Choke Canyon Reservoir - 2011 Survey Report

Prepared by Greg Binion and John Findeisen
Inland Fisheries Division
District 1-E, Mathis, Texas

This is the authors' summary from a 37-page report. For a copy of the complete report, use the download link in the sidebar.

Fish populations were surveyed using electrofishing (2008, 2009, 2010 and 2011), trap nets (2007, 2009 and 2011) and gill nets (2009, 2010, 2011 and 2012) to assess population trends for important sport fish communities. A creel survey was conducted during the survey period spanning 1 June 2008 to 31 May 2011. This report summarizes the results and contains a management plan for the reservoir based on those findings.

Reservoir Description

Choke Canyon is a 25,989-acre reservoir (averaged 19,975 acres in 2011- 2012) located on the Frio River in the Nueces River Basin, approximately 80 miles south of San Antonio. Its main purposes are for water supply and recreation (angling and pleasure boating). The reservoir has a history of substantial water level fluctuations. The substrate is composed primarily of silt, sand, clay, and some gravel/rock. Littoral habitat consists of native aquatic vegetation, periodically flooded terrestrial vegetation, standing timber, and seasonally abundant water hyacinth and hydrilla.

Management History

Important sport fish species include largemouth bass, blue and channel catfish, white bass, and white crappie. Recent management efforts have focused on control of nuisance aquatic vegetation, collecting catch and harvest statistics on important sport fish species, documenting catch of trophy largemouth bass, and supplementing the naturally occurring largemouth bass population through stockings in 2009 thru 2011. The district has worked with the city of Corpus Christi to develop and implement a water hyacinth control program. District staff conducted herbicide treatments on water hyacinth in 2008 (195 acres), 2009 (80 acres), 2010 (525 acres) and 2011 (45 acres). Staff annually monitored access areas where hydrilla could restrict use. Angler harvest of all sport fishes has been regulated according to statewide size and bag limits.

Fish Community

• Prey species: Gizzard shad and sunfishes (primarily bluegill and redear) formed the reservoirs forage base. Threadfin shad also contributed to the prey base. Population size structure for prey species was suitable to support sport fish populations.
• Catfishes: Although channel catfish were present, the catfish community was predominately blue catfish. Flathead catfish were also present in the reservoir, but in low numbers. The blue catfish population continued to have high relative abundance and comprised a wide size-range of fish. Angling effort and total harvest of catfishes were substantially lower in 2010-2011 compared to 2008-2009 and 2009-2010.
• White bass: Abundance and size structure of white bass was excellent in 2012. The majority of individuals collected were available for angler harvest.
• Largemouth bass: Largemouth bass abundance remained high over the survey period. Largemouth bass were the most sought species in the reservoir and the population continued to provide excellent angling opportunities. Numerous trophy-sized largemouth bass were caught and documented in creel surveys and 7 ShareLunker fish were donated to TPWD since 2009. The lake record was broken in 2009 and now stands at 15.45 pounds.
• Crappies: White crappie was the predominant crappie species and relative abundance, while low, was consistent with previous surveys. Angling effort and harvest dropped substantially in 2010- 2011.

Management Strategies

• Continue to manage sport fish populations under existing harvest regulations.
• Conduct creel survey to collect quantitative data on angler use.
• Continue to assist the city of Corpus Christi with the water hyacinth control program.
• Monitor access areas where hydrilla could restrict use.
• Stock Florida largemouth bass when water level increases.

Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-221-M-2 Statewide Freshwater Fisheries Monitoring and Management Program