‘I feel like a ghostbuster’: How Austin tests for harmful lake algae

Brent Bellinger slung his Hydrolab over his shoulder and closed the trunk of his city-issued Chevy Equinox just before noon last Wednesday at the Festival Beach boat ramp on the north shore of Lady Bird Lake.

“I feel like a ghostbuster,” Bellinger said, referring to the Hydrolab, whose gray, cylindrical sensor peeking out of a black backpack looks like something out of a science fiction movie.

The science fact is that Bellinger, a senior environmental scientist for the Austin Watershed Protection Department, is the first line of defense in protecting the city’s residents and pets from harmful blue-green algae that killed several dogs last summer.

But this year, the coronavirus pandemic overshadows the sampling and testing of algae for toxins, and the process to get toxin results is now taking about five days, instead of two or three. Other parts of the sampling and testing process also have changed because of pandemic protocols.

Bellinger tosses the Hydrolab sensor into Lady Bird Lake to test for temperatures and pH levels, which helps Watershed Protection understand what conditions the algae thrives in. When algae became more visible in the lake earlier this month, the city started collecting water samples from Festival Beach, Red Bud Isle, the mouth of Barton Creek and Vic Mathias Shores each week.

One harmful toxin found in the lake last summer, dihydroanatoxin, was confirmed to be in blue-green algae at Red Bud Isle and Festival Beach on July 20.

Sampling and testing

Bellinger was at Festival Beach around 11:30 a.m. Wednesday, making his last stop of the day. In water shoes, a hat and cargo shorts, Bellinger dunked plastic bottles into the water to get samples. Then he placed chunks of algae on a square metal tray and put the pieces into a bottle.

Bellinger noted that the water looked clearer than it had in the last three weeks. A large swath of algae had been present in the water, but it’s possible recent rains helped push it away, he said.

He then dropped the cylindrical sensor into the water and checked on a second underwater sensor hidden in a PVC pipe attached to a tree that also registered water temperature and pH levels. Within 20 minutes, the sampling was done.

The pandemic hasn’t affected the sampling portion of the process, save for the wearing of a face mask, Bellinger said.

But pandemic protocols do compel Bellinger to make a curbside drop-off of the samples instead of meeting Schonna Manning, a research assistant professor in the department of molecular biosciences at the University of Texas, inside the Biological Laboratories building.

“I pull up, turn on the flasher and wait by the trunk of the car,” Bellinger said.

Once the pair makes the hand-off, Manning puts the water samples through multiple enrichment processes so toxins can be more easily detected in the algae. Algae samples also are disrupted with vibrations so any toxins will be released for inspection.

Things slow down when Manning goes across West 24th Street to a building where the samples undergo liquid chromatography mass spectrometry, which detects toxins.

Before the pandemic, Manning could run the samples through the instrument herself, but now the testing requires another coordinated hand-off. Results are now taking roughly five days to receive because of social distancing restrictions the university has in place.

“Nothing has really changed, it’s just the laboratories are more restrictive on the number of personnel that can actually be in a laboratory,” Manning said.

Getting rid of the harmful algae

The toxins, while contained in the algae, are extremely dangerous when ingested by humans and animals, Manning said. The dogs that died last summer likely swallowed algae while grooming themselves, causing the toxins to be released inside the animal, she said.

Scooping out all the algae is impractical, Bellinger said, and if the city attempted to kill off all the algae, which has always been in Lady Bird Lake, Manning said that could release toxins into the water.

Several factors can stave off algae blooms: reducing the runoff of fertilizer or animal poop, including from dogs, entering Lady Bird Lake, cooler temperatures and higher water flow.

Manning said invasive zebra mussels also could be making things worse.

Zebra mussels feed on what Manning called “good algae,” or algae that does not have toxins in it. If the zebra mussels are eating up all the good algae, only harmful blooms would be left, she explained.

“Dog poop has always been there but zebra mussels are fairly new,” she said.