The Lake Tahoe basin’s landscape is ever-changing, hosting a full four seasons year-round. From warm summer days basking in alpine sunshine, to historical snowfall during winter seasons, Lake Tahoe is coined the jewel of the Sierra Nevada Mountains for good reason. 

Further studying Lake Tahoe’s fluctuating environment, University of California, Davis’ Tahoe Environmental Research Center, also known as TERC, has been taking charge for years, analyzing the Lake Tahoe region overall and the impact that human development has had on the Lake Tahoe basin in the past five decades. 

Along with analyzing the impact of urbanization in Lake Tahoe, TERC scientists analyze Lake Tahoe’s lake clarity, aquatic invasive species, microplastics, lake mixing, forest conservation, wildfire impacts, and much more. The research center is motivated to continue their proactive research and be a resource to the public. 

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“UC Davis Tahoe Environmental Research Center is dedicated to interdisciplinary research and education to advance the knowledge of aquatic and terrestrial ecosystems and their interactions within nature and developed Earth systems, and to communicate science-informed solutions worldwide,” TERC’s mission statement reads. 

While the physical research center opened in 2004 in Incline Village, Nev., the founding scientific research dates back centuries, to what TERC still uses as its foundation in the present day. 

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18th century physicist John LeConte was the first professor hired by the University of California Davis in 1868. LeConte initiated the first scientific readings in Lake Tahoe, including the first measurements on Lake Tahoe’s lake clarity. Close to a century later, UC Davis began conducting research on Lake Tahoe in 1958, resulting in over 60 years of modern data that describes and further analyzes Lake Tahoe’s ecosystem, as well as its watershed and airshed. 

From decades of research, in the present day, TERC scientists still measure Lake Tahoe’s lake clarity every 10 days, lowering a white, 10-inch Secchi disk into the lake from a UC Davis research vessel. The lake clarity measurement composes the data that is included in the annual State of the Lake report, in turn providing scientists as well as local, state and federal government agencies detailed information on Lake Tahoe’s overall health to assess and guide future decisions.

“This pivotal research stands apart in importance from any other that has been conducted in the country, [it’s] particularly useful in understanding the impact of change in freshwater environments over time,” Director of TERC Geoff Schladow said. 

The ongoing study of Lake Tahoe’s lake clarity is constantly being observed by TERC scientists, and the lake’s clarity statistics are constantly evolving. 

“The lake has responded to increased nutrient loading from the streams, atmosphere and groundwater with steadily increasing algal growth and a progressive reduction of clarity,” TERC research states. “The lake has lost approximately 33 feet, or one-third of its famous transparency, during the last 40 years and oxygen concentrations in the deep waters have declined significantly; in turn resulting in thick growths of attached algae now coating the shoreline rocks in the spring.”

According to 2022’s State of the Lake report, Lake Tahoe’s annual lake clarity was 71.7 feet, compared to 61 feet in the previous year. 

“The key finding from 2022 was the great improvement in lake clarity from August through December, when the average Secchi depth was 80.6 feet,” TERC research states. “This statistic coincided with the zooplankton Daphnia and Bosmina.” 

According to TERC’s research, the primary factors affecting Lake Tahoe’s lake clarity are the concentration of particles in a specific size range, such as silt and clay, tiny phytoplankton, or algae. Zooplankton Daphnia and Bosmina aid Lake Tahoe in the lake’s clarity, consuming these particles, resulting in overall better clarity. 

“Daphnia and Bosmina largely disappeared from the lake after they were grazed down following the introduction of Mysis shrimp in the 1960s,” Schladow said. “In late 2021, the Mysis shrimp population unexpectedly crashed, and it took 12 months for the Daphnia and Bosmina to build up their numbers and start naturally cleansing the lake again.” 

While last year’s report reflects better lake clarity than previous years, there is still an overall reduction in lake clarity when analyzing the past several decades and human impact to the Tahoe area. Along with the concentration of particles in a specific area, the reduction of lake clarity is also attributed to human-induced factors, including the influx of tourism to the Tahoe basin, trafficked roads increasing runoff into the lake, trash and microplastics, recurring wildfires and smoke, and more. While these ongoing threats to Lake Tahoe are imminent, TERC scientists are constantly analyzing these impacts, to come up with solutions and spread awareness for a better overall environment and future for the Tahoe basin.

TERC has a staffed team of expert scientists that are paving the way with their research. While lake clarity plays a vital role in TERC’s research, the research center also explores other areas of study that influence Tahoe’s environment, to further analyze Lake Tahoe and make for a better future for the area. 

Below is a chart of TERC’s main fields of study along with corresponding research projects that TERC scientists are avidly working on to analyze for Lake Tahoe’s evolving environment: 

Long Term Monitoring	Atmospheric Deposition Meteorology of Lake Tahoe Periphyton Monitoring Stream Monitoring  Stormwater Projects Forest Health Real-time Monitoring of Lake Tahoe  Phytoplankton Lake Chemical Process: Nutrients & Cycling
Forest Conservation	Climate Resilient Restoration Forest Health  Population Dynamics  Ecological Genetics & Evolutionary Potential Conservation & Restoration  Raising Baby Trees
Lake Tahoe Nearshore	Shoreline algae Nearshore Network: Improving understanding of water quality on perimeter of Lake Tahoe  Metaphyton Wave Forcing Citizen Science App
Scientific Models	Lake Clarity Model 3D Modeling Modeling Climate Change Impacts  Periphyton Modeling

With TERC scientists constantly studying Tahoe’s environmental landscape, the research center also serves as a hub for education in the Lake Tahoe basin. Being a research center under the UC Davis name, TERC’s main building on the University of Nevada, Lake Tahoe campus serves as a

resource to students to study and conduct their own research, learn more about Lake Tahoe’s environment themselves, as well as participate in laboratory work further analyzing Tahoe’s environment. 

Currently, TERC interacts with over 11,000 individuals annually, including 4,000 local students at the University of Nevada Reno, Lake Tahoe Campus, giving them the opportunity to learn about Tahoe’s unique ecosystem, and what students, as well as those who visit TERC, can do to help make for a better Tahoe for the future. 

“Education and outreach is an integral component of TERC,” Schladow said. “The goal of our education program is to provide science-based information about the Lake Tahoe region in order to foster responsible action and stewardship.”

Madison Schultz is a reporter for the Tahoe Daily Tribune and Sierra Sun.