Austin investigating algae at Bull Creek after swimmer falls ill

The release did not specify details of the swimmer’s illness, but common symptoms of toxic algae exposure include fever, headache and eye irritation as well as gastrointestinal, neurologic and respiratory signs.

Locally, blue-green algae has also been connected to the death of dogs. The city of Austin is aware of five dogs who died after swimming in Lady Bird Lake in 2019. Similarly, west of Austin, the Lower Colorado River Authority reported multiple dogs had fallen ill earlier this year after swimming in Lake Travis. In dogs, symptoms of algae exposure can include vomiting, excessive drooling and respiratory paralysis, among other ailments.

Following these incidents, both the city of Austin and the LCRA have been regularly updating the community on the presence of blue-green algae in local waterways. Samples collected from Red Bud Isle on July 20 detected low levels of dihydroanatoxin, a toxin emitted by cyanobacteria, according to Austin’s Aug. 6 update. The city is continuing biweekly monitoring of Lady Bird Lake and Lake Austin and will display results on online dashboards.

“To date, the city of Austin has only detected toxins in mats of algae that can be found growing on the bottom of the lake or floating on the surface,” the release stated.

Based on those results, the city said toxic algae exposure would occur after touching or swallowing visible algae. Austin is encouraging the public to report signs of exposure in people or pets by calling 311 or 512-974-2000.