Alan Henry Reservoir - 2017 Survey Report

Prepared by John Clayton and Charles Munger
Inland Fisheries Divisio
Amarillo District, Canyon, Texas

This is the authors' summary from a 39-page report. For a copy of the complete report, use the download link in the sidebar.

Fish populations in Alan Henry Reservoir were surveyed in 2017 using electrofishing and in 2018 using gill netting. Anglers were surveyed from March 2015 through May 2015 and April 2018 through June 2018 with creel surveys. Historical data are presented with the 2015-2018 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

Alan Henry Reservoir was constructed in 1993 on the South Fork of the Double Mountain Fork of the Brazos River. It is located 6 miles east of Justiceburg in Garza County, Texas. At conservation pool (2,220 feet above mean sea level; FMSL), Alan Henry Reservoir is a 2,884-acre impoundment. Productivity of Alan Henry Reservoir is characterized as low. Habitat features consist of flooded terrestrial vegetation, rocks, and very small amounts of native submerged aquatic plants.

Management History

Sport fish in the reservoir includes Blue Catfish, Channel Catfish, Flathead Catfish, Alabama Bass, Largemouth Bass, and White Crappie. Alabama Bass were managed with an 18-inch minimum length limit since their introduction in 1996 until September 1, 2011 in order to establish a self-sustaining population. Largemouth Bass harvest regulations were liberalized with the allowance of 2 fish under the 18-inch minimum length limit in 2002 to promote recruitment of fish into size classes larger than the 18 inch minimum length limit. Alan Henry Reservoir has produced 27 entries into the ShareLunker program since 2000.

Fish Community

• Prey species: Gizzard Shad and Bluegill are the primary prey species in the reservoir, and their relative abundance is low.
• Catfishes: Blue, Channel, and Flathead Catfishes were present in the reservoir. However, relative abundance was low for all three species. Angling effort targeting catfishes accounted for only 2.7% of the total angling effort at the reservoir during spring 2015 and 8.6% in spring 2018.
• Black basses: From 2001 to 2011 electrofishing catch rates of Alabama Bass have shown a general increase. In recent years catch rates have ranged between 51.0/h in 2016 and 12.0/n in 2013. The 2017 Largemouth Bass catch rate was slightly better than the Alabama Bass catch rate. The majority of Largemouth Bass sampled were less than 15 inches in length, and all Alabama Bass samples were less than 13 inches.
• White Crappie: Creel survey results report that approximately 10-26% of angler effort targets crappie each spring. White Crappie were present in the reservoir. A total of seventeen White Crappie were collected with electrofishing (N=8) and gill netting (N=9) during the 2017-2018 survey period. The majority of fish sampled were smaller than the 10-inch minimum length limit.

Management Strategies

• Recommend stocking Bluegill and Threadfin Shad each at 50 fish/acre.
• Study options for a regulation change from current black bass regulation to options which would promote an increase in Largemouth Bass over 18 inches.
• Inform the public about the negative impacts of aquatic invasive species.
• Conduct additional electrofishing surveys in 2018, 2019, 2020, and 2021.
• Conduct exploratory hoop net survey in 2019 and exploratory trap net survey in 2020.
• Access and vegetation surveys will be conducted in 2020.

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