The patch of algae to the east of the boat ramp continues to expand but LCRA does not intend to conduct any more tests for now, even though low levels of dihydroanatoxin-a and two other toxins were detected there earlier this month. LCRA does not have the resources to conduct single water samples all over Lake Travis hence the preference for SPATT bags to monitor toxin levels over a longer period of time. Unfortunately, there are no test strips for dihydroanatoxin-a so we can’t do the testing ourselves.

 

 

On a more positive note, LCRA is working closely with the City of Austin to research possible ways to treat toxic algae and has been following the Red Bud Isle experiments that started back in June of last year. The Watershed Protection department spent $300,000 on three treatments of Phoslock, a grey clay-like material that binds phosphorus in surface water and sediment, to see if it could reduce nutrient levels and the amount and/or toxicity of blue-green algae. The pilot area of about 20 acres of Lady Bird Lake also received 50 biochar units (which work rather like Brita water filters) in a separate experiment.

 

While the results of the pilot program have not yet been announced, a person familiar with the projects said that both show promise for small bodies of water that experience planktonic blooms. Less is known about the effectiveness on benthic blooms such as those occurring in Lake Travis. The sheer size of Lake Travis would make these types of treatments very expensive in any case. Studies have also shown that while biochar and Phoslock can bind up nutrients in the water column, the subsequent die off of algae results in more toxins being released as cell death occurs.

 

At this time, LCRA has no intention of using Biochar or Phoslock in the Highland Lakes. Binding up excess nutrients in small areas may make sense in privately owned ponds and bodies of water, but more information is needed to understand how it would impact the lake ecosystem at large. There are important, non-harmful algae and plant species that rely on nutrients to provide food for all the organisms in the lake.

 

For more information about the experiments click on the following link: Harmful Algae Mitigation | AustinTexas.gov

 

Here is a summary of the most recent Travis Landing results collected by John Anderson and LCRA. To see historic data going back to May 2021, go to the LCRA Site List and see the entry for Site 463 (Travis Landing), located in segment 1404.