Shadowed by giant pine trees and towering granite peaks, one look out at the vast, dark blue shimmering water of Lake Tahoe is all it takes to know it is a natural phenomenon. In the eyes of scientists, it’s also very special – and the reasons are just as crystal-clear.
In terms of ecological condition – Lake Tahoe is defined as“oligotrophic.” Basically, that is scientific jargon for saying it is a clear, mostly nutrient-free body of water. Because of the ever-expanding global human population and the impacts it has on the surrounding areas, there are not many oligotrophic lakes left in the world.
Whether it’s an increase in erosion, particles discharged through runoff, or elements entering through the atmosphere, most lakes witness an influx of nutrients over time. This not only clouds the water, but fuels the growth of algae, which feeds off the nitrogen and phosphorus. This causes the lake to eutrophy – scientific jargon for turning murky and green.
That is one main reason why Lake Tahoe remains so exceptional. Not only is it and the surrounding Sierra Nevada breath-taking to look at, but the water itself is still relatively pure and blue.
Unfortunately, though, things are changing. It takes but one swim at Burnt Cedar Beach in Incline to realize that. Granite rocks that were once easily identifiable by their varying colors of quartz are now covered by a thin, green slime. The water that Mark Twain once called in 1871 “…not merely transparent, but dazzlingly, brilliantly so” is slowly losing clarity.
For the past 40 years or so, researchers have studied the ecological condition of the lake. The results of which are showing that developments and the exhaust from automobiles in the greater area are causing the water to turn opaque. Less than a half of century ago, one could see objects on the lake floor at depths of 100 feet. Today, that is roughly hovering at an average of 68 feet.
The good news is studies conducted over the past 10 years have shown the overall clarity has held steady. By identifying fine particles as the main culprit, area agencies have taken steps – mainly erosion control projects – to keep sediment from pouring into the lake. Academic institutions, such as UC Davis, public agencies, and the private sector in and around the Tahoe Basin are working hard to restore the watershed.
Because of this, Lake Tahoe still remains one of the clearest alpine lakes in the world and, thus, retains the term “oligotrophic.” To all residents and visitors, that is clearly scientific jargon for special.
To learn more about the ecological state of Lake Tahoe, feel free to visit http://terc.ucdavis.edu or http://www.trpa.org.