Golden Alga Bloom Status Reports

Please note: Evidence of a fish kill due to golden alga may be difficult to track and discover. Large numbers of small fish may be killed, and predators such as birds and raccoons can eat the large dead fish before they are observed or counted. Additionally, the dead fish sink below the surface very quickly; this also interferes with complete counts. For this reason, an area that had large numbers of dead fish one day may show nothing the next day, while other areas that are without dead fish may have large numbers of fish die soon after. These rapid changes necessitate quick notification of kills. Accurate numbers are only as good as the evidence available on the scene. The public is asked to please report all dead or dying fish and wildlife as soon as possible to the Texas Parks and Wildlife Department. Call one of the 24-Hour Communications Centers (512-389-4848 (Austin) or 281-842-8100 (Houston)), one of the Kills and Spills Team biologists, or your local Game Warden.

View Most Recent Statewide Updates

View Reports by Basin

Texas River Basins Map
Click on a river basin above to view
expanded status reports by basin

Golden Alga Update

March 3, 2015 - Brazos River Basin

Brazos River, Kirby Reservoir, Hubbard Creek Reservoir – These three sites were sampled and showed no cell concentrations of P. parvum; the water was classified as not toxic.

Lake Stamford – Water samples showed high concentrations of P. parvum, but were classified as not toxic.

February 12, 2015 - Brazos River Basin

Lake Granbury – Water samples were taken February 5 at three locations. The sample from the US Business 377 site contained moderate cell concentrations and was not toxic. All other samples showed no trace of P. parvum.

Possum Kingdom Reservoir – Water samples were taken February 9 and showed no trace of P. parvum.

Lake Whitney – Water samples were taken on February 3. The McCowan Valley Park and Lofers Bend sites contained low cell concentrations and were classified as not toxic. The Steele Creek site showed no trace of P. parvum.

February 9, 2015 - Brazos and Colorado River Basins

Brazos River – The lower Brazos was sampled February 5 and no P. parvum cells were found.

Colorado Basin:

C.J. Kelly and Beal Park ponds in Midland were sampled February 5 and were found to have low cell concentrations and were classified as not toxic.

February 3, 2015 - Brazos River Basin

Lake Sweetwater – Water samples collected on January 31 have confirmed that the fish kill was the result of golden alga. The three sites where water samples were taken all contained extremely high cell counts and were characterized as highly toxic.

January 30, 2015 - Brazos River Basin

Lake Sweetwater - TPWD biologists are investigating a fish kill on Lake Sweetwater. The biologists reported that the dead fish were mostly common carp, but there were a few channel catfish as well. Golden alga is the suspected cause, but has not been confirmed at this time.

January 26, 2015 - Brazos and Rio Grande River Basins

Brazos Basin:

Kirby Reservoir – The boat ramp contained no P. parvum cells. The fishing pier water sample contained low cell concentrations and was not toxic.

Lake Woodson – Water samples contained low cell concentrations and were not toxic.

Hubbard Creek Reservoir – Water sampled from the bridge contained no P. parvum cells, while Stokes Ramp at the dam contained low cell concentrations and was not toxic.

Lake Throckmorton – Samples had no P. parvum cells present.

Fort Phantom Hill Lake – Samples had no P. parvum cells present.

Lake Stamford – Both the marina and west sample site had moderate cell concentrations, but neither was found to be toxic.

Rio Grande Basin:

Lake Ascarate – Lake Ascarate was sampled on January 21 and no P. parvum cells were found at the north or south sample site. The duck pond was found to have low cell concentrations and was not toxic.

January 21, 2015 - Brazos River Basin

Brazos River – The Brazos River was sampled on January 21 and no P. parvum cells were found.

January 8, 2015 - Brazos River Basin

Lake Granbury – Three sites were sampled on January 8. All three sites contained low to moderate cell concentrations and were classified as not toxic.

