O.H. Ivie Reservoir - 2013 Survey Report
Prepared by Mandy K. Scott
Inland Fisheries Division
District 1-C, San Angelo, Texas
This is the authors' summary from a 35-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 2013 using electrofishing and trap netting, and in 2014 using gill netting. Anglers were interviewed from June 2010 to May 2013 during a creel survey. Historical data are presented with the 2013-2014 data for comparison. This report summarizes the results of the surveys and contains a management plan for the reservoir based on those findings.
O. H. Ivie Reservoir is a 19,200-acre impoundment, when full, 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 was approximately 43 feet below conservation pool during the 2013-2014 sampling period. In April 2014, reservoir surface area totaled 3,142 acres. Habitat features consisted of standing timber, rocks, and flooded saltcedar.
Important sport fish include Largemouth Bass, White Bass, White Crappie, and catfishes. Annual electrofishing and creel surveys have been conducted since 2001 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). Annual aquatic vegetation surveys have been conducted to monitor changes in hydrilla coverage. 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.
- Prey species: Gizzard Shad increased from the previous two samples, but Bluegill decreased. Approximately two thirds of Gizzard Shad were available to existing predators. Threadfin Shad continued to be present in the reservoir. A low percentage of anglers targeted Bluegill.
- Catfishes: Blue Catfish gill netting catch rate was much higher in 2014 than in previous surveys, whereas Channel Catfish gill netting catch rate was lower. Flathead Catfish were present in low abundance. Directed effort by anglers was much higher for Channel Catfish than for Blue Catfish; however the creel survey did not account for trotline/jugline anglers that utilize the reservoir. Most legal-sized Channel Catfish that anglers caught were harvested.
- White Bass: White Bass gill netting catch rate, size structure, and body condition were good in 2014 and better than in previous surveys. Angler catch rate was also higher than in the past. White Bass up to 17 inches in length were documented in the creel survey.
- Largemouth Bass: Largemouth Bass electrofishing catch rate in 2013 was slightly less than the 15-year average of 71/h. Body condition was slightly better in 2013 than in the previous two years. Electrofishing catch rate of 18-inch-plus fish was low. The majority of O. H. Ivie anglers targeted Largemouth Bass, and the percentage of legal-size fish released was high.
- Smallmouth Bass: Very few Smallmouth Bass have been collected in recent electrofishing surveys and no anglers targeted them specifically during this survey period. However, anglers have reported catching a few Smallmouth Bass in recent creel surveys.
- White Crappie: Trap netting Catch Per Unit Effort (CPUE) of White Crappie was higher in 2013 than in previous years, and more legal-sized crappie were available to anglers.
- Remove special harvest regulation on Smallmouth Bass.
- Collect additional information on catfish and catfish anglers using non-traditional surveys.
- Work with authorities to prevent spread of invasive species in O. H. Ivie Reservoir.
- Conduct electrofishing and trap netting surveys in 2015/2016 and 2017/2018, and gill netting and vegetation surveys in 2017/2018.
Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-221-M-4 Inland Fisheries Division Monitoring and Management Program