O.H. Ivie Reservoir - 2017 Survey Report

Prepared by Lynn Wright
Inland Fisheries Division
San Angelo District

This is the author's summary from a 32-page report. For a copy of the complete report, use the download link in the sidebar.

Fish populations in O.H. Ivie Reservoir were surveyed in 2017 using electrofishing and trap netting and in 2018 using gill netting. Historical data are presented with the 2017-2018 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

At conservation pool, O.H. Ivie Reservoir is a 19,200-acre impoundment and is located on the Colorado and Concho Rivers in Concho, Runnels, and Coleman counties, Texas, approximately 55 miles east of San Angelo. Water level fluctuations are common; the reservoir surface elevation ranged from 37 to 40 feet below conservation pool during the 2017-2018 sampling period. In May 2018, reservoir surface area totaled 5,034 acres. Habitat features consisted of standing timber, rocks, and flooded saltcedar.

Management History

Important sport fish include Largemouth Bass, White Bass, White Crappie, and catfishes. Annual electrofishing and creel surveys were conducted from 2001 to 2013 to evaluate the effectiveness of the 2001 Largemouth Bass length limit change (from 18-inch minimum length and 5-fish bag to a 5-fish bag, 2 of which may be <18 inches). The 18-inch MLL on Smallmouth Bass was removed in 2015 and replaced with statewide regulations. A variety of fish species have been stocked in the reservoir including Threadfin Shad; Bluegill; Channel, Blue and Flathead Catfishes; Florida Largemouth Bass; Smallmouth Bass; White Crappie; and Walleye. Walleye stockings were discontinued after failing to produce a fishery.

Fish Community

• Prey species: Threadfin Shad were present in the reservoir in low abundance. Electrofishing catch of Gizzard Shad was below average and Gizzard Shad IOV was poor. Electrofishing catch of Bluegill was higher than average with most fish measuring between 4 to 5 inches.
• Catfishes: Blue, Channel, and Flathead Catfish are all present in the reservoir, but gill net catch rates were too low to accurately assess the population.
• White Bass: White Bass were present in the reservoir in good abundance. Many legal size White Bass were present with fish up to 16 inches.
• Largemouth Bass: Stock size Largemouth Bass abundance was above average due to a strong year-class from 2016, while abundance of bass over 18 inches was near historical averages. Size structure continued to be poor with approximately 7% of catchable size bass over 15 inches.
• White Crappie: White Crappie catch rates in trap nets were low, but fish up to 13 inches were collected. Good numbers of small crappie indicate a successful year-class was produced in 2017.

Management Strategies

• Continue to stock Florida Largemouth Bass contingent upon adequate water levels and habitat.
• Discontinue trap netting for White Crappie due to poor catch rates.
• Conduct additional electrofishing surveys in 2018, 2019, and 2020, and general monitoring surveys with gill nets and electrofishing surveys in 2021-2022.
• Additional vegetation surveys will be conducted in 2018, 2019, and 2020 to survey hydrilla coverage.
• Access and vegetation surveys will be conducted in 2021.
• Conduct year-long creel survey in 2019-2020.
• Water samples will be taken annually to monitor for golden alga cell counts and toxicity.

Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-221-M-3 Inland Fisheries Division Monitoring and Management Program