Robot checks out depths of Lake Tahoe

There are many myths about what lies beneath the surface of Lake Tahoe, but if you happen to spot an underwater robot anytime soon, chances are it’s the real deal.

Researchers at the University of California, Davis released an underwater autonomous vehicle, sometimes called an unmanned underwater vehicle, into Lake Tahoe on Friday, Aug. 4. The device is expected to be in the lake anywhere from a few weeks to two months, depending on how things go.

“Measurements like this are extremely important, particularly as the lake changes … Whether or not that’s wetter winters or more severe snowpacks like we saw last winter, we know things are in a state of flux,” said UC Davis Assistant Professor Alex Forrest.

“And trying to capture that flux or capture that change, we can do by making long-term observations with long-term monitoring programs that we have here on the lake that happen every week and every month, but then also looking at the short-term changes when we get more severe storm events or when we have more severe winters,” he said. “This is something that we can understand by having autonomous robots out sampling when we otherwise couldn’t be out there.”

The robot in this case is similar to a glider; only instead of gliding through the air it adjusts its buoyancy to glide through the water as it continuously measures temperature, salinity or conductivity, dissolved oxygen, chlorophyll, and turbidity.

“The advantage to using this as opposed to bringing a boat out and doing sampling is this is able to work continuously, even during big storm events,” Forrest said.

Another benefit to using the robot for data collection is that it can be controlled remotely.

“We can log onto it from anywhere in the world and talk to it as long as it’s on the surface,” he said. “We have it configured for every 3-4 hours it’ll come to the surface and send the data it has collected.”

Forrest said that the reason that collecting data in Lake Tahoe is important is because the ecosystem is changing.

“One of the things that’s truly unique is the clarity of the water, and understanding the clarity is something that drives a lot of the research out here because long-term climate change and human effects are making an impact on the lake,” he said. “When I say impact, it’s not just a change in the clarity like we always talk about, but a change in the dynamics of the ecosystem.”

Last year, Lake Tahoe experienced warmer surface temperatures than ever before, since the data started being recorded. The lake is also warming 14 times faster than average, according to a recent UC Davis “State of the Lake” report.

“Monitoring the ongoing change is of critical importance, so being able to use these technologies and also mirror technology like this with advancing technologies and remote sensing, so using satellite imagery, using other techniques that we have developed around the lake, to integrate them all together allows us to have a better idea of how the entire lake is responding,” Forrest said.

The current mission is a follow-up to a 2013 project done in collaboration between the University of Minnesota and UC Davis. Data collected will be compared with the data collected in 2013 to better understand how the lake has changed.

Amanda Rhoades is a news, environment and business reporter for the Sierra Sun. She can be reached at arhoades@sierrasun.com or 530-550-2653. Follow her on Twitter, Facebook and Instagram @akrhoades.