Delta Lake - 2008 Survey Report
Prepared by John Findeisen and Greg Binion
Inland Fisheries Division
District 1-E, Mathis, Texas
This is the authors' summary from a 23-page report. For a copy of the complete report, use the download link in the sidebar.
Fish populations in Delta Lake were surveyed in fall 2008 using trap nets and electrofishing and in spring 2009 using gill nets. This report summarizes the results of the surveys and contains a management plan for the reservoir based on those findings.
Delta Lake is a 2,261-acre reservoir located in Hidalgo County, 2.5 miles north of Monte Alto. The reservoir is divided into a public section (approximately 1,500 acres, east side) and a private section (approximately 761 acres, west side). The two sections of the reservoir are divided by State Highway 88 and are only connected via a pipeline. The reservoir is used for water supply, irrigation and recreation. The lake is very shallow and turbid. Substrate is composed primarily of small rock, clay, sand and silt. Littoral habitat consists of periodically flooded terrestrial vegetation, large stands of bulrush and cattail, and standing timber.
Important sport fish species included channel catfish, white bass, largemouth bass, and white crappie. Exotic species include grass carp and suckermouth catfish collected from the reservoir since the last report. The previous fisheries management plan focused on rebuilding the fisheries following the 2004 reservoir renovation projects, habitat enhancement, and the construction of a boat ramp. During summer 2004, the Delta Lake Irrigation District began draining the reservoir to begin a bank stabilization project and construct a canal on the east side of the reservoir for the purposes of moving water around the reservoir for irrigation needs during drought years. Both projects were completed in March 2006, however, the reservoir was reduced to approximately 300 acre-feet throughout the project. Fisheries enhancement included stocking both predator (i.e., largemouth bass and channel catfish) and prey species as needed, and monitoring the fisheries with supplemental surveys. Reservoir enhancement projects consisted of flooding terrestrial vegetation in the spring and initiating the process to construct a boat ramp.
- Prey species: Gizzard and threadfin shad were the primary prey species and appeared to have recovered following the renovation project. Nearly all shad were of sizes available to most predators. Sunfish, were present in the reservoir but not abundant. Sunfish abundance appeared to still be recovering following the renovation project. Bluegill were stocked in 2007.
- Catfishes: Blue catfish, not previously established in the reservoir, appeared to be expanding. Channel catfish, once abundant in the reservoir, appeared to still be recovering following the renovation project. Channel catfish were stocked in 2007.
- White bass: White bass were not as abundant as they were before the renovation projects.
- Largemouth bass: Despite two stockings of Florida largemouth bass (2007 and 2008), few largemouth bass were collected and a fishery failed to develop, suggesting problems with survival and possibly recruitment to larger sizes.
- Crappie: White crappie were not as abundant as they were before the renovation projects.
- Continue managing the fish populations under current regulations.
- Continue to work with the Delta Lake Irrigation District on optimizing water level fluctuations as a method for enhancing fish habitat and possibly controlling exotic flora and fauna.
- Consider stocking advanced fingerling largemouth bass.
- Continue to monitor recovery of sport fish populations and exotic fish species population growth in the reservoir.
- Write and distribute press releases concerning the blue catfish angling opportunities.
Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-30-R-34 Statewide Freshwater Fisheries Monitoring and Management Program