Thanks to microscopic animals, Lake Tahoe is the clearest it has been for more than 40 years. Bordering California and Nevada, Lake Tahoe is the largest alpine lake in North America, measuring at 191.6 mi².
The popular tourist destination draws more than 15 million visitors a year as visitors flock all times of the year to explore the freshwater lake and its surroundings. But, like most of the surrounding region over the past half-century, the clarity of the water has been in decline.
Recently, the UC Davis Tahoe Environmental Research Center and the Tahoe Regional Planning Agency (TRPA) put together the “Lake Tahoe Clarity Report 2022” which showed a significant improvement in water clarity.
The process to measure the level of clarity was done by lowering what is called a Secchi disk into the water until it disappears from the surface view. This 10-inch white disk reaches what is called the Secchi depth, or the depth of disappearance, to measure the transparency of the water.
Records show that the Secchi depth went from 61 feet in 2021 to 71.7 feet in 2022 and they are expecting even clearer water through 2023. The hope is to get back to a Secchi depth of 97.4 feet.
The report detailed that the native zooplankton has surged eating away at the microscopic particles that create cloudy water conditions. They have thrived as the population of their main predator, the Mysis shrimp, unexpectedly crashed in 2021.
Along with the ever-busy zooplankton, pollution control has been a major aid in clearer waters. The report goes on to share that around 500,000 pounds of “fine sediment and other clarity-harming pollutants” are being kept out of the lake, yearly.
The lodging industry has also done its part to give back to the environment. The Ritz-Carlton, Lake Tahoe hosts “Keep Lake Tahoe Blue”, a clean-up event twice a year, while Edgewood Tahoe Resort partners with Clean Up the Lake (CUTL) which focuses on scuba dive, beach, and community clean-ups.