AUSTIN (KXAN) — Trace amounts of cyanobacteria, better known as blue-green algae, are present at multiple City of Austin testing locations in Lady Bird Lake, and that prompted city officials to issue a warning Monday.

The current risk level is classified as high even though there are only trace amounts detected, but with temperatures still very hot and stagnant spots in the lake, blue-green algae has an increased chance to thrive.

Blue-green algae toxins have been found most recently at the city’s testing sites at Red Bud Isle and Festival Beach. Those areas came back with positive readings July 13. Those areas also came back as having algal mats present July 13. Auditorium Shores also came back as having algal mats on July 9 but not July 13, and has not tested positive for toxins.

The city says currently the toxin is contained within the algae itself, it’s not in the water yet, so exposure to the toxin is done through touching or eating the algae.

The city tests for blue-green algae on a weekly basis, typically at 1:30 p.m., so most of the sites are due for a test Monday. The city tests at Red Bud Isle, Auditorium Shores, the mouth of Barton Creek and Festival Beach.

Any time the water temperature reaches 81 degrees or above, along with a flow of less than 600 cubic-feet per second, chances for blue-green algae to grow are increased.

The bacteria is especially harmful to dogs, so it’s best to check the city’s algae information dashboard every time you think about taking your pooch for a swim. The best advice is to go where water is flowing and isn’t stagnant, city officials say.