January 7, 2015 - Brazos River Basin

Kirby Reservoir – The Kirby boat dock was sampled on January 7 and low P. parvum cell concentrations were found and were not toxic.

Lake Daniel – The Daniel boat dock was sampled on January 7 and no P. parvum cells were found.

January 6, 2015- Brazos River Basin

Possum Kingdom Reservoir – Water samples were collected at four sites on January 6. The dam, Johnson Rd., and Deep Elm Arm sites showed no P. parvum cells. The Sandy Beach site had low cell concentrations and was not toxic.

Lake Whitney – Water samples were collected from three sites on January 6. No P. parvum cells were detected at Lofers Bend. The McCowan Valley Park and Steele Creek sites had low cell concentrations and were not toxic.

Tradinghouse Creek Reservoir – Water samples collected on January 6 and contained no P. parvum cells.

January 5, 2015 - Brazos and Colorado River Basins

Lower Brazos River – The lower Brazos River was sampled on January 5 and no P. parvum cells were found.

Colorado Basin:

C.J. Kelly Pond – Water samples from January 5 contained low cell concentrations and were not toxic.

Midland’s Beal Park Pond - Water samples from January 5 contained low cell concentrations and were not toxic.

Comanche Trails Park in Odessa – Water samples collected from January 5 showed no P. parvum cells.

December 15, 2014 - Colorado River Basin

Lake Colorado City, Moss Creek Reservoir, Lake E.V. Spence, Champion Creek Reservoir
These four sites were sampled on December 15. Moss Creek Reservoir had low cell concentrations and was non-toxic. Lake E.V. Spence contained moderate cell concentrations and was not toxic. Champion Creek Reservoir had moderate P. parvum cell concentrations and Lake Colorado City had high P. parvum cell concentrations, with the water at Lake Colorado City classified as slightly toxic and the water at Champion Creek Reservoir classified as highly toxic.

December 9, 2014 - Brazos River Basin

North Anson Lake, Hubbard Creek Reservoir, Lake Stamford, Lake Sweetwater
These four sites were sampled on December 9. Water from Stokes ramp at the dam on Hubbard Creek Reservoir had zero P. parvum cells. Water from North Anson Lake, the east end bridge of Hubbard Creek Reservoir, Stamford Reservoir and Lake Sweetwater had low cell concentrations of P. parvum and no toxic water.

November 19, 2014

Rio Grande Basin – A fish kill occurred along the Pecos River within Amistad National Recreational Area (NRA). Amistad NRA staff reported that the fish kill included gar, largemouth bass, white bass, white crappie, sunfish, shad, catfish and minnows. Six water samples were collected for golden algae (Prymnesium parvum) and four were analyzed for toxicity. All four water samples contained high cell concentrations and were characterized as highly toxic.

September 25, 2014

Colorado River Basin - An on-going fish kill at Lake Colorado City was reported by Lake Colorado State Park staff. Approximately 300-500 fish have died and are at different stages of decay. The fish range from large carp to small sunfish/bait fish. They are believed to have died near the dam/southern end of the lake based on two days of strong northwestern wind, which has pushed the fish onto the state park shoreline. Two water samples collected for golden algae contained high cell concentrations and was characterized as highly toxic.

January 30, 2014

Brazos River Basin – Lake Sweetwater is currently experiencing a fish kill. Affected species are mostly forage fishes. TPWD is monitoring the situation and will plan to do recovery stockings once the golden alga bloom subsides. 

January 27, 2014

Colorado River Basin –TPWD investigated a fish kill on Lake E.V. Spence that was dominated by shad, sunfish and silversides. Water samples indicated dense golden alga bloom; characterized as highly toxic.

September 9, 2013

Colorado River Basin – Things are quiet along the Colorado. Water samples collected from Lake Colorado City State Park, Moss Creek and Lake E.V. Spence all contained low to moderate cell concentrations and nontoxic water.

