Lake Tahoe Clarity Improves; Concerns over Effect of Climate Change Remain
Lake Tahoe has become clearer for the second consecutive year, according to a new report. Researchers warn that the clarity is due to less precipitation in the area and that climate change could lead to an even drier Lake Tahoe.
The report called, "Tahoe: State of the Lake Report 2013," was released by Tahoe Environmental Research Center at the University of California, Davis. The researchers have been collecting data on the subject since 1968.
"Every year brings surprises, but with them come new insights. In this last year we saw how nature, combined with the results of the many projects that have been completed in the basin, produced an amazing increase in clarity. The real challenge is to be able to sustain the improvements when nature is working against us," said Geoffrey Schladow, director of the UC Davis Tahoe Environmental Research Center, according to a news release.
Scientists found that the average clarity at the lake was 75.3 feet, an improvement of 6.4 feet since 2012.
A 10-inch, white Secchi disk is used to measure the water clarity. Researchers lower the disk and note the depth at which it can be seen. In 1968, the disk could be seen at a depth of 102.4 feet.
Reasons behind the improved clarity include reduced precipitation, fewer Cyclotella algae and the absence of deep mixing. Every winter, the water at the lake's surface moves downwards while the warmer water rises. Deep mixing helps algae grow.
Researchers also found that the surface temperature at the lake was 52.8 degrees Fahrenheit, which is the highest ever recorded for Lake Tahoe.