breakdown of plastics

Day at the beachThis project is a collaborative effort from TERC's researchers and the TERC education and outreach team. Microplastics are not a specific kind of plastic, but are defined as any type of plastic fragment that is less than 5 mm in length. Each year over 300 million metric tons of plastic are produced across the globe. Plastics enter the natural environment from a variety of sources including cosmetics, clothing, and industrial processes. They easily break down into smaller and smaller fragments by UV light and physical abrasion from wind and waves, but never disappear. Research has shown microplastics are entering the food chain, leaching chemicals, and showing up in soils and drinking water. There has been extensive microplastics research conducted in marine research, however not a lot of information is available on its impacts on a freshwater ecosystems. TERC, in collaboration with the League to Save Lake Tahoe and the Desert Research Institute, currently lead the research and education efforts at Lake Tahoe in this emerging field. For more information contact Heather Segale or Katie Senft.


TERC microplastics pilot project
TERC summer interns, Hannah and Maddie, collect beach sand along a transect line at Commons Beach in Tahoe City. 

The UC Davis research team, headed by Katie Senft, will begin further research into the plastic problem at Tahoe with a research plan funded by the Nevada Division of Environmental Protection (NDEP). In summer 2018, TERC researchers conducted the first sampling around Lake Tahoe to quantify microplastics in beach sand. Microplastics were found at all beaches sampled, although in relatively low levels compared to other U.S. waterbodies such as the Great Lakes and Tennessee River. All subsequent sampling examining beach sediment found plastic in every sample. For several years, microplastics have been a hot topic of study in the realm of marine sciences, but until recently the effect on freshwater ecosystems has gone relatively understudied. That’s what makes TERC’s research on Lake Tahoe even more pertinent to the growing body of global plastics research.

Senft’s team will extend studies to microplastics in the waters at every depth of the lake and other areas of the surrounding watershed. This summer, they will perform trawls with a net funded with support from the Tahoe Water Suppliers Association (TWSA) both at the surface of the lake and at the thermocline about 20-30 meters down from the surface in the water column. They will also sample bottom sediments for microplastics as well as some of the filter-feeding organisms that are likely to accidentally consume tiny plastics. In order to assess how these plastics might affect the human community, they will also be taking samples from water treatment sites on the North and South Shores of Lake Tahoe.  

Microplastics FAQ


The TERC education team is continuing to work on the campaign to reduce reliance on single-use plastics in the Tahoe basin. This multifaceted project is funded by Nevada Division of Environmental Protection (NDEP) and includes an exhibit explaining the science of microplastics, direct classroom programming, development of an outreach campaign as part of Take Care Tahoe (takecaretahoe.org), and a partnership to sell reusable water bottles at the local Raley’s grocery store.


In order to communicate TERC’s important microplastics research to the public, the education team is hard at work creating an exhibit to be displayed at the rescheduled Earth Day celebration and “Below the Blue: Lake Tahoe’s Litter Crisis” Art Exhibit at the Boatworks Mall and ultimately at the Tahoe Science Center.

The exhibit features a large five-panel wall display and three tables of hands-on activities aimed to engage visitors in both the science of plastics as well as the solutions to the current global plastic crisis. The panels across the wall tell the story of “A Day at the Beach,” with a large photo of a Lake Tahoe scene laden with everyday, single-use plastics: water bottles and straws, zip-top plastic bags, a Styrofoam cooler, plastic utensils, and more. The exhibit then follows those plastics as they break apart into tiny pieces and shows how they impact the food web and the ecosystem. The activity tables allow visitors to test their knowledge of the plastic types #1–#7 and learn that the chasing arrow symbol does not necessarily mean that this type of plastic is recyclable. There is also an activity which gives guests the opportunity to practice some of the same methods used by scientists studying microplastics. The exhibit wraps up with a call to action: it is not enough to change our habits of buying and disposing of single-use plastics, we must also stop the production of the non-essential, single-use plastics in the first place. 

TERC’s science team takes a multidisciplinary approach. Only by looking at the watershed as a whole—with its trees, animals, roadways, and people—can we truly understand what’s happening to the lake. The plastic problem is similar. We cannot understand the ecological harms without exploring the human industries and big corporations that created the plastic problem in the first place.

This exhibit will highlight the ways in which TERC is a leader in the realms of scientific research as well as in education and outreach.

Education programs

Together with the Tahoe Water Suppliers Association (TWSA) and Sierra Watershed Education Partnership (SWEP), the UC Davis TERC education team has developed curricula to teach Tahoe students about the plastic problem facing Lake Tahoe.

Incline Village High School students use TERC lab protocols to analyze microplastics in local beach sand.
Incline Village High School students use TERC lab protocols to analyze microplastics in local beach sand.

Early in the year, TERC began meeting with Incline High School’s Roots and Shoots Club and Advanced Placement Environmental Science class to implement programs that reduce usage of single-use plastic. The education team developed a series of informative and hands-on classroom activities to get the high school students engaged in the local environmental problem of plastic litter.

In the first session, students sorted their own school cafeteria’s recycling and discovered that only 5% of what was deposited could actually be recycled. Students then participated in a discussion about what this problem looks like from a local to global scale and potential solutions that could be implemented as individuals and as a community.

In the second session, students were provided with a 1-meter quadrant of beach sand collected from Hidden Beach in Incline Village. Students then used the lab methodology used by TERC and other scientists to analyze the sand for microplastics. Students learned how plastics break apart into smaller and smaller pieces, but never decompose or biodegrade in the environment.

Reusable Water Bottles

Raley’s grocery store in Incline Village has partnered with TERC in order to print reusable metal water bottles that feature “Drink Tahoe Tap ®” and plastic-free messaging. Raley’s has also agreed to place signs that encourage customers to make the more sustainable choice of going reusable in the single-use plastic water bottle aisle.

The components of the marketing campaign were designed to build on the highly visible and effective Take Care Tahoe campaign. By using eye-catching bright colors and witty phrases like “Break Up With Plastic”, “Water in Plastic Bottles is Trucked Up,” and “Fill Anywhere, Take Everywhere,” the water bottles will not only serve as a sustainable way to fill up on water, but will also encourage others to rethink their plastic use as well.

In conjunction with the sale of reusable water bottles, TERC also conducted a survey on single-use water bottle usage in the Tahoe area by residents and visitors. If you haven’t taken it already, the survey is available at https://www.tinyurl.com/TahoeWaterBottleSurvey.

The sale of these reusable water bottles will be coupled with a push to increase accessibility to drinking water filling stations around the basin. In partnership with Sierra Nevada University and Incline High School, TERC plans to double the number of refill stations on the mobile “Tap App,” which points folks toward locations where they can refill their water bottles. Working with the Take Care Tahoe team, TERC also intends to roll out a badge system that businesses can use to display their commitment to sustainability and to attract more customers.

Community Forum

In order to better engage with the local community, TERC obtained a viewing link for the Story of Plastic for people to watch for free. This movie was featured in the 2019 Tahoe Film Fest and provided an excellent foundation for building conversation. The idea was to use this movie to spark questions specific to the plastic problems in our area, then provide an open forum where community members could engage with twelve local experts. These experts/panelists discussed their current actions addressing the plastic problem, spanning from education to research to art, and their collective knowledge and expertise was then made available to the participating community. We hope that sharing some of our work with the community will spark ideas and conversation about how we can do better moving forward. This presentation and forum was recorded and is available through the UC Davis YouTube Channel