Fayette County Reservoir - 2003 Survey Report
Prepared by C. Craig Bonds and Stephan J. Magnelia
Inland Fisheries Division
District 2-C, San Marcos, Texas
This is the authors' summary from a 28-page report. For a copy of the complete report, use the download link in the sidebar.
Fayette County Reservoir was surveyed in 2003 using trap nets and boat electrofisher, and in 2004 using gill nets. Structural habitat, aquatic vegetation, and angler access surveys were conducted in 2004. This report summarizes the results of these surveys and contains a fisheries management plan for the reservoir based on those findings.
Fayette County Reservoir is a 2,394 acre impoundment of Cedar Creek; an intermittent stream in the Colorado River watershed. It was constructed in 1978 by the Lower Colorado River Authority (LCRA) for the purpose of supplying cooling water for steam-electric power generation. The reservoir is located in Fayette County, approximately seven miles east of La Grange, Texas. The reservoir lies within the Post Oak Savannah ecological area. Water in the reservoir is maintained at a near-constant level (1-2 ft annual fluctuation). During periods of low rainfall, water is pumped into the reservoir from the Colorado River. Shorelines surrounding the reservoir are undeveloped and are used primarily for ranching and livestock grazing. Shoreline length is approximately 19 miles. Fayette County Reservoir was opened to fishing in 1979.
- Angler access: Access to the reservoir was controlled by the LCRA. The entire reservoir shoreline was owned by the LCRA, limiting bank access to two parks on the north shore. Bank fishing access was excellent within the park boundaries although, historically, excessive aquatic vegetation has limited bank angling. A public, multi-lane, concrete boat ramp was located within each park, offering adequate boat access to the reservoir. Each park contains a fishing pier accessible to physically challenged persons.
- Aquatic vegetation: The exotic plant hydrilla was present in this reservoir along with a diverse group of native aquatic plant species. Hydrilla covered as much as 8.0% of total surface acreage (192 acres) in 1986, but declined to less than 1% (< 5 acres) in 2000. The LCRA facilitated herbicide treatments to control hydrilla growth in 1984, 1985, and 1987. The 2003 survey documented the lowest amount of hydrilla coverage (1.1 acres; < 1.0%) since the invasion of the aquatic plant in the early 1980s. Hydrilla growth was relegated to the area immediately around the Park Prairie boat ramp. Summer total coverage estimates of all plant species in 2003 was 169 acres (7.0%). Marine naiad has continued to expand since 2001, comprising 87.3% (147 acres) of the total aquatic vegetation coverage in 2003. The combination of these plants offered excellent fish habitat, especially for largemouth bass and sunfishes.
- Prey species: Gizzard shad electrofishing catch-per-unit-effort (CPUE) in 2002 was 29.0/hour, which was less than in 2000 (54.0/hour), but similar to 1999 (27.0/hour). Annual variability in production of young shad has occurred, but catch rates of adult shad (> 7 inches) have been consistent (1999 = 26.0/hour; 2000 = 24.0/hour; and 2003 = 29.0/hour). The index of vulnerability (IOV) for the gizzard shad sample was 7, which suggests the majority of gizzard shad were greater than 8 inches in length, making them less susceptible to predation by most sport fish. The IOV values have varied considerably among recent surveys, ranging from 4 (1999) to 67 (2000). Threadfin shad were present in greater numbers in 2003 (393.0/hour) compared to surveys conducted in 1999 (43.0/hour) and 2000 (30.0/hour). Size structure and CPUE (129.0/hour) for bluegill did not differ greatly from previous surveys (1999 = 119.0/hour; 2000 = 84.0/hour). In each year, 3-to 5-inch bluegill dominated the sample. Redear sunfish CPUE (7.0/hour) and size structure were also consistent with previous surveys. The majority of redear sunfish collected typically measured 4 to 7 inches in length. Other sunfish and cichlid species were sampled by electrofishing in low or moderate numbers in 2003: blue tilapia, 15.0/hour; Rio Grande cichlid, 4.0/hour; green sunfish, 8.0/hour; redbreast sunfish, 2.0/hour; and warmouth, 5.0/hour. Although blue tilapia were collected in relatively low numbers by electrofishing, this species comprised the highest gill netting catch rate of any other species (19.0/net night; Appendix A).
- Catfishes: The gill netting catch rate for channel catfish in 2004 (14.8/net night) supported the assumption that the elevated 1999 catch rate (17.2/net night) was not anomalous. Prior to 1999, channel catfish catch rates were much lower (average CPUE for 1993 and 1996 = 2.3/net night). Although channel catfish relative abundance has increased since the mid-1990s, relative weights remained above 100. Blue catfish were stocked concurrently with channel catfish in 1976 into nursery ponds prior to reservoir filling, and again in 1985 and 1986 into the main reservoir, but failed to produce a viable fishery. No blue catfish have been collected in a gill netting survey since 1990 (0.4/net night). Flathead catfish were collected in the 2004 gill netting survey in low numbers (0.2/net night). Historical catch rates have varied but were typically less than 2.0/net night. This species was also introduced into the reservoir by stocking nursery ponds in 1976.
