Recently, there have been multiple cases in Texas of blue-green algae found in bodies of water, such as Lake Travis and Belton Lake. The occurrences can be especially concerning since there have been cases of death among dogs.
It’s unclear if we’re hearing more about blue-green algae in recent years because it’s becoming more prevalent or because the general public is more familiar with it. Regardless, blue-green algae is something found in all types of water. And while not all blue-green algae create toxins, those that do can be of concern.
Jill Csekitz, a technical specialist with TCEQ’s Water Quality Planning Division, explains that actually, it’s not even algae.
“Blue-green algae is kind of a misnomer,” Csekitz said. “It’s called cyanobacteria because it’s actually a bacteria, although it can act similar to algae in that they do conduct photosynthesis and produce oxygen, so they need light and nutrients to grow.”
Because cyanobacteria need sunlight, you’ll typically find the benthic form of cyanobacteria near the shoreline in reservoirs, although wind and other movement could push detached clumps to other areas within the body of water. Planktonic forms can be seen on the surface of the water column in open water, coves or washed up along the shoreline.
It used to be thought that cyanobacteria only flourish in Texas during hot and stagnant weather, but after the benthic form was found in various bodies of water following the recent Texas winter storm, that does not seem to be strictly true. Multiple environmental factors can limit or promote the growth of different types of cyanobacteria. Additionally, this variety of factors could also prompt the production of toxin by cyanobacteria, such as water temperature, nutrients in the water, sunlight, slow-moving water, competition and grazing within the plankton community and the change in water quality due to the presence of invasive species, such as zebra mussels.
Ingestion of cyanotoxins can be dangerous to both humans and animals, including dogs. Even if dogs don’t drink the water, they may ingest the toxins when eating clumps or licking their fur, if not immediately cleaned well with tap water.
Jill gives a few tips to follow when you’re around bodies of water:
- It’s best for you and your pets to avoid visible clumps of cyanobacteria entirely. Blooms may appear green, blue, brown, gold or red. Seeing colors, scum, mats, foam, or paint-like streaks in the water or clumps on the shore may indicate a bloom. Neither you, nor your pets should touch it. While not all cyanobacteria are toxin producers, it’s better to avoid them since you can’t tell whether they’re producing toxins just by looking at them.
- Wash your dog’s paws and fur with tap water after having visited lakes, rivers or ponds.
- Heed advice of local water managers, such as river authorities.
- Be vigilant in looking for clumps of blue-green algae year-round.
TCEQ coordinates with local water entities when it comes to harmful cyanobacteria, as well as the Texas Department of State Health Services and Texas Parks and Wildlife Department. If you have concerns about your local bodies of water, reach out to yourlocal water authority.
For more information about cyanobacteria and cyanotoxins, visit EPA’s website.