Preliminary results show low levels of neurotoxin in algae near Red Bud Isle

"Harmless" varieties in other parts of Lady Bird Lake, city says

Talk 1370 Newsroom
August 09, 2019 - 5:45 pm

AUSTIN ( -- Pet owners should continue to keep their dogs out of Lady Bird Lake, city officials said Friday, but preliminary test results indicate a potential neurotoxin may be limited to the Red Bud Isle area.

City officials said samples of water and algae were taken from eight locations on Lady Bird Lake, with additional samples taken at the Walsh Boat Ramp on Lake Austin and downstream of Longhorn Dam.

Two samples of the algae taken near Red Bud Isle showed low levels of a neurotoxin, officials said. However, the toxin was not found in any of the water samples or in other algae samples. Additionally, the sampling has shown that much of the algae in other parts of Lady Bird Lake are presently harmless varieties.

Based on the test results, officials say the toxin appears to be localized to the algae near Red Bud Isle, which remains closed to the public.

At least three dogs have died soon after swimming in Lady Bird Lake. While officials can't confirm that the deaths are connected to the algae, officials said earlier this week there's little reason to dispute a connection.

Officials say at this point residents should continue to minimize their exposure to water and avoid all contact with the algae, for both themselves and their pets. The algae can move and there may be potentially harmful algae in other parts of the lake. To that end, city officials are taking additional algae samples at the mouth of Barton Creek to identify the type of algae at that location.

The algae is naturally occurring, and officials say most of the time it is harmless. It is not uncommon for there to be algae, including blue-green algae, in Austin's lakes. The algae tends to be more abundant near shorelines and in areas with low water flow.

Based on this event, city staff are working on a protocol to monitor Lady Bird Lake for toxic algae in the future. City staff tests water samples from the lake nine times each year for possible pollutants, water chemistry, and other indicators of water quality.

Drinking water remains unaffected by this situation. Austin Water regularly looks at algae levels on Lake Austin and Lake Travis and has not seen levels of concern for drinking water. Austin Water does not currently use Lady Bird Lake as a source for drinking water.

Dogs who ingest water contaminated with this toxin could have a number of symptoms. On the severe end, it could result in respiratory paralysis and death. City officials say you should look for these signs in your pet within minutes to hours of exposure:

  • 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

The amount of toxins that a dog ingests and licking of the fur are factors in the severity of the symptoms.

In people, possible health effects include:

  • Dermatologic signs or symptoms such as rash, irritation, swelling, or sores
  • Gastrointestinal signs or symptoms
  • Respiratory signs or symptoms
  • Fever
  • Headache
  • Neurologic signs or symptoms
  • Ear symptoms
  • Eye irritation

So far, Austin Public Health officials say there has not been an increase in emergency room visits or unusual conditions that may be related to exposure to the algae. Anyone with questions is urged to call 3-1-1 or (512) 974-2000.

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