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Austin’s toxic lake algae problem continues, precautions advised

Blue-green bloom that appears to have killed five dogs doesn’t seem to be spreading, but remains in areas of Lady Bird Lake

Exposed, tangled bald cypress roots at end of island looking out over a calm river with hills and trees beyond.
Redbud Isle is closed due to discovery of toxic algae in Lady Bird Lake
Shutterstock

Update, August 28: According to a Tuesday story on the KUT website, recent testing by the city confirms the toxic algae blooms found in Lady Bird Lake earlier this month continue to pose a threat. Austin’s Watershed Protection Department is still finding the blue-green algal blooms at Red Bud Isle, Barton Creek and downstream from Barton Springs Pool, according to the story. The algae produce neurotoxin that caused the deaths of at least five dogs that swam near Red Bud Isle, which continues to be closed.

Danger continues, especially for dogs

While the blooms haven’t spread much, the city cautions people using the lake to stay away from any algae they see and warns that the blooms have been known to break up and spread. Dogs, of course, should not be allowed in or near the lake water at all.

While the city has had outbreaks of the the blue-green algae before, this month’s appears to be the most severe and fatal to be recorded.

What’s climate change got to do with it?

An August 16 KUT story laid out the causes of the outbreak: A combination of increased silt, agricultural, and waste runoff from October floods (remember having to boil all that drinking water?)—on which the algae thrives—followed by warm, dry weather that allowed more sunlight to reach the algae as areas of the lake became shallower. Then there’s the zebra-mussel factor (they make the water clearer and allow more sunlight to get to the blooms).

While the combination of factors seems unique, most of its elements (upstream development, floods, drought, and heat) aren’t new to Austin. The blooms could become a regular seasonal occurrence—one exacerbated by climate change, according to researchers.

August 15, 2019: A toxic algae bloom in Lady Bird Lake presumed responsible for the recent deaths of several dogs in is spreading, KUT reported Wednesday.

After at least three dogs died suddenly and traumatically following varied levels of interaction with the lake water, the city closed the area around Red Bud Isle. Neurotoxins in the blue-green algae are thought to have caused the deaths.

Now the city says it has found potentially dangerous blue-green algae blooms at Auditorium Shores and Barton Creek, downstream from Barton Springs Pool. The algae samples contain neurotoxins that are similar to those found earlier this month at Red Bud Isle, according to KUT, but the city says the concentration is higher.

There are various schools of thought about entering the Barton Creek Spillway (“Barking Springs”), which didn’t test positive for the algae. Most of them can be summed up as: Why risk it?

In a statement Wednesday, city officials said dogs should have no contact at all with the water in Lady Bird Lake and that people should avoid swimming in the lake.

City representatives also stated that people who are still into using the lake “should avoid going downstream to areas with floating algae” and that “they should be aware that bacteria is always a concern in smaller waterways where there is a high concentration of dogs.”

KUT reported that the Austin Watershed Department tested eight sites last week for the algae and would test more sites on Lady Bird Lake tomorrow. The city hasn’t yet found an “effective way to treat or remove” the potentially dangerous algae at Red Bud Isle, so it will likely be closed for the next several weeks.

The city says the blue-green algae could be harmful to humans, but so far the most tragic and dramatic effects have been on dogs, in which it appears to cause respiratory failure. Officials urge owners to monitor pets if they think they have ingested lake water and to take pets to a veterinarian if they exhibit the following symptoms:

• Excessive drooling, vomiting, diarrhea

• Foaming at the mouth

• Jaundice, hepatomegaly

• Blood in urine or dark urine

• Stumbling

• Loss of appetite

• Photosensitization in recovering animals

• Abdominal tenderness

• Progression of muscle twitches

• Respiratory paralysis

Lady Bird Lake

Lady Bird Lake Trail, Austin, TX 78704