Microplastics: Tahoe’s tiniest trash

Only a small fraction of the trash and plastic pulled from Lake Tahoe. | Courtesy Desert Research Institute

Editor’s Note: This is the fourth part in a series covering the tourism impacts that locals and visitors alike have experienced this summer. Read more in the series:

Part I, “Tahoe’s tourism tipping point,”
Part II, “
Grappling with garbage & grievances,”
Part III, “
Trash kills bears,”
and Part V “Fire, fear & red flags.”

Read the February 2021 followup to the original series:
Tahoe’s trash trouble continues.”

It starts with a cigarette butt tossed on the sand, or an abandoned dog poop bag, a water bottle cast aside near the water’s edge. Each of these items threaten the water quality of Lake Tahoe and other pristine bodies of water in the Tahoe Sierra. When cigarette butts, plastic bags, water bottles and other garbage break down, they are reduced into smaller pieces called microplastics and pollute the water. Microplastics have been found in the oceans, lakes and water bodies around the globe, in drinking water and now they are in Lake Tahoe.

Microplastics are an emerging field of science and the Reno, Nev.-based Desert Research Institute (DRI) is one of the organizations at the forefront of studying microplastics.

Microplastics collected during a trawl of Lake Tahoe and documented in a petri dish. | Courtesy TERC

“We define microplastics as smaller than the size of a pencil eraser or less than 5 millimeters to about 1 micron, which is about the size of a bacteria. It’s the breakdown of larger pieces of plastic, what we call macroplastics, that can break down into these smaller pieces of plastic,” explains Monica Arienzo, lab director at DRI.

A petri dish with microplastic samples taken from Lake Tahoe. | Courtesy TERC

“For example, we can think about the human activity that’s happening on Lake Tahoe. Somebody is driving their boat around the lake. Their Styrofoam cooler flies off and into the lake or people who put their cigarette butts out along the beach, which breaks down into smaller pieces of plastic,” says Arienzo.

Arienzo adds that scientists have even found evidence of microplastics in the atmosphere.

“Studies have shown that rainfall can contain microplastics, and our work has shown that the snowpack itself can contain back microplastics, so when the snow falls, it can have plastic falling with it,” says Arienzo.

Meghan Collins and Monica Arienzo in the lab. | Courtesy Desert Research Institute

“Synthetic fibers that are either woven into clothing, upholstery, can enter the waterways or even the air,” explains Meghan Collins, education program manager at DRI.

DRI, UC Davis Tahoe Environmental Research Center (TERC), Incline Village General Improvement District (IVGID), the League to Save Lake Tahoe and Clean Up the Lake are all working on reducing litter that ultimately become microplastics.

Fighting the litter
In an effort to clean up Lake Tahoe, the nonprofit League to Save Lake Tahoe hosts clean up days where volunteers pick up litter along the beaches, much of which could turn into microplastics.

“A lot of the broken-down trash found is cigarette butts and single-use plastics. And 98 percent of cigarettes have plastic fibers in the filters and are plastics themselves. They don’t biodegrade, and in their broken-down state, the plastic is really toxic. It leaches out chemicals in the water,” explains Marilee Movius, community engagement manager for the League.

Thirty percent of all the litter the organization collected from its cleanup efforts was plastic. When people litter on beaches, it can eventually make its way into the Lake Tahoe and nearby waterways.

Diving for trash during the making of the film “Making a Difference” | Courtesy Dylan Silver

“Since 2014, the League to Save Lake Tahoe has been instrumental in implementing solutions such as supporting the plastic bag ban in 2015 and the polystyrene ban in 2018 in the South Lake Tahoe city limits,” explains Morvius.

“In 2018, we collected 19,819 butts at cleanup events. In 2019, that figure was 21,969. From 2019 through today, we’ve collected 9,215 cigarette butts through our [cigarette] canister program,” says Chris Joseph, The League’s communications manager. The League has distributed 250 cigarette canisters in high traffic areas around Lake Tahoe in an effort to divert cigarette butts from being tossed onto the ground and leaching toxic chemicals into the environment or ending up as microplastics.

Trawling on Lake Tahoe to collect microplastics and other trash. | Courtesy TERC

Clean Up the Lake, a nonprofit environmental organization that coordinates cleanup efforts, is currently focused on Lake Tahoe and Donner Lake. The organization dives for garbage that eventually will break down into microplastics. Volunteers recently completed a cleanup along Lake Tahoe retrieving 2,248 lbs. of garbage in a 6-mile stretch in 6 days.

“We’re going to be cleaning Tahoe for years to come,” says Colin West, founder and executive director of Clean Up the Lake, noting that they couldn’t retrieve heavier items including a 100-lb. anchor, construction metal, pieces of boats and abandoned buoys markers.

“It is somewhat comparative to Donner Lake, where we collected 3,700 pounds in 10 days in only 3 miles. Donner is definitely dirty per mile,” says West of volunteer work earlier this summer. Clean Up the Lake’s efforts have yielded rubber tires, shoes, hats, old boom boxes and all manner of trash in both Lake Tahoe and Donner Lake.

According to Sadye Easler, program manager for Clean Up the Lake, the organization uses an archeological application called Wild Note to mark the heavy items and tag the GPS locations enabling them to go back and retrieve the items later.

“We noticed we had a lot of large accumulation of trash in areas along the Nevada side of [Lake Tahoe]. We will be returning to clean up the things that we weren’t able to pull out,” says Easler.

