AUSTIN (KXAN) — Since 2019, toxic blue-green algae in the Highland Lakes has been linked to the deaths of seven dogs in the Austin area. It has also caused people who live here to change the way they play in the summertime. But will this be the new normal we have to adjust to?
Dr. Brent Bellinger, the city’s chief algae scientist and a dog owner himself, is working with a team to discover the long-term effects of blue-green algae in Austin.
“Cyanobacteria actually evolved three billion years ago. That’s with a B,” Dr. Bellinger said. “Unfortunately, in July of 2019, we received reports of dogs that had gotten ill and passed away at Redbud Isle and down at Auditorium Shores.”
Dr. Bellinger and his team sent samples of this slimy algae to the University of Texas and Texas A&M-Corpus Christi, who both independently confirmed the presence of a potent neurotoxin. Since then, dog owners have had to be very conscious of where they let their furry friends cool off.
“Obviously we can’t sample the entire reservoir. The algae does move,” Dr. Bellinger said. “So it could be anywhere at any time.”
So how exactly did we get here? A few things are to blame.
“The invasion and proliferation of zebra mussels. And they’re known ecosystem engineers,” Dr. Bellinger said. “But also our land use, development, and increased use of fertilizers and other organic matter on our nicely-manicured lawns.”
Dr. Bellinger says warmer water due to climate change is responsible as well.
“The incidence, occurrences, magnitude, frequency and toxicity of the cyanobacteria is increasing across water bodies,” Dr. Bellinger said.
It may not be a coincidence that we first detected the toxins here in 2019. That was just after the historic October 2018 floods on the Highland Lakes.
“Lake Superior, about a decade ago, had a 500-year flood event at the headwaters,” Dr. Bellinger said. “And it turned the river estuary into chocolate milk like what we saw here in the Highland Lakes. And all of that organic matter, sediment, nutrients moving along the coast and out to the Apostle Islands stimulated a cyanobacteria bloom that basically never happens out there.”
Even though a weather event in part caused this problem, Dr. Bellinger doesn’t foresee a weather event that could end it. The City is relying on signage and education, a nutrient management program that tries to sink the toxins, and incentivizing homeowners to replace green lawns with native vegetation and rain gardens. These help slow runoff into creeks, preventing sudden flow spikes during floods, and keep some of the harmful chemicals out of the lakes.
“While we don’t want people to just accept it as the new norm, we do want people to be aware and be cautious while they’re out here. While we at the city, our partners and researchers across the globe try to find solutions to these problems,” Dr. Bellinger said.
The City of Austin says that toxins have only been detected in the actual algae, and not in the water itself. Since the algae typically grows in warm, stagnant water, letting your dogs swim in a flowing creek is a safer alternative.
The City also recommends rinsing off your dog after swimming – especially long-haired breeds whose fur may trap algae and put them at risk of ingesting it. Dr. Bellinger noted that all of the dogs who have died from neurotoxin ingestion have been long-haired breeds.