Timpson Reservoir - 2020 Survey Report

Prepared by Dan Ashe and Todd Driscoll
Inland Fisheries Division
Jasper District, Brookeland, Texas

This is the authors' summary from a 26-page report. For a copy of the complete report, use the download link in the sidebar.

Fish populations in Lake Timpson were surveyed in 2020 using fall electrofishing and trap netting and in 2021 using spring electrofishing (Largemouth Bass only). Historical data are presented with the 2020-2021 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

Lake Timpson is located in Shelby County. The Shelby County Freshwater Supply District is the controlling authority. Primary uses are water supply and recreation. This reservoir has a surface area of 223 acres, a shoreline length of 8 miles, and an average depth of 8 feet. Water level fluctuations average 1-3 feet annually. Boat and bank access are adequate, with one boat ramp present.

Management History

Important sport fish included Largemouth Bass and crappie. Prior to 1994, Largemouth Bass were managed under statewide regulations. In 1994, Largemouth Bass regulations were changed to a 14- to 21-inch slot length limit. This regulation has had the desired effect of producing increased numbers of Largemouth Bass that are within the protective slot length limit. In 2003, hydrilla was found in Lake Timpson, and coverage expanded to 40% of the reservoir surface area in 2004. Triploid Grass Carp were stocked in 2004 at a rate of 5 fish/vegetated acre (448 fish) to reduce hydrilla coverage. Since 2006, no hydrilla has been observed. In 2010, giant salvinia was discovered, and eradication efforts were attempted with numerous herbicide treatments; no plants were observed in 2011 or 2012. However, giant salvinia reappeared in 2013 and coverage peaked at 13 acres in 2017. Since then, routine herbicide treatments have maintained abundance at < 1 acre.

Fish Community

• Prey species: Threadfin and Gizzard Shad were present in the reservoir, with Gizzard Shad first detected in 2016. Since the previous survey in 2016, electrofishing catch rates of Redbreast Sunfish and Bluegill increased while Redear Sunfish relative abundance decreased. Potential exists for a sunfish fishery, as a high number of Redbreast and Redear Sunfish > 6 inches were collected.
  
• Catfishes: Blue Catfish were stocked in 1998, but only four large fish (> 36 inches) have been collected since 2008, indicating no natural recruitment. Channel Catfish catch in past surveys has also been low, indicating poor recruitment. Anecdotal information indicates few anglers target catfish. Directed sampling effort for catfish was discontinued in 2016.
  
• Largemouth Bass: Largemouth Bass were relatively abundant. Population size structure from recent surveys indicate the protective slot length limit has had the desired effect, with an abundance of Largemouth Bass within the 14-21 inch slot length limit. Largemouth Bass had adequate growth rates and were in moderate condition.
  
• Crappies: White Crappie abundance was relatively low. Black Crappie were abundant, although trap net catch rates in 2020 did decline from those observed in 2016. High numbers of legal length fish were available to anglers.

Management Strategies

• Continue to manage Largemouth Bass with a 14- to 21-inch slot length limit.
• Continue to monitor trends of hydrilla and giant salvinia coverage through annual aquatic vegetation surveys.
• Promote status of crappie and sunfish populations in local media to increase interest in these fisheries.

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