September 3-4, 2013

Red River Basin – Lake Arrowhead was sampled at the state park and Deer Creek. No P. parvum were found in either sample. A number of sites along the Red River were sampled as well; very high cell concentrations were found at County Road 2940 but the water was not toxic. Moderate cell concentrations and nontoxic water were found Highway 79 and Highway 81, and low concentrations and nontoxic water were found at Ketchum Bluff.

July 2013 – Brazos, Colorado and Red River basins

Brazos River Basin – Lake Possum Kingdom
A water sample collected at the dam on June 25 contained low concentrations of P. parvum and nontoxic water.

Colorado River Basin – Lake Colorado City, Moss Creek Reservoir, E.V. Spence Reservoir
Three sites along the Colorado were sampled on July 1. Water from Lake Colorado City State Park contained moderate cell concentrations and moderately toxic water. The Moss Creek boat ramp and Wildcat Recreation Area at Lake E.V. Spence both contained moderate cell concentrations and slightly toxic water.

Red River Basin – Lake Texoma
Water samples were collected June 18. The highway 377 sample had moderate P. parvum concentrations and nontoxic water, while the sample collected at the island contained low cell concentrations and slightly toxic water.

May 1-9, 2013 – Brazos and Rio Grande Basins

Brazos River Basin – Water collected on Wednesday from the Possum Kingdom dam contained low concentrations of golden alga in a mixed algal community; the water was not toxic. A minor fish kill consisting mostly of shad is occurring on Squaw Creek Reservoir. Three water samples were collected on May 1; all samples contained low to moderate concentrations of P. parvum and toxicity ranged from low to moderate as well.

Rio Grande Basin – On Monday, May 6, Salt Creek was sampled at FM 652. Algal densities were low overall and no P. parvum cells were found.

April 16-17, 2013

Colorado River Basin
Water samples were collected from a number of sites along the Colorado River on Wednesday, April 17. Lake Colorado City State Park, Moss Creek Lake, Twin Buttes Reservoir and E.V. Spence Reservoir had no P. parvum. Lake Nasworthy contained low concentrations of the alga. All sites had nontoxic water.

Brazos River Basin
A water sample collected Tuesday, April 16 from the dam at Possum Kingdom Reservoir contained no P. parvum cells and nontoxic water. Three sites on Lake Whitney were also monitored; McCown Valley Park, Steele Creek and Lofers Bend all has nontoxic water and low concentrations of P. parvum.

April 1-12, 2013 – Brazos and Rio Grande basins

Brazos River Basin

Possum Kingdom Reservoir – On Thursday, April 11, water samples were collected from the dam, Johnson Road, Sandy Beach and the Deep Elm Arm. P. parvum concentrations were low and the water was nontoxic.

Lake Granbury – Water samples collected April 11 from the dam, FM 51 and US 377 all contained low cell concentrations and nontoxic water.

Lower Brazos River – No P. parvum were found in samples collected April 2 from US 59 at Richmond, Brazos Bend State Park or Brazoria County Road 849.

Rio Grande Basin

Lake Ascarate - Water samples collected Monday, April 1 from the bridge, duck pond and boat ramp all contained moderate concentrations of P. parvum cells and nontoxic water.

March 21, 2013 – Brazos River Basin

Water samples collected Monday at FM 200 near Glen Rose contain moderate concentrations of P. parvum and moderate-high toxicity.

Dead shad, yellow water and foam were reported Thursday on Lake Possum Kingdom, particularly in the areas of Cedar Creek, Caddo Creek and South D and D. Golden alga is the suspected cause. Water samples collected on Monday found low concentrations of P. parvum and nontoxic water at the dam, FM 51 and U.S. Highway 377.

March 14, 2013 – Brazos River Basin

The fish kill on the Clear Fork of the Brazos River has been confirmed to be P. parvum-related. The water sample contained highly toxic water and very high concentrations of P. parvum.

Fish kills have been reported on Lake Granbury and on the Paluxy River at Glen Rose. P. parvum is suspected but not confirmed at this time.

Three sites along the lower Brazos River were sampled on March 13: Highway 59 at Rosenberg, Brazos Bend State Park and Brazoria County Road 849. P. parvum was not found in any of the samples.

March 12-13, 2013 – Brazos and Colorado basins

Brazos River Basin – Biologists are investigating a fish kill on the Clear Fork of the Brazos downstream of Eliasville. The fish are a mixture of old dead and fresh dead. Golden alga is suspected but has not been confirmed at this time.

Colorado River Basin – A water sample taken at Lake Colorado Colorado City State Park contained low cell concentrations of P. parvum, while samples taken at the Moss Creek boat ramp and Lake E.V. Spence at Wildcat Creek contained no cells. All water was nontoxic.

March 5-6, 2013 – Brazos River Basin

Lakes Possum Kingdom and Whitney

Samples were collected at Possum Kingdom. No P. parvum cells were found at Johnson Road or the Deep Elm arm, and samples taken at the dam and Sandy Beach only contained low cell concentrations. All samples contained nontoxic water.

Sampling on Lake Whitney yielded both toxic and nontoxic water. Moderate cell concentrations and moderately toxic water were found at the SH 174 bridge. Moderate concentrations were also found at Steele Creek, but the water was nontoxic. Low concentrations and nontoxic water were found at FM 1713 and the Nolan River. No cells were in the sample collected from the dam.

February 20, 2013 – Rio Grande Basin

Lakes Balmorhea and Ascarate

Lake Balmorhea was monitored on Wednesday, February 20; no P. parvum cells were found and the water was nontoxic. The news is not so good for El Paso’s Ascarate Lake. Samples collected February 20 at the fire station, the bridge and the boat ramp all contained moderate concentrations of p. parvum and the water was found to be moderately to highly toxic. Due to the toxic bloom, TPWD has decided not to stock 2000 rainbow trout into Ascarate Lake as planned. Those fish will instead go into the lake at Comanche Trails Park in Odessa.

February 15, 2013 – Red, Brazos and Rio Grande Basins

Red River Basin – Two samples were collected from Plum Lake on Wednesday, February 13. One contained no P. parvum cells and the second contained low numbers of cells; the water was not toxic in either sample and both contained lots of sediment and a diverse algal community.

Brazos River Basin – Lakes Whitney and Granbury

Water samples were collected Tuesday, February 12 at Lake Whitney. The Steele Creek location contained no P. parvum cells. McCowan Valley and Lofer’s Bend both had low concentrations of P. parvum but the water was not toxic and the algal community was diverse.

A fish kill has been occurring at Lake Granbury since the end of January. The makeup of the event has differed from typical golden alga events; most of the dead fish have been carp, gar, catfish, drum and crappie. Only a few minnows and shiners have been found. Water samples collected on Wednesday, February 6 confirmed the presence of P. parvum; low concentrations and slightly toxic water were found at the dam, with moderate to high concentrations at FM 51 and Highway 377. The FM 51 and Highway 377 sites also had highly toxic water.

Rio Grande Basin – Salt Creek was sampled at FM 652. Algal densities were low overall and no P. parvum cells were found.

top of page


Aditional Information:

Would you like to know more?
The Biology of Golden Alga summarizes what we know about the alga and its toxins.

Where does golden alga fit compared to other single-celled organisms?
The Golden Alga Family Tree gives examples of and information about golden alga and other protists.

What does golden alga look like?
TPWD Golden Alga Images has photos of fish kills, golden algal cells, and short videos of live golden alga. These images may be used for noncommercial/educational purposes as long as TPWD is given credit and other site policies are followed.

Golden Alga Information Card: TPWD has collaborated with the Texas Commission on Environmental Quality and other entities to produce a golden alga information card. Download a PDF from the TCEQ website or request a free hard copy from TPWD at hab@tpwd.texas.gov.

Back to Top
Back to Top