San Augustine City Lake - 2018 Survey Report

Prepared by Dan Ashe and Todd Driscoll
Inland Fisheries Division - Jasper District

This is the authors' summary from a 20-page report. For a copy of the complete report, use the download link in the sidebar.

Fish populations in San Augustine City Reservoir were surveyed in 2018 using electrofishing and trap netting and in 2019 using gill netting. 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

San Augustine City Reservoir is an impoundment of Carrizo and Caney creeks. The City of San Augustine is the controlling authority, and primary uses are water supply and recreation. This reservoir has a surface area of 200 acres, a shoreline length of 5.5 miles, and a mean depth of 10 feet. Water level fluctuations average three feet annually. Boat and bank access are adequate, with one boat ramp present.

Management History

Important sport fish include Largemouth Bass, White and Black Crappie, and Channel Catfish. Historically, hydrilla has been problematic. In 2002, coverage was 75% of the reservoir surface area, and Largemouth Bass growth and body condition were poor. During 2002 and 2003, Triploid Grass Carp were stocked at a rate of 4 fish/vegetated acre (600 fish total) in an attempt to reduce hydrilla coverage to 10-15%. In 2005, hydrilla coverage was reduced to a manageable level (50 acres), but drought conditions throughout 2006 (coupled with Triploid Grass Carp presence) resulted in the eradication of hydrilla. No hydrilla has been observed since 2006. Largemouth Bass were managed with a 14- to 18-inch slot length limit from 2004 until 2018. In 2018, the regulation was changed to the statewide 14-inch minimum length limit due to ineffectiveness and to simplify regulations statewide.

Fish Community

• Prey species: Threadfin Shad were present in the reservoir. Electrofishing catch of sunfish was adequate (combined 296 fish/h) and primarily consisted of Redbreast Sunfish, Bluegill, and Redear Sunfish. Redbreast and Redear Sunfish have the potential to support a quality fishery, as abundance of fish >6 inches was relatively high.
• Catfishes: Gill netting indicated a decrease in abundance of Channel Catfish compared to the previous two survey periods. An increase in the Redbreast Sunfish population may have resulted in increased competition for preferred food items (i.e., benthic invertebrates), suppressing recruitment and survival.
• Largemouth Bass: Largemouth Bass abundance has been consistently low over the past three surveys, a likely result of poor littoral habitat. Size structure has remained consistent, with most fish < 15 inches in length. Largemouth Bass were in average condition.
• Crappies: Only White Crappie were observed during the 2018 trap net survey; however Black Crappie have been observed in previous surveys in low abundance. White Crappie abundance from the 2018 survey was significantly less compared to the previous two survey periods. The majority of the fish collected were > 10 inches in length.

Management Strategies

Promote the quality sunfish populations in local media to establish a fishery. Monitor for invasive species and coordinate with the controlling authority to either control or eradicate any infestations that may occur.

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