Dunlap Reservoir - 2017 Survey Report

Prepared by Dusty McDonald and Greg Binion
Inland Fisheries Division
Corpus Christi District, Mathis, 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 Lake Dunlap were surveyed in 2017 using electrofishing and trap netting and in 2018 using gill netting and additional trap 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

Lake Dunlap is a 410-acre impoundment located in New Braunfels, Texas and is part of the Guadalupe River chain lakes. Lake Dunlap is classified as a mainstream reservoir and has a fairly constant water level. Substrate in the upper section is composed primarily of rock and gravel, while the middle and lower sections of the reservoir are composed of clay, sand, and silt. Habitat features included boat docks, rocks, flooded timber, and several native vegetation species.

Management History

Important sport fish include Channel and Flathead Catfishes, Largemouth Bass, and crappie species. The management plan from the 2013 survey report focused on refining trap net sampling for crappies, monitoring and management of invasive vegetation, supplement losses of fisheries habitat with a native vegetation planting, and publicizing the Largemouth Bass and catfish populations.

Fish Community

• Prey species: Gizzard Shad and sunfishes (primarily Redbreast Sunfish and Bluegill) formed the reservoirs forage base. Catch rates of Gizzard Shad have increased since the 2013 report whereas sunfish species have decreased within the same timeframe. Prey species populations were comprised primarily of small size classes benefitting most predatory fish species. Several larger (> 6 in) Redbreast Sunfish were collected providing anglers with excellent angling opportunities.
• Catfishes: Blue, Channel, and Flathead Catfish were present in the reservoir, with Channel Catfish being the predominant species. Harvestable-sized catfish in the population were abundant; the majority of fish sampled were greater than legal length limits. Body condition of larger-sized Channel and Flathead Catfish was excellent. Two Channel Catfish over 32” were collected signifying Memorable (Memorable-size) opportunities for anglers.
• Largemouth Bass: Smallmouth and Largemouth Bass were present in the reservoir with Largemouth Bass being the predominant species. Largemouth Bass relative abundance has decreased since the 2013 report, however, body conditions have since improved. A few Largemouth Bass over 20” were collected during the fall electrofishing survey and two fish were entered into the ShareLunker program in early 2018 as Legacy Class (between 8.0 – 9.9 pounds) catches.
• White Crappie: White Crappie were present in the reservoir in low abundance. Fall and spring trap net surveys at both random and biologist-selected stations resulted in low, inconsistent catch rates and poor data resolution (i.e., high RSEs).

Management Strategies

• Continue to manage fisheries under the current regulations.
• Continue to monitor the reservoir for nuisance aquatic vegetation through vegetation surveys.
• Conduct a creel survey to gather baseline fisheries dependent data.
• Stock Florida Largemouth Bass to maintain trophy production potential in the population.

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