Lake Balmorhea - 2013 Survey Report
Prepared by Mandy Scott
Inland Fisheries Division
District 1-C, San Angelo, Texas
This is the author's summary from a 14-page report. For a copy of the complete report, use the download link in the sidebar.
Fish populations in Balmorhea Reservoir were surveyed in 2013 using electrofishing, and in 2014 using gill nets. Historical data are presented with the 2013-2014 data for comparison. This report summarizes the results of the surveys and contains a management plan for the reservoir based on those findings.
Balmorhea Reservoir is a 573-acre impoundment located in the Pecos River Basin approximately 5 miles southwest of Balmorhea. Due to heavy irrigation demand, the reservoir water level usually drops severely each summer, reaching a low point in the fall, and then refills from spring inflows during the winter. Balmorhea Reservoir experienced a mild golden alga (Prymnesium parvum) bloom and subsequent fish kill in winter 2004. A severe bloom and fish kill occurred in winter 2006, and moderate blooms were observed in 2007, 2008, and 2010. Habitat was mostly nondescript (natural) shoreline or flooded dead terrestrial vegetation, with a small amount of native emergent vegetation.
Important sport fish have included Largemouth Bass, Redear Sunfish, White Crappie, and catfish species. Fish populations were mostly eradicated in August 1998 in an effort to eliminate the introduced Sheepshead Minnow and improve the sportfish population that had been overtaken by Common Carp, large Gizzard Shad, and small sportfish. Texas Parks and Wildlife Department re-stocked the reservoir with Channel and Blue Catfish, Northern Largemouth Bass, sunfish species, and White Crappie during 1998-2001. A special research project included the introduction of triploid Florida Largemouth Bass from 1999 through 2003. Genetic analyses demonstrated that some cross-breeding was occurring between Northern and Florida Largemouth Bass, indicating that not all of the stocked Florida Largemouth Bass were sterile. After a golden alga fish kill in 2004, TPWD restocked the reservoir with fingerling Blue and Channel Catfish, Bluegill, Florida and Northern Largemouth Bass, and adult White Crappie. No White Crappie have been collected in surveys since 2005; therefore trap net sampling has been suspended pending reestablishment of this population.
- Prey species: Gizzard Shad and Bluegill have declined to very low numbers.
- Catfishes: Channel Catfish were present in extremely low numbers; no Blue Catfish were collected.
- Largemouth bass: Abundance has declined to low numbers.
- Suspend stocking and other management activities until water quality conditions improve.
- Conduct at least annual water quality tests to detect changes in golden alga presence and toxicity.
- Monitor fish populations with electrofishing every other year and gill netting every four years.
- Write next management report in 2017/2018.
Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-221-M-4 Inland Fisheries Division Monitoring and Management Program