Mono Lake just outside of Yosemite National Park in California is a hauntingly beautiful place. In 1941, water that fed the lake through tributary streams was diverted 350 miles south to meet the water needs of Los Angeles. Without its natural sources of fresh water, the volume of Mono Lake dropped to half. This caused its salinity level to double and led to the collapse of the lake ecosystem. Exposed lake beds produced toxic alkali dust storms on windy days.
One of the oldest lakes in North America had, in a very short period of time, became a poisoned alkaline lake containing chlorides, carbonates and sulfates. At one point, it was three times as salty as the ocean. In 1994, the California State Water Resources Control Board issued an order to protect and restore Mono Lake and its tributary streams, and since then, the water level in the lake has steadily risen. Water restoration efforts are estimated to last 20 years.
Today, NASA held a press conference to announce the discovery of an arsenic-based life form at Mono Lake. Bacteria found living in the lake sediment have incorporated the poisonous element into their proteins and DNA. It shakes up the idea that life is mostly made up of just six elements: carbon, hydrogen, oxygen, nitrogen, sulphur and phosphorus. Since the bacterium, strain GFAJ-1 of the Halomonadaceae family of Gammaproteobacteria, had replaced phosphorus with arsenic, it became the only known living thing to ever break out of the established formula.