As summer temperatures rise in Austin, a familiar yet problematic plant, Cabomba Caroliniana, or fanwort, has once again commandeered the surface of Lady Bird Lake, presenting a lush barrier that deters recreation for paddlers and kayakers alike, reports KXAN. The aquatic plant, which thrives in warmer climates, has seen considerable growth in recent weeks, with some areas witnessing a complete stretch across the water, as David Ward, a local kayaker highlighted the difficulty of navigating a large patch near Lamar.
Despite its invasive appearance, the Watershed Protection Department regards the fanwort as indicative of the lake's ecological health, noting its role as a critical habitat for aquatic species, the plant, however, also poses risks as it can ensnare individuals who may fall into the water and harbor toxic blue-green algae dangerous to pets, as Gerardo Gomez visiting from Boston observed its unappealing sci-fi film-like presence stating, "It looks like something out of a sci-fi film like literally," and expressing complete aversion to swimming there. Although the city does not actively remove the fanwort, it disbands naturally with significant rainfall, and local businesses have the option to mechanically clear the plant provided they have the requisite permits from Texas Parks and Wildlife.
Amid the burgeoning fanwort, the presence of harmful blue-green algae known as Cyanobacteria is a growing concern, particularly during Austin's sweltering summers; the toxin-laden algae has been present in Lady Bird Lake since 2019 and has been linked to the fatalities of dogs who swam in the infested waters, as KVUE reports. In response, city officials are calling on the community to play an active role in curbing algal proliferation, such as limiting the use of fertilizers, cleaning up pet waste, and planting more vegetation to reduce runoff into the waterways, which according to Dr. Brent Bellinger, "fuels algae growth in the creeks," KVUE reported.
In tackling the issue, the city has resorted to dispensing clay over the lake to impede the algae's spread by binding phosphorus, a key nutrient, the application of clay has shown varied effectiveness with some success at Red Bud Isle in June, but not in the peak months of July or August; near the Festival Beach Boat Ramp, results were negligible with algae flourishing as usual, the city has allocated significant resources into a five-year pilot program scheduled to run through next year, costing around $300,000 annually, addressing the Cyanobacteria issue before it potentially escalates into a more pressing health risk to the local community and their canine companions.
