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Mono Lake A unique ecosystem
Lake Characteristics Mono Lake now covers an area of about 70 square miles and reaches a maximum depth of about 150 feet, but averages about 60 feet in depth. For much of the year, the lake water stratifies into cold and warm layers, that mix with the cooler weather of the autumn.
Lake Characteristics • Like other lakes in the Great Basin, Mono Lake is a terminal lake— water entering the lake from streams leaves the lake only by evaporation. As water evaporates, it leaves behind chemicals that have become more concentrated over the millennia. As a result, the water of Mono Lake became twice as salty as sea water, but less salty than the Great Salt Lake in Utah.
Where is it? California
Watershed Characteristics • The Mono Basin covers 695 square miles of arid lands east of the towering slope of the Sierra Nevada. On the east, north, and south are much lower mountain ranges and hills formed by relict volcanoes. Five major streams feed Mono Lake: Lee Vining Creek, Parker Creek, Walker Creek, Rush Creek, and Mill Creek. Besides the lake itself, habitats in the basin include alkaline shoreline, pinion pine-sagebrush, and riparian forest.
Geological History • The history of Mono Lake begins more than 760,000 years ago. Since then, the level of the lake has fluctuated widely with the coming and going of glaciers. About 60,000 years ago, the lake level stood at about 7,140 feet above sea level, or about 800 feet higher than its present level. About 13,000 years ago, the lake’s surface was five times larger and its depth was six times greater than it is now.
Biological Characteristics • Brine shrimp (Artemia) are a type of aquatic crustacean. They are found worldwide in saltwater, though not in oceans. Artemia is a well known genus as one variety, the Artemia nyos, a hybrid of Artemia salina, are sold as novelty gifts, most commonly under the marketing name Sea-Monkeys.
Biological Characteristics • Adult alkali-flies are 4-7mm long with a dark brown body. The thorax segment is a metallic bluish or greenish reflection and the wings are a smoky brown color
Mono Lake is famed for its unique tufa formations. These carbonate formations were formed due to the underground hot springs which feed into Mono Lake having a high density of calcium. The weirdly shaped formations became visible when the lake level fell as a result of Los Angeles drawing water from the streams which feed the lake.
Vocabulary for Mono Lake • Feeding relationship—when organisms eat each other • Food chain—the path that food takes from one organism to another organism • Food web—a diagram that shows all the feeding relationships
Producers—organisms that make their own food (photosynthesis) • Consumers—organisms that eat other organisms
Primary or first-level consumers—consumers that eat producers (animals that eat plants) • Secondary or second-level consumers—consumers that eat primary consumers (animals that eat animals that eat plants)
Tertiary or third-level consumers—consumers that eat secondary consumers • This process continues with fourth level and so on…
Decomposers—dead organisms are broken down and consumed by microorganisms. Example: bacteria and fungi. Everything that is not eaten by a consumer is eventually eaten by a decomposer.
