When Algae Turns Toxic

It is the perfect environment for algae to bloom: long stretches of high temperatures and no significant rainfall, which results in slow moving or stagnant water. Add in nutrients like nitrogen and phosphorus, and algae blooms.

While most Texas are accustomed to this seasonal pattern, this year much of the algae in our waterways has become toxic. In fact, in the lakes and creeks around central Texas, the algae is producing anatoxin, a neurotoxin that caused the death of three dogs in early August. And just two weeks ago, a Sisterdale resident let her dog swim in the nearby Guadalupe River, and it died within an hour after ingesting some of the water.

Dr. Murl Bailey with the Texas A&M School of Veterinary Medicine said in an interview with a San Antonio TV station that if a dog ingests the algae, it can be fatal. “Some of the toxins that affect the nervous system are very fast acting, and if the animal drinks it in, it can be dead in a minute or two,” he said.

It is very difficult to determine what algae is toxic, but be aware of scum, foam or floating mats on the water surface. Algae can be a variety of colors, too—blue, green, brown or red. And though many times the algae is visible, sometimes it could be deep under the surface. A person or dog jumping in the body of water can stir up algae lurking on the bottom.

The EPA gives a warning on their website “Algal blooms can be toxic. Keep people and pets away from water that is green, scummy or smells bad.”
So as Labor Day approaches, check with local authorities if you have plans to swim in natural waterways. If you see any growth that is suspicious, better be safe and head to a chlorinated pool.