Walter E. Long Reservoir - 2018 Survey Report

Prepared by Mukhtar Farooqi and Marcos J. De Jesus
Inland Fisheries Division - San Marcos-Austin District

This is the authors' summary from a 38-page report. For a copy of the complete report, use the download link in the sidebar.

Fish populations in Walter E. Long Reservoir were surveyed in 2018 using electrofishing and in 2019 using gill netting. Anglers were surveyed from September 2018 through November 2018, and March 2019 through May 2019 with a creel survey. Historical data are presented with the 2018-2019 data for comparison. This report summarizes the results of the surveys and contains a management plan for the reservoir based on those findings.

Reservoir Description

Walter E. Long Reservoir is a 1,269-acre constant-level impoundment of Decker Creek, a tributary of the Colorado River, and is located east of Austin, Travis County, Texas. The dam was constructed in 1967 for supplying water to a power plant operated by the City of Austin. The reservoir is eutrophic, has a drainage area of 9.3 square miles, a shoreline length of 16 miles, and a shoreline development index of 3.3. The reservoir lies within the blackland prairies ecological region. Habitat features consisted of standing timber, rocks, native submerged aquatic plants, and hydrilla.

Management History

Important sport fish included Largemouth Bass, Hybrid Striped Bass (Palmetto Bass and Sunshine Bass), and Channel Catfish. Palmetto Bass were stocked from 2007-2010 at a reduced rate of 5/acre to evaluate density-dependent growth and condition of the predatory fish population. Sunshine Bass were first stocked in 2014 in addition to Palmetto Bass, and separately in 2015. Largemouth Bass have been managed since 1993 with a 14- to 21-inch slot-length limit. An analysis of that length limit change suggested it had been successful in increasing density and angler catch rate of bass greater than 14 inches in length. However, anglers did not harvest enough sub-slot fish which we believed would increase growth rates. Florida Largemouth Bass were last stocked in 1995. Aquatic vegetation habitat surveys have been conducted annually to monitor invasive species and evaluate angler access conditions.

Fish Community

• Prey species: Redbreast Sunfish, Bluegill, Redear Sunfish, and Threadfin Shad were the predominant prey species. Inland Silverside and Gizzard Shad were also available as prey, but the Index of Vulnerability (IOV) for Gizzard Shad was zero, indicating that no Gizzard Shad of vulnerable size (≤ 8 inches) were available to existing predators. Large sunfish, up to 10 inches in length were present.
• Channel Catfish: Abundance, size and body condition of Channel Catfish were excellent. This is one of the best Channel Catfish fisheries in the district. Fish up to 27 inches in length were present.
• Hybrid Striped Bass: Overall abundance was good and there was an increase in harvestablesize fish (≥18 inches) in the last two surveys. Body condition was good (>90) for most length classes of fish. On average, Hybrid Striped Bass reached legal length (18 inches) between age 2 and 3. The largest fish sampled measured 24 inches in length.
• Largemouth Bass: Largemouth Bass: Largemouth Bass were very abundant, displayed good body condition, and adequate growth. Fish above the slot limit (≥ 21 inches) were present as well. This is the most sought-after species at this reservoir. • Smallmouth Buffalo: The Smallmouth Buffalo population provides a low-density trophy fishery. Thirteen Smallmouth Buffalo were caught (and released) with gill nets, weighing from 22.9 lbs to 60.6 lbs; eight of the fish caught were over 40.0 lbs each.

Management Strategies

Continue stocking Hybrid Striped Bass at 5 fish/acre for Palmetto Bass fingerlings and/or an equivalent rate for Sunshine Bass fry. Promote the excellent Channel Catfish fishery. Inform the public about the negative impacts of aquatic invasive species. Continue monitoring for Smallmouth Buffalo and determine age and growth characteristics. Conduct additional electrofishing and gill netting surveys in 2020-2021, and general monitoring surveys with gill nets and electrofishing surveys and an access survey in 2022-2023. Aquatic vegetation surveys should be conducted annually to monitor invasive species.

Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-221-M-5 Inland Fisheries Division Monitoring and Management Program