches) FISH/HR 50 45 40 35 30 25 20 15 10 5 0 RAINBOW TROUT LENGTH FREQUENCY LAKE TANEYCOMO - 2012 Effort = 4.3 hr. 248 Total RBT/hr. N = 1073 PSD (13) = 56% PSD (16) = 9% 0 3 6 9 12 15 18 21 24 Length (Inches) Figure 1. Length frequencies for Rainbow Trout sampled in all zones 2012-2014. back to text FISH/HR 50 45 40 35 30 25 20 15 10 5 0 RAINBOW TROUT LENGTH FREQUENCY SPECIAL MANAGEMENT ZONE LAKE TANEYCOMO - 2014 Effort = 3.8 hr. 225 Total RBT/hr. N = 865 PSD (13) = 60% PSD (16) = 9% 0 3 6 9 12 15 18 21 24 FISH/HR Length (Inches) 50 45 40 35 30 25 20 15 10 5 0 RAINBOW TROUT LENGTH FREQUENCY SPECIAL MANAGEMENT ZONE LAKE TANEYCOMO - 2013 Effort = 3.5 hr. 271 Total RBT/hr. N = 951 PSD (13) = 53% PSD (16) = 6% 0 3 6 9 12 15 18 21 24 Length (Inches) FISH/HR RAINBOW TROUT LENGTH FREQUENCY SPECIAL MANAGEMENT ZONE LAKE TANEYCOMO - 2012 50 45 40 35 30 25 20 15 10 5 0 Effort = 3.5 hr. 278 Total RBT/hr. N = 983 PSD (13) = 58% PSD (16) = 9% 0 3 6 9 12 15 18 21 24 Length (Inches) Figure 2. Length frequencies for Rainbow Trout sampled above Fall Creek 2012-2014. back to text FISH/HR RAINBOW TROUT LENGTH FREQUENCY BELOW SPECIAL MANAGEMENT ZONE LAKE TANEYCOMO - 2014 50 45 40 35 30 25 20 15 10 5 0 Effort = 0.83 hr. 94 Total RBT/hr. N = 78 PSD (13) = 17% PSD (16) = 0% 0 3 6 9 12 15 18 21 24 Length (Inches) FISH/HR RAINBOW TROUT LENGTH FREQUENCY BELOW SPECIAL MANAGEMENT ZONE LAKE TANEYCOMO - 2013 50 45 40 35 30 25 20 15 10 5 0 Effort = 1.0 hr. 94 Total RBT/hr. N = 90 PSD (13) = 44% PSD (16) = 9% 0 3 6 9 12 15 18 21 24 Length (Inches) FISH/HR RAINBOW TROUT LENGTH FREQUENCY BELOW SPECIAL MANAGEMENT ZONE LAKE TANEYCOMO - 2012 50 45 40 35 30 25 20 15 10 5 0 Effort = 0.8 hr. 112 Total RBT/hr. N = 90 PSD (13) = 24% PSD (16) = 2% 0 3 6 9 12 15 18 21 24 Length (Inches) Figure 3. Length frequencies for Rainbow Trout sampled below Fall Creek 2012-2014. back to text 14 12 FISH/HR 10 8 BROWN TROUT LENGTH FREQUENCY LAKE TANEYCOMO - 2014 Effort = 4.7 hr. 36 Total BNT/hr. N = 170 PSD (13) = 79% PSD (16) = 44% PSD (20) = 12% 6 4 2 0 0 3 6 9 12 15 18 21 24 27 30 Length (Inches) 14 12 FISH/HR 10 8 BROWN TROUT LENGTH FREQUENCY LAKE TANEYCOMO - 2013 Effort = 4.5 hr. 61 Total BNT/hr. N = 271 PSD (13) = 75% PSD (16) = 35% PSD (20) = 3% 6 4 2 0 0 3 6 9 12 15 18 21 24 27 30 Length (Inches) 14 12 FISH/HR 10 8 BROWN TROUT LENGTH FREQUENCY LAKE TANEYCOMO - 2012 Effort = 4.3 hr. 107 Total BNT/hr. N = 463 PSD (13) = 51% PSD (16) = 7% PSD (20) = 2% 6 4 2 0 0 3 6 9 12 15 18 21 24 27 30 Length (Inches) Figure 4. Length frequencies for Brown Trout sampled in all zones 2012-2014. back to text Figure 5. 29 inch, 20.8 pound Brown Trout captured in 2014 trout sample. back to text BROWN TROUT TRIPLOID LENGTH FREQUENCY ELECTROFISHING - 2014 10 Total Fish 8 N = 33 PSD (13) = 50% PSD (16) = 8% PSD (20) = 0% 6 4 2 0 0 3 6 9 12 15 18 21 24 27 30 Length (Inches) Figure 6. Length frequency for triploid Brown Trout sampled in all zones in 2014. N = number of individuals captured. back to text LAKE TANEYCOMO BROWN TROUT LENGTH FREQUENCY FISH LADDER - 2014 25 Total Fish 20 N = 263 PSD (13) = 94% PSD (16) = 54% PSD (20) = 10% 15 10 5 0 0 3 6 9 12 15 18 21 24 27 30 Length (Inches) LAKE TANEYCOMO BROWN TROUT LENGTH FREQUENCY ELECTROFISHING - 2014 25 Total Fish 20 N = 170 PSD (13) = 79% PSD (16) = 44% PSD (20) = 12% 15 10 5 0 0 3 6 9 12 15 18 21 24 27 30 Length (Inches) BROWN TROUT LENGTH FREQUENCY ELECTROFISHING AND FISH LADDER - 2014 35 30 Total Fish 25 N = 433 PSD (13) = 89% PSD (16) = 50% PSD (20) = 10% 20 15 10 5 0 0 3 6 9 12 15 18 21 24 27 30 Length (Inches) Figure 7. Length frequencies for Brown Trout from the fish ladder, electrofishing samples, and combined in 2014. N = number of individuals captured. back to text 2014 LARGEMOUTH BASS LENGTH FREQUENCY LOWER LAKE TANEYCOMO 10 Effort = 1.96 hr. 112 Total LMB/hr. 93 Stock LMB/hr. N = 219 PSD (12) = 79% PSD (15) = 39% FISH/HR 8 6 4 2 0 0 3 6 9 12 15 18 21 24 Length (Inches) 2011 LARGEMOUTH BASS LENGTH FREQUENCY LOWER LAKE TANEYCOMO 10 FISH/HR 8 6 Effort = 1.10 hr. 100 Total LMB/hr. 82 Stock LMB/hr. N = 110 PSD (12) = 60% PSD (15) = 29% 4 2 0 0 3 6 9 12 15 18 21 24 Length (Inches) 2009 LARGEMOUTH BASS LENGTH FREQUENCY LOWER LAKE TANEYCOMO 10 FISH/HR 8 6 Effort = 1.76 hr. 24 Total LMB/hr. 19 Stock LMB/hr. N = 43 PSD(12) = 56% PSD(15) = 24% 4 2 0 0 3 6 9 12 15 18 21 24 Length (Inches) Figure 8. Lower Taneycomo Largemouth Bass length frequencies 2009-2014. back to text 2014 BLUEGILL LENGTH FREQUENCY LOWER LAKE TANEYCOMO 30 FISH/HR 25 20 15 Effort = 1.96 hr. 173 Total BG/hr. 168 Stock BG/hr. N = 340 PSD (6) = 30% PSD (8) = 0% 10 5 0 0 3 6 9 Length (Inches) 2011 BLUEGILL LENGTH FREQUENCY LOWER LAKE TANEYCOMO 30 FISH/HR 25 20 15 Effort = 1.10 hr. 61 Total BG/hr. 51 Stock BG/hr. N = 67 PSD (6) = 38% PSD (8) = 0% 10 5 0 0 3 6 9 Length (Inches) 2009 BLUEGILL LENGTH FREQUENCY LOWER LAKE TANEYCOMO 30 FISH/HR 25 20 15 Effort = 1.76 hr. 35 Total BG/hr. 35 Stock BG/hr. N = 61 PSD (6) = 31% PSD (8) = 0% 10 5 0 0 3 6 9 Length (Inches) Figure 9. Lower Taneycomo Bluegill length frequencies 2009-2014. back to text 2013 BLACK CRAPPIE LENGTH FREQUENCY LAKE TANEYCOMO - ANGLING 8 N = 46 7 Total Fish 6 5 4 3 2 1 0 3 4 5 6 7 8 9 10 11 Length (Inches) 12 13 14 15 16 Figure 10. Length frequency of Black Crappie caught via angling in Lake Taneycomo in 2014. back to text 6/3/14 7/15/14 Figure 11. Before and after aquatic vegetation treatments at Empire Park. back to text 6/3/14 7/15/14 Figure 12. Before and after aquatic vegetation treatments at Rockaway Beach. back to text Appendix A. Fish population parameters. back to text Rainbow Trout PSD (13): The percentage of Rainbow Trout > 13” that are also > 11”. PSD (16): The percentage of Rainbow Trout > 16” that are also > 11”. The objective range is 5-10%. PSD (20): The percentage of Rainbow Trout > 20” that are also > 11”. Brown Trout PSD (13): The percentage of Brown Trout > 13” that are also > 11”. PSD (16): The percentage of Brown Trout > 16” that are also > 11”. PSD (20): The percentage of Brown Trout > 20” that are also > 11”. The objective range is 3-6%. Largemouth Bass PSD12: The percentage of Largemouth Bass ≥ 8” that are also ≥ 12”. The objective range is 45%. PSD15: The percentage of Largemouth Bass ≥ 8” that are also ≥ 15”. Bluegill PSD: The percentage of Bluegill ≥ 3” that are also ≥ 6”. The objective range is 30%. PSD8: The percentage of Bluegill ≥ 3” that are also ≥ 8”. Appendix B. MDC guidelines for aquatic vegetation treatment at Lake Taneycomo. back to text Appendix B. (continued) back to text