How the green plant growing on Lady Bird Lake is beneficial to its habitat

AUSTIN (KXAN) — Thousands of paddleboarders and kayakers are expected to float on Lady Bird Lake for the Fourth of July.

If you’ve looked at the lake lately, you may have wondered what’s growing out on the water?

From all sides of the surface, large green plant patches paint the waterways.

According to the Austin Watershed Protection Department, these pervasive plants are Cabomba Caroliniana, also known as fanwort.

Brent Bellinger is the department’s conservation program supervisor.

“The growth really gets going in the summer and the plant is kind of living its best life right now in these warm waters,” he said.

Bellinger said the plant lives in Austin’s waterways year-round. Yet, it grows a lot larger in the summer.

“This is a plant that can get 15 feet tall,” he said. “If you're in five feet of water, there's going to be a lot more biomass at the surface.”

Berezi Fenix got tangled in it, while kayaking under the Barton Springs Bridge.

“I’ve been seeing all this moss and grass build-up, especially over the years as it gets worse,” he said. “You just really don't want to see it, it’s kind of an eyesore.”

Jacob Furr regularly runs on the Ann and Roy Butler Hike-and-Bike Trail at Lady Bird Lake.

He wants the city staff to clean and clear out the green plant patches.

“Three years ago, there was no algae here,” he said. “It was like perfectly clear and now there's like algae everywhere.”

Although the fanwort plant isn't poisonous, it can collect toxic blue-green algae.

Yet, Bellinger believes it brings a big benefit to the aquatic ecosystem.

“It’s providing a lot of habitat and structure for beneficial algae, bugs, small fish, all the way up the food web,” he concluded.