- Temperate basses: Gill net catch rates of white bass increased from 1.13/NN in 2003 to 1.20/NN in 2004. Historically white bass reached legal size at age 1. Gill net catch rates of striped bass increased slightly from 0.60/NN in 2003 to 0.67/NN in 2004. Historically striped bass reached legal size by age 3.
- Largemouth bass: The largemouth bass population has been managed under increasingly restrictive harvest regulations since opening to public angling in 1979. The current 14- to 24-inch slot-length limit was implemented in 1994 to provide greater protection for bass between 21 and 24 inches in the hopes of producing greater numbers of trophy-sized bass. Fall electrofishing catch rates under the 14- to 24-inch slot length limit were consistently high for a broad range of sizes, averaging 121.6/hour (all sizes), 79.6/hour (> 8 inches), 52.6/hour (> 14 inches), and 3.1/hour (> 21 inches) in years 1996 – 2003 (6 surveys). Catch rates under the 14- to 24-inch slot length limit have varied little from the 14- to 21-inch slot-length limit implemented in 1988 (1988 – 1993 average CPUEtotal = 138.2/hour; CPUE> 8 = 79.8/hour; CPUE>14 = 48.0/hour; CPUE>21 = 1.0/hour; 4 surveys). Spring electrofishing surveys were conducted annually from 2001 – 2004, attempting to better monitor the population characteristics of larger bass (> 21 inches). However, average spring catch rates for this size group (CPUE>21 = 3.8/hour) remained similar to fall surveys (3.1/hour). Spring surveys did sample slot-size (14 – 24 inches) fish in greater numbers and proportion than fall surveys. For example, the spring 2004 survey collected slot-size fish at a rate of 145.0/hour (69% of all fish sampled). Despite high abundance, largemouth bass grew quickly, reaching 14 inches in their third growth year (age 2), and some attained 20 inches between 4 and 5 years. Largemouth bass measuring 20 – 23 inches were comprised of at least 6 age classes (ages 4 – 9; Appendix E), and these data suggest that a minimum of 7 – 8 years would be required to reach 24 inches. Body condition typically has been excellent, evidenced by a high proportion of relative weight values exceeding 100. Florida largemouth bass fingerlings were originally stocked in 1977 into nursery ponds prior to reservoir filling. Despite few stockings, Florida bass genetic influence remained high. Electrophoresis samples collected in 2002 indicated 90% of the alleles represented Florida largemouth bass introgression, and 70% of the individuals sampled were pure Florida bass. A spring-quarter (March – May) creel survey was conducted in 2001 primarily to monitor angler catch and harvest of largemouth bass. Anglers spent 12.3 hours/acre fishing at Fayette Reservoir during those 3 months. A high proportion of all anglers (93.5%) and of boat anglers (98.4%) targeted largemouth bass. Anglers caught largemouth bass at a rate of 0.3/hour, and of those caught, 98.2% were released. The few harvested largemouth bass observed during creel surveys measured between 13 and 15 inches. Sub-slot and above-slot fish comprised 26.7% and 1.4%, respectively, of all fish caught and released. Angler catch and harvest statistics were similar to the spring-quarter 1998 creel survey, but the calculated directed angler effort (41.4 hours/acre) was much greater in 1998. Changes in methodology for measuring angler pressure likely contributed greater to this discrepancy than a significant reduction in angler effort.
- Crappie: Anecdotal evidence from anglers suggests Fayette Reservoir contained a white crappie population. No white or black crappies have been collected with any gear type in over a decade. Stockings of hybrid (black x white) crappie in 1994, 1996, and 1997 were not successful.
- Based on current information, the reservoir should continue to be managed with existing regulations. The largemouth bass population exhibited favorable characteristics of plump body condition, fast growth, and abundant numbers in a wide range of sizes. The prey base for largemouth bass appeared sufficient to sustain the predator population at levels recently observed.
- The abundance of largemouth bass greater than 21 inches, and especially over 24 inches, is difficult to monitor using current strategies (i.e., electrofishing and spring creel surveying). An annual creel survey should be conducted which includes questions related to catches of largemouth bass greater than 21 and 24 inches. A volunteer angler reporting program should be implemented to more effectively monitor catches of large bass.
- The channel catfish population has expanded since the mid 1990s, and legal-sized fish were plentiful in the 1999 and 2004 gill netting surveys. However, less than 5% of the total angling effort was directed at channel catfish in past creel surveys. This population was highly underutilized and should be promoted to anglers through appropriate media outlets.
- Hydrilla has been present in this reservoir for several decades, but has not recently covered areas large enough to be considered problematic or access inhibiting. Marine naiad has replaced hydrilla as the dominant species. These plants offer excellent habitat for littoral fishes (e.g., largemouth bass and sunfishes) and changes in plant coverage has the potential to impact fish populations. Percent coverage of all plant species will require annual monitoring to remain abreast of aquatic plant community changes.
Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-30-R-29 Statewide Freshwater Fisheries Monitoring and Management Program