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Toxic algae in Lake Marble Falls, Inks Lake

LCRA finds toxin in algae samples from Lake Marble Falls, Inks Lake

The Lower Colorado River Authority is urging people not to let their dogs play near or ingest algae from the Highland Lakes after blue-green algae samples from three locations taken March 16-17, including near the city of Cottonwood Shores boat ramp, showed low levels of cyanotoxins. Staff photo by Daniel Clifton

The Lower Colorado River Authority reported that blue-green algae samples collected from Inks Lake and Lake Marble Falls on March 16-17 tested positive for cyanotoxins, which can be fatal to dogs.

The authority also located additional blue-green algae on Lake Travis that also tested positive for cyanotoxins. The LCRA reported toxic samples from Travis earlier in March.

LCRA collected blue-green algae samples from five Highland Lakes — Buchanan, Inks, LBJ, Marble Falls, and Travis — March 16-17. Samples collected from monitoring sites on lakes LBJ and Buchanan did not test positive for cyanotoxins. 

However, officials are still warning people against letting their dogs play near or ingest algae in any of the Highland Lakes.

“The key here is not to let your guard down,” said John Hofmann, LCRA executive vice president of Water. “We encourage people in the strongest terms possible not to let dogs play near algae in the lakes. Our tests show what was present at a specific site we tested on the day we took the samples, but conditions change.”

In late February, two dogs died and five more became ill after swimming near the Lake Travis Landing neighborhood by Hudson Bend or Comanche Point, located on the opposite side of the lake. On March 3, LCRA staff collected blue-green algae samples from Lake Travis, and samples from 10 sites came back positive for the cyanotoxins.

During the more recent rounds of sample collection and testing, LCRA reported that low concentrations of cyanotoxins were detected in algae taken from the shoreline near the Inks Lakes State Park boat ramp and the Cottonwood Shores boat ramp on Lake Marble Falls. 

The amount detected was much lower than what was detected downstream at Hudson Bend on Lake Travis earlier in March, officials said. LCRA staff collected samples from the Travis Landing area near Hudson Bend again during March 16-17, and tests detected cyanotoxins but at lower levels than previous tests.

Algae naturally occurs in Texas waters and most of it is harmless. However, some, such as blue-green algae, a cyanobacteria, can produce toxins that are harmful to humans or animals. Dogs are particularly susceptible to blue-green algae because they often play, swim, and drink in shallow water.

It can also be difficult to determine if an algae is the blue-green variety or another type just by the color as blue-green algae can appear dark green, brown, and black. 

“Blue-green algae are common in Texas lakes, and it is not easy to predict if or when algae will start producing toxins,” Hofmann said. “Out of an abundance of caution — whether our tests detected toxic algae in the area or not — we encourage people to avoid contact with algae in the lakes and to especially make sure dogs don’t play in or eat it.”

For more information, visit the LCRA’s Algae in the Highland Lakes webpage.