Now, research at one of the clearest, cleanest lakes in the world – Lake Tahoe, on the California/Nevada border – suggests that the problem is also widespread in freshwater systems.
Katie Senft is a staff researcher at the UC Davis Tahoe Environmental Research Center. Senft began sampling beaches last summer, and continued this summer, in the first study of microplastics in Lake Tahoe. The research team found microplastics – that is, plastic fragments less than 5 mm (.2 inches) in length – at every beach they sampled. Senft said in a statement:
The ocean gets a lot of attention about plastic in the water, and our freshwater lakes don’t. This issue has flown under the radar in the Tahoe Basin.
When plastics enter the environment, be it terrestrial or aquatic, they stick around for a long time. We don’t know the long-term implications of having plastics in our water and in our soil.
To look for microplastics, the team scoops sand into glass mason jars at defined distances across the lake’s shoreline. Back at the lab, the samples are analyzed under a microscope for plastics.
Unlike many freshwater systems, the wastewater produced in the Tahoe Basin is piped out and does not return to the lake. Wastewater is the main source of microplastics in most freshwater systems. That’s why Senft thinks that the microplastics in Lake Tahoe have a different source. She said:
The microplastics we’re finding at Lake Tahoe are most likely from improperly disposed trash.
Residents and visitors can help, Sendt said, by reducing the amount of plastic brought to the beach from the beginning. Lake Tahoe has some of the nation’s cleanest drinking water, so foregoing the packs of small plastic water bottles for a reusable one is an easy place to start.
Bottom line: Researchers are finding microplastics in the water of Lake Tahoe.
Eleanor Imster has helped write and edit EarthSky since 1995. She was an integral part of the award-winning EarthSky radio series almost since it began until it ended in 2013. Today, as Lead Editor at EarthSky.org, she helps present the science and nature stories and photos you enjoy. She also serves as one of the voices of EarthSky on social media platforms including Facebook, Twitter and G+. She and her husband live in Tennessee and have two grown sons.