Impacts from the Sierra’s largest recorded wildfire to Lake Tahoe and surrounding water bodies is the topic of a new scientific study.
“The whole ecology of the lake might shift,” said Geoffrey Schladow, director of the UC Davis Tahoe Environmental Research Center in Incline Village. “… I’m not saying it will happen, but it could happen and that’s what we’re trying to understand — the likelihood.”
In fall 2013, researchers from TERC, the University of Nevada, Reno, and three other institutions began a one-year study on the effects of last year’s Rim fire.
The study focuses on how lakes respond to major wildfires by examining how organic compounds and particulates entering the water alter clarity, light penetration, algae concentrations and zooplankton populations, explained Brant Allen, field lab director and staff researcher for UC Davis.
“There has been a great deal of study on how the landscape recovers following fire but relatively little is known about how lakes are effected over the short- and long-term,” he said.
Cherry Lake and Lake Eleanor, located in the heart of the burn area, along with smoke-impacted lakes, including Lake Tahoe, Emerald Bay and Cascade Lake, are being studied. Rock Creek Lake, located south of Mammoth, will serve as the control, since it was not impacted by either the fire or smoke.
Started by an illegal campfire on Aug. 17, 2013, in Stanislaus National Forest, the Rim fire burned more than 250,000 acres (roughly 400 square miles) in Tuolumne and Mariposa counties near Yosemite National Park before it was fully contained on Oct. 24.
It was the largest wildfire ever to scorch the Sierra Nevada, and the third largest on record in California.
Due to wind patterns, heavy smoke settled in the Tahoe-Reno region for weeks. Contributing to the hazy skies was the American fire, which raged around the same time an hour or so west of Truckee in the Tahoe National Forest.
In response to the Rim fire, researchers obtained a roughly $150,000 National Science Foundation Rapid Response Grant, funding used for time-sensitive proposals that intend to study major unanticipated events such as wildfires and large oil spills.
An initial assessment of the lakes’ water quality and zooplankton community was completed in late October 2013, according to TERC. Scientists will collect additional data later this year; a final assessment will be ready late this summer, Schladow said.
A past wildfire in the mountains north of Los Angeles revealed that persistent smoke over Lake Tahoe can cause an increase in algae growth at shallow depths, diminishing short-term clarity, Allen said.
“The smoke essentially created a greenhouse-like condition favoring algae growth short-term,” he said.
It’s unknown what the Rim fire’s effects on Cherry Lake and Lake Eleanor will be, Allen added.
“With this study we can start making predications of what will happen in the future,” Schladow said.
More wildfires are expected across the West as the region continues to experience a higher average temperature and less snowfall, a trend that’s grown over the past few years due to dry winters.