Clean Up the Lake plans to finish cleaning up the south side of Donner Lake in the next few weeks and will conduct a few more dives in Lake Tahoe this fall. They will complete a 72-mile clean-up effort around Lake Tahoe next year.

Understanding microplastics
The California Water Boards, a collective of state and regional water agencies, recently designated microplastics as an emerging contaminant, and will conduct research and studies to ensure that the state’s drinking water is safe. Arienzo adds that there are also a number of research projects being conducted to reduce the microplastics in the water included better recycling programs, wastewater treatment processes that reduce microplastics and a program that explores microbes that eat plastics. Arienzo also mentions efforts being made by Patagonia and REI to minimize microplastics in clothing.

Collins suggests there are several ways people can stop items from becoming microplastics. Don’t use single-use plastics like plastic water bottles and plastic bags. Install filters on washing machines to prevent microplastics from synthetic clothing from going down the drain, empty the lint catcher in the dryer frequently and buy clothing made from natural fibers like wool and cotton.

In 2018, TERC gathered several samples of sand from different beaches around Lake Tahoe and found microplastics in every beach sample. TERC is currently engaged in a yearlong study on microplastics funded by the Nevada Dept. of Environmental Protection.

“The study explores where the plastics end up in the Lake [Tahoe],” explains Katie Senft, staff researcher for TERC. The study will examine five aspects of Lake Tahoe – the surface of the water, the different depths of the water, the sediment on the lake floor, drinking water and aquatic life, specifically Asian clams and kokanee salmon, which Senft says are indicators of species that might have microplastics in its system.

TERC has also introduced a program that engages the community in efforts to help save Lake Tahoe. The Citizen Scientist Tahoe app is an education and outreach application that engages the public to make observations about lake quality, garbage and detect algae blooms.

“The microplastics research group at DRI is unique because we’re a group of scientists and educators seeking to involve people in science from the very beginning. In doing so, we could help to build community member understanding. People are involved in monitoring microplastics stormwater and outflows from dryer vents. So as people monitor their community, it helps build their awareness. It also helps us as scientists understand community members’ perceptions and motivations for being involved in the solutions because we are a solution-oriented,” explains Collins.

The impact
“We still don’t know all the impacts of microplastics. We’ve seen the pictures of whales and turtles and other aquatic life with their guts full of macroplastics. We know microplastics are in the environment. We’ve got to understand where [microplastics] are at in the food web,” says Dr. John Umek at DRI. He also says DRI scientists don’t know the full impact on humans yet either.

Will Richardson of Tahoe Institute of Science points out that the impact of garbage on humans is concerning, especially when it comes to microplastics.

“Any plastic trash is going to have Endocrine-disrupting chemicals that can affect our hormones, may cause cancer, or mess with things like reproductive rates and behavioral stuff. A lot of these chemicals are occurring on the landscape at pretty high levels that are no good for us at all. They need to be contained and managed in some way and not just strewn about everywhere. You wouldn’t think a plastic bag thrown out of a car could cause that much damage, but it can,” says Richardson.

All of the researchers agree that the need to reduce garbage in the environment is essential, so it doesn’t end up as microplastics in local waterways impacting drinking water, wildlife or aquatic species. The proper disposal of cigarette butts and litter is imperative, and they encourage making informed choices like reducing or eliminating the use of single-use plastics, choosing natural fiber clothing and maintaining washers and dryers.


California Water Boards | waterboards.ca.gov
Citizen Science Tahoe app | citizensciencetahoe.org/home
Clean Up the Lake | cleanupthelake.org
Desert Research Institute | dri.edu
League to Save Lake Tahoe | keeptahoeblue.org
Tahoe Environmental Research Center | tahoe.ucdavis.edu
Tahoe Institute of Natural Science | tinsweb.org

Kayak for science
TERC will host a day kayaking trips from Sept. 20 to 26 in support of the Citizen Science Tahoe. Using the app, participants will collect valuable water quality, algal growth and microplastics data. Visit TheTahoeWeekly.com for the itinerary. | Register hmsegale@ucdavis.edu, amyshyakova@ucdavis.edu


El Dorado County
Eastern Slope area | (530 573-3450, edcgov.us

Douglas County
Code Enforcement Office | (775) 782-6214, douglascountynv.gov

Nevada County
Illegal dumping | (530) 265-7111, mynevadacounty.com 

Placer County
Garbage complaints | (530) 581-6240, placer.ca.gov
Tahoe Truckee Sierra Disposal | (530) 583-7800, waste101.com

South Lake Tahoe
City of South Lake Tahoe | (530) 542-6000, cityofslt.us
South Tahoe Refuse | (530) 541-5105, southtahoerefuse.com
Clean Tahoe Program | (530) 544-4210, clean-tahoe.org

Town of Truckee Trash complaints | recycle@townoftruckee.com
Keep Truckee Green | (530) 582-7700, keeptruckeegreen.org
Truckee-Donner Recreation & Parks District | (530) 582-7720, tdrpd.org

Washoe County
Garbage complaints | (775) 328-6106, washoecounty.us

EDITOR’S NOTE: This is the fourth part in a series covering the tourism impacts that locals and visitors alike have experienced this summer. Read Part I, “Tahoe’s tourism tipping point,” Part II, “Grappling with garbage & grievances,” and Part III “Trash kills bears” at TheTahoeWeekly.com.