If you’ve been near Austin’s Lady Bird Lake recently you may have discovered a little less water shows up. Parts of the lake, particularly along the coasts and inlets, are covered in mats of green plant life. It can look goopy, perhaps even harmful, provided the existence of hazardous blue-green algae in regional waterways.
But the majority of what you’re seeing is not just safe, it’s a sign of a flourishing body of water, says Dr. Brent Bellinger, a researcher with Austin’s Watershed Protection Department who keeps track of the lake.
Bellinger says most of the plant life nowadays is a native water plant called fanwort or cabomba, and it is among the couple of plants that flower undersea. You can find their fragile looking flowers from coast with a cautious eye.
Cabomba exists in the lake year-round, however is most likely to grow to the surface area, or end up being separated from the lake bottom and float, in the summer season once it has actually grown to maturity.
Within that cabomba you can discover an intricate environment for other plants, bugs and animals looking for shelter and food — almost like a kelp forest.
“You’ll see a lot of fish, turtles that are mixed in with the plants. There’s carnivorous plants [called] bladder wort,” says Bellinger, who fulfilled KUT by a cluster of drifting cabomba on a recent sweltering early morning. “The health of the ecosystem goes up with the presence of these plants.”
There has actually been more plant life, consisting of cabomba, in the lake in recent years. That’s due to dry spell, heat and nutrient-rich overflow from fertilizer, septic waste and other sources.
The overflow supplies food for plant life, the dry spell indicates there have actually been no huge storms to “flush” the plant life out and the heat has actually heated up the water.
“In general, biology accelerates with warmer temperatures, plant growth, algae growth, etcetera,” Bellinger says. “All these things are going to be [growing] at a higher rate in these warmer waters.”
He says the harmless plants, like cabomba, are actually helping the waterway, by gobbling up excess nutrients that could otherwise encourage more algae growth.
But, he warns, the lake is still home to blue-green algae, also known as toxic cyanobacteria. So, even if most of the stuff you see on the water is harmless, the city urges boaters or paddleboarders to avoid areas of high vegetation.
“Stick to the open water, stay away from the margins in the backwaters,” Bellinger says.
