Mono Lake is a truly remarkable and beautiful lake in the Mono Basin, California. The geological processes behind its formation are sincerely fascinating.
In 1913, the city of Los Angeles began diverting water from the lake, which threatened the fragile and unique alkaline ecosystem. In 1994, in a wonderful win for the environment, a conservation movement succeeded in halting any further diversion.
Since that time, water levels have slowly begun to climb back towards historic levels, though they have not yet reached them. Due to this fact, exposed shorelines continue to be a source of alkaline dust, which can be picked up and carried by high winds.
Mono Lake Formation and Description
The eerily beautiful Mono Lake is part of a large basin with no outlet to the ocean. This basin was formed by the actions of geological forces during the past five million years. The lake itself formed approximately 760,000 years ago, and the runoff from enormous salt deposits in the region has made Mono Lake extremely alkaline.
The region is still geologically active, with the most recent eruption occurring slightly more than 350 years ago. This formed a small island within the lake, named Paoha Island. Numerous amazing tufa towers are present around the perimeter of the lake.
Presently, this amazing site covers an area of roughly 70 sq mi (181 sq km). Its maximum depth currently sits at nearly 600 ft (183 m). The surface of the lake sits at an average altitude of 6,380 ft (1,945 m) above sea level.
Mono Lake Ecosystem
Despite being part of a desert environment, Mono Lake is home to a thriving ecosystem. Fish cannot live in these waters, but Nature adapts.
At the heart of this astonishing system is the presence of a vast population of a diminutive brine shrimp species. They are an indigenous creature which actually thrives in the lake’s alkaline waters. These tiny crustaceans (about the size of a fingernail) are inedible to humans, yet shorebirds thrive on them.
A huge volume of microscopic algae live in the lake, sometimes turning it bright green in color. The native crustaceans feed on the algae. The enormous quantities of these invertebrates (as many as six trillion) populating the lake provide an essential food supply for numerous species of shorebirds during their migrations.
Each year, as many as two million migrating shorebirds pause there to rest and feed.