Lake Cadagno is a meromictic

Meromictic

A meromictic lake has layers of water that do not intermix. In ordinary, "holomictic" lakes, at least once each year there is a physical mixing of the surface and the deep waters...

 lake

Lake

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

 in the Piora valley (canton of Ticino

Ticino

Canton Ticino or Ticino is the southernmost canton of Switzerland. Named after the Ticino river, it is the only canton in which Italian is the sole official language...

), Switzerland

Switzerland

Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

. As one of a few meromictic

Meromictic

A meromictic lake has layers of water that do not intermix. In ordinary, "holomictic" lakes, at least once each year there is a physical mixing of the surface and the deep waters...

 lakes in Europe, it is the object of numerous scientific studies. The Piora valley - located in the Gotthard massif (central Swiss Alps) in the Southern part of Switzerland near Airolo at an altitude of 2000 m above sea level - is a landlocked alpine valley whose scientific value has been recognized for more than two centuries. In the past, the lake was used as a reservoir

Reservoir

A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...

.

Lake Cadagno is a rare example of crenogenic meromixis. Its waters show a permanent stratification due to a natural geological phenomenon. The lower abounds with dissolved mineral salts (sulphate, magnesium, calcium, carbonate) originating from sublacustrine springs, whereas the separate upper layer is permanently oxygenated. Anaerobic phototrophic bacteria – among them Chromatium okenii -- thrive between the two layers where they find the ideal conditions for their development. Such an ecosystem provides a good opportunity to study the metabolisms connected with eutrophication on a stable model, as it is well-known that one of the advanced stages of eutrophication is biogenic meromixis.

Research

For the last 25 years the area has been increasingly used for scientific purposes, both for teaching and researching various environmental subjects. In view of stimulating educational and scientific activities at a university level, the Alpine Biology Center (ABC) has been set up by the Canton of Ticino, in cooperation with the universities of Geneva and Zurich. For this purpose, two 16th century buildings of the Alpe Piora have been turned into a laboratory and lodgings. The Microbiology Institute of the canton of Ticino is responsible both for managing the center and coordinating its activities.

Cyclobotryococcatriene, a botryococcene-related hydrocarbon, was isolated from and identified in organic-rich sediments in Lake Cadagno in 2000.