Toxic algae is back in Austin’s waterways.
The city’s Watershed Protection Department is warning dog owners to keep them away from the blue-green algae growths, which can kill pets. The department said it found likely blooms at Red Bud Isle and Jessica Hollis Park on Lake Austin.
Stay safe outdoors + avoid algae. We have seen blue-green algae, which may be toxic, at Red Bud Isle on Lady Bird Lake and Jessica Hollis Park on Lake Austin. It may be mixed in with green algae in other places as well. (1/2) pic.twitter.com/FRptoR9Jdu
— Watershed Protection (@AustinWatershed) March 10, 2023
The blue-green algae contains a harmful neurotoxin. It first cropped up here in 2019 at Red Bud Isle, near Barton Springs spillway, and on the north shore of Lady Bird Lake.
While not fatal to humans, it can cause skin irritation after prolonged contact with algal blooms.
The department spotted this bloom, but has not tested it yet. It typically does tests in summer and fall.
"The blue-green algae is mixed in with lots of green algae," the department said. "Please assume it may be toxic and avoid it."
Cyanobacteria occurs in algae blooms fueled by sunlight, warmer water and runoff up the chain of Highland Lakes. Rising temperatures mean those blooms are occurring more frequently. Invasive zebra mussels are also filtering the water, allowing more sun to reach blooms.