Tahoe contaminated by microplastics

A plastic degrading on a Lake Tahoe beach, in June 2023. | Jennifer Kent, UNR

Microplastics, small fragments of fibers from clothing, packaging and other plastic residue, have invaded freshwater lakes and watersheds globally and in alarming quantities, according to new research published in the scientific journal Nature under the title “Plastic debris in lakes and reservoirs.”

Lake Tahoe, known for its purity and high level of legal protection, had the third highest concentration of plastic of 38 lakes tested around the world and higher than in the surface water at the ocean’s gyres where the floating islands of debris emblematic of the world’s plastic pollution crisis collect, according to a press release.

“One of the highest priorities at Lake Tahoe is to keep the water quality clear and pristine,” Sudeep Chandra, professor of limnology and director of the Global Water Center at the University of Nevada, Reno, said. “Clarity is the signature of Lake Tahoe and the mantra Keep Tahoe Blue is not taken lightly. With this study, we now know that plastics exist in high concentrations in Lake Tahoe and could be having an impact on the ecosystem and the animals living in the lake.”

“The mechanism of transport of these plastics is not clear, especially when we talk about very small fragments or textile fibers,” Veronica Nava, postdoctoral scholar at the University of Nevada, Reno, who led the research. “We are wearing a lot of synthetic clothes, the majority of which are made of polyester, and they end up in aquatic systems.”

Another culprit is single-use plastics. Discarded items break down and are believed to enter the watershed in a number of ways.

Tahoe Weekly first reported on the presence of microplastics in Lake Tahoe in 2020 in the article “Microplastics: Tahoe’s tiniest trash” available at TheTahoeWeekly.com/trash.

“We still believe that the concentration of plastics is linked to the human presence, whether from leaving trash on the beach or other small ways where plastic can end up in the water,” Nava continued. | nature.com

Read more about Tahoe’s trash problem at TheTahoeWeekly.com/trash