Lake clarity

Last week the Tahoe Environmental Research Center at the University of California, Davis released the “Tahoe: State of the Lake Report 2012.” The report is released annually, and highlights factors impacting the lake, including its “clarity, physics, chemistry and biology,” according to the report.

The report discusses the unusual winter of 2010-2011, noting its low temperatures and high precipitation. However, the average water temperature increased by 0.6 F, indicating change in the lake’s infrastructure. Scientists then tested the lake’s stability and found that stratification—separate levels of water with different temperatures—lasted longer than usual, indicating a potential impact of climate change.

In 2010, clarity improved but fluctuated in 2011. The report says that algae Cyclotella might be the cause. In 1968, clarity was 102.4 feet. The lowest level in 2011, the second worse recorded, was 51.5 feet.

The report also discusses present and future research projects. Scientists are investigating surrounding areas of the lake, including a study done on the impact of the 2007 Angora fire, which was shown to have no effect on the water. Others are looking at the mortality of trees in the Tahoe forests.