Note: This item is more than six months old. Please take the publication date into consideration for any date references.

PrintPlain TextPermalink

News Release
Media Contact:
TPWD News,, 512-389-8030

Dec. 20, 2017

Golden alga returns to several West Texas reservoirs

SAN ANGELO – Biologists with the Texas Parks and Wildlife Department are monitoring increasing golden alga levels in reservoirs and rivers around San Angelo.

Golden alga is a single-celled organism that, under certain environmental conditions, can release toxins that affect fish, freshwater mussels and the juvenile stage of frogs and other amphibians. Golden alga only effects gill-breathing animals and poses no threat to humans or livestock.

Concern over increasing golden alga cell counts began when golden alga monitoring on Nov. 7 showed low toxicity in E.V. Spence Reservoir. Then in early December, anglers reported several large dead fish at the reservoir, which prompted additional samples. Water samples collected on Dec. 11 indicated moderate toxicity and a significant increase in golden alga cells in E.V Spence Reservoir.

“Although several large dead fish, including largemouth bass, catfish, and carp were reported by anglers, we have not yet seen a widespread fish kill at E.V. Spence,” said Lynn Wright, TPWD Fisheries Biologist in San Angelo. “At this time, it appears golden alga is having a limited impact on fish populations in the reservoir, but it is early in the season and further development is possible.”

Additionally, two reservoirs that have a history of golden alga problems, Colorado City and Moss Creek Reservoir, are also currently being affected. Colorado City Reservoir, which has been severely impacted annually by golden alga since 2001, showed high toxicity. Dead fish, including bullhead catfish and common carp, were also observed along the shoreline. Moss Creek had low toxicity on Nov. 7, but no dead fish were observed.

Golden alga was also found in the Concho River at Mullins Crossing at a moderate toxicity, but to date no dead fish have been observed in the Concho River. This section of the Concho River experienced a golden alga fish kill in the spring this year.

The good news is that locations where golden alga had previously been documented, including the Colorado River, O.H. Ivie Reservoir, Champion Creek and Brady Creek Reservoir were sampled and showed no toxicity in the samples.

The San Angelo fisheries management office, in coordination with other agencies, will continue to monitor golden alga throughout the winter and spring. Although large-scale treatment for golden alga is not feasible, TPWD biologists will evaluate the need for fish stocking after the golden alga blooms subside.

First discovered in Texas in 1985, golden alga (Prymnesium parvum) has since been responsible for fish kills in the Colorado, Canadian, Wichita, Red and Brazos river systems.

Additional information about golden alga and its effects on Texas reservoirs can be found online at


More Information:

Publication — Permission is granted to publish, in whole or in part, any news releases on this page.

Print — A print-friendly version of the news release shows only the release with font sizes set to the browser default.

Plain Text — Plain text versions of TPWD news releases are provided for copying and pasting into editing software.

To copy text into an editing software:

  • Click a Plain Text link to display the plain text page in your browser.
  • Select all.
  • Copy.
  • Paste in a document in your editing program.

Permalink — This is a direct link to the news release, omitting the navigation context from the URI.

English/Spanish — News releases posted in both English and Spanish have one of these links.

If you have any suggestions for improving these pages, send an e-mail to and mention Plain Text Pages.

(5.4.16 i)