From Tahoe's mountaintops to the lake's sandy bottom, scientists from the University of Nevada, Reno continue to study and find solutions to the breadth of issues that face the entire Lake Tahoe Basin. Their research is making a tangible contribution to the decisions, policies and practices that guide the basin's environmental health.

It's been 16 years since the first Lake Tahoe Summit and, while there has been significant progress on protecting the pristine lake, much work remains to be done. Researchers, policy makers, state and federal agencies are turning their attention to the lake for this year's Lake Tahoe Summit Aug. 19.

From the first rustic snow survey by a University professor in 1906 - an advancement still in use today - to the latest technology using sonar and rocket guidance systems, University scientists continue to take the pulse of Tahoe's climate and environment.

"While clarity is improving in the offshore this year, things are not as positive on the nearshore, which is where most of the public engages the lake," Sudeep Chandra, University of Nevada, Reno researcher and long-time limnologist at Lake Tahoe, said.

Chandra, director of the University's Aquatic Ecosystems Analysis Laboratory, is collaborating with other scientists to study the nearshore - among other issues - and how ultraviolet light levels, which are affected by particulates, help invasive species to thrive and cause native species to decline.

Working in collaboration with other research institutions and management agencies, the University's scientists have taken an expansive view of the lake and its environs. Their research on the lake is extensive; they have looked at the basin as a whole to learn how its health relates to the clarity and health of the water.

"Our institutions have helped lead the way in discoveries on nutrient loading, water quality and watershed ecology," Presidents Marc Johnson of the University and Stephen Wells of the Desert Research Institute wrote in the annual research review annually produced by the two  institutions for the Summit. "Our scientists have helped develop innovative ways to monitor Tahoe's precious ecology and in finding management strategies for the air, land and water of Tahoe that help, not hinder, the overall health of this unique natural resource.

"Our approach will continue to be interdisciplinary and inter-institutional. Our pledge to Lake Tahoe remains firm: our two institutions work in common cause, so that the lake's heritage of beauty and clarity can be shared by our children's grandchildren and beyond."

A few current, ongoing Tahoe research projects are:

1. Warm-water invasive fish: Christine Ngai, project lead and researcher in the University's Aquatic Ecosystems Analysis Laboratory. This pilot project is to determine the effectiveness of mechanical removal methods for management of non-native fish and the restoration of native fish in Lake Tahoe. Her project received international attention this year when her team found a 4-pound goldfish in the Tahoe Keys while electrofishing.
2. Huge decline in bottom dwelling invertebrates: Annie Caires, project lead and researcher in the Aquatic Ecosystems Analysis Laboratory. The bugs living in the muck at the deepest, darkest depths of Lake Tahoe have disappeared in substantial numbers - a 90 percent decline. New funding has allowed continued research to search for the sensitive species and look for ways to support their survival. Sampling of plants and soil in the Camp Richardson area was documented with video from underwater specialists New Millennium Dive Expeditions: http://youtu.be/GfHVt0_bvqM
3. Mountaintop environmental monitoring stations: Graham Kent, director of the University's Nevada Seismological Laboratory. The multiple sites will be connected via the Seismological Laboratory's statewide seismic network to collect and transmit climate and environmental information from remote sensing equipment. The network features 360-degree high-definition cameras to scan the forest and Tahoe communities for wildland fires.
4. Tahoe ozone nearing unsafe levels: Alan Gertler, vice president for research at DRI. Tahoe is one of the few areas in the region where ozone is increasing. It is now at a point where it will likely violate ambient air quality standards. Research also shows that air is a significant source of pollutants that lead to declining water clarity. The largest sources of nitrogen and hydrocarbons are cars, trucks and boats. These sources are also a significant source of particulate pollution.
5. Megadroughts in the Sierra Nevada: Graham Kent, geophysicist and director of the University's Seismological Laboratory confirmed evidence of 200-year-long megadroughts through earthquake fault research at Fallen Leaf Lake in the Tahoe Basin. Underwater stands of pre-Medieval trees in the lake suggest the region experienced severe drought at least every 650 to 1,150 years during the mid- and late-Holocene period. The last one ended 750 years ago. "It is uncertain when the next megadrought will occur. With climate change upon us, it will be interesting to see how carbon dioxide loading in the atmosphere will affect this cycle," Kent said
6. Re-photographing Tahoe's environment: Peter Goin, a University art professor, is tracking the changes to the environment matching new photos to old. His latest work is retaking photos and comparing them to photos from 1916 along Tahoe's west shore. "The visual history of Tahoe precedes scientific research at the lake by some 60 years," Goin said. "Within this broad range of time, there are some important visual images of the pre-scientific era of Tahoe."

The 2013 Nevada research booklet is available online at the Lake Tahoe Research website, where profiles of the two dozen Nevada researchers working at Tahoe and more information on our extensive research can be found. The printed edition will be available at the Lake Tahoe Summit on Monday, Aug